| virulence in actinobacillus pleuropneumoniae and rtx toxins. | rtx toxins are pore-forming, cytolytic protein toxins that occur widely among pathogenic gram-negative bacteria. rtx toxins appear to play a direct role in the virulence of actinobacillus pleuropneumoniae, the etiological agent of porcine pleuropneumonia. this discovery has led to the development of new diagnostic and epidemiological tools, as well as vaccines, that are useful for a broad variety of serotypes. | 1995 | 7551637 |
| evaluation of pig lungs following an experimental challenge with actinobacillus pleuropneumoniae serotype 1 and 5 in pigs inoculated with either hemolysin protein and/or outer membrane proteins. | histopathological changes were compared in pigs challenged with actinobacillus pleuropneumoniae serotype 1 and serotype 5 after inoculation with subunit vaccines. the vaccines consisted of outer membrane protein and/or hemolysin protein isolated from actinobacillus pleuropneumoniae serotype 1 or both subunits combined. twenty-seven cross-bred pigs were separated into six groups: groups i and iv were vaccinated and boostered with 1500 micrograms outer membrane protein; groups ii and v were vaccin ... | 1995 | 7557344 |
| mapping of functional regions on the transferrin-binding protein (tfba) of actinobacillus pleuropneumoniae. | actinobacillus pleuropneumoniae can use porcine transferrin as the sole source of iron. two proteins with molecular masses of approximately 60 kda (tfba) and 110 kda have been shown to specifically bind porcine transferrin; from the tfba protein, three isoforms from a. pleuropneumoniae serotypes 1, 5, and 7 have been identified and characterized by nucleotide sequence analysis. here we defined the transferrin-binding region(s) of the tfba protein of a. pleuropneumoniae serotype 7 by tnphoa mutag ... | 1995 | 7558290 |
| lymphocyte subsets in bronchoalveolar lavage after exposure to actinobacillus pleuropneumoniae in pigs previously immunized orally or by aerosol. | young pigs were immunized with the lung-pathogenic bacterium actinobacillus (haemophilus) pleuropneumoniae by aerosol or orally using viable and inactivated bacteria. the cellular changes in the bronchoalveolar lavage (bal) were studied in repeated lavages after the pigs were infected with live bacteria. the nucleated cells in the bal were differentiated and lymphocyte subsets determined. there were no major differences between the two routes of immunization or between viable and inactivated bac ... | 1995 | 7564482 |
| molecular investigation of the role of apxi and apxii in the virulence of actinobacillus pleuropneumoniae serotype 5. | the extracellular hemolytic toxins (apxi and apxii) of actinobacillus pleuropneumoniae are thought to be important factors in this microorganism's virulence and the pathogenesis of swine pleuropneumonia. using the polymerase chain reaction, the apxi locus of a non-hemolytic, avirulent mutant of a. pleuropneumoniae serotype 5 (mit4-h) generated by chemical mutagenesis (inzana t. j., todd j., veit h. p. microb pathog 1991; 10: 281-96) was found to contain deletions that affected major parts of the ... | 1995 | 7565014 |
| selective effects of a bacterial infection (actinobacillus pleuropneumoniae) on the hepatic clearances of caffeine, antipyrine, paracetamol, and indocyanine green in the pig. | 1. in order to investigate the effect of a bacterial acute phase response model on drug disposition in vivo, plasma clearances of antipyrine, caffeine, paracetamol and indocyanine green were investigated in the healthy and actinobacillus pleuropneumoniae-infected pig. 2. indocyanine green plasma and endogenous creatinine clearance were not changed during the infection, which indicates that hepatic blood flow and renal function were not significantly affected. 3. in the a. pleuropneumoniae-infect ... | 1995 | 7571722 |
| sequence, genetic analysis, and expression of actinobacillus pleuropneumoniae transferrin receptor genes. | the tbpa and tbpb genes encoding the transferrin receptor proteins tbp1 and tbp2 from a serotype 7 strain of actinobacillus pleuropneumoniae were cloned, sequenced, and expressed in escherichia coli. the tbpb gene was preceded by putative promoter and regulatory sequences and was separated from the downstream tbpa gene by a 13 bp intercistronic sequence suggesting that the two genes may be coordinately transcribed. determination of the nucleotide sequence of this region facilitated pcr amplifica ... | 1995 | 7582000 |
| oral immunization of pigs with viable or inactivated actinobacillus pleuropneumoniae serotype 9 induces pulmonary and systemic antibodies and protects against homologous aerosol challenge. | a dose-defined aerosol infection of pigs was used to study the immunogenic and protective potentials of oral immunization with dead or live actinobacillus pleuropneumoniae serotype 9 reference strain cvi 13261 against an aerogenic challenge. pigs were vaccinated with a single dose of 10(11) cfu of viable (n = 8) or inactivated (n = 8) a. pleuropneumoniae given orally in a gelatin capsule. after 3 weeks, vaccinated pigs and nonvaccinated controls were challenged aerogenically with a dose of 10(8) ... | 1995 | 7622229 |
| construction of actinobacillus pleuropneumoniae-escherichia coli shuttle vectors: expression of antibiotic-resistance genes. | we constructed several cloning vectors, designated pgzrs-18/19 and pgzrs-38/39, which were based on an endogenous actinobacillus pleuropneumoniae (apl) 4.3-kb plasmid. they carry the lacz alpha-complementation fragment and mcs from puc18/19, and either the bla gene under the control of a putative apl promoter or the kmr gene from tn903. these vectors replicate in representative strains of apl serotypes 1 and 7, escherichia coli, pasteurella haemolytica (ph) and haemophilus (actinobacillus) actin ... | 1995 | 7628722 |
| construction of an actinobacillus pleuropneumoniae-escherichia coli cosmid cloning vector [gene 160 (1995) 81-86]. | we constructed a cosmid vector, psw206, which should be useful for the construction of genomic libraries of actinobacillus pleuropneumoniae (apl) dna. psw206 is based on the broad-host-range plasmid rk2 and can be introduced into apl by conjugation. | 1995 | 7628723 |
| inflammatory cytokine expression in swine experimentally infected with actinobacillus pleuropneumoniae. | an actinobacillus pleuropneumoniae infection model in swine was established to study the expression of inflammatory cytokines during acute respiratory disease. lavage fluid, lavage cells consisting primarily of alveolar macrophages, and lung tissue were analyzed for the presence of various cytokines at 2, 4, 8, and 24 h following endotracheal inoculation of a. pleuropneumoniae. interleukin-1 beta (il-1) and il-8 mrna levels were elevated within 2 h in lavage cells of animals inoculated with a. p ... | 1995 | 7642295 |
| comparative study of iron acquisition by biotype 1 and biotype 2 strains of actinobacillus pleuropneumoniae. | four strains of the swine pathogen, actinobacillus pleuropneumoniae, namely, the type strain (atcc 27088; biotype 1), the 'reference' strain of biotype 2 (bertschinger 2008/76), and two additional biotype 1 strains, strain bc181, which is less virulent than the type strain, and strain k17, which was isolated from a lamb, were investigated with respect to iron acquisition. all strains produced iron-repressible outer membrane proteins. however, only the type and biotype 2 strains could acquire iro ... | 1995 | 7667902 |
| cloning and characterization of btr, a bordetella pertussis gene encoding an fnr-like transcriptional regulator. | to determine whether hemolytic factors other than the bifunctional hemolysin-adenylate cyclase toxin (cyclolysin) are expressed by bordetella pertussis, a gene library was constructed from a virulent strain of b. pertussis, bp504, transformed into nonhemolytic escherichia coli, and screened on blood agar plates. a strongly hemolytic colony which contained the plasmid phly1a was isolated. nucleotide sequencing of phly1a revealed an open reading frame that could encode a 27-kda protein. no similar ... | 1993 | 7693656 |
| the value of different serological tests in serotyping of actinobacillus pleuropneumoniae strains. | immune sera were raised in rabbits against 12 serotypes of actinobacillus pleuropneumoniae biotype i in order to compare serological tests for simplicity and sensitivity in serotype determination. the serological tests included the tube agglutination test with and without 2-mercaptoethanol addition, the indirect haemagglutination test with and without 2-mercaptoethanol, the immunodiffusion test and the coagglutination test. all these tests proved suitable for serotype determination with the refe ... | 1994 | 7697319 |
| porcine lung lesions at slaughter and their correlation to the incidence of infections by mycoplasma hyopneumoniae and actinobacillus pleuropneumoniae during the rearing period. | porcine lungs were macroscopically and microscopically examined at slaughter, with special regard to different stages of lesions similar to those caused by mycoplasma hyopneumoniae. there was good conformity between the macroscopical and microscopical findings. in an extended abattoir survey, lesions were found in 4210 out of 4508 lungs examined. the majority of lungs with pleuritic lesions (274 out of 369) revealed by the extended examination were registered by the official procedure. no correl ... | 1994 | 7701856 |
| the camp effect of actinobacillus pleuropneumoniae is caused by apx toxins. | actinobacillus pleuropneumoniae shows synergistic haemolysis when cocultured with staphylococcus aureus on blood agar plates. this camp effect has been attributed to a discrete camp factor, but also to the a. pleuropneumoniae-rtx-toxins i, ii, and iii. we examined the camp effect of recombinant escherichia coli strains that secreted each of these toxins, and of a. pleuropneumoniae mutant strains that were devoid of one or more these toxins. we found that the e. coli strains were camp positive, w ... | 1995 | 7705605 |
| recovery of long-chain lipopolysaccharides from liquid culture of actinobacillus pleuropneumoniae (serotype 5) for elisa serodiagnosis. | actinobacillus pleuropneumoniae (serotype 5) long-chain lipopolysaccharides (lc-lps) may be used as the antigen for elisa serodiagnosis of pig pleuropneumonia. a method was developed in order to augment the recovery of this antigen compared to the previously described method. in liquid culture, a pleuropneumoniae was shown to produce 2.4 times more cells than in solid medium. lc-lps could be recovered by phenol extraction of the crude extract. only 1 additional phenol extraction was required to ... | 1995 | 7711778 |
| infection (actinobacillus pleuropneumoniae)-mediated suppression of oxidative hepatic drug metabolism and cytochrome p4503a mrna levels in pigs. | the effect of actinobacillus pleuropneumoniae infection, a well-characterized pig infection model, on both phase i (oxidative) and phase ii (conjugative) microsomal enzyme activities was investigated in castrated male conventional pigs. a. pleuropneumoniae infection resulted after 24 hr in a significant suppression of 33% or more of all oxidative enzyme activities determined. after 40 hr, the activities were still suppressed, but did not differ from the results after 24 hr. on the contrary, all ... | 1995 | 7720523 |
| actinobacillus pleuropneumoniae serotype-2 antibodies in sow colostrum in finnish pig-health-scheme herds. | a direct elisa with phenol-extracted antigen for actinobacillus pleuropneumoniae serotype 2 was developed. the test was specific when tested with rabbit antisera prepared against different a. pleuropneumoniae serotypes. it had better-than-moderate repeatability and it made a clear distinction between positive and negative samples. a total of 5477 colostrum samples from breeding sows from herds participating in the finnish pig-health scheme were tested using the elisa test. a total of 1307 positi ... | 1994 | 7740855 |
| the fnr family of transcriptional regulators. | homologues of the transcriptional regulator fnr from escherichia coli have been identified in a variety of taxonomically diverse bacterial species. despite being structurally very similar, members of the fnr family have disparate regulatory roles. those from shewanella putrefaciens, pseudomonas aeruginosa, pseudomonas stutzeri and rhodopseudomonas palustris are functionally similar to fnr in that they regulate anaerobic respiration or carbon metabolism. four rhizobial proteins (from rhizobium me ... | 1994 | 7747934 |
| convalescent pigs are protected completely against infection with a homologous actinobacillus pleuropneumoniae strain but incompletely against a heterologous-serotype strain. | to study whether actinobacillus pleuropneumoniae induces a species-specific immunity, we infected pigs in the left lung with serotype 3 or 9 and after 3 weeks we infected their right lungs with serotype 9. convalescent pigs were protected against homologous strain reinfection, but after heterologous strain reinfection the degree of protection varied. neutralizing antibodies were not essential for protection. | 1995 | 7768619 |
| molecular cloning of an actinobacillus pleuropneumoniae outer membrane lipoprotein (omla) from serotype 5a. | the gene encoding an outer membrane lipoprotein (omia) was cloned from actinobacillus pleuropneumoniae strain ng-8 (serotype 5a). the deduced amino acid sequence of omia from strain ng-8 showed 61% identity to the omia from serotype 1 strain, which confers protective immunity to pigs. southern blot analysis showed the presence of a sequence highly homologous to the omia gene of strain ng-8 in strains of serotype 5a, 5b and 10. a specific serum against omia of ng-8 also detected a homologous prot ... | 1995 | 7783596 |
| detection of antibodies against actinobacillus pleuropneumoniae, serotype 2 in porcine colostrum using a blocking enzyme-linked immunosorbent assay specific for serotype 2. | a blocking enzyme-linked immunosorbent assay (elisa) developed for detection of antibodies to actinobacillus pleuropneumoniae serotype 2 in sera from pigs (nielsen et al., 1991) was evaluated for its suitability to detect antibodies in colostrum to this serotype. using colostrum from sows experimentally infected with serotype 2 and from herds known to be infected with this serotype, the sensitivity of the test was 100%. antibodies to a. pleuropneumoniae serotype 2 could be detected in colostrum ... | 1995 | 7785187 |
| cloning and characterization of a protective outer membrane lipoprotein of actinobacillus pleuropneumoniae serotype 5. | the gene encoding an outer membrane lipoprotein (omla) of actinobacillus pleuropneumoniae serotype 5 was cloned, and the protein was expressed in escherichia coli. one open reading frame of 1,104 bp was detected that encoded a protein (omla) with a predicted molecular mass of 40 kda. a comparison with the omla gene and the corresponding protein of a. pleuropneumoniae serotype 1 (g.-f. gerlach, c. anderson, s. klashinsky, a. rossi-kampos, a.a. potter, and p.j. wilson, infect. immun. 61:565-572, 1 ... | 1995 | 7790104 |
| comparison of serum responses in swine after vaccination and challenge exposure with actinobacillus pleuropneumoniae serotype 1. | clinical trials have shown that currently available commercial vaccines against porcine pleuropneumonia provide inconsistent, serotype-specific protection from the disease. recovery from naturally acquired infection, however, provides solid, serotype cross-protective immunity. we examined various serum responses of pigs receiving 1 of 4 commercial vaccines or a cell extract, and compared the serologic responses of these pigs after challenge exposure with virulent actinobacillus pleuropneumoniae ... | 1994 | 7802390 |
| knockout mutants of actinobacillus pleuropneumoniae serotype 1 that are devoid of rtx toxins do not activate or kill porcine neutrophils. | the actinobacillus pleuropneumoniae rtx-toxins apxi, apxii, and apxiii are important virulence factors of this swine pathogen. it is hypothesized that the apx toxins are deleterious to defense cells of the host, enabling the bacterium to infect the host. to confirm this, we studied the effect on porcine polymorphonuclear neutrophils of mutant strains of a. pleuropneumoniae that were devoid of apx toxins. for this purpose, we developed a system for targeted mutagenesis of a. pleuropneumoniae base ... | 1995 | 7806365 |
| association of the camp phenomenon in actinobacillus pleuropneumoniae with the rtx toxins apxi, apxii and apxiii. | a non-hemolytic mutant of actinobacillus pleuropneumoniae serotype 5 has a deletion spanning the entire apxi operon. therefore it does not produce apxi and is unable to secrete apxii. this mutant also has lost the co-hemolytic camp effect which is characteristic of the species a. pleuropneumoniae. the camp effect is restored when the mutant is complemented in trans by the apxibd genes cloned in a broad host range vector, thus permitting secretion of apxii, or when the entire apxi operon is clone ... | 1994 | 7813893 |
| lipopolysaccharides of actinobacillus pleuropneumoniae bind pig hemoglobin. | a previous study indicated that lipopolysaccharides (lps) extracted from actinobacillus pleuropneumoniae bind two low-molecular-mass proteins, of approximately 10 and 11 kda, present in porcine respiratory tract secretions (m. bélanger, d. dubreuil, and m. jacques, infect. immun. 62:868-873, 1994). in the present study, we determined the n-terminal amino acid sequences of these two proteins, which revealed high homology with the alpha and beta chains of pig hemoglobin. some isolates of a. pleuro ... | 1995 | 7822035 |
| the rtx haemolysins apxi and apxii are major virulence factors of the swine pathogen actinobacillus pleuropneumoniae: evidence from mutational analysis. | the involvement of the rtx haemolysins (apxi and apxii) of the swine pathogen actinobacillus pleuropneumoniae in virulence was investigated using haemolysin-deficient mutants constructed by a mini-tn10 mutagenesis procedure. two types of haemolysin mutant with single insertions of the transposon were obtained from a serotype 1 strain producing both apxi and apxii. one presented a complete loss of haemolytic activity because of the absence of apxi and apxii production. the other displayed weaker ... | 1994 | 7830567 |
| an analysis of the complete nucleotide sequence of the haemophilus ducreyi broad-host-range plasmid pls88. | we present an analysis of the complete nucleotide sequence of pls88, a naturally occurring, 4.8-kb broad-host-range plasmid isolated from haemophilus ducreyi and encoding resistance to sulfonamides, streptomycin, and kanamycin. sequence analysis of the genes encoding sulfonamide and streptomycin resistance revealed homology to the rsf1010 sulii and stra genes. the sulii-stra intergenic region of pls88 has a 38-bp deletion identical to that of the rsf1010-like plasmid phd8.1, isolated from actino ... | 1994 | 7846148 |
| rtx toxin genotypes and phenotypes in actinobacillus pleuropneumoniae field strains. | actinobacillus pleuropneumoniae serotype reference strains and 204 a. pleuropneumoniae field strains representing all 12 serotypes and both biovars 1 and 2, obtained from laboratories from various countries worldwide, were analyzed for the presence of the toxin genes apxic, apxia, apxib, apxid, apxiic, apxiia, apxiiic, apxiiia, apxiiib, and apxiiid by dna-dna hybridization with specific gene probes. expression of the toxins apxi, apxii, and apxiii was assessed by immunoblot analysis with monoclo ... | 1994 | 7852567 |
| the immune system of the respiratory tract in pigs. | although the lung is not a lymphoid organ it contains large numbers of lymphocytes. these can be found in different compartments: (1) the pulmonary intravascular pool, which is organ-specific and shows a unique migration pattern; (2) the interstitial lymphocyte pool, which is equivalent in size to the whole blood pool; (3) the bronchus-associated lymphoid tissue (balt) which develops as a result of microbial stimulation; (4) the intraepithelial and lamina propria lymphocytes of the bronchi, with ... | 1994 | 7856047 |
| antibacterial activity of tilmicosin against pasteurella multocida and actinobacillus pleuropneumoniae isolated from pneumonic lesions in swine. | sixty one strains of pasteurella multocida and 35 strains of actinobacillus pleuropneumoniae isolated from pneumonic lesions of porcine lungs during the period from 1985 to 1989 in japan were tested for antibiotic susceptibility to chlortetracycline (ctc), thiamphenicol (tp), tylosin (ts), acetylisovaleryl-tylosin (aiv-ts), tilmicosin (tms), mirosamycin (mrm). most strains of both species were sensitive to ctc, tp and tms. growth of fifty-one strains (83.6%) and forty-six strains (75.4%) of p. m ... | 1994 | 7865594 |
| functional and structural changes of porcine alveolar macrophages induced by sublytic doses of a heat-labile, hemolytic, cytotoxic substance produced by actinobacillus pleuropneumoniae. | alterations in the size and functions of porcine alveolar macrophages exposed to sublytic amounts of heat-labile, hemolytic cytotoxin produced by actinobacillus pleuropneumoniae (app) serotype 1, strain hs54 into the culture medium were studied in vitro. alveolar macrophages were sensitive to the cytotoxin; treatment of the macrophages with low concentrations of cytotoxin (0.016 hemolytic unit) resulted in severe, irreversible cell swelling. however, high doses of cytotoxin (2.0 hemolytic units) ... | 1994 | 7879978 |
| evaluation of a saline boiled extract, capsular polysaccharides and long-chain lipopolysaccharides of actinobacillus pleuropneumoniae serotype 1 as antigens for the serodiagnosis of swine pleuropneumonia. | a saline boiled extract (sbe), capsular polysaccharides (cps) and long-chain lipopolysaccharides (lc-lps) of actinobacillus pleuropneumoniae serotype 1 have been evaluated in elisa for the serodiagnosis of swine pleuropneumonia caused by this serotype. mean optical densities (ods) obtained with the three antigens using sera from negative herds as well as from animals experimentally and naturally exposed to a. pleuropneumoniae serotypes 1, 9 or 11 were not significantly different. the positive el ... | 1994 | 7886937 |
| characterization of an actinobacillus pleuropneumoniae seeder pig challenge-exposure model. | five strains of actinobacillus pleuropneumoniae serotype 1 were used to intranasally infect 5 groups of pigs. using each bacterial strain, infected pigs (termed seeder pigs) were commingled for 48 hours with 5 groups of noninfected test pigs, then were removed. seeder and test pigs were maintained in isolation and were observed for 14 days. seeder pigs had mortality that was threefold greater than that of test pigs (24% vs 8%). rectal temperature in excess of 40.3 c was achieved for 84% of test ... | 1994 | 7887514 |
| in vivo association of actinobacillus pleuropneumoniae serotype 2 with the respiratory epithelium of pigs. | the ability of an actinobacillus pleuropneumoniae serotype 2 strain to associate in vivo with the epithelium of the porcine respiratory tract was investigated in a sequential study after intranasal inoculation of hysterectomy-derived and colostrum-deprived pigs. at 30 min postinoculation more than 95% of the bacteria present in the lungs were intimately associated with the epithelium of the alveoli or the cilia of the terminal bronchioli, as observed by light and electron microscopy. at 90 and 1 ... | 1994 | 7907578 |
| actinobacillus pleuropneumoniae: virulence and gene cloning. | actinobacillus pleuropneumoniae is the causal agent of porcine contagious pleuropneumonia (pcp). the infection produces important economic losses in porciculture due to its high morbidity and mortality. survivors are asymptomatic carriers infectious to other pigs and have low alimentary conversion. the causative agent possesses several virulence factors: adhesion fimbriae, lipopolysaccharide of the outer membrane, capsule, and cytolysins. in addition, our group has reported secretion proteases o ... | 1994 | 7919819 |
| mycoplasma hyopneumoniae: interaction with other agents in pigs, and evaluation of immunogens. | mycoplasmal pneumonia of swine causes considerable economic losses in porciculture. diverse agents, such as environmental stress and infectious microorganisms, increase the possibility of infection, and the damage to pulmonary tissue when the infection is established. it is known that mycoplasma hyopneumoniae has an important role in this disease, in addition to secondary microbial agents, such as pasteurella multocida and actinobacillus pleuropneumoniae. however, the characteristics of this dis ... | 1994 | 7919820 |
| identification of veterinary pathogens by use of commercial identification systems and new trends in antimicrobial susceptibility testing of veterinary pathogens. | veterinary diagnostic microbiology is a unique specialty within microbiology. although isolation and identification techniques are similar to those used for human pathogens, many veterinary pathogens require unique cultivation or identification procedures. commercial identification systems provide rapid, accurate identification of human pathogens. however, the accuracy of these systems with veterinary pathogens varies widely depending on the bacterial species and the host animal from which it wa ... | 1994 | 7923054 |
| genetic map of the actinobacillus pleuropneumoniae rtx-toxin (apx) operons: characterization of the apxiii operons. | actinobacillus pleuropneumoniae rtx-toxin iii (apxiii) is implicated as an important virulence factor of a. pleuropneumoniae, the causative agent of porcine pleuropneumonia. recently, the genes coding for apxiii (apxiiica) of serotype 8 were cloned and characterized. the toxin appeared to be a member of the rtx-toxin family, as are the other two secreted toxins of a. pleuropneumoniae, i.e., apxi and apxii. in this report, we describe the cloning and sequencing of the remaining part of the apxiii ... | 1994 | 7927703 |
| a novel experimental model for the study and evaluation of experimental vaccines to actinobacillus pleuropneumoniae. | a novel experimental model to study immune protection to actinobacillus pleuropneumoniae in the rat is described. one-week-old rats born from immunized mothers were challenged intraperitoneally with a suspension of a. pleuropneumoniae serotype 1 and mortality recorded up to 48 h postinfection. immunization with inactivated whole cells (iwc) or a whole cell extract (wce) from a. pleuropneumoniae serotype 1 resulted in protection against an homologous challenge, particularly in the case of wce whe ... | 1994 | 7941315 |
| clinical pharmacokinetic characterization of norfloxacin nicotinate in swine following systemic administration. | norfloxacin nicotinate (nfn) is a new water-soluble fluoroquinolone antibacterial agent. the in vitro activity of nfn for microorganisms isolated from swine and the pharmacokinetic properties of nfn following single intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) administration were investigated. the minimal inhibitory concentrations (mic's) of nfn for a wide range of reference (atcc-american type culture collection) microbial swine isolates, comprising 21 bacterial and 5 mycopl ... | 1994 | 7941848 |
| effects of ketoprofen and flunixin in pigs experimentally infected with actinobacillus pleuropneumoniae. | the antipyretic effect of the non-steroidal anti-inflammatory drugs (nsaids) ketoprofen (3 mg/kg) and flunixin (2 mg/kg) were studied in pigs. the drugs were administered intramuscularly at 8 and 32 h following endobronchial challenge with actinobacillus pleuropneumoniae. infected (non-medicated) and non-infected (non-medicated) controls were used. endobronchial challenge with actinobacillus pleuropneumoniae induced laboured breathing, coughing, fever, reduced food and water consumption and incr ... | 1994 | 7966550 |
| the induction of specific protection against actinobacillus pleuropneumoniae infection by specific dle. | immunoprophylactic and immunotherapeutic effects of specific actinobacillus dle (dialysable leukocyte extract) were studied in model pigs experimentally infected with actinobacillus pleuropneumoniae. specific dle used for immunoprophylactic purposes was administered intramuscularly to pigs either in two doses in combination with one dose of actinobacillus vaccine (1st group) or in a single dose (2nd group). all animals of the two experimental groups survived the intranasal a. pleuropneumoniae ch ... | 1993 | 7976208 |
| chemiluminescence properties of porcine pulmonary alveolar macrophages and polymorphonuclear cells. | a luminol-enhanced chemiluminescence (cl) technique was developed for porcine pulmonary alveolar macrophages (pam) and polymorphonuclear cells (pmn). pam were obtained from lung washings of 3 week old gnotobiotic pigs. pmn were obtained from peripheral blood by separation on a discontinuous percoll gradient. optimum cl signals were obtained with 10(5) pam/tube and 5 x 10(4) pmn/tube. stimulation indexes (si) for pam were approximately 10 for phorbol myristate acetate (pma), 8 for opsonized actin ... | 1994 | 7985362 |
| secreted proteases from actinobacillus pleuropneumoniae serotype 1 degrade porcine gelatin, hemoglobin and immunoglobulin a. | it was found that 48 hour cultures of actinobacillus pleuropneumoniae secreted proteases into the medium. electrophoresis in polyacrylamide gels (10%) copolymerized with porcine gelatin (0.1%), of the 70% (nh4)2so4 precipitate from the culture supernatants, displayed protease activities of different molecular weights: > 200, 200, 90, 80, 70 and 50 kda. they had activity over a broad range of phs (4-8), with an optimal ph of 6-7. all were inhibited by 10 mm edta, and reactivated by 10 mm calcium. ... | 1994 | 8004545 |
| dna sequence analysis of an allelic variant of the actinobacillus pleuropneumoniae-rtx-toxin i (apxia) from serotype 10. | the structural gene encoding actinobacillus pleuropneumoniae-rtx-toxin i (apxia), one of the major hemolytic and cytolytic toxins of the organism, was cloned from serotype 10. the nucleotide sequence data showed that the gene from serotype 10 was 98% identical to that from serotype 1 at both dna and amino acid levels. the sequence difference was found to localize at the 3' terminal region of the gene. we then analyzed the 3' terminal region of the apxia gene from other serotypes, 5a, 5b, 9 and 1 ... | 1993 | 8007819 |
| serotyping and quantitative determination of in vitro antibiotic susceptibility of actinobacillus pleuropneumoniae strains isolated in belgium (july 1991-august 1992). | one hundred and ninety nine actinobacillus pleuropneumoniae isolates obtained from the respiratory tract of pigs in belgium (1991-1992) were serotyped using slide agglutination and slide precipitation tests. biotype 1-serotype 2 and 3 strains were isolated most frequently and represented 36% and 21% of the isolates, respectively. serotype 9 and serotype 5b strains represented 15% and 10% of the total number of isolates, respectively, while serotypes 7, 8, 10 and 11 were isolated only sporadicall ... | 1994 | 8009811 |
| regulation of gene expression by the hlyx protein of actinobacillus pleuropneumoniae. | the hlyx gene of the swine pathogen actinobacillus pleuropneumoniae and the fnr gene of escherichia coli encode very similar proteins. the hlyx gene is able to complement delta fnr mutations and will permit the growth of e. coli fnr strains in nitrate minimal salts medium under anoxic conditions. in addition, the hlyx gene product appears to induce the expression of a latent haemolytic activity as evidenced by the presence of a strong zone of haemolysis around e. coli (hlyx+) colonies grown on b ... | 1994 | 8012601 |
| high-molecular-mass lipopolysaccharides are involved in actinobacillus pleuropneumoniae adherence to porcine respiratory tract cells. | actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. the major adhesin of a. pleuropneumoniae has been identified as the lipopolysaccharides (lpss) (m. bélanger, d. dubreuil, j. harel, c. girard, and m. jacques, infect. immun. 58:3523-3530, 1990). using immunoelectron microscopy and flow cytometry, we showed in the present study that lpss were well exposed at the surface of this encapsulated microorganism. immunolocalization with porcine lung and tracheal frozen sec ... | 1994 | 8039902 |
| nad-independent actinobacillus pleuropneumoniae strains: production of rtx toxins and interactions with porcine phagocytes. | actinobacillus pleuropneumoniae rtx toxin (apx) production by a. pleuropneumoniae biotype 2 (nad-independent) serotype 2 strains was studied. western blot analysis of culture supernatants of all biotype 2 strains tested revealed the presence of a 103 kda protein which reacted with a monoclonal antibody against apxiia. this protein was also recognized by sera of pigs infected with a biotype 2-serotype 2 strain. furthermore, antibodies that could neutralize apxiia were present in these sera. prote ... | 1994 | 8042269 |
| lipopolysaccharides of actinobacillus pleuropneumoniae (serotype 1): a readily obtainable antigen for elisa serodiagnosis of pig pleuropneumonia. | a saline extract of boiled-formalinized whole cells of actinobacillus pleuropneumoniae serotype 1 reference strain (shope 4074) has been previously used as the antigen in an enzyme-linked immunosorbent assay (elisa) for serodiagnosis of swine pleuropneumonia. phenol extraction of this crude extract permitted the recovery of lps with long o-chains in the aqueous phase. this antigen was shown to be specific for serotypes 1, 9 and 11 as they all possess structurally similar o-chains. immunoblotting ... | 1994 | 8042270 |
| detection of actinobacillus pleuropneumoniae serotype 2 antibodies in pig sera by an inhibition enzyme immuno assay (eia). | an inhibition enzyme immuno assay (eia) for detection of antibodies against a. pleuropneumoniae serotype 2 (app-2) in pig sera, based on the inhibition of the binding of an app-2 specific monoclonal antibody was established. the monoclonal antibody (mab 102-g02) was found to be directed against an epitope on the o-chain of app-2 lps. some app-2 isolates did not react with the mab 102-g02. these isolates are referred to as app-2x. in the inhibition eia highly purified app-2 lps ws used to coat mi ... | 1994 | 8042271 |
| [evaluation of a selective medium with dilutions for the isolation of actinobacillus pleuropneumoniae and haemophilus spp. in pigs]. | the aim of the present research was to evaluate the efficiency of a method used to enhance the isolation of actinobacillus pleuropneumoniae and haemophilus spp. 134 samples of pneumonic lungs of swine were directly grown in blood agar medium, 120 of these samples were simultaneously processed by a dilution method inoculating then into a selective and enriched broth (1% poly-enriched, 5% yeast extract. 5 micrograms/ml bacitracin, 1 microgram/ml lincomycin and 1 microgram/ml crystal violet). the d ... | 1993 | 8047732 |
| porcine pleuropneumonia. | | 1994 | 8050966 |
| resistance of actinobacillus pleuropneumoniae to bactericidal antibody and complement is mediated by capsular polysaccharide and blocking antibody specific for lipopolysaccharide. | actinobacillus pleuropneumoniae is resistant to complement-mediated killing, even in the presence of specific ab. our studies focused on identifying the mechanism(s) responsible for this resistance. encapsulated a. pleuropneumoniae was susceptible to killing in precolostral calf serum (pcs) but not in normal serum as a complement source in the presence of anti-capsular polysaccharide (cp) igg. in contrast, two capsule-deficient mutants were sensitive to killing in normal serum and one was sensit ... | 1994 | 8051416 |
| production of apx toxins by field strains of actinobacillus pleuropneumoniae and actinobacillus suis. | the three apx toxins of actinobacillus pleuropneumoniae have potential value for use in vaccines and diagnostic tests which will be species specific instead of serotype specific, provided that the apx toxins are species specific and all field strains produce these toxins. we examined 114 a. pleuropneumoniae field strains and found that they secreted either apxi, apxii, apxi and apxii, or apxii and apxiii and secreted no other cytolytic activities. however, proteins similar to apxi and apxii were ... | 1994 | 8063425 |
| efficacy of an actinobacillus pleuropneumoniae bacterin against serotypes 1, 3, 5 and 9. | a trial was performed in a swine research facility to ascertain the protection provided by a polyvalent actinobacillus pleuropneumoniae (app) bacterin containing serotypes 1, 3, 5 and 9. the test animals consisted of 60, eight-week-old, piglets, which were randomly divided into four main groups. the four main groups were further divided into three sub-groups (i, ii, iii) of five pigs each. subgroup i was vaccinated intramuscularly, sub-group ii was vaccinated subcutaneously, and sub-group iii se ... | 1994 | 8076279 |
| identification of porcine respiratory tract mucus proteins binding lipopolysaccharides of actinobacillus pleuropneumoniae. | | 1994 | 8080176 |
| use of dna fingerprinting for accurate typing of actinobacillus pleuropneumoniae. | dna fingerprinting was tested as a method for detailed differentiation of 23 strains of the causal agent of porcine pleuropneumonia--actinobacillus pleuropneumoniae. the set consisted of twelve reference strains, each representing one serotype, and eleven field strains belonging to serotype 9 which occurs most frequently in the czech republic. nine of the reference strains could be differentiated from each other and from serotypes 1, 9 and 11, but a very close relatedness was demonstrated among ... | 1994 | 8085302 |
| serotypes of actinobacillus pleuropneumoniae isolated in the british isles. | | 1994 | 8085311 |
| proteins found within porcine respiratory tract secretions bind lipopolysaccharides of actinobacillus pleuropneumoniae. | affinity for porcine respiratory tract secretions was found in some isolates of actinobacillus pleuropneumoniae and involved lipopolysaccharides (lps) (m. bélanger, s. rioux, b. foiry, and m. jacques, fems microbiol. lett. 97:119-126, 1992). in the present study, the affinity for a crude preparation of porcine respiratory tract mucus of isolates of the pasteurellaceae family, i.e., actinobacillus, haemophilus, and pasteurella spp., and of some unrelated gram-negative bacteria was examined. affin ... | 1994 | 8112857 |
| testing of remedial measures in fattening pig herds affected with subclinical infections of actinobacillus pleuropneumoniae serotype 2. | the present investigation comprised 5 specialized herds of slaughter pigs, each with a production of 1,500 to 4,000 fatteners per year. high prevalence of pleuritis was demonstrated in all herds at slaughter. serological investigations by means of elisa were carried out to determine antibody titres to actinobacillus pleuropneumoniae (a. pl.) serotype 2 during the fattening period and at slaughter. the investigations showed that this agent was a predominant cause of the subclinical pleuritis alth ... | 1993 | 8122444 |
| antimicrobial susceptibility of actinobacillus pleuropneumoniae, pasteurella multocida and salmonella choleraesuis isolates from pigs. | the in vitro susceptibility of 839 isolates of actinobacillus pleuropneumoniae, 969 isolates of pasteurella multocida and 104 isolates of salmonella choleraesuis from pigs to the fluoroquinolone danofloxacin, and eight other commonly used antimicrobial drugs was determined by veterinary diagnostic laboratories in europe, japan, south africa and north america between 1989 and 1991, by using a broth microdilution technique. the minimum inhibitory concentrations of danofloxacin, amoxycillin, ceftio ... | 1994 | 8128570 |
| experimental model of swine pneumonic pasteurellosis using crude actinobacillus pleuropneumoniae cytotoxin and pasteurella multocida given endobronchially. | this study was designed to develop and characterize a swine pneumonic pasteurellosis model by concurrent introduction of pasteurella multocida type a and actinobacillus pleuropneumoniae crude cytotoxin. after a series of preliminary experiments, a combination of 4 x 10(9) p. multocida and 4,000 toxic units of a. pleuropneumoniae crude cytotoxin was determined to produce optimal results. a total of 48 pigs were divided into four groups of 12 pigs each. the control group received buffered saline o ... | 1994 | 8143249 |
| actinobacillus pleuropneumoniae in gnotobiotic piglets: ultrastructural changes in the pulmonary alveoli with dose and time. | the ultrastructural changes in pulmonary alveoli produced by transtracheal inoculation of 10(6) and 10(8) cfu of actinobacillus pleuropneumoniae serotype 5 in gnotobiotic piglets were studied after 1 and 4 h. at 1 h postinoculation (p.i.) with 10(6) or 10(8) cfu, no gross change in lung and no evidence of infiltration of cells into alveoli was observed. at 4 h p.i., at a dose of 10(6) cfu, a generalized red mottling occurred in the dorsal half of the caudal lobe, which revealed ultrastructural e ... | 1994 | 8149331 |
| oral and aerosol immunization with viable or inactivated actinobacillus pleuropneumoniae bacteria: antibody response to capsular polysaccharides in bronchoalveolar lavage fluids (balf) and sera of pigs. | to investigate the antibody response after local application of lung-pathogenic bacteria, pigs were immunized with viable or inactivated actinobacillus pleuropneumoniae by the oral and aerogenous route. after 3 weeks class-specific immunoglobulins against purified a. pleuropneumoniae capsular polysaccharides (cp) were determined in serum and balf by elisa. a significant increase of iga antibodies was found in balf but not in sera of all immunized pigs. oral immunization with viable a. pleuropneu ... | 1994 | 8149673 |
| evaluation of long chain lipopolysaccharides (lc-lps) of actinobacillus pleuropneumoniae serotype 5 for the serodiagnosis of swine pleuropneumonia. | long chain lipopolysaccharides (lc-lps) of actinobacillus pleuropneumoniae serotype 5 have been evaluated and compared with a crude boiled extract (cbe) in elisa for the serodiagnosis of swine pleuropneumonia caused by this serotype. the mean optical density (od) obtained with the lc-lps in elisa using sera from negative herds as well as from animals experimentally and naturally exposed to a. pleuropneumoniae serotype 5 was not significantly different from that obtained with the cbe. however, se ... | 1994 | 8160347 |
| antigenic differences within actinobacillus pleuropneumoniae serotype 1. | two distinct antigenic subtypes of actinobacillus pleuropneumoniae serotype 1 were identified via coagglutination (co-a) and designated as 1a and 1b. the reference strains, atcc 27088 (1a) and isu 158 (1b), were used to prepare hyperimmune rabbit sera for co-a reagents. of 75 serotype 1 field isolates tested by co-a, 35 isolates typed as 1a, 12 as 1b and 28 as 1a/1b. significant cross-reactivity between the 2 subtypes was found in the co-a and was eliminated in 20/28 1a/1b strains by using co-a ... | 1994 | 8160348 |
| differential expression of the cytotoxic and hemolytic activities of the apxiia toxin from actinobacillus pleuropneumoniae. | the apxiia protein secreted from actinobacillus pleuropneumoniae is both hemolytic and cytotoxic. however, when the cloned apxii operon is expressed in escherichia coli, two forms of the apxiia protein can be recovered. toxin which remains intracellular has hemolytic and cytotoxic activities, while toxin that is secreted is cytotoxic with little or no hemolytic activity. this indicates that the cytotoxicity of apxiia is independent of its hemolytic activity. | 1994 | 8168980 |
| characterization of a 3-dehydroquinase gene from actinobacillus pleuropneumoniae with homology to the eukaryotic genes qa-2 and qute. | a gene was cloned from actinobacillus pleuropneumoniae strain 4074 by complementation of an arod strain of escherichia coli. the e. coli gene arod codes for a 3-dehydroquinase enzyme of type i, active in the aromatic biosynthesis pathway. the a. pleuropneumoniae gene, termed aroq, displays no base or amino acid sequence homology to arod of e. coli. it is instead homologous to the qute and qa-2 genes, respectively of aspergillus nidulans and neurospora crassa. these genes code for 3-dehydroquinas ... | 1994 | 8170389 |
| sensitivity of a pleuropneumoniae and p multocida to ceftiofur. | | 1994 | 8171805 |
| prophylaxis of pleuropneumonia in pigs by in-feed medication with oxytetracycline and the subsequent transmission of infection. | the prophylactic effect of in-feed medication with oxytetracycline was tested by using an actinobacillus pleuropneumoniae aerosol challenge model. groups of 10 conventional pigs were provided with feed containing 400, 800, 1200 or 1600 mg oxytetracycline/kg and fed ad libitum. after six days of medication the pigs were challenged and clinical signs were recorded. two groups of four unmedicated pigs served as controls and were euthanased 36 to 48 hours after challenge and dissected. the feed medi ... | 1994 | 8171809 |
| sequence analysis and transcription of the apxi operon (hemolysin i) from actinobacillus pleuropneumoniae. | the dna sequence of the entire apxi operon from actinobacillus pleuropneumoniae serotype 1 reference strain 4074 has been determined. this 8292-bp fragment of the chromosomal dna contains four open reading frames (orfs) of the strongly hemolytic apxi toxin. these orfs correspond to the genes apxic, apxia, apxib and apxid, encoding the activator, the structural toxin protein and the two secretion proteins, respectively. each of the four orfs is preceded by a consensus sequence for a putative ribo ... | 1994 | 8181764 |
| protection of mice and swine against infection with actinobacillus pleuropneumoniae by vaccination. | cacl2 and licl cell extracts and a crude hemolysin preparation were isolated from actinobacillus pleuropneumoniae serotype 1 strain 4074 and tested for protection against a. pleuropneumoniae serotype 1 and 5 in mice. the licl cell extract adsorbed on alpo4 and the crude hemolysin preparation adsorbed on al(oh)3 showed a highly significant protection (p < 0.01) against both serotypes. different vaccine preparations were used to immunize pigs by intra-muscular injection at days 0 and 14; the pigs ... | 1994 | 8203129 |
| serological characterisation of actinobacillus pleuropneumoniae strains of serotypes 1, 9 and 11. | various serological tests such as agglutination, coagglutination, indirect haemagglutination, immunodiffusion and counterimmunoelectrophoresis were used to characterise serologically actinobacillus pleuropneumoniae isolates of serotypes 1, 9 and 11 using rabbit hyperimmune sera against serotypes 1 to 12. the rapid slide agglutination test using whole-cell suspension and the indirect haemagglutination test using whole-cell saline extract as antigens gave type specific reactions for serotypes 1 an ... | 1993 | 8235084 |
| [comparison of two polysaccharide antigens for the serological diagnosis by elisa of porcine pleuropneumonia (serotype 5)]. | two antigens of polysaccharidic nature were evaluated for their specificity in serodiagnosis of porcine pleuropneumonia (serotype 5). recently, long chains lipopolysaccharides (lc-lps) was shown to increase the specificity of the elisa test for a. pleuropneumoniae serotype 5 compared to a saline extract of boiled-formalinized whole cells. nevertheless, some cross reactions were noticed with lc-lps. we have thus cleaved the lps molecule at the ketosidic bond between the lipid a and the core. the ... | 1993 | 8237195 |
| purification of surface-exposed integral outer membrane proteins of actinobacillus pleuropneumoniae and their role in opsonophagocytosis. | previously identified 39-, 50-, and 76-kd integral outer membrane proteins (iomp) of actinobacillus pleuropneumoniae, a respiratory tract pathogen, were separated by electroelution of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-obtained fragments and their role in opsonophagocytosis by porcine leukocytes was investigated by flow cytometry of fluorescein-labeled a pleuropneumoniae. using specific antisera, immunoblot analysis indicated that the 3 proteins were antigenically distinct ... | 1993 | 8239134 |
| [pneumonia diagnosis in living swine using lung lavage]. | in pigs coming from fattening units with tenacious pneumonitis problems the attempt was made to find an etiological diagnosis in living pigs by bronchoalveolar lavage (bal) and serological examinations on antibodies against mycoplasma hyopneumonia, actinobacillus pleuropneumoniae and influenza-a-virus (serotypes h1n1 and h3n2). in some cases the results of the bacteriological examinations of the bal were compared with the post mortem findings. both methods yield similar results. mycoplasma hyopn ... | 1993 | 8250824 |
| identification of actinobacillus pleuropneumoniae serotype 2 by monoclonal or polyclonal antibodies in latex agglutination tests. | | 1993 | 8266903 |
| optimalization of the detection of nad dependent pasteurellaceae from the respiratory tract of slaughterhouse pigs. | nad dependent members of the family pasteurellaceae were cultured from the nasal cavity, surface and cut surface of the tonsils, and from the apical and caudal lobes of the lungs of 303 slaughterhouse pigs from 5 different herds in order to obtain information on the ecology of these bacteria. the specimens were plated on two different selective agar media using a special dilution technique that resulted in a good separation of individual colonies. bacteriological results were compared with serol ... | 1993 | 8273273 |
| protective immunity following immunisation of pigs with aerosol of actinobacillus pleuropneumoniae serotype 2. | to introduce antigen to the respiratory mucosa, killed actinobacillus pleuropneumoniae with quil a as adjuvant was administered to pigs as an aerosol. immunisation by this aerosol induced a marked iga response in the bronchoalveolar and nasal fluids, and in the serum. following challenge with live bacteria two weeks after the last exposure to the aerosol, the immunised pigs were protected from the severe pleuropneumonia which developed in non-immunised pigs. the immunised pigs had lower antibody ... | 1993 | 8284489 |
| passive protection of mice against actinobacillus pleuropneumoniae infection by monoclonal antibodies. | mouse monoclonal antibodies (mabs), y-4b, f-6b and k-6a recognized as capsular antigens of a. pleuropneumoniae serotypes 1, 2 and 5, respectively, and mab h-1b as lipopolysaccharide (lps) of serotype 2 were produced. we examined the passive immunizing efficacy of these mabs on a. pleuropneumoniae infection in c3h/hej mice. on the challenge infection of homologous serotype strains, they showed a sufficient protective effect in immunized mice. it was concluded that mabs recognized as capsular anti ... | 1993 | 8286520 |
| hlyia-like sequence present in a genetic locus with low homology to appa in actinobacillus pleuropneumoniae serotype 10. | using the appa gene encoding actinobacillus pleuropneumoniae-rtx-toxin ii (apxii) as a probe, southern hybridization demonstrated the presence of appa-sequence in all 12 serotypes except serotype 10. serotype 10 strains had a genetic locus with low homology to appa (tentatively designated lha). dna sequence analysis revealed that lha contained a part of hlyia gene encoding a 105-kda hemolysin apxi. southern hybridization demonstrated the presence of lha (hlyia) sequence not only in serotype 10 b ... | 1993 | 8286536 |
| the importance of secreted virulence factors in actinobacillus pleuropneumoniae bacterin preparation: a comparison. | current bacterins provide only partial protection against morbidity and mortality in swine following infection by actinobacillus pleuropneumoniae. we compared the efficacy of a cell-free concentrate from mid-log phase growth cultures of actinobacillus pleuropneumoniae (app) serotype 1 to four commercial bacterins. this cell-free preparation contained carbohydrate, endotoxin, and protein, and had hemolytic and cytotoxic activity. sodium dodecyl-sulfate polyacrylamide gel electrophoresis analysis ... | 1993 | 8296454 |
| characterization of newly isolated plasmids from actinobacillus pleuropneumoniae. | the genetic basis of drug-resistant strains of actinobacillus pleuropneumoniae in japan was studied. the a pleuropneumoniae strains av277 and av281 that belong to serotype 2 were resistant to streptomycin (sm) and sulfonamide (sa). both strains had an 8.1-kilobase (kb) sm-sa plasmid that was previously classified in the h1 group. the av177 (serotype 1) strain was resistant to sm, sa, ampicillin, and kanamycin (km), but did not have any plasmids. the av319 and av324 (serotype 1) strains were resi ... | 1993 | 8317761 |
| effect of passive immunization with serotype-specific monoclonal antibodies on actinobacillus pleuropneumoniae infection of mice. | specific monoclonal antibodies (moabs) to actinobacillus pleuropneumoniae (app) serotypes 1 and 2 which recognized serotype-specific antigens were produced. it was revealed that the two serotype-specific moabs h1-18 and h22-7 recognized o polysaccharides of the lipopolysaccharide (lps) from app serotypes 1 and 2, respectively, in the results of antigen analysis by means of sds-page and western blotting. furthermore, ddy mice immunized passively with the above type-specific moabs were protected a ... | 1994 | 8204768 |
| evaluation of an immunoperoxidase technique using an only biotin-labeled antibody for the demonstration of actinobacillus pleuropneumoniae in tissue sections. | in this report an immunoperoxidase technique (ipb) using an only biotin-labeled antibody is compared to culture isolation method (cim) for the demonstration of actinobacillus pleuropneumoniae serotype 1 in tissues of mice inoculated intravenously. the organism was isolated in 86.7% of mice and detected by ipb in 100% of cases. a. pleuropneumoniae antigen was mainly demonstrated in the liver, spleen and lungs, but also in the kidney and brain, being especially located in the cytoplasm of macropha ... | 1993 | 8322547 |
| pulmonary lesions in mice inoculated with actinobacillus pleuropneumoniae hemolysin and lipopolysaccharide. | non-swiss albino (cf1) male mice were used as a model to study the effects of specific toxic components of actinobacillus pleuropneumoniae on the respiratory system. mice were divided into five groups of ten each and were inoculated by the intranasal route with whole-cell actinobacillus pleuropneumoniae serotype 1, cell-free culture supernatant fluid (cfcsf) containing hemolysin protein, purified lipopolysaccharide (lps), heat-treated cfcsf, or phosphate-buffered saline solution. pulmonary lesio ... | 1993 | 8333104 |
| actinobacillus pleuropneumoniae haemolysin ii is secreted from escherichia coli by a. pleuropneumoniae pleurotoxin secretion gene products. | actinobacillus pleuropneumoniae serotype 2 secretes type ii haemolysin and pleurotoxin activities. here, the genes for type ii haemolysin were cloned in escherichia coli, but type ii haemolysin antigen and haemolysin activity were only detected intracellularly and not exported to culture supernatant. it has been reported that the genes for type ii haemolysin are not linked to functional secretion genes, while those for pleurotoxin are. in this report the means of secretion of type ii haemolysin ... | 1993 | 8339922 |
| the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) colorimetric assay for the quantitation of actinobacillus pleuropneumoniae cytotoxin. | using swine neutrophils as target cells, two mtt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) colorimetric assay systems, one with and one without phorbol 12-myristate 13-acetate (pma) stimulation were established for the quantitation of actinobacillus pleuropneumoniae cytotoxin. the mtt assays were optimized for the number of neutrophils, incubation time, and pma concentration by a series of experiments. the optimal conditions were 25 x 10(4) cells/well incubated for four hours for th ... | 1993 | 8358675 |
| actinobacillus pleuropneumoniae culture supernatants interfere with killing of pasteurella multocida by swine pulmonary alveolar macrophages. | the effect of actinobacillus pleuropneumoniae culture supernatant on swine pulmonary alveolar macrophage (pam) functions was studied. the a. pleuropneumoniae culture supernatant was toxic to pams when tested by mtt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (ldh) release assays. biological activity of the supernatant was ascribed to cytotoxins. both the ldh and mtt assays were used for measurement of crude a. pleuropneumoniae cytotoxin concentration ... | 1993 | 8358680 |
| detection of actinobacillus pleuropneumoniae in the porcine upper respiratory tract as a complement to serological tests. | attempts were made to isolate actinobacillus pleuropneumoniae from the nasal cavities and tonsils of 442 healthy pigs from 15 herds. samples were streaked onto different media formulations. serum samples were assayed for antibodies to a. pleuropneumoniae by enzyme-linked immunosorbent assay and complement fixation test. actinobacillus pleuropneumoniae was isolated from the nasal cavities only in 24 pigs, from tonsils only in 90 pigs, and from both the nasal cavities and the tonsils in 11 pigs. a ... | 1993 | 8358682 |
| structural analysis of the actinobacillus pleuropneumoniae-rtx-toxin i (apxi) operon. | actinobacillus pleuropneumoniae-rtx-toxin i (apxi), an important virulence factor, is secreted by serotypes 1, 5, 9, 10, and 11 of a. pleuropneumoniae. however, sequences homologous to the secretion genes apxibd of the apxi operon are present in all 12 serotypes except serotype 3. the purpose of this study was to determine and compare the structures of the apxi operons of the 12 a. pleuropneumoniae serotypes. we focused on the nucleotide sequence comparison of the apxi-coding genes, the structur ... | 1993 | 8359891 |
| genetic analysis of actinobacillus pleuropneumoniae, and comparison with haemophilus spp. taxon "minor group" and taxon c. | the genetic diversity among 52 field isolates, mainly from australia, and 15 reference strains of actinobacillus pleuropneumoniae was examined using multilocus enzyme electrophoresis. thirty three electrophoretic types (ets) were recognised, with a mean genetic diversity per locus of 0.312. australian strains of serovars 1, 2, 5 and 7 belonged to the same clonal lines as strains of these serovars in other countries, but distinct clones of serovars 3, 7, 11 and 12 were also identified. the type s ... | 1993 | 8369588 |
| development and evaluation of a mixed-antigen elisa for serodiagnosis of actinobacillus pleuropneumoniae serotypes 1, 5, and 7 infections in commercial swine herds. | a mixed-antigen enzyme-linked immunosorbent assay (elisa) containing serotype-specific polysaccharide antigens from serotypes 1, 5, and 7 of actinobacillus pleuropneumoniae was developed. this elisa was evaluated using sera from experimentally infected pigs. with a negative cutoff value of 0.250 (optical density at 405 nm), sensitivity and specificity were determined to be 96% and 99.5%, respectively. the elisa was further evaluated using sera from commercial swine. sows and suckling piglets wer ... | 1993 | 8373847 |
| phagocytosis by pig alveolar macrophages of actinobacillus pleuropneumoniae serotype 2 mutant strains defective in haemolysin ii (apxii) and pleurotoxin (apxiii). | the ability of pig alveolar macrophages to phagocytose actinobacillus pleuropneumoniae hk 361, which produces both haemolysin ii (apxii) and pleurotoxin (apxiii), has been studied. macrophages incubated with hk 361 in the presence of normal pig serum were rapidly killed. incubation of the macrophages with a haemolysin-deficient mutant (hk 361 e), which possesses only cytotoxic activity (apxiii), also caused gross damage to the macrophages. a mutant (hk 361 h) which produces neither apxii nor apx ... | 1994 | 8180688 |
| experimental pneumonia of pigs infected with aujeszky's disease virus and actinobacillus pleuropneumoniae. | experimental infections were induced out to examine whether aujeszky's disease virus (adv) infection in pigs results in a severe pneumonia by actinobacillus pleuropneumoniae. intranasal inoculation of adv (10(6.9) median tissue culture infective dose/head) in 4-month-old primary specific-pathogen-free pigs was followed by the inoculation of a. pleuropneumoniae type 1 (10(3.1) or 10(5.1) colony-forming-units/head). the pigs inoculated with adv alone developed clinical signs of aujeszky's disease ... | 1993 | 8399736 |
| protective effect of dihydroheptaprenol in combination with vaccine to experimental actinobacillus pleuropneumoniae infection in guinea pigs and pigs. | we investigated the effects of dihydroheptaprenol (dhp) on resistance of guinea pigs and pigs inoculated with actinobacillus pleuropneumoniae (apn) vaccine to subsequent challenge with apn. guinea pigs with complement-fixation (cf) antibody titers of 1:8 and 1:16 after intramuscular (i.m.) inoculation with inactivated apn vaccine showed enhanced resistance to intraperitoneal (i.p.) infection with a homologous apn strain (5 x 10(10) cfu/animal) when injected with dhp (20 mg/kg, i.m.) on the day b ... | 1993 | 8399745 |