Publications

[the characteristics of the antibiotic therapy of acute dysentery in an immunodeficiency body state in children with leukopenia].	course of the disease and some indices of immunity were studied in 100 children with sonne's and flexner's dysentery. parameters of immunity in 32 children (the 1st group) were normal. 68 patients (the 2-nd group) had secondary immune deficiency and leukopenia. recovery of immunodeficient children in use of antibiotics and prodigiosan was slowed down by 5.2 days as compared to that of children without immunodeficiency. antibiotics used in combination with lysozyme in patients of the 1st group re ...	1994	8067000
cloning and sequencing of sara of staphylococcus aureus, a gene required for the expression of agr.	to evaluate the effect of a sar mutation on the agr locus, northern (rna) blotting was performed to determine the levels of rnaiii, the agr regulatory molecule, in two isogenic pairs of staphylococcus aureus strains. our results demonstrated that rnaiii was either significantly diminished or absent in both sar mutants compared with the parents. the rnaiii level was partially restored in sar mutants complemented with an intact sar gene (designated sara). additionally, we were able to complement s ...	1994	8021198
a role for h-ns in the thermo-osmotic regulation of virulence gene expression in shigella flexneri.	the role of the hns gene (coding for the curved-dna-binding protein h-ns) in the thermo-osmotic regulation of shigella flexneri virulence gene transcription was investigated. two structural genes, mxic and icsb, which are transcribed divergently on the high-molecular-weight virulence plasmid, were found to be transcriptionally inhibited in cultures grown in a low-osmolarity medium, even at the inducing temperature. this repression was relieved by inactivation of the hns gene, establishing a role ...	1994	8021202
shigellosis in neonates and young infants.	to determine the clinical features and outcome of shigellosis in young infants, we reviewed the hospital records of 159 infants < or = 3 months of age (including 30 neonates) and 159 children 1 to 10 years of age with shigellosis who were admitted to the diarrhoea treatment centre in dacca, bangladesh. infants more commonly had a history of nonbloody diarrhea (82.8% vs 42.7%; p < 0.001), moderate or severe dehydration (59.9% vs 32.1%; p < 0.001), or bacteremia (12.0% vs 5.0%; p = 0.027) and less ...	1994	8021764
immunopathological patterns in the rectal mucosa of patients with shigellosis: expression of hla-dr antigens and t-lymphocyte subsets.	expression of hla-dr antigens and infiltration of t-lymphocyte subsets (cd4, cd8), cell activation marker (cd25), b cells (cd20), macrophages (cd68 and ber-mac 3) and natural killer cells (cd56) in the rectal mucosa of patients with bacillary dysentery and in healthy controls were studied in an effort to interpret the immunopathological changes taking place in the rectal mucosa during the acute phase of shigellosis. the epithelium of the rectal mucosa from 21 of 32 patients was hla-dr+. conventi ...	1994	8024739
yscu, a yersinia enterocolitica inner membrane protein involved in yop secretion.	pathogenic yersiniae secrete antihost yop proteins by a recently discovered secretion pathway which is also encountered in several animal and plant pathogens. the components of the export machinery are encoded by the vira (lcra), virb (lcrb), and virc (lcrc) loci of the 70-kb pyv plasmid. in the present paper we describe yscu, the last gene of the virb locus. we determined the dna sequence and mutated the gene on the pyv plasmid. after inactivation of yscu, the mutant strain was unable to secret ...	1994	8045883
vacc, a virulence-associated chromosomal locus of shigella flexneri, is homologous to tgt, a gene encoding trna-guanine transglycosylase (tgt) of escherichia coli k-12.	the genetic determinants required for invasion of epithelial cells by shigella flexneri and for the subsequent bacterial spreading are encoded by the large virulence plasmid. expression of the virulence genes is under the control of various genes on the large plasmid as well as on the chromosome. we previously identified one of the virulence-associated loci near phobr in the noti-c fragment of the chromosome of s. flexneri 2a ysh6000 and designated the locus vacc. the vacc mutant showed decrease ...	1994	8045893
characterization of endemic shigella flexneri strains in somalia: antimicrobial resistance, plasmid profiles, and serotype correlation.	one hundred twelve shigella flexneri strain isolated from children with diarrheal disease in somalia in 1983, 1984, 1988, and 1989 were analyzed for serotype, plasmid profile, and genetic location of antimicrobial resistance determinants. the prevalent serotypes were 4 (46% of the isolates), 1b (16%), 2a (16%), 3a (12%), and 6 (8%). each serotype was associated with a characteristic predominant plasmid profile, whereas no specific correlation between antimicrobial resistance patterns and single ...	1994	8051242
constitutive expression of the virulence genes improves the efficiency of plant transformation by agrobacterium.	inducible virulence (vir) genes of the agrobacterium tumefaciens tumor-inducing (ti) plasmid are under control of a two-component regulatory system. in response to environmental factors (phenolic compounds, sugars, ph) vira protein phosphorylates virg, which in turn interacts with the promoters of other vir genes, causing induction. a mutation of virg, virgn54d (which codes for a asn-54-->asp amino acid change in the product), causes constitutive expression of other vir genes independent of vira ...	1994	8052627
detailed structural characterization of lipid a: electrospray ionization coupled with tandem mass spectrometry.	previous studies have defined specific functional relationships within monophosphoryl lipid a (mla) preparations. to extend this understanding to all contributing entities, mla samples have been structurally characterized using electrospray ionization, collision-induced dissociation (cid), and tandem mass spectrometry (ms/ms). mla profiles of salmonella minnesota re595 have been compared with shigella flexneri for sample type and component distribution. in excess of 20 individual structures comp ...	1994	8053569
a mutation in the receiver domain of the agrobacterium tumefaciens transcriptional regulator virg increases its affinity for operator dna.	we fused the wild-type agrobacterium tumefaciens virg gene and the constitutive virgn54d allele to the male gene of escherichia coli, and studied the binding of mbp-virg fusions to the autoregulated virg promoter. mbp-virgn54d protein bound this promoter with 10-fold higher affinity than mbp-virg, and bound to vir box i with eightfold higher affinity than to vir box iii. disruption of vir box iii did not alter the affinity for vir box i, suggesting a lack of cooperativity between these sites. we ...	1994	8057837
deregulation of temperature-dependent transcription of the invasion regulatory gene, virb, in shigella by rho mutation.	expression of the virb gene, the transcriptional regulator for the invasion genes encoded by the large plasmid of shigella flexneri, is temperature-regulated. virb transcription is under the control of virf and h-ns, which act as positive and negative regulators, respectively, and is highly responsive to changes in dna superhelicity. to further investigate the molecular mechanisms underlying the thermoregulation of virb transcription, a mutant which expressed an invasion phenotype at both 30 deg ...	1994	8057851
molecular characterization of intact, but cryptic, flagellin genes in the genus shigella.	flagellin genes (flic) were detected in two species of the genus shigella. the flicsf gene cloned from shigella flexneri produced normal-type flagella in an escherichia coli delta flic strain while the flicss genes from two shigella sonnei strains produced curly-type flagella and their expression is repressible by salmonella flja repressor. the flicsf gene (1650 bp) shared high similarity with the e. coli flice gene not only in the 5' and 3' constant sequences but also in the upstream and downst ...	1994	8057852
polymicrobial and recurrent bacteremia with shigella in a patient with aids.	shigella gastroenteritis is uncommon among hiv seropositive patients and may be complicated in some patients by bacteremia; s. flexneri being the most frequently detected serogroup. while recurrent salmonella bacteremia is common among hiv-seropositive patients, recurrent shigella bacteremia is not. we report here an hiv-seropositive patient with shigella gastroenteritis, polymicrobial bacteremia due to s. flexneri and s. boydii, and recurrent gastroenteritis and bacteremia with s. boydii. relap ...	1994	7984973
serum igg antibody responses to shigella invasion plasmid-coded antigens detected by immunoblot.	serum igg antibody responses to shigella invasion plasmid-coded antigens (ipa) from 58 shigella flexneri, s. sonnei, and s. dysenteriae infected swedish patients were investigated by immunoblot technique. intense responses to most components of ipa (ipas a, b, c, d, and virg-virulence determinant on sali fragment g of the plasmid) were evident in sera from s. flexneri infected patients. the strongest response was to ipa b and the weakest, to ipa d. in contrast, there were weaker responses to ipa ...	1994	7984976
[a rapid specific reaction of the blood phagocytes to bacteria and the new possibilities for its diagnostic determination in infections].	materials on the study of specific reaction of phagocytes, rapidly appearing after the contact of the body with soluble microbial substances, are presented. the study has established that of the reaction-inducing stimulus has a non-antigenic character and it acts directly on phagocytes. the method for the determination of phagocytic reaction by the ratio of the phagocytosis levels in the specific and control objects has been developed, which makes it possible to use a common diagnostic criterion ...	1994	7992518
shigellosis in jordanian children: a clinico-epidemiologic prospective study and susceptibility to antibiotics.	during a 2-year prospective study of children hospitalized with gastroenteritis, shigellosis was detected in 66 cases (9 per cent of 726 admissions). the age group for peak shigella incidence was 1-4 years. the incidence increased from 8 per cent in 1991, to 11 per cent in 1992. shigella flexneri was the most common isolate (65 per cent), followed by shigella sonnei (17 per cent), shigella boydi (11 per cent), and shigella dysenteriae (7 per cent). at presentation, 44 per cent had watery diarrho ...	1994	7853441
shigella flexneri: genetics of entry and intercellular dissemination in epithelial cells.		1994	7859507
molecular cloning of the wild-type and mutant thya gene from shigella flexneri y.	the thya gene which codes for thymidylate synthase has been cloned and sequenced from the wild-type shigella flexneri y strain sh4 and a thya mutant tsf21 after amplifying the gene by polymerase chain reaction (pcr). the nucleotide sequence revealed 98% homology to the e. coli k-12 thya gene. the sequence of the wild-type thya gene of shigella flexneri y was identical with that of the thya mutant except that the residue t at position 345 was replaced by residue a in the thya mutant. this change ...	1994	7935051
[the effect of shigellae on delayed hypersensitivity in mice infected by different routes].	the influence of virulent and avirulent shigellae on delayed hypersensitivity in the case of infection by different methods has been examined. it was found that the stimulating effect of avirulent shigellae and suppressive effect of virulent shigellae were displayed after intranasal infection. intraperitoneal and intravenous infection was accompanied by only immunosuppressive influence, which was displayed by the virulent bacteria. the discrimination of t-suppressors by low doses of cyclophospha ...	1994	7952228
lps injected into the pregnant rat late in gestation does not induce fetal endotoxemia.	endotoxin is abortifacient. abortion may be due to maternal, fetal or combined endotoxemia. the present study was performed to evaluate if fetal rat endotoxemia was induced by maternal endotoxemia in late gestation. an intraperitoneal injection of smooth lipopolysaccharide (escherichia coli lps and shigella flexneri lps) or rough lps (rc mutant escherichia coli lps) induced limulus activity in maternal plasma, but not fetal plasma. these results suggest that fetal rat endotoxemia is not induced ...	1994	7953189
extracellular association and cytoplasmic partitioning of the ipab and ipac invasins of s. flexneri.	shigella species cause bacillary dysentery in humans by invading colonic epithelial cells. ipab and ipac, two major invasins of these pathogens, are secreted into the extracellular milieu. we show here that ipab and ipac form a complex in the extracellular medium and that each binds independently to a 17 kda polypeptide, ipgc, in the bacterial cytoplasm. the ipgc polypeptide was found to be necessary for bacterial entry into epithelial cells, to stabilize the otherwise unstable ipab protein, and ...	1994	7954817
the secretion of the shigella flexneri ipa invasins is activated by epithelial cells and controlled by ipab and ipad.	shigella species are enteropathogens that invade epithelial cells of the human colon. entry into epithelial cells is triggered by the ipab, ipac and ipad proteins which are translocated into the medium through the specific mxi-spa machinery. in vitro, shigella cells secrete only a small fraction of the ipa proteins, the majority of which remains in the cytoplasm. we show here that upon interaction with cultured epithelial cells or in the presence of fetal bovine serum, s.flexneri release pre-syn ...	1994	7957095
shigella flexneri: from in vitro invasion of epithelial cells to infection of the intestinal barrier.		1994	7958310
regulation of surface presentation of icsa, a shigella protein essential to intracellular movement and spread, is growth phase dependent.	after lysing the phagocytic vacuole, shigella spp. accumulate filaments of polymerized actin on their surface at one pole, leading to the formation of actin tails that enable them to move through the cytoplasm. we have recently demonstrated that the shigella protein icsa is located at the pole that is adjacent to the growing end of the actin tail (m. b. goldberg, o. barzu, c. parsot, and p. j. sansonetti, j. bacteriol. 175:2189-2196, 1993). not every bacterium that is observed within the cytopla ...	1994	7960150
mutational analysis of the transcriptional activator virg of agrobacterium tumefaciens.	to find virg proteins with altered properties, the virg gene was mutagenized. random chemical mutagenesis of single-stranded dna containing the agrobacterium tumefaciens virg gene led with high frequency to the inactivation of the gene. sequence analysis showed that 29% of the mutants contained a virg gene with one single-base-pair substitution somewhere in the open reading frame. thirty-nine different mutations that rendered the virg protein inactive were mapped. besides these inactive mutants, ...	1994	7961391
[diarrheal disease in hospitalized patients during the first year of the war].	during the period from april 1992 to april 1993 at the clinic for infectious disease in sarajevo were hospitalized 213 patients. the major causative agents were different kinds of shigella. shigella sonnei with 159 (74.6%) was the most frequent isolated organism, then subsequent shigella species with 38 (23.9%) and shigella flexneri 3 with 23 (14.5%). bacillary dysentery (shigellosis) was manifested as acute gastroenteritis with 60 patients (37.7%). this disease was manifested in the form of acu ...	1994	7967796
measurement of invasion by gentamicin resistance.		1994	7968625
shigella flexneri: isolation of noninvasive mutants of gram-negative pathogens.		1994	7968634
asymptomatic shigella infections in a cohort of mexican children younger than two years of age.	the proportion of shigella infections that occur asymptomatically in young children has not been established. a community-based cohort study of 367 infants was followed prospectively by weekly home visits from january, 1990, through december, 1991. stool samples were collected weekly and when diarrhea occurred and were tested for shigella and other enteropathogens. there were 2925 child months of observation and 65 episodes of shigella infection. there were 3.1 episodes/100 child months during t ...	1994	7970946
the n-terminal domain of virg of agrobacterium tumefaciens: modelling and analysis of mutant phenotypes.	fourteen mutants in the n-terminal domain of virulence factor g (virg) were obtained by random mutagenesis. two mutants showed an altered phenotype, all others were non-functional. all mutants can still be phosphorylated and bind to dna. a 3-d model was built based on the coordinates of chemotaxis protein y (chey). many of the observed phenotypic changes of virg are explained qualitatively. combination of model building and biochemical information leads to the conclusion that the active sites of ...	1994	7971952
polymorphonuclear leukocyte transmigration promotes invasion of colonic epithelial monolayer by shigella flexneri.	in vivo and in vitro, shigella flexneri, an invasive pathogen of the human colon, cannot invade epithelial cells through their apical pole. to identify ways by which it may reach the cellular basolateral domain in order to invade, we have established an assay using the human colonic t-84 cell line grown on permeable filters. human pmn were added to the basal pole of the cells, and invasive shigellae to their apical pole. apical addition of bacteria induced strong transmigration of pmn, reaching ...	1994	7906696
is protection against shigellosis induced by natural infection with plesiomonas shigelloides?	shigellosis due to shigella sonnei is rare among people growing up and living in developing countries; however, infections due to s sonnei becomes more common than those due to s flexneri as societies develop economically. the relation between risk of s sonnei infection and economic development may be explained by the exposure of developing-country populations to plesiomonas shigelloides. p shigelloides is often found in surface water, and one serotype (serotype 17) possesses a cell-wall lipopol ...	1994	7910890
construction and characterization of attenuated delta aroa delta virg shigella flexneri 2a strain cvd 1203, a prototype live oral vaccine.	we engineered an oral shigella vaccine prototype that can invade intestinal epithelial cells but cannot undergo extensive intracellular replication or extend to adjacent epithelial cells. strain cvd 1203, derived from wild-type shigella flexneri 2a by introducing deletions in chromosomal aroa and invasion plasmid virg, was highly attenuated in the sereny test. two 10(9)-cfu orogastric doses (2 weeks apart) stimulated production of secretory immunoglobulin a antibodies to s. flexneri 2a and prote ...	1994	7927802
enhancement of anti-shigella lipopolysaccharide (lps) response by addition of the cholera toxin b subunit to oral and intranasal proteosome-shigella flexneri 2a lps vaccines.	addition of the cholera toxin b subunit to oral and intranasal proteosome-shigella flexneri 2a lipopolysaccharide vaccines improved their immunogenicities. enhancement of anti-o-shigella immunoglobulin a levels was most evident in lung lavages following oral immunization and in lung and intestinal fluids when suboptimal doses were used with either immunization route.	1994	7927807
involvement of escherichia coli dna polymerase ii in response to oxidative damage and adaptive mutation.	dna polymerase ii (pol ii) is regulated as part of the sos response to dna damage in escherichia coli. we examined the participation of pol ii in the response to oxidative damage, adaptive mutation, and recombination. cells lacking pol ii activity (polb delta 1 mutants) exhibited 5- to 10-fold-greater sensitivity to mode 1 killing by h2o2 compared with isogenic polb+ cells. survival decreased by about 15-fold when polb mutants containing defective superoxide dismutase genes, soda and sodb, were ...	1994	7928992
acute inflammation causes epithelial invasion and mucosal destruction in experimental shigellosis.	the gram-negative pathogen shigella flexneri causes bacillary dysentery, an invasive disease of the human colonic mucosa. a major characteristic of the infectious process is the occurrence of an acute inflammatory reaction of mucosal tissues which is generally consequence of primary invasion and destruction of colonic epithelial cells by the pathogen. confirming in vitro demonstration that s. flexneri is unable to invade the apical pole of colonic cells and that polymorphonuclear (pmn) cells may ...	1994	7931064
effect of subinhibitory concentrations of antimicrobial agents on virulence factors of shigella flexneri 2a and escherichia coli o124.	the effect of subinhibitory concentrations of rifampicin, chloramphenicol, tetracycline and nalidixic acid on the interaction of shigella flexneri 2a and escherichia coli o124 with hela cells was examined. antimicrobial agents altered adhesion, penetration and intracellular multiplication of the bacteria, as well as re-infection of adjacent cells. chloramphenicol increased the virulence of the bacterial strains whereas nalidixic acid, tetracycline and rifampicin diminished it.	1994	7932621
dna rearrangement of the shufflon determines recipient specificity in liquid mating of inci1 plasmid r64.	the shufflon is a unique dna rearrangement found in plasmid r64. r64 shufflon consists of four dna segments, which are flanked and separated by seven 19-bp repeat sequences. site-specific recombination between any inverted repeats results in a complex dna rearrangement where four dna segments invert independently or in groups. the shufflon is a biological switch to select one of the seven c-terminal segments of the pilv gene. to examine the biological significance of the shufflon, r64 derivative ...	1994	7932741
from the centers for disease control and prevention. outbreak of shigella flexneri 2a infections on a cruise ship.		1994	7933412
[epidemics and history: the berlin 1962 dysentery epidemic].		1994	7825366
[the blood circulation of the rectal mucosa and the functional status of the rectal sphincter in acute infectious enterocolitis].	significant decrease in the tone of the rectal mucosa venules was to be seen at the climax of acute proteus and klebsiella enterocolitis, as evidenced by examinations with the aid of rheorectograph and an analyzer of intracavitary motor activity, general blood supply to the intestinal segment under study being not compromised. the tone of the rectal mucous membrane arterioles is raised at the climax of acute dysentery caused by a flexner type of organism in erosive and haemorrhagic proctosigmoid ...	1994	7831889
acute bacterial diarrhoea in the emergency room: therapeutic implications of stool culture results.	empiric treatment with ciprofloxacin and norfloxacin has been recommended recently for patients with acute diarrhoeal disease. in a retrospective 6-month study period the results of stool cultures from 209 patients with acute diarrhoea admitted to the emergency room were analysed. seventy-eight cultures (37%) were positive for one or more bacteria. shigella was the most commonly isolated pathogen (68%). shigella sonnei comprised 72% and shigella flexneri 19% of all the bacterial isolates. while ...	1994	7804582
[triple shigellosis in the same patient contracted during operation "turquoise" in rwanda].	we report a case of shigellosis observed in a young french sanitary assistant, returning from a refugees camp in goma after a 5-week stay. three different species were isolated from stool samples: shigella flexneri, s. boydii and s. sonnei. this observation raises the matter of a chemical prophylaxis during a short stay in developing countries where sanitary conditions are poor.	1994	7866040
antimicrobial resistance of shigella isolates causing traveler's diarrhea.	shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in spain. ampicillin and chloramphenicol resistance was more frequent in shigella flexneri (60 and 46%, respectively) than in shigella sonnei (32 and 18%, respectively) and in travel-related isolates (p < 0.05 and 0.04, respectively). of s. sonnei isolates from patients with tr ...	1994	7872767
model for the combined effects of temperature, initial ph, sodium chloride and sodium nitrite concentrations on anaerobic growth of shigella flexneri.	a fractional factorial design was used to measure the effects and interactions of temperature (12-37 degrees c), initial ph (5.5-7.5), nacl (0.5-4.0%) and nano2 (0-1000 ppm) on the anaerobic growth kinetics of shigella flexneri in brain-heart infusion broth. anaerobic conditions were established by flushing the culture flasks with n2. a total of 375 cultures representing 124 variable combinations were analyzed, with growth curves being generated using the gompertz equation. growth rates decrease ...	1994	7873336
[the role of the activity of pathogenic enterobacteria in inactivating the antibacterial constituent of interferon during phagocytosis].		1994	7879491
[an evaluation of the efficacy of measures to limit the activity of the water factor in the transmission of shigellosis in the city of blagoveshchensk].		1994	7879538
[an analysis of the plasmid profile of shigella flexneri strains used for obtaining vaccinal preparations].		1994	7879547
[the etiological structure of shigellosis in monkeys of the adler nursery].		1994	7879549
safety and immunogenicity of the oral e. coli k12-s. flexneri 2a vaccine (ecsf2a-2) among israeli soldiers.	a double-blind placebo-controlled study was carried out on the safety and immunogenicity of the oral shigella flexneri (ecsf2a-2) vaccine among israeli soldiers. sixty volunteers received the vaccine and 59 received placebo. fifty-three were given the full vaccine regimen (four doses). doses ranged between 4.1 x 10(8) and 1.1 x 10(9) c.f.u. visits to the unit clinic for mild gastrointestinal symptoms were common after the first dose in vaccinees (13%) as compared with placebo recipients (5%), bu ...	1994	7887022
[the epithelial proliferative activity of the mucosa of the large intestine in dysentery patients at the acute period of the disease depending on the expression of morphological changes].	the dependence of proliferative activity on the degree of histomorphological changes in colonic mucosa of patients with dysentery was studied histoautoradiographically in colonic biopsies. morphological changes were evaluated according to n. b. shalygina's schema (catarrhal, exudative, erosive or ulcerous inflammation) a 2.5-3-fold increase of the labelled nuclei index (lni) and label intensity (li) was found in the catarrhal inflammation. lni was increased 1.2-fold and li 1.5-fold in cases of o ...	1994	7695494
[bacteriostasis of rhizoma coptidis combined with trimethoprim (tmpo)].	the agar-dilution method was adopted to study contrastively the bacteriostasis of rhizoma coptidis and tmp, and also of the two drugs in combination. the results indicate that the combination works in good cooperation against escherichia coli, bacillus pyocyaneus, staphylococcus aureus, shigella flexneri and s. dysenteriae.	1994	7718141
[diarrhea, dysentery, cholera, new frontiers?].		1994	7746137
reiter's syndrome and reactive arthritis: a current view.	this paper reviews advances in the understanding of the pathogenesis of reactive arthritis that have occurred over the last decade. inflammatory aseptic joint disease has been linked with prior infection initiated by many different species of microorganisms. the presence of intra-articular bacterial antigens has now been firmly established with the demonstration of bacteria, bacterial fragments, dna, rna, and bacterial lipopolysaccharide in joints of patients with reactive arthritis. chlamydia t ...	1994	7534942
local immune response and protection in the guinea pig keratoconjunctivitis model following immunization with shigella vaccines.	this study used the guinea pig keratoconjunctivitis model to examine the importance of route of administration (mucosal versus parenteral), frequency and timing of immunization (primary versus boosting immunization), and form of antigen given (live attenuated vaccine strain versus o-antigen-protein conjugate) on the production of protective immunity against shigella infection. since local immune response to the lipopolysaccharide (lps) o-antigen of shigella spp. is thought to be important for pr ...	1994	7507892
characterization of the rfc region of shigella flexneri.	the o antigen of the shigella flexneri lipopolysaccharide (lps) is an important virulence determinant and immunogen. we have isolated s. flexneri mutants which produce a semi-rough lps by using an o-antigen-specific phage, sf6c. western immunoblotting was used to show that the lps produced by the semi-rough mutants contained only one o-antigen repeat unit. thus, the mutants are deficient in production of the o-antigen polymerase and were termed rfc mutants. complementation experiments were used ...	1994	7507920
division inhibition gene dicf of escherichia coli reveals a widespread group of prophage sequences in bacterial genomes.	the genomes of various eubacteria were analyzed by southern blot hybridization to detect sequences related to the segment of the defective lambdoid prophage kim which encodes dicf rna, an antisense inhibitor of cell division gene ftsz in escherichia coli k-12. among the homologous sequences found, one fragment from e. coli b, similar to a piece of rac prophage, and two fragments from shigella flexneri were cloned and sequenced. dicf-like elements similar to transcriptional terminators were found ...	1994	7508908
genetic analysis of the o-specific lipopolysaccharide biosynthesis region (rfb) of escherichia coli k-12 w3110: identification of genes that confer group 6 specificity to shigella flexneri serotypes y and 4a.	we recently reported a novel genetic locus located in the sbcb-his region of the chromosomal map of escherichia coli k-12 which directs the expression of group 6-positive phenotype in shigella flexneri lipopolysaccharide, presumably due to the transfer of o-acetyl groups onto rhamnose residues of the s. flexneri o-specific polysaccharide (z. yao, h. liu, and m. a. valvano, j. bacteriol. 174:7500-7508, 1992). in this study, we identified the genetic region encoding group 6 specificity as part of ...	1994	7517390
some structures and processes of human epithelial cells involved in uptake of enterohemorrhagic escherichia coli o157:h7 strains.	several enterohemorrhagic escherichia coli (ehec) strains of serotype o157:h7 isolated from patients with hemorrhagic colitis, ischemic colitis, or hemolytic uremic syndrome were all found to be able to invade certain human epithelial cell lines in vitro. their ability to gain entry into epithelial cells was compared with those of known invasive shigella flexneri and salmonella typhi strains and the noninvasive e. coli strain hb101 in invasion assays utilizing gentamicin to kill extracellular ba ...	1994	7523304
effect of outer membrane proteins (omp) of shigella on interleukin 2 (il-2) production by spleen cells of mice.	the kinetics of interleukin (il-2) release from mouse spleen cells incubated with different doses of outer membrane proteins (omp) from shigella was investigated. omp induced very low activity of il-2 after 2 and 4 h, and only a slightly higher level of the cytokine was detected after 6 h. however, il-2 activity increased markedly after 20 and 24 h of incubation, and doses of 5 and 10 micrograms of omp were found to be the most effective. spleen cells cultured with omp for 48 h contained reduced ...	1994	7487346
[ampicillin resistance mediated by the r plasmid in strains of shigella flexneri].	forty shigella flexneri strains isolated from children attended to at the children's hospital of camagüey during an outbreak of acute diarrheal disease were studied; the minimal inhibitory concentration of ampicillin was determined. 33 strains (82.5%) were resistant to higher concentrations: 8 to 16 micrograms/ml, and 7 were susceptible to 4 micrograms/ml concentrations. resistance plasmid (r) extraction was carried out in all the isolated strains and a common plasmid was found this plasmid was ...	1994	9768253
mechanism of antigenic variation in shigella flexneri. ii. sensitivity to complement as a selection factor for antigenic mutant 3b in 1b serotype.	in the first report we stated that the antigenic mutant of shigella flexneri 6713 3b serovar with antigenic formula iii: 3, 4, 6 was less sensitive to bactericidal action of normal calf serum in comparison to its parent strain s. flexneri 6713 1b with antigenic formula iii: 3, 4, 6. in this paper we show that the phenomenon is rather a general one; the difference in sensitivity was observed in three other strains s. flexneri 1b of independent clinical origin and its antigenic mutants 3b respecti ...	1994	7503650
ph and acidity in lactic-fermenting cereal gruels: effects on viability of enteropathogenic microorganisms.	survival of bacillus cereus, campylobacter jejuni, enterotoxigenic escherichia coli, salmonella typhimurium and shigella flexneri during lactic acid fermentation of cereal gruels prepared from low-tannin (white) and high-tannin (red) sorghum varieties was studied. a previously fermented gruel (starter culture, sc) recycled daily or stored for 7, 14 or 28 days, germinated cereal flour (power flour, pf), or a combination of pf and sc (pf+sc) were used as starters. at 24 h, the ph of all gruels wit ...	1994	24421191
serogroup prevalence of shigellae in bombay.	prevalence of shigellae serotypes in bombay was studied from june 1988 to may 1991. a total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs) with acute gastroenteritis. a total of 90 shigella were isolated giving the isolation rate of 3.2%. shigella flexneri was the predominant serogroup (73.3%) followed by shigella dysenteriae (16.6%). all the isolates were sensitive to nalidixic acid. eighty percent of the shigellae were multidrug resistant. present data were compare ...	1995	10707731
identification of a novel virulence gene, vira, on the large plasmid of shigella, involved in invasion and intercellular spreading.	a novel virulence gene (vira) was identified upstream of the virg gene on the large plasmid of shigella flexneri 2a ysh6000. characterization of vira mutants infecting mk2 epithelial cell monolayers revealed that their invasive capacity was decreased to less than one fifth of the wild-type level. nevertheless, the bacteria were capable of expressing and secreting ipab, ipac and ipad proteins. the vira mutants were also impaired in their ability to spread intercellularly, since the bacteria gave ...	1995	7494473
entry of microbes into the host: using m cells to break the mucosal barrier.	enteric microbial pathogens interact with the gut epithelium to establish infection. recently, it has become clear that many microorganisms that colonize or traverse the intestinal mucosa do so via the specialized m cells. recent work has shown that shigella flexneri and salmonella typhimurium specifically target m cells to initiate infection of the host.	1995	7495510
mucosal immune response in patients with dysentery.		1995	7502926
avirulence of rough mutants of shigella flexneri: requirement of o antigen for correct unipolar localization of icsa in the bacterial outer membrane.	mutations in the lipopolysaccharide (lps) of shigella spp. result in attenuation of the bacteria in both in vitro and in vivo models of virulence, although the precise block in pathogenesis is not known. we isolated defined mutations in two genes, galu and rfe, which directly affect synthesis of the lps of s. flexneri 2a, in order to determine more precisely the step in virulence at which lps mutants are blocked. the galu and rfe mutants invaded hela cells but failed to generate the membrane pro ...	1995	7528731
molecular, genetic, and topological characterization of o-antigen chain length regulation in shigella flexneri.	the rfb region of shigella flexneri encodes the proteins required to synthesize the o-antigen component of its cell surface lipopolysaccharides (lps). we have previously reported that a region adjacent to rfb was involved in regulating the length distribution of the o-antigen polysaccharide chains (d. f. macpherson et al., mol. microbiol. 5:1491-1499, 1991). the gene responsible has been identified in escherichia coli o75 (called rol [r. a. batchelor et al., j. bacteriol. 173:5699-5704, 1991]) a ...	1995	7532168
[pathogenicity of shigella flexneri and its regulation].		1995	7474338
sepa, the major extracellular protein of shigella flexneri: autonomous secretion and involvement in tissue invasion.	in addition to ipa proteins and icsa, which are involved in entry into epithelial cells and intercellular spread, respectively, shigella secretes a 110 kda protein, designated sepa. we report the identification, cloning, and nucleotide sequence determination of the sepa gene, analysis of sepa secretion, and construction and characterization of a sepa mutant. the sepa gene is carried by the virulence plasmid and codes for a 150 kda precursor. upon secretion, which does not involve accessory prote ...	1995	7476198
phop/phoq transcriptional repression of salmonella typhimurium invasion genes: evidence for a role in protein secretion.	previously, the phop-repressed locus prgh was identified as important for signalling epithelial cells to endocytose salmonella typhimurium. characterization of prgh revealed that it is an operon of four genes encoding polypeptides of 392 (prgh), 80 (prgi), 101 (prgj) and 252 amino acid residues (prgk). synthesis of the 2.6 kb prghijk transcript was repressed in bacteria that activate phop/phoq, indicating that phop/phoq regulates prghijk by transcriptional repression. the prgi, prgj and prgk pre ...	1995	7476203
use of confocal microscopy in studying bacterial adhesion and invasion.		1995	7476384
n-terminal amino-acid sequence of beta-lactamase from shigella flexneri ucsf-129.	a beta-lactamase (ec 3.5.2.6 penicillinase, penicillin amino beta-lactam-hydrolase) was purified from shigella flexneri uscf-129 by an efficient two-stage procedure involving chromatography in sephadex g-75 and hplc on a c18-reverse phase column. the homogeneity of the purified enzyme was confirmed by capillary zone electrophoresis (cze), hplc electrospray mass spectrometry (lc-esms) and amino acid sequence analyses. the highly purified enzyme was a monomeric protein with a molecular mass of 28. ...	1995	7476560
antigenic variability of shigella flexneri serovars 1-5.	data on the genetic basis of the classification of shigella flexneri serological variants 1-5 are presented. subserovars "a" are related to monolysogenic variants of the basic lipopolysaccharide (lps) structure 0 antigen 3,4, "b" to bilysogenic ones. a scheme of their antigenic variability, with regard to loss of one or both prophages is presented. this scheme helps differentiate between antigenic variability and mixed or superinfections. recent reports confirming our previously published sugges ...	1995	7477027
outbreak of shigella flexneri linked to salad prepared at a central commissary in michigan.	in august 1992, the michigan department of public health was notified of a cluster of persons with shigella flexneri infections, all of whom had eaten at different outlets of a single restaurant chain. the chain prepared many foods at a central kitchen. a matched case-control study to determine risk factors for illness among patrons of the restaurant chain was undertaken. an inspection of the commissary and a review of commissary inspection and employee records were conducted. of the 46 patients ...	1995	7480612
invasion of epithelial cells by shigella flexneri induces tyrosine phosphorylation of cortactin by a pp60c-src-mediated signalling pathway.	shigella flexneri causes bacillary dysentery in humans by invading epithelial cells of the colon. cell invasion occurs via bacterium-directed phagocytosis, a process requiring polymerization of actin at the site of bacterial entry. we show that invasion of hela cells by s.flexneri induces tyrosine phosphorylation of cortactin, a host cell protein previously identified as a cytoskeleton-associated protein tyrosine kinase (ptk) substrate for the proto-oncoprotein pp60c-src. immunolocalization expe ...	1995	7540134
structural elucidation of the o-antigen lipopolysaccharide from two strains of plesiomonas shigelloides that share a type-specific antigen with shigella flexneri 6, and the common group 1 antigen with shigella flexneri spp and shigella dysenteriae 1.	sugar and methylation analyses of native polysaccharides together with one-dimensional 1h- and 13c-nmr spectroscopy revealed that the two polysaccharides from strains 22074 and 12254 of plesiomonas shigelloides are identical. the structure of the polysaccharide from strain 22074 was deduced from a uronic acid degradation and by nmr spectroscopy where heteronuclear multiple bond connectivity and two-dimensional nuclear overhauser effect spectroscopy experiments established the pentasaccharide rep ...	1995	7544287
monoclonal immunoglobulin a antibody directed against serotype-specific epitope of shigella flexneri lipopolysaccharide protects against murine experimental shigellosis.	to determine the role of humoral mucosal immune response in protection against shigellosis, we have obtained a monoclonal dimeric immunoglobulin a (iga) antibody specific for shigella flexneri serotype 5a lipopolysaccharide (miga) and used a murine pulmonary infection model that mimics the lesions occurring in natural intestinal infection. adult balb/c mice challenged with 10(7) s. flexneri organisms developed a rapid inflammatory response characterized by polymorphonuclear cell infiltration aro ...	1995	7544397
expression of shigella dysenteriae serotype 1 o-antigenic polysaccharide by shigella flexneri arod vaccine candidates and different s. flexneri serotypes.	the potential utility of shigella flexneri arod vaccine candidates for the development of bi- or multivalent vaccines has been explored by the introduction of the genetic determinants rfp and rfb for heterologous o antigen polysaccharide from shigella dysenteriae serotype 1. the serotype y vaccine strain sfl124 expressed the heterologous antigen qualitatively and quantitatively well, qualitatively in the sense of the o antigen polysaccharide being correctly linked to the s. flexneri lipopolysacc ...	1995	7545156
live attenuated shigella flexneri mutants as vaccine candidates against shigellosis and vectors for antigen delivery.	up to now, no effective vaccine is available against shigellosis, a dysenteric syndrome caused by shigella, a gram-negative bacterium which invades the human colonic mucosa. about 40 years of research in the field have led to the conclusion that orally administered live shigella vaccine strains are more effective in eliciting protection than killed bacteria given parenterally. recently, the construction of promising new live attenuated vaccines has come with a better understanding of the fundame ...	1995	7546655
[the resistance to antibiotics and chemotherapeutic agents of shigella strains isolated from hiv-seropositive children].		1995	7549258
functional conservation of the secretion and translocation machinery for virulence proteins of yersiniae, salmonellae and shigellae.	virulent bacteria of the genera yersinia, shigella and salmonella secrete a number of virulence determinants, yops, ipas and sips respectively, by a type iii secretion pathway. the ipab protein of shigella flexneri was expressed in yersinia pseudotuberculosis and found to be secreted under the same conditions required for yop secretion. likewise, yope was secreted by the wild-type strain lt2 of salmonella typhimurium, but yope was not secreted by the isogenic inva mutant. secretion of both ipab ...	1995	7556059
recognition of three epitopic regions on invasion plasmid antigen c by immune sera of rhesus monkeys infected with shigella flexneri 2a.	the invasive ability of shigella spp. is correlated with the expression of several plasmid-encoded proteins, including invasion plasmid antigen c (ipac). by characterizing the antigenic structure of ipac with monoclonal antibodies and convalescent-phase sera, it may be possible to determine the physical location of specific epitopes as well as the involvement of epitopes in a protective immune response or the host's susceptibility to disease. by using overlapping octameric synthetic peptides, wh ...	1995	7558301
evaluation of commercial antisera for shigella serogrouping.	shigella serogrouping antisera from six companies (becton dickinson, denka, difco, murex, roach, and sanofi-pasteur) intended for the slide agglutination test and those of the wellcolex colour shigella latex agglutination test were evaluated to identify quality products for shigella identification. forty-six reference shigella strains (one for each serotype and species), 50 clinical strains (21 s. flexneri, 21 s. sonnei, 4 s. dysenteriae, 4 s. boydii) representing the most prevalent species and ...	1995	7559936
comparison of preservation media for storage of stool samples.	transportation of clinical samples and long-term recoverability of pathogens are critical to epidemiological studies, particularly when conditions do not permit immediate processing. this study confirms that cary-blair medium (cb) is suitable for the preservation of salmonella and shigella isolates for more than 2 weeks at 25, 4, or -70 degrees c. campylobacter jejuni was not recovered after 2 days of storage in cb at 25 degrees c when an inoculum of 12 x 10(8) cells per ml was used. lower tempe ...	1995	7559972
enhanced secretion through the shigella flexneri mxi-spa translocon leads to assembly of extracellular proteins into macromolecular structures.	genes required for entry of shigella flexneri into epithelial cells in vitro are clustered in two adjacent loci, one of which encodes secretory proteins, the ipaa-d proteins, and the other their dedicated secretion apparatus, the mxi-spa translocon. ipa secretion, which is induced upon contact of bacteria with epithelial cells, is prevented during growth in vitro. here, we show that ipab and ipad mutations lead to enhanced secretion of a set of about 15 proteins. these extracellular proteins and ...	1995	7565091
attenuated shigella as a dna delivery vehicle for dna-mediated immunization.	direct inoculation of dna, in the form of purified bacterial plasmids that are unable to replicate in mammalian cells but are able to direct cell synthesis of foreign proteins, is being explored as an approach to vaccine development. here, a highly attenuated shigella vector invaded mammalian cells and delivered such plasmids into the cytoplasm of cells, and subsequent production of functional foreign protein was measured. because this shigella vector was designed to deliver dna to colonic mucos ...	1995	7569980
structural analysis of invasion plasmid antigen d (ipad) from shigella flexneri.	invaison plasmid antigen d (ipad) and water-extracted outer-membrane proteins (omps) from shigella flexneri were used to investigate some of the structural relationships of this pathogen's invasions. extracellular presentation of the three invasion plasmid antigens (ipa) b, c, and d is required for the s. flexneri invasive phenotype; however, little is known of the structural properties of these essential virulence components. biochemical data suggest ipab, c, and d present in s. flexneri omps f ...	1995	7575570
the complete hrp gene cluster of pseudomonas syringae pv. syringae 61 includes two blocks of genes required for harpinpss secretion that are arranged colinearly with yersinia ysc homologs.	pseudomonas syringae pv. syringae 61 contains a 25-kb hrp cluster that is sufficient to elicit the hypersensitive response (hr) in nonhost plants. previous studies have shown that mutations in complementation groups viii, ix, and xi in the hrp cluster abolished the ability of the bacterium to cause the hr. the sequence of a 3.7-kb smai-ssti fragment covering groups viii and ix now reveals five open reading frames (orfs) in the same transcript, designated as hrpu, hrpw, hrpo, hrpx, and hrpy, and ...	1995	7579617
sequence and analysis of the o antigen gene (rfb) cluster of escherichia coli o111.	the o antigens found in salmonella enterica (se) and escherichia coli (ec) show a great deal of diversity, and only three structures are known to be common to both genera. two of them contain the 3,6-dideoxyheoxse colitose, not found in other serogroups of the two species. the first of these is common to ec o111 and se o:35 (sv adelaide); the other is found in both ec o55 and se o:50 (sv greenside). the genes specific for the synthesis of o antigen are generally located in the rfb gene cluster a ...	1995	7590310
development of an improved animal model of shigellosis in the adult rabbit by colonic infection with shigella flexneri 2a.	rabbits are not usually susceptible to intestinal shigella infection without extensive pretreatment, including starvation and administration of antimicrobial, antimotility, and toxic agents (carbon tetrachloride). most animals infected this way die rapidly and do not always develop colonic lesions and signs of dysentery. we describe here a successful experimental infection in the adult rabbit which does not require preparatory treatment and which reproduced characteristic features of human shige ...	1995	7591070
identification and cloning of a novel plasmid-encoded enterotoxin of enteroinvasive escherichia coli and shigella strains.	we have employed a molecular genetic approach to characterize the nature of enteroinvasive escherichia coli (eiec) enterotoxic activity, as previously observed in ussing chambers (a. fasano, b.a. kay, r.g. russell, d.r. maneval, jr., and m.m. levine, infect. immun. 58:3717-3723, 1990). the screening of tnphoa mutants of eiec yielded a single insertion mutant which had significantly reduced levels of enterotoxic activity in the ussing chamber assay. dna flanking the insertion was used as a probe ...	1995	7591128
prevalence of shigella enterotoxin 1 among shigella clinical isolates of diverse serotypes.	shigella enterotoxin 1 (shet1) is a novel, iron-dependent, toxin encoded by chromosomal genes (set1). to determine the prevalence of this enterotoxin, 172 shigella clinical isolates (and 10 enteroinvasive escherichia coli [eiec]) from distant areas worldwide, representing all 4 groups and 45 serotypes of shigella, were screened for set1 by dna colony hybridization and polymerase chain reaction amplification. set1 was present in all 22 shigella flexneri 2a strains tested but was rare in isolates ...	1995	7594690
shigella flexneri surface protein icsa is sufficient to direct actin-based motility.	shigella flexneri is a gram-negative bacterial pathogen that can grow directly in the cytoplasm of infected host cells and uses a form of actin-based motility for intra- and intercellular spread. moving intracellular bacteria are associated with a polarized "comet tail" composed of actin filaments. icsa, a 120-kda outer membrane protein necessary for actin-based motility, is located at a single pole on the surface of the organism, at the junction with the actin tail. here, we demonstrate that st ...	1995	7604035
cell movement tale told by bacterial tail protein.		1995	7604275
comparative analysis of extreme acid survival in salmonella typhimurium, shigella flexneri, and escherichia coli.	several members of the family enterobacteriaceae were examined for differences in extreme acid survival strategies. a surprising degree of variety was found between three related genera. the minimum growth ph of salmonella typhimurium was shown to be significantly lower (ph 4.0) than that of either escherichia coli (ph 4.4) or shigella flexneri (ph 4.8), yet e. coli and s. flexneri both survive exposure to lower ph levels (2 to 2.5) than s. typhimurium (ph 3.0) in complex medium. s. typhimurium ...	1995	7608084
shigella flexneri adherence to and multiplication in coxsackie b1 virus-infected hep-2 cells.	coxsackie b1 virus infection enhances the susceptibility of in vitro cultured hep-2 cells to invasiveness by shigella flexneri. we have studied the effect of viral infection on two phases of the invasiveness. only a minor part was mediated by enhanced bacterial adherence to the cells, and the intracellular multiplication was unaffected by the virus. enhanced adherence was not dependent on the presence of the gene product of the 140 md virulence associated plasmid. our data indicate that enhanced ...	1995	7612255
[the colicin selection of the s forms of representatives in the enterobacteriaceae family].	a method based on a lower sensitivity of s forms to colicines, in comparison with r forms, was used for the selection of s forms of bacteria from dissociated cultures of e. coli o.124:k72, s. sonnei, and s. flexneri. the cultures are inoculated in nutrient agar from the external segment of the zone of bacterial growth suppression by colicines d, e1, and v+m, where the content of s forms is relatively higher at the expense of death of r forms. the content of s forms in the resultant cultures of d ...	1995	7620780