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observations on the persistence and vertical transmission of salmonella enterica serovars pullorum and gallinarum in chickens: effect of bacterial and host genetic background.commercial laying hens inoculated with a strain of salmonella enterica ser. pullorum when they were 4 days old showed no morbidity, but harboured infection until they came into lay, and then produced s. pullorum-contaminated eggs and infected progeny. there was limited evidence of transmission of maternal immunity to the progeny. attempts were made to set up similar infections in hens with salmonella gallinarum, but without success. infection either resulted in clinical disease or elimination of ...200119184904
host-specificity of salmonella enterica serovar gallinarum: insights from comparative genomics.in this study, we have identified the possible genetic factors responsible for fowl-adaptation of salmonella entericaserovar gallinarum (s. gallinarum). by comparing the genes related to salmonella pathogenicity islands (spi) of s. gallinarum with those of salmonella entericaserovar enteritidis (s. enteritidis) we have identified twenty-four positively selected genes. our results suggest that the genes encoding the structural components of spi-2 encoded type three secretion apparatus (ttss) and ...200919454277
comparative proteomic analysis on salmonella gallinarum and salmonella enteritidis exploring proteins that may incorporate host adaptation in poultry.comparative proteomics analysis of the cytosolic proteins of salmonella gallinarum (sg) and salmonella enteritidis (se) isolated from poultry was performed. the constantly detected spots of serovar sg with concomitant absence in se serovar as well as those markedly over expressed in serovar se were selected for maldi-tof-ms identification. the ncbi-matched proteins that show overregulation were then further confirmed on the mrna level by quantitative real time pcr. identified proteins were repre ...200919477309
assessment of antimicrobial usage and residues in commercial chicken eggs from smallholder poultry keepers in morogoro municipality, tanzania.occurrence of antimicrobial residues in commercial chicken eggs was determined in morogoro municipality between january and february 2007. twenty smallholder farmers were interviewed on the types of antimicrobials, reasons of use and their awareness on antimicrobial withdrawal period. seventy egg samples were collected for qualitative antimicrobial drug residues analysis by use of agar well diffusion and delvotest sp assays. it was found that farmers use antimicrobial drugs as prophylaxis and tr ...201019486498
prevalence of salmonella in vegetables from mexico.the present study is an overview of the role of vegetables as a transmission vehicle of salmonella in mexico. one hundred samples of each of 17 different vegetables were analyzed during a period of 18 months. salmonella was isolated from 98 samples. salmonella enterica serovar typhimurium was isolated from the highest percentage of samples with typeable salmonella isolates (23.9%), followed by s. enterica subsp. arizonae and salmonella choleraesuis each from 16.9%, salmonella gallinarum from 11. ...200919610340
towards the selection of chickens resistant to salmonella and campylobacter infections.resistance to infection with enteric pathogens such as salmonella and campylobacter can be at many levels and include both non-immune and immune mechanisms. immune resistance mechanisms can be specific, at the level of the adaptive immune response, or non-specific, at the level of the innate immune response. whilst we can extrapolate to some degree in birds from what is known about immune responses to these pathogens in mammals, chickens are not "feathered mice", but have a different repertoire ...200919718951
seroprevalence of antibodies against salmonella enterica subsp. enterica serovar gallinarum-pullorum in wild doves (zenaida asiatica and zenaida macroura) from the northeast of mexico.a cross-sectional survey was conducted in order to determine the seroprevalence and to identify some factors associated with the presence of antibodies against salmonella enterica subsp. enterica serovar gallinarum-pullorum in white-winged (zenaida asiatica) and mourning doves (zenaida macroura) from hunting areas of northeast mexico. from september to october 2006, 201 serum samples were analyzed with the seroagglutination test. the overall seroprevalence of s. enterica subsp. enterica serovar ...201019800701
identification of salmonella pullorum genomic sequences using suppression subtractive hybridization.pullorum disease affecting poultry is caused by salmonella enterica serovar pullorum and results in severe economic loss every year, especially in countries with a developing poultry industry. the pathogenesis of s. pullorum is not yet well defined, as the specific virulence factors still need to be identified. thus, to isolate specific dna fragments belonging to s. pullorum, this study used suppression subtractive hybridization. as such, the genome of the s. pullorum c79-13 strain was subtracte ...200919809245
efficacy of several vaccination programmes in commercial layer and broiler breeder hens against experimental challenge with salmonella enterica serovar enteritidis.two experiments were performed to evaluate the protective effect of various vaccination combinations given at 5 and 9 weeks of age against experimental challenge with salmonella enterica serovar enteritidis (se) phage type 4 at 12 weeks of age. in experiment 1, groups of commercial layers were vaccinated by one of the following programmes: group 1, two doses of a se bacterin (layermune se); group 2, one dose of a live salmonella enterica serovar gallinarum vaccine (cevac sg9r) followed by one do ...200919937524
agglutination affinities of a pathogenic bacillus from fowls (fowl typhoid) (bacterium sanguinarium, moore) with the typhoid bacillus of man. 191519972217
the pathogenic action of the fowl typhoid bacillus with special reference to certain toxins. 191519972218
a note on the relation between b. pullorum (rettger) and the fowl typhoid bacillus (moore). 191519972219
antibacterial activity of ecklonia cava against methicillin-resistant staphylococcus aureus and salmonella spp.ecklonia cava is a brown alga (laminariales, phaeophyta) growing on the subtidal rocky shores of korea. it has antioxidant, antidiarrhea, and anticoagulant effects. in this study, the antimicrobial activity of e. cava etoh extract and its fractions (n-hexane, ch2cl2, etoac, n-buoh, and h2o) were investigated against methicillin-resistant staphylococcus aureus and salmonella spp. the e. cava etoac fraction showed good antibacterial activity against all bacteria. eckol isolated from e. cava etoac ...201020001325
prevalence and characterization of salmonella gallinarum in the chicken in korea during 2000 to 2008.salmonella enterica serovar gallinarum (salmonella gallinarum) is the causative agent of fowl typhoid (ft), a severe systemic disease of chickens that results in high mortality. since 1992, ft has become one of the most serious bacterial diseases in poultry in korea. the purpose of this study was to investigate the prevalence of ft during 2000 to 2008 and characterize the phenotype and genetic diversity of salmonella gallinarum isolates before and after adopting national-wide vaccination with a ...201020075274
control of salmonella enteritidis and salmonella gallinarum in birds by using live vaccine candidate containing attenuated salmonella gallinarum mutant strain.the ideal live vaccine to control salmonella in commercial chicken flocks should engender protection against various strains. the purpose of the present study was to confirm the attenuation of a salmonella gallinarum (sg) mutant strain with deletion on genes cobs and cbia, that are involved in the biosynthesis of cobalamin. furthermore, evaluate its use as a live vaccine against salmonella. for the evaluation of the vaccine efficacy, two experiments were conducted separately. birds from a commer ...201020153354
humoral immune response in breeding hens and protective immunity provided by administration of purified salmonella gallinarum porins.the current studies were undertaken to assess the ability of humoral immune response in breeding hens to provide protective maternal antibody in the progeny. a highly purified outer membrane protein, 34 kda, was isolated from a virulent strain of salmonella gallinarum. cross-reactivity was observed between this protein and salmonella typhi porins; thus we consider this outer membrane protein as a salmonella gallinarum porin. to evaluate passive immunity against salmonella gallinarum, 200 broiler ...201020181865
[not available]. 194620287118
the agglutination test as a means of detecting fowl typhoid infection. 194720290832
isolation of salmonella enterica serovar enteritidis in blue-fronted amazon parrot (amazona aestiva).avian salmonellosis is a disease caused by bacteria of the genus salmonella that can cause three distinct diseases in birds: pullorum diseases, fowl typhoid, and paratyphoid infection. various wildlife species are susceptible to infections by salmonella, regardless of whether they live in captivity or freely in the wild. the present study verified the presence of salmonella enterica serovar enteritidis in three captive specimens of amazona aestiva. the study involved a total of 103 birds undergo ...201020408416
physiology, pathogenicity and immunogenicity of lon and/or cpxr deleted mutants of salmonella gallinarum as vaccine candidates for fowl typhoid.to construct a novel live vaccine candidate for fowl typhoid (ft) caused by salmonella gallinarum (sg), the lon and cpxr genes that are related to host-pathogen interaction were deleted from a wild type sg using the allelic exchange method. the mutants were grown normally, as was the wild type. the biochemical properties of the mutants remained very similar to those of the wild-type, while jol914 (deltalon) and jol916 (deltalondeltacpxr) were mucoid. extracellular polysaccharide increased 30.6-, ...201020487719
characterization of antimicrobial resistance of recent salmonella enterica serovar gallinarum isolates from chickens in south korea.salmonella enterica serovar gallinarum isolates (n=105) from chickens in south korea between 2002 and 2007 were tested for antimicrobial susceptibility by determining minimum inhibitory concentrations of 16 antimicrobials, and their predominant resistance profiles were genetically characterized. most isolates (99/105; 94.3%) were resistant to nalidixic acid and resistant/intermediately resistant to fluoroquinolones, and 63.8% (67/105) of the isolates were resistant to three or more antimicrobial ...201020544426
contribution of the type vi secretion system encoded in spi-19 to chicken colonization by salmonella enterica serotypes gallinarum and enteritidis.salmonella gallinarum is a pathogen with a host range specific to poultry, while salmonella enteritidis is a broad host range pathogen that colonizes poultry sub-clinically but is a leading cause of gastrointestinal salmonellosis in humans and many other species. despite recent advances in our understanding of the complex interplay between salmonella and their hosts, the molecular basis of host range restriction and unique pathobiology of gallinarum remain largely unknown. type vi secretion syst ...201020661437
dietary supplementation with a probiotic fermented four-herb combination enhances immune activity in broiler chicks and increases survivability against salmonella gallinarum in experimentally infected broiler chicks.herbs including curcuma longa, houttuynia cordata, prunus mume and rubus coreanus have potential immune enhancing and antimicrobial effects. probiotics also have antibacterial effects, and some are important in regulating the immune system. the aims of the present study were to evaluate the immune enhancing effects of a probiotic fermented four-herb combination (pfh) in broiler chicks and to demonstrate the prophylactic effect of pfh against salmonella gallinarum in experimentally infected broil ...201020675965
fowl typhoid; certain aspects of the experimentally produced disease. 194620990794
immune response induced by ppgpp-defective salmonella enterica serovar gallinarum in chickens.to protect chickens from typhoid caused by salmonella enterica serovar gallinarum (s. gallinarum), the attenuated 9r strain has been used in the field as a vaccine. however, safety concerns have been raised because the mutations in 9r are undefined while its efficacy is still a question under debate. a global regulator, ppgpp, synthesized by rela and spot, has been shown to induce various virulence genes in s. gallinarum (jeong et al., 2008). in this study, two mutant strains defective in ppgpp- ...201021046347
differential identification of salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum based on polymorphic regions of glgc and spec genes.salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum cause fowl typhoid and pullorum disease in avian species, respectively, and have been of considerable economic importance to the poultry industry in parts of the world. the definitive diagnosis of these diseases can be made only by isolation and identification of the causative agent. however, rapid identification of biovars gallinarum and pullorum is not easily feasible due to their common antigenic structure ...201021111918
evaluation of safety and protection efficacy on cpxr and lon deleted mutant of salmonella gallinarum as a live vaccine candidate for fowl typhoid.we evaluated a recently developed live fowl typhoid (ft) vaccine candidate, jol916, the cpxr/lon mutant of salmonella gallinarum (sg), for safety and protection efficacy in 5-week-old layer chickens. intramuscular vaccination with jol916 revealed no or very few lesions in livers and spleens of the animals until the fourth week post-vaccination (wpv). this candidate clearly induced cellular immune responses in 5 of 5 chickens on the first and second wpv based on the peripheral lymphocyte prolifer ...201021115058
pathogenicity of sg 9r, a rough vaccine strain against fowl typhoid.sg 9r, a rough vaccine strain of salmonella gallinarum, has been used for the prevention of fowl typhoid and paratyphoid in the world despite the presence of residual virulence. sg 9r-like rough strains have been recently isolated from fowl typhoid cases; however, molecular markers to differentiate sg 9r from field strains are not well-characterized and the molecular mechanisms of sg 9r residual virulence are unclear. therefore, we analyzed lps biosynthesis (rfa gene cluster) and virulence genes ...201021134445
multilocus variable-number of tandem-repeats analysis of salmonella enterica serotype gallinarum and comparison with pulsed-field gel electrophoresis genotyping.salmonella enterica serovar gallinarum is the causative agent of fowl typhoid, a severe disease of poultry, responsible for heavy economic losses. epidemiologic investigation of fowl typhoid significantly benefits from molecular typing tools, rapd and pfge have been proposed for this purpose. pfge, a well established technique, is still the gold standard among typing methods for most bacteria, including salmonella. nevertheless, it has some limitations regarding execution and reproducibility, in ...201021208755
validation of a seminested pcr approach for rapid detection of salmonella enterica subsp. enterica serovar gallinarum.salmonella enterica subsp. enterica serovar gallinarum (s. gallinarum) is the causative agent of fowl typhoid, one of the major causes of mortality and morbidity on poultry farms. even though it has been substantially eradicated in many developed countries, the disease still remains endemic in central and south america, in africa and in the mediterranean countries of europe. this leads to the routine screening of flocks, mainly by cultivation and serological techniques, which are expensive, as w ...201121256889
molecular epidemiology and in vitro antimicrobial susceptibility of salmonella isolated from poultry in kashmir.a total of 480 samples, comprising 429 faecal samples from healthy adult birds and 51 tissue samples from dead birds, were collected from four government poultry farms in the kashmir valley from september 2007 to april 2008. in all, 33 salmonella isolates were obtained. of these, 28 (84.85%) isolates were salmonella gallinarum, 3 (9.09%) were salmonella enteritidis and the remaining 2 (6.06%) were salmonella typhimurium. all the isolates harboured the inva, sefa, stn and spvc virulence-specific ...201021309466
pullorum disease and fowl typhoid--new thoughts on old diseases: a review.fowl typhoid and pullorum disease are two distinct septicaemic diseases largely specific to avian species and caused by salmonella gallinarum and salmonella pullorum, respectively. they were first described more than one century ago. since their discovery, many efforts have been made to control and prevent their occurrence in commercial farming of birds. however, they remain a serious economic problem to livestock in countries where measures of control are not efficient or in those where the cli ...201121331943
population dynamics of salmonella enterica serotypes in commercial egg and poultry production.fresh and processed poultry have been frequently implicated in cases of human salmonellosis. furthermore, increased consumption of meat and poultry has increased the potential for exposure to salmonella. while advances have been made in reducing the prevalence and frequency of salmonella contamination in processed poultry, there is mounting pressure on commercial growers to prevent and/or eliminate these human pathogens in preharvest production facilities. several factors contribute to salmonell ...201121571882
comprehensive analysis of salmonella sequence polymorphisms and development of a ldr-ua assay for the detection and characterization of selected serotypes.salmonella is a major cause of food-borne disease, and salmonella enterica subspecies i includes the most clinically relevant serotypes. salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. this task will be facilitated by the disclosure of salmonella serotype sequence polymorphisms, here annotated in seven genes (sefa, safa, safc, biga, inva, fima, and phsb) from 139 s. enterica strains, of which 109 belonging to 44 serotypes of s ...201121611799
safety and efficacy of a virulence gene-deleted live vaccine candidate for fowl typhoid in young chickens.the safety and efficacy of a live lon-and-cpxr-deleted salmonella enterica serovar gallinarum (sg) vaccine candidate (jol916) was evaluated in young layer chickens. vaccinated (n=25) and unvaccinated (n=25) groups were organized, respectively, at 1, 2, 3, and 4 weeks of age. one-week-old and 2-week-old chickens were orally inoculated with 2+ù10(7) colony-forming units of jol916, and orally challenged with 2 x 10(6) colony-forming units of a wild-type sg strain at the third week post vaccination ...201121711190
safety evaluation and immunogenicity of arabinose-based conditional lethal salmonella gallinarum mutant unable to survive ex vivo as a vaccine candidate for protection against fowl typhoid.in seeking to develop a safe fowl typhoid (ft) vaccine, a novel candidate lacking cpxr, lon, and asd salmonella gallinarum (sg) genes was constructed with the plasmid-containing arac::p(arabad)::asd system. a balanced-lethal host-vector system based on the essential bacterial gene for aspartate beta-semialdehyde dehydrogenase (asd) was used to construct the sg mutant strain. a plasmid (p15a ori) with an arac::p(arabad)::asd cassette was introduced into an auxotrophic mutant to prevent ex vivo su ...201121793429
oxygenated drinking water enhances immune activity in broiler chicks and increases survivability against salmonella gallinarum in experimentally infected broiler chicks.it has been suggested that drinking oxygenated water may improve oxygen availability, which may increase vitality and improving immune activity. the present study evaluated the immune enhancing effects of oxygenated drinking water in broiler chicks and demonstrated the protective efficacy of oxygenated drinking water against salmonella gallinarum in experimentally infected broiler chicks. continuous drinking of oxygenated water markedly increased serum lysozyme activity, peripheral blood mononuc ...201121997234
Comparison of the safety and efficacy of a new live Salmonella Gallinarum vaccine candidate, JOL916, with the SG9R vaccine in chickens.We evaluated a recently developed live vaccine candidate for fowl typhoid (FT)-JOL916, a lon/cpxR mutant of Salmonella Gallinarum (SG)-by comparing its safety and efficacy with that of the well-known rough mutant strain SG9R vaccine in 6-wk-old Hy-Line hens. Forty-five chickens were divided into three groups of 15 chickens each. The chickens were then intramuscularly inoculated with 2 x 10(7) colony-forming units (CFUs) of JOL916 (JOL916 group), 2 x 10(7) CFUs of SG9R (SG9R group), or phosphate- ...201122017038
efficacy of bacteriophage therapy on horizontal transmission of salmonella gallinarum on commercial layer chickens.a salmonella gallinarum (sg)-specific bacteriophage isolated from sewage effluent was used to prevent horizontal transmission of sg in commercial layer chickens. six-week-old chickens, each challenged with 5 x 10(8) colony-forming units of sg, cohabited with contact chickens treated with 10(6) plaque-forming units/kg of bacteriophage, prepared in feed additives, for 7 days before, and 21 days after challenge with sg. mortality was observed for 3 wk after challenge and sg was periodically reisola ...201122017042
Multilocus variable-number tandem-repeat analysis for subtyping Salmonella enterica serovar Gallinarum.Salmonella enterica serovar Gallinarum causes a severe systemic disease, fowl typhoid, primarily in chickens and turkeys, and it remains a disease of worldwide significance. Multilocus variable-number tandem-repeat analysis (MLVA) has proved to be very useful for subtyping other Salmonella serovars. We describe the development of a simple MLVA assay for S. enterica serovar Gallinarum that is comparable with pulsed-field gel electrophoresis (PFGE) in resolution. The genome sequence of S. enterica ...201122107089
comparison of 2 culture methods and pcr assays for salmonella detection in poultry feces.the present work compared 2 culture methods and the combinations of pre-enrichment and enrichment culture methods with pcr assays [buffered peptone water-pcr and tetrathionate-pcr or modified semisolid rappaport-vassiliadis (msrv)-pcr] for motile and nonmotile salmonella strain detection using artificially contaminated poultry feces. the specificity and positive predictive values were equal to one in both culture methods. specificity and positive predictive values, accuracy, sensitivity, and neg ...201222334736
decreased colonization of chicks by salmonella enterica serovar gallinarum expressing mannose-sensitive fimh adhesin from salmonella enterica serovar enteritidis.to investigate the role of non-hemagglutinating type 1 fimbriae in the pathogenesis of salmonella gallinarum, the isogenic mutant elaborating type 1 fimbriae with mannose-sensitive (ms) variant of the fimh adhesin from salmonella enteritidis and the mutant strain with no fimh expression were constructed. their binding to chicken leukocytes in vitro and invasiveness in 1-day-old chicks were studied. our results demonstrated that s. gallinarum type 1 fimbriae with an endogenous variant of the fimh ...201222364838
immune dynamics following infection of avian macrophages and epithelial cells with typhoidal and non-typhoidal salmonella enterica serovars; bacterial invasion and persistence, nitric oxide and oxygen production, differential host gene expression, nf-κb signalling and cell cytotoxicity.poultry-derived food is a common source of infection of human with the non-host-adapted salmonellae while fowl typhoid and pullorum disease are serious diseases in poultry. development of novel immune-based control strategies against salmonella infection necessitates a better understanding of the host-pathogen interactions at the cellular level. intestinal epithelial cells are the first line of defence against enteric infections and the role of macrophages is crucial in salmonella infection and ...201222475571
early immune dynamics following infection with salmonella enterica serovars enteritidis, infantis, pullorum and gallinarum: cytokine and chemokine gene expression profile and cellular changes of chicken cecal tonsils.salmonella enterica subspecies enterica infection remains a serious problem in a wide range of animals and in man. poultry-derived food is the main source of human infection with the non-host-adapted serovars while fowl typhoid and pullorum disease are important diseases of poultry. we have assessed cecal colonization and immune responses of newly hatched and older chickens to salmonella serotypes enteritidis, infantis, gallinarum and pullorum. s. enteritidis and s. infantis colonized the ceca m ...201222512820
pathomorphological, immunohistochemical and bacteriological findings in budgerigars (melopsittacus undulatus) naturally infected with s. gallinarum.the present study describes the pathological and bacteriological findings and diagnosis by immunoperoxidase and immunofluorescence methods in budgerigars (melopsittacus undulatus) naturally infected with salmonella gallinarum obtained from three commercial budgerigar rearing farms. the course of the disease in young budgerigars was peracute or acute, whereas in adult budgerigars the disease was acute or chronic. clinically, yellow-white diarrhoea was observed in the young budgerigars with the ac ...201222515538
distribution of salmonella serovars and antimicrobial susceptibility of salmonella enteritidis from poultry in zimbabwe.a study was carried out to determine the distribution and antimicrobial susceptibility profiles of salmonella serovars from chickens from large-scale commercial (lsc), small-scale commercial (ssc), and rural free-range (rfr) farms of zimbabwe. pooled cloacal swabs were collected for culture and isolation of salmonella spp. a chi-square test was used to assess distribution differences of salmonellas among the farming sectors. approximately 10% (283/2833) of the swabs were positive for salmonella ...201222515540
construction of a salmonella gallinarum ghost as a novel inactivated vaccine candidate and its protective efficacy against fowl typhoid in chickens.in order to develop a novel, safe and immunogenic fowl typhoid (ft) vaccine candidate, a salmonella gallinarum ghost with controlled expression of the bacteriophage phix174 lysis gene e was constructed using pmmp99 plasmid in this study. the formation of the salmonella gallinarum ghost with tunnel formation and loss of cytoplasmic contents was observed by scanning electron microscopy and transmission electron microscopy. no viable cells were detectable 24 h after the induction of gene e expressi ...201222620989
differential identification of salmonella enterica serovar gallinarum biovars gallinarum and pullorum and the biovar gallinarum live vaccine strain 9r.salmonella enterica serovar gallinarum biovar gallinarum causes fowl typhoid in chickens and has been of economic importance to the chicken industry in many countries. the biovar gallinarum live vaccine strain 9r (sg 9r) has been used to control fowl typhoid in many areas where the disease is endemic. therefore, a definitive diagnosis of this disease may require differentiation of wild-type field isolates of biovar gallinarum from the live vaccine strain sg 9r. here, we report the development of ...201222728122
cpg oligonucleotides and recombinant interferon-γ in combination improve protection in chickens to salmonella enterica serovar enteritidis challenge as an adjuvant component, but have no effect in reducing salmonella carriage in infected chickens.salmonella enterica serovar enteritidis is the most common cause of human salmonellosis in many developed nations. it is frequently associated with both poultry meat and eggs. in the present study we have determined whether cpg oligonucleotides that stimulate the immune system via toll like-receptors 15 and 21 in the chicken can be used as immunomodulatory agents to break carriage of s. enteritidis in in vitro and in vivo infection models. we also investigated its use as a component in an adjuva ...201222845324
comparative proteome and transcriptome analyses of wild-type and live vaccine strains of salmonella enterica serovar gallinarum.salmonella enterica serovar gallinarum causes fowl typhoid in chickens and is of economic importance to the chicken industry. a serovar gallinarum live vaccine strain 9r (sg 9r) has been used to control fowl typhoid in many areas where the disease is endemic. because the attenuation mechanism of sg 9r was not defined, there has been continued concern about reversion to virulence. in this study, we examined the molecular characteristics, which might provide better insight into attenuation of sg 9 ...201222944630
bacteria isolations from broiler and layer chicks in zambia.chick mortality (cm) is one of the major constraints to the expansion of the poultry industry in zambia. of the 2,829 avian disease cases submitted to the national diagnostic laboratory based at the central veterinary research institute in lusaka between 1995 and 2007, 34.39% (973/2,829) were from cm cases. the disease accounted for 40.2% (218,787/544,903) mortality in the affected flocks with 89.6% (196,112/218,787) of the affected birds dying within seven days. major bacteria species involved ...201222988514
the long view: salmonella--the last forty years.as a part of the 40th anniversary celebrations of avian pathology we review the last four decades of salmonella research which has led to major progress in our understanding of the bacteriology and infection biology of the organism through the huge advances in molecular biology and immunology that have accompanied technical advances in biology generally. in many countries combinations of improvements in management, sometimes under legislative pressure and supported by a number of basic biologica ...201223025669
health assessment of captive tinamids (aves, tinamiformes) in brazil.ninety-five (95) captive tinamids (aves, tinamiformes) of species crypturellus obsoletus (brown tinamou), crypturellus parvirostris (small-billed tinamou), crypturellus tataupa (tataupa tinamou), crypturellus undulatus (undulated tinamou), rhynchotus rufescens (red-winged tinamou), and tinamus solitarius (solitary tinamou) were evaluated for diseases of mandatory control in the brazilian poultry health program (pnsa). antibodies were detected by serum agglutination test (sat) in 4 birds for myco ...201223082518
attenuated salmonella gallinarum secreting an escherichia coli heat-labile enterotoxin b subunit protein as an adjuvant for oral vaccination against fowl typhoid.in our previous study, we constructed a vaccine candidate (jol916) for fowl typhoid (ft). a live adjuvant salmonella gallinarum (sg) strain was generated in the present study to facilitate efficacious oral vaccination with this vaccine. the escherichia coli eltb gene secreting heat-labile enterotoxin b subunit (ltb) was cloned into an asd(+) plasmid pjhl65. this was transformed into a δlon δcpxr δasd sg strain and the resulting strain was designated jol1229. secretion of ltb from jol1229 was con ...201223083937
the effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro.the use of glyphosate modifies the environment which stresses the living microorganisms. the aim of the present study was to determine the real impact of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. the presented results evidence that the highly pathogenic bacteria as salmonella entritidis, salmonella gallinarum, salmonella typhimurium, clostridium perfringens and clostridium botulinum are highly resistant to glyphosate. however, most of beneficial bac ...201323224412
a comparative study of culture methods and pcr assay for salmonella detection in poultry drinking water.the present work compared 2 culture methods and pcr assays for motile and nonmotile salmonella detection using artificially contaminated poultry drinking water. the specificity was 1 for all methods studied. the accuracy and sensitivity were 1 for all motile strains, whereas these parameters were between 0 and 0.7 for nonmotile salmonella strains. the positive predictive value and negative predictive value were 1 for all motile salmonella strains in the 3 methods used. nonmotile salmonella strai ...201323243252
safety and protective efficacy of live attenuated salmonella gallinarum mutants in rhode island red chickens.salmonella enterica serovar gallinarum is the causative agent of fowl typhoid, an important systemic disease of poultry with economic consequences in developing nations. a live attenuated orally applied s. gallinarum vaccine could provide a low cost method for controlling this disease. we constructed s. gallinarum strains in which the expression of the crp, rfc and rfah genes, important for virulence of salmonella typhimurium in mice, were under the control of an arabinose-regulated promoter. we ...201323261043
the type vi secretion system encoded in salmonella pathogenicity island 19 is required for salmonella enterica serotype gallinarum survival within infected macrophages.salmonella enterica serotype gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. we have reported that s. gallinarum harbors a type vi secretion system (t6ss) encoded in salmonella pathogenicity island 19 (spi-19) that is required for efficient colonization of chicks. in the present study, we aimed to characterize the spi-19 t6ss functionality and to investigate the mechanisms behind t ...201323357385
serologic, parasitic, and bacteriologic assessment of captive cracids (aves: galliformes: cracidae) in brazil.captive cracids (aves: galliformes: cracidae), including endangered species, were studied (n = 130) for the assessment of health status, including aburria jacutinga (black-fronted piping-guan, n = 42), crax blumenbachii (red-knobbed curassow, n = 54), craxfasciolata (bare-faced curassow, n = 28), and penelope obscura (dusky-legged guan, n = 6). the exposure to mycoplasma gallisepticum (mg), mycoplasma synoviae (ms), salmonella pullorum (sp), salmonella gallinarum (sg), avian paramyxovirus-1 (apm ...201323505700
polymerase chain reaction assay based on rata gene allows differentiation between salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum.salmonella pullorum and salmonella gallinarum are classified as biovars of salmonella enterica subsp. enterica serovar gallinarum. these salmonellae are the causative agents of pullorum disease and fowl typhoid, respectively, and are widely distributed throughout the world. although many developed countries have eradicated these diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. when serovar gallinarum is isolated, it is difficult to ...201323512922
genomic comparison between salmonella gallinarum and pullorum: differential pseudogene formation under common host restriction.salmonella serovars enteritidis and gallinarum are closely related, but their host ranges are very different: the former is host-promiscuous and the latter can infect poultry only. comparison of their genomic sequences reveals that gallinarum has undergone much more extensive degradation than enteritidis. this phenomenon has also been observed in other host restricted salmonella serovars, such as typhi and paratyphi a. the serovar gallinarum can be further split into two biovars: gallinarum and ...201323555032
oral immunization with an attenuated salmonella gallinarum mutant as a fowl typhoid vaccine with a live adjuvant strain secreting the b subunit of escherichia coli heat-labile enterotoxin.the salmonella gallinarum (sg) lon/cpxr deletion mutant jol916 was developed as a live vaccine candidate for fowl typhoid (ft), and a sg mutant secreting an escherichia coli heat-labile enterotoxin b subunit (ltb), designated jol1229, was recently constructed as an adjuvant strain for oral vaccination against ft. in this study, we evaluated the immunogenicity and protective properties of the sg mutant jol916 and the ltb adjuvant strain jol1229 in order to establish a prime and boost immunization ...201323647814
a flagellated motile salmonella gallinarum mutant (sg fla+) elicits a pro-inflammatory response from avian epithelial cells and macrophages and is less virulent to chickens.salmonella enterica subspecies enterica serovar gallinarum biovar gallinarum (sg) is a non-flagellated bacterium which causes fowl typhoid, a systemic disease associated with high mortality in birds. it has been suggested that the absence of flagella in sg is advantageous in the early stages of systemic infection through absence of tlr-5 activation. in order to investigate this hypothesis in more detail a flagellated and motile sg mutant (sg fla(+)) was constructed. the presence of flagella incr ...201323664623
safety and efficacy of a metabolic drift live attenuated salmonella gallinarum vaccine against fowl typhoid.fowl typhoid (ft), a systemic disease that results in septicemia in poultry, is caused by salmonella enterica serovar gallinarum biovar gallinarum (sg). mortality and morbidity rates from ft can reach up to 80%. attenuated live salmonella vaccine candidates have received considerable attention because they confer solid immunity, and they can produce systemic and mucosal immunity in the gut when administered orally. in the present study, five metabolic drift (md) mutants with a single-(designated ...201323678726
comparison of 3 culture methods and pcr assays for salmonella gallinarum and salmonella pullorum detection in poultry feed.to detect salmonella gallinarum or salmonella pullorum in artificially contaminated poultry feed, 9 culture combinations were compared, including 3 preenrichment/enrichment methods (tryptic soy broth plus ferrous sulfate/tetrathionate hajna, tryptic soy broth plus ferrous sulfate/selenite cystine broth, and salmosyst) in combination with 3 selective agars (xylose lysine desoxicholate agar added with tergitol 4, ef-18, and önöz), respectively. additionally, a single pcr technique was applied comb ...201323687146
immunoprophylactic effects of administering honeybee (apis melifera) venom spray against salmonella gallinarum in broiler chicks.antibiotics continue to be used as growth promoters in the poultry industry. honeybee (apis melifera) venom (hbv) possesses a number of beneficial biological activities, particularly for regulating the immune system. the aim of the present study was to evaluate the immunoprophylactic effects of hbv against salmonella gallinarum in broiler chicks as an initial step towards developing eco-friendly alternatives to reduce antibiotic use. hbv was administered using a spray technique. hbv improved bod ...201323719751
outbreaks of salmonellosis in three different poultry farms of kerala, india.avian salmonellosis is an important disease causing serious impediment to the development of poultry industry especially in developing countries of asia and africa. since no "effective" immunoprophylactic measures are available for the disease till date, strict biosecurity is the only alternative to preclude the disease. for formulating the control measures, an understanding of the epidemiology of the disease, proper diagnosis and identification of the causative agent is quintessential. this rep ...201323730565
passive maternal exposure to environmental microbes selectively modulates the innate defences of chicken egg white by increasing some of its antibacterial activities.egg defence against bacterial contamination relies on immunoglobulins (igy) concentrated in the yolk and antimicrobial peptides/proteins predominantly localized in the egg white (ew). hens contaminated with pathogenic microorganisms export specific igys to the egg (adaptative immunity). no evidence of such regulation has been reported for the antimicrobial peptides/proteins (innate immunity) which are preventively secreted by the hen oviduct and are active against a large range of microbes. we i ...201323758641
therapeutic effects of bacteriophages against salmonella gallinarum infection in chickens.in this study the isolation and characterization of three bacteriophages (st4, l13, and sg3) infecting salmonella gallinarum were carried out. they were further tested for their in vivo efficacy in phage therapy. all three phages belong to the siphoviridae family with isometric heads and non-contractile tails. they have a broad host range among serovars of salmonella enterica. the burst sizes were observed to be 1670, 80, and 28 for st4, l13, and sg3, respectively. the in vivo efficacy of the ph ...201323801253
salmonella gallinarum field isolates from laying hens are related to the vaccine strain sg9r.salmonella enterica subspecies enterica serotype gallinarum can cause severe systemic disease in chickens and a live salmonella gallinarum 9r vaccine (sg9r) has been used widely to control disease. using whole-genome sequencing we found point mutations in the pyruvate dehydrogenase (acee) and/or lipopolysaccharide 1,2-glucosyltransferase (rfaj) genes that likely explain the attenuation of the sg9r vaccine strain. molecular typing using pulsed field gel electrophoresis and multiple-locus variable ...201323994381
molecular differentiation between salmonella enterica subsp enterica serovar pullorum and salmonella enterica subsp enterica serovar gallinarum.s. pullorum (sp) and s. gallinarum (sg) are very similar. they are the agents of pullorum disease and fowl typhoid, respectively, and the two diseases are responsible for economic losses in poultry production. although sp and sg are difficult to be differentiated in routine laboratory procedures, the ability to metabolize ornithine is a biochemical test that may be used to achieve this aim. while sp is able to decarboxylate this amino acid, sg is not. however, the isolation of strains showing at ...200924031341
a defective mutant of salmonella enterica serovar gallinarum in cobalamin biosynthesis is avirulent in chickens.salmonella enterica serovar gallinarum (sg) is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. it is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. the survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. mutants of salmonella gal ...200924031393
the contribution of genes required for anaerobic respiration to the virulence of salmonella enterica serovar gallinarum for chickens.salmonella enterica serovar gallinarum (sg) is an intracellular pathogen of chickens. to survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. the fumarate reductase (frdabcd), dimethyl sulfoxide (dmso)-trimethylamine n-oxide (tmao) reductase (dmsabc), and nitrate reductase (narghij) operons in salmonella typhimurium (stm) encode enzymes involved in anaerobic respiration to the electron acceptors fumara ...200924031452
requirement for cobalamin by salmonella enterica serovars typhimurium, pullorum, gallinarum and enteritidis during infection in chickens.salmonella enterica serovar typhimurium synthesizes cobalamin (vitamin b12) only during anaerobiosis. two percent of the s. typhimurium genome is devoted to the synthesis and uptake of vitamin b12 and to b12-dependent reactions. to understand the requirement for cobalamin synthesis better, we constructed mutants of salmonella serovars enteritidis and pullorum that are double-defective in cobalamin biosynthesis (δcobsδcbia). we compared the virulence of these mutants to that of their respective w ...201124031771
prevalence, characterization, and antimicrobial susceptibility of salmonella gallinarum isolated from eggs produced in conventional or organic farms in south korea.to determine the prevalence of salmonella serotype enteritidis in eggs in south korea, we conducted a microbiological survey of commercially available eggs produced in conventional or organic farms during the period from 2010 to 2012. the contents of 7,000 raw shell eggs (6,000 of conventional and 1,000 of organic origin) were examined to evaluate the extent and type of salmonella enteritidis contamination. a total of 26 salmonellae (7.4% of all pooled samples) were isolated from 350 homogenized ...201324046429
virulence determinants of salmonella gallinarum biovar pullorum identified by pcr signature-tagged mutagenesis and the spic mutant as a candidate live attenuated vaccine.salmonella gallinarum biovar pullorum (s. gallinarum biovar pullorum) is the causative agent of pullorum disease (pd) in chickens which results in considerable economic losses to the poultry industries in developing countries. pcr-signature tagged mutagenesis was used to identify virulence determinants of s. gallinarum biovar pullorum and novel attenuated live vaccine candidates for use against this disease. a library of 1800 signature-tagged s. gallinarum biovar pullorum mutants was constructed ...201424355532
generation of a safety enhanced salmonella gallinarum ghost using antibiotic resistance free plasmid and its potential as an effective inactivated vaccine candidate against fowl typhoid.a safety enhanced salmonella gallinarum (sg) ghost was constructed using an antibiotic resistance gene free plasmid and evaluated its potential as fowl typhoid (ft) vaccine candidate. the antibiotic resistance free pya3342 plasmid possesses aspartate semialdehyde dehydrogenase gene which is complimentary to the deletion of the chromosomal asd gene in the bacterial host. this plasmid was incorporated with a ghost cassette containing the bacteriophage phix174 lysis gene e, designated as pjhl101. t ...201424406393
an immunoproteomic approach for characterization of the outer membrane proteins of salmonella gallinarum.salmonella enterica serovar gallinarum (sg) is an important pathogen that causes fowl typhoid in chickens. in order to investigate sg outer membrane proteins (omps) as potential vaccine candidate proteins, we established a proteomic map and database of antigenic sg-omps. a total of 174 spots were detected by 2de. twenty-two antigen-reactive spots were identified as nine specific proteins using pmf. ompa was the most abundant protein among all of the identified omps, and it exhibited seven protei ...201424420792
draft genome sequence of salmonella enterica subsp. enterica serovar gallinarum biovar pullorum strain fcav198, a brazilian chicken pathogen.salmonella enterica subsp. enterica serovar gallinarum biovar pullorum is a bird-restricted pathogen which causes pullorum disease. the strain fcav198 was isolated from a pool of chicken ovaries in brazil, and its genome may be helpful for studies involving molecular mechanisms related to pathogenesis and other related applications.201424558231
polyamines are essential for virulence in salmonella enterica serovar gallinarum despite evolutionary decay of polyamine biosynthesis genes.serovars of salmonella enterica exhibit different host-specificities where some have broad host-ranges and others, like s. gallinarum and s. typhi, are host-specific for poultry and humans, respectively. with the recent availability of whole genome sequences it has been reported that host-specificity coincides with accumulation of pseudogenes, indicating adaptation of host-restricted serovars to their narrow niches. polyamines are small cationic amines and in salmonella they can be synthesized t ...201424602405
generation of a safe salmonella gallinarum vaccine candidate that secretes an adjuvant protein with immunogenicity and protective efficacy against fowl typhoid.we constructed a live, attenuated salmonella gallinarum (sg) that secretes heat-labile enterotoxin b subunit protein (ltb), and evaluated this strain as a new vaccine candidate by assessing its safety, immunogenicity and protective efficacy against fowl typhoid. an asd(+) p15a ori low-copy plasmid containing eltb encoding ltb was transformed into a δlonδcpxrδasd sg (jol967) to construct the candidate, jol1355. in experiments 1 and 2, birds were orally immunized with jol1355 at 4 weeks of age, wh ...201424689430
presence of salmonella enteritidis and salmonella gallinarum in commercial laying hens diagnosed with fowl typhoid disease in colombia.a severe outbreak of salmonellosis in commercial brown table egg layers first occurred in colombia in 2006. from 2008 to 2012, 35 samples collected from commercial layers farms in the states of cundinamarca, santander, bolivar, and san andres, were positive for salmonella enterica. salmonella was isolated from liver and spleen (71.42%), pools of organs (liver, spleen, and ovarian follicles; 25.71%), and drag swabs (2.85%). serotype was assigned using single nucleotide polymorphisms or dna microa ...201424758131
γ-hydroxynitrile glucosides from the seeds of prinsepia utilis.γ-hydroxynitrile glucosides (prinsepicyanosides a-e) were isolated alongside 11 known compounds from seeds of prinsepia utilis royle. their structures were determined by detailed analysis of nmr and ms spectroscopic data. the relative configuration of prinsepicyanoside c was established by cu-kα x-ray crystallography. prinsepicyanoside a, osmaronin, and 4-(hydroxylmethyl)-5h-furan-2-one exhibited borderline antibacterial activity against salmonella gallinarum, vibrio parahaemolyticus, and vibrio ...201424952469
evaluation of protective efficacy of live attenuated salmonella enterica serovar gallinarum vaccine strains against fowl typhoid in chickens.salmonella enterica serovar gallinarum is the etiological agent of fowl typhoid, which constitutes a considerable economic problem for poultry growers in developing countries. the vaccination of chickens seems to be the most effective strategy to control the disease in those areas. we constructed s. gallinarum strains with a deletion of the global regulatory gene fur and evaluated their virulence and protective efficacy in rhode island red chicks and brown leghorn layers. the fur deletion mutant ...201424990908
deciphering why salmonella gallinarum is less invasive in vitro than salmonella enteritidis.salmonella gallinarum and salmonella enteritidis are genetically closely related however associated with different pathologies. several studies have suggested that s. gallinarum is less invasive in vitro than s. enteritidis. in this study we confirm that the s. gallinarum strains tested were much less invasive than the s. enteritidis strains tested in cells of avian or human origin. in addition, the s. gallinarum t3ss-1-dependent ability to invade host cells was delayed by two to three hours com ...201425175996
comparative evaluation of safety and efficacy of a live salmonella gallinarum vaccine candidate secreting an adjuvant protein with sg9r in chickens.we previously reported jol916, a live attenuated salmonella gallinarum (sg), as a vaccine candidate for protection from fowl typhoid (ft). in the present study, we evaluated jol1355, an sg that secretes heat-labile enterotoxin b subunit protein, for safety, immunogenicity, and protective efficacy against ft. in a single intramuscular inoculation, live attenuated sg (jol916) and commercial live attenuated sg9r immunized groups showed gross lesions and bacterial persistence up to 21 days post-immu ...201425239101
a novel approach for the generation of salmonella gallinarum ghosts and evaluation of their vaccine potential using a prime-booster immunization strategy.a novel, regulatory e-lysis cassette was used in this study to avoid the untimely expression of lysis gene e and to achieve stable and improved production of salmonella gallinarum (sg) ghosts. a prime-booster immunization strategy using these ghosts was subsequently utilized with the aim of inducing a robust immune response for the prevention of acute fowl typhoid infection. in the first animal experiment, a total of 54 chickens were equally divided into three groups (n=18): group a (non-immuniz ...201425454861
effect of dietary supplementation of bacteriophage on performance, egg quality and caecal bacterial populations in laying hens.1. bacteriophages (bp) have gained increasing attention as a treatment of bacterial infection for animals. however, the data pertaining to dietary application of bp for laying hens have been limited. 2. this study aimed to investigate the effect of dietary bp on laying performance, egg quality and caecal bacterial populations in laying hens. 3. the dietary bp used in this experiment was a mixture of individual bp targeting salmonella gallinarum, salmonella pullorum, salmonella typhimurium, salmo ...201525471539
soluble plantain nonstarch polysaccharides, although increasing caecal load, reduce systemic invasion of salmonella gallinarum in the chicken.soluble plantain (musa paradisiaca) nonstarch polysaccharides (nsps) have previously been shown to prevent pathogenic interaction with the intestinal epithelium. here, we examined whether plantain nsp could prevent the invasion of the intestinal mucosa by salmonella enterica gallinarum, a causative agent of fowl typhoid. in vitro assays using b1oxi cells were performed with monolayers pretreated with/without plantain nsp, before inoculation with salm. gallinarum 287/91. chicks were fed from hatc ...201525483316
identification of isolated salmonella enterica serotype gallinarum biotype pullorum and gallinarum by pcr-rflp.salmonella spp. is the major bacterial pathogen in poultry and is responsible for significant economic losses of the poultry industry in many parts of the world. among salmonella spp., salmonella gallinarum and salmonella. pullorum are the most common causative agents of chicken salmonellosis resulting in high mortality and morbidity.201425485068
identification and characterization of regions of difference between the salmonella gallinarum biovar gallinarum and the salmonella gallinarum biovar pullorum genomes.salmonella gallinarum is the causative agent of fowl typhoid, a severe septicaemic disease that affects birds of all ages, whereas s. pullorum causes pullorum disease, a systemic disorder affecting primarily young birds. a proportion of birds with pullorum disease become carriers and are thereby able to transmit s. pullorum vertically. although these two pathogens cause distinct diseases, they are otherwise phenotypically and genetically similar. therefore, the small variations that lead to the ...201525497350
fowl typhoid (salmonella gallinarum) outbreak in japanese quail (coturnix coturnix japonica).a fowl typhoid (ft) outbreak is reported in a flock of 400 japanese quail (coturnix coturnix japonica) at 91 days of age. of these, 222 died suddenly, and necropsy revealed swollen liver and spleen with off-white to yellowish granules and reddish small intestine mucosa. histopathology showed severe multifocal necrosis of liver and spleen (5/5), pulmonary congestion with macrophage infiltration in air capillaries (5/5), discrete interstitial nephritis (2/2), superficial necrosis of the intestinal ...201425518448
the role of rpos, hmp, and ssrab in salmonella enterica gallinarum and evaluation of a triple-deletion mutant as a live vaccine candidate in lohmann layer chickens.salmonella enterica gallinarum (sg) causes fowl typhoid (ft), a septicemic disease in avian species. we constructed deletion mutants lacking the stress sigma factor rpos, the nitric oxide (no)-detoxifying flavohemoglobin hmp, and the ssra/ssrb regulator to confirm the functions of these factors in sg. all gene products were fully functional in wild-type (wt) sg whereas mutants harboring single mutations or a combination of rpos, hmp, and ssrab mutations showed hypersusceptibility to h2o2, loss o ...201525549217
protection against salmonella typhimurium, salmonella gallinarum, and salmonella enteritidis infection in layer chickens conferred by a live attenuated salmonella typhimurium strain.in the present study, we investigated the protection conferred by a live attenuated salmonella enterica serovar typhimurium (st) strain against salmonella typhimurium, salmonella gallinarum (sg), and salmonella enteritidis (se) infection in layer chickens. birds were orally primed with the attenuated st strain at 7 days of age and then boosted at 4 weeks post prime immunization (ppi). sequential monitoring of plasma igg and mucosal secretory iga (siga) levels revealed that inoculation with st in ...201525713506
type 1 fimbriae are important factors limiting the dissemination and colonization of mice by salmonella enteritidis and contribute to the induction of intestinal inflammation during salmonella invasion.we have recently shown that salmonella gallinarum type 1 fimbriae with endogenous mannose-resistant (mr) variant of the fimh protein increase systemic dissemination of s. gallinarum and colonization of internal organs in comparison to the s. gallinarum fimh knockout strain or the mutant expressing mannose-sensitive (ms) fimh variant from s. enteritidis. elaborating from these studies, we proposed that ms variants of fimh are advantageous in gastrointestinal infections, in contrast to mr fimh var ...201525914682
evaluation of the salmonella enterica serovar pullorum pathogenicity island 2 mutant as a candidate live attenuated oral vaccine.salmonella enterica serovar pullorum (s. pullorum) is a highly adapted pathogen that causes pullorum disease (pd), an important systemic disease of poultry that causes severe economic losses in developing countries. in the interests of developing a safe and immunogenic oral vaccine, the efficacy of a salmonella pathogenicity island 2 (spi2)-deleted mutant of s. pullorum (s06004δspi2) was evaluated in chickens. s06004δspi2 was severely less virulent than the parental wild-type strain s06004 as de ...201525924763
understanding the poultry trade network in kenya: implications for regional disease prevention and control.infectious diseases in poultry can spread quickly and lead to huge economic losses. in the past decade, on multiple continents, the accelerated spread of highly pathogenic avian influenza a (h5n1) virus, often through informal trade networks, has led to the death and culling of hundreds of millions of poultry. endemic poultry diseases like newcastle disease and fowl typhoid can also be devastating in many parts of the world. understanding trade networks in unregulated systems can inform policy d ...201526002998
a live oral fowl typhoid vaccine with reversible o-antigen production.salmonella enterica serovar gallinarum causes fowl typhoid, recognized worldwide as an economically important disease. the current vaccine, 9r, lacks a complete o antigen, which is a salmonella virulence factor, and, in addition, has a number of other less well characterized chromosomal mutations. for optimal efficacy, 9r is administered by injection. in an effort to develop a vaccine suitable for oral administration, we constructed salmonella gallinarum strains with a reversible o-antigen pheno ...201526292534
eric-pcr genotyping of field isolates of salmonella enterica subsp. enterica serovar gallinarum biovars gallinarum and pullorum.salmonella gallinarum (sg) and salmonella pullorum (sp) have been classified as biovars belonging to salmonella enterica subsp. enterica serovar gallinarum. genetic diversity among isolates of the same biovar can be detected by dna fingerprinting techniques which are useful in epidemiological investigations. in this study, we applied the pcr amplification of enterobacterial repetitive intergenic consensus sequences (eric-pcr) to analyse 45 strains of sg and sp, most of which were isolated from d ...201526365161
utilization of a modified phage e protein lysis system accounts for increased biomass in salmonella gallinarum ghosts.a major limiting issue of bacterial ghost technology involves the stable maintenance of phix174 lysis gene e expression. unwanted leaky expression of gene e in the absence of induction temperature results in reduced biomass production of host bacterium, consequently leading to the lower yield of bacterial ghost. to mitigate the leaky expression status of lysis gene e, we utilized a novel e-lysis system in which gene e is located between sense λpr promoter with a ci857 regulator and antisense par ...201526473678
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