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Genome Research Oct 2008We have determined the complete genome sequences of a host-promiscuous Salmonella enterica serovar Enteritidis PT4 isolate P125109 and a chicken-restricted Salmonella... (Comparative Study)
Comparative Study
We have determined the complete genome sequences of a host-promiscuous Salmonella enterica serovar Enteritidis PT4 isolate P125109 and a chicken-restricted Salmonella enterica serovar Gallinarum isolate 287/91. Genome comparisons between these and other Salmonella isolates indicate that S. Gallinarum 287/91 is a recently evolved descendent of S. Enteritidis. Significantly, the genome of S. Gallinarum has undergone extensive degradation through deletion and pseudogene formation. Comparison of the pseudogenes in S. Gallinarum with those identified previously in other host-adapted bacteria reveals the loss of many common functional traits and provides insights into possible mechanisms of host and tissue adaptation. We propose that experimental analysis in chickens and mice of S. Enteritidis-harboring mutations in functional homologs of the pseudogenes present in S. Gallinarum could provide an experimentally tractable route toward unraveling the genetic basis of host adaptation in S. enterica.
Topics: Adaptation, Physiological; Animals; Chickens; Evolution, Molecular; Genome, Bacterial; Mice; Molecular Sequence Data; Salmonella; Salmonella Infections, Animal; Salmonella enteritidis
PubMed: 18583645
DOI: 10.1101/gr.077404.108 -
Medical and Veterinary Entomology Mar 2019Dermanyssus gallinae (Mesostigmata: Dermanyssidae, De Geer, 1778) is an ectoparasite of poultry, suspected to play a role as a vector of Salmonella enterica subsp....
Dermanyssus gallinae (Mesostigmata: Dermanyssidae, De Geer, 1778) is an ectoparasite of poultry, suspected to play a role as a vector of Salmonella enterica subsp. enterica ser. Gallinarum. Despite an association between them being reported, the actual dynamics in field remain unclear. Therefore, the present study aimed to confirm the interactions among mites, pathogen and chickens. The study was carried out in an industrial poultry farm infested by D. gallinae, during an outbreak of fowl typhoid. The presence of S. Gallinarum in mites was assessed and quantified by a semi-nested polymerase chain reaction (PCR) and real-time PCR, respectively, in mites collected during two subsequent productive cycles and the sanitary break. The anti-group D Salmonella antibodies were quantified by an enzyme-linked immunosorbent assay. During the outbreak and the sanitary break, S. Gallinarum was constantly present in mites. In the second cycle, scattered positivity was observed, although hens did not exhibit signs of fowl typhoid, as a result of the vaccination with BIO-VAC SGP695 (Fatro, Ozzano Emilia Bo, Italy). The data strongly suggest that D. gallinae acts as reservoir of S. Gallinarum, thus allowing the pathogen to persist in farms. Furthermore, the present study has highlighted the interactions among D. gallinae, S. Gallinarum and hens with respect to enhancing the mite-mediated circulation of S. Gallinarum in an infested poultry farm.
Topics: Animals; Chickens; Disease Reservoirs; Female; Italy; Mite Infestations; Mites; Polymerase Chain Reaction; Poultry Diseases; Salmonella Infections, Animal; Salmonella enterica
PubMed: 30160309
DOI: 10.1111/mve.12333 -
Veterinary Microbiology Nov 2022The present study describes creating an attenuated Salmonella Gallinarum (SG) strain with reduced endotoxicity to prevent fowl typhoid. The strain was attenuated by...
The present study describes creating an attenuated Salmonella Gallinarum (SG) strain with reduced endotoxicity to prevent fowl typhoid. The strain was attenuated by deleting the lon, cpxR, and rfaL virulence-related genes. Endotoxicity was reduced by deleting the pagL open reading frame and replacing it with the lpxE gene derived from Francisella tularencis. Both events, (1) deletion of the pagL and (2) introduction of the lpxE genes, conferred reduced endotoxicity by detoxifying the lipid A structure. The detoxified SG strain (SGVSdt) was well tolerated in 7-day-old chicks when administered orally at 1 × 10 CFU/bird and in 14-day-old birds administered 1 × 10 CFU/bird subcutaneously. Parenteral immunization of detoxified vaccine strain was completely safe in birds and free of environmental contamination. Subcutaneous immunization conferred disease protection and induced humoral and cell-mediated immune responses marked by Th1-skewed patterns similar to those produced by the commercial SG9R vaccine strain. Compared with the SG9R-based vaccine, the SGVSdt construct generated significantly fewer inflammatory TNF-α responses while significantly inducing IFN-γ cytokine levels as an indication of an adaptive antibacterial response. The differentiating infected from vaccinated animals (DIVA) capability was on par with the predecessor SGVS. This study presents an appealing biological strategy to minimize lipid A-mediated endotoxicity without compromising protective efficacy against the SG challenge. Reduced endotoxicity permits the utilization of higher inoculation doses to maximize protection against fowl typhoid.
Topics: Animals; Salmonella Vaccines; Salmonella Infections, Animal; Poultry Diseases; Lipid A; Endotoxins; Typhoid Fever; Tumor Necrosis Factor-alpha; Prospective Studies; Vaccines, Attenuated; Salmonella; Chickens; Anti-Bacterial Agents
PubMed: 36113357
DOI: 10.1016/j.vetmic.2022.109572 -
Poultry Science Feb 2010Salmonella enterica serovar Gallinarum (Salmonella Gallinarum) is the causative agent of fowl typhoid (FT), a severe systemic disease of chickens that results in high...
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 live attenuated strain (SG 9R) in 2001. For 9 yr, a total of 983 farms were affected with FT outbreaks, and after reaching a peak in 2002 (206 farms affected), the prevalence of the disease gradually declined, whereas magnitude sales of the vaccine increased every year. According to the analysis based on the chicken breeds (n=521 farms), the incidence of FT in commercial broilers, Baeksemi (a mixed breed of male meat-type breeder and female commercial layer), commercial layers, native chickens, and broiler breeders was 47.7, 28.4, 17.2, 5.1, and 1.3%, respectively. Of the affected broilers, over 90% birds were under 2 wk of age, indicating it was possible that they were infected with Salmonella Gallinarum via vertical transmission. In the phenotypic analysis, Salmonella Gallinarum strains (n=142) isolated during 2001 to 2007 showed the same pattern in the majority of the biochemical tests such as carbohydrate fermentation and amino acid decarboxylation. Interestingly, all of the strains could not ferment rhamnose, but SG 9R could, making rhamnose a potential biomarker to distinguish the vaccine strain. In analyzing the genetic diversity by the pulsed field gel electrophoresis method with XbaI digestion, we examined a total 68 isolates of Salmonella Gallinarum obtained in 5 provinces in Korea (2001 to 2007). The pulsed field gel electrophoresis profiling produced 7 different patterns, but isolates within the same group did not show clear geographic or breed relationships. In conclusion, there were close epidemiological linkages between prevalence of FT and the sales volume of the live FT vaccine in Korea. In addition, a low phenotypic and genetic heterogeneity was observed among Korean Salmonella Gallinarum isolates and the live vaccine strain (SG 9R).
Topics: Animals; Chickens; Female; Male; Poultry Diseases; Republic of Korea; Salmonella; Salmonella Infections, Animal; Time Factors
PubMed: 20075274
DOI: 10.3382/ps.2009-00420 -
Microbiology (Reading, England) Dec 2000Salmonella enterica is a facultative intracellular pathogen that is capable of causing disease in a range of hosts. Although human salmonellosis is frequently associated... (Comparative Study)
Comparative Study
Salmonella enterica is a facultative intracellular pathogen that is capable of causing disease in a range of hosts. Although human salmonellosis is frequently associated with consumption of contaminated poultry and eggs, and the serotypes Salmonella gallinarum and Salmonella pullorum are important world-wide pathogens of poultry, little is understood of the mechanisms of pathogenesis of Salmonella in the chicken. Type III secretion systems play a key role in host cell invasiveness and trigger the production of pro-inflammatory cytokines during invasion of mammalian hosts. This results in a polymorphonuclear cell influx that contributes to the resulting enteritis. In this study, a chicken primary cell culture model was used to investigate the cytokine responses to entry by the broad host range serotypes S. enteritidis and S. typhimurium, and the host specific serotype S. gallinarum, which rarely causes disease outside its main host, the chicken. The cytokines interleukin (IL)-1ss, IL-2, IL-6 and interferon (IFN)-gamma were measured by quantitative RT-PCR, and production of IL-6 and IFN-gamma was also determined through bioassays. All serotypes were invasive and had little effect on the production of IFN-gamma compared with non-infected cells; S. enteritidis invasion caused a slight down-regulation of IL-2 production. For IL-1ss production, infection with S. typhimurium had little effect, whilst infection with S. gallinarum or S. enteritidis caused a reduction in IL-1ss mRNA levels. Invasion of S. typhimurium and S. enteritidis caused an eight- to tenfold increase in production of the pro-inflammatory cytokine IL-6, whilst invasion by S. gallinarum caused no increase. These findings correlate with the pathogenesis of Salmonella in poultry. S. typhimurium and S. enteritidis invasion produces a strong inflammatory response, that may limit the spread of Salmonella largely to the gut, whilst S. gallinarum does not induce an inflammatory response and may not be limited by the immune system, leading to the severe systemic disease fowl typhoid.
Topics: Animals; Biological Assay; Cell Line; Cells, Cultured; Chickens; Cytokines; Interferon-gamma; Interleukin-1; Interleukin-2; Interleukin-6; Kidney; Macrophage Activation; Macrophages; Molecular Sequence Data; Reverse Transcriptase Polymerase Chain Reaction; Salmonella; Salmonella enteritidis; Salmonella typhimurium
PubMed: 11101679
DOI: 10.1099/00221287-146-12-3217 -
Poultry Science Nov 2019Fowl typhoid (FT), which is caused by Salmonella enterica serovar Gallinarum (S. Gallinarum), leads to high morbidity and acute or subacute mortality in chickens of all...
Fowl typhoid (FT), which is caused by Salmonella enterica serovar Gallinarum (S. Gallinarum), leads to high morbidity and acute or subacute mortality in chickens of all ages. Although a live S. Gallinarum 9R vaccine was introduced in 2001 for commercial layer chickens in Korea, until recently, a variety of antimicrobials were widely used to prevent or treat FT. In this study, we investigated antimicrobial resistance in S. Gallinarum strains isolated from 2014 to 2018 and characterized the multidrug-resistant (MDR) strains to better understand the resistance trends in recent isolates. A total of 130 S. Gallinarum isolates were collected from chickens with FT, and the isolates showed highest rates of resistance to nalidixic acid (78.5%), followed by gentamicin (52.3%), ciprofloxacin (26.9%), and ampicillin (14.6%). Particularly, significant increases (P < 0.05) in the frequencies of resistance to the following antimicrobials were observed: ampicillin (from 7.7 to 28.6%), amoxicillin-clavulanate (from 0.0 to 10.7%), nalidixic acid (from 69.2 to 100.0%), ciprofloxacin (from 15.4 to 50.0%), chloramphenicol (from 0.0 to 17.9%), and colistin (from 0.0 to 14.3%). The prevalence of MDR isolates also rapidly increased from 23.1% in the 2014 to 60.7% in the 2018 (P < 0.05). The distribution of antimicrobial resistance genes in the 39 MDR S. Gallinarum isolates was as follows: ant(2")-I gene (22 isolates), blaTEM-1 gene (13 isolates), sul1 (9 isolates), sul2 (3 isolates), cmlA (3 isolates), and qnrB (3 isolates). Of 39, 25 (64.1%) MDR S. Gallinarum isolates also carried class 1 integrons, and these showed 5 types of resistance gene cassettes: dfrA12+aadA2 (36.0%), aadA2 (36.0%), aadA1-aadA2 (20.0%), dfrA12+catB3+aadA2 (4.0%), and dfrA12 (4.0%). Among the plasmid replicons, B/O (33.3%) was more prevalent than the other replicon types, followed by Frep (25.0%), FIIA (19.4%), FIB (13.9%), and I1 (8.3%). Antimicrobial resistance may become a serious problem because many drugs are likely ineffective for the treatment of FT. Therefore, these data support the critical need for comprehensive surveillance of antimicrobial resistance in poultry.
Topics: Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Multiple, Bacterial; Poultry Diseases; Prevalence; Republic of Korea; Salmonella Infections, Animal; Salmonella enterica
PubMed: 31350992
DOI: 10.3382/ps/pez376 -
Veterinary Microbiology Mar 2003The purpose of this investigation was to study the host specific infection of Salmonella Gallinarum in chickens and to determine the contribution of intestinal invasion... (Comparative Study)
Comparative Study
The purpose of this investigation was to study the host specific infection of Salmonella Gallinarum in chickens and to determine the contribution of intestinal invasion and macrophage survival in relation to systemic infection in the host. This was carried out by comparing the kinetics of infection of S. Gallinarum to that of other Salmonella host-adapted (S. Cholerae-suis, S. Dublin and S. Typhimurium) and host-specific (S. Pullorum and S. Abortus-ovis) serovars. Establishment of the rate of colonisation in intestinal tissue, bursa and systemic sites was carried out by oral infection in day-old and week-old birds. Salmonella Gallinarum was the only serovar capable of causing systemic infection in chickens, however, general colonising ability in the intestine and bursa demonstrated no apparent selective advantage for S. Gallinarum. Further quantification of gastrointestinal invasion was carried out using ligated loops in the small intestine. Invasion in the jejunum of the chicken intestine over 3h demonstrated that Salmonella Typhimurium invasion was statistically higher (P<0.01) when compared with S. Gallinarum. Specific sites of high lymphoid tissue concentration in the chicken, including the bursa of Fabricius and caecal tonsils, were also targeted in invasion assays to investigate possible areas of tissue tropism. S. Typhimurium demonstrated significantly higher (P<0.01) invasion at these sites when compared with S. Gallinarum. Infection of chicken macrophages with S. Gallinarum did not demonstrate increased multiplication and survival intracellularly when compared with other Salmonella serotypes. The only difference seen was with S. Abortus-ovis, which demonstrated a significantly lower (P<0.05 to 0.001) intracellular survival. Together these data suggest that although S. Gallinarum host specificity in the chicken correlates with systemic infection, intestinal and lymphoid tissue invasion in the bursa and caeca, and macrophage survival does not influence this outcome.
Topics: Animals; Chickens; Colony Count, Microbial; Cytotoxicity Tests, Immunologic; Female; Gastrointestinal Diseases; In Vitro Techniques; Intestinal Mucosa; Lymphoid Tissue; Macrophages; Mice; Microscopy, Fluorescence; Poultry Diseases; Salmonella; Salmonella Infections, Animal
PubMed: 12488070
DOI: 10.1016/s0378-1135(02)00290-0 -
Advances in Experimental Medicine and... 1997Research on the control of intestinal and tissue colonization of breeder and table-egg producing flocks by invasive Salmonella enteritidis (SE) has focused on the... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Research on the control of intestinal and tissue colonization of breeder and table-egg producing flocks by invasive Salmonella enteritidis (SE) has focused on the advancement of anti-salmonella feed additives, microbiological strategies, and the development of vaccines. Recent investigations in our laboratories have concentrated on the development of immunoprophylactic measures to control Salmonella infections. We have found an increased resistance to Salmonella enteritidis (SE) organ infectivity in chickens conferred by the prophylactic administration of SE-immune lymphokines (SE-ILK). Fowl typhoid, caused by Salmonella gallinarum (SG), is a septicemic disease of domestic birds resulting in morbidity with moderate to very high mortality within the first 2 weeks of age. The objective of the present studies was to evaluate the effect of a prophylactic treatment of neonatal broiler chicks with lymphokines derived from S. enteritidis (SE)-immunized chickens (SE-ILK) on the birds' resistance to an experimental infection with S. gallinarum (SG). On the day-of- hatch, chicks were intraperitoneally administered either SE-ILK, control nonimmune lymphokines (NILK), or nothing. Thirty min later, all chicks were gavaged with either 10(4) cfu or 10(6) cfu SG. For 10 days after challenge, the chicks were observed twice daily for morbidity and mortality. Chicks that died during the experiment had their livers cultured for SG. Chicks that survived throughout the 10 day experimental period were killed and their livers, spleens, and cecal tonsils cultured for SG. The prophylactic treatment of chickens with SE-ILK induced significant protection against an extraintestinal SG infections when compared to NILK as evidenced by: 1) a significant reduction (P < 0.005) in the mortality of chicks challenged with either 10(4) and 10(6) cfu sg; 2) increased average weight gains of chicks challenged with either 10(4) and 10(6) efu SG; and 3) a significant (P < 0.001) reduction in the total number of SG-organ-culture positive chicks. The results suggest that the prophylactic administration of SE-ILK can non-specifically confer protection to chicks against a pathogenic salmonellae as seen by reduced morbidity, mortality, and organ infectivity of SG in broiler chicks while enhancing weight gain during the first ten days of life.
Topics: Animals; Body Weight; Chickens; Lymphokines; Poultry Diseases; Salmonella; Salmonella Infections, Animal; Salmonella enteritidis
PubMed: 9192048
DOI: 10.1007/978-1-4899-1828-4_64 -
Infection and Immunity Nov 1995Salmonella typhi and Salmonella gallinarum phenotypes correlated with mouse host restriction have been identified by using in vitro and in vivo systems. S. typhi is...
Salmonella typhi and Salmonella gallinarum phenotypes correlated with mouse host restriction have been identified by using in vitro and in vivo systems. S. typhi is capable of entering the murine intestinal epithelium via M cells, as is Salmonella typhimurium, which causes systemic infection in the mouse. But, unlike S. typhimurium, S. typhi does not destroy the epithelium and is cleared from the Peyer's patches soon after M-cell entry. S. gallinarum appears to be incapable of entering the murine Peyer's patch epithelium. Our in vitro evidence suggests that S. gallinarum is taken up in murine phagocytic cells by a mechanism different from that of S. typhimurium. S. typhimurium is taken up at a higher frequency and is maintained at higher viable counts throughout a 24-h time course in a murine macrophage-like cell line than are S. gallinarum and S. typhi.
Topics: Animals; Bacterial Adhesion; Cells, Cultured; Cytoskeleton; Female; Ileum; Intestinal Mucosa; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Peyer's Patches; Salmonella; Salmonella typhi; Species Specificity; Video Recording
PubMed: 7591067
DOI: 10.1128/iai.63.11.4329-4335.1995 -
PloS One 2015The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements... (Comparative Study)
Comparative Study
The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content between strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. The loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars.
Topics: Genome, Bacterial; Mutation; Polymorphism, Single Nucleotide; Salmonella enteritidis; Serogroup
PubMed: 26039056
DOI: 10.1371/journal.pone.0126883