O:8 serotype Yersinia enterocolitica strains in China.
ABSTRACT Serotypes O:3, O:8 and O:9 Yersinia enterocolitica strains carrying virulence determinants are common pathogens causing human infections. In many years of surveillance in China for Y. enterocolitica, no pathogenic O:8 strains have been found where the isolated O:8 serotypes lacked the major virulence genes and in contrast to O:3 and O:9 strains, none of the O:8 isolates were from humans. These O:8 isolates lack ail, ystA, yadA and virF genes but possess the ystB gene and all belong to Biotype 1A. These O:8 strains did not kill mice and could protect immunized mice against challenge with a pathogenic O:8 strain. Compared to the Chinese pathogenic O:3 and O:9 strains which have similar pulsed-field gel electrophoresis patterns, the 39 Chinese O:8 animal and food isolates were different from the pathogenic O:8 reference strains. This suggests the O:8 strains lacking virulence determinants may not disseminate rapidly in humans and are maintained in animal reservoirs; and therefore exhibit higher variance and divergence from the virulent type.
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ABSTRACT: The predominant bioserotypes of pathogenic Yersinia enterocolitica in China are 2/O: 9 and 3/O: 3; no pathogenic O: 8 strains have been found to date. Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA) based on seven loci was able to distinguish 104 genotypes among 218 pathogenic Y. enterocolitica isolates in China and from abroad, showing a high resolution. The major pathogenic serogroups in China, O: 3 and O: 9, were divided into two clusters based on MLVA genotyping. The different distribution of Y. enterocolitica MLVA genotypes maybe due to the recent dissemination of specific clones of 2/O: 9 and 3/O: 3 strains in China. MLVA was a helpful tool for bacterial pathogen surveillance and investigation of pathogenic Y. enterocolitica outbreaks.PLoS ONE 01/2012; 7(5):e37309. · 3.73 Impact Factor
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ABSTRACT: Yersinia enterocolitica is a Gram-negative enteric pathogen responsible for a number of gastrointestinal disorders; the most pathogenic bio-serotype is 1B/O: 8. In this study, we compared the antigenicity of the outer membrane proteins and proteomics of the whole-cell proteins of a pathogenic bio-serotype 2/O: 9 isolated in China and a bio-serotype 1B/O: 8 strain isolated in Japan. Using two-dimensional gel electrophoresis, we showed that the outer membrane proteins A (OmpA), C (OmpC) and F (OmpF) were the major antigens for both strains, although proteins located on the bacterial cell membrane and enzymes involved in energy metabolism were also identified as antigenic. We compared the whole-cell proteins of the two strains cultured at 25°C and 37°C and found portions of the outer membrane proteins (OmpX, OmpF and OmpA) were downregulated when the bacteria were cultured at 37°C, whereas urease subunit gamma (UreA), urease subunit alpha (UreC) and urease accessory protein (UreE), which are involved in urease synthesis, were upregulated when the bacteria were grown at 37°C. These observations will lay a foundation to selection of diagnostic markers for pathogenic Yersinia enterocolitica, and maybe contribute to choose the vaccine targets.Microbiology and Immunology 06/2012; 56(9):583-94. · 1.55 Impact Factor
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ABSTRACT: The distribution of Yersinia enterocolitica in slaughtered pigs in China was studied. A total of 8,773 samples were collected and examined from different pig abattoirs in 11 provinces from 2009 to 2011. Of these, 4,495 were oral-pharyngeal swab (tonsils) samples from pigs, 1,239 were from intestinal contents, and 3,039 were feces samples from abattoirs or local pigpens. The data showed that 1,132 strains were obtained, from which the isolation rate for Yersinia enterocolitica was 19.53% (878/4,495) from the tonsil samples, 7.51% (93/1,239) from intestinal contents, and 5.30% (161/3,039) from feces. Of the 850 pathogenic Yersinia strains, except for three of bioserotype 2/O:9 and three of bioserotype 4/O:3, most (844/850) were of bioserotype 3/O:3. Interestingly, pathogenic Y. enterocolitica accounted for the majority of the isolated strains from most provinces (85.17% to 100%), whereas from Heilongjiang, 96.52% (111/115) were classified as nonpathogenic biotype 1A with various serotypes, and only 3.48% of the strains (4/115) were pathogenic 3/O:3. All of the pathogenic strains were analyzed using pulsed-field gel electrophoresis (PFGE), and 49 patterns were obtained for the O:3 pathogenic strains; most of them were K6GN11C30021 (53.13%: 450/847) and K6GN11C30012 (21.37%: 181/847). Several strains from diarrhea patient samples revealed PFGE patterns identical to that from samples of local pigs, suggesting a possible link between porcine isolates and human infection. The results above suggested that Yersinia enterocolitica in slaughtered pigs from Chinese abattoirs was characterized by region-specific PFGE patterns and confirmed that strains isolated from pigs are closely related to those from human infections.Applied and environmental microbiology 02/2012; 78(8):2949-56. · 3.69 Impact Factor