Distribution of pathogenic Yersinia enterocolitica in China

Abstract

Yersinia enterocolitica (1,295 strains) was isolated from diarrhea patients, livestock, poultry, wild animals, insect vectors, food, and the environment. They were studied for epidemiology distribution using bacterial biochemical metabolism tests, their virulence genes, and pulsed-field gel electrophoresis (PFGE) sub-typing. The data showed that 416 of the 1,295 strains were pathogenic, where the pathogenic Chinese isolates were of serotypes O:3 and O:9. These two serotypes were found in livestock and poultry, with swine serving as the major reservoir. The geographic distribution of pathogenic isolates was significantly different, where most of the strains were isolated from the cold northern areas, whereas some serotype O:3 strains were recovered from the warm southern areas. By the analysis of the data of the Ningxia Hui Autonomous Region, we find the phenomenon of 'concentric circle distribution' around animal reservoirs and human habitation. The clustering of PFGE showed that the patterns of the pathogenic strains isolated from diarrhea patients were identical compared to those from the animals in the same area, thus, suggesting that the human infection originated from the animals.

Complete Genome Sequence of a Yersinia enterocolitica “Old World” (3/O:9) Strain and Comparison with the “New World” (1B/O:8) Strain

“…Although the predominant bioserotype in China is 2/O:9, we chose a 3/O:9 strain for analysis in this study as a representative of the Old World strains due to the high level of homology between biotypes 2 and 3 (42). The genome sequences of strain 105.5R(r) agreed with the results obtained using eight biotype 3 strains in the previous microarray analysis; specifically, they (39).…”

“…In contrast, all of the O:8 isolates recovered from patients and animals in China have been biotype 1A strains and have lacked virulence determinants (44). The only pathogenic strains isolated from China have been of serotypes O:3 and O:9 (42). China has a distribution and a pathogenic pattern similar to those of the European countries and Japan, making it a region where Old World strains predominate.…”

Homology Analysis of Pathogenic Yersinia Species Yersinia enterocolitica, Yersinia pseudotuberculosis, and Yersinia pestis Based on Multilocus Sequence Typing

“…Among 35 Y. pestis strains isolated from different natural plague foci in China, 15 were isolated from patients (seven from Yunnan Province, six from Qinghai Province, one from Gansu Province, and one from Inner Mongolia), and the rest were from rats, Marmota spp., Xenopsylla cheopis, and Suncus murinus. The sample collection and detection protocols were approved by the ethics review committee of the National brain heart infusion (BHI) agar (Beijing Land Bridge Technology Co., Ltd., China) plates incubated at 25°C for 24 to ϳ48 h to obtain pure cultures (4,12). The inoculation of Y. pestis was performed using the method described by Achtman et al (20).…”

“…The virulence genes (ail, ystA, ystB, virF, and yadA) of the Y. enterocolitica isolates were amplified. Pathogenic Y. enterocolitica strains were positive for all (ail ϩ , ystA ϩ , virF ϩ , and yadA ϩ ) virulence genes; however, some pathogenic strains lost virulence genes that were carried on a plasmid (ail ϩ , ystA ϩ , virF-negative, and yadA-negative strains) (3,4). Serotype identification of the Y. pseudotuberculosis strains was conducted using multiplex PCR as described by Bogdanovich et al (21).…”

“…Y. pestis is the deadliest bacterium known in human history; it is primarily a rodent pathogen transmitted via the bite of an infected flea. Y. pseudotuberculosis and Y. enterocolitica are zoonotic food-borne pathogens that spread through the fecal-oral route; they have a broad host range, infecting animals, including swine, dogs, rodents, birds, and wild animals (3,4). Many studies show that swine and dogs are the most common sources of Y. enterocolitica infections in humans (5,6).…”