Analysis on prevalence and epidemic risk of animal plague in different ecological plague foci in Inner Mongolia Autonomous Region / 中华预防医学杂志

The risk of plague epidemics and relapse of various types of plague foci persists in Inner Mongolia Autonomous Region. For Marmota sibirica plague foci, the animal plague has not been found but antibody has been detected positive. Nowadays, Marmota sibirica has been increasing in population and distribution in China. In bordering countries Mongolia and Russia, the animal plague has been continuously prevalent. For Spermophilus dauricus plague foci, the animal plague has been taken place now and then. Compared to the above foci, the animal plague is most prevalent in Meriones unguiculatus plague foci and frequently spread to humans. Due to higher strain virulence and historical disaster in Marmota sibirica plague foci and Spermophilus dauricus plague foci, plague prevention and control should be strengthened on these foci. In addition to routine surveillance, epidemic dynamics need to be further monitored in these two foci, in order to prevent their relapse and spread to humans.

Genetic Diversity, Antimicrobial Resistance, and Virulence Genes of Isolates from Clinical Patients, Tap Water Systems, and Food / 生物医学与环境科学（英文）

Objective@#This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of isolates from clinical patients, tap water systems, and food.@*Methods@#Ninety isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.@*Results@#The 90 isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes , , , and found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new variant.@*Conclusions@#Sequence type, virulence properties, and antibiotic resistance vary in isolates from clinical patients, tap water systems, and food.

An etiological survey on a foodborne disease epidemic outbreak caused by Salmonella enteritidis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To conduct an etiological molecular epidemiological survey and laboratory test on a foodborne disease epidemic outbreak to make clear of the cause and implement effective prevention and control on it.</p><p><b>METHODS</b>On May 12th 2012, 135 kindergarten children were sent to Xuzhou City People's Hospital and Children's Hospital with gastrointestinal infection disease. A total of 34 anus swab samples and 4 vomit samples were collected from the patients. Real-time PCR rapid detection, strains separation and cultivation, phage lysis experiments, ATB automated identification system were used to make etiological detection and identification. The genomic DNA of salmonella enteritidis were typed with the pulsed-field gel electrophoresis (PFGE), cluster analysis were carried out together with the patterns of local Salmonella infections.</p><p><b>RESULTS</b>Children in 20 classes were suffered from the gastrointestinal infection among the 21 classes. There were no significant aggregation of class distribution. Among the 135 patients, 76 were boys (56.3%) and 59 were girls (43.7%). The main symptoms were fever (above 38°C), diarrhea and bellyache. Through real-time PCR detection and strains separation, 19 salmonella enteritidis were isolated from 34 anus swab samples of suspected cases and the detection rate was 56%. There were no strains detected from vomit samples. All of the 19 salmonella enteritidis showed the same serological subtype, biochemical reaction, drug sensitivity and phage lysis pattern. The salmonella enteritidis had the identical PFGE pattern (100% similarity), and were different from the pattern of local sporadic infection cases.</p><p><b>CONCLUSION</b>It was confirmed that this was an epidemic outbreak of foodborne disease caused by homologous salmonella enteritidis by epidemiological survey, clinical information, lab etiological test and molecular typing.</p>

Analysis of the variation and changes of Yersinia enterocolitica in Ningxia area from 1984 to 2011 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the genetic evolution and bacterial type changes of Yersinia enterocolitica in the Ningxia area between year 1984 and 2011.</p><p><b>METHODS</b>A total of 296 strains of Yersinia enterocolitica was collected from diarrhea patients, pig, rodents, sheep and dogs between year 1984 and 2011. The serotype, biotype, ail, ystA, ystB, yadA, virF and other toxic genes were detected. The PFGE subtypes of serotype O:3 and O:9 strains and the cluster features were analyzed.</p><p><b>RESULTS</b>Out of 296 Yersinia enterocolitica strains, pig was the main host, accounting for 65.20% (193/296), followed by rodents, accounting for 32.43% (96/296). Serotype and biotype had their own respective dominant types in different periods. During 1984 and 1985, 2 strains of serotype O:3 and 3 strains of serotype O:9 were isolated, all belonged to biotype 3. Because of lack of strains, there were no obvious dominant types found. Between 1997 and 1999, 177 strains of serotype O:9 Yersinia enterocolitica were isolated as the dominant strain; and there were 178 strains of biotype 2 Yersinia enterocolitica were found. During 2007 and 2011, 54 strains of serotype O:3 Yersinia enterocolitica were isolated as dominant strain; followed by 26 strains of serotype O:5. There were separately 44 and 59 strains of biotype 1A and biotype 3. The PCR test divided the 248 strains into 4 types, including pathogenic strains as type I (ail(+), ystA(+), ystB(-), yadA(+), virF(+)). The PFGE divided the serotype O:3 into 12 types, in which K6GN11C30021 and K6GN11C30012 were the dominant types, accounting for 63.64% (42/66). The serotype O:9 were divided into 14 types, in which K6GN11C90010, K6GN11C90008, K6GN11C30018 and K6GN11C90003 were the dominant types, accounting for 89.01% (162/182).</p><p><b>CONCLUSION</b>The different serotypes of isolated strains in Ningxia district showed different dominant bacteria in different periods; while the biotypes also changed with serotypes. The Yersinia enterocolitica isolated from different years showed great variation.</p>