Molecular characterization and drug-resistance of Mycobacterium tuberculosis strains in Xuzhou, China / 生物医学与环境科学（英文）

To understand the genetic diversity and drug resistance status of Mycobacterium tuberculosis (M. tuberculosis) circulating in Xuzhou of China, the spacer-oligonucleotide typing (Spoligotyping) and multi-loci VNTRs (variable number tandem repeats) analysis (MLVA) were utilized for the genotyping of the isolates. Drug susceptibility test (DST) was performed by the proportion method on the Lowenstein-Jensen (L-J) medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-loci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.

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>

Etiological analysis of influenza surveillance data in Xuzhou from 2005 to 2011 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence and subtypes of influenza viruses in Xuzhou city from 2005 to 2011 and to provide the scientific supports for influenza prevention and control in this religion.</p><p><b>METHODS</b>The throat swab samples were collected from the influenza-like cases from national influenza like illness sentinel hospital in Xuzhou. The samples were used for influenza virus isolation and identification, sent on the national flu center to confirm according to the "national influenza surveillance program" and "influenza virus and experimental technology".</p><p><b>RESULTS</b>From Oct. 2005 to Dec. 2011, a total of 9561 swab specimens were collected in which 1152 strains were identified for influenza viruses with total isolated rate of 12.0%. Among these strains, 708 strains were A1 (H1N1) subtype (14.2%), 466 strains were A3 (H3N2) subtype (40.5%), 78 strains were new H1N1 subtype (6.8%), 362 strains were BV (Victoia) subtype (31.4%) and 82 strains were BY (Yamagate) subtype (7.1%). The top detection rate (25.9%) arose in 2007, secondary detection rate (17.4%) occurred at 2009 and the lowest one (2.3%) appeared in 2011. From the winter of 2005 to the spring of 2006 A1 (H1N1) subtype had appeared as predominant strains but in the winter of 2006 the predominant strains were BV subtype. It changed to A3 subtype in 2007 to 2009 and the other three dominant strains were A1, BV and BY in 2008. In the winter of 2009, both A3 (H3N2) and new H1N1 subtype were predominant strains. BV subtype was predominant strains in 2010 to 2011. The prevalence of A3 subtype appeared in all the year while prevalence of BV only arose in the spring and winter. So the detection rate was high in January (34.4%) but low in August (2.2%). The influenza population is correlated with age, the highest detection rate arose in 5-age group and the lowest detection rate appeared in 25-age group.</p><p><b>CONCLUSION</b>Influenza subtype A1, A3, New H1N1 are all appeared as predominant strains in Xuzhou city from 2005 to 2010. Besides, the prevalence of BV subtype is stronger in recently.</p>

Analysis on pathogen detection for 53 influenza outbreaks / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>In order to provide a scientific basis for influenza prevention and control, analyzing the epidemic characteristics and laws of influenza outbreaks in Xuzhou area during 2005-2011.</p><p><b>METHOD</b>Using fluorescent-PCR method to detect influenza virus nucleic acid on Nasopharyngeal swab specimens collected from influenza outbreak cases during 2005-2011 and fast classifying influenza virus A1 (H1N1), A3 (H3N2), new H1N1 BV (Victoria) and BY (Yamagate) on subtypes. At the same time, isolating the influenza virus with MDCK cells, and sending them to the National Influenza Center for review, after the preliminary identification of the isolated influenza virus.</p><p><b>RESULTS</b>During 2005-2011, there are 53 influenza outbreaks in Xuzhou area, which caused by influenza virus subtype BV accounting for 26.42% (14/53), A3 accounting for 49.1% (26/53), A3 and A1 mixture accounting for 3.77% (2/53) and the new H1N1 accounting for 20.75% (11/53). The outbreaks in 2007 and 2009 mainly caused by A3, and show that the winter spring (January) and summer autumn (September) as two popular peaks during 2005-2011; BV mainly causes the outbreaks from Feb. to Jun.</p><p><b>CONCLUSION</b>In Xuzhou area, since the winter of 2005, influenza virus subtype BV, the A3, and new H1N1 has alternately as mainly predominant strain, caused local influenza outbreaks. In which BV has increased trend year by year during 2005-2011. The students in primary and secondary schools are the major crowd of influenza outbreaks. Fluorescent-PCR detection methods could be a preferred method for reliable and rapid diagnostic of epidemic influenza outbreaks.</p>

Research on the aetiology of suspected enterovirus infected patients in Xuzhou district in 2009 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand and master the situation in which enterovirus caused hand-foot-and-mouth disease (HFMD) in Xuzhou district in 2009 so as to provide scientific basis for the control and prevention of hand-foot-and-mouth disease.</p><p><b>METHODS</b>The researchers adopted fluorescence RT-PCR method to detect EV and EV71 as well as the CA16 specificity RNA from 222 samples of anal swabs and oropharyngeal swabs from the 240 cases who were diagnosed clinically as hand-foot-mouth disease infected by enterovirus. Also, the researchers conducted EV71-IgM antibody detection on 114 samples of acute phase serum with ELA method.</p><p><b>RESULTS</b>Among the 240 enterovirus infected patients, the total EV infection rate is 72.50% (174/240), among which EV71 infection rate is 57.92% (139/240), CoxA16 infection rate is 9.17% (22/240), and other EV infection rate is 5.42% (13/240). The EV71-RNA positive rate of the samples of 222 anus swabs among the 240 suspected enterovirus infected patients is 45.94% (102/222), the samples of swallow swab EV71-RNA positive rate is 25.68% (57/222) and the EV71-IgM antibody positive rate of 114 samples of acute phase serum is 86.84% (99/114). The EV71-RNA positive rate of oropharyngeal swabs of 254 healthy children is 1.57% (4/254) , and no CoxA16-RNA was detected. In the oropharyngeal swabs of 54 close contacts (medical personnel), the EV-RNA detected is negative. The positive rate of EV71-IgM antibody of the 258 healthy children's serum samples is 2.71% (7/258).</p><p><b>CONCLUSION</b>The widespreading of hand-foot-mouth disease in Xuzhou district is caused mainly by type 71 enterovirus. Inapparent infection of type 71 enterovirus exists among children under the age of 3 during the time of widespreading period and IgM antibody develops in them. It is difficult for adults to be infected by EV71 even if they contact the contagion source closely. The positive rate of EV71-IgM antibody in the samples of acute phase serum of suspected cases is the highest (86.84%), and the second highest is the positive rate of RNA of EV71 of anal swabs (45.94%) and of the EV71 of oropharyngeal swabs (25.68%). ELA reagent kit is used in the early diagnosis of EV71 infection for it is easy to operate, fast and economic, so, it is worth popularizing in the grass-root medical units.</p>

Molecular epidemiology of enterohaemorrhagic Esacherichia coli O157 in some areas in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the epidemiological characteristics of enterohaemorrhagic Escherichia coli (EHEC) O157 and to determine the degree of its genetic relations.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) techniques and chromosomal DNA digested by restriction enzyme Xba I according to PulseNet directions by pulsed field gel electrophoresis (PFGE) method were applied to 300 E. coli O157 strains isolated from patients and animal sources from 1988 to 2005 from Henan, Jiangsu and Anhui provinces.</p><p><b>RESULTS</b>Very high prevalence of stx2 gene in EHEC O157:H7 strains isolated from some provinces of China was found and variation existed in some strains. We got 161 PFGE patterns from 300 strains. The stx2-producing strains could be clearly separated from stx2 variation-producing strains.</p><p><b>CONCLUSION</b>The variability of restriction enzyme-digestion patterns of O157 genomes suggested that the presence of some genomic diversity among the strains did exist.</p>

Molecular typing of the pathogenic Yersinia enterocolitica strains with pulsed field gel electrophores isolated in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological and molecular typing features of the pathogenic Yersinia enterocolitica strains isolated in China,using pulsed field gel electrophoresis(PFGE) and standardized PFGE method as well as typing database of Yersinia enterocolitica.</p><p><b>METHODS</b>PFGE analysis was performed as Laboratory Directions for molecular subtyping of Salmonella by PFGE (PulseNet,USA) with some modifications and the results of PFGE were analyzed by BioNumerics soft (Version 4.0, Applied Maths BVBA, Belium).</p><p><b>RESULTS</b>114 O:3 Yersinia enterocolitica strains were typed by 25 patterns to have found that K6GN11C30012 (50 strains), K6GN11C30015(19 strains) and K6GN11C30016(10 strains) were the major patterns. K6GNllC30012 had 92.2% cluster similarity with K6GN11C30009-K6GN11C30023. This clone included 91.23% strains of 114 0:3 Yersinia enterocolitica strains. 51 0:9 Yersinia enterocolitica strains were typed by 14 patterns; K6GN11C90004 (22 strains) and K6GN11C90010 (13 strains)were the major patterns. K6GN11C90004 had 81.8% cluster similarity with K6GN11C90010 patterns. The major patterns of 0:3 and 0:9 serotypes were quite different.</p><p><b>CONCLUSION</b>O:3 Yersinia enterocolitica strains might originate from the same clone and had very few variation in different years and provinces but O:9 Yersinia enterocolitica strains from two different clones with some changes.</p>

Epidemiological study on an outbreak caused by E. coli O157:H7 in Jiangsu province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To carry out epidemiological study on an outbreak caused by E. coli O157:H7 infection in Jiangsu province in 1999.</p><p><b>METHODS</b>Epidemiological, microbiological and moleculebiological methods were used to find out the source, route of transmission and risk factors.</p><p><b>RESULTS</b>95 severe O157:H7 infected patients with acute renal failure in 9 counties and districts of 2 municipalities were reported in Jiangsu province, 1999 while 83 of the patients died with a death rate of 87.37%. Most patients were seen in mid or late June. The ratio of male to female was 1 to 1.44 and 88.42% of the patients were over 50 years old. 38 patients occurred in 2000 with 34 deaths. Major factors contributing to the outbreak would include without drinking tap water, eating leftover food, poor sanitary status in kitchen, not washing hands before meal and after bowl movement. 2 strain of O157:H7 was isolated from severe patients and 3 from diarrhea cases. Carrier rate among animals was up to 9.62% and 99.41% of the strains carried toxic gene. Strains isolated from feces of patients and animals belonged to the same colonies.</p><p><b>CONCLUSION</b>This outbreak was severe which caused by O157:H7 and was first seen in China, which was closely related to the high carrier rate of O157:H7 in animals and to the positive rate of high toxic gene of the strains. There were various routes of transmission and the main factors of infection would include poor personal health habits and poor sanitation of the household.</p>