Interpretation for the group standards of the Isolation and Identification of Campylobacter jejuni and Campylobacter coli / 中华流行病学杂志

Foodborne Campylobacter is recognized as the leading causes of the bacterial diarrheal illness in both developing and developed countries. C. jejuni and C. coli caused 95% of the human campylobacterisosis. Bacteria culture has been recognized as the "Gold standard" for the diagnosis of the Campylobacter infection. The National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention coordinated the experienced researchers from China National Center for Food Safety Risk Assessment and other local Centers for Disease Control and Prevention to write up the standards for entitled Isolation and Identification of Campylobacter jejuni and Campylobacter coli (T/CPMA 006-2019). The standard is drafted with principles of emphasizing the scientific, normative, applicability and feasible nature. This group standard recommended the procedures and steps for the isolation and identification of C. jejuni and C.coli from variant samples. The standard aims to improve the capacity for Campylobacter identification in China.

Antibiotic-resistant genes and multilocus sequencing typing of Pseudomonas aeruginosa / 中国人兽共患病学报

We investigated the antibiotic‐resistant genes and genetic diversity of Pseudomonas aeruginosa from patients in hospital ,the smear samples from hospital and clinic environment ,and from medical staff’ hands respectively in 2011‐2012 in Nanshan District of Shenzhen .Polymerase chain reaction were used to detect the 20 kinds of antibiotic‐resistant genes (TEM , VEB,CARB,OXA,SHV,PER,GES,GTX,SPM,GIM,IMP,VIM,DHA,oprD,Aac(6′)‐Ⅰ ,Aac(6′)‐Ⅱ ,Aac (3′)‐Ⅰ ,A ac(2″)‐Ⅰ ,qacE1‐sull and int‐Ⅰ) .Multilocus sequencing typing was used to analyze the clonal complexes .The 11 kinds resistant genes TEM ,SHV ,IMP ,DHA ,Aac(6′)‐Ⅰ ,Aac(6′)‐Ⅱ ,Aac(3′)‐Ⅰ ,Aac(2″)‐Ⅰ ,qacE1‐sull ,int‐Ⅰand oprD were detected ,for the positive rates respectively ,and which were 8 .1% ,6 .4% ,4 .8% ,9 .7% ,4 .8% ,14 .5% ,9 .7% , 56 .5% ,8 .1% ,and 8 .1% ;the loss rate of oprD gene was 61 .2% .The 19 antibiotic resistance gene profiles existed in 52 Pseudomonas aeruginosa strains .Multilocus sequencing typing found 39 sequence types and 5 clonal complexes in 62 Pseudo‐monas aeruginosa strains ,CC244 and ST856 were dominant .There were some differences of antibiotic resistance gene profiles between different samples ,the Pseudomonas aeruginosa strains from patients carried multiple resistant genes .In our research , the Pseudomonas aeruginosa had the genetic diversity and the dominant clonal complexes existed .

Genetic characterization of Vibrio parahaemolyticus O3: K6 serovariant isolated in Shenzhen / 中华预防医学杂志

<p><b>OBJECTIVE</b>To characterize the O3: K6 serovariant of Vibrio parahaemolyticus on virulence gene and molecular typing, and analyze the genetic relationship between O3: K6 and O3: K6 serovariants.</p><p><b>METHODS</b>PFGE was performed on 115 strains of V.parahaemolyticus which were collected from the anal swab of cases of foodbrone diseases in Shenzhen during 2006-2012. According to isolation times and locations, 7 strains of O3: K6 were selected as control strains. Tdh gene, trh gene, orf8 gene were detected, GS-PCR, multi-locus sequence typing (MLST) were used to chracterize 7 strains of O3: K6 and O3: K6 serovariants.</p><p><b>RESULTS</b>PFGE indicated that 58.3% (67/115) of V. parahaemolyticus strains shared a high similarity of band pattern (similarity > 80%) , which comprised of O3: K6 (44/67), O1: KUT(4/67), and O3: K6 serovariants(19/67). Among the O3: K6 serovariants, O1: K25 accounted for 7% (5/67), O4: K68 accounted for 10% (7 /67), O11: K36 accounted for 10% (7 /67). They all carried both tdh and trh gene, and 53% (10/19) was GS-PCR positive and carried orf8 gene, 26% (5/19) was both GS-PCR and orf8 gene negative, 21% (4/19) was GS-PCR negative, orf8 gene positive, 89% (17/19) was assigned to ST-3, 11% (2/19) was assigned to ST-305. Seven strains of O3: K6 was GS-PCR positive, carried orf8 gene, assigned to ST-3. ST-305 and ST-3 had differences in 2 housekeeping genes, which was dtdS gene and pntA gene. In the 305th base of dtdS gene, ST-305(147 allele profile) was T, while ST-3(4 allele profile) was C. In the 33th base of pntA gene, ST-305(93 allele profile) was T, while ST-3(29 allele profile ) was C.</p><p><b>CONCLUSION</b>O4: K68,O1: K25 and O11: K36 were highly similar in virulencec gene carriage, MLST type of O3: K6, and aslo shared a close genetic relationship with O3: K6, thus were considered as O3: K6 serovirants.</p>