Epidemiological characteristics of Yersinia enterocolitica in patients with diarrhea from 2013 to 2019 in Pudong New Area, Shanghai / 中华预防医学杂志

Objective: To investigate the epidemiological characteristics of Yersinia enterocolitica in patients with diarrhea in Pudong New Area, Shanghai. Methods: Active surveillance of diarrhea was conducted in 14 sentinel hospitals (three tertiary-level hospitals, nine secondary-level hospitals, and two primary-level hospitals) from January 2013 to December 2019 in Pudong New Area of Shanghai, China base on their location, catchment area, and patient volume. Cold enrichment method was used to isolate Y. enterocolitica and further detection of bioserotype, virulence genes and antimicrobial susceptibility of the isolates were conducted. The difference of rates was determined using chi-square test or Fisher's exact test. Results: A total of 12 941 diarrhea cases were included, and 0.7% (88/12 941) cases were confirmed with Yersinia enterocolitica infection. 67.0% (59/88) cases were single infection, 33.0% (29/88) cases were mixed infections. Detection rates of Y. enterocolitica increased annually (0.3%-1.2%) and were highest in children<5 years of age (1.1%, 37/3 218) and in spring (1.1%, 32/2 998) (χ2 were 18.64 and 9.76, respectively, P<0.05). 58.0% (51/88) cases had watery diarrhea, 15.9% (14/88) had fever and 14.8% (13/88) had vomiting. The predominant bioserotypes were 3/O:3 (53.4%, 47/88), followed by 1A/O:8 (15.9%, 14/88) and 1A/O:5(6.8%, 6/88), respectively. Bioserotype 3/O:3 counted for the highest proportions (89.2%, 33/37) in children <5 years of age. All the strains of bioserotype 3/O:3 harbored ail, ystA, yadA and virF genes, which encoded pathogenic Y. enterocolitica. 11/14 strain of 1A/O:8 and 4/6 strains of 1A/O:5 harbored ystB gene. Most strains were resistant to ampicillin (80.7%,71/88) and amoxicillin/clavulanic acid (71.6%,63/88), and 63.8% (56/88) strains were multidrug resistance (MDR). The difference of antimicrobial resistance rates between 3/O:3 and non 3/O:3 was statistically significant in ampicillin, cefoxitin, nalidixic acid, tetracycline and ampicillin/sulbactam (χ2 was 14.68, 43.80, 41.86, 30.54 and 5.07, respectively, P<0.05). Conclusion: The detection rate of Yersinia enterocolitica was higher in children than in adults in Pudong New Area , Shanghai. The predominant bioserotype was pathogenic 3/O:3 with multidrug resistance.

Salmonella serotyping and molecular subtyping analysis on diarrhea cases in Hongkou District of Shanghai, in 2010-2012 ZHANG Jing1,SHEN Jing1,TANG Yi-ling1,CHEN Zhen1,YAO Hong1,WANG / 上海预防医学

Objective ] To study the molecular characteristics and antibiotic resistance of Salmonella diarrhea cases in sentinel hospitals through active surveillance system conducted by public health laboratory. [ Methods] Two sentinel hospitals were chosen for collection of stool specimens from food-borne infectious diarrhea cases and for Salmonella separation and detection immediately following serotyping and antimicrobial susceptible test ( AST ) on those isolates .Moreover , pulsed field gel electrophoresis ( PFGE) was used for the genetic homology analysis . [ Results] A total of 2 579 diarrhea specimens were collected and analyzed from 2010 to 2012, with 185 Salmonella isolates, covering 23 different serotypes (annual positive rates were 9.1%, 6.8%, 5.1%, with an average 7.2%).Salmonella enterica serovar Enteritidis(S.Enteritidis) and Typhimurium(S.Typhimurium) were the most common serotypes, of which 68.9% cases were seen in those aged 21 to 60 and 21.4% cases in those over 60 years old. 27.7%-96.9%S.Enteritidis and 2.6%-63.2% S.Typhimurium(P all <0.05) proved resistant to Nalidixic acid, Sultisoxazole, Streptomycin, Sulfamethoxydiazine, Gentamicinand Tetracycline. PFGE analysis on 22 S.Enteritidis strains showed 11 different clusters , while 20 S.Typhimurium strians showed 6. [Conclusion] S.Enteritidis and S.Typhimurium are the most common Salmonella serotypes, and molecular typing indicates the existence of clustering and sporadic outbreaks caused by dominance clones . We should be alert to early warnings on potential outbreaks of multiple-drug-resistant ( MDR ) S.Enteritidis.Active surveillance system based on public health laboratory should play an important role in the control of food-borne infectious diseases .

Assessment and application of a molecular diagnostic method on the detection of four types of diarrheagenic Escherichia coli / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish and evaluate a molecular diagnostic method for routine monitoring of four types of diarrheagenic Escherichia (E.) coli (DEC)and to study the distribution of four types of DEC isolated from diarrheal patients in Shanghai.</p><p><b>METHODS</b>DEC-PCR standard operation procedure(SOP)had been developed for DEC detection and isolation, using the Statens Serum Institute (SSI) DEC PCR kits with multiplex PCR technique after verification tests on reference strains. Diarrhea specimens from 3 clinical hospitals in Shanghai were tested from June to September, 2012.</p><p><b>RESULTS</b>Specificity of the PCR kit was 100% by verification on the 26 DEC reference strains. A total number of 218 DEC isolates, including 181 fermented lactose and 37 unfermented lactose were identified from the 1887 stool specimens of diarrhea patients, with positive rate as 11.6%. The most common pathogen(54.1%, 118/218)was enteropathogenic E. coli(EPEC), followed by enterotoxigenic E. coli(ETEC, 41.3%, 90/218), enteroinvasive E. coli (EIEC, 4.1%, 9/ 218) and Shigatoxin-producing E. coli(STEC, 0.5%, 1/218)in addition to 18 Shigella isolates. ETEC dominated in diarrhea patients with foreign residency, as well as 1/3 were perinatal stage of neonatal ETEC of all diarrhea cases under the age of 5, while EPEC dominated in the Chinese diarrhea patients especially among young kids under the age of 2.</p><p><b>CONCLUSION</b>Data was reliable after assessment on this molecular diagnostics and seperation procedures used for the routine monitoring on four types of DEC, while the diagnosis and reference ability of DEC regarding the laboratories net-working on food-borne pathogens need to be built up and improved.</p>

The fundamental role of stage control technology on the detectability for Salmonella networking laboratory / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluated the fundamental role of stage control technology (SCT) on the detectability for Salmonella networking laboratories.</p><p><b>METHODS</b>Appropriate Salmonella detection methods after key point control being evaluated, were establishment and optimized. Our training and evaluation networking laboratories participated in the World Health Organization-Global Salmonella Surveillance Project (WHO-GSS) and China-U.S. Collaborative Program on Emerging and Re-emerging infectious diseases Project (GFN) in Shanghai. Staff members from the Yunnan Yuxi city Center for Disease Control and Prevention were trained on Salmonella isolation from diarrhea specimens. Data on annual Salmonella positive rates was collected from the provincial-level monitoring sites to be part of the GSS and GFN projects from 2006 to 2012.</p><p><b>RESULTS</b>The methodology was designed based on the conventional detection procedure of Salmonella which involved the processes as enrichment, isolation, species identification and sero-typing. These methods were simultaneously used to satisfy the sensitivity requirements on non-typhoid Salmonella detection for networking laboratories. Public Health Laboratories in Shanghai had developed from 5 in 2006 to 9 in 2011, and Clinical laboratories from 8 to 22. Number of clinical isolates, including typhoid and non-typhoid Salmonella increased from 196 in 2006 to 1442 in 2011. The positive rate of Salmonella isolated from the clinical diarrhea cases was 2.4% in Yuxi county, in 2012. At present, three other provincial monitoring sites were using the SBG technique as selectivity enrichment broth for Salmonella isolation, with Shanghai having the most stable positive baseline.</p><p><b>CONCLUSION</b>The method of SCT was proved the premise of the network laboratory construction. Based on this, the improvement of precise phenotypic identification and molecular typing capabilities could reach the level equivalent to the national networking laboratory.</p>

Characteristics of Salmonella enterica serovar Senftenberg lacking Salmonella pathogenicity island 1 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the characteristics of the strains of Salmonella enterica (S. enterica) serovar Senftenberg lacking Salmonella pathogenicity island 1 (SPI-1).</p><p><b>METHODS</b>A total of 10 strains of S. enterica serovar Senftenberg were isolated from 10 cases of diarrhea patients. Pulsed field gel electrophoresis (PFGE), PCR, sequencing techniques and cell invasion test were adapted to study the molecular types and invasiveness of the genes and cells; and made a comparison between the 10 strains and the strains (C02013) isolated in Shenzhen in 2002.</p><p><b>RESULTS</b>The 10 Senftenberg isolated (S09007-S09012, S09014-S09017) in Shanghai showed three PFGE patterns, which were significantly different from the strains isolated in Shenzhen. PCR-amplified results indicated the invasion gene (invA), secreted effector protein gene (sipA) and gene fragments as fhlA-hilA, hilA-spaP and spaP-invH in the 10 strains of SPI-1 were all negative. The sequencing results revealed that the 10 strains isolated in Shanghai lacked most parts of SPI-1 genes, as fragments from orgA to invH and parts of orgA gene itself; however, compared with strains isolated in Shenzhen, the sprB-orgC gene existed. The missing parts of genes were replaced by a simple insertion sequence (IS) of 1000 bp in the strains isolated both in Shenzhen in 2002 and in Shanghai in 2006. The invasiveness rates of the 10 strains (S09007-S09012, S09014-S09017) towards Hela cells were (0.0053 ± 0.0024)%, (0.0046 ± 0.0006)%, (0.0047 ± 0.0003)%, (0.0064 ± 0.0012)%, (0.0065 ± 0.0011)%, (0.0070 ± 0.0020)%, (0.0115 ± 0.0030)%, (0.0099 ± 0.0039)%, (0.0180 ± 0.0135)% and (0.0031 ± 0.0012)%, respectively; which were all significantly lower than the rate of invA-positive control strain STM1344 ((5.0800 ± 0.6333)%); lower or close to the rate of invA-lacked artificial-mutated strain STMinvA-((0.0193 ± 0.0045)%).</p><p><b>CONCLUSION</b>SPI-1 genes are not essential for the diarrhea caused by S. enterica serovar Senftenberg.</p>

Effect of PG0839 gene of Porphyromonas gingivalis on inflammatory cytokine in human oral epidermoid carcinoma KB cell / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of PG0839 gene form Porphyromonas gingivalis (Pg) on inflammatory cytokine expression in human oral epidermoid carcinoma KB cell.</p><p><b>METHODS</b>A mutant in the PG0839 gene of Pg was created by insertional inactivation. Group 1 was chanllenged with PgW83 strain, group 2 with PG0839-defective mutant, and the control group with Dulbecco's modified Eagle's medium only. KB cells were co-cultured with presence of bacteria for 24 h. At the time point of 0.5, 2, 6, 12 and 24 h, cells were stored in Trizol. The mRNA expression of interleukin-1β (IL-1β) and Toll like recepector-4 (TLR-4) was examined by reverse transcription polymerase chain reaction.</p><p><b>RESULTS</b>At 2 h and 6 h, IL-1β mRNA expression was lower in group 2 than in group 1 (2 h: 0.31 ± 0.11 versus 0.95 ± 0.48, P < 0.05; 6 h: 0.57 ± 0.20 versus 1.29 ± 0.55, P < 0.05). At 0.5 h and 6 h, TLR-4 mRNA expression was lower in group 2 than in group 1 (0.5 h: 0.20 ± 0.09 versus 0.58 ± 0.09, P < 0.05; 6 h: 0.34 ± 0.04 versus 0.71 ± 0.18, P < 0.05).</p><p><b>CONCLUSIONS</b>PG0839 gene may play an important role in Pg-induced inflammatory effects of KB cell.</p>

Study on the epidemiological characteristics and molecular typing of Salmonella enterica subsp. enterica serovar Senftenberg in Shanghai / 中华流行病学杂志

ation were complicated, with the characteristics as the obvious decreasing number of patients, with no food-borne isolates in 2007.

Study of caries polarization in 2-5 year-old children of Shenyang, China / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate dental caries polarization in 2-5 year-old children.</p><p><b>METHODS</b>3 799 random samples of 2-5 year-old children from attending kindergarten in Shenyang were selected. Means of dmft index and SiC index for each age group were calculated by WHO Collaborating Center. The subjects of each age group were further divided into subgroups of different level of dmft: the dmft of subgroup I was 0, the dmft of subgroup II was 1, the dmft of subgroup III was 2, the dmft of sub-group IV was equal to or more than 3. The obtained data were analyzed statistically with SPSS 10.0.</p><p><b>RESULTS</b>4.5% of 2-year-old children were carriers of 60.0% of the total dmft in that age group, 13.2% of 3-year-old children were carriers of 69.4% of the total dmft in that age group, 34.4% of 4-year-old children were carriers of 86.6% of the total dmft in that age group, and 47.8% of 5-year-old children were carriers of 89.8% of the total dmft of that age group.</p><p><b>CONCLUSION</b>This study supports the assertion that a small percentage of persons with high dental caries rate and a large percentage of caries-free persons of early childhood caries.</p>