Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

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.

Objective To investigate the association between RNF213 rs6565666 polymorphisms and intracranial cystic aneurysms in patients from Guangdong province. Methods Two hundred and fifty patients with intracranial cystic aneurysms, admitted to and conformed by digital substraction angiography (DSA) in our hospital from February 2016 to October 2018, were selected as experimental group; and 250 patients without intracranial aneurysms conformed by DSA, CT angiography or magnetic resonance angiography at the same time period were used as control group. The genotypes of rs6565666 locus of RNF213 gene were detected by polymerase chain reaction-ligase detection reaction (PCR-LDR). Results As compared with those in the control group, percentages of AG and AA genotypes were significantly higher and percentage of GG genotype was statistically higher at rs6565666 locus of patients from the experimental group (P<0.05). The proportion of allele A at rs6565666 locus in the experimental group was statistically higher as compared with that in the control group (P<0.05). In the experimental group, 112 patients had ruptured aneurysms and 138 patients did not have ruptured aneurysms; there was no statistically significant difference in the genotype distribution of rs6565666 between the ruptured group and the non-ruptured group (P>0.05). Conclusion RNF213 gene rs6565666 polymorphism is associated with intracranial cystic aneurysms in patients from Guangdong province.

Objective: Tests were carried out for obtaining contamination level and antimicrobial resistance of Salmonella on broiler carcasses after chilling in four poultry slaughterhouses in Henan. Methods: Totally, two hundred sixty nine broiler carcasses after chilling were collected in four slaughterhouses with the daily slaughter amount around 15 000 to 50 000. For qualitative analysis of Salmonella EFSA method was used and for quantitative analysis of Salmonella modified Rappaport-Vassiliadis most probable number (MSRV-MPN) method was used. All of the isolates were subjected to antimicrobial susceptibility testing of 8 antibiotics by minimum inhibitory concentration (MIC). Results: Overall, 48.7% (131/269) of the broiler carcasses after chilling were contaminated by Salmonella, and the average of contamination level is 1.32 most probable number MPN/g. Eight serotypes were detected. The dominant serotype is Salmonella enteritidis (93, 71.0%) followed by Salmonella Indiana (21, 16.0%). Only 2 (1.5%) Salmonella enteritidis strains were sensitive to all the tested antibiotics and the remaining 129 isolates were resistant to at least one kind of eight class antibiotics. Among them, resistant to NAL was the common (104, 79.4%) and 51 (38.9%) Salmonella isolates were multidrug-resistant. Conclusion The contamination rate and multiple antimicrobial resistant of Salmonella on broiler carcasses after chilling from slaughterhouses was very serious, while the isolates contained various serotypes.

Objective: To determine the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler production process in 4 provinces of China. Methods: Using convenience sampling method, 238 sample sites from broiler whole production process were chosen in Henan, Jiangsu, Heilongjiang and Shandong provinces in 2012. A total of 11 592 samples were collected and detected to analyze prevalence baseline, including 2 090 samples from breeding chicken farms and hatcheries, 1 421 samples from broiler farms, 5 610 samples from slaughterhouses and 2 471 samples from distribution and retail stores. All Salmonella strains were isolated through selective enrichment, and were serotyped according to Kauffmann-White scheme. The antimicrobial susceptibilities of selected Salmonella strains were determined by the broth microdilution method and fourteen antimicrobial agents were examined. Results: During incubation course, the average prevalence of Salmonella was 5.5% in feces of breeding hens, feces of chicks, and hatching eggs, 123 Salmonella strains were isolated. During cultivation course, the prevalence of Salmonella was 8.0% in feces from broiler farms, soil, feed, and workers, 114 Salmonella strains were isolated. During slaughter course, the prevalence of Salmonella was 24.9% in swabs pre-slaughter, dressed broiler carcasses, pre-cooled broiler carcasses, water from precooling pool, cutter and chipping boards, frozen chicken portions, and workers, 1 438 Salmonella strains were isolated. During distribution and sale course, the prevalence of Salmonella was 20.9% in transport carts, frozen chicken portions, retail chicken portions and workers, 551 Salmonella strains were isolated. The dominant Salmonella serotypes were Salmonella Enteritidis (n=1 229) and Salmonella Indiana (n=621). Among 1 231 examined strains, 97.2% Salmonella isolates were resistant to at least one antimicrobial, 69.9% Salmonella strains were multi-drug resistant isolates. Conclusion Our findings indicated that Salmonella contamination was common and serious in commercial broiler whole production process in China, especially in the course of defeathering, precooling and selling. The environment of broiler farm is the important source of Salmonella contamination. Additionally, antibiotic resistance of Salmonella was serious for common antimicrobials and multi-drug resistant strains existed widespread, which can pose potential risk on public health and clinical therapy.

Foodborne disease is one of the most important public health issues worldwide. China faces various and unprecedented challenges in all aspects of the food chain. Data from laboratory-based foodborne disease surveillance systems from 2013 to 2016, as well as different regions and ages, can be found along with differences in the patterns of pathogens detected with diverse characteristics. Vibrio parahaemolyticus has been the leading cause of infectious diarrhea in China, especially among adults in coastal regions. Salmonella has been a serious and widely distributed pathogen responsible for substantial socioeconomic burden. Shigella was mostly identified in Northwest China and the inland province (Henan) with less-developed regions among children under 5 years. Data from foodborne disease outbreak reporting system from 2011 to 2016 showed that poisonous animals and plant factors responsible for most deaths were poisonous mushrooms (54.7%) in remote districts in southwest regions. The biological hazard that caused most cases reported (42.3%) was attributed to V. parahaemolyticus, the leading cause of foodborne outbreaks. In this review, we summarize the recent monitoring approach to foodborne diseases in China and compare the results with those in developed countries.
Bacteria ; classification ; isolation & purification ; China ; epidemiology ; Disease Outbreaks ; Food Microbiology ; Foodborne Diseases ; epidemiology ; microbiology ; Forecasting ; Humans ; Laboratories ; Mushroom Poisoning ; epidemiology ; Population Surveillance ; Public Health

Objective To explore the effect of Willis circle variation and hemodynamic forces alteration arised from vascular structural abnormity on intracranial aneurysm (IA) rupture using 3D-digital subtraction angiography (DSA) and transcranial color Doppler (TCCD) detection.Methods Two hundred and twenty-three patients with IA,admitted to and conformed by DSA in our hospital from November 2010 to November 2011,were divided into ruptured IA group (n=182) and un-ruptured IA group (n=41).The 3D-DSA was applied in all patients to carefully evaluate the aneurysm sizes,locations,and morphous features,and to confirm the presence of A1 dominance and Willis circle variation.Moreover,aneurysmal neck area,diameter of parent artery,angle between A2 segments of bilateral anterior cerebral artery,angle between aneurysmal longitudinal axis and parent artery,aortic diameter (AD) and aspect ratio (AR) were measured with assistance of 3D-DSA images.Besides,TCCD was applied to all patients,and the hemodynamic parameters were recorded to calculate wall shear stress (WSS) and mechanical stretch.The risk factors of IA rupture were analyzed by receiver operating characteristic (ROC) curve and multivariate Logistic regression with emphasis on Willis circle variation and hemodynamic forces alteration.Results Whether it was in ruptured IA group or in un-ruptured IA group,the incidence rate of variation of anterior Willis circle was higher than that of variation of posterior Willis circle.A1 dominance on the left side was the most common asymmetry.As compared with those in un-ruptured IA group,statistically elder age,smaller AD,larger angle between aneurysmal longitudinal axis and parent artery,decreased WSS and increased mechanical stretch in the ruptured IA group were noted (P＜0.05).ROC curve indicated that angle between aneurysmal longitudinal axis and parent artery,AD,WSS and mechanical stretch could be used to evaluate IA rupture (area under the curve:0.606、0.618、0.396、0.637).Age (OR=8.618,95％CI:2.866-25.917,P=0.000),hypertension (grade Ⅲ OR=16.320,95％CI:1.628-163.556,P=0.018),angle between aneurysmal longitudinal axis and parent artery (OR=3.053,95％CI:1.131-8.242,P=0.028),AD (OR=5.638,95％CI:1.507-20.251,P=0.008) and mechanical stretch (OR=4.230,95％CI:1.554-11.516,P=0.000) were risk factors of IA rupture.A1 dominance (OR=0.242,95％CI:0.074-0.785,P=0.018),small aneurysms (2-5 mm,OR=0.207,95％CI:0.054-0.788,P=0.002) and WSS (OR=0.021,95％CI:0.060-0.672,P=0.009) were identified as protective factors.Conclusions Willis circle variation exists in IA patients.Age,hypertension (grade ⅢD,angle between aneurysmal longitudinal axis and parent artery,AD and mechanical stretch are risk factors of IA rupture,while A1 dominance,small aneurysm (2-5 mm) and WSS are identified as protective factors.Accurate assessment of these factors is of great clinical significance for the prevention and treatment of IA in the future.

Objective To investigate the feasibility and effectiveness of focused ultrasound on the acne of rabbit ear.Methods Eighteen male rabbits were randomly divided into blank control group,model control group and ultrasound irradiation group.Acne rabbit ear model was established by Kligman's method in model control group and ultrasound irradiation group.Then,continuous ultrasonic irradiation was given in ultrasound irradiation group.Pathological changes were observed at the time of before and after ultrasound irradiation and 14 days after ultrasound irradiation.Results After modeling,hair follicle expansion,hyperkeratosis,acupoint hypertrophy were observed in blank control group.Compared with blank control group,the thickness of horn layer,the sebaceous gland diameter and other index in model controlgroup were statistically significant (P＜0.01);After irradiation,there were hyperemia and edema in epidermis,angiotelectasis and inflammatory infiltrating,but coagulative necrosis in slice was not observed,14 days later,hair follicle mild expansion,mild keratosis,spiny thinning were observed in ultrasound irradiation group,when compared with model control group,the thickness of horn layer,sebaceous gland diameter and other index were decreased in ultrasound irradiation group,and the differences were statistically significant(P＜0.01).Conclusion The ultrasonic focusing treatment on rabbit ear acne is feasible and effective.

OBJECTIVETo investigate antimicrobial resistance profiles and genetic diversity of staphylococcus aureus isolated from lactating cows of 5 provinces in China, 2013.

METHODSA total of 680 samples were collected from 15 herds (12 farms, 3 artels) in 5 provinces of China in 2013, including swabs of extramammary sites (bovine teat skin and milking machine liners) and quarter milk samples from lactating cows diagnosed with subclinical mastitis. The antimicrobial resistance of the isolates were tested by broth microdilution method and the genotypes were determined by PFGE (pulsed-field gel electrophoresis) method.

RESULTSA total of 111 isolates were isolated and identified as staphylococcus aureus. Resistance to penicillin (90.1% (100/111)), erythromycin (48.6% (54/111)), ciprofloxacin (36.9% (41/111)), clindamycin (27.9% (31/111)), gentamycin (18.9% (21/111)), chloramphenicol (9.0% (10/111)), tetracycline (7.2% (8/111)) of these strains were observed. All isolates were sensitive to oxacillin, vancomycin and selectrin. 92.8% (103/111) staphylococcus aureus isolates were resistant to at least one antimicrobial. 38.7% (43/111) strains were multi-drug resistant isolates. The resistance rate of isolates in artels (100% (48/48)) was higher than it in farms (87% (55/63)) and the difference was statistically significant (χ(2) = 4.80, P < 0.05). The multi-resistance rate of isolates in artels (54% (26/48)) was higher than it in farms (27% (17/63)) and the difference was also statistically significant (χ(2) = 8.48, P < 0.05). The 111 strains were clustered into 8 types, 6 out of which were consisted of 98% isolates (109/111), and were prevalent in 2 to 9 herds. Every herd had 1 to 4 types, and tend to be comprised by one major type. Most swab isolates were indistinguishable from isolates infecting the mammary gland. There were no relationship between antimicrobial resistance profiles and genotypes of these isolates.

CONCLUSIONThe drug resistance of staphylococcus aureus isolates associated with lactating cows of 5 provinces in China is serious, especially the isolates collected from artels. A few specialized clones were responsible for most of the cases of bovine mastitis in a single herd and some clones might have a broad geographic distribution.

Animals ; Anti-Bacterial Agents ; Cattle ; China ; Drug Resistance, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; Female ; Genetic Variation ; Genotype ; Humans ; Lactation ; Mastitis, Bovine ; Microbial Sensitivity Tests ; Milk ; Staphylococcal Infections ; epidemiology ; Staphylococcus aureus ; genetics

OBJECTIVETo explore the phenetic and genetic features of clinical Vibrio parahaemolyticus strains from 2007-2009 in China.

METHODSA total of 135 clinical Vibrio parahaemolyticus strains, isolated from Zhejiang, Jiangsu, Sichuan, Guangxi, Liaoning Provinces during 2007 to 2009, were selected for the research. The occurrence of virulence genes thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh), species-specific genes thermolabile hemolysin (tlh), toxR, VPM and gyrB, the pandemic clone gene markers(GS-PCR, PGS-PCR, orf8 and HU-α) in 135 Vibrio parahaemolyticus strains was detected by PCR. The antimicrobial susceptibilities to eight antimicrobial agents of the experimental strains were determined by the broth microdilution method. All strains were serotyped and underwent the cluster analysis with pulsed-field gel electrophoreses.

RESULTSThe results of PCR methods claim that all experiment strains carry species-specific genes such as tlh, toxR, gyrB, VPM. Among clinical strains, 85.9% (116/135) carry tdh and/or trh. 85.2% (115/135) were positive for tdh, and 3.0% (4/135) were positive for trh; while 3 strains carried both.66.7% (90/135) , 80.7% (109/135) , 65.2% (88/135) , 66.7% (90/135) clinical strains carried the genes of GS-PCR, PGS-PCR, orf8, HU-α, respectively. The results of antibiotics susceptibility test showed that 8.1% (11/135) strains were resistant to at least one agent, including 9 strains were resistant to ampicillin, 2 strains were resistant to trimethoprim and sulphamethoxazole, and 1 strain were resistant to tetracycline. All clinical strains were sensitive to cefotaxime, ceftazidime, gentamicin, ciprofloxacin and chloromycetin.Serological analysis of the O and K antigens claimed that a total of 29 serotypes were identified for clinical strains, predominantly O3, O4 and O1 groups, accounting for 89.6% (121/135). O3: K6 was dominant serotype, accounting for 56.3% (76/135). The pandemic flora in China included O3: K6, O4: K68, O1: K36, O1: K25, O1: K5 and O3: K29 serotypes.Genomic DNAs of 135 clinical strains were digested with SfiI and NotI, the molecular size of PFGE restriction fragments used for analysis mainly ranged from 30-700 kb.When subjected to UPGMA clustering, 6 and 9 clusters were grouped by SfiI and NotI, and the minimal similarity was 52.6% and 58.7%, and pandemic flora were located in C groups and D group, respectively.

CONCLUSIONMost of Vibrio parahaemolyticus strains isolated from clinical sources in China were pathogenic. The pandemic clone, especially O3: K6 was prevalent. The GS-PCR and HU-α genes were reliable markers to identify the pandemic flora. The serotype by PFGE was reliable to distinguish the pandemic flora and the sporadic strains.

China ; epidemiology ; Drug Resistance, Bacterial ; Genes, Bacterial ; Humans ; Molecular Epidemiology ; Vibrio Infections ; epidemiology ; microbiology ; Vibrio parahaemolyticus ; genetics ; isolation & purification ; pathogenicity ; Virulence ; genetics