1. Prevalence and antimicrobial susceptibility of Salmonella isolated from broiler whole production process in four provinces of China
Weiwei LI ; Li BAI ; Xiuli ZHANG ; Xiaojie XU ; Zhen TANG ; Zhenwang BI ; Yunchang GUO
Chinese Journal of Preventive Medicine 2018;52(4):352-357
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
2.Association between RNF213 rs6565666 polymorphism and intracranial cystic aneurysms in patients from Guangdong Province
Haiyan FAN ; Shenquan GUO ; Yunchang CHEN ; Xin ZHANG ; Xifeng LI ; Xuying HE ; Chuanzhi DUAN
Chinese Journal of Neuromedicine 2019;18(3):238-242
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.
3.Study on detection of Salmonella in poultry samples by real-time PCR with Taqman probes.
Lin YAN ; Xiaoying WANG ; Yunchang GUO ; Xiaoyan PEI ; Dongmin YU ; Dajin YANG
Chinese Journal of Preventive Medicine 2014;48(8):731-735
OBJECTIVETo develop a RT-PCR method for a rapid and sensitive detection of Salmonella in poultry samples.
METHODSThe RT-PCR method was established and its specificity was testified on the basis of invA gene. Serial 10-fold diluted pure suspension culture of CMCC 50041 was detected by RT-PCR, the standard curve was constructed and the amplification efficiency was calculated. Artificially contaminated experiment was done, six artificially-inoculated samples containing final concentration of Salmonella CMCC 50041 (1, 10, 10(2), 10(3), 10(4), 10(5) and 10(6) CFU per 25 g poultry samples) were prepared respectively. All the samples were incubated for 0, 4, 8, 12 and 18 h and the DNA was extracted for RT-PCR detection, meanwhile by PCR detection and the traditional method. The sensitiveness and specificity were compared among the three methods. At the same time, 16 samples of retail whole poultry were collected from markets and detected by the above three methods as well, and thereby to further compare the positive detection among the three methods.
RESULTSThe established RT-PCR method was specific for the detection of Salmonella. The sensitivity was 5.2×10(3) CFU/ml for pure Salmonella culture without enrichment. Correlation coefficients of standard curves constructed using the Ct versus log value of concentration of Salmonella showed good linearity over a 8-log dynamic range (5.2×10(3)-5.2×10(10) CFU/ml), with the R(2) at 0.999. RT-PCR detection limit for artificially contaminated samples after enriching for 12 h was 1 CFU/25 g sample, which was the same with the limit of PCR and 10 times more sensitive than the limit of traditional method. Standard curve of sample after enrichment for 12 h was established. Seven of 16 samples were detected positive by RT-PCR, which were also tested positive by PCR, while only five samples were positive by traditional method. The positive ones were quantitatively analyzed using standard curve of sample and determined the initial Salmonella numbers of CFU/25 g.
CONCLUSIONThe established RT-PCR technology was simple, rapid, sensitive and specific, which was suitable to quickly detect Salmonella in poultry samples.
Animals ; Bacterial Proteins ; Food Microbiology ; Poultry ; Real-Time Polymerase Chain Reaction ; methods ; Salmonella ; Sensitivity and Specificity
4.Epidemiological characteristics of Salmonella in animal source foods in Hunan.
Huayun JIA ; Lidong GAO ; Yunchang GUO ; Weiwei LI ; Lan WANG ; Shuai CHEN ; Hong ZHANG
Chinese Journal of Preventive Medicine 2014;48(8):699-704
OBJECTIVETo study the molecular epidemiological characteristics of Salmonella in animal source foods in Hunan.
METHODSThe fair trade markets and supermarkets of ten cities were chosen to sample animal source foods for isolating Salmonella in Hunan province in 2010. A total of 692 samples were collected by aseptic sampling, included 159 livestock meats, 152 poultry meats, and 381 aquatic products.Salmonella strains isolated were subjected to stereotyping, antimicrobial susceptibility testing and pulsed field gel electrophoresis (PFGE).
RESULTSSalmonella was detected in 93 of 692 animal food samples with the detection rate of 13.4%. The detection rates of Salmonella in poultry meats, livestock meats and aquatic products were 23.0% (35/152), 22.6% (36/159) and 5.8% (22/381) respectively. Therefore, the detection rate in aquatic products was lower than that of poultry meats and livestock meats (χ(2) = 33.86, P < 0.05; χ(2) = 33.29, P < 0.05, respectively). The serotypes of isolates showed diversity, and Salmonella Derby (33/94, 35.1%) was the predominant serotypes.79.8% (75/94) strains showed resistant to more than one antibiotic used in the test, 31.9% (30/94) strains showed resistant to more than 5 antibiotics. A significant difference was observed for multidrug resistance between Salmonella isolated from poultry (47.2%, 17/36) and livestock meats (22.2%, 8/36) (χ(2) = 4.96, P < 0.05). And the highest resistant rate was found in tetracycline, as high as 62.8% (59/94). All the strains were divided into 69 PFGE subtypes.Furthermore the dominating subtypes were type 7 (6 strains), type 15 (4 strains), type 22 (6 strains).
CONCLUSIONInspection results showed that Salmonella contamination in animal source foods were serious in Hunan province, and the isolates expressed high level resistance to the antibiotics.Furthermore the PFGE results indicated that there were epidemic strains of Salmonella in Hunan.
Animals ; Anti-Bacterial Agents ; China ; epidemiology ; Drug Resistance, Multiple, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Food Microbiology ; Meat ; microbiology ; Microbial Sensitivity Tests ; Poultry ; microbiology ; Salmonella ; classification ; Salmonella enterica ; Seafood ; microbiology ; Tetracycline Resistance
5.Antimicrobial resistance profiles and genetic diversity of bovine staphylococcus aureus isolated in 5 provinces of China in 2013.
Wei WANG ; Xiaojie YU ; Xiaorong YANG ; Lingling MEI ; Wenying GUAN ; Guozhu MA ; Weiwei LI ; Yunchang GUO
Chinese Journal of Preventive Medicine 2014;48(5):406-411
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
6.Analysis of molecular features of clinical Vibrio parahaemolyticus strains in China.
Weiwei LI ; Lingling MEI ; Zhen TANG ; Xiaorong YANG ; Xiugui LI ; Xiaoyan PEI ; Gang WANG ; Ping FU ; Yongning WU ; Yunchang GUO
Chinese Journal of Preventive Medicine 2014;48(1):44-52
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
7. Surveillance of contamination level and antimicrobial resistance analysis of Salmonella on broiler carcasses after chilling in 4 poultry slaughterhouses of Henan Province
Li BAI ; Weiwei LI ; Haihong HAN ; Jikai LIU ; Ping FU ; Xiuli ZHANG ; Yunchang GUO
Chinese Journal of Preventive Medicine 2018;52(2):124-128
Objective:
Tests were carried out for obtaining contamination level and antimicrobial resistance of
8.Multivariate predictors of intracranial aneurysm rupture by regression analysis of Willis circle variation and hemodynamic forces alteration arised from vascular structural abnormity
Xin ZHANG ; Zhiqiang YAO ; Chuanzhi DUAN ; Xifeng LI ; Xuying HE ; Shenquan GUO ; Yunchang CHEN ; Wenchao LIU ; Ran LI ; Haiyan FAN
Chinese Journal of Neuromedicine 2018;17(3):282-289
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.
9.Therapeutic effect of focused ultrasound on rabbit ear acnevv
Xiaoyong DONG ; zhangyou GUO ; Qingyi LI ; Yunchang LIU ; Yu TIAN ; Fangying ZHONG ; Jianzhong ZOU
Chongqing Medicine 2017;46(34):4763-4765,4770
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.
10. Interpretation for the group standards of the Isolation and Identification of Campylobacter jejuni and Campylobacter coli
Maojun ZHANG ; Yixin GU ; Ying LI ; Changyan JU ; Guilan ZHOU ; Yunchang GUO ; Xiaojie YU ; Yongxiang DUAN ; Jianzhong ZHANG
Chinese Journal of Epidemiology 2019;40(9):1052-1054
Foodborne