1.Active surveillance on Listeria monocytogenes in seven kinds of food in 11 provinces of China in 2001.
Shu-yu WU ; Ying-hui LI ; Lu RAN ; Ping FU ; Zhi-gang LI ; Jing-hui YAO
Chinese Journal of Epidemiology 2003;24(8):657-660
OBJECTIVETo carry out national active surveillance on Listeria monocytogenes in foods in China.
METHODSFour thousand and thirty-four random samples from raw meat, meat product, raw milk, vegetable, yoghurt, icecream and aquatic product were collected in 11 provinces (cities), and examined for Listeria monocytogenes according to the national standard method and confirmed by BAX system (DuPont Qualicon, Wilmington, DE).
RESULTSSeventy isolates four kinds of foods in seven provinces were found to have LM according to the national standard method with a total isolate rate of 1.74%. In Fujian, the rate was higher than in the other provinces. Raw meat was found to be most heavily contaminated in seven kinds of foods. Comparing to national standard method, BAX system showed good sensitivity (> 98%) and specificity (> 97%).
CONCLUSIONIn each province seven kinds of food were all contaminated by Listeria monocytogenes to some degrees, suggesting that local sanitary surveillance should be strengthened. BAX system can be used to correctly and quickly screen Listeria monocytogenes.
Animals ; Cattle ; China ; Food Microbiology ; Listeria monocytogenes ; isolation & purification ; Meat ; microbiology ; Meat Products ; microbiology ; Milk ; microbiology ; Seafood ; microbiology ; Sensitivity and Specificity ; Sheep ; Swine
2.Risk assessment of Listeria monocytogenes in deli meats and vegetable salads.
Chinese Journal of Preventive Medicine 2009;43(9):781-784
OBJECTIVETo analysis risk from Listeria monocytogenes in deli meats and vegetable salads.
METHODSUse Risk Ranger which is a software programme developed by the University of Hobart, Australia and answer 11 questions on affecting the risk from hazards in the specific foods by combining data from national foodborne diseases surveillance network and some references to make semi-quantitative risk assessment for the specific food.
RESULTSRelative risk from Listeria monocytogenes in deli meats and vegetable salads is 61 and 52, respectively. Incidence of listeriosis caused by deli meats-Listeria monocytogenes pairs and vegetable salads-Listeria monocytogenes pairs is 5.4 and 0.2 cases per million people, respectively. Risk from the former is 32 times than that from the latter. By changing the selection for some risk factors in the model, it was known that the risks from two food-hazard combinations could decrease 10 times, if taking necessary actions after processing.
CONCLUSIONDeli meats is a kind of high risk food for listeriosis.
Food Microbiology ; Listeria monocytogenes ; isolation & purification ; Meat Products ; microbiology ; Risk Assessment ; Vegetables ; microbiology
3.Prevalence and Molecular Epidemiology of Vancomycin-Resistant Enterococci (VRE) Strains Isolated from Animals and Humans in Korea.
Joon Young SONG ; In Sook HWANG ; Joong Sik EOM ; Hee Jin CHEONG ; Won Ki BAE ; Yong Ho PARK ; Woo Joo KIM
The Korean Journal of Internal Medicine 2005;20(1):55-62
BACKGROUND: To assess the possibility of VRE transmission from animals to humans, we studied the prevalence of vancomycin-resistant enterococci (VRE) in farm animals, raw chicken meat, and healthy people. We then determined the molecular relatedness of VRE isolates between animals and humans in Korea. METHODS: We aimed to isolate VRE from 150 enterococci specimens of farm animals, 15 raw chicken meat samples, and stools from 200 healthy people. Species differentiation was done with conventional biochemical tests. Vancomycin resistance genotyping was done by polymerase chain reaction (PCR). Using the agar dilution method, antimicrobial susceptibility was tested for 8 antimicrobials and pulsed-field gel electrophoresis (PFGE) was done to evaluate the molecular relatedness of VRE isolates. RESULTS: The prevalence of VRE was 14.7% (22/150) in farm animal specimens, 1% (2/200) in healthy people, and 60% (9/15) in raw chicken meat. Of 22 animal VRE isolates, 1 vanA E. faecium, 15 vanC1 E. gallinarum, and 6 vanC2 E. casseliflavus were identified. All of the 9 VRE from raw chicken meat and all of the 20 clinical VRE strains were vanA E. faecium. However, in healthy people, only 2 vanC2 E. casseliflavus were isolated. These showed low-level resistance to vancomycin and susceptibility to teicoplanin. However, 9 VRE strains from raw chicken meat had high-level resistance to vancomycin (MIC50, 90: > 128 microgram/mL), teicoplanin (MIC50, 90: > 128 microgram/mL), ampicillin (MIC50, 90: > 128 microgram/mL), erythromycin (MIC50, 90: > 128 microgram/mL), and tetracycline (MIC50/90: 128/> 128 microgram/mL). CONCLUSION: This study demonstrated little evidence of VRE colonization in healthy people despite high recovery of VRE among raw chicken meat. It is suggested that there is little evidence of VRE transmission from animals to healthy people. However, we assumed that there exists the possibility of VRE contamination during the processing of chicken meat.
Animals
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Cattle/microbiology
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Chickens
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Enterococcus/*drug effects/*isolation & purification
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Feces/microbiology
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Humans
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Korea
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Meat/microbiology
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Prevalence
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Research Support, Non-U.S. Gov't
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Swine/microbiology
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*Vancomycin Resistance
4.Rapid detection of Vibrio cholerae by loop mediated isothermal amplification (LAMP) method.
Yigang XU ; Sulong LI ; Dandan LI ; Hongxiang ZHANG ; Yanchun JIANG
Chinese Journal of Biotechnology 2010;26(3):398-403
Vibrio cholerae is an important foodborne pathogen, mainly causes acute intestinal infectious disease. The development of rapid method for detecting Vibrio cholerae is critical for early diagnosis of its infection. In this study, two pairs of specific primers were designed according to housekeeping gene mdh of Vibrio cholerae. Following optimization of the reaction, DNA loop-mediated isothermal amplification (LAMP) for rapidly detecting Vibrio cholerae was successfully established. The optimal reaction for the LAMP assay is 65 degrees C for 60 min, with detection limit for cultivated Vibrio cholerae of 25 CFU/mL and for its contaminated food of 32 CFU/g. The specificity of the assay was determined using thirty-three kinds of same species or closely related bacteria, only Vibrio cholerae strains were specifically amplified. In practice, 85 pieces of positive samples were detected from 1057 pieces of shrimps, crabs, oysters, meat and human diarrhea complex using the LAMP method, which accorded with the detection result by ISO TS 21872-1-2007. Thus, the LAMP assay established in this study is a sensitive, rapid and simple tool for detecting Vibrio cholerae and will facilitate the surveillance for its control.
Cholera
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microbiology
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Food Microbiology
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methods
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Meat
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microbiology
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Nucleic Acid Amplification Techniques
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methods
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Seafood
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microbiology
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Sensitivity and Specificity
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Vibrio cholerae
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genetics
;
isolation & purification
5.Prevalence and molecular characteristics of Listeria monocytogenes in cooked products and its comparison with isolates from listeriosis cases.
Hong WANG ; Lijuan LUO ; Zhengdong ZHANG ; Jianping DENG ; Yan WANG ; Yimao MIAO ; Ling ZHANG ; Xi CHEN ; Xiang LIU ; Songsong SUN ; Bo XIAO ; Qun LI ; Changyun YE
Frontiers of Medicine 2018;12(1):104-112
This study aimed to investigate the prevalence and molecular characteristics of Listeria monocytogenes in cooked products in Zigong City, China. The overall occurrence of the L. monocytogenes in the ready-to-eat (RTE) shops and mutton restaurants surveyed was 16.2% (141/873). An occurrence of 13.5% was observed in RTE pork, 6.5% in RTE vegetables, and more than 24.0% in either cooked mutton or cooked haggis. Serotype 1/2b (45.4%), 1/2a (33.3%), and 1/2c (14.2%) were the predominant types. By comparing the clonal complexes (CCs) based on multilocus sequence typing (MLST) of the L. monocytogenes from cooked foods in Zigong City and 33 listeriosis cases from different districts of China, CC87, CC9, CC8, and CC3 were showed to be prevalent in cooked products and CC87 and CC3 were the first two frequent types in the 33 clinic-source strains. All CC87 stains harbored the newly reported Listeria pathogenicity island 4 (LIPI-4) gene fragment ptsA, and all CC3 strains possessed the Listeria pathogenicity island 3 (LIPI-3) gene fragment llsX. These may increase the occurrence of the strains belonging to CC87 and CC3 in listeriosis cases in China and also underline the risk of infection owing to the consumption of the cooked products from Zigong. ST619 (serotype 1/2b) harbored both llsX and ptsA, indicating a potential hypervirulent sequence type in Zigong.
China
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epidemiology
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Cooking
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Fast Foods
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microbiology
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Food Contamination
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Food Microbiology
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Humans
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Listeria monocytogenes
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genetics
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pathogenicity
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Listeriosis
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epidemiology
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microbiology
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Meat
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microbiology
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Multilocus Sequence Typing
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Prevalence
;
Seasons
6.A multiplex real-time PCR for differential detection and quantification of Salmonella spp., Salmonella enterica serovar Typhimurium and Enteritidis in meats.
Su Hwa LEE ; Byeong Yeal JUNG ; Nabin RAYAMAHJI ; Hee Soo LEE ; Woo Jin JEON ; Kang Seuk CHOI ; Chang Hee KWEON ; Han Sang YOO
Journal of Veterinary Science 2009;10(1):43-51
Salmonella (S.) Typhimurium and S. Enteritidis are the major causative agents of food-borne illnesses worldwide. Currently, a rapid detection system using multiplex real-time polymerase chain reaction (PCR) has been applied for other food-borne pathogens such as Escherichia coli, Staphylococcus aureus and Streptococcus spp. A multiplex real-time PCR was developed for the simultaneous detection of Salmonella spp., especially S. Typhimurium and S. Enteritidis, in beef and pork. For the specific and sensitive multiplex real-time PCR, three representative primers and probes were designed based on sequence data from Genbank. Among the three DNA extraction methods (boiling, alkaline lysis, and QIAamp DNA Mini Kit), the QIAamp DNA Mini Kit was the most sensitive in this study. The optimized multiplex real-time PCR was applied to artificially inoculated beef or pork. The detection sensitivity of the multiplex real-time PCR was increased. The specificity of the multiplex real-time PCR assay, using 128 pure-cultured bacteria including 110 Salmonella isolates and 18 non-Salmonella isolates, was 100%, 100% and 99.1% for Salmonella spp., S. Typhimurium and S. Enteritidis, respectively. The sensitivity was 100%, 100% and 91.7% for Salmonella spp., S. Typhimurium and S. Enteritidis, respectively. The multiplex real-time PCR assay developed in this study could detect up to 0.54 +/- 0.09 and 0.65 +/- 0.07 log10 CFU/ml for S. Typhimurium and S. Enteritidis for beef, 1.45 +/- 0.21 and 1.65 +/- 0.07 log10 CFU/ml for S. Typhimurium and S. Enteritidis for pork, respectively, with all conditions optimized. Our results indicated that the multiplex real-time PCR assay developed in this study could sensitively detect Salmonella spp. and specifically differentiate S. Typhimurium from S. Enteritidis in meats.
Animals
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Cattle
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DNA, Bacterial
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*Food Microbiology
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Meat/*microbiology
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Polymerase Chain Reaction/*veterinary
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Salmonella/*isolation & purification
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Sensitivity and Specificity
;
Swine
7.Detection and analysis of antibiotic resistance of Salmonella from retail meats in some districts of Shaanxi province.
Jin-ling SHEN ; Bao-wei YANG ; Shuai ZHI ; Sheng-hui CUI ; Mei-li XI ; Peng-fei YANG ; Jiang-hong MENG
Chinese Journal of Preventive Medicine 2008;42(10):758-761
OBJECTIVESalmonella isolates recovered from retail meats that were collected in supermarkets and free markets in Xi'an and Yangling areas of Shaanxi province were studied to determine antibiotic susceptibility.
METHODAntimicrobial susceptibility to 14 antibiotics of 193 salmonella isolates were determined by using agar dilution method, which was recommended by National Committee of Clinical Laboratory Standard (NCCLS), and E.coli ATCC25922 and E.faecalis ATCC29212 as standard control strains.
RESULTSThe 44.6% of the salmonella isolates were resistant to sulfamethoxazole, followed by resistance to kanamycin (40.9%), tetracycline (37.8%), amoxicillin (26.9%), ampicillin (25.4%), gentamicin (23.3%) and chloramphenicol (21.8%). Some isolates also showed resistance to fluoroquinolones, the rates for ciprofloxacin, enrofloxacin, levofloxacin and gatifloxacin were 22.3%, 21.8%, 20.8% and 21.2%, respectively. 55 isolates (28.5%) were multidrug resistant (MDR) strains, 28 of 193 isolates (14.5%) could resist at least 13 antibiotics, 24 isolates (12.4%) were resistant to from 4 to 12 antibiotics.
CONCLUSIONSalmonella isolates recovered from retail meats in Xi'an district of Shaanxi province were seriously resistant to antimicrobials commonly used as human and veterinary medicine.
Animals ; Cattle ; Chickens ; Drug Resistance, Multiple, Bacterial ; Food Microbiology ; Goats ; Meat Products ; microbiology ; Salmonella ; drug effects ; isolation & purification ; Sheep ; Swine
8.An investigation of brucellosis in occupational population in Yuxi, China.
Yanhua ZHOU ; Shunwu ZUO ; Yingbo YAO ; Rusong YANG ; Shukun WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2015;33(12):913-914
OBJECTIVETo investigate the epidemic status of brucellosis in the occupational population in Yuxi, China, and to develop effective prevention and control strategies.
METHODSSerological test was performed for 2320 employees involved in breeding, slaughtering, meat and dairy product processing, veterinary medicine, and sales in counties and districts where brucellosis was detected from 2008 to 2014 in Yuxi; pathogenic detection was performed for those in the occupational population who were suspected of brucellosis.
RESULTSThe results of serological test showed that the infection rate of brucellosis reached 3.32% , and 15 cases of brucellosis had clinical symptoms. The employees involved in breeding had the highest infection rate (4.89%) (χ2=25.75, P<0.05). From 2008 to 2014, the infection rate of brucellosis was 0.37%~4.93% and tended to increase; 67.85% of the occupational population did not take personal protective measures and had a significantly higher infection rate than those who took personal protective measures (4.45% vs 0.94%; χ2=19.42, P<0.05). Among the 161 patients suspected of brucellosis, 42 cases were diagnosed as current brucellosis confirmed by laboratory pathogenic detection.
CONCLUSIONThe infection rate of brucellosis and the number of newly diagnosed cases tend to increase in the occupational population in Yuxi, and the employees involved in breeding are the major infected population.
Animal Husbandry ; Brucellosis ; epidemiology ; China ; epidemiology ; Dairying ; Humans ; Meat ; Occupational Diseases ; epidemiology ; microbiology ; Veterinary Medicine
9.Characterization of antimicrobial resistances and molecular characteristics of Salmonella isolates from the pork production chain in Sichuan province, 2010-2011.
Xinfeng HAN ; Shuliang LIU ; Xiaogang HOU ; Xun CHEN ; Zhen PENG ; Dongmei ZHU
Chinese Journal of Epidemiology 2014;35(5):519-523
OBJECTIVETo investigate the antimicrobial resistance and resistance profiles of Salmonella isolates, from the pork production chain in several districts of Sichuan province and to determine the correlation between serotype and the pulse field gel electrophoresis (PFGE) patterns.
METHODSFrom 2010 to 2011, a total of 112 Salmonella isolates from pork production chain were examined for their antimicrobial susceptibility, using the micro-dilution method against 10 antimicrobial agents.
RESULTSwere assessed by the standard by the Clinical and Laboratory Standards Institute (CLSI, 2010). In addition, PFGE patterns were investigated among the Salmonella strains from different sources, under different serovars and antimicrobial profiles.
RESULTSFor Salmonella isolated from the pork production chain, resistance to tetracycline (89.29%) was frequently observed. Many isolates were resistant to spectinomycin (36.61%), trimethoprim/sulfamethoxazole (35.71%), nalidixic acid (33.93%) and ampicillin (24.11%), but all of the isolates were susceptible to ceftiofur. 33.93% of the isolates were multi-drug resistant. Salmonella isolates from the pork production chain had 19 antibiotic resistance profiles. Totally, 34 PFGE patterns were detected among 74 Salmonella isolates from the pork production chain, with the PFGE patterns of the 74 Salmonella isolates sharing 40% to 100% similarities.
CONCLUSIONThe antimicrobial resistances of the Salmonella isolates were commonly detected from the pork production chain in Sichuan province suggesting that Salmonella might horizontally spread from food animals to retail meat products.
Animals ; Drug Resistance, Bacterial ; Meat ; microbiology ; Salmonella ; drug effects ; isolation & purification ; Swine
10.Prevalence and antibiogram distribution of Salmonella isolated from broiler production and processing course in four provinces, China.
Wei-wei LI ; Li BAI ; Xiu-li ZHANG ; Xin QIAO ; Xiao-rong YANG ; Yu-zhen CHEN ; Xiao-yan PEI ; Yong-ning WU ; Yun-chang GUO
Chinese Journal of Preventive Medicine 2013;47(5):435-438
OBJECTIVETo determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.
METHODSFive large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.
RESULTSIn total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.
CONCLUSIONOur findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.
Animals ; Chickens ; microbiology ; China ; Drug Resistance, Multiple, Bacterial ; Food Contamination ; Meat-Packing Industry ; Salmonella ; classification ; drug effects ; isolation & purification ; Serotyping