四重荧光定量PCR法鉴定肠炎、鼠伤寒以及伤寒沙门氏菌

目的建立四重荧光定量PCR体系鉴定肠炎沙门氏菌、鼠伤寒沙门氏菌以及伤寒沙门氏菌。方法针对沙门氏菌属特异性ompC基因、肠炎沙门氏菌sdf基因、鼠伤寒沙门氏菌STM4495和伤寒沙门氏菌STY2021序列设计引物和TaqMan探针,建立多重荧光定量PCR体系,进行特异性与敏感性研究。结果 28株不同血清型的沙门氏菌均扩增出ompC基因,其他13株非沙门氏菌均未出现ompC的非特异性扩增。sdf、STM4495、STY2021的探针和引物分别特异性扩增出肠炎沙门氏菌、鼠伤寒沙门氏菌以及伤寒沙门氏菌,而25株其他血清型沙门氏菌以及13株非沙门氏菌均未见扩增曲线。敏感性试验显示,该体系的最低检测限分别为48 pg/mL(ompC)、560 pg/mL(sdf)、530 pg/mL(STM4495)、35 pg/mL(STY2021)。结论该方法特异好、灵敏高、能够快速检测沙门氏菌并鉴定肠炎沙门氏菌、鼠伤寒沙门氏菌以及伤寒沙门氏菌。     

2011~2018年吉林省食品中沙门氏菌的污染监测及血清型别分布

目的： 了解吉林省食品中沙门氏菌的污染状况,为预防食源性疾病提供科学依据。方法： 采集 2011~2018年吉林省16类共13507份食品样品,对沙门氏菌进行监测分析。结果： 13507份样品中检出沙门氏菌75株,总检出率为0.56%。其中2016年检出率最高,为1.02%;9个地区中白城市检出率最高(2.63%);不同食品类别中生肉及生肉制品检出率最高,为2.29%;75株沙门菌主要以肠炎沙门氏菌和鼠伤寒沙门氏菌为主,分别占总数的37.33%和13.33%。结论：吉林省食品中存在沙门氏菌污染,具有潜在的食源性疾病风险,应加强食品安全风险监测,预防食源性疾病暴发。     

北京市顺义区腹泻病例分离沙门氏菌耐药特征分析

目的 对北京市顺义区腹泻病例分离的沙门氏菌进行耐药特征分析.方法 2个收集2013-2018年北京市顺义区腹泻病例粪便标本,对标本进行沙门氏菌分离培养、生化鉴定和血清分型,使用微量肉汤法对分离的沙门氏菌菌株进行26种抗菌药物的敏感性检测,开展耐药率、非敏感率、多重耐药率和耐药谱分析.结果 腹泻病例沙门氏菌检出率为5.4...     

沙门氏菌噬菌体在动物和食品中的生物防控研究进展

随着沙门氏菌耐药性持续发展、耐药菌不断出现以及食物中毒事件频发,噬菌体已成为一种新型防控耐药性沙门氏菌的生物杀菌剂.噬菌体的作用机制与抗生素完全不同,在控制耐药性沙门氏菌感染与污染方面具有良好的应用前景,尤其在治疗超级耐药沙门氏菌方面有着极大的优势,但是由于沙门氏菌血清型众多,需要开展针对不同血清型的沙门氏菌特异性噬菌...     

Prevalence of Salmonella infecting bacteriophages associated with Ontario pig farms and the holding area of a high capacity pork processing facility

BACKGROUND: There is interest in applying bacteriophages to control Salmonella in pig production and pork processing. The following reports on the prevalence of Salmonella infecting bacteriophages within Ontario pig farms and associated with the holding area of a pork slaughterhouse. RESULTS: Salmonella infecting bacteriophages were present in 30 and 28 of the effluent manure samples collected from 36 farms using S. Typhimurium DT104 or S. Heidelberg as host cell respectively. Bacteriophages were recovered in 95–100% of the 48 samples taken from holding pens within a high capacity slaughterhouse over a 12 month period. Bacteriophages isolated from farms exhibited similar host ranges which differed to that of slaughterhouse isolates. Salmonella (n = 21) from the slaughterhouse were susceptible to the endogenous bacteriophages. Despite being susceptible to the resident phages, the Salmonella populations were found to be genetically stable with the same genotypes being recovered over successive visits. Salmonella isolated from the farms were frequently resistant to the endogenous phages. CONCLUSIONS: Bacteriophages are prevalent in the pig slaughterhouse environment although they do not have a significant impact on the genetic structure of Salmonella populations. However, there was evidence that the Salmonella population structure on farms is influenced by the presence of infecting phages. Copyright © 2010 Society of Chemical Industry     

2018年上海市非伤寒沙门菌感染流行病学特征分析

目的 了解上海市非伤寒沙门菌(以下简称“沙门菌”)感染的流行病学特征,为沙门菌感染的预防和控制提供科学依据。方法 应用描述流行病学的方法,对上海市26家食源性疾病监测哨点医院感染性腹泻病例的流行病学信息和沙门菌检测结果进行统计分析。结果 收集到5 580例感染性腹泻病例和其标本,沙门菌检出率为4.19%(234/5 580),其血清型以肠炎沙门菌和鼠伤寒沙门菌为主。不同性别、年龄和职业人群的沙门菌检出率差异无统计学意义(P＞0.05),春夏季节是沙门菌检出的高发季节。有发热症状或者发生水样便的病例,其沙门菌检出率高于无发热症状和无水样便的病例。餐饮服务业和单位食堂的病例中沙门菌检出率相对较高。结论 上海市沙门菌感染的血清型以肠炎沙门菌和鼠伤寒沙门菌为主,感染高峰出现在春夏季节。考虑到餐饮服务业和单位食堂的风险相对较高,食品安全监督管理部门应加强对其卫生监管。     

云南省肠炎沙门菌及德尔卑沙门菌脉冲场凝胶电泳分子分型及耐药性研究

目的 了解云南省沙门菌患者中分离最多的肠炎沙门菌及食品中分离最多的德尔卑沙门菌脉冲场凝胶电泳(pulse field gel electrophoresis, PFGE)分子分型及耐药状况。方法 参照中国细菌性传染病分子分型实验室监测网络Pulse Net China的沙门菌PFGE分子分型方法进行分子分型。分析耐药板最低抑菌浓度(minimal inhibitory concentration, MIC)值, 根据美国临床实验室标准化协会(Clinical and Laboratory Standard Institute, CLSI)的相应标准获得S、I、R结果。结果 56株肠炎沙门菌呈11种PFGE带型, 有4种优势带型, 对氨苄舒的耐药率最高, 为57.14%, 对亚胺培南最敏感。27株德尔卑沙门菌呈25种PFGE带型, 对复合磺胺的耐药率最高, 为64.29%, 对亚胺培南最敏感。结论 肠炎沙门菌分子分型有明显的优势带型, 本地区肠炎沙门菌对氨苄舒的耐药率最高。德尔卑沙门菌分子分型呈多样分布, 复方磺胺是本地区德尔脾沙门菌最耐药抗生素。2种沙门菌都对亚胺培南最敏感。     

Multiplex PCR for the simultaneous detection of Salmonella spp. and Salmonella Enteritidis in food

Multiplex PCR assay (mPCR) for the detection of Salmonella spp. and S. Enteritidis was developed in this study using artificially contaminated chicken carcasses. The assay showed 100% specificity to detect approximately 1 CFU of Salmonella in 10 g of chicken skin after non‐selective enrichment. The mPCR was evaluated in Minas cheese, fresh pork sausage and chicken carcasses commercially available. Salmonella spp. was detected in nine of sixty‐six chicken carcasses, five of fifty‐two cheese samples, and five of fifty‐two sausage samples. The serovar Enteritidis was detected in two samples of contaminated sausage. The mPCR results were confirmed by conventional culture and biochemical identification of the isolates. Serotyping confirmed the presence of S. Enteritidis in sausage samples and showed contamination by serovars Schwarzengrund and Montevideo in chicken carcasses.     

Survival and Growth of Salmonella hadar on Minimally Processed Cabbage as Influenced by Storage Abuse Conditions

Shredded, washed and centrifuged cabbage was packaged in monooriented polypropylene (OPP) bags, inoculated with Salmonella hadar and stored 10 days at 4°C, 12°C and 20°C. Microbiological, appearance, odor and headspace gas analysis were evaluated throughout storage. S. hadar and mesophilic aerobic and psychrotrophic microorganism growth was affected by storage time and temperature. S. hadar counts were lower (p<0.05) at 4°C than at 12°C and 20°C. The score ratings for general appearance, wilting, browning and off-odor showed that all samples were commercially acceptable. Results indicated that S. hadar could survive and proliferate on minimally processed cabbage, thereby posing a potential hazard to consumers.     

Frequency and antimicrobial resistance of Salmonella serotypes on beef carcasses at small abattoirs in Jalisco State, Mexico

The prevalence and antimicrobial resistance of Salmonella serotypes on beef carcasses from four small abattoirs in Jalisco State, Mexico, were investigated during a 10-month period. Following U.S. Department of Agriculture Food Safety and Inspection Service protocols, Salmonella was isolated from 78 (15.4%) beef carcasses (n = 505) after the final carcass water wash. Isolation frequency differed by establishment (P < 0.05) and was higher (P < 0.05) during the wet season (May through September) for all establishments. Thirteen Salmonella serotypes and four serogroups (partially serotyped isolates) were identified. The most prevalent were Salmonella enterica Give (24.4%), Salmonella Typhimurium (17.9%), and Salmonella Group B (14.1%). Antimicrobial susceptibility was tested against 11 drugs, and results indicated that 46.2% of the isolates were resistant to tetracycline, 42.3% were resistant to streptomycin, 23.1% were resistant to chloramphenicol, 21.8% were resistant to trimethoprim-sulfamethoxazole, and 19.2% were resistant to gentamicin. No resistance to ceftriaxone or ciprofloxacin was observed, and 33% of the isolates were resistant to three or more antimicrobials. Although Salmonella Give was the most prevalent serotype, 95% of the isolates of this serotype were susceptible to all antimicrobials tested. Antimicrobial resistance was more common in Salmonella Typhimurium, and 93% (13 of 14) of the isolates of this serotype were resistant to at least five antimicrobials. The frequency of multidrug-resistant Salmonella isolates differed among establishments (P < 0.05) and may be related to the origin of the cattle presented for harvesting. These findings highlight the need for control measures to reduce Salmonella prevalence on beef carcasses in small abattoirs in Mexico and for strategies to ensure the cautious use of antimicrobials in animal production to prevent and control the spread of antimicrobial-resistant foodborne pathogens.     

生鲜猪肉中沙门氏菌的分离、鉴定及耐药性检测

调查本地区生鲜猪肉中沙门氏菌的污染情况及耐药性情况,为进一步对肉及肉制品中耐药性沙门氏菌的风险评估奠定基础。采集超市和集贸市场的生鲜猪肉,采用实时荧光定量PCR对生鲜猪肉中沙门氏菌污染进行初筛,然后根据沙门氏菌检验国家标准进行分离鉴定,并对分离到的沙门氏菌进行耐药性检测。结果从83份肉样中分离到21株沙门氏菌,沙门氏菌检出率为25.3%。21株沙门氏菌中有7株对11种抗生素中的至少一种产生耐药性,耐药率33.3%。结果表明本地区生鲜猪肉微生物污染较为严重,沙门氏菌检出率较高且四环素耐药严重;另外在菌落总数和沙门氏菌检出率方面冷却肉的质量好于热鲜肉,超市和集贸出售的肉的质量无显著差异。     

Effect of coffee filtrate, methylglyoxal, glyoxal, and caffeine on Salmonella typhimurium and S. enteritidis survival in ground chicken breasts

The antimicrobial effect of roasted coffee filtrate (CF) and dicarbonyls on Salmonella Typhimurium and Salmonella Enteritidis in raw ground chicken breast meat (GCB) was investigated. Coffee was brewed and filtered before addition to GCB. Coffee filtrate with and without added caffeine, methylglyoxal, and/or glyoxal was added to GCB and then inoculated with Salmonella Typhimurium and Salmonella Enteritidis. Ground chicken samples were stomached with peptone water at days 1, 3, 5, and 7, plated on XLD agar with a TSA overlay, and Salmonella survivors were enumerated. CF alone gave less than a 1 Log reduction in all runs compared to control GCB with no treatment. Methylglyoxal (2.28 mg/g GCB) had the greatest antimicrobial effect against Salmonella Typhimurium and Salmonella Enteritidis in GCB with average Log reductions of 2.27 to 3.23, respectively, over the 7 d duration of the experiment compared to control GCB with no treatment. A 1 Log reduction was observed in GCB with CF, 0.93 mg glyoxal, and 1 mg caffeine/g chicken compared to the control and GCB with only CF. Heat-produced coffee compounds could potentially reduce Salmonella in retail ground chicken and chicken products.     

巧克力中沙门氏菌检验能力验证研究

目的 对参加中国食品药品检定研究院组织的NIFDC-PT-135巧克力中沙门氏菌检验能力验证进行分析。方法 在参照GB 4789.4-2016《食品国家安全标准 食品微生物学检验 沙门氏菌检验》和能力验证作业指导书传统方法鉴定的基础上, 借助miniVIDAS和VITEK2 2种仪器进行检验分析。结果 CODE0002未检出沙门氏菌、CODE0485检出肠沙门菌双相亚利桑那亚种, CODE0633检出鼠伤寒沙门氏菌。结论 本次能力验证实验结果为满意。实验室在进行沙门氏菌检验时可以使用仪器与传统分析方法相结合的检验方法, 但是要注意一些细节问题, 防止漏检和误检。     

沙门氏菌检验及鉴定方法研究进展

沙门氏菌在一个多世纪以来被认为是引起人类和动物疾病的主要食源性病原体,因此也导致了高昂的医疗和经济成本。努力开发有效和可靠的沙门氏菌检测方法至关重要。本文主要对目前用于沙门氏菌检测的技术和方法进行了综述,根据检测原理的不同分为常规培养方法、基于免疫学测定的方法、基于核酸测定的方法和生物传感器。传统常规培养法虽然在沙门的鉴定方面的准确性和特异性有不可否认的优势,但是也具有一定的缺陷,比如耗时长等。新兴的分子生物学快速检测及鉴定等方法能够快速、准确的对沙门氏菌进行鉴定,但可能对设备、技术人员、环境要求较高。随着生物学、化学、物理等学科的快速发展,应寻求多学科结合、取长补短,使准确、快速、灵敏检测食品中沙门氏菌成为现实。     

乳粉能力验证中沙门氏菌的分离鉴定和血清分型

目的参加编号为NIFDC-PT-220的能力验证,考核从乳粉中检出沙门氏菌及血清分型能力。方法参照国标方法对中国食品药品检定研究院提供的随机乳粉样品(CODE140、CODE121)进行沙门氏菌的检验,并将荧光酶联免疫法和荧光定量PCR技术作为辅助方法。对分离出的疑似菌进行生化鉴定,并且采用全自动微生物鉴定系统进行全面鉴定。结果编号CODE140血清分型为O:4,5,12, H:i; 1,2被确定为鼠伤寒沙门氏菌。编号CODE121未检出。结论荧光酶联免疫法和荧光定量PCR技术缩短了检测时间,特异性和敏感性好,与国标方法配合可确保实验结果的准确性。     

安宁市食品从业人员携带沙门氏菌血清型分布特征及耐药性分析

目的 了解云南省安宁市2016~2018年食品从业人员门氏菌的血清型分布状况与耐药性情况。 方法 选取2016~2018年食品从业人员肛拭标本60533份进行血清学分型鉴定试验和药物敏感性试验。 结果 共检出沙门菌186株, 总检出率为0.307%。沙门菌经生化和血清学鉴定分43个血清型, 其中最常见的血清型依次为鼠伤寒沙门氏菌、肠炎沙门氏菌和伦敦沙门氏菌。在13种抗生素中, 对11种抗生素产生不同程度的耐药性。结论 食品从业人员携带的沙门菌种类多, 血清型呈多样性的趋势, 且耐药形势严峻, 需加强从业人员的健康体检管理。     

Occurrence,Characterization, and Antimicrobial Susceptibility of Salmonella enterica in Slaughtered Pigs in Sardinia

The aim of this study was to determine Salmonella occurrence in slaughtered finishing pigs and piglets and in slaughterhouse environment in order to characterize the isolates with phenotypical (antimicrobial testing) and molecular (PFGE, MLVA) methods. Nine slaughterhouses located in Sardinia were visited. Six hundred and eight samples collected from 106 pigs and 108 environmental samples were collected and analyzed. Salmonella was isolated in 65 of 504 (12.9%) samples from finishing pigs, with an occurrence of 15.1% in colon content, 12.7% in lymph nodes and liver, and 11.1% in carcass surface samples. Salmonella was never detected in piglets. The combined results of serotyping and PFGE showed a possible self‐contamination in 71.5% of Salmonella positive carcasses of lymph nodes and/or colon content carriers, pointing out the role of healthy pigs for carcass contamination. A significantly higher (P < 0.05) occurrence was detected in finishing pigs of EC countries origin (23%) than in pigs of local farms (8%). Salmonella was also detected in 3.7% of environmental samples. The most prevalent serovar was S. Anatum, followed by S. Rissen, S. Derby, and monophasic S. Typhimurium. Resistance to at least 3 antimicrobial was observed in 97.1% of strains and 7 different patterns of multiple resistance were identified. The most common resistance was detected against sulphonamide compounds. A strict slaughterhouse application of hygiene standards is essential to control the risk of Salmonella contamination.     

鸡蛋生产环节沙门氏菌检测及洁蛋对蛋品质影响的研究

目的 对鸡蛋生产过程中沙门氏菌污染环节进行研究, 探明规模化蛋鸡养殖场鸡蛋生产中沙门氏菌污染状况和洁蛋效果。方法 选择规模化蛋鸡场一个, 对可能造成鸡蛋沙门氏菌污染的水、饲料、蛋网、传输带等环节的样本进行采样, 并取清洁前后的鸡蛋各60个, 分为两组, 每组中30个蛋用于当天检测, 另外30个, 在室温环境下放置10 d后检测。所有样品经前增菌和选择性增菌后, 提取细菌DNA进行鉴定。结果 水、饲料和清洁后的鸡蛋表面未检出沙门氏菌, 蛋网、传输带、未清洁的鸡蛋表面检出沙门氏菌, 进一步检测表明, 检出的沙门氏菌均不是肠炎沙门氏菌和伤寒沙门氏菌。鸡蛋放置10 d后检测, 未清洁组的蛋白高度和哈氏单位显著低于清洁组的蛋白高度和哈氏单位, 二者均显著低于当天检测的结果, 而各组的蛋壳强度差异均不显著。结论 鸡蛋清洁涂膜处理后可以有效减少蛋壳表面沙门氏菌污染, 并延长鸡蛋的保存时间。     

能力验证试验中沙门氏菌的分离与鉴定

目的研究能力验证试验中沙门氏菌的分离与鉴定。方法以中国合格评定认可委员会提供的冻干细菌混合物作为能力验证样品,根据能力比对试验中给定盲样可以水化的特性,采用GB 4789.4-2010中的方法对沙门氏菌进行传统鉴定和快速鉴定,并对检出的沙门氏菌进行生化鉴定和血清学鉴定。结果采用沙门氏菌快速鉴定方法,盲样的鉴定结果与GB 4789.4-2010中的结果一致,确定所检出的沙门氏菌为都柏林沙门氏菌。结论与传统鉴定方法相比,沙门氏菌快速鉴定方法在同等试验条件下具有快速准确、操作简单的特点,可以作为一种快速筛查方法运用在微生物能力验证领域。