餐饮从业人员肠道菌群喹诺酮及头孢类耐药基因的携带与转移研究

发布时间：2018-08-19 17:14

【摘要】：目的：分析餐饮行业从业人员肠道中头孢类和喹诺酮类抗生素耐药菌的携带状况,并分析耐药基因的质粒携带的状况及流行情况。方法：2015年5月至2015年8月间自江西南昌市疾控中心餐饮行业从业人员健康体检门诊,选择从事厨师、洗菜工等餐饮行业体检时无腹泻人群,收集肛拭样本(1份/人)。调查时询问近3个月抗生素使用史,未使用抗生素者纳入研究群体。采集的体检肛拭样本分别用含头孢曲松钠(4μg/ml)和环丙沙星(4μg/ml)的营养琼脂筛选能够在营养琼脂培养条件下生长的耐药菌。随机挑选培养的头孢曲松钠耐药菌和环丙沙星耐药菌,分别检测CTX-M型超广谱p内酰胺酶携带情况和喹诺酮质粒介导的喹诺酮类耐药(plasmid-mediated quinolone resistance,PMQR)的相关基因携带和染色体突变的情况。结果：纳入符合条件的头孢曲松钠耐药检测标本共有140人份的肛拭子标本。所有140份标本在头孢曲松钠抗性平板上均有菌落生长。这些肛拭样本中有125份样本分离到头孢曲松钠耐药的革兰阴性菌,携带率为89.3%(125/140)。分离得到的125株耐药菌株中CTX-M的检出率为97.6%；五组CTX中检出率最高的为CTX-M-9组56.0%,其次为CTX-M-1组38.4%,有4株菌同时检测到CTX-M-9组和CTX-M-1组基因。通过测序比对,共检测到9种CTX基因亚型,检出率最高的是CTX-M-14和CTX-M-15.随机挑选了10株含CTX-M-14型的菌株做接合转移,6株菌发生了接合,接合效率分别在1.4×10-5到7.7×10-3之间。纳入环丙沙星耐药检测的共159份样品,其中127份样品分离到革兰阴性菌,分离率79.9%(127/159),127株革兰阴性菌17株检测到qnr基因携带阳性,检出率10.7%,其中qnrSl型检出有10株,qnAl型有1株,qnrB型有6株(其中qnrB2有2株、qnrB6有4株),20株菌经测序确定携带aac(6')-Ib-cr基因,检出率为15.7%(20/127)。112株环丙沙星耐药的大肠埃希菌检测到gyrA基因的Ser83→eu替代、Asp87→Asn和Asp87→Tyr 3种突变类型；对gyrB检测到两种突变类型,分别是Ser343→Phe和Ser492→Asn;parC共检测到7种突变类型,分别为Ala56→Thr、Ser80→Ile、GLU84→Val、 Glu84→Gly、Glu84→Lys、Ala108→Thr、和Vall44→Gly;parE检测到2种突变类型,为Leu445→His和Ser458→Ala。结论：餐饮行业从业人员肠道内细菌普遍存在对p-内酰胺类和喹诺酮类药物有抗性的肠道细菌,并且携带多种序列型的抗性基因以及质粒。这类人群在体检时并没有腹泻,其多接触食品,一方面可能从食品原材料中获得耐药菌,另一方面也可能将耐药菌传播到其他人。另外,检测到的携带耐药质粒的肠杆菌,当肠道有致病细菌入侵时,这些携带耐药质粒的正常定居的肠杆菌可能会在肠道内将抗性传递给致病菌,造成致病菌产生耐药性。我们对餐饮从业人群的耐药肠杆菌监测,显示了人群非腹泻时依然携带较多的耐药肠杆菌,鉴于其工作特点,获得并导致耐药菌粪-口途径传播的风险性很高,提示当前食品卫生管理、以及阻断细菌耐药性传递的策略中应关注餐饮服务人群的耐药菌携带和可能的播散。
[Abstract]:Objective: To analyze the carrying status of cephalosporins and quinolones antibiotics resistant bacteria in the intestine of employees in catering industry, and to analyze the plasmid carrying status and epidemic situation of drug resistant genes. Anal swabbing samples (1/person) were collected from non-diarrhea patients in the catering industry such as vegetable workers. Antibiotic use history in the past three months was questioned and non-antibiotic users were included in the study group. Anal swabbing samples were screened by nutritional agar containing ceftriaxone sodium (4ug/ml) and ciprofloxacin (4ug/ml). Drug-resistant bacteria were randomly selected and cultured to detect CTX-M type extended-spectrum p-lactamases and plasmid-mediated quinolone resistance (PMQR) related gene carrying and chromosome mutation. A total of 140 anal swabs were obtained from eligible ceftriaxone-resistant samples. Colonial growth was observed in all 140 samples on ceftriaxone-resistant plates. Among these swabs, 125 were found to be Gram-negative bacteria resistant to ceftriaxone, with a carrier rate of 89.3% (125/140). The detection rate of CTX-M was 97.6%. The highest detection rate of CTX was 56.0% in CTX-M-9 group, followed by 38.4% in CTX-M-1 group. CTX-M-9 group and CTX-M-1 group genes were simultaneously detected in 4 strains. Nine CTX genotypes were detected by sequencing comparison. The highest detection rate was CTX-M-14 and CTX-M-15. Ten strains containing CTX-M-14 were randomly selected. A total of 159 samples were tested for ciprofloxacin resistance, of which 127 samples were isolated from gram-negative bacteria, the isolation rate was 79.9% (127/159), and 17 strains of 127 Gram-negative bacteria were positive for qnr gene, the detection rate was 10.7%. Among 10 strains, 1 strain of qnAl type, 6 strains of qnrB type (including 2 strains of qnrB2 and 4 strains of qnrB6), 20 strains were identified to carry the AAC (6') - Ib-cr gene by sequencing, the detection rate was 15.7% (20/127). 112 ciprofloxacin-resistant Escherichia coli strains detected gyrA gene Ser83 substitution, Asp87 Asn and A87 Tyr mutations; and two types of gyrB were detected. Seven mutation types were detected in parC, namely Ala56 Thr, Ser80 Ile, GLU84 Val, Glu84 Lys, Ala108 Thr, and Vall44 Gly. Conclusion: Bacteria in the intestinal tract of catering workers are prevalent. Intestinal bacteria that are resistant to p-lactams and quinolones and carry a variety of sequence-specific resistance genes and plasmids. These people do not have diarrhea at the time of physical examination. They are exposed to foods that may acquire drug-resistant bacteria from food raw materials on the one hand, and may spread the drug-resistant bacteria to other people on the other. In addition, detection has been made. When Enterobacteriaceae carrying drug-resistant plasmids invade the intestine, these normally colonized Enterobacteriaceae carrying drug-resistant plasmids may transmit resistance to pathogens in the intestine, resulting in resistance to pathogens. Our surveillance of drug-resistant Enterobacteriaceae in catering professionals shows that the population is still carrying more when non-diarrhea occurs. Drug-resistant Enterobacter spp. is highly risky to acquire and lead to fecal-oral transmission of drug-resistant bacteria in view of its characteristics, suggesting that current food hygiene management, as well as strategies to block the transmission of drug resistance, should pay attention to drug-resistant bacteria carrying and possible dissemination in catering services.
【学位授予单位】：中国疾病预防控制中心
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R155.7

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