Environmental Microbiology Laboratory, Department of Botany, Banaras Hindu University, Varanasi, India.
Infect Genet Evol. 2013 Mar;14:83-91. doi: 10.1016/j.meegid.2012.09.019. Epub 2012 Nov 28.
Listeria monocytogenes isolated from Ganges water, human clinical and milk samples were characterized by antibiotic susceptibility, serotype identification, detection of virulence genes and ERIC- and REP-PCR fingerprint analyses. All isolates were uniformly resistant to ampicillin, except two isolates, and showed variable resistance to gentamicin, cotrimoxazole, ofloxacin, rifampicin and tetracycline. Of the 20 isolates found positive for pathogens, seven (four human and three water isolates) belong to serogroups 4b, 4d and 4e; six (one human and five water isolates) belong to serogroups 1/2c and 3c; four milk isolates belong to serogroups 1/2b and 3b; and three milk isolates belong to serogroups 1/2a and 3a. Two water isolates, all human isolates, except one (Pb1) lacking inlJ gene, and three milk isolates possess inlA, inlC, plcA, prfA, actA, hlyA and iap genes. The remaining water and milk isolates showed variable presence of inlJ, plcA, prfA, and iap genes. ERIC- and REP-PCR based analyses collectively indicated that isolates of human clinical samples belong to identical or similar clone and isolates of water and milk samples belong to different clones. Overall study demonstrates the prevalence of pathogenic L. monocytogenes species in the environmental and clinical samples. Most of the isolates were resistant to commonly used antibiotics.
从恒河水中、人类临床和牛奶样本中分离出的单核细胞增生李斯特菌通过抗生素敏感性、血清型鉴定、毒力基因检测以及 ERIC 和 REP-PCR 指纹分析进行了特征描述。所有分离株均对氨苄西林表现出一致的耐药性，除了两个分离株，且对庆大霉素、复方新诺明、氧氟沙星、利福平以及四环素表现出不同程度的耐药性。在发现的 20 株病原体阳性的分离株中，有 7 株（4 株来自人类，3 株来自水样本）属于 4b、4d 和 4e 血清群；6 株（1 株来自人类，5 株来自水样本）属于 1/2c 和 3c 血清群；4 株牛奶分离株属于 1/2b 和 3b 血清群；3 株牛奶分离株属于 1/2a 和 3a 血清群。2 株水分离株、除了一个缺乏 inlJ 基因的人类分离株（Pb1）以外的所有人类分离株，以及 3 株牛奶分离株均携带 inlA、inlC、plcA、prfA、actA、hlyA 和 iap 基因。其余的水和牛奶分离株显示 inlJ、plcA、prfA 和 iap 基因的存在情况各不相同。基于 ERIC 和 REP-PCR 的分析表明，人类临床样本的分离株属于相同或相似的克隆，而水和牛奶样本的分离株属于不同的克隆。总的研究表明，致病性单核细胞增生李斯特菌在环境和临床样本中普遍存在。大多数分离株对常用抗生素具有耐药性。
