Department of Biomedical Sciences-Section of Microbiology, Polytechnic University of Marche, Tronto 10/A, 60020 Torrette di Ancona, Italy.
Curr Microbiol. 2011 May;62(5):1438-47. doi: 10.1007/s00284-011-9880-x. Epub 2011 Feb 1.
Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6')-Ie aph (2'')-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.
从鸡肉、猪肉和粪便中的 53 株抗药性肠球菌中筛选出 48 株至少对两种抗生素有抗药性的分离株，并对其特定的抗药性决定因素进行分析。在 48 株多药耐药（MDR）菌株中，31 株对两种抗生素（29 株对红霉素和四环素，1 株对红霉素和万古霉素，1 株对万古霉素和四环素）耐药，14 株对三种（红霉素、四环素和万古霉素或氨苄西林）耐药，3 株对四种（红霉素、万古霉素、氨苄西林和庆大霉素）耐药。erm（B）、tet（M）、vanA 和 aac（6'）-Ie aph（2'）-Ia 是最常检测到的抗生素耐药基因。所有 48 株 MDR 肠球菌均对利奈唑胺和达托霉素敏感。在肉类中鉴定出粪肠球菌（16）、屎肠球菌（8）、曼氏肠球菌（2）和鸡肠球菌（1），粪便中鉴定出屎肠球菌（13）和耐久肠球菌（13）。未检测到克隆传播，这表明基因转移在抗生素耐药性的传播中起着重要作用。当供体为来自粪便的肠球菌分离株时，耐药基因的接合转移更成功；vanA 和 erm（B）可从粪肠球菌和耐久肠球菌猪粪便株共转移至人屎肠球菌。这些数据表明，多药耐药性可在食品和动物物种中发现，而不是粪肠球菌和屎肠球菌，并且这些物种可在种间交配中有效地将抗生素耐药性转移给人类菌株。特别是，MDR 耐久肠球菌在动物宿主中的出现可能在人类肠球菌感染难以用抗生素根除的情况下发挥作用。
