Costa Daniela, Poeta Patricia, Sáenz Yolanda, Coelho Ana Cláudia, Matos Manuela, Vinué Laura, Rodrigues Jorge, Torres Carmen
Universidade de Trás-os-Montes e Alto Douro, Departamento de Ciências Veterinárias, Vila Real, Portugal.
Vet Microbiol. 2008 Feb 5;127(1-2):97-105. doi: 10.1016/j.vetmic.2007.08.004. Epub 2007 Aug 15.
Faecal samples of healthy dogs (n=39) and cats (n=36) obtained in Northern Portugal were seeded on Levine agar plates, and two Escherichia coli isolates per sample were recovered (78 of dogs and 66 of cats). The susceptibility to 16 antimicrobial agents was tested in this series of 144 E. coli isolates. Almost 20% of them showed tetracycline resistance and 12 and 15% presented ampicillin or streptomycin resistance, respectively. The percentage of resistance to the other antimicrobial agents was in all cases below 4%, and no resistant isolates were detected for ceftazidime, imipenem, cefoxitin or amikacin. Two isolates (from one dog) showed cefotaxime-resistance and harboured both the CTX-M-1 and OXA-30 beta-lactamases. A bla(TEM) gene was detected in 12 of 17 ampicillin-resistant isolates, the aac(3)-II gene in the three gentamicin-resistant isolates, aadA in 7 of 22 streptomycin-resistant isolates, and tet(A) and/or tet(B) gene in all 28 tetracycline-resistant isolates. The gene encoding class 1 integrase was detected in six E. coli isolates, including the four trimethoprim-sulfamethoxazole-resistant isolates and those two harbouring CTX-M-1 and OXA-30 beta-lactamases; different gene cassette arrangements were identified: dfrA1+aadA1 (two isolates), dfrA12+orfF+aadA2 (two isolates) and bla(OXA30)+aadA1 (two isolates). One amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in four nalidixic acid-resistant and ciprofloxacin-susceptible isolates and two amino acid changes in GyrA (Ser83Leu+Asp87Asn) and one in ParC (Ser80Ile) were identified in one nalidixic acid- and ciprofloxacin-resistant isolate. Faecal E. coli isolates of healthy pets could be a reservoir of antimicrobial resistance genes.
在葡萄牙北部采集的39只健康犬和36只健康猫的粪便样本，接种于莱文氏琼脂平板上，每个样本分离出两株大肠杆菌（犬78株，猫66株）。对这144株大肠杆菌分离株进行了16种抗菌药物的敏感性测试。其中近20%表现出四环素耐药性，分别有12%和15%对氨苄西林或链霉素耐药。对其他抗菌药物的耐药百分比在所有情况下均低于4%，未检测到对头孢他啶、亚胺培南、头孢西丁或阿米卡星耐药的分离株。两株分离株（来自一只犬）表现出头孢噻肟耐药性，携带CTX-M-1和OXA-30β-内酰胺酶。在17株氨苄西林耐药分离株中的12株中检测到bla(TEM)基因，在3株庆大霉素耐药分离株中检测到aac(3)-II基因，在22株链霉素耐药分离株中的7株中检测到aadA基因，在所有28株四环素耐药分离株中检测到tet(A)和/或tet(B)基因。在6株大肠杆菌分离株中检测到编码1类整合酶的基因，包括4株对甲氧苄啶-磺胺甲恶唑耐药的分离株以及携带CTX-M-1和OXA-30β-内酰胺酶的那两株；鉴定出不同的基因盒排列：dfrA1+aadA1（两株）、dfrA12+orfF+aadA2（两株）和bla(OXA30)+aadA1（两株）。在4株对萘啶酸耐药但对环丙沙星敏感的分离株中检测到GyrA蛋白的一个氨基酸变化（Ser83Leu或Asp87Tyr），在1株对萘啶酸和环丙沙星耐药的分离株中鉴定出GyrA的两个氨基酸变化（Ser83Leu+Asp87Asn）和ParC的一个氨基酸变化（Ser80Ile）。健康宠物的粪便大肠杆菌分离株可能是抗菌药物耐药基因的储存库。
