Middleton J H, Ambrose A
Department of Biological and Allied Health Sciences, Fairleigh Dickinson University, Madison, New Jersey 07940, USA.
J Wildl Dis. 2005 Apr;41(2):334-41. doi: 10.7589/0090-3558-41.2.334.
Thermotolerant fecal indicator organisms carried by migratory waterfowl may serve as reservoirs of antibiotic resistance. To determine the extent to which such antibiotic resistance markers were present in migratory Canada geese (Branta canadensis) on the Maryland Eastern Shore, we isolated Enterococcus spp. and Escherichia coli from fresh feces and examined the antibiotic resistance profiles of these bacteria. Samples were obtained in October 2002, January 2003, and March 2003. Thermotolerant E. coli counts ranged from 0 to 1.0x10(7) colony forming units (CFU)/0.1g (g-1) wet weight of feces, whereas Enterococcus spp. counts ranged from 1.0x10(2)-1.0x10(7) CFU g-1 wet weight of feces. Primary isolates of each indicator organism were tested against a panel of 10 antibiotics. Greater than 95% of E. coli isolates were resistant to penicillin G, ampicillin, cephalothin, and sulfathiazole; no E. coli were resistant to ciprofloxacin. Enterococcal isolates showed highest resistance to cephalothin, streptomycin, and sulfathiazole; no enterococci were resistant to chloramphenicol. The tetracyclines, streptomycin, and gentamycin provided the greatest discrimination among E. coli isolates; chlortetracycline, cephalothin, and gentamycin resistance patterns provided the greatest discrimination between enterococcal strains. Multiple antibiotic resistance (MAR) profiles were calculated: fall (E. coli=0.499; enterococci=0.234), winter (E. coli=0.487; enterococci=0.389), and spring (E. coli=0.489; enterococci=0.348). E. faecalis and E. faecium, which are recognized human nosocomial pathogens, were cultured from winter (44 and 56%, respectively) and spring (13 and 31%, respectively) fecal samples.
迁徙水鸟携带的耐热粪便指示生物可能是抗生素耐药性的储存库。为了确定在马里兰州东海岸的加拿大迁徙鹅（加拿大黑雁）中此类抗生素耐药性标志物的存在程度，我们从新鲜粪便中分离出肠球菌属和大肠杆菌，并检测了这些细菌的抗生素耐药谱。样本于2002年10月、2003年1月和2003年3月采集。耐热大肠杆菌计数范围为0至1.0×10⁷菌落形成单位（CFU）/0.1克（g⁻¹）粪便湿重，而肠球菌属计数范围为1.0×10²至1.0×10⁷CFU g⁻¹粪便湿重。每种指示生物的主要分离株针对一组10种抗生素进行了测试。超过95%的大肠杆菌分离株对青霉素G、氨苄青霉素、头孢噻吩和磺胺噻唑耐药；没有大肠杆菌对环丙沙星耐药。肠球菌分离株对头孢噻吩、链霉素和磺胺噻唑耐药性最高；没有肠球菌对氯霉素耐药。四环素、链霉素和庆大霉素在大肠杆菌分离株中区分度最大；金霉素、头孢噻吩和庆大霉素耐药模式在肠球菌菌株之间区分度最大。计算了多重抗生素耐药（MAR）谱：秋季（大肠杆菌=0.499；肠球菌=0.234）、冬季（大肠杆菌=0.487；肠球菌=0.389）和春季（大肠杆菌=0.489；肠球菌=0.348）。从冬季（分别为44%和56%）和春季（分别为13%和31%）的粪便样本中培养出了被认为是人类医院病原体的粪肠球菌和屎肠球菌。
