ABSTRACT

This study aimed to compare the prevalence of antibiotic-resistant coliforms and Escherichia coli strains between industrial and antimicrobial-free poultry manure. The mean counts of high-level antibiotic-resistant coliforms were determined using the spread plate technique. Metal and antibiotic resistance of Escherichia coli strains in manure samples was compared using plate dilution and CLSI procedures, respectively. Several multi-drug resistant Escherichia coli strains were screened for plasmids using alkaline lysis method as well. The relative abundance of high-level antibiotic-resistant coliforms was significantly (p < 0.05 and 0.001) higher in industrial manure than in antimicrobial-free manure. Metal analysis indicated that the concentrations of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) in manure samples were significantly (p < 0.05) correlated with the percentage of coliforms resistant to several antibiotics. The number of multidrug-resistant Escherichia coli strains was significantly (p < 0.001) higher in industrial manure (97.4%) than in antimicrobial-free manure (80.7%). Four out of twelve screened Escherichia coli strains harbored plasmids. Considering the high number of drug-resistant isolates in both samples, reductions in co-selecting agents is essential for the effectiveness of antibiotics, along with controlling the activities which cause the spread of resistance.

摘要

本研究旨在比较工业和无抗菌剂家禽粪便中耐抗生素大肠菌群和大肠杆菌菌株的流行情况。使用扩散板技术确定高水平抗生素耐药大肠菌群的平均计数。分别使用平板稀释和 CLSI 程序比较粪便样品中大肠杆菌菌株的金属和抗生素耐药性。还使用碱裂解法筛选了几种多重耐药大肠杆菌菌株的质粒。高水平耐药大肠菌群的相对丰度显着（p < 0.05 和 0.001) 在工业肥料中比在不含抗菌素的肥料中高。金属分析表明，粪便样品中铜 (Cu)、锌 (Zn)、铅 (Pb) 和镉 (Cd)的浓度与大肠菌群对几种抗生素耐药的百分比显着相关( p < 0.05)。工业肥料（97.4%）中的多重耐药大肠杆菌菌株数量显着（p <  0.001）高于不含抗生素的肥料（80.7%）。十二个筛选出的大肠杆菌中有四个菌株含有质粒。考虑到两个样本中的大量耐药分离株，减少共同选择剂对于抗生素的有效性以及控制导致耐药性传播的活动至关重要。