AUTHOR=Gao Lili , Hu Jiaqing , Zhang Xiaodan , Wei Liangmeng , Li Song , Miao Zengmin , Chai Tongjie 

TITLE=Application of swine manure on agricultural fields contributes to extended-spectrum β-lactamase-producing Escherichia coli spread in Tai'an, China

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00313

DOI=10.3389/fmicb.2015.00313

ISSN=1664-302X

ABSTRACT=<p>The prevalence of extended-spectrum beta-lactamase (ESBL)-producing <italic>Escherichia coli</italic> (<italic>E. coli</italic>) is increasing rapidly in both hospital environments and animal farms. A lot of animal manure has been directly applied into arable fields in developing countries. But the impact of ESBL-positive bacteria from animal manure on the agricultural fields is sparse, especially in the rural regions of Tai'an, China. Here, we collected 29, 3, and 10 ESBL-producing <italic>E. coli</italic> from pig manure, compost, and soil samples, respectively. To track ESBL-harboring <italic>E. coli</italic> from agricultural soil, these isolates of different sources were analyzed with regard to antibiotic resistance profiles, ESBL genes, plasmid replicons, and enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) typing. The results showed that all the isolates exhibited multi-drug resistant (MDR). CTX-M gene was the predominant ESBL gene in the isolates from pig farm samples (30/32, 93.8%) and soil samples (7/10, 70.0%), but no SHV gene was detected. Twenty-five isolates contained the IncF-type replicon of plasmid, including 18 strains (18/32, 56.3%) from the pig farm and 7 (7/10, 70.0%) from the soil samples. ERIC-PCR demonstrated that 3 isolates from soil had above 90% genetic similarity with strains from pig farm samples. In conclusion, application of animal manure carrying drug-resistant bacteria on agricultural fields is a likely contributor to antibiotic resistance gene spread.</p>