Antimicrobial resistance and integron gene cassette arrays in commensal Escherichia coli from human and animal sources in IRI
نویسندگان
چکیده
BACKGROUND The human and animal intestinal tract harbors a complex community of microbes which enables bacteria to inherit antibiotic resistance genes. The aims of this study were to investigate clonality, antimicrobial resistance, prevalence and gene cassette arrays of class I and II integrons among commensal Escherichia coli from human and animals. METHODS A total of 200 E. coli isolates from human, chicken, cattle, and sheep were isolated followed by phenotypic antibiotic susceptibility testing and detection of class I and II integrons gene cassettes arrays. The clonal relationship of the isolates were analyzed by (GTG)5-PCR. RESULTS Of 200 isolates, 136 isolates were multi drug resistance (MDR) including 47, 40, 31 and 18 isolates from chicken, human, cattle and sheep, respectively. Class I integron was detected in 50, 38, 6 and 16 %, while class II was detected in 26, 8, 0 and 4 % of chicken, human, cattle and sheep isolates, respectively. Variable regions were amplified and sequenced. Cassette arrays in class I integrons were: dfrA1, dfrA5, dfrA7, dfrA12, aadA1, dfrA17 aadA1, aadA22, aadB-aadA2 and dfrA12-orfF-aadA2, and for class II, dfrA1-sat-aadA1, and sat-sat1-aadA1 were detected. Six class I and three class II positive strains did not produce any amplicons for variable region. Integron-positive isolates showed higher rate of resistance to streptomycin and trimethoprim-sulphamethoxazole, especially in chicken isolates which were fed antibiotics. Low similarity and great genetic diversity of class I and II integrons carrying isolates indicated no clonal relation. CONCLUSIONS Integrons encoding for antibiotic resistance are significantly present among non-pathogenic commensal E. coli, especially from the hosts medicated by antibiotics. Uncontrolled use of antibiotics will increase the numbers of multiple drug resistant isolates and integrons prevalence.
منابع مشابه
The contribution of Escherichia coli from human and animal sources to the integron gene pool in coastal waters
To understand the contribution of animal- and human-derived fecal pollution sources in shaping integron prevalence and diversity in beach waters, 414 Escherichia coli strains were collected from beach waters (BW, n = 166), seagull feces (SF, n = 179), and wastewaters (WW, n = 69), on the World Biosphere Reserve of the Berlenga Island, Portugal. Statistical differences were found between the pre...
متن کاملCharacterization of antimicrobial resistance and class 1 integrons found in Escherichia coli isolates from humans and animals in Korea.
OBJECTIVES Antimicrobial resistance and class 1 integrons found in Escherichia coli isolates from humans and animals in Korea were characterized. METHODS E. coli isolates were examined for susceptibility to antimicrobial agents. Integrase genes were amplified. Gene cassette regions for classes 1 and 2 integrons were amplified and sequenced. Conjugal transfer and Southern hybridization were pe...
متن کاملآنالیز اینتگرونها و کاستهای ژنی مربوطه در ایزولههای بالینی اشریشیاکلی
Background and Objective: Horizontal transfer of integrons is the most successful transfer of antimicrobial resistance genes and the emergence of multi-drug resistance strains. The aim of the present study was to investigate the prevalence of class I and II integrons and their gene cassette assortments and antibiotic resistance profile in Escherichia coli strains isolated from diarrheal and uri...
متن کاملNew trimethoprim-resistant dihydrofolate reductase cassette, dfrXV, inserted in a class 1 integron.
The nucleotide sequence of a plasmid-borne trimethoprim resistance gene from a commensal fecal Escherichia coli isolate revealed a new dihydrofolate reductase gene, dfrXV, which occurred as a gene cassette integrated in a site-specific manner in a class 1 integron. The new gene shows 84% nucleotide identity and the predicted protein shows 90% amino acid identity with dfrI and DHFR type I, respe...
متن کاملPrevalence of Class 1 Integrons and Extended Spectrum Beta Lactamases among Multi-Drug Resistant Escherichia coli Isolates from North of Iran
Background: Extended spectrum beta lactamases (ESBLs) are an important cause of transferable multidrug resistance (MDR) in gram-negative bacteria. The most described ESBL genes are generally found within integron-like structures as mobile genetic elements. The aim of this study was to identify the accompanying of class 1 integrons and ESBLs in the MDR E. coli isolates. Methods: Susceptibility t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 8 شماره
صفحات -
تاریخ انتشار 2016