RESUMO
BACKGROUND: Pet birds have close contact to human and resistant bacteria can transfer from birds to intestinal flora of human. AIMS: This study was carried out to determine the tetracycline resistance genes in Escherichia coli strains associated with enteric problem in pet birds. METHODS: Totally, 295 cloacal swabs were collected from 195 healthy and 100 diarrheic pet birds in Isfahan province, Iran. The presence of E. coli was identified by conventional bacteriological, biochemical, and molecular examinations. The presence of tetracycline resistance genes (tetA, tetB, tetC, tetD, tetE, tetG, tetK, tetL, tetM, tetO, and tetS genes) were examined using three multiplex PCR. RESULTS: The results showed that 18.9% and 43% of cloacal samples of healthy and diarrheic pet birds contained E. coli, respectively. The mean percentage of E. coli isolated from cloacal samples of diarrheic birds was significantly higher than the healthy birds (46.6 vs 23.1%). In healthy birds, out of 37 E. coli isolates, 10 isolates were resistant to tetracycline, harboring tetA and tetB genes (3 tetA vs 7 tetB), but in the diarrheic birds, of 26 resistance E. coli, 11, 12, and 3 strains contained tetA (42.3%), tetB (46.15), and tetA+tetB (11.53%) genes. The percentage of tet genes were significantly higher in diarrheic birds than healthy birds (58.9 vs 24.0%). CONCLUSION: Both resistant genes of tetA and tetB were detected in E. coli isolates that are related with efflux pump activity. These genes can be transferred between Gram-negative bacteria and they have the potential ability to be transferred to the environment and human flora.
RESUMO
INTRODUCTION: Staphylococcus aureus, in particular its enterotoxigenic strains, is a well-known pathogen in food microbiology as one of the most common causes of food poisoning. This study aimed to investigate the prevalence of S. aureus enterotoxigenic strains in Iranian food resources by using a systematic review and meta-analysis. METHODS: A systematic search was performed using electronic databases from papers that were published by Iranian authors to the end of July 2017. Then, 34 publications which met our inclusion criteria were selected for data extraction and analysis. RESULTS: The average pooled prevalence of S. aureus in food resources was 15.5% (95% CI: 12.7%-18.9%) ranging from 1.1% to 52%. According to the examined publications the estimated average prevalence of enterotoxigenic strains was estimated at 53.7% (95% CI: 41.4%-65.6%) ranging from 13% to 83.3%. The average prevalence of methicillin-resistant S. aureus in contaminated resources was estimated at 15.5% (95% CI: 11.1%-21.4%) ranging from 0% to 32%. The results showed that SEA and SEG were the most prevalent classic and new staphylococcal enterotoxins' (SEs) types. The results of antibiotic resistance pattern showed the highest resistance rates to ß-lactams, tetracycline and erythromycin. CONCLUSIONS: The present analysis showed a significant presence of enterotoxigenic strains of S. aureus and a high rate of staphylococcal enterotoxins among food resources in Iran. However, also the prevalence of MRSA strains is remarkable and requires an improvement of the hygienic conditions to reduce the risk of MRSA dissemination in community and hospitals. Furthermore, the rational use of antibiotics in the environments related to food resources is recommended.
