ABSTRACT
The present study aimed to evaluate TEM-1 or -2 and SHV-1 ß-lactamases frequency in multidrug-resistant (MDR) Enterobacteriaceae isolated from patients' urine in northern Iran. The resistance pattern to 20 antibiotics and ESBL production in 200 MDR Enterobacteriaceae was detected using the disk diffusion test and double-disk synergy test (DDST), respectively. Multiplex PCR was applied to detect blaTEM-1 or -2 and blaSHV genes in isolates. DDST findings were inconsistent with multiplex PCR results. The distribution of each of blaTEM-1 or -2 and blaSHV genes, either alone or in combination, in the ESBL-producing isolates was higher than the non-ESBL-producing isolates. There was a significant effect of the presence of blaTEM-1 or -2 gene on resistance to cephalotin at the p < 0.01 level and cefepime, tetracycline, and streptomycin at the P < 0.05 level, and the presence of blaSHV-1 gene on resistance to fosfomycin at the P < 0.05 level as well as the presence both blaTEM-1 or -2 and blaSHV-1 genes on resistance to cephalotin and fosfomycin at the P < 0.01 level. In all isolates, ESBL production, except for cephalotin resistance, did not improve resistance to other antibiotics used and even non-ESBL-producing isolates showed higher resistance to antibiotics compared to ESBL-producing isolates. It seems that mechanisms other than production of ESBL to be involved as part of the resistance mechanisms of the studied isolates against the used antibiotics. For epidemiological studies, both phenotypic and molecular tests must be included to identify the blaTEM-1 or -2 and blaSHV-1 genotypes to ensure infection prevention and control.
Subject(s)
Drug Resistance, Multiple/genetics , Enterobacteriaceae/pathogenicity , beta-Lactamases/analysis , Adult , Analysis of Variance , Enterobacteriaceae/immunology , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/urine , Female , Humans , Iran/epidemiology , Male , Microbial Sensitivity Tests/methods , Polymerase Chain Reaction/methods , Prevalence , beta-Lactamases/metabolismABSTRACT
BACKGROUND AND OBJECTIVES: Larval therapy refers to the use of Lucilia sericata larvae on chronic wounds, which is a successful method of chronic wounds treatment. The secretions of these larvae contain antibacterial compounds and lead to death or inhibition of bacterial growth. MATERIALS AND METHODS: In this study, we investigated the antibacterial effects of Lucilia sericata larvae secretions which were in sterilized and multi antibiotic-resistant bacteria-treated forms on Gram-positive Bacillus subtilis bacteria and Gram-negative Escherichia coli bacteria. In the following, we evaluated changes in gene expression of lucifensin and attacin during treatment with multi antibiotic-resistant bacteria. Investigation of the antibacterial effect was carried out using optical absorption and antibiotic disk diffusion in order to study the expression of the aforementioned genes. RESULTS: The results of this study showed that E. coli-treated larvae were able to inhibit the growth of E. coli and secretions of B. subtilis-treated larvae and were also able to inhibit the growth of B. subtilis. Gene expression of antibacterial peptides in multi antibiotic-resistant bacteria-treated larvae was increased in comparison to non-treated larvae. CONCLUSION: Due to the significant antibacterial potency of bacteria-treated larvae secretions, the secretions can be a suitable candidate as a drug against antibiotic resistant bacteria, but additional tests are required. Since the antimicrobial peptides of insects have not yet produced any resistance in human pathogenic bacteria, they can be considered as a promising strategy for dealing with resistant infections.
