Murat Cengiz; Pinar Sahinturk; Gulce Hepbostanci; Halis Akalin; Songul Sonal
Volume 13, Issue 2 , June 2022, , Pages 149-153
Abstract
Due to the high prevalence of multi-drug resistant bacteria, combination therapy is an efficient choice for treatment of infections caused by highly resistant strains. In this study, the efficacy of ceftiofur plus danofloxacin combination was investigated against resistant Escherichia coli. The interaction ...
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Due to the high prevalence of multi-drug resistant bacteria, combination therapy is an efficient choice for treatment of infections caused by highly resistant strains. In this study, the efficacy of ceftiofur plus danofloxacin combination was investigated against resistant Escherichia coli. The interaction between the two drugs was determined by checkerboard tests and time-kill assays. The combination was defined as bactericidal or bacteriostatic based on the minimum bactericidal concentration test results. Mutant prevention concentration test was used to evaluate the resistance tendency suppression potential of the combination. The combination had a synergistic effect against 83.00% of the isolates as verified by the checkerboard and time-kill assays. The combination was defined as bactericidal against all E. coli strains, since minimum bactericidal concentration: minimum inhibitory concentration ratios were below four thresholds and also markedly reduced mutant prevention concentration values of ceftiofur up to 4000-fold compared to its single use. Ceftiofur plus danofloxacin combination inhibited growth of E. coli strains which were resistant to ceftiofur or newer generation of fluoroquinolones. Our results suggest that ceftiofur plus danofloxacin combination has a bactericidal characteristic and can be an important alternative for the treatment of infections caused by resistant E. coli.
Mohsen Kalantari; Hassan Sharifiyazdi; Keramat Asasi; Bahman Abdi-Hachesoo
Volume 12, Issue 1 , March 2021, , Pages 101-107
Abstract
The objective was to investigate the multidrug resistance and presence of class 1 and 2 integrons in 300 Escherichia coli isolates obtained from 20 broiler farms during three rearing periods (one-day-old chicks, thirty-day-old chickens, and one day before slaughter) in Fars, South Iran. Results ...
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The objective was to investigate the multidrug resistance and presence of class 1 and 2 integrons in 300 Escherichia coli isolates obtained from 20 broiler farms during three rearing periods (one-day-old chicks, thirty-day-old chickens, and one day before slaughter) in Fars, South Iran. Results showed that 81.00%, 82.00%, and 85.00% of isolates were multidrug-resistant on the first day, thirty-day-old chickens, and one day before slaughter, respectively. Multidrug-resistant E. coli isolates were further examined for the presence of class 1 and 2 integrons using PCR assay. The existence of class 1 integron-integrase gene (intI1) was confirmed in 68.40%, 72.70%, and 60.90% of multidrug-resistant isolates from stage 1, stage 2, and stage 3 of the rearing period, respectively. The frequency of class 2 integron-integrase gene (intI2) during the first to the third stage of sampling was 2.60%, 25.50%, and 30.40%. Also, sequence analysis of the cassette arrays within class 1 integron revealed the presence of the genes associated with resistance for trimethoprim (dfrA), streptomycin (aadA), erythromycin (ereA), and orfF genes. The results revealed that percentages of antimicrobial resistance in E. coli isolates were significantly higher in the middle and end stages of the rearing period. In conclusion, widespread dissemination of class 1 integrons in all three stages and rising trends of class 2 integrons existence in E. coli isolates during the rearing period of broiler chickens could exacerbate the spread of resistance factors among bacteria in the poultry industry. Future research is needed to clarify its implication for human health.
