ABSTRACT
Background@#Acinetobacter baumannii is one of the most important hospital pathogenic bacteria that cause infectious diseases. The present study aimed to determine the frequency of carbapenem resistance genes in association with transposable elements and molecular typing of carbapenem-resistant A. baumannii bacteria collected from patients in Shiraz, Iran. @*Materials and Methods@#A total of 170 carbapenem-resistant A. baumannii isolates were obtained from different clinical specimens in two hospitals. The minimum inhibitory concentrations (MIC) of imipenem were determined and the prevalence of OXA Carbapenemases, Metalloβ-lactamases genes, insertion sequences (IS) elements, and transposons were evaluated by the polymerase chain reaction (PCR) method. Finally, molecular typing of the isolates was performed by the Enterobacterial Repetitive Intergenic Consensus-PCR method. @*Results@#The MICs ranged from 16 to 1,024 µg/mL for imipenem-resistant A. baumannii isolates. Out of the 170 carbapenem resistant A. baumannii isolates, bla OXA-24-like (94, 55.3%) followed by bla OXA-23-like (71, 41.7%) were predominant. In addition, A. baumannii isolates carried bla VIM (71, 41.7%), bla GES (32, 18.8%), bla SPM (4, 2.3%), and bla KPC (1, 0.6%). Moreover, ISAba1 (94.2%) and Tn2009 (39.2%) were the most frequent transposable elements. Furthermore, (71, 44.0%) and (161, 94.7%) of the ISAba1 of the isolates were associated with bla OXA-23 and bla OXA-51 genes, respectively. Besides (3, 1.7%), (1, 0.6%) and (5, 2.9%) of bla OXA-23 were associated with IS18, ISAba4, and ISAba2, respectively. Considering an 80.0% cut off, clusters and four singletons were detected. @*Conclusion@#According to the results, transposable elements played an important role in the development of resistance genes and resistance to carbapenems. The results also indicated carbapenem-resistant A. baumannii bacteria as a public health concern.
ABSTRACT
Background: Escherichia coli, known as a clinically significant bacteria, can cause a wide range of infections, including urinary tract infections [UTIs], blood stream infections [BSIs], and can frequently be isolated from various clinical specimens. Evaluation of antimicrobial resistant pattern is a necessary action, especially about such bacteria which are frequent and life threatening. The aim of this study was to determine the frequency and antimicrobial resistance pattern of E. coli isolates obtained from various clinical specimens
Methods: This retrospective study was performed within a seven month period from January 2015 to August 2015 at a specialized women and children hospital in Shiraz, Iran. E. coli isolates were obtained from various clinical specimens and identified using standard microbiological procedure. Antimicrobial susceptibility patterns were determined using disk diffusion method in accordance with CLSI recommendation
Results: Of the total 130 positive cultures, the majority of E. coli isolates were obtained from urine [96=73.8%] and blood [11=8.5%] specimens. Overall, gentamicin [70.8%] was the effective antibiotic for the tested E. coli isolates. E. coli isolates obtained from urine specimens showed the highest resistance rates against ampicillin [84.4%] and nalidixic acid [61.5%]; while they showed the most sensitivity to gentamicin [79.2%], nitrofurantoin [70.8%] and ciprofloxacin [66.7%]. Moreover, the highest antibiotic resistance rates belonged to the isolates recovered from endotracheal tube [ETT]
Conclusion: The results showed that gentamicin was the most effective antibiotic against E. coli infections. However, in addition to the gentamicin, we can recommend nitrofurantoin and ciprofloxacin as the other effective agents for UTIs