Investigating Aminoglycoside Resistance in E.coli Isolates from Pneumonia: A Dual Phenotypic and Genotypic Approach

Abstract

Introduction: Escherichia coli is a gram-negative facultative anaerobe bacteria of the family Enterobacteriaceae and causes a plethora of infections, both community and hospital-acquired. This is a Gram-negative bacillus, which is a facultatively anaerobic, organism with fermentative ability and is known for its pathogenicity. Main Antibiotic resistance mechanisms include; decreased expression and function of porins, modification of antibiotic targets, as well as enzymatic degradation of antibiotics.

Objective: The primary purpose of the study was to observe E. coli profiles of aminoglycoside-resistant E. coli isolated from clinical samples based on genotypic and phenotypic analysis.

Methodology: Isolation of bacterial pathogens was done as per CLSI guidelines, and conventional microbiological techniques were used. The bacterial pathogens from the respiratory specimens were identified through culture and confirmed by PCR, after which DNA was extracted and the DNA bands were stained with the aid of gel electrophoresis. Primers for aminoglycoside resistance genes in Escherichia coli were obtained by PCR with the aid of specific primers of aminoglycoside resistance genes in Escherichia coli. Descriptive statistical analysis was therefore conducted using SPSS to produce a frequency distribution graph for patients of different ages. The study also presented percentage-based gender distribution, means, and standard deviations and bar charts were used to display the data.

Results: There were 42 males and 38 females among the 80 isolates obtained from patients. On microscopy, it was confirmed to be a Gram-negative, rod-shaped Bacillus. The organism showed clear biochemical differentiation through biochemical tests. About 85 % of the samples were resistant to aminoglycosides, carbapenems, cephalosporins and fluoroquinolones. Moreover, 80% of the bacterial isolate was resistant to colistin bacterial antibiotic. In samples of aminoglycoside-resistant Escherichia coli strains, the armA gene was identified in about 86%. The rest of the 14% (positive strains) were sensitive to aminoglycoside showing the absence of any bands in the electrophoresis test.

Conclusion: The results of the study confirm a highly studied bacterium, Escherichia coli, as a multidrug-resistant bacterium, especially against aminoglycosides and also reemphasize the importance of further research and practice of proper use of antibiotics. The need to design therapeutic approaches which would effectively address the increasing phenomenon of MDR in E. coli is therefore highlighted in the study as an essential step towards enhancing the nature and quality of treatment.