Bacteriological analysis and antibiotic resistance in patients with suspected septicemia in Dhaka, Bangladesh

Abstract

The objective of our study was to isolate bacteria from septicemia patient’s blood and subsequently analyze their antibiotic resistance pattern. We collected 80 blood samples from four different branches of Islami Bank Hospital (Mirpur, Kakrail, Motijheel, and Nayapaltan) in Dhaka, Bangladesh. Isolating one bacterial colony from a blood culture plate of selective media. Then, based on colony morphology, selecting the bacterial colonies and subculturing them for presumptive identification. Confirming their identity through biochemical tests (catalase test, oxidase test) and molecular test (polymerase chain reaction) followed by gel electrophoresis (for visualizing the band size of targeted microorganisms). Among the 80 samples, 66 samples were culture positive. From positive cultures, 65.2% were Salmonella typhi, 13.6% were Klebsiella pneumoniae, 12.1% were Escherichia coli, and 9.1% were Staphylococcus aureus. 22% were gram-positive and 77% were gram-negative) For antibiotic susceptibility tests (AST), we selected one isolate from each culture-positive sample. Total 8 Escherichia coli, 43 Salmonella typhi, 9 Klebsiella pneumoniae, and 6 Staphylococcus aureus isolates were selected and AST was performed using the Kirby-Bauer disc diffusion method. We observed that 90% to 100% of the Salmonella typhi isolates 89% and 79% were resistant to Nalidixic acid and Ampicillin respectively. 68%, 79% and 39 % of Klebsiella pneumoniae isolates were resistant to Amoxicillin, Cefixime and Erythromycin respectively. 69% and 80% of all Escherichia coli isolates were resistant to Amoxicillin and Cefixime respectively, and 28% of the isolates were resistant to Azithromycin, Ciprofloxacin, Imipenem, Ceftriaxone. 49% of all Staphylococcus aureus isolates were resistant to Cefixime, Sulfamethoxazole and Ceftazidime, 28% were resistant to Erythromycin and Ceftriaxone, and 19% were resistant to Imipenem and Gentamicin. In this study, a total of 18 isolates were identified as multi-drug resistant (MDR), including 7 Salmonella typhi, 6 Klebsiella pneumoniae, 2 Escherichia coli, and 3 Staphylococcus aureus strains. Among these, 3 isolates were further classified as extensively drug-resistant (XDR), comprising 1 Salmonella typhi, 1 Klebsiella pneumoniae, and 1 Staphylococcus aureus isolate.