Molecular Identification and Antibiotic Profile of Respiratory Tract Escherichia coli and Enterobacter Species Isolated from HIV Patients Attending Gombe State Specialist Hospital, Nigeria

Abstract

A significant worldwide health burden, respiratory tract infections (RTIs) are particularly destructive to immunocompromised people, such as those living with HIV. Treatment of infections in HIV patients is severely hampered by the advent of multidrug-resistant (MDR) bacteria, such as Enterobacter species and Escherichia coli. This study used molecular techniques to identify respiratory tract Escherichia coli and Enterobacter species. It assessed the antibiotic profile of the prevalent bacteria among HIV patients attending Gombe State specialist hospital from August 2023 to May 2024. Three hundred and ten (310) sputum samples were taken from the ART clinic at Gombe State Specialist Hospital, and cultured for 18–24 hours at 37oC on Blood agar and MacConkey agar. The putative discrete colonies obtained after incubation were identified based on cultural characteristics, gram staining, conventional biochemical tests, and molecular analysis. The results revealed that 121 (39.0%) yielded positive growth of 82(67.77%) and 39(32.2%) for Gram-positive and Gram-negative bacteria, respectively. The results of phenotypic identification revealed that, all the 39 Gram-negative bacteria were found to be Enterobacter species (25) and E. coli (14). Based on the nucleotide BLAST search of the sequenced 16SrRNA genes at the National Centre for Biotechnology, the 16S rRNA identification from two representative bacteria, one isolate each for Enterobacter species and E. coli corroborates with cultural, morphological, and biochemical testing, demonstrating that the isolated bacteria belonged to Enterobacter species and Escherichia coli. The antimicrobial susceptibility testing showed that the isolates demonstrated varying degrees of susceptibility and resistance to fourteen (14) antibiotics of different classes used in the study. Amoxiclav was more active against Enterobacter (20/25, 80.0%) and E. coli (14/14, 100%) while Cefotaxime was completely resisted by the Enterobacter (11/11, 100%) and E. coli (12/12, 100%). High resistance rates were observed for third and fourth generation cephalosporins (Ceftriaxone, Cefotaxime, Cefepime), indicating the possible production of extended-spectrum beta-lactamase (ESBL) by the bacteria. Meropenem, Amoxiclav, and Gentamicin were the most effective antibiotics, showing sensitivity rates above 50% in both bacterial groups. The prevalence of multidrug-resistant (MDR) strains of both Enterobacter species and Escherichia coli was 66.7%, which highlights the need for exploring combination therapy, particularly Meropenem + Amoxiclav or Aminoglycosides + Beta- lactamase inhibitors, to enhance treatment efficacy. Carbapenems (Meropenem), Beta-lactamase inhibitors (Amoxiclav), and Aminoglycosides (Gentamicin) should be prioritized for empirical treatment, given their higher sensitivity rates (>50%) against Enterobacter species and Escherichia coli. The findings emphasize the urgent need for enhanced antimicrobial stewardship, infection control measures, and molecular surveillance to mitigate the rising threat of MDR Enterobacter species and E. coli in HIV patients.