Understanding bacterial diversity, infection dynamics, prevention of antibiotic resistance: an integrated study in an Algerian hospital context.

Abstract

Bacterial infections, particularly bacteremia, urinary tract infections (UTIs), and pus infections, remain among hospitals' most worrying medical problems. This study aimed to explore bacterial diversity, infection dynamics, and antibiotic resistance profiles of bacterial isolates. We analyzed data from 1750 outpatients and 920 inpatients, of whom 1.6% and 8.47% respectively had various bacterial infections. The analysis revealed that UTIs were the most prevalent at 41.01%, particularly affecting women. UTIs also showed a distinct distribution across admission departments, notably in emergency (23.07%) and pediatric (14.10%) units. The most frequently isolated microorganisms were Escherichia coli (E. coli), followed by Klebsiella ornithinolytica. Skin infections followed UTIs, accounting for 35.88% of cases, more prevalent in men, with Staphylococcus aureus (S. aureus) being the primary pathogen (57%). Gram-negative bacteria (GNB) like E. coli and Pseudomonas aeruginosa contributed significantly to skin infections (43%). Bacteremia cases constituted 11.52% of bacterial infections, predominantly affecting women (67%) and linked to GNB (78%). A comparative study of antibiotic susceptibility profiles revealed more pronounced resistance in GNB strains isolated from inpatients, particularly to antibiotics such as Amoxicillin/clavulanic acid, Tetracyclin, Gentamicin, Chloramphenicol, and Ampicillin. In contrast, strains from ambulatory patients showed greater resistance to Colistin. Gram-positive bacteria from hospitalized patients showed higher resistance to quinolones and cephalosporins, while ambulatory strains showed high resistance to aminoglycosides, macrolides, fluoroquinolones, and penicillin. Furthermore, these analyses identified the most effective antibiotics for the empirical treatment of both community-acquired and nosocomial infections. Ciprofloxacin, aztreonam, and amikacin exhibited low resistance rates among GNB, with gentamicin and chloramphenicol being particularly effective for community-acquired strains. For S. aureus, ciprofloxacin, rifampicin, and cefoxitin were especially effective, with vancomycin showing high efficacy against community-acquired isolates and fosfomycin and chloramphenicol being effective for hospital-acquired strains. These results are essential for guiding antibiotic therapy and improving clinical outcomes, thus contributing to precision medicine and antimicrobial stewardship efforts.