Five-year antimicrobial resistance trends and facility antibiogram at Dodoma Regional Referral Hospital, Tanzania: a retrospective study (2018–2023)

Abstract Background: Antimicrobial resistance (AMR) represents an escalating public health crisis, disproportionately affecting low- and middle-income countries where empirical prescribing and limited diagnostic capacity drive inappropriate therapy. No published longitudinal antibiogram data exist for Dodoma Regional Referral Hospital, leaving clinicians reliant on uninformed empirical prescribing. This study characterized AMR patterns and antibiogram trends among bacterial isolates at Dodoma Regional Referral Hospital (DRRH), Tanzania. Methods: A hospital-based retrospective study was conducted using Laboratory records covering 363 culture-positive bacterial isolates from January 2018 to May 2023 were extracted using a structured checklist and analyzed following Clinical and Laboratory Standards Institute guidelines (CLSI) guidelines. Antimicrobial Susceptibility Testing (AST) followed CLSI data were analyzed using SPSS version 25, with chi-square to identify significant resistance associations at 0.05 significance level. Results: Among 363 bacterial isolates generating 591 resistance events, Staphylococcus aureus (41.6%) and Escherichia coli (32.8%) predominated. Resistance burden peaked in 2022 (26.2%) and 2020 (20.6%). Among Gram-negative isolates, ceftazidime resistance was disproportionately elevated in blood p = 0.01), while ciprofloxacin resistance predominated in urine (p = 0.02). Enterobacter spp. showed significantly higher ceftriaxone resistance than expected (p =0.02), whereas E. coli contributed 52 resistant isolates each for gentamicin and ciprofloxacin. Meropenem retained near-complete activity (99.5%). Among Gram-positive isolates, clindamycin resistance was most strongly specimen-associated (χ² = 13.71; p < 0.01), with gentamicin (χ² = 8.06; p = 0.02) and cefoxitin (χ² = 5.66; p = 0.03) resistance also significantly specimen-dependent. Ciprofloxacin resistance remained persistently elevated across all years, peaking at 29.5% in 2020. Conclusion: Significant, specimen- and organism-dependent AMR was demonstrated across common pathogens at DRRH. Ciprofloxacin and gentamicin resistance warrant prioritization in facility stewardship protocols, while carbapenem preservation should be actively monitored. Additionally, these findings underscore the urgent need for continuous surveillance and facility-specific antibiograms to guide empirical therapy and reinforce stewardship programs in Tanzania.