WHO Bacterial Priority Pathogens in Skin and Soft Tissue Infections: Prevalence, Antimicrobial Resistance and Risk Factors in Mwanza, Tanzania

Objectives Antimicrobial resistance (AMR), particularly among World Health Organization bacterial priority pathogens (WHO-BPPs), poses a major global health threat. We assessed the epidemiology of wound infections, including bacterial profiles, WHO-BPP burden, and associated factors, during and after the National Action Plan on AMR (NAP-AMR) in Mwanza, Tanzania. Methods A cross-sectional study was conducted during (June 2019–June 2020) and after (March–August 2023) NAP-AMR. Pus samples were cultured aerobically. Isolates were identified using Vitek mass spectrometry and 16S rRNA sequencing. Antimicrobial susceptibility testing and MICs were determined using VITEK 2. Results Among 630 patients (median age 29 years; IQR 15–47), 257 (40.8%) had positive cultures. Skin and soft tissue infections increased significantly after NAP-AMR (27.8% vs. 68.3%, p<0.001). Resistance to third-generation cephalosporins (3GCs) increased significantly in E. coli (p<0.05). Additionally, meropenem resistance among Gram-negative bacteria (GNB) increased from 2.6% to 21.0% (p=0.327), primarily attributable to the increased isolation of Acinetobacter spp. and P. aeruginosa after NAP-AMR. WHO-BPPs accounted for 45.2% of isolates, and ESBL-producing Enterobacterales (ESBL-PE) increased significantly (64.8% vs. 82.5%, p=0.025), particularly in higher-tier hospitals (45.4% vs. 77.9%, p=0.002). Conclusion We recorded significant increases in resistance to 3GCs among E. coli , increased resistance to meropenem among GNB notably Acinetobacter spp. and P. aeruginosa , and high proportion of WHO-BPPs, particularly ESBL-PE, after NAP-AMR, potentially reflecting improved diagnostics, enhanced laboratory capacity, or heightened antimicrobial use during the COVID-19 pandemic, underscoring the need for sustained surveillance and strengthened antimicrobial stewardship.