Ephrem Tamrat

Uropathogenic Escherichia coli (UPEC) is a major cause of urinary tract infections (UTIs), with multidrug resistance (MDR) and biofilm formation complicating treatment. This study isolated and phenotypically characterized bacteriophages targeting MDR and biofilm-forming UPEC from hospital sewage in Ethiopia. Twenty-three archived MDR UPEC isolates were screened for biofilm formation, and phages were characterized by host range, efficiency of plating, multiplicity of infection (MOI), adsorption kinetics, one-step growth, environmental stability, and biofilm biomass reduction. Eight isolates (34.8%) formed biofilms, including 3 strong, 1 moderate, and 4 weak biofilm formers. Two phages, ΦET-3175 and ΦFETA-207, were isolated with titers of 1.35 × 10⁹ and 1.12 × 10⁹ PFU/mL, respectively. ΦET-3175 showed broader activity, with detectable activity against 6/23 (26.1%) isolates, an optimal MOI of 0.1, > 95% adsorption within 20 min, a latent period of approximately 30 min, and a burst size of 147 ± 4.6 PFU per infected cell. Both phages retained detectable activity across pH 4–10 and at temperatures up to 50 °C. ΦET-3175 reduced biofilm biomass by 3.2–39.5% among four susceptible biofilm-forming isolates, but the paired difference was not statistically significant (Z = − 1.826, p = 0.068). These findings provide preliminary in-vitro phenotypic evidence and support further genomic, structural, and biological characterization.

Acinetobacter baumannii and Pseudomonas aeruginosa are multidrug-resistant Gram-negative pathogens increasingly resistant to colistin, a last-resort antibiotic. This study estimated the pooled prevalence of colistin resistance among clinical isolates of these bacteria in Africa. Relevant studies were retrieved from PubMed, Scopus, ScienceDirect and Google Scholar. Eligible studies reported colistin resistance in A. baumannii and P. aeruginosa from clinical specimens in Africa using EUCAST or CLSI standards. Data were analysed in STATA 17 using a random-effects model. Heterogeneity was assessed with the I² statistic, and publication bias with Egger’s test. Subgroup and sensitivity analyses explored heterogeneity sources. Twenty-five studies on A. baumannii and seventeen on P. aeruginosa were included. The pooled prevalence of colistin resistance was 13.75% (95% CI: 5.99%–21.51%), for A. baumannii and 14.42% (95% CI: 3.35%–25.48%) for P. aeruginosa, both showing high heterogeneity I² > 99%. Resistance varied significantly across countries P ≤ 0.001. In A. baumannii, prevalence was 18.26% in Egypt and 10.89% in South Africa, with regional rates of 10.9%, 13.53% and 20.05% in Southern, North and East Africa, respectively. For P. aeruginosa, regional rates were 20.73% in East, 10.85% in North and 7.19% in Southern Africa. Resistance rose over time; from 5.64% to 16.45% in A. baumannii and from 2.26% to 30.54% in P. aeruginosa between 2010–2017 and 2018–2023. Colistin resistance in A. baumannii and P. aeruginosa is rising across Africa, emphasizing the urgent need for robust antimicrobial stewardship, infection control and molecular surveillance.

Enterococcus faecalis (E. faecalis) is a major cause of healthcare-associated infections (HAIs). It exhibits a strong biofilm-forming ability, which contributes to treatment resistance and persistence. Despite its clinical relevance, the global prevalence of biofilm-forming E. faecalis remains poorly defined. This study aimed to estimate the pooled prevalence of biofilm-forming E. faecalis in clinical isolates worldwide. Following PRISMA 2020 guidelines, we systematically searched PubMed, Scopus, ScienceDirect, Google Scholar, and institutional repositories for studies published between 2015 and 2024. A total of 56 studies involving 3,739 clinical isolates met the inclusion criteria. We used a random-effects model to estimate pooled prevalence and conducted subgroup analyses based on WHO region, continent, publication year, specimen type, and biofilm detection method. Meta-regression and sensitivity analyses assessed heterogeneity and robustness. Publication bias was evaluated using Egger’s test and corrected with trim-and-fill analysis. The global pooled prevalence of biofilm-forming E. faecalis was 68.68% (95% CI: 61.33–76.02%), with significant heterogeneity (I² = 99.30%). By WHO region, prevalence ranged from 57.93% (95% CI: 41.01–71.85%) in South-East Asia to 73.66% (95% CI: 63.40–83.92%) in the Eastern Mediterranean. By continent, South America (all from Brazil) showed the highest prevalence at 89.79% (95% CI: 73.02–106.56%). Studies from 2021 to 2024 reported higher prevalence (76.18%, 95% CI: 66.25–86.11%) than those from 2015 to 2020. Among specimens, urine showed the highest prevalence (80.47%, 95% CI: 61.17–99.77%). Among biofilm-positive isolates, 47.92% (95% CI: 39.34–56.51%) were strong producers. Meta-regression identified WHO region (p = 0.005) and specimen type (p = 0.043) as significant sources of heterogeneity. Egger’s test indicated publication bias (p = 0.0066), but trim-and-fill analysis yielded a consistent adjusted prevalence of 68.08%. Biofilm formation is highly prevalent in E. faecalis clinical isolates globally, with substantial regional and specimen-based variation. These findings highlight the urgent need for standardized biofilm detection protocols, improved infection prevention and control, tailored antibiotic stewardship, and the development of anti-biofilm therapies to mitigate biofilm-associated resistance and enhance patient outcomes.