Multidrug Resistance in Bacterial Isolates from Clinical Samples Submitted to a National Veterinary Diagnostic...

Background/Objectives: Antimicrobial Resistance (AMR) is a pressing global animal and public health challenge. There is limited data on AMR prevalence, trends, and drivers in bacterial pathogens from animal sources in Uganda. Thus, this study investigated the occurrence and factors associated with multidrug resistance (MDR) in bacterial isolates recovered from clinical samples of animals submitted to the national veterinary diagnostic laboratory in Uganda. Methods: A retrospective study analyzed antibiogram data of bacteria from animal samples submitted to the Central Diagnostic Laboratory, Makerere University in Uganda between 2014 and 2020. The cleaned dataset comprised 590 cases with antibiogram data. Statistical analyses were conducted using R software version 4.5.2. Results: Gram-negative bacteria were predominant (74.4%) among the samples from clinical cases. The overall MDR proportion in the general bacteria population was 41.7% over the seven-year period. Among the clinically relevant bacteria, MDR was highest in Escherichia coli (57.2%), followed by Staphylococcus aureus (35.8%) and Salmonella (15.5%). Univariable screening of predictors hypothesized that MDR was influenced by year of case submission, animal host type, and bacterial group (p < 0.05). Multivariable logistic regression showed that isolates submitted in 2019 (vs. 2015) had significantly higher odds of MDR (aOR = 4.21; 95% CI: 1.62-13.14), indicating a marked temporal increase in resistance. Gram-negative bacteria (vs. Gram-positives) were also more likely to exhibit MDR (aOR = 1.62; 95% CI: 1.07-2.48). Conclusions: The high occurrence of MDR in bacterial pathogens from animal clinical submissions revealed the need for improved antimicrobial stewardship and integrated AMR surveillance in Uganda, particularly within the central region from which most diagnostic samples originated.