Cockroaches as Reservoirs, Vectors, and Potential Sentinels of Multidrug-Resistant Bacteria in Ugandan Communities: A...

Background: Cockroaches could play a role in the transmission dynamics of antimicrobial-resistant bacteria (ARB) at variable interfaces in Ugandan communities, acting as both reservoirs and vectors. This study investigated the burden and diversity of ARB carried by cockroaches in human settlements in Uganda, so as to understand their role in the spread of these pathogens and their potential as sentinels in antimicrobial resistance (AMR) surveillance programs. Materials and Methods: A retrospective analysis was conducted on two unpublished studies by Makerere University students. Study one and study two sampled 58 and 110 cockroaches, respectively, from secondary schools in Kampala. Cockroach species identification was determined based on physical characteristics. Bacterial isolation and characterization were performed through microbiological analyses including standard culture methods, biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), disc diffusion method, and polymerase chain reaction (PCR). Results: Majority of the cockroaches (over 80%) were Periplaneta americana. Multidrug resistance (MDR) was prevalent among the isolates, with over 30% of the isolates being resistant to three or more antibiotic classes. Specifically, MDR (over 90%) was rampant in the extended spectrum beta-lactamase (ESBL)- or AmpC-producing Escherichia coli and enterococci isolates. Critical World Health Organization (WHO) priority pathogens, such as ESBL-/AmpC-producing Enterobacteriaceae, and carbapenem-resistant E. coli, were also identified. The most abundant resistance determinants (tetracycline and sulphonamide) were tetA, sul1, and sul2 for E. coli, and tetM and tetL for enterococci. Conclusion: The findings accentuate the potential role of cockroaches: (1) in transmitting multidrug-resistant bacteria at the human-animal-environment interface and (2) as sentinels in the surveillance of community-generated AMR.