Plasmid-Mediated Multidrug Resistance in Bacteria from Hibiscus sabdariffa (Zobo) Beverages: Public Health Implications for University Communities in Nigeria

Foodborne pathogens and antimicrobial resistance (AMR) pose escalating global health challenges, particularly in low- and middle-income countries, where the informal food and beverage sectors remain largely unregulated. Hibiscus sabdariffa–based beverages, popularly known as zobo in Nigeria, are widely consumed for their nutritional and medicinal properties. However, traditional preparation may predispose them to microbial contamination. This study examined the presence of plasmid-mediated multidrug resistance bacteria in zobo drinks sold within Edo State University Iyamho, Nigeria. Bacteria isolation from five zobo drink samples was carried out using standard microbiological methods. Isolated bacteria were assessed for multidrug resistance (MDR) using the Kirby-Bauer disc diffusion method. The presence of extrachromosomal DNA, hlb and pbp genes were detected using polymerase chain rection (PCR). The zobo drinks revealed the presence of pathogenic as well as opportunistic bacteria, including Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis, Micrococcus luteus, and Enterococcus faecalis. Antibiotic susceptibility testing revealed MDR with resistance indices ranging from 0.4 to 0.6. Plasmid curing experiments indicated that resistance was largely plasmid-mediated with resistance indices ranging from 0.0 to 0.2. Plasmid profiling confirmed the presence of extrachromosomal DNA in isolated bacteria. Molecular assays further amplified the hlb (beta-hemolysin) and pbp (penicillin-binding protein) genes in bacteria isolates, underscoring the virulence and resistance potential of the isolates. These findings highlight zobo drinks as potential reservoirs of AMR bacteria, with implications for food safety and public health in densely populated university settings and calls for the urgent need for improved hygiene practices and AMR surveillance in informal food sectors.