Isolation and Characterization of Bacteria Culture Mimics of Vibrio Cholerae from Drinking Water Samples in Internally Displaced Persons (IDPS) Camps Within North Central Nigeria

Accurate identification of waterborne pathogens is critical for preventing outbreaks in humanitarian settings, particularly in internally displaced persons (IDP) camps where overcrowding and poor sanitation heighten disease risk. This study investigated the isolation and characterization of Vibrio cholerae culture mimics from drinking-water sources across IDP camps in Benue, Nasarawa, and Plateau States within North Central Nigeria. A total of 144 water samples were collected from wells, boreholes, streams, dams, water tanks, and rivers. Water samples were processed using membrane filtration, a 0.45 µm pore-size membrane filter was used to concentrate bacteria, after which the filters were placed into alkaline peptone water (APW) and incubated for 6–8 hours at 37 °C for enrichment. Following enrichment, the filter paper were aseptically picked and placed onto thiosulfate-citrate-bile salts-sucrose (TCBS) agar and incubated at 37 °C for 24 hours. Yellow sucrose-fermenting colonies presumed to be Vibrio-like were further sub-cultured on nutrient agar to obtain pure cultures and were subjected to oxidase testing and phenotypic characterization. Thirteen isolates (9.0%) exhibited Vibrio-like phenotypes, including yellow TCBS colonies, oxidase positivity, and motility. These isolates were suspected to be Vibrio cholerae based on conventional and some biochemical reactions especially the negative reaction they gave with polyvalent typing sera for Vibrio cholerae 01 and 0139. However, whole genome sequencing (WGS) confirmed no Vibrio cholerae among the recovered organisms. Instead, six isolates were successfully sequenced and identified as Aeromonas dhakensis (n = 3), Aeromonas hydrophila (n = 1), and Providencia alcalifaciens (n = 2). The distribution of these bacteria varied across water sources, with Aeromonas species predominantly isolated from surface-related sources such as rivers, dams, and wells, while Providencia alcalifaciens was recovered from borehole and well water. These results demonstrate that reliance on culture-based identification alone can lead to misclassification of Vibrio species, potentially resulting in incorrect epidemiological interpretations. The presence of Aeromonas and Providencia species—both associated with gastrointestinal infections—indicates compromised water quality and underscores the public-health risks faced by displaced populations. The study highlights the importance of integrating molecular tools into water-surveillance systems to ensure accurate detection and guide effective interventions in resource-limited settings.