Reservoirs, Antibiotic Susceptibility, and Molecular Characterization of Pseudomonas Species in Community and Hospital Environments in Kisumu County, Kenya
| dc.contributor.author | Mubassu, Polly N. | |
| dc.date.accessioned | 2026-03-26T08:56:08Z | |
| dc.date.available | 2026-03-26T08:56:08Z | |
| dc.date.issued | 2025-08 | |
| dc.description | A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science in Infectious Diseases (Clinical Bacteriology) in the School of Health Sciences of Kenyatta University, August, 2025 Supervisor: 1.Abednego Musyoki 2.Lillian Musila | |
| dc.description.abstract | Pseudomonas are Gram-negative bacteria that easily form biofilms in moist environments, enabling their prolonged persistence and colonization in water piping systems, sinks and swimming pools. They present risk of severe opportunistic infections in people with lowered immunity. Multidrug-resistant (MDR), carbapenem non-susceptible Pseudomonas species are more difficult to treat. MDR strains present serious challenges within healthcare settings; however, there are scanty reports about reservoirs of these strains in resource-constrained settings with high community-acquired Pseudomonas infections to inform infection prevention interventions. This study determined reservoirs, antibiotic susceptibility, molecular characteristics, and genetic relatedness of Pseudomonas species in the hospital and community sources of water in Kisumu, Kenya where communal derived infections due to Pseudomonas are on the rise. A cross-sectional study design was conducted, purposively collecting samples (297) from tanks, tap-heads, sinks, household and vendor water jerry cans in six sub-locations and Kisumu County Referral Hospital (KCRH) within Kisumu municipality. Standard microbiological tests were utilized for analysis. Bacterial isolation was conducted on CHROMagarTM Pseudomonas, identification done using standard biochemical tests, and antimicrobial susceptibility testing (AST) performed on VITEK 2, The AST data was interpreted based on 2022 Clinical Laboratory Standards Institute (CLSI). Carbapenem and colistin resistance genes were screened using multiplex PCR while Enterobacterial repetitive Intergenic Consensus- Polymerase Chain Reaction (ERIC-PCR) typing was used to infer strain diversity between the environmental and clinical isolates. Pseudomonas species were isolated from 14.1% (42/297) of the sample, mainly in the community environment at 10.4% (31/297). Seven dissimilar Pseudomonas species were isolated, the predominant overall being P. aeruginosa (6.7%, 20/297), in the community (5.7%, 17/297) and in tanks. Different levels of non-susceptibility to antibiotics were documented among the isolates; piperacillin -62% (26/42), tigecycline-57% (24/42), meropenem -24% (10/42), cefepime - 21% (9/42), levofloxacin- 19% (8/42) and colistin- 14% (6/42). Most of the carbapenem-resistant strains were P. aeruginosa 80% (8/10), mostly isolated in Milimani sub-location. MDR rate of 45% (19/42) was recorded among the study isolates, majorly community-related carbapenem resistant P. aeruginosa (CRPA) (42%, 8/19) strains sensitive to colistin. The MDR Pseudomonas species displayed an increased multiple antibiotic resistance index of between 0.43 and 1. Two genes blaOxa-48 and blaNDM-1 were found among carbapenem-resistant isolates in this study while none of the screened colistin resistance genes (mcr1-5) was identified. There was minimal genetic relatedness between environmental and clinical isolates in all the 7 Pseudomonas species and regarding source, location and AMR. This study shows the increased presence of MDR Pseudomonas in community water sources, among them CRPA, these potential drug resistance conduits are a public health threat to immune-challenged individuals. Scheduled maintenance of municipal water pipes coupled with structured cleaning and treatment of facilities used to store water as well as religious execution of antimicrobial stewardship initiatives, are necessary in eradicating environmental reservoirs of Pseudomonas that predispose the vulnerable populations to antibiotic resistance. | |
| dc.description.sponsorship | Kenyatta University | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/32854 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Reservoirs, Antibiotic Susceptibility, and Molecular Characterization of Pseudomonas Species in Community and Hospital Environments in Kisumu County, Kenya | |
| dc.type | Thesis |