Background Free-living amoeba (FLA) such as Acanthamoeba spp. are ubiquitous protozoa that graze on microorganisms such as bacteria, viruses and algae. However, amoebic resistant microorganisms (ARM) such as Pseudomonas spp. evade being killed by amoeba thus multiplying within the free-living amoeba. Free-living amoeba may therefore enhance transmission of Pseudomonas spp. across hospital environments thus contributing to the burden of nosocomial infections and spread of antimicrobial

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... . In Kenya, nosocomial Pseudomonas spp. infections present a major health challenge but the role of free-living amoeba such as Acanthamoeba spp. in transmission of these infections has so far not been assessed. This study aimed at the isolation of Acanthamoeba spp. from various surfaces and equipment and molecular detection of the Acanthamoeba-associated Pseudomonas spp. Methods This was a descriptive cross-sectional study in which 153 swabs in duplicate (306) were collected from selected surfaces and equipment. Acanthamoeba spp. cultures were performed on one batch of 153 swabs and bacterial cultures on the other batch of 153 swabs. Polymerase chain reaction (PCR) was performed to detect Pseudomonas sp. genomic deoxyribonucleic acid (DNA) within Acanthamoeba spp. isolates. Results The proportion of swabs that had Acanthamoeba spp. isolates was 93.5% (n = 153) while that of bacterial isolates was 82.4% (n = 153). Of 168 bacterial isolates obtained, 10.7% was Pseudomonas spp. Acanthamoeba spp. subcultures were done on 62.7% (n = 153) primary Acanthamoeba spp. isolates. Only 22.9% (n = 96) of the Acanthamoeba spp. subcultures were successful. Pseudomonas sp. genomic DNA was detected in 45.5% (n = 22) of all positive Acanthamoeba spp. subcultures using PCR. Conclusion Pseudomonas sp., an ARM, exists within Acanthamoeba spp. on various surfaces and equipment at KNH ICU. This suggests a possible role of Acanthamoeba spp. in Acanthamoeba- ARM associated nosocomial infections transmission and in spread of antimicrobial resistant genes across microorganisms in hospitals.