Swabs from dishwasher samples were collected and cultured on different media, and then a gram stain was conducted on pure colonies to find whether they were Gram-positive or negative. 32-gram negative Isolates were obtained from the dishwasher; then, we chose isolates under study depending on morphological features on previous media for further investigation. 32 Gram-negative isolates were obtained from a dishwasher, and three isolates of Klebsiella pneumoniae were diagnosed by some phenotypic characteristics and approved by using 16 SrRNA partial sequencing analyses. The 3 isolates deposited in the NCBI database under accession number OK 254156.1 for K.pneumoniae strain NPK 323, OK 247423.1 for K. pneumonia as strain CUMB SAM-61, and OK245427.1 for K. pneumonia strain PD17. The phylogenetic tree for 3 isolates was done by using MEGA II software. Many experiments have been conducted on two isolates (OK 247423.1 and OK245427.1 ) because the OK 254156.1 strain was lost during laboratory work and repeated cultures. A hemolysis test on blood agar and a lipase test on egg–yolk agar were done; both isolates showed negative results for hemolysis blood and producing lipase enzyme, while both isolates showed their ability to produce lecithinase enzyme. The two isolates gave an excellent result in the tube method for the biofilm formation test. Also, a good candidate production test was obtained for these two isolates using L.B. acetate agar medium. Conclusion: Bacterial species differ according to the environments in which they live, as the species that are isolated from clinical sources and possess many virulence factors that make them more dangerous and pathogenic to humans differ about the same species if isolated from a variety of external environments, which makes them virulent or have new characteristics that make them adapted to live in the environments from which they are isolated.
Keywords: Klebsiella pneumonia, virulence factor, extreme conditions, phylogenetic tree.