Abstract
Klebsiella pneumoniae is zoonotic, Gram-negative bacteria belong to the family
Enterobacteriaceae. The primary goal of this study was to identify and characterize genetic relationship among K. pneumoniae that isolated from clinically infected broilers, human and mastitis milk, and expression of virulence factors, and antimicrobial resistance in multi-drug resistant (MDRs). A total of 88 klebsiella pneumoniae strains were isolated from different hosts (22 from broiler chickens, 48 human and 18 cows) during 2019 -2020 in El -Behira governorate. These strains were primary identified by microscopic examination, traditional biochemical tests and confirmed by using VITEK. Investigation of antibiotic susceptibility of identified isolates revealed that more than 70% of k .pneumoniae strains are multi-drug resistant. ESBL (Extended-spectrum beta-lactamase-producing k.pneumoniae) screening by using the double-disk synergy method and VITEK were determined (4388) (10chicken, 27human, and 6 cows). Capsule, hypermucoviscosity, and hemolytic activity were also, assayed phenotypically.
Results showed that Capsule, hypermucoviscosity, and hemolytic activity were detected in 100%, 30.7%, and 25%, respectively. Biofilm binding activity showed highly, moderately, and weakly adherent observed in 18.1%, 38.6%, and 18.2, respectively. The detection of two virulence genes: one encoding invasion (uge: uridine diphosphate galactose 4 epimerase) and the other encoding siderophores (kfu: iron uptake system) by using PCR technique reveal the existence of The uge gene in all examined isolates (n=15/15; 100%), while the kfu gene was detected in (n=2/5) broiler chicken and (n=3/5) human but absent at all from cow strains. Fifteen (15) MDR strains (5broilers, 5 human, and 5cows) that had high biofilm formation, ESBL, hypermucoviscosity, and capsule were investigated for their genetic relatedness using ERIC –PCR , showed that there is a more or less a narrow diversity among strains that are isolated from each same host (chicken or human or cows). However, the results indicated the occurrence of transverse infections between the three hosts. This fact to be confirmed it needs more investigation of many numbers of strains.

Key words: Klebsiella pneumoniae, virulence factors, biofilm formation, ERIC – PCR.