Abstract
Background: Klebsiella pneumoniae is a serious pathogen that causes many disorders in humans and animals. Klebsiella pneumoniae, which is one of the most important pathogens in hospitals, often causing many clinical manifestations, including pneumonia, urinary tract infections, and meningitis. Interest in this bacterium has increased due to the increasing incidence of infection caused by it, as well as its high resistance to antibiotics, especially broad-spectrum antibiotics.
Aim: this study showed the efflux pump mechanism of clinical Klebsiella pneumoniae isolates and antibiotic resistance in samples collected from sheep and human respiratory tract infection in southern Iraq.
Methods: Three hundred samples were collected, and the samples included : 150 nasal swabs from sheep and 150 sputum samples from humans. Through bacteriological and biochemical examinations. The isolates were identified Klebsiella pneumoniae isolates were also confirmed by 16S rRNA. Susceptibility testing of the antibiotics used in the study. To determine the phenotypic efflux pump activity, the agar ethidium bromide cartwheel method (AEBCM) was used.
Results: Of 150 sputum human specimens and 150 nasal swabs for sheep were tested, 25 and 17 klebsiella pneumoniae species isolates from patients and sheep, respectively of the resistance of the bacteria isolated from humans to antibiotics . The highest rate of resistance was to piperacillin (88%) , and the lowest rate was to antibiotics (36%). imipenem . The highest of bacterial susceptibility to the antibiotic imipenem were (44%) and (36%) for levofloxacin, respectively. . For the bacterial isolates from sheep, the highest percentage of resistance to rifampin was (82.3%), and the highest percentage of sensitivity was to imipenem and Levofloxacin antibiotics. The results showed that most of the 39 bacterial isolates (92.8%) possessed an efflux pump mechanism. The result of genotyping to identify the efflux pump genes tolC and acrAB revealed that all isolates carried the genes.
Conclusion: All the isolates were resistant to antibiotics and the bacterial isolates under study most possess the efflux pump mechanism. All bacteria also have efflux pump genes, and this gives the bacteria more resistance against many antibiotics.

Key words: Klebsiella pneumoniae, efflux pump , Antibiotic Resistance