Objectives: The purpose of current research was to investigate the existence of the aac(6´)-Ib-cr and qnr (qnrS, qnrD, qnrC, qnrB, qnrA) genes and determine the antibiotic sensitivity patterns in the strains of Klebsiella pneumonia, recovered from hospitalized patients in Shiraz, southern Iran.

Materials and Methods: In the current cross-sectional work, the strains isolated from clinical specimens of hospitalized individuals between 2014 and 2016 in Shiraz, Iran, were tested. Culture was done on microbiological media. The strains were recognized as K. pneumonia, based on the bio-chemical tests in the API-20E diagnostic strip. All the strains were investigated for antibacterial sensitivity using the CLSI standard guidelines. Genes encoding antibiotic resistance markers consisting of aac(6’)-Ib-cr, qnrS, qnrD, qnrC, qnrB, and qnrA were evaluated by PCR assay.

Results: Ninety-six strains of K.pneumoniae, isolated from hospitalized patients were entered into the research. 51.04% of strains were recovered from females. 35.66% of the patients were hospitalized in intensive care unit. Sixty-two strains were isolated from urine. Imipenem was the most efficient drug against the strains (81.52%). Less than 50% were sensitive to the new generation of quinolones. All the isolates harboring antibiotic resistance genes were non-susceptible or intermediate level resistance to ciprofloxacin. Most of aac(6’)-Ib-cr⁺ strains were non-susceptible or intermediate level resistance to piperacillin/tazobactam. In PCR assay, 27.08% isolates had antibiotic resistance traits (aac(6’)-Ib-cr, qnrS, qnrD, qnrC, qnrB, qnrA). The aac(6’)-Ib-cr, qnrS, and qnrB markers were found in 7.3%, 10.4% and 7.3%, respectively.

Conclusion: In this research, the emergence of potentially virulent and carbapenem non-susceptible cases in conjugation with a quinolones resistant genotype is alarming, as a possible result would be vigorous clinical manifestations along with drastic constraints in therapy.