RESUMEN
Background: Klebsiella species cause 3-7% of all nosocomial infections, placing them in the top 10 of nosocomial bacterial pathogens
Materials: In this respect, we evaluated the differences in some quinolone resistance determinants among 70 clinical isolates of Klebsiella pneumoniae collected from Mansoura University Hospitals
Results: In the present investigation, some molecular typing techniques were applied on 70 isolates of K. pneumoniae isolated from Mansoura University Hospitals from different clinical lesions. The distribution of antibiotic resistance among the isolated strains showed high incidence of resistance to extended-spectrum cephalosporins [70 to 94.29%] and to quinolones [38.57 to 55.7 %] was also observed. Imipenem was the most active antibiotic so; it could be considered the drug of choice for treatment of infections caused by multi-resistant K. pneumoniae. Plasmid profiles of the tested strains appear to be diverse, although some similarities were found among tested strains. Sixty seven out of 70 strains contained plasmid DNA. PCR amplification was used to detect some quinolone resistance determinant genes such as gyrA, gyrB and Onr in the collected Klebsiella pneumoniae isolates. Using pyrosequencing technique, the sequenced region of gyrA gene was able to differentiate between resistant and sensitive strains however, the sequenced region of gyrB gene failed to differentiate between resistant and sensitive strains. Qnr gene was detected in all tested strains except strains No. 24 and 28
Conclusion: Using PCR and DNA sequencing of the target region of gyrA gene, we were able to differentiate between resistant and sensitive strains. While, amplification of another region of gyrB or Qnr genes failed to differentiate between the isolates. But, it could detect different types of mutations between the clinical isolates