Prevalence and Molecular Characterization of β-Lactamases in Clinical Isolates of Klebsiella pneumoniae from North of Palestine

Fifty-one clinical isolates of Klebsiella pneumoniae were obtained from different hospitals in Jenin, Nablus and Tulkarem districts-Palestine, during September - December 2015. Identification of isolates were confirmed in Microbiology laboratories at An-Najah National University-Nablus, Palesine; using different tests such as growth on MacConkey, detection of growth at 5°C and 44.5°C, Gram stain reaction, motility test and other biochemical tests were used such as Indole test and Voges-Proskauer test. Multiplex PCR was used to detect and determine the molecular epidemiology of MBL, ESBL and AmpC β-lactamase producing K. pneumoniae isolates. Results showed that the prevalence of possible ESBL, MBL and AmpC β-lactamase using multiplex PCR technique were 92.2%, 9.8 and 3.9%, respectively. TEM gene was the most dominant (72.5%) among the K. pneumoniae isolates. Other genes were (0.0%), (17.6%) and (31%) for CTX-M, SHV and OXA genes, respectively. For MBLs and AmpC β-lactamases (9.8%) NDM and (3.9%) DHA genes were detected, respectively, among the collected isolates. Six isolates (11.8%) showed coexistence with at least another type of β-lactamases. Molecular analysis and phylogenetic relationships showed that all sequenced TEM, SHV, OXA, NDM and DHA genes belonged to TEM-1, SHV-1, OXA-1, NDM-1 and DHA-1, respectively. Results of the current study showed that all K. pneumoniae isolates were sensitive to Imipenem (100%), while 68.6% and 54.9% of the isolates were resistant to Meropenem and Cefotaxime, respectively. A total of 26 of K. pneumoniae isolates (51%) harbored class 1 integrons, whereas other classes were not detected. All integrons were detected in K. pneumoniae isolates carrying β-lactamase genes. ERIC-PCR typing of 40 clinical isolates of K. pneumoniae harbored β-lactamase genes were genetically diverse and consisted of a heterogeneous population with a total of 16 ERIC PCR profiles (clusters) at a 50% similarity level. Results of the current research showed high occurrence of β-lactamases among clinical isolates of K. pneumoniae in Palestine. To restrict the further spread of β-lactamases producing K. pneumoniae isolates within hospitals in this country, we recommend the continuous monitoring and surveillance of the prevalence, proper prevention practices and effective antimicrobial drugs use.