Klebsiella pneumoniae Infections in Hospitalized Patients: Characterization of Antibiotic Cross-resistance and Detection of Cefepime Susceptible-dose Dependent (SDD) Strains

Klebsiella pneumonia (K. pneumoniae) is a Gram-negative enteric bacterium that causes nosocomial infections. The aims of the present study were to identify the Klebsiella pneumoniae infections in hospitalized patients: the characterization of cross-resistance and antibiotic resistance patterns in isolates and the detection of cefepime susceptible-dose dependent in strains.
In the present study (during 2014-2015), samples were collected from patients hospitalized in Ghotbadden, Faghihi and Nemazee hospitals (Shiraz, Iran). The isolates were identified as K. pneumoniae, based on the biochemical tests embedded in the API-20E system. The susceptibility testing (disc diffusion) was performed according to the clinical and laboratory standards institute guidelines (CLSI 2014). The dDetection of cefepime susceptible-dose dependent (SDD) was performed. The detection of AmpC β-lactamases producing strains was done based on the cefoxitin and cefepime disk tests.
In this study 111 strains of Klebsiella pneumoniae were isolated. The less effective drug was ceftazidime (37.8% were sensitive). All SDD strains were susceptible to colistin and imipenem. Colistin (96.4%) and imipenem (88.3%) were the most effective antibiotics against isolates. Respectively, 41.4% and 35.1% isolates displayed resistance to gentamicin and amikacin. All colistin resistant isolates were imipenem sensitive.
Carbapenem drugs are effective against Klebsieella pneumoniae infections. These results indicate that multidrug-resistant strains of K. pneumoniae are rising. The routine investigation and reporting of antibiotics resistance profile in patients presenting with Klebsiella infections is suggested.