Emergence of AmpC β-Lactamase– and Metallo-β-Lactamase–producing Klebsiella pneumoniae in Sebha, Libya

The emergence of AmpC β-lactamase– and metallo-β-lactamase–producing Gram-negative bacteria has become a global concern. In the last 2 years, the resistance to broad-spectrum β-lactam antibiotics caused by Klebsiella pneumoniae has been noted among clinical isolates in Sebha Medical Center, Libya. During a period of 2 years, 22 nonrepetitive K. pneumoniae strains were obtained from neonates and identified in the microbiology unit. This study aimed to assess the antimicrobial resistance profile and phenotype of extended-spectrum β-lactamase (ESBL)– and AmpC β-lactamase–producing K. pneumoniae isolates. The antibiotic susceptibility of all isolates was evaluated according to the Clinical Laboratory Standards Institute guideline. Further screening using boric acid and ethylenediaminetetraacetate (EDTA) were performed to study metallo-β-lactamase (MBL and AmpC enzyme production. The study found that 100% of isolates were resistant to β-lactam group, and 91% were resistant to β-lactamase inhibitors. Moreover, 23% (5/24) of all isolates exhibited ESBL phenotype, and 59% (13/22) were AmpC enzyme producers. The resistance to other broad-spectrum antibiotics, for example, aminoglycosides and quinolones, was also observed in this study. This study reported the first case of carbapenem-resistant K. pneumoniae MBL in Sebha, in the south of Libya. This carbapenemase-producing strain exhibited remarkable resistance to cephalosporins, fluoroquinolones, and aminoglycosides. This study showed that AmpC and MBL screen tests were simple and could routinely be performed in the clinical laboratory using EDTA and boric acid.