In vitro activity of tigecycline against local clinical isolates of some Enterobacteriaceae

Abstract

BackgroundInfectious diseases that Enterobacteriaceae cause are spreading on a wide scale. Examples of these infections are gastrointestinal tract infections, meningitis, pneumonia, septicemia, urinary tract infections, and wound infections. Antibiotic resistance among Enterobacteriaceae is a critical problem that makes treatment difficult. Tigecycline is a broad spectrum antibiotic that is effective against multi-drug resistant organisms (MDR) and beneficial in the therapy of infections caused by Enterobacteriaceae.ObjectivesThis study aims to evaluate the in vitro activity of tigecycline against clinical isolates of Enterobacteriaceae species and detect the possible resistance mechanisms of them against β-lactams.MethodsThe sensitivity of different isolates to antibiotics was determined by standard disc diffusion method. Phenotypic detection of resistance mechanisms such as extended spectrum β-lactamase (ESBL), AmpC, ESBL& AmpC co-producers and metallo β-lactamase (MBL) β-lactamases enzymes producer isolates was investigated.ResultsA total of eighty three Enterobacteriaceae clinical isolates were collected. The common bacteria isolated were Escherichia coli and Klebsiella pneumoniae. Multidrug resistance was found in 59.04% of tested isolates. The isolates were resistant to sulphamethaxzole-trimethoprim, ciprofloxacin, tetracycline and impenem. The highest resistance was found to sulphamethaxazole-trimethoprim followed by ciprofloxacin, tetracycline and imipenem. Phenotypic detection of resistance mechanisms revealed that 69.4% of clinical isolates were ESBL producers, 12.2% were AmpC producers, 8.2% were ESBL and AmpC co-producers, while 10.2% were MBL producers. There was no resistance found to tigecycline among all Enterobacteriaceae isolates tested.ConclusionThis study showed that tigecycline has potent in vitro activity against ESBL, AmpC, combined ESBL and AMPC and MBL β-lactamases producing Enterobacteriaceae.