Abstract

Cystic fibrosis (CF) necessitates long-term treatment with multiple antibiotics creating selection pres-sure for the development of antibiotic resistance in infecting and/or colonizing organisms, impacting on disease management, morbidity and mortality. Sputum samples were obtained from patients attending the only two CF clinics in Durban over a year. The patient demographics and clinical data were recorded. Bacterial isolates were subjected to identification, susceptibility testing and phenotypic screening for extended spectrum β-lactamases (ESBLs), AmpC β-lactamases and metallo-β-lactamases (MBLs). Twenty-five patients constituted the study sample. The most common genotype was F508del and the most common pathogen was Pseudomonas aeruginosa with susceptibility to antibiotics ranging from 14-100% with marginal differences between mucoid and non-mucoid phenotypes. All P. aeruginosa isolates were putative ESBL producers and 75% were putative MBL producers. The incidence, prevalence and susceptibility patterns of bacterial pathogens and colonizers isolated from cystic fibrosis patients should be closely monitored to optimize management and treatment options in a disease requiring chronic antibiotic therapy which increases the propensity for the development of antibiotic resistance.

Key words: Pseudomonas aeruginosa, cystic fibrosis, extended spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs).