Identification and characterization of bacteria isolated from patients with cystic fibrosis in Jordan

BACKGROUND: Notable emergence of multidrug-resistant bacteria has become increasingly problematic worldwide. Most patients with cystic fibrosis (CF) suffer from chronic persistent infections with frequent occurrence of acute exacerbations. Routine screening of bacterial strains, epidemiological characteristics, and resistance patterns are particularly useful for patient management and maintenance of infection control procedures METHODS: In this study, 43 pharyngeal samples were taken from patients with CF. Microbiological bacterial culture and identification, antimicrobial susceptibility testings, biofilm formation, including minimum biofilm eradication concentration (MBEC) and PCR for detecting resistance genes were performed. RESULTS: All samples were positive for bacterial growth. The predominant species were Staphylococcus aureus (41.86%; n = 18) and Pseudomonas aeruginosa (39.53%; n = 17). 30% of isolated bacteria were multidrug-resistant, resisting high concentrations of tested antibiotics. Among the 42 biofilm-forming isolates, 23.8% (n = 10) were strong biofilm formers. The occurance of resistance genes varied with blaKPC detected in 71% (n = 17) of all Gram-negative isolates and mecA found in 61% (n = 11) of all S. aureus strains. CONCLUSIONS: The majority of isolated bacteria were S. aureus and P. aeruginosa. The high frequency of antimicrobial resistance, the presence of resistance genes, and biofilm formation highlight the challenge in treatment and infection control measures in patients with CF. KEY MESSAGES: Staphylococcus aureus and Pseudomonas aeruginosa are the most prevalent pathogens found in patients with CF in Jordan. Detection of antimicrobial resistance genes in patients with CF confirms that antimicrobial resistance patterns must always be monitored. Biofilm formation significantly increases the tolerance of bacteria to antimicrobial agents.