Antimicrobial Susceptibility Testing and Biofilm Production of Burkholderia cepacia Complex Organisms from Ultrasound Gels in In

Abstract

Burkholderia cepacia complex (Bcc) bacteria are versatile difficult to treat pathogens with extraordinary metabolic diversity. They are important nosocomial pathogens having multi-drug resistant potential. Contamination and biofilm formation on medical devices and equipment are the important reasons for the multiple outbreaks in recent decades. In this study, we subjected 32 isolates of Bcc to the two important virulent traits such as antimicrobial susceptibility and biofilm producing ability with and without different stress conditions. All the isolates were susceptible to co-trimoxazole (TMP-SMX) (100%) suggesting it as the preferred drug or the drug of the first choice for treating Bcc from ultrasound gels infections. The isolates showed the varied degree of susceptibility to meropenem (91%), doxycycline (85%), gatifloxacin (85%), piperacillin+ tazobactam (82%), ceftazidime (79%), and levofloxacin (71%). Multiple antibiotic resistance (MAR) indices for all the isolates were >0.2 and three isolates had >0.5. Most of the Bcc isolates (81.25%) were weak biofilm producers, while three strains each of B.cepacia, B. cenocepacia and B. pseudomultivorans produced moderate and strong types of biofilms under standard laboratory conditions. The combination of change in pH with other stress conditions significantly increased the biofilm formation. This study found the difference in the antimicrobial susceptibility pattern of Bcc isolates from ultrasound gels and the adaptability to in-vitro stress conditions explaining the variability of virulence among Bcc species. Keywords: Burkholderia cepacia Complex (Bcc); Ultrasound Gels; Antimicrobial Susceptibility Testing; Multiple Antibiotic Resistance