Disc susceptibility testing for thermomphilic campylobacters

Area of Science:

• Microbiology
• Antimicrobial Resistance
• Clinical Diagnostics

Background:

• Thermophilic Campylobacter species are significant foodborne pathogens.
• Antimicrobial resistance in Campylobacter poses a growing public health concern.
• Accurate and accessible methods for resistance detection are crucial for effective treatment and surveillance.

Purpose of the Study:

• To determine antimicrobial susceptibility profiles of clinical isolates of thermophilic Campylobacter species.
• To establish tentative interpretive zone diameter criteria for disc diffusion testing.
• To evaluate the prevalence of antimicrobial resistance in Campylobacter jejuni subsp. jejuni, C. coli, and C. lari.

Main Methods:

• Minimum inhibitory concentrations (MICs) and zone diameters were determined for 12 antimicrobials using NCCLS strength discs.
• Error-rate bounded analysis and adjusted MIC breakpoints were applied.
• 100 clinical isolates and 3 type strains of thermophilic Campylobacter were tested.

Main Results:

• Resistance to quinolones was only detected in Campylobacter lari.
• Two strains of Campylobacter jejuni subsp. jejuni showed susceptibility to cephalothin.
• Nine strains exhibited resistance to tetracycline; no full resistance to erythromycin, chloramphenicol, or gentamicin was observed.

Conclusions:

• The disc diffusion method offers a simple and effective approach for detecting antimicrobial resistance in Campylobacter.
• Established criteria aid in routine testing and surveillance of invasive Campylobacter isolates.
• The study highlights varying resistance patterns across different Campylobacter species and antimicrobials.