[Simple and efficient method for clinical isolation of Bordetella pertussis]

Area of Science:

• Clinical Microbiology
• Bacterial Pathogenesis
• Infectious Disease Diagnostics

Background:

• Pertussis, caused by Bordetella pertussis, remains a significant public health concern.
• Accurate and efficient laboratory isolation of B. pertussis is crucial for timely diagnosis and treatment.
• Optimizing transport and culture media is essential for maximizing diagnostic yield in clinical settings.

Purpose of the Study:

• To evaluate the efficiency of Amies transport medium for preserving B. pertussis viability.
• To compare the performance of three different isolation media for B. pertussis detection.
• To establish a simple and effective protocol for the clinical isolation of B. pertussis.

Main Methods:

• Nasopharyngeal specimens were tested for B. pertussis isolation using direct inoculation versus storage in Amies transport medium (≤8 hours).
• Specimens were subsequently cultured on Bordet-Gengou (BG), Cyclodextrin Solid Medium (CSM), and Charcoal Agar (CA), all supplemented with CEX.
• Incubation was performed at 35°C for 5 days, and isolation rates were compared.

Main Results:

• Amies transport medium showed an 81% isolation rate, comparable to direct inoculation.
• BG, CSM, and CA media yielded high isolation rates of 91-93% for B. pertussis.
• CSM offered advantages of no blood requirement and anytime preparation; CA provided better flora suppression.

Conclusions:

• Amies transport medium is effective for short-term preservation of B. pertussis.
• BG, CSM, and CA are all highly efficient for B. pertussis isolation, with minor differences in colony appearance and flora suppression.
• A recommended protocol involves storing specimens in Amies medium and culturing on one of the tested media for 5 days at 35°C.