Haemophilus parasuis diagnostics

Abstract

Five techniques are currently available for H parasuis diagnosis: bacterial isolation, antimicrobial susceptibility testing, serotyping, detection by PCR, and genotyping. These techniques provide unique and complementary diagnostic information that can be used for surveillance, prevention, and control of H parasuis. Detection of H parasuis in clinical samples by PCR can be used to define the role of this pathogen in mortality, especially when bacterial isolation is negative. However, H parasuis isolation is still necessary for antibiotic susceptibility testing, serotyping, and genotyping. Antimicrobial susceptibility profiles may vary between laboratories, especially if different techniques are used for testing. Serotyping can be performed using AGPT and IHA. Although IHA is reportedly more sensitive than AGPT, nontypable isolates are still obtained using both techniques. Genotyping is an excellent epidemiological tool that can be used for surveillance and control of H parasuis infections. Epidemiological studies are more robust if information from isolation site, serotyping, genotyping, and antimicrobial susceptibility profiles are analyzed in combination.