PYROLYSIS MASS-SPECTROMETRY IN EPIDEMIOLOGIC AND POPULATION GENETIC-STUDIES OF HAEMOPHILUS-INFLUENZA

Haemophilus influenzae serotype b (Hib) vaccines have reduced the amou nt of invasive Hib disease in immunised infants, However Hib disease r emains in unvaccinated infants and adults and non-capsulate H. influen zae (NCHi) still causes infections, including outbreaks of respiratory disease, Characterisation of strains and the bacterial population as a,whole is therefore necessary to detect outbreaks of infection with N CHi or changes in the population, for example, to vaccine-resistant cl ones of Hib, The rapid, simple and objective technique of pyrolysis ma ss spectrometry (PMS) was investigated as an alternative to current co mplex, subjective methods, PMS nas compared with ribotyping and multil ocus enzyme electrophoresis (MLEE) for population genetic analyses of Hib and with ribotyping and protein profiling for epidemiological anal yses of NCHi PMS clustered all the isolates of Hib together whereas ML EE and ribotyping distinguished certain clones - this is probably beca use the three methods examine different (and unrelated) characteristic s of the organisms, The PMS results were essentially similar to those from ribotyping and protein profiling for the epidemiological analyses of outbreaks of NCHi disease, Therefore, PMS is probably unsuitable f or comparisons of Hib populations but it is a useful addition to the a rsenal of techniques for the characterisation of NCHi.