title: Molecular characterization of four Haemophilus influenzae serotype a strains isolated from patients in Quebec, Canada.
abstract: Four epidemiologically unrelated Haemophilus influenzae serotype a (Hia) strains from patients in Quebec, Canada, were characterized and found to represent 3 distinct groups. One isolate, found to be biotype I and sequence type (ST)-62 by multilocus sequence typing, was shown to possess the copper- and zinc-containing superoxide dismutase gene, sodC, and was suspected to belong to clonal division II. The other 3 isolates were classified as clonal division I based on the absence of the sodC gene. Among the 3 sodC-negative Hia strains, 2 were biotype II and had related STs (ST-23 and ST-403) and highly similar DNA fingerprints, similar to a group of previously described Hia isolates causing invasive disease in Manitoba, Canada. The remaining sodC-negative strain belonged to biotype I and ST-4 and shared no common allele with ST-23, ST-403, or ST-62. This isolate also possessed the IS1016-bexA partial deletion, which is often associated with increased virulence. Despite the small number of isolates used in this study, our finding of 3 distinct groups shows the existence of a potential genetic diversity not previously described for Hia. Whether this genetic diversity is related to the severity and epidemiology of Hia disease requires further studies.
authors.affiliation: Vaccine Preventable Bacterial Diseases, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Sill
authors.forename: Jianwei
authors.initials: J
authors.lastname: Zhou
authors.forename: Dennis K S
authors.initials: DK
authors.lastname: Law
authors.forename: Manon
authors.initials: M
authors.lastname: Lorange
authors.forename: Louise
authors.initials: L
authors.lastname: Ringuette
authors.forename: Sadjia
authors.initials: S
authors.lastname: Bekal
authors.forename: Raymond S W
authors.initials: RS
authors.lastname: Tsang
mesh_terms: D015373:Bacterial Typing Techniques; D002675:Child, Preschool; D005260:Female; D014644:Genetic Variation; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000382:microbiology; D006193:Haemophilus influenzae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011792:Quebec / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013482:Superoxide Dismutase / Q000235:genetics
chemical_list: D013482:Superoxide Dismutase