Characteristics of invasive Haemophilus influenzae serotype a (Hia) from Nunavik, Canada and comparison with Hia strains in other North American Arctic regions

- Characteristics of Haemophilus influenze serotype a from Nunavik, Canada are described.
- H. influenzae serotype a (Hia) in northern Canada and Alaska, USA are compared.
- A single Sequence Type (ST-23) of Hia caused invasive disease in Nunavik.
- A clone of Hia caused invasive disease in the North American Arctic.
- This Hia clone consisted of one major Sequence Type (ST)-23 in northern Canada.

Objective: This study examines the microbiological characteristics of invasive Haemophilus influenae serotype a (Hia) isolates from Nunavik (northern Quebec), Canada. The relationship between invasive Hia isolates from Nunavik, Nunavut, Canada, and Alaska, USA will be discussed.MethodsTwenty invasive Hia isolates were recovered from patients in Nunavik from 2010 to 2013 and characterized by biotype, multi-locus sequence typing, IS1016-bexA deletion, antibiotic susceptibility and pulsed field gel electrophoresis (PFGE).ResultsAll 20 Hia isolates were biotype II, sequence type −23, did not have IS1016-bexA deletions and were susceptible to all antibiotics tested. PFGE showed only two patterns, with 19 isolates giving identical molecular fingerprints, and the remaining isolate gave a PFGE pattern >95% similar.ConclusionOne major clone of Hia appears to be causing invasive disease in Nunavik, Canada. Based on previous studies, Hia from Nunavut were also typed as ST-23, while invasive Hia isolates from Alaska belonged to either ST-23 or closely related STs. Thus invasive Hia in the North America Arctic belonged to the ST-23 clonal complex and lacked the IS1016-bexA partial deletion.