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Published on: April 4, 2011
Identification and Characterization of "Haemophilus quentini" Strains Causing Invasive Disease in Ontario, Canada
Julianne V Kus1,2, Michelle Shuel3, Deirdre Soares4
1Public Health Ontario, Toronto, Ontario, Canada julianne.kus@oahpp.ca.
Abstract:
Haemophilus influenzae is a well-established human pathogen capable of causing a range of respiratory and invasive diseases. Since the 1970s, it has been observed that a nontypeable cryptic genospecies of H. influenzae, most often biotype IV, has been associated with the genitourinary tracts of females and with invasive neonatal infections. This distinct genospecies has been provisionally named "Haemophilus quentini" Here, we report seven cases of invasive H. quentini disease in patients from Ontario, Canada, over a 2-year period. Significantly, while most reports of invasive disease with H. quentini to date have been in neonates, we observed five cases in adults (three in women of childbearing age and two in seniors) as well as two in neonates. Identification of H. quentini is challenging and was not possible for frontline laboratories, requiring work at the reference laboratory level. We describe in detail the biochemical results, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-Tof MS) results, and PCR results with several targets, including the 16S rRNA gene and multilocus sequence typing (MLST) genes, for the seven Ontario H. quentini isolates and several controls. Our data, combined with those of other publications, support the fact that H. quentini is distinct from H. influenzae and Haemophilus haemolyticus This organism is recognized as a pathogen of neonates, but we hypothesize that it may be underrecognized as an important pathogen in adults as well, particularly pregnant women. By sharing the detailed descriptions of these isolates, we hope to enable other laboratories to better identify H. quentini so that the true prevalence of this organism and disease can be explored.
Insights
A novel bacterium, Haemophilus quentini, previously linked to neonatal infections, is now identified in adult invasive diseases in Ontario. This finding suggests H. quentini may be an underrecognized pathogen in adults, particularly pregnant women.
Area of Science:
- Microbiology
- Infectious Diseases
- Genomics
Background:
- Haemophilus influenzae is a known pathogen. A distinct genospecies, provisionally named Haemophilus quentini, has been associated with female genitourinary tracts and neonatal infections since the 1970s.
Observation:
- Seven cases of invasive H. quentini disease were identified in Ontario, Canada, over two years.
- Unlike previous reports, five cases occurred in adults (three women of childbearing age, two seniors), alongside two neonatal cases.
Findings:
- Detailed biochemical, MALDI-Tof MS, and PCR analyses confirmed H. quentini isolates are distinct from H. influenzae and H. haemolyticus.
- Identification of H. quentini is challenging for frontline laboratories, requiring specialized reference laboratory capabilities.
Implications:
- H. quentini may be an underrecognized cause of invasive disease in adults, especially pregnant women.
- Improved identification methods are needed to understand the true prevalence of H. quentini infections.
- This study provides detailed characterization to aid other laboratories in identifying H. quentini.
