Michelle Shuel1, Linda Hoang, Dennis K S Law, Raymond Tsang. 1. Vaccine Preventable Bacterial Diseases, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3R2.
Abstract
OBJECTIVES: To characterize invasive Haemophilus influenzae and to examine the population at risk for invasive H. influenzae disease in British Columbia, Canada, 2008-2009. METHODS: H. influenzae recovered from individual patients were characterized by serotyping, biotyping, multilocus sequence typing (MLST), and antibiotic susceptibility testing. Age information was recorded from specimen requisition forms. RESULTS: Of the 98 cases, 66% were caused by non-typeable strains, followed by serotypes b (12%), a (10%), f (10%), and e (1%). Cases caused by serotypes b and f and non-typeable strains were mainly in adults over 18 years of age, while cases due to serotype a were mainly in children under the age of 2 years. Different sequence types were found in encapsulated strains according to their serotypes, and non-typeable strains had their own unique sequence types. No capsule switching was documented. Antibiotic resistance was common among non-typeable strains, with 31% identified as genotypic β-lactamase-negative ampicillin-resistant (BLNAR) strains. CONCLUSION: Invasive H. influenzae disease in a population vaccinated against Hib was age-dependent and involved both non-typeable and encapsulated strains. Adults were susceptible to invasive diseases due to non-typeable and serotype b and f strains, while in children, most diseases were due to serotype a bacteria. Crown
OBJECTIVES: To characterize invasive Haemophilus influenzae and to examine the population at risk for invasive H. influenzae disease in British Columbia, Canada, 2008-2009. METHODS:H. influenzae recovered from individual patients were characterized by serotyping, biotyping, multilocus sequence typing (MLST), and antibiotic susceptibility testing. Age information was recorded from specimen requisition forms. RESULTS: Of the 98 cases, 66% were caused by non-typeable strains, followed by serotypes b (12%), a (10%), f (10%), and e (1%). Cases caused by serotypes b and f and non-typeable strains were mainly in adults over 18 years of age, while cases due to serotype a were mainly in children under the age of 2 years. Different sequence types were found in encapsulated strains according to their serotypes, and non-typeable strains had their own unique sequence types. No capsule switching was documented. Antibiotic resistance was common among non-typeable strains, with 31% identified as genotypic β-lactamase-negative ampicillin-resistant (BLNAR) strains. CONCLUSION: Invasive H. influenzae disease in a population vaccinated against Hib was age-dependent and involved both non-typeable and encapsulated strains. Adults were susceptible to invasive diseases due to non-typeable and serotype b and f strains, while in children, most diseases were due to serotype a bacteria. Crown
Authors: Julianne V Kus; Michelle Shuel; Deirdre Soares; William Hoang; Dennis Law; Raymond S W Tsang Journal: J Clin Microbiol Date: 2019-11-22 Impact factor: 5.948
Authors: Raymond S W Tsang; Michelle Shuel; Kathleen Whyte; Linda Hoang; Gregory Tyrrell; Greg Horsman; John Wylie; Frances Jamieson; Brigitte Lefebvre; David Haldane; Rita R Gad; Gregory J German; Robert Needle Journal: J Antimicrob Chemother Date: 2017-05-01 Impact factor: 5.790
Authors: Shamez N Ladhani; Sarah Collins; Anna Vickers; David J Litt; Carina Crawford; Mary E Ramsay; Mary P E Slack Journal: Emerg Infect Dis Date: 2012-05 Impact factor: 6.883