%0 Journal Article %A Watson, Michael E. %A Nelson, Kevin L. %A Nguyen, Victoria %A Burnham, Carey-Ann D. %A Clarridge, Jill E. %A Qin, Xuan %A Smith, Arnold L. %T Adhesin genes and serum resistance in Haemophilus influenzae type f isolates %D 2013 %J Journal of Medical Microbiology, %V 62 %N 4 %P 514-524 %@ 1473-5644 %R https://doi.org/10.1099/jmm.0.052175-0 %I Microbiology Society, %X The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipo-oligosaccharide (LOS) biosynthetic island, and assessment of β-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced β-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.052175-0