Affiliation:
1. Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
2. Global Health Research Institute, University of Southampton, Southampton SO17 1BJ, UK
3. NIHR Southampton Biomedical Research Centre, University Hospital Southampton Foundation NHS Trust, Southampton SO16 6YD, UK
Abstract
Moraxella catarrhalis
is a common cause of respiratory tract infection, particularly otitis media in children, whilst it is also associated with the onset of exacerbation in chronic obstructive pulmonary disease in adults. Despite the need for an efficacious vaccine against
M. catarrhalis
, no candidates have progressed to clinical trial. This study, therefore, aimed to characterize the diversity of
M. catarrhalis
isolated from the upper respiratory tract of healthy children and adults, to gain a better understanding of the epidemiology of
M. catarrhalis
and the distribution of genes associated with virulence factors, to aid vaccine efforts. Isolates were sequenced and the presence of target genes reported. Contrary to prevailing data, this study found that lipooligosaccharide (LOS) B serotypes are not exclusively associated with 16S type 1. In addition, a particularly low prevalence of LOS B and high prevalence of LOS C serotypes was observed.
M. catarrhalis
isolates showed low prevalence of antimicrobial resistance and a high gene prevalence for a number of the target genes investigated: ompB2 (also known as copB), ompCD, ompE, ompG1a, ompG1b, mid (also known as hag), mcaP, m35, tbpA, lbpA, tbpB, lbpB, msp22, msp75 and msp78, afeA, pilA, pilQ, pilT, mod, oppA, sbp2, mcmA and mclS.