(2009) primers for detecting the N526K substitution in BLNAR isolates by amplification (sensitivity 96% specificity 26%). Similar findings were reported for the sensitivity and specificity of the Nakamura et al. Isolates were taken from 1) the University of Tasmania (UTAS) culture collection (n=44), isolates was unreliable (sensitivity 84% specificity 26%). influenzae.Ī working strain collection comprising a total of 393 Haemophilus isolates was established and used for all the subsequent studies conducted in this thesis. influenzae, which further complicates the role of the diagnostic laboratory in guiding antibiotic therapy for infections involving H. haemolyticus isolates are frequently mis-identified as H. influenzae, in diagnostic specimens from the respiratory tract, has compounded the issue. Furthermore, the recent recognition of Haemophilus haemolyticus, a close non-pathogenic relative of H. As a result genotypic testing methods are being increasingly adopted for BLNAR detection. This type of resistance, termed β-lactamase-negative ampicillin-resistance (BLNAR), is difficult to detect in the diagnostic laboratory, as many BLNAR isolates do not actually show an ampicillin resistant phenotype using standard susceptibility testing methods. However, the efficacy of these antibiotics is currently threatened by the increasing prevalence of β-lactam resistance mediated by specific mutations in the ftsI gene that produce an N526K substitution in the encoded penicillin-binding protein 3 (PBP3), a protein that is the target of these antibiotics. These infections frequently require antibiotic therapy for management, with antibiotics of the β-lactam class such as amoxicillin, cefaclor, and amoxicillin-clavulanate historically used as first line therapies. Haemophilus influenzae is a significant opportunistic pathogen that causes a range of respiratory infections, including community-acquired pneumonia (CAP), acute exacerbations of chronic obstructive pulmonary disease (COPD) and acute otitis media (AOM). | Document not available for request/download (Complete thesis including published material) (Complete thesis excluding published material)Īvailable under University of Tasmania Standard License.