Outer-membrane-protein subtypes of Haemophilus influenzae isolates from North India

Abstract

Haemophilus influenzae serotype b and non-typable isolates from blood, cerebrospinal fluid, sputum and throat swabs of patients and carriers in North India were analysed by outer-membrane protein (OMP) profiling. OMP analysis could differentiate the samples into 18 different subtypes. The non-typable isolates were more variable than the serotype b samples. OMP subtypes 1-6 were found only among the serotype b isolates and subtypes 7-18 among the non-typable isolates, while subtypes 2 and 8 were exhibited by both. The OMP profiles of isolates from blood, cerebrospinal fluid and sputum are in complete agreement with their ribotypes and RAPD fingerprints. The present study demonstrates for the first time the subtyping of Indian H. influenzae isolates by an easy and less-expensive method that is applicable to developing countries like India.

Outer membrane protein analysis of ampicillin-resistant isolates of Haemophilus influenzae from Saudi Arabia

“…This is the first report of OMP analysis of serotype b and non-typable strains isolated from confirmed clinical cases in Saudi Arabia although international isolates including Indian strains have been investigated previously [13]. NTHi subtyping by outer membrane protein analysis has proved useful for investigating the transmission of H. influenzae and re-infection epidemiology studies with patients over time [15] but we have shown in this study that sub-typing appears less useful for rapid tracking/surveillance of ampicillin-resistant H. influenzae in populations.…”

“…Outer membrane protein profiling has been shown to be highly discriminatory in bacterial populations and has been used extensively in the investigation of H. influenzae outbreaks [11][12][13]. In our study, we have differentiated the ampicillin-resistant strains of H. influenzae into two major categories by OMP analysis.…”