Direct detection, capsular typing and β-lactamase resistance genes in Haemophilus influenzae isolated from sinusitis samples

Objective: Haemophilus influenzae is the causative agent of invasive and noninvasive infections such as chronic obstructive lung disease exacerbation, sinusitis, otitis media, and conjunctivitis. The study was undertaken to direct detection, capsular typing, and investigate the occurrence of beta-lactamase resistance genes in H. influenzae strains isolated from sinusitis samples. Materials and methods: We investigated the presence of H influenzae in 137 sinusitis samples obtained from the patients had referred to Rasoole-Akram Hospital in Tehran in 2017. DNA extraction was performed according to the QIAamp kit. polymerase chain reaction (PCR) amplification was performed with specific primers to determine H. influenzae and capsular-typing and to detect resistance genes. Results: Eleven samples were positive for the presence of H. influenzae. Overall, 5, 2, and 4 isolates were H. influenzae type b, type A, and nontypeable H. influenzae, respectively. Of 11 isolates of H. influenzae, only two isolates (18%) were beta-lactamase positive and carried the TEM-1 gene, but others were negative for the ROB-1 gene. As well, the current study showed that 45.5% (n; five of 11 encapsulated H. influenzae) of isolates were type b, which were the predominant types. Conclusion: Our data suggest that the conventional PCR can help increase detection rates of bacterial cause of sinusitis and resistance genes in clinical samples for effective treatment in individual sensitive to invasive infection. Copyright (C) 2018 Wolters Kluwer Health, Inc. All rights reserved.