Haemophilus influenzae and Haemophilus parainfluenzae occurrence in the ear effusion in pediatric patients prone to recurrent respiratory tract infections (RRTI) and with otitis media with effusion (OME)

Introduction. Haemophilus influenzae and Haemophilus parainfluenzae are known as human-restricted respiratory microbiota representatives. The aim of the present paper was to assay haemophili prevalence in middle ear effusion specimens in pediatric patients with otitis media with effusion (OME).

Methods. A total of 86 ear effusion specimens (from the left and right ear independently) were collected from 43 pediatric patients with OME. For comparison, 58 nasopharyngeal specimens were taken from 58 pediatric patients prone to recurrent respiratory tract infections (RRTI). Isolation and identification of haemophili biotypes and antimicrobial susceptibility was accomplished by standard microbiological methods. The cell surface hydrophobicity (CSH) of isolates was assayed by the method of aggregation in ammonium sulfate (SAT).

Results. Haemophili were isolated in 25.6% (11/43) of all OME patients: in 5/43 (11.6%)– H. influenzae (biotypes II, III), in 5/43 (11.6%) – H. parainfluenzae, in 1/43 (2.3%) – both species were found. Haemophili-positive nasopharyngeal specimen was found in 27/58 (46.6%) RRTI patients: in 19/58 (32.8%) – H. influenzae, in 8/58 (13.8%) – H. parainfluenzae. About 90% of all haemophili isolates were characterised by extreme to strong CSH. Antimicrobial resistance occurred mainly among H. parainfluenzae (80%) and to a much lower percentage among H. influenzae (33.3%) isolates. The obtained data suggest that both H. influenzae and H. parainfluenzae can be involved in pathology of OME in pediatric patients. The high cell surface hydrophobicity can affect on the haemophili prevalence and ear colonization, and induces predisposition to the presence of these bacteria as a biofilm that serves as a virulence factor with great importance for the survival of these opportunistic bacteria and their persistence in the ear environment.