Bacterial and viral interactions within the nasopharynx contribute to the risk of acute otitis media

Abstract

Summary Objectives To understand relationships between microbes in pathogenesis of acute otitis media during respiratory tract infections, we compared nasopharyngeal bacteria and respiratory viruses in symptomatic children with and without AOM. Methods We enrolled children (6–35 months) with acute symptoms suggestive of AOM and analyzed their nasopharyngeal samples for bacteria by culture and for 15 respiratory viruses by PCR. Non-AOM group had no abnormal otoscopic signs or only middle ear effusion, while AOM group showed middle ear effusion and acute inflammatory signs in pneumatic otoscopy along with acute symptoms. Results Of 505 children, the non-AOM group included 187 and the AOM group 318. One or more bacterial AOM pathogen (Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis) was detected in 78% and 96% of the non-AOM and AOM group, respectively (P < .001). Colonization with S. pneumoniae and H. influenzae, each alone, increased risk of AOM (odds ratio (OR) 2.92; 95% confidence interval (CI), .91–9.38, and 5.13; 1.36–19.50, respectively) and co-colonization with M. catarrhalis further increased risk (OR 4.36; 1.46–12.97, and 9.00; 2.05–39.49, respectively). Respiratory viruses were detected in 90% and 87% of the non-AOM and AOM group, respectively. RSV was significantly associated with risk of AOM without colonization by bacterial AOM pathogens (OR 6.50; 1.21–34.85). Conclusions Co-colonization by M. catarrhalis seems to increase risk of AOM and RSV may contribute to AOM pathogenesis even without nasopharyngeal bacterial colonization.

Pneumococcal Neuraminidase A (NanA) Promotes Biofilm Formation and Synergizes with Influenza A Virus in Nasal Colonization and Middle Ear Infection

“…Coinfection with S. pneumoniae and IAV is linked both experimentally and epidemiologically with the development of OM (6,7,45). The activity of the viral neuraminidase altering the respiratory and eustachian tube epithelium has long been proposed to be a mechanism by which preceding IAV infection potentiates the initiation of this disease by pneumococci (15,46).…”

Influenza A Virus Alters Pneumococcal Nasal Colonization and Middle Ear Infection Independently of Phase Variation

“…Epidemiologic evidence strongly indicates a role for upper respiratory tract viruses, particularly influenza A virus (IAV), in the dissemination of S. pneumoniae from its nasopharyngeal niche to the middle ear (7)(8)(9)(10)(11). Indeed, experimental IAV infection of human volunteers was shown to increase both nasal pneumococcal burden and incidence of OM (12,13).…”

“…The development of mouse models, though often requiring either the use of artificial or invasive procedures (17,18) or infant mice (19)(20)(21), has further significantly contributed to and widened the field. Largely stemming from these models, the viral factors which predispose to OM are well-studied and include eustachian tube dysfunction, ciliary dysmotility, mucosal inflammation, and neutrophil impairment (8,11,(22)(23)(24). How this viral predisposition affects specific pneumococcal subpopulations during middle ear infection, however, is less well understood.…”

The aetiology of diarrhoea, pneumonia and respiratory colonization of HIV-exposed infants randomized to breast- or formula-feeding

“…While previous studies have also shown that Gram-negative organisms are more commonly found colonizing the respiratory tract of formula-fed infants than breastfed infants, 39-41 these studies were not undertaken in HIV-exposed infants. Furthermore, while prior studies have shown that colonization by Gram-negative organisms can lead to an increased risk of otitis media and other upper respiratory tract infections in healthy infants, [42][43][44] our results suggest that it could also increase the risk of lower respiratory tract infection outside intensive care units and in non-cystic fibrosis patients. Despite the association between Gram-negative colonization and increased pneumonia, this study did not find Gram-negatives to be a common cause of pneumonia by blood culture (though all Gram-negative pneumonias occurred in formula-fed infants).…”