In vitro inhibition of S. pneumoniae, nontypable H. influenzae and M. catharralis by alpha-hemolytic streptococci from healthy children

• Published in: International journal of pediatric otorhinolaryngology 1999-01, Vol.47 (1), p.49-56
• Main Authors: Tano, Krister, Olofsson, Carin, Grahn-Håkansson, Eva, Holm, Stig E.
• Format: Article
• Language: English
• Subjects: Adenoids - microbiology; Agar overlay; Alpha-hemolytic streptococci; Antibiosis - physiology; Bacterial interference; Biological and medical sciences; Child; Child, Preschool; Children; Ent. Stomatology; Eustachian Tube - microbiology; Haemophilus influenzae - growth & development; Haemophilus influenzae - isolation & purification; Humans; In Vitro Techniques; Investigative techniques, diagnostic techniques (general aspects); M. catharralis; Medical sciences; Moraxella (Branhamella) catarrhalis - growth & development; Moraxella (Branhamella) catarrhalis - isolation & purification; Nasopharynx; Nontypable H. influenzae; Normal flora; Otitis Media - microbiology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; S. pneumoniae; Streptococcus - physiology; Streptococcus pneumoniae - growth & development; Streptococcus pneumoniae - isolation & purification
• ISSN: 0165-5876; 1872-8464
• DOI: 10.1016/S0165-5876(98)00174-8

The present study aimed to investigate the inhibitory activity of the normal epipharyngeal flora against the three most common acute otitis media (AOM) pathogens in healthy children, and to study if the inhibitory activity differs between alpha-hemolytic streptococci (AHS) sampled from the tubal orifice and from those sampled from the adenoid. A total number of ten isolates of AHS were collected from the tubal orifice and the adenoid, respectively, in ten children undergoing adenoidectomy or tonsillectomy. None of the children had a history of otitis media, neither secretory otitis media (SOM) nor AOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The results showed that the AHS from nasopharynx were able to inhibit the majority of the S. pneumoniae, nontypable Haemophilus influenzae and Moraxella catharralis isolates tested. The AHS isolates from the tubal orifice inhibited growth of 93% of S. pneumoniae, 79% of H. influenzae and 84% of M. catharralis isolates. The corresponding figures among isolates from the adenoid were 76, 48 and 62%. This difference in the inhibitory capacity between the AHS isolates collected from the adenoid, compared with the AHS collected from the tubal orifice, is statistically significant ( P