Affiliations: Department of Pediatrics, Georgetown University,
Washington DC, USA
Note: [] Correspondence: Itzhak Brook, MD, MSc, 4431 Albemarle St. NW,
Washington DC 20016, USA. Tel.: +1 301 295 2698; Fax: +1 202 244 6809; E-mail:
ib6@georgetown.edu
Abstract: Interactions between bacteria that include antagonism (interference)
and synergism maintain balance between members of the normal endogenous flora,
and play a role in preventing colonization by potential pathogens. Bacteria
with interference capability of potential respiratory pathogens include
alpha-hemolytic streptococci, non-hemolytic streptococci, and Prevotella and
Peptostreptococcus spp. The role of bacterial interference in the emergence of
upper respiratory tract infections and its effect on their eradication is
discussed. These infections include pharyngo-tonsillitis, otitis media, and
sinusitis. Treatment with antimicrobials can affect the balance between the
interfering organisms and potential pathogens. Introduction into the indigenous
microflora of low virulence bacterial strains that are capable of interfering
with colonization and infection with virulent organisms has been used as a
means of preventing the failure of antimicrobials in the treatment of
pharyngo-tonsillitis and otitis media.