Bacterial Interference by anaerobes in ear, sinus, and tonsillar infections

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.  Bacterial interference can assist in the recovery from infections, in promotion of health and prevention of upper respiratory tract infection. Bacteria capable of interfering with the growth of potential respiratory pathogens include alpha- hemolytic streptococci, non-hemolytic streptococci, and the anaerobic bacteria Prevotella and Peptostreptococcus spp.

Bacterial Interference in colonization by pathogens

Bacterial interference plays a role in the emergence of upper respiratory tract infections and their eradication. These infections include recurrent pharyngo-tonsillitis, otitis media , and sinusitis. The tonsils, and nasopharyngeal flora of patients with these infections harbor less interfering bacteria than those without that history. The presence of interfering bacteria may therefore play a role in preventing pharyngo-tonsillitis, otitis media, and sinusitis.

Treatment with antimicrobials and smoking can affect the balance between the interfering organisms and potential pathogens.  Antimicrobials that spare the normal flora, can assist in preserving the interfering flora.

Balance between interfering bacteria and pathogens

Introduction into the indigenous microflora of low virulence bacteria 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.