Dale D. Rohn

Amoxicillin-clavulanate potassium compared with cefaclor for acute otitis media in infants and children.

One hundred thirty-three infants and children with documented acute otitis media (OM) were randomized to receive the oral suspension of either amoxicillin-clavulanate potassium or cefaclor. Beta-lactamase-producing bacteria were found in 10.9 and 14.5% of subjects treated with amoxicillin-clavulanate potassium and cefaclor, respectively. Subjects were reexamined at 5, 10, 30, 60 and 90 days after the initiation of therapy and whenever signs/symptoms of acute otitis media recurred. All but two children had resolution of otalgia/otorrhea during the initial treatment period. The drug groups were not significantly different in the percentage of evaluable subjects with otitis media with effusion at each scheduled follow-up visit. Recurrence of acute OM/otorrhea [corrected] developed in a similar percentage of subjects in both treatment categories. Both subjects with and those without middle ear effusion at 10 days had approximately a 50% recurrence rate of subsequent middle ear disease. Adverse side effects/complaints, which occurred in significantly more children treated with amoxicillin-clavulanate potassium, were generally mild and primarily gastrointestinal.

An Animal Model of Acute Otitis Media Consequent to β-Lactamase-Producing Nontypable Haemophilus Influenzae

A chinchilla model of acute otitis media with effusion consequent to β-lactamase-producing nontypable Haemophilus influenzae was developed using the method of direct inoculation of 145 colony-forming units (CFU) or 252 CFU of β-lactamase—producing nontypable H influenzae into the right superior bullae of 40 chinchillas. The course of the disease was documented longitudinally by otomicroscopy, tympanometry, and periodic culturing of the middle ears. Onset of the disease occurred in 100% of the animals between two and six days postinoculation and resolution was complete in all ears by day 36. Results of rechallenge with the same organism support the combined effect of a local and weaker systemic middle ear protective mechanism rendering resistance to reinfection with a homologous organism in the chinchilla.

Microbiology of chronic and recurrent otitis media with effusion in young infants

Chronic otitis media with effusion (OME) has been assumed to be sterile, since several reports in the literature have described unsuccessful attempts to culture bacteria from it. However, several recent studies have confirmed an earlier report that there is a significant frequency of bacteria in the middle ears of children with chronic and/or recurrent OME. Similar studies in young infants with chronic and/or recurrent OME have not been previously reported. In this study, cultures were obtained at the time of myringotomy and tympanostomy tube insertion from 50 infants aged 1-12 months who had chronic and/or recurrent OME. From the 80 ears of 40 infants without cleft palate, 32% had bacteria isolated from their middle ears; 22% had Streptococcus pneumoniae or Haemophilus influenzae. In 21 of these ears, no effusion was apparent at myringotomy, but in 28% bacteria were isolated from middle ear washings. From the 20 ears of 10 infants with an unrepaired cleft palate, 55% had bacteria present in their middle ear aspirates; 50% had S. pneumoniae or H. influenzae. Even though the significance of bacteria in chronic OME in children, and now in young infants, is unclear at present, a therapeutic trial with an antimicrobial agent prior to surgical intervention would appear to be reasonable until such therapy is tested in a randomized, clinical trial.

Bacteriology of the Maxillary Sinus of Rhesus Monkeys

Quantitative cultures of transantral aspirates of the maxillary sinuses of rhesus monkeys were performed to determine whether the sinuses have a normal bacterial flora. Of 13 sinus aspirate cultures 11 (85%) were sterile. The two positive sinus aspirate cultures had extremely low colony counts of the same bacteria present on the nasal mucosa prior to the sinus puncture. The maxillary sinuses of rhesus monkeys are sterile.

1068 THE NORMAL BACTERIAL FLORA OF THE MAXILLARY SINUS OF RHESUS MONKEYS

It is not known whether the paranasal sinuses have a normal bacterial flora which may play a role in the pathogenesis of sinusitis. Factors such as viral infection or allergy may impair normal sinus drainage and potentiate bacterial multiplication and infection. If the maxillary sinus (MS) is sterile, then the infecting bacteria may be introduced by other factors, such as nose blowing or intermittent negative intrasinus pressure accompanied by impairment of mucociliary transport. The MS of rhesus monkeys provides an animal model for investigation. Transantral punctures of 13 MS of rhesus monkeys were performed after Betadine cleansing of the overlying nasal mucosa. Quantitative nasal cultures were done before and after the cleansing. Saline was gently instilled into the MS, then aspirated and quantitatively cultured both aerobically and anaerobically. Eleven of 13 (85%) of the sinus aspirates were sterile. One sinus aspirate grew 2 colonies of S. pneumoniae and the other aspirate grew 3 colonies of S. epidermidis and one colony each of alpha streptococcus and a Micrococcus species. The very low colony counts suggest nasal contamination rather than in situ colonization. The MS of rhesus monkeys is either sterile or is colonized with extremely small numbers of bacteria.