Quantitative bacteriology of a case of acute parotitis

It is generally assumed that the microorganisms responsible for acute suppurative parotitis are facultative anaerobes, primarily Staphylococcus aureus and Streptococcus viridans. A quantitative microbiologic investigation of an aspirate of pus from the case we report revealed a microbial flora (5.1 X 10(6) CFU/ml) consisting entirely of strict anaerobes (Fusobacterium nucleatum and Peptostreptococcus anaerobius). The strain of F. nucleatum was sensitive to metronidazole but resistant to penicillin, amoxicillin, and erythromycin (minimum inhibitory concentration greater than 16 micrograms/ml). P. anaerobius was sensitive to the antibiotics tested. It is concluded that a high concentration of viable anaerobic bacteria may be present in acute suppurative parotitis and thus pus obtained from cases of sialadenitis should be cultured with microbiologic methods capable of isolating strict anaerobes. Additionally, antibiotic sensitivity should be determined routinely.