PREVALENCE OF BETA-LACTAMASE ENZYME-PRODUCTION IN BACTERIA ISOLATED FROM WOMEN WITH POSTPARTUM ENDOMETRITIS

One hundred eighty-four postpartum patients with the diagnosis of endo myometritis underwent intrauterine culturing. Beta-Lactamase productio n was tested using nitrocephin-impregnated discs in 278 bacterial isol ates from patients with postpartum endometritis. Beta-Lactamase produc tion was found to be present in 149 of 278 (54%) isolates tested: 0 of 39 Streptococcus faecalis (0%), 22 of 41 Escherichia coli (54%), 66 o f 68 Bacteroides bivius (97%), 0 of 13 Proteus mirabilis (0%) and 15 o f 42 Staphylococcus epidermidis (36%). Anaerobes, as a group, had the highest rate of beta-lactamase production, 94 of 102 (93%), followed b y gram negatives, 34 of 84 (40%), then gram positives, 21 of 91 (23%). However, it was the beta-lactamase produced by the gram-negative bact eria that was most responsive to the addition of a beta-lactamase inhi bitor. The frequent isolation of beta-lactamase-producing bacteria fro m patients with postpartum endometritis raises concern about the use o f antibiotics not resistant to these enzymes. Therefore, antibiotics c ombined with a beta-lactamase inhibitor may have potential as single-a gent therapy in obstetric and gynecologic infections.