Four methods (chromogenic, acidimetric, inhibition, and iodometric) for demonstration of the beta-lactamase production by 70 isolates of Neisseria gonorrhoeae, were evaluated in Cuba. There was 100% correlation between all beta-lactamase methods and the standardized penicillin dilution susceptibility test for penicillinase-non-producing N. gonorrhoeae. For penicillinase-producing N. gonorrhoeae strains, there was a perfect correlation between the chromogenic method and penicillin susceptibility testing, but one and two strains failed to give a positive result for beta-lactamase with the inhibition/acidimetric and the iodometric methods, respectively. There was a high concordance between the chromogenic method, considered as gold standard and the rest of penicillinase tests evaluated: Kappa Index (KI) = 0.98 for inhibition/acidimetric methods and KI = 0.97 for the iodometric method. The four methods evaluated were accurate, reproducible, easily readable, economical, and ease to use for screening primary isolates of N. gonorrhoeae in Cuba. We recommended the use of the inhibition method, when testing the penicillinase activity in gonococcal isolates in provincial and municipal reference laboratories.

5 methods of utilization of sugars were evaluated in 25 strains previously identified as N. gonorrhoeae: CTA agar, modified CTA agar, gelatin starch agar, Mueller Hinton agar plus bromotimol blue and rapid method. 100 % of the strains of N. gonorrhoeae were identified by the CTA and rapid methods, whereas 96 % were identified by the modified CTA and gelatin starch agar methods. No strain of gonoccocus was identified by the Mueller Hinton agar method plus bromotimol blue. The cystine tripticase agar medium (CTA) is the elective method to confirm the isolates of Neisseria gonorrhoeae. As it is mainly made by U.S. companies, it is difficult for Cuba to acquire it. The gelatin-starch agar.method and the rapid method are useful alternative of the CTA medium, so their use is proposed in this paper.

Se evaluaron 5 métodos de utilización de azúcares en 25 cepas identificadas previamente como Neisseria gonorrhoeae: agar CTA, agar CTA modificado, agar gelatina almidón, agar Mueller Hinton más azul de bromotimol y método rápido. Por los métodos de CTA y rápido fueron identificadas 100 % de las cepas de N. gonorrhoeae, mientras que por los métodos de CTA modificado y agar gelatina almidón fue 96 %. Ninguna cepa de gonococo fue identificada por el método de agar Mueller Hinton más azul de bromotimol. El medio de agar cistina tripticasa (CTA), constituye el método de elección para confirmar los aislamientos de Neisseria gonorrhoeae; es elaborado fundamentalmente por compañías norteamericanas, por lo que su adquisición en Cuba resulta difícil. Los métodos de agar gelatina almidón y rápido constituyen alternativas útiles del medio CTA, por lo que su uso se propone en este trabajo.

The susceptibility to penicillin of 111 Neisseria meningitidis strains was assessed by the agar-dilution procedure and serosubtypes were determined by a whole-cell enzyme-linked immunoassay using monoclonal antibodies reagents. Thirty-five isolates showed reduced sensitivity to penicillin (MIC > or = 0.1 mg/l and <= 1 mg/l) and no resistant strains were detected. The most common phenotype was B:4:P1.15 (77.5%) and a rising trend of non-typeable and non-subtypeable strains was detected. The increase in levels of minimal inhibitory concentrations of meningococci to penicillin gives cause for concern and the increase in non-typeable and non-subtypeable isolation demand the use of molecular biology techniques for their typing.