Proline aminopeptidase activity as a rapid diagnostic test to confirm bacterial vaginosis.

Two biochemical indicators of bacterial vaginosis, proline aminopeptidase activity and gas-liquid chromatographic analysis, were compared. Five hundred women had their vaginal secretions tested for pH, presence of a positive amine test, levels of volatile and nonvolatile short-chain organic acids, and proline aminopeptidase activity. In addition, direct microscopic and Gram stain examinations were performed. Of the 500 women, 349 (70%) had some form of vaginitis. One hundred sixteen were diagnosed as having bacterial vaginosis, and 69 of these (59%) had Mobiluncus sp on either direct microscopic or Gram stain examination. Two hundred thirty-three had either mixed or other forms of vaginitis. One hundred fifty-one patients were normal. The sensitivity of the proline aminopeptidase assay was 83 and 79%, respectively, in patients having bacterial vaginosis with and without Mobiluncus morphotypes. In contrast, gas-liquid chromatography of short-chain organic acids had sensitivities of 71 and 30%, respectively. Specificity of both assays was about 95%. The greater sensitivity of the proline aminopeptidase assay, especially in patients without Mobiluncus morphotypes, proves its superiority.

A selective and differential agar for anaerobic comma-shaped bacteria recovered from patients having motile rods and non-specific vaginosis.

A selective and differential agar for optimal growth of the large curved motile anaerobic rods isolated from patients having non-specific vaginosis (NSV) was developed. A basal medium of Columbia CNA agar was used with colony growth found to be optimal by the addition of 7% fetal calf serum and 5% rabbit blood (CNARS). Beta-Haemolysis was found to be demonstrated most readily on a bilayer plate with a basal layer consisting of CNA agar with fetal calf serum, overlaid with a layer of CNA agar containing fetal calf serum and rabbit blood. Optimal growth was found by anaerobic incubation at 37 degrees C, after 5 days.

Evaluation of the BactiCard Neisseria for identification of pathogenic Neisseria species and Moraxella catarrhalis.

The BactiCard Neisseria (Remel, USA) is a chromogenic enzyme substrate system for identifying Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria lactamica, and Moraxella catarrhalis. The identification system consists of a card with four test circles impregnated with chromogenic substrates for indoxyl butyrate esterase (IB), prolyl aminopeptidase (PRO), gamma-glutamyl aminopeptidase (GLUT), and ss-galactosidase (BGAL). These substrates permit the identification of Moraxella catarrhalis, Neisseria gonorrhoeae, Neisseria meningitidis, and Neisseria lactamica, respectively. After hydration of the circles with buffer, colonies from growth on selective media or a subculture are applied to the four circles. IB and BGAL reactions are read for a blue-green color after 2 and 15 min, respectively. PRO and GLUT reactions are read at 15 min for a red color after addition of a developer reagent. Identifications obtained with the BactiCard Neisseria were compared with those obtained using conventional procedures for 558 isolates in a blinded fashion. The BactiCard Neisseria identified 100% of 254 Neisseria gonorrhoeae, 100% of 125 Neisseria meningitidis, 53 (98.2%) of 54 Neisseria lactamica, and 123 (98.4%) of 125 Moraxella catarrhalis isolates. The BactiCard Neisseria is an accurate and rapid system for identification of these microorganisms in the clinical laboratory.

Comparison of monoclonal antibody methods and a ribosomal ribonucleic acid probe test for Neisseria gonorrhoeae culture confirmation.

Recently, a chemiluminescent nucleic acid probe test that specifically detects the ribosomal ribonucleic acid of Neisseria gonorrhoeae has been released for clinical laboratory use (AccuProbe Neisseria gonorrhoeae). In this study, three coagglutination tests (GonoGen I, Meritec GC, and GC Omni), the GonoGen II immunofiltration method and the Micro Trak Neisseria gonorrhoeae fluorescent monoclonal antibody test were compared with AccuProbe for identification of gonococci. Strains tested (n = 376) included 194 Neisseria gonorrhoeae, 82 Neisseria meningitidis, 32 Neisseria lactamica, 32 Neisseria species, 32 Moraxella catarrhalis, 2 Moraxella spp. and 2 Kingella denitrificans. The GonoGen I, Meritec GC and GC Omni coagglutination tests produced clearly positive results for 93.8%, 92.3% and 95.9% of the gonococci, respectively. The GonoGen II unequivocally identified 91.8% and the MicroTrak fluorescent antibody test identified 90.7% with 2+ or greater fluorescence. AccuProbe identified 100% of the gonococci tested. GonoGen I and GonoGen II were 98% specific, Meritec GC was 99% specific and the specificity of the GC Omni, MicroTrak fluorescent antibody and AccuProbe tests was 100%. While antibody-based tests were reliable when results were clearly interpretable, the AccuProbe was the only confirmatory test that was 100% accurate. Serotyping studies indicate that an array of beta-lactamase positive and negative gonococcal serotypes fail to react with the monoclonal antibody-based tests in general and with the fluorescent antibody test in particular.