Kirk C.S. Chen

Nonspecific vaginitis: Diagnostic criteria and microbial and epidemiologic associations☆

Numerous previous studies of nonspecific vaginitis have yielded contradictory results regarding its cause and clinical manifestations, due to a lack of uniform case definition and laboratory methods. We studied 397 consecutive unselected female university students and applied sets of well defined criteria to distinguish nonspecific vaginitis from other forms of vaginitis and from normal findings. Using such criteria, we diagnosed nonspecific vaginitis in up to 25 percent of our study population; asymptomatic disease was recognized in more than 50 percent of those with nonspecific vaginitis. A clinical diagnosis of nonspecific vaginitis, based on simple office procedures, was correlated with both the presence and the concentration of Gardnerella vaginalis (Hemophilus vaginalis) in vaginal discharge, and with characteristic biochemical findings in vaginal discharge. Nonspecific vaginitis was also correlated with a history of sexual activity, a history of previous trichomoniasis, current use of nonbarrier contraceptive methods, and, particularly, use of an intrauterine device. G. vaginalis was isolated from 51.3 percent of the total population using a highly selective medium that detected the organism in lower concentration in vaginal discharge than did previously used media. Practical diagnostic criteria for standard clinical use are proposed. Application of such criteria should assist in clinical management of nonspecific vaginitis and in further study of the microbiologic and biochemical correlates and the pathogenesis of this mild but quite prevalent disease.

Identification of conserved regions for species and subspecies specific epitopes on the major outer membrane protein of Chlamydia trachomatis

Proteolytic peptides containing the serological epitopes present on the major outer membrane protein of Chlamydia trachomatis were studied by immunoblots. Monoclonal antibodies which have been defined by micro-immunofluorescence typing as serovar-, subspecies and species-specific were utilized. The reactivity of either serovar-specific or species-specific monoclonal antibodies in the immunoblots was similar to that in the micro-immunofluorescence test. However, monoclonal antibodies which demonstrated subspecies-specific reactivity by the micro-immunofluorescence test expressed species-specific reactivity by the immunoblot method. The serovar-specific epitope which was identified on the major outer membrane protein was lost after proteolytic digestion with Staphylococcus aureus V8 protease. Immunoblots of the proteolytic fragments identified the species-specific epitope on several peptides and the subspecies-specific epitope on fewer peptides than those in which the species-specific epitope was identified. In addition, both the species and subspecies epitopes were present on the same fragments of different serovars. The data indicate that the species epitope is on conserved regions of the major outer membrane protein and is structurally clustered with a subspecies-specific epitope.

Determination of biogenic amines using heterocyclic cation and aromatic anion elution

Abstract Heterocyclic cation and aromatic anion are used in the chromatographic buffers for the analysis of monoamines and diamines on a sulfonated cation-exchange column using an amino acid analyzer. All elution buffers employed for these analyses had a pH of 5.0 to maximize the ninhydrin color reaction. These methods have been successfully used for biological samples. Using a two-column (0.8 × 12 cm) system, with a buffer flow rate of 50 ml/h, analysis can be carried out in 330 min for monoamine and diamine mixtures on 0.5 to 10 nmol of each amine.

A rapid procedure for detection of bacterial amino acid decarboxylases

Abstract The detection of decarboxylases of arginine, glutamic acid, histidine, lysine, ornithine, phenylalanine, tryptophan, and tyrosine in bacteria by thin-layer chromatography on polyamide sheets is described. The bacteria were grown on agar medium plates supplemented with eight amino acids at pH 5.5 for induction of amino acid decarboxylases, then transferred to amine-production media. The decarboxylation products in the spent media (amines and/or γ-amino-n-butyric acid) were dansylated and the dansyl derivatives were separated by thin-layer chromatography on polyamide sheets. This method requires only two separate incubations of the decarboxylase-induced bacteria in amine-production media for 1 h at 37°C for simultaneous detection of eight bacterial amino acid decarboxylases using 0.4 μl of the spent media.