The performance of a plasmid-based ligase chain reaction (LCR) with urine specimens was compared with those of cell culture of cervical swabs and enzyme immunoassay with urine specimens for the detection of Chlamydia trachomatis infection in women who had attended a family planning clinic. The prevalence of chlamydial infection determined by LCR was 3.1%. Discrepant results among the three assays were resolved by testing urine by a second LCR assay based on the C. trachomatis chromosomal gene encoding the major outer membrane protein. Sensitivity, specificity, and positive and negative predictive values for the cell cultures were 56.3, 100, 100, and 98.4%, respectively, whereas those for the enzyme immunoassay were 18.8, 100, 100, and 97.1%, respectively, and those for LCR were 87.5, 100, 100, and 99.5%, respectively. LCR thus provides a highly sensitive and specific noninvasive screening method for detecting genital chlamydial infections in women.

During oxidative burst, neutrophils selectively generate HOCl to destroy invading microbial pathogens. Excess HOCl reacts with taurine, a semi-essential amino acid, resulting in the formation of the longer-lived biogenerated broad-spectrum antimicrobial agent, N-chlorotaurine (NCT). In the presence of an excess of HOCl or under moderately acidic conditions, NCT can be further chlorinated, or it can disproportionate to produce N,N-dichlorotaurine (NNDCT). In the present study, 2,2-dimethyltaurine was used to prepare a more stable N-chlorotaurine, namely, N,N-dichloro-2,2-dimethyltaurine (NVC-422). In addition, we report on the chemical characterization, in vitro antimicrobial properties, and cytotoxicity of this compound. NVC-422 was shown effectively to kill all 17 microbial strains tested, including antibiotic-resistant Staphylococcus aureus and Enterococcus faecium. The minimum bactericidal concentration of NVC-422 against Gram-negative and Grampositive bacteria ranged from 0.12 to 4 g/ml. The minimum fungicidal concentrations against Candida albicans and Candida glabrata were 32 and 16 g/ml, respectively. NVC-422 has an in vitro cytotoxicity (50% cytotoxicity ‫؍‬ 1,440 g/ml) similar to that of NNDCT. Moreover, our data showed that this agent possesses rapid, pH-dependent antimicrobial activity. At pH 4, NVC-422 completely killed both Escherichia coli and S. aureus within 5 min at a concentration of 32 g/ml. Finally, the effect of NVC-422 in the treatment of an E. coli-infected granulating wound rat model was evaluated. Treatment of the infected granulating wound with NVC-422 resulted in significant reduction of the bacterial tissue burden and faster wound healing compared to a saline-treated control. These findings suggest that NVC-422 could have potential application as a topical antimicrobial.As part of the innate immune system, leukocytes are capable of generating and releasing reactive oxygen species. During oxidative burst, neutrophils selectively generate hypochlorous acid to destroy invading microbial pathogens. In a secondary reaction, hypochlorous acid reacts with taurine, a semi-essential amino acid. The resulting N-chlorotaurine (NCT) is a wellknown antimicrobial and anti-inflammatory oxidant (12, 15). Furthermore, NCT has shown significant bactericidal and fungicidal properties with relatively low toxicity compared to other oxidants (13,14). In the presence of an excess of hypochlorous acid or under moderately acidic conditions, NCT can be further chlorinated or, alternatively, it can disproportionate to form N,N-dichlorotaurine (NNDCT), which also has broadspectrum antimicrobial activity (9). Unfortunately, both NCT and NNDCT have relatively short solution half-lives, decomposing by hydrolytic dehydrochlorination (5, 6, 16). Because of this instability, the potential usefulness of the endogenous Nchlorotaurines as marketable therapeutics is limited. Replacement of the hydrogens at the ␤-carbon of taurine by methyl groups prevents the dehydrochlorination process, thereby circumventing this instabi...

A new PCR kit (AMPLICOR CT/NG; Roche Diagnostic Systems, Inc., Branchburg, N.J.) was used as a screening tool for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in first-void urine (FVU) specimens from 3,340 asymptomatic women attending European health care units for contraceptive advice or pregnancy termination. All samples were kept frozen (؊20°C) prior to testing. Chlamydia-positive samples were retested once by the plasmid-based PCR kit and also by a major outer membrane protein (MOMP) primer-based PCR. Discrepancies were resolved by using the direct immunofluorescence test (DIF) with the centrifuged sediment of the FVU specimens. Samples positive for N. gonorrhoeae were retested by chromosomal primer-based PCR and verified by a 16S RNA PCR. Of the samples tested, 1.8% were considered inhibitory by using the internal amplification control. Of 81 samples positive for C. trachomatis, 74 samples were positive by both plasmid-and MOMP-based PCRs, 6 samples were positive by plasmid-based PCR and DIF, and one sample was positive by both MOMP-based PCR and DIF. Nine samples (0.3%) were positive for N. gonorrhoeae by the chromosomal primer-based PCR; however, none of the results could be confirmed. The test offers the unique ability to identify inhibition of amplification with the optional internal control.

Vaginal sampling performed by the woman herself is a sensitive approach and might serve as an important stimulus for screening for C. trachomatis infections in young women at risk.

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An enzyme-linked immunosorbent assay (EIA) (MikroTrak; Syva) was compared with PCR (Amplicor; Roche) for detection of Chlamydia trachomatis in first-void urine (FVU) from 184 men attending a skin and venereal disease clinic. The prevalence of C. trachomatis in the population studied was 18.5%. Discrepant results between Syva EIA and Roche PCR were retested by using major outer membrane protein primer-based PCR. After retesting, the sensitivity, the specificity, and the positive and negative predictive values for the Syva EIA were 85.3, 100, 100, and 77.5%, respectively, and those for the Roche PCR 100, 100, 100, and 100%, respectively. It was concluded that PCR provides a highly sensitive and specific noninvasive screening method for genital chlamydial infection in asymptomatic men.

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Rinderpest is a highly contagious viral disease of ruminants and has greater than 95% morbidity and mortality. The etiological agent, rinderpest virus (RPV), is a member of the family Paramyxoviridae and the genus Morbillivirus. Immune responses to both the hemagglutinin (H) and the fusion (F) antigens of morbilliviruses play an important role in the prevention of infection, and only attenuated live vaccines have been shown to provide protective immunity against the group. The lack of protection with inactivated vaccines has been attributed to the denaturation of the F glycoprotein of the virus. Our previous study, however, demonstrated complete protection of cattle vaccinated with infectious vaccinia virus recombinants expressing the H (vRVH) or F (vRVF) protein alone, even in the presence of only 4 U of serum-neutralizing (SN) antibody to RPV (T. Yilma, D. Hsu, L. Jones, S. Owens, M. Grubman, C. Mebus, M. Yamanaka, and B. Dale, Science 242:1058-1061, 1988). We have constructed recombinant baculoviruses that express the F (Fb) and H (Hb) glycoproteins of RPV. Furthermore, we have analyzed the immune responses of mice and cattle to these antigens. Cattle vaccinated with Fb or Hb or a mixture of both antigens were not protected from challenge inoculation with RPV, even when the SN titer was greater than in cattle vaccinated with vRVF alone. This lack of protection, in the presence of SN antibody, would indicate that live attenuated and recombinant vaccines induce immune responses necessary for protection (e.g., cell-mediated immunity) that are not generated by subunit or inactivated whole-virus vaccines.