Sequencing-based molecular typing of treponema pallidum strains in the Czech Republic: all identified genotypes are related to the sequence of the SS14 strain.

A set of 415 clinical samples isolated from 294 patients suspected of having syphilis collected in the Czech Republic between 2004 and 2010 was tested for the presence of treponemal DNA. Standard serological tests showed that 197 patients were syphilis-seropositive and 97 patients were syphilis-seronegative. In each sample, PCR tests for polA (TP0105), tmpC (TP0319), TP0136, TP0548 and 23S rRNA genes were performed. Samples taken from 91 patients were PCR-positive. Molecular typing of treponemal DNA was based on the sequencing of TP0136, TP0548 and 23S rRNA genes. Treponemal DNA was typeable in samples taken from 64 PCR-positive patients and 9 different genotypes were found. The proportion of treponemal strains resistant to macrolide antibiotics was 37.3%. In the DNA samples taken from 39 patients, a parallel treponemal typing approved by Centers for Disease Control and Prevention was performed. The variants of arp and tpr genes appear to combine independently with sequence variants of TP0136, TP0548 and 23S rRNA genes.

Bacteriocin synthesis in uropathogenic and commensal Escherichia coli: colicin E1 is a potential virulence factor.

BACKGROUND: Bacteriocin production is an important characteristic of E. coli strains of human origin. To date, 26 colicin and 9 microcin types have been analyzed on a molecular level allowing molecular detection of the corresponding genes. The production incidence of 29 bacteriocin types and E. coli phylogroups were tested in a set of 361 E. coli strains isolated from human urinary tract infections (UTI) and in 411 control strains isolated from feces of patients without bacterial gut infection. RESULTS: Production of 17 and 20 individual bacteriocin types was found in the UTI and control strains, respectively. Microcin H47 encoding determinants were found more often among UTI strains compared to controls (37.9% and 27.0% respectively, p = 0.02) and strains producing microcin H47 belonged predominantly to phylogroup B2 when compared to other bacteriocin producers (67.4% and 36.7%, respectively; p < 0.0001). Producers of 3 or more identified bacteriocin types were more common in the UTI group (20.0% compared to 12.4% in controls, p = 0.03). In the UTI strains, there was a markedly higher number of those producing colicin E1 compared to controls (22.1% to 10.2%, respectively, p = 0.0008). Moreover, colicin E1 production was more common in the UTI bacteriocinogenic strains with multi-producer capabilities. As shown by Southern blotting, pColE1 DNA was not recognized by the ColIa probe and vice versa suggesting that pColE1 was independently associated with pColIa in UTI strains. CONCLUSION: E. coli strains isolated from human urinary tract infections showed increased incidence of microcin H47 and colicin E1 production, respectively. Moreover, colicin E1 itself appears to be a potentially important virulence factor of certain uropathogenic E. coli strains.

Performance of CAPTIA SelectSyph-G enzyme-linked immunosorbent assay in syphilis testing of a high-risk population: analysis of discordant results.

Using the Captia Select Syph-G enzyme-linked immunosorbent assay (ELISA), we analyzed the sera of 1,771 patients from a high-risk population attending sexually transmitted disease (STD) clinics. We focused on discrepancies between the results of the immunoglobulin G (IgG) ELISA and the Treponema pallidum hemagglutination (TPHA) test. We identified 57 patients (3.22%) with conflicting results in the IgG ELISA and TPHA test. In order to resolve these discrepancies, these patients' health records were reviewed and additional serological tests (rapid plasma reagin, IgM ELISA, fluorescent treponemal antibody absorption, and Western blotting) were performed. We subsequently diagnosed 22 of these 57 (38.6%) patients with late latent syphilis. None of the patients with discordant test results was diagnosed with early syphilis. We followed 35 of these 57 patients, analyzing two consecutive serum samples at 3 weeks and at 3 months. Discordant results persisted in 12 (33.3%) patients. We successfully resolved the test result discrepancies for 28 patients (80%) involved in follow-up. Captia SelectSyph-G ELISA showed a sensitivity of 99.0%, a specificity of 98.0%, and positive and negative predictive values of 99.3% and 97.2%, respectively. Based on the results of this study, we conclude that the Captia SelectSyph-G ELISA is a reliable tool for syphilis testing in a high-risk population and recommend the utilization of the Captia SelectSyph-G ELISA as a confirmatory test in at-risk patients.