[Leptospirosis screening: performance of the Serion Elisa Classic Leptospira IgM KIT]. / Dépistage de la Leptospirose: performance de la trousse Sérion Elisa classic Leptospira IgM.

AIM OF THE STUDY: Evaluate the sensitivity and the specificity of anti-Leptospira IgM detection with the Serion Elisa classic kit in comparison to the Panbio Elisa kit. METHODS: Twenty-three sera of patients whom Taqman probe real time PCR is positive and 19 sera positive by the microscopic agglutination test (MAT) are studied for sensitivity. Specificity is evaluated with 49 pairs of sera negative by MAT and with sera positive in IgM to EBV, to syphilis, to Borrelia and positive to influenza virus antibodies. RESULTS: 14/23 (61%) of the sera positive by PCR and 27/30 (90%) of the sera positive at significant level by MAT are positive by Serion IgM Elisa. Serogroups Icterohaemorrhagiae, Grippotyphosa, Australis, Tarassovi, Canicola, Sejroe, Patoc and Cynopteri are detected. 40/49 sera (82%) negative by MAT are negative by Serion IgM Elisa. Agreement with the Panbio kit is 61% (30/49). Results are discrepant in 19/49 cases corresponding to a positive result by Panbio IgM and to a negative result by Serion IgM. Serological cross-reactions are more frequent with IgM to syphilis and to Borrelia than with IgM to EBV and to influenza virus antibodies. CONCLUSION: A similar sensitivity is observed between the two kits but specificity is higher with Serion. Positivity in IgM is 61% in cases of leptospirosis diagnosed by PCR.

French situation concerning the Swedish Chlamydia trachomatis variant.

In 2006, a plasmid deletion mutant of Chlamydia trachomatis was identified in Sweden that can not be detected with those commercial tests targeting the deleted area. In order to study the spread of this strain in France, a laboratory-based surveillance system was set up by the National Reference Centre for Chlamydiae and the Institut de Veille Sanitaire. Among 1,141 C. trachomatis-positive specimens from all over France, the new variant was only detected in one case. This case was a non-French resident consulting a sexually transmitted infections clinic. Although the new variant does not seem to be established in France as yet, surveillance based on the testing of C. trachomatis-positive samples from all over France continues.

[Evaluation of a in house serology reagent for the diagnosis of cat-scratch disease defined by PCR]. / Evaluation d'un réactif maison de sérologie pour le diagnostic de la maladie des griffes du chat définie par la PCR.

AIM OF THE STUDY: evaluate the sensitivity and the specificity of the cat scratch disease serology by indirect immunofluorescence assay, realized from an in-house antigenic suspension, with PCR defined cases. Describe the epidemiological characteristics of the cases. METHODS: the antigenic suspension is realized by culture of a Houston 1 ATCC 49882 B. henselae reference strain on horse blood agar suspended in egg formoled PBS. Real time PCR from clinical samples is performed by amplification of a 998-bp 16S rDNA sequence with Bart and r-BH primers. RESULTS: In 57 out of 92 (62%) positive patients in PCR, the serology is positive in IgG at low or significative level or positive in IgG with presence of IgM or shows a seroconversion. The specificity in serum samples from 40 control patients is 100%. The average age of the 165 positive patients in PCR is 27.6 years old (3-80). The localization of the lymph nodes is more often axillary (47%) than inguinal (32%) or cervical (16%). CONCLUSION: Our in-house indirect immunofluorescence assay for the cat scratch disease serology shows a sensitivity equivalent to other technics described in the literature, with an excellent specificity.

[Contribution of PCR for detection of Mycobacterium tuberculosis complex in respiratory and nonrespiratory specimens]. / Apport de la détection des mycobactéries du complexe tuberculosis par PCR dans des prélèvements pulmonaires et extrapulmonaires.

AIM OF THE STUDY: To evaluate the sensitivity of PCR versus culture of complex tuberculosis mycobacteria and to determine the delay between PCR results and identification of mycobacteria in culture. MATERIALS AND METHODS: Ninety-nine pulmonary and 66 extrapulmonary specimens were analyzed. Samples were inoculated on liquid (MGIT, Bactec) and solid media (Coletsos) and respectively incubated 6 and 12 weeks. Identification was performed by reverse hybridization of PCR products to their complementary probes immobilized on membrane strips (Genotype MTBC, HAIN). Specimens DNA detection was realized by PCR (Cobas Amplicor Mycobacterium tuberculosis test, Roche). RESULTS: Sensitivity of PCR for acid fast bacilli smear positive pulmonary (50/50) and extrapulmonary (7/7) specimens was 100%. Delay between PCR result and identification was 11 days for pulmonary specimens and 8 days for extrapulmonary specimens. Sensitivity of PCR for smear negative samples was, respectively, of 78.7% (37/47) and 51.8% (29/56) for pulmonary and extrapulmonary specimens. In case of PCR positive result of a smear negative sample, a gap of respectively 13 and 12 days was obtained for pulmonary and extrapulmonary specimens compared to identification. CONCLUSION: Positive PCR result for respiratory specimens allows a gap of 11 to 13 days in diagnosis in comparison with identification of mycobacteria in culture.