Impact of serodiagnosis on the management of Lyme borreliosis at Angers University Hospital.

INTRODUCTION: Lyme borreliosis (LB) is an emerging arthropod-borne disease the diagnosis of which is made on clinical and biological data. We assessed the Angers University Hospital physicians' management of LB, in case of positive serology, and estimated their compliance to European recommendations (EUCALB). METHODS: We retrospectively included 75 cases with positive ELISA serologies confirmed by Western-Blot, performed at the Angers University Hospital between 2008 and 2012. RESULTS AND DISCUSSION: There were 4 cases of early localized phase, 26 of early-disseminated phase (including 17 cases of neuroborreliosis), and one case of late phase. The curative management complied with EUCALB guidelines in 28 cases out of 31. CONCLUSION: Serology remains a reference diagnostic tool for LB, as long as the practitioner is aware of the main clinical and biological criteria.

Identification and genotyping of Mycobacterium tuberculosis complex species by use of a SNaPshot Minisequencing-based assay.

The aim of the present study was to investigate the use of the SNaPshot minisequencing method for the identification of Mycobacterium tuberculosis complex (MTBC) isolates to the species level and for further genotyping of M. tuberculosis isolates. We developed an innovative strategy based on two multiplex allele-specific minisequencing assays that allowed detection of eight species-specific and eight lineage-specific single nucleotide polymorphisms (SNPs). Each assay consisted of an eightplex PCR amplification, followed by an eightplex minisequencing reaction with the SNaPshot multiplex kit (Applied Biosystems) and, finally, analysis of the extension products by capillary electrophoresis. The whole strategy was developed with a panel of 56 MTBC strains and 15 negative controls. All MTBC strains tested except one M. africanum clinical isolate were accurately identified to the species level, and all M. tuberculosis isolates were successfully further genotyped. This two-step strategy based on SNaPshot minisequencing allows the simultaneous differentiation of closely related members of the MTBC, the distinction between principal genetic groups, and the characterization of M. tuberculosis isolates into one of the seven prominent SNP cluster groups (SCGs) and could be a useful tool for diagnostic and epidemiological purposes.

Relevance of the antibody index to diagnose Lyme neuroborreliosis among seropositive patients.

BACKGROUND: No consensual criteria exist to diagnose neuroborreliosis. The intrathecal anti-Borrelia antibody index (AI) is a necessary criterion to diagnose neuroborreliosis in Europe, but not in the United States. Previous studies to determine the diagnostic value of the AI found a sensitivity ranging from 55% to 80%. However, these studies included only typical clinical cases of meningitis or meningoradiculitis, and none had a control group with CSF anti-Borrelia antibodies. METHODS: We studied a sample of 123 consecutive patients with clinical signs of neurologic involvement and CSF anti-Borrelia antibodies. We determined the AI for all patients and a final diagnosis was made. Patients were then divided into three groups (neuroborreliosis, possible neuroborreliosis, control). RESULTS: Thirty of the 40 patients with neuroborreliosis had a positive AI (AI sensitivity = 75%). Two of the 74 patients with another neurologic diagnosis had a positive AI (AI specificity = 97%). CONCLUSION: The antibody index has a very good specificity but only moderate sensitivity. Given the lack of consensual criteria for neuroborreliosis and the absence of a "gold standard" diagnostic test, we propose pragmatic diagnostic criteria for neuroborreliosis, namely the presence of four of the following five items: no past history of neuroborreliosis, positive CSF ELISA serology, positive anti-Borrelia antibody index, favorable outcome after specific antibiotic treatment, and no differential diagnosis. These new criteria will need to be tested in a larger, prospective cohort.

[Role of biological assays in the diagnosis of Lyme borreliosis presentations. What are the techniques and which are currently available?]. / Place des méthodes biologiques dans le diagnostic des différentes manifestations de la borréliose de Lyme. Quelles sont les techniques? Quelles sont celles disponibles actuellement?

The biological diagnosis of Borrelia burgdorferi sensu lato infection is usually made by antibody detection in patient sera. Thus, serological testing (Elisa, immunoblotting) is essential for a biological diagnosis. Specific antibody detection is usually done in serum and CSF of patients suspected of Lyme borreliosis. Laboratories must follow European recommendations to validate these assays in routine practice. Antibody detection lacks sensitivity in the early cutaneous phase of the infection. Therefore, serological testing is not recommended for the diagnosis of erythema migrans. The interpretation of serology must take into account the variability of Elisa sensitivity and specificity and the lack of standardization for Western-blotting in Europe. Besides these indirect diagnosis techniques, there is also direct detection of spirochetes by culture or by in vitro DNA amplification but these require adequate samples. These molecular tests must not be performed routinely, but only for specific clinical situations and in specialized laboratories only.

Detection of Chlamydia trachomatis DNA using MagNA Pure DNA extraction and Cobas Amplicor CT/NG amplification.

The automated MagNA Pure DNA extraction method for Chlamydia trachomatis was compared with the manual Cobas Amplicor protocol using 100 microL of input sample volume from 964 specimens. Agreement between protocols was 96.1%. The automated extraction method had a sensitivity of 99% and a specificity of 100%. Amplification inhibition observed after manual preparation of samples (3.8%) was not apparent following automated extraction. Using 200 microL of sample in the automated extraction process lowered the detection limit without raising the inhibition rate. Furthermore, the automated extraction method halved the hands-on time required for the procedure.

Peripartum bacteremias due to Leptotrichia amnionii and Sneathia sanguinegens, rare causes of fever during and after delivery.

We report three cases of delivery and postpartum bacteremia due to unusual anaerobic bacteria in healthy young women. Leptotrichia amnionii bacteremia occurred during delivery in two mothers and was associated with fetal distress during labor. Conversely, Sneathia sanguinegens bacteremia occurred postpartum, 2 days after delivery, without consequence for the neonate.