MLVA Subtyping of Genovar E Chlamydia trachomatis Individualizes the Swedish Variant and Anorectal Isolates from Men who Have Sex with Men

This study describes a new multilocus variable number tandem-repeat (VNTR) analysis (MLVA) typing system for the discrimination of Chlamydia trachomatis genovar D to K isolates or specimens. We focused our MLVA scheme on genovar E which predominates in most populations worldwide. This system does not require culture and therefore can be performed directly on DNA extracted from positive clinical specimens. Our method was based on GeneScan analysis of five VNTR loci labelled with fluorescent dyes by multiplex PCR and capillary electrophoresis. This MLVA, called MLVA-5, was applied to a collection of 220 genovar E and 94 non-E genovar C. trachomatis isolates and specimens obtained from 251 patients and resulted in 38 MLVA-5 types. The genetic stability of the MLVA-5 scheme was assessed for results obtained both in vitro by serial passage culturing and in vivo using concomitant and sequential isolates and specimens. All anorectal genovar E isolates from men who have sex with men exhibited the same MLVA-5 type, suggesting clonal spread. In the same way, we confirmed the clonal origin of the Swedish new variant of C. trachomatis. The MLVA-5 assay was compared to three other molecular typing methods, ompA gene sequencing, multilocus sequence typing (MLST) and a previous MLVA method called MLVA-3, on 43 genovar E isolates. The discriminatory index was 0.913 for MLVA-5, 0.860 for MLST and 0.622 for MLVA-3. Among all of these genotyping methods, MLVA-5 displayed the highest discriminatory power and does not require a time-consuming sequencing step. The results indicate that MLVA-5 enables high-resolution molecular epidemiological characterisation of C. trachomatis genovars D to K infections directly from specimens

Development of a real-time PCR for the detection of Chlamydia psittaci.

International audienc

Oligonucleotide primers used for MLVA-5.

a<p>fwd, forward primer; rev, reverse primer.</p

Diabetes Mellitus in Prader-Willi Syndrome: Natural History during the Transition from Childhood to Adulthood in a Cohort of 39 Patients

International audienceType 2 diabetes mellitus (T2DM) affects 20% of patients with Prader-Willi syndrome (PWS), with many cases diagnosed during the transition period. Our aim was to describe the natural history of T2DM in patients with PWS before the age of 25 years and to develop screening and preventive strategies. Thirty-nine patients followed in the French PWS Reference Center were included (median age 25.6 years [23.7; 31.7]). Twenty-one had been treated with growth hormone (GH), fifteen had not, and three had an unknown status. The median age at T2DM diagnosis was 16.8 years (11–24) and the median BMI was 39 kg/m2 [34.6; 45], with 34/35 patients living with obesity. The patients displayed frequent psychiatric (48.3% hospitalization,) and metabolic (56.4% hypertriglyceridemia,) comorbidities and a parental history of T2DM (35.7%) or overweight (53.6%) compared to the PWS general population. There was no difference in BMI and metabolic complications between the GH-treated and non-GH-treated groups at T2DM diagnosis. Patients with PWS who develop early T2DM have severe obesity, a high frequency of psychiatric and metabolic disorders, and a family history of T2DM and overweight. These results underline the need for early identification of patients at risk, prevention of obesity, and repeated blood glucose monitoring during the transition period

Discriminatory index for the molecular typing methods, single or combined, on genovar E <i>C. trachomatis</i> isolates.

a<p>HGDI, Hunter-Gaston discriminatory index. The HGDI was calculated on 38 isolates that were epidemiologically unrelated.</p

MST of the MLVA-5 types of genovar E <i>C. trachomatis</i> isolates and positive specimens.

<p>Each circle denotes a particular MLVA-5 type. The size of the circle is proportional to the number of isolates or specimens belonging to the indicated MLVA-5 genotype. The distance between neighbouring genotypes is expressed as the number of allelic changes and is outlined by short bold lines for one change. No cluster is emphasised as shown by the distance, equal to one, between neighbouring genotypes. <b>⁺</b> MLVA-5 types encompassing anorectal isolates and specimens. ^★ MLVA-5 type containing nvCT isolate and specimens.</p

Number of repeat units of the five VNTR markers in 220 genovar E and 94 non-E genovar <i>C. trachomatis</i> isolates and clinical specimens.

<p>Number of repeat units of the five VNTR markers in 220 genovar E and 94 non-E genovar <i>C. trachomatis</i> isolates and clinical specimens.</p

Description of the 12 new MLST sequences types.

a<p>new allelic variants are indicated in bold.</p>b<p>na: no amplification.</p>c<p>nd: not determined.</p

Characteristics of the five VNTR markers.

a<p>Position (5′ end) on the <i>C. trachomatis</i> D/UW-3/Cx genome sequence.</p