Comparison of Real-Time PCR Assays for Detection of Pathogenic Leptospira spp. in Blood and Identification of Variations in Target Sequences

International audienceLeptospirosis is considered an underdiagnosed disease. Although several PCR-based methods are currently in use, there is little information on their comparability. In this study, four quantitative real-time PCR (qPCR) assays (SYBR green and TaqMan chemistries) targeting the secY, lfb1, and lipL32 genes were evaluated as diagnostic assays. In our hands, these assays can detect between 102 and 103 bacteria/ml of pure culture, whole-blood, plasma, and serum samples. In three independent experiments, we found a slightly higher sensitivity of the PCR assays in plasma than in whole blood and serum. We also evaluated the specificity of the PCR assays on reference Leptospira strains, including newly described Leptospira species, and clinical isolates. No amplification was detected for DNA obtained from saprophytic or intermediate Leptospira species. However, among the pathogens, we identified sequence polymorphisms in target genes that result in primer and probe mismatches and affect qPCR assay performance. In conclusion, most of these assays are sensitive and specific tools for routine diagnosis of leptospirosis. However, it is important to continually evaluate and, if necessary, modify the primers and/or probes used to ensure effective detection of the circulating Leptospira isolates

Isolation of a Yersinia enterocolitica biotype 1B strain in France, and evaluation of its genetic relatedness to other European and North American biotype 1B strains.

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First isolation and characterization of Leptospira interrogans serogroup Australis from swine in Brazil

The purpose of this study was to report the first recovery and characterization of Leptospira interrogans (serogroup Australis) from urine of swine in Brazil. The isolate was studied by serogrouping, MLVA, PGFE, and partial sequencing of rrs and secY. It was serogrouped as serogroup Australis, probably serovar Bratislava (titre 1,600), and sequenced as Leptospira interrogans. The MLVA and PGFE profiles also suggested the isolate as serovar Bratislava, since they were indistinguishable from reference strains Balico and Jez Bratislava. This is the first Leptospira interrogans serogroup Australis isolate, probably serovar Bratislava, obtained in Brazil

A comparative phenotypic study of kallmann syndrome patients carrying monoallelic and biallelic mutations in the prokineticin 2 or prokineticin receptor 2 genes.

Context: Both biallelic and monoallelic mutations in PROK2 or PROKR2 have been found in Kallmann syndrome (KS). Objective: The objective of the study was to compare the phenotypes of KS patients harboring monoallelic and biallelic mutations in these genes. Design and Patients: We studied clinical and endocrine features that reflect the functioning of the pituitary-gonadal axis, and the nonreproductive phenotype, in 55 adult KS patients (42 men and 13 women), of whom 41 had monoallelic mutations and 14 biallelic mutations in PROK2 or PROKR2. Results: Biallelic mutations were associated with more frequent cryptorchidism (70% vs. 34%, P < 0.05) and microphallus (90% vs. 28%, P < 0.001) and lower mean testicular volume (1.2 +/- 0.4 vs. 4.5 +/- 6.0 ml; P < 0.01) in male patients. Likewise, the testosterone level as well as the basal FSH level and peak LH level under GnRH-stimulation were lower in males with biallelic mutations (0.2 +/- 0.1 vs. 0.7 +/- 0.8 ng/ml; P = 0.05, 0.3 +/- 0.1 vs. 1.8 +/- 3.0 IU/liter; P < 0.05, and 0.8 +/- 0.8 vs. 5.2 +/- 5.5 IU/liter; P < 0.05, respectively). Nonreproductive, nonolfactory anomalies were rare in both sexes and were never found in patients with biallelic mutations. The mean body mass index of the patients (23.9 +/- 4.2 kg/m(2) in males and 26.3 +/- 6.6 kg/m(2) in females) did not differ significantly from that of gender-, age-, and treatment-matched KS individuals who did not carry a mutation in PROK2 or PROKR2. Finally, circadian cortisol levels evaluated in five patients, including one with biallelic PROKR2 mutations, were normal in all cases. Conclusion: Male patients carrying biallelic mutations in PROK2 or PROKR2 have a less variable and on average a more severe reproductive phenotype than patients carrying monoallelic mutations in these genes. Nonreproductive, nonolfactory clinical anomalies associated with KS seem to be restricted to patients with monoallelic mutations

Rapid Improvement after Starting Elexacaftor–Tezacaftor–Ivacaftor in Patients with Cystic Fibrosis and Advanced Pulmonary Disease

International audienceRationale: Elexacaftor-tezacaftor-ivacaftor is a CFTR (cystic fibrosis [CF] transmembrane conductance regulator) modulator combination, developed for patients with CF with at least one Phe508del mutation. Objectives: To evaluate the effects of elexacaftor-tezacaftor- ivacaftor in patients with CF and advanced respiratory disease. Methods: A prospective observational study, including all patients aged ⩾12 years and with a percent-predicted FEV1 (ppFEV1) <40 who initiated elexacaftor-tezacaftor-ivacaftor from December 2019 to August 2020 in France was conducted. Clinical characteristics were collected at initiation and at 1 and 3 months. Safety and effectiveness were evaluated by September 2020. National-level transplantation and mortality figures for 2020 were obtained from the French CF and transplant centers and registries. Measurements and Main Results: Elexacaftor-tezacaftor- ivacaftor was initiated in 245 patients with a median (interquartile range) ppFEV1 = 29 (24-34). The mean (95% confidence interval) absolute increase in the ppFEV1 was +15.1 (+13.8 to +16.4; P < 0.0001), and the mean (95% confidence interval) in weight was +4.2 kg (+3.9 to +4.6; P < 0.0001). The number of patients requiring long-term oxygen, noninvasive ventilation, and/or enteral tube feeding decreased by 50%, 30%, and 50%, respectively (P < 0.01). Although 16 patients were on the transplant waiting list and 37 were undergoing transplantation evaluation at treatment initiation, only 2 received a transplant, and 1 died. By September 2020, only five patients were still on the transplantation path. Compared with the previous 2 years, a twofold decrease in the number of lung transplantations in patients with CF was observed in 2020, whereas the number of deaths without transplantation remained stable. Conclusions: In patients with advanced disease, elexacaftor-tezacaftor-ivacaftor is associated with rapid clinical improvement, often leading to the indication for lung transplantation being suspended