High seroreactivities to orthoebolaviruses in rural Cameroon: a case-control study on non-human primate bites and a cross-sectional survey in rural population.

BACKGROUND: Ebola (EBOV) and Sudan (SUDV) orthoebolaviruses are responsible for lethal haemorrhagic fever outbreaks in humans in Central and West Africa, and in apes that can be at the source of human outbreaks for EBOV. METHODS: To assess the risk of exposure to orthoebolaviruses through contact with non-human primates (NHP), we tested the presence of antibodies against different viral proteins with a microsphere-based multiplex immunoassay in a case-control study on bites from NHPs in forest areas from Cameroon (n=795), and in cross-sectional surveys from other rural populations (n=622) of the same country. RESULTS: Seroreactivities against at least two viral proteins were detected in 13% and 12% of the samples for EBOV and SUDV, respectively. Probability of seroreactivity was not associated with history of NHP bites, but was three times higher in Pygmies compared to Bantus. Although no neutralizing antibodies to EBOV and SUDV were detected in a selected series of highly reactive samples, avidity results indicate strong affinity to SUDV antigens. CONCLUSION: The detection of high level of seroreactivities against orthoebolaviruses in rural Cameroon where no outbreaks have been reported, raises the possibilities of silent circulation of orthoebolavirus, or of other not yet documented filoviruses, in these forested regions.

Direct metagenomic and amplicon-based Nanopore sequencing of French human monkeypox from clinical specimen.

We report the whole-genome sequence of monkeypox virus obtained using MinION technology (Oxford Nanopore Technologies) from a French clinical specimen during the 2022 epidemic. Amplicon-based sequencing and shotgun metagenomic approaches were directly applied to the sample.

Complete Genome Sequences of Monkeypox Virus from a French Clinical Sample and the Corresponding Isolated Strain, Obtained Using Nanopore Sequencing.

We report the whole-genome sequences of a monkeypox virus from the skin lesion of a French patient and the corresponding isolated viral strain. Both viral genomic sequences were successfully obtained by applying shotgun metagenomics using the Oxford Nanopore Technologies sequencing approach.

Seroepidemiological Reconstruction of Long-term Chikungunya Virus Circulation in Burkina Faso and Gabon.

Chikungunya virus (CHIKV) is a major public health concern worldwide. However, infection levels are rarely known, especially in Africa. We recruited individuals from Ouagadougou, Burkina Faso and Lambaréné, Gabon (age range, 1-55 years), tested their blood for CHIKV antibodies, and used serocatalytic models to reconstruct epidemiological histories. In Ouagadougou, 291 of 999 (29.1%) individuals were seropositive, ranging from 2% among those aged <10 years to 66% in those aged 40-55 years. We estimated there were 7 outbreaks since the 1970s but none since 2001, resulting in 600 000 infections in the city, none of which were reported. However, we could not definitively conclude whether infections were due to CHIKV or o'nyong-nyong, another alphavirus. In Lambaréné, 117 of 427 (27%) participants were seropositive. Our model identified a single outbreak sometime since 2007, consistent with the only reported CHIKV outbreak in the country. These findings suggest sporadic outbreaks in these settings and that the burden remains undetected or incorrectly attributed.

Heat inactivation of monkeypox virus.

Different kinds of media spiked with monkeypox virus (MPXV) were subjected to heat inactivation at different temperatures for various periods of time. The results showed that MPXV was inactivated in less than 5 min at 70 °C and less than 15 min at 60 °C, with no difference between viruses from the West African and Central African clades. The present findings could help laboratory workers to manipulate MPXV in optimal biosafety conditions and improve their protocols.

Development and clinical validation of loop-mediated isothermal amplification (LAMP) assay to diagnose high HBV DNA levels in resource-limited settings.

OBJECTIVE: A massive scale-up of testing and treatment is indicated to globally eliminate hepatitis B virus (HBV) infection. However, access to a polymerase chain reaction (PCR), a key test to quantify HBV DNA levels and determine treatment eligibility, is limited in resource-limited countries. We have developed and evaluated the loop-mediated isothermal amplification (LAMP) assay to diagnose clinically important HBV DNA thresholds defined by the WHO (≥20 000 and ≥ 200 000 IU/mL). METHODS: Pan-genotypic primer sets were designed on conserved HBV gene regions. Accuracy of LAMP to identify highly viraemic patients was evaluated in 400 and 550 HBV-infected people in France and Senegal, respectively. RESULTS: Our primers successfully detected eight major HBV genotypes/sub-genotypes (A1/2/3/B/C/D/E/F) with a detection limit ranging between 40 and 400 IU/mL. In France, the area under the receiver operating characteristic curve (AUROC), sensitivity and specificity of bead-based extraction and real-time turbidimetric LAMP were 0.95 (95% CI 0.93-0.97), 91.1% and 86.0%, respectively, to diagnose HBV DNA ≥20 000 IU/mL; and 0.98 (0.97-0.99), 98.0% and 94.6% for ≥200 000 IU/mL. The performance did not vary by viral genotypes. In Senegal, using a field-adapted method (reagent-free boil-and-spin extraction and inexpensive end-point fluorescence detection), the AUROC, sensitivity and specificity were 0.95 (0.93-0.97), 98.7% and 91.5%, respectively, to diagnose HBV DNA ≥200 000 IU/mL. The assay was not adapted to discriminate low-level viraemia. DISCUSSION: We have developed a simple, rapid (60 min), and inexpensive (US$8/assay) alternative to PCR to diagnose high viraemia ≥200 000 IU/mL. HBV-LAMP may contribute to eliminating HBV mother-to-child transmission by identifying high-risk pregnant women eligible for antiviral prophylaxis in resource-limited countries.

Zika virus outbreak in New Caledonia and Guillain-Barré syndrome: a case-control study.

Zika virus (ZIKV) infection has been associated with neurologic disorders including Guillain-Barré syndrome (GBS). In New Caledonia during the ZIKV outbreak (2014-2015), case-control and retrospective studies have been performed to assess the link between ZIKV and GBS. Among the 15 cases included, 33% had evidence of a recent ZIKV infection compared to only 3.3% in the 30 controls involved. All patients were Melanesian, had facial diplegia and similar neurophysiological pattern consistent with acute inflammatory demyelinating polyneuropathy, and recovered well. Furthermore, during the peak of ZIKV transmission, we observed a number of GBS cases higher than the calculated upper limit, emphasizing the fact that ZIKV is now a major trigger of GBS.

Misidentification of Saprochaete clavata as Magnusiomyces capitatus in clinical isolates: utility of internal transcribed spacer sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry and importance of reliable databases.

Saprochaete clavata and Magnusiomyces capitatus are human pathogens that are frequently mistaken for each other due to their similar phenotypes and erroneous or limited databases. Based on internal transcribed spacer (ITS) sequences, we propose species-specific carbon assimilation patterns and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) fingerprints that enable the identification of S. clavata, M. capitatus, and Galactomyces candidus to the species level.

Successful triple combination therapy of disseminated absidia corymbifera infection in an adolescent with osteosarcoma.

Mucormycosis are opportunistic infections mostly observed in immunocompromised patients. We report the case of a 13-year-old girl who suffered a systemic mucormycosis without presenting the usual risk factors. She was undergoing antineoplastic chemotherapy for advanced osteosarcoma of the femur with an uncommunicative pathologic fracture and pulmonary metastasis. Absidia corymbifera was isolated from skin lesions at the primary tumor site. She subsequently developed fungal pulmonary localizations and blood vessel thrombosis. Surgical treatment together with systemic, high doses of liposomal amphotericin B, posaconazole, and caspofungin cured the local infection and controlled systemic lesions. Unfortunately, the break in chemotherapy led to pulmonary metastasis progression.

Molecular and phenotypic evaluation of Lichtheimia corymbifera (formerly Absidia corymbifera) complex isolates associated with human mucormycosis: rehabilitation of L. ramosa.

Thirty-eight isolates (including 28 isolates from patients) morphologically identified as Lichtheimia corymbifera (formerly Absidia corymbifera) were studied by sequence analysis (analysis of the internal transcribed spacer [ITS] region of the ribosomal DNA, the D1-D2 region of 28S, and a portion of the elongation factor 1alpha [EF-1alpha] gene). Phenotypic characteristics, including morphology, antifungal susceptibility, and carbohydrate assimilation, were also determined. Analysis of the three loci uncovered two well-delimited clades. The maximum sequence similarity values between isolates from both clades were 66, 95, and 93% for the ITS, 28S, and EF-1alpha loci, respectively, with differences in the lengths of the ITS sequences being detected (763 to 770 bp for isolates of clade 1 versus 841 to 865 bp for isolates of clade 2). Morphologically, the shapes and the sizes of the sporangiospores were significantly different among the isolates from both clades. On the basis of the molecular and morphological data, we considered isolates of clade 2 to belong to a different species named Lichtheimia ramosa because reference strains CBS 269.65 and CBS 270.65 (which initially belonged to Absidia ramosa) clustered within this clade. As neotype A. corymbifera strain CBS 429.75 belongs to clade 1, the name L. corymbifera was conserved for clade 1 isolates. Of note, the amphotericin B MICs were significantly lower for L. ramosa than for L. corymbifera (P < 0.005) but were always

Mutations in the fks1 gene in Candida albicans, C. tropicalis, and C. krusei correlate with elevated caspofungin MICs uncovered in AM3 medium using the method of the European Committee on Antibiotic Susceptibility Testing.

Mutations in two specific regions of the Fks1 subunit of 1,3-beta-D-glucan synthase are known to confer decreased caspofungin susceptibility on Candida spp. Clinical isolates of Candida spp. (404 Candida albicans, 62 C. tropicalis, and 21 C. krusei isolates) sent to the French National Reference Center were prospectively screened for susceptibility to caspofungin in vitro by the broth microdilution reference method of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST-EUCAST). Twenty-eight isolates (25 C. albicans, 2 C. tropicalis, and 1 C. krusei isolate) for which the caspofungin MIC was above the MIC that inhibited 90% of the isolates of the corresponding species (MIC(90)) were subjected to molecular analysis in order to identify mutations in the fks1 gene. Substitutions in the deduced protein sequence of Fks1 were found for 8 isolates, and 20 isolates had the wild-type sequence. Among the six C. albicans isolates harboring mutations, six patterns were observed involving amino acid changes at positions 641, 645, 649, and 1358. For C. tropicalis, one isolate showed an L644W mutation, and for one C. krusei isolate, two mutations, L658W and L701M, were found. Two media, RPMI medium and AM3, were tested for their abilities to distinguish between isolates with wild-type Fks1 and those with mutant Fks1. In RPMI medium, caspofungin MICs ranged from 0.25 to 2 microg/ml for wild-type isolates and from 1 to 8 micro for mutant isolates. A sharper difference was observed in AM3: all wild-type isolates were inhibited by 0.25 micro of caspofungin, while caspofungin MICs for all mutant isolates were >or=0.5 microg/ml. These data demonstrate that clinical isolates of C. albicans, C. tropicalis, and C. krusei with decreased susceptibility to caspofungin in vitro have diverse mutations in the fks1 gene and that AM3 is potentially a better medium than RPMI for distinguishing between mutant and wild-type isolates using the AFST-EUCAST method.

Comparison of microsatellite length polymorphism and multilocus sequence typing for DNA-Based typing of Candida albicans.

For genotyping Candida albicans isolates, two PCR-based methods have recently emerged: multilocus sequence typing (MLST), based on the sequence of selected genes, and microsatellite length polymorphism (MLP), based on the length of PCR products containing variable numbers of short DNA repeats. To compare the two methods in their abilities to differentiate and group C. albicans isolates, we selected 50 independent isolates collected at the National Reference Center for Mycoses and Antifungals. MLST typing was performed using sequencing of seven loci as described at (http://test1.mlst.net). The MLP method consisted of a single multiplex PCR testing three different loci. Dendrograms were constructed by the unweighted pair group cluster method with Euclidean metric for both methods. The correlation between the distance matrices was performed with a Mantel test tested with 1,000 random permutations. The sensitivity and specificity of the MLP typing system were determined after allocating MLST groups for the greater number of isolates of each distinct MLP group. The discriminatory power index was >0.99, and the distances between the isolates were highly correlated with both systems. The Mantel coefficient and the Pearson product-moment correlation coefficient were 35,699 and 0.32, respectively (P < or = 1.2 x 10(-6)). Using MLP, the average specificity and sensitivity of clustering compared to MLST were 83% and 73%, respectively, when the singletons were excluded. The two methods are similarly discriminatory and can be interchangeable depending on the objectives. MLP is less expensive and faster than MLST. However, MLST is currently more accurate and additional standardization is needed for MLP.

In vitro susceptibility to posaconazole of 1,903 yeast isolates recovered in France from 2003 to 2006 and tested by the method of the European committee on antimicrobial susceptibility testing.

The posaconazole MIC(90) for 1,903 yeast isolates from France was 1 microg/ml (range, < or =0.015 to 8 microg/ml). Ninety percent of isolates with fluconazole MICs of > or =8 microg/ml (n = 509) and 90% of those with voriconazole MICs of > or =2 microg/ml (n = 80) were inhibited by 2 and 8 microg/ml of posaconazole, respectively.