Biomedical subjects

M-E Bougnoux

Publications and source records attributed to M-E Bougnoux.

4 recordsLinked to original sources

PubMed2006

[Acute schistosomiasis in French travellers].

OBJECTIVE: The clinical presentation of acute schistosomiasis in travellers differs from those observed with chronic schistosomiasis in people from endemic areas. The objective of this study is to describe the main clinical and biological characteristics of the acute schistosomiasis in French travellers. METHODS: Retrospective study conducted in 42 hospital laboratories of parasitology in France, based on a questionnaire filled out for each case of schistosomiasis diagnosed in subjects non-originating from an endemic country and returning from of a stay in Africa, between 2000 and 2004. RESULTS: Seventy-seven cases of acute schistosomiasis diagnosed between 2000 and 2004 were reported by 15 of the 33 laboratories having taken part in the study. The patients were 26 years old on average and 60% were contaminated in West Africa. Seventy patients (91%) presented at least one symptom at the moment of the diagnosis, but only 44 (57%) presented sufficiently intense symptoms to justify a medical consultation spontaneously. The most frequently reported clinical signs were fever (44%), diarrhoea (40%), pruritus (25%), cough (21%) and hematuria (20%). Hypereosinophilia (82%), elevated liver enzymes and positive serology were respectively reported in 82, 23 and 90% of the cases. Ova were found in the urines or the stool in 60% of the cases. Eleven patients were hospitalized. DISCUSSION: Acute schistosomiasis must be evoked in patients returning from endemic country and presenting with non-specific symptoms; including patients whose bathes in contaminated water was limited to a short contact of the feet in a river. The high frequency of the asymptomatic or paucisymptomatic forms exposes the infected people to a delayed diagnosis and therefore to an evolution towards the chronic form of schistosomiasis. The increase in tourism towards the endemic areas could be accompanied by an increase in the frequency of the schistosomiasis, and encourages setting-up an active monitoring of acute schistosomiasis.

Acute Disease↗

PubMed2006

Multilocus sequence typing reveals intrafamilial transmission and microevolutions of Candida albicans isolates from the human digestive tract.

Candida albicans is a human commensal that is also responsible for superficial and systemic infections. Little is known about the carriage of C. albicans in the digestive tract and the genome dynamics that occur during commensalisms of this diploid species. The aim of this study was to evaluate the prevalence, diversity, and genetic relationships among C. albicans isolates recovered during natural colonization of the digestive tract of humans, with emphasis on Crohn's disease patients who produce anti-yeast antibodies and may have altered Candida sp. carriage. Candida sp. isolates were recovered from 234 subjects within 25 families with multiple cases of Crohn's disease and 10 control families, sampled at the oral and fecal sites. Prevalences of Candida sp. and C. albicans carriage were 53.4% and 46.5%, respectively, indicating frequent commensal carriage. No differences in prevalence of carriage could be observed between Crohn's disease patients and healthy subjects. Multilocus sequence typing (MLST) of C. albicans isolates revealed frequent colonization of a subject or several members of the same family by genetically indistinguishable or genetically close isolates. These latter isolates differed by loss-of-heterozygosity events at one or several of the MLST loci. These loss-of-heterozygosity events could be due to either chromosome loss followed by duplication or large mitotic recombination events between complementary chromosomes. This study was the first to jointly assess commensal carriage of C. albicans, intrafamilial transmission, and microevolution. The high frequency of each of these events suggests that the digestive tract provides an important and natural niche for microevolutions of diploid C. albicans through the loss of heterozygosity.

Bacterial Typing Techniques↗

PubMed2003

Collaborative consensus for optimized multilocus sequence typing of Candida albicans.

A panel of 86 different Candida albicans isolates was subjected to multilocus sequence typing (MLST) in two laboratories to obtain sequence data for 10 published housekeeping gene fragments. Analysis of data for all possible combinations of five, six, seven, eight, and nine of the fragments showed that a set comprising the fragments AAT1a, ACC1, ADP1, MPIb, SYA1, VPS13, and ZWF1b was the smallest that yielded 86 unique diploid sequence types for the 86 isolates. This set is recommended for future MLST with C. albicans.

Candida albicans↗

PubMed2002

Usefulness of multilocus sequence typing for characterization of clinical isolates of Candida albicans.

Molecular characterization of Candida albicans isolates is essential for understanding the epidemiology of nosocomial infections caused by this yeast. Here, we investigated the potential value of multilocus sequence typing (MLST) for characterizing epidemiologically related or unrelated C. albicans strains of various clinical origins. Accordingly, we sequenced the internal regions (loci) of six selected housekeeping genes of 40 C. albicans clinical isolates and 2 reference strains. In all, 68 polymorphic nucleotide sites were identified, of which 65 were found to be heterozygous in at least one isolate. Ten to 24 different genotypes were observed at the different loci, resulting, when combined, in 39 unique genotype combinations or diploid sequence types (DSTs). When MLST was applied to 26 epidemiologically unrelated isolates and the 2 reference strains, it allowed the identification of 27 independent DSTs, thus demonstrating a discriminatory power of 99.7. Using multidimensional scaling together with the minimum spanning tree method to analyze interstrain relationships, we identified six groups of genetically related isolates on the basis of bootstrap values of greater than 900. Application of MLST to 14 epidemiologically related isolates showed that those recovered from patients in the same hospital ward during the same 3 months had specific DSTs, although 73% of these isolates were genetically very close. This suggests that MLST can trace minute variations in the sequences of related isolates. Overall, MLST proved to be a highly discriminatory and stable method for unambiguous characterization of C. albicans.

Bacterial Proteins↗