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Evolution of Mycobacterium ulcerans and other mycolactone-producing mycobacteria from a common Mycobacterium marinum progenitor
No full textIt had been assumed that production of the cytotoxic polyketide mycolactone was strictly associated with Mycobacterium ulcerans, the causative agent of Buruli ulcer. However, a recent study has uncovered a broader distribution of mycolactone-producing mycobacteria (MPM) that includes mycobacteria cultured from diseased fish and frogs in the United States and from diseased fish in the Red and Mediterranean Seas. All of these mycobacteria contain versions of the M. ulcerans pMUM plasmid, produce mycolactones, and show a high degree of genetic relatedness to both M. ulcerans and Mycobacterium marinum. Here, we show by multiple genetic methods, including multilocus sequence analysis and DNA-DNA hybridization, that all MPM have evolved from a common M. marinum progenitor to form a genetically cohesive group among a more diverse assemblage of M. marinum strains. Like M. ulcerans, the fish and frog MPM show multiple copies of the insertion sequence IS2404. Comparisons of pMUM and chromosomal gene sequences demonstrate that plasmid acquisition and the subsequent ability to produce mycolactone were probably the key drivers of speciation. Ongoing evolution among MPM has since produced at least two genetically distinct ecotypes that can be broadly divided into those typically causing disease in ectotherms (but also having a high zoonotic potential) and those causing disease in endotherms, such as humans
Apport de la microbiologie dans la prise en charge thérapeutique de la tuberculose au Rwanda
No full textPopulation preference of net texture prior to bed net trial in kala-azar-endemic areas
No full textPrior to a community-based efficacy trial of long-lasting insecticidal nets (LLINs) in the prevention of visceral leishmaniasis (VL; also called kala-azar), a pilot study on preference of tools was held in endemic areas of India and Nepal in September 2005.LLINs made of polyester and polyethylene were distributed to 60 participants, who used the nets sequentially for 7 d. Acceptability and preference were evaluated via indirect indicators through questionnaires at three defined time points before and after use of the LLINs and through focus group discussions (FGDs). In the latter, preferences for color and size were also assessed. Untreated bed nets were owned by 87% of the households prior to the study. All users liked textures of both LLIN types after 7 d of use, but had a slight preference for those made of polyester if they were to recommend a LLIN to relatives or friends (p<0.05), mainly because of their relatively greater softness in comparison to polyethylene LLINs. Users reported that both net types reduced mosquito bites and number of insects, including sand fly (bhusana; genus Phlebotomus), inside the house. Side effects were minor and disappeared quickly.The large-scale intervention trial considered the preferences of the study population to decide on the best tool of intervention-light-blue, rectangular, polyester LLINs of different sizes
Validation of a PCR-oligochromatography test for detection of Trypanozoon parasites in a multicenter collaborative trial
No full textA PCR-oligochromatography test for diagnosis of human and animal trypanosomiasis was evaluated through a multicenter ring trial with six laboratories testing a set of 21 blinded samples, resulting in qualitative data (positive or negative). Results showed an intralaboratory repeatability (accordance) of 88.7% (credible interval [CI], 84.4 to 92.5%) and an interlaboratory repeatability (concordance) of 88.1% (CI, 84.3 to 92.3%)
Determinants of seeking needed outpatient care in Iran: results from a national services utilization survey
No full textBACKGROUND: To assess the inequity in seeking needed outpatient services in Iran and to investigate its influential factors. METHOD: The data were taken from a nation-wide Iranian health survey conducted in 2003. This study is based on individuals aged 15 years and over who had mentioned their need to seek outpatient care within two weeks prior to the day of the interview. The outcome was seeking needed outpatient care. The independent variables included respondents' age, gender, marital status, education, occupation, index of household economic status, health insurance status and residential place (urban vs. rural).RESULTS: Sixty-nine point five percent of those in need sought outpatient care. The rich (OR: 2.38, 95% CI: 1.64 - 3.43) and the health insured (OR: 1.62, 95% CI: 1.25 - 2.08), the pensioners and the retired (OR: 2.26, 95% CI: 1.22 - 4.20), the housewives (OR: 1.77, 95% CI: 1.07 - 2.95) were more likely to seek outpatient care than other occupations. On the other hand, people living in remote rural areas (OR: 0.40, 95% CI: 0.28 - 0.57) were less likely to seek their needed outpatient care than those living in main rural areas and urban areas. CONCLUSIONS: As in different parts of the world, differences in seeking needed healthcare still exist across different groups in Iran. Indeed, seeking outpatient care in Iran is related not only to health system functions--like health insurance and health facilities--but also on factors beyond the scope of health authorities such as economic status and occupation. This study can be instrumental for the recent five-year Economic, Social and Cultural Development Plan of Iran which identified the reduction of inequalities in social determinants of health [corrected
Molecular epidemiology with subtype analysis of Cryptosporidium in calves in Belgium
No full textThe prevalence of Cryptosporidium in calves younger than 10 weeks was estimated in a cross-sectional epidemiological study on 100 dairy (n=499) and 50 beef (n=333) farms in East Flanders (Belgium), using a previously evaluated immunofluorescence assay (Merifluor). The calf prevalence was 37% (95% Probability Interval (PI): 7-70%) in dairy calves and 12% (95% PI: 1-30%) in beef calves. To elucidate the genetic diversity, the Cryptosporidium 18S ribosomal DNA and the 70 kDa heat shock protein gene were targeted. In the majority of the samples C. parvum was present, although C. bovis was also identified, all but one in calves older than 1 month. The porcine-specific C. suis was identified in 1 beef calf. Subtyping of C. parvum positive isolates by sequence analysis of the 60 kDa glycoprotein gene indicated the presence of 4 allele IIa subtypes, along with 1 subtype IIdA22G1. The subtype IIaA15G2R1 was most prevalent, next to subtype IIaA13G2R1 and IIaA16G2R1, and a new subtype IIaA14G2R1. The results of the present study indicate a high prevalence of Cryptosporidium infections in calves in Belgium and confirm that these calves should be considered as a potential zoonotic reservoir for human infections
Importance of a canteen lunch on the dietary intake of acrylamide
No full textA food and drink intake survey was carried out among university students and staff members. Consumption data were collected on days when the participants took hot lunch in a university canteen. The dietary acrylamide exposure was calculated through a probabilistic approach and revealed a median intake of 0.40 microg/kg bw/day [90% confidence interval: 0.36-0.44], which is in accordance with previous exposure calculations. Biscuits (35.4%), French fries (29.9%), bread (23.5%), and chocolate (11.2%) were identified to be the main sources of dietary acrylamide. Foodstuffs consumed in between the three main meals of the day (so called snack type foods) contributed the most to the intake (42.2%). The exposure was lower in an intervention group which received free portions of fruit and vegetables, indicating that a nutritionally balanced diet may contribute to a decreased acrylamide intake. French fries had a significant impact on the acrylamide intake, due to the frequent consumption in the canteen. This demonstrates the important responsibility of caterers and canteen kitchens in the mitigation of acrylamide exposure through reduction of acrylamide in their prepared products, in particular in French fries
