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OBJECTIVE: Since the beginning of the 21st century, Reunion Island has experienced a syphilis epidemic. Infected patients are mostly heterosexual, with a high proportion of women, suggesting that congenital syphilis is present on the island. To determine whether azithromycin can be used for mass treatment of syphilis on Reunion Island, we assessed the prevalence of macrolide resistance in Treponema pallidum (TP). METHODS: This monocentric cross-sectional study was conducted at the Reunion Island University Hospital. Samples were collected from lesions suggestive of primary or secondary syphilis. Samples positive for TP by multiplex polymerase chain reaction (PCR) were sent to the French National Reference Centre (NRC) for further analysis. Nested PCR-tpp47 was performed on these samples for detection of TP-DNA; 23s rRNA was amplified by PCR in confirmed positive samples. The Restriction Fragment Length Polymorphism (RFLP) technique was performed on samples with amplified 23s rRNA for detection of the A2058G mutation. RESULTS: A total of 129 samples were collected from 119 patients. Of these, 18 tested positive for TP using multiplex PCR and were sent to the NRC. Fifteen (83.3%) of the 18 samples were confirmed positive by nested PCR-tpp47, and 23s rRNA was amplified in only 7 (38.9%) samples. Azithromycin resistance was detected in all TP strains with amplified 23s rRNA. CONCLUSION: Amplification of 23s rRNA was successful in only 7 TP strains, all of which displayed resistance to macrolides. Keeping in mind the small sample size of our study, this suggests that azithromycin should not be used for mass treatment of syphilis in Reunion Island.
Assuntos
Sífilis , Treponema pallidum , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Estudos Transversais , Farmacorresistência Bacteriana/genética , Feminino , Humanos , Macrolídeos , Reunião/epidemiologia , Sífilis/tratamento farmacológico , Sífilis/epidemiologia , Treponema pallidum/genéticaRESUMO
Fusarium head blight (FHB) is a fungal disease of wheat (Triticum aestivum L.) causing frequent economic losses to farmers under growing conditions of Eastern Canada. To assess risks associated with this disease and guide fungicide use decisions, many researchers from numerous countries have developed weather-based forecasting models. This work aims at evaluating which model produces the most accurate predictions of disease infection or deoxynivalenol (DON) content under climatic conditions occurring in Quebec. Spring wheat was grown during two seasons and winter wheat during one season at four experimental sites located in Quebec. Nine selected models for evaluation produced predictions of DON content (Canada and Italy), disease incidence (Argentina and Italy), and probability of epidemics (United States). Data from plots without fungicide (52 samples) were used to test the models listed above. Reliability of the selected forecasting models was evaluated with receiver operating characteristic (ROC) curve analysis. DON content (≥1 ppm) was the best crop damage indicator to differentiate epidemic (cases) and nonepidemic (controls) situations. Two American and the Argentinean forecasting models were more reliable than the others when the thresholds recommended in the literature were adjusted using the results for the ROC curve analyses. Those models are a good starting point for the implementation of an FHB forecasting system adapted to wheat production in Quebec.
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OBJECTIVES: Infectious disease (ID) advice is a major part of antimicrobial stewardship programs. The objective of this study was to assess general practitioners' (GPs)' opinions and compliance with advice given by ID hotlines. PATIENTS AND METHODS: This multicenter survey was based on the 7-day assessment of initial advice requested by GPs to a hotline set up by volunteer hospital ID teams to record advice for 3 years. The primary endpoint was the GPs' satisfaction with the advice given by ID specialists. RESULTS: Ten ID teams participated in the study and recorded 4138 requests for advice, of which 1325 requests included a proposal for antibiotic therapy and justified a follow-up call at seven days. Only 398 follow-up calls (30%) were carried out because many GPs were not reachable. GPs were very satisfied with ID hotlines: 58% considered them indispensable and 38% very useful. The recommendations provided by ID specialists were followed by GPs in more than 80% of cases. The two main motivations for GPs to call the hotline were to get quick advice (86%) and to receive help in managing a patient (76%). CONCLUSIONS: The ID telephone consultations and advice systems for GPs are highly appreciated and are effective in terms of following the recommendations.
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Doenças Transmissíveis , Clínicos Gerais , Humanos , Linhas Diretas , Doenças Transmissíveis/tratamento farmacológico , Inquéritos e Questionários , Atenção Primária à SaúdeRESUMO
ABSTRACT In controlled environment studies, the influence of temperature and wetness duration on infection of strawberry leaves by Mycosphaerella fragariae was quantified by inoculating plants with a conidial suspension and incubating them at various combinations of temperature (5 to 35 degrees C) and leaf wetness duration (0 to 96 h). Infection was expressed as the number of lesions per square centimeter of leaf surface and relative infection was used to develop an infection model. Younger leaves were more susceptible to infection. Regardless of temperature and duration of leaf wetness, only few lesions developed on the oldest (19 to 21 days old) and intermediate leaves (12 to 15 days old), respectively (maximum of 1.7 and 2.3 lesions per cm(2)) as compared to the youngest leaves (5 to 7 days old; maximum of 12.6 lesions per cm(2)). On the youngest leaves, lesions developed at all temperatures except at 35 degrees C, and the number of lesions, for all leaf wetness durations, increased gradually from 5 to 25 degrees C and decreased sharply from 25 to 30 degrees C. For temperatures of 15 and 20 degrees C, the number of lesions increased gradually when leaf wetness duration increased from 12 to 96 h. At 25 degrees C, the number of lesions increased with increasing leaf wetness from 12 to 48 h and then at a higher rate from 48 to 96 h. The optimal temperature for infection was 25 degrees C. For most temperatures, a minimum of 12 h of leaf wetness was necessary for infection (more than 1 lesion per cm(2)). Relative infection was modeled as a function of both temperature and wetness duration using a modified version of the Weibull equation (R (2) = 0.98). The resulting equations provided a precise description of the response of M. fragariae to temperature. The model was sufficiently flexible to account for most characteristics of the response of M. fragariae to wetness duration. The model was used to construct a risk chart that can be used to estimate the potential risk for infection based on observed or forecasted temperature and leaf wetness duration.
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Isariins B, C and D, isolated from a strain of Isaria felina, were shown to be cyclodepsipeptides constituted by a pentapeptide cyclized through a beta-hydroxyacid. The nature of the latter and the sequence of the peptide were determined for each compound. Relations between insecticidal activity and structure of the depsipeptides were pointed out.
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Inseticidas/análise , Fungos Mitospóricos/análise , Peptídeos/análise , Aminoácidos/análise , Fenômenos Químicos , Química , Espectrometria de MassasRESUMO
The cabbage maggot, Delia radicum L., has a bimodal pattern of emergence caused by the presence in populations of early and late-emerging genotypes that differ in their pupal development time. These genotypes could also express different egg-laying strategies. To examine oviposition patterns between genotypes and, particularly, their response to temperature, the egg-laying activity of females and egg mortality from each genotype were evaluated at temperatures from 12 to 30°C. Several criteria were used to describe the oviposition pattern: longevity of females, preoviposition period, lifetime fecundity, number of oviposition bouts, duration and number of eggs for each oviposition bout, duration of an oviposition cycle, and time interval between oviposition bouts. All criteria were similar between genotypes, except the preoviposition period and time interval between oviposition bouts. The preoviposition period was 1-4 d longer for the early emerging genotype than for the late-emerging genotype at temperatures <25°C, but similar at temperatures ≥25°C. The time interval between oviposition bouts of early emerging genotype was a few hours longer than for the late-emerging genotype at all temperatures. All oviposition pattern criteria responded to temperature, except the duration of oviposition bouts (â6.5 d) and egg mortality (â11%). The duration of a bout could be a compromise between oogenesis duration and the risks associated with egg deposition. According to these results, early and late-emerging genotypes express similar egg-laying strategies for all temperatures tested.
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Dípteros/fisiologia , Genótipo , Oviposição , Temperatura , Animais , Dípteros/genética , Feminino , Fertilidade/genética , Longevidade/genética , Masculino , Oviparidade/genéticaRESUMO
Edaphic factors such as soil temperature and moisture influence soil-dwelling insects, whose most vulnerable stages typically are eggs and young larvae. In this study, the survival of eggs and first-instar larvae of the cabbage maggot, Delia radicum L., was measured under laboratory conditions after exposure to a range of soil temperatures and moistures. When eggs were exposed to constant temperature (20-29°C) and humidity (5-200% [wt:wt]), temperature had no significant effect on survival, whereas humidity <25% [wt:wt] caused egg mortality. The gradual exposure of eggs to high temperatures resulted in low mortality below 33°C, but <5% of eggs survived at 40°C. When first-instar larvae were exposed to constant temperature (17-29°C) and humidity (5-100% [wt:wt]), both factors as well as their interaction had a significant effect on larval survival, which was nil at 5% (wt:wt) for all temperatures but increased from 21.9 to 42.8% at 17°C and from 34.1 to 55.0% at 29°C, for soil moisture contents of 15% and 100% (wt:wt), respectively. Eggs of D. radicum are resistant to low soil moisture and high temperature conditions. Larval survival tends to increase with an increase in soil temperature and moisture. It is suggested that soil temperature be integrated into insect development simulation models instead of air temperature, to build more effective models for cabbage maggot management.
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Dípteros/crescimento & desenvolvimento , Controle de Insetos/métodos , Solo/química , Animais , Brassica napus , Dípteros/fisiologia , Monitoramento Ambiental , Umidade , Larva/crescimento & desenvolvimento , Larva/fisiologia , Óvulo/crescimento & desenvolvimento , Óvulo/fisiologia , Quebeque , TemperaturaRESUMO
The noncontingent distribution ofO. nubilalis Hbn. eggs on various corn varieties has allowed their classification as either "favorable" or "nonfavorable" hybrids. This classification is based on a chemical communication system using volatile compounds active at a distance from the insect or active when in contact with the insect as soluble sugar components. Under this hypothesis, gas chromatography is the best way of investigating for the chemical differences between corn silk extracts from the two types of hybrids. A first experiment, using a "desorption-trapping" system on Tenax coupled to a gas chromatograph showed a quantitative difference between two compounds from the two hybrids. A second experiment showed the advantages and disadvantages of this method and allowed the development of two complementary techniques: (1) direct extraction of corn silk with trichlorofluo-romethane and direct injection into a capillary column with an apolar stationary phase using an "on-column" system; and (2) extraction under vacuum of volatile compounds from corn silk and their trapping on Tenax, followed by a second desorption. This allows a direct injection on the same capillary column. The first technique allows identification by mass spectrometry of many alkanes with high molecular weights. The second technique seems to confirm the presence of phenylacetaldehyde. Both techniques show quantitative differences in the composition of corn silk extracts from "favorable" and "nonfavorable" hybrids; however, the biologically active chemicals remain unknown.
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Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions were performed. Their co-ordinates were corrected from adjustments based on peroperative electrophysiological data and compared to those planned. MR image distortion (maximum: 1 mm) and chemical shift of petroleum oil-filled localiser rods (2.2 mm) induced an anterior target displacement of 2.6 mm (at a field strength of 1.5 T, frequency encoding bandwidth of 187.7 kHz, on T1-weighted images). The average absolute error of the stereotactic material was 0.7 mm for anteroposterior (AP), 0.5 mm for mediolateral (ML) and 0.8 mm for dorsoventral (DV) co-ordinates (maximal absolute errors: 1.6 mm, 2.2 mm and 1.7 mm, respectively; mean euclidean error: 1 mm). Three-dimensional MRI reconstructions showed an average absolute error of 0.8 mm, 0.9 mm and 1.9 mm in AP, ML and DV co-ordinates, respectively (maximal absolute errors: 2.4 mm, 2.7 mm and 5.7 mm, respectively; mean euclidean error: 2.3 mm). MRI distortion and chemical-shift errors must be determined by a phantom study and then compensated for. The most likely explanation for an average absolute error of 1.9 mm in the DV plane is displacement of the brain under the pressure of the penetrating electrode. When this displacement is corrected for by microelectrode recordings and stimulation data, MRI offers a high degree of accuracy and reliability for thalamic stereotaxy.