[Imported malaria: prevention should strengthened]. / Paludisme d'importation: il faut renforcer le message de prévention.

INTRODUCTION: The risk of acquiring malaria infection can largely be prevented by the regular use of chemoprophylactic drugs combined with protective measures against mosquito bites. In a retrospective study we had for aim to evaluate the compliance to malaria chemoprophylaxis in patients presenting with malaria infection. METHODS: We analyzed the compliance to the recommended malaria chemoprophylaxis of French travelers hospitalized in a department of infectious diseases because of malaria infection, between January 1999 and December 2003. RESULTS: Eighty-five patients, with a mean age of 34.1 years (16-65) were treated for malaria infection. Seventy-seven were due to Plasmodium falciparum. The outcome was favorable for all patients, despite four severe accesses. Forty-six patients (54%) did not take any chemoprophylaxis (CP), 19 (22%) had an inadequate CP for the risk, 13 (15%) badly complied with intermittent intake of CP and seven (8%) complied well with the recommended malaria CP. Among the 85 patients, 27 (32%) had come to the travelers' consultation and been given recommendations and a recommended malaria CP prescription before traveling. CONCLUSION: These results confirm that the majority of imported malaria cases is a consequence of bad compliance to CP. Understanding user profiles and factors predicting non-compliance may help us to improve pretravel counseling, thereby reducing the risk for travelers to acquire malaria infection.

Effect of matrix metalloprotease inhibitors on the 95 kDa metallopeptidase of Candida albicans.

A 95 kDa metallopeptidase of Candida albicans could be involved in the process of dissemination of the yeast. Matrix metalloproteases (MMPs) are also responsible for collagen breakdown in inflammatory and malignant processes. We tested six compounds on the C. albicans enzyme. Doxycycline, gentamicin, cefalothin, galardin, and elaidic and oleic acids are known for their capacity to inhibit some MMPs. Amongst these agents, only oleic acid was able to markedly inhibit the purified metallopeptidase at very low concentrations. Moreover, this fatty acid inhibited the secretion of the enzyme in the culture medium without altering the yeast viability.

Influence of sub-inhibitory concentrations of conventional antifungals on metabolism of Candida albicans and on its adherence to polystyrene and extracellular matrix proteins.

Five antifungal agents with different mechanisms of action were compared for their ability to affect mitochondrial dehydrogenase activity and adherence capacity of Candida albicans to polystyrene and extracellular matrix proteins. Only amphotericin B inhibited mitochondrial dehydrogenase activity when the culture medium was supplemented with galactose. 5-Fluorocytosine and terbinafine did not affect this activity, whereas itraconazole and fluconazole improved it. Furthermore, in these experimental conditions, the effect of sub-inhibitory concentrations of antifungals on adherence was dependent on the tested antifungal and the adherence surface: amphotericin B inhibited adherence to polystyrene and fibrinogen, but improved adherence to extracellular matrix. For all surfaces tested, when culture medium was supplemented with galactose, fluorocytosine did not affect adherence, and itraconazole, fluconazole and terbinafine inhibited adherence. Our results also confirmed the influence of the carbohydrates: sub-minimum inhibitory concentrations (MIC) of itraconazole increased or did not modify the mitochondrial metabolism of yeasts when the culture medium was supplemented with galactose, but this antifungal always decreased mitochondrial metabolism when the culture medium was supplemented with glucose. These data indicate that antifungals used below their MIC values can have various effects. It is important to distinguish the effects of antifungals on the metabolism of C. albicans from effects on its adherence capacity. The former effects are linked to the viability of the yeast and the latter depends on the colonization of cellular as opposed to inert surfaces.

Imported Plasmodium vivax malaria in France: geographical origin and report of an atypical case acquired in Central or Western Africa.

A total of 73 cases of Plasmodium vivax infections acquired in Western or Central Africa were diagnosed on microscopical criteria in French travellers from 1995 to 1998. We report a case of P. vivax infection in a non immune traveller confirmed by polymerase chain reaction and presenting an atypical P. ovale morphology. The infection was acquired in Western or Central Africa. These microscopical observations, together with the molecular evidence for P. vivax in Western and Central Africa suggest that P. vivax is transmitted in this area despite lacking the Duffy receptor in autochthonous population.

The effects of subcurative doses of chloroquine on Plasmodium vinckei petteri gametocytes and on their infectivity to mosquitoes.

The effects of subcurative doses of chloroquine on rodent and human Plasmodium transmission to the mosquito have been studied by several authors who showed a short-term (12 h) enhancement of gametocyte infectivity by the drug, restricted to chloroquine-resistant strains, and a long term (4-6 days) enhancement of gametocytogenesis of chloroquine-sensitive strains of Plasmodium chabaudi. We investigated both short- and long-term effects of chloroquine on Plasmodium vinckei petteri, a chloroquine-sensitive rodent Plasmodium strain. Chloroquine treatment reduced the index of gametocytogenesis to 73% (5 mg/kg) and 55% (2.5 mg/kg) of controls, on day 6 post-infection (p.i.). The reduction was statistically significant with 5 mg/kg chloroquine. However, the reduction of gametocyte numbers did not affect the transmission capabilities of the strain. Our experiments showed that doses of 1 mg/kg chloroquine had no effect on the oocyst counts, 12 h post-administration to mice. A statistically non-significant 61% reduction of oocyst numbers was observed in mosquitoes fed on mice treated with 5 mg/kg chloroquine. The effect of 5 mg/kg chloroquine administration on the infectivity of gametocytes to mosquitoes fed 1 h post-treatment was also investigated. An overall 41% reduction of oocyst numbers was observed. This immediate effect was statistically significant in 73% of the mice. These results are consistent with the hypothesis that the short-term enhancing effect of chloroquine on transmission is restricted to the drug-resistant strains of Plasmodium.

Toxoplasma gondii: purification and characterization of an immunogenic metallopeptidase.

A Toxoplasma gondii aminopeptidase specific for the fluorogenic substrate L-arginine 7-amino-4-methylcoumarin was identified in cell-free extract. This enzyme was purified by high-performance liquid chromatography using first size exclusion, then anion exchange, followed by a second size exclusion. The purified enzyme exhibited a pl of 4.7 by chromatofocusing and had an apparent molecular weight of 110 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. The purification factor was 80.9 and the yield was 14%. The optimal activity was at pH 7.4 and was strongly inhibited by EDTA and o-phenanthroline. Antibodies against this T. gondii metallopeptidase were detected by immunoprecipitation and immunoblotting in human sera obtained from patients undergoing toxoplasmosis.

Possible role of catheters in Saccharomyces boulardii fungemia.

Four cases of Saccharomyces boulardii fungemia, a very rare side effect of Saccharomyces boulardii therapy, are reported. The clinical impact of Saccharomyces boulardii infection appeared to be moderate. However, even though organ involvement was never demonstrated, septic shock with no other etiology was observed in one of our patients. All patients had an indwelling vascular catheter. Contamination of the air, environmental surfaces, and hands following the opening of a packet suggests that catheter contamination may have been a source of infection. To prevent catheter contamination it is recommended that packets or capsules of Saccharomyces boulardii be opened with gloves, outside the patient's room.

Case report and review. Onychomycosis due to Candida parapsilosis.

We report a case of onychomycosis with melanonychia due to Candida parapsilosis alone. Candida parapsilosis is now identified in the great majority of candidal onychomycosis, mainly in association with other yeasts. The criteria allowing the distinction between invasion and colonization, the risk factors and the treatment of C. parapsilosis onychomycosis are discussed.

A Candida albicans metallopeptidase degrades constitutive proteins of extracellular matrix.

Among potential virulence factors of Candida albicans, enzymes seem to play an important role. Many studies concern the secreted aspartic proteinases (saps), and the degradation of some components of the subendothelial extracellular matrix by the isoenzyme sap2 has been proved. Nevertheless, other proteolytic enzymes could be involved in the pathogenicity of the yeast. We studied the degradation of four constitutive proteins of the extracellular matrix: type I and IV collagens, laminin and fibronectin, by a 95-kDa metallopeptidase, localised in the cell wall of C. albicans. Each of these constituents was incubated with the purified enzyme and its degradation products analysed by an electrophoretic method. We observed that type I collagen and fibronectin were totally degraded by the enzyme whereas type IV collagen and laminin were only partially degraded. The C. albicans metallopeptidase may play a role in the degradation of the subendothelial extracellular matrix components. This enzyme could facilitate the migration of the yeast in the tissues after crossing the endothelial layer, allowing the fungal invasion of target organs.

[Subconjunctival localization of a Wuchereria bancrofti adult female]. / Localisation sous-conjonctivale d'une femelle adulte de Wuchereria bancrofti.

The authors describe a case of conjunctival localization of a living adult Wuchereria bancrofti female observed in a 6 year old native Haitian girl, two years after her arrival in France. The adult was surgically removed from the conjunctiva. Microfilariae were evidenced in blood samples obtained at midnight. This is the first case of sub-conjunctival localization of W. bancrofti. This case stresses the necessity to identify the filaria by studying the microfilariae in blood samples obtained at different times of the nycthemere and/or by observing the adult after surgical extraction. The presence of a Loa, a Dirofilaria, a Mansonella, or a Wuchereria calls for different medical therapies.

[Comparison of two techniques for detection of anti-Plasmodium falciparum antibodies: Falciparum-spot IF (Biomérieux) and Malaria IgG Celisa (BMD). Preliminary results]. / Comparaison de deux techniques de détection des anticorps anti-Plasmodium falciparum: Falciparum-spot IF (Biomérieux) et Malaria IgG Celisa (BMD). Résultats préliminaires.

We compared a new Elisa assay to detect malaria antibodies: Malaria IgG Celisa (BMD) with the IFAT technique Falciparum-spot IF (Biomérieux): sensitivity, specificity, predictive positive and negative values were 81%, 99%, 95%, 95%, respectively. Eight patients had positive thick blood smear out of 23 performed. For these eight confirmed acute malaria cases, the Elisa assay was negative in five instances. For two recent malaria attacks both Elisa and IFI were negative. With blood donors, two sera were IFAT positive and Elisa negative; 16 were IFAT doubtful and Elisa negative. Doubtful results rose up to 13.5% by IFAT against 1.5% by Elisa assay. We preferred kappa coefficient instead of chi 2 test for data analysis, which measures the concordance degree between the two techniques. Here concordance is moderate. Choosing an Elisa assay to detect the transmission of malaria for at-risk blood donors collides with the method sensitivity compared with IFAT as reference.

Improved immunodiagnosis of human candidiasis by an enzyme-linked immunosorbent assay using a Candida albicans 52-kilodalton metallopeptidase.

An immunogenic aminopeptidase of Candida albicans was purified by high-performance liquid chromatography. It was then used for the development of an enzyme-linked immunosorbent assay to detect antibodies directed against this antigen in sera from patients with candidiasis. This enzyme specifically cleaves the L-Arg-7-amino-4-methyl-coumarin substrate at pH 7.4 and was detected in the crude extract of different C. albicans isolates. Sera used for this study were obtained from healthy blood donors or from patients with one of the following: systemic candidiasis, aspergillosis, cryptococcosis, toxoplasmosis, or malaria. The statistical analysis demonstrates significant differences between absorbency values obtained with sera from patients with candidiasis and with sera from the other groups (P = 0.000001). Diagnostic parameters show high diagnostic specificity of 97% and a sensitivity of 83% at a cutoff value of 0.425 and suggest the usefulness of this aminopeptidase for the diagnosis of systemic candidiasis.

Purification and characterization of N-acetylglucosaminidase from Trypanosoma cruzi.

N-Acetyl-beta-D-glucosaminidase activity was recovered in cell-free extracts of Trypanosoma cruzi epimastigotes. This enzyme was identified on the basis of its ability to hydrolyze the fluorogenic substrate 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide. This activity was purified to apparent homogeneity by anion exchange and molecular sieve high-performance liquid chromatography. It eluted at a native molecular weight of approximately 48,000 Da and migrated as a single band upon reducing or nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum pH of the activity was around pH 5.4 and the enzyme gave a single peak of activity on a chromatofocusing column with an isoelectric point of 4.2. The enzyme hydrolyzed 4-methylumbelliferyl-GlcNAc, suggesting that it should be characterized as a N-acetyl-beta-D glucosaminidase, with a K(m) value of 1.5 mM from Lineweaver-Burk plots. Many inhibitors as potential enzyme effectors were investigated.

Purification and characterisation of a metallopeptidase of Candida albicans.

A novel aminopeptidase was purified by high performance liquid chromatography from a cytosoluble 100,000 g extract of Candida albicans on the basis of its ability to cleave L-arginine 7-amino-4-methylcoumarin. The purification factor was 36 and the yield was 20%. The native enzyme had a mol. wt of 52 kDa as demonstrated by SDS-PAGE in the presence or absence of reducing conditions and exhibited an iso-electric point of 4.3. The aminopeptidase showed optimum activity at pH 7.2, a Michaelis constant of c. 50 microM and a Vmax at 19 mM AMC released/min/mg of protein for L-Arg-AMC. This enzyme was shown to cleave at low affinity L-leucine-7-amino-4-methylcoumarin as demonstrated by the spectrofluorimetric method. The enzyme was strongly inhibited by specific metallo-enzyme inhibitors-EDTA and o-phenanthroline. Furthermore, there is evidence that a similar or identical enzyme occurs in other C. albicans clinical isolates and other Candida spp.

Seroprevalences of Toxoplasma, malaria, rubella, cytomegalovirus, HIV and treponemal infections among pregnant women in Cotonou, Republic of Benin.

Seroprevalences for toxoplasmosis, malaria, rubella, cytomegalovirus, HIV and treponemal infections were evaluated among 211 pregnant women residing in the Cotonou area, Republic of Benin. One hundred and thirteen women (53.6%) had toxoplasma antibodies, 185 (87.7%) malaria antibodies and 181 (85.8%) rubella antibodies. Among the 205 (97.2%) women with cytomegalovirus antibodies, 6 presented recent or current infection. No HIV seropositivity was detected. Five (2.4%) of these women had a positive treponematosis serology corresponding to previous infection or reinfection. These results were compared with previous studies conducted in Africa. Routine serological screening should be recommended in young age and in pregnancy for rubella, only in pregnant women for HIV and toxoplasma infections, in order to control their possible consequences on women and newborns.

Detection and immunolocalization of human erythrocyte spectrin immunoanalogues in Toxoplasma gondii (Protozoan, Parasite).

We demonstrated here the presence of proteins antigenically related to human erythroid spectrin in the parasitic protozoan Toxoplasma gondii. A high molecular weight doublet (M(r) 245-240,000), present in equimolar ratio, and low molecular weight poly-peptides (M(r) 75,000) were reacted with monoclonal and polyclonal anti-human erythroid spectrin antibodies on electroblotted nitro-cellulose sheets. Indirect immunofluorescence assay clearly showed that these proteins were localized in the anterior pole of the organism. Immunogold staining further revealed specific labeling of conoid, rhoptries, micronemes, and dense granules of the apical complex. The presence of the M(r) 245-240,000 doublet and the M(r) 75,000 spectrin-like proteins in the anterior pole of T. gondii may probably be consistent with a structural stabilizer function in its organelles which are suspected to be involved in the process of host cell invasion.

Detection of myosin immunoanalogue in the yeast Candida albicans.

Detection and localization of myosin immunoanalogue protein in the yeast Candida albicans were achieved by immunoblotting, indirect immunofluorescence assay, and immunoelectron microscopy. A polypeptide with an M(r) about 110,000, from cytosolic extract and insoluble fraction in the corresponding membrane pellet, was reacted with polyclonal and monoclonal antibodies raised against vertebrate muscle myosin. This protein was located by immunofluorescence and immunoelectron microscopy in the cell cortex along the plasmalemma, in the cytoplasm, and in the septum corresponding to bud scar region situated between the yeast-mother cell and the bud.