Terapia fotodinámica en el tratamiento de la leishmaniasis cutánea / Photodynamic Therapy in the Treatment of Cutaneous Leishmaniasis

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Aetiology and epidemiology of human cryptosporidiosis cases in Galicia (NW Spain), 2000-2008.

Cryptosporidium infects millions of people worldwide causing acute gastroenteritis, but despite its remarkable epidemiological and economic impact, information on the epidemiological trends of human cryptosporidiosis is still scarce in most countries. Here we investigate a panel of 486 cases collected in Galicia (NW Iberian Peninsula) between 2000 and 2008, which sheds new light on the epidemiology in this region of the South Atlantic European façade. Incidence rates in Galicia are one order of magnitude higher than those reported in other regions of Spain, suggesting that this parasite remains largely underdiagnosed in this country, and are also larger than those typical of other European countries with available data. Two species dominate our dataset, Cryptosporidium hominis (65%) and C. parvum (34%). The sex ratio of patients infected by either species was 0·5, but C. hominis was significantly more common in younger males. C. parvum infections were more acute and required more specialized medical attention, which suggests a differential adaptation of each species to human hosts. The parasites display strong seasonal and geographical variation. C. parvum incidence peaked during summer and was mainly detected in rural areas while C. hominis infections were more frequent in autumn and exhibited a more even geographical distribution. Such differences probably reflect their distinct sources of infection - C. parvum is mainly zoonotic and C. hominis anthroponotic - and the effects of climatic variables, like temperature and rainfall.

High-throughput genotyping assay for the large-scale genetic characterization of Cryptosporidium parasites from human and bovine samples.

The epidemiological study of human cryptosporidiosis requires the characterization of species and subtypes involved in human disease in large sample collections. Molecular genotyping is costly and time-consuming, making the implementation of low-cost, highly efficient technologies increasingly necessary. Here, we designed a protocol based on MALDI-TOF mass spectrometry for the high-throughput genotyping of a panel of 55 single nucleotide variants (SNVs) selected as markers for the identification of common gp60 subtypes of four Cryptosporidium species that infect humans. The method was applied to a panel of 608 human and 63 bovine isolates and the results were compared with control samples typed by Sanger sequencing. The method allowed the identification of species in 610 specimens (90·9%) and gp60 subtype in 605 (90·2%). It displayed excellent performance, with sensitivity and specificity values of 87·3 and 98·0%, respectively. Up to nine genotypes from four different Cryptosporidium species (C. hominis, C. parvum, C. meleagridis and C. felis) were detected in humans; the most common ones were C. hominis subtype Ib, and C. parvum IIa (61·3 and 28·3%, respectively). 96·5% of the bovine samples were typed as IIa. The method performs as well as the widely used Sanger sequencing and is more cost-effective and less time consuming.

Multilocus patterns of genetic variation across Cryptosporidium species suggest balancing selection at the gp60 locus.

Cryptosporidium is an apicomplexan protozoan that lives in most vertebrates, including humans. Its gp60 gene is functionally involved in its attachment to host cells, and its high level of genetic variation has made it the reference marker for sample typing in epidemiological studies. To understand the origin of such high diversity and to determine the extent to which this classification applies to the rest of the genome, we analysed the patterns of variation at gp60 and nine other nuclear loci in isolates of three Cryptosporidium species. Most loci showed low genetic polymorphism (πS <1%) and similar levels of between-species divergence. Contrastingly, gp60 exhibited very different characteristics: (i) it was nearly ten times more variable than the other loci; (ii) it displayed a significant excess of polymorphisms relative to between-species differences in a maximum-likelihood Hudson-Kreitman-Aguadé test; (iii) gp60 subtypes turned out to be much older than the species they were found in; and (iv) showed a significant excess of polymorphic variants shared across species from random expectations. These observations suggest that this locus evolves under balancing selection and specifically under negative frequency-dependent selection (FDS). Interestingly, genetic variation at the other loci clusters very well within the groups of isolates defined by gp60 subtypes, which may provide new tools to understand the genome-wide patterns of genetic variation of the parasite in the wild. These results suggest that gp60 plays an active and essential role in the life cycle of the parasite and that genetic variation at this locus might be essential for the parasite's long-term success.

Palpebro-orbital myiasis in a patient with basal cell carcinoma.

PURPOSE: We report a patient with basal cell carcinoma presenting with severe myiasis in a large ulcer involving the upper and lower eyelid. METHODS: Myiasis is an infestation of vertebrate animals by larvae of certain fly species. About 70 larvae were removed manually. A biopsy of the tissue underneath demonstrated a basal cell carcinoma. The myiasis was produced by the fly Lucilia sericata, currently used for treating chronic nonhealing ulcers. Because of the stage of the carcinoma, an orbital exenteration was carried out. RESULTS: The patient died 2 days later because of cardiopulmonary failure not related to the myiasis. CONCLUSIONS: We present a case of a severe orbital myiasis focusing on its management and life-threatening nature.

Lectin typing of five medically important Candida species.

This study reports the patterns of agglutination of 93 clinical Candida isolates by 14 commercial lectins. The isolates were of the species Candida albicans (55), C. tropicalis (12), C. guilliermondii (10). C. glabrata (eight) and C. parapsilosis (eight). Hundred percent of isolates were agglutinated, at least, by a panel of three lectins: Canavalia ensiformis (ConA), Lens culinaris (LCA) and Pisum sativum (PSA), all of them with alpha-D-mannose specificity. In addition, another panel of three lectins could distinguish between C. glabrata, C. tropicalis and C. albicans. Lectin typing may be of potential value for taxonomic and epidemiological studies of yeasts in clinical laboratories.

Onychomycosis due to Onychocola canadensis: report of the first two Spanish cases.

Onychocola canadensis is a non-dermatophytic mould that may cause distal and lateral subungual or white superficial onychomycosis. It was first reported in 1990. To date, it has been reported only from temperate countries, namely Canada (14 cases), New Zealand (3), France (9) and the United Kingdom (4). We report the first two cases from Spain.

Cecal ligation and puncture as a model of sepsis in the rat: influence of the puncture size on mortality, bacteremia, endotoxemia and tumor necrosis factor alpha levels.

BACKGROUND: Cecal ligation and puncture is a widely used experimental model of sepsis. AIM OF THE STUDY: The present study was aimed to evaluate the influence of the size of the cecal puncture on mortality, bacteremia, endotoxemia and plasma TNF-alpha levels. MATERIALS AND METHODS: Female Sprague-Dawley rats underwent cecal ligation and puncture, divided into the following groups, defined by the diameter of the cecal puncture: 0.5-cm blade incision (n = 25), 13-gauge (n = 25), 16-gauge (n = 25), 18-gauge puncture (n = 25) and 4 punctures with a 22-gauge needle (n = 25). A sham operation was performed in another 25 rats. Three animals of each group were sacrificed 5 h after the procedure for blood cultures as well as determination of plasma endotoxin and TNF-alpha. The remaining animals were followed up for a week after cecal ligation and puncture for evaluation of mortality. RESULTS: Five hours after cecal ligation and puncture, bacteremia was present in all animals, independently of the puncture size. Endotoxemia and plasma TNF levels tended to increase along with the diameter of the cecal puncture. Mortality gradually increased with the puncture size, from 27% with a 22-gauge needle to 95% with the blade incision. CONCLUSIONS: The severity of sepsis obtained with cecal ligation and puncture in rats can be easily modulated varying the size of the puncture.

Lectin typing of methicillin-resistant Staphylococcus aureus.

This study reports the patterns of agglutination of 77 clinical isolates of methicillin-resistant Staphylococcus aureus by 32 commercially available lectins. Cell suspensions were not pre-treated. Each isolate was cultured on three media: Columbia blood agar, trypticase-soy agar and Chapman Stone agar. The lectins agglutinating each isolate varied widely depending on culture medium; only five isolates were agglutinated by the same set of lectins regardless of the culture medium used. Lectin typing could be a useful epidemiological tool, but it is necessary to standardise assay conditions (notably culture medium) to enable meaningful comparison of the results produced by different research groups or centres.

[Influence of incubation time in the in vitro antifungal activity of terbinafine against Trichophyton rubrum.]. / Influencia del tiempo de incubación en la determinación de la actividad antifúngica in vitro de la terbinafina frente a Trichophyton rubrum.

Antifungal susceptibility tests are influenced by a number of technical variables, including inoculum size, temperature, medium formulation and duration of incubation. In this study, we have compared the in vitro susceptibility of 20 strains de Trichophyton rubrum against clotrimazole and terbinafine, and studied the influence of incubation time on MICs of both drugs. The assay was performed by agar dilution, the medium used was Saboraud glucose agar without an antibiotic. The MIC was evaluated at 15, 30 and 45 days' incubation. The MICs ranges of terbinafine were 0.002 to 0.0975 microg/ml, 0.0975 to 0.39 microg/ml and 0.195 to 0.39 microg/ml at 15, 30 and 45 days' incubation, respectively. The MICs ranges of clotrimazole at 15, 30 and 45 days' incubation were 3.125 to 50 microg/ml. T. rubrum was markedly more susceptible to terbinafine than to clotrimazole (p<0.001). In addition, we observed that an increase of incubation time causing an increase in the MIC value of terbinafine (p<0.001), but MIC values for clotrimazole remained constant with time (p=0.464). In conclusion, the MIC is dependent on reading time and the antifungal compound.

Lectin typing of beta-haemolytic streptococci of groups A and B.

Patterns of agglutination of 124 clinical isolates of beta-haemolytic streptococci (30 group A and 94 group B isolates) by 21 commercial lectins are reported. Cell suspensions were untreated. Nine (30%) of the group A isolates, and 23 (24%) of the group B isolates, were agglutinated by at least one of the lectins. Ten different patterns of agglutination were observed with group A and 15 with group B streptococci. No pattern, except that of non-agglutination by any lectin, was common to group A and group B isolates. In view of the growing interest in the use of lectin typing there is a need for standardisation of assay procedures to enable meaningful comparison of the results of different research groups.

Interaction of lectins with Cryptosporidium parvum.

Cell surface carbohydrates from four clinical isolates of Cryptosporidium parvum were analyzed by agglutination assays using a battery of 20 highly purified lectins with affinity for receptor molecules containing N-acetyl-D-glucosamine (GlcNAc), N-acetyl-D-galactosamine, galactose, mannose, glucose, fucose, and N-acetyl-neuraminic acid. Tomentine, a lectin from the green seaweed Codium tomentosum, and UEA-II lectin, from Ulex europeus, both of them GlcNAc-specific lectins, agglutinated the oocysts. Subsequent inhibition assay confirmed the presence of this sugar on the surface of Cryptosporidium parvum oocysts. Codium fragile lectin, from another green seaweed, also exhibited agglutination activity against the oocysts. This is the first published demonstration of such an interaction between a human coccidian and lectins from seaweeds.

Effects of amphetamine on T-cell immune response in mice.

Mice chronically injected with amphetamine (0.4 mg/kg/day) showed a reduction in thymus and spleen cellularity, and in peripheral T lymphocyte population. The blastogenic response of spleen lymphoid cells was assessed and amphetamine was found to inhibit T-cell proliferation. Amphetamine also reduced the capacity of mice to the development and passive transfer of immunity to Listeria monocytogenes.

Differentiation of Candida guilliermondii varieties by lectin-like substances from marine algae.

Lectin-like substances of 54 marine algae, corresponding to 30 red algae and 24 brown algae, were studied to estimate the agglutination activity against Candida guilliermondii. Extracts of Dictyopteris membranacea, Bifurcaria bifurcata, Halidrys siliquosa, Ascophyllum nodosum, Fucus serratus and F. spiralis algae showed selective agglutinating activities for C. guilliermondii "sensu stricto" and some of its varieties. According to their response to agglutination (positive or negative), certain algal extracts enabled the differentiation of varieties of C. guilliermondii independently of the titre values. Three extracts of brown algae were sufficient to identify 4 varieties of C. guilliermondii. The results suggest that lectin-like substances from marine algae may be valuable reagents as assistant tools for the identification of yeast strains.