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1.
Parasitology ; 150(5): 416-425, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36760183

RESUMEN

Attempts to control cystic echinococcosis (CE) caused by Echinococcus granulosus in the Falkland Islands have been ongoing for over 50 years. No human cases have been recorded since the 1980s but there is a need to establish if the parasite has been completely eliminated from domestic animals. A study was carried out in 2018/2019 to identify dogs infected with E. granulosus using copro-antigen and copro-polymerase chain reaction (PCR) analysis. In addition, annual slaughter data were analysed to establish infection levels of E. granulosus and 2 other taeniid parasites. Results showed that 4 out of 589 dogs (0.7%) tested positive by copro-antigen analysis. Results from similar surveys carried out in 2010, 2012 and 2014 showed 17 (3%), 0 and 6 (1%) copro-antigen-positive dogs, respectively, with 8 dogs being confirmed by PCR in 2010. Annual abattoir data showed that from 2006 to 2020, 36 sheep were identified with E. granulosus (mean 0.0055%), 14 186 sheep with Taenia hydatigena (mean 2.2%) and 465 with Taenia ovis (mean 0.072%). Prevalences of T. hydatigena and T. ovis showed spontaneous rises in certain years where the infections could also be detected in lambs indicating that viable taeniid eggs were present. Observations of farm management procedures indicated that there were occasions when dogs could get access to infective taeniid material. In conclusion, E. granulosus is still present in sheep and dogs but at low prevalences. The increasing presence of T. hydatigena however, indicates that control measures are defective in some areas and there is potential for a re-emergence of CE.


Asunto(s)
Enfermedades de los Perros , Equinococosis , Echinococcus granulosus , Taenia , Animales , Ovinos , Perros , Islas Malvinas , Heces/parasitología , Equinococosis/epidemiología , Equinococosis/prevención & control , Equinococosis/veterinaria , Echinococcus granulosus/genética , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/prevención & control , Enfermedades de los Perros/parasitología
2.
J Helminthol ; 93(5): 589-600, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30117407

RESUMEN

Examination of rajid skates off the Algerian coast in the Mediterranean Sea revealed that three of the 33 Dipturus batis Linnaeus, 1758 examined harboured a new tapeworm species: Echeneibothrium algeriensis n. sp. This new species, collected from the anterior half of the spiral valves, is described on the basis of morphological data from light and scanning electron microscopy. The new species differs from previously described Echeneibothrium species by details of the scolex and loculi, total length, the length of the myzorhynchus, the number of proglottides, and the number of testes. Comparison of the diets of the ten skate species common in the Mediterranean basin indicates some varying degree of overlap, suggesting that host specificity in this host-parasite system is determined by other host and/or ecological variables such as adaptations of the parasites to their respective hosts, either on the morpho-anatomical level, in physiological characteristics of the parasite's habitat, in the trophic requirements for the successful transmission of the parasite, or in adaptations to the behavioural characteristics of the host. Furthermore, restricted overlap of E. algeriensis n. sp. with congeners in parasite assemblages of D. batis indicates some structuring according to attachment-site preferences. However, attachment-site preferences are not explained solely by morphological compatibility between bothridia and villi. This study reiterates the need to examine multiple factors synergistically in studies on host specificity of parasites, and the need to examine the parasite fauna of hosts across their entire geographical range in order to truly appreciate the biodiversity they harbour.


Asunto(s)
Cestodos/clasificación , Cestodos/aislamiento & purificación , Infecciones por Cestodos/veterinaria , Enfermedades de los Peces/parasitología , Rajidae/parasitología , Animales , Biodiversidad , Cestodos/anatomía & histología , Ecosistema , Femenino , Especificidad del Huésped , Interacciones Huésped-Parásitos , Mucosa Intestinal/parasitología , Masculino , Mar Mediterráneo , Microscopía Electrónica de Rastreo
3.
J Helminthol ; 93(6): 738-751, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30205854

RESUMEN

An understanding of the mechanisms that determine host and parasite relationships is a central aim in parasitology. Association of a parasite species with a host species may be influenced primarily by phylogenetic constraints that cause parasite species to co-speciate with their host species, or predominantly by ecological parameters that influence all other co-evolutionary scenarios. This study aimed to investigate the role of co-speciation as well as other co-evolutionary scenarios in influencing the assemblages of tapeworm parasites (marine cestodes) in skate hosts (Rajiformes) using a modification of the PACo (Procrustean Approach to Cophylogeny) method. The study found that phylogeny and host ecology are both significant predictors of skate-tapeworm relationships, implying that co-speciation as well as other co-evolutionary scenarios are shaping these associations. The study also investigated the key ecological parameters influencing host-switching and found that host diet, distribution depth, average body size and geographical location have a combined effect. Given the importance of parasites in ensuring healthy and stable marine ecosystems, the findings of this study have implications for conservation management worldwide.


Asunto(s)
Cestodos/genética , Infecciones por Cestodos/veterinaria , Enfermedades de los Peces/parasitología , Filogenia , Rajidae/parasitología , Animales , Evolución Biológica , Tamaño Corporal , Cestodos/clasificación , Cestodos/crecimiento & desarrollo , Cestodos/aislamiento & purificación , Infecciones por Cestodos/parasitología , Ecosistema , Femenino , Masculino
4.
J Helminthol ; 92(2): 187-196, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28424102

RESUMEN

Despite the fact that tapeworms comprise the bulk of parasite communities of sharks in marine ecosystems, little is known about their life cycles and, more specifically, about the potential intermediate hosts they utilize as transmission routes. In the absence of morphological features required for specific identification of larval tapeworms from potential intermediate hosts, recent molecular advances have contributed to linking larval and adult parasites and, in some instances, uncovering unknown trophic links. Host-parasite checklists are often the first source of information consulted to assess the diversity and host specificity of parasites, and provide insights into parasite identification. However, these host-parasite checklists are only useful if they encompass the full spectrum of associations between hosts and parasites. A checklist of New Zealand fishes and their parasites has been published, but recent parasitological examinations of commercial fish species reveal that the checklist appears to be far from complete. We focused our current study on a comprehensive survey of macroparasites of a commercial species, the New Zealand sole (Peltorhamphus novaezeelandiae) off the coast of Otago, New Zealand. Specifically, we were expecting to recover marine tapeworms using sharks as their definitive hosts that are generally underreported in parasite surveys. The parasites recovered included tapeworms, flukes, round worms and thorny-headed worms. Surprisingly, a large proportion of the non-tapeworm parasites we recovered were not previously reported from this fish species. A discussion on the potential ecological roles played by this fish species in the transmission of parasites is included.


Asunto(s)
Ecosistema , Peces/fisiología , Peces/parasitología , Parásitos/aislamiento & purificación , Trematodos/aislamiento & purificación , Animales , Enfermedades de los Peces/parasitología , Especificidad del Huésped , Interacciones Huésped-Parásitos , Larva/fisiología , Estadios del Ciclo de Vida , Nueva Zelanda , Parásitos/clasificación , Trematodos/clasificación
5.
J Mycol Med ; 25(4): 287-92, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26597146

RESUMEN

The pathogenicity of Candida viswanathii, PCI 501/1 (CBS 4024), originally isolated from CSF of a fatal case of meningitis in India, is reported. Also, included is a global overview of the occurrence of C. viswanathii in clinical and environmental sources. The investigation was done in normal and cortisone-treated albino mice challenged intravenously with variable doses of 1×10(6), 4×10(6) and 16×10(6) actively growing yeast cells of the fungus. The animals were kept under observation up to 3 weeks when they were sacrificed for a mycological and histopathologic study. As apparent from the data on morbidity and mortality, the species exhibited low virulence for normal mice, whereas it caused significantly higher mortality (P<0.0008) and morbidity (macroscopic lesions) (P<0.0004) in cortisone group. Likewise, there was overall higher recovery of C. viswanathii in culture from the cortisone-treated than in the normal group of mice. These observations are indicative of C. viswanathii being an opportunistic pathogen. It is recognized that a definitive identification of C. viswanathii requires mycological expertise for comprehensive phenotypic characterization or the application of expensive techniques such as Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and molecular techniques, facilities for which are generally lacking in a vast majority of laboratory diagnostic centers especially in developing countries. Consequently, the prevalence of C. viswanathii in clinical and environmental samples is currently likely to be underestimated.


Asunto(s)
Candida/patogenicidad , Candidiasis/microbiología , Cortisona , Huésped Inmunocomprometido , Estructuras Animales/microbiología , Estructuras Animales/patología , Animales , Candida/clasificación , Candida/inmunología , Candidiasis/inmunología , Candidiasis/mortalidad , Candidiasis/patología , Cortisona/administración & dosificación , Huésped Inmunocomprometido/efectos de los fármacos , Masculino , Ratones , Técnicas de Tipificación Micológica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Virulencia/efectos de los fármacos
6.
Mol Breed ; 31(2): 405-418, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23396999

RESUMEN

Leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis f. tritici Eriks.) and stem rust (Puccinia graminis f. sp. tritici) cause major production losses in durum wheat (Triticum turgidum L. var. durum). The objective of this research was to identify and map leaf, stripe and stem rust resistance loci from the French cultivar Sachem and Canadian cultivar Strongfield. A doubled haploid population from Sachem/Strongfield and parents were phenotyped for seedling reaction to leaf rust races BBG/BN and BBG/BP and adult plant response was determined in three field rust nurseries near El Batan, Obregon and Toluca, Mexico. Stripe rust response was recorded in 2009 and 2011 nurseries near Toluca and near Njoro, Kenya in 2010. Response to stem rust was recorded in field nurseries near Njoro, Kenya, in 2010 and 2011. Sachem was resistant to leaf, stripe and stem rust. A major leaf rust quantitative trait locus (QTL) was identified on chromosome 7B at Xgwm146 in Sachem. In the same region on 7B, a stripe rust QTL was identified in Strongfield. Leaf and stripe rust QTL around DArT marker wPt3451 were identified on chromosome 1B. On chromosome 2B, a significant leaf rust QTL was detected conferred by Strongfield, and at the same QTL, a Yr gene derived from Sachem conferred resistance. Significant stem rust resistance QTL were detected on chromosome 4B. Consistent interactions among loci for resistance to each rust type across nurseries were detected, especially for leaf rust QTL on 7B. Sachem and Strongfield offer useful sources of rust resistance genes for durum rust breeding.

7.
Parasitology ; 140(5): 587-97, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23343907

RESUMEN

The range of hosts used by a parasite is influenced by macro-evolutionary processes (host switching, host-parasite co-evolution), as well as 'encounter filters' and 'compatibility filters' at the micro-evolutionary level driven by host/parasite ecology and physiology. Host specialization is hypothesized to result in trade-offs with aspects of parasite life history (e.g. reproductive output), but these have not been well studied. We used previously published data to create models examining general relationships among host specificity and important aspects of life history and reproduction for nematodes parasitizing animals. Our results indicate no general trade-off between host specificity and the average pre-patent period (time to first reproduction), female size, egg size, or fecundity of these nematodes. However, female size was positively related to egg size, fecundity, and pre-patent period. Host compatibility may thus not be the primary determinant of specificity in these parasitic nematodes if there are few apparent trade-offs with reproduction, but rather, the encounter opportunities for new host species at the micro-evolutionary level, and other processes at the macro-evolutionary level (i.e. phylogeny). Because host specificity is recognized as a key factor determining the spread of parasitic diseases understanding factors limiting host use are essential to predict future changes in parasite range and occurrence.


Asunto(s)
Evolución Biológica , Modelos Biológicos , Nematodos/fisiología , Animales , Femenino , Fertilidad/fisiología , Interacciones Huésped-Parásitos , Nematodos/clasificación , Filogenia , Especificidad de la Especie
8.
Mycoses ; 56(3): 222-8, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23336629

RESUMEN

We report the first environmental isolation from India of Cryptococcus gattii, genotype amplified fragment length polymorphism 5 (AFLP5), which is one of the rarely reported genotypes of this pathogen. It originated from decayed wood inside a trunk hollow of Manilkara hexandra, a native tree in Delhi. We investigated 101 isolates of C. gattii, originating from 556 samples of decayed wood inside trunk hollows of 311 heterogeneous tree species and their surrounding soil. Of these, only a solitary isolate proved to be AFLP5, the remainder belonged to AFLP4. Antifungal susceptibility testing showed a low MIC90 (0.25 µg ml(-1) ) of the new azoles posaconazole and isavuconazole for these environmental isolates. Genotype AFLP5 has been mainly reported from environmental sources in Colombia and from clinical sources in California (USA), where it seems to be endemic. Phylogenetic analysis of multi-locus sequence typing data showed that the Indian AFLP5 C. gattii isolate had a distinct profile compared with a cluster of mainly Colombian and Californian C. gattii AFLP5 isolates. As molecular typing of human pathogenic fungi is still in its infancy and not accessible to many countries, our current knowledge cannot be taken as reflective of the true geographic distribution of C. gattii AFLP5 or its other rarely reported molecular types.


Asunto(s)
Cryptococcus gattii/aislamiento & purificación , Genotipo , Manilkara/microbiología , Microbiología del Suelo , Anfotericina B/farmacología , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Antifúngicos/farmacología , Cryptococcus gattii/clasificación , Cryptococcus gattii/efectos de los fármacos , Cryptococcus gattii/genética , ADN de Hongos/genética , Humanos , India , Pruebas de Sensibilidad Microbiana , Filogenia , Enfermedades de las Plantas/microbiología
9.
Mycoses ; 56(1): 1-10, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22524529

RESUMEN

We report Schizophyllum commune as the aetiological agent of one case each of allergic broncho-pulmonary mycosis (ABPM) and pulmonary fungal ball, and present a literature review. The fungus was characterised by clamp connections, hyphal spicules, and formation of basidiocarps with basidiospores. The phenotypic identification was confirmed by sequencing of the ITS region. To-date, ABPM and pulmonary fungal ball to S. commune have been reported exclusively from Japan and North America respectively. Of the 71 globally reported cases due to S. commune, 45 (63%) were bronchopulmonary, 22 (31%) sinusitis and 4 extrapulmonary. Taken together, cases of bronchopulmonary disease and sinusitis numbered 67 (94%), indicating the respiratory tract as the primary target of disease. Concerning the country-wise distribution, Japan topped the list with 33 cases (46%), followed by Iran - 7 cases (10%), U.S.A. - 6 cases (9%), and a lower prevalence of 1.4-6% for the remaining 12 countries. The preponderance of the disease in Japan may be attributed to its greater awareness vis-à-vis that in other countries rather than to any geographical/climatic factors. We believe that the burden of S. commune-incited disease is currently underestimated, warranting comprehensive prospective studies to determine its prevalence.


Asunto(s)
Enfermedades Pulmonares Fúngicas/microbiología , Schizophyllum/aislamiento & purificación , Adulto , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunodifusión , Inmunoglobulina E/sangre , Masculino , Pruebas de Sensibilidad Microbiana , Schizophyllum/efectos de los fármacos , Schizophyllum/patogenicidad , Pruebas Cutáneas
10.
Parasitol Res ; 111(6): 2455-60, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22752698

RESUMEN

On two occasions in November and December 2009, whilst being captured and handled for banding in Tasman Bay, New Zealand, two variable oystercatchers (Haematopus unicolor Forster, 1844) voided a number of cestode strobilae from their cloaca. Their morphology indicates that they belong to the family Hymenolepididae, confirmed by BLASTn searches of large and small subunits of ribosomal DNA partial sequences (18S and 28S, respectively). However, they cannot currently be assigned to any species reported for any oystercatcher species from New Zealand nor from oystercatchers worldwide. We present a checklist of all cestode parasites reported in the literature for Haematopus species, along with their sources and synonyms. While the taxonomy of New Zealand oystercatchers is currently uncertain, more detailed knowledge of the parasite fauna of this bird group may help to elucidate the historical biogeography of the oystercatchers. The means of collection of these tapeworms is unusual and does not appear to have been reported in the literature previously.


Asunto(s)
Enfermedades de las Aves/parasitología , Cestodos/aislamiento & purificación , Infecciones por Cestodos/veterinaria , Charadriiformes/parasitología , Animales , Cestodos/clasificación , Infecciones por Cestodos/parasitología , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Nueva Zelanda , ARN Ribosómico 18S/genética , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN
11.
Med Mycol ; 50(8): 890-6, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22563857

RESUMEN

A rare case of allergic bronchopulmonary mycosis (ABPM), caused by Alternaria alternata, is reported in an immunocompetent resident of Delhi. Her complaints included a generalized, urticarial skin rash and occasional pain in the right lower chest. Her differential count showed eosinophils, 22%; absolute eosinophil count (AEC), 2400 cells/µl; and total IgE, 4007 IU/ml. The computerised tomogram (CT) scan of her thorax showed an enhancing lesion with surrounding ground glass haziness in the right lower lobe. Histopathologic examination of the resected lung revealed a necrotizing granulomatous inflammation, parenchymal infiltration by eosinophils, lymphocytes, neutrophils, plasma cells and some exudative bronchiolitis suggestive of ABPM. Observation of KOH wet mounts of repeat sputum and BAL samples demonstrated the presence of septate, brownish hyphae and cultures of these specimens yielded A. alternata (identified by sequencing of the ITS region). Her serum showed a three-fold higher specific IgE to A. alternata antigens than control levels, and the type I cutaneous hypersensitivity response to antigens of A. alternata was strongly positive. She was treated successfully with oral glucocorticoids and itraconazole. To our knowledge, ABPM due to Alternaria alternata has not been reported previously.


Asunto(s)
Alternaria/aislamiento & purificación , Alternariosis/diagnóstico , Alternariosis/microbiología , Aspergilosis Pulmonar Invasiva/diagnóstico , Aspergilosis Pulmonar Invasiva/microbiología , Adulto , Alternariosis/patología , Alternariosis/cirugía , Eosinofilia/diagnóstico , Eosinofilia/etiología , Femenino , Humanos , Inmunoglobulina E/sangre , India , Aspergilosis Pulmonar Invasiva/patología , Aspergilosis Pulmonar Invasiva/cirugía , Pulmón/patología , Pulmón/cirugía , Radiografía Torácica , Tomografía Computarizada por Rayos X
12.
J Evol Biol ; 25(1): 66-79, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22022929

RESUMEN

Studying resource specialization at the individual level can identify factors constraining the evolution of generalism. We quantified genotypic and phenotypic variability among infective stages of 20 clones of the parasitic trematode Maritrema novaezealandensis and measured their infection success and post-infection fitness (growth, egg output) in several crabs and amphipods. First, different clones varied in their infection success of different crustaceans. Second, neither genetic nor phenotypic traits had consistent effects on infection success across all host species. Although the results suggest a relationship between infection success and phenotypic variability, phenotypically variable clones were not better at infecting more host species than less variable ones. Third, genetic and phenotypic traits also showed no consistent correlations with post-infection fitness measures. Overall, we found no consistent clone-level specialization, with some clones acting as specialists and others, generalists. The trematode population therefore maintains an overall generalist strategy by comprising a mixture of clone-level specialists and generalists.


Asunto(s)
Anfípodos/parasitología , Braquiuros/parasitología , Aptitud Genética , Genotipo , Especificidad del Huésped/genética , Fenotipo , Trematodos/fisiología , Animales , Evolución Biológica , Interacciones Huésped-Parásitos/genética , Modelos Lineales , Caracoles/parasitología , Trematodos/anatomía & histología , Trematodos/genética
13.
J Helminthol ; 86(4): 453-64, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22152219

RESUMEN

Metacestodes are often found in the body cavity of the common bully (Gobiomorphus cotidianus McDowall), from freshwater habitats in Otago, New Zealand. Identification of metacestodes relies only on the number, size and shape of the rostellar hooks. To attempt species determination, we cultivated metacestodes in vitro for up to 23 days, during which they matured to at least the male stage of development, although female organs were not discernable. Identified as members of the genus Paradilepis Hsü, 1935 (family Gryporhynchidae), these specimens are compared to previously described species, in particular P. minima (Goss, 1940), from Australia, the closest species, both geographically and morphologically. Although the size of scolex, suckers and proglottids differ significantly from those of P. minima, we are cautious about interpreting 'adults' grown in vitro, because we are unsure whether the artificial conditions alter development. For this reason, and because of the lack of female organs, we refrain from erecting a new species, and refer to the specimens as Paradilepis cf. minima until such time as the adults are found in the definitive host. With this proviso we present here a description of the in vitro-grown worms and the metacestodes as a preliminary study of this cestode. A molecular analysis of small subunit (SSU) rDNA sequences, shows the position of P. cf. minima and another gryporhynchid, Neogryporhynchus cheilancristrotus (Wedl, 1855), to be equivocal, but confirms their exclusion from the Dilepididae and Hymenolepididae. This is the first record of a gryporhynchid from New Zealand, and the first from the fish family Eleotridae.


Asunto(s)
Cestodos/clasificación , Cestodos/aislamiento & purificación , Perciformes/parasitología , Animales , Cestodos/anatomía & histología , Cestodos/genética , Análisis por Conglomerados , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Masculino , Microscopía , Datos de Secuencia Molecular , Nueva Zelanda , Filogenia , Análisis de Secuencia de ADN
14.
Med Mycol ; 49(3): 320-3, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20854229

RESUMEN

This study presents a 7-year retrospective analysis of seasonal variations in the prevalence of Cryptococcus neoformans var. grubii and Cryptococcus gattii in decayed wood inside trunk hollows of 518 trees belonging to 20 species in north-western India during 2000-2007. Of the 1,439 wood samples investigated, 406 (28.2%) were found to be positive for the Cryptococcus neoformans species complex which included 247 samples from which C. neoformans var. grubii was recovered and 171 which yielded C. gattii. While both of the pathogens were isolated through all the seasons, the overall prevalence of C. neoformans var. grubii was significantly higher (17.2%) than that of C. gattii serotype B (11.9%, P < 0.0001), indicating that decayed wood was as good, if not better, a natural habitat of C. neoformans var. grubii as that of C. gattii. The highest recovery of both yeasts was in the autumn, followed by that in the summer. For C. gattii, the lowest prevalence occurred during the winter and for C. neoformans var. grubii during the rainy season. The low prevalence of C. gattii during winter is similar to that reported from Bogota, Colombia, where C. gattii had a low population density in bark samples but it was not found in decayed wood of trunk hollows investigated during the period of January and February. The prevalence of C. neoformans var. grubii was significantly lower in the rainy season than in the other portions of the year. This finding is similar to the reported low isolation frequency (4%) of C. neoformans var. grubii from chicken feces in the rainy season in northern Thailand. Further investigations are warranted to determine the clinical significance of seasonal variations in the prevalence of C. neoformans var. grubii and C. gattii in decayed trunk wood of various trees in climatically divergent regions of India.


Asunto(s)
Cryptococcus gattii/aislamiento & purificación , Cryptococcus neoformans/aislamiento & purificación , Enfermedades de las Plantas/microbiología , Madera/microbiología , India , Prevalencia , Estudios Retrospectivos , Estaciones del Año
15.
Parasitology ; 137(11): 1707-20, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20444305

RESUMEN

SUMMARY: Parasites have evolved a myriad of attachment structures closely adapted to their hosts and sites of attachment. Here, using members of the genus Acanthobothrium van Beneden, 1850 (Cestoda: Tetraphyllidea: Onchobothriidae), we (i) examined the influence of host body size and phylogeny, in addition to morphological features of these tapeworms, on the size of 3 structures used in attachment (bothridia, accessory suckers and hooks) by means of general linear models and phylogenetic-independent contrasts methods, and (ii) quantified the scaling exponents of relationships between size of attachment structures and tapeworm body size. Our results indicate that there exists a positive relationship, albeit not directly proportional, between size of attachment structures and Acanthobothrium spp. body size, and hook size and size of bothridia and accessory suckers. These results suggest that the resource investment in whole-body growth is greater than that in attachment structures, and that a greater investment in development of bothridia and accessory suckers is required to maintain an equivalent functional efficacy to hooks. In addition, host body size also influences, though less markedly, the size of attachment structures in Acanthobothrium spp. independently of parasite size itself. Acanthobothrium species have evolved a generalized mode of attachment that is successful in maintaining their position on various intestinal mucosal topographies across a variety of hosts exploiting different food resources.


Asunto(s)
Evolución Biológica , Tamaño Corporal , Cestodos/anatomía & histología , Infecciones por Cestodos/veterinaria , Elasmobranquios/parasitología , Animales , Cestodos/clasificación , Cestodos/patogenicidad , Infecciones por Cestodos/parasitología , Enfermedades de los Peces/parasitología , Filogenia
16.
Med Mycol ; 48(6): 870-9, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20482451

RESUMEN

Rhinoentomophthoromycosis due to Conidiobolus coronatus is a rare, chronic, granulomatous disease, occurring mainly in tropical Africa, South and Central America and south-east Asia, including India. We report a case of rhinoentomophthoromycosis in a 30-year-old male farmer, a resident of Gorakhpur city in Uttar Pradesh, which was diagnosed by histopathology and isolation C. coronatus in culture. The patient presented with a swollen nose with obstruction that had progressed slowly over one year. His nasal swelling was bilateral, diffuse, mildly tender, erythematous, non-pitting, with mucosal crusting and hypertrophy of inferior turbinates but no regional lympha-denopathy. A contrast-enhanced computed tomography (CECT) scan revealed bilateral pan-sinusitis with nasoethmoid polyposis. Culture of tissue from the nasal biopsy on Sabouraud glucose agar yielded multiple colonies of a mold with satellite smaller colonies at periphery. The isolate demonstrated the macroscopic and microscopic morphologic characteristics of C. coronatus. Its identity was further confirmed by direct DNA sequencing of internal transcribed spacer (ITS) and D1/D2 regions of rDNA. Haemotoxylin and eosin stained tissue sections of the skin biopsy revealed irregular epidermal acanthosis, marked inflammatory and granulomatous reaction with sparse, non-septate hyphae. The patient was treated successfully with a combination therapy of oral saturated potassium iodide solution, itraconazole, and intravenous infusion of amphotericin B. An overview of rhinoentomophthoromycosis cases reported to-date in India is presented.


Asunto(s)
Conidiobolus/aislamiento & purificación , Rinitis/diagnóstico , Rinitis/patología , Cigomicosis/diagnóstico , Cigomicosis/patología , Adulto , Agricultura , Antifúngicos/uso terapéutico , Conidiobolus/clasificación , Conidiobolus/citología , Conidiobolus/genética , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Cabeza/diagnóstico por imagen , Histocitoquímica , Humanos , India , Masculino , Microscopía , Datos de Secuencia Molecular , Pólipos Nasales/diagnóstico , Pólipos Nasales/patología , Rinitis/complicaciones , Rinitis/microbiología , Análisis de Secuencia de ADN , Sinusitis/diagnóstico , Sinusitis/patología , Tomografía Computarizada por Rayos X , Cigomicosis/complicaciones , Cigomicosis/microbiología
17.
Med Mycol ; 48(2): 416-20, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19626545

RESUMEN

We randomly screened 363 yeast isolates during 2008 for their ability to form white colonies on CHROM agar Candida medium. Two of these isolates (0.5%) were identified as Candida nivariensis based on detailed phenotypic characterization and DNA sequencing. One was recovered from the sputum of an HIV-positive patient with a pneumonic lesion and the second from the blood of a diabetic with oropharyngeal lesions. Direct DNA sequencing of the D1/D2 region of 28S rRNA gene and/or the internal transcribed spacer (ITS) regions of rDNA confirmed that both of the isolates were C. nivariensis. The carbohydrate assimilation profiles with the ID 32 C and VITEK 2 yeast identification systems revealed only glucose assimilation. In vitro antifungal susceptibility profiles by broth microdilution and Etest methods revealed susceptibility of both isolates to fluconazole, itraconazole, voriconazole, amphotericin B and 5-flucytosine, with low MICs for posaconazole and caspofungin. These results document the occurrence of Candida nivariensis for the first time in India and focus on its potential as an opportunistic human pathogen.


Asunto(s)
Candida/aislamiento & purificación , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Anciano , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Candida/efectos de los fármacos , Candida/genética , Candida/crecimiento & desarrollo , Enfermedades Transmisibles Emergentes/tratamiento farmacológico , Enfermedades Transmisibles Emergentes/microbiología , ADN de Hongos/análisis , ADN de Hongos/aislamiento & purificación , Farmacorresistencia Fúngica , Humanos , India , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , ARN Ribosómico 28S/genética
18.
Int J Antimicrob Agents ; 33(6): 559-63, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19195846

RESUMEN

This study presents antifungal susceptibility data for environmental isolates of Cryptococcus neoformans serotype A (n=32) and Cryptococcus gattii serotype B (n=18) to fluconazole and voriconazole employing disc diffusion and Etest methods. The disc diffusion test was performed on Mueller-Hinton agar as recommended by the Clinical and Laboratory Standards Institute (CLSI). For comparison, the disc diffusion test and Etest were also performed on RPMI-1640 agar supplemented with 2% glucose. The plates were incubated at 35 degrees C and read after 48h. Comparison of geometric mean inhibition zone diameters revealed that C. gattii isolates were significantly less susceptible than C. neoformans isolates to fluconazole (P=0.001) and voriconazole (P<0.0001). Similar results were obtained on RPMI agar by disc diffusion test and Etest, showing significantly reduced susceptibility for C. gattii isolates. Notwithstanding differences in the susceptibilities of the two species to fluconazole and voriconazole, they appeared susceptible according to the CLSI breakpoints recommended for some Candida spp. To what extent these differences in the susceptibilities of C. neoformans and C. gattii impact on the therapeutic management of cryptococcosis is unclear, although some studies have reported less favourable response in cases caused by the latter species.


Asunto(s)
Antifúngicos/farmacología , Cryptococcus neoformans/efectos de los fármacos , Cryptococcus/efectos de los fármacos , Fluconazol/farmacología , Pirimidinas/farmacología , Triazoles/farmacología , Madera/microbiología , Cryptococcus/aislamiento & purificación , Cryptococcus neoformans/clasificación , Cryptococcus neoformans/aislamiento & purificación , Pruebas de Sensibilidad Microbiana/métodos , Voriconazol
19.
Med Mycol ; 46(8): 823-33, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18608895

RESUMEN

This study reports the widespread prevalence of Cryptococcus neoformans and Cryptococcus gattii in decayed wood inside trunk hollows of 14 species representing 12 families of trees and from soil near the base of various host trees from Delhi and several places in the Indian states of Uttar Pradesh, Haryana, Tamil Nadu and Chandigarh Union Territory. Of the 311 trees from which samples were obtained, 64 (20.5%) were found to contain strains of the C. neoformans species complex. The number of trees positive for C. neoformans var grubii (serotypeA) was 51 (16.3%), for C. gattii (serotype B) 24 (7.7%) and for both C. neoformans and C. gattii 11 (3.5%). The overall prevalence of C. neoformans species complex in decayed wood samples was 19.9% (111/556). There was no obvious correlation between the prevalence of these two yeast species and the species of host trees. The data on prevalence of C. gattii (24%) and C. neoformans (26%) in soil around the base of some host trees indicated that soil is another important ecologic niche for these two Cryptococcus species in India. Among our sampled tree species, eight and six were recorded for the first time as hosts for C. neoformans var grubii and C. gattii, respectively. A longitudinal surveillance of 8 host tree species over 0.7 to 2.5 years indicated long term colonization of Polyalthia longifolia, Mimusops elengi and Manilkara hexandra trees by C. gattii and/or C. neoformans. The mating type was determined for 153 of the isolates, including 98 strains of serotype A and 55 of serotype B and all proved to be mating type alpha (MAT alpha). Our observations document the rapidly expanding spectrum of host tree species for C. gattii and C. neoformans and indicate that decayed woods of many tree species are potentially suitable ecological niches for both pathogens.


Asunto(s)
Cryptococcus neoformans/aislamiento & purificación , Cryptococcus/aislamiento & purificación , Corteza de la Planta/microbiología , Microbiología del Suelo , Árboles/microbiología , Recuento de Colonia Microbiana , Cryptococcus/crecimiento & desarrollo , Cryptococcus neoformans/crecimiento & desarrollo , India , Manilkara/microbiología , Mimusops/microbiología , Polyalthia/microbiología
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