Ergasilus tipurus n. sp. (Copepoda: Ergasilidae), A Parasite of Brazilian Amazon Fish Species.

INTRODUCTION: Copepods are common components in all types of fish assemblages, being present in fishes of all ecosystems. The Ergasilidae Burmeister, 1835 is one of the biggest families in the order Cyclopoida Burmeister, 1834, with the majority of species found on freshwater fishes. MATERIAL AND METHODS: Ergasilus tipurus n. sp. is described from the nasal fossae of Calophysus macropterus and Sorubim lima captured in the rivers Guaporé and Mamoré in the State of Rondônia, Brazil, and from the nasal fossae and the gills of Rhaphiodon vulpinus collected from floodplain lakes of the Solimões River in the State of Amazonas, Brazil. RESULTS: The new species differs from all known species of Ergasilus from Brazilian waters by: (1) antennule setal formula 3:7:3:4:2:5; (2), having three-segmented first endopod of leg I; and (3) having leg V with a single well-developed segment with one middle distal setae, two distal setae placed laterally and two basal papillae, each provided with a simple seta. DISCUSSION: From all Ergasilus species described in the neotropics, this is the first species that can be found parasitizing the gills and nasal fossae of the reported hosts.

First morphological and molecular analysis of Eucoleus boehmi like eggs in dogs from Argentina.

The canid parasites Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi) parasitize the lower and the upper respiratory tract, respectively. Reports and descriptions of these nematodes are scarce in Argentina, possibly due to misdiagnosis of morphologically similar trichuroids eggs, and the lack of knowledge about the species of Eucoleus in this geographical area. Scanning electron microscopy is a useful tool for identification of E. boehmi eggs based on the characteristics of the shell structure which differentiate between species. Molecular analysis complements morphological identification. Until now, there are no studies based on the analysis of E. boehmi eggs in Argentina. The aim of the present work was to study by morphological, morphometric, and molecular analysis, eggs attributable to E. boehmi isolated from dogs naturally infected in Mar del Plata city, Argentina. Eggs isolated from two dog fecal samples were analyzed by light and scanning electron microscopy. A fragment of mitochondrial DNA (mtDNA) of the cytochrome c oxidase subunit I gene (cox1) from eggs was sequenced, and phylogenetic analysis was performed in this study. According to morphological results based on the wall surface ultrastructure, the eggs studied were assigned to E. boehmi. Molecular analysis supported the morphological identification. The divergence of 9-12% with the European isolated could suggest a new geographical genetic variation of E. boehmi, but also question the possible existence of cryptic species. This is the first characterization of E. boehmi eggs in dogs from Argentina.

Nasal mites (Mesostigmata, Rhinonyssidae) in Sternidae (Aves: Charadriiformes) on the southern Coast of Brazil.

Six species of birds of the family Sternidae are often found on the southern coast of South America. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus and Sternula superciliaris are South American residents and Sterna hirundo, a Nearctic migrant. At least 500 species of nasal mites have been described around the world, and Rhinonyssidae is the most diverse family. These mites are bloodsucking endoparasites that inhabit the respiratory system of birds. This study aimed to report on occurrences of nasal mites in Sternidae on the southern coast of Brazil. Of the 106 birds analyzed, 8.5% (9 birds) were parasitized by nasal mites. This report provides the first record in the Neotropical region for two mite species, Sternostoma boydi and Larinyssus orbicularis parasitizing Thalasseus acuflavidus and Sternula superciliaris. No nasal mites were found in Sterna trudeaui or Thalasseus maximus. One host individual (T. acuflavidus) was parasitized by two species of nasal mites, S. boydi and L. orbicularis.

Expression of matrix metalloproteinase-2 and metalloproteinase-9 in the skin of dogs with visceral leishmaniasis.

The skin is the first organ to be infected by the parasite in canine visceral leishmaniasis. The enzyme matrix metalloproteinase (MMP) acts towards degradation of the extracellular matrix (ECM) and modulation of the inflammatory response against many kinds of injuries. The aims of this study were to evaluate the expression of MMP-2 and MMP-9 through immunohistochemistry and zymography on the skin (muzzle, ears, and abdomen) of dogs that were naturally infected by Leishmania spp. and to compare these results with immunodetection of the parasite and with alterations to the dermal ECM. Picrosirius red staining was used to differentiate collagen types I and III in three regions of the skin. The parasite load, intensity of inflammation, and production of MMP-2 (latent) and MMP-9 (active and latent) were higher in the ear and muzzle regions. MMP-9 (active) predominated in the infected group of dogs and its production was significantly different to that of the control group. Macrophages, lymphocytes, and plasma cells predominated in the dermal inflammation and formed granulomas in association with degradation of mature collagen (type I) and with discrete deposition of young collagen (type III). This dermal change was more pronounced in dogs with high parasite load in the skin. Therefore, it was concluded that the greater parasite load and intensity of inflammation in the skin led consequently to increased degradation of mature collagen, caused by increased production of MMPs, particularly active MMP-9, in dogs with visceral leishmaniasis. This host response profile possibly favors systemic dissemination of the parasite.

Nasal mites (Mesostigmata, Rhinonyssidae) in Sternidae (Aves: Charadriiformes) on the southern Coast of Brazil / Ácaros nasais (Mesostigmata, Rhinonyssidae) em Sternidae (Aves: Charadriiformes) na Costa do Extremo Sul do Brasil

Abstract Six species of birds of the family Sternidae are often found on the southern coast of South America. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus and Sternula superciliaris are South American residents and Sterna hirundo, a Nearctic migrant. At least 500 species of nasal mites have been described around the world, and Rhinonyssidae is the most diverse family. These mites are bloodsucking endoparasites that inhabit the respiratory system of birds. This study aimed to report on occurrences of nasal mites in Sternidae on the southern coast of Brazil. Of the 106 birds analyzed, 8.5% (9 birds) were parasitized by nasal mites. This report provides the first record in the Neotropical region for two mite species, Sternostoma boydi and Larinyssus orbicularis parasitizing Thalasseus acuflavidus and Sternula superciliaris. No nasal mites were found in Sterna trudeaui or Thalasseus maximus. One host individual (T. acuflavidus) was parasitized by two species of nasal mites, S. boydi and L. orbicularis.

Resumo Seis espécies de aves pertencentes à família Sternidae são encontradas frequentemente na costa sul da América do Sul. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus e Sternula superciliaris residentes sul-americanos e Sterna hirundo, migrante neártico. Existem pelo menos 500 espécies descritas de ácaros nasais ao redor do mundo, sendo Rhinonyssidae a família mais diversa. Estes ácaros são endoparasitos hematófagos que habitam o sistema respiratório das aves. Este estudo objetivou reportar a ocorrência de ácaros nasais em Sternidae na costa do sul do Brasil. Das 106 aves analisadas, 8,5% (9 aves) estavam parasitadas por ácaros nasais. Este é o primeiro registro para duas espécies de ácaros na região neotropical, Sternostoma boydi e Larinyssus orbicularis, parasitando Thalasseus acuflavidus and Sternula superciliaris. Em Sterna trudeaui e Thalasseus maximus não foram encontrados ácaros nasais. Um único hospedeiro (T. acuflavidus) estava parasitado por duas espécies de ácaros nasais, S. boydi e L. orbicularis.

Parasitic copepods infesting the olfactory sacs of skates from the southwestern Atlantic with the description of a new species of Kroeyerina Wilson, 1932.

The olfactory sacs of 488 specimens belonging to 18 species of rajid and arhynchobatid skates from the Argentine Sea were sampled for parasites. No parasitic copepods were found in 11 host species, but siphonostomatoid specimens referable to Kroeyerina Wilson, 1932 (Kroyeriidae) and Brianella corniger Wilson, 1915 (Lernaeopodidae) were found on the spotback skate Atlantoraja castelnaui (Miranda Ribeiro, 1907), the smallnose fanskate Sympterygia bonapartii Müller & Henle, 1841, the bignose fanskate Sympterygia acuta Garman, 1877 and the zipper sand skate Psammobatis extenta (Garman, 1913) (Rajiformes: Arhynchobatidae). Additionally, specimens of B. corniger were found in the olfactory sacs of the Rio skate Rioraja agassizii (Müller & Henle, 1841) and attached to the pectoral fins of the Magellan skate Bathyraja magellanica (Philippi, 1902) and the smallthorn sand skate Psammobatis rudis Günther, 1870. A new species, Kroeyerina sudamericana sp. nov., is described and illustrated. The new species most closely resembles Kroeyerina nasuta Wilson, 1932, but can be distinguished from it by the different armature of the antennule, a proportionally shorter genital complex and the chela of the antenna which, when closed, leaves a gap between the corpus and claw, the latter having no spines. The new species represents the first record of Kroeyerina in South American marine waters. The present study also extends the distribution range of B. corniger, previously known only from the Pacific, to include Atlantic waters, and records seven new host species, all of which are members of the Arhynchobatidae.

Rhinosporidium seeberi Nuclear Cycle Activities Using Confocal Microscopy.

Rhinosporidium seeberi is an uncultivated Ichthyosporean infecting animals, including humans. Recent studies suggested R. seeberi undergoes synchronized nuclear division without cytokinesis. We used confocal microscopy to investigate R. seeberi nuclear division cycles in formalin-fixed tissues stained with DAPI and phalloidin. We report that R. seeberi nuclei in juvenile and intermediary sporangia synchronously divided without cytokinesis. Intermediary sporangia display numerous 3-4 µm nuclei at different mitotic stages as well as a thick inner layer with strong affinity for phalloidin. Mature sporangia showed numerous 5-12 µm cell-walled endospores, each containing a 2-4 µm in diameter nucleus. Phalloidin did not bind to the inner layers of mature sporangia or endospores. The development of a "germinative zone" in the inner layer of mature sporangia containing hundreds of nuclei was also confirmed. This study establishes that during the R. seeberi life cycle synchronous nuclear divisions without cytokinesis takes place, resulting in the formation of thousands of nuclei. Cytokinesis, on the other hand, is a 1-time event and occurs in the latest stages of intermediate sporangia, after the formation of thousands of nuclei and just before mature sporangia development.

Oral manifestations in the American tegumentary leishmaniasis.

INTRODUCTION: American tegumentary leishmaniasis (ATL) can affect the skin or mucosa (mucocutaneous leishmaniasis - MCL) including the oral cavity. MCL oral lesions are often confused with other oral diseases, delaying diagnosis and specific treatment, and increasing the likelihood of sequelae. Thus, increasing the knowledge of the evolution of ATL oral lesions can facilitate its early diagnosis improving the prognosis of healing. OBJECTIVES: Evaluate the frequency of ATL oral lesion and describe its clinical, laboratory and therapeutic peculiarities. METHODS: A descriptive transversal study was carried out, using data from medical records of 206 patients with MCL examined at the outpatient clinics-IPEC-Fiocruz between 1989 and 2013. Proportions were calculated for the categorical variables and the association among them was assessed by the Pearson's chi-square test. Measures of central tendency and dispersion were used for the continuous variables and their differences were assessed by both parametric (t test) and non parametric (Mann-Whitney) tests. P-values <0.05 were considered as significant. RESULTS: The most affected site was the nose, followed by the mouth, pharynx and larynx. Seventy eight (37.9%) have oral lesions and the disease presented a lower median of the evolution time than in other mucous sites as well as an increased time to heal. The presence of oral lesion was associated with: the presence of lesions in the other three mucosal sites; a smaller median of the leishmanin skin test values; a longer healing time of the mucosal lesions; a higher recurrence frequency; and a smaller frequency of treatment finishing and healing. When the oral lesion was isolated, it was associated with an age 20 years lower than when the oral lesion was associated with other mucosal sites. CONCLUSION: Considering the worst therapy results associated with the presence of oral lesions, we suggest that lesions in this location represent a factor of worse prognosis for MCL.

Miíase nasal secundária a carcinoma escamocelular: relato de caso / Nasal Myiasis Secondary to Squamous Cell Carcinoma: Case Report

Introdução: A infestação de larvas de dípteros, conhecida como miíase, é uma dermatose comum em países tropicais esubtropicais e tem como fator predisponente lesões malignas em pele. Objetivo: Relatar um caso clínico de miíase nasal, secundária a um carcinoma escamocelular, diagnosticado no Serviço de Cirurgia e Traumatologia Bucomaxilofacial da Escola Bahiana de Medicina e Saúde Pública/Hospital Geral Roberto Santos, Salvador, Bahia. Relato de caso: Paciente masculino, 49 anos, leucoderma, apresentou lesão ulcerativa com perda de substância cutânea e cartilaginosa em região de dorso e ápice nasal, além de exposição de cartilagem e ossos nasais. A lesão apresentava bordos necróticos, evertidos,endurecidos, avermelhados e possuía infestação de larvas de dípteros. Após o tratamento combinado de remoçãomecânica associada ao uso de ivermectina 12mg/dia, foi realizada uma biópsia incisional dos bordos granulomatosos da lesão que apresentou laudo histopatológico conclusivo para carcinoma escamocelular bem diferenciado. Conclusão: O tratamento proposto para erradicar as larvas mostrou-se eficaz no caso descrito, a realização de uma biópsia incisional para confirmação da suspeita de lesão maligna no momento da abordagem cirúrgica do paciente foi de extrema importância para se estabelecer um correto diagnóstico e encaminhamento do paciente

Nasal, oral and ear swabs for canine visceral leishmaniasis diagnosis: new practical approaches for detection of Leishmania infantum DNA.

BACKGROUND: The aim of this study was to evaluate the potential use of nasal, oral, and ear swabs for molecular diagnosis of canine visceral leishmaniasis (CVL) in an endemic urban area in Brazil. METHODOLOGY/PRINCIPAL FINDINGS: Sixty-two naturally infected and ten healthy dogs were enrolled in this study. Bone marrow aspirates, peripheral blood, skin biopsy, and conjunctival, nasal, oral, and ear swabs were collected. All samples, except blood, were submitted to conventional PCR (cPCR) and quantitative real time PCR (qPCR) to detect and quantify Leishmania infantum DNA, respectively. All dogs were submitted to thorough clinical analysis and were included based on a combination of serological (ELISA immunoassay and immunofluorescent antibody test) and parasitological methods. The cPCR positivity obtained from nasal swab samples was 87% (54/62), equivalent to those from other samples (P>0.05). Positive results were obtained for 79% (22/28) in oral swabs and 43% (12/28) in ear swab samples. A significant difference was observed between these data (P=0.013), and the frequency of positive results from oral swab was equivalent to those from other samples (P>0.05). The use of ear swab samples for cPCR assays is promising because its result was equivalent to skin biopsy data (P>0.05). The qPCR data revealed that parasite loads in mucosal tissues were similar (P>0.05), but significantly lower than the parasite burden observed in bone marrow and skin samples (P<0.05). CONCLUSIONS: Nasal and oral swab samples showed a high potential for the qualitative molecular diagnosis of CVL because their results were equivalent to those observed in samples collected invasively. Considering that mucosae swab collections are painless, noninvasive, fast and practical, the combination of these samples would be useful in massive screening of dogs. This work highlights the potential of practical approaches for molecular diagnosis of CVL and human leishmaniasis infections.

Sheep and goat immune responses to nose bot infestation: a review.

Oestrus ovis L. (Diptera: Oestridae) is a cosmopolitan agent of myiasis in sheep and goats. The parasitic phase begins after adult females deposit first-stage larvae (L1) into the nostrils of hosts; these larvae develop into L2 and L3 in the nasal and sinus horn cavities. Sneezing and nasal discharges are the major clinical signs in infected animals. The pathogenesis of O. ovis infection is caused by: (a) the trauma resulting from the mechanical action of spines and hooks during larval movement on mucosal membranes, and, more importantly, (b) an allergenic reaction provoked by molecules excreted/secreted by larvae, of which salivary antigens are those mainly recognized by the host's immune system. The recruitment of immune reactive cells increases gradually from the nasal to sinus cavities in infected hosts. Mast cells, eosinophils, macrophages and lymphocytes are always more numerous in infected than non-infected animals. Humoral (antibody) systemic response of immunoglobulin G (IgG) usually reaches seroconversion 2-4 weeks post-first infection and the highest levels are observed during the development of L2 and L3 larvae. Local antibody responses include specific IgG, which has been found to negatively correlate with larval survival and development. Hypersensitivity reaction, immunomodulation, immunization trials and mixed infections of O. ovis and helminths are discussed.

Tyrannobdella rex n. gen. n. sp. and the evolutionary origins of mucosal leech infestations.

BACKGROUND: Leeches have gained a fearsome reputation by feeding externally on blood, often from human hosts. Orificial hirudiniasis is a condition in which a leech enters a body orifice, most often the nasopharyngeal region, but there are many cases of leeches infesting the eyes, urethra, vagina, or rectum. Several leech species particularly in Africa and Asia are well-known for their propensity to afflict humans. Because there has not previously been any data suggesting a close relationship for such geographically disparate species, this unnerving tendency to be invasive has been regarded only as a loathsome oddity and not a unifying character for a group of related organisms. PRINCIPAL FINDINGS: A new genus and species of leech from Perú was found feeding from the nasopharynx of humans. Unlike any other leech previously described, this new taxon has but a single jaw with very large teeth. Phylogenetic analyses of nuclear and mitochondrial genes using parsimony and Bayesian inference demonstrate that the new species belongs among a larger, global clade of leeches, all of which feed from the mucosal surfaces of mammals. CONCLUSIONS: This new species, found feeding from the upper respiratory tract of humans in Perú, clarifies an expansion of the family Praobdellidae to include the new species Tyrannobdella rex n. gen. n. sp., along with others in the genera Dinobdella, Myxobdella, Praobdella and Pintobdella. Moreover, the results clarify a single evolutionary origin of a group of leeches that specializes on mucous membranes, thus, posing a distinct threat to human health.

[New hosts for the nasal mite Rhinonyssus rhinolethrum (Trouessart) (Gamasida: Rhinonyssidae) in Brazil]. / Novos Hospedeiros para o Acaro Nasal Rhinonyssus rhinolethrum (Trouessart) (Gamasida: Rhinonyssidae) no Brasil.

The black-necked swan, Cygnus melanocoryphus, and the ringed teal, Callonetta leucophrys, are reported as new hosts for the nasal mite Rhinonyssus rhinolethrum (Trouessart) in Brazil.

Novos Hospedeiros para o Ácaro Nasal Rhinonyssus rhinolethrum (Trouessart) (Gamasida: Rhinonyssidae) no Brasil / New Hosts for the Nasal Mite Rhinonyssus rhinolethrum (Trouessart) (Gamasida: Rhinonyssidae) in Brazil

O cisne-do-pescoço-preto, Cygnus melanocoryphus, e a marreca-de-coleira, Callonetta leucophrys, são relatados como novos hospedeiros para o ácaro nasal Rhinonyssus rhinolethrum (Trouessart) no Brasil.

The black-necked swan, Cygnus melanocoryphus, and the ringed teal, Callonetta leucophrys, are reported as new hosts for the nasal mite Rhinonyssus rhinolethrum (Trouessart) in Brazil.

Clinical etiology of myiasis in ENT: a reterograde period--interval study.

UNLABELLED: Myiasis in ENT, once a deadly disease still presents as a significant outdoor problem, though advances in management including supportive therapy has led to early healing with significant reduction in bed occupancy rate. AIMS: To assess the clinico etiology, relationship of myiasis to habit and habitat of patients and to assess the changes in age, seasonal, socioeconomic incidence, nasal bacterial flora and usefulness of certain commonly done tests with reference to a gap of 25 years. MATERIALS & METHODS: The presenting study was conducted on 80 patients selected over a period of two time intervals ; first 40 cases were chosen from 1979 to 1980 and next 40 over 2003 to 2004. Cases were studied in a retrograde manner and data tabulated. RESULTS & CONCLUSIONS: Atrophic turbinates was the commonest pathological finding in nose in 30% of cases . Significant change seen was in the age group 51 and above with a rise of 30%. Mode during 2003-04 was 60 years. Incidence of palatal perforation dropped from 17.88 to 2.5% . Klebsiella emerged as a significant contributor to the nasal microbial flora. VDRL and split skin smear showed poor etiological association for the diseases.

Clinical etiology of myiasis in ENT: a reterograde period - interval study / Etiologia clínica da miíase em otorrinolaringologia: um estudo retrospectivo

Myiasis in ENT, once a deadly disease still presents as a significant outdoor problem, though advances in management including supportive therapy has led to early healing with significant reduction in bed occupancy rate. AIMS: To assess the clinico etiology, relationship of myiasis to habit and habitat of patients and to assess the changes in age, seasonal, socioeconomic incidence, nasal bacterial flora and usefulness of certain commonly done tests with reference to a gap of 25 years. MATERIALS & METHODS: The presenting study was conducted on 80 patients selected over a period of two time intervals ; first 40 cases were chosen from 1979 to 1980 and next 40 over 2003 to 2004. Cases were studied in a retrograde manner and data tabulated. RESULTS & CONCLUSIONS: Atrophic turbinates was the commonest pathological finding in nose in 30 percent of cases . Significant change seen was in the age group 51 and above with a rise of 30 percent. Mode during 2003-04 was 60 years. Incidence of palatal perforation dropped from 17.88 to 2.5 percent . Klebsiella emerged as a significant contributor to the nasal microbial flora. VDRL and split skin smear showed poor etiological association for the diseases.

Miíase em ORL não é mais uma doença fatal, mas ainda está presente como um significativo problema em ambientes externos. Entretanto, progressos alcançados no tratamento, incluindo terapêutica de suporte, têm levado à cura precoce com significativa redução na taxa de internação hospitalar por causa dessa enfermidade. OBJETIVOS: Avaliar a etiologia clínica e as associações entre miíase e os hábitos e habitats dos pacientes; e avaliar diferenças no tocante à idade, estação do ano, incidência socioeconômica, flora bacteriana nasal e a utilidade de certos exames comumente feitos - um estudo retrospectivo de 25 anos. MATERIAIS E MÉTODOS: O presente estudo envolveu 80 pacientes selecionados em dois períodos; os primeiros 40 casos foram selecionados de 1979 a 1980, e os 40 seguintes foram coletados entre 2003 e 2004. Os casos foram estudados de forma retrospectiva e os dados foram analisados em tabelas. RESULTADOS E CONCLUSÕES: Cornetos atróficos representaram o achado nasal patológico mais comum - em 30 por cento dos casos. Alterações significativas foram encontradas na faixa etária dos 51 anos e acima, com um aumento de 30 por cento nestes. A média etária entre 2003-04 foi de 60 anos. A incidência de perfuração palatina caiu de 17,88 por cento para 2,5 por cento. Klebsiella foi o germe mais significativamente presente na flora microbiana nasal. Os exames de VDRL e teste cutâneo mostraram pobre associação etiológica entre as doenças.

Feline leishmaniasis due to Leishmania (Leishmania) amazonensis in Mato Grosso do Sul State, Brazil.

A case of leishmaniasis in a domestic cat (Felis domesticus) is described. The animal showed a single, nodular lesion on the nose and many nodules of different size on the ears and digital regions of all the paws. Diagnosis was made by microscopic detection of amastigotes in Giemsa-stained smears from the lesions. By monoclonal antibodies the aetiological agent was identified as Leishmania (Leishmania) amazonensis, one of the seven species implicated in human leishmaniasis in Brazil. The clinical signs in feline leishmaniasis are unspecific and similar to those observed in other diseases such as cryptococcosis and in sporotrichosis, commonly found in cats. Leishmaniasis should therefore, be added to the differential diagnosis by feline veterinary practitioners and adequate investigations should carried out for dermal leishmaniasis in the area where the feline infection is detected.

An extended proof of migration routes of immature parasites inside hosts: pathways of Nippostrongylus brasiliensis and Strongyloides ratti in the rat are mutually exclusive.

Rigorous proofs applicable to the routes of migration of Strongyloides ratti and Nippostrongylus brasiliensis skin-penetrating juveniles inside the rat are extended. By applying the inequality principle (Tindall & Wilson, 1988) it was confirmed with a probability of error of 1 in 10(10) that N. brasiliensis larvae applied to the skin passed through the lungs on their way to the intestine. Taking the analysis further, migrating larvae of S. ratti or N. brasiliensis were extracted from the nose or lungs, respectively, of donor rats and transferred to recipients by stomach tube to assay their ability to colonize the intestine. Results showed that (a) changes undergone by each parasite in its proven, specific transit site were essential before larvae could establish in the intestines of recipients, (b) these changes could be monitored by morphological criteria, and [corrected] (c) these changes were not completed until larvae had been in the nose or lung for a significant period. It follows from (c) that anywhere in the body of the host, termed a 'nursery', that supports a substantial amount of this mandatory development must be detectable by the conventional procedure of sampling at autopsy. Conversely, absence of parasites judged by sampling at autopsy is positive proof that a site is not a nursery when sampling is timed in relation to reliable estimates of overall kinetics (Tindall & Wilson, 1990), and with control information on the efficiency of sampling. Comparative data from sampling at autopsy using the same extraction techniques for both species met these criteria: they demonstrated that no part of the head of the rat was a nursery for N. brasiliensis, and that the lung did not serve in this capacity for S. ratti.(ABSTRACT TRUNCATED AT 250 WORDS)

Inefficacy of metronidazole in experimental infections of Leishmania donovani, L. mexicana, and Trypanosoma brucei brucei.

Metronidazole has been claimed in several earlier reports to be active in human cases of leishmaniasis and trypanosomiasis. Its efficacy against the protozoa causing these diseases was tested in hamsters infected with Leishmania mexicana or L. donovani, and in mice infected with Trypanosoma brucei brucei. In separate experiments, hamsters were either inoculated intradermally into the nose with 5 million amastigotes of L. mexicana or intracardially with 10-30 million amastigotes of L. donovani, and mice were infected intraperitoneally with 30 million T. b. brucei. Metronidazole was administered in four oral doses on alternate days for a total of 375 mg/kg to hamsters and 500 mg/kg to mice. Sodium stibogluconate (Pentostam) served as a positive control. In hamsters the extent of infection was assessed by the appearance of flagellates in blood agar cultures of nose and spleen, by counting amastigotes in nose and liver impression smears, and by measuring the size of nose lesions. Ultrastructure of nose lesions before and after treatment with metronidazole or Pentostam was also evaluated. Infection in mice was assessed by the extent of parasitemia and/or survival to 30 days. In no case did metronidazole-treated animals differ from untreated controls. Metronidazole shows no activity against experimental infections of leishmaniasis or trypanosomiasis in these animal models.