RESUMO
Previous descriptions of Corynosoma bullosum (Linstow, 1892) show that specimens vary greatly in the proportions of different body structures, measurements of females and males, number of rows of hooks, and egg measurements, among other features. We redescribe this species from specimens found in southern elephant seal faeces from King George Island. We also provide a molecular characterization, in addition to 5.8S and internal transcribed spacer (ITS) existing sequences. We examined 41 elephant seals, and 30 adult acanthocephalans were found in 15 of them. The specimens were identified as belonging to the genus Corynosoma due to each having a tubular body with an inflated anterior part forming a thorny disk and the posterior part bearing somatic spines on the ventral surface, and genital spines surrounding the genital pore. Individual morphology corresponded to C. bullosum: large size, marked sexual dimorphism, and proboscis with 16-18 rows of spines with 11-15 spines per row. The molecular profile of three specimens of C. bullosum was analysed using 18S rDNA. We inferred phylogenetic relationships of the family Polymorphidae using maximum likelihood and Bayesian inference. We provide an updated morphological redescription for C. bullosum including electron microscopy photographs and molecular data. The 18S gene sequences showed low genetic variation and supported that C. bullosum is a sister to Corynosoma australe.
Assuntos
Acantocéfalos , Focas Verdadeiras , Animais , Feminino , Masculino , Regiões Antárticas , Teorema de Bayes , FilogeniaRESUMO
Cottage cheese disease is caused by microsporidian parasites that infect a wide range of animal populations. Despite its potential to affect economically important activities, the spatial patterns of prevalence of this disease are still not well understood. Here, we analyse the occurrence of the microsporidian Areospora rohanae in populations of the king crab Lithodes santolla over ca 800 km of the southeastern Pacific shore. In winter 2011, conical pots were deployed between 50 and 200 m depth to capture crabs of a wide range of sizes. The infection was widely distributed along the region, with a mean prevalence of 16%, and no significant association between prevalence and geographical location was detected. Males, females and ovigerous females showed similar prevalence values of 16.5 (13-18.9), 15 (9.2-15) and 16.7% (10-19%), respectively. These patterns of prevalence were consistent across crab body sizes, despite the ontogenetic and sex-dependent variations in feeding behaviour and bathymetric migrations previously reported for king crabs. This study provided the first report of the geographical distribution of A. rohanae infecting southern king crabs.
RESUMO
Thorny-headed acanthocephalan worms of the genus Profilicollis are widely distributed in the oceans of the world and present complex life cycles with intermediate and definitive hosts. The genus is still poorly known, with an unstable taxonomy and, for most species, incompletely characterized geographical distributions. In this study, based on molecular and morphological evidence, we report that the species Profilicollis altmani is also distributed along the South American Atlantic coast, using the mole crab Emerita brasiliensis as an intermediate host. As such, our record shows that P. altmani has a Pan-American distribution where five species of Emerita are utilized as intermediate hosts.
Assuntos
Acantocéfalos/crescimento & desenvolvimento , Anomuros/parasitologia , Organismos Aquáticos/parasitologia , Filogeografia , Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , América , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filogenia , Água do Mar , Análise de Sequência de DNA , Homologia de SequênciaRESUMO
Resolving complex life cycles of parasites is a major goal of parasitological research. The aim of this study was to analyse the life cycle of two species of the genus Profilicollis, the taxonomy of which is still unstable and life cycles unclear. We extracted individuals of Profilicollis from two species of crustaceans (intermediate hosts) and four species of seagulls (definitive hosts) from sandy-shore and estuarine habitats along the south-east Pacific coast of Chile. Mitochondrial DNA analyses showed that two species of Profilicollis infected intermediate hosts from segregated habitats: while P. altmani larvae infected exclusively molecrabs of the genus Emerita from fully marine habitats, P. antarcticus larvae infected the crab Hemigrapsus crenulatus from estuarine habitats. Moreover, P. altmani completed its life cycle in four seagulls, Chroicocephalus maculipennis, Leucopheus pipixcan, Larus modestus and L. dominicanus, while P. antarcticus, on the other hand, completed its life cycle in the kelp gull L. dominicanus. Accordingly, our results show that two congeneric parasites use different and spatially segregated species as intermediate hosts, and both are capable of infecting one species of definitive hosts. As such, our analyses allow us to shed light on a complex interaction network.
Assuntos
Acantocéfalos/classificação , Acantocéfalos/fisiologia , Charadriiformes/parasitologia , Crustáceos/parasitologia , Estágios do Ciclo de Vida , Filogenia , Acantocéfalos/genética , Acantocéfalos/isolamento & purificação , Animais , Análise por Conglomerados , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , Análise de Sequência de DNARESUMO
The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that contains some of the most damaging pests in tropical and subtropical regions. Recent studies suggested that this complex is composed of at least 24 distinct species. We use the approach from these studies to consider the identity of B. tabaci in Argentina. Previous studies have suggested the presence of a B. tabaci presumably indigenous to the Americas and referred to as the BR biotype in Argentina. We placed the entity referred to as the BR biotype within the B. tabaci cryptic species complex using whiteflies collected in soybean and bean crops in northern and central Argentina. The whiteflies were assigned using the mitochondrial cytochrome oxidase (mtCOI) gene. Four unknown haplotypes plus two Argentina sequences from GenBank formed a cluster that was basal to the rest of the New World sequences. These sequences diverged from the consensus sequence across the range of 3.6 to 4.3%. Applying the species assignment rules of recent studies suggests that the individuals from Argentina form a separate species. A fifth unknown haplotype fell within the New World putative species and formed a distinct cluster with haplotypes from Panama. These results suggest that Argentina has two indigenous species belonging to the B. tabaci cryptic species complex. Rather than using mtCOI sequencing for all B. tabaci collected, a simple random amplified polymorphic DNA-polymerase chain reaction diagnostic was used and tested along with previously published primers designed to work specifically with the BR biotype from Brazil. These primers were either unable to distinguish between the two indigenous members of the complex in Argentina or indicated a difference when none was evident on the basis of mtCOI sequence comparison.
Assuntos
Hemípteros/classificação , Hemípteros/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Animais , Argentina , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fabaceae , Feminino , Haplótipos , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized adherence to HEp-2 cells, and produced enterohemolysin. A serological response to lipopolysaccharide O26 was observed at the onset of diarrhea.
Assuntos
Camelídeos Americanos , Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Toxina Shiga/biossíntese , Animais , Aderência Bacteriana , Linhagem Celular , Diarreia/microbiologia , Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Humanos , Reação em Cadeia da Polimerase , América do SulRESUMO
Faecal samples from 76 diarrhoeic calves belonging to 36 farms located in the Pampas plain, Argentina, were examined for Shiga toxin-producing Escherichia coli (STEC). A total of 15 STEC strains were isolated from 12 (15.8%) calves which came from six different farms. All stx positive strains assayed by PCR were also positives in the Vero cell cytotoxicity test. The majority (60.0%) of the STEC strains carried the stx(1) gene. Twelve (80.0%) of the STEC isolates which belonged to serotypes O5:H- (n = 4), O26:H11 (n = 4), O26:H- (n = 1), O111:H- (n = 2), and O123:H38 (n = 1) were also enterohaemolysin (EHly) positive and carried the gene encoding for intimin (eae). All the stx positive strains were negative for the bfpA gene. Localized adherence to HEp-2 cells were observed in 83.3% of the eae+ STEC strains. STEC belonging to serotype O5:H- showed atypical biochemical properties, including urease production. Urease was also produced by two strains belonging to serotypes O153:H? and non-typeable, respectively. Resistance to three or more antibiotics was observed in 12 (80.0%) of the STEC isolates. Most of the serotypes of STEC recovered in this survey carried virulence traits that are associated with increased human and bovine pathogenicity. The present study shows that highly virulent STEC strains are being shed by diarrhoeic calves from farms located in a high incidence area of human STEC infections.
Assuntos
Anti-Infecciosos/farmacologia , Doenças dos Bovinos/epidemiologia , Diarreia/veterinária , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Animais , Animais Recém-Nascidos , Argentina/epidemiologia , Aderência Bacteriana , Bovinos , Doenças dos Bovinos/etiologia , Doenças dos Bovinos/microbiologia , Primers do DNA , DNA Bacteriano/análise , Diarreia/epidemiologia , Farmacorresistência Bacteriana , Escherichia coli/genética , Escherichia coli/fisiologia , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase/veterinária , Toxinas ShigaRESUMO
CS31A is a K88-related non-fimbrial adhesin first described on Escherichia coli strains isolated from diarrhoeic and septicaemic calves. In this report, CS31A antigen was screened by immunological methods and confirmed by PCR among bovine E. coli isolates. In addition, CS31A-producing strains were characterized with respect to different fimbrial antigens, O-serogroup and other properties related to virulence. Faecal or tissue specimens of 100 diarrhoeic or septicaemic calves and 27 older cattle with different pathologies from 71 outbreaks or individual cases that occurred in Buenos Aires province, Argentina, were examined. CS31A + E. coli strains were isolated from 21 (21.0%) calves from 16 outbreaks or individual cases. No CS31A + E. coli was detected in samples from cattle more than 1 year old. Fimbriae F5, F41, F17a and F17b were not detected among the CS31A-producing strains. Three (14.3%) of the CS31A+ E. coli strains expressed the F17c fimbria. All of the 21 isolates exhibited at least one property of septicaemic strains (resistance to serum, production of aerobactin or colicins) but none of them demonstrated heat-stable enterotoxigenic activity. CS31A + E. coli isolates belonged to 10 serogroups, more commonly O8, O7, O17 and O21. The results obtained here confirm the worldwide distribution of CS31A antigen in bovine E. coli strains. However, CS31A + or CS31A + /F17c + E. coli were less frequently isolated than they were in North hemisphere countries.
Assuntos
Proteínas de Bactérias/imunologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Diarreia/veterinária , Surtos de Doenças/veterinária , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli , Escherichia coli/patogenicidade , Sepse/veterinária , Animais , Animais Recém-Nascidos , Antígenos de Bactérias/isolamento & purificação , Argentina/epidemiologia , Aderência Bacteriana , Proteínas de Bactérias/genética , Bovinos , Diarreia/epidemiologia , Diarreia/microbiologia , Eletroforese em Gel de Poliacrilamida/veterinária , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/imunologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Fímbrias Bacterianas/imunologia , Reação em Cadeia da Polimerase/veterinária , Sepse/epidemiologia , Sepse/microbiologiaRESUMO
The presence of gelatinolytic activity in dust mite and Periplaneta americana allergenic crude extracts were studied. The former presented major activity in a broad band between 45 and 66 kDa and minor activity at 32 kDa, while the latter showed a more complex pattern with gelatinolytic activity at 90, 78, 65, 34, 32 and 24 kDa. When the proteolytic activity patterns of dust mites and cockroach crude extracts were analyzed at three different pH levels, the proteases in both cases were optimally active at pH 6, showed no activity at pH 3.5 and little activity at pH 8.5. The susceptibility of both extracts to a set of well-known protease inhibitors suggested that they are composed of cysteine and serine proteinases, the latter probably being a trypsin-like type. When immunochemical properties were studied, dust mite bands of about 200, 110, 65, 60 and 43 kDa showed immunoreactivity against a polyclonal human anti-dust mite serum, with the band of approximately 200 kDa presenting the highest antigenicity. A similar analysis was applied to the cockroach extract, which exhibited immunoreactive bands at 90, 78, 65 and 34 kDa when incubated with a polyclonal rabbit anti-Blatta serum. Only those of 90, 78 and 65 kDa reacted against a polyclonal human anti-Blatta serum. These results suggested a correlation between some proteases with gelatinolytic activity and the allergenicity of both extracts.
Assuntos
Baratas/enzimologia , Cisteína Endopeptidases/metabolismo , Gelatinases/metabolismo , Ácaros/enzimologia , Serina Endopeptidases/metabolismo , Animais , Western Blotting , Eletroforese em Gel de Poliacrilamida , Humanos , Concentração de Íons de Hidrogênio , Peso Molecular , CoelhosRESUMO
Data concerning the experimental induction of hypersensitivity pneumonitis in guinea pigs using a glycoprotein derived from Penicillium notatum are presented. This antigen was obtained from the mycelial and metabolic products of the cultures passed through a Sephadex G-50 column. It was aerosolized for inhalation by adult guinea pigs for 12 weeks to detect specific serum IgM, IgG and IgE antibodies as well as sensitized leukotriene CD4 cells. Histopathological studies of the lungs showed interstitial infiltrates of macrophages and leukotriene cells, cellular bronchiolitis and single non-necrotizing granulomas. The results from this animal model suggest that this hypersensitivity pneumonitis is a typical delayed-type reaction due to chronic contact with the heterologous glycoprotein of Penicillium.