Brote familiar por el nematodo Trichostrongylus colubriformis en una zona rural de la provincia de Valdivia: una zoonosis de rara ocurrencia / Family outbreak caused by the nematode Trichostrongylus colubriformis in a rural area of the province of Valdivia: a rare occurrence zoonoses

Resumen La trichostrongylosis es una zoonosis de rara ocurrencia causada por nematodos intestinales, favorecida por el consumo de vegetales crudos o agua contaminada con larvas infectantes de Trichostrongylus spp. En 2015, se registró un brote familiar transmitido por alimentos en una zona rural de Valdivia, afectando a una mujer de 51 años de edad y su pareja e hija de 56 y 12 años; respectivamente. Solo la mujer adulta, el caso índice, presentó síntomas como diarrea, dolor abdominal, astenia y náuseas. Los pacientes eliminaron huevos de Trichostrongylidae gen. sp. en sus deposiciones, identificándose en dos de ellos, adultos de Trichostrongylus colubriformis. Tuvieron una buena respuesta a albendazol. En Chile, se han registrado prevalencias de infección de 0,1 a 3,5%, incluyendo un total de 93 casos diagnosticados entre las provincias de Concepción y Llanquihue.

Abstract Trichostrongylosis is a rare occurrence zoonosis caused by intestinal nematodes, favored by the consumption of raw vegetables or water contaminated with infective larvae of Trichostrongylus spp. In 2015, a family outbreak of foodborne disease was registered in a rural zone of Valdivia, affecting to 51-year-old woman and her 56-year-old partner and her 12-year-old daughter. Only the adult woman, the index case, presented symptoms such as diarrhea, abdominal pain, asthenia, and nausea. The patients revealed Trichostrongylidae gen. sp. eggs in their stools, identifying Trichostrongylus colubriformis adults in two of them. They had a good response to treatment with albendazol. In Chile, 0.1 to 3.5% prevalence of infection has been reported, including a total of 93 cases recorded between the provinces of Concepción and Llanquihue.

Immune and haematological parameters of Blackbelly ewes infected with gastrointestinal nematodes / Parámetros inmunológicos y hematológicos en ovejas Blackbelly infectadas con nematodos gastrointestinales / Parâmetros imunes e hematológicos de ovelhas Blackbelly infectadas por nematoides gastrintestinais

Abstract Background: It is necessary to identify phenotypic traits related to natural resistance against gastrointestinal nematodes (GIN) in order to know the host immunity status in productive ewes. Objetive: To determine haematological and immunological parameters (IgA and IgG) during pregnancy and lactation in Blackbelly ewes naturally infected with GIN Methods: The number of eggs per gram (EPG), packed cell volume (% PCV), plasmatic protein (PP), and peripheral eosinophils were determined during eight months. In addition, sera and saliva samples were collected to establish IgG and IgA kinetics by indirect enzyme-linked immunosorbent assay (ELISA). Results: The results showed 2,592 ± 2,403 EPG and 22.2 ± 4.0% PCV during lactation and 595 ± 901 EPG and 25.1 ± 2.5% PCV during pregnancy. A higher percentage of Trichostrongylus colubriformis larvae were observed in pregnancy (84 to100%) than in lactation (36 to 44%). The IgA activity in serum samples showed a marked reduction (from 80 to 10%) during lambing for both Haemonchus contortus and T. colubriformis antigens. In saliva samples, IgA activity with regard to the standard decreased from 56% at 60 days to 30% at 45 days before lambing and remained low for 45 days during lactation (23 to 32% activity). The eosinophils numbers were 2.0 x 109 cells L-1 in pregnancy and remained low at 0.7 x 109 cells L-1 in lactation. Conclusion: The studied variables reflect the breakdown of immunity against GIN in Blackbelly ewes before and after lambing.

Resumen Antecedentes: La identificación del fenotipo relacionado con la resistencia contra nematodos gastrointestinales (GIN) es necesaria para conocer la inmunidad del huésped en ovejas en producción. Objetivo: Determinar los parámetros hematológicos e inmunológicos (IgA e IgG) en gestación y lactancia en ovejas Blackbelly infectadas naturalmente con GIN. Métodos: Se determinó el número de huevos por gramo de heces (EPG), se identificaron las larvas y se registró el porcentaje del volumen celular aglomerado (% PCV), proteína plasmática (PP) y eosinófilos periféricos durante ocho meses. Además, se colectó suero y saliva para determinar la cinética de IgG e IgA por medio de un ensayo inmuno-enzimático (ELISA) indirecto. Resultados: Los resultados mostraron 2.592 ± 2.403 EPG y 22,2 ± 4,0% PCV durante la lactancia y 595 ± 901 EPG y 25,1 ± 2,5% PCV durante la gestación. Se observó un mayor porcentaje de larvas de Trichostrongylus colubriformis en gestación (84 a 100%) que en lactancia (36 a 44%). La actividad de la IgA en las muestras de suero mostró una marcada reducción después del parto para ambos antígenos de Haemonchus contortus y T. colubriformis (80 a 10%). En saliva, la actividad de la IgA disminuyó de 56 a 30% del día 60 al 45 antes del parto y se mantuvo baja en los primeros 45 días de la lactancia (actividad de 23 a 32%). El número de eosinófilos fue de 2,0 x 109 células L-1 durante la gestación, y se redujo a 0,7 x 109 células L-1 en la lactancia. Conclusión: Las variables estudiadas reflejan la ruptura de la inmunidad contra GIN en ovejas Blackbelly antes y después del parto.

Resumo Antecedentes: A identificação de traços fenotípicos relacionados à resistência natural contra nematóides gastrintestinais (GIN) é necessária para saber a imunidade do hospedeiro em ovelhas produtivas. Objetivo: Determinar parâmetros hematológicos e imunológicos (IgA e IgG) em períodos de gestação e lactação em ovelhas Blackbelly naturalmente infectados com GIN. Métodos: O número de ovos por grama (EPG), volume empacotado de células (% PCV), proteína plasmática (PP) e eosinófilos periféricos foram determinados durante oito meses. Além disso, as amostras de soro e saliva foram recolhidas para determinar a cinética de IgG e IgA por ELISA indireto. Resultados: Os resultados mostraram 2.592 ± 2.403 EPG e 22,2 ± 4,0% PCV durante a lactação e 595 ± 901 EPG e 25,1 ± 2,5% PCV durante a gravidez. A percentagem mais elevada de larvas de Trichostrongylus colubriformis foi observada na gravidez (84 a 100%) do que na lactação (36 a 44%). A atividade de IgA em amostras de soro mostrou uma redução acentuada (80 a 10%) durante o parto nos antígenos de Haemonchus contortus e T. colubriformis. Em amostras de saliva, a atividade de IgA diminuiu de 56 a 30% do dia 60 ao 45 antes do parto e permaneceu baixa por 45 dias durante a lactação (atividade de 23 a 32%). O número de eosinófilos foi de 2,0 x 109 células L-1 na gravidez e manteve-se baixo, com 0,7 x 109 células L-1 na lactação. Conclusaõ: As variáveis estudadas refletem a quebra da imunidade contra GIN em ovelhas Blackbelly antes e depois do parto.

Molecular Phylogenetics of Trichostrongylus Species (Nematoda: Trichostrongylidae) from Humans of Mazandaran Province, Iran

The present study was performed to analyze molecularly the phylogenetic positions of human-infecting Trichostrongylus species in Mazandaran Province, Iran, which is an endemic area for trichostrongyliasis. DNA from 7 Trichostrongylus infected stool samples were extracted by using in-house (IH) method. PCR amplification of ITS2-rDNA region was performed, and products were sequenced. Phylogenetic analysis of the nucleotide sequence data was performed using MEGA 5.0 software. Six out of 7 isolates had high similarity with Trichostrongylus colubriformis, while the other one showed high homology with Trichostrongylus axei registered in GenBank reference sequences. Intra-specific variations within isolates of T. colubriformis and T. axei amounted to 0–1.8% and 0–0.6%, respectively. Trichostrongylus species obtained in the present study were in a cluster with the relevant reference sequences from previous studies. BLAST analysis indicated that there was 100% homology among all 6 ITS2 sequences of T. colubriformis in the present study and most previously registered sequences of T. colubriformis from human, sheep, and goat isolates from Iran and also human isolates from Laos, Thailand, and France. The ITS2 sequence of T. axei exhibited 99.4% homology with the human isolate of T. axei from Thailand, sheep isolates from New Zealand and Iran, and cattle isolate from USA.

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil / Infecções por nematódeos gastrintestinais em ovinos criados em Botucatu, estado de São Paulo, Brasil

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

A ocorrência de infecções por nematódeos gastrintestinais foi avaliada de abril de 2008 até março de 2011em ovinos criados em Botucatu, estado de São Paulo. Todos os meses, dois cordeiros traçadores foram expostos à infecção natural por nematódeos gastrintestinais, durante 28 dias consecutivos, ao pastejar junto com um rebanho de ovelhas. Ao final desse período, os animais foram sacrificados para a identificação e quantificação dos helmintos. Haemonchus contortus apresentou prevalência de 100%. Não houve influência significativa das estações do ano na intensidade média de H. contortus, que variou de 315 vermes em novembro/2010 a 25.205 vermes em janeiro/2011. Trichostrongylus colubriformis também apresentou prevalência de 100% com a menor intensidade média (15 vermes) em fevereiro/2011 e a maior (9.760 vermes) em outubro/2009. No caso de T. colubriformis, houve correlação significativa entre as contagens de vermes x precipitação (r = −0,32; P <0,05). Outras três espécies de nematódeos foram encontradas nos cordeiros traçadores, no entanto em pequenas quantidades, com as seguintes prevalências e intensidades médias (entre parênteses): Oesophagostomum columbianum 28% (25,2), Cooperia curticei 7% (4,5) e Trichuris spp. 2 % (1). Em conclusão, as condições ambientais da área foram muito favoráveis durante todo o ano para a transmissão de H. contortus e T. colubriformis.

Parasitic helminths of the digestive system of wild boars bred in captivity / Helmintos parasitas do sistema digestório de javalis criados em cativeiro

This study aimed to identify the parasites that inhabit the digestive system of Sus scrofa scrofa from a commercial breeding facility in southern Brazil, and reports the first occurrence of Trichostrongylus colubriformis in wild boars. The gastrointestinal tracts of 40 wild boars from a commercial breeding facility were collected and individualized during slaughter in a cold-storage slaughterhouse. Out of this total, 87.5% were parasitized by the helminths Ascaris suum, Trichostrongylus colubriformis, Oesophagostomum dentatum and Trichuris suis. T. colubriformis presented a prevalence of 45%, mean intensity of 28.4 and mean abundance of 12.8. The data from this study showed that T. colubriformis not only has a capacity to develop in the small intestines of wild boars, but also adapts well to animals raised in captivity, thus representing a possible cause of economic loss in commercial wild boar farming.

O estudo teve por objetivo identificar os parasitos que habitam o sistema digestório de Sus scrofa scrofa provenientes de criatório comercial do sul do Brasil, reportando a primeira ocorrência de Trichostrongylus colubriformis em javalis. Foram coletados e individualizados os tratos gastrintestinais de 40 javalis oriundos de criatório comercial durante abate em frigorífico. Destes, 87,5% estavam parasitados por helmintos, sendo eles, Ascaris suum, Trichostrongylus colubriformis, Oesophagostomum dentatum e Trichuris suis. T. colubriformis apresentou prevalência de 45%, intensidade média de 28,4 e abundância média de 12,8. Os dados deste trabalho demonstram que T. colubriformis além da capacidade de desenvolvimento no intestino delgado de javalis, adapta-se bem às criações, representando uma possível causa de perdas econômicas nas criações de javalis.

Recovery of Trichostrongylus colubriformis infective larvae from three grass species contaminated in the autumn / Recuperação de larvas infectantes de Trichostrongylus colubriformis em três espécies de gramíneas contaminadas no outono

This experiment aimed to assess the recovery of infective larvae (L3) of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm). TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM), recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.(AU)

O experimento teve como objetivo avaliar a recuperação de larvas infectantes (L3) de Trichostrongylus colubriformis em Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross e Panicum maximum cv. Aruana. Foram utilizados módulos experimentais constituídos por seis canteiros, perfazendo dois canteiros por espécie forrageira. A sobrevivência larval foi avaliada do outono até o inverno, sob o efeito de duas alturas de poda (5 e 30 cm). A poda foi realizada imediatamente antes da deposição das fezes contaminadas com ovos de T. colubriformis. A colheita das fezes e da forragem foi realizada uma, duas, quatro, oito, 12 e 16 semanas após a deposição das fezes nos canteiros experimentais. De modo geral, foram recuperadas larvas das forragens e das fezes até a 16ª semana. Essas larvas persistiram por mais tempo no ambiente, provavelmente em razão das temperaturas mais amenas. O número de L3 recuperadas nas pastagens não foi influenciado pela altura das plantas, exceto nos capins braquiária e aruana na quarta semana. Já em relação às concentrações de larvas (L3/kg MS) recuperadas das três forrageiras, houve maior concentração nas pastagens baixas. Durante o outono, o desenvolvimento e a sobrevivência de estádios de vida livre de T. colubriformis não foram afetados pelos diferentes tipos de espécies de forrageiras.(AU)

Differential diagnosis of Trichostrongylus and hookworm eggs via PCR using ITS-1 sequence

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.

Differential diagnosis of Trichostrongylus and hookworm eggs via PCR using ITS-1 sequence

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.