Fernando Fredes

Immunodiagnosis of fasciolosis in horses and pigs using Western blots

Crude and partially purified somatic (S) and excretory-secretory (ES) antigens of Fasciola hepatica were subjected to Western blot analysis in order to identify polypeptides that would enable specific and sensitive immunodiagnosis of horse and pig fasciolosis to be undertaken. Sera from 20 horses and 20 pigs with natural infections of F. hepatica and the same number of uninfected hosts of each species were tested, together with sera from 2 pigs with Cysticercus cellulosae infections. Using crude S antigens, sera from infected horses and pigs reacted specifically with a wide range of polypeptides of 14-19, 22-30, 35-37 and 42 kDa. Likewise, specific reactivity between polypeptides of 14-17, 22-30 and 40-42 kDa in crude ES antigens and sera from infected horses and pigs was obtained. Against the criteria of high sensitivity and specificity, the 22-30-kDa polypeptides would appear to be the most suitable candidate antigens for use in the immunodiagnosis of fasciolosis in horses and pigs.

Gastrointestinal parasite fauna of gentoo penguins ( Pygoscelis papua ) from the Península Munita, Bahía Paraíso, Antarctica

An increase in interest in the diseases of seabirds has developed as a part of a worldwide strategy for environmental conservation (Clarke & Kerry 1993, Jones & Shellam 1999). According to Clarke & Kerry (1993) most studies on penguin enteroparasites were published before 1986 and most of them are post mortem diagnoses. This paper provides new data on the intestinal parasitic fauna of gentoo penguins nesting on the Antarctic Península.

Sociality, exotic ectoparasites, and fitness in the plural breeding rodent Octodon degus

Social animals are susceptible to high infection levels by contact-transmitted parasites due to increased conspecific interaction. Exotic parasites are known to have adverse consequences on native hosts. We examined the relationship between social group size and exotic ectoparasite loads, and adult infection levels with per capita fitness and offspring survival in the plural breeding rodent Octodon degus in central Chile. Degus at our site were almost entirely infected by two exotic ectoparasites: the fleas Leptopsylla segnis and Xenopsylla cheopis. Neither group size nor number of females per group predicted the abundance of either exotic flea species. The per capita number of pups (per capita fitness) that emerged from burrow systems used by known social groups was negatively correlated with abundance of L. segnis but not X. cheopis. On adults, X. cheopis abundance was three times greater than L. segnis but was not significantly correlated with per capita fitness. In females, L. segnis abundance was negatively correlated with peak body mass during pregnancy. Adult ectoparasite load was not correlated with offspring survival. Based on these results, we hypothesize that high infection levels of L. segnis result in decreased reproductive fitness of adult female degus but are not a cost of sociality because parasite loads are not predicted by social group size. Further work is needed to experimentally test this hypothesis and to determine if L. segnis serves as a vector for a deleterious pathogen. Lastly, the lack of native ectoparasites may explain why a previous study at our site determined that behavioral adaptations needed to cope with high ectoparasite burdens (e.g., grooming) are not extensive in degus; they simply have not had the coevolutionary time needed for selection of these behaviors.

Cryptosporidium spp. oocysts detected using acid-fast stain in faeces of gentoo penguins (Pygoscelis papua) in Antarctica

Cryptosporidium is considered to be one of the indicators of environmental contamination and water quality (Garcia 2001, Fayer 2004, Ramirez & Sreevatsan 2006). At the present time the presence of this parasite has been recorded on all the continents, including Antarctica (Fredes et al. 2007a).

Fauna parasitaria gastrointestinal en polluelos de Pingüino Papua (Pygoscelis papua) encontrados muertos en zona antártica especialmente protegida (ZAEP Nº150)

. El presentetrabajo se realizo para aportar informacion delparasitismo gastrointestinal del pinguino Papuaen la Isla Ardley (62o13’ S, 58o54’ W), peninsulaFildes, isla Rey Jorge, archipielago Shetland delSur, territorio Antartico (ZAEP No150).MATERIAL Y METODOSEl muestreo se realizo durante los meses de

Cryptosporidium parvum in diarrheic calves detected by microscopy and identified by immunochromatographic and molecular methods.

Cryptosporidium is an important protozoan parasite that causes diarrhea in neonates and young bovines. The objective of the present study was to determine the frequency of Cryptosporidium infection in animals of dairy farms of the Metropolitan Region (Santiago), Chile. Fecal samples of 205 newborn calves with diarrhea were studied and used for comparing the efficiency of two microscopic staining methods for diagnosis of the parasite, the auramine (AU) and a modified Ziehl-Neelsen (ZN) procedure. Out of the 205 fecal samples, we detected oocysts in 115 (56.1%) with AU and 102 (49.8%) with ZN. Comparison of results obtained with the two microscopic techniques showed significant difference (p<0.05), AU being more sensitive. On the other hand, concordance between the two methods was almost perfect (kappa value of 0.83). The results with these two operator dependent methods were confirmed using an operator independent immunochromatographic (IC) method. The IC method also enabled us to determine the identity of the parasite species as that of Cryptosporidium parvum. Identification of the parasite species was further corroborated by performing a Cryptosporidium species-specific polymerase chain reaction (PCR) test on few samples taken at random. Overall, the results showed a high number of infected animals suggesting the parasite C. parvum as a major parasitic disease agent of neonatal calves with diarrhea in dairy farms of the Metropolitan Region (Santiago) of Chile.

Short Note: First report of Cryptosporidium spp. oocysts in stool of Adélie penguin from the Antarctic using acid-fast stain

Cryptosporidium is an intracellular parasite that belongs to the phylum Protozoa and subphylum Apicomplexa (Sporozoa). It was first described by from the digestive tract of laboratory mice (Garcia 2001), and has been found in several animal groups including fishes, reptiles, birds and mammals, including humans (Jellison et al. 2002).

Fauna parasitaria gastrointestinal en el pingüino Adelia (Pygoscelis adeliae) de zona antártica especialmente protegida (ZAEPN°150)

One hundred and sixty seven fecal samples and three complete digestive tracts obtained from these penguins were analyzed using different parasitological methodologies. The presence of Tetrabothrius spp. eggs (Cestoda: Pseudophyllida), and the observation of Sporozoa oocists and Nematoda eggs both of undetermined species in the fecal samples is reported. In the same way a large number of nematodes identified as Streptocara spp. (Nematoda: Acuariidae) in different evolutionary stages in stomach, and the recovery of a whole 81 cm. Tetrabothrius spp. specimen (without the scolex) and one inmature tapeworm (Cestoda: Cyclophyllida) with unarmed rostellum in guts of Adelie penguins chiks found dead in a protected zone of the Antarctic territory is reported.

Multiple Cryptosporidium parvum subtypes detected in a unique isolate of a Chilean neonatal calf with diarrhea

To further understand the composition of population of parasite in a single host, we analyzed the GP60 gene of Cryptosporidium parvum amplified from DNA of a randomly selected isolate found in the feces of a diarrheic calf from a dairy farm in Central Chile. Direct sequencing of the amplicon yield the IIaA17G4R1 C. parvum subtype. The same amplicon was cloned in Escherichia coli (22 clones) and sequenced, yielding three different GP60 subtypes, IIaA17G4R1 (16/22), IIaA16G4R1 (1/22), and IIaA15G4R1 (1/22), and four sequences with nucleotide substitutions in the serine repeats, which subtype would be otherwise IIaA17G4R1. It is thus possible to determine allelic polymorphism using Sanger sequencing with an additional step of bacterial cloning. The results also indicate the necessity to further characterize parasite populations in a single host to better understand the dynamics of Cryptosporidium epidemiology.

First meeting "cystic echinococcosis in Chile, update in alternatives for control and diagnostics in animals and humans"

This report summarizes the outcomes of a meeting on cystic echinococcosis (CE) in animals and humans in Chile held in Santiago, Chile, between the 21st and 22nd of January 2016. The meeting participants included representatives of the Departamento de Zoonosis, Ministerio de Salud (Zoonotic Diseases Department, Ministry of Health), representatives of the Secretarias Regionales del Ministerio de Salud (Regional Department of Health, Ministry of Health), Instituto Nacional de Desarrollo Agropecuario (National Institute for the Development of Agriculture and Livestock, INDAP), Instituto de Salud Pública (National Institute for Public Health, ISP) and the Servicio Agrícola y Ganadero (Animal Health Department, SAG), academics from various universities, veterinarians and physicians. Current and future CE control activities were discussed. It was noted that the EG95 vaccine was being implemented for the first time in pilot control programmes, with the vaccine scheduled during 2016 in two different regions in the South of Chile. In relation to use of the vaccine, the need was highlighted for acquiring good quality data, based on CE findings at slaughterhouse, previous to initiation of vaccination so as to enable correct assessment of the efficacy of the vaccine in the following years. The current world’s-best-practice concerning the use of ultrasound as a diagnostic tool for the screening population in highly endemic remote and poor areas was also discussed.