Background & methodsBlastocystis sp. is one of the most prevalent unicellular eukaryote of the human large intestine in Chile and worldwide. It is classified in subtypes (STs), where using the polymorphic sequences of its 18S rRNA genes currently recognizes 22. STs 1–9 and ST12 have been reported in humans. It has been hypothesized that different STs of Blastocystis sp. differentially affect the clinical severity of the digestive disease in Irritable Bowel Syndrome (IBS) patients, but more studies ar4e needed to establish this statement. To contribute in the elucidation of the potential relationship between Blastocystis sp. subtypes and IBS severity, 37 IBS patient fecal samples were collected at hospitals in Santiago (Chile) and were screened for the presence of vacuolated forms of Blastocystis sp. by using conventional microscopy. Positive samples were submitted to PCR and sequencing for determining STs. The same procedure was performed in fecal samples from five non-IBS Blastocystis sp. carriers for preliminary comparative purpose.Results and discussionFour out of the 37 samples from the IBS patients were found positive for Blastocystis sp. (10.81%) by using microscopy. The presence of this microorganism in these four samples were confirmed by PCR and sequencing. Subtypes and their respective closest match alleles were searched and the ST1, ST2 and ST4 subtypes were found in these patients. ST4 subtype is scarcely detected in South America countries, being reported previously only in Colombia and Brazil. In this ST4 subtype we determined the allele 42 which is the most frequent allele observed in human Blastocystis isolates. In the non-IBS individuals' carriers, three subtypes were found: ST1, ST2 and ST3, even belonging to the same family group. Closest match alleles: 2, 12 and 34 here detected were also commonly reported globally. Instead of the small number of IBS patients studied here, the frequency of blastocystosis detected (10.81%) was lower than the prevalence of Blastocystis sp. infections described for the Chilean general population (30.4%). In Chile, clear correlation of Blastocystis sp. subtypes and IBS severity is still lacking with this study but it may lead and contribute to a better understanding of its pathogenicity and worldwide epidemiology.

Introduction: Anisakidosis is a zoonotic disease caused by the consumption of raw or undercooked fish or crustaceans parasitized by nematode larvae of the Anisakidae family. In this study, the presence of anisakid larvae was identified in fish species of consumer of the Pacific coast in Ecuador and Colombia.Methods: We obtained 438 samples grouped into twenty species of fish caught in the fishing ports of Manta, Santa Rosa, Buenaventura and Tumaco. The morphological identification of the larvae was made by taxonomy and the percentage of infection, were calculated. For the identification of species, a multiplex PCR was carried.Results: The taxonomic review identified eight species of fish as hosts of the genders Anisakis andPseudoterranova. The larvae were isolated mainly from  the intestine with a percentage of infection between 18 and 100%. The percentage of infection and identification of anisakids in these fish will aid in the prevention and control of anisakiasis as a possible emerging disease for this area of the Pacific. With the multiplex PCR, A. pegreffii, A. physeteris, and P. decipiens were identified.Conclusion: The identification of these species is reported for the first time in this geographical area, providing the basis for future research into the Anisakidae family.

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.

Objetivo. Identificar nematodos de la familia Anisakidae en el pez de consumo Mugil curema. Materiales y métodos. Para este estudio, se recolectaron 16 peces Lisa (M. curema) del puerto de Tumaco, una ciudad en la costa colombiana del Pacífico. La identificación morfológica de las larvas se realizó mediante taxonomía clásica y se calculó el porcentaje de infestación de larvas. Para la identificación molecular, se realizó una PCR múltiple con cebadores para las especies Anisakis physeteris, Pseudoterranova decipiens, Anisakis simplex sensu stricto, Contracaecum osculatum, Hysterothylacium aduncum y Anisakis pegreffii. Resultados. La revisión taxonómica permitió la identificación de larvas de tipo II del género Anisakis y larvas del género Pseudoterranova. Las larvas se aislaron principalmente del intestino, donde se encontró que el 94% de los peces estaban parasitados por nematodos anisakidos. La PCR multiplex permitió la identificación de la especie A. physeteris (Larva tipo II) y P. decipiens. Conclusiones. Este estudio en el primer reporte del nematodo Anisakidae en Tumaco, Colombia. Estos resultados proporcionan una justificación convincente para un estudio adicional sobre la familia Anisakidae en Colombia, como un problema de salud pública.

Background Cryptosporidium is an apicomplexan zoonotic pathogen primary causing diarrhea in vertebrate hosts notably bovines and humans. Here, we characterized Cryptosporidium isolates by using the GP60 gene fragment of C. parvum to observe the dynamics of cryptosporidiosis transmission in dairy calves from two distant biogeographical regions of Chile (Metropolitan and Los Rios Regions). We collected 72 fecal samples from diarrheic calves screening the parasite carried out microscopy of an acid-fast staining smear and molecular characterization employing PCR to directly detect the Sanger GP60 C. parvum subtype and simultaneously in one selected sample the NGS profile of the GP60 same gene fragment to determine same and/or others Cryptosporidium subtypes Results The IIaA15G2R1 subtype was present in the 100% of the bovine fecal samples studied from Los Rios Region. Along with this same subtype, another two were observed in the Metropolitan Region, IIaA17G2R1 and IIaA17G4R1. The NGS analysis of a single selected GP60 PCR amplicon of one selected sample of our study showed similarly the Sanger sequencing determined subtype, the IIaA17G4R1 in 90% of readable sequences observed. By using this approach another multiple low frequency IIa subtypes of C. parvum were observed confirming that in an infected host multiple subtypes of the parasite can be present. Conclusions Cryptosporidiosis in these dairy farms calves in Chile is produced by C. parvum limited number of subtypes, being IIaA15G2R1 the most frequent. The IIa subtype family is considered prevalent in calves in South America. Subtypes IIaA17G2R1 and IIaA17G4R1 had been worldwide distribution. As all C. parvum subtypes observed in calves in Chile were isolated from diarrheic animals, so, it can be possible to relate its presence with the pathogenic role in the bovine host and with a potential digestive disease risk for humans.