Enterocytozoon bieneusi y Giardia duodenalis son considerados como los parásitos intestinales más comunes de seres humanos, animales domésticos, silvestres y en cautiverio. Estos patógenos son responsables de causar diarrea en individuos inmunocomprometidos e inmunocompetentes. El presente estudio tuvo por objetivo identificar los genotipos de E. bieneusi y G. duodenalis en muestras de heces de crías de alpaca. Las muestras de heces usadas en el estudio correspondieron a 126 crías de alpaca de 1 a 30 días de edad, de tres regiones geográficas en los andes del Perú (Huancavelica, Cuzco y Puno). Para el diagnostico se amplifico mediante PCR anidado la región espaciador transcrito interno (ITS) del gen ARNr de E. bieneusi, así como el locus triosafosfato isomerasa (TPI) de G. duodenalis. Todas las muestras positivas (E. bieneusi = 65; G. duodenalis = 42) fueron secuenciadas. Sesenta y cinco crías (51.6%) resultaron ser positivas en el PCR para E. bieneusi. Se encontró diez distintos genotipos de E. bieneusi en los aislamientos de crías de alpaca, seis de los aislamientos pertenecen a nuevos genotipos (ALP1, ALP2, ALP3, ALP4, ALP5 y ALP6). Cinco crías (7.7%) fueron positivos para el genotipo P, cuatro crías (6.2%) fueron positivos para el genotipo Tipo IV, dos (3.1%) al genotipo D, una (1.5%) al genotipo Beb6, 48 (73,8%) al genotipo ALP1, y cinco crías fueron positivos para cada genotipo nuevo (ALP2, ALP3, ALP4, ALP5 y ALP6). Así mismo, cuarenta y dos muestras fueron positivas para G. duodenalis. Los ensamblajes A (n = 33) y E (n = 9) fueron detectados en las crías. El ensamblaje A fue el más frecuentemente en crías de Puno y Huancavelica, mientras que el ensamblaje E se encontró en 8 crías en Cuzco y uno de Huancavelica. El papel potencial de E. bieneusi y G. duodenalis en el síndrome diarreico neonatal de la alpaca necesita ser seriamente considerada y evaluada, a pesar de no haber asociación entre la presencia de los parásitos y la presentación de diarrea. Palabras claves: Enterocytozoon bieneusi, Giardia duodenalis, alpaca, diarrea, zoonosis / --- Enterocytozoon bieneusi and Giardia duodenalis are considered the most common intestinal parasites found in humans and domestic, captive and wild animals. These pathogens are responsible for causing diarrhea in immunocompromised and immunocompetent individuals. The aim of the present study was to identify E. bieneusi and G. duodenalis genotypes in fecal samples from alpaca crias. Fecal samples were collected from 126 alpaca crias up to 30 days of age from three geographic regions in the highland of Peru (Huancavelica, Cuzco and Puno). The internal transcribed spacer (ITS) region of the rRNA gene of E. bieneusi, and the amplification of the triosephosphate isomerase (TPI) locus of G. duodenalis, were amplified for a nestedPCR. All positives samples were sequenced. Sixty-five crias (51.6%) were found to be PCR positive for E. bieneusi. Ten distinct genotypes of E. bieneusi were found in alpaca cria isolates, six of all isolates belong to novel genotypes (ALP1, ALP2, ALP3, ALP4, ALP5, and ALP6). Five (7.7%) crias were positive to genotype P, four (6.2%) crias were positive to genotype Type IV, two (3.1%) to genotype D, one (1.5%) to genotype Beb6, 48 (73.8%) to genotype ALP1, and five crias were positive each to new genotype (ALP2, ALP3, ALP4, ALP5, and ALP6). Forty-two samples were positive for G. duodenalis. Assemblages A (n=33) and E (n=9) were detected in crias, Assemblage A was the most frequently found in Puno and Huancavelica, while Assemblage E was found in 8 crias in Cuzco and one from Huancavelica. The potential role of E. bieneusi and G. duodenalis in the neonatal diarrhea syndrome of alpaca needs to be seriously considered and further evaluated, although had not association between the presence of parasites and diarrhea. Key words: Enterocytozoon bieneusi, Giardia duodenalis, alpaca, diarrhea, zoonosis.

White feces syndrome (WFS) is an emerging problem for penaeid shrimp farming industries in SE Asia countries, Thailand, Malaysia, Vietnam, Indonesia, China, and in India. This occurrence of this syndrome is usually first evidenced by the appearance of white fecal strings floating on surface of the shrimp ponds. The gross signs of affected shrimp include the appearance of a whitish hindgut and loose carapace, and it is associated with reduced feeding and growth retardation. To investigate the nature of the white feces syndrome, samples of white feces and shrimp hepatopancreas tissue were collected from Penaeus vannamei in affected farms in Indonesia, and these were examined histologically. Within the white feces, we found densely packed spores of the microsporidian Enterocytozoon hepatopenaei (abbreviated as EHP) and relatively fewer numbers of rod-shaped bacteria. From WFS ponds, hepatopancreas samples form 30 individual shrimp were analyzed by histology and in situ hybridization. The results showed that all of the shrimp examined were infected with EHP accompanied by septic hepatopancreatic necrosis (SHPN). Midgut epithelial cells were also infected and this increased the number of tissue types being affected by EHP. By PCR, EHP was detected in all the samples analyzed from WFS-affected ponds, but not in those sampled from healthy shrimp ponds. To determine the modes of transmission for this parasite, we performed feeding and cohabitation bioassays, the results showed that EHP can be transmitted through per os feeding of EHP-infected hepatopancreas tissue to healthy shrimp and through cohabitation ofinfected and healthy shrimp. In addition, we found the use of Fumagillin-B, an antimicrobial agent, was ineffective in either reducing or eliminating EHP in infected shrimp.

The Microsporidia are obligate intracellular parasites that have jettisoned oxidation phosphorylative capabilities during their early evolutionary history and so rely on ATP import from their host and glycolysis for their energy needs. Some species form tight associations with the host’s mitochondria and this is thought to facilitate ATP sequestration by the developing intracellular microsporidian. The human parasite, Enterocytozoon bieneusi has however lost glycolytic capabilities and may rely entirely on ATP import from its host for energy. E. bieneusi belongs to the Enterocytozoonidae microsporidian family and recent rDNA-based phylogenetic studies have suggested it has close evolutionary ties with Enterospora canceri, a crab-infecting intranuclear parasite. Such a close evolutionary relationship implied that glycolysis might also be absent in the intranuclear parasite raising questions as to how this parasite obtains energy from its unusual niche that is physically walled off from the host mitochondria, the main source of ATP in the host cell. In this study, draft genomes of four species of the Enterocytozoonidae namely, Ent. canceri, E. hepatopenaei, Hepatospora eriocheir and Hepatospora eriocheir canceri and one non-Enterocytozoonidae species, Thelohania sp. were assembled and annotated (The genome assembly of Hepatospora eriocheir was provided by Dr. Bryony Williams). Phylogenomics performed with this and publicly available genomic data confirmed the close evolutionary ties between Ent. canceri and E. bieneusi. Comparative genomic analyses also revealed that glycolysis is indeed lost in all members of the Enterocytozoonidae family sequenced in this study, hinting to the relaxation of evolutionary pressures to maintain this pathway at the base of this microsporidian family. Despite this absence, the hexokinase gene was retained in all aglycolytic genomes analysed, and that of Ent. canceri was fused to a PTPA gene. Functional assays and yeast complementation assays suggest that this chimera is able to recognise glucose as a substrate but the heterologously expressed homolog of H. eriocheir cannot. Finally, phylogenomics have been used here to demonstrate that despite the morphological differences between three Hepatospora-like organisms parasitizing different crab hosts, they are the same species. This finding adds more weight to current evidence suggesting that morphology is not an ideal marker for taxonomical classification in the Microsporidia.