Giane Serafim da Silva

Detection and characterization of Cryptosporidium species and genotypes in three chicken production systems in Brazil using different molecular diagnosis protocols

The objective of this study was to determine the occurrence of Cryptosporidium spp. in domestic chickens raised in different chicken production systems in Brazil using three nested PCR protocols. The purification and concentration of oocysts present in 190 fecal samples from chickens raised in extensive, semi-intensive and intensive production systems were accomplished by centrifugal flotation in Sheathers solution and were followed by the extraction of genomic DNA. The detection and molecular characterization of Cryptosporidium species and genotypes were performed using three nested polymerase chain reaction (nested PCR) protocols targeting the 18S rRNA gene followed by sequencing of the amplified fragments. Subgenotyping of C. meleagridis was performed using a nested PCR reaction targeting the gp60 gene. Sample identified as Cryptosporidium sp. genetically similar to Cryptosporidium xiaoi and Cryptosporidium bovis by 18S rRNA gene sequencing were further analyzed by nested PCR targeting the actin gene and subsequent sequencing of the amplified fragment. Positive amplification for Cryptosporidium spp. was observed in 12.6% (24/190) of the samples, including C. baileyi (9.8%; 18/190), C. meleagridis (0.5%, 1/190), C. parvum (2.1%; 4/190) and Cryptosporidium sp. (0.5%; 1/190). Subgenotyping of C. meleagridis revealed the presence of the zoonotic subtype IIIgA23G3R1. Sequencing of the 18S rRNA gene and the actin gene fragments revealed a Cryptosporidium genotype in an extensive poultry system genetically related to C. xiaoi and C. bovis. There was no significant difference in the frequency of positive results obtained by the three nested PCR protocols (p > 0.05); additionally, the agreement obtained by Kappa index ranged from substantial (0.70) to almost perfect (0.9).

Método Mello e Campos (1974) adaptado para recuperação de cestódeos de aves (Gallus domesticus)

Arq. Inst. Biol., v.83, 1-5, e0752015, 2016 RESUMO: O diagnóstico específico e a avaliação da intensidade da infecção helmíntica em aves são fundamentais em estudos de eficácia e determinação de doses de medicamentos direcionados ao seu controle. O presente trabalho avaliou a aplicação e adaptação da metodologia de Mello e Campos, descrita originalmente para diagnóstico parasitológico em cães, na recuperação de escólices de cestódeos parasitos de aves domésticas (Gallus domesticus). Foram empregadas 52 aves naturalmente infectadas e oriundas de produções rurais, as quais foram submetidas à necropsia parasitológica, adaptando-se a metodologia Mello e Campos. O método consistiu na realização de quatro etapas: conteúdo, imersão, raspado e avaliação. O número de escólices recuperadas por ave variou de 1 a 4.345, e o maior número de escólices foi recuperado do material oriundo da etapa de imersão. As espécies de cestódeos identificadas foram Amoebotaenia cuneata, Choanotaenia infundibulum, Hymenolepis sp., Raillietina tetragona, Raillietina echinobothrida e Raillietina cesticillus. Os resultados foram avaliados estatisticamente, concluindo-se que a metodologia adotada é eficaz para a recuperação de cestódeos de aves, uma vez que possui a etapa de imersão, que permite a recuperação mais eficiente de escólices.The specific diagnosis and evaluation of the intensity of avian helminth infections are essential for efficacy studies and the determination of drug doses targeted to their control. This study evaluated the Mello and Campos method, originally described for parasitological diagnosis in dogs, in the recovery of scolices from cestode parasites of poultry (Gallus domesticus ). A total of 52 naturally infected birds obtained from farms underwent parasitological necropsy using the Mello and Campos method. The method consisted of four steps: content, soaking, scraping and evaluation. The number of scolices recovered per bird ranged from 1 to 4,345, and the highest number of scolices was recovered from material derived from the soaking step. The cestodes species diagnosed were Amoebotaenia cuneata , Choanotaenia infundibulum , Hymenolepis sp., Raillietina tetragona , Raillietina echinobothrida and Raillietina cesticillus . The Mello and Campos method, originally used to test for helminths in dogs, was effective in avian cestode testing because it includes a soaking step, which enables a more efficient recovery of scolices.