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 Sheather's 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).

Helminth infections in chickens (Gallus domesticus) raised in different production systems in Brazil.

The current study evaluated helminth infections in birds raised in different production systems for different purposes (extensive/dual-purpose, semi-intensive/broiler, semi-intensive/hen, intensive/hen and intensive/broiler) in Brazil. A total of 374 birds was assessed for helminths at necropsy using standard parasitological methods. During the necropsies, organs from the gastrointestinal tract (crop, esophagus, proventriculus, gizzard, small intestine, large intestine and ceca) of each bird were collected and the contents fixed in 70% ethanol. Additionally, the trachea and eyes were assessed for the presence of helminths. The small intestine was examined using a methodology that allowed the recovery of cestode scolices attached to the intestinal mucosa. Stereomicroscopy and optical microscopy were used to detect and identify helminth species based on their morphological characteristics. Fifteen helminth species were found among birds from the different systems. The extensive system presented the highest number of helminth species (six cestodes, seven nematodes and one trematode) and the highest number of parasites (mean helminths/bird), followed by the semi-intensive system (broiler: six cestode and four nematode species; hens: five cestode and three nematode species). Hens from the intensive system were parasitized by five cestode, four nematode and one trematode species. No parasites were detected in broilers raised in the intensive systems. The results obtained in this study highlight the need for special attention and the implementation of biosecurity measures for the prevention of helminth infections in intensive systems (hens) and particularly in extensive and semi-intensive alternative poultry production systems.

Multidrug and multispecies resistance in sheep flocks from São Paulo state, Brazil.

The economic importance of sheep production is increasing worldwide simultaneously with the emergence of parasitic resistance. This study aimed to survey the current situation of management practices and parasite resistance in sheep flocks in São Paulo state, Brazil. A questionnaire was given to 35 sheep farmers to obtain information related to flock management practices. Of these flocks, 30 were submitted to the fecal egg count reduction test (FECRT) with at least one of the five following anthelmintics: albendazole, closantel, ivermectin, levamisole, and moxidectin, for comparison against an untreated control group. In the survey, the median number animals per flock was 301, mainly of the Santa Ines breed (in 75.8% of the flocks) and crossbred animals (in 54.5% of the flocks). The predominant farming system was semi-intensive (82.9%), using rotational grazing (80%). Selective treatment was based on FAMACHA grade (47.1%) and in clinical signs (41.2%). The most often applied anthelmintics were macrocyclic lactones (42.9-54.2% in the last three applications). Considering the anthelmintics employed in this study, 10.7% of the farms' flocks were resistant to three, 35.7% to four, and 53.6% to all five anthelmintics. The main helminth genera observed before and after treatments were Haemonchus sp. (75.8%) and Trichostrongylus sp. (19.1%), but all observed genera (Cooperia sp., Oesophagostomum sp., and Strongyloides sp.) were detected by the FECRT. Considering efficacy values less than or equal to 90% in the FECRT as resistant, 100% of flocks were resistant to albendazole and ivermectin, 96.6% to moxidectin, 92.9% to closantel, and 53.6% to levamisole. It is thus possible to conclude that multidrug resistance is widespread in sheep flocks in São Paulo state, Brazil, and this involves all prevalent helminth genera.