Parasitological and molecular survey of scattered parasitism by trichomonads in some avian species in Iran.

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.

Evaluating the resistance of eimeria spp. Field isolates to anticoccidial drugs using three different indices.

BACKGROUND: In this study, the presence of resistance to diclazuril, amprolium+ethopabate and salinomycin, representing some of the commonest anticoccidials in Iran's poultry industry, against three mixed Eimeria field isolates were investigated. METHODS: Three Eimeria field isolates, collected from typical broiler farms in Iran, were propagated once, inoculated to 480 broilers, comprising 30 chicks in each treatment. The non-medicated or medicated diets containing one of the above mentioned anticoccidials were provided ad-lib. Drug efficacy was determined using the Global index (GI), Anticoccidial Sensitivity Test (AST) and Optimum Anticoccidial Activity (OAA). RESULTS: None of the field isolates were fully sensitive to the selected anticoccidials. All isolates showed reduced sensitivity/partial resistance to salinomycin. Resistance to amprolium+ethopabate was evident and partial to complete resistance was recorded for diclazuril. CONCLUSION: Limited efficacy of the selected anticoccidials is obvious. Considering the cost of continuous use of anticoccidials in the field, altering the prevention strategy and rotation of the anticoccidials with better efficacy, would prevent further economic losses induced by coccidiosis.

Biopathologic Characterization of Three Mixed Poultry Eimeria spp. Isolates.

BACKGROUND: Coccidiosis of domestic fowl, caused by species of the Genus Eimeria, is responsible for important economic losses in poultry production. Because different species and/or strains can vary in pathogenicity and other biological parameters, their precise characterization is important for epizootiological studies. METHODS: Fifty samples from litter, whole intestinal tract and feces were collected from poultry houses located in different provinces of Iran. One hundred twenty male day-old broiler chicks were challenged with three selected isolates. Data on weight gain, Food Conversion Ratio (FCR), food intake, lesion scoring and shedding of oocysts per gram of feces were recorded and analyzed by the Duncan's test. RESULTS: In all treatments, the challenged groups had statistically significant lower weight gain than that of unchallenged control group. Isolate three caused the lowest weight gain and food intake and the worst lesion score as well as FCR. Despite originating from close geographical regions for isolates 1 and 2, the difference in biopathologic factors may be either due to different proportion of identified species or the different pathogenicity of the species present in the isolates. CONCLUSION: The results highlight the importance of considering various species of Eimeria in designing the preventive, control and treatment strategies to prevent coccidiosis in different regions of Iran. Further characterization of each isolate would be the next step to provide a basis for coccidiosis research with well-characterized local isolates.

The housefly, Musca domestica, as a possible mechanical vector of Newcastle disease virus in the laboratory and field.

Newcastle disease (Paramyxoviridae) is a highly infectious virus shed in the faeces of infected birds. Non-biting Muscid flies characteristically visit manure and decaying organic material to feed and oviposit, and may contribute to disease transmission. The housefly, Musca domestica (Linnaeus, 1758) (Diptera: Muscidae), has been implicated as a mechanical vector of numerous pathogens. In this study 2000 aerial net-captured houseflies were examined for their ability to harbour Newcastle disease virus (NDV). In an adjacent study, laboratory-reared flies were experimentally exposed to NDV La Sota strain. The virus was detected in the dissected gastrointestinal tract of laboratory-exposed flies for up to 72 h post-exposure, whereas the untreated control flies were negative.