ABSTRACT: Coccidian infection may promote the proliferation of gut bacteria of the family Enterobacteriaceae. Bacterial infections by members of this family in rabbits can induce a negative impact on their health and lead to high mortality, especially in young individuals. This study aimed to investigate the effect of prebiotic treatment on Escherichia coli and Salmonella species during natural intestinal coccidiosis in rabbits. Forty-five rabbits were selected from a rabbit farm in Beni-Suef, Egypt. Out of the 45 rabbits, 15 were coccidia-free and used as the negative control group (NC group) and 30 were naturally infected with coccidia. The infected rabbits were randomly divided into two equal groups, the positive control group (PC) and the prebiotic treated group (PT) which was orally treated with prebiotic for 8 successive days. Faecal oocyst count was assessed daily during the course of treatment. At 8 days post-treatment, 5 rabbits from each group were euthanised for the microbiological examination of the intestinal tract. On day 8 post treatment, the PT group showed a significant (P<0.05) reduction in the oocyst count (5.33 x103 ± 0.89) with a significant (P<0.05) decline in the prevalence of E. coli and Salmonella (66.7 % and 26.4%, respectively). The PC group showed highly a significant oocyst count (21.67x103 ± 0.82 OPG), with a significant increase in the prevalence of E. coli and Salmonella (86.7 % and 46.7 %, respectively). The NC group remained coccidian free and exhibited only E. coli with no Salmonella infection. The in vitro susceptibility test showed that E. coli isolates were highly resistant to most of the tested antimicrobials while Salmonella isolates showed variable resistance profiles. In conclusion, the prebiotic treatment significantly reduced the prevalence of E. coli and Salmonella infections coexisted with intestinal coccidiosis naturally infected rabbits.

Resumo Hepatozoon pyramidumi sp. n. é descrito a partir do sangue da víbora em escamas e quilhas serrilhadas, Echis pyramidum, capturada na Arábia Saudita. Cinco de dez espécimes de víbora examinadas (50%) foram encontradas infectadas com Hepatozoon pyramidumi sp. n. com nível de parasitemia de 20% a 30%. A infecção foi restrita apenas aos eritrócitos. Foram observadas duas formas morfologicamente diferentes de estágios intra-eritrocíticos: gamontes de tamanho pequeno e madura. As formas menores de gamontes apresentaram média de 10,7 × 3,5 μm. Os gamontes maduros apresentaram forma de salsicha, com pequenos polos recurvados, medindo 16,3 × 4,2 μm, em média. Os eritrócitos infectados estavam aumentados de tamanho; seus núcleos encontravam-se deformados e, algumas vezes, deslocados de sua posição central, quando comparados às células normais não-infectadas. Foram observados estágios merogônicos em células endoteliais pulmonares e nas células do parênquima hepático. Os merontes maduros apresentavam 17,8 × 13,6 µm e continham merozoítos em forma de banana com tamanho médio de ~ 15 × 2 µm. A análise filogenética baseada nas sequências SSU rDNA agrupou Hepatozoon pyramidumi sp. n com Hepatozoon spp. detectados em répteis de várias regiões geográficas. Por meio de análises morfológicas e moleculares com espécies intimamente relacionadas, demonstrou-se a singularidade dessa nova espécie de Hepatozoon.

Abstract Hepatozoon pyramidumi sp. n. is described from the blood of the Egyptian saw-scaled viper, Echis pyramidum, captured from Saudi Arabia. Five out of ten viper specimens examined (50%) were found infected with Hepatozoon pyramidumi sp. n. with parasitaemia level ranged from 20-30%. The infection was restricted only to the erythrocytes. Two morphologically different forms of intraerythrocytic stages were observed; small and mature gamonts. The small ganomt with average size of 10.7 × 3.5 μm. Mature gamont was sausage-shaped with recurved poles measuring 16.3 × 4.2 μm in average size. Infected erythrocytes were hypertrophied; their nuclei were deformed and sometimes displaced from their central position in the normal uninfected cell. Merogonic stages were observed in the lung endothelial cell and the liver parenchyma cells. Mature meront was 17.8 × 13.6 µm and contained banana-shaped merozoites with average size of ~15 × 2 µm. Phylogenetic analysis based on the SSU rDNA sequence clustered Hepatozoon pyramidumi sp. n with previously sequenced Hepatozoon spp., most of them infected reptilian hosts without geographic consideration. The morphological and molecular comparison with closely related species proved the taxonomic uniqueness and novelty of the present form.

Myxidium volitans sp. nov. (Myxozoa: Myxidiidae) parasitizing the hypertrophied green-brownish gallbladder of the teleost Dactylopterus volitans, collected in the Atlantic coast near Niterói, Brazil was described based on ultrastructural studies. The spores were fusiform, sometimes slightly crescent-shaped on average 21.7 ± 0.3 µm (mean ± standard deviation) (n = 50) long and 5.6 ± 0.4 µm (n = 30) wide. The spore wall was thin and smooth, comprising two equally-sized valves joined by a hardly visible sutural ridge. Spores containing two pyriform polar capsules (PC) (5.0 ± 0.4 × 2.3 ± 0.3 µm) (n = 30) are situated in each extremity of the spore. The PC wall was composed of hyaline layer (0.20-0.29 µm thick) and by a thin external granular layer. Each PC contains a polar filament (PF) with irregular arrangements that was projected from its apical region to the bases of PC and coiled laterally from bases to the tip of PC. Some regular striations and S-like structures in the periphery of the PFs with four-five irregular sections were observed. Based on the spore morphology, ultrastructural differences and the specificity of the host we describe this parasite as a new myxosporidian, named M. volitans sp. nov.