Seroprevalence of Rift Valley fever virus in cattle in the Democratic Republic of the Congo

Tropical Animal Health and Production - This study aimed at assessing the serological and virological status of Rift Valley fever virus (RVFV) in cattle from four climatically diverse zones of the...     

Tissue composition and allometric growth of carcass of lambs Santa Inês and crossbreed with breed Dorper

Tropical Animal Health and Production - This study aimed to assess the tissue composition and allometric growth of carcasses of Santa Inês and crossbred Dorper x Santa Inês lambs confined...     

Summer-grown seed potatoes: an attempt to produce seed for the spring season in Israel

Seed potatoes were grown in Israel during summer (June-October) at Ramat haNegev (the Negev plateau). This is the hottest season in the semi-arid climate prevailing in the region. Because of the high temperature, no tuberization occurred in cv. ‘Up-to-Date; and ‘Draga’ and ‘Cara’ showed a marked yield reduction. Reasonable yields were, however, obtained at Ramat haNegev during summer growth with the cvs. ‘Désirée’, ‘Blanka’, ‘Spunta’ and ‘Alpha’. At Bet Dagan (coastal plain) Désirée grown during summer met with many problems and yields were negligible, probably because of the higher night temperature as compared with Ramat haNegev. Growth during summer in Ramat haNegev offers the advantages of relative isolation from other potato fields (potatoes are not grown in summer) and low aphid activity, in contrast to the common growing seasons — spring and autumn. Insecticide application and planting high quality seeds — imported elite or Class A — in summer, reduced potato leaf roll virus (PLRV) infection to an average of 4.5% in 1984 and 1.8% in 1985, in comparison with an average of 20.8% in 1979, when poor quality seeds were used and no insecticides were applied. Infection with potato virus Y (PVY) was 1.7% in 1984 and 0.1% in 1985. The yielding capacity in spring 1980 of seed potato produced at Ramat haNegev in the summer of 1979, was significantly lower than that of imported and Golan Heights seed. This is attributed mainly to the high level of virus infection of the former seeds. PLRV-free seed potatoes from the same batch yielded similarly to imported seed potatoes or seed potatoes from the Golan Heights. This was reconfirmed in the 1985 experiment in which Ramat haNegev seeds were much less infected with PLRV and produced yields similar to the imported and Golan ones. Seed potatoes from Ramat haNegev behave like young seeds when planted in the spring. Therefore, their yielding capacity probably increases the earlier the harvest and the longer the subsequent growing period.     

The use of insecticides to control potato leafroll virus in seed-potato crops on the Golan Heights

Experiments were carried out in the laboratory and in the field for 3 years, in an attempt to protect seed-potato crops on the Golan Heights from potato leafroll virus (PLRV) by means of insecticides. The best results with spray compounds were obtained with pirimicarb (Pirimor), methamidophos (Tamaron) and ethiofencarb (Croneton); the commonly used and recommended aphicides oxydemetonmethyl (Metasystox R) and endosulfan (Thionex) were less efficient. The best results with granular insecticides were obtained with aldicarb (Temik) and ethiofencarb, while phorate (Thimet), carbofuran (CURATERR) and oxamyl (Vydate) were much less efficient. Dimethoate (Rogor) gave good results in the laboratory test, but was less efficient in the field trials. The flight of aphids in the Golan Heights is characterized by two close peaks: in May-June, and from late July to September. Potatoes are planted in early May, and hence crops need to be protected throughout almost the entire season. Weekly sprays using, in turn, pirimicarb, methamidophos and ethiofencarb, reduced PLRV incidence in seed-potato plots in 1977 from 33.4% (in the untreated controls) to 2.8%, thus ensuring their certification. A single pre-emergence treatment with aldicarb reduced PLRV incidence from 12.6% (in the untreated controls) to 1.8%; however, the best results (no infection) were obtained by the addition of weekly sprays, starting at the end of July, to a pre-emergence treatment with a granular insecticide.     

Toxoplasma gondii in edible fishes captured in the Mediterranean basin

The issue of whether market fish can be involved in the transmission of Toxoplasma gondii in the marine environment is highly debated since toxoplasmosis has been diagnosed frequently in cetaceans stranded along the Mediterranean coastlines in recent times. To support the hypothesis that fishes can harbour and effectively transmit the parasite to top‐of‐the‐food‐chain marine organisms and to human consumers of fishery products, a total of 1,293 fishes from 17 species obtained from wholesale and local fish markets were examined for T. gondii DNA. Real‐time PCR was performed in samples obtained by separately pooling intestines, gills and skin/muscles collected from each fish species. Thirty‐two out of 147 pooled samples from 12 different fish species were found contaminated with T. gondii DNA that was detected in 16 samples of skin/muscle and in 11 samples of both intestine and gills. Quantitative analysis of amplified DNA performed by both real‐time PCR and digital PCR (dPCR) confirmed that positive fish samples were contaminated with Toxoplasma genomic DNA to an extent of 6.10 × 10^?2 to 2.77 × 10⁴ copies/ml (quantitative PCR) and of 1 to 5.7 × 10⁴ copies/ml (dPCR). Fishes are not considered competent biological hosts for T. gondii; nonetheless, they can be contaminated with T. gondii oocysts flowing via freshwater run‐offs (untreated sewage discharges, soil flooding) into the marine environment, thus acting as mechanical carriers. Although the detection of viable and infective T. gondii oocysts was not the objective of this investigation, the results here reported suggest that fish species sold for human consumption can be accidentally involved in the transmission route of the parasite in the marine environment and that the risk of foodborne transmission of toxoplasmosis to fish consumers should be further investigated.     

In vivo morphological and antigenic characteristics of Photobacterium damselae subsp. piscicida

The present study was conducted to examine the morphology and antigenicity of Photobacterium damselae subsp. piscicida by culturing the bacterium in vivo in the peritoneal cavity of sea bass (Dicentrarchus labrax) within dialysis bags with either a low molecular weight (LMW) cut-off of 25 kDa or a high molecular weight (HMW) cut-off of 300 kDa. Differences were observed in the growth rate between the bacteria cultured in vivo or in vitro. Bacteria cultured in vivo were smaller and produced a capsular layer, which was more prominent in bacteria cultured in the HMW bag. Antigenicity was examined by Western blot analysis using sera from sea bass injected with live Ph. d. subsp. piscicida. The sera recognised bands at 45 and 20 kDa in bacteria cultured in vivo in the LMW bag. Bacteria cultured in vivo in the HMW bag did not express the 45 kDa band when whole cell extracts were examined, although the antigen was present in their extracellular products. In addition, these bacteria had a band at 18 kDa rather than 20 kDa. Differences in glycoprotein were also evident between bacteria cultured in vitro and in vivo. Bacteria cultured in vitro in LMW and HMW bags displayed a single 26 kDa band. Bacteria cultured in the LMW bag in vivo displayed bands at 26 and 27 kDa, while bacteria cultured in vivo in the HMW bag possessed only the 27 kDa band. These bands may represent sialic acid. The significance of the changes observed in the bacterium''s structure and antigenicity when cultured in vivo is discussed.     

PET AND CAPTIVE BIRDS AS POTENTIAL RESERVOIRS OF ZOONOTIC BACTERIA

Thermophilic Campylobacter spp. and Salmonella spp. are zoonotic bacteria, commonly harbored in the enteric tract of avian species. This survey aimed at verifying the presence of these microorganisms in a heterogeneous Italian population of pet birds and captive birds of prey (e.g., Passeriformes, Psittaciformes, Accipitriformes, Falconiformes, and Strigiformes) that live in close contact with humans. A total of 151 individuals were tested for thermophilic Campylobacter spp. and 444 for Salmonella spp. Six C. jejuni and one S. Livingstone were isolated from birds of prey: 4 Accipitriformes (2 Buteo regalis, 2 Parabuteo unicinctus), 1 Falconiformes (Falco peregrinus) and 1 Strigiformes (Strix aluco) were positive for C. jejuni, and 1 Falconiformes (Falco peregrinus) for S. Livingstone. Five C. jejuni strains were genotyped by Multilocus Sequence Typing (MLST) and identified as ST 2116, assigned to ST-353 CC. Results of this study suggest that these microorganisms are not common inhabitants of the digestive tract of pet birds and captive birds of prey, but occasional findings. However, as potential reservoirs of zoonotic bacteria, pet birds should be monitored in order to preserve human health.     

MESENTERIC HETEROTOPIC OSSIFICANS IN A FERRET (MUSTELA PUTORIUS FURO): A RARE CAUSE OF SOFT TISSUE OSSIFICATION

Heterotopic ossification (HO) is a rare condition characterized by abnormal bone production in soft tissue. Very few cases of HO have been reported in animals (e.g., dogs and horses) and this disease process is often a consequence of a traumatic incident. A 5-year-old, male European ferret (Mustela putorius furo) was referred for anorexia, generalized weakness, and weight loss. Clinical examination revealed multiple abdominal masses. An explorative laparotomy identified omental, white/tan, nodular to coalescing hard lesions. The omentum and spleen were surgically removed during the surgical procedure, with both subsequently submitted for histopathologic evaluation. Microscopically, the omental masses were composed of a meshwork of lamellar and woven bone admixed with islands of cartilage and lacunae containing either blood, fat, and/or bone marrow. Multifocal mineralization and bone lamellae were also present in the grossly normal omentum. The finding of multiple bone nodules containing bone marrow and/or adipose tissue, with no Harversian system, and minimal intratrabecular connective tissue favored a diagnosis of HO.