Historical perspectives and current global challenges of Trichinella and trichinellosis

Trichinella spiralis and related species of Trichinella have had a long history of causing human disease, and as a foodborne pathogen have had a major impact on international commerce of pork and other meat animal species which are known to transmit the parasite. Our knowledge of Trichinella has increased substantially over the past few years particularly in the areas of phylogeny, host diversity, epidemiology and control. In this paper, we provide a brief overview of our understanding of Trichinella from its discovery to present time. Past and current challenges of the control of Trichinella and trichinellosis are summarized. As editors of this special issue of Veterinary Parasitology, we introduce a series of invited review articles prepared by experts from around the world, summarizing recent knowledge in Trichinella and trichinellosis.     

Ureaform as a Slow Release Fertilizer: A Review

Ureaform (UF) is a condensation product between urea and formaldehyde consisting of short chains from methylene-diurea to tetramethylenepentaurea. The rate of nitrogen release is mainly related to chain solubility. The mineralization of UF is governed by microbial activity. A wide spectrum of organisms is known to be involved. The degradation is mainly influenced by the biological fertility of the soil, temperature and to a limited degree by moisture, whereas pH and particle size have no pronounced effect. The importance of the activity index (A.I.) as a unit to evaluate the quality of an UF product and the versatility of the UF system in general are discussed. More recent trial results with UF products show the beneficial effects of the particular kind of slow release nitrogen fertilizer in meeting needs for improved fertility management and reduced pollution of drainage waters.     

The origin of rhizomania resistance in sugar beet

In the last 35 years, breeding has greatly reduced the damages caused by rhizomania in sugar beet crops. After the first encouraging results using the Alba genotypes, the cultivar Rizor represented a substantial step forward and has given good yield improvement in diseased fields in many parts of the world. The original variety and subsequent improved versions continued to offer good performances for about a decade, after which it was surpassed by other hybrids derived in part from the Rizor itself. Further progress in terms of sugar production became possible in 1986, when the Holly monogerm lines were released in USA and Europe. In spite of the incomplete information about the genealogy of the first resistant materials,many evidences and the molecular analyses on the different genotypes suggest a possible common progenitor and lineage. The resistant cultivars have kept the yield at an adequate level, allowing cultivation to continue in countries where the disease has reached epidemic proportions. The case of rhizomania resistance in sugar beet can therefore be considered as one of the most important achievements in plant breeding. This revised version was published online in August 2006 with corrections to the Cover Date.     

Stimulation of acidic reduction of nitrite to nitric oxide by soybean phenolics: possible relevance to gastrointestinal host defense

This study aimed to evaluate the potential of soybean-promoted acidic nitrite reduction and to correlate this activity with the content of phenolics and with the bactericidal activity against Escherichia coli O157:H7. Extracts of embrionary axes and cotyledons enriched in phenolics increased ?NO formation at acidic pH at values that were 7.1 and 4.5 times higher, respectively, when compared to the reduction of the nonenriched extracts. Among the various phenolics accumulated in the soybean extracts, five stimulated nitrite reduction in the following decreasing order of potency: epicatechin gallate, chlorogenic acid, caffeic acid, galic acid and p-coumaric acid. Extracts of embrionary axes presented higher contents of epicatechin gallate and caffeic acid, compared to that of cotyledons, indicating a positive correlation between activity of the extracts and content of phenolics with regard to nitrite reducing activity. Soybean extracts enriched in phenolics interacted synergistically with acidified nitrite to prevent E. coli O157:H7 growth. The results suggest that soybean phenolics may interfere with the metabolism of ?NO in an acidic environment by accelerating the reduction of nitrite, with a potential antimicrobial effect in the stomach.     

Disseminated fungal infection in two species of captive sharks

In this report, two cases of systemic mycosis in captive sharks are characterized. These cases were progressive and ultimately culminated in terminal disease. Paecilomyces lilacinus, an uncommon pathogen in human and veterinary medicine, was associated with areas of necrosis in the liver, heart, and gill in a great hammerhead shark (Sphyrna mokarran). Fungal growth was observed from samples of kidney, spleen, spinal fluid, and coelomic cavity swabs. Dual fungal infection by Exophiala pisciphila and Mucor circinelloides was diagnosed in a juvenile zebra shark (Stegostoma fasciatum). Both fungi were present in the liver, with more severe tissue destruction associated with E. pisciphila. E. pisciphila also produced significant necrosis in the spleen and gill, while M. circinelloides was associated with only minimal tissue changes in the heart. Fungal cultures from liver, kidney, and spleen were positive for both E. pisciphila and M. circinelloides. Identification of P. lilacinus and M. circinelloides was based on colonial and hyphal morphology. E. pisciphila was identified by sequence analysis of the 28S rRNA D1/D2 region and the internal transcribed spacer (ITS) region between the 18S and 28S rRNA subunit. These cases, and a lack of information in the literature, highlight the need for further research and diagnostic sampling to further characterize the host-pathogen interaction between elasmobranchs and fungi.     

Association of eosinophilic myositis with an unusual species of Sarcocystis in a beef cow.

The carcass of a mature cow had numerous, disseminated lesions typical of eosinophilic myositis. To elucidate the nature and possible cause of the lesions, histological sections were examined by light microscopy and selected areas were removed and processed for electron microscopy. The lesions were granulomatous in nature. Each granuloma contained at its centre an intact or ruptured sarcocyst associated with degenerate muscle fibers. Surrounding this was a layer of epithelioid cells and an intense accumulation of inflammatory cells, most of which were eosinophils. The primary cyst wall of the sarcocysts in these granulomas consisted of hair-like protrusions that featured many unusual electron-dense bodies. Sarcocysts with ultrastructures characteristic of Sarcocystis cruzi and Sarcocystis hirsuta were also present in muscle from the same animal, but these sarcocysts lacked any associated cellular responses. The eosinophilic myositis in this case appeared to be associated with sarcocystosis of an unknown species. Possibly, the inflammatory reaction was due to the host-parasite interaction in an unusual host.     

Facial reconstructive surgery

Reconstruction of facial defects can be very challenging, even in the hands of an experienced surgeon. Most defects can be repaired using local available tissues. Lip defects can be reconstructed using geometric closure techniques and advancement of local tissues. Forehead defects can be reconstructed using skin grafts, caudal auricular flaps, or rotational or transposition flaps. Care must be taken to minimize tension on eyelids and maintain the integrity of the facial nerve. Cheek defects can be reconstructed using local advancement, superficial temporal, omocervical, and caudal auricular flaps. The bridge of the nose can be very difficult to reconstruct due to a paucity of local tissues; however, skin grafts, indirect pedicle flaps, and superficial temporal flaps can be considered. .     

Fatal enterocolitis in harbour seals (Phoca vitulina) caused by infection with Eimeria phocae

Coccidiosis due to Eimeria phocae infection has been described in harbour seals (Phoca vitulina) from the western Atlantic population, but not in any detail in seals from the eastern Atlantic population. This paper describes fatal enterocolitis due to E phocae infection in three juvenile harbour seals at a rehabilitation centre in the Netherlands in July 2003. The clinical signs were lethargy, bloody faeces, and intermittent convulsions and muscle tremors just before they died; the nervous signs resembled those of nervous coccidiosis in calves. The main pathological finding was severe, diffuse, haemorrhagic enterocolitis; there were diffuse inflammatory changes in the lamina propria of the jejunal, ileal, caecal and colonic mucosa that were associated with the presence of the sexual stages and oocysts of a coccidian species identified as E phocae. A retrospective microscopical examination of intestinal tissues from 113 harbour seals that had died between 1999 and 2004 revealed one seal that was positive for E phocae.     

Resection of inflammatory polyps in dogs using laparoscopic-assisted cystoscopy

Inflammatory polyps in the urinary bladder of two dogs were removed via laparoscopic-assisted cystoscopy. In addition, one dog had a calculus removed and liver biopsies taken using the same two trocar sites. The laparoscopic-assisted cystoscopic technique provided clear surgical margins and permitted a thorough examination of the inside of the bladder and urethra. The technique was minimally invasive, produced little abdominal injury, and limited urine contamination of the abdomen.