Identification of optimal regions for phylogenetic studies on VP1 gene of foot-and-mouth disease virus: analysis of types A and O Argentinean viruses

An analysis of the informative content of sequence stretches on the foot-and-mouth disease virus (FMDV) VPI gene was applied to two important viral serotypes: A and O. Several sequence regions were identified to allow the reconstruction of phylogenetic trees equivalent to those derived from the whole VPI gene. The optimal informative regions for sequence windows of 150 to 250 nt were predicted between positions 250 and 550 of the gene. The sequences spanning the 250 nt of the 3' end (positions 400 to 650), extensively used for FMDV phylogenetic analyses, showed a lower informative content. In spite of this, the use of sequences from this region allowed the derivation of phylogenetic trees for type A and type O FMDVs which showed topologies similar to those previously reported for the whole VP1 gene. When the sequences determined for viruses isolated in Argentina, between 1990 and 1993, were included in these analyses, the results obtained revealed features of the circulation of type A and type O viruses in the field, in the months that preceded the eradication of the disease in this country. Type A viruses were closely related to an Argentinean vaccine strain, and defined an independent cluster within this serotype. Among the type O viruses analysed, two groups were distinguished; one was closely related to the South American vaccine strains, while the other was grouped with viruses of the O3 subtype. In addition, a detailed phylogeny for type A FMDV is presented.     

Oral anatomy of the dog and cat in veterinary dentistry practice.

The study of anatomy is important to accomplish any kind of surgical and medical procedure and to understand the physiology and diseases of animals. It is no different in veterinary dentistry. The study of oral anatomy helps the veterinarian to accomplish any kind of surgical procedure more quickly and with less damage to tissues, especially in cases of major oral surgery. In fact, under-standing the anatomy is easier when this knowledge is acquired directly, with surgical application. This article describes the essentials of the oral anatomy of the dog and cat, correlating this knowledge with the dental procedures to be used by veterinarians as a guide.     

An in vitro study of hematopoietic progenitor cells from peripheral blood of rabbits

The purpose of this study was to isolate and cultivate a subpopulation of pluripotent stem cells (PSCs) from the peripheral blood of rabbits, which are frequently used in veterinary research as an animal model. Pluripotent stem cells, as described in human beings, are fibroblast-like cells that exhibit a CD34 marker, specific from other hematopoietic stem cells. Commonly used human commercial media has been researched for culturing rabbit PSCs. These findings allow us to contemplate the direct application of this simple and standardized methodology in several areas of study, such as of the pharmacological effect of many drugs on hematopoietic cells, veterinary practice, and even the study of new strategies in cellular therapy for some human diseases.     

Evaluation of Natural Chemical Compounds Against Root-lesion and Root-knot Nematodes and Side-effects on the Infectivity of Arbuscular Mycorrhizal Fungi

The survival of two species of plant parasitic nematodes: the root-lesion nematode Pratylenchus brachyurus, and the root-knot nematode Meloidogyne javanica, was evaluated in saturated atmospheres of 12 natural chemical compounds. The infectivity of two isolates of arbuscular mycorrhizal fungi: Glomus mosseae and Glomus intraradices, under identical experimental conditions, was also determined. All the compounds tested exerted a highly significant control against M. javanica and among them, benzaldehyde, salicilaldehyde, borneol, p-anisaldehyde and cinnamaldehyde caused a mortality rate above 50% over P. brachyurus. The infectivity of G. intraradices was inhibited by cinnamaldehyde, salicilaldehyde, thymol, carvacrol, p-anisaldehyde, and benzaldehyde, while only cinnamaldehyde and thymol significantly inhibited mycorrhizal colonization by G. mosseae.     

Multispecies and multiple anthelmintic resistance on cattle nematodes in a farm in Argentina: the beginning of high resistance?

There are very few resistance records on cattle nematodes. South American successive records have been increasing rapidly since the year 2000. In Argentina, increasing dissatisfaction based on the exclusive use of macrocyclic lactones has prompted the use of benzimidazoles in the Pampean region. The studied farm is located in the Argentina humid Pampas and had apparently poor results after anthelmintic treatments. Evaluation of resistance was firstly based on faecal egg reduction after treatment in November 2001 and June 2002 and was complemented with worm counts obtained by necropsy in June 2002. The study reports that the reduction of faecal egg excretion after benzimidazole (reduction 31-79%) or ivermectin treatments (76-97%) in November 2001 was insufficient and these poor results were confirmed in June 2002 (benzimidazoles (65-89%) and ivermectin (47-77%)). Several methods for evaluating faecal egg count reduction were performed and yielded different results. A new method based on the estimated faecal egg counts (corrected from the initial faecal egg counts and animal type using a general linear model) was used and gave higher flexibility in the interpretation of putative resistance to anthelmintics. From necropsy results, it could be concluded that Cooperia oncophora was resistant to avermectins and benzimidazoles and that Cooperia punctata, Ostertagia ostertagi and Haemonchus placei were resistant to benzimidazoles. This case of multispecies and multidrug resistance is probably not unique and could reflect the emergence of resistances in Argentina. This emergence is probably due to the intensive use of anthelmintics, the absence of refugia, and the frequent circulation of infected cattle.     

Coinfection by Cryptosporidium parvum and porcine circovirus type 2 in weaned pigs

Routine histopathological diagnosis of one representative 3-month-old pig from a group suffering from diarrhoea revealed a massive degree of parasitation by Cryptosporidium parvum, with a concomitant infection by porcine circovirus type 2 (PCV2), that was confirmed by immunohistochemical procedures. The areas of intestine where parasites were more numerous presented abundant PCV2 infected cells in mucosa and submucosa. The concurrence of C. parvum, a rare primary intestinal pathogen in post-weaning and growing pigs, and PCV2 infections suggest an increased susceptibility as a result of an immunosuppression state.     

Maxillary dentigerous cyst in a cat

A dentigerous cyst was diagnosed in the right rostral maxilla of a 6-month-old Siamese cat affecting the maxillary right canine tooth. The deciduous maxillary right canine tooth was extracted and the dentigerous cyst wall was curetted. The permanent tooth was not removed, however it was mobile following the surgical procedure. Examination 6-months following surgery indicated appropriate development of the tooth with no mobility or periodontal pocket formation. The maxillary right canine tooth had an abnormal shape but was functional with an acceptable appearance.     

Disseminated pythiosis in three horses

Three cases of equine subcutaneous pythiosis with dissemination to the internal organs were investigated. The subcutaneous lesions were observed on the mammary gland, nostrils and limbs of the infected horses. Histopathological analysis of the infected tissues revealed a strong eosinophilic reaction, with macrophages, mast cells and giant cells. Sparsely septated hyphal filaments of 4-6 microm diameter were identified in the center of the eosinophilic areas. Specific fluorescent antibody against Pythium insidiosum confirmed the hyphae in the infected tissues in three examined horses. In one of the three cases, the DNA sequences amplified from the infected subcutaneous tissues and internal organs, revealed that P. insidiosum's 18S SSU rDNA amplicons shared 100% identity with those sequences deposit in GenBank. This is the first report confirming by immunochemical and genetic techniques that P. insidiosum can disseminated from superficial to deep structures.