Genetic diversity of human zoonotic leishmaniasis in Iberian Peninsula

Leishmaniasis caused by Leishmania (Leishmania) infantum is a zoonotic disease endemic in South Europe, from Portugal to the Middle East. The aim of the present study was to investigate the genetic diversity of L. infantum parasites in Iberian Peninsula. Twenty-four L. infantum strains isolated from immunocompetent patients with leishmaniasis from several localities of Portugal and Spain were studied. The use of kinetoplast DNA-PCR-restriction fragment length polymorphism as a molecular marker revealed intra-specific variation. No association was found between genotype and clinical form of the disease or patients age group. Two main clusters were identified with this marker: (i) zymodeme MON-1 strains and (ii) non-MON-1 strains. However, no association was found between strains variability and geographical distribution suggesting that parasite populations of different regions in the Iberian Peninsula are homogenous.     

Feline retroviruses: a brief review

Representatives of all three retrovirus subfamilies are recognized in the cat: feline leukaemia virus (an Oncovirus), feline syncytium-forming virus (a Spumavirus) and feline immunodeficiency virus (a Lentivirus). Each of these is briefly reviewed.     

Scrapie: Report of an outbreak and brief review

An outbreak of scrapie in western Canada is described. The disease was confirmed in seven sheep, all originating from the same flock; six were Suffolk ewes and one was a Hampshire ewe. The main clinical signs were pruritus with a positive “nibbling reflex”, weight loss and seizures precipitated by handling or excitement. At presentation four ewes were between 35 and 38 months of age; two were approximately four years old and the oldest was six years old. No evidence of scrapie was seen in six goats on the original farm. The clinical signs, epizootiology, pathology, and pathogenesis of the disease are reviewed.     

Rotaviral diarrhea in pigs: brief review.

Rotavirus is a name given to a group of viruses that have similar characteristics and are generally capable of causing diarrhea in the young. Infection of pigs with porcine rotavirus is common and widespread and can result in diarrhea, especially in 1- to 4-week-old pigs. This virus is frequently associated with a diarrheal syndrome popularity known as "white scours," "milk scours," or "3-week-old scours." Pigs less than 1 week old are infrequently infected, presumably because of adequate passive immunity. The infection resembles enzootic transmissible gastroenteritis. Diagnosis can be made by immunofluorescent staining of mucosal scrappings from the small intestines.     

中国基干鸟类综述

"基于鸟类(basal birds)"为一种类数量相对较少的化石鸟类,基干鸟类较另一鸟类群--"鸟胸类(Ornithothoraces)"原始;鸟胸类(包括现生鸟类和反鸟类)为一类种类数量很大、具有同一祖先、且来源于基干鸟类的鸟类群.在过去的15年里,共有产自中国的8个属、12个有效种基干鸟类发表,而产自的德国的始祖鸟为唯一的非中国产基干鸟类;当然,孔子鸟化石也发现于朝鲜.本文对产自中国的基干鸟类的形态学、系统发生和生态学进行了简单的综述.中国的化石材料对科学地了解鸟类的早期演化具有重要意义,揭示了基干鸟类个体相对较大、形态特征和生态环境变异也相对较大等特点.尽管有些明显的不确定因素的存在(例如热河鸟、会鸟和中鸟的相对系统关系存有争议),但是由于中国化石材料的存在,鸟类早期演化的真实场景已经愈加清晰.     

Feline immunodeficiency virus: a brief review.

Feline immunodeficiency virus (FIV), previously known as feline T-lymphotropic lentivirus (FTLV), was first described by Pedersen et al. (1987) who isolated the virus from cats with a variety of clinical signs suggestive of immunodeficiency. Since then FIV has become one of the most studied feline viruses, not least because of its similarity to human immunodeficiency viruses (HIV) which cause acquired immunodeficiency syndrome (AIDS) in man.     

Conventional and marked BHV-1 vaccines in Germany: a brief review

Since 1997 infections of cattle with bovine herpesvirus type 1 (BHV-1) are regulated by the German government with obligatory measures. Eradication of the virus is based on two different concepts: German federal states with a low BHV-1-seroprevalence comply with a selection concept, that provides deletion of BHV-1-positive cattle and only exceptional vaccination. States with a high BHV-1-prevalence attempt to eradicate the virus using the marker concept. The marker concept is based on the vaccination with glycoprotein E (gE)-deleted marker vaccines and the accompanying serological differentiation between vaccinated and infected animals. This review deals with both, conventional and marked BHV-1 vaccines, that are commercially available in Germany. Efficacy and safety of different inactivated vaccines and modified live vaccines have been evaluated in detail in several international experimental studies and field trials. Results of these studies are briefly reviewed and discussed in this article.     

扁蓿豆遗传多样性的研究进展

扁蓿豆（Medicago ruthenica）为二倍体豆科优良牧草,其抗逆性强、适应性广,生长于温带和寒温带。通过对扁蓿豆在表型、染色体、蛋白质及DNA水平的遗传多样性的研究进展,表明扁蓿豆是很具潜力的牧草植物,研究其遗传多样性具有重要的理论和实践意义。并根据国内的扁蓿豆的研究现状,提出了建议。     

Spotted fever group rickettsiae: a brief review and a Canadian perspective

Spotted fever group rickettsioses (SFGR) are infections caused by established and emerging human pathogens worldwide. These rickettsial agents are transmitted to humans via arthropods and may result in mild to severe and potentially fatal diseases. Spotted fever group rickettsioses are characterized by similar clinical features, including fever, rash, headache and myalgias, with the development of an inoculation eschar in many, but not all cases. Endemic rickettsial infections do occur but are infrequent in Canada, in contrast to the United States, where these infections are far more prevalent. Travel-associated rickettsioses, however, are being diagnosed with increasing frequency in Canadian travellers returning from international trips abroad, in particular in travellers returning from Africa. The diagnosis of rickettsial infections can be challenging owing to the non-specific nature of the clinical symptoms and the requirement for specialized testing. Serology cannot distinguish between the approximately 20 spotted fever group rickettsial species currently known or suspected to be capable of causing human infection. Molecular testing is required to determine the rickettsial species responsible for infection, but requires greater effort on the part of the clinician to collect appropriate samples, including cutaneous skin swabs from under the eschar or skin punch biopsies of the eschar or rash. Infections with spotted fever group rickettsiae likely occur more commonly than currently recognized and should be considered in patients with appropriate symptoms and exposure histories.     

Cryptosporidium: a water-borne zoonotic parasite

Of 155 species of mammals reported to be infected with Cryptosporidium parvum or C. parvum-like organisms most animals are found in the Orders Artiodactyla, Primates, and Rodentia. Because Cryptosporidium from most of these animals have been identified by oocyst morphology alone with little or no host specificity and/or molecular data to support identification it is not known how many of the reported isolates are actually C. parvum or other species. Cryptosporidiosis is a cause of morbidity and mortality in animals and humans, resulting primarily in diarrhea, and resulting in the most severe infections in immune-compromised individuals. Of 15 named species of Cryptosporidium infectious for nonhuman vertebrate hosts C. baileyi, C. canis, C. felis, C. hominis, C. meleagridis, C. muris, and C. parvum have been reported to also infect humans. Humans are the primary hosts for C. hominis, and except for C. parvum, which is widespread amongst nonhuman hosts and is the most frequently reported zoonotic species, the remaining species have been reported primarily in immunocompromised humans. The oocyst stage can remain infective under cool, moist conditions for many months, especially where water temperatures in rivers, lakes, and ponds remain low but above freezing. Surveys of surface water, groundwater, estuaries, and seawater have dispelled the assumption that Cryptosporidium oocysts are present infrequently and in geographically isolated locations. Numerous reports of outbreaks of cryptosporidiosis related to drinking water in North America, the UK, and Japan, where detection methods are in place, indicate that water is a major vehicle for transmission of cryptosporidiosis.     

Hepatitis E virus: Animal reservoirs and zoonotic risk

Hepatitis E virus (HEV) is a small, non-enveloped, single-strand, positive-sense RNA virus of approximately 7.2 kb in size. HEV is classified in the family Hepeviridae consisting of four recognized major genotypes that infect humans and other animals. Genotypes 1 and 2 HEV are restricted to humans and often associated with large outbreaks and epidemics in developing countries with poor sanitation conditions, whereas genotypes 3 and 4 HEV infect humans, pigs and other animal species and are responsible for sporadic cases of hepatitis E in both developing and industrialized countries. The avian HEV associated with Hepatitis-Splenomegaly syndrome in chickens is genetically and antigenically related to mammalian HEV, and likely represents a new genus in the family. There exist three open reading frames in HEV genome: ORF1 encodes non-structural proteins, ORF2 encodes the capsid protein, and the ORF3 encodes a small phosphoprotein. ORF2 and ORF3 are translated from a single bicistronic mRNA, and overlap each other but neither overlaps ORF1. Due to the lack of an efficient cell culture system and a practical animal model for HEV, the mechanisms of HEV replication and pathogenesis are poorly understood. The recent identification and characterization of animal strains of HEV from pigs and chickens and the demonstrated ability of cross-species infection by these animal strains raise potential public health concerns for zoonotic HEV transmission. It has been shown that the genotypes 3 and 4 HEV strains from pigs can infect humans, and vice versa. Accumulating evidence indicated that hepatitis E is a zoonotic disease, and swine and perhaps other animal species are reservoirs for HEV. A vaccine against HEV is not yet available.     

Cattle industry and zoonotic risk

The intensive farming of dairy and beef cattle has elicited a decrease in the herds and an increase in the number of animals per herd. The high concentration of cattle and the movement of the animals among herds has led to an increase in the health risks. In this context we have to consider the role of microbial agents of zoonoses, such as bacteria, parasites, and in some cases viruses. Notably, foodstuffs, such as meat, milk and dairy products, are the main sources of zoonoses of bovine origin. In particular, raw milk must be considered at high risk for trasmission of pathogens from cattle to humans. The European Regulation concerning food safety provides specific requirements for animal products and in bovine health management. Given the direct responsibility of the producer, the adoption of a self-regulation regimen on animal health, dairy and meat products must be planned by farmers.     

Cattle industry and zoonotic risk

The intensive farming of dairy and beef cattle has elicited a decrease in the herds and an increase in the number of animals per herd. The high concentration of cattle and the movement of the animals among herds has led to an increase in the health risks. In this context we have to consider the role of microbial agents of zoonoses, such as bacteria, parasites, and in some cases viruses. Notably, foodstuffs, such as meat, milk and dairy products, are the main sources of zoonoses of bovine origin. In particular, raw milk must be considered at high risk for trasmission of pathogens from cattle to humans. The European Regulation concerning food safety provides specific requirements for animal products and in bovine health management. Given the direct responsibility of the producer, the adoption of a self-regulation regimen on animal health, dairy and meat products must be planned by farmers.     

Humoral immune response to human cytomegalovirus proteins: a brief review.

Although human cytomegalovirus (HCMV) has a genome of 150 x 10(6) Da, and a protein-coding content of over 200 open reading frames, few viral proteins seem able to elicit a strong antibody response in the natural host during viral infection. The immunodominant polypeptides include a component of 72 kDa among immediate early proteins, a polypeptide of 52 kDa among delayed early proteins and a glycoprotein complex of 58 and 93-130 kDa and two phosphoproteins of mol. wt 150 and 65 kDa among the structural proteins. Following a general overview of the humoral immune response, this brief survey mainly deals with the antibody response to these proteins. As significant epitopes of the major HCMV immunogenic polypeptides have been expressed in procaryotic cells over the last few years, an overview of the state of the art in this particular field will also be given.