The genetic epidemiology of joint shape and the development of osteoarthritis

Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed

Occurrence and molecular characterization of Cryptosporidium spp. isolated from domestic animals in a rural area surrounding Atlantic dry forest fragments in Teodoro Sampaio municipality, State of São Paulo, Brazil Ocorrência e caracterização molecular de Cryptosporidium spp. isolados de animais domésticos de propriedades rurais circunvizinhas a fragmentos de Floresta Atlântica Seca do Estado de São Paulo, Brasil

The aim of this study was to assess the occurrence of Cryptosporidium in domestic animals in rural properties surrounding rain forest fragments within the municipality of Teodoro Sampaio, southeastern Brazil. Conventional sucrose flotation method followed by molecular characterization of the parasites by sequencing PCR products amplified from SSU rRNA gene were used. Stool samples were collected from domestic animals raised as pets and livestock in all rural properties surrounding three forest fragments. Samples from cattle (197), equine (63), pigs (25), sheep (11), and dogs (28) were collected from 98 rural properties. The frequency of occurrence of Cryptosporidium within each animal species was 3.0% (6/197) among cattle and 10.7% (3/28) among dogs. Cryptosporidium was not detected in stool samples from equine, sheep, and pigs. All sequences obtained from the six samples of calves showed molecular identity with Cryptosporidium andersoni while all sequences from dog samples were similar to C. canis. The frequency of occurrence of Cryptosporidium in these domestic animal species was low. The absence of C. parvum in the present study suggests that the zoonotic cycle of cryptosporidiosis may not be relevant in the region studied. The presence of Cryptosporidium species seldom described in humans may be, otherwise, important for the wild fauna as these animals are a source of infection and dissemination of this protozoan to other animal species. The impact and magnitude of infection by C. andersoni in wild ruminants and C. canis in wild canids have to be assessed in future studies to better understand the actual importance of these species in this region.<br>O objetivo deste estudo foi avaliar a ocorrência de Cryptosporidium, em animais domésticos de propriedades rurais ao redor de fragmentos de mata Atlântica de interior no município de Teodoro Sampaio, por exame convencional de flutuação em solução de sacarose, seguido de caracterização molecular dos parasitas através do sequenciamento dos produtos amplificados na PCR do gene SSU rRNA. Foram coletadas amostras fecais de animais domésticos criados para subsistência e estimação nas propriedades rurais do entorno de três fragmentos florestais. Amostras de bovinos (197), equinos (63), suínos (25), ovinos (11) e cães (28) foram coletadas de 98 propriedades rurais. A ocorrência de Cryptosporidium para a espécie bovina foi de 3,0% (6/197); para os cães, de 10,7% (3/28); e para os demais animais os resultados foram negativos. Todas as sequências obtidas das seis amostras de bovinos apresentaram identidade molecular com Cryptosporidium andersoni, enquanto as sequências oriundas de amostras de fezes de cães revelaram-se similares ao C. canis. A ocorrência do Cryptosporidium entre os animais estudados foi baixa. Diante dos resultados do presente estudo, o ciclo zoonótico da criptosporidiose parece ter menos importância nesta região. A presença de espécies de Cryptosporidium ainda pouco relatadas em humanos pode ser, por outro lado, importante para a fauna silvestre, uma vez que estes animais podem ser considerados como uma fonte de infecção e disseminação deste protozoário. O impacto e a magnitude da infecção de C. andersoni, em ruminantes selvagens, e de C. canis, em cães silvestres, deve ser avaliado em estudos futuros, com intuito de verificar a real importância dessas espécies nesta região

Multilocus Fragment Typing and Genetic Structure of Cryptosporidium parvum Isolates from Diarrheic Preweaned Calves in Spain▿

A collection of 140 Cryptosporidium parvum isolates previously analyzed by PCR-restriction fragment length polymorphism (PCR-RFLP) and sequence analyses of the small-subunit (SSU) rRNA and 60-kDa glycoprotein (GP60) genes was further characterized by multilocus fragment typing of six minisatellite (MSB and MS5) and microsatellite (ML1, ML2, TP14, and 5B12) loci. Isolates were collected from diarrheic preweaned calves originating from 61 dairy cattle farms in northern Spain. A capillary electrophoresis-based tool combining three different fluorescent tags was used to analyze all six satellites in one capillary. Fragment sizes were adjusted after comparison with sizes obtained by sequence analysis of a selection of isolates for every allele. Size discrepancies at all but the 5B12 locus were found for those isolates that were typed by both techniques, although identical size differences were reported for every allele within each locus. A total of eight alleles were seen at the ML2 marker, which contributed the most to the discriminatory power of the multilocus approach. Multilocus fragment typing clearly improved the discriminatory power of GP60 sequencing, since a total of 59 multilocus subtypes were identified based on the combination of alleles at the six satellite loci, in contrast to the 7 GP60 subtypes previously reported. The majority of farms (38) displayed a unique multilocus subtype, and individual isolates with mixed multilocus subtypes were seen at 22 farms. Bayesian structure analysis based on combined data for both satellite and GP60 loci suggested the presence of two major clusters among the C. parvum isolates from cattle farms in this geographical area