Application of randomly amplified polymorphic DNA (RAPD) analysis for typing avian Salmonella enterica subsp. enterica

Randomly amplified polymorphic DNA (RAPD) analysis was performed for the molecular genetic typing of 30 Salmonella enterica subsp. enterica strains isolated from chickens and ducks in Thailand. Six different primers were tested for their discriminatory ability. While some of the primers could only differentiate between the different serovars, the use of multiple primers showed that the RAPD method could also subdivide within a given serovar. The Ready-To-Go RAPD analysis beads used, resulted in reproducible and stable banding patterns. As the RAPD technique is simple, rapid and rather cheap, we suggest that it may be a valuable new tool for studying the molecular genetic epidemiology of S. enterica ssp. enterica, both inter- and intra-serovars.     

A feasibility study of an in vitro differentiation potential toward insulin-producing cells by dental tissue-derived mesenchymal stem cells

Dental tissue-derived mesenchymal stem cells have been proposed as an alternative source for mesenchymal stem cells. Here, we investigated the differentiation ability toward insulin producing cells (IPCs) of human dental pulp stem cells (hDPSCs) and human periodontal ligament stem cells (hPDLSCs). These cells expressed mesenchymal stem cell surface markers and were able to differentiate toward osteogenic and adipogenic lineages. Upon 3 step-IPCs induction, hDPSCs exhibited more colony number than hPDLSCs. The mRNA upregulation of pancreatic endoderm/islet markers was noted. However, the significant increase was noted only for PDX-1, NGN-3, and INSULIN mRNA expression of hDPSCs. The hDPSCs-derived IPCs expressed PRO-INSULIN and released C-PEPTIDE upon glucose stimulation in dose-dependent manner. After IPCs induction, the Notch target, HES-1 and HEY-1, mRNA expression was markedly noted. Notch inhibition during the last induction step or throughout the protocol disturbed the ability of C-PEPTIDE release upon glucose stimulation. The results suggested that hDPSCs had better differentiation potential toward IPCs than hPDLSCs. In addition, the Notch signalling might involve in the differentiation regulation of hDPSCs into IPCs.     

Identification of Escherichia coli Recovered from Milk of Sows with Coliform Mastitis by Random Amplified Polymorphic DNA (RAPD) Using Standardized Reagents

A standardized-reagents commercial kit for random amplified polymorphic DNA (RAPD) analysis was used for typing 58 Escherichia coli strains that were recovered from the milk of sows, having coliform mastitis, within a single swineherd in Sweden. Previously, the 58 E. coli strains were characterized serologically and profiled biochemically. They were also evaluated for their serum resistance and their ability to adhere to fibronectin and bovine fetal fibroblasts. The RAPD analysis was fast, easily performed, and required only a nanogram of DNA. The indistinguishable banding patterns obtained with repeated analyses of 2 isolates from each strain demonstrated that RAPD analysis using standardized beads is a technique that provides reproducible results for typing E. coli strains that cause mastitis in sows. The results of the RAPD analyses demonstrated that E. coli sow mastitis strains are highly variable in serotype, biochemical profiles, virulence factors, and RAPD type, and that all 58 strains can be differentiated by means of the RAPD technique. The strains grouped into 24 RAPD types by combining the results of 2 primers, and into 38 groups by combining the results of serotype and RAPD type. No relationship between serotypes, virulence factors and RAPD types was found.     

Efficacy of live B1 or Ulster 2C Newcastle disease vaccines simultaneously vaccinated with inactivated oil adjuvant vaccine for protection of Newcastle disease virus in broiler chickens

Two hundred, one-day-old broiler chicks were divided into groups 1, 2 and 3 containing 60, 70 and 70 chicks, respectively. The groups were divided into subgroups of 10 chicks that were vaccinated according to the following scheme: group 1 unvaccinated control, group 2 vaccinated subcutaneously at 1 day old with inactivated oil adjuvant vaccine (IOAV) in combination with live B1 vaccine. Group 3 was vaccinated in the same mode as group 2 with IOAV and live Ulster 2C vaccine. All birds were challenged when they were 28 days old. Mortality rate, body weight gain and feed conversion ratio (FCR) were monitored before and after challenge. All the chickens in group 1 died, indicating that there was no disease resistance of this unvaccinated control group of chickens. Conversely, the monitored disease resistance of chickens in groups 2 and 3 was 68.57% ± 18.64 and 88.57% ± 9.00, respectively (P < 0.05). The morbidity of chickens in groups 2 and 3 was 37.89% ± 14.36 and 14.76% ± 12.40, respectively (P < 0.05). The body weight gain, feed intake and FCR of group 3 were significantly better than those of group 2 (P < 0.05) during 1–42 days old. The simultaneous vaccination with B1 or Ulster 2C and IOAV of 1-day-old chicks gave some protection of 28-day-old broilers without a booster vaccination.