A global analysis of Y-chromosomal haplotype diversity for 23 STR lociJosephine Purps, Sabine Siegert, Sascha Willuweit et al.|Forensic Science International Genetics|2014 In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.
[Evaluation of the effect of probiotic cultures added to commercial yogurt over a known population of Listeria monocytogenes and Escherichia coli O157:H7].The effect of probiotic cultures over Listeria monocytogenes and Escherichia coli O157:H7 during yogurt storage was evaluated. Two different yogurt brands, one with additional probiotic cultures (Lactobacillus casei and L. acidophilus) were inoculated with known populations (106 UFC/g) of either L. monocytogenes or E. coli O157:H7 in three different times and stored for 32 days at 5 degrees C. Every four days the count of lactic bacteria, the added pathogens and pH was evaluated, according to the methodology described in the Bacteriological Analytical Manual. The pH and lactic bacteria population were constant during the testing period. Yogurt with additional probiotic cultures reduced the population of L. monocytogenes in 8 days, the population of E. coli O157:H7 in 16; yogurt with no additional probiotics took 20 days to reduce L. monocytogenes to non-detectable levels and even after 28 days of storage, E. coli O157:H7 was cultured. In this work, the beneficial effects of additional probiotic cultures in yogurt is confirmed again.
Detection of Borna Virus Disease by real-time RT-PCR in Costa Rican equines and humansXinia Barrantes, RA Silva, Gabriel Macaya et al.|Archives of Clinical Microbiology|2012 Background: BDV causes immunopathology of the central nervous system in many animal species. Detection is based on serology and PCR. Due to low viremia, it is hard to detect and antibodies are found only in 0.5% of the human population. Evidence suggests an association of viral infection with disorders like bipolar disease and schizophrenia. Methods and Findings: We developed a Real Time RT-PCR for BDV p40 and p24. A total of 212 horses were tested, 18 resulted positive for BDV RNA. A group of 76 human samples were also tested: 51 bipolar patients and 25 healthy volunteers. Five bipolar patients were positive for p24, three were positive for p40 and one was positive for p40 strain No98. All healthy donors were negative. Conclusions: BDV detection is reported for the first time in Costa Rica. Although the number of samples tested was low, a high incidence was observed in horses and a strong association in humans with bipolar disease is suggested.