Salmonella strains (n = 75) isolated from foods involved in foodborne outbreaks occurred in Rio Grande do Sul State, Brazil, during 1999 and 2000 were studied. Strains were serotyped and submitted to PCR analysis to verify the prevalence of Salmonella plasmid virulence (spvR) regulatory gene. Among the 75 isolates, 73 (97%) were classified as Salmonella enterica serovar Enteritidis. All of the Salmonella strains isolated in 1999 were classified as serotype Enteritidis, whereas in 2000 two isolates were serotyped as Salmonella Derby and Salmonella Typhimurium. Regarding the prevalence of spvR gene, 62 strains (82.7%) were PCR positive, and a positive correlation (P < 0.05) between the strains of Salmonella Enteritidis and the presence of spvR gene was demonstrated, which suggests that this gene is a characteristic of the Salmonella Enteritidis analyzed.

important for breeding programs that considerably influence animal productivity as well as the quality of meat and milk.

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Aims: The aim of this study was to identify and characterize heat stable proteinases of psychrotrophic proteolytic bacteria isolated from raw milk. Methods and Results: A strain of Klebsiella oxytoca producing a high proteolytic activity when cultured on milk was isolated. Maximum proteolytic activity was observed at the stationary phase during growth on milk or caseinpeptone broth. The bacterium demonstrated the capability to grow at 7°C, classified as psychrotrophic. The crude enzyme showed optimum activity at 37°C, and pH 5AE0 and 7AE0. The proteinase was very resistant to heat, maintaining 74% of initial activity after incubation at 142°C. Conclusions: A heat stable protease of a psychrotrophic strain of K. oxytoca was identified and partially characterized. Significance and Impact of the Study: Thermal stable proteases may constitute a serious problem to ultra-high temperature (UHT) processed milk, leading to undesirable physical and sensory alterations.

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BackgroundUrochloa humidicola is a warm-season grass commonly used as forage in the tropics and is recognized for its tolerance to seasonal flooding. This grass is an important forage species for the Cerrado and Amazon regions of Brazil. U. humidicola is a polyploid species with variable ploidy (6X–9X) and facultative apomixis with high phenotypic plasticity. However, this apomixis and ploidy, as well as the limited knowledge of the genetic basis of the germplasm collection, have constrained genetic breeding activities, yet microsatellite markers may enable a better understanding of the species’ genetic composition. This study aimed to develop and characterize new polymorphic microsatellite molecular markers in U. humidicola and to evaluate their transferability to other Urochloa species.FindingsA set of microsatellite markers for U. humidicola was identified from two new enriched genomic DNA libraries: the first library was constructed from a single sexual genotype and the second from a pool of eight apomictic genotypes selected on the basis of previous results. Of the 114 loci developed, 72 primer pairs presented a good amplification product, and 64 were polymorphic among the 34 genotypes tested. The number of bands per simple sequence repeat (SSR) locus ranged from 1 to 29, with a mean of 9.6 bands per locus. The mean polymorphism information content (PIC) of all loci was 0.77, and the mean discrimination power (DP) was 0.87. STRUCTURE analysis revealed differences among U. humidicola accessions, hybrids, and other Urochloa accessions. The transferability of these microsatellites was evaluated in four species of the genus, U. brizantha, U. decumbens, U. ruziziensis, and U. dictyoneura, and the percentage of transferability ranged from 58.33% to 69.44% depending on the species.ConclusionsThis work reports new polymorphic microsatellite markers for U. humidicola that can be used for breeding programs of this and other Urochloa species, including genetic linkage mapping, quantitative trait loci identification, and marker-assisted selection.

Background Paspalum notatum exhibits both sexual and apomictic cytotypes and, thus, is considered a good model for studies of apomixis because it facilitates comparative approaches. In this work, transcriptome sequencing was used to compare contrasting P. notatum cytotypes to identify differential expression patterns and candidate genes involved in the regulation of expression of this trait. Results We built a comprehensive transcriptome using leaf and inflorescence from apomictic tetraploids and sexual diploids/tetraploids and a coexpression network based on pairwise correlations between transcript expression profiles. We identified genes exclusively expressed in each cytotype and genes differentially expressed between pairs of cytotypes. Gene Ontology enrichment analyses were performed to better interpret the data. We de novo assembled 114,306 reference transcripts. In total, 536 candidate genes possibly associated with apomixis were detected through statistical analyses of the differential expression data, and several interacting genes potentially linked to the apomixis-controlling region, genes that have already been reported in the literature, and their neighbors were transcriptionally related in the coexpression network. Conclusions Apomixis is a highly desirable trait in modern agriculture due to the maintenance of the characteristics of the mother plant in the progeny. The reference transcriptome, candidate genes and their coexpression network identified in this work represent rich resources for future grass breeding programs.