Retail fresh sushi is gaining popularity in Europe. This study was conducted to investigate the microbiological quality of selected samples of fresh sushi with a shelf life of 2 to 3 days offered as complete meals in Norwegian supermarkets. Analysis of aerobic plate counts in 58 sushi samples from three producers revealed large variations in microbiological quality, and 48% of the analyzed sushi boxes were rated as unsatisfactory (> 6.0 log CFU/g). Mesophilic Aeromonas spp. was detected in 71% of the samples. In a follow-up study, we collected products and raw materials directly from the production facility of one producer and observed a significant decrease (P < 0.01) in aerobic plate counts compared with the initial sampling. The observed difference between products purchased in stores compared with those collected directly from the factory suggests that poor temperature control during distribution and display in stores leads to reduced microbiological quality. Microbiological analysis of the sushi ingredients revealed that potentially pathogenic bacteria such as mesophilic Aeromonas spp. or bacteria belonging to the Enterobacteriaceae can be introduced into sushi through both raw vegetables and fish. The results highlight the importance of high quality ingredients and proper temperature control to ensure stable quality and safety of these food products.

Summary• Polygalacturonase-inhibiting proteins (PGIPs) have been demonstrated to play a role in host defence in several plants.• The PGIP now cloned from strawberry ( Fragaria × ananassa ) showed a high degree of homology to other fruit PGIPs. The gene expression of strawberry PGIP was monitored in healthy leaves, flowers and fruit at different maturity stages. PGIP transcript levels were also analysed following fruit inoculation with the fungal pathogen Botrytis cinerea in strawberry cultivars displaying variation in susceptibility.• Healthy mature berries showed the highest constitutive PGIP gene expression levels compared with leaves, flowers and immature fruit, indicating that the gene is developmentally regulated. Among the cultivars studied ('Elsanta', 'Korona', 'Polka', 'Senga sengana', 'Tenira'), 'Polka' had the highest constitutive expression level of PGIP. After inoculation with B. cinerea , all five cultivars displayed a significant induction of PGIP gene expression, but the differences between them were not statistically significant.• The high induction of the PGIP gene after inoculation with B. cinerea indicates that PGIP has a role in defence of strawberry.

9In this study, coagulase positive staphylococci (CPS) were detected in 45% of the 69 bovine 10 milk, whey and cheese samples from five farm dairies, and all raw milk samples were 11 contaminated. Genetic diversity, staphylococcal enterotoxin genes and antimicrobial 12 susceptibility in putative Staphylococcus aureus isolates were investigated. Sixty-one percent 13 of the 72 isolates analysed belonged to the same PFGE group. The spa-typing revealed seven 14 different spa types, t2678 being the most prevalent, but t127 and t197 were also detected. 15Sixteen different toxin gene profiles were identified in 87.5% of the isolates with sec and tst 16 being the most frequent (52.5%), followed by seg and seh. All isolates were MSSA 17 (methicillin-sensitive S. aureus), and sensitive to the 12 antibiotics tested. The prevalence of 18 S. aureus, and the high diversity of isolates carrying enterotoxin genes, constitute grounds for 19 food safety concern in artisanal cheese making, whether pasteurized or not.

Summary• Strawberry Fragaria × ananassa (cv. Korona) was inoculated with Botrytis cinerea by dipping berries in a conidial suspension.• Colonization by the pathogen was monitored using real-time PCR, ELISA and ergosterol assays, the first showing the highest sensitivity. The expression of pathogen β -tubulin and six polygalacturonases ( Bcpg 1-6) and three host defence genes (polygalacturonase-inhibiting protein ( FaPGIP ) and two class II chitinases) were monitored using real-time RT-PCR.• The maximum transcript levels of the host defence genes occurred at 16 h postinoculation (hpi) at the presumed initial penetration stage. The unique transcript profile of Bcpg 2 over the 96-h incubation time and its high transcript levels relative to those of the other Bcpg s at 8 -24 hpi suggest that the gene has a specific role in the penetration stage.• Bcpg 1 was expressed constitutively at a relatively high level in actively growing mycelia throughout the experimental period. Comparison of the transcript profiles indicated that Bcpg 1 and Bcpg 3-6 were coordinately regulated.

SummaryRecent studies indicate that allele-specific differences in gene expression are a common phenomenon. The extent to which differential allelic expression exists might be underestimated, due to the limited accuracy of the methods used so far. To demonstrate allele-specific expression, we investigated the transcript abundance of six individual, highly homologous alleles of a polygalacturonase-inhibiting protein gene (FaPGIP) from octoploid strawberry (Fragaria · ananassa). We applied the highly quantitative Pyrosequencing method which, for the gene under study, detected allele frequency differences as small as 4.0 AE 2.8%. Pyrosequencing of RT-PCR products showed that one FaPGIP allele was preferentially expressed in leaf tissue, while two other alleles were expressed in a fruit-specific way. For fruits that were inoculated with Botrytis cinerea a strong increase in overall FaPGIP gene expression was observed. This upregulation was accompanied by a significant change in FaPGIP allele frequencies when compared with non-treated fruits. Remarkably, in the five cultivars tested, the allele frequency in cDNA from the inoculated fruits was similar to that in genomic DNA, suggesting uniform upregulation of all FaPGIP alleles present as a result of pathogenesis-related stress. The results demonstrate that when Pyrosequencing of RT-PCR products is performed, novel allele-specific gene regulation can be detected and quantified.