BackgroundCronobacter sakazakii is considered as an emerging foodborne pathogen. The aim of this study was to isolate and characterize virulent strains of Cronobacter sakazakii from food samples of Bangladesh.ResultSix (6) Cronobacter sakazakii was isolated and identified from 54 food samples on the basis of biochemical characteristics, sugar fermentation, SDS-PAGE of whole cell protein, plasmid profile and PCR of Cronobacter spp. specific genes (esak, gluA, zpx, ompA, ERIC, BOX-AIR) and sequencing. These strains were found to have moderately high antibiotic resistance against common antibiotics and some are ESBL producer. Most of the C. sakazakii isolates were capable of producing biofilm (strong biofilm producer), extracellular protease and siderophores, curli expression, haemolysin, haemagglutinin, mannose resistant haemagglutinin, had high cell surface hydrophobicity, significant resistance to human serum, can tolerate high concentration of salt, bile and DNase production. Most of them produced enterotoxins of different molecular weight. The isolates pose significant serological cross-reactivity with other gram negative pathogens such as serotypes of Salmonella spp., Shigella boydii, Shigella sonnei, Shigella flexneri and Vibrio cholerae. They had significant tolerance to high temperature, low pH, dryness and osmotic stress.ConclusionSpecial attention should be given in ensuring hygiene in production and post-processing to prevent contamination of food with such stress-tolerant virulent Cronobacter sakazakii.Electronic supplementary materialThe online version of this article (doi:10.1186/0717-6287-47-63) contains supplementary material, which is available to authorized users.

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Blackleg disease caused by the fungus Leptosphaeria maculans is one of the most devastating diseases of Brassica napus. Association mapping was used to evaluate the response of 139 B. napus accessions originated from 16 countries with 4 growth habit types to inoculation with L. maculans isolates from pathogenicity group 4. All accessions were inoculated at the seedling stage and 37,346 single nucleotide polymorphism markers based upon genotyping-bysequencing were used for analysis. One major QTL associated with the blackleg disease was identified on chromosome A01 at 9.66 Mbp and explains about 14.7 % of phenotypic variation (p value \2.2E-05).Orthologs of Arabidopsis thaliana hydroxyproline-rich glycoprotein family protein, acyl-CoA oxidase 1 and cysteine-/histidine-rich C1 domain family protein that are involved in plant defense mechanism were identified in this QTL region. At a lower significance (p value \0.00139), thirty-five additional markers were identified which are located on 13 other chromosomes. Stepwise regression identified that these markers belong to ten QTL regions and together explain 51.04 % of phenotypic variations. Additional twenty orthologs of A. thaliana disease resistance genes, transcription factors, genes in phytohormone pathway and signaling in plant defense pathway have been identified to be associated with the blackleg disease. Based on the haplotype at the most significant QTL, a total of 22 genotypes were evaluated in the greenhouse. As expected with the haplotype, we had 100 % success in predicting the phenotype. These markers could further be used for identification of phenotype that can be used in the breeding program.Keywords Brassica napus Á Association mapping Á SNP Á Blackleg IntroductionRapeseed (Brassica napus, 2n = 4x = 38) is one of the most important oilseed crops cultivated in many Electronic supplementary material The online version of this article (

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