RESUMO
Development of rapid and simple typing methods is required for analyzing the distribution and contamination routes of food-borne pathogens. We established a simple typing method for Listeria monocytogenes using MLSSCP (Multilocus Single Strand Conformation Polymorphism) analysis. Four virulence genes, hlyA, iap, actA and inlB were amplified by PCR, digested with endonucleases and applied to gels for SSCP. As banding patterns have been shown to reflect even a single nucleotide difference, this method has a potential discriminatory power comparable to that of sequencing analysis. The 64 strains isolated from five meat processing plants were divided into 18 groups by this MLSSCP. Additionally, clustering obtained with this method showed strong correspondence with phylogenetic lineages I and II, and was achieved with much less expenditure in time and cost than is required for other methods, such as MLST. The validity of the MLSSCP lineage classification was confirmed by PFGE, AFLP and ribotyping results. This newly developed MLSSCP method is suitable when obtaining accurate results quickly and simply is crucial.
Assuntos
Contaminação de Alimentos/análise , Listeria monocytogenes/patogenicidade , Produtos da Carne/microbiologia , Polimorfismo Conformacional de Fita Simples , Fatores de Virulência/genética , Análise por Conglomerados , Microbiologia de Alimentos , Amplificação de Genes , Genótipo , Listeria monocytogenes/classificação , Filogenia , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Especificidade da EspécieRESUMO
The incidence of Listeria monocytogenes in raw fish, shellfish, and fish roe was investigated in seafood products collected from randomly selected retail stores in and around Tokyo, Japan. Of the 10 samples of 208 examined found positive for L. monocytogenes by mini-VIDAS LMO, seven were fish roe (cod, salmon) and three were minced tuna. Three serotypes (1/2a, 1/2b, 3b) were detected among the isolated strains; serotype 1/2a was predominant (8 of 10).
Assuntos
Comércio , Listeria monocytogenes/isolamento & purificação , Alimentos Marinhos/microbiologia , Animais , Qualidade de Produtos para o Consumidor , Produtos Pesqueiros/microbiologia , Microbiologia de Alimentos , Humanos , Incidência , Japão/epidemiologia , Listeria monocytogenes/classificaçãoRESUMO
The triphenyl phosphite-palladium complex was found to effect catalytic substitution reactions of allylic alcohols via a direct C-O bond cleavage. The dehydrative etherification proceeded efficiently without any cocatalysts and bases to give allylic ethers in good to excellent yields.