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''Cronobacter'' is a genus of Gram-negative, facultatively anaerobic, oxidase-negative, catalase-positive, rod-shaped bacteria of the family Enterobacteriaceae. They are generally motile, reduce nitrate, use citrate, hydrolyze esculin and arginine, and are positive for L-ornithine decarboxylation. Acid is produced from D-glucose, D-sucrose, D-raffinose, D-melibiose, D-cellobiose, D-mannitol, D-mannose, L-rhamnose, L-arabinose, D-trehalose, galacturonate and D-maltose. ''Cronobacter'' spp. are also generally positive for acetoin production (Voges–Proskauer test) and negative for the methyl red test, indicating 2,3-butanediol rather than mixed acid fermentation. The type species of the genus ''Cronobacter'' is ''Cronobacter sakazakii'' comb. nov. The genome of one strain of ''Cronobacter sakazakii'' (BAA-894) has been sequenced and annotated.〔 〕 According to multilocus sequence analysis (MLSA) the genus originated ~40 MYA, and the most clinically significant species, ''C. sakazakii'', was distinguishable ~15-23 MYA. . ==Clinical significance== All ''Cronobacter'' species, except ''C. condimenti'', have been linked retrospectively to clinical cases of infection in either adults or infants. The majority of ''Cronobacter'' cases occur in adults, most often bacteraemia and have not been studied in detail. However the majority of neonatal and infant infections have been associated with ''C. sakazakii'' and have received considerable attention.〔 〕 Additionally, ''Cronobacter'' spp. are associated as causative agents of neonatal bacteraemia, meningitis and necrotising enterocolitis. However multilocus sequence typing 〔 〕 has shown that the majority of neonatal meningitis cases in the past 30 years, across 6 countries have been associated with only one genetic lineage of the species ''Cronobacter sakazakii'' called 'Sequence Type 4' or 'ST4', and therefore this clone appears to be of greatest concern with infant infections. Two cases of infants infected with ''Cronobacter sakazakii'' were reported to the Missouri Department of Health and Senior Services during the month leading up to Dec 18, 2011. One of the infants died from the infection. Enfamil announced that one lot of their newborn baby formula was pulled off of shelves (recalled) following the death of the infant, but Enfamil says their product has been tested and is safe.〔 〕 CDC analysis of the two cases, using PFGE, revealed the cases were unrelated, and that one of the strains was isolated from both an opened infant formula tin, nursery water and reconstitution feed. No ''Cronobacter'' were isolated from unopened tins of infant formula from the same batch.〔 〕 It is notable that the isolates of ''C. sakazakii'' from meningitis cases were from the ST4 clonal complex, and therefore support the previously retrospect study.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cronobacter」の詳細全文を読む スポンサード リンク
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