Chapter 7 Culture media for enterococci and group D-streptococci

摘要: Enterococci, formerly classified as faecal streptococci, belong with few exceptions to the Lancefield group D-streptococci. They are contaminants of various foods, especially those animal origin. The genus Enterococcus currently comprises 26 species. Some them, and some species streptococci e.g. Stretococcus bovis, suis , equinus have their habitat in intestine man animals. Serologically based grouping may no longer constitute best definition for these bacteria. same applies term “faecal streptococci” it seems reasonable therefore look enterococci sensu stricto . Food hygiene monitoring systems use indicators contamination such requires reliable methods selective cultivation identification marker strains. More than 100 modifications media been described past isolating or from specimens. selection a medium consideration specimen type (solid liquid), method (pre-enrichment/enrichment, plate count membrane filter technique) whether is heavily contaminated other organisms. choice made more difficult commercial versions culture vary formulation and/or performance producer producer. Therefore, reviewing literature help confirmatory tests. Recent research clinical microbiology suggests glycopeptide-resistant strains cause nosocomial infections. Enterococci food chain function transmitters animals man. Hence, detection vancomycin-resistant (VRE) indicated special procedures are, needed. selectivity productivity commonly used cited reported here: citrate azide tween carbonate (CATC) agar, kanamycin aesculin (KAA) M-Enterococcus (ME) bile (ABA) thallous acetate tetrazolium glucose (TITG) agar. In ABA mostly Enterococcosel (ECS), ME Slanetz Bartley No completely productive all but species, E. faecalis faecium which serve primarily responsible Confirmatory tests must be performed where sensitivity procedure limited. Selective should only after while simultaneously checking (false positive) negative) against appropriate test organisms representative kind specimen.