Biomaterial Database

Evaluation of chromogenic media for the isolation of vancomycin-resistant enterococci from stool samples. 2009

K Asir, and K Wilkinson, and J D Perry, and R H Reed, and F K Gould

Department of Microbiology, Freeman Hospital, Newcastle upon Tyne, UK. kerry.asir@nuth.nhs.uk

OBJECTIVE This study sought to evaluate the performance of two chromogenic media designed for the isolation of vancomycin-resistant enterococci (VRE) and compare them with a traditional bile-esculin medium for the isolation of VRE from stool samples. RESULTS A total of 285 stool samples were inoculated onto Chromogenic VRE Agar (AES VRE agar; AES Chemunex), chromID VRE (bioMérieux) and VRE Agar (Oxoid) both directly and also following broth enrichment. In total 18 strains of vancomycin-resistant Enterococcus faecium were recovered, including 17 harbouring the vanA gene and one with vanB. On direct culture, the sensitivity of the three media was 66.7%, 77.8% and 44.4% and after broth enrichment 66.7%, 83.3% and 77.8% using AES VRE Agar, chromID VRE and Oxoid VRE Agar respectively. CONCLUSIONS All three media are useful tools for the isolation of VRE from stool samples. AES VRE Agar and bioMérieux chromID VRE are easier to use than Oxoid VRE Agar due to diffusion of black coloration from the latter. CONCLUSIONS This is the first study to evaluate the performance of AES VRE Agar and the first to compare two media containing synthetic chromogens for the isolation of VRE.

UI	MeSH Term	Description	Entries
D002863	Chromogenic Compounds	Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).	Chromogenic Compound,Chromogenic Substrate,Chromogenic Substrates,Compound, Chromogenic,Compounds, Chromogenic,Substrate, Chromogenic,Substrates, Chromogenic
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D005243	Feces	Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015169	Colony Count, Microbial	Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.	Agar Dilution Count,Colony-Forming Units Assay, Microbial,Fungal Count,Pour Plate Count,Spore Count,Spread Plate Count,Streak Plate Count,Colony Forming Units Assay, Microbial,Colony Forming Units Assays, Microbial,Agar Dilution Counts,Colony Counts, Microbial,Count, Agar Dilution,Count, Fungal,Count, Microbial Colony,Count, Pour Plate,Count, Spore,Count, Spread Plate,Count, Streak Plate,Counts, Agar Dilution,Counts, Fungal,Counts, Microbial Colony,Counts, Pour Plate,Counts, Spore,Counts, Spread Plate,Counts, Streak Plate,Dilution Count, Agar,Dilution Counts, Agar,Fungal Counts,Microbial Colony Count,Microbial Colony Counts,Pour Plate Counts,Spore Counts,Spread Plate Counts,Streak Plate Counts
D016908	Gram-Positive Bacterial Infections	Infections caused by bacteria that retain the crystal violet stain (positive) when treated by the gram-staining method.	Bacterial Infections, Gram-Positive,Infections, Gram-Positive Bacterial,Bacterial Infection, Gram-Positive,Bacterial Infections, Gram Positive,Gram Positive Bacterial Infections,Gram-Positive Bacterial Infection,Infection, Gram-Positive Bacterial,Infections, Gram Positive Bacterial
D016983	Enterococcus	A genus of gram-positive, coccoid bacteria consisting of organisms causing variable hemolysis that are normal flora of the intestinal tract. Previously thought to be a member of the genus STREPTOCOCCUS, it is now recognized as a separate genus.
D020713	Vancomycin Resistance	Nonsusceptibility of bacteria to the action of VANCOMYCIN, an inhibitor of cell wall synthesis.