Effects of media, atmosphere, and incubation time on colonial morphology of Arcanobacterium haemolyticum
| Autor: | Marie B. Coyle, S E Gavin, Lisa A. Cummings, J S Fine, Ann M. Larson, W K Wu |
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| Rok vydání: | 1993 |
| Předmět: |
Microbiology (medical)
Time Factors food.ingredient Arcanobacterium haemolyticum Hemolysis Incubation period Microbiology Throat culture Gram-Positive Rods chemistry.chemical_compound food medicine Humans Agar Trypticase soy agar Incubation Gram-Positive Bacterial Infections Bacteriological Techniques biology medicine.diagnostic_test Atmosphere Pharyngitis biology.organism_classification medicine.disease Culture Media chemistry Evaluation Studies as Topic Pharynx Bacteria Research Article |
| Zdroj: | Journal of Clinical Microbiology. 31:3223-3226 |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.31.12.3223-3226.1993 |
| Popis: | Arcanobacterium haemolyticum causes pharyngitis as well as skin and other wound infections. Although it is a beta-hemolytic organism, the hemolysis is less well defined than that of beta-hemolytic streptococci and may be overlooked in cultures with heavy growth of commensal throat flora. To determine whether routine throat culture conditions are sufficient to produce recognizable colonies of A. haemolyticum, the morphology of six distinct strains was studied after various combinations of incubation time, medium, and atmosphere. The agar media, containing 5% sheep blood, were Trypticase soy agar, Columbia agar, and heart infusion agar. Cultures were incubated in ambient air, 6 to 8% CO2, or an anaerobic atmosphere. Cultures were compared after 24, 48, and 72 h of incubation for colony size, clarity and size of hemolytic zone, and macroscopic evidence of agar pitting. A minimum of 48 h was needed for expression of beta-hemolysis and pitting. Trypticase soy agar was the superior medium and CO2 was the superior atmosphere for beta-hemolysis. Agar pitting was not significantly affected by variations in medium or atmosphere. Strains differed in their expression of hemolysis and production of pits at 48 h. After 72 h of incubation, beta-hemolysis and pitting were visible in over 96% of culture observations. |
| Databáze: | OpenAIRE |
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