Methods and articles for detecting hemolytic microorganisms
A thin film culture plate device useful for detecting hemolysin-producing microorganisms is included. The device can further include selective agents and/or indicators to differentiate groups or species microorganisms. Methods of use include detecting or enumerating hemolysin-producing microorganisms.
1. A method for detecting microorganisms, the method comprising:
providing i) a thin film culture plate device comprising a dry, cold water-soluble gelling agent, ii) a nutrient medium for the growth of microorganisms, iii) an indicator system comprising a suspension of red blood cells, and iv) a sample suspected of containing microorganisms;
contacting the sample, nutrient medium, and indicator system with the dry, cold water-soluble gelling agent to form an aqueous mixture comprising the gelling agent and the sample;
incubating the mixture for a period of time; and
detecting a microorganism, wherein the detecting a microorganism comprises detecting a hemolytic reaction.
2. The method of claim 1 , wherein detecting a microorganism comprises counting colonies of microorganisms.
3. The method of claim 2 , wherein counting colonies comprises enumerating one or more types of microorganisms.
4. The method of claim 3 , wherein the one or more types of microorganisms are enumerated on the basis of a colony color, fluorescence, size, shape, hemolytic reaction or a combination of any two or more of the foregoing.
5. The method of claim 1 , further comprising a step wherein a portion of at least one colony is subjected to a supplemental test.
6. The method of claim 5 , wherein the portion of at least one colony is removed from the nutrient medium to conduct the supplemental test.
7. The method of claim 1 , wherein the sample comprises a capture element.
8. A method for detecting microorganisms, the method comprising:
providing i) a thin film culture plate device comprising a dry, cold water-soluble gelling agent, ii) a nutrient medium for the growth of microorganisms, iii) an indicator system comprising a suspension of red blood cells, and iv) a sample suspected of containing microorganisms;
contacting the dry, cold water-soluble gelling agent with an aqueous mixture comprising the indicator system and the nutrient medium to form a hydrated gel;
contacting the hydrated gel with the sample;
incubating the device comprising the hydrated gel and the sample for a period of time; and
detecting a microorganism, wherein the detecting a microorganism comprises detecting a hemolytic reaction.
9. The method of claim 8 , where contacting the hydrated gel with the sample comprises streaking a portion of the sample onto the hydrated gel.