Field of the Invention
This invention relates to the field of test panels or trays. More particularly, the present invention provides a microbiological test panel having a plurality of sample wells segregated into two sections so that test samples and reagents used for microorganism identification (ID) and antimicrobial susceptibility testing (AST) can be placed therein.
Known test trays are used for performing tests on microbiological samples related to patient diagnosis and therapy. The microorganism samples may come from a variety of sources, including infections, bodily fluids and abscesses. From those microorganism samples an inoculum is prepared in accordance with established procedures which produce a bacterial or cellular suspension of a predetermined concentration. The inoculum is then used, for example, in ID testing to determine the types of microorganisms present in a patient's sample.
In ID testing, reagents are typically placed in cupules, or test sample wells, contained in ID test trays. Alternatively, paper disks with reagents may be placed in those wells. In the presence of an actively fermenting culture of microorganisms in the inoculum, the reagents may change color, cause turbidity or grow into a formation of a predetermined shape. By examining the reaction of the inoculum and reagents over a period of time, or lack thereof, and comparing that reaction to known reactions, the types of microorganisms can be identified.
However, filling test wells one-by-one with the required inoculum and reagents is tedious, time-consuming and messy. Moreover, any delay in the identification process will cause a delay in diagnosis and treatment to the detriment of the patient. Delays may still result even if a reagent dispensing pipette is used to fill the test wells. For example, when a multi-nozzle pipette, or other type of dispensing apparatus, is used to dispense reagents into a group of test wells, the test wells must be place directly underneath the nozzle so that each is filled properly. This process has many of the same drawbacks as when each well is manually filled. For example, manual placement of the test tray under the nozzles is time consuming and the possibility of misalignment between them exists.
Other microbiological test trays have been used for AST testing of microorganisms. AST testing is used to determine the susceptibility of a microorganism in an inoculum to various therapeutics, such as antibiotics. Based on the test results, physicians can then, for example, prescribe an antimicrobial product which will be successful in killing that microorganism.
Test wells of AST test trays are filled with reagents, in similar fashion to ID testing, and concentrations of antibiotics. Accordingly, the same problems are encountered as discussed with filling the wells for the ID test trays.
The ID/AST testing usually requires that the test trays be incubated at a controlled temperature for an extended period of time. This allows the reaction between the inoculum and reagent to occur as the microorganisms process biologically the reagents mature and stabilize. At predetermined time intervals, each well of the test tray is examined for an indication of color change, turbidity, or the growth of a formation of a predetermined shape. This is a long and tedious process when done manually by a technician.
This process of examining the wells of the test trays is made even longer and more tedious because AST and ID tests typically require using separate test trays, i.e., one tray for each type of test. Thus, even when the same microorganism sample is to be ID and AST tested, the technician would need to keep track of and record the reaction results for at least two separate test trays.
Some attempts have been made to address the problems discussed above, but they have failed. Some of these attempts require complicated procedures such as using a bell chamber to create a negative vacuum so that wells within a test tray can be filled with reagents via a maze of tunnels. Other attempts require the user to follow multiple and arduous steps to fill the wells of a test tray, as well as requiring the user to complete assembly of the test tray. Additional descriptions of other known test trays and ID/AST testing devices can be found in U.S. Pat. Nos. 5,182,082, 4,038,151, and 3,963,355, incorporated herein by reference.
Accordingly, there is a need for a test tray that solves the above described problems. In particular, there is a need for a single microbiological test tray in which all the test wells contained therein can be easily and conveniently filled with the reagents, inocula and therapeutics required for both AST and ID testing without the complicated steps of filling or assembly of the test tray.