Indicator for use in selection of bactericidal and bacteristatic drugs and method for producing same

• US 4,087,332 A
• Filed: 07/22/1977
• Issued: 05/02/1978
• Est. Priority Date: 05/07/1976
• Status: Expired due to Term

• Current Assignee: Kai Aage Hansen
• Original Assignee: Kai Aage Hansen
• Inventors: Hansen, Kai Aage
• Primary Examiner(s): Tanenholtz, Alvin E.
• Application Number:
  US05/818,075
• Time in Patent Office: 284 Days
• Field of Search: 195/103.5 K, 195/127, 23/253 TP
• US Class Current: 435/33
• CPC Class Codes: C12Q 1/18 Testing for antimicrobial activity of a material
• CPC Class Codes: C12Q 1/20 using multifield media
• CPC Class Codes: Y10S 435/805 Test papers

Abstract

A test strip is provided for visually indicating the effectiveness of selected antibiotics, bactericidal drugs, or the like in combatting microorganisms in specimens taken from a patient. The test strip comprises a porous, water absorbent or adsorbent body which may be made of plastic foam material, upon the porous surface of which spaced stripes of testing material are applied by automatic printing or coating apparatus. One of the stripes contains a nutrient substrate for the tested microorganisms and the other stripes contain a mixture of the same nutrient substrate and various selected bactericidal and bacteristatic drugs. The test strip is initially manufactured as a strip of long length with the stripes extending longitudinally thereon, and is then separated into short transverse panels for use in the testing. Moisture barriers are formed between the stripes by the application of pressure or heat to the porous surface of the test strip.

Claims

1. An indicator for use in the selection of bactericidal and bacteristatic drugs, comprising a solid elongated carrier sheet having an upper layer with a porous front surface and a moisture-tight backing, said upper layer being made of heat or pressure sensitive material that has interconnected passages pervious to moisture and being of a material consistency that permits said passages to be closed solely by application of heat or pressure without application of any additional moisture-sealing material, a plurality of testing coatings arranged on said front surface in spaced relationship to each other, said testing coatings comprising a plurality of spaced stripes on said porous front surface and extending parallel to the longitudinal axis of said carrier sheet, one of said coating stripes consisting only of a nutrition substrate for bacteria and constituting a comparison stripe, the other coating stripes constituting a mixture of a nutrition substrate and a different bactericidal or bacteristatic drug, and a moisture barrier band consisting of said passages that have been closed between each adjacent pair of said coating stripes formed by the application of heat or pressure to the front surface of said carrier sheet, said carrier sheet comprising a continuous length of adsorbent or absorbent sheet material with said porous front surface serving as an integral mechanical carrier for said testing coatings, said carrier sheet being adapted to be separated transversely at even intervals into small transverse panels, each containing said coating stripes, the coating stripe sections on said panels, when impregnated by a testing specimen, serving as individual bacteria culture media, whereby differences in bacteria colonization between the comparison stripe and the other coating stripes may be ascertained by direct visual observation.

2. An indicator according to claim 1 which also includes a plurality of evenly spaced separation lines extending transversely of said carrier sheet and perpendicular to said coating stripes, for separation of said sheet.

3. An indicator according to claim 1 in which said carrier is a thin layer of plastic foam.

4. An indicator according to claim 1 in which said carrier is a strip or sheet of paper having pulp impregnated with a resin.

5. An indicator according to claim 2 in which said separation lines comprise transverse grooves formed in the foam plastic body of said carrier.

6. An indicator according to claim 3 in which said plastic foam has open cells on its front surface and closed cells on its rear surface. With said rear surface being planar and capable of receiving printed matter thereon.

7. A method for the fabrication of an indicator for use in the selection of bactericidal and bacteristatic drugs, said method comprising the steps of introducing into a sterile environment a sterilized length of a sheet-like carrier made of a porous material having interconnected passages capable of becoming moisture sealing when exposed solely to heat or pressure, applying to a porous surface of said carrier a plurality of spaced coatings in the form of parallel stripes extending longitudinally along the length of said carrier and separated by porous linear bands, one of said coatings consisting of a nutrition substrate for bacteria and the other coatings consisting of a mixture of said nutrition substrate with respective different bactericidal or bacteristatic drugs, applying heat or pressure to said porous bands between said spaced stripes in an amount sufficient to close the interconnected passages of said porous material so as to provide moisture barriers between said stripes, and packaging at least a portion of said carrier in a sealed container prior to removing it from said sterile environment.

8. A method according to claim 7 which includes the additional step of cutting the coated carrier into transverse strips along cut lines extending perpendicularly to said longitudinal stripes, said packaging step comprising the insertion of said transverse strips into sterile re-closable containers.

9. A method according to claim 7 in which said longitudinal stripes containing said nutrition substrate and drugs are applied to the carrier surface by printing.

10. A method according to claim 7 in which said moisture barriers are applied by heated rollers.

11. A method according to claim 8 in which said moisture barriers are applied by pressure rollers.

12. A method according to claim 7 which includes the additional step of providing on said sheet-like carrier a plurality of evenly-spaced separation lines extending transversely thereof and perpendicularly to said longitudinal stripes before insertion of said carrier into said sealed container.