Scherr v. National Bio-Test, Inc.

• Decision Date: 10 March 1961
• Docket Number: Civ. No. 0436.
• Citation: 197 F. Supp. 372
• Parties: George H. SCHERR, an Individual, Plaintiff, v. NATIONAL BIO-TEST, INC., a corporation, Defendant.
• Court: U.S. District Court — District of Nebraska

197 F. Supp. 372

George H. SCHERR, an Individual, Plaintiff, v. NATIONAL BIO-TEST, INC., a corporation, Defendant.

Civ. No. 0436.

United States District Court D. Nebraska.

March 10, 1961.

Howard T. Markey, of Parker & Carter, Chicago, Ill. (Young, Holm & Miller, Omaha, Neb., of counsel), for plaintiff.

Arthur Raisch, Detroit, Mich. (McCowan & Troia, Omaha, Neb., of counsel), for defendant.

ROBINSON, Chief Judge.

This action is for infringement of claims 1, 3, 4, 6, and 8 of Letters Patent No. 2,787,581 (now Re 24,557), issued to plaintiff, George M. Scherr, on April 2, 1957, and entitled "Means for Assessing the Effect of Various Agents on the Growth of Microorganisms".

The plaintiff is a resident of Cook County, Illinois, and the defendant is a Nebraska corporation with its offices and principal place of business at Omaha, Nebraska.

The patent in suit and the alleged infringing devices relate to a device for use in assessing the activity of chemical agents comprising a flat sheet of absorbent material such as blotting paper having two or more spaced areas impregnated with the chemical agents to be tested. The principal use of the patented device is in testing the sensitivity of bacteria to two or more antibiotics.

Sensitivity testing is a procedure widely used today in clinics, hospitals and research laboratories for determining the susceptibility of disease microorganisms to antibiotics and other chemotherapeutic agents. From a sensitivity test, a physician is able to determine whether an antibiotic will or will not inhibit the growth of a given disease microorganism. This information then aids the physician in deciding which drug to prescribe to the patient from whom the disease microorganism was taken.

In the usual procedure a specimen which has been taken from a patient is streaked over the surface of a growth medium. The growth medium, which may be a solution of blood agar and water hardened to a jello-like consistency in a standard round petrie dish, stimulates growth of the disease microorganism. After the specimen has been streaked over the surface of the growth medium, a device carrying an antibiotic or antibiotics which will inhibit the growth of the disease are placed on the specimen. After the antibiotic-carrying device is placed on the specimen, the dish is sealed and placed in an incubator for from 12 to 24 hours. The incubator is kept at a temperature closely equivalent to the temperature of the human body so as to reproduce the conditions the disease microorganism normally encounters.

If the antibiotic in contact with the microorganism has no effect on the microorganism, the microorganism will grow right up to the antibiotic-carrying device. However, if the antibiotic has the property of destroying or retarding the growth of the disease microorganism, the growth medium will be unclouded about the device. This unclouded area is designated a "zone of inhibition". By merely examining the petrie dish after a period of incubation, the worker in the art can decide, by noting the presence or absence of the zone of inhibition, whether the disease microorganism is resistant or sensitive to the antibiotic being tested.

During the past decade the number of antibiotics in chemical use has increased and in the early 1950's there was an upsurge in the antibiotic disc field. In testing a culture from a patient to ascertain which antibiotic would be most effective in destroying the bacteria causing the infection, it is necessary to test more than one antibiotic and consequently use more than one sensitivity disc in each test because each individual disc carries only one antibiotic.

In 1954 Doctor Scherr conceived the idea of an integral sensitivity testing disc having a plurality of impregnated extensions or a multiple tipped disc. By aggregating two or more of the sensitivity discs into one unit, the laboratory technician as a matter of convenience would only have to handle one device comprising two or more sensitivity discs instead of handling two or more discs individually. Doctor Scherr combined the sensitivity discs in the form of a star made from the same material as the prior individual sensitivity discs with each of the projecting arms of the star impregnated with a different antibiotic. However, with respect to the multiple disc, the Scherr patent states: "In use, the procedure for handling the specimen does not differ from that described * * * for simple circular paper discs impregnated with a single antibiotic". The expert testimony at the trial was that there is no information obtained by testing with multiple arm sensitivity discs that cannot be obtained with individual discs.

For 15 to 20 years prior to the Scherr patent, the antibiotics were placed on the specimen by several methods:

In the Oxford cup method a small hollow metal cylinder filled with a liquid solution of the antibiotic was placed on the growth medium. For each antibiotic to be tested, a separate cylinder had to be placed on the plate at an appropriately spaced distance from its neighbors, and each individual cylinder filled with the antibiotic solution.

Other methods, such as the tube dilution method and the Trench method were also known. In the mid-1940's the disc method was developed.

The original disc was a tablet or pellet of the antibiotic in compressed, granulated form having a shape similar to the common aspirin tablet. In 1947 a wet paper sensitivity disc was developed by Vincent & Vincent. These scientists completely saturated circular discs of blotting or filter paper with a solution of liquid antibiotic and then placed the wet disc on a specimen. A little later, dried paper discs were utilized.

Plaintiff demonstrated in open court sensitivity tests employing the conventional dried circular discs and also employing the device of the patent, the latter test requiring approximately 1/7 the time of the former.

The claims in issue here are as follows:

"1. For use in assessing the activity of chemical agents in relation to microorganisms, an essentially flat sheet of absorbent material, said sheet having a central area and a plurality of radially extending arms spaced about the periphery of said central areas, the outer terminal areas of said arms being impregnated with different chemical compounds having activity in relation to microorganisms."

"3. For use in assessing the activity of chemical agents a plurality of substantially flat, generally curved disk-like areas of absorbent material, said areas being spaced one from the other and joined one to the other by additional areas of the same material, said first named areas projecting radially from said additional areas and being impregnated with chemical agents.

"4. A testing device for use in assessing (pre-determined properties of chemical agents) the activity of chemical agents in relation to microorganisms, said testing device comprising a member formed entirely of an absorbent material, said member having chemical agent-carrying portions being joined by integral portions of the same material and of the same thickness."

"6. A testing device for use in testing substances which comprises an essentially flat, integral piece of absorbent material having a plurality of peninsular areas individually impregnated with said substances."

"8. Means useable in the determination of the activity of antibiotic substances in relation to microorganisms, comprising an essentially flat piece of absorbent material having a plurality of laterally extending integral portions, said portions being spaced one from the other on said piece and extending from an edge of said piece, said portions individually carrying, at the outer free end thereof, said antibiotic substances."

The problem of handling large numbers of individual items is a problem that is present in every day life and the solution has always been the same; namely, the handling in multiple of items otherwise handled individually. This problem has manifested itself many times in scientific and medical laboratories and has always been solved in the same manner. A brief history of the prior patented and published art shows the handling of items consisting of areas of chemically impregnated absorbent material in multiple which had been handled individually.

Dieterich 691,249 describes a chemical testing litmus paper for making two or more chemical tests at one time. Blue litmus paper is sensitive to acid and when it is immersed in a solution, if the blue turns to red, this indicates that the solution is acid. The red litmus paper is sensitive to alkali and when the red strip of litmus paper is dipped in a solution, if it turns blue, this indicates the solution is alkaline. The Dieterich patent teaches that in testing a solution to determine whether it is alkaline or acid, it was common practice to use two strips of litmus paper, one red and one blue. The person conducting the test first immersed a strip of red litmus paper in the solution, then a blue strip of litmus paper. Dieterich solved the problem of the two strips of paper and the duplicate handling by combining the blue and red litmus paper on strips into one unit. Dieterich's multiple blue and red litmus...