NO138578B - INSTRUMENT TO USE DIRECT DETECTION OF NEISSERIA GONORRHEAE WITHOUT CULTURE - Google Patents

Description

The present invention relates to an instrument for use

by direct detection of Neisseria Gonorrhoeae without culture,

by inducing an initial distinct color change on a wat-

stick in the instrument after collecting a sample on it.

It is known that in the United States and in most of the world

moreover, there is an epidemic with regard to venereal diseases

judge. In the United States alone, the disease has reached pan-

different dimensions. It is estimated that only 1/5 of the cases are reported and that only 1/3 reach doctors or the public health authorities for treatment. If it was available

a simple, quick and cheap test method, this would support the detection and control of this disease.

The usual clinical sign of a gonorrhea infection in men is a discharge of material from the urethra and urethral orifice. A routine examination is necessary to make a differential

diagnosis with regard to the nature of the discharge before antibiotics can be prescribed. As a rule, the first test is to decide

whether the urethritis is caused by gonococci or is of a non-specific nature.

From US-PS 2,970,945 it is known to use a dried

reagent in tablet form and a wetting agent for activating the reagent when examining clinical preparations for the diagnosis of Neisseria Gonorrhoeae. A phenylenediamine is used as a color reagent. From US-PS 2,721,552 and US-PS 3,360,440 it is

known devices which are made up of one or more non-communicating containers, whereby one of the containers contains an aqueous and the other a dry substance, which can be mixed with each other in a suitable way. Likewise, a method for examining clinical preparations for diagnostic purposes can be read from the latter patent. The known devices have it

deficiency that they during routine examinations of the directly taken samples

of exudates in a suspicious case, are not simple enough, so that a quick and simple differential diagnosis cannot be made.

Finally, mention should be made of US-PS 3,450,129 which makes use

of a fragile container for transporting reagent to a laboratory

ium and aims to keep the bacteria alive until they can be cultured.

The object of the invention is therefore to produce a

system that is applied directly to the patient, and which provides the attending physician with a differential diagnosis tool that is time-saving, cheap and reliable.

The present invention thus relates to an instrument

use in the direct detection of Neisseria Gonorrhoeae without culture by inducing an initial distinct color change on a swab

stick in the instrument after collecting a sample on it, and the instrument is characterized in that it comprises a dry carrier for an oxidase testing reagent which is p-amino-dimethylaniline oxalate, N,N-dimethyl-p-phenylenediamine dihydrochloride, N,N-dimethyl -P-phenylenediamine oxalate, N,N,-dimethyl-p-phenylenediamine monohydrochloride or N,N,N',NHietramethyl-p-phenylenediamine dihydrochloride, and a crush-

bare container for an activation liquid consisting of water, physiological salt solution or a buffer solution with a pH of 6.5-7.2, both of which are placed in a flexible tube with a telescopic cap, as well as a swab known per se intended for introducing a sample into the flexible tube, as a color change occurs on the swab when the sample is introduced and the container is crushed.

As an assessment test for gonorrhea in public clinics

not for venereal diseases, hospitals, doctor's offices and in the armed forces, the present device will serve as a cheap and accurate differential diagnosis aid to help the doctor or clinic with the choice of drug treatment.

The need for a simple and cheap diagnostic system, which can be used in the field independently of bacteriological and microscopic samples,

is thus large. One of the difficulties in making a quick and reliable diagnosis of the infection in the man is the initially confusing resemblance to urinary tract infection.

A urinary discharge in men can occur as a result of the following other cases, prostatitis, trauma, Escherichia coli, staphylococcus, tuberculosis, balanitis, intact substances that irritate the urinary tract, cantharades, vegetable substances rich in oxalates and others that can cause urinary tract inflammation. Pellagra, diabetes and gout are responsible in some cases. Trichomonas vaginalis can be found frequently in abacterial urethritis. Entomoeba histolytica, as a cause of urethral discharge, is found exclusively in the presence of recto-urethral or vesical fistula. Bilfarizia is a metozoan that causes urethritis rather frequently in endemic areas. Such systemic diseases as typhus, mumps, influenza and smallpox can, if septicemic, produce urethritis.

In a large percentage of individuals with acute or chronic urethral discharge, detection of neisseria is not possible, even if a gonorrheal infection is suspected. Many of these are treated, like gonorrhoeal infections, and it is only if they are obstinate after several therapeutic treatments that their abacterial nature can be recognized. Subsequent thorough examination of the entire anterior and posterior urethra and upper urinary tract can reveal that the signs of inflammation are present, with that. structural deformity is not predisposed, and that further etiological organisms are completely absent.

It is estimated that 80% of non-specific urethritis is. abacterial. Two forms are predominant: the acute type which resembles acute gonorrhea and the subacute or Welsh type. Abacterial pyuric conditions of the prostate and upper urinary tract have been known for a long time, and occasionally urethritis is associated with symptoms due to the upper urinary tract. Acute abacterial urethritis usually begins 1-5 days after intercourse. A violent discharge of matter occurs while the urinary opening becomes red, and accompanying dysuria occurs. That the posterior urinary tract is inflamed is indicated by frequent urination, pressure and finally hematuria. The clinical picture is so similar to what appears. in gonorrhea, that it is astonishing when Neisseria is not detectable. The differential diagnosis of a urethral discharge depends on the exclusion of the urethritis that presents as gonorrhea, as the first step after the exclusion of others, bacteria, foreign bodies, trauma, local tumors and specific inflammatory diseases, sensitivity reactions. urethral confirmation of systemic disease and attack by protozoa, metazoa

.and fungi.

The main object of the present invention is, as

mentioned above, to produce an instrument that will detect Neiss-

eria Gonorrhoeae in the man, without the use of culture or the classic gram stain method, both of which are time-consuming and expensive to perform, and which both require trained personnel and laboratory equipment.

The instrument according to the invention comprises, as mentioned, a carrier for a reagent from the group of oxidase testing reagents,

known as phenylenediamines, and a reagent selected from the following is used: p-aminodimethylaniline oxalate, N,N-dimethyl-p-phenylenediamine dihydrochloride, N,N-dimethyl-p-phenylenediamine oxalate, N,N-dimethyl-p-phenylenediamine-mono -hydrochloride and N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride. A support of any suitable material, such as dacron fiber, cotton fiber, or other porous material, is impregnated or saturated with one of these reagents under special conditions, described below, and then dried. It remains in a dry state until it is activated with a moisturizer.

The carrier is one of the main components of the instrument according to the invention, and it contains the reactive chemical compound

else able to identify gonococci. In a dry state, the carrier will remain stable and have a long life. Another important component is the wetting agent, which is separated from the carrier by being contained in a breakable container. When the crushable container is crushed, the wetting agent in it is released, and this activates the reagent on the carrier. This, after being sensitized, is brought into contact with the sample on the tip of a swab, reacts with the gonococci present and causes the sample on the swab to assume a characteristic color, depending on the reagent chosen.

The carrier is almost colorless in appearance and causes no disturbing reaction as it does not react colorimetrically. The color change occurs on the sample collected on the swab. The reaction time to indicate a positive sample usually lies

show within the range 30-120 sec.

The wetting agent in the container may consist of water, physiologically

salt, pH buffer solutions or any solution or combination of solutions which promotes the oxidase reaction or sensitizes it. The regulation of the pH value i

the wetting agent is desirable to prevent autoxidation of the reagent on the support. The preferred pH range for the wetting agent is 6.5-7.2. To further illustrate the procedure for carrying out the test using the aforementioned reagents, reference is made to the drawing where: fig. 1 shows a type of instrument suitable for use in carrying out the method for the detection of Neisseria Gonorrhoeae, and it shows the instrument before use in a sample in

the form in which it is sold, as a packaged system consisting of two main parts; and

fig. 2 shows the instrument which is shown in fig. 1, after it has been used for a test.

With further reference to the drawings; which shows a type of instrument for carrying out the method, 10 is a former of transparent flexible plastic into which a support 12 of cotton is pushed, which is impregnated or saturated with the reagent and dried. The carrier is placed in a crushable container 14, which is placed in the closed end of the tube, and a cap 16 is placed over the open end of the tube, while a sterile swab 18 with a plastic handle 20, which is to be used for collecting a. sample •

of the exudate, is sealed in a separate sterile envelope 22,

and the tube and envelope are packaged together in a wrapper or other suitable container not shown. While the wall structure of the plastic tube is flexible, the tube has sufficient rigidity to - usually maintain a general cylindrical shape and to allow easy insertion of the swab after a sample of the exudate is taken. The container contains a suitable wetting agent, such as. described herein, and is sufficiently brittle to that it can be easily V. crushed when the sides of the flexible tube are pressed inward between the thumb and the index finger, thereby shattering the container so that the liquid content moistens the material which is impregnated. usually pressed into the fluid and the broken glass, when the swab is introduced into the tube. When the swab, which contains the sample, comes into contact with the carrier, an instant - a - reaction takes place between the sample on the swab and the reagent in the carrier, and, ;:> ; " if gonococci are present, the swab sample will change '; color, usually to purple, red-orange or dark grey, depending on the reagent used in the carrier, thus indicating a •_ . positive sample. The reaction time to indicate one positive sample is usually in the range of 30-120 sec.; - v

Preferred components of the instrument according to the invention are illustrated below.

A 1% solution of N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride is prepared as follows: 1 gram of reagents is added to 35 ml of distilled water which has been brought to a boil and then cooled. The solution is effected by rapid stirring.

64 ml of ethyl alcohol ("Fisher A-407") is then added and this is stirred. Strips of cotton "vebril", 19.05 mm wide and 508 mm long, are then dipped one at a time in the solution, placed on a nylon sheet in a horizontal position and allowed to air dry. The dry strips are then cut into lengthwise pieces

of 14.29 mm. These are the carriers.

A physiological saline solution is prepared by adding 85 grams of sodium chloride to 99 ml of distilled water, and the pH

adjusted to 7.0. This solution becomes the wetting agent. Crushable containers containing \ml of this solution are prepared, as this is the amount necessary to completely wet a 19.05 mm wide by 14.29 mm long carrier.

The container, which has an approximate diameter of 7 mm and a length of 35 mm, is placed at the bottom of a flexible glass tube with an internal diameter of approximately 8 mm and a length of 160 mm. A carrier, which is produced by the above-mentioned technique, is rolled up and pressed down into the tube so that it comes into contact with the container. A telescopic hood with a length of approximately 65 mm is placed over it. the open end of the plastic tube to close the system. A sterile dacron swab, placed on a plastic stick, with a length of approximately 150 mm, is packed together with the reagent system, and this combination becomes the diagnostic instrument. This swab is available separately in its own sterile parchment envelope.

The above-mentioned simple package consisting of two units is suitable for sale through normal pharmaceutical channels to doctors, clinics and hospitals, and the package is immediately available for a sample, and rapid diagnosis of the patient's condition at the place where the sample is taken. When a diagnostic test for gonorrhea is to be carried out, the package is opened, the sterile swab is removed from its cover and a sample of the exudate is collected on the tip of the swab. The telescopic cap is then removed from the plastic tube, and the swab is inserted point first into the plastic tube. The telescopic cap is then put back on. The flexible. tubes are then pressed where the container is located to crush it and quadrate the contents. At the same time, the telescopic cap is pressed down and forces the sample-bearing swab into contact with the carrier. This also forces the wearer into the wetting agent to activate the system. The sample on the swab turns purple within two minutes, if there is a positive test for gonorrhea. The swab can be pulled out from the carrier about 2.5 cm to facilitate reading the test result, i.e. the color change that takes place in the sample on the swab. The use of this test therefore gives the doctor or clinic a quick and accurate diagnostic tool as the first step in the differential diagnosis.

To further demonstrate the sensitivity of this system and the ability to detect gonococci precisely at the point where the sample is collected on the swab, the above procedure is repeated and a culture of Neisseria Gonorrhoeae is used as representative of the exudate in the previous example. In this example, the swab is used to collect some colonies from a Petri dish culture. The same procedure is carried out with this instrument. A distinct purple staining of the bacteria on the swab will be noted within 1 min. The nearly colorless carrier and white background of the dacron swab makes identification of the organisms on the swab clear and distinct, just as it would be with the exudate directly from a patient.

Claims (1)

Instrument for use in the direct detection of Neisseria Gonorrhoeae without cultivation by inducing an initial distinct color change on a swab in the instrument after collecting a sample thereon, characterized in that the instrument comprises a dry carrier for an oxidase testing reagent which is p-amino-dimethylaniline oxalate , N,N-dimethyl-p-phenylenediamine dihydrochloride, N,.N-dimethyl-p-phenylenediamine oxalate, N,N-dimethyl-p-phenylenediamine monohydrochloride or N,N,N',N'-tetra-methyl-p- phenylenediamine dihydrochloride, and a crushable container for an activation fluid consisting of water, physiological saline or a buffer solution of pH 6.5-7.2, both of which known per se placed in a flexible tube with a telescopic cap, as well as a per se known swab designed for entering guiding a sample into the flexible tube, as a color change occurs on the swab when the sample is introduced and the container is crushed.