Treatment of clostridium difficile diarrhoea and pseudomembranous colitis.

0001This invention relates to a preventive and/or curative pharmaceutical composition for <u style="single">Clostridium</u><u style="single">difficile</u> diarrhoea and pseudomembranous colitis.

0002The antibacterial agent vancomycin (VCM) is particularly active against <u style="single">Clostridium difficile</u> and has therefore been used in the treatment of <u style="single">Clostridium difficile</u> diarrhoea and pseudomembranous colitis. However, <u style="single">Clostridium difficile</u> is known to form spores in the gastrointestinal tract and these spores are resistant to antibacterial agents and therefore cannot be easily eliminated even by prolonged chemotherapy with vancomycin. Because the spores of <u style="single">Clostridium difficile</u> can survive the therapy it is possible for them to germinate and propagate, resulting in a recurrence of the disease. In addition, it is possible that the prolonged administration of vancomycin to a patient will cause further disturbance of that patient's intestinal microflora which may induce new infections under the disturbed microflora and/or increase the resistance of the pathogenic bacteria to chemicals or other substances.

0003If vancomycin is administered over a short period of time, further problems occur in that the ratio of survival of the spores is high and consequently, frequent recurrences of the disease induce asthenia in the patient.

0004The object of the present invention is therefore to overcome the problems in the treatment of <u style="single">Clostridium difficile</u> diarrhoea and pseudomembranous colitis by the short term use of an antibacterial agent such as vancomycin together with an agent which is capable of eliminating surviving spores whilst not obstructing the restoration of intestinal microflora.

0005In order to achieve this object, the present invention provides a pharmaceutical and/or veterinary composition, comprising cells or spores of a butyric acid bacterium and an antibacterial agent. The antibacterial agent is preferably vancomycin.

0006The use of such a composition is particularly advantageous because it not only prevents and/or cures the diseases mentioned above but also has extremely low toxicity.

0007Preferred embodiments of the invention will now be described.

0008The present inventors have conducted various experiments with the aim of expediting the cure of <u style="single">Clostridium difficile</u> diarrhoea and pseudomembranous colitis and preventing the recurrence of these diseases using a shortened period of administration of an anti-bacterial agent such as vancomycin. The experiments comprise inducing diarrhoea in golden hamsters by the administration of Cefatrizine (CFT), an antibiotic substance generally known as a morbidity model for <u style="single">Clostridium difficile</u> diarrhoea and monitoring the recurrence of the diseases after therapy with vancomycin by observing symptoms of diarrhoea. The affected hamsters were fed with <u style="single">Clostridium butyricum</u> MIYAIRI 588 (CbM), a species of a butyric acid bacteria, as a remedy. The remedy was found to produce highly favourable results.

0009It was observed that in the recurrence models, when the administration of vancomycin was terminated (after 3 days administration) on improvement of faecal condition, the <u style="single">Clostridium difficle</u> showed positive culture and was detected in the form of spores. Toxicogenic <u style="single">Clostridium difficile</u> and its toxins were detected in the gastrointestinal tracts of the dead animals indicating that the disease had reccurred. Even when administration of vancomycin was continued after improvement of faecal condition (for a total of 10 days), the animals still showed discernible signs of recurrence of the disease within about 5 days although the <u style="single">Clostridium difficile</u> did show negative culture.

0010In a further experiment, vancomycin was administered to the animals for 3 days and the animals were then fed for 20 days with a feed incorporating ground dry cells of CbM in a proportion such that the animals could ingest approximately 10⁸CFU of the CbM spores per day after which they were fed with a feed containing no CbM. In this experiment, there was a conspicuous decrease in the ratio of recurrence of the diseases and negative culture of <u style="single">Clostridium difficile</u> was attained. CbM is an anaerobic sporal bacterium which propagates and forms spores in an ordinary culture medium under anaerobic conditions. An example of suitable conditions is a bouillon containing 2% corn starch.

0011From the results of the experiments it can be concluded that an antibacterial agent such as vancomycin is capable of destroying abnormally over propagated <u style="single">Clostridium difficile</u>. The treatment of the animals with ground dry cells of CbM in a daily dose of about 10⁹CFU/kg is effective in preventing recurrence of the disease.

0012In the composition of the invention, it is preferred that the amount of vancomycin is in the range of 1mg to 10g and preferably 10mg to 10g and 10⁸CFU of the cells or spores of butyric acid bacterium. The amount of the composition administered to a patient should be in the range of 10⁶ to 10⁹CFU and preferably 10⁶ to 10⁸CFU as cell or spores of butyric acid bacterium per kg of human body weight. The composition is for medical or veterinary use and may be orally administered to patients. The composition may also include a pharmaceutically acceptable carrier.

0013The term "butyric acid bacterium" refers to a microorganism which yields butyric acid as a product of its metabolism. <u style="single">Clostridium butyricum</u> has been found to be particularly effective in the compositions of the invention.

0014A major advantage of the compositions of the invention is that they exibit extremely low accute and chronic toxicity.

0015Specific embodiments of the invention will now be described with reference to the examples.

0016<u style="single">Clostridium butyricum</u> MIYAIRI 588 used in the experiments has been deposited at Fermentation Research Institute under FERM-BP 2789 and <u style="single">Clostridium difficile</u> Ha.16 has been deposited at the same institute under FERM-BP 2877.

Example 1

0017Morbidity models of recurring <u style="single">Clostridium difficile</u> diarrhoea were produced by orally administering to five golden hamsters (60g, male) a suspension of 4.5mg potency of CFT in 0.2ml of purified water with the aid of a catheter. After the CFT treatment, the animals were observed. When any of the animals showed a sign of faecal abnormalities such as diarrhoea or loose passage, a solution of 3mg potency of vancomycin in 0.2ml of purified water was orally administered to that animal six times at 12 hour intervals. All of the treated animals were observed and their rectal faeces were sampled at intervals. The samples were anaerobically cultured for bacterial isolation in a CCFA culture medium (37°C, 72 hours). The isolated <u style="single">Clostridium difficile</u> was placed in a BHI broth and was again cultured (37°C, 48 hours). In the resultant culture broth, the bacteria was tested for toxin-producing ability using a latex reagent (the D-1 toxin of <u style="single">Clostridium difficile</u> can be detected at 500mg/ml (sample)). The diarrhoea faeces of live hamsters and the gastrointestinal tract contents of dead hamsters were also tested for presence or absence of toxin.

0018Table 1 compares a number of samples and, for each sample shows whether the D-1 toxin of <u style="single">Clostridium difficile</u> was present, and if so, the lethal activity of a toxin on healthy hamsters when the sample was administered to the hamsters in an amount of 1.4 x 10⁸CFU/g.

0019Table 2 gives an analysis of the biochemical characteristics of <u style="single">Clostridium difficile</u> Ha. 16.

0020Table 3 shows an analysis of cases in which six doses of vancomycin were administered to the animals and bought about a discernible improvement in the faecal state but was not so effective as to show negative culture of <u style="single">Clostridium difficile</u>. As can be seen from Table 3, all of the animals died of recurrence diarrhoea within 6 to 11 days after the termination of the administration of vancomycin. The limit of detection of <u style="single">Clostridium difficile</u> from faeces was 400CFu/g (faeces).

Example 2

0021Animals were treated with long term administration of vancomycin with or without subsequent feeding with CbM. The purpose of this was to attempt to prevent the recurrence of <u style="single">Clostridium difficile</u> diarrhoea and to effect speedy elimination of <u style="single">Clostridium difficile</u> from the interior of the intestinal tract. In the experiment, five animals were treated in the same manner as for example 1 (A group), five animals were subjected to administration of 14 doses of VCM after the end of the treatment of example 1 (B group) and five animals were treated in the same manner as for example 1 and were then allowed to consume for 17 days a feed incorporating ground dry cells of CbM in such a proportion as to allow ingestion of 1 to 5x10⁸CFU of CbM spores per day and thereafter were allowed to consume an ordinary feed containing no CbM (C group). After the treatment, all of the animals were observed and <u style="single">Clostridium difficile</u> was isolated from their intestinal faeces and tested for detection of D-1 toxin. The culture (37°C, 72 hours) for isolation of CbM was anaerobically carried out in a 5% horse blood BL Agar containing 350mg of cycloserine, 1mg of kanamycin, 75 µg of clindamycin and 12mg of trimethoprim per litre of culture medium.

0022As can be seen from Tables 4 and 5, the B group, when compared with the à group 48 hours after the termination of administration of vancomycin, showed improvement in the faecal state and a discernible decrease of the ratio of <u style="single">Clostridium difficile</u> detection (one out of five animals). In all of the animals under test, the disease recurred after 5 to 8 days follwing the termination of long term administration of vancomycin. This is because, in a gastrointestinal tract which has sub-axenic conditions caused by the long term adminstration of vancomycin, a small number of spores which would normally be prevented from propagation by the intestinal microflora are allowed to germinate and propagate. This effect results in the recurrence of the disease in the B group. In contrast, in the C group, although the recurrence of the disease was observed in two of the five animals, negative culture of <u style="single">Clostridium difficile</u> was finally attained in the remainder of the animals, representing a survival rate of 60%. It can therefore be seen that the therapy comprising short term administration of vancomycin together with a continuous administration of CbM was effective in preventing germination and propagation of <u style="single">Clostridium difficile</u> in the intestine without imparing the intestinal microflora and thereby obtaining complete cure of the disease including prevention of the recurrence of the disease.