JPH06122606A - Antibacterial material selective to gram-negative bacteria and selective sterilization - Google Patents

Abstract

PURPOSE:To provide an antibacterial material selective to Gram-negative bacteria and a sterilization method selective to Gram-negative bacteria. CONSTITUTION:A thiosulfato silver complex solution is prepared by using silver chloride as the raw material and reacting sodium thiosulfate, sodium sulfite and sodium hydrosulfite therewith. Silica gel is added to the resultant solution to support the silver complex thereon. The mixture containing the thiosulfato silver complex solution and silica gel is evaporated to dryness and the silver complex-supporting silica gel is separated, thus producing the objective antibacterial material. It became clear after measuring MIC(minimal inhibitory concentration) of this antibacterial material that this antibacterial material exhibits an antibacterial activity selective to Gram-negative bacteria.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial material in which silver complex salt is supported on silica gel, and more particularly to an antibacterial material having selectivity for Gram-negative bacteria. Further, the present invention relates to a sterilization method using the antimicrobial material.

[0002]

2. Description of the Related Art Conventionally, an antibacterial material in which an antibacterial and antifungal material is supported on porous particles such as silica gel has been known. As one of such antibacterial materials, there is an antibacterial material in which a silver complex salt is supported on silica gel.

[0003]

However, an antibacterial material using a silver complex salt, which is selectively effective against a specific bacterium, is
It was not known yet. On the other hand, in the industrial world, particularly, only Gram-negative bacteria are cultivated, such as grading Gram-negative bacteria from a colony containing other useful bacteria and Gram-negative bacteria to propagate other useful bacteria. There was a long-awaited desire to become fungi.

In order to solve the above problems, an object of the present invention is to provide an antibacterial material having selectivity for Gram-negative bacteria and a sterilization method for selectively erasing Gram-negative bacteria.

[0005]

In order to solve the above-mentioned problems, an antibacterial material having selectivity for Gram-negative bacteria of the first invention of the present invention comprises a silver complex salt prepared from silver chloride supported on silica gel. The main point is that.

The selective sterilization method of the second invention is the first
The gist of the present invention is to selectively remove Gram-negative bacteria by using the antibacterial material of the invention. Hereinafter, the first invention of the present invention will be described in more detail. The silver complex salt usable in the present invention is not particularly limited except that it is prepared by using silver chloride as a starting material, but is not limited to cyano silver complex salt, ammine silver complex salt, silver sulfite complex salt, silver hydrogen sulfite complex salt, and thiosulfato silver complex salt. , Or a mixture thereof and the like, and particularly thiosulfato silver complex salt is preferable.

When silica gel is loaded with a silver complex salt other than silver chloride as a starting material, it exhibits antibacterial activity but shows no selectivity for Gram-negative bacteria. Further, in the case of an antibacterial material in which a silver complex salt using silver nitrate or silver acetate as a starting material is supported on silica gel, when water containing a halogen (excluding fluorine) such as tap water comes into contact with the antibacterial material, cloudiness may occur, In particular, when silver nitrate was used, browning due to light was a problem, but when silver chloride was used, these defects were not observed.

The silica gel used in the present invention is not particularly limited and can be manufactured by a known method such as a vapor phase method or a wet method. Also, the particle size of silica gel is not particularly limited, and an appropriate particle size can be selected and used according to the purpose of use. For example, when the antibacterial material of the present invention is mixed with a synthetic resin for the purpose of imparting antibacterial properties to the surface of the synthetic resin product, the average particle size thereof is preferably in the range of about 0.1 to 100 μm. Within this particle size range, the mixing efficiency with the synthetic resin becomes particularly good, and the antibacterial effect can be imparted evenly to the surface of the synthetic resin. Even if the particle size of the antibacterial material is smaller than this, there is no great difference in the antibacterial effect obtained on the surface of the synthetic resin, and the antibacterial material is likely to aggregate in the resin, resulting in poor dispersion. Further, when the particle size of the antibacterial material is large, there are disadvantages such that the tensile strength of the mixed synthetic resin is partially reduced. Therefore, the particle size of the antibacterial material when mixed with the synthetic resin is preferably within the above range.

The pore volume and the average pore diameter of silica gel can be selected in an appropriate range depending on the application. The method for supporting the silver complex salt on silica gel is not particularly limited, but silica gel is added to the solution containing the silver complex salt as a solute and stirred,
A method of adsorbing the silver complex salt on silica gel and then separating the silica gel from the solution by filtration or evaporation is convenient.

Further, a silica coating layer may be provided in order to impart a sustained release property to the silica gel carrying the silver complex salt. The coating method is not particularly limited, and examples thereof include a method in which silica gel carrying a silver complex salt is added to a solution of a silicon compound having a leaving group such as tetraalkoxysilane, and the mixture is stirred and dried, and the like.

In the antibacterial material of the present invention, most of the silver complex salt is adsorbed and carried by the pores of silica gel, and this silver complex salt is gradually released from the pores to exert an antibacterial effect on the surroundings. When the silica coating layer is provided on the surface, the release of the silver complex salt can be further restricted, and the effect of the antibacterial material can be maintained for a long period of time.

Next, the selective sterilization method of the second invention will be described in detail. In order to selectively remove Gram-negative bacteria by using the antibacterial material of the first invention, the antibacterial material is sprayed directly on the object or the target area, or the surface of the molded product is removed by mixing with the synthetic resin. It is possible to employ means such as sterilizing, mixing with a coating material and applying it to a target object or a target portion, or filling a column or the like with a liquid such as water that is in a sterilizing symmetry to pass through the antibacterial material. In addition to these, it is possible to use an appropriate means depending on the sterilization target and the like.

Since the antibacterial material of the present invention selectively eliminates Gram-negative bacteria, it is possible to eliminate only Gram-negative bacteria from colonies in which useful bacteria and Gram-negative bacteria are mixed.

[0014]

EXAMPLES The present invention will be described in detail below with reference to preferred examples of the present invention. However, it goes without saying that the present invention is not limited to the following examples and can be implemented in various modes. [Example 1] 32 g of sodium thiosulfate was added to 300 ml of ion-exchanged water at 40 ° C, and mixed and stirred to dissolve,
4 g of silver chloride was added and stirred to completely dissolve silver chloride. Sodium sulfite (0.8 g) and sodium hydrogen sulfite (0.8 g) were added to this solution with stirring, and the stirring was continued until the solution became transparent to obtain a thiosulfato silver complex salt solution.

This thiosulfato silver complex salt solution was added to silica gel having an average particle diameter of 2.6 μm (trade name: Sylysia # 55).
0, 100 g of Fuji Silysia Chemical Ltd. was added and stirred for about 5 minutes to support the silver complex salt on silica gel. continue,
The mixture of the thiosulfato silver complex salt solution and silica gel was heated by a rotary evaporator (trade name: rotary evaporator RE47, manufactured by Yamato Scientific Co., Ltd.) at a temperature of about 60 ° C.
The antibacterial material of the present invention was obtained by evaporating and removing the solvent component while maintaining the pressure at about 3000 Pa or less. Example 2 64 g of sodium thiosulfate was added to 300 ml of ion-exchanged water at 40 ° C., mixed and stirred to dissolve, and then 8 g of silver chloride was added and stirred to completely dissolve silver chloride. Sodium sulfite (1.6 g) and sodium hydrogen sulfite (1.6 g) were added to this solution with stirring, and the stirring was continued until the solution became transparent to obtain a thiosulfato silver complex salt solution.

In this thiosulfato silver complex salt solution, silica gel having a mean particle size distribution of 2.6 μm (trade name Sylysia # 55
0, 100 g of Fuji Silysia Chemical Ltd. was added and stirred for about 5 minutes to support the silver complex salt on silica gel. continue,
The mixture of the thiosulfato silver complex salt solution and silica gel was heated by a rotary evaporator (trade name: rotary evaporator RE47, manufactured by Yamato Scientific Co., Ltd.) at a temperature of about 60 ° C.
The antibacterial material of the present invention was obtained by evaporating and removing the solvent component while maintaining the pressure at about 3000 Pa or less. [Example 3] 50 g of the antibacterial material of Example 1, 50 g of tetraethoxysilane, 90 g of methanol and 10 parts of ion-exchanged water.
The mixture is mixed with g and the solvent component is removed by a rotary evaporator while keeping the temperature at 50 ° C. and the pressure at about 3000 Pa or less, and simultaneously silica coating is applied. The solidified product was further dried in a rotary evaporator under vacuum for 12 hours to obtain an antibacterial material of the present invention. [Example 4] A silica coating was applied in the same manner as in Example 3 except that 50 g of the antibacterial material of Example 2 was used to obtain an antibacterial material of the present invention. [Comparative Example 1] 2.32 g of silver acetate was added to 300 ml of ion-exchanged water at 40 ° C., and the mixture was stirred with a homogenizer for about 5 minutes to obtain a silver acetate solution. Sodium sulfite 1 in this silver acetate solution
0.0 g was added with stirring and stirring was continued until the solution became clear. Then, 6.6 g of sodium thiosulfate was added to this solution and stirred for about 5 minutes to obtain a thiosulfato silver complex salt solution.

This thiosulfato silver complex salt solution was added to silica gel having an average particle diameter of 2.6 μm (trade name: Sylysia # 55).
0, 50.0 g of Fuji Silysia Chemical Ltd. was added and stirred for about 10 minutes to support a silver complex salt on silica gel. Subsequently, the mixture of the thiosulfato silver complex salt solution and silica gel was heated at a temperature of about 5 with a rotary evaporator (trade name: rotary evaporator RE47, manufactured by Yamato Scientific Co., Ltd.).
The solvent component was removed by evaporation by keeping the pressure at 0 ° C. and the pressure at about 3000 Pa or less to obtain a silica gel carrying a silver complex salt. [Measurement of MIC (Minimum Inhibitory Concentration)] Examples 1 to 1 above
Using the antibacterial material obtained in No. 5 and Comparative Example 1 as samples, the minimum inhibitory concentration was measured by the following method.

That is, a plurality of agar plate media to which a sample is added at an arbitrary concentration is inoculated with the inoculum bacterial solution and cultured. The minimum concentration of the sample when the growth of the bacteria was inhibited was defined as the minimum inhibitory concentration. The results are shown in Table 1. The preparation of the agar plate medium, the preparation of the inoculum bacterial solution and the culture were performed as follows. -Preparation of agar plate medium A sample suspension having the following concentration was prepared with sterile purified water. Sample concentration is 40,000ppm, 20,000ppm, 1
50,000ppm, 5,000ppm, 2,500pp
m, 1,250 ppm, 625 ppm, 313 ppm,
It is 156 ppm and 78 ppm.

Next, each of the above suspensions was added to a medium for sensitivity measurement (Mueller-Hinton agar medium (manufactured by DIFCO)) which became 50 to 60 ° C. after thawing to 1 / of the medium.
After adding 9 volumes and thoroughly mixing, the mixture was divided into a petri dish and solidified to obtain an agar plate medium. In addition, an agar plate medium was prepared in the same manner as above using the same silica gel used in the examples as a sample, and this was used as a comparative example.・ Preparation of bacterial solution for inoculation Enrichment medium [Mueller Hinton Broth (Muel
Ler-Hinton Broth (manufactured by DIFCO)], the bacterial solution of the test strain that had been cultured overnight at 35 ° C. was diluted with the same medium so that the number of bacteria per ml was about 10 ⁶ . The test strains used are as follows.

Staphylococcus aureus: Staphylococcus aureu
s) IFO 12732 E. coli: Escherichia coli
ia coli) IFO 3301 Pseudomonas aeruginosa: Pseudomonas aeruginosa (Pseudo)
monas aeruginosa) IID P-1 CYTOLOBACTOR: CYTOBACTER FREUNDII IF
O 12681 Klebshulla: Klebshulla New Monnier (Kleb
siella pneumoniae) IFO 13
277 Proteus: Proteus Bulgaris
vulgalis) IFO 3988 Salmonella: Salmonella Galinarum (Salmone)
lla gallinarum) IFO 3163 Serratia: Serratia marcescens (Serratia)
marcescens) IFO 12648 While Staphylococcus aureus belongs to Gram-positive bacteria,
Escherichia coli, Cytobacter, Klebsiella, Proteus, Salmonella and Serratia belong to Gram-negative bacteria. -Culturing The bacterial solution for inoculation was smeared on an agar plate medium with a nichrome wire loop (internal diameter of about 1 mm) for about 2 cm, and cultured at 35 ° C for 1 day.

[0021]

[Table 1]

As is clear from Table 1, the growth of gram-negative bacteria was selectively inhibited on the agar plate medium containing the antibacterial materials of Examples 1 to 5 as a sample. Therefore, the antibacterial material of the present invention has selectivity for Gram-negative bacteria. On the other hand, Comparative Example 1 has antibacterial activity, but no selectivity for Gram-negative bacteria was observed.

[0023]

INDUSTRIAL APPLICABILITY As described above, the antibacterial material of the present invention having selectivity for Gram-negative bacteria is selectively effective against Gram-negative bacteria, and when it is used, it selectively removes Gram-negative bacteria. Can be fungi.

Claims (3)

[Claims] 1. An antibacterial material having selectivity for Gram-negative bacteria, which comprises supporting a silver complex salt prepared from silver chloride on silica gel. 2. The antibacterial material having selectivity for Gram-negative bacteria according to claim 1, wherein the silver complex salt is a thiosulfato silver complex salt. 3. A selective sterilization method comprising using the antibacterial material according to claim 1 to selectively eradicate Gram-negative bacteria.