Disinfection method and disinfection device

Abstract

To provide a disinfection method and disinfection apparatus that can achieve high disinfection efficacy even with low concentrations of low-level disinfectants. [Solution] The disinfection method according to the present invention is a disinfection method for disinfecting a pathogen 1 having a lipid bilayer 3 using a flowable disinfectant 10, wherein the disinfectant 10 and the pathogen 1 are reacted within a temperature range of 40 to 55°C.

Description

【Technical Field】 【0001】 The present invention relates to a disinfection method and a disinfection device. 【Background Art】 【0002】 Patent Document 1 discloses a contact lens disinfection and storage solution using high molecular weight polyhexamethylene biguanide (Polyhexanide, hereinafter referred to as "PHMB") as a disinfectant. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Publication No. 06-049642 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 However, generally, PHMB is a disinfectant with a relatively low disinfection effect (hereinafter referred to as "low-level disinfectant"), so there is a problem that contact lenses cannot be sufficiently disinfected depending on the usage state, usage mode, etc. 【0005】 Such problems can be solved by using a disinfectant with a high disinfection effect (for example, a high-level disinfectant such as glutaral or a medium-level disinfectant such as sodium hypochlorite) or adopting a disinfection method (environmental disinfection) such as ultraviolet irradiation or boiling. 【0006】 However, in the former case, since the toxicity inevitably increases, there are concerns about the impact on the human body (safety), and in some cases, it may cause environmental pollution. 【0007】 On the other hand, in the latter case, the overall configuration of the device becomes complex and costly, and the risks involved in operating it (for example, skin damage due to heat or ultraviolet rays) increase. In addition, problems such as discoloration or deterioration of the contact lenses being disinfected may occur. 【0008】 The present invention aims to provide a disinfection method and a disinfection apparatus that can achieve a high disinfection effect even with low-level disinfectants. [Means for solving the problem] 【0009】 The disinfection method in the present invention is a disinfection method for disinfecting a pathogen having a lipid bilayer using a flowable disinfectant, wherein the disinfectant and the pathogen are reacted within a temperature range of 40 to 55°C. 【0010】 Preferably, the time for which the temperature is maintained is within 3 hours. 【0011】 Furthermore, the disinfection apparatus in the present invention is a disinfection apparatus for disinfecting pathogens having a lipid bilayer using a flowable disinfectant, and comprises a disinfection container for reacting the disinfectant and the pathogen at a temperature range of 40 to 55°C. 【0012】 Preferably, the disinfection container is a container for disinfecting contact lenses. [Effects of the Invention] 【0013】 According to the present invention, despite its relatively simple configuration, a high disinfecting effect can be reliably obtained even with low-concentration, low-level disinfectants that are ineffective at room temperature (25°C). [Brief explanation of the drawing] 【0014】 [Figure 1] This is a schematic diagram of the pathogen according to this embodiment, where (a) shows the outer membrane (lipid bilayer) of the pathogen in the gel phase state, and (b) shows the lipid bilayer of the pathogen in the liquid crystal phase state. [Figure 2]This graph shows the relationship between emission intensity and fluorescence wavelength obtained during a test to evaluate the membrane fluidity of pathogens. [Modes for carrying out the invention] 【0015】 Embodiments of the present invention will be described below with reference to the drawings. 【0016】 Figure 1 is a schematic diagram of the lipid bilayer of the pathogen according to this embodiment, and Figure 2 is a graph showing the relationship between emission intensity and fluorescence wavelength obtained when a test was conducted to evaluate the membrane fluidity of the pathogen. 【0017】 <Overall Structure> As shown in Figure 1, the disinfection method and disinfection apparatus according to this embodiment are used when disinfecting and sterilizing pathogens 1 using a fluid disinfectant 10. 【0018】 (Pathogen 1) Pathogen 1 is composed of protoplasm 2 having cytoplasm containing a nucleus and proteins, and a lipid bilayer 3 covering protoplasm 2. The lipid bilayer 3 forms the basic structure of the cell membrane (biological membrane) and is a two-layer membrane mainly composed of phospholipids. In the following, to facilitate understanding of the invention, pathogen 1 will be described using a cyst-formed "Acanthamoeba" (hereinafter referred to as "Acanthamoeba (cyst)") as an example. However, the present invention is not limited to the Acanthamoeba (cyst) described above, but can also be applied to other pathogens having a lipid bilayer, such as bacteria (Pseudomonas aeruginosa, Serratia, Clostridium, Streptococcus pneumoniae, Staphylococcus aureus, etc.), fungi (Candida, Aspergillus, etc.), protozoa (Amoebae, Cryptosporidium, etc.), and viruses (especially enveloped viruses such as influenza virus, coronavirus, and herpesvirus). In bacteria, this includes the spore form, and in protozoa, it also includes the cyst (oocyst) form. 【0019】 (Disinfectant 10) The disinfectant 10 is a drug capable of disinfecting and sterilizing the pathogen 1 to be disinfected. In this embodiment, as the disinfectant 10 for disinfecting and sterilizing the pathogen 1 (Acanthamoeba (cyst)), Benzalkonium chloride (hereinafter referred to as "BAC") or the above-mentioned PHMB (Polyhexamethylene biguanide) is used. These BAC and PHMB are drugs classified as low-level disinfectants. Note that the disinfectant 10 is not limited to BAC and PHMB, and can be appropriately selected according to the desired pathogen on the condition that it has fluidity. That is, the disinfectant here means all disinfectants effective against the target pathogen. Such disinfectants include, for example, surfactant-based disinfectants (one of which is BAC), biguanide-based disinfectants (one of which is PHMB), chlorine-based disinfectants, low-concentration peracetic acid preparations, hydrogen peroxide preparations, and the like. 【0020】 Here, the Acanthamoeba as the pathogen 1 according to this embodiment will be described. Generally, Acanthamoeba is known as a pathogen that causes keratitis and encephalitis in humans and other animals in some of its species. In particular, in contact lens users, using contact lenses contaminated with Acanthamoeba may cause keratitis (Acanthamoeba keratitis), so it is important to properly clean and maintain the contact lenses. 【0021】 As a method for disinfecting contact lenses, a technique of immersing the contact lenses in a disinfectant (disinfecting solution) stored in a contact lens case is typical. Such disinfectants include, for example, known multi-purpose solutions (Multi-Purpose Solution, hereinafter referred to as "MPS") containing the above-mentioned PHMB, BAC, etc. In this regard, the PHMB and BAC used in this embodiment can be said to be effective disinfectants for disinfecting and sterilizing contact lenses. 【0022】 <Test> In this embodiment, in order to verify the disinfecting effect of the disinfectant 10, under multiple temperature environments, • A test to evaluate the membrane fluidity of pathogen 1 (hereinafter referred to as "Test 1") • A test to evaluate the disinfecting effect of pathogen 1 upon exposure to disinfectant solution 10, etc. (hereinafter referred to as "Test 2") The following was conducted. It should be noted that Acanthamoeba (cyst), used as pathogen 1 in this study, is one of the pathogens with the strongest disinfectant resistance among the pathogens 1. Cysts of other protozoa and bacterial spores also exhibit similar resistance. 【0023】 (Test 1) In Experiment 1, fluorescence measurements using Laurdan were performed under multiple temperature conditions, and the GP (Generalized Polarization) value for each temperature was calculated to evaluate the membrane fluidity of pathogen 1. 【0024】 Specifically, Test 1 was conducted using the following procedure. (1) Stain pathogen 1 with Raurdan at 37°C for 4 hours, then centrifuge and 10 5 The concentration was adjusted to 1 / ml. (2) Using a blade reader, the fluorescence intensity of pathogen 1 prepared in (1) above was measured at excitation wavelength: 380 nm and fluorescence wavelengths: 440 nm (I440) and 490 nm (I490) under various temperature conditions of 25°C, 30°C, 35°C, 40°C, 45°C, and 50°C. (3) Based on the measurement results in (2) above, the GP value was calculated using the following formula. GP value = (I440 - I490) / (I440 + I490) 【0025】 Figure 2 is a graph showing the relationship between emission intensity and fluorescence wavelength, created based on the measurement results in (2) above, and Table 1 below shows the GP values ​​for each temperature obtained in (3) above. 【0026】 [Table 1] 【0027】 Figure 2 and Table 1 show that both the luminescence intensity (see Figure 2) and the GP value (see Table 1) decrease with increasing temperature ("25°C → 50°C"). In particular, it was found that the rate of decrease in the GP value increases significantly from around "40°C," with the rate of decrease being greatest between "45 and 50°C." 【0028】 Such a rapid decrease in GP values ​​indicates that the fluidity of the lipid bilayer 3 (membrane) of pathogen 1 has increased, causing pathogen 1 to transition from a gel-like state (gel phase, see Figure 1(a)) to a liquid crystal state (liquid crystal phase, see Figure 1(b)), that is, • The disinfectant 10 (disinfectant component) is in a state where it can easily pass through the lipid bilayer 3 and reach the interior (protoplasm 2), or, • The lipid bilayer 3 itself is destroyed, making it easier for the disinfectant 10 to reach the interior. It means that. 【0029】 From the results of this experiment 1, it was found that when the temperature reaches around "40°C", the lipid bilayer 3 begins to undergo a phase transition from the gel phase to the liquid crystal phase, and when the temperature reaches "45-50°C", the membrane fluidity of pathogen 1 improves dramatically. 【0030】 (Exam 2) In Test 2, a fixed amount of pathogen 1 was exposed to multiple predetermined media for a fixed period of time under various temperature conditions. Based on the results, the logarithmic reduction value (LRV) was calculated to evaluate the disinfectant effect of pathogen 1. 【0031】 Test 2 was conducted under the following conditions. ·Temperature environment: 25℃, 40℃, 45℃, 50℃ • Materials used: Pure water, disinfectant 10 containing 0.001 w / v% BAC, and disinfectant 10 containing 0.001 w / v% PHMB • Exposure time: 1 hour In the following, for the sake of clarity, disinfectant 10 containing 0.001 w / v% BAC will also be referred to as "disinfectant 10A," and disinfectant 10 containing 0.001 w / v% PHMB will also be referred to as "disinfectant 10B." 【0032】 Furthermore, the highest known ratio of PHMB(BAC) contained in MPS is approximately 0.001 W / V%, which is roughly the same value as disinfectants 10A and 10B used in this study 2. 【0033】 Table 2 below shows the logarithmic decrease values ​​for each of the above conditions in Test 2. 【0034】 [Table 2] 【0035】 Now, let's discuss logarithmic decrease. The logarithmic decrease value is a value that represents the degree (degree) of reduction of pathogen 1, and that value is, for example, • If the result is "0", it means that pathogen 1 has not decreased. • If the result is "1", it means that pathogen 1 has decreased by 90%. • In the case of "2", it means that pathogen 1 has been reduced by 99%. • In the case of "3", it means that pathogen 1 has been reduced by 99.9%. Each is shown. In other words, an increase of 1 in the logarithmic decrease value means that the disinfection effect increases significantly. 【0036】 Table 2 shows that when "used medium: pure water," pathogen 1 was not reduced at all at "usage environment: 25°C (1 hour)," and was hardly reduced (not killed) even at "usage environment: 40°C, 45°C, and 50°C (1 hour)." From this, it can be seen that pathogen 1 (Acanthamoeba (shift)) has heat resistance and is hardly killed by heating to 50°C alone. 【0037】 On the other hand, in the case of "medium used: disinfectant 10A", the following results were obtained: "logarithmic reduction value: 0.25" at "usage environment: 25℃ (1 hour)", "logarithmic reduction value: 1.5" at "usage environment: 40℃ (1 hour)", "logarithmic reduction value: 3.0" at "usage environment: 45℃ (1 hour)", and "logarithmic reduction value: 5.0" at "usage environment: 50℃ (1 hour)". In other words, in the case of "medium used: disinfectant 10A", the disinfection effect began to increase from "40℃", and it was found that the disinfection effect improved dramatically when pathogen 1 was exposed to disinfectant 10A under temperature environments of "45℃" and "50℃". In particular, it was found that pathogen 1 could be roughly sterilized under temperature environments of "50℃". 【0038】 On the other hand, in the case of "medium used: disinfectant 10B", the following results were obtained: "logarithmic reduction value: 1.25" at "usage environment: 25℃ (1 hour)", "logarithmic reduction value: 2.5" at "usage environment: 40℃ (1 hour)", "logarithmic reduction value: 3.75" at "usage environment: 45℃ (1 hour)", and "logarithmic reduction value: 4.0" at "usage environment: 50℃ (1 hour)". In other words, in the case of "medium used: disinfectant 10B", the disinfection effect begins to increase from "40℃", and when pathogen 1 is exposed to disinfectant 10B under temperature environments of "45℃" and "50℃", the disinfection effect is significantly improved, similar to disinfectant 10 containing 0.001 W / V% BAC, and in particular, it was found that pathogen 1 can be roughly sterilized under temperature environments of "50℃". 【0039】 Thus, in the case of "medium used: disinfectants 10A and 10B," the disinfection effect began to improve when the temperature was raised to "40°C," the disinfection effect of disinfectant 10 improved dramatically when the temperature was raised to "45°C," and it was found that pathogen 1 could be roughly sterilized when the temperature was raised to "50°C." 【0040】 Furthermore, the results of Test 2 confirmed that, in the case of disinfectants 10A and 10B (disinfectant components of known MPS), pathogen 1 could not be effectively disinfected at a temperature of "25°C" (room temperature). 【0041】 In addition, in Test 2, the above conditions apply. • Exposure time: 1 hour or more We then added these additional conditions and conducted the test. 【0042】 As a result, it was found that when pathogen 1 was exposed to disinfectants 10A and 10B for 3 hours under temperature conditions of 45°C and 50°C, pathogen 1 could be disinfected almost completely. 【0043】 In Test 2, we used BAC (disinfectant 10A) with a content of 0.001 W / V% and PHMB (disinfectant 10B) with a content of 0.001 W / V% as examples. However, provided that the concentration is sufficient to exhibit disinfectant effects, for example, 0.001 W / V% GCH (chlorhexidine gluconate) may be used instead of 0.001 W / V% PHMB, or the PHMB content may be changed to 0.0005% or more and less than 0.001 W / V%, and polydronium chloride or known MPS may also be used. 【0044】 To summarize the results of the above tests 1 and 2, by setting the reaction temperature between pathogen 1 and disinfectant 10 to "40-50°C", (1) The lipid bilayer 3 of pathogen 1 transitions from the gel phase to the liquid crystal phase, causing a rapid decrease in the GP value. (2) The permeability of the disinfectant 10 to pathogen 1 is improved. (3) The lipid bilayer 3 becomes fragile, (4) The disinfectant 10 (disinfectant component) is in a state that allows it to easily pass through the lipid bilayer 3 and reach the interior (protoplasm 2), or the lipid bilayer 3 itself is destroyed so that the disinfectant 10 can easily reach the interior. This became clear, and as a result, (5) The disinfectant effect of the disinfectant 10 against pathogen 1 is improved. (6) More specifically, when the temperature reaches "40°C", the membrane fluidity decreases and the disinfection effect begins to increase, and these values ​​reach their maximum around "45-50°C". It was revealed that... 【0045】 Furthermore, looking at Tables 1 and 2, from the trend of change (transition trend) in the values ​​(GP value and logarithmic decrease value) when the temperature is increased from "45°C" to "50°C", it is possible to predict that the disinfection effect when the temperature is increased from "50°C" to "55°C" will be maintained at "55°C" or slightly increase (decrease) compared to "50°C". 【0046】 Therefore, it is desirable to set the upper limit of the temperature at which pathogen 1 and disinfectant 10 react (the upper limit of the temperature at which the disinfectant effect is exerted) to "55°C" rather than "50°C" as measured in tests 1 and 2, from the standpoint of facilitating temperature adjustment when disinfecting pathogen 1. 【0047】 Furthermore, although Acanthamoeba (cyst) was used as an example of pathogen 1 in the above embodiment, other pathogens can of course be used. In this case, it is preferable to determine the temperature at which the disinfection effect against other pathogens can be exerted (optimal disinfection temperature). Such a temperature can be determined by determining the GP value of the pathogen in question, following the example of Test 1 described above. 【0048】 Table 3 below shows the GP values ​​for each temperature when the test was conducted under the same conditions as Test 1 described above, using "fungus (Candida)" (pathogen), which is an example of another pathogen. 【0049】 [Table 3] 【0050】 When the pathogen is a fungus (Candida), as shown in Table 3, it can be seen that the membrane fluidity of the fungus (Candida) improves significantly when the temperature is set to 40°C or higher. 【0051】 Taking these results into account, it can be seen that for other pathogens besides Acanthamoeba (cysts), the lower limit of the temperature at which disinfectants can be reacted is "40°C". 【0052】 In this regard, it can be said that the temperature range for disinfectants to effectively exert their disinfecting effect against pathogens (almost all pathogens) is "40 to 55°C". 【0053】 As described above, according to this embodiment, by reacting the pathogen 1 and the disinfectant 10 within the range of "40 to 55°C", the membrane fluidity of the pathogen 1 can be increased, and consequently, the disinfectant effect of the disinfectant 10 on the pathogen 1 can be significantly improved. 【0054】 Furthermore, in this embodiment, since the temperature at which the pathogen 1 and the disinfectant 10 react is relatively low ("40-55°C"), the risk of burns, etc., when disinfecting the pathogen 1 can be reduced, and discoloration or deterioration (thermal damage) of the object to be disinfected (for example, contact lenses) can be effectively prevented. [Examples] 【0055】 The following describes specific examples of the present invention, but the present invention is not limited to these. 【0056】 (Example 1) The present invention can be applied to a contact lens case capable of containing disinfectant solution 1. In this case, the contact lens case should be equipped with a heating means (e.g., a heater) capable of heating the contained disinfectant solution 1 to a temperature range of "40 to 55°C". The above contact lens case corresponds to the "disinfectant container" described in the claims. 【0057】 With this configuration, by placing a drug containing BAC or PHMB (for example, a known MPS) in the contact lens case, it is possible to effectively disinfect Acanthamoeba (pathogen 1) as described above. 【0058】 Furthermore, in the contact lens case according to this embodiment 1, it is possible to disinfect contact lenses at a relatively low temperature, which can suppress the denaturation of protein deposits (protein denaturation) attached to the contact lenses, and effectively prevent adverse effects such as deterioration of wearing comfort caused by protein denaturation. 【0059】 (Example 2) Furthermore, the present invention can also be applied to systems for disinfecting tap water. Such a configuration can be realized, for example, in a water treatment plant that disinfects raw water (e.g., water from a river, etc.), by providing a heating means capable of heating the water to a range of "40 to 55°C" in a water treatment tank or the like into which chlorine is added. The above-mentioned water treatment tank or the like corresponds to the "disinfection container" described in the claims. 【0060】 This configuration makes it possible to effectively disinfect pathogens that were previously difficult to disinfect (for example, Acanthamoeba, Cryptosporidium, and bacteria that parasitize them) with a lower chlorine concentration. 【0061】 (Example 3) Furthermore, the present invention can also be used as a device for disinfecting tableware, kitchen utensils, etc., in a household setting. Such a configuration can be realized, for example, by providing a container in which tableware, etc., can be soaked, with a heating means capable of heating commercially available household bleach (a disinfectant containing sodium hypochlorite) in the range of "40 to 55°C". The above-mentioned container in which tableware, etc., can be soaked corresponds to the "disinfection container" described in the claims. 【0062】 With this configuration, dishes and other items can be effectively disinfected with a lower chlorine concentration, thereby reducing the consumption of household bleach and, as a result, reliably suppressing risks that may arise when disinfecting dishes and other items (for example, inflammation of the hands). 【0063】 <Configuration and Effects of the Embodiment> As described above, the disinfection method according to this embodiment is a disinfection method for disinfecting a pathogen 1 having a lipid bilayer 3 using a flowable disinfectant 10, wherein the disinfectant 10 and the pathogen 1 are reacted within a temperature range of 40 to 55°C. Because of this configuration, despite its relatively simple structure, it can achieve a high disinfecting effect even with low concentrations of disinfectants that are less effective at room temperature (25°C). 【0064】 Furthermore, the duration for which the aforementioned temperature is maintained is within 3 hours. Due to this configuration, pathogen 1 can be disinfected almost completely in a shorter time compared to conventional disinfection methods. 【0065】 The disinfection apparatus according to this embodiment is a disinfection apparatus for disinfecting a pathogen 1 having a lipid bilayer 3 using a flowable disinfectant 10, and comprises a disinfection container for reacting the disinfectant 10 and the pathogen 1 at a temperature range of 40 to 55°C. Because of this configuration, similar to the disinfection method described above, it is possible to obtain a high disinfection effect even with low-concentration disinfectants that are less effective at room temperature (25°C). 【0066】 Furthermore, the aforementioned disinfection container is a container for disinfecting contact lenses. With this configuration, by placing a drug containing BAC or PHMB (for example, a known MPS) in the contact lens case, it is possible to effectively disinfect pathogens such as Acanthamoeba. Furthermore, this configuration allows for disinfection of contact lenses at relatively low temperatures, effectively suppressing the denaturation of protein deposits (protein denaturation) attached to the contact lenses, thereby effectively preventing adverse effects such as deterioration of wearing comfort. 【0067】 The materials, chemical substances, etc., of this invention can be modified in various ways without altering the essence of the invention. The disinfectant components that make up the disinfectant 10 can also be appropriately selected according to the pathogen 1 to be disinfected. For example, the disinfectant component contained in disinfectant 10 can be just one type, or it can be multiple types. Furthermore, the above-described embodiment is merely one of the best possible forms at present, and can be modified as appropriate as long as it achieves the desired effect. [Explanation of symbols] 【0068】 1: Pathogen 2: Protoplasm 3: Lipid bilayer 10: Disinfectant

Claims

[Claim 1] A disinfection method for disinfecting pathogens having a lipid bilayer using a fluid disinfectant, A disinfection method comprising reacting the disinfectant with the pathogen at a temperature range of 40 to 55°C. [Claim 2] The disinfection method according to claim 1, wherein the time for maintaining the temperature is within 3 hours. [Claim 3] A disinfection apparatus for disinfecting pathogens having a lipid bilayer using a fluid disinfectant, A disinfection apparatus comprising a disinfection container for reacting the disinfectant with the pathogen at a temperature range of 40 to 55°C. [Claim 4] The disinfection apparatus according to claim 3, wherein the disinfection container is a container for disinfecting contact lenses.

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