The intent for this literature reappraisal was to analyze the literature presently available to the general populace on the application of a scope of germicides used within a microbiology research lab in both the public e.g. infirmary research labs and the private sector e.g. university research labs. This literature reappraisal was carried out on the effectivity of germicides so that old and current cognition on the usage of these germicides can be analysed. This will assist give an penetration into the capable country and aid with the readying and production of the concluding study based on the research being carried during the literature reappraisal and research undertaking. The chief intent of the research undertaking being conducted was to compare the effectivity of a assortment of germicides particularly Trigene which has been endorsed for usage in the microbiology research labs of the Greater Glasgow and Clyde wellness board and that of Virkon which is presently used by the microbiology research lab at the University of the West of Scotland.
The literature examined showed that the germicides used in clinical research labs and any other country where micro-organisms can do a job with cross-contamination, should be evaluated for their effectivity against the scope of beings which might be encountered. It is an of import demand that the germicides being used are able to suppress or kill the micro-organisms rapidly and by utilizing the lowest concentration available. ( Isenberg, 1985 )
A survey conducted by Kasthjerg et Al ( 2010 ) which looked at the effects of a scope of germicides on the look of virulency cistrons nowadays in the bacteria Listeria monocytogenes. This survey showed that effects on the virulency cistron in the bacteria could be linked to the chemicals found in the germicide with some doing an suppression of the cistron while others showed an initiation of the cistron
Disinfectants
A germicide is a chemical which is widely used to eliminate a assortment of micro-organisms that are presently found in the samples received into a research lab or are presently used within an educational scene for the instruction of microbiology to pupils.
Disinfectants can hold any of the undermentioned chemicals as their chief active ingredient: halogenated third aminoalkanes, Cl incorporating compounds, phenols, quaternate ammonium compounds and peroxygen ‘s. ( Tyski et al, 2009 ) Thus the germicides can be divided into groups associating to the chemical nowadays as the active ingredient and these groups will be discussed subsequently in the study. It is of import that certain standards are met when sorting a chemical as a germicide, these include: –
That the chemical constituents of the germicide will non hold an inauspicious consequence on the wellness of the user and if any wellness issue is realised so appropriate action can be taken to take this hazard i.e. utilize PPE such as baseball mitts or respiratory mask. ( Severs & A ; Lamontagne, 2002 )
It. is besides of import that the germicide has the ability to render inactive or kill a broad scope of micro-organisms including viruses, bacteriums and Fungis. ( Severs & A ; Lamontagne, 2002 )
It is besides of import that a germicide does non hold an inauspicious consequence when used on equipment.
The research conducted by Kim, Ryu & A ; Beuchat, ( 2007 ) showed that the effectivity of certain germicides can be diminished when they are in contact with biofilm surfaces. It is presently thought that there is really small opposition to the germicides used due to the presence of a assortment of chemicals considered to hold an antimicrobic consequence in each germicide. ( Kasthjerg et al, 2010 )
Efficiency testing of germicides has been around for approximately 50 – 60 old ages ago. ( Werner, 2007 ) In more recent old ages a working group was set up which set Standards which govern the microbic activity testing of chemicals used as antiseptics and germicides. ( Werner, 2007: Tyski, S. , et Al, 2009 ) The debut of these criterions has allowed the efficiency tests to go more quantitative and bring forth lower border of mistake. ( Werner, 2007 )
Peroxygen
This group of germicides consists of chemical germicides which contain the chemical peroxygen and includes Virkon which is one of the germicides which will be evaluated during the research undertaking being carried out. Virkon is available as a pulverization and is diluted for usage by fade outing it in distilled H2O to give the needed concentration. Virkon ‘s method of action is through the combination of the chemicals chlorine, hydrogen peroxide and paraoxymonosulphate. ( Alegente, G. , et Al, n.d. ) These chemicals act by oxidization of the plasma membranes of microbic cell organs. The effects of peroxygen germicides was investigated by a survey conducted by Quilez et Al, ( 2005 ) to detect what concentration of the germicide and clip required for the germicide to be most effectual when covering with Cryptosporidium parvum oocysts.
The literature reappraisal conducted by Severs & A ; Lamontagne, ( 2002 ) indicated that there was merely a “ moderate hazard of annoyance ” to the user when the Virkon is in pulverization signifier. The Virkon may bring on coughing, chocking or wheezing if inhaled while fixing the diluted germicide. However, when the pulverization has been diluted into a liquid signifier it is thought to do no injury to the user ‘s tegument or eyes. ( Severs & A ; Lamontagne, 2002 )
As the suggested research to be conducted is related to the efficiency of germicides so it was of import to reexamine current literature which gives an indicant of the effectivity on a scope of micro-organisms. From the literature it was shown that Virkon is effectual when used as indicated against a broad scope of micro-organisms including Gram positive and gram negative bacteriums, viruses, Fungis and spore forming bacterium. The survey conducted by ( Severs & A ; Lamontagne 2002 ) showed that these beings were inactivated utilizing a 1 % solution of Virkon.
A survey conducted by Gaparini et Al, ( 1992 ) showed that Virkon was effectual when used against spores which had been cultivated onto alimentary agar. This survey besides indicated that the effects of Virkon were speedy playing ; this could be attributed to the high concentration coefficient of the germicide.
Group 2 – Halogenated Tertiary Amine
This type of germicide is considered wide spectrum and biodegradable and is by and large found in combination with detergents. ( Health and Safety Executive, 2005 ) . The halogenated Tertiary Amine group of germicides includes Trigene on which portion of the research undertaking is based. Trigene is available as a concentrated liquid or as a maker diluted liquid. ( Trigene Company ) Trigene is besides available in sachets which have been approved for usage on pigboats used by the Armed forces in the UK. ( Severs & A ; Lamontagne, 2002 ) The findings of the survey by Severs & A ; Lamontagne, ( 2002 ) showed that as with Virkon the usage of Trigene was effectual at rendering inactive viruses, bacteriums and Fungis when used in conformity with the maker ‘s instructions.
Health and safety trials were carried out on Trigene and the consequences have shown that the germicide poses a low hazard to the users if accidently inhaled or ingested and there are no known wellness jeopardies with the usage of Trigene. ( MediChem international )
Quaternate ammonium compounds
This group of germicides is considered to be effectual against most bacteria strains ; nevertheless they are uneffective against viruses, bacteriums which form spores and Mycobacterium. It is likely that this would non be an efficient germicide to be used within a clinical or university microbiology research lab due to the hazard of having samples incorporating spore forming bacteriums, Mycobacterium species. The germicide can go inactivated by a low PH or the presence of organic stuff. ( Health and Safety Executive, 2005 ) The manner of action for members of this group of germicides is that they damage the cell membrane which will ensue in cell escape. ( Ioannou et al, 2007 ) This survey besides showed that an addition in temperature increased the clip taken to eliminate the bacteria.
The survey done by, Kim, Ryu & A ; Beuchat, ( 2007 ) showed that the efficiency of the germicide could be linked to the chemical construction of the Benzylalkonmium chloride ‘s hydrophobic alkyl concatenation. It besides showed that the presence of organic stuff ( infant expression ) can diminish the efficiency of the germicide.
Hypochlorite and other chlorine-releasing agents
This is a germicide which contains Cl as its active ingredient, and an illustration of this germicide is Milton which is presently used to sterilize babe utensils. It is considered a wide spectrum germicide as it can demobilize or kill a scope of bacteriums and viruses. However, it is considered less effectual against bacterial spores. As with the quaternate ammonium compounds this group of germicides has been shown to be inactivated by organic stuff and has to be prepared day-to-day, this is due to the instability of the chemicals caused by concentration and temperatures at which the germicide is stored. ( Health and Safety Executive, 2005 ) The hypochlorite germicide is provided in the signifier of Sodium Hypochlorite and it is normally used within a clinical research lab particularly for the cleansing of equipment when recommended by the industry.
Phenolic resin
This group includes the germicide Hibetine which is presently used at the University of Glasgow and the active chemical is phenol. It has been shown to be a wide spectrum germicide which is effectual against certain bacteriums including Mycobacterium TB and some viruses, although shows no action against bacterial spores. The germicide is used with a combination of the phenolic chemical and a detergent. The advantages of utilizing this type of germicide is that it is considered stable in undiluted signifier and organic stuff does non look to hold the same negative consequence on the efficiency of the germicide as has been observed in other disinfectants..
Microorganisms ‘ an debut
The chief intent of carry oning the research undertaking was to detect the efficiency of germicides when used against a scope of micro-organisms. The micro-organism to be investigated include a Gram positive bacteriums such as Staphylococcus aureus, a Gram negative bacteriums such as Escherichia coli, a spore organizing bacteriums such as Bacillus Cereus and a barm e.g. Saccharomyces cerevisiae. The survey conducted by Tyski, S. , et Al, ( 2009 ) used micro-organisms which could easy be isolated from infirmaries.
The survey carried out by Ioannou et Al, ( 2007 ) suggests that a common characteristic of bacteriums particularly staphylococcus aureus can get a plasmid which contains cistrons which will let the bacterium to go immune to certain disinfectants.
The literature hunt carried out showed that the beings which are normally used in research to demo the efficiency of germicides are normally isolated from hospital patient samples. ( Gasparini, et Al, 1992 )
Gram negative bacteriums
Gram positive bacteriums
Yeast
Sporing bacteriums
The usage of germicides in battling the spread of infections from bacterial spores from beings such as C. parvum, Bacillus anthraxis, Clostridium difficile and B Cereus is of import as these are the most hard of all micro-organisms to eliminate. ( Quilez et al, 2005 )
Discussion
The literature reviewed has shown that germicides are an of import portion of the working environment of a research lab as it is indispensable that the germicide has the ability to demobilize or destruct a broad scope of micro-organisms.
The survey by ( Severs & A ; Lamontagne, 2002 ) showed that both Virkon and Trigene could be classed as efficient and wide spectrum germicides as they both killed a assortment of micro-organisms runing from viruses ( both enveloped and non-enveloped ) to fungi and bacteria including spore forming species.
The survey by Kasthjerg et Al, ( 2010 ) deduced that the germicides which contained the peroxygen and chloride compounds decreased the virulency cistron look ; nevertheless, the germicides incorporating the quaternate ammonium compounds encouraged the look of the virulency cistron.
Decision
The survey conducted by Severs and Lamontagne, ( 2002 ) suggested that Both Virkon and Trigene were effectual at extinguishing the bacterium which could present a wellness hazard to frogmans but they felt that as the Virkon merchandise had managed to eliminate more bacterial and viral strains than Trigene and that these effects were produced quicker with Virkon so the decision was that this merchandise ( Virkon ) should be considered a better germicide and be recommended for usage by frogmans.
