Sporicidal

Sporicide kills (inactivates) bacterial spores, and is therefore expected to kill all other microorganisms of less resistance. According to the AO AC International it may not kill 100% of the spores, and therefore may not be as powerful as a sterilant. However, according to the EPA, sporicide and sterilant are considered identical. 

Germicide destroys microorganisms, with emphasis on pathogenic agents, called germs. It maybe a disinfectant or an antiseptic. It does not claim to be a sporicide. 

Phenols are considered to be low-to-intermediate level disinfectants, appropriate for general disinfection of noncritical and semicritical areas. They are not sporicidal and should not be used when sterilisation is required. They are dispensed in aqueous formulations or in mixed water—alcohol solutions. Levels of 400—1300 ppm in the diluted formulation are typical. 

Sudol uses fractions of coal tar rich in xylenols and ethylphenols. It is much more active and less corrosive than lysol, and remains more active in the presence of organic matter. The phenol coefficients of sudol against Mycobacterium tuberculosis, Staphylococcus aureus, and Pseudomonas aeruginosa are 6.3, 6, and 4, respectively. It also is slowly sporicidal (97). 

Disinfection tests can be classified according to the test organism, ie, whether the test employs certain species of bacteria, fungi, or vimses classified as to whether it is a static test or a cidal test, as in a bactericidal vs bacteriostatic test or sporicidal vs sporistatic test or classified as to whether it is a microbial reduction test or an end-point test where all the organisms in the test are apparently killed. Procedures may be distinguished by in vitro or in vivo testing. Another way to consider tests is whether they are screening tests, practical type laboratory tests, or field tests. 

Bacterial spores are the most resistant of all microbial forms to chemical treatment. The majority of antimicrobial agents have no useful sporicidal action, with the exception of the aldehydes, halogens and peroxygen compounds. Such chemicals are sometimes used as an alternative to physical methods for sterilization ofheat sensitive equipment. In these circumstances, correct usage of the agent is of paramount importance since safety margins are lower in comparison with physical methods of sterilization (Chapter 20). 

A number of aldehydes possess antimicrobial properties, including sporicidal activity however, only two, formaldehyde and glutaraldehyde, are used for disinfection. Both these aldehydes are highly effective biocides and their use as chemosterilants reflect this. 

The acridine dyes, including proflavine, acriflavine and aminacrine, have also been employed for skin disinfection and treatment of infected wounds or burns. They are slow-acting and mainly bacteriostatic in effect, with no useful fungicidal or sporicidal... 

Russell A.D. (1990) Bacterial spores and chemical sporicidal agents. Clin Microbiol Rev, 3, 99-119. Russell A.D. (1996) Activity of biocides ogidn X mycoh CtQno.. JApplBacteriol Symp Suppl, 81, 87S-lOlS. 

This type of test may be used to investigate bactericidal, sporicidal or fungicidal activity. 

Sporicidal activity can be determined against spores in liquid suspension or against spores dried on carriers. In principle, techniques are similar to those described for bactericidal tests. However, it should be realized that spores must germinate and outgrow before colony formation is observed. For this reason, incubation of recovery media should be continued for several days. 

Note that the ethanol-based hand sanitizers are not sporicidal Pharmacological... 

Other Standard Precautions After an invasive procedure or autopsy, all instruments used and locations need to be disinfected with a sporicidal agent. Recommended for use is... 

Selenium sulfide is a cytostatic and sporicidal agent available without prescription in a variety of shampoos and lotions for treatment of scalp seborrheic dermatitis. Higher concentrations are available by prescription for the treatment of pityriasis versicolor, which is caused by the yeast M. furfur, and tinea capitis. 

Iodophors are complexes of iodine with a surface-active agent such as polyvinyl pyrrolidone (PVP povidone-iodine). Iodophors retain the activity of iodine. They kill vegetative bacteria, mycobacteria, fungi, and lipid-containing viruses. They may be sporicidal upon prolonged exposure. Iodophors can be used as antiseptics or disinfectants, the latter containing more iodine. The amount of free iodine is low, but it is released as the solution is diluted. An iodophor solution must be diluted according to the manufacturer s directions to obtain full activity. 

Iodophors are less irritating and less likely to produce skin hypersensitivity than tincture of iodine. They act as rapidly as chlorhexidine and have a broader spectrum of action, including sporicidal action, but they lack the persistent action of chlorhexidine. 

Phenolic compounds disrupt cell walls and membranes, precipitate proteins, and inactivate enzymes. They are bactericidal (including mycobacteria) and fungicidal and they are capable of inactivating lipophilic viruses. They are not sporicidal. Dilution and time of exposure recommendations of the manufacturer must be followed. 

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