May 3, 2012  3  US 2012/0108878 Al  or illness to a host. These biopathogens include, but are not  limited to, bacteria, bacterial spores, viruses, molds, fungi,  and their toxins. Pathogenic bacteria can cause infectious  diseases; the most common bacterial disease is tuberculosis,  which is caused by the bacterium  Mycobacterium tuberculo› sis. Mycobacterium  is a genus of Actinobacteria, which  includes many pathogens known to cause serious diseases in  mammals, including tuberculosis and leprosy. Pathogenic  bacteria also contribute to other globally important diseases,  such as pneumonia, which can be caused by bacteria such as  Streptococcus  and  Pseudomonas,  and foodborne illnesses,  which can be caused by bacteria such as  Shigella, Campylo› bacter,  and  Salmonella.  Pathogenic bacteria also cause infec› tions such as tetanus, typhoid fever, diphtheria, syphilis and  leprosy. Pathogenic viruses are mainly those of the families  of: Adenoviridae, Picornaviridae, Herpesviridae, Hepad› naviridae, Flaviviridae, Retroviridae, Orthomyxoviridae,  Paramyxoviridae, Papovaviridae, Rhabdoviridae, Togaviri› dae. Some notable pathogenic viruses cause smallpox, influ› enza, mumps, measles, chickenpox, and rubella.  [0020]  The threat from biological toxants can be even more  serious than the chemical warfare threat. This is in part  because of the high toxicity of BW agents, their ease of  acquisition and production, and their difficulty in detection  but also, as in the case of pandemics, their ease of transmis› sion and spread. There are hundreds of biological warfare  toxants known, with new viruses appearing constantly. For  decontamination purposes, biological toxants can be usefully  distinguished as spore forming bacteria which can exist in a  vegetative state ( e.g.,  Bacillus anthracis  which causes  anthrax), bacteria which are vegetative but non-sporulating  ( e.g.,  Yersinia pestis  the cause of plague,  Vibrio cholerae  the  cause of cholera), non-lipid and small viruses (e.g., polio  viruses), fungi (e.g.,  Trichophyton  spp.), lipid and medium  size viruses (e.g., retroviruses like HIV, Hepatitis B viruses),  and bacterial toxins (e.g., botulism, ricin).  [0021]  With the exception of prions, bacterial spores are  recognized to be the most difficult microorganism to kill.  Prions are infectious agents composed of protein which  propagate by transmitting in a mis-folded protein state, and  are not generally considered biological warfare agents. Bac› terial spores are highly resistant structures formed by certain  gram-positive bacteria usually in response to stresses in their  environment. The most important spore-formers are mem› bers of the genera  Bacillus  (e.g.,  Bacillus anthracis)  and  Clostridium  (e.g.,  Clostridium difficile).  Spores are consider› ably more complex than vegetative cells. The outer surface of  a spore consists of the spore coat that is typically made up of  a dense layer of insoluble proteins usually containing a large  number of disulfide bonds. The cortex consists of peptidogly› can, a polymer primarily made up of highly crosslinked  N-acetylglucosamine and N-acetylmuramic acid. The spore  core contains normal (vegetative) cell structures such as ribo› somes and a nucleoid.  [0022]  Antiseptics and disinfectants are used extensively in  hospitals and other health care settings for a variety of topical  and hard-surface applications to deal with biological toxants.  In particular, they are an essential part of infection control  practices and aid in the prevention of nosocomial infections.  There are a variety of sterilants and disinfectants that can be  used to address decontamination of one or more biological  pathogens, as shown in Table 1.  [0023]  "Biocide" is a general term describing a chemical  agent, usually broad spectrum, that inactivates microorgan› isms. Because biocides range in antimicrobial activity, other  terms are more specific, including "-static," referring to  agents which inhibit growth (e.g., bacteriostatic, fungistatic,  and sporistatic) and" -cidal," referring to agents which kill the  target organism (e.g., sporicidal, virucidal, and bactericidal).  Disinfectants are generally products or biocides that are used  on inanimate objects or surfaces. Disinfectants can be sporo› static but are not necessarily sporicidal. Sterilization refers to  a physical or chemical process that completely destroys or  removes all microbial life, including spores.  [0024]  Different types of microorganisms vary in their  response to decontaminants and disinfectants, as shown  below, in descending order.  [0025]  Prions*  [0026]  (CJD, BSE)  [0027]  Coccidia  [0028]  (  Cryptosporidium)  [0029]  Spores  [0030]  (Bacillus,  C.  Difficile)  [0031]  Mycobacteria  [0032]  (M. tuberculosis, M. avium)  [0033]  Cysts  [0034]  (Giardia)  [0035]  Small non-enveloped viruses  [0036]  (Polio Virus)  [0037]  Trophozoites  [0038]  (Acanthamoeba)  [0039]  Gram-negative bacteria (non-sporulating)  TABLE 1  Mechanisms of antibacterial actions of disinfectants and sterilants  Target  Cell wall,  outer  membrane  Cyto- plasmic  membrane  Cross- linking of  macro- molecules  DNA  intercalation  Interaction  with thiol  groups  Effects on  DNA  Oxidizing  agents  Disinfectant  Glutaraldehyde  EDTA, other  permeab ilizers  QACs  Chlorhexidine  Diarnines  PHMB,  Alexi dine  Phenols  Formal- dehyde  Glutaraldehyde  Acri dines  Silver  compounds  Halogens  Hydrogen  peroxide,  silver ions  Halogens  Peroxygens  Mechanism of Action  Cross-linking of proteins  Gram-negative bacteria: removal of  Mg 2 +,  release of some LPS  Generalized membrane damage involving  phospholipid bilayers  Low concentrations affect membrane  integrity,  high concentrations  cause congealing of cytoplasm  Induction of leakage of amino acids  Phase separation and domain formation of  membrane lipids  Leakage; some cause uncoupling  Cross-linking of proteins, RNA, and DNA  Cross-linking of proteins in cell envelope  and elsewhere in the cell  Intercalation of an acridine molecule  between two layers of base pairs in DNA  Membrane-bound enzymes (interaction  with thiol groups)  Inhibition of DNA synthesis  DNA strand breakage  Oxidation ofthiol groups to disulfides,  or disulfoxides  Hydrogen peroxide: activity due to from  formation of free hydroxy radicals  (-OH), which oxidize thiol  groups in enzymes and proteins;  PAA: disruption ofthiol groups in  proteins and enzymes 