Dramatic Increase of Multiresistant Microorganisms

For people in the 21st century, it is hard to imagine the world before antibiotics. At the beginning of the 20th century, as many as nine women out of every 1,000 who gave birth died, 40 percent from sepsis. In some cities as many as 30 percent of children died before their first birthday. One of every nine people who developed a serious skin infection died, even from something as simple as a scrape or an insect bite. Pneumonia killed 30 percent of those who contracted it; bacterial meningitis was almost universally fatal. Ear infections caused deafness; sore throats were not infrequently followed by rheumatic fever and heart failure. Surgical procedures were associated with high morbidity and mortality due to infection. This picture changed dramatically with three major developments: improvements in public health, vaccines, and antibiotics. Over the course of the 20th century, deaths from infectious diseases declined markedly and contributed to a substantial increase in life expectancy.

Intensive care units however is limited and greatly overestimated.
Fact is, that bacterial superinfection ensues in 25-40% of infants and children as a consequence of a viral respiratory tract infection by clogging the paranasal opening, the Eustachian tube and impairing mucociliary clearance.
Stagnant secretions in the paranasal sinus and the middle ear cavity are contaminated with bacterial microorganisms and result in serious infections -early administration of antibiotics it thought to prevent this. However, this is less effective than anticipated and induces simultaneously the emergence of resistant microorganisms.
It is feasable to prevent bacterial superinfections by antiinflammatory properties and improvement of the mucociliary clearance of various herbal extracts e.g., triterpenes and 1.8. Cineol, contained in a number of herbal extracts e.g., thyme, gentian, sorrel, primulae, 1.8. cineol [7].

Animal Agriculture
Medically important antibiotics are also extensively used in animal agriculture not only to treat sick animals, but also to promote animal growth and to prevent infections. All of these uses promote the development of antibiotic resistance among bacteria in animals, and these resistant strains do, at least in some cases, spread to humans. Antibiotics administered to piglets prevent diarrhea and death and also result in improved gain of weight.
These antibiotics select resistant microorganisms in the faecal flora which are excreted by slurry. This is distributed as fertilizers in the environment contaminating vegetables and fruits. The extent to which antibiotic resistance in animal agriculture contributes to human infections is a matter of controversy, the risks to human health posed by the agricultural use of antibiotics are however, appropriately, a matter of serious concern. There is a highly efficient innovative technology which prevents adherence and colonization of mucous membranes in the gut a necessary requirement for pathogenicity of pathogenic microorganisms.
Gram negative bacteria, mainly E. coli adhere on gal 1-4 gal structures on epithelial cells with fimbriae. Pectin is composed of several gal 1-4 galactose molecules. These di-or tri terpenes i.e., acid galacturonides obtained by cooking of pectines function as receptor analogues and block as receptor analogue carbohydrates the adherence of bacterial microorganisms on epithelial cells; the microorganisms are eliminated in the faeces without induction of resistance [8]. Figure 1 shows the prevention of diarrhea in piglets by comparing acid galacturonides versus an antibiotic (tylosin phosphate). The galacturonide turns out to be more effective in prevention of diarrhea than the antibiotic just as well as prevention of death due to adnexitis in a laying hen population. Figure 2 Herbal extracts are effective, not toxic and highly cost effective.  of these drugs. Formation of an ester is an example of a prodrug methodology for modification of a functional group of the active drug to improve lipophilicity for passive membrane transport or to increase aqueous solubility.
Such broad-spectrum antibiotic shows an excellent bioavailability but if eliminated by the biliary route -an accumulation of unabsorbed antimicrobial active substance in the large intestine is observed again with selection of multi resistant microorganisms. For prodrugs renal elimination is therefore required [7]. Another problem is an excessive long half-life of an antibiotic. The usually observed half-life of a macrolide antibiotic is 60 minutes. Azitromycin has a halflife to 3 days which results in subinhibitory concentrations in the oral cavity responsible for the induction of macrolide resistant microorganisms. In addition, the initial poor absorption does not result in rapidly bactericidal concentration at the site of an infection [10]. It is therefore necessary for the approval of new antibiotics to take also pharmacokinetic and pharmacodynamics properties of antimicrobial agents into serious consideration ( .

Investigation of the Origin of Resistant Microorganisms
10 years ago, a multi resistant microorganism has been isolated on a surface which has been just disinfected with a Quaternary Ammonium Base Disinfectant (QAC). Initially this was a surprise but antibiotics has been confirmed by the Norwegian food and fishery administration which prohibited the use of quaternary ammonium compound disinfectants in the fish industry [11].
Review of the international literature (pubmed) provides more than 8000 articles which describe the resistance of microorganisms against disinfectants and 800 papers report the cross resistance with antibiotics. Disinfectant resistance has the potential to change our way of life from threatening our medical health systems to compromising food security. Resistance to antimicrobial agents occurs through either intrinsic or acquired resistance mechanisms. It is well known that microorganisms in a biofilm cannot be eradicated by antibiotics nor disinfectants [12]. The initial investigative work excluded the theory, that antimicrobial substances are prevented from diffusion into the biofilm. Further investigations disclosed that microorganisms in a biofilm are hibernating and don't take up anything from the outside. However, they can be eradicated by a technology which affects the pathogens from the outside. The requirements of self-sanitizing surfaces for application in hospitals, public transportation, the food industry is extraordinarily high. concern in hospitals such as taps, showers and drains, where biofilms appear frequently. Last not least certain technologies for a self-sanitizing surface can also be used for implantable biomaterials.

a) Active Eluting Agents Show Several Disadvantages:
The active substances must be eluted from of the surface i.e. the polymer or the coating. This means that their activity is limited to a short period of time. For antibiotics this means a duration of activity of less than 3 days, for silver 3 weeks [14].
Copper cannot embedded into polymers to achieve a sufficient antimicrobial activity; in addition, the activity of copper is too low to be considered as a valuable compound [15].
Quaternary ammonium compounds must be excluded from considerations as these products may even enhance the growth of microorganisms on surfaces and induce cross resistance with antibiotics by induction of efflux pumps. Various drug eluting substances e.g., Polybiguanides, halogenated phenols, and polyethyleneimines have been investigated but showed toxic side effects with human tissues as they have to be eluted from the polymer of the surface [16][17][18][19][20][21][22][23].

Chemical Modifications to Achieve Functional Antimicrobial Coatings
In addition to chemical modifications, the topography of a surface can by itself significantly affect its hygienic status, either in a beneficial manner (reducing microbial retention) or otherwise (increasing retention). As such, modifications of surfaces to Therefore, efforts should be undertaken to characterize typical wear, assess interactions with the most likely microorganisms in that environment, and define the most appropriate and least damaging cleaning and sanitizer regimes. Antimicrobial agents adjacent to a surface showed the risk of abrasion with cleaning.
The agents have not been consistently insoluble in water-, alcohol-, detergents, acid, alkaline, in addition UV light stability has not been confirmed. which is not guaranteed by several of the abovementioned compounds Strategies to achieve antimicrobial coatings can be classified according to their functional principle as: (i) antiadhesive, (ii) contact active, and (iii) biocide release.
Whereas the first two principles may be considered as SbD, biocide release incorporates the release of a toxic substance and can therefore be considered as toxic by design. Sometimes two functional principles are combined to achieve synergistic effects, e.g. by embedding biocidal substances into anti-adhesive surfaces.
Today, the majority of chemical modifications includes hydrogels or poly (ethylene glycol) (PEG) to repel approaching microbes, metals

Anti-Adhesive Surfaces
Anti-adhesive surfaces could reduce the adhesion force between bacteria and a solid surface to enable the easy removal of bacteria before a biofilm layer is formed on the surface [24].
Such surfaces may suppress HCAI by blocking transmission paths involving surfaces, but they will not reduce the number of germs on the contacting media by killing them. Attachment of bacteria or cells starts with an initial adsorption of proteins on to the material surface [20]. Strategies to prevent protein attachment include superhydrophobic surfaces, often augmented by a hierarchical nanostructure as well as zwitterionic polymers [25,26]. The most important requirement of a "self-sanitizing" surface is the ability of the surface to actively eradicate pathogens within a reasonable short period of time. It has to be emphasized that microorganisms are deposited by the hand of the personnel with considerable force. For prevention of recontamination of a second person, rapid eradication of microorganisms is mandatory (i.e., less than 1 hour or shorter).

Reduction of adherence, blockage of proliferation and biofilm
formation although also important -are in no way sufficient as method. Superhydrophobic surfaces are characterized by a water contact angle >150" and they are inspired by the lotus leaf in nature [25]. It was further revealed that the lotus leaf has a hierarchical micro/nanostructure [26]. Reducing bacterial adhesion via superhydrophobicity is a relatively new topic and has yet to be studied thoroughly and systematically [27].

Analysis of superhydrophobic siloxane and fluor siloxane
surfaces showed also minimal protein adsorption, both before and after protein adsorption trials [28].

Nanostructured Surfaces
One proposed technology is the use of nanocoating's: Antimicrobial technologies using nanomaterials e.g. chitosan, cellulose etc. have to be applied into nanorods or nanosats which can however not stabil anchored on the surface. Nanostructured surfaces were also prepared using electro spun polystyrene nanofibers. When oxygen plasma-treated, a super hydrophilic surface was generated, which exhibited limited Escherichia coli attachment due to negative zeta potential of e40mV. After fluorination, a superhydrophobic surface was obtained, which exhibited self-cleaning ability against bacteria, where the initially adhered bacteria were effectively removed with subsequent washing [26]. Anti-adhesion and killing was achieved by combining an upper superhydrophobic surface layer (silane coated poly (acrylic acid)) with limited bacterial adhesion and self-cleaning properties with a hydrophilic bottom layer (poly(ethyleneimine)e Agþ complex) which could deliver bactericidal silver ions [27].
Addition of silver has been described a technology for antimicrobial surfaces. One technology describes that free silver ions are antimicrobials active -where silver has to be released from the surface and incorporated into the bacterial metabolism.
A strong disadvantage: a limited activity of silver of a few days has been described! Silver submicron particles can be incorporated into polymers and coatings, a hydrophilizing agent must also be added for an enhanced activity! Silver in form of nanoparticles function in a different way: Some studies have reported that nano-silver causes oxidative damage, leading to the production of reactive oxygen species (ROS) as well as free-radicals, and it has been suggested that the production of ROS is one of the primary mechanisms of nanoparticle toxicity. Hence, it was suggested that nano-silver affects bacterial membrane permeability by attaching to the cell membrane surface and modifying the cell potential.

Observation of large numbers of nanoparticles inside bacteria
suggests that this is important to the antibacterial mechanism. An interesting anti-adhesive and killing approach is found in nature.
The nano-patterned cicada wing surface uses an adsorption and stretching mechanism with eventual rupture. As the bacterial cells adsorb on to the nano pillared structures present on the wing surfaces, the bacterial cell membrane stretches in the regions suspended between the pillars. If the degree of stretching is sufficient, cell rupture will occur [28]. The cicadia wings technology as well as the gecko foot technology which relies on the same properties is not physically stabile the cicadia wings surface can be easily destroyed by mechanical wiping/cleaning, rubbing.
Zwitterionic polymer brushes may also delay or even prevent microbial attachment to a surface, since the hydration layer surrounding the ionic surface prevents non-specific protein adsorption [21]. Using barnacle cement, a biological adhesive from barnacles, and 'click' chemistry, poly(2-(methacryloyloxy) ethyl trimethylammonium chloride) polymer brushes were successfully attached to stainless steel and antimicrobial properties were demonstrated [27]. Zwitterionic polymer brushes cannot inactivate bacterial cells.
Therefore, synergistic anti-adhesion and bacterial inactivation was achieved by grafting zwitterionic poly (sulfobetaine methacrylate) brushes with embedded biocidal silver nanoparticles [28]. Addition of silver is possible b u t only silver ions are active -in other words silver has to be released from the hydrophilic bottom layer and incorporated into the bacterial metabolism (mode of action well known) Limited activity to probably a few hours! The importance of anti-adhesive properties for biofilm formation was also demonstrated by measuring the adhesive forces on brush-coated silicone rubber and uncoated silicon rubber. On the brush-coated rubber, adhesion was so weak that the bacteria were no longer able to sense the surface and therefore remained in their planktonic state, susceptible to antibiotics rather than forming a protected biofilm.

Contact-Active Surfaces
Contact

Biocide-Releasing Surfaces
Biocide-releasing surfaces may have some conceptual disadvantages since they are toxic by design in terms of releasing biocidal substances. In addition, they will gradually become inactive and they may induce the formation of resistance. Any substance eluting from the surface is also emanating into the environment.
Toxic substances may affect various cell lines in the body e.g.

epithelia cells, osteoblasts, fibroblasts if incorporated into the
body. The chance that these biocides meet the requirements of the European Commission is improbable and requires extensive testing.
Catalytically active surfaces, such as photocatalytically active surfaces (e.g. TiO 2 ) which regenerate reactive oxygen species upon UV radiation, provide an alternative. The activity of a photocatalytic mechanism e.g. oxygen radicals and hydroxyl radicals can only be documented with the JIS method. By this method the antimicrobial activity is determined in the capillary space between the surface and a foil which prevents these photocatalytic molecules from evaporating into the environment. This is a highly arbitrary method of testing and is far away from the determination of an antimicrobial surfaces investigated by the push plate method (RODAC Plate method). One of the problems of a technology due to biocide releasing agents is the induction of resistance. There is a law by nature that all substances with antimicrobial activity which require the incorporation of the agent into the metabolism of microorganisms induce resistance. This is well known for antibiotics but also disinfectants. Therefore, it is required that a technology is developed which is not incorporated However, in combination with silver the antimicrobial activity is enhanced. However again only silver ions show antimicrobial activity and have to be incorporated into the metabolism of microorganisms: consequences: limited duration of activity whereas graphene is enhancing the release of silver ions. Carbon nanotubes have also been widely studied as antimicrobial material since they can be easily embedded into polymers. Again, a variety of morphologies has been studied such as single wall or multi-wall, but it seems that GO-based materials show higher antimicrobial activity.  In addition also a positive Zeta potential is formed on the surface, responsible for the observed rapid eradication of microorgansism on surfaces documented by scanning electron microscopy. 6 log 10 reduction within 15 minutes. The technology is approved by the BPR as in situ generated biocide and is legitimately on the market.
In the future no easy approval for in situ generated biocides is possible by ECHA, this opportunity expired September 1, 2018. This is also an additional favourable asset of the presently available This is in no way a practical approach and has to be banned. Also the incorporation of disinfectants has to be banned due to the induction of cross resistance with antibiotics,Many plant extracts are well known for their antimicrobial properties and much research is devoted to their application to protect food from pathogens.

Impact of Topography on Surface Effectiveness
It is generally acknowledged that defects or design features on any inert surface can retain soil and/or micro-organisms, and therefore affect cleanability, disinfection, and hygienic status of the surface. Implications in the clinical environment in terms of cross-infection control, the choice of surface material to be used, and the cleaning and sanitization protocols are significant. However, the assumption 'the rougher the surface, the worse the hygienic status' is somewhat simplistic, although many publications make this type of claim. Cells are easily removed from 'smooth' surfaces, but they may be retained within features approximating in size to that of the cells. In larger features, the cells may again be relatively easily removed. Easy cleanability is in addition to an optical attractive surface one of the prerequisites. If easy cleaning is also accompanied by a germfree surface this is the ideal approach as this can avoid the use of disinfectants which hence are responsible for the dramatic induction of resistant microorganisms seen.
Technologies which combine easy cleaning and antimicrobial activity are preferable. It has been documented that the technology with surfaces decorated with metal oxide Lewis acids such as downstream. This is a particular issue with joints in pipework.
However, on open surfaces, at a solid air interface, the cells tend to be deposited on the surface through contact with vectors such as food, fingers, equipment, or splashing.
In this case, replication is less likely, since water availability is low, and the survival of cells on these surfaces is key to maintaining hygienic status. Antimicrobial surfaces, and/or surfaces which are hard or difficult to abrade, coupled with effective cleaning regimes, are strategies employed to counter this phenomenon. The continued cleaning/soiling cycle can itself affect the surface, causing abrasions that result in increased soiling and require increasing force in cleaning which in turn may increase abrasion. The nature of the surface itself can affect how it wears: steel and other metals tend to scratch; glass and ceramics tend to fracture; softer materials such as plastics will abrade more easily. Antimicrobial surfaces that actively leach out active agents might prove more effective if the surface area is increased through abrasion, but the presence of retained organic material (blood, food, sputum) in addition to micro-organisms might impede the antimicrobial effect and protect the microbial cells. It might be argued that the increase in surface area presented by surfaces with increased roughness is the driver for the increased retention, but this has not been convincingly proven.
The features themselves, in terms of shape, profile, and size As noted above, this work has led to the fabrication of surfaces with designed topographies that are targeted at inhibiting attachment of particular cells, where surface features smaller than cells might reduce their ability to strongly attach to the surface, and therefore improve cleanability. The robustness of these surfaces is essential to ensuring a long-lasting effect, and the potentially interfering effect of organic material must also be considered.
When considering open surfaces that are usually present at a solideair interface, which is the main focus of this paper, biofilms are of less concern. In the clinical/medical environment, high- This initially leads to leakage of cellular contents then cell lysis and may be followed by complete mineralization of the organism.
Killing is most efficient when there is close contact between the organisms and the TiO (2)  Their mechanism of action is based on the in-situ generation of H3O+ ions through the reaction with moisture from the air inspired by the bodys own defense mechanism imitating e.g. the acid coating of the skin.
The resulting acidified surfaces have a pH of 4.5 and the H3O+ ions are able to diffuse through the cell membranes where they can distort the pH-equilibrium and transport systems of the cell. In addition also free radicals e.g. oxygen radicals and hydroxyl radicals are formed which result in a synergistic mode of action and can be documented by the push plate (RODAC plate) method. Last but most Again, technologies which attack microorganisms from the outside also eradicate microorganisms in a biofilm an important asset. However also technologies based on oxygen radicals alone are also substantially less active as these free radicals are not able to penetrate the biofilm. In addition, also a positive Zeta potential is formed on the surface, responsible for the observed rapid eradication of microorganisms on surfaces documented by scanning electron microscopy. 6 log 10 reduction within 15 minutes has been observed. The technology is approved by the BPR as in situ generated biocide and is legitimately on the market.
In the future no easy approval for in situ generated biocides is possible by ECHA, this opportunity expired two years ago. This is also an additional favorable asset of the presently available technology. Surveillance and Response. Situational awareness is crucial for addressing national and international threats. Yet, the world currently lacks comprehensive monitoring for antibiotic resistance emerging domestically and being imported from abroad.
The surveillance systems are woefully underfunded. Powerful tools that emerged from the Human Genome Project have the ability to reveal how antibiotic resistance arises and spreads across health care facilities, agriculture, the environment and international borders, but they are not being routinely used. And adequate public and animal health infrastructure for monitoring antibiotic use and resistance is lacking in many states and localities. Specific actions and investments intended to achieve better surveillance, stewardship of currently used antibiotics, and development of new antibiotics.