FIELD OF THE INVENTION:
The present invention relates to the development of a new type of antimicrobial molecule (AbTids) combining the best therapeutic properties of antibodies (Ab-) and cationic antimicrobial peptides (-Tids) to target microbes such as bacteria, fungi, viruses, and particularly multidrug resistant bacteria.
More particularly an AbTid molecule consists of cationic antimicrobial peptides, which have the ability to instantly lyse the bacteria on contact, and a pathogen specific heavy chain antibody, which are generated against drug resistant clinical samples of Pseudomonas aeurginosa and Staphylococcus aureus.
BACKGROUND OF THE INVENTION:
Evolution is a constantly occurring phenomenon and microorganisms such as bacteria are champions of evolution. Today, quite a few microbes have evolved to a point where they pose a serious clinical challenge to human health. It has become increasingly tough to imagine undertaking a surgical procedure, organ transplant, any form of therapy, or even going through a common cold without consuming effective antimicrobial agents. Humans have come to a point where it appears to have lack of efficient safe drugs for patients infected with bacteria that are resistant to multiple drugs thereby earning the name 'superbugs'.
Penicillin, one of the world's first antibiotics has now become less effective than before. The overuse of antibiotics in humans and livestock has led towards the rapid evolution of microorganisms, which are resistant to not just a single, but a multitude of drugs. This resistance poses a grave danger, as even vancomycin, the

drug of last resort, is no longer effective against some strains of bacteria. Research and development departments are constantly on the lookout for improved or novel drugs, which effectively battle multiple resistance strains of bacteria and other microbes however, there have been few new antibiotics developed in recent years.
Both the gram-positive and gram -negative bacteria are important human and animal pathogens. Effective drugs against both these groups are lacking due to the rapid emergence of resistant mutations. Although multidrug-resistant microbes such as Pseudomonas aeruginosa and Acinetobacter are the more predominantly well-known therapeutic challenges among gram-negative bacteria, strong resistance to the most potent antibiotics have been observed in members of the Enterobacteriaceae family, which includes hospital-associated strains of Klebsiella, Escherichia coli, Enterobacter and firmicutes like Staphylococcus aureus and Staphylococcus epidermis. . Resistant variants of microbial strains are not limited to the hospital anymore and multidrug-resistant gram-negative bacteria have been found in otherwise healthy patients outside of hospitals as well. For example, the urinary tract infections caused by E. coli and Pseudomonas that are resistant to trimethoprim sulfamethoxazole, fluoroquinolones, or both and that tend to produce extended-spectrum p-lactamases (enzymes that can destroy the most potent cephalosporins). There have also been cases of major outbreaks of food poisoning caused by multidrug-resistant Salmonella and E.coli strains as well.
Thus, with a rise in multi-drug variants of microbes there exists a need for new solutions to destroy these pathogens. The most prominent form of human therapeutics utilised today are antibodies, which also constitute the second largest

class of drugs after vaccines. Antibodies offer target specific activity and are thus predominantly explored and utilised today for use against a plethora of diseases, infections and conditions.
Another class of bactericidal antimicrobials are peptides that act by lysing the microorganism. Peptides are antimicrobial naturally occurring in nature and are produced by all organisms, including plants, insects and human beings, as a part of their non-specific defences against infections. However, use of peptides as drug for treating infection has not proved to be an effective measure as peptides have a poor pharmacokinetic profile, are toxic in nature and can lyse human cells along with bacterial lysis. Thus, with an increasing development of antibiotic resistance among a variety of bacterial pathogens, there is now an essential need to develop such a drug, which can overcome the above limitations and provide effective ways to improve immunity against infections.
Thus, the present invention proposes a safe and fast acting, nontoxic yet highly effective solution for overcoming the above listed limitations. The present invention proposes development of a new molecule AbTids, a combined molecule encompassing the best properties of heavy chain antibodies and cationic antimicrobial peptides.
PRIOR ART:
US patent no. 20140206081 discloses an invention for the production of a therapeutic agent which consists of a variable domain of camelid heavy-chain antibodies (VHH domains) and a peptide vector, directed against glial fibrillary

acidic protein (GFAP). Also disclosed is its use as a delivering therapeutic of diagnosticcompounds across the mammal blood-brain barrier and cell membranes.
US patent no. 20120213848 discloses a method for treating HIV and other intra-cellular parasites and toxins by using intrabodies composed of a camelid antibody and a peptide with TRIM21 affinity, which are delivered directly to leukocytes.
US patent no. 9,005,579 discloses methods and compositions for inhibiting the growth and/or reducing the virulence of gram-positive bacteria. The cell wall or cell membrane is disrupted and rendered exposed such that the cell wall/membrane target is also exposed or accessible for destruction. The method utilises a disrupting agent selected from a group of antibiotics, anti-microbial peptides, poly-cationic peptides, cell wall degrading enzymes, and catalytic antibodies (including heavy chain camelid antibodies) having inherent antimicrobial activity. One of the methods suggested to disrupt the cell wall of a gram positive bacterium is to combine an antibody covalently or non-covalently with a bioactive peptide.
US patent no. 20040052814 discloses a fusion protein comprising of an antimicrobial peptide and a recognition sequence for the targeted delivery of said antimicrobial molecule to a microorganism to treat a microbial infection. A linker peptide connects the antimicrobial peptide with the recognition sequence. The recognition sequence may be an immunoglobulin molecule, or fragment thereof, that specifically binds to a target antigen present on a pathogen; it could also be non-immunological in nature. The antimicrobial peptide is selected from a group of bistatin 5 and dhvar 1, cecropin, indolicidin, magainin, nisin, ranalexin, protegrin,

alexomycin, defensin and immunoglobulin from a group of SWLA1, SWLA2 and SWLA3.
The prior arts mentioned above fail to provide a simple, effective, quick acting and non-toxic solution for eliminating pathogens such as multi-drug resistance bacterial infections. The AbTid molecules express the specific affinity of the antibody and the antimicrobial activity of peptides together.
OBJECTS OF THE INVENTION:
The primary object of the present invention is to provide an effective, low toxic, simple to produce, specific, stable, and fast acting molecule (AbTids) which, has a modular structure encompassing a cationic antimicrobial peptide and an antibody specific to targeted pathogens.
Another object of the present invention is to provide an AbTid molecule, which can be adapted against a number of pathogenic bacteria by simply generating the bacteria specific antibody from the library of camelid antibodies and replacing them in the same AbTid scaffold of the modular structure. The peptides and antibodies can be altered in the same modular structure depending on the need.
Another object of the present invention is to provide interchangeable modular structure of AbTids, in which, the peptides and the linkers can be interchanged, and new peptides can be added singly or in tandem depending on the need.
Another object of the present invention is to provide an antibacterial AbTid molecule that consists of five components arranged in tandem , a cationic

antimicrobial peptide, two signal peptidase 1 cleavage sequences , a flexible anionic linker, a bacteria specific heavy chain antibody fragment derived from camels and a hexahistidine tag to enable identification and purification.
SUMMARY OF THE INVENTION:
Before the present invention is described, it is to be understood that present invention is not limited to particular methodologies and materials described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention.
The present invention relates to AbTids molecules which are small sized (ranging 15-20 kDa ) molecules consisting of heavy chain antibodies derived from camels that act in combination with antimicrobial peptides made up of cationic and hydrophobic amino acids to lyse microbes particularly pathogenic cell structures. The AbTid molecule is a quick acting antibacterial molecule that does not target any particular enzyme mediated cellular process inside the bacteria. Enzymes that are proteins made by the microorganisms usually mediate cellular processes. These enzymes are easily mutated making the small molecule antibiotics currently being used ineffective giving rise to the problem of drug resistance. The AbTids molecule overcomes these limitations by attacking the structural component of the bacteria sterically, instead of some mutable enzyme component inside bacteria against which resistance will be difficult to evolve by the bacteria. Furthermore, being modular in nature, the components can easily be switched, increasing the complexity of the molecule making it difficult for the bacteria to mount an effective anti AbTid

challenge. These molecules are evolution proof molecules having the capacity to overcome the antibiotic resistance challenge by bacteria and will be highly effective as antibiotics.
According to one of the embodiment of the present invention, the AbTids molecule, with a modular structure is such that it can be quickly adapted against a number of pathogenic microbes by simply generating the bacteria specific antibody from the library of camelid antibody molecules and replacing them in the AbTid scaffold. Similarly, the peptides and the linkers can be interchanged, new peptides added singly or in tandem depending on the need.
Another embodiment of the present invention describes the mode of action of this molecule as simple and fast acting, as illustrated in Figure 1, wherein the AbTid molecule bonds with the target antigen and latches on to it. The attached peptide (connected by a flexible linker peptide) is then freed from the AbTid molecule by Type 1 peptidase enzyme, which then disrupts the bacterial membrane
and lyses the cell.
*■
Another embodiment of the invention provides an AbTid molecule that is adaptable for a multiple applications and can be administered by various alternative routes as opposed to previous drugs utilising a single administrative route for doses. AbTids can be used for various applications such as, but not limiting to, formulations for topical or parenteral applications, as pills for gastrointestinal pathogens, topical applications for bacterial, fungal and viral infections, as for intra nasal applications, as dressings for burn patients, as mouth washes, as skin lotions, as chemical condoms

for prevention of transmission of sexually transmitted diseases, as cosmetics in the
form of lotions, ointments and hair oil, as shampoos and, as sterilising agents. other objects, features and advantages of the present invention will become
apparent from the following description when taken in conjunction with the
accompanying drawings wherein like characters of reference designate
corresponding parts throughout the several views.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
These and other features, aspects and advantages of the present invention are better understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which:
Figure 1 of the accompanying drawing illustrates the anti-bacterial action of AbTids.
In this, the AbTids homes on the target antigen and latches on to it. The attached peptide is then detached /freed from the complex by Type 1 peptidase enzyme (1.6), which then disrupts the bacterial membrane and lyses the cell.
Figure 2a(i) of the accompanying drawing illustrates an amino acid sequence of an anti-Pseudomonas AbTid molecule.
The anti-pseudomonas AbTid molecule consists of cationic peptide composed of Mellitin Cercopin (1) combination followed by Signal peptidase 1 cleavage sequences (2); a Yol tag (3) and a heavy chain antibody (6) along with

restriction enzyme sites (4) and hexahistidine tag (5) of the modular AbTids molecule.
Figure 2a (ii) of the accompanying drawing illustrates an amino acid
sequence of an anti-Pseudomonas AbTid molecule:
The anti-pseudomonas AbTid molecule consists of cationic peptide composed of Arginine and Tryptophan (1) combination followed by Signal peptidase 1 cleavage sequences (2); a Yol tag (3) and a heavy chain antibody (6) along with restriction enzyme sites (4) and hexahistidine tag (5) of the modular AbTids molecule.
Figure 2b (i) of the accompanying drawing illustrates another amino acid sequence of an anti-staphylococcus AbTid molecule.
It consists of cationic peptide composed of Arginine and Tryptophan (1) followed by two Signal peptidase 1-cleavage sequences (2); an Anionic Tag (3) and a heavy chain antibody (7) along with a Hexahistidine Tag (5) and the restriction enzyme sites (4) of the modular AbTids molecule.
Figure 2b.(ii) of the accompanying drawing illustrates an amino acid sequence of an anti-staphylococcus AbTid molecule:
The anti-staphylococcus AbTid molecule consists of cationic peptide composed of composed of Arginine and Tryptophan (1) combination followed by Signal peptidase 1 cleavage sequences (2); a Yol tag (3) and a heavy chain antibody (6) along with restriction enzyme sites (4) and hexahistidine tag (5) of the modular AbTids molecule.

Figure 3a and 3b are microbiological test results of the antimicrobial action of the AbTids against drug resistant forms of Pseudomonas aeruginosa (resistant against Amikacin, Cefepime, Ceftazidime, Gentimycin, Inipemen, Meropenem, Mezocillin, Piperacilin and Tobramycin) and Staphylococcus aureus (Resistant against Amoxicillin, Ciprofloxacin, Clarithromycin, Clindamycin. Erithromycin, Fusidic acid, Gentamycin, Oxacillin, Rifampicin, Teiciolanin and, Vancomycin) respectively.
In fig 3a, use of crude extracts of antibody alone causes an 80% inhibition of growth in Pseudomonas aeruginosa while addition of the AbTids cause 95% inhibition, in fig 3b, the antibody extract causes a 50% inhibition in the growth of Staphylococcus aureus whereas the AbTids caused more than 80% inhibition.
DETAILED DESCRIPTION OF THE INVENTION:
Before the present invention is described, it is to be understood that this invention is not limited to particular methodologies and materials described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention.
Before the present invention is described, it is to be understood that unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention-'belongs. Further, it is to be understood that the present invention is not limited to the methodologies and materials similar, equivalent to those described

herein canjre used in the practice, or testing of the present invention, the preferred methods and materials are described, as these may vary within the specification indicated. Unless stated to the contrary, any use of the words such as "including," "containing," "comprising," "having" and the like, means "including without limitation" and shall not be construed to limit any general statement that it follows to the specific or similar items or matters immediately following it. Embodiments of the invention are not mutually exclusive, but may be implemented in various combinations. The described embodiments of the invention and the disclosed examples^are given for the purpose of illustration rather than limitation of the invention as set forth the appended claims. Further, the terms disclosed embodiments are merely exemplary methods of the invention, which may be embodied in various forms.
In the specification herein below
"AbTids" is interchangeable with modular structure, means an antimicrobial molecule (AbTids) combining the best therapeutic properties of antibodies (Ab-) and cationic antimicrobial peptides (-Tids) to target microbes such as bacteria, fungi, viruses, and particularly multidrug resistant bacteria.
"Cationic antimicrobial peptide" interchangeable with (ctAMP), means a positively charged peptide that can lyse the bacterial membrane on contact. Bacterial membranes are usually anionic (negatively charged) and the positive charge of the ctAMP disrupts the membrane integrity by displacing the metal cations and stoically lodging into it.

The ctAMP is composed of a hybrid of mellitin and cercopin with the sequence KWKLFKKIGAVLKVLG as indicated in Figure 2aland 2bl (top) and alternately as a combination of Arginines (R) and tryptophans (W) as indicated in Figure 2al and 2b 1 (bottom) The peptides consist of a chain of positively charged amino acids, such as but not limiting to, Leucine ( L), valine (V) , Isoleucine (I), Glycine ( G ) along with neutral non polar and aromatic functional group amino acids such as , but not limiting to, lysine (K), Tyrosine ( T), Arginine (R) and Tryptophan (W). Alternatively, the cationic peptides can consist of very short synthetic chains of neutral Arginines and Tryptophans.
"Flexible Polypeptide Linker" means short peptide sequences that occur between peptide domains, composed predominantly of anionic amino acids such as but not limiting to Aspartate (D) or Glutamic acid (E) used in order to construct the linker consisting of the following amino acids EEGEFSEAR. This can be engineered with another flexible tag consisting of tandemly repeated nonpolar amino acids with uncharged functional groups such as, but not limiting to, Glycines (G) and Serines (S) of the following sequence GGGGS GGGGS GGGGS. The G and S units can be increased further to increase the length of the linker that might result in higher efficacy of the AbTids molecule. Lysine rich tags like GSADDAKKDAAKKDGKS or SSADDAKKDAAKKDDAKKDDAKKDA can be used as well.
The present invention relates to a stable, low toxicity, simple to produce, specific, fast acting antimicrobial agent (AbTids) comprising of heavy chain antibodies and cationic antimicrobial peptides lacking cysteine, together forming a

molecule with a alpha helix structure with the help of a peptide linker that disrupts and lyses the cell wall/membrane or outer cellular structure of the microbes.
According to the present invention, the AbTids molecule consisting of the heavy chain antibodies that are generated against surface molecules of drug resistant clinical samples of pathogens such as Pseudomonas and Staphylococcus binding to the outer membrane proteins, which are derived from camelids, such as camels, selected by phage display methodology. AbTids, composed of camelid antibodies are small, extremely stable, do not require cold chain storage and have high tissue penetrability.
Another embodiment of the present invention describes AbTids molecules as composed of the following five components, arranged in tandem (as illustrated in Figures 2a and 2b of the accompanying drawings) -
1. Cationic antimicrobial peptide (1) having a net positive charge which helps disrupting the negatively charged cell wall/membrane of the microbes
2. Tandem signal peptidase 1 cleavage sequences (2) derived from conserved regions of microbes in order to enable signal peptidase 1 enzymes present on the outer membrane of bacteria to bind with sequences and be cleaved.
3. A flexible polypeptide linker (Yol Tag) (3) allows the cationic peptide to form a complex with the linker and attach to the antibody until a final thermodynamically stable configuration is reached.
4. Across-reacting antibody (6 and 7), the CDR3 region of the antibody is engaged with the bacterial antigen.
5. A hexahistidine tag (5) for detection and purification of AbTid molecules

Yet another embodiment of the present invention describes AbTids as a safe yet quick acting antibacterial molecule that does not target any particular cellular process inside the bacteria. Enzymes are proteins made by the microorganisms mediating cellular processes, which can easily mutate and make antibiotics ineffective resulting in drug resistance. AbTids overcome the limitations by attacking the structural component of the bacteria sterically, instead of some mutable enzyme component inside a bacterium, against which resistance will be difficult to evolve by the bacteria. Furthermore, being modular in nature, the components can easily be switched, increasing the complexity of the molecule making it difficult for the bacteria to mount an effective anti AbTid challenge.
Yet another embodiment of the present invention describes the tandem peptidase cleavage sequences present in the AbTids as Tandem signal peptidase 1 cleavage sequences (2) derived from the conserved regions of sequences from gram positive and gram-negative bacteria having the sequences of ASA and ALA. Signal peptidase 1 enzymes, present on the outer membrane of bacteria attach to the above sequences and cleave it thereby freeing the ctAMP to function as effective as an antimicrobial peptide. These signal peptidase cleavage signals that are conserved in bacteria are designed by the 3/1 rule that states that the residues in the -3 and -1 position of the cleavage sites should be small and neutral for effective cleavage to occur.-A flexible, non-polar aliphatic amino acid Alanine (A) is chosen based on homology searches, two tandem sites are created with Serine and Leucine between the Alanine which results in a small uncharged side chain with a hydrophobic central core. The cleavage occurs on the first cleavage sequence.


Yet another embodiment of the present invention includes a flexible polypeptide linker (Yol Tag) that allows the cationic peptide (1) to link with the linker (3) and attaches to the antibody (6 and 7) until a final thermodynamically stable configuration is reached. This configuration changes only when the AbTid molecule is exposed to the bacterial outer membrane that has a negative charge. As the peptide is cationic, it will not attach to the linker and will utilize its antibacterial activity even without disassociating from the AbTid complex. The cationic peptides present in AbTids lack cysteine (C) residues hence no disulphide bridges are formed. The AbTid structure results in an alpha helix configuration once released from the AbTid. Such a configuration allows the cationic peptide to form a barrel like structure, which can lodge itself into the pathogen membrane 'thereby disrupting it to release the cytoplasmic contents leading to cell lysis as can been seen in Figure 1 of the accompanying figure.
Yet another embodiment of the present invention describes a hexahistidine tag (5), present in the antimicrobial molecule, located downstream of the heavy chain antibody (6 and 7) for the detection of the antimicrobial molecule with the help of anti-histidine antibodies or for the purification of the antimicrobial molecule with the help of metal affinity chromatography such as Ni NTA column (Ni2+-affinity chromatography).
Another embodiment of the present invention describes the mode of action of AbTids, as shown in Figure 1, which illustrates the AbTid molecule (1.0) targeting the bacterial membrane via antigen antibody reaction where the antibody linked to the cationic peptide (1.2) docks with the membrane entigen (1.3). A suitably

designed neutralising antibody will have the ability to neutralise the pathogen without the need for the peptide. When the antibody is non-neutralising, such as in the present invention, the antibody acts as a targeting molecule and the killing by lysis is done by the antimicrobial peptide alone. Once docked to the pathogen with the help of the linker peptide (1.4), electrostatic attraction dislodges the peptide from the AbTid as the bacterial outer membrane has a negative charge. The cationic peptide having a positive charge displaces the native cations like Ca++ and Na+ from the bacterial outer membrane leading to a disturbance in structure. The barrel like peptide connected to a linker is lodged in the phospholipid bilayer through the destabilised area and the peptide is snipped off from the AbTids by the bacterial outer membrane signal peptidase 1 (1.6.) that acts on the signal peptidase cleavage site ALAASA. As more and more peptides (from the AbTid molecules) dock onto the membrane, the membrane structure collapses resulting in a leakage of the cytoplasmic contents into the medium, eventually resulting in the killing of the pathogen. This action happens in a fraction of seconds resulting in the instant killing of the pathogen.
Another embodiment of the present invention illustrates the versatile nature of AbTids against pathogens. Different types of AbTids against different types of bacteria can be generated by using different bacteria specific antibody cationic peptides and signal peptidase recognition sequences. The AbTid molecule has a modular structure and the peptides and antibodies can be changed on the same scaffold depending on the need. If an AbTid against different bacteria is required, the bacteria specific andbody can be generated from the library of camelid antibody

molecules and replaced in the same AbTid scaffold. Similarly, the peptides and the linkers can be interchanged, new peptides added singly or in tandem depending on the need.
Another embodiment of the present invention describes the procedure for obtaining antibodies (Figure 2a and Figure 2b). Two antibodies binding to drug resistant strains of Pseudomonas species and Staphylococcus species that has been isolated from clinical samples (pathogens) binding to the outer membrane proteins are derived from camels. These molecules are isolated from a library of heavy chain antibody molecules of Camelus dromedarius found in India by phage display methodology. The camelid antibodies are small (15 Kd, about one tenth the size of a full sized antibody molecule) and are extremely stable without a need for a cold chain for storage with high tissue penetrability. This molecule is isolated from a library of such molecules generated for the purpose by affinity purification against Pseudomonas and Staphylococcus surface displayed molecules (antigen). The purpose of the antibody molecule is for a targeted delivery of the peptide molecule to the surface of the pathogens and attaching to it. The sequence of the antibody is indicated in Fig 2a and 2b of the accompanying drawings.
The camelid antibody consists of three Framework regions that are conserved and three complimentary determining regions (CDR) that vary depending on the antigens. The CDR 3 region that is the main antigen-binding region is extended to compensate for the loss of light chains in this format of antibodies.
Yet another embodiment of the present invention describes the antimicrobial activity of AbTids, which also attacks biofilms. Almost 80% of the human infections

are due to biofilm formations and the AbTid molecules prevent this by killing the colony forming bacteria thereby displaying their effective usage as sterilising agents for medical equipments like catheters, endoscopes, orthopaedic implants and stents.
Yet another embodiment of the present invention describes an AbTid that can be formulated for various applications and delivered by aerosol sprays for upper respiratory tract infections, or as creams for topical applications, hydrophobic solutions for urogenital tract infections or formulated with probiotics for gastrointestinal tract infections. They can also be used as sanitising agents in hand
sanitisers, mouthwash, antimicrobial wipes for sterilising the equipments of clean rooms like operation theatres and pharmaceutical manufacturing units, antibacterial filters in air conditioners to coat prosthetic devices that are prone to bacterial contamination. The antimicrobial molecules can be formulated for topical applications for bacterial, fungal and viral infections and will be suitable for intra nasal applications dressings for burn patients, and a topical application for bedsore in patients' mouth washes skin lotions as well as chemical condoms for prevention of transmission of sexually transmitted diseases.
Yet another embodiment of the present invention describes the versatility of AbTids for use against various pathogens such as not limiting to, common drug resistant bacteria such as Pseudomonas that cause urinary tract infections and lung infections, Clostridium dificile, Helicobacter pylori, E coli, Salmonella typhimurium and Salmonella enteritidis causing infections in the human gut, Streptococcus and Klebsiella pneumoniae causing lung infections and many gram positive and gram negative pathogenic bacteria of the humans, viral infections, particularly enveloped

viruses like Influenza A virus, HIV virus, Vesicular stomatitis virus, respiratory syncytial virus, Chicken pox virus and vaccinia viruses. When applied in the entry routes of the viruses like the nasal and urogenital cavity AbTids will act as a passive
vaccine and prevent the spread of infections; cosmetic uses against fungus and bacteria that causes skin conditions body odour and acne like Melassezia pachydermis, Propiyonibacter acnes and against Melassezia furfur that cause dandruff and hair fall, formulated as scalp and skin care products like lotions, antibacterial body oil ointments and hair oil and as soaps and shampoos; as sterilising agents to stop the spread of drug resistant bacteria in the environment and can be impregnated in air conditioner filters and facemasks; in operation theatres and the wards of hospitals that have a significant bacterial and viral load, fitted into air conditioners in public places like theatres and auditoriums, aircraft and buses that is a major source of transmission of drug resistant bacteria; as antibacterial hand sanitiser solutions or gels for hospital or personal use.
Yet another embodiment of the present invention describes the use of the AbTid molecules in animal husbandry applications to treat infections in animals; like treatment of bovine mastitis caused by a consortium of different bacteria, treatment of diseases in livestock and poultry, that will have the potential to replace antibiotic usage andcontrol the problem of the drug resistance at its source. These molecules can also be used in agriculture like pisciculture and apiculture where antibiotics are widely used.
Yet another embodiment of the present invention describes the use of the AbTid molecules in food processing both in human and petfood industries as a

solution to coat the surfaces of the machinery used for preparing food like cold cuts of meat and salads and in dairy industry producing milk, butter yoghurt and cheese as well as a solution to coat the papers used for wrapping the material prior to delivery that will control the spread of food borne infection.
ADVANTAGES:
The advantage of the AbTid molecules over conventional drugs for use against multiple resistance stains of pathogens currently present are as follows:
1. Fast acting but nontoxic: The peptide by itself lyses the bacteria in a few seconds. The outer membrane pf the pathogen is negatively charged and attracts the positive charge of the peptide that disturbs the membrane structure, however the outer membrane of the host cells where the bacteria reside (e.g. human organs) are also negatively charged and so the peptides by itself damages the host cells with equal efficacy and are be toxic. When the peptide is attached with the antibody in the AbTid that has an overall net negative charge at physiological pH, the peptide wraps around the antibody, loses its toxicity, and does not cause collateral damage.
2. Stability: The camelid antibody is an extremely stable molecule that does not need a cold chain for transportation. It is stable in a pH of 2 and a temperature of 75°C and beyond. The peptide molecule however is labile by itself but when attached to the antibody its stability increases. The stable AbTid molecule can thus be formulated for a number of uses like topical applications, as sterilising reagents and for cosmetic uses other than its ultimate use as a parenterally administered drug molecule.
3. Specificity: The antibody molecule is specific to the surface proteins of the pathogen and will not bind hon-specificaily* to other targets. As the peptide molecule is attached to the antibody, the peptide is targeted to the pathogen only. The specificity of the molecule ensures that it can be administered in sufficiently low doses overcoming previous problems associated with its toxicity whilst maintaining its efficacy.

4. Efficacy: The peptide molecule is followed by two signal peptide 1-cleavage sequences. These are recognised by the signal peptidases on the surface of the bacteria and lyse the fusion peptide, thereby releasing the cationic peptide from the AbTid. The cationic peptide regains its toxicity after being released from the antimicrobial combination molecule and acts against the specific pathogen.
5. Dosage: The Antibody cationic peptide complex is a target specific molecule thus; it acts in minimal doses in comparison to cationic peptides and heavy chain antibodies, when used individually to attain similar results. Along with minimising the cationic peptide toxicity, AbTids also tend to reduce the host immune reaction against the antibody.
6. Increased bioavailability and pharmacokinetic profile: The cationic peptide molecule has a small size, is rapidly cleared from circulation by the kidney thus showcasing an extremely short half-life. Hence it is most effective when administered continuously over a period of time parenterally by drip. The AbTids molecule is a small yet slightly larger molecule in size when compared to the peptide and tends to have a better pharmacokinetic profile than the peptide or the antibody alone. AbTids will remain in the body long enough after a single dosing and be effective.
7. Ease of production: The AbTid molecule can be produced in a simple vector such as E coli or yeast system as the combination molecule by itself is nontoxic. As fermenters will produce them microbially, the cost of production will be significant lower than the current mode of production by solid phase chemistry. The toxic peptide and antibody molecule'combine will result in a harmless molecule that can be purified by a metal affinity column that will bind to the hexahistidine tag of the AbTid molecule. Toxicity is restored only when the molecule is applied on the outer membrane of the bacteria that cleaves the molecule at the signal peptidase 1 recognition site freeing the peptide that can then lyse the membrane of the bacteria it is applied against.
While considerable emphasis has been placed herein on the specific elements of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in preferred embodiment without departing from the principles of the invention.

These and other changes in the preferred embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is
to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We Claim,
1. An antimicrobial molecule comprising of a combined properties of a cationic antimicrobial peptide and a heavy chain antibody against microbes.
2. The antimicrobial molecule of claim 1, wherein the antimicrobial molecule consists of the said cationic antimicrobial peptide, a tandem signal peptidase 1 cleavage sequence, at least one flexible polypeptide linker, at least one cross-reacting antibody and at least one hexahistidine tag.
3. The antimicrobial molecule of claim 1, wherein the said cationic antimicrobial peptide is made up of positively charged amino acid sequences not limiting to Leucine (L) , Valine (V) , Isoleucine (I), Glycine (G), lysine (K), Tyrosine (T), Arginine (R) and Tryptophan (W) and a combination thereof.
4. The antimicrobial molecule of claim 1, wherein the said cationic antimicrobial peptides includes a hybrid sequence made up from mellitin and Cercopin( KWKLFKKIGAV LKVLG), a sequence of Arginines and tryptophans (RWRWRW), alpha helical antimicrobial peptides like Human LL37, mice CRAMP, Ascaris cercopin P1, Pig VIP, Frog maganin 2, peptides rich in Proline or tryptophan like Pig PR-39 and cow indolicidin or a combination thereof.
5. The antimicrobial molecule of claim 1, wherein the said tandem signal peptidase 1 cleavage sequence are derived from conserved regions of target pathogens, not limiting to sequences selected from the group of ALU, ASA, ALA, AAA, AQA, AGA, ASA, AFS, AYS, AFG, ALG, ANA, ADA, AIS, AVA; and combination thereof and wherein the hydrophobic central amino acid are selected from a group of Glycine, Alanine, Valine, Leucine, Isoleucine, Tryptophan, Proline, Phenylalanine or a combination thereof.
6. The antimicrobial molecule of claim 1, wherein the said tandem signal peptidase 1 cleavage sequence can have flanking -3 and the -1 Alanine which can be replaced by amino acids selected from Serine or Glycine or having similar properties.

7. The antimicrobial molecule of claim 1, wherein the said flexible polypeptide linker is selected from a group of the amino acid sequence not limiting to EEGEFSEAR where Aspartate (D) can be used instead of Glutamic acid (E) or from a sequence of tandemly repeated Glycine and Serine (GGGGSGGGGSGGGGS) or from Lysine rich tags like GSADDAKKDAAKKDGKS or SSADDAKKDAAKKDDAKKDDAKKDA or a combination thereof.
8. The antimicrobial molecule of claim 1, wherein the said cross-reacting antibody is derived from a library of heavy chain antibodies from camelids not limiting to dromedary camel, bactrian camels, wild or feral camels, llamas, alpacas, vicunas, or guanacos, prefarably Camelus dromedaries, wherein the said antibody are generated against surface molecules of the said target pathogens.