333
exhibit broad spectrum antimicrobial activities. These peptides differ in their amino
acid composition and are classified into a number of families based on amino acid
sequence homology. The main AMP families are defensins, thionins, lipid transfer
proteins, cyclotides, snakins, and hevein-like proteins. Certain plants synthesize
hundreds of different AMPs. Due to their broad spectrum activity and efficiency,
AMPs would be a suitable alternative to less-efficient drugs currently in use
(Pinheiro Da Silva and MacHado 2012).
13.5.2 Animals
A number of bioactive compounds have been isolated from various types of animals, mainly insects and reptiles. Biomolecules with antimicrobial potential are
believed to be produced by such animals by virtue of the physiological and morphological adaptations they acquire for survival in local ecological conditions (Latifi
et al. 2015). An example is the identification of small molecules that suppress environmental pathogens produced by bacterial symbionts of insect-agricultural systems (Ramadhar et al. 2014). Potential antimicrobial antibiotic properties from
brain extracts of cockroaches and locusts that inhabit the environment prone to bacterial infection are also identified (Khan et al. 2008; Lee et al. 2011). There are other
instances where peptides and proteins with antimicrobial properties are identified
from hemolymph of insects (Moreno-Garcia et al. 2013) that are experimentally
challenged with live bacteria (Qu et al. 1982). Cecropin, insect defensins, attacinlike (glycinerich) proteins, proline-rich peptides, and lysozymes are the major
groups of antimicrobial peptides identified from insects so far (Hultmark et al.
1983). All these findings, and more, point fingers toward the need of active research
in this field for identification and commercial availability of novel antimicrobials.
Interestingly, peptides or proteins of animal venom, including that of wasps,
honeybees, spiders, scorpions, and snakes, are also shown to have antimicrobial
effect (Dani et al. 2003; Benli and Yigit 2008; Fennell et al. 1967; Perumal samy
et al. 2007). Venoms of different species of rattle snake, viper, cobra, and krait show
high antimicrobial activity in vitro which are as effective as commercially available
antibiotics such as chloramphenicol and ceftazidime (Perumal Samy et al. 2006).
Crude venom of wasp (Vespa orientalis) is effective against both Gram positive
(Staphylococcus aureus and Bacillus subtilis) and Gram negative (E. coli and K.
pneumonia) bacteria (Jalaei et al. 2014). Venom of funnel web spider (Agelena labyrinthica) is shown to be active against common human bacterial pathogens by
causing loss of bacterial cytoplasm and eventually its death. A number of antimicrobial peptides were isolated from venoms of different animal species and their mechanisms of action are being identified by various research groups across the globe,
keeping the expectations of the world high for better antimicrobials that can tackle
issues associated with drug resistance.
Antimicrobial peptides (AMPs) of animal origin are a diverse group of small
peptides that are essential components of nonspecific defence mechanisms of host
13 Novel Sources of Antimicrobials
exhibit broad spectrum antimicrobial activities. These peptides differ in their amino
acid composition and are classified into a number of families based on amino acid
sequence homology. The main AMP families are defensins, thionins, lipid transfer
proteins, cyclotides, snakins, and hevein-like proteins. Certain plants synthesize
hundreds of different AMPs. Due to their broad spectrum activity and efficiency,
AMPs would be a suitable alternative to less-efficient drugs currently in use
(Pinheiro Da Silva and MacHado 2012).
13.5.2 Animals
A number of bioactive compounds have been isolated from various types of animals, mainly insects and reptiles. Biomolecules with antimicrobial potential are
believed to be produced by such animals by virtue of the physiological and morphological adaptations they acquire for survival in local ecological conditions (Latifi
et al. 2015). An example is the identification of small molecules that suppress environmental pathogens produced by bacterial symbionts of insect-agricultural systems (Ramadhar et al. 2014). Potential antimicrobial antibiotic properties from
brain extracts of cockroaches and locusts that inhabit the environment prone to bacterial infection are also identified (Khan et al. 2008; Lee et al. 2011). There are other
instances where peptides and proteins with antimicrobial properties are identified
from hemolymph of insects (Moreno-Garcia et al. 2013) that are experimentally
challenged with live bacteria (Qu et al. 1982). Cecropin, insect defensins, attacinlike (glycinerich) proteins, proline-rich peptides, and lysozymes are the major
groups of antimicrobial peptides identified from insects so far (Hultmark et al.
1983). All these findings, and more, point fingers toward the need of active research
in this field for identification and commercial availability of novel antimicrobials.
Interestingly, peptides or proteins of animal venom, including that of wasps,
honeybees, spiders, scorpions, and snakes, are also shown to have antimicrobial
effect (Dani et al. 2003; Benli and Yigit 2008; Fennell et al. 1967; Perumal samy
et al. 2007). Venoms of different species of rattle snake, viper, cobra, and krait show
high antimicrobial activity in vitro which are as effective as commercially available
antibiotics such as chloramphenicol and ceftazidime (Perumal Samy et al. 2006).
Crude venom of wasp (Vespa orientalis) is effective against both Gram positive
(Staphylococcus aureus and Bacillus subtilis) and Gram negative (E. coli and K.
pneumonia) bacteria (Jalaei et al. 2014). Venom of funnel web spider (Agelena labyrinthica) is shown to be active against common human bacterial pathogens by
causing loss of bacterial cytoplasm and eventually its death. A number of antimicrobial peptides were isolated from venoms of different animal species and their mechanisms of action are being identified by various research groups across the globe,
keeping the expectations of the world high for better antimicrobials that can tackle
issues associated with drug resistance.
Antimicrobial peptides (AMPs) of animal origin are a diverse group of small
peptides that are essential components of nonspecific defence mechanisms of host
13 Novel Sources of Antimicrobials