full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and PharmacyVol. 5 (2) 1134-1148 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1135side effect to the host (6). We have performedin-silico genomic analysis of virulent foodbornepathogens Listeria monocytogenes and Bacilluscereus for identification of potential drug targetsfor novel drug discovery. Listeriamonocytogenes causes Listeriosis a virulentfoodborne clinical infection. Similarly, Bacilluscereus a, Gram-positive, rod-shaped, betahemolytic bacterium causing causing severenausea, vomiting and diarrhoea. These data couldbe used for the identification of conserved proteinsequences which are essential for bacterialsurvival (7). These conserved proteins are veryimportant in finding drug targets in pathogens, idealantimicrobial targets should be highly conservedamong as well as essential for the pathogenicbacteria (8).MethodsThe BLAST executable of proteinsequences for these two bacterial species weredownloaded from NCBI By using CD-HITparalog sequences at 60% identity were excludedfrom further study as earliesr described (9, 10).The essential gene sequences were taken formfrom the Database of Essential Gene (DEG). Nonhuman homologous sequences were identified byBLASTP analysis of non redundant sequencesat E-value cut-off of 10 -3 against human proteinsequences (9, 10). Non human homologoussequences were aligned with sequencesdownloaded from DEG database using BLASTPat an E-value cut-off of 10 -10 and 30% identity.The resultant protein sequences were consideredas essential drug target proteins. Further usingKEGG (http://www.genome.jp/kegg.html.)pathway prediction these essential drug targetproteins were analyzed whether these are activerole in various metabolic and cellular pathways.Results and DiscussionBacteria are the greatest threat to foodsafety and may cause food poisoning. Listeriamonocytogenes is a causative agent of Listeriosis,a most virulent foodborne clinical infection andleading cause of death among foodborne bacterialpathogens (11). The majority of human listeriosiscases occur in neonates, immunosupressed,pregnant women and old people. This is a majorthreat to human health (12). The recent studydescribes the way Listeria grabs onto molecularhandles on cells in the small intestine and thenswitches on those cells’ own uptake systems tohitch a ride inside (13). Similarly, Bacillus cereusis a, Gram-positive, rod-shaped, beta hemolyticbacterium causing nausea, vomiting and diarrhea.Generally speaking, Bacillus foodborne illnessesoccur due to survival of the bacterial endosporeswhen food is improperly cooked.The computational analysis of fullgenome sequences for identification of probableantimicrobial drug targets has become a new trendin pharmacogenomics. Two bacterial pathogenscausing foodborn human disease (Table1) werecovered for genome analysis and summary of theresults are listed in Table 1. The current studyhas been included in our database (14).List of all drug targets for each pathogenis listed in Tables 2 & 3. We got adequate numberTable 1. Summary of genome analysis of selected bacterial speciesTotal No. of Non-paralogs Non human Number ofSpeciesDiscase causedprotein coding homologous proteins withsequence proteins matchesin DEG(Essentialprotiens)Bacillus cereus B. cereus food poisoning 5754 5486 4256 99Listeria maonocytogenes Listeriosis, perinatal septicemia, meningitis, 2846 2814 1973 82encepthalitis, intrauterine infectionsSushil Kumar Shakyawar et al