Int.J.Curr.Microbiol.App.Sci (2015) 4(4): 384-396 384 Original Research Article Comparative Antimicrobial Susceptibility Profiling of Tigecycline and Other Antibiotics against Clinical and Environmental Isolates I.Mantzourani 1 , M.Panopoulou 2 , I.Theodoridou 1 , I.Tsirogiannis 3 , V.Papaemmanouil 3 , B. Johnson 4 , D. Biedenbach 4 , S. Bouchillon 4 , E.Stavropoulou 5 and E. Bezirtzoglou 1 * 1 Democritus University of Thrace, Faculty of Agricultural Development, Department of Food Science and Technology, Laboratory of Microbiology, Biotechnology and Hygiene,GR68200, Orestiada, Greece, 2 Democritus University of Thrace, Laboratory of Clinical Microbiology, School of Medicine, GR68200, Alexandroupolis, Greece, 3 Microbiological Laboratory, Metaxa Anticancer Hospital, Piraeus GR18537, Greece, 4 International Health Management Associates, Inc., Schaumburg, IL, 60173, USA 5 Democritus University of Thrace, School of Medicine, GR68200, Alexandroupolis, Greece* Corresponding author ABSTRACT ISSN: 2319-7706 Volume 4 Number 4 (2015) pp. 384-396 http://www.ijcmas.com The study of the irrational extensive use of antibiotics has led to an increase in the rate of resistant strains of bacteria. Likewise, the study of new antibiotic agents is very critical. In this manner tigecycline was studied in this research survey. The activity of 11 antibiotics against 264 pathogens isolated from clinical specimen and 225 pathogens isolated from environmental samples was evaluated. The comparison of similar strains reveals higher total resistance to the environmental ecosystem than to the clinical ones. Study groups included Escherichia coli, Enterobacter spp., Enterococcus faecium and other Enteroccoccus spp., Klebsiella oxytoca and other Klebsiella spp., Pseudomonas spp., and Staphylococcus aureus. Isolates tested by the broth microdilution method under common concentrations and the results interpreted according to the CLSI criteria. Up to 38% of environmental E. coli was resistant to amoxycillin/clavulanic acid, 65% of S. aureus to levofloxacin, 39% of Klebsiella spp., and 33% of Klebsiella oxytoca to ceftriaxone, 50% of environmental E. coli, 35% of Enterobacter spp., and 23% of Pseudomonas spp., shown resistance against cefepime. Resistant to tigecycline was the 27% of E. coli, 8% of Enterococcus spp., and 62% of S. aureus, all isolated from the environment. Our results indicate a certain dispersion of antibiotic resistance into environment.The comparison of similar strains reveals significantly higher total resistance to the environmental ecosystem than to the clinical ones. As far as tigecycline is concerned, it is obvious that there is a rapid spread of new antibiotics in the environment, which is granted during the last seven years in Greece only in clinical practice. Keywords Tigecycline, in vitro Susceptibility, Resistance, Clinical Environment