The bacterial isolates showed more resistance to three groups of antibiotics: ampicillin, amoxicillin/clavulanic acid and cephalotin. However, some pathogens such as P. aeruginosa, P. putida, and E. cloacae were also resistant to other classes of antibiotics. E. coli was the only specie sensitive to all antibiotics tested ( Table 3). The influence of P. motoro venom on the proliferation of all Gram-negative

bacterial strains isolated in Antiinfection Compound Library supplier this work was determined by incubating the bacterial isolates in TSB for 18 h in the presence of 5, 1 or 0.5 mg/mL of venom and subsequent determination of the absorbance at 600 nm. The results obtained in this experiment showed that the proliferation of all bacterial strains tested were not influenced by the venom even in a concentration as high as 5 mg/mL ( Fig. 1). Fig. 1 presents the results of one experiment only, however, similar results were obtained from all isolates tested. Human epithelial cells were incubated in the presence of mucus or different concentrations of venom to determine their cytotoxic effect by measuring the mitochondrial metabolic rate in terms of MTT bioreduction.

The results obtained in this experiment showed that P. motoro venom ( Fig. 2a) and P. motoro mucus ( Fig. 2b) are both toxic to epithelial cells. The toxic effect of all A. hydrophila, A.

sobria and P. aeruginosa culture supernatants on human epithelial cells was measured by the MTT method. The results showed Crenolanib order that all culture supernatants tested were toxic to epithelial cells ( Fig. 3). It FER is common knowledge that open wounds raise the chance for infection, becoming one of the most prevalent causes of non-healing of wounds. It is also known that injuries induced by aquatic animals such as stingrays and catfish can be infected by environmental microorganisms such as A. hydrophila, Pseudomonas spp. Vibrio spp. ( Broderick et al., 1985, Ho et al., 1998, Polack et al., 1998 and Baldinger, 1999). The capacity of environmental bacteria to cause tissue damage, however, is determined by their ability to colonize the tissue, produce toxins that damage host cells and invade the organism. Their degree of pathogenicity is also influenced by the number of virulent factors released by them which varies between strains of the same bacterial species. Consequently, it is possible to encounter non-pathogenic and pathogenic strains in the same species. A good example is A. hydrophila, whose ability to produce hemolysis is not enough for pathogenicity which requires highly hemolytic and highly proteolytic activities ( Cipriano, 2001). In contrast, the results obtained in this work indicate that most strains of A.