Eradication of pseudomonas aeruginosa biofilms by zinc and its influence on the permeation of some antibiotics

Pseudomonas aeruginosa biofilms were prepared on membrane filters incubated at 37C for 10 days. The biofilms were characterized by dense colonization of bacteria as measured by viable counting and scanning electron microscopy. Incubation of formed biofilms with zinc concentrations between 0.03 and 26.25 UM resulted in a gradual decrease [68.2 - 99.95%] in the number of viable cells. Such decrease was accompanied with a gradual eradication of the biofilms as shown by scanning electron micrographs. Ps. aeruginosa biofilms were found to retard the diffusion of gentamicin, neomycin, tobramycin and ofloxacin. Prior treatment of the biofilms with zinc [2.6 and 26.3 muM] resulted in overcoming such retardation. The implication of such result is possible in the treatment of biofilm associated infections was discussed

In vitro and in vivo microbiological evaluation of six mouthwashes manufactured in Egypt

Six antiseptic mouthwash, manufactured in Egypt, were microbiologically evaluated by in vitro and in vivo techniques. The level and type of microbial contaminants were determined. The mouthwash clinitol and citrolin were significantly contaminated, while Antiseptol, Betadine, Hexitol and Oraldene were not. Tube dilution and sub-culturing on solid media were used to assess the antimicrobial efficacies of the mouthwash against 24 clinical strains also kill times were determined for undiluted and half- concentrated mouthwash in presence and absence of human blood and saliva. Generally, the results varied not only between test strains but also mouthwash including those containing identical active principles thus implicating formulation factors