Among these "non-antibiotics", most studies have focused on NSAIDs, drugs thatin addition to anti-inflammatory actionhave analgesic and antipyretic properties. These drugs are among the most widely used in the

Escherichia coli isolated from the intestinal tract of marine fish captured along polluted beaches of the city of Rio de Janeiro, Brazil, were investigated in terms of resistance to seven antibiotics and to four heavy metals. Approximately 40% of the strains were resistant to one or more antibiotics, with predominance of mono‐ and biresistance. Overall resistance to heavy metals was 70.7%, and exclusive resistance to these elements was more elevated than resistance to antibiotics only. Resistance to mercury was closely associated with resistance to antibiotics and with multiple resistance in particular. Most of the strains analyzed transferred resistance determinants to standard receptor strains during conjugation, the phenomenon being particularly outstanding for the transfer of the copper marker. The epidemiological and ecological aspects of the results obtained are discussed. © 1993 John Wiley & Sons, Inc.

Staphylococcus aureus is a pathogen commonly resistant to antibiotics. Biofilm formation is one of the important factors related to its virulence. Non-antibiotics drugs, such as nonsteroidal anti-inflammatory agents (NSAIDs), have been studied as an alternative for treating infections by multiresistant pathogens and biofilm-associated infections. In this study, the effects of NSAID sodium diclofenac on growth inhibition and biofilm formation of S. aureus were evaluated. The minimum inhibitory concentration (MIC) of diclofenac for fifty isolates ranged from 200 to 400 μg/mL. Diclofenac sub-MICs induced biofilm in 32.3% of biofilm-negative strains in tryptic soy broth. All biofilms induced by the drug showed a PIA- (polysaccharide intercellular adhesion-) independent composition, and the scanning electron microscopy showed that the induced biofilm presented a very discrete matrix. The combination of diclofenac with rifampicin sub-MICs induced strong production of PIA-dependent biofilm in three of four strains, while combination of NSAID with NaCl induced the formation of partially polysaccharide biofilm in two strains and PIA-independent biofilm in another strain. The combination of NSAID with glucose resulted in PIA-independent biofilms in all four strains tested. The results showed that diclofenac can commonly induce biofilm production by a PIA-independent pathway. However, when this NSAID is combined with other types of inducing agents, the composition of the biofilm produced may vary.

Background and Objective: Poly-γ-glutamic acid (γ-PGA) is a constituent of the Bacillus anthracis capsule and a potential virulence factor of S. epidermidis. In this study, a methodology for the isolation, purification and quantification of γ-PGA in the isolates was adapted. In addition, the fate of the produced γ-PGA and its antiphagocytic activity were investigated. Methods: The capB gene was investigated by the PCR method in 50 isolates of S. epidermidis. A modified methodology was used for the extraction, purification, and quantification of γ-PGA using Cetyltrimethylammonium Bromide (CTAB) solution. The fate of γ-PGA was determined in Tryptic Soy Broth (TSB) medium, as well as the effect of ethanol, NaCl and KCl on the induction of the polymer production. The ability of neutrophils to phagocyte both FITC-labeled latex particles in the presence of free γ-PGA and S. epidermidis with and without anchored γ-PGA was evaluated by cytometry. Results: The production of γ-PGA was detected in 40 isolates; all of them were capB gene carriers. Free γ-PGA was detected and in the strain, the amount of released γ-PGA in the supernatant was 67% greater than the cell anchored γ-PGA. Phagocytosis tests performed with one γ-PGA producer isolate showed a significant reduction in neutrophil internalization. Conclusion: The adapted methodology was able to detect γ-PGA in the isolates studied. In addition to being found attached to the cell wall, it was demonstrated in this study that γ-PGA can also be found in the culture supernatant. Free γ-PGA did not determine a reduction in the internalization of latex by neutrophils, but cells with anchored γ-PGA showed significant protection against phagocytosis.