In vitro effect of subinhibitory concentrations of antibiotics on biofilm formation by clinical strains of Salmonella enterica serovar Typhimurium isolated in Slovakia.
OBJECTIVE
In this study, we examined the biofilm formation of 75 Salmonella enterica serovar Typhimurium (Salm. Typhimurium) human clinical isolates and the effect of subinhibitory concentrations (sub-MICs) of gentamicin, ciprofloxacin and cefotaxime on biofilm formation and exopolysaccharides (EPS) production.


RESULTS
Quantification of biofilm formation and EPS production were carried out using a modified microtitre plate assay and spectrophotometric method, respectively. The results indicate that 38 isolates (50.7%), which are predominantly of DT104 phage type, presented as the strong biofilm producers in vitro on plastic surface. When strains with the highest biofilm-forming capacity were grown in the presence of sub-MICs of gentamicin and ciprofloxacin, the inhibition of biofilm formation and EPS production was observed. In contrast, cefotaxime at 1/2 MIC (0.039 microg ml(-1)) was able to significantly induce the production of biofilm as well as EPS in three isolates with nontypable and DT104 phage type, respectively.


CONCLUSIONS
These results clearly indicate that all the three antibiotics tested are able to interfere with biofilm formation and EPS production by Salm. Typhimurium isolates.


CONCLUSIONS
The current study demonstrated that cefotaxime at sub-MIC can be beneficial for the behaviour of pathogen Salm. Typhimurium in vitro.
Majtán
J
J
Department of Microbiology, Slovak Medical University, Bratislava, Slovak Republic. juraj.majtan@szu.sk
Majtánová
L
L
Xu
M
M
Majtán
V
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects*; D002439:Cefotaxime / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002939:Ciprofloxacin / Q000627:therapeutic use; D004334:Drug Administration Schedule; D024881:Drug Resistance, Bacterial; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D012480:Salmonella Infections / Q000188:drug therapy*; D012483:Salmonella Phages; D012486:Salmonella typhimurium / Q000145:classification / Q000187:drug effects* / Q000378:metabolism; D018154:Slovakia; D013053:Spectrophotometry
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D011135:Polysaccharides, Bacterial; D002939:Ciprofloxacin; D002439:Cefotaxime