Antibacterial, antibiofilm, and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant bacteria.

To evaluate the antibacterial, antibiofilm and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant (MDR) bacteria. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration of Biofilm (MICB50), as well as synergistic and antivirulence assays for eight diterpenes against MDR. The tests revealed that two diterpenes (named 1 and 5) showed the best results, with MIC and MBC between 12.5 and 50 µg/mL against most MDR bacteria. These diterpenes exhibited promising MICB50 in concentration between 3.12-25 µg/mL but showed no synergistic antimicrobial activity. In the assessment of antivirulence activity, diterpenes 1 and 5 inhibited only one of the virulence factors evaluated (Dnase) produced by some strains of S. aureus at subinhibitory concentration (6.25 µg/mL). Results obtained indicated that diterpenes isolated from Copaifera oleoresin plays an important part in the search of new antibacterial and antibiofilm agents that can act against MDR bacteria.

Single-species (bacterial, fungal, or mycobacterial) biofilms or dual-species (mycobacterial-fungal) biofilms formed in dialysis fluids.

Continuous hemodialysis system monitoring is necessary to prevent microorganism growth and health problems. This study evaluates single- and dual-species biofilm formation in microtiter plates by using dialysis solutions under aerobiosis or 5% CO2 atmosphere. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, Candida parapsilosis sensu lato, and Mycobacterium smegmatis produce single-species biofilms in all dialysis solutions in both oxygenation conditions. Dual-species biofilm cultures grown at 5% CO2 atmosphere and in dialysate containing glucose reveal that M. smegmatis benefits from its association with C. parapsilosis. The dialysate and its constituent solutions support the growth of all the mono-species and the inter-kingdom mycobacterial/yeast biofilms in both aerobiosis and microaerophilic conditions.

[A study on protozoan cysts, helminth eggs and larvae in pacifiers]. / Pesquisa de cistos de protozoários, larvas e ovos de helmintos em chupetas.

OBJECTIVE: Due to the high prevalence of enteroparasitoses among Brazilian children and the possible involvement of objects in carrying these diseases, a study was conducted to investigate the presence of protozoan cysts, larvae and helminth eggs in pacifiers. METHODS: Over the period of March to December of 1993, 86 pacifiers of zero to seven-year-old children resident in Vila Promessa, a suburb in Alfenas, MG, were examined. The investigation of cysts, larvae and eggs was made by the microscopic exam of the sediment obtained from centrifuging the liquid resulting from washing the pacifiers. The results were evaluated by employing the percentile analysis. Along with the examination of the pacifiers, an interview was carried out with the people responsible for the children whose pacifiers were examined, aiming at detecting how much was known about the transmission of intestinal parasitoses and the proper hygiene of pacifiers. RESULTS: Among the 86 pacifiers examined, 10 were found to be contaminated (11.63%) and presenting eggs of Ascaris lumbricoides, Enterobius vermicularis, Trichuris trichiura, Taenia sp and Ancylostomatidae larvae. CONCLUSION: Pacifiers were found to be an important means of transmitting intestinal parasites in the age range studied what makes it a need to set a proper and persistent sanitary policy in fighting intestinal parasitoses.