Actividad bactericida de superficies de cobre frente a bacterias asociadas a infecciones nosocomiales, en un modelo in vitro de adherencia y sobrevivencia / Adherence to copper and stainless steel metal coupons of common nosocomial bacterial strains

Background: Copper has a bactericidal activity against a series of bacterial strains. Aim: To measure resistance to bacterial adherence of copper (Cu) and stainless steel (SS) metal coupons. Material and Methods: Bacterial strains causing nosocomial infections in Chile were analyzed. Bacterial adherence was studied using apreviously described method based on a system of metal coupons that are immersed in culture media containing the bacteria ofinterest at room temperature. Results: Adherence to Cu and SS coupons was differentfor Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae and Acinetobacter baumannii strains. For these strains, no adherence to Cu coupons occurred during the 48 h observation period compared to a rapidly increasing adherence to SS coupons, with a final colony count of 1.00E + 07 cfu/mL. For two different Pseudomonas aeruginosa clinical strains, inhibition of adherence was not observed on Cu coupons, and colony counts were similar for Cu and SS using the standard inoculum (2-3 xlO7 cfu).Apartial decrease in adherence was observed for Cu but not for SS coupons, when a lower inoculum was used. Conclusions: Copper surfaces represent an interesting option to reduce bacterial contamination in the hospital environment due to its resistance to bacterial adhesión ofmost ofthe common nosocomial bacterial strains.

Ação antibacteriana e antiaderente de pithecellobium cochliocarpum (Gomez) macbr sobre microrganismos orais / Antimicrobial and antiadherent activity of pithecellobium cochliocarpum (gomez) macbr tested on oral microorganisms

O biofilme dental é o fator de maior importancia na etiologia da cárie e das doenças periodontais. Diversos produtos de origem vegetal mostraram ser potencialmente interessantes no que se refere a sua atividade antimicrobiana. O objetivo do estudo foi o de avaliar a atividade antibacteriana e antiaderente do Pithecellobium cochliocarpum (Gomez) Macbr. (babatenon) frente Streptococcus mutans, S. sanguinis, S. salivarius, S. mitis, S. oralis e Lactobacillus casei. Para a determinação da Concentraçao Inibitória Mínima (CIM), os ensaios foram realizados em triplicata, em meio sólido, através da técnica de Ágar-Difusão em placas de Petri. Em relação à determinação da Concentração Inibitória Mínima de Aderência (CIMA) da bactéria ao vidro na presença de sacarose a 5%, utilizou-se a técnica dos tubos inclinados. Em estudo comparativo, foi determinada a CIM e a CIMA do digluconato de clorexidina a 0,12%. Quanto a CIM, o Pithecellobium cochliocarpum apresentou atividade antibacteriana similar ao digluconato de clorexidina frente a todas as linhagens ensaiadas. Os halos variaram entre 10 a 30mm com resultado destacado (até a diluição 1:512) frente a S. sanguinis, S. oralis e L. casei. Já a CIMA frente ao babatenon mostrou-se efetivo na inibição da aderência até a última diluição considerada (1:512) para S. sanguinis, S. mitis e S. oralis, apresentando desempenho médio superior à clorexidina. Conclui-se que o Pithecellobium cochliocarpum apresentou potencial atividade antimicrobiana e antiaderente, ressaltando a importância de se avaliar um agente fitoterápico mais acessivel à população com perspectiva da prescrição nos serviços de Atenção Básica, estando em consonância com as novas diretrizes do Ministério da Saúde.

The dental biofilm is the major factor in the etiology of caries and periodontal diseases. Several plant products have shown to be potentially interesting with regard to its antimicrobial activity. The aim of this study was to evaluate the antibacterial and adherent the ethanol extract of Pithecellobium cochliocarpum (Gomez) Macbr (babatenon) front Streptococcus mutans, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus mitis, Streptococcus oralis and Lactobacillus casei. To determine the minimum inhibitory concentration (MIC) tests were perfomed in triplicate on solid medium, using the technique of Agar Diffusion in petri dishes relation to determining the minimum inhibitory concentration of adherence (CIMA) of the bacteria to glass in the presence of sucrose at 5%, we used the technique of inclined tubes. In a comparative study, it was determined the CIM and CIMA values of chlorhexidine 0.12%. As for CIM, Pithecellobium cochliocarpum showed antibacterial activity similar to chlorhexidine gluconate against all strains tested. The zones ranged from 10 to 30 mm with outstanding results (up to dilution 1:512) against S. sanguinis, S. oralis and L. casei. Already the CIMA in relation the babatenon was effective in inhibiting adhesion to the last dilution was considered (1:512) for S. sanguinis, S.oralis and S. mitis, showing average performance than chlorhexidine. It is concluded that Pithecellobium cochliocarpum showed significant antimicrobial activity and antiadherent emphasizing the importance of evaluating an agent herbal medicine more accessible to people with perspective of the prescription in primary care services, and in line with new guidelines from the Ministry of Health.