ent-Copalic acid antibacterial and anti-biofilm properties against Actinomyces naeslundii and Peptostreptococcus anaerobius.

Diterpenes are an important class of plant metabolites that can be used in the search for new antibacterial agents. ent-Copalic acid (CA), the major diterpene in Copaifera species exudates, displays several pharmacological properties. This study evaluates the CA antibacterial potential against the anaerobic bacteria Peptostreptococcus anaerobius and Actinomyces naeslundii. Antimicrobial assays included time-kill and biofilm inhibition and eradication assays. Time-kill assays conducted for CA concentrations between 6.25 and 12.5 µg/mL evidenced bactericidal activity within 72 h. CA combined with chlorhexidine dihydrochloride (CHD) exhibited bactericidal action against P. anaerobius within 6 h of incubation. As for A. naeslundii, the same combination reduced the number of microorganisms by over 3 log10 at 24 h and exerted a bactericidal effect at 48 h of incubation. CA at 500 and 2000 µg/mL inhibited P. anaerobius and A. naeslundii biofilm formation by at least 50%, respectively. CA at 62.5 and 1.000 µg/mL eradicated 99.9% of pre-formed P. anaerobius and A. naeslundii biofilms, respectively. These results indicated that CA presents in vitro antibacterial activity and is a potential biofilm inhibitory agent. This diterpene may play an important role in the search for novel sources of agents that can act against anaerobic bacteria.

Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections

In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212) and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections.

Avaliação de soluções antibacterianas na descontaminação de escovas dentais de pré-escolares / Evaluation of bacterial solutions in the decontamination of toothbrushes collected from preschool students

O objetivo deste estudo foi avaliar o efeito antimicrobiano de diferentes soluções desinfetantes na descontaminação de escovas dentais de pré-escolares. Foram selecionados aleatoriamente 30 pré-escolares, com idade entre 6-7 anos, de uma escola municipal de Franca-SP. Cada pré-escolar recebeu uma escova dental, que foi utilizada com dentifrício durante cinco dias consecutivos na escovação realizada após a ingestão da merenda escolar. Após a escovação, as escovas foram enxaguadas com água de torneira e borrifadas com água deionizada esterilizada (1), hipoclorito de sódio a 1% (2) e ácido acético a 0,05% (3), sendo uma solução por semana. Ao final de cada semana, cada estudante recebeu uma nova escova, e as já utilizadas eram recolhidas, introduzidas em um tubo de ensaio contendo meio de cultura e encaminhadas ao Laboratório de Microbiologia da Universidade de Franca. As amostras foram sonificadas, diluídas, aliquotadas e semeadas nos seguintes meios de cultura: ágar sangue, ágar Mitis Salivarius e ágar MacConkey. Após o período de incubação, foi realizada a contagem de UFC.mL–1. Houve crescimento de bactérias aeróbias totais em 96,42; 10,34 e 84,61% das amostras quando do uso das soluções 1, 2 e 3 respectivamente, e de estreptococos em 85,71; 10,34 e 76,72% das amostras respectivamente. Não houve recuperação de bacilos Gram-negativos aeróbios nas amostras. Concluiu-se que, com o uso da solução de hipoclorito de sódio a 1%, houve uma significante redução no crescimento bacteriano (p < 0,01), resultando em uma maior eficácia na descontaminação das escovas dentais quando comparada com as outras soluções.

The objective of this study was to evaluate the antimicrobial effect of different disinfectant solutions on the decontamination of kindergarten students’ toothbrushes. Thirty (30) preschool students between 6 and 7 years of age were randomly selected from a municipal school in Franca (SP). Each student received one toothbrush to be used during five days, with toothpaste, in the brushing process after lunchtime. After brushing, the toothbrushes were washed with running tap water and sprayed with: sterilized water (1); sodium hypochlorite 1% (2), and acetic acid 0.05% (3), which were used during one week each. At the end of each week, each student received a new toothbrush, and the used ones were collected, inserted in a tube containing culture media and sent to the Microbiological Laboratory of the University of Franca. The samples were sonicated, aliquotated and plated in the following culture media: blood agar, Mitis Salivarius agar, and MacConkey agar. After the incubation period the CFU.mL–1 was counted. Growth of total aerobic introspecieswas observed in 96.42, 10.34 and 84.61% of the samples with the use of solutions 1, 2, and 3 respectively; and streptococci grew in 85.71, 10.34 and 76.72% of the samples, respectively. No growth of aerobic Gram-negative bacilli was observed. We concluded that the use of sodium hypochlorite solution at 1% caused a significant (p < 0.01) reduction of bacterial growth, resulting in an effective decontamination of the toothbrushes when compared to the other solutions.