Maximum inhibitory dilution of mouthwashes containing chlorhexidine and polyhexamethylene biguanide against salivary staphylococcus aureus

OBJECTIVE: The aim of the present study was to determine the in vitro maximum inhibitory dilution (MID) of two chlorhexidinebased oral mouthwashes (CHX): Noplak®, Periogard®, and one polyhexamethylene biguanide-based mouthwash (PHMB): Sanifill Premium® against 28 field Staphylococcus aureus strains using the agar dilution method. MATERIALS AND METHODS: For each product, decimal dilutions ranging from 1/10 to 1/655,360 were prepared in distilled water and added to Mueller Hinton Agar culture medium. After homogenization, the culture medium was poured onto Petri dishes. Strains were inoculated using a Steers multipoint inoculator and dishes were incubated at 37ºC for 24hours. For reading, MID was considered as the maximum dilution of the mouthwash still capable of inhibiting microbial growth. RESULTS: Sanifill Premium® inhibited the growth of all strains at 1/40 dilution and of 1 strain at 1/80 dilution. Noplak® inhibited the growth of 23 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Periogard® showed inhibited growth of 7 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Data were submitted to Kruskal-Wallis statistical test, showing significant differences between the mouthwashes evaluated (p<0.05). No significant difference was found between Noplak® and Periogard® (p>0.05). Sanifill Premium® was the least effective (p<0.05). CONCLUSION: It was concluded that CHX-based mouthwashes present better antimicrobial activity against S. Aureus than the PHMB-based mouthwash.

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus / Atividade antibacteriana de quatro anti-sépticos bucais contendo triclosan contra Staphylococcus aureus da saliva

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.

A Diluição Inibitória Máxima (DIM) de anti-sépticos bucais à base de triclosan contra 28 cepas de Staphylococcus aureus foi avaliada. Diluições de 1/10 a 1/655.360 foram preparadas. As cepas foram inoculadas com inoculador multipontual Steers. A DIM foi a maior diluição do anti-séptico que inibiu crescimento microbiano. Os anti-sépticos apresentaram diferentes DIMs.

Determination of the maximum inhibitory dilution of cetylpyridinium chloride-based mouthwashes against staphylococcus aureus: an in vitro study

The aim of this in vitro study was to determine the maximum inhibitory dilution (MID) of four cetylpyridinium chloride (CPC)-based mouthwashes: CPC+Propolis, CPC+Malva, CPC+Eucaliptol+Juá+Romã+Propolis (Natural Honey®) and CPC (Cepacol®), against 28 Staphylococcus aureus field strains, using the agar dilution method. Decimal dilutions ranging from 1/10 to 1/655,360 were prepared and added to Mueller Hinton Agar. Strains were inoculated using Steers multipoint inoculator. The inocula were seeded onto the surface of the culture medium in Petri dishes containing different dilutions of the mouthwashes. The dishes were incubated at 37ºC for 24 h. For readings, the MID was considered as the maximum dilution of mouthwash still capable of inhibiting microbial growth. The obtained data showed that CPC+Propolis had antimicrobial activity against 27 strains at 1/320 dilution and against all 28 strains at 1/160 dilution, CPC+Malva inhibited the growth of all 28 strains at 1/320 dilution, CPC+Eucaliptol+Juá+Romã+Propolis inhibited the growth of 2 strains at 1/640 dilution and all 28 strains at 1/320 dilution, and Cepacol® showed antimicrobial activity against 3 strains at 1/320 dilution and against all 28 strains at 1/160 dilution. Data were submitted to Kruskal-Wallis test, showing that the MID of Cepacol® was lower than that determined for the other products (p<0.05). In conclusion, CPC-mouthwashes showed antimicrobial activity against S. aureus and the addition of other substances to CPC improved its antimicrobial effect.

Efficacy of mouthrinse spray in inhibiting cariogenic biofilm formation on toothbrush bristles

Aim: The aim of this study was to evaluate the efficacy of Periogard® (Colgate-Palmolive) and Plax® (Colgate-Palmolive) in inhibiting biofilm formation of mutans streptococci (MS) on toothbrush bristles used just once for 2 minutes with no dentifrice. Methods: This study was performed into 3 phases in which mouthrinses and sterile distilled water (control group) were sprayed 6 times (to standardize the method) on toothbrush bristles used by 53 university students. Toothbrushes were kept at room temperature for 3 hours and put into test tubes each containing bacitracin sucrose broth (selective enrichment for MS). After incubation at 37ºC for 3 to 4 days, MS biofilm on the bristles were analyzed and colony-forming units (CFU) were counted by stereomicroscope under reflected light. Results: 41 students completed the 3 phases of this study and 38 (92.7%) control group toothbrushes had CFU of MS that varied from 1 to uncountable. Periogard® and Plax® inhibited biofilm formation on the bristles of 97.4% and 84.2% toothbrushes, respectively. Conclusion: Periogard® and Plax®, in spray, reduced/eliminated biofilm formation of MS on the toothbrush bristles. However, Periogard® was more efficacious than Plax® for this purpose.

Atividade antibacteriana in vitro de géis com diferentes concentrações de papaína / In vitro antibacterial activity of gels with different papain concentrations

A papaína é uma enzima proteolítica proveniente do mamão, Carica papaya Linn., e é muito empregada na indústria alimentícia, cosmética e farmacêutica. Objetivou-se determinar a atividade antibacteriana in vitro de géis com diferentes concentrações de papaína frente às bactérias padrão: Staphylococcus aureus (ATCC 6538) e Echerichia coli (ATCC 10538), bem como 4 Pseudomonas aeruginosa hospitalares. Alíquotas de 2,0ml dos inóculos bacterianos (metade da escala 1,0 de McFarland) foram semeadas em duplicata na superfície de placas de Petri. Os géis com as diferentes concentrações de papaína foram gotejados na superfície dos meios de cultura pela técnica de gotejamento e a incubação realizada a 35ºC por 24 horas. A leitura dos resultados da atividade antibacteriana foi efetuada pela mensuração dos halos de inibição ao redor das gotas dos géis de papaína. Apenas o gel de papaína a 10% foi capaz de inibir o crescimento do S. aureus e de 2 P. aeruginosa. Em conclusão, de acordo com a literatura a papaína apresenta ação proteolítica sobre os tecidos mortos, porém apenas a formulação em gel a 10% apresentou atividade antibacteriana in vitro. Assim, antes de utilizar alguma substância ou produto contra microrganismos é necessário saber se a mesma apresenta realmente atividade antimicrobiana.

The papain is a proteolytic enzyme from papaya, Carica papaya Linn., and it is so used in food, cosmetic and pharmaceutical industry. The aim of this study was to determine in vitro antibacterial activity of gels with different papain concentrations against standard bacteria: Staphylococcus aureus (ATCC 6538) and Echerichia coli (ATCC 10538), as well as 04 hospital Pseudomonas aeruginosa. Aliquots of 2.0ml from bacterial inocula (0.5 McFarland scale) were seeded in duplicate onto Petri plates? surface. The papain gels with different concentrations were dropped onto culture medium surface by the drop technique and the incubation realized at 35ºC for 24 hours. The results of antibacterial activity were obtained by measuring of growth inhibition halos around the drops of papain gels. Only the papain gel 10% was able to inhibit S. aureus and 2 P. aeruginosa growth. In conclusion, according to literature the papain has action on dead tissues, but only the gel formulation 10% presented in vitro antibacterial activity. So, before using any substance or product against microorganisms it is necessary to know if it really has antimicrobial activity.

La papaína es una enzima proteolitica de la papaya, Carica papaya Linn., y es muy utilizado en la industria del alimento, cosmética y farmacéutica. La puntería de este estudio era determinar la actividad anti-bacteriana in vitro de geles con diversas concentraciones de la papaína contra bacterias estándares: Staphylococcus aureus (ATCC 6538) y Echerichia coli (ATCC 10538), así como 4 Pseudomonas aeruginosa del hospital. Alícuotas de 2,0ml de inóculos bacterianos (0,5 de la escala McFarland) fueron sembradas por duplicado en la superficie de placas de Petri. Los geles con diferentes concentraciones de papaína fueron goteados en la superficie de los medios de cultura por la técnica de goteo y la incubación se celebró a 35ºC por 24 horas. La lectura de los resultados fue hecha por la medición de los halos de inhibición alrededor de las gotas de geles. Solamente el gel el 10% de la papaína fue capaz de inhibir inhibir el crecimiento de S. aureus y de 2 P. aeruginosa. En la conclusión, según la literatura la papaína tiene acción en tisúes muertos, pero solamente la formulación el 10% del gel presentó actividad anti-bacteriana in vitro. Así pues, antes de usar cualquier sustancia o producto contra microorganismos es necesario saber si realmente tiene actividad anti-microbiana.

Biofilme: avaliação do nível de contaminação de escovas dentais Monobloc® em função do dentifrício / Biofilm: evaluation of contamination level on Monobloc® toothbrushes in function of dentifrice

A escova dental pode se tornar um veículo de disseminação de microrganismos da boca. O objetivo deste estudo foi avaliar, in vivo, a contaminação de estreptococos do grupo mutans (EGM) em escovas dentais Monobloc®, que foram usadas uma única vez por 2,0min, em função de 2 diferentes tipos de dentifrício. O estudo clínico randomizado foi realizado em 3 etapas (I, II, III), por 52 estudantes de farmßcia da Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP. Na etapa I, os alunos efetuaram a escovação sem a utilização de dentifrício. Na etapa II, utilizaram o dentifrício Sorriso Super Refrescante®, sem agente antimicrobiano, e na etapa III, o dentifrício Colgate Tripla Ação®, com agente antimicrobiano triclosan. Apenas 30 (57,7%) dos 52 estudantes foram considerados para o estudo. Ao término de cada escovação, as escovas permaneceram em suporte por 1h e depois foram semeadas em tubo de ensaio com meio de cultura CaSa B. Decorrido o período de incubação, o número de unidades formadoras de colônia/biofilme nas hastilhas das escovas foram analisadas, com auxílio de um microscópio estereoscópico. O biofilme de EGM estava presente em 22 (73,3%) escovas utilizadas na etapa I, em 4 (18,2%) da etapa II, e em nenhuma da etapa III. Em conclusão, não houve diferença estatisticamente significante (p > 0,05) entre os resultados dos dentifrícios. O uso de ambos reduziu a formação de biofilme de EGM nas hastilhas das escovas dentais (p < 0,05).