Influence of EDTA and its Association with Benzalkonium Chloride on Enterococcus faecalis Adhesion to Dentin / Influencia del EDTA y su Asociación con Cloruro de Benzalconio en la Adhesión de Enterococcus faecalis a la Dentina

ABSTRACT: The aim of this in vitro study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) associated with the benzalkonium chloride (BAK) on the adhesion and formation of Enterococcus faecalis biofilms attached to coated dentin. Discs standard bovine dentin blocks were treated with the coating materials evaluated: Saline solution (control), 17 % EDTA, 17 % EDTA associated with 1 % BAK for 5 minutes and subsequently washed with saline solution. Afterwards, biofilms of E. faecalis (ATCC 29212) were grown on the surface of coated dentin blocks for time intervals of 1 hour and 7 days (n = 20) and were subsequently washed with phosphate-buffered saline (PBS). Bacterial viability and total biovolume were analyzed by confocal laser scanning microscopy (CLSM) using the Live/Dead technique. Nonparametric Kruskal-Wallis followed by Dunn tests were used to determine statistical differences (a = 5 %). The 17 % EDTA + 1 % BAK group showed significantly lower biovolume and bacterial viability values at the end of 1 hour (p < 0.05). After 7 days of contamination, the 17 % EDTA and 17 % EDTA + 1 % BAK groups showed similar results that differed statistically from those of the control group (p < 0.05). The saline solution group showed higher values. The use of BAK associated with EDTA on dentin blocks surfaces before exposure to contamination was able to interfere in the adhesion of E. faecalis to dentin. Also, dentin treatment by BAK associated with a chelating agent influences the secondary biofilm formation, which could have important effects on the long-term success of root canal treatment.

RESUMEN: El objetivo del estudio consistió en investigar in vitro, la influencia del ácido etilendiamino-tetraacético (EDTA) con cloruro de benzalconio (BAK) en la adhesión y formación de biopelículas de Enterococcus faecalis a la dentina. Discos de dentina bovina fueron tratadas con solución salina (control), 17 % de EDTA, 17% de EDTA asociado con 1 % de BAK durante 5 minutos y lavadas con solución salina. Las biopelículas de E. faecalis (ATCC 29212) se cultivaron sobre los discos de dentina durante intervalos de tiempo de 1 hora y 7 días (n = 20), lavados con solución salina tamponada con fosfato (PBS). La viabilidad bacteriana y el biovolumen total se analizaron mediante microscopía de barrido por láser (CLSM) utilizando la técnica Live / Dead. Se realizó prueba no paramétrica de Kruskal-Wallis, seguida por Dunn con una diferencia estadística (a = 5 %). El grupo de 17 % EDTA + 1 % BAK mostró valores significativamente menores de biovolumen y viabilidad bacteriana al final de 1 hora (p < 0,05). Después de 7 días de contaminación, los grupos de 17 % EDTA y 17 % EDTA + 1 % BAK mostraron resultados similares que diferían estadísticamente del grupo control (p < 0,05). La solución salina mostró valores más altos. La asociación de BAK con EDTA antes de la contaminación interfirió en la adhesión de E. faecalis. Además, el tratamiento de la dentina por BAK asociado con EDTA influye en la formación de biopelículas secundarias, lo que podría tener efectos importantes sobre el éxito a largo plazo del tratamiento del conducto radicular.

Botulinum toxin as a treatment for short bowel syndrome in rats

Abstract Purpose: The denervation of the intestine with benzalkonium chloride (BAC) reduces mortality and improves weight gain in rats with short bowel syndrome (SBS). Nevertheless, translating these promising findings from bench to bedside is not feasible because BAC promotes peritonitis and irreversible denervation which may be followed by an uncontrolled dilatation of the viscera. The use of botulinum toxin (BT) instead of BAC to achieve the denervation of the remaining small intestine in SBS could be an interesting option because it leads to a mild and transient denervation of the intestine. Methods: Here we evaluated the effects of the ileal denervation with BT in rats with SBS by verifying the body weight variation and intestinal morphological parameters. Four groups with 6 animals each were submitted to enterectomy with an ileal injection of saline (group E) or BT (group EBT). Control groups were submitted to simulated surgery with an ileal injection of BT (group BT) or saline (group C - control). Results: We observed that the treatment of the remaining ileum with BT completely reversed the weight loss associated to extensive small bowel resection. Conclusion: This may provide a new promising approach to the surgical treatment of SBS.

Influence of surfactants addition on the properties of calcium hypochlorite solutions

Abstract Objectives The aim of this study was to evaluate the influence of surfactants 0.2% or 0.1% cetrimide (Cet) or 0.008% benzalkonium chloride (BAK) on 2.5% calcium hypochlorite (Ca(OCl)2), and compare to sodium hypochlorite (NaOCl), regarding the properties of pH, free chlorine content, surface tension, contact angle, pulp dissolution and antimicrobial activity. Material and Methods The pH and free chlorine content were evaluated by digital pHmeter and by titration, respectively. Surface tension was measured by the platinum ring technique with a Du Noüy tensiometer. The solution's contact angle in human dentin surfaces was checked by Drop Shape Analyzer software. Bovine pulps were used for pulp dissolution analysis and the dissolving capacity was expressed by percent weight loss. Antimicrobial activity over Enterococcus faecalis was evaluated by the agar diffusion method. Results Surfactants addition to Ca(OCl)2 and NaOCl did not alter the pH, free chlorine content and pulp dissolution properties. Ca(OCl)2 had the highest surface tension among all tested solutions. When surfactants were added to Ca(OCl)2 and NaOCl, there was a significant reduction of surface tension and contact angle values. The addition of 0.2% or 0.1% Cet enhanced antimicrobial activity of both Ca(OCl)2 and NaOCl. Conclusion Surfactant addition to 2.5% Ca(OCl)2 has shown acceptable outcomes for pH, free chlorine content, surface tension, contact angle, pulp dissolution and antimicrobial activity. Furthermore, the addition of 0.2% Cet showed better results for all tested properties.

Modulation of drug resistance and biofilm formation of Staphylococcus aureus isolated from the oral cavity of Tunisian children

Abstract Objectives: This study aims to investigate the antimicrobial and the anti-biofilm activities of Lactobacillus plantarum extract (LPE) against a panel of oral Staphylococcus aureus (n = 9) and S. aureus ATCC 25923. The in vitro ability of LPE to modulate bacterial resistance to tetracycline, benzalchonium chloride, and chlorhexidine were tested also. Methods: The minimum inhibitory concentrations (MICs) and the minimal bactericidal concentrations of Lactobacillus plantarum extract, tetracycline, benzalchonium chloride and clohrhexidine were determined in absence and in presence of a sub-MIC doses of LPE (1/2 MIC). In addition, the LPE potential to inhibit biofilm formation was assessed by microtiter plate and atomic force microscopy assays. Statistical analysis was performed on SPSS v. 17.0 software using Friedman test and Wilcoxon signed ranks test. These tests were used to assess inter-group difference (p < 0.05). Results: Our results revealed that LPE exhibited a significant antimicrobial and anti-biofilm activities against the tested strains. A synergistic effect of LPEs and drug susceptibility was observed with a 2–8-fold reduction. Conclusion: LPE may be considered to have resistance-modifying activity. A more detailed investigation is necessary to determine the active compound responsible for therapeutic and disinfectant modulation.

Effects of prostaglandin analogs on blood flow velocity and resistance in the ophthalmic artery of rabbits / Efeitos dos análogos da prostaglandina na velocidade do fluxo sanguíneo e resistência na artéria oftálmica de coelhos

ABSTRACT Purpose: The aim of this study was to investigate the effects of prostaglandin analogs on blood flow in the ophthalmic artery of clinically healthy rabbits. Methods: Fifty-five clinically healthy New Zealand white rabbits were divided into six groups, and the left eyes were treated for four weeks with the preservative benzalkonium chloride (BAK) only or a topical formulation of different prostaglandin analogs (bimatoprost BAK, tafluprost BAK-free, travoprost BAK, travoprost POLYQUAD, and latanoprost BAK). Color Doppler imaging was performed before and after the treatments. The mean values of the peak systolic velocity (PSV) and end diastolic velocity and the resistive index (RI) were calculated. Statistical analysis was performed to compare the differences pre- and post-treatment for each drug and post-treatment among the drugs. Results: The prostaglandin analogs did not affect PSV. Bimatoprost BAK, travoprost POLYQUAD, and latanoprost BAK did not change RI. Tafluprost BAK-free and travoprost BAK therapy resulted in similar reductions in RI. No significant differences pre- and post-treatment were found when BAK was administered alone. Conclusion: The prostaglandin analogs tafluprost BAK-free and travoprost BAK improved blood flow in the ophthalmic artery in healthy New Zealand white rabbits, which suggests that these drugs enhance the prevention of the progression the progression of glaucoma.

RESUMO Objetivo: O objetivo deste estudo foi investigar os efeitos dos análogos da prostaglandina (PGAs) no fluxo sanguíneo da artéria oftálmica em coelhos. Métodos: Cinquenta e cinco coelhos da raça Nova Zelândia clinicamente saudáveis foram divididos em seis grupos para tratamento com formulação tópica de diferentes APGs (bimatoprosta BAK, tafluprosta BAK-free, travoprosta BAK, travoprosta POLYQUAD e latanoprosta BAK) e formulações contendo apenas o conservante cloreto de benzalcônio (BAK). Foi realizada ultrassonografia com Doppler antes e após os tratamentos. Os valores do pico da velocidade sistólica (PSV) e da velocidade diastólica final foram obtidos e o índice de resistência (RI) foi então calculado. A análise estatística foi realizada para comparar as diferenças entre cada droga no pré e pós-tratamento, além das diferenças no pós-tratamento entre as drogas. Resultados: Estes colírios PGAs não afetaram o PSV. A bimatoprosta com o conservante BAK, travoprosta com o conservante POLYQUAD e latanoprosta com o conservante BAK não alteraram o RI. Já o tratamento com tafluprosta sem conservante (BAK-free) e travoprosta com o conservante BAK promoveram redução similar dos valores do RI. Não houve diferença significativa na comparação entre valores pré e pós-tratamento quando BAK foi administrado isoladamente. Conclusão: Os PGAs tafluprosta BAK-free e travoprosta BAK melhoraram o fluxo sanguíneo na artéria oftálmica em coelhos da raça Nova Zelândia sugerindo que estes medicamentos possam contribuir na prevenção da progressão do glaucoma.

Effect of antibacterial agents on the surface hardness of a conventional glass-ionomer cement

In atraumatic restorative treatment (ART), caries removal with hand excavation instruments is not as efficient as that with rotary burs in eliminating bacteria under the glass ionomer cements (GICs). Thus, different antibacterial agents have been used in recent studies to enhance the antibacterial properties of the GICs, without jeopardizing their basic physical properties. OBJECTIVE: The objective of this study was to evaluate the effect of antibacterial agents on the surface hardness of a conventional GIC (Fuji IX) using Vickers microhardness [Vickers hardness number (VHN)] test. MATERIAL AND METHODS: Cetrimide (CT), cetylpyridinium chloride (CPC) and chlorhexidine (CHX) were added to the powder and benzalkonium chloride (BC) was added to the liquid of Fuji IX in concentrations of 1 percent and 2 percent, and served as the experimental groups. A control group containing no additive was also prepared. After the completion of setting reaction, VHN measurements were recorded at 1, 7, 15, 30, 60, and 90 days after storage in 37°C distilled water. A one-way ANOVA was performed followed by a Dunnett t test and Tamhane T2 tests and also repeated measurements ANOVA was used for multiple comparisons in 95 percent confidence interval. RESULTS: VHN results showed significant differences between the control and the experimental groups at all time periods (p<0.05 for all). Significant differences were observed between all study periods for individual groups (p<0.05). After 7 days, VHNs were decreased in all experimental groups while they continued to increase in the control group. BC and CHX groups demonstrated the least whereas CT and CPC groups exhibited most adverse effect on the hardness of set cements. CONCLUSIONS: Despite the decreased microhardness values in all experimental groups compared to the controls after 7 up to 90 days, incorporating certain antibacterial agents into Fuji IX GIC showed tolerable microhardness alterations within the limitations of this in vitro study.

Occurrence of qacE/qacEDelta1 genes and their correlation with class 1 integrons in salmonella enterica isolates from poultry and swine.

In this study, a total of 122 Salmonella enterica isolates from poultry and swine were assessed for susceptibility to clinically important antibiotics and to benzalkonium chloride (BKC). All isolates were examined for the presence of the antiseptic resistance genes qacE and qacEDelta1 and intl1 (class 1 integrase). The intl1-positive strains were further investigated for the presence of the 3' conserved region. The results demonstrated widespread distribution of qacEDelta1 (27%) but no isolate with qacE was observed. The intl1 gene was identified in 23 isolates (70%) with qacEDelta1. All of the intl1-postive strains carried qacEDelta1 in 3' conserved segment, confirming that the qacEDelta1 gene is linked to the integrons. Increased MIC value to BKC was independent of the presence of qacEDelta1, and multiple antibiotic-resistant bacteria were no more tolerant to BKC than the non-multidrugresistant strains, regardless of the presence of qacEDelta1.

Efeitos da desnervação intrínseca do jejuno após enterectomia extensa na síndrome do intestino curto em ratos / Effects of intrinsic denervation of the jejunum after extensive enterectomy in the rat bowel syndrome

OBJETIVO: Investigar em ratos Wistar as respostas adaptativas da mucosa em conseqüência da desnervação intrínseca do jejuno após ressecção intestinal extensa. MÉTODOS: Utilizaram-se 30 ratos distribuídos em três grupos segundo o procedimento realizado: C (controle), R (ressecção intestinal) e D (ressecção intestinal e desnervação intrínseca do jejuno). Posteriormente foi avaliado o ganho de peso e realizado estudos morfométrico da mucosa intestinal. RESULTADOS: Os animais do grupo D apresentaram ganho ponderal consideravelmente maior do que os do grupo R (D=312,2±21g e R=196,7±36,2g). A contagem neuronal mostrou diminuição na população de neurônios mientéricos no grupo D (344,8±34,8 neurônios/mm de jejuno) em relação aos outros grupos (R=909,0±55,5 e C=898,5±73,3). A área do epitélio da mucosa jejunal foi maior no grupo D (10,8±4,3mm²) em comparação aos grupos R (7,3±3,9mm²) e C (5,8±3,0mm²). O índice de proliferação celular epitelial da mucosa foi maior no grupo D (48,7 por cento), em relação aos grupos R (31,9 por cento) e C (23,6 por cento). CONCLUSÕES: O modelo experimental mostrou-se eficaz em melhorar o ganho ponderal dos animais submetidos à ressecção intestinal extensa, provocando intensificação da resposta hiperplásica da mucosa, a qual provavelmente levou a aumento da superfície de absorção de nutrientes. Abrem-se boas perspectivas para novas abordagens cirúrgicas para a síndrome do intestino curto.

Avaliaçäo da contaminaçäo bacteriana em desinfetantes de uso domiciliar / Evaluation of bacterial contamination in disinfectants for domestic use

Objetivo: Avaliar desinfetantes de uso domiciliar, identificando a presença de bactérias contaminantes, e conhecer o nível de tolerância dessas bactérias ao cloreto de benzalcônio. Métodos: Foram adquiridos aleatoriamente no comércio da regiäo metropolitana de Säo Paulo, SP, Brasil, 52 amostras de desinfetantes de uso domiciliar para análise quanto à presença de bactérias contaminantes. O nível de tolerância dessas bactérias ao cloreto de benzalcônio foi determinado pelo método da macrodiluiçäo em caldo. Resultados: De 52 amostras, 16 (30,77 por cento) estavam contaminadas por bactérias Gram negativas, com contagens variando entre 104 e 106 UFC/ml. Esses contaminantes foram identificados como Alcaligenes xylosoxidans, Burkholderia cepacia e Serratia marcescens. As Concentraçöes Inibitórias Mínimas (CIM: mg/ml) do cloreto de benzalcônio para S. marcescens, A. xylosoxidans e B. cepacia foram: 2,48, 1,23 e 0,30, respectivamente. Conclusöes: Os desinfetantes de uso domiciliar a base de compostos de amônio quaternário säo passíveis de contaminaçäo por bactérias. As CIMs do cloreto de benzalcônio para as bactérias contaminantes estavam abaixo das concentraçöes do princípio ativo presente nos desinfetantes, indicando que a tolerância ao biocida näo é estável, podendo ser perdida com o cultivo das bactérias em meios de cultura sem o biocida

Evaluation of efficacy of Dettol-H in hospital use.

A study was conducted at Safdarjang Hospital, New Delhi, to elucidate the bactericidal effect of a new disinfectant having benzalkonium chloride (40%) + disodium edetate (1.5%) and commercially available as Dettol-H, in comparison with that of a disinfectant already in-use in this hospital and having chlorhexidine gluconate (7.5%) + cetrimide (15%) + isopropyl alcohol (commercially available as Alpilon). The modified Capacity test of Kelsey-Sykes and In-use test of Kelsey-Maurer were carried out using control strains and random gram positive and gram negative bacterial isolates from clinical specimens. The two disinfectant solutions were analysed at three dilutions viz. weak, recommended and strong. From the study it could be inferred that both Dettol-H and Alpilon were equally effective in recommended and strong dilutions against the organisms tested. Weak dilutions were not effective in both and hence Dettol-H and Alpilon are effective only if used in prescribed concentrations.

Desnervaçäo mioentérica jejunal induzida pelo cloreto de benzalcônio / Jejunal myenterec denervation induced by benzalkonium chloride

Os efeitos do cloreto de benzalcônio (CB) sobre o número de neurônios, a espessura da musculatura própria e o perímetro intestinal externo foram determinados após desenervaçäo aguda (até 10 dias pós-aplicaçäo do CB) e crônica (30 e 60 dias pós-aplicaçäo do CB) do jejuno proximal de ratos. Houve reduçäo significativa no número de neurônios mioentéricos em todos os segmentos tratados. A extensäo da desnervaçäo variou em funçäo do tempo decorrido após o tratamento: nos segmentos desnervados cronicamente o número de neurônios era superior àquele nos segmentos desnervados agudamente. Este achado pode ser resultado de fenômenos de neuroplasticidade ocorrendo durante a fase crônica. A desenervaçäo mioentérica induziu aumento da espessura da musculatura própria, especialmente da camada muscular longitudinal, sugerindo maior sensibilidade desta camada à desnervaçäo mioentérica