The cell surface hydrophobicity and adhesion to abiotic and cellular surfaces was tested in five clinical strains of Acinetobacter baumannii isolated from catheter tips. Biochemical and molecular characteristics of these strains were also studied. Hydrophobicity was characterized by a test for affinity to xylene. Adhesion to abiotic surfaces (polystyrene, formica, latex and glass) was evaluated in Petri plates using the stamp technique. Buccal epithelial cells were used for tests of adhesion to cellular surfaces. Adhesion to the catheter was evaluated by repeatedly rinsing the catheters and rolling them over nutrient agar. Molecular typing of the strains was done by the ERIC-PCR technique. The degree of hydrophobicity of the strains varied from hydrophobic to hydrophilic. All the strains adhered to the cell surfaces and to the catheters, and three of them strongly adhered to latex, polystyrene and formica. Catheter adhesion was reduced by meropenem. We found a direct relationship between the degree of bacterial hydrophobicity and adhesion to the abiotic surfaces, but not with adhesion to cellular surfaces, which suggests that different mechanisms are involved in adherence.

Nós comparamos a eficácia do álcool gel com a dos tradicionais agentes degermantes preconizados para a lavagem das mãos na remoção de amostras clínicas de Acinetobacter baumannii, Staphylococcus aureus resistente a meticilina, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa e Candida albicans das mãos artificialmente contaminadas. As pontas dos dedos dos voluntários (n=6) foram contaminadas com aproximadamente 10(6) de células/microrganismo teste. A seguir, as mãos foram lavadas com sabonete líquido não medicamentoso, álcool gel, álcool etílico 70% (concentração por peso) e soluções anti-sépticas detergentes de polivinilpirrolidona-iodo a 10% (PVP-I) e de gluconato de clorhexidina 4%. Os experimentos foram realizados segundo um quadrado latino com seis blocos aleatorizados 6 x 5. Os resultados foram estimados por ANOVA. Os produtos reduziram de 93,83% (sabão líquido) a 100% (PVP-I 10%) a população microbiana aplicada nas mãos. Em 4 dos 6 microrganismos testes analisados, o PVP-I 10%, o álcool gel, o álcool etílico 70% e a clorhexidina 4% mostraram uma taxa de remoção significantemente superior a do sabão líquido (P < 0,05). Os resultados confirmam a eficácia do álcool gel na higienização das mãos e sugerem que o PVP-I 10%, o álcool gel, o álcool etílico 70% e a clorhexidina 4% podem ser os agentes mais eficazes do que o sabão líquido não medicamentoso na remoção de Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis e Candida albicans das mãos altamente contaminadas.

We compared the effectiveness of alcohol gel with that of the traditional hand-cleansing agents in removing clinical strains of Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans from artificially contaminated hands. The fingertips of 6 volunteers were contaminated with approximately 10(6) of microbial cells, and then were washed with: plain liquid soap, alcohol gel, 70% ethyl alcohol (by weight), 10% povidone-iodine liquid soap (PVP-I), and 4% chlorhexidine gluconate detergent. The experiments were performed using a Latin square statistical design, with six 6 x 5 randomized blocks, and the results were estimated by ANOVA. The products reduced from 93.83% (plain liquid soap) to 100% (PVP-I) of the microbial population applied to the hands. In 4 of 6 test microorganisms analyzed, 10% PVP-I, alcohol gel, 70% ethyl alcohol, and 4% chlorhexidine had significantly higher removal rates than plain liquid soap (P < 0.05). The results confirm the effectiveness of alcohol gel for hand hygiene and suggest that 10% PVP-I, alcohol gel, 70% ethyl alcohol, and 4% chlorhexidine may be more effective than plain liquid soap for removing A. baumannii, E. coli, E. faecalis, and C. albicans strains from heavily contaminated hands.

We used a slide culture technique to detect tubercle bacilli surviving in sputum smears (n=46) after conventional heat fixation and Ziehl-Neelsen staining. In all heat-fixed sputum smears, tubercle bacilli survived after time 0 (n=22), 24 h (n=7), 48 h (n=7), 72 h (n=4), and seven days (n=6). None of the stained sputum smears showed growth on slide cultures. Viable tubercle bacilli remaining in heat-fixed sputum smears for at least seven days may present an infection risk to laboratory staff. Thus, sputum smears should be stained immediately by the Ziehl-Neelsen method or stored in a safe container to avoid transmission of tuberculosis.

Comparou-se a eficácia de sete agentes químicos, usados na prática odontológica, na descontaminação rápida de 32 cones de guta-percha aderidos com Staphylococcus aureus, Enterococcus faecalis, Escherichia coli ou esporos de Bacillus subtilis. Os cones foram tratados por 1, 5, 10 e 15 minutos com glutaraldeído 2%, hipoclorito de sódio 1%, álcool etílico 70%, álcool-iodado 0,3% e 1%, clorhexidina 2%, água oxigenada 6% e polivinilpirrolidona-iôdo 10%. Cada cone após o tratamento foi transferido para caldo tioglicolato e incubado a 37ºC por 7 dias. Os produtos foram bactericidas após 1 a 5 minutos e esporocidas, com exceção do álcool e do álcool iodado, após 1 a 15 minutos de exposição. Os resultados sugerem que a clorhexidina, o hipoclorito, a polivinilpirrolidona-iôdo, a água oxigenada e o glutaraldeído foram os produtos mais eficazes na descontaminação dos cones de guta-percha.

The effectiveness of seven disinfectant compounds used in dentistry for a rapid decontamination of 32 gutta-percha cones adhered with Staphylococcus aureus, Enterococcus faecalis, Escherichia coli strains or Bacillus subtilis spores was compared. Cones were treated with 2% glutaraldehyde, 1% sodium hypochlorite, 70% ethyl alcohol, 1% and 0.3% iodine alcohol, 2% chlorhexidine, 6% hydrogen peroxide, and 10% polyvinylpyrrolidone-iodine, for 1, 5, 10, and 15 minutes. After treatment, each cone was transferred to thioglycollate broth and incubated at 37ºC for 7 days. The products were bactericidal after 1 to 5 minutes and, with exception of ethyl alcohol and iodine-alcohol, sporicidal after 1 to 15 minutes of exposure. Results suggest that chlorhexidine, sodium hypochlorite, polyvinylpyrrolidone-iodine, hydrogen peroxide, and glutaraldehyde were the most effective products in the decontamination of gutta-percha cones.