Bruna Webber

Antiseptics and microcosm biofilm formation on titanium surfaces

Oral rehabilitation with osseointegrated implants is a way to restore esthetics and masticatory function in edentulous patients, but bacterial colonization around the implants may lead to mucositis or peri-implantitis and consequent implant loss. Peri-implantitis is the main complication of oral rehabilitation with dental implants and, therefore, it is necessary to take into account the potential effects of antiseptics such as chlorhexidine (CHX), chloramine T (CHT), triclosan (TRI), and essential oils (EO) on bacterial adhesion and on biofilm formation. To assess the action of these substances, we used the microcosm technique, in which the oral environment and periodontal conditions are simulated in vitro on titanium discs with different surface treatments (smooth surface - SS, acid-etched smooth surface - AESS, sand-blasted surface - SBS, and sand-blasted and acid-etched surface - SBAES). Roughness measurements yielded the following results: SS: 0.47 µm, AESS: 0.43 µm, SB: 0.79 µm, and SBAES: 0.72 µm. There was statistical difference only between SBS and AESS. There was no statistical difference among antiseptic treatments. However, EO and CHT showed lower bacterial counts compared with the saline solution treatment (control group). Thus, the current gold standard (CHX) did not outperform CHT and EO, which were efficient in reducing the biofilm biomass compared with saline solution.

Salmonella spp. isolated by miniaturized most probable number and conventional microbiology in poultry slaughterhouses

Background: Salmonella spp. are frequently isolated from fowls, and their detection in poultry products varies according to the breeding system and the slaughtering process, bringing risks to the consumer and compromising the marketability. The control of Salmonella in poultry slaughterhouses is based on the detection of bacteria, but the quantification of the agent would be important in assessing risk, as well as in obtaining data to determine the capacity of each step of the process to decrease or increase bacterial contamination. The aims of this study were to propose a method for the quantification of Salmonella in poultry slaughterhouses, frequency of isolation and serovars identified. Materials, Methods & Results: Twenty-one broiler flocks from seven federally inspected slaughterhouses in southern Brazil, totaling 1,071 samples, were assessed by miniaturized most probable number (mMPN) and conventional microbiology. The samples were collected in triplicate at 17 points, which included cloacae, transportation cages before and after sanitization, water (scald tank, supply, pre-chiller and chiller), and carcasses (before and after scalding, defeathering, rinsing, evisceration, final rinsing, chilling at 4oC, and freezing at -12°C for 24 h, 30 and 60 days). Typical Salmonella colonies were submitted to TSI, LIA, SIM, urea, and polyvalent anti-O antiserum tests, and to final identification by Microarray by Check&Trace. Nine of the 1,071 (0.83%) samples analyzed by mMPN and by conventional microbiology were positive for Salmonella and the following serovars were identified: Anatum, Brandenburg, Agona, Tennessee, Bredeney, Schwarzengrund and Infantis. Discussion: This positive rate was lower than that described by other authors, whose rates ranged from 3% and 39% for the isolation of Salmonella spp. from different sources, such as slaughterhouses and retail sales in samples collected in Brazil. The low frequency of isolation of Salmonella in this study can be attributed to the efficiency of control systems used from the field to the slaughterhouse, such as Good Manufacturing Practices (GMP) and Sanitation Standard Operating Procedures (SSOP), which are HACCP requirements. Also, when slaughtering technology actions are properly managed, such as water replacement and temperatures lower than 4oC in the chiller, the initial contamination by Salmonella spp. can be reduced, with a decline in contamination from 70% to 20%, and with a reduction in the contamination of broiler carcasses after chilling from 15.8% to 3.3%. On the other hand the contamination of carcasses by Salmonella before pre-chilling and in post-chilling might be due to the automated system, inadequate temperatures during chilling, and inappropriate water chlorination in the assessed meat-packing plant. Of the 17 points evaluated, seven were positive for Salmonella, especially the cages after sanitization and frozen carcasses. The contamination by Salmonella spp. in transportation cages after sanitization indicates inefficiency of the automated system as well as possible bacterial resistance to the sanitizers used in SSOP while the isolation in carcasses frozen for 24 h and 60 days demonstrates the thermal resistance of the bacterium to a conservation method widely used in the food industry. In this work, just one of the nine positive samples for Salmonella was identified by conventional methods (CM) and mMPN. The discrepancy between methods can be explained by the heterogeneous distribution of Salmonella and other bacteria in naturally contaminated samples. Samples that were positive in the qualitative test but negative in the mMPN protocol could have had a number of Salmonella below the detection amount.

Análise do perfil oxidativo de diferentes amostras biológicas de pacientes com lesão de ligamento cruzado anterior

La rodilla es una de las articulaciones mas importantes para locomocion. Sin embargo, debido a su complejidad, se torna susceptible a diversos tipos de lesiones, como la ruptura del ligamento cruzado anterior (LCA). Esa complicacion desencadena un proceso inflamatorio, que puede culminar en formacion de radicales libres y, en consecuencia, en estres oxidativo (EO). El objectivo del estudio fue comparar el perfil oxidativo de pacientes con lesion del LCA, analizando dos muestras biologicas: fluido sinovial y suero. Fueron analizados 11 individuos del genero masculino, con ruptura total del LCA, con edad superior a 18 anos. Se recogio muestras de sangre y fluido sinovial 15 minutos antes de la artroplastia y se analizo biomarcadores de EO, catalasa, flavonoides y peroxidacion de las grasas, o sea, substancias reactivas al acido tiobarbiturico (TBARS). Los resultados apuntan menor concentracion de flavonoides, combinada a aumento de TBARS e de actividad de catalasa en el suero cuando comparado con el fluido sinovial. El analisis de los resultados indica que la lesion de LCA induce a cuadro de EO, caracterizado por consumo de antioxidantes y elevacion de dano de las grasas en el fluido sinovial cuando comparado con el suero, indicando que analisis sericas pueden no ser adecuadas para medir EO en partes como la articulacion de la rodilla

Microcosm Biofilm Formation on Titanium Surfaces

Risk factors associated with peri-implantitis are related to the biofilm composition around the implant and the ability of bacterial adhesion. This study evaluated the biofilm formation on different surfaces of commercially pure titanium (CP Ti) grade 4 after 12, 24, 48 and 168 hours using the microcosm technique and scanning electron microscopy (SEM). The following surface conditions were examined: S (control)- smooth and plain; B- sand-blasted with aluminum oxide; E- etched using nitric acid; and BE- the combination of J and A treatments. Statistical differences on biofilm formation (CFU/ mg) were found between the control (S) and B surfaces at the first 12 hours, which are related to the lowest (Ra = 0.21 µm) and highest (Ra = 0.62 µm) mean roughness values. At 168-hour all surfaces showed similar biofilm formation. Yet, microbial growth occurred on all surfaces, regardless of the surface treatment.

Oxidative profile of patients with osteoarthrosis undergoing total knee arthroplasty

Introduction Total knee arthroplasty may be the most appropriate method of treatment in several cases of osteoarthritis. This disease causes tissue damage, which is closely related to the production of free radicals, leading to oxidative stress and to lipid damage. Because of that, the body has several antioxidative defense systems involved in detoxification (antioxidants).Objective Based on the previous information, the goal of this study was to establish the systemic and local oxidative profile of individuals with osteoarthritis submitted to total knee arthroplasty.Materials and methods The sample consisted of four female patients (65.5 ± 0.7 years) with osteoarthritis of the knee. Blood and synovial fluid (SF) samples were collected from the patients 15 minutes before surgery. The concentrations of flavonoids, catalase, and TBARS were then quantified.Results The results indicate a higher catalase activity in the SF than in the serum (S), (SF = 1 S = 14.3 ± 3.1 ± 0.8). The concentration of TBARS proved to be higher in the SF (SF = 0.29 ± 0.02 S = 0.09 ± 0.05), whereas the concentration of phenols was higher in the serum (SF = 3.2 S = 5.2 ± 0.2 ± 0.6).Conclusion Osteoarthritis is a disease that increases the oxidative stress markers in the serum and in the SF.