Staphylococcus epidermidis is a safer surrogate of Staphylococcus aureus in testing bacterial filtration efficiency of face masks

Face masks play a role in reducing the spread of airborne pathogens, providing that they have a good filtration performance, are correctly fitted and maintained. Bacterial Filtration Efficiency (BFE) is a key indicator for evaluating filtration performance according to both European and US standards, requiring the use of Staphylococcus aureus loaded aerosol. However, the generation and handling of a Biohazard group 2 bacterium aerosol require a careful management of the biological risk and pose limitations to the accessibility to this method. To mitigate these drawbacks, we investigated the use of S. epidermidis ATCC 12228, a Biohazard group 1 bacterium, as surrogate in BFE test. To this end, tests with the surrogate strain were performed to tune the method. Then, three face mask models, representative for both surgical and community masks, were tested according to the standard method and then using an aerosolized suspension of S. epidermidis. BFE% values were calculated for each mask model and tested microorganisms. Results showed that BFE test can be performed using the S. epidermidis instead of S. aureus, preserving results validity and turnaround time, but reducing residual risk for laboratory operators

Effects of Mushroom and Chicory Extracts on the Physiology and Shape of Prevotella intermedia, a Periodontopathogenic Bacterium

Contrary to the common assumption that food has a negative impact on oral health, research has shown that several foods contain a number of components with antibacterial and antiplaque activity. These natural compounds may be useful for improving daily oral hygiene. In this study we evaluate the mode of antimicrobial action of fractions of mushroom and red chicory extracts on Prevotella intermedia, a periodontopathogenic bacterium. The minimal inhibitory concentration corresponded to 0.5x compared to the natural food concentration for both extracts. This concentration resulted in a bacteriostatic effect in mushroom extract and in a slightly bactericidal effect in chicory extract. Cell mass continued to increase even after division stopped. As regards macromolecular synthesis, DNA was almost totally inhibited upon addition of either mushroom or chicory extract, and RNA to a lesser extent, while protein synthesis continued. Cell elongation occurred after septum inhibition as documented by scanning electron microscopy and cell measurement. The morphogenetic effects are reminiscent of the mode of action of antibiotics such as quinolones or β-lactams. The discovery of an antibiotic-like mode of action suggests that these extracts can be advantageously employed for daily oral hygiene in formulations of cosmetic products such as mouthwashes and toothpastes

Il processo tutoriale nell’ambito della formazione del Tecnico Sanitario di Laboratorio Biomedico neoassunto nel Laboratorio di Microbiologia

The tutorship in the training of the new engaged Biomedical Technician in the Microbiology Laboratory The training period for a new engaged laboratory technician in the microbiological laboratory is considered in this work. Experience and reflective practice are the key elements in order to develope professional skills and new knowledge in adults. Learning occurs through the interaction between persons and their concrete experience. The main subject, acting as a training developer, is the mentor: he/she is the expert colleague that create an ad personam relationship with the neophyta, to support the development of professionals skills and to psychologically sustain the new member in such a difficult period. The high complexity of the laboratory framework requires an intense and articulated tutorship, in order to link the learning times of the new technician with the working times and priorities, managing the learning incentives by a careful planning. In the tutorial function is particulary important the use of methods that facilitate the experential learning reflective practice, e.g. contract, briefing, practice and debriefing. In the working agreement the needs are taked in account, the training objectives and the time for the final skills are defined. The main operating instrument is the training plan, where the specific goals are divided in professional activities that will enable the acquisition of the final skills in a well defined working period, also taking into account a specific progressive control. Regarding the specific framework of the microbiology lab, eight points have been identified in the training plan to reach the main professional skills, while the activities, that are necessary to reach the desired results in a specific time period, have been defined

Esperienza del Laboratorio di Microbiologia e Virologia dell’Ospedale di Trento nell’Accreditamento Joint Commission International

The Accreditation is a standard based process provided by the Joint Commission International (JCI), in order to evaluate the health organization.The aim of this program, according to international standards and indicators, is both to promote and systematically test the continuous improvement of the health care services, with high regard for local needs. The work focuses on analysing the role played by the Microbiology and Virology Laboratory of Trento Hospital within the JCI Accreditation process.We therefore tried to examine and improve its different activities, in compliance with the specific JCI standards

La sterilità dei dispositivi monouso rigenerati. Studio su cateteri per cardiologia interventistica dopo riutilizzo simulato

The reuse of single use devices is of particular interest in interventional cardiology where the economic load of the devices represents a significant share of the whole procedure. The sterility of the reprocessed device must be tested and warranted, together with chemical-physical and functional performances. This study evaluates the efficiency and limitations of an experimental reprocessing protocol in order to assess the sterility of cardiac electrophysiology catheters and the maximum number of regeneration cycles sustainable by the device. A first lot of 54 devices, collected after clinical use in the Cardiology Department of S.Chiara Hospital in Trento, was reprocessed and tested for sterility. Devices underwent repeated cycles of simulating-use (bacteria spiked blood) and regeneration (decontamination, cleaning and hydrogen peroxide gas plasma sterilization): 36, 24, 28, 35, 22 devices were regenerated respectively 2, 3, 4, 5 and 6 times. Entire devices were cultured for 28 days in trypticase soy broth. On the whole,we tested 199 samples, six cycles of regeneration and four inoculation species. No positive sample to inoculated strain was found until the fourth cycle of reprocessing. The inoculated Bacillus subtilis strain was recovered in samples reprocessed five and six times. Reprocessing procedures following the adopted protocol turned out efficient to guarantee device’s sterility up to five reuses in experimental conditions representing the worst case scenario for bacterial load. However, complexity of reprocessing protocols, organizational issues, economic and legal requirements addressed to qualifying and certifying all steps of the reprocessing procedure discourage “in house” reprocessing

La sterilità dei dispositivi monouso rigenerati. Studio su cateteri per cardiologia interventistica dopo riutilizzo simulato

The reuse of single use devices is of particular interest in interventional cardiology where the economic load of the devices represents a significant share of the whole procedure. The sterility of the reprocessed device must be tested and warranted, together with chemical-physical and functional performances. This study evaluates the efficiency and limitations of an experimental reprocessing protocol in order to assess the sterility of cardiac electrophysiology catheters and the maximum number of regeneration cycles sustainable by the device. A first lot of 54 devices, collected after clinical use in the Cardiology Department of S.Chiara Hospital in Trento, was reprocessed and tested for sterility. Devices underwent repeated cycles of simulating-use (bacteria spiked blood) and regeneration (decontamination, cleaning and hydrogen peroxide gas plasma sterilization): 36, 24, 28, 35, 22 devices were regenerated respectively 2, 3, 4, 5 and 6 times. Entire devices were cultured for 28 days in trypticase soy broth. On the whole,we tested 199 samples, six cycles of regeneration and four inoculation species. No positive sample to inoculated strain was found until the fourth cycle of reprocessing. The inoculated Bacillus subtilis strain was recovered in samples reprocessed five and six times. Reprocessing procedures following the adopted protocol turned out efficient to guarantee device’s sterility up to five reuses in experimental conditions representing the worst case scenario for bacterial load. However, complexity of reprocessing protocols, organizational issues, economic and legal requirements addressed to qualifying and certifying all steps of the reprocessing procedure discourage “in house” reprocessing