Applied Microbiology Laboratory

Macroarea: Microbiology

ERC sectors: LS6 Immunity, Infection and Immunotherapy

Lab manager: Pietro Grisoli (PA)

Technician: Marco Albertoni 

1. DIFFUSION OF MICRO-ORGANISMS AND MICROBIOLOGICAL RISK FACTORS IN LIFE AND WORK ENVIRONMENTS

Microbiological-health studies have been carried out aimed at assessing the spread of microorganisms in the workplace. The assessment of air quality in the workplace has assumed considerable importance following evidence that relates the prolonged stay in confined spaces with the onset of pathologies in exposed workers. The purpose of the research is to identify and measure the extent of the spread of biological agents that contribute to the definition of the healthiness of the air and to the classification of the types of risk in the various work environments, also in relation to the entry into force of the legislation. which concerns the improvement of the safety and health of workers in the workplace. These studies have made it possible to propose investigation protocols aimed at assessing air contamination in non-industrial and hospital environments. In particular, the studies were conducted in offices, hospitals (including operating theaters), university classrooms, sports centers and evaluation indices were proposed, based on measures of bacteriological and fungal contamination, with the aim of allowing the evaluation of the risk, deriving from exposure to microbiological agents.

2. STUDY OF NANOTECHNOLOGIES FOR THE RELEASE OF DRUGS / DISINFECTANTS WITH ANTIMICROBIAL ACTION

The research studies the antimicrobial properties of innovative smart materials with the aim of preventing, for example, nosocomial infections caused mainly by medical devices, already contaminated at the time of use, or which become contaminated during their application. Surfaces modified with monolayers of silver nanoparticles, monolayers of transition metal ion complexes and solutions of silver nanoparticles with biocompatible molecules were studied to determine their antimicrobial activity. In addition, NanoRods (NR) and Asymmetric Nano-Particles (NPA) of gold have been studied which absorb effectively in the near IR (NIR, 750-1200 nm) by thermally de-energizing, while at these wavelengths blood and tissues are almost- transparent. These nano-objects can be loaded with cations and drugs whose release can be activated on command: when irradiated in the NIR they emit heat and release their load, with both thermal and pharmacological antimicrobial action localized and measurable over time. A new, ad hoc, method has been developed for these materials to determine the antibacterial activity in conditions that simulate real use.

3. STUDY OF NEW BACTERIAL LEVEL TARGETS TO REDUCE THE DIFFUSION OF ANTIBIOTIC RESISTANT BACTERIA

Research has been carried out for the development of new therapeutic strategies and combined treatments to combat the phenomenon of antibiotic resistance and the spread of multi-resistant strains. The antimicrobial activity of antibiotic molecules, in use, reformulated through delivery in micro- and nano-structured polymeric therapeutic systems was evaluated; this allows localized activity at the site of action, avoiding systemic administration. The goal is to improve efficacy, to prevent any nosocomial infections and reduce antibiotic resistance.

4. STUDY OF SYSTEMS FOR THE CONTROLLED SITE-SPECIFIC RELEASE OF COMPOUNDS WITH ANTIMICROBIAL ACTIVITY

This line of research studies the antimicrobial activity of new modified release pharmaceutical forms. The activity of thermosensitive gels based on trimethylchitosan and benzydamine was verified; these formulations could be used for applications on the buccal mucosa, above all, to treat and prevent mucositis, induced by radio-chemotherapy. The antimicrobial activity of dressings based on chitosan hydrochloride (HCS), 5-methyl-pyrrolidinone chitosan (MPC) loaded with antibacterial compounds such as chlorhexidine has also been demonstrated. These “sponge-like” dressings seem to have suitable characteristics for the delivery of antimicrobial drugs and could find application in the treatment of pressure ulcers. Finally, the effectiveness of using microspheres, for the controlled release of antibiotics in the treatment of osteomyelitis, has been demonstrated.

5. ANTIMICROBIAL ACTIVITY OF MEDICINAL PLANTS AND SUBSTANCES DERIVED THEREOF

Several medicinal plants, used in traditional medicine from different countries, have been studied. These assays are performed in vitro using different microbial strains. The study of these plants and their extracts has shown antimicrobial activity against some bacterial and fungal species.

• PVA Films with Mixed Silver Nanoparticles and Gold Nanostars for Intrinsic and Photothermal Antibacterial Action. P. Grisoli, L. De Vita, C. Milanese , A. Taglietti, Y.D. Fernandez, M. Bouzin, L. D’Alfonso , L. Sironi, S. Rossi, B. Vigani, P. Sperandeo, A. Polissi and P. Pallavicini. Nanomaterials 2021, 11(6), 1387; https://doi.org/10.3390/nano11061387.
• Tobramycin Supplemented Small-Diameter Vascular Grafts for Local Antibiotic Delivery: A Preliminary Formulation Study. M. Rosalia, P. Ravipati, P. Grisoli, R. Dorati, Ida Genta, E. Chiesa, G. Bruni and B. Conti. Int. J. Mol. Sci. 2021, 22(24), 13557; https://doi.org/10.3390/ijms222413557
• Microstructured Lipid Carriers (MLC) Based on N-Acetylcysteine and Chitosan Preventing Pseudomonas aeruginosa Biofilm”, Guerini, M.; Grisoli, P.; Pane, C.; Perugini, P, Int J molecular sciences, 2021, 22, 891. https://doi.org/10.3390/ijms22020891
• A New In Vitro Model to Evaluate Anti-Adhesive Effect against Fungal Nail Infections Perugini, P.; Bonetti, M.; Guerini, M; Musitelli, G., Grisoli, P. Applied Sciences 2021 , 11, 5 https://doi.org/10.3390/app11051977
• Evaluation of the Effectiveness of N-Acetylcysteine (NAC) and N-acetylcysteine-cyclodextrins Multi-Composite in Pseudomonas aeruginosa Biofilm Formation”. Guerini, M.; Perugini, P.; Grisoli, P. Applied sciences, 2020, 10, 3466. https://doi.org/10.3390/app10103466
• Adipose Mesenchymal Extracellular Vesicles as Alpha-1-Antitrypsin Physiological Delivery Systems for Lung Regeneration. E. Bari, I. Ferrarotti, D. Di Silvestre, P. Grisoli, V. Barzon, A. Balderacchi, M. L. Torre, R. Rossi, P. Mauri, A. G. Corsico and S. Perteghella. Cells 2019, 8(9), 965 https://doi.org/10.3390/cells8090965
• Application of Airborne Microorganism Indexes in Offices, Gyms, and Libraries .P. Grisoli, M. Albertoni, M. Rodolfi. Appl. Sci., 9(6), 1101 (2019). https://doi.org/10.3390/app9061101
• Bulk Surfaces Coated with Triangular Silver Nanoplates: Antibacterial Action Based on Silver Release and Photo-Thermal Effect. A. D’Agostino, A. Taglietti, R. Desando, M. Bini, M. Patrini, G. Dacarro, L. Cucca, P. Pallavicini and P. Grisoli. Nanomaterials, 7(1), 7 (2017). https://doi.org/10.3390/nano7010007
• Antibacterial Activity of Glutathione-Coated Silver Nanoparticles against Gram Positive and Gram Negative Bacteria. Taglietti, A, Diaz-Fernandez, YA, Amato, E, Cucca, Dacarro, G, Grisoli, P, Necchi, V, Pallavicini, P, Pasotti, L, Patrini. Langmuir, 28(21), pp. 8140-8148 (2012). https://doi.org/10.1021/la3003838 
• Evaluation of microbiological air quality and of microclimate in university classrooms. Environmental Monitoring and Assessment. Grisoli P., Rodolfi M., Chiara T., Zonta L. A., and Dacarro C. 184 (7), pp 4171-4180 (2012). https://doi.org/10.1007/s10661-011-2253-x

National collaborations

• inLAB (inhorganic nanochemistry laboratory) (Dip. di Chimica, Università di Pavia)
• Lab. Pharmaceutical Technology and Law (PT&L) (Dip. di Scienze del Farmaco Università di Pavia)
• Biopharmaceutics and Formulation Development Laboratory, (Dip. di Scienze del Farmaco Università di Pavia)
• Medicinal Chemistry Laboratorium (MedChemLab) (Dip. di Scienze del Farmaco Università di Pavia)
• Cell Delivery System Lab (Dip. di Scienze del Farmaco Università di Pavia). Pharmaceutical Analysis Laboratory (PAL) (Dip. di Scienze del Farmaco Università di Pavia)
• Fondazione Salvatore Maugeri, Clinica del Lavoro e della Riabilitazione, Centro Ricerche Ambientali (Pavia)
• Smart Materials Group, Istituto Italiano di Tecnologia, (Genova).

International collaborations

• European Commission Joint research center, Institute for Health and Consumer Protection (ISPRA).

Fondazione Cariplo: “Gold nanorods (NR) and asymmetic nanoparticles coated with biocompatible polymers with binding functions for molecules and metal cations: antimicrobial action of pharmacological and thermal nature, activated by NearIR irradiation"[project #2010-0454]

• Microbiological analysis for the detection of microorganisms in air samples, on surfaces and in water samples: from € 25 to € 85 / determined microbiological parameter.
• Search for bacteria belonging to the genus Legionella in water or air samples: from € 50 to € 90 / sample analyzed.
• Microbiological analysis for the research of microorganisms in solid matrices.
• Identification with biochemical tests of isolated microbial strains: from € 25 to € 100 / determined microbiological parameter.
• Microbiological analysis for the research of microorganisms in sewage samples coming from purification plants: from € 50 to € 100 / determined microbiological parameter.
• Search for bacteria belonging to the genus Legionella in water or air samples: from € 45 to € 90 / sample analyzed.
• Preliminary analyzes for the determination of antibacterial activities: from € 80 to € 400 / sample analyzed
• Analysis for the determination and dosage of antibacterial activities: from € 350 to € 1,500 / sample analyzed.
• Validation of antimicrobial treatments on matrices of different nature: From € 400 to € 1,000 for validation.