1,721,009 research outputs found
Investigating the role of environmental and human microbiome in health and disease: focus on pathogen’s monitoring and control
No full textMy PhD thesis focused on the correlations between environmental and human microbiomes and their relation with health or disease conditions.
In particular, at the environmental level, the hospital environment was analyzed, as it is a reservoir of pathogens responsible for the onset of healthcare-associated infections (HAI), thus its monitoring could be crucial to optimize HAI prevention strategies. To this aim, molecular methods were used in comparison with conventional microbiological methods, showing that NGS, due to its high sensitivity, could be a useful tool for microbial environmental monitoring, especially if flanked by PCR methods for species identification and resistome characterization (Comar et al., 2019).
Next, the data obtained from NGS characterization of the microbiome in a pediatric hospital were used to assess the potential of environmental pathogens to colonize the nasal cavities of preterm newborns in a Neonatal Intensive Care Unit (NICU), since the risk for contracting HAI is particularly high in preterm infants. The results, obtained by NGS and qPCR microarray, showed increasing amount of HAI-associated environmental pathogens in the newborn nose with increased stay time in the NICU, highlighting the role of the hospital microbiome in pathogen transmission (Cason et al., 2021).
Last, we tested the microbiome variations associated with the use of a probiotic cleaning hygiene system (PCHS) in the Emergency ward of a pediatric hospital during the COVID-19 pandemics, showing that PCHS use was associated with a stable decrease of pathogens (>80% compared to chemical disinfection), and an up to 2-Log decrease of antibiotic resistance genes (ARG) in the microbial population. Notably, despite the presence of SARS-CoV-2 infected patients, the virus was never detected during the PCHS use, supporting the PCHS antiviral activity previously reported in vitro, and suggesting that PCHS may effectively control both the spread of resistant HAI-associated pathogens and of SARS-CoV-2 (Soffritti et al., 2022).
On the human microbiome side, we focused on the study of oral and vaginal niches, to clarify whether specific microbiome compositions may be related to increased risk to develop specific virus-induced diseases.
First, a comprehensive characterization of the healthy human oral microbiome (HOM) was obtained by WGS, showing the presence of a recognizable core healthy HOM, including bacteria, fungi and viruses. Furthermore, HOM ARG analysis highlighted the presence of several resistances to antibiotics, including macrolide, lincosamides, streptogramin and tetracycline (Caselli, Fabbri, et al., 2020).
Since SARS-CoV-2 virus enters the body through the oropharynx, we next investigated the role of HOM in favoring/counteracting the virus replication at the site of entry, showing that HOM dysbiosis correlated with inflammation, COVID-19 severity, and poor with mucosal sIgA response, thus suggesting that HOM could be an important factor in determining the individual susceptibility to SARS-CoV-2 infection and the early virus control (Soffritti et al., 2021).
Last, we studied the role of vaginal microbiome in determining the persistence/clearance of HPV infection in CIN2/CIN3 patients undergoing lesion surgical excision. The results showed that dysbiotic microbiomes and inflammation were observed before excision, correlating with the neoplastic disease severity, whereas a decrease of microbiome dysbiosis and pro-inflammatory cytokines were observed in HPV-cleared patients, compared to HPV-recurrent ones (Caselli, D’Accolti, et al., 2020).
Overall, the data collected during my PhD support the existence of a deep interconnection between the environmental and human microbiome, and a significant role of the human microbiome in maintaining the health or favoring disease onset
Scrubbing Wipes to Dislodge Dental Biofilm Can Remove and Inactivate Viruses from Tooth Surface: Perspectives for Covid-19 Prevention
No full textPoor dental hygiene and periodontitis have been associated with increased risk of admission to intensive care units, assisted ventilation, and death in COVID-19 patients. Consistent with this, chlorhexidine-based mouth washes have been suggested to limit virus spread, as they can transiently decrease the virus load in saliva. However, no data are available on the potential effectiveness of wipe-scrubbing procedures on virus removal/inactivation from tooth surface. Here, as a proof of concept, teeth were artificially contaminated in vitro with human coronavirus 229E or herpes simplex virus type 1 and scrubbed with wipes routinely used to dislodge oral biofilm. The results showed that 30-second wipe-scrubbing removed almost completely viruses from tooth surface, and that 0.12% chlorhexidine-soaked wipes inactivated >99% of the removed viruses, suggesting that this procedure may potentially limit SARS-CoV-2 penetration into the deeper airways and reduce the emission of contaminated droplets. This simple maneuver may be considered as a potentially effective tool against the spread of COVID-19 or other virus-induced diseases and pave the way for clinical studies to prove its effectiveness in virus removal from the oral cavity of COVID-19 patients, as a potential
tool for infection control
Potential use of phages as sanitizing agents to reduce hospital pathogens on hard surfaces
No full textIntroduction: Hospital-acquired infections (HAI) can be transmitted by pathogens persistently contaminating hospital surfaces,1 often multidrug-resistant (MDR), and not efficiently controlled by conventional sanitation protocols, which indeed contribute to selection of drug-resistant strains.2 Due to the selective killing of specific bacteria, bacteriophages have been repeatedly suggested as decontaminating agents.3,4 This work was aimed to assess phage usability as sanitizing agents in routine hospital sanitation.
Materials & Methods: Phage activity was assessed in vitro and in situ, in aqueous buffer or probiotic eco-sustainable detergents,5 on glass, plastic or ceramic surfaces artificially contaminated by S. aureus, E. coli and P. aeruginosa. Both ATCC strains and wild-type MDR hospital isolates were used, at a density consistent with what detected on hospital surfaces.
Results: Phage application significantly reduced (up to 90%) all tested bacteria on all treated surfaces. Notably, phages suspended in probiotic detergents not only retained their full activity, but resulted even more effective especially at later times.
Conclusions: Results suggest that phages might be successfully included in probiotic detergents currently used for hospital sanitation, potentially resulting in innovative products highly effective in the safe elimination of MDR nosocomial pathogens from the hospital environment.
References:
1. Otter JA, Yezli S, French GL. The role played by contaminated surfaces in the transmission of nosocomial pathogens. Infect Control Hosp Epidemiol 2011; 32(7): 687-99.
2. Wand ME, Bock LJ, Bonney LC, Sutton JM. Mechanisms of Increased Resistance to Chlorhexidine and Cross-Resistance to Colistin following Exposure of Klebsiella pneumoniae Clinical Isolates to Chlorhexidine. Antimicrob Agents Chemother 2017; 61(1).
3. Jensen KC, Hair BB, Wienclaw TM, et al. Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant. PLoS One 2015; 10(7): e0131714.
4. Tomat D, Quiberoni A, Mercanti D, Balague C. Hard surfaces decontamination of enteropathogenic and Shiga toxin-producing Escherichia coli using bacteriophages. Food Res Int 2014; 57: 123-9.
5. Caselli E, D'Accolti M, Vandini A, et al. Impact of a Probiotic-Based Cleaning Intervention on the Microbiota Ecosystem of the Hospital Surfaces: Focus on the Resistome Remodulation. PLoS One 2016; 11(2): e0148857
Probiotic‐Based Approaches for Sustainable Control of Infectious Risk in Mass Transport: Current Data and Future Perspectives
No full textThe built environments of high-traffic areas can play a significant role in the transmission of microorganisms and associated infections, sometimes favouring the selection of multidrug-resistant (MDR) organisms due to the excessive use of conventional disinfectants. Probiotic-based sanitation (PBS) was suggested as a novel alternative approach to control the infectious risk in crowded community environments due to its effectiveness in reducing fungal, bacterial, and viral pathogens in sanitary settings. PBS may thus trigger a paradigm shift from chemical to biological strategies in cleaning environments with high human occupancy, offering an ecological and economically sustainable alternative to conventional chemical disinfection. Providing robust data supporting the results reported so far, it has the potential to optimise bioburden control and infection prevention in mass transportation spaces. This review brings together existing research on PBS in mass transportation areas, pinpoints areas of lack of information, and explores its potential future uses, including the creation of probiotic-based materials for sustainable biocontrol in high-traffic areas
Atopobium vaginae and Porphyromonas somerae induce proinflammatory cytokines expression in endometrial cells: A possible implication for endometrial cancer?
No full textNo abstract availabl
A Sustainable Combined Approach to Control the Microbial Bioburden in the School Environment
No full textThe indoor microbiome is a dynamic ecosystem including pathogens that can impact human health. In this regard, the school environment represents the main living space of humans for many years, and an unhealthy environment can significantly condition students’ health. School rooms can suffer from insufficient ventilation and the use of building materials that may favor pathogen contamination, mostly sanitized by conventional chemical-based methods, which can impact pollution, have temporary effects, and induce the selection of antimicrobial resistance (AMR) in persistent microbes. In the search for sustainable and effective methods to improve the healthiness of the classroom environment, a pre–post case–control study was performed in an Italian high school. Over a year, different interventions were sequentially placed and evaluated for their impact on bioburden and air quality, including the introduction of plants, a mechanical ventilation system, and probiotic-based sanitation (PBS) in substitution for chemical sanitation. Through continuous microbial monitoring of the enrolled school rooms, via culture-dependent and -independent methods, a remarkable bioburden level was detected at baseline (around 12,000 and 20,000 CFU/m2, before and after classes, respectively), composed mostly of Staphylococcus spp. and fungi. Some decrease in fungal contamination was observed following the introduction of plants. Still, the most significant decrease in pathogens and associated AMR was detected following the introduction of ventilation and PBS, which decreased pathogen level by >80% (p < 0.001) and AMR by up to 3 Log10 (p < 0.001) compared to controls. Collected data support the use of combined strategies to improve indoor microbial quality and confirm that PBS can effectively control bioburden and AMR spread not only in sanitary environments
Corrigendum: Efficient removal of hospital pathogens from hard surfaces by a combined use of bacteriophages and probiotics: Potential as sanitizing agents (Infect Drug Resist 2018, (11) (1015-1026), 10.2147/IDR.S170071)
No full textPurpose
Many hospital-acquired infections (HAI) can be transmitted by pathogens contaminating hospital surfaces, not efficiently controlled by conventional sanitation, which can indeed contribute to the selection of multidrug-resistant (MDR) strains. Bacteriophages have been suggested as decontaminating agents, based on their selective ability to kill specific bacteria. However, there are no data on their stability in detergents and their potential use in routine sanitation. On the other hand, a probiotic-based sanitation (Probiotic Cleaning Hygiene System, PCHS) was recently shown to stably reduce pathogens on treated surfaces. However, its action is not specific and slow, being based on competitive antagonism. This work was aimed to assess the effectiveness of a combined use of phages and PCHS in removing HAI-associated pathogens from different hard surfaces.
Methods
The decontamination ability of phages in PCHS was tested in vitro and in situ, against drug-susceptible or resistant S. aureus, E. coli and P. aeruginosa strains, and using bacterial densities similar to those detected on hospital surfaces.
Results
Phages targeted efficiently all tested bacteria, maintaining their full activity when added to PCHS detergent. Notably, the combined use of phages and PCHS not only resulted in a rapid reduction (up to >90%) of the targeted pathogens, but, due to the stabilizing effect of probiotics, the pathogens were maintained at low levels (>99%) also at later times, when instead the effect of phages tends to diminish.
Conclusion
These results suggest that a combined biological system might be successfully used in hospital sanitation protocols, potentially leading to an effective and safe elimination of MDR pathogens from the hospital environment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Impatto di un sistema biologico di sanificazione sull’incidenza di ICA e AMR: risultati di uno studio multicentrico
No full textLe infezioni correlate all’assistenza (ICA) rappresentano un problema globale, ulteriormente aggravato dall’incremento di antibiotico-resistenza (AMR) dei patogeni ICA-associati. È noto che la persistente contaminazione dell’ambiente ospedaliero contribuisce alla trasmissione delle ICA, e che i sistemi di sanificazione tradizionale non riescono a controllare la ricontaminazione, oltre ad avere un elevato impatto ambientale e la capacità di favorire la selezione di ceppi farmaco-resistenti. Recentemente, un sistema di cleaning ecosostenibile a base di probiotici (Probiotic Cleaning Hygiene System, PCHS) si è dimostrato in grado di modulare il microbiota ospedaliero sulle superfici trattate, inducendo, rispetto ai sanificanti tradizionali, un calo significativo dei patogeni e della AMR, con basso impatto ambientale e bassi costi. È stato pertanto effettuato uno studio multicentrico in 6 Ospedali pubblici italiani per verificare se gli effetti osservati a livello ambientale avessero un impatto sull’incidenza delle ICA e sulla AMR dei patogeni ICA-associati. Lo studio, durato di 18 mesi, ha coinvolto i reparti di Medicina Interna, in cui la sanificazione convenzionale è stata sostituita dal PCHS, mantenendo inalterate tutte le altre procedure in grado di influenzare il controllo delle ICA. Nel complesso, sono stati analizzati 11,842 pazienti e 24,875 campioni ambientali. I dati ambientali hanno confermato l’effetto di riduzione dei patogeni superficiali (-83%) e della loro AMR (fino a 100 volte). L’uso del PCHS è risultato associato ad un significativo decremento dell’incidenza globale delle ICA, dal 4.8% (284 pazienti con ICA su 5.930 pazienti totali) al 2.3% (128 pazienti con ICA su 5.531 pazienti totali) (OR=0.44, IC 95% 0.35-0.54) (P<0.0001). Tali dati supportano l’ipotesi che le procedure di sanificazione abbiano un impatto sull’incidenza ICA, mostrando che un singolo intervento ambientale a base di probiotici può essere associato ad un significativo decremento del rischio di contrarre un’ICA durante il ricovero. Questo approccio biologico ed eco-sostenibile potrebbe quindi essere considerato come parte di strategie di controllo e prevenzione delle infezioni
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