Efficacy assessment of different time-cycles of nebulized hydrogen peroxide against bacterial and yeast biofilm

BACKGROUND

The prevention of healthcare-associated infections requires a continuous effort. In order to achieve better practical results, the control of environmental microbial biofilms with effective disinfection strategies should be addressed.

AIM

This study aims to test the efficacy of different time-cycles of nebulized H₂O₂ against bacterial and yeast dry biofilm.

METHODS

The efficacy of a standard cycle (SC) and of a fast cycle (FC) of nebulized H₂O₂ was compared. Microbial biofilms were previously grown on different material coupons. The biofilm metabolic activity was determined by XTT assay and the biofilm total biomass by crystal violet assay.

FINDINGS

Regarding the efficacy of nebulized H₂O₂ against biofilms, the mean reduction of metabolic activity of the SC was 55.2% (±19.4%), comparing to a reduction of 50.4% (±17.7%) of the FC. The mean reduction of total biomass of the SC was 45.5% (±22.7%), versus 46.7% (±21.7%) of the FC. No statistical significant differences were found when comparing the tested cycles and distinct materials.

CONCLUSION

H₂O₂ nebulization was found to exhibit a good efficacy against healthcare-associated microbial dry biofilms. Moreover, similar efficacies were found between the tested cycles.

MAMMALS IN PORTUGAL: A data set of terrestrial, volant, and marine mammal occurrences in Portugal

Mammals are threatened worldwide, with ca. 26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated to habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished geo-referenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of Azores and Madeira that includes 107,852 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (42%), sign surveys (38%), camera trapping (16%), bioacoustics surveys (4%) and radio-tracking and inquiries that represent less than 1% of the records. The data set includes 13 types of records: 1) burrows | soil mounds | tunnel, 2) capture, 3) colony, 4) dead animal | hair | skulls | jaws, 5) genetic confirmation, 6) inquiries, 7) observation of live animal, 8), observation in shelters, 9) photo trapping | video, 10), predators diet | pellets | pine cones/nuts, 11) scat | track | ditch, 12) telemetry and 13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n = 34,754) has the highest number of records followed by Chiroptera (n = 18,858), Carnivora (n = 18,594), Lagomorpha (n = 17,679), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 6400). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus (n = 12,407), Monachus monachus (n = 1512), and Lynx pardinus (n = 197)]. We believe that this data set may stimulate the publication of other European countries data sets which would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications.

Fast-cycle hydrogen peroxide nebulization against frequent healthcare-associated micro-organisms: efficacy assessment

BACKGROUND

Hydrogen peroxide (H₂O₂)-based technology is currently used with the aim of controlling microbial contamination in hospital settings. However, the long cycles required result in prolonged room turnover time, thus precluding a wider implementation of the technology.

AIM

To assess the efficacy of a shorter cycle of nebulized H₂O₂ against healthcare-associated micro-organisms, further comparing among multidrug-resistant and multidrug-susceptible strains.

METHODS

The efficacy of a standard cycle (1 h) and of a faster cycle (15 min) of a 7% H₂O₂ nebulized solution was compared against bacteria and yeasts. MDR and MDS strains were inoculated on polyvinyl chloride, stainless steel, linoleum, napa leather, and formica coupons, and their growth ability was compared.

FINDINGS

Globally, the mean efficacy of the standard cycle ranged between 82.5% (±17.0) and 95.9% (±8.3), while the efficacy of the fast cycle ranged between 84.4% (±17.0) and 95.7% (±10.5). No statistically significant differences were found for the majority of the tested cycles and materials. For all the tested strains, no differences were found regarding the efficacy of cycles.

CONCLUSION

The very high disinfection efficacy of the fast cycle was found to be similar to that of the standard cycle. Moreover, a similar efficacy was also demonstrated when comparing between multidrug-resistant and multidrug-susceptible strains. This study supports a wider implementation of the technology, with the expected advantages of reducing room turnover time, costs, and indirect infection transmission. Further assessment of the efficacy of this faster cycle against other emergent microbial global threats would be highly recommended.

A pilot study to evaluate the serum Alpha-1 acid glycoprotein response in cats suffering from feline chronic gingivostomatitis

BACKGROUND

Feline chronic gingivostomatitis (FCGS) is a multifactorial immune-mediated disease that can lead to chronic pain, anorexia, and weight loss and has substantial health and welfare effects. Currently, the recommended treatment includes dental extractions to decrease the inflammatory stimulation associated with dental plaque. However, complete remission is observed in less than half of the cases, and the majority need comprehensive medical management. This study aimed to evaluate the serum levels of the acute phase protein alpha-1 acid glycoprotein (AGP) in cats with FCGS and to examine whether dental extractions contribute to a significant decrease in the systemic inflammatory response at two postoperative time points.

RESULTS

AGP serum concentrations in the cats with FCGS were significantly higher at all time points than that in the control groups and were significantly correlated with the global caudal stomatitis score at day 0 but not at day 30 or 60. A significant improvement of some clinical scores, such as perceived comfort and global caudal stomatitis, was observed 60 days after the dental extraction. However, the levels of AGP did not significantly change over time.

CONCLUSIONS

Cats with FCGS were more likely to have a systemic inflammatory response compared with age- and dental disease-matched controls. Dental extractions, in most cases, did not contribute to a significant decrease of AGP both at 30 and 60 days. Therefore, this study reinforces the need to pursue comprehensive medical management after dental extractions to attenuate the systemic inflammatory response as a result of this disease.

Omega-3 therapeutic supplementation in a patient with metastatic adenocarcinoma of the pancreas with muscle mass depletion

Pancreatic adenocarcinoma has an extremely poor prognosis. With the best available treatments, the median overall survival duration is still less than 1 year. Most patients develop anorexia and major muscle mass loss that interfere with chemotherapy tolerance and survival. In this paper, we present a case in which these problems were a major concern. A multidisciplinary approach with chemotherapy and close nutritional support permitted better control of the disease and longer survival. We also review the literature on nutritional interventions that show an improvement in quality of life and survival in these patients.

Janelas Curriculares de Educação Popular na Universidade de Évora: dar utilidade social ao conhecimento académico

O projeto Janelas Curriculares de Educação Popular no Ensino Superior Universitário pretende proporcionar aos estudantes da Universidade de Évora – através da sua participação em projetos educativos da Universidade Popular Túlio Espanca/UPTE – oportunidades de conceber, planificar e concretizar projetos de educação não formal abertos à participação da população do Alentejo, decorrentes da mobilização do conhecimento e da competência científica, cultural, técnica e tecnológica oriundos da respetiva formação académica e enquadrados, sempre que possível, no âmbito dos planeamentos didáticos das unidades curriculares frequentadas. Neste contexto, o projeto aposta em convocar as aprendizagens concretizadas no âmbito curricular das diferentes formações da Universidade de Évora para o esforço de promoção de oportunidades de aprendizagem de natureza menos formal e de divulgação científica e cultural dirigidas a públicos menos frequentes no contexto universitário e, habitualmente, com níveis de escolaridade menos qualificados. Numa perspetiva inovadora, concretiza, de uma forma concomitante, a missão de qualquer universidade: a produção do conhecimento, a formação superior e o serviço à comunidade, neste caso, através de projetos de extensão educacional inscritos no conceito de ALV (Aprendizagem ao Longo da Vida), nas diferentes áreas científicas presentes na academia. O presente projeto tenta, ainda, consolidar e institucionalizar esta realidade no ensino superior universitário em Portugal, assentando no pressuposto de que, em contexto curricular, é possível e qualitativamente vantajoso para a qualidade das aprendizagens, a substituição ou articulação de alguns instrumentos didáticos e de avaliação pela participação discente em projetos de divulgação e promoção científicas, nos quais, se mobilizam e aplicam, em contexto real de educação popular, os conhecimentos e as competências edificados na academia. Por outro lado, a certificação desta participação, em complementaridade com a certificação académica tradicional, diferencia o CV dos estudantes participantes, porque o enriquece com competências habitualmente ausentes dos currículos académicos mas valorizadas em contextos profissionais. Por último, será de salientar de que a participação de professores e estudantes no presente projeto, através da construção e concretização de janelas curriculares de educação popular na Universidade de Évora poderá abrir uma outra dimensão na formação dos estudantes e no trabalho dos seus professores: a Solidariedade. Na realidade, a transferência, para a sociedade, dos conhecimentos e das capacidades construídas nas salas de aula e nos laboratórios universitários possibilitará a criação de uma diferente perceção da utilidade do conhecimento, do seu papel no exercício da cidadania e da relevância que o mesmo pode desempenhar na coesão social. Simetricamente, poderá ocorrer uma diferente leitura do trabalho educativo realizado pelas universidades, por parte dos participantes nestes projetos. O papel dos órgãos de comunicação social, nesta dimensão, será crítico, atendendo ao seu poder de divulgação junto de toda a sociedade. Através da comunicação social, a Universidade também cumpre o seu papel de Responsabilidade Social, como a instituição mais qualificada do território local e regional e como centro, por excelência, produtor e difusor do conhecimento e da cultura.

Polyethyleneimine and polyethyleneimine-based nanoparticles: novel bacterial and yeast biofilm inhibitors

Biofilms are commonly involved in medical device-related infections. The purpose of this study was to determine the antimicrobial and anti-biofilm activity of polyethyleneimine (PEI) and PEI-based nanoparticles (nanoPEI) against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii and Candida albicans (clinical and ATCC strains), and to evaluate their effect upon biofilm formation on polyurethane (PUR)-like catheters. MICs and minimal lethal concentrations of PEI and nanoPEI were determined according to CLSI microdilution reference protocols. For PEI, the MIC value was 195.31 mg l−1 for all the bacteria and 48.83 mg l−1 for the yeast strains. For nanoPEI, the MIC value was 1250 mg l−1 for all the strains except A. baumannii, for which it was 2500 mg l−1. Biofilm formation was assessed with PUR-like catheter segments and biofilm metabolic activity was quantified by colorimetry with a tetrazolium reduction assay. Plasma membrane integrity and membrane potential were assessed by flow cytometry after staining microbial cells with a membrane-impermeable dye, propidium iodide, and a membrane-potential marker, DiBAC4(3). PEI inhibited growth of all microbial species; higher concentrations of nanoPEI were needed to inhibit growth of all species. Biofilm formation in the presence of anti-bacterial PEI activity was dose-dependent (except for S. epidermidis) and species-related. NanoPEI at 0.5×MIC and MIC significantly reduced the metabolic activity of biofilms of S. aureus, S. epidermidis and A. baumannii, whereas 2×MIC was required in order to inhibit biofilm metabolic activity.

Helicobacter pylori virulence genotypes in Portuguese children and adults with gastroduodenal pathology

The aim of this study was to evaluate the prevalence of virulence genotypes, namely cagA, vacA and babA2, of Helicobacter pylori strains isolated from Portuguese adults and children presenting gastroduodenal pathology. One hundred thirty-six strains were studied, 82 isolated from adult patients (50 with nonulcerative gastritis and 32 with active peptic ulcer) and 58 isolated from children (54 with nonulcerative gastritis and 4 with duodenal ulcer). Genotyping of cagA, vacA and babA2 was assessed by polymerase chain reaction. Overall, Helicobacter pylori strains carrying more virulent genotypes were much more prevalent in adults than in children, particularly the type I ( vacAs1- and cagA-positive) and the triple-positive ( vacAs1-, cagA- and babA2-positive) strains ( P<0.001). A subpopulation of adults and children with nonulcerative gastritis was also studied, and differences in the prevalence of virulent genotypes were observed, either for individual genotypes ( P=0.017 for cagA, P=0.010 for vacAs1) or in combinations, i.e. the type I genotype ( P=0.005) and the triple-positive strains ( P=0.031). There was no difference between the two populations in the distribution of babA2 and m1/m2 genotypes. Considering the cohort effect in the epidemiology of Helicobacter pylori infection, these results suggest that different strains might circulate during different periods of time, or that, after infection in childhood, individual strains will undergo changes during the course of infection.

Features and trends in Helicobacter pylori antibiotic resistance in Lisbon area, Portugal (1990-1999)

The features of Helicobacter pylori antibiotic resistance in Lisbon from 1990 to 1999 were studied. Overall resistance rates to amoxycillin, tetracycline, metronidazole, clarithromycin and ciprofloxacin were 0, 0, 30.6, 19.0 and 9.6%, respectively. The incidence of resistance to clarithromycin was much higher in isolates from children (44.8%) than adults (14.6%). For metronidazole, the contrary was observed (children: 19.0%, adults: 32.3%). Ciprofloxacin-resistant isolates were all from adult patients. Concerning the adult population, the resistance rate to metronidazole showed a slight increase during the decade, while for clarithromycin and ciprofloxacin a significant increase was observed (4.6 to 22.0% and 0 to 20.9%, respectively).