Search results for "pathogen"

Listeria monocytogenes Differential Transcriptome Analysis Reveals Temperature-Dependent Agr Regulation and Suggests Overlaps with Other Regulons

2012

Listeria monocytogenes is a ubiquitous, opportunistic pathogenic organism. Environmental adaptation requires constant regulation of gene expression. Among transcriptional regulators, AgrA is part of an auto-induction system. Temperature is an environmental cue critical for in vivo adaptation. In order to investigate how temperature may affect AgrA-dependent transcription, we compared the transcriptomes of the parental strain L. monocytogenes EGD-e and its Delta agrA mutant at the saprophytic temperature of 25 degrees C and in vivo temperature of 37 degrees C. Variations of transcriptome were higher at 37 degrees C than at 25 degrees C. Results suggested that AgrA may be involved in the regu…

Experimental Evaluation of a New Thermal Process for Microorganisms Inactivation

2015

A new thermal process for the inactivation of microorganisms in beverages has been studied and is presented in this paper. The treatment, not yet studied in the scientific literature, mainly consists of a thermal shock characterized by temperature increases up to 30°C/s, with final temperatures up to 65°C. This study presents the first experimental results obtained by the application of the new thermal treatment, with different combinations of the process parameters (rate of temperature rise, final temperature and holding time), on separate suspensions of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Listeria innocua and Candida albicans. The required rapid temperature in…

What Do We Know about Candida auris? State of the Art, Knowledge Gaps, and Future Directions

2021

Candida auris has unprecedently emerged as a multidrug resistant fungal pathogen, considered a serious global threat due to its potential to cause nosocomial outbreaks and deep-seated infections with staggering transmissibility and mortality, that has put health authorities and institutions worldwide in check for more than a decade now. Due to its unique features not observed in other yeasts, it has been categorised as an urgent threat by the Centers for Disease Control and Prevention and other international agencies. Moreover, epidemiological alerts have been released in view of the increase of healthcare-associated C. auris outbreaks in the context of the COVID-19 pandemic. This review su…

Outbreak of multi-resistant Corynebacterium striatum infection in an Italian general intensive care unit.

2007

The Independent Biological Activity of Bacillus thuringiensis Cry23Aa Protein Against Cylas puncticollis

2020

The Cry23Aa/Cry37Aa proteins from Bacillus thuringiensis (Bt) have been described toxic to Cylas puncticollis larvae. In general, it is believed that Cry23Aa and Cry37Aa act jointly to exert the insecticidal activity, while there is no evidence of their toxicity individually. Therefore, in the present study, the contribution of each protein in the insecticidal activity toward C. puncticollis larvae has been assessed. The results showed that both proteins were toxic for C. puncticollis larvae when tested individually. Contrary to what was claimed previously, our results suggest that the presence of both proteins is not necessary to exert toxicity against C. puncticollis larvae. Also, the bin…

Captivity and infection by the fungal pathogen batrachochytrium salamandrivorans perturb the amphibian skin microbiome

2019

The emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal) is responsible for the catastrophic decline of European salamanders and poses a threat to amphibians globally. The amphibian skin microbiome can influence disease outcome for several host-pathogen systems, yet little is known of its role in Bsal infection. In addition, many experimental in-vivo amphibian disease studies to date have relied on specimens that have been kept in captivity for long periods without considering the influence of environment on the microbiome and how this may impact the host response to pathogen exposure. We characterized the impact of captivity and exposure to Bsal on the skin bacterial and fung…

Anti-adhesion agents against Gram-positive pathogens

2014

The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…

Potential association of specific Candida parapsilosis genotypes, bloodstream infections and colonization of health workers' hands.

2014

AbstractFungal nosocomial infections continue to be a serious problem among hospitalized patients, decreasing quality of life and adding millions of euros to healthcare costs. The aim of this study was to describe the pattern of fungi associated with the hands of healthcare workers and to genotype Candida parapsilosis isolates in order to understand whether their high clinical prevalence stems from endemic nosocomial genotypes or from the real emergence of epidemiologically-unrelated strains. Approximately 39% (50/129) of healthcare workers were positive for yeasts and among 77 different fungal isolates recovered, C. parapsilosis was the most frequent (44/77; 57%). Twenty-seven diverse geno…

Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium

2020

Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radi…

The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis

2015

ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically id…