Bacterial growth and recovery on hospital biometric devices: effect of two types of disinfectants

Objectives: The aim of the study was to evaluate the presence of bacterial contamination on biometric identification devices in a public hospital; identify the species of bacteria implicated in the contamination and assess bacterial recovery after the use of 2 types of disinfectants: alcohol 70% and isopropyl alcohol chlorhexidine. Design: Before and after trial. Setting: Public hospital, tertiary referral center. Participants: All existing biometric identification devices in the hospital (n = 20). Methods: Collection of 2 microbiological samples from the fingerprint reading surface of biometric devices immediately before and after applying the solution with alcohol 70% and in separate time periods with isopropyl alcohol chlorhexidine. Results: It have been identified 21 different bacterial species in a total of 78 samples, mostly Staphylococcus epidermidis (32 samples) and S aureus (7 samples). S epidermidis was eliminated in 61.5% of the samples after disinfecting with alcohol 70% and in 92.3% of the samples disinfected with isopropyl alcohol chlorhexidine. S aureus was eliminated in 33.3% and 100% of the samples, respectively. We found no bacterial growth in 10% of the devices after disinfection with 70% alcohol and in 78.9% of devices after disinfection with isopropyl alcohol chlorhexidine. We also found that there was a decrease in the frequency of species isolated after using both disinfection solutions, although isopropyl alcohol chlorhexidine appeared to be more effective. Conclusions: The biometric identification devices used in this hospital seem to be safe regardless of the products used for its cleaning. The majority of the bacteria found are commensal skin microorganisms. We did not find pathogenic bacteria for immunocompetent individuals, in particular methicillin-resistant S aureus

Cryo-EM structures show the mechanistic basis of pan-peptidase inhibition by human α<inf>2</inf>-macroglobulin

Human α2-macroglobulin (hα2M) is a multidomain protein with a plethora of essential functions, including transport of signaling molecules and endopeptidase inhibition in innate immunity. Here, we dissected the molecular mechanism of the inhibitory function of the ∼720-kDa hα2M tetramer through eight cryo-electron microscopy (cryo-EM) structures of complexes from human plasma. In the native complex, the hα2M subunits are organized in two flexible modules in expanded conformation, which enclose a highly porous cavity in which the proteolytic activity of circulating plasma proteins is tested. Cleavage of bait regions exposed inside the cavity triggers rearrangement to a compact conformation, which closes openings and entraps the prey proteinase. After the expanded-to-compact transition, which occurs independently in the four subunits, the reactive thioester bond triggers covalent linking of the proteinase, and the receptor-binding domain is exposed on the tetramer surface for receptor-mediated clearance from circulation. These results depict the molecular mechanism of a unique suicidal inhibitory trap

Evaluation of the activity and substrate specificity of the human SENP family of SUMO proteases

Protein modification with the small ubiquitin-like modifier (SUMO) is a reversible process regulating many central biological pathways. The reversibility of SUMOylation is ensured by SUMO proteases many of which belong to the sentrin/SUMO-specific protease (SENP) family. In recent years, many advances have been made in allocating SENPs to specific biological pathways. However, due to difficulties in obtaining recombinant full-length active SENPs for thorough enzymatic characterization, our knowledge on these proteases is still limited. In this work, we used in vitro synthesized full-length human SENPs to perform a side-by-side comparison of their activities and substrate specificities. ProSUMO1/2/3, RanGAP1-SUMO1/2/3 and polySUMO2/3 chains were used as substrates in these analyses. We found that SENP1 is by far the most versatile and active SENP whereas SENP3 stands out as the least active of these enzymes. Finally, a comparison between the activities of full-length SENPs and their catalytic domains suggests that in some cases their non-catalytic regions influence their activity.We thank Dr. Frauke Melchior (University of Heidelberg, Germany), Dr. Guy Salvesen (Sanford-Burnham Medical Research Institute, USA), Dr. Hidde Ploegh (Whitehead Institute, USA) and Dr. Joanna Morris (University of Birmingham, UK) for kindly providing plasmids. This work was funded by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the Operational Competitiveness Programme COMPETE and by National Funds through FCT - Fundação para a Ciência e a Tecnologia under the project FCOMP-01-0124-FEDER-027627 (EXPL/BEX-BCM/0320/2012) and by project “ NORTE-07-0124-FEDER-000003- Cell homeotasis tissue organization and organism biology ”co-funded by Programa Operacional Regional do Norte (ON.2 — O Novo Norte), under the Quadro de Referência Estratégico Nacional (QREN), through FEDER and by FCT. A. V. M. was supported by project FCOMP-01-0124-FEDER-027627-EXPL/BEX-BCM/0320/2012. C. P. G. (SFRH/BPD/64388/2009)and M. P. P. (SFRH/BPD/47447/2008)were supported by FCT, COMPETE, Programa Operacional Potencial Humano (POPH) do QREN, FEDER and Fundo Social Europeu (FSE)

The de novo synthesis of ubiquitin: Identification of deubiquitinases acting on ubiquitin precursors

Protein ubiquitination, a major post-translational modification in eukaryotes, requires an adequate pool of free ubiquitin. Cells maintain this pool by two pathways, both involving deubiquitinases (DUBs): recycling of ubiquitin from ubiquitin conjugates and processing of ubiquitin precursors synthesized de novo. Although many advances have been made in recent years regarding ubiquitin recycling, our knowledge on ubiquitin precursor processing is still limited, and questions such as when are these precursors processed and which DUBs are involved remain largely unanswered. Here we provide data suggesting that two of the four mammalian ubiquitin precursors, UBA 52 and UBA 80 , are processed mostly post-translationally whereas the other two, UBB and UBC, probably undergo a combination of co-and post-translational processing. Using an unbiased biochemical approach we found that UCHL 3 , USP 9 X, USP 7 , USP 5 and Otulin/Gumby/FAM 105 b are by far the most active DUBs acting on these precursors. The identification of these DUBs together with their properties suggests that each ubiquitin precursor can be processed in at least two different manners, explaining the robustness of the ubiquitin de novo synthesis pathway.We are grateful to Dr. Cheryl Arrowsmith (University of Toronto, Canada) for providing the plasmids pET28a-LIC-USP5 (Addgene plasmid 25299) and pET28a-LIC-USP5(C335A). We thank Dr. João M. Cabral (IBMC, University of Porto, Portugal) for critically reading the manuscript. This work was supported by national funds through FCT - Fundação para a Ciência e a Tecnologia/MEC – Ministério da Educação e Ciência and when applicable co-funded by Fundo de Desenvolvimento Regional (FEDER) funds within the partnership agreement PT2020 related with the research unit number 4293; by Project “NORTE-07-0124-FEDER-000003 -Cell homeotasis tissue organization and organism biology”, co-funded by Programa Operacional Regional do Norte (ON.2—O Novo Norte), under the Quadro de Referência Estratégico Nacional (QREN), through FEDER and by FCT; by Portuguese National Mass Spectrometry Network (RNEM) through the project REDE/1504/REM/2005; and by Química Orgânica, Produtos Naturais e Agroalimentares (QOPNA) research unit funds provided by FCT, European Union, QREN, FEDER and Operational Competitiveness Programme (COMPETE) under the projects PEst-C/QUI/UI0062/2013 and FCOMP-01-0124-FEDER-037296. C.P.G. and M.P.P. were supported by FCT, COMPETE and Fundo Social Europeu. A.V.M. was supported by the project FCOMP-01-0124-FEDER-027627-EXPL/BEX-BCM/0320/2012 financed by national funds from FCT/Ministério da Educação e Ciência (PIDDAC) and co-funded by FEDER through COMPETE—Programa Operacional Factores de Competitividade (POFC)

Could Public Restrooms Be an Environment for Bacterial Resistomes?

PMCID: PMC3547874This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Reduction of volatile acidity of wines by selected yeast strains

Herein we isolate and characterize wine yeasts with ability to reduce volatile acidity of wines using a refermentation process, which consists in mixing the acidic wine with freshly crushed grapes or musts or, alternatively, in the incubation with the residual marc. From a set of 135 yeast isolates, four strains revealed ability to use glucose and acetic acid simultaneously. Three of them were identified as Saccharomyces cerevisiae and one as Lachancea thermotolerans. Among nine commercial S. cerevisiae strains, strains S26, S29 and S30 display similar glucose and acetic acid initial simultaneous consumption pattern and were assessed in refermentation assays. In a medium containing an acidic wine with high glucose/low ethanol concentrations, under low oxygen availability, strain S29 is the most efficient one, whereas L. thermotolerans 44C is able to decrease significantly acetic acid similar to the control strain Zygosaccharomyces bailii ISA 1307, but only under aerobic conditions. Conversely, for low glucose/high ethanol concentrations, under aerobic conditions, S26 is the most efficient acid degrading strain, while under limited-aerobic conditions, all the S. cerevisiae strains studied display acetic acid degradation efficiencies identical to Z. bailii. Moreover, S26 strain also reveals capacity to decrease volatile acidity of wines. Together, the S. cerevisiae strains characterized herein appear promising for the oenological removal of volatile acidity of acidic wines.Fundação para a Ciência e a Tecnologia (FCT) - Programa POCI 2010 (FEDER/FCT, POCI/AGR/56102/2004, PTDC/AGRALI/71460/2006