Biofilm Formation and Control in a Simulated Spacecraft Water System: Interim Results

Abstract Background Candida pelliculosa is an ecological fungal species that can cause infections in immunocompromised individuals. Numerous studies globally have shown that C. pelliculosa infects neonates. An outbreak recently occurred in our neonatal intensive care unit; therefore, we aimed to evaluate the risk factors in this hospital-acquired fungal infection. Methods We performed a case-control study, analysing the potential risk factors for neonatal infections of C. pelliculosa so that infection prevention and control could be implemented in our units. Isolated strains were tested for drug resistance and biofilm formation, important factors for fungal transmission that give rise to hospital-acquired infections. Results The use of three or more broad-spectrum antimicrobials or long hospital stays were associated with higher likelihoods of infection with C. pelliculosa. The fungus was not identified on the hands of healthcare workers or in the environment. All fungal isolates were susceptible to anti-fungal medications, and after anti-fungal treatment, all infected patients recovered. Strict infection prevention and control procedures efficiently suppressed infection transmission. Intact adhesin-encoding genes, shown by genome analysis, indicated possible routes for fungal transmission. Conclusions The use of three or more broad-spectrum antimicrobials or a lengthy hospital stay is theoretically associated with the risk of infection with C. pelliculosa. Strains that we isolated are susceptible to anti-fungal medications, and these were eliminated by treating all patients with an antifungal. Transmission is likely via adhesion to the cell surface and biofilm formation.

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Investigation and control of an outbreak due to a contaminated hospital water system, identified following a rare case of Cupriavidus pauculus bacteraemia

Journal of Hospital Infection ◽

10.1016/j.jhin.2021.02.001 ◽

2021 ◽

Vol 111 ◽

pp. 53-64 ◽

Cited By ~ 1

Author(s):

T. Inkster ◽

C. Peters ◽

T. Wafer ◽

D. Holloway ◽

T. Makin

Keyword(s):

Rare Case ◽

Water System ◽

And Control ◽

Cupriavidus Pauculus

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Control of Systems of Reservoirs with the Use of Risk Analysis

Acta Polytechnica ◽

10.14311/538 ◽

2004 ◽

Vol 44 (2) ◽

Author(s):

P. Fošumpaur ◽

L. Satrapa

Keyword(s):

Risk Analysis ◽

Flood Control ◽

Water System ◽

Water Reservoir ◽

The Czech Republic ◽

Run Off ◽

Hydropower Plants ◽

Basic Functions ◽

And Control

A system of reservoirs is usually defined as a system of water management elements, that are mutually linked by inner and outer connections in a purpose-built complex. Combined elements consist of reservoirs, river sections, dams, weirs, hydropower plants, water treatment plants and other hydraulic structures. These elements also include the rainfall system, the run-off system, the ground water system, etc. A system of reservoirs serves many purposes, which result from the basic functions of water reservoirs: storage, flood control and environmental functions. Most reservoirs serve several purposes at the same time. They are so called multi-purposes reservoirs. Optimum design and control of a system of reservoirs depends strongly on identifying the particular purposes. In order to assess these purposes and to evaluate the appropriate set of criteria, risk analysis can be used. Design and control of water reservoir functions is consequently solved with the use of multi-objective optimisation. This paper deals with the use of the risk analysis to determine criteria for controlling the system. This approach is tested on a case study of the Pastviny dam in the Czech Republic.

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Reduction of Energy Consumption in Hotels with Aerothermal Energy. Case Study: Canary Islands (Spain)

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.32.18412 ◽

2018 ◽

Vol 7 (3.32) ◽

pp. 127

Author(s):

Francisco Javier Díaz Perez ◽

David Chinarro ◽

M Rosa Pino Otín ◽

Ricardo Díaz Martín ◽

Adib Guardiola Mouhaffel

Keyword(s):

Canary Islands ◽

Water System ◽

Heat Pumps ◽

Hot Water ◽

Hourly Rate ◽

The Hours ◽

Reduction Of Energy Consumption ◽

Opening And Closing ◽

And Control

This article presents a management model and control of energy efficiency in hotels adapted to the consumption patterns that ensure the comfort requirements of customers and integrated into the environment of an intelligent tourist complex. The analysis of the hot water system (DHW) of two hotels in the Canary Islands (Spain) in relation to their occupation, yields a solution based on renewable energies using high temperature heat pumps with aerothermal dissipation and supported by boilers of existing LPG propane. The control by programmable automatons (PLC) integrated in a system of control and acquisition of data (SCADA) optimizes the systems to maintain the maximum accumulated energy during the periods of cheapest electric tariff, by means of a system of opening and closing of hydraulic Valves that It manages to adjust the demand of DHW consumption to achieve the highest energy accumulation during the hours with the cheapest electricity tariff. The result after two and a half years of activity registration is a faster return on investment due to the optimized energy management of the system, through the control of operating hours adjusted to the needs of customers and the hourly rate. It has also been predicted that during the estimated 12 years of the system will have saved more than € 1,179,737 and thermal 8,780,005 kWh in a hotel 1 and € 1,315,104 and thermal 9,522,301 kWh in the hotel 2. This model shown can be seen how economically and energetically very efficient.

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The S-layer protein of a Clostridium difficile SLCT-11 strain displays a complex glycan required for normal cell growth and morphology

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.004530 ◽

2018 ◽

Vol 293 (47) ◽

pp. 18123-18137 ◽

Cited By ~ 4

Author(s):

Emma Richards ◽

Laura Bouché ◽

Maria Panico ◽

Ana Arbeloa ◽

Evgeny Vinogradov ◽

...

Keyword(s):

Clostridium Difficile ◽

Biofilm Formation ◽

Bacterial Pathogen ◽

Low Molecular Weight ◽

Major Health ◽

Archaeal Species ◽

Core Peptide ◽

And Control ◽

Protein Attachment ◽

Complex Glycan

Clostridium difficile is a bacterial pathogen that causes major health challenges worldwide. It has a well-characterized surface (S)-layer, a para-crystalline proteinaceous layer surrounding the cell wall. In many bacterial and archaeal species, the S-layer is glycosylated, but no such modifications have been demonstrated in C. difficile. Here, we show that a C. difficile strain of S-layer cassette type 11, Ox247, has a complex glycan attached via an O-linkage to Thr-38 of the S-layer low-molecular-weight subunit. Using MS and NMR, we fully characterized this glycan. We present evidence that it is composed of three domains: (i) a core peptide–linked tetrasaccharide with the sequence -4-α-Rha-3-α-Rha-3-α-Rha-3-β-Gal-peptide; (ii) a repeating pentasaccharide with the sequence -4-β-Rha-4-α-Glc-3-β-Rha-4-(α-Rib-3-)β-Rha-; and (iii) a nonreducing end–terminal 2,3 cyclophosphoryl-rhamnose attached to a ribose-branched sub-terminal rhamnose residue. The Ox247 genome contains a 24-kb locus containing genes for synthesis and protein attachment of this glycan. Mutations in genes within this locus altered or completely abrogated formation of this glycan, and their phenotypes suggested that this S-layer modification may affect sporulation, cell length, and biofilm formation of C. difficile. In summary, our findings indicate that the S-layer protein of SLCT-11 strains displays a complex glycan and suggest that this glycan is required for C. difficile sporulation and control of cell shape, a discovery with implications for the development of antimicrobials targeting the S-layer.

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Relationship Between Membrane Vesicles, Extracellular ATP and Biofilm Formation in Antarctic Gram-Negative Bacteria

Microbial Ecology ◽

10.1007/s00248-020-01614-6 ◽

2020 ◽

Author(s):

Nicolas Baeza ◽

Elena Mercade

Keyword(s):

Biofilm Formation ◽

Membrane Vesicles ◽

Metabolic Cost ◽

Extracellular Atp ◽

Gram Negative Bacteria ◽

Bacterial Survival ◽

Gram Negative ◽

Two Factors ◽

And Control

Abstract Biofilms offer a safe environment that favors bacterial survival; for this reason, most pathogenic and environmental bacteria live integrated in biofilm communities. The development of biofilms is complex and involves many factors, which need to be studied in order to understand bacterial behavior and control biofilm formation when necessary. We used a collection of cold-adapted Antarctic Gram-negative bacteria to study whether their ability to form biofilms is associated with a capacity to produce membrane vesicles and secrete extracellular ATP. In most of the studied strains, no correlation was found between biofilm formation and these two factors. Only Shewanella vesiculosa M7T secreted high levels of extracellular ATP, and its membrane vesicles caused a significant increase in the speed and amount of biofilm formation. In this strain, an important portion of the exogenous ATP was contained in membrane vesicles, where it was protected from apyrase treatment. These results confirm that ATP influences biofilm formation. Although the role of extracellular ATP in prokaryotes is still not well understood, the metabolic cost of its production suggests it has an important function, such as a role in biofilm formation. Thus, the liberation of extracellular ATP through membrane vesicles and its function deserve further study.

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Differential regulation of physiological activities by RcsB and OmpR in Yersinia enterocolitica

FEMS Microbiology Letters ◽

10.1093/femsle/fnz210 ◽

2019 ◽

Vol 366 (17) ◽

Cited By ~ 4

Author(s):

Jiao Meng ◽

Jiaqi Bai ◽

Junhong Xu ◽

Can Huang ◽

Jingyu Chen

Keyword(s):

Yersinia Enterocolitica ◽

Biofilm Formation ◽

Bacterial Colonization ◽

Sodium Dodecyl ◽

Extreme Temperature ◽

Polymyxin B ◽

Differential Regulation ◽

Physiological Processes ◽

And Control ◽

Gmp Production

ABSTRACT A thorough understanding of the mechanisms of Rcs and EnvZ/OmpR phosphorelay systems that allow Yersinia enterocolitica to thrive in various environments is crucial to prevent and control Y. enterocolitica infections. In this study, we showed that RcsB and OmpR have the ability to function differently in modulating a diverse array of physiological processes in Y. enterocolitica. The rcsB mutant stimulated flagella biosynthesis and increased motility, biofilm formation and c-di-GMP production by upregulating flhDC, hmsHFRS and hmsT. However, mutation in ompR exhibited a non-motile phenotype due to the lack of flagella. Biofilm formation was reduced and less c-di-GMP was produced through the downregulation of flhDC, hmsHFRS and hmsT expression when Y. enterocolitica was exposed to low osmolarity conditions. Furthermore, OmpR was identified to be important for Y. enterocolitica to grow in extreme temperature conditions. Importantly, ompR mutations in Y. enterocolitica were more sensitive to polymyxin B and sodium dodecyl sulfate than rcsB mutations. Since motility, biofilm formation and environmental tolerance are critical for bacterial colonization of the host, these findings indicated that OmpR is more critical than RcsB in shaping the pathogenic phenotype of Y. enterocolitica.

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Efficacy of Synthetic Furanones on Listeria monocytogenes Biofilm Formation

Foods ◽

10.3390/foods8120647 ◽

2019 ◽

Vol 8 (12) ◽

pp. 647 ◽

Cited By ~ 1

Author(s):

Pedro Rodríguez-López ◽

Andrea Emparanza Barrenengoa ◽

Sergio Pascual-Sáez ◽

Marta López Cabo

Keyword(s):

Listeria Monocytogenes ◽

Biofilm Formation ◽

Epifluorescence Microscopy ◽

Dependent Manner ◽

Antifouling Activity ◽

Aisi 316 ◽

Novel Strategy ◽

And Control ◽

Acylated Homoserine Lactones ◽

Dose Dependent

Furanones are analogues of acylated homoserine lactones with proven antifouling activity in both Gram-positive and Gram-negative bacteria though the interference of various quorum sensing pathways. In an attempt to find new strategies to prevent and control Listeria monocytogenes biofilm formation on stainless steel (SS) surfaces, different concentrations of six synthetic furanones were applied on biofilms formed by strains isolated from food, environmental, and clinical sources grown onto AISI 316 SS coupons. Among the furanones tested, (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone and 3,4-Dichloro-2(5H)-furanone significantly (p < 0.05) reduced the adhesion capacity (>1 log CFU cm−2) in 24 h treated biofilms. Moreover, individually conducted experiments demonstrated that (Z-)-4-Bromo-5-(bromomethylene)-2(5H)-furanone was able to not only significantly (p < 0.05) prevent L. monocytogenes adhesion but also to reduce the growth rate of planktonic cells up to 48 h in a dose-dependent manner. LIVE/DEAD staining followed by epifluorescence microscopy visualisation confirmed these results show an alteration of the structure of the biofilm in furanone-treated samples. Additionally, it was demonstrated that 20 µmol L−1 of 3,4-Dichloro-2(5H)-furanone dosed at 0, 24 and 96 h was able to maintain a lower level of adhered cells (>1 log CFU cm−2; p < 0.05). Since furanones do not pose a selective pressure on bacteria, these results represent an appealing novel strategy for the prevention of L. monocytogenes biofilm grown onto SS.

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