Behavior of Foodborne PathogensListeria monocytogenesandStaphylococcus aureusin Mixed-Species Biofilms Exposed to Biocides

ABSTRACTIn nature and man-made environments, microorganisms reside in mixed-species biofilms, in which the growth and metabolism of an organism are different from these behaviors in single-species biofilms. Pathogenic microorganisms may be protected against adverse treatments in mixed-species biofilms, leading to health risk for humans. Here, we developed two mixed five-species biofilms that included one or the other of the foodborne pathogensListeria monocytogenesandStaphylococcus aureus. The five species, including the pathogen, were isolated from a single food-processing environmental sample, thus mimicking the environmental community. In mature mixed five-species biofilms on stainless steel, the two pathogens remained at a constant level of ∼105CFU/cm2. The mixed five-species biofilms as well as the pathogens in monospecies biofilms were exposed to biocides to determine any pathogen-protective effect of the mixed biofilm. Both pathogens and their associate microbial communities were reduced by peracetic acid treatments.S. aureusdecreased by 4.6 log cycles in monospecies biofilms, but the pathogen was protected in the five-species biofilm and decreased by only 1.1 log cycles. Sessile cells ofL. monocytogeneswere affected to the same extent when in a monobiofilm or as a member of the mixed-species biofilm, decreasing by 3 log cycles when exposed to 0.0375% peracetic acid. When the pathogen was exchanged in each associated microbial community,S. aureuswas eradicated, while there was no significant effect of the biocide onL. monocytogenesor the mixed community. This indicates that particular members or associations in the community offered the protective effect. Further studies are needed to clarify the mechanisms of biocide protection and to identify the species playing the protective role in microbial communities of biofilms.IMPORTANCEThis study demonstrates that foodborne pathogens can be established in mixed-species biofilms and that this can protect them from biocide action. The protection is not due to specific characteristics of the pathogen, hereS. aureusandL. monocytogenes, but likely caused by specific members or associations in the mixed-species biofilm. Biocide treatment and resistance are a challenge for many industries, and biocide efficacy should be tested on microorganisms growing in biofilms, preferably mixed systems, mimicking the application environment.

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Antia, a Natural Antioxidant Product, Attenuates Cognitive Dysfunction in Streptozotocin-Induced Mouse Model of Sporadic Alzheimer’s Disease by Targeting the Amyloidogenic, Inflammatory, Autophagy, and Oxidative Stress Pathways

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/4386562 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Nesrine S. El Sayed ◽

Mamdooh H. Ghoneum

Keyword(s):

Oxidative Stress ◽

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Diseases ◽

Protective Effect ◽

Cognitive Dysfunction ◽

Protective Role ◽

Sporadic Alzheimer’S Disease ◽

Stat3 Pathway ◽

And Oxidative Stress

Background. Many neurodegenerative diseases such as Alzheimer’s disease are associated with oxidative stress. Therefore, antioxidant therapy has been suggested for the prevention and treatment of neurodegenerative diseases. Objective. We investigated the ability of the antioxidant Antia to exert a protective effect against sporadic Alzheimer’s disease (SAD) induced in mice. Antia is a natural product that is extracted from the edible yamabushitake mushroom, the gotsukora and kothala himbutu plants, diosgenin (an extract from wild yam tubers), and amla (Indian gooseberry) after treatment with MRN-100. Methods. Single intracerebroventricular (ICV) injection of streptozotocin (STZ) (3 mg/kg) was used for induction of SAD in mice. Antia was injected intraperitoneally (i.p.) in 3 doses (25, 50, and 100 mg/kg/day) for 21 days. Neurobehavioral tests were conducted within 24 h after the last day of injection. Afterwards, mice were sacrificed and their hippocampi were rapidly excised, weighed, and homogenized to be used for measuring biochemical parameters. Results. Treatment with Antia significantly improved mice performance in the Morris water maze. In addition, biochemical analysis showed that Antia exerted a protective effect for several compounds, including GSH, MDA, NF-κB, IL-6, TNF-α, and amyloid β. Further studies with western blot showed the protective effect of Antia for the JAK2/STAT3 pathway. Conclusions. Antia exerts a significant protection against cognitive dysfunction induced by ICV-STZ injection. This effect is achieved through targeting of the amyloidogenic, inflammatory, and oxidative stress pathways. The JAK2/STAT3 pathway plays a protective role for neuroinflammatory and neurodegenerative diseases such as SAD.

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A Fungal Cu/Zn-Containing Superoxide Dismutase Enhances the Therapeutic Efficacy of a Plant Polyphenol Extract in Experimental Influenza Virus Infection

Zeitschrift für Naturforschung C ◽

10.1515/znc-2010-5-616 ◽

2010 ◽

Vol 65 (5-6) ◽

pp. 419-428 ◽

Cited By ~ 1

Author(s):

Julia Serkedjieva ◽

Tsvetanka Stefanova ◽

Ekaterina Krumova

Keyword(s):

Superoxide Dismutase ◽

Influenza Virus ◽

Virus Infection ◽

Protective Effect ◽

Influenza A ◽

Influenza Virus Infection ◽

Protective Role ◽

Combined Application ◽

Combined Use ◽

Experimental Influenza

The combined protective effect of a polyphenol-rich extract, isolated from Geranium sanguineum L. (PC), and a novel naturally glycosylated Cu/Zn-containing superoxide dismutase, produced from the fungal strain Humicula lutea 103 (HL-SOD), in the experimental influenza A virus infection (EIVI) in mice, induced with the virus A/Aichi/2/68 (H3N2), was investigated. The combined application of HL-SOD and PC in doses, which by themselves do not defend significantly mice in EIVI, resulted in a synergistically increased protection, determined on the basis of protective indices and amelioration of lung injury. Lung weights and consolidation as well as infectious lung virus titers were all decreased significantly parallel to the reduction of the mortality rates; lung indices were raised. The excessive production of reactive oxygen species (ROS) by alveolar macrophages (aMØ) as well as the elevated levels of the lung antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), induced by EIVI, were brought to normal. For comparative reasons the combined protective effect of PC and vitamin C was investigated. The obtained results support the combined use of antioxidants for the treatment of influenza virus infection and in general indicate the beneficial protective role of combinations of viral inhibitors of natural origin with diverse modes of action.

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Cervicovaginal Microbiome Composition Is Associated with Metabolic Profiles in Healthy Pregnancy

mBio ◽

10.1128/mbio.01851-20 ◽

2020 ◽

Vol 11 (4) ◽

Author(s):

Andrew Oliver ◽

Brandon LaMere ◽

Claudia Weihe ◽

Stephen Wandro ◽

Karen L. Lindsay ◽

...

Keyword(s):

Mass Spectrometry ◽

Reproductive Health ◽

Microbial Communities ◽

Carbon Sources ◽

Amplicon Sequencing ◽

Vaginal Microbiome ◽

Content Type ◽

Healthy Women ◽

Healthy Pregnancy ◽

Tof Ms

ABSTRACT Microbes and their metabolic products influence early-life immune and microbiome development, yet remain understudied during pregnancy. Vaginal microbial communities are typically dominated by one or a few well-adapted microbes which are able to survive in a narrow pH range and are adapted to live on host-derived carbon sources, likely sourced from glycogen and mucin present in the vaginal environment. We characterized the cervicovaginal microbiomes of 16 healthy women throughout the three trimesters of pregnancy. Additionally, we analyzed saliva and urine metabolomes using gas chromatography-time of flight mass spectrometry (GC-TOF MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) lipidomics approaches for samples from mothers and their infants through the first year of life. Amplicon sequencing revealed most women had either a simple community with one highly abundant species of Lactobacillus or a more diverse community characterized by a high abundance of Gardnerella, as has also been previously described in several independent cohorts. Integrating GC-TOF MS and lipidomics data with amplicon sequencing, we found metabolites that distinctly associate with particular communities. For example, cervicovaginal microbial communities dominated by Lactobacillus crispatus have high mannitol levels, which is unexpected given the characterization of L. crispatus as a homofermentative Lactobacillus species. It may be that fluctuations in which Lactobacillus dominate a particular vaginal microbiome are dictated by the availability of host sugars, such as fructose, which is the most likely substrate being converted to mannitol. Overall, using a multi-“omic” approach, we begin to address the genetic and molecular means by which a particular vaginal microbiome becomes vulnerable to large changes in composition. IMPORTANCE Humans have a unique vaginal microbiome compared to other mammals, characterized by low diversity and often dominated by Lactobacillus spp. Dramatic shifts in vaginal microbial communities sometimes contribute to the presence of a polymicrobial overgrowth condition called bacterial vaginosis (BV). However, many healthy women lacking BV symptoms have vaginal microbiomes dominated by microbes associated with BV, resulting in debate about the definition of a healthy vaginal microbiome. Despite substantial evidence that the reproductive health of a woman depends on the vaginal microbiota, future therapies that may improve reproductive health outcomes are stalled due to limited understanding surrounding the ecology of the vaginal microbiome. Here, we use sequencing and metabolomic techniques to show novel associations between vaginal microbes and metabolites during healthy pregnancy. We speculate these associations underlie microbiome dynamics and may contribute to a better understanding of transitions between alternative vaginal microbiome compositions.

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Impact of Substratum Surface on Microbial Community Structure and Treatment Performance in Biological Aerated Filters

Applied and Environmental Microbiology ◽

10.1128/aem.03001-13 ◽

2013 ◽

Vol 80 (1) ◽

pp. 177-183 ◽

Cited By ~ 10

Author(s):

Lavane Kim ◽

Eulyn Pagaling ◽

Yi Y. Zuo ◽

Tao Yan

Keyword(s):

Microbial Community ◽

Microbial Communities ◽

Bacterial Species ◽

Community Analysis ◽

Microbial Community Analysis ◽

Rrna Gene ◽

Content Type ◽

Property Change ◽

And Control ◽

Start Ups

ABSTRACTThe impact of substratum surface property change on biofilm community structure was investigated using laboratory biological aerated filter (BAF) reactors and molecular microbial community analysis. Two substratum surfaces that differed in surface properties were created via surface coating and used to develop biofilms in test (modified surface) and control (original surface) BAF reactors. Microbial community analysis by 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) showed that the surface property change consistently resulted in distinct profiles of microbial populations during replicate reactor start-ups. Pyrosequencing of the bar-coded 16S rRNA gene amplicons surveyed more than 90% of the microbial diversity in the microbial communities and identified 72 unique bacterial species within 19 bacterial orders. Among the 19 orders of bacteria detected,BurkholderialesandRhodocyclalesof theBetaproteobacteriaclass were numerically dominant and accounted for 90.5 to 97.4% of the sequence reads, and their relative abundances in the test and control BAF reactors were different in consistent patterns during the two reactor start-ups. Three of the five dominant bacterial species also showed consistent relative abundance changes between the test and control BAF reactors. The different biofilm microbial communities led to different treatment efficiencies, with consistently higher total organic carbon (TOC) removal in the test reactor than in the control reactor. Further understanding of how surface properties affect biofilm microbial communities and functional performance would enable the rational design of new generations of substrata for the improvement of biofilm-based biological treatment processes.

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Enzymatic Degradation of Phenazines Can Generate Energy and Protect Sensitive Organisms from Toxicity

mBio ◽

10.1128/mbio.01520-15 ◽

2015 ◽

Vol 6 (6) ◽

Cited By ~ 26

Author(s):

Kyle C. Costa ◽

Megan Bergkessel ◽

Scott Saunders ◽

Jonas Korlach ◽

Dianne K. Newman

Keyword(s):

Microbial Communities ◽

Pathogenic Fungi ◽

Cell Types ◽

Redox Activity ◽

Mycobacterium Fortuitum ◽

Active Metabolites ◽

Content Type ◽

Phenazine Production ◽

Physiological Benefits

ABSTRACTDiverse bacteria, including severalPseudomonasspecies, produce a class of redox-active metabolites called phenazines that impact different cell types in nature and disease. Phenazines can affect microbial communities in both positive and negative ways, where their presence is correlated with decreased species richness and diversity. However, little is known about how the concentration of phenazines is modulatedin situand what this may mean for the fitness of members of the community. Through culturing of phenazine-degrading mycobacteria, genome sequencing, comparative genomics, and molecular analysis, we identified several conserved genes that are important for the degradation of threePseudomonas-derived phenazines: phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), and pyocyanin (PYO). PCA can be used as the sole carbon source for growth by these organisms. Deletion of several genes inMycobacterium fortuitumabolishes the degradation phenotype, and expression of two genes in a heterologous host confers the ability to degrade PCN and PYO. In cocultures with phenazine producers, phenazine degraders alter the abundance of different phenazine types. Not only does degradation support mycobacterial catabolism, but also it provides protection to bacteria that would otherwise be inhibited by the toxicity of PYO. Collectively, these results serve as a reminder that microbial metabolites can be actively modified and degraded and that these turnover processes must be considered when the fate and impact of such compounds in any environment are being assessed.IMPORTANCEPhenazine production byPseudomonasspp. can shape microbial communities in a variety of environments ranging from the cystic fibrosis lung to the rhizosphere of dryland crops. For example, in the rhizosphere, phenazines can protect plants from infection by pathogenic fungi. The redox activity of phenazines underpins their antibiotic activity, as well as providing pseudomonads with important physiological benefits. Our discovery that soil mycobacteria can catabolize phenazines and thereby protect other organisms against phenazine toxicity suggests that phenazine degradation may influence turnoverin situ. The identification of genes involved in the degradation of phenazines opens the door to monitoring turnover in diverse environments, an essential process to consider when one is attempting to understand or control communities influenced by phenazines.

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Hepatotoxicity of methoxychlor and camel milk restoration

Nutrition & Food Science ◽

10.1108/nfs-12-2020-0469 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Eman E. Elsharkawy ◽

Neveen A. El-Nisr ◽

Nahed M. Wahba ◽

Walaa M. Elsherif

Keyword(s):

Liver Toxicity ◽

Portal Tract ◽

Liver Homogenate ◽

Protective Role ◽

Camel Milk ◽

Content Type ◽

Camel's Milk ◽

Serum Transaminases ◽

Restoration Effect

Purpose The purpose of this paper is to investigate the restoration effect of camel's milk against methoxychlor induced liver toxicity. Design/methodology/approach The present study was carried out to investigate the restoration effect of camel's milk against methoxychlor induced liver toxicity. Findings Methoxychlor (MXC) caused a significant increase in serum transaminases (aspartate transaminase and alanine transaminase) and alkaline phosphatase, while MXC induced a significant reduction in total protein and albumin levels. MXC significantly inhibited lipid peroxidation and markedly enhanced glutathione in liver homogenate. Pathological damages as degeneration and coagulative necrosis of hepatocytes were established in liver. Newly formed bile ducteules denotes neoplastic changes in the portal tract with abnormal mitotic pattern were associated with the long-term exposure. Originality/value The present study concluded that camel milk treatment may play a protective role against methoxychlor-induced liver damage in rats.

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From single-species advice to mixed-species management: taking the next step

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2004.08.018 ◽

2004 ◽

Vol 61 (8) ◽

pp. 1398-1409 ◽

Cited By ~ 45

Author(s):

Morten Vinther ◽

Stuart A. Reeves ◽

Kenneth R. Patterson

Keyword(s):

North Sea ◽

Fishery Management ◽

Single Species ◽

Mixed Species ◽

The North ◽

Recent Approach ◽

Starting Point ◽

The North Sea ◽

Management Advice ◽

Management Priorities

Abstract Fishery management advice has traditionally been given on a stock-by-stock basis. Recent problems in implementing this advice, particularly for the demersal fisheries of the North Sea, have highlighted the limitations of the approach. In the long term, it would be desirable to give advice that accounts for mixed-fishery effects, but in the short term there is a need for approaches to resolve the conflicting management advice for different species within the same fishery, and to generate catch or effort advice that accounts for the mixed-species nature of the fishery. This paper documents a recent approach used to address these problems. The approach takes the single-species advice for each species in the fishery as a starting point, then attempts to resolve it into consistent catch or effort advice using fleet-disaggregated catch forecasts in combination with explicitly stated management priorities for each stock. Results are presented for the groundfish fisheries of the North Sea, and these show that the development of such approaches will also require development of the ways in which catch data are collected and compiled.

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Population-Wide Survey of Salmonella enterica Response to High-Pressure Processing Reveals a Diversity of Responses and Tolerance Mechanisms

Applied and Environmental Microbiology ◽

10.1128/aem.01673-17 ◽

2017 ◽

Vol 84 (2) ◽

Cited By ~ 3

Author(s):

Sandeep Tamber

Keyword(s):

High Pressure ◽

Foodborne Pathogens ◽

Salmonella Enterica ◽

High Pressure Processing ◽

Food Preservation ◽

Iodide Uptake ◽

Membrane Fatty Acid Composition ◽

Content Type ◽

Pressure Resistance ◽

Treatment Sensitivity

ABSTRACTHigh-pressure processing is a nonthermal method of food preservation that uses pressure to inactivate microorganisms. To ensure the effective validation of process parameters, it is important that the design of challenge protocols consider the potential for resistance in a particular species. Herein, the responses of 99 diverseSalmonella entericastrains to high pressure are reported. Members of this population belonged to 24 serovars and were isolated from various Canadian sources over a period of 26 years. When cells were exposed to 600 MPa for 3 min, the average reduction in cell numbers for this population was 5.6 log10CFU/ml, with a range of 0.9 log10CFU/ml to 6 log10CFU/ml. Eleven strains, from 5 serovars, with variable levels of pressure resistance were selected for further study. The membrane characteristics (propidium iodide uptake during and after pressure treatment, sensitivity to membrane-active agents, and membrane fatty acid composition) and responses to stressors (heat, nutrient deprivation, desiccation, and acid) for this panel suggested potential roles for the cell membrane and the RpoS regulon in mediating pressure resistance inS. enterica. The data indicate heterogeneous and multifactorial responses to high pressure that cannot be predicted for individualS. entericastrains.IMPORTANCEThe responses of foodborne pathogens to increasingly popular minimal food decontamination methods are not understood and therefore are difficult to predict. This report shows that the responses ofSalmonella entericastrains to high-pressure processing are diverse. The magnitude of inactivation does not depend on how closely related the strains are or where they were isolated. Moreover, strains that are resistant to high pressure do not behave similarly to other stresses, suggesting that more than one mechanism might be responsible for resistance to high pressure and the mechanisms used may vary from one strain to another.

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Oral Spirochetes Implicated in Dental Diseases Are Widespread in Normal Human Subjects and Carry Extremely Diverse Integron Gene Cassettes

Applied and Environmental Microbiology ◽

10.1128/aem.00564-12 ◽

2012 ◽

Vol 78 (15) ◽

pp. 5288-5296 ◽

Cited By ~ 17

Author(s):

Yu-Wei Wu ◽

Mina Rho ◽

Thomas G. Doak ◽

Yuzhen Ye

Keyword(s):

Microbial Communities ◽

De Novo ◽

Human Subjects ◽

Human Microbiome ◽

Metagenomic Data ◽

De Bruijn Graph ◽

Content Type ◽

Gene Cassettes ◽

Dental Diseases ◽

Normal Human

ABSTRACTThe NIH Human Microbiome Project (HMP) has produced several hundred metagenomic data sets, allowing studies of the many functional elements in human-associated microbial communities. Here, we survey the distribution of oral spirochetes implicated in dental diseases in normal human individuals, using recombination sites associated with the chromosomal integron inTreponemagenomes, taking advantage of the multiple copies of the integron recombination sites (repeats) in the genomes, and using a targeted assembly approach that we have developed. We find that integron-containingTreponemaspecies are present in ∼80% of the normal human subjects included in the HMP. Further, we are able tode novoassemble the integron gene cassettes using our constrained assembly approach, which employs a unique application of the de Bruijn graph assembly information; most of these cassette genes were not assembled in whole-metagenome assemblies and could not be identified by mapping sequencing reads onto the known referenceTreponemagenomes due to the dynamic nature of integron gene cassettes. Our study significantly enriches the gene pool known to be carried byTreponemachromosomal integrons, totaling 826 (598 97% nonredundant) genes. We characterize the functions of these gene cassettes: many of these genes have unknown functions. The integron gene cassette arrays found in the human microbiome are extraordinarily dynamic, with different microbial communities sharing only a small number of common genes.

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Generation and Characterization of Indoor Fungal Aerosols for Inhalation Studies

Applied and Environmental Microbiology ◽

10.1128/aem.04063-15 ◽

2016 ◽

Vol 82 (8) ◽

pp. 2479-2493 ◽

Cited By ~ 18

Author(s):

Anne Mette Madsen ◽

Søren T. Larsen ◽

Ismo K. Koponen ◽

Kirsten I. Kling ◽

Afnan Barooni ◽

...

Keyword(s):

Species Composition ◽

Indoor Environment ◽

Building Materials ◽

Inhalation Exposure ◽

Single Species ◽

Fungal Species ◽

Exposure Level ◽

Exposure System ◽

Content Type ◽

Water Damage

ABSTRACTIn the indoor environment, people are exposed to several fungal species. Evident dampness is associated with increased respiratory symptoms. To examine the immune responses associated with fungal exposure, mice are often exposed to a single species grown on an agar medium. The aim of this study was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols containing 107CFU of fungi/m3air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols containedAspergillus nidulans,Aspergillus niger,Aspergillus ustus,Aspergillus versicolor,Chaetomium globosum,Cladosporiumherbarum,Penicillium brevicompactum,Penicillium camemberti,Penicillium chrysogenum,Penicillium commune,Penicillium glabrum,Penicillium olsonii,Penicillium rugulosum,Stachybotrys chartarum, andWallemia sebi. They were all among the most abundant airborne species identified in 28 homes. Nine species from gypsum boards and 11 species in the homes are associated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization of fungi from the indoor environment, cultured on gypsum boards, it was possible to generate realistic aerosols in terms of species composition, concentration, and particle sizes. The inhalation-exposure system can be used to study responses to indoor fungi associated with water damage and the importance of fungal species composition.

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