Scholarly Work - Center for Biofilm Engineering
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/9335
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Item Noninflammatory comedones have greater diversity in microbiome and are more prone to biofilm formation than inflammatory lesions of acne vulgaris(Wiley, 2020-12) Loss, Manisha; Thompson, Katherine G.; Agostinho‐Hunt, Alessandra; James, Garth A.; Mongodin, Emmanuel F.; Rosenthal, Ian; Cheng, Nancy; Leung, Sherry; Chien, Anna L.; Kang, SewonBackground: The ability of C. acnes strains to form biofilms has been correlated with their virulence. Objective: This study examined biofilm and skin microbiota in acne patients in order to understand their role in the development of acne lesions. Methods: Thin sections of punch biopsy specimens of (1) uninflamed comedones, (2) inflammatory lesions, and (3) uninvolved adjacent skin of acne patients were examined. Epiflourescence and confocal laser scanning microscopy were used for biofilm detection, and pyrosequencing with taxonomic classification of 16s rRNA gene amplicons was used for microbiota analysis. Results: Of the 39 skin specimens from patients with mild-moderate acne (n=13) that were studied, 9 (23%) contained biofilm. Among these specimens, biofilm was most frequently detected in comedones (55.6%) and less frequently in inflammatory papules (22.2%) and uninvolved skin (22.2%). Comedones demonstrated the highest mean alpha diversity of all the lesion subtypes. The relative abundance of Staphylococcus was significantly higher in comedones (11.400% ±12.242%) compared to uninvolved skin (0.073% ±0.185%, p=0.024). Conclusions: The microenvironment of the comedone differs from that of inflammatory lesions and unaffected skin. The increased frequency of biofilm in comedones may account for the lack of host inflammatory response to these lesions.Item Answer Set Programming for Computing Constraints-Based Elementary Flux Modes: Application to Escherichia coli Core Metabolism(MDPI AG, 2020-12) Mahout, Maxime; Carlson, Ross P.; Peres, SabineElementary Flux Modes (EFMs) provide a rigorous basis to systematically characterize the steady state, cellular phenotypes, as well as metabolic network robustness and fragility. However, the number of EFMs typically grows exponentially with the size of the metabolic network, leading to excessive computational demands, and unfortunately, a large fraction of these EFMs are not biologically feasible due to system constraints. This combinatorial explosion often prevents the complete analysis of genome-scale metabolic models. Traditionally, EFMs are computed by the double description method, an efficient algorithm based on matrix calculation; however, only a few constraints can be integrated into this computation. They must be monotonic with regard to the set inclusion of the supports; otherwise, they must be treated in post-processing and thus do not save computational time. We present aspefm, a hybrid computational tool based on Answer Set Programming (ASP) and Linear Programming (LP) that permits the computation of EFMs while implementing many different types of constraints. We apply our methodology to the Escherichia coli core model, which contains 226×106 EFMs. In considering transcriptional and environmental regulation, thermodynamic constraints, and resource usage considerations, the solution space is reduced to 1118 EFMs that can be computed directly with aspefm. The solution set, for E. coli growth on O2 gradients spanning fully aerobic to anaerobic, can be further reduced to four optimal EFMs using post-processing and Pareto front analysis.Item Community-led, integrated, reproducible multi-omics with anvi’o(Springer Science and Business Media LLC, 2020-12) Eren, A. Murat; Kiefl, Evan; Shaiber, Alon; Veseli, Iva; Miller, Samuel E.; Schechter, Matthew S.; Fink, Isaac; Pan, Jessica N.; Yousef, Mahmoud; Fogarty, Emily C.; Trigodet, Florian; Watson, Andrea R.; Esen, Ozcan C.; Moore, Ryan M.; Clayssen, Quentin; Lee, Michael D.; Kivenson, Veronika; Graham, Elaina D.; Merrill, Bryan D.; Karkman, Antti; Blankenberg, Daniel; Eppley, John M.; Sjodin, Andreas; Scott, Jarrod J.; Vazquez-Campos, Xabier; McKay, Luke J.; McDaniel, Elizabeth A.; Stevens, Sarah L.R.; Anderson, Rika E.; Fuessel, Jessika; Fernandez-Guerra, Antonio; Maignien, Lois; Delmont, Tom O.; Willis, Amy D.Big data abound in microbiology, but the workflows designed to enable researchers to interpret data can constrain the biological questions that can be asked. Five years after anvi’o was first published, this community-led multi-omics platform is maturing into an open software ecosystem that reduces constraints in ‘omics data analyses.Item Role of hibernation promoting factor in ribosomal protein stability during Pseudomonas aeruginosa dormancy(MDPI, 2020-12) Theng, Sokuntheary; Williamson, Kerry S.; Franklin, Michael J.Pseudomonas aeruginosa is an opportunistic pathogen that causes biofilm-associated infections. P. aeruginosa can survive in a dormant state with reduced metabolic activity in nutrient-limited environments, including the interiors of biofilms. When entering dormancy, the bacteria undergo metabolic remodeling, which includes reduced translation and degradation of cellular proteins. However, a supply of essential macromolecules, such as ribosomes, are protected from degradation during dormancy. The small ribosome-binding proteins, hibernation promoting factor (HPF) and ribosome modulation factor (RMF), inhibit translation by inducing formation of inactive 70S and 100S ribosome monomers and dimers. The inactivated ribosomes are protected from the initial steps in ribosome degradation, including endonuclease cleavage of the ribosomal RNA (rRNA). Here, we characterized the role of HPF in ribosomal protein (rProtein) stability and degradation during P. aeruginosa nutrient limitation. We determined the effect of the physiological status of P. aeruginosa prior to starvation on its ability to recover from starvation, and on its rRNA and rProtein stability during cell starvation. The results show that the wild-type strain and a stringent response mutant (∆relA∆spoT strain) maintain high cellular abundances of the rProteins L5 and S13 over the course of eight days of starvation. In contrast, the abundances of L5 and S13 reduce in the ∆hpf mutant cells. The loss of rProteins in the ∆hpf strain is dependent on the physiology of the cells prior to starvation. The greatest rProtein loss occurs when cells are first cultured to stationary phase prior to starvation, with less rProtein loss in the ∆hpf cells that are first cultured to exponential phase or in balanced minimal medium. Regardless of the pre-growth conditions, P. aeruginosa recovery from starvation and the integrity of its rRNA are impaired in the absence of HPF. The results indicate that protein remodeling during P. aeruginosa starvation includes the degradation of rProteins, and that HPF is essential to prevent rProtein loss in starved P. aeruginosa. The results also indicate that HPF is produced throughout cell growth, and that regardless of the cellular physiological status, HPF is required to protect against ribosome loss when the cells subsequently enter starvation phase.Item Change Rippling through Our Waters and Culture(Wiley, 2020-04) Martin, Christine; Doyle, John; LaFrance, JoRee; Lefthand, Myra J.; Young, Sara L.; Three Irons, Emery; Eggers, Margaret J.It is well established that climate change is already causing a wide variety of human health impacts in the United States and globally, and that for many reasons Native Americans are particularly vulnerable. Tribal water security is particularly threatened; the ways in which climate changes are damaging community health and well-being through impacts on water resources have been addressed more thoroughly for Tribes in coastal, arid, and sub-arctic/arctic regions of the United States. In this article, Crow Tribal members from the Northern Plains describe the impacts of climate and environmental change on local water resources and ecosystems, and thereby on Tribal community health and well-being. Formal, qualitative research methodology was employed drawing on interviews with 26 Crow Tribal Elders. Multiple determinants of health are addressed, including cultural, social, economic, and environmental factors. The sense of environmental-cultural-health loss and despair at the inability to address the root causes of climate change are widespread. Yet the co-authors and many other Tribal members are actively prioritizing, addressing, and coping with some of the local impacts of these changes, and are carrying on Apsáalooke [Crow] lifeways and values.Item The use of a CDC biofilm reactor to grow multi-strain Listeria monocytogenes biofilm(Elsevier BV, 2020-12) Mendez, Ellen; Walker, Diane K.; Vipham, Jessie; Trinetta, ValentinaListeria monocytogenes is one of the most concerning pathogens for the food industry due to its ability to form biofilms, particularly in difficult-to-clean sites of processing facilities. There is a current industry-wide lack of data to refer to when selecting a strategy to control L. monocytogenes biofilms in the food premises. Many strategies have been developed to study biofilm formation of bacteria; however, few have targeted L. monocytogenes biofilms under dynamic conditions. This study addresses the biofilm formation ability of L. monocytogenes on stainless steel and polycarbonate under dynamic conditions using TSBYE or BHI as media culture at 30 °C or 37 °C. Higher cell counts were recovered at 30 °C in TSBYE on polycarbonate while lower counts were obtained at 37 °C in BHI on stainless steel (P < 0.05). Nonetheless, all factors (temperature, media and material) were statistically significant (P < 0.05) and an interaction between temperature and media was observed (P < 0.05). To our knowledge, this work represents an initial framework to develop L. monocytogenes biofilms under different dynamic conditions. The use of CDC Biofilm Reactor is not widely used yet in the food industry and represent a novel approach to help sanitary control strategies implementation.Item Next-generation physiology approaches to study microbiome function at single cell level(Springer Science and Business Media LLC, 2020-02) Hatzenpichler, Roland; Krukenberg, Viola; Lange Spietz, Rachel K.; Jay, Zackary J.The function of cells in their native habitat often cannot be reliably predicted from genomic data or from physiology studies of isolates. Traditional experimental approaches to study the function of taxonomically and metabolically diverse microbiomes are limited by their destructive nature, low spatial resolution or low throughput. Recently developed technologies can offer new insights into cellular function in natural and human-made systems and how microorganisms interact with and shape the environments that they inhabit. In this Review, we provide an overview of these next-generation physiology approaches and discuss how the non-destructive analysis of cellular phenotypes, in combination with the separation of the target cells for downstream analyses, provide powerful new, complementary ways to study microbiome function. We anticipate that the widespread application of next-generation physiology approaches will transform the field of microbial ecology and dramatically improve our understanding of how microorganisms function in their native environment.Item Streptococcus mutans and actinomyces naeslundii interaction in dual-species biofilm(MDPI AG, 2020-01) de Oliveira, Rosa Virginia Dutra; Bonafé, Fernanda Salloume Sampaio; Spolidorio, Denise Madalena Palomari; Koga-Ito, Cristiane Yumi; de Farias, Aline Leite; Kirker, Kelly R.; James, Garth A.; Brighenti, Fernanda LourençãoThe study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim of this study was to characterize—with an emphasis on biofilm formation and composition and metabolic activity—single- and dual-species biofilms of S. mutans or A. naeslundii, and to use a drip flow reactor (DFR) to evaluate biofilm stress responses to 0.2% chlorhexidine diacetate (CHX). Single- and dual-species biofilms were grown for 24 h. The following factors were evaluated: cell viability, biomass and total proteins in the extracellular matrix, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide—“XTT”—reduction and lactic acid production. To evaluate stress response, biofilms were grown in DFR. Biofilms were treated with CHX or 0.9% sodium chloride (NaCl; control). Biofilms were plated for viability assessment. Confocal laser-scanning microscopy (CLSM) was also performed. Data analysis was carried out at 5% significance level. S. mutans viability and lactic acid production in dual-species biofilms were significantly reduced. S. mutans showed a higher resistance to CHX in dual-species biofilms. Total protein content, biomass and XTT reduction showed no significant di erences between singleand dual-species biofilms. CLSM images showed the formation of large clusters in dual-species biofilms. In conclusion, dual-species biofilms reduced S. mutans viability and lactic acid production and increased S. mutans’ resistance to chlorhexidine.Item The establishment of the CBE launched biofilms as a field of specialized research(The establishment of the CBE launched biofilms as a field of specialized research, 2020-12) Fields, Matthew W.; Sturman, Paul; Anderson, SkipThe Center for Biofilm Engineering was the first center of excellence focused on biofilms and was originally funded through the Engineering Research Center Program from the U.S. National Science Foundation. After almost 30 years, biofilm continues to be a stand-alone scientific topic of inquiry that has broad implications for fundamental and applied science and engineering of bio-systems. However, much remains to be done, not only for research discovery but also education and outreach, to increase and grow the biofilm paradigm as well as our understanding of the microbial world.Item Sulfenate Esters of Simple Phenols Exhibit Enhanced Activity against Biofilms(American Chemical Society, 2020-03) Walsh, Danica J.; Livinghouse, Tom; Durling, Greg M.; Chase-Bayless, Yenny; Arnold, Adrienne D.; Stewart, Philip S.The recalcitrance exhibited by microbial biofilms to conventional disinfectants has motivated the development of new chemical strategies to control and eradicate biofilms. The activities of several small phenolic compounds and their trichloromethylsulfenyl ester derivatives were evaluated against planktonic cells and mature biofilms of Staphylococcus epidermidis and Pseudomonas aeruginosa. Some of the phenolic parent compounds are well-studied constituents of plant essential oils, for example, eugenol, menthol, carvacrol, and thymol. The potency of sulfenate ester derivatives was markedly and consistently increased toward both planktonic cells and biofilms. The mean fold difference between the parent and derivative minimum inhibitory concentration against planktonic cells was 44 for S. epidermidis and 16 for P. aeruginosa. The mean fold difference between the parent and derivative biofilm eradication concentration for 22 tested compounds against both S. epidermidis and P. aeruginosa was 3. This work demonstrates the possibilities of a new class of biofilm-targeting disinfectants deploying a sulfenate ester functional group to increase the antimicrobial potency toward microorganisms in biofilms.