scholarly journals Role of Type IV Pilins in Persistence of Vibrio vulnificus in Crassostrea virginica Oysters

2007 ◽  
Vol 73 (15) ◽  
pp. 5041-5044 ◽  
Author(s):  
Rohinee N. Paranjpye ◽  
Asta B. Johnson ◽  
Anne E. Baxter ◽  
Mark S. Strom
Keyword(s):  
United States ◽  
Epithelial Cells ◽  
Crassostrea Virginica ◽  
Biofilm Formation ◽  
Vibrio Vulnificus ◽  
The United States ◽  
Type Iv ◽  
Abiotic Surfaces ◽  
Prepilin Peptidase

ABSTRACT Vibrio vulnificus is part of the natural estuarine microflora and accumulates in shellfish through filter feeding. It is responsible for the majority of seafood-associated fatalities in the United States mainly through consumption of raw oysters. Previously we have shown that a V. vulnificus mutant unable to express PilD, the type IV prepilin peptidase, does not express pili on the surface of the bacterium and is defective in adherence to human epithelial cells (R. N. Paranjpye, J. C. Lara, J. C. Pepe, C. M. Pepe, and M. S. Strom, Infect. Immun. 66:5659-5668, 1998). A mutant unable to express one of the type IV pilins, PilA, is also defective in adherence to epithelial cells as well as biofilm formation on abiotic surfaces (R. N. Paranjpye and M. S. Strom, Infect. Immun. 73:1411-1422, 2005). In this study we report that the loss of PilD or PilA significantly reduces the ability of V. vulnificus to persist in Crassostrea virginica over a 66-h interval, strongly suggesting that pili expressed by this bacterium play a role in colonization or persistence in oysters.

scholarly journals A Role of Epithelial Cells and Virulence Factors in Biofilm Formation by Streptococcus pyogenes In Vitro

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Feiruz Alamiri ◽  
Yashuan Chao ◽  
Maria Baumgarten ◽  
Kristian Riesbeck ◽  
Anders P. Hakansson
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Biofilm Formation ◽  
Model Systems ◽  
Respiratory Epithelial Cells ◽  
Abiotic Surfaces ◽  
Respiratory Epithelial

ABSTRACT Biofilm formation by Streptococcus pyogenes (group A streptococcus [GAS]) in model systems mimicking the respiratory tract is poorly documented. Most studies have been conducted on abiotic surfaces, which poorly represent human tissues. We have previously shown that GAS forms mature and antibiotic-resistant biofilms on physiologically relevant epithelial cells. However, the roles of the substratum, extracellular matrix (ECM) components, and GAS virulence factors in biofilm formation and structure are unclear. In this study, biofilm formation was measured on respiratory epithelial cells and keratinocytes by determining biomass and antibiotic resistance, and biofilm morphology was visualized using scanning electron microscopy. All GAS isolates tested formed biofilms that had similar, albeit not identical, biomass and antibiotic resistance for both cell types. Interestingly, functionally mature biofilms formed more rapidly on keratinocytes but were structurally denser and coated with more ECM on respiratory epithelial cells. The ECM was crucial for biofilm integrity, as protein- and DNA-degrading enzymes induced bacterial release from biofilms. Abiotic surfaces supported biofilm formation, but these biofilms were structurally less dense and organized. No major role for M protein, capsule, or streptolysin O was observed in biofilm formation on epithelial cells, although some morphological differences were detected. NAD-glycohydrolase was required for optimal biofilm formation, whereas streptolysin S and cysteine protease SpeB impaired this process. Finally, no correlation was found between cell adherence or autoaggregation and GAS biofilm formation. Combined, these results provide a better understanding of the role of biofilm formation in GAS pathogenesis and can potentially provide novel targets for future treatments against GAS infections.

The Role of Gender and Sensation Seeking in Film Choice

2008 ◽  
Vol 20 (3) ◽  
pp. 97-105 ◽  
Author(s):  
Smita C. Banerjee ◽  
Kathryn Greene ◽  
Marina Krcmar ◽  
Zhanna Bagdasarov ◽  
Dovile Ruginyte
Keyword(s):  
United States ◽  
Undergraduate Students ◽  
Sensation Seeking ◽  
Negative Mood ◽  
Positive Mood ◽  
The United States ◽  
High Arousal ◽  
Subject Design ◽  
Happy Mood

This study demonstrates the significance of individual difference factors, particularly gender and sensation seeking, in predicting media choice (examined through hypothetical descriptions of films that participants anticipated they would view). This study used a 2 (Positive mood/negative mood) × 2 (High arousal/low arousal) within-subject design with 544 undergraduate students recruited from a large northeastern university in the United States. Results showed that happy films and high arousal films were preferred over sad films and low-arousal films, respectively. In terms of gender differences, female viewers reported a greater preference than male viewers for happy-mood films. Also, male viewers reported a greater preference for high-arousal films compared to female viewers, and female viewers reported a greater preference for low-arousal films compared to male viewers. Finally, high sensation seekers reported a preference for high-arousal films. Implications for research design and importance of exploring media characteristics are discussed.

The link between coronavirus, anxiety, and religious beliefs in the United States and United Kingdom

2020 ◽  
Author(s):  
Francesco Rigoli
Keyword(s):  
United States ◽  
United Kingdom ◽  
Religious Beliefs ◽  
Well Being ◽  
The United States ◽  
Christian Faith ◽  
Stressful Event ◽  
Cultural Implications ◽  
The Impact

Research has shown that stress impacts on people’s religious beliefs. However, several aspects of this effect remain poorly understood, for example regarding the role of prior religiosity and stress-induced anxiety. This paper explores these aspects in the context of the recent coronavirus emergency. The latter has impacted dramatically on many people’s well-being; hence it can be considered a highly stressful event. Through online questionnaires administered to UK and USA citizens professing either Christian faith or no religion, this paper examines the impact of the coronavirus crisis upon common people’s religious beliefs. We found that, following the coronavirus emergency, strong believers reported higher confidence in their religious beliefs while non-believers reported increased scepticism towards religion. Moreover, for strong believers, higher anxiety elicited by the coronavirus threat was associated with increased strengthening of religious beliefs. Conversely, for non-believers, higher anxiety elicited by the coronavirus thereat was associated with increased scepticism towards religious beliefs. These observations are consistent with the notion that stress-induced anxiety enhances support for the ideology already embraced before a stressful event occurs. This study sheds light on the psychological and cultural implications of the coronavirus crisis, which represents one of the most serious health emergencies in recent times.

‘Does Law Matter to Anthropology?’

2018 ◽  
Vol 2 (2) ◽  
pp. 86-91
Author(s):  
Sally Engle Merry
Keyword(s):  
United States ◽  
The United States ◽  
Legal Anthropology ◽  
American Anthropological Association ◽  
Law Schools ◽  
Relevant Question ◽  
Law Faculty ◽  
Way Of Thinking ◽  
Legal Training

This provocative question became the basis for a spirited discussion at the 2017 meeting of the American Anthropological Association. My first reaction, on hearing the question, was to ask, does anthropology care whether it matters to law? As a discipline, anthropology and the anthropology of law are producing excellent scholarship and have an active scholarly life. But in response to this forum’s provocation article, which clearly outlines the lack of courses on law and anthropology in law schools, I decided that the relevant question was, why doesn’t anthropology matter more to law than it does? The particular, most serious concern appears to be, why are there not more law and anthropology courses being offered in law schools? It is increasingly common for law faculty in the United States to have PhDs as well as JDs, so why are there so few anthropology/law PhD/JD faculty? Moreover, as there is growing consensus that law schools instil a certain way of thinking but lack preparation for the practice of law in reality and there is an explosion of interest in clinical legal training, why does this educational turn fail to provide a new role of legal anthropology, which focuses on the practice of law, in clinical legal training?

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