Read by QxMD icon Read

persister cells in biofilm

Wendy Stone, Otini Kroukamp, Darren R Korber, Jennifer McKelvie, Gideon M Wolfaardt
The human environment is predominantly not aqueous, and microbes are ubiquitous at the surface-air interfaces with which we interact. Yet microbial studies at surface-air interfaces are largely survival-oriented, whilst microbial metabolism has overwhelmingly been investigated from the perspective of liquid saturation. This study explored microbial survival and metabolism under desiccation, particularly the influence of relative humidity (RH), surface hygroscopicity, and nutrient availability on the interchange between these two phenomena...
2016: Frontiers in Microbiology
Maren Seitz, Peter Valentin-Weigand, Jörg Willenborg
Use of antimicrobial agents in veterinary medicine is essential to control infectious diseases, thereby keeping animals healthy and animal products safe for the consumer. On the other hand, development and spread of antimicrobial resistance is of major concern for public health. Streptococcus (S.) suis reflects a typical bacterial pathogen in modern swine production due to its facultative pathogenic nature and wide spread in the pig population. Thus, in the present review we focus on certain current aspects and problems related to antimicrobial use and resistance in S...
October 15, 2016: Current Topics in Microbiology and Immunology
Chandradhish Ghosh, Mohini Mohan Konai, Paramita Sarkar, Sandip Samaddar, Jayanta Haldar
In the global effort to thwart antimicrobial resistance, lipopeptides are an important class of antimicrobial agents, especially against Gram-negative infections. In an attempt to circumvent their synthetic complexities, we designed simple membrane-active agents involving only one amino acid and two lipid tails. Herein we show that the use of two short lipid tails instead of a single long one significantly increases selective antibacterial activity. This study yielded several selective antibacterial compounds, and investigations into the properties of this compound class were conducted with the most active compound...
October 12, 2016: ChemMedChem
Anika C Jahns, Hinnerk Eilers, Oleg A Alexeyev
Propionibacterium acnes is a well-known commensal of the human skin connected to acne vulgaris and joint infections. It is extensively studied in planktonic cultures in the laboratory settings but occurs naturally in biofilms. In this study we have developed an in vitro biofilm model of P. acnes and studied growth features, matrix composition, matrix penetration by fluorescent-labeled antibiotics as well as gene expression. Antibiotic susceptibility of biofilms was studied and could be enhanced by increased glucose concentrations...
October 7, 2016: Anaerobe
Hechao Du, Maoda Pang, Yuhao Dong, Yafeng Wu, Nannan Wang, Jin Liu, Furqan Awan, Chengping Lu, Yongjie Liu
Bacterial biofilms are involved in adaptation to complex environments and are responsible for persistent bacterial infections. Biofilm formation is a highly complex process during which multifarious genes work together regularly. In this study, we screened the EZ-Tn5 transposon mutant library to identify genes involved in biofilm formation of Aeromonas hydrophila. A total of 24 biofilm-associated genes were identified, the majority of which encoded proteins related to cell structure, transcription and translation, gene regulation, growth and metabolism...
2016: Frontiers in Microbiology
Fanny Larsonneur, Fernando A Martin, Adeline Mallet, Marta Martinez-Gil, Vincent Semetey, Jean-Marc Ghigo, Christophe Beloin
Initial adhesion of bacterial cells to surfaces or host tissues is a key step in colonisation and biofilm formation processes, and is mediated by cell surface appendages. We previously demonstrated that Escherichia coli K-12 possesses an arsenal of silenced chaperone-usher fimbriae that are functional when constitutively expressed. Among them, production of prevalent Yad fimbriae induces adhesion to abiotic surfaces. We undertook functional characterisation of Yad fimbriae, and identified YadN as the most abundant and potential major pilin, and YadC as the potential tip-protein of Yad fimbriae...
October 3, 2016: Environmental Microbiology
Shivali Jindal, Sanjeev Anand, Kang Huang, Julie Goddard, Lloyd Metzger, Jayendra Amamcharla
The development of bacterial biofilms on stainless steel (SS) surfaces poses a great threat to the quality of milk and other dairy products as the biofilm-embedded bacteria can survive thermal processing. Established biofilms offer cleaning challenges because they are resistant to most of the regular cleaning protocols. Sporeforming thermoduric organisms entrapped within biofilm matrix can also form heat-resistant spores, and may result in a long-term persistent contamination. The main objective of this study was to evaluate the efficacy of different nonfouling coatings [AMC 18 (Advanced Materials Components Express, Lemont, PA), Dursan (SilcoTek Corporation, Bellefonte, PA), Ni-P-polytetrafluoroethylene (PTFE, Avtec Finishing Systems, New Hope, MN), and Lectrofluor 641 (General Magnaplate Corporation, Linden, NJ)] on SS plate heat exchanger surfaces, to resist the formation of bacterial biofilms...
September 28, 2016: Journal of Dairy Science
Jia Zhao, Paisa Seeluangsawat, Qi Wang
A multiphasic, hydrodynamic model for spatially heterogeneous biofilms based on the phase field formulation is developed and applied to analyze antimicrobial tolerance of biofilms by acknowledging the existence of persistent and susceptible cells in the total population of bacteria. The model implements a new conversion rate between persistent and susceptible cells and its homogeneous dynamics is bench-marked against a known experiment quantitatively. It is then discretized and solved on graphic processing units (GPUs) in 3-D space and time...
September 22, 2016: Mathematical Biosciences
Hyeri Son, Sunhyung Park, Larry R Beuchat, Hoikyung Kim, Jee-Hoon Ryu
The goal of this study was to develop a desiccation resistant antimicrobial surface using biofilm of competitive exclusion (CE) microorganism inhibitory to Staphylococcus aureus. We isolated 161 microorganisms from soils, foods, and food-contact surfaces that are inhibitory to S. aureus. Among them, three CE microorganisms (Streptomyces spororaveus strain Gaeunsan-18, Bacillus safensis strain Chamnamu-sup 5-25, and Pseudomonas azotoformans strain Lettuce-9) exhibiting strong antibacterial activity and high growth rates were selected for evaluation...
December 5, 2016: International Journal of Food Microbiology
Chirantana Sengupta, Oindrilla Mukherjee, Rukhsana Chowdhury
Vibrio cholerae, etiological agent of the disease cholera, is known to form biofilms for persistence in the environment. It is demonstrated here that even during infection, biofilm genes are upregulated and microscopic observation indicated that biofilm formation is initiated almost immediately after adherence of V. cholerae to intestinal cells. About 7 fold upregulation of the biofilm regulatory gene vpsT was observed within 30 minutes of adherence of V. cholerae to the intestinal cell line INT 407 and a massive induction of about 700 fold was observed in rabbit ileal loops...
September 16, 2016: Journal of Infectious Diseases
Wenzheng Liu, Henriette L Røder, Jonas S Madsen, Thomas Bjarnsholt, Søren J Sørensen, Mette Burmølle
Interspecies interactions are essential for the persistence and development of any kind of complex community, and microbial biofilms are no exception. Multispecies biofilms are structured and spatially defined communities that have received much attention due to their omnipresence in natural environments. Species residing in these complex bacterial communities usually interact both intra- and interspecifically. Such interactions are considered to not only be fundamental in shaping overall biomass and the spatial distribution of cells residing in multispecies biofilms, but also to result in coordinated regulation of gene expression in the different species present...
2016: Frontiers in Microbiology
Lindsay J Marshall, Wilson Oguejiofor, Robert Price, Jagdeep Shur
The airways of most people with cystic fibrosis are colonized with biofilms of the Gram-negative, opportunistic pathogen Pseudomonas aeruginosa. Delivery of antibiotics directly to the lung in the form of dry powder aerosols offers the potential to achieve high local concentrations directly to the biofilms. Unfortunately, current aerosolised antibiotic regimes are unable to efficiently eradicate these biofilms from the airways. We investigated the ability of the innate antimicrobial, lactoferrin, to enhance the activity of two aminoglycoside antibiotics (tobramycin and gentamicin) against biofilms of P...
September 11, 2016: International Journal of Pharmaceutics
Michael B Winter, Eugenia C Salcedo, Matthew B Lohse, Nairi Hartooni, Megha Gulati, Hiram Sanchez, Julie Takagi, Bernhard Hube, David R Andes, Alexander D Johnson, Charles S Craik, Clarissa J Nobile
UNLABELLED: Candida albicans is a fungal species that is part of the normal human microbiota and also an opportunistic pathogen capable of causing mucosal and systemic infections. C. albicans cells proliferate in a planktonic (suspension) state, but they also form biofilms, organized and tightly packed communities of cells attached to a solid surface. Biofilms colonize many niches of the human body and persist on implanted medical devices, where they are a major source of new C. albicans infections...
2016: MBio
Amy Huei Teen Teh, Sui Mae Lee, Gary A Dykes
Campylobacter jejuni is one of the most common causes of bacterial gastrointestinal food-borne infection worldwide. It has been suggested that biofilm formation may play a role in survival of these bacteria in the environment. In this study, the influence of prior modes of growth (planktonic or sessile), temperatures (37 and 42 °C), and nutrient conditions (nutrient broth and Mueller-Hinton broth) on biofilm formation by eight C. jejuni strains with different antibiotic resistance profiles was examined. The ability of these strains to form biofilm on different abiotic surfaces (stainless steel, glass, and polystyrene) as well as factors potentially associated with biofilm formation (bacterial surface hydrophobicity, auto-aggregation, and initial attachment) was also determined...
December 2016: Current Microbiology
Marina Berditsch, Hannah Lux, Oleg Babii, Sergii Afonin, Anne S Ulrich
An intrinsic clindamycin-resistant Enterococcus faecalis, the most common single species present in teeth after failed root canal therapy, often possesses acquired tetracycline resistance. In these cases, root canal infections are commonly treated with Ledermix(®) paste, which contains demeclocycline, or the new alternative endodontic paste Odontopaste, which contains clindamycin; however, these treatments are often ineffective. We studied the killing activity of the cyclic antimicrobial peptide gramicidin S (GS) against planktonic and biofilm cells of tetracycline-resistant clinical isolates of E...
September 7, 2016: Pharmaceuticals
Valeri V Mossine, James K Waters, Deborah L Chance, Thomas P Mawhinney
Persistent infections of biofilm forming bacteria, such as Pseudomonas aeruginosa, are common among human populations, due to the bacterial resistance to antibiotics and other adaptation strategies, including release of cytotoxic virulent factors such as pigment pyocyanin (PCN). Urinary tract infections harbor P. aeruginosa strains characterized by the highest PCN-producing capacity, yet no information is available on PCN cytotoxicity mechanism in kidney. We report here that renal tubular epithelial cell (RTEC) line NRK-52E responds to PCN treatments with paraptosis-like activity features...
September 9, 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
Yogesh D Walawalkar, Yatindra Vaidya, Vijayashree Nayak
Salmonella Typhi can chronically persist within the gallbladder of patients suffering from gallbladder diseases. This study, intended to improve our understanding of bacterial mechanisms underlying bile adaptation, revealed that bile, which is a bactericidal agent, led to the generation of reactive oxygen species in S Typhi. Salmonella Typhi in response showed a significant increase in the production of anti-oxidative enzymes, namely superoxide dismutase and catalase. The work reports that the quorum-sensing (QS) system of S Typhi regulates the level of these enzymes during oxidative stress...
November 2016: Pathogens and Disease
C Rumbo, J A Vallejo, M P Cabral, M Martínez-Guitián, A Pérez, A Beceiro, G Bou
OBJECTIVES: Biofilm formation and bacterial adherence are important requirements for persistence, multidrug resistance and infection. The d-amino acids play a role as modulators of bacterial growth and persistence, though their ability to inhibit biofilms is much debated. In this study, we analysed the effects of 18 different d-amino acids on the pathogens Acinetobacter baumannii and Pseudomonas aeruginosa. METHODS: In vitro assays were carried out to analyse the effect of d-amino acids on bacterial growth, biofilm formation/disassembly, capacity to attach to eukaryotic cells and cellular death...
September 7, 2016: Journal of Antimicrobial Chemotherapy
Maria P Conte, Marta Aleandri, Massimiliano Marazzato, Antonietta L Conte, Cecilia Ambrosi, Mauro Nicoletti, Carlo Zagaglia, Guido Gambara, Fioretta Palombi, Paola De Cesaris, Elio Ziparo, Anna T Palamara, Anna Riccioli, Catia Longhi
Adherent/invasive Escherichia coli (AIEC) strains are recently receiving increased attention because they are more prevalent and persistent in the intestine of Crohn (CD) patients than in healthy subjects. Since AIEC strains show a high percentage of similarity with ExPEC NMEC and UPEC, here we compared AIEC strain LF82 with a UPEC isolate (strain EC73) to assess whether LF82 could be able to infect prostate cells, as an extra-intestinal target. The virulence phenotypes of both strains were determined by using the RWPE-1 prostate cell line...
September 6, 2016: Infection and Immunity
Fernando Gil, Daniel Paredes-Sabja
Alternative antimicrobial therapies based on acyldepsipeptides may hold promising results, based on the fact that they have shown to efficiently eradicate persister cells, stationary cells and cell in biofilm structures of several pathogenic bacteria from the infected host. Clostridium difficile infection is considered the result of extensive hospital use of expanded-spectrum antibiotics, which cause dysbiosis of the intestinal microbiota, enhancing susceptibility to infection and persistence. Considering the urgent need for the development of novel and efficient antimicrobial strategies against C...
September 2016: Future Microbiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"