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persister cells in biofilm

Francesco Strati, Antonio Calabrò, Claudio Donati, Claudio De Felice, Joussef Hayek, Olivier Jousson, Silvia Leoncini, Daniela Renzi, Lisa Rizzetto, Carlotta De Filippo, Duccio Cavalieri
BACKGROUND: Rett syndrome (RTT) is a neurological disorder mainly caused by mutations in MeCP2 gene. It has been shown that MeCP2 impairments can lead to cytokine dysregulation due to MeCP2 regulatory role in T-helper and T-reg mediated responses, thus contributing to the pro-inflammatory status associated with RTT. Furthermore, RTT subjects suffer from an intestinal dysbiosis characterized by an abnormal expansion of the Candida population, a known factor responsible for the hyper-activation of pro-inflammatory immune responses...
May 2, 2018: BMC Gastroenterology
Juan F González, Mark M Hahn, John S Gunn
Many of the deadliest bacterial diseases that plague humanity in the modern age are caused by bacterial biofilms that produce chronic infections. However, most of our knowledge of the host immune response comes from the study of planktonic pathogens. While there are similarities in the host response to planktonic and biofilm bacteria, specific immune responses toward biofilms have not been well studied; the only apparent difference is the inability to clear the bacteria allowing the biofilm infection to become chronic...
April 1, 2018: Pathogens and Disease
Yan-Hua Li, Yong-Hui Zhou, Yong-Zhi Ren, Chang-Geng Xu, Xin Liu, Bing Liu, Jian-Qing Chen, Wen-Ya Ding, Yu-Lin Zhao, Yan-Bei Yang, Shuai Wang, Di Liu
Streptococcus suis is difficult to treat and responsible for various infections in humans and pigs. It can also form biofilms and induce persistent infections. Rhizoma Coptidis is a medicinal plant widely used in Traditional Chinese Medicine. Although the inhibitory effects of Rhizoma Coptidis on biofilm formation have been investigated in several studies, the ability of Rhizoma Coptidis to inhibit S. suis biofilm formation and the underlying mechanisms have not yet been reported. In this study, we showed that sub-minimal inhibitory concentrations (25 and 50 μg mL-1 ) of water extracts of Rhizoma Coptidis ( Coptis deltoidea C...
2018: Frontiers in Pharmacology
Amreesh Parvez, Samir Giri, Gorkha Raj Giri, Monika Kumari, Renu Bisht, Priti Saxena
Mycobacterial pathogenesis is hallmarked by lipidic polyketides that decorate the cell envelope and mediate infection. However, factors mediating persistence remain largely unknown. Dynamic cell wall remodeling could facilitate the different pathogenic phases. Recent studies have implicated type III polyketide synthases (PKSs) in cell wall alterations in several bacteria. Comparative genome analysis revealed several type III pks gene clusters in mycobacteria. In this study, we report the functional characterization of two novel type III PKSs, MMAR_2470 and MMAR_2474, in Mycobacterium marinum...
April 25, 2018: Scientific Reports
Melissa K LeTourneau, Matthew J Marshall, John B Cliff, Robert F Bonsall, Alice C Dohnalkova, Dmitri V Mavrodi, S Indira Devi, Olga V Mavrodi, James B Harsh, David M Weller, Linda S Thomashow
Phenazine-1-carboxylic acid (PCA) is produced by rhizobacteria in dryland but not in irrigated wheat fields of the Pacific Northwest, USA. PCA promotes biofilm development in bacterial cultures and bacterial colonization of wheat rhizospheres. However, its impact upon biofilm development has not been demonstrated in the rhizosphere, where biofilms influence terrestrial carbon and nitrogen cycles with ramifications for crop and soil health. Furthermore, the relationships between soil moisture and the rates of PCA biosynthesis and degradation have not been established...
April 24, 2018: Environmental Microbiology
Annamarija Raic, Sophie Riedel, Elena Kemmling, Karen Bieback, Joerg Overhage, Cornelia Lee-Thedieck
In this work, we define the requirements for a human-based osteomyelitis model which overcomes the limitations of state of the art animal models. Osteomyelitis is a severe and difficult to treat infection of the bone that develops rapidly, making it difficult to study in humans. We have developed a 3D in vitro model of the bone marrow, comprising a macroporous material, human hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). Inclusion of biofilms grown on an implant into the model system allowed us to study the effects of postoperative osteomyelitis-inducing bacteria on the bone marrow...
April 18, 2018: Acta Biomaterialia
Sergey Chernysh, Natalia Gordya, Dmitry Tulin, Andrey Yakovlev
Purpose: The aim of this study is to improve the anti-biofilm activity of antibiotics. We hypothesized that the antimicrobial peptide (AMP) complex of the host's immune system can be used for this purpose and examined the assumption on model biofilms. Methods: FLIP7, the AMP complex of the blowfly Calliphora vicina containing a combination of defensins, cecropins, diptericins and proline-rich peptides was isolated from the hemolymph of bacteria-challenged maggots...
2018: Infection and Drug Resistance
Xiao-Lin Tian, Hasan Salim, Gaofeng Dong, Madison Parcells, Yung-Hua Li
PURPOSE: Streptococcus mutans is a primary cariogenic pathogen worldwide. In dental biofilms, S. mutans often faces life-threatening insults, such as killing by antimicrobial compounds from competing species and from the host. How such insults affect the physiology and virulence of S. mutans is poorly understood. In this study, we explored this question by investigating the responses of S. mutans strains to several host defence peptides and bacitracin. METHODOLOGY: S...
April 19, 2018: Journal of Medical Microbiology
Tricia A Van Laar, Saika Esani, Tyler J Birges, Bethany Hazen, Jason M Thomas, Mamta Rawat
Pseudomonas aeruginosa is a ubiquitous Gram-negative bacterium that can cause severe opportunistic infections. The principal redox buffer employed by this organism is glutathione (GSH). To assess the role of GSH in the virulence of P. aeruginosa , a number of analyses were performed using a mutant strain deficient in gshA , which does not produce GSH. The mutant strain exhibited a growth delay in minimal medium compared to the wild-type strain. Furthermore, the gshA mutant was defective in biofilm and persister cell formation and in swimming and swarming motility and produced reduced levels of pyocyanin, a key virulence factor...
April 25, 2018: MSphere
Marzia Sultana, Suraia Nusrin, Nur A Hasan, Abdus Sadique, Kabir U Ahmed, Atiqul Islam, Anwar Hossain, Ira Longini, Azhar Nizam, Anwar Huq, Abul K Siddique, David A Sack, Richard B Sack, Rita R Colwell, Munirul Alam
Vibrio cholerae , an estuarine bacterium, is the causative agent of cholera, a severe diarrheal disease that demonstrates seasonal incidence in Bangladesh. In an extensive study of V. cholerae occurrence in a natural aquatic environment, water and plankton samples were collected biweekly between December 2005 and November 2006 from Mathbaria, an estuarine village of Bangladesh near the mangrove forests of the Sundarbans. Toxigenic V. cholerae exhibited two seasonal growth peaks, one in spring (March to May) and another in autumn (September to November), corresponding to the two annual seasonal outbreaks of cholera in this region...
April 17, 2018: MBio
Michael M Maiden, Alessandra M Agostinho Hunt, Mitchell P Zachos, Jacob A Gibson, Martin E Hurwitz, Martha H Mulks, Christopher M Waters
One of the most important clinical obstacles in cystic fibrosis (CF) is antibiotic treatment failure due to biofilms produced by Pseudomonas aeruginosa The ability of this pathogen to survive eradication by tobramycin and pathoadapt into a hyper-biofilm state leading to chronic infections is key to its success. Retrospective studies have demonstrated that preventing this pathoadaptation by improving eradication is essential to extend the lives of CF patients. To identify adjuvants that enhance tobramycin eradication of P...
April 16, 2018: Antimicrobial Agents and Chemotherapy
Laura Di Sante, Armanda Pugnaloni, Francesca Biavasco, Eleonora Giovanetti, Carla Vignaroli
The multicellular behavior designated "red dry and rough" (rdar) morphotype-characterized by production of extracellular matrix mainly comprising curli fimbriae and cellulose-is a potential survival strategy of Escherichia coli outside the host. This study documents the ability of Escherichia cryptic clades, which have recently been recognized as new lineages genetically divergent from E. coli, to grow in unfavorable conditions through expression of distinct phenotypes. Growth under low-temperature and nutrient-poor conditions induced the rdar morphotype in all cryptic clade strains tested, especially after preincubation in broth supplemented with uracil...
May 2018: Microbiological Research
Jin-Hyung Lee, Yong-Guy Kim, Jintae Lee
Pseudomonas aeruginosa biofilms are problematic and play a critical role in the persistence of chronic infections because of their ability to tolerate antimicrobial agents. In this study, various cell-wall degrading enzymes were investigated for their ability to inhibit biofilm formation of two P. aeruginosa strains, PAO1 and PA14. Xylanase markedly inhibited and detached P. aeruginosa biofilms without affecting planktonic growth. Xylanase treatment broke down extracellular polymeric substances and decreased the viscosity of P...
April 4, 2018: Biofouling
Sarah Shabayek, Barbara Spellerberg
Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of serious neonatal infections. GBS is an opportunistic commensal constituting a part of the intestinal and vaginal physiologic flora and maternal colonization is the principal route of GBS transmission. GBS is a pathobiont that converts from the asymptomatic mucosal carriage state to a major bacterial pathogen causing severe invasive infections. At present, as many as 10 serotypes (Ia, Ib, and II-IX) are recognized. The aim of the current review is to shed new light on the latest epidemiological data and clonal distribution of GBS in addition to discussing the most important colonization determinants at a molecular level...
2018: Frontiers in Microbiology
Jacek Dutkiewicz, Violetta Zając, Jacek Sroka, Bernard Wasiński, Ewa Cisak, Anna Sawczyn, Anna Kloc, Angelina Wójcik-Fatla
<i>Streptococcus suis</i> is a re-emerging zoonotic pathogen that may cause severe disease, mostly meningitis, in pigs and in humans having occupational contact with pigs and pork, such as farmers, slaughterhose workers and butchers. The first stage of the pathogenic process, similar in pigs and humans, is adherence to and colonisation of mucosal and/or epithelial surface(s) of the host. The second stage is invasion into deeper tissue and extracellular translocation of bacterium in the bloodstream, either free in circulation or attached to the surface of monocytes...
March 14, 2018: Annals of Agricultural and Environmental Medicine: AAEM
Gabriel Carvalho, Damien Balestrino, Christiane Forestier, Jean-Denis Mathias
Persisters form sub-populations of stress-tolerant cells that play a major role in the capacity of biofilms to survive and recover from disturbances such as antibiotic treatments. The mechanisms of persistence are diverse and influenced by environmental conditions, and persister populations are more heterogeneous than formerly suspected. We used computational modeling to assess the impact of three switching strategies between susceptible and persister cells on the capacity of bacterial biofilms to grow, survive and recover from antibiotic treatments...
2018: NPJ Biofilms and Microbiomes
Calvin K Lee, Jaime de Anda, Amy E Baker, Rachel R Bennett, Yun Luo, Ernest Y Lee, Joshua A Keefe, Joshua S Helali, Jie Ma, Kun Zhao, Ramin Golestanian, George A O'Toole, Gerard C L Wong
Using multigenerational, single-cell tracking we explore the earliest events of biofilm formation by Pseudomonas aeruginosa During initial stages of surface engagement (≤20 h), the surface cell population of this microbe comprises overwhelmingly cells that attach poorly (∼95% stay <30 s, well below the ∼1-h division time) with little increase in surface population. If we harvest cells previously exposed to a surface and direct them to a virgin surface, we find that these surface-exposed cells and their descendants attach strongly and then rapidly increase the surface cell population...
March 20, 2018: Proceedings of the National Academy of Sciences of the United States of America
Shengli Chen, Huafang Hao, Ping Zhao, Wenheng Ji, Mingxia Li, Yongsheng Liu, Yuefeng Chu
Mycoplasma bovis is a major bovine pathogen that causes considerable economic losses in the cattle industry worldwide. Moreover, M. bovis biofilm can persist in the environment and its host. To date, M. bovis biofilm antigens recognized by bovine convalescent sera and their comparison with planktonic cells have not yet been explored. This study utilized an immunoproteomic approach using two-dimensional electrophoresis, immunoblotting using convalescent bovine serum, and subsequent matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) to identify the immunoreactive proteins expressed in biofilm- and planktonic-grown M...
2018: Frontiers in Microbiology
Lara Thieme, Mareike Klinger-Strobel, Anita Hartung, Claudia Stein, Oliwia Makarewicz, Mathias W Pletz
Background: Enterococci frequently cause severe biofilm-associated infections such as endocarditis. The combination of ampicillin/ceftriaxone has recently been clinically evaluated as non-inferior compared with the standard therapy of ampicillin/gentamicin for treatment of Enterococcus faecalis endocarditis. Ceftaroline is a novel cephalosporin with enhanced activity against Gram-positive bacteria. Objectives: To compare the in vitro effectiveness of the ceftaroline/ampicillin combination with those of gentamicin/ampicillin and ceftriaxone/ampicillin in planktonic and biofilm cultures of clinical E...
February 28, 2018: Journal of Antimicrobial Chemotherapy
Alison Parnham, Chrissie Bousfield
Chronicity in wound healing is a challenge for health services financially and scientifically, with negative consequences on patients' lives. This paper seeks to explore why chronic wounds fail to heal in relation to the inflammatory cellular dysfunction associated with biofilm development. Findings demonstrate an association between chronic wounds failing to heal, the presence of devitalised tissue and abnormal immune cell activity with a consequential excessive release of harmful matrix metalloproteases (MMPs)...
March 2, 2018: British Journal of Community Nursing
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