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level of biofilm formation

Maria T Brock, Galya C Fedderly, Grace I Borlee, Michael M Russell, Liliana K Filipowska, Doreene R Hyatt, Ryan A Ferris, Bradley R Borlee
Overuse of antibiotics is contributing to an emerging antimicrobial resistance crisis. To better understand how bacteria adapt tolerance and resist antibiotic treatment, Pseudomonas aeruginosa isolates obtained from infection sites sampled from companion animals were collected and evaluated for phenotypic differences. Selected pairs of clonal isolates were obtained from individual infection samples and were assessed for antibiotic susceptibility, cyclic di-GMP levels, biofilm production, motility and genetic-relatedness...
October 16, 2017: Microbiology
Renan Marrichi Mauch, Peter Østrup Jensen, Claus Moser, Carlos Emilio Levy, Niels Høiby
P. aeruginosa chronic lung infection is the major cause of morbidity and mortality in patients with cystic fibrosis (CF), and is characterized by a biofilm mode of growth, increased levels of specific IgG antibodies and immune complex formation. However, despite being designed to combat this infection, such elevated humoral response is not associated with clinical improvement, pointing to a lack of anti-pseudomonas effectiveness. The mode of action of specific antibodies, as well as their structural features, and even the background involving B-cell production, stimulation and differentiation into antibody-producing cells in the CF airways are poorly understood...
October 12, 2017: Journal of Cystic Fibrosis: Official Journal of the European Cystic Fibrosis Society
Cameron Parsons, Ben Costolo, Phillip Brown, Sophia Kathariou
Listeria monocytogenes raises major food safety and public health concerns due its potential for severe foodborne disease and persistent colonization of food processing facilities. Copper is often employed to control pathogens in agriculture and is increasingly used in healthcare facilities, but mechanisms mediating tolerance of L. monocytogenes to copper remain poorly understood. A mariner-based mutant library of L. monocytogenes 2011L-2858, implicated in the 2011 listeriosis outbreak via whole cantaloupe, was screened for growth at sublethal levels of copper yielding mutant G2B4 with decreased copper tolerance...
October 4, 2017: FEMS Microbiology Letters
Qinfeng Ding, Kai Soo Tan
Aggregatibacter actinomycetemcomitans is the primary etiological agent of aggressive periodontal disease. Identification of novel virulence factors at the genome-wide level is hindered by lack of efficient genetic tools to perform mutagenesis in this organism. The Himar1 mariner transposon is known to yield a random distribution of insertions in an organism's genome with requirement for only a TA dinucleotide target and is independent of host-specific factors. However, the utility of this system in A. actinomycetemcomitans is unknown...
2017: Frontiers in Microbiology
Olga Sarenko, Gisela Klauck, Franziska M Wilke, Vanessa Pfiffer, Anja M Richter, Susanne Herbst, Volkhard Kaever, Regine Hengge
The bacterial second messenger bis-(3'-5')-cyclic diguanosine monophosphate (c-di-GMP) ubiquitously promotes bacterial biofilm formation. Intracellular pools of c-di-GMP seem to be dynamically negotiated by diguanylate cyclases (DGCs, with GGDEF domains) and specific phosphodiesterases (PDEs, with EAL or HD-GYP domains). Most bacterial species possess multiple DGCs and PDEs, often with surprisingly distinct and specific output functions. One explanation for such specificity is "local" c-di-GMP signaling, which is believed to involve direct interactions between specific DGC/PDE pairs and c-di-GMP-binding effector/target systems...
October 10, 2017: MBio
Maribel Riveros, Wilfredo García, Coralith García, David Durand, Erik Mercado, Joaquim Ruiz, Theresa J Ochoa
Escherichia coli is an important cause of Gram-negative bacteremia. The aim of this study was to characterize at the molecular and phenotypic levels E. coli strains belonging to different diarrheagenic pathotypes [diarrheagenic E. coli (DEC)] isolated from bacteremia in children younger than 5 years of age. Seventy bacteremia E. coli strains were collected in a prospective study in 12 hospitals in Lima, Peru. The presence of virulence genes associated with DEC [enterotoxigenic (lt and st), enteropathogenic (eaeA), shiga toxin-producing (stx1and stx2), enteroinvasive (ipaH), enteroaggregative (aggR), and diffusely adherent (daaD)] was determined by multiplex real-time polymerase chain reaction (PCR)...
October 9, 2017: American Journal of Tropical Medicine and Hygiene
Kasumi Takeuchi
In Pseudomonas protegens CHA0 and other fluorescent pseudomonads, the Gac/Rsm signal transduction pathway is crucial for the expression of secondary metabolism and the biological control of fungi, nematodes, and insects. Based on the findings of a previous metabolomic study, the role of intracellular -aminobutyrate (GABA) as a potential signal in the Gac/Rsm pathway was investigated herein. The function and regulation of a gabDT (c01870-c01880) gene cluster in strain CHA0 were described. The gabT gene encoded -aminobutyrate transaminase (GABAT) and enabled the growth of the bacterium on GABA, whereas the upstream gabD gene (annotated as a gene encoding succinic semialdehyde dehydrogenase) had an unknown function...
October 9, 2017: Molecular Plant-microbe Interactions: MPMI
Zhenshun Zeng, Xingsheng Cai, Pengxia Wang, Yunxue Guo, Xiaoxiao Liu, Baiyuan Li, Xiaoxue Wang
Pseudoalteromonas is an important bacterial genus present in various marine habitats. Many strains of this genus are found to be surface colonizers on marine eukaryotes and produce a wide range of pigments. However, the exact physiological role and mechanism of pigmentation were less studied. Pseudoalteromonas sp. SM9913 (SM9913), an non-pigmented strain isolated from the deep-sea sediment, formed attached biofilm at the solid-liquid interface and pellicles at the liquid-air interface at a wide range of temperatures...
2017: Frontiers in Microbiology
Xuelian Huang, Meng Deng, Mingdong Liu, Lei Cheng, R A M Exterkate, Jiyao Li, Xuedong Zhou, Jacob M Ten Cate
OBJECTIVES: Galla chinensis water extract (GCE) has been demonstrated to inhibit dental caries by favorably shifting the demineralization/remineralization balance of enamel and inhibiting the biomass and acid formation of dental biofilm. The present study focused on the comparison of composition and anticaries effect of Galla chinensis extracts with different isolation methods, aiming to improve the efficacy of caries prevention. METHODS: The composition of water extract (GCE), ethanol extract (eGCE) and commercial tannic acid was compared...
2017: Open Dentistry Journal
Ryan B McLay, Hang N Nguyen, Yuly Andrea Jaimes-Lizcano, Narendra K Dewangan, Simone Alexandrova, Debora F Rodrigues, Patrick C Cirino, Jacinta C Conrad
Adhesion of bacteria to interfaces is the first step in pathogenic infection, in biofilm formation, and in bioremediation of oil spills and other pollutants. Bacteria use a variety of surface structures to promote interfacial adhesion, with the level of expression of these structures varying in response to local conditions and environmental signals. Here, we investigated how overexpression of type 1 fimbriae, one such appendage, modifies the ability of Escherichia coli to adhere to solid substrates, via biofilm formation and yeast agglomeration, and to oil/water interfaces, via a microbial adhesion to hydrocarbons assay...
October 4, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Allison R Eberly, Kyle A Floyd, Connor J Beebout, Spencer J Colling, Madison J Fitzgerald, Charles W Stratton, Jonathan E Schmitz, Maria Hadjifrangiskou
One of the most common urologic problems afflicting millions of people worldwide is urinary tract infection (UTI). The severity of UTIs ranges from asymptomatic bacteriuria to acute cystitis, and in severe cases, pyelonephritis and urosepsis. The primary cause of UTIs is uropathogenic Escherichia coli (UPEC), for which current antibiotic therapies often fail. UPEC forms multicellular communities known as biofilms on urinary catheters, as well as on and within bladder epithelial cells. Biofilm formation protects UPEC from environmental conditions, antimicrobial therapy, and the host immune system...
September 30, 2017: International Journal of Molecular Sciences
Shi-Qi An, Ji-Liang Tang
Stenotrophomonas maltophilia is an antibiotic-resistant Gram-negative pathogen, which is associated with hospital-acquired infection. The genome encodes a protein highly related to the Ax21 protein of Xanthomonas oryzae that is implicated in interactions of this plant pathogen with rice. Here, we report on the pleiotropic nature of ax21 mutation in S. maltophilia and the effects of addition of the Ax21 protein on the restoration of the wild-type phenotype. We show that loss by mutation of Ax21 leads to reduced motility, reduced biofilm formation, reduced tolerance to the antibiotic tobramycin and reduced virulence to larvae of Galleria mellonella, as well as alteration in the expression of specific genes associated with virulence or antibiotic resistance...
September 30, 2017: Archives of Microbiology
Bahareh Attaran, Tahereh Falsafi
BACKGROUND: A few reports confirm the ability of Helicobacter pylori to form biofilm. However, conclusive data do not exist concerning the factors that favor this ability. OBJECTIVES: Evaluation of the factors associated with the biofilm formation ability of H. pylori including bacterial, physical and chemical, and environmental factors was the research's aim. MATERIALS AND METHODS: H. pylori isolates from gastric biopsy specimens of patients infected chronically were screened for biofilm formation ability...
March 2017: Iranian journal of biotechnology
Juping Zhao, Yicheng Sun
Yersinia pestis, the cause of plague, is transmitted by flea bite. Y. pestis forms a biofilm in the proventriculus of its flea vector to enhance transmission. Biofilm formation in Y. pestis is positively regulated by the intracellular levels of the second messenger cyclic diguanylate (c-di-GMP). The c-di-GMP in Y. pestis is synthesized by two diguanylate cyclases (DGC), HmsT and HmsD, and degraded by phosphodiesterase (PDE), HmsP. Here we summarized the regulators that modulate c-di-GMP metabolism and biofilm formation in Y...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Xinfeng Li, Fang Chen, Jinfeng Xiao, Jin He
Cyclic diguanosine monophosphate (c-di-GMP) is a ubiquitous nucleotide second messenger present in a wide variety of bacteria. It regulates many important bacterial physiological functions such as biofilm formation, motility, adhesion, virulence and extracellular polysaccharide synthesis. It binds with many different proteins or RNA receptors, one of which is called riboswitch that is usually located at the 5'-untranslational region (5'-UTR) in some mRNA. Riboswitch usually comprises a specific ligand-binding (sensor) domain (named aptamer domain, AD), as well as a variable domain, termed expression platform (EP), to regulate expression of downstream coding sequences...
September 25, 2017: Sheng Wu Gong Cheng Xue Bao, Chinese Journal of Biotechnology
Seyma Hande Tekarslan-Sahin, Ceren Alkim, Tugba Sezgin
Salt-resistant yeast strains are highly demanded by industry due to the exposure of yeast cells to high concetrations of salt, in various industrial bioprocesses. The aim of this study was to perform a physiological and transcriptomic analysis of a salt-resistant Saccharomyces cerevisiae (S. cerevisiae) mutant generated by evolutionary engineering. NaCl-resistant S. cerevisiae strains were obtained by ethyl methane sulfonate (EMS) mutagenesis followed by successive batch cultivations in the presence of gradually increasing NaCl concentrations, up to 8...
September 27, 2017: Bosnian Journal of Basic Medical Sciences
Xiaofei Wang, Haiyan Han, Zhihui Lv, Zhiwei Lin, Yongpeng Shang, Tao Xu, Yang Wu, Ying Zhang, Di Qu
PhoU, a conserved protein that has been proposed to coordinate phosphate import, is a negative regulator of drug tolerance in most bacteria. In Staphylococcus epidermidis, the role of PhoU in biofilm formation and drug tolerance has not yet been investigated. Two PhoU homologs in the genome of S. epidermidis have been identified by the presence of the conserved motif [(E(D)XXXD] of PhoU. We separately constructed ΔphoU1 and ΔphoU2 of S. epidermidis 1457 strain. The ΔphoU2 displayed growth retardation, weakened biofilm formation capacity, higher sensitivity to H2O2 and reduced tolerance to multiple antibiotics...
September 25, 2017: Journal of Bacteriology
Haijun Ma, Xuezhu Wang, Yan Zhang, Haidong Hu, Hongqiang Ren, Jinju Geng, Lili Ding
Although AHL-mediated quorum sensing (QS) signaling has been proved to be ecologically important in biofilm formation and aerobic granulation process, the biological role of AHL in anaerobic granule has not been experimentally investigated. In this paper, we explored the AHL level in 10 full-scale industrial anaerobic granular bioreactors and detected a total of 4 kinds of AHLs. C8-HSL and C10-HSL were indicated to be the potentially universal QS signal molecules in anaerobic granules and involved in extracellular polymeric substance (EPS) production and granulation process...
September 8, 2017: Bioresource Technology
Hanna Ainelo, Andrio Lahesaare, Annika Teppo, Maia Kivisaar, Riho Teras
LapA is the biggest protein in Pseudomonas putida and a key factor for biofilm formation. Its importance and posttranslational regulation is rather thoroughly studied but less is known about the transcriptional regulation. Here we give evidence that transcription of lapA in LB-grown bacteria is initiated from six promoters, three of which display moderate RpoS-dependence. The global transcription regulator Fis binds to the lapA promoter area at six positions in vitro, and Fis activates the transcription of lapA while overexpressed in cells...
2017: PloS One
James T Lyles, Austin Kim, Kate Nelson, Angelle L Bullard-Roberts, Avni Hajdari, Behxhet Mustafa, Cassandra L Quave
Hypericum perforatum L. (Hypericaceae), or St. John's Wort, is a well-known medicinal herb often associated with the treatment of anxiety and depression. Additionally, an oil macerate (Oleum Hyperici) of its flowering aerial parts is widely used in traditional medicine across the Balkans as a topical wound and ulcer salve. Other studies have shown that Oleum Hyperici reduces both wound size and healing time. Of its active constituents, the naphthodianthrone hypericin and phloroglucinol hyperforin are effective antibacterial compounds against various Gram-positive bacteria...
2017: Frontiers in Microbiology
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