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swarming motility

Taylor Evart Woo, Jessica Duong, Nicole M Jervis, Harvey R Rabin, Michael D Parkins, Douglas Gordon Storey
Pseudomonas aeruginosa is a major pathogen in chronic lung diseases such as cystic fibrosis (CF) and non-cystic fibrosis bronchiectasis (nCFB). Much of our understanding regarding infections in nCFB patients is extrapolated from findings in CF with little direct investigation on the adaptation of P. aeruginosa in nCFB patients. As such, we investigated whether the adaptation of P. aeruginosa was indeed similar between nCFB and CF. From our prospectively collected biobank we identified 40 nCFB patients who had repeated P...
November 8, 2016: Microbiology
Michelle M C Buckner, Jessica M A Blair, Roberto M La Ragione, Jane Newcombe, Daniel J Dwyer, Alasdair Ivens, Laura J V Piddock
: For over 20 years, bacterial multidrug resistance (MDR) efflux pumps have been studied because of their impact on resistance to antimicrobials. However, critical questions remain, including why produce efflux pumps under non-antimicrobial treatment conditions, and why have multiple pumps if their only purpose is antimicrobial efflux? Salmonella spp. possess five efflux pump families, including the resistance-nodulation-division (RND) efflux pumps. Notably, the RND efflux pump AcrD has a unique substrate profile, distinct from other Salmonella efflux pumps...
November 22, 2016: MBio
Tianyi Zhou, Beiyan Nan
The biofilm-forming bacterium Myxococcus xanthus moves on surfaces as structured swarms utilizing type IV pili-dependent social (S-) motility. In contrast to isolated cells that reverse their moving direction frequently, individual cells within swarms rarely reverse. The regulatory mechanisms that inhibit cellular reversal and promote the formation of swarms are not well understood. Here we show that exopolysaccharides (EPS), the major extracellular components of M. xanthus swarms, inhibit cellular reversal in a concentration-dependent manner...
November 22, 2016: Molecular Microbiology
R H V Pereira, R S Leão, A P Carvalho-Assef, R M Albano, E R A Rodrigues, M C Firmida, T W Folescu, M C Plotkowski, V G Bernardo, E A Marques
Achromobacter spp. are opportunistic pathogens increasingly recovered from adult patients with cystic fibrosis (CF). We report the characterization of 122 Achromobacter spp. isolates recovered from 39 CF patients by multilocus sequence typing, virulence traits, and susceptibility to antimicrobials. Two species, A. xylosoxidans (77%) and A. ruhlandii (23%) were identified. All isolates showed a similar biofilm formation ability, and a positive swimming phenotype. By contrast, 4·3% and 44·4% of A. xylosoxidans and A...
November 22, 2016: Epidemiology and Infection
Aggeliki Skagia, Eleni Vezyri, Markezina Sigala, Areti Kokkinou, Michael Karpusas, Anastasia Venieraki, Panagiotis Katinakis, Maria Dimou
Escherichia coli cyclophilin PpiB is a peptidyl-prolyl cis/trans isomerase (PPIase, EC:, involved in the negative modulation of various bacterial processes, such as swimming and swarming motility and biofilm formation ability. In this study, we show that PpiB possesses also a chaperone function as it can prevent the thermal denaturation of citrate synthase even with essentially eliminated PPIase activity. We demonstrate, using active site mutations, that the PPIase activity of PpiB is required in all processes, except for the negative effect on swimming, indicating a possible isomerase-independent function...
November 21, 2016: Genes to Cells: Devoted to Molecular & Cellular Mechanisms
P C Zee, J Liu, G J Velicer
Understanding how multiple mutations interact to jointly impact multiple ecologically important traits is critical for creating a robust picture of organismal fitness and the process of adaptation. However, this is complicated by both environmental heterogeneity and the complexity of genotype-to-phenotype relationships generated by pleiotropy and epistasis. Moreover, little is known about how pleiotropic and epistatic relationships themselves change over evolutionary time. The soil bacterium Myxococcus xanthus employs several distinct social traits across a range of environments...
October 19, 2016: Journal of Evolutionary Biology
Zaixiang Lou, Hongxin Wang, Yuxia Tang
AIMS: This study aimed to evaluate the effect of a fraction of burdock (Arctium lappa L.) leaf on the initial adhesion, biofilm formation, quorum sensing and virulence factors of P. aeruginosa. METHODS AND RESULTS: Anti-biofilm activity of the burdock leaf fraction was studied by the method of crystal violet staining. When the concentration of the burdock leaf fraction was 2.0 mg mL(-1) , the inhibition rates on biofilm formation of P. aeruginosa were 100%. The burdock leaf fraction was found to inhibit the formation of biofilm by reducing bacterial surface hydrophobicity, decreasing bacterial aggregation ability and inhibiting swarming motility Interestingly, the burdock leaf fraction inhibited the secretion of quorum sensing (QS) signaling molecule 3-oxo-C12-HSL and interfered quorum sensing...
November 12, 2016: Journal of Applied Microbiology
Juanni Chen, Yanmei Yu, Shili Li, Wei Ding
Bacterial wilt is a destructive disease caused by the phytopathogen Ralstonia solanacearum (R. solanacearum), which is widely found in various tobacco-growing areas all over the world. Botanical bactericidal substances have gradually emerged as a hot topic in modern pesticide research. In this study, the antibacterial activities of two phytochemicals (resveratrol and coumarin) against R. solanacearum and their in vivo and in vitro efficacy for controlling tobacco bacterial wilt were evaluated. We rule out significant biological effects of both phytochemicals using transmission electron microscope (TEM) and fluorescence microscope, which suppressed the growth of R...
November 9, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
John D Lippolis, Brian W Brunelle, Timothy A Reinhardt, Randy E Sacco, Tyler C Thacker, Torey P Looft, Thomas A Casey
Bacterial motility is thought to play an important role in virulence. We have previously shown that proficient bacterial swimming and swarming in vitro is correlated with the persistent intramammary infection phenotype observed in cattle. However, little is known about the gene regulation differences important for different motility phenotypes in Escherichia coli. In this work, three E. coli strains that cause persistent bovine mastitis infections were grown in three media that promote different types of motility (planktonic, swimming, and swarming)...
July 2016: MSystems
Diletta Mazzantini, Francesco Celandroni, Sara Salvetti, Sokhna A Gueye, Antonella Lupetti, Sonia Senesi, Emilia Ghelardi
Besides sporulation, Bacillus cereus can undergo a differentiation process in which short swimmer cells become elongated and hyperflagellated swarmer cells that favor migration of the bacterial community on a surface. The functionally enigmatic flagellar protein FlhF, which is the third paralog of the signal recognition particle (SRP) GTPases Ffh and FtsY, is required for swarming in many bacteria. Previous data showed that FlhF is involved in the control of the number and positioning of flagella in B. cereus...
2016: Frontiers in Microbiology
Haowa Madi, Jovanka Lukić, Zorica Vasiljević, Marjan Biočanin, Milan Kojić, Branko Jovčić, Jelena Lozo
BACKGROUND: Stenotrophomonas maltophilia is an environmental bacterium and an opportunistic pathogen usually associated with healthcare-associated infections, which has recently been recognized as a globally multi-drug resistant organism. The aim of this study was genotyping and physiological characterization of Stenotrophomonas maltophilia isolated in a large, tertiary care pediatric hospital in Belgrade, Serbia, hosting the national reference cystic fibrosis (CF) center for pediatric and adult patients...
2016: PloS One
Bing Guo, Yongqiang Zhang, Shili Li, Ting Lai, Liang Yang, Juanni Chen, Wei Ding
Many cereals accumulate hydroxamic acids involved in defense of plant against various fungi, bacteria, and insects. 2,4-dihydroxy-7-methoxy-1,4-benzoxazine-3-one, commonly known as DIMBOA, is one of the principal cyclic hydroxamic acids in aqueous extracts of maize. The aim of this study was to evaluate the antibacterial activity of the isolated DIMBOA and its derivatives 2-benzoxazolinone (BOA), 6-chloro-2-benzoxazolinone (CDHB), and 2-mercaptobenzothiazole (MBT) against Ralstonia solanacearum. MBT showed the strongest antibacterial activity, followed by CDHB and DIMBOA, with minimum inhibitory concentrations (MICs) of 50, 100 and 200 mg/L, respectively, better than the BOA with 300 mg/L...
October 19, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Oihane Irazoki, Jesús Aranda, Timo Zimmermann, Susana Campoy, Jordi Barbé
In addition to its role in DNA damage repair and recombination, the RecA protein, through its interaction with CheW, is involved in swarming motility, a form of flagella-dependent movement across surfaces. In order to better understand how SOS response modulates swarming, in this work the location of RecA and CheW proteins within the swarming cells has been studied by using super-resolution microscopy. Further, and after in silico docking studies, the specific RecA and CheW regions associated with the RecA-CheW interaction have also been confirmed by site-directed mutagenesis and immunoprecipitation techniques...
2016: Frontiers in Microbiology
Ramanathan Srinivasan, Kannan Rama Devi, Arunachalam Kannappan, Shunmugiah Karutha Pandian, Arumugam Veera Ravi
ETHNOPHARMACOLOGICAL RELEVANCE: Piper betle, a tropical creeper plant belongs to the family Piperaceae. The leaves of this plant have been well known for their therapeutic, religious and ceremonial value in South and Southeast Asia. It has also been reported to possess several biological activities including antimicrobial, antioxidant, antinociceptive, antidiabetic, insecticidal and gastroprotective activities and used as a common ingredient in indigenous medicines. In Indian system of ayurvedic medicine, P...
October 6, 2016: Journal of Ethnopharmacology
Christina C Saak, Karine A Gibbs
Proteus mirabilis is a social bacterium that is capable of self (kin) versus non-self recognition. Swarming colonies of this bacterium expand outward on surfaces at centimeter-scale distances due to the collective motility of individual cells. Colonies of genetically distinct populations remain separate while those of identical populations merge. Ids proteins are essential for this recognition behavior. Two of these proteins, IdsD and IdsE, encode identity information for each strain. These two proteins bind in vitro in an allele-restrictive manner, and IdsD-IdsE binding is correlated with populations merging whereas a lack of binding correlates with populations separating...
September 26, 2016: Journal of Bacteriology
Liaoyuan Zhang, Zewang Guo, Hufang Gao, XiaoQian Peng, Yongyu Li, Shujing Sun, Jung-Kul Lee, Wenxiong Lin
Many plant-pathogenic bacteria were dependent on quorum sensing (QS) to evoke disease. In this study, the population of QS and quorum quenching (QQ) bacteria was analyzed in consecutive monoculture system of Pseudostellaria heterophylla. The isolated QS strains were identified as Serratia marcescens with SwrIR-type QS system and exhibited a significant increase over the years of monoculture. Only one QQ strain was isolated from new planted soil sample and identified as Bacillus thuringiensis which secreted lactonase to degrade QS signal molecules...
September 23, 2016: Journal of Microbiology and Biotechnology
Olaya Rendueles, Gregory J Velicer
Evolutionary adaptation can be achieved by mechanisms accessible to all organisms, including faster growth and interference competition, but self-generated motility offers additional possibilities. We tested whether 55 populations of the bacterium Myxococcus xanthus that underwent selection for increased fitness at the leading edge of swarming colonies adapted by swarming faster toward unused resources or by other means. Populations adapted greatly but diversified markedly in both swarming phenotypes and apparent mechanisms of adaptation...
September 23, 2016: ISME Journal
James G Lefevre, Alexander N Combes, Melissa H Little, Nicholas A Hamilton
This article provides detailed information on manually tracked cap mesenchyme cells from timelapse imaging of multiple ex vivo embryonic mouse kidneys. Cells were imaged for up to 18 h at 15 or 20 min intervals, and multiple cell divisions were tracked. Positional data is supplemented with a range of information including the relative location of the closest ureteric tip and a correction for drift due to bulk movement and tip growth. A subset of tracks were annotated to indicate the presence of processes attached to the ureteric epithelium...
December 2016: Data in Brief
Weng Chun Tan, Nor Ashidi Mat Isa
In human sperm motility analysis, sperm segmentation plays an important role to determine the location of multiple sperms. To ensure an improved segmentation result, the Laplacian of Gaussian filter is implemented as a kernel in a pre-processing step before applying the image segmentation process to automatically segment and detect human spermatozoa. This study proposes an intersecting cortical model (ICM), which was derived from several visual cortex models, to segment the sperm head region. However, the proposed method suffered from parameter selection; thus, the ICM network is optimised using particle swarm optimization where feature mutual information is introduced as the new fitness function...
2016: PloS One
Yijing Zhuang, Weidong Chen, Fen Yao, Yuanchun Huang, Shuqin Zhou, Haiyan Li, Zijie Zhang, Congyi Cai, Yi Gao, Qing Peng
BACKGROUND/AIMS: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE) on the swarming and swimming motility of Escherichia coli (E. coli) remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. METHODS: After exposure to sub-inhibitory concentrations (0...
2016: Cellular Physiology and Biochemistry
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