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Bacterial persistence

Joseph Y Ting, Anne Synnes, Ashley Roberts, Akhil Deshpandey, Kimberly Dow, Eugene W Yoon, Kyong-Soon Lee, Simon Dobson, Shoo K Lee, Prakesh S Shah
Importance: Excessive antibiotic use has been associated with altered bacterial colonization and may result in antibiotic resistance, fungemia, necrotizing enterocolitis (NEC), and mortality. Exploring the association between antibiotic exposure and neonatal outcomes other than infection-related morbidities may provide insight on the importance of rational antibiotic use, especially in the setting of culture-negative neonatal sepsis. Objective: To evaluate the trend of antibiotic use among all hospitalized very low-birth-weight (VLBW) infants across Canada and the association between antibiotic use rates (AURs) and mortality and morbidity among neonates without culture-proven sepsis or NEC...
October 24, 2016: JAMA Pediatrics
Daria Matyushkina, Olga Pobeguts, Ivan Butenko, Anna Vanyushkina, Nicolay Anikanov, Olga Bukato, Daria Evsyutina, Alexandra Bogomazova, Maria Lagarkova, Tatiana Semashko, Irina Garanina, Vladislav Babenko, Maria Vakhitova, Valentina Ladygina, Gleb Fisunov, Vadim Govorun
What strategies do bacteria employ for adaptation to their hosts and are these strategies different for varied hosts? To date, many studies on the interaction of the bacterium and its host have been published. However, global changes in the bacterial cell in the process of invasion and persistence, remain poorly understood. In this study, we demonstrated phase transition of the avian pathogen Mycoplasma gallisepticum upon invasion of the various types of eukaryotic cells (human, chicken, and mouse) which was stable during several passages after isolation of intracellular clones and recultivation in a culture medium...
October 24, 2016: Scientific Reports
Campana Raffaella, Luca Casettari, Laura Fagioli, Marco Cespi, Giulia Bonacucina, Wally Baffone
Food safety is a fundamental concern for both consumers and the food industry, especially as the numbers of reported cases of food-associated infections continue to increase. Industrial surfaces can provide a suitable substrate for the development and persistence of bacterial organized in biofilms that represent a potential source of food contamination. The negative consumer perception of chemical disinfectants has shifted the attention to natural substances, such as plant extracts. The aim of this study was to investigate the possibility of using the essential oils (EOs) in the fight against S...
October 17, 2016: International Journal of Food Microbiology
Daniel Nichol, Mark Robertson-Tessi, Peter Jeavons, Alexander R A Anderson
Non-genetic variation in phenotypes, or bet-hedging, has been observed as a driver of drug resistance in both bacterial infections and cancers. Here, we study how bet-hedging emerges in the genotype-phenotype mapping through a simple interaction model: a molecular switch. We use simple Chemical Reaction Networks to implement stochastic switches that map gene products to phenotypes and investigate the impact of structurally distinct mappings on the evolution of phenotypic heterogeneity. Bet-hedging naturally emerges within this model and is robust to evolutionary loss through mutations to both the expression of individual genes and to the network itself...
October 21, 2016: Genetics
Shivanand Hegde, Martina Zimmermann, Martina Flöck, Rene Brunthaler, Joachim Spergser, Renate Rosengarten, Rohini Chopra-Dewasthaly
Mycoplasmas are amongst the most successful pathogens of both humans and animals yet the molecular basis of mycoplasma pathogenesis is poorly understood. This is partly due to the lack of classical virulence factors and little similarity to common bacterial pathogenic determinants. Using Mycoplasma agalactiae as a model we initiated research in this direction by screening a transposon mutant library in the natural sheep host using a negative selection method. Having successfully identified putative factors involved in the colonization of local infection and lymphogenic sites, the current study assessed mutants unable to spread systemically in sheep after experimental intramammary infection...
October 20, 2016: Veterinary Research
Fabio Marchetti, Jessica Palmucci, Claudio Pettinari, Riccardo Pettinari, Mirko Marangoni, Stefano Ferraro, Rita Giovannetti, Stefania Scuri, Iolanda Grappasonni, Mario Cocchioni, Francisco José Maldonado Hodar, Roberto Gunnella
Novel composite materials PEn (n = 1-9) have been prepared by an easily up-scalable embedding procedure of three different families of Ag(I) acylpyrazolonato complexes in polyethylene (PE) matrix. In details, PE1-PE3 composites contain polynuclear [Ag(Q(R))]n complexes, PE4-PE6 contain mononuclear [Ag(Q(R))(L)m] complexes and PE7-PE9 are loaded with mononuclear [Ag(Q(R)) (PPh3)2] complexes, respectively (where L = 1-methylimidazole or 2-ethylimidazole, m = 1 or 2, and HQ(R) = 1-phenyl-3-methyl-4-RC(═O)-5-pyrazolone, where in detail HQ(fb), R = -CF2CF2CF3; HQ(cy), R = -cyclo-C6H11; HQ(be), R = -C(H)═C(CH3)2)...
October 20, 2016: ACS Applied Materials & Interfaces
Carlo Luca Romanò, Delia Romanò, Ilaria Morelli, Lorenzo Drago
Biofilms have a tremendous impact on industrial machines working in moist environments, while in biological systems their effect is further complicated by the host's response.Implant-related infections are a complex process, starting with bacterial adhesion and biofilm formation, followed by the variable interaction between host, implant, microorganisms and their by-products. Depending on the balance of these factors, different clinical presentations are observed, which may eventually, at times, shift from one into the other...
October 19, 2016: Advances in Experimental Medicine and Biology
Suchawan Pornsukarom, Siddhartha Thakur
Land application of swine manure in commercial hog farms is an integral part of their waste management system which recycles the nutrients back to the soil. However, manure application can lead to the dissemination of bacterial pathogens in the environment and pose a serious public health threat. The aim of this study was to determine the dissemination of antimicrobial resistant Salmonella in the environment due to manure application in commercial swine farms in North Carolina (n = 6) and Iowa (n = 7), two leading pork producing states in the US...
2016: PloS One
S S Garcia, Q Du, H Wu
The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ)...
December 21, 2015: Molecular Oral Microbiology
Valmiki B Koli, Sagar D Delekar, Shivaji H Pawar
In this study, nanocomposites of Fe-doped TiO2 with multi-walled carbon nanotubes (0.1- 0.5 wt. %) were prepared by using sol-gel method. The structural and morphological analysis were carried out with using X-ray diffraction pattern and transmission electron microscopy, which confirm the presence of pure anatase phase and particle sizes in the range 15-20 nm. X-ray photoelectron spectroscopy was used to determine the surface compositions of the nanocomposites. UV-vis diffuse reflectance spectra confirm redshift in the optical absorption edge of nanocomposites with increasing amount of multi-walled carbon nanotubes...
December 2016: Journal of Materials Science. Materials in Medicine
Shu-Cheng Liu, Xiao-Min Han, Ming Shi, Zi-Li Pang
This study aimed to provide evidence of persistent uropathogenic Escherichia coli (UPEC) in female patients with recurrent urinary tract infection (UTI) after antibiotic therapy. We collected biopsies of the bladder, and clean-catch urine samples from 32 women who had episodes of recurrent UTI and were given antibiotic therapy. Urine samples and biopsies were analyzed by conventional bacteriological techniques. Phylogenetic group and 16 virulence factors (VFs) of UPEC were determined using polymerase chain reaction (PCR)...
October 2016: Journal of Huazhong University of Science and Technology. Medical Sciences
Andrew Kd Younger, Neil Chandra Dalvie, Austin G Rottinghaus, Joshua N Leonard
Efforts to engineer microbial factories have benefitted from mining biological diversity and high throughput synthesis of novel enzymatic ensembles, yet screening and optimizing metabolic pathways remain rate-limiting steps. Metabolite-responsive biosensors may help to address these persistent challenges by enabling the monitoring of metabolite levels in individual cells and metabolite-responsive feedback control. We are currently limited to naturally-evolved biosensors, which are insufficient for monitoring many metabolites of interest...
October 17, 2016: ACS Synthetic Biology
Theresia E B Stradal, Sonia C P Costa
A key aspect of bacterial pathogenesis is the colonization and persistence within the host and, later on, its dissemination to new niches. During evolution, bacteria developed a myriad of virulence mechanisms to usurp the host's sophisticated defense mechanisms in order to establish their colonization niche. Elucidation of the highly dynamic and complex interactions between host and pathogens remains an important field of study. Here, we highlight the conserved manipulation of the actin cytoskeleton by some Gram-negative gastrointestinal pathogens, addressing the role of type III secreted bacterial GEFs at the different steps of pathogenesis...
October 16, 2016: Current Topics in Microbiology and Immunology
Y Lin, W Zhao, Z D Shi, H R Gu, X T Zhang, X Ji, X T Zou, J S Gong, W Yao
Meat duck deep litter is considered to be an ideal environment for the evolution of bacterial antibiotic resistance if it is under poor management. The aim of this study was to characterize the accumulation of antibiotics and heavy metals in the deep litter and their role in the persistence of antibiotic resistance of Escherichia coli, and evaluate the service life of the deep litter. Samples were collected from initial, middle, and final stages of deep litter within 3 barns (zero, 4, and 8 rounds of meat duck fattening, d 34) and 9 flocks, with known consumption of antibiotics in the controlled trail...
October 14, 2016: Poultry Science
Devyani Deshpande, Shashikant Srivastava, Eric Nuermberger, Jotam G Pasipanodya, Soumya Swaminathan, Tawanda Gumbo
BACKGROUND:  The regimen of linezolid and moxifloxacin was found to be efficacious in the hollow fiber system model of pediatric intracellular tuberculosis. However, its kill rate was slower than the standard 3-drug regimen of isoniazid, rifampin, and pyrazinamide. We wanted to examine the effect of adding a third oral agent, faropenem, to this dual combination. METHODS:  We performed a series of studies in the hollow fiber system model of intracellular Mycobacterium tuberculosis, by mimicking pediatric pharmacokinetics of each antibiotic...
November 1, 2016: Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
Ye Cao, Kai Guan, Xiang He, Congwen Wei, Zirui Zheng, Yanhong Zhang, Shengli Ma, Hui Zhong, Wei Shi
The Yersinia outer protein J (YopJ) plays a pivotal role in evading the host immune response and establishes a persistent infection in host cells after bacterial infection. YopJ is a cysteine protease and can act as a deubiquitinating enzyme that deubiquitinates several targets in multiple signaling pathways. Stimulator of interferon genes (STING) is a critical adapter for the induction of interferon regulatory factor 3 (IRF3) phosphorylation and subsequent production of the cytokines in response to nucleic acids in the cytoplasm...
October 11, 2016: Biochimica et Biophysica Acta
Jennifer Bh Martiny, Adam C Martiny, Claudia Weihe, Ying Lu, Renaud Berlemont, Eoin L Brodie, Michael L Goulden, Kathleen K Treseder, Steven D Allison
Terrestrial ecosystem models assume that microbial communities respond instantaneously, or are immediately resilient, to environmental change. Here we tested this assumption by quantifying the resilience of a leaf litter community to changes in precipitation or nitrogen availability. By manipulating composition within a global change experiment, we decoupled the legacies of abiotic parameters versus that of the microbial community itself. After one rainy season, more variation in fungal composition could be explained by the original microbial inoculum than the litterbag environment (18% versus 5...
October 14, 2016: ISME Journal
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
Ulrich Nübel
Driven by progress of DNA sequencing technologies, recent population genomics studies have revealed that several bacterial pathogens constitute 'measurably evolving populations'. As a consequence, it was possible to reconstruct the emergence and spatial spread of drug-resistant bacteria on the basis of temporally structured samples of bacterial genome sequences. Based on currently available data, some general inferences can be drawn across different bacterial species as follows: (1) Resistance to various antibiotics evolved years to decades earlier than had been anticipated on the basis of epidemiological surveillance data alone...
October 15, 2016: Current Topics in Microbiology and Immunology
Chih-Ho Lai, Ju-Chun Huang, Chuan Chiang-Ni, Ju-Pi Li, Lii-Tzu Wu, Hua-Shan Wu, Yu-Chen Sun, Mei-Ling Lin, Ju-Fang Lee, Hwai-Jeng Lin
Background. Persistent Helicobacter pylori infection may induce several upper gastrointestinal diseases. Two major virulence factors of H. pylori, vacuolating cytotoxin A (VacA) and cytotoxin-associated gene A (CagA), are thought to be associated with the severity of disease progression. The distribution of vacA and cag-pathogenicity island (cag-PAI) alleles varies in H. pylori isolated from patients in different geographic regions. Aim. To assess the association between mixed infection of H. pylori clinical isolates from Taiwanese patients and the severity of gastrointestinal diseases...
2016: Gastroenterology Research and Practice
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