keyword
MENU ▼
Read by QxMD icon Read
search

biofilm and efflux pump

keyword
https://www.readbyqxmd.com/read/28731269/biofilm-formation-and-antibiotic-resistance-in-klebsiella-pneumoniae-urinary-strains
#1
Claudia Vuotto, Francesca Longo, Chiara Pascolini, Gianfranco Donelli, Maria Pia Balice, Maria Francesca Libori, Valentina Tiracchia, Antonino Salvia, Pietro Emanuele Varaldo
AIMS: Multi-drug resistant Klebsiella pneumoniae has become a relevant healthcare-associated pathogen. Capsule, type 1 and 3 fimbriae (mrkA gene), type 2 quorum-sensing system (luxS), synthesis of D-galactan I (wbbM), LPS transport (wzm) and poly-beta-1,6-N-acetyl-D-glucosamine (pgaA) seem involved in K. pneumoniae biofilm. Non-enzymatic antibiotic resistance is related to non-expression or mutation of porins (OmpK35 and OmpK36), and efflux pump (acrB) over-expression. The aim of this study was to analyse some virulence factors of K...
July 21, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28710521/efflux-drug-transporters-at-the-forefront-of-antimicrobial-resistance
#2
REVIEW
Tahmina Rahman, Benjamin Yarnall, Declan A Doyle
Bacterial antibiotic resistance is rapidly becoming a major world health consideration. To combat antibiotics, microorganisms employ their pre-existing defence mechanisms that existed long before man's discovery of antibiotics. Bacteria utilise levels of protection that range from gene upregulation, mutations, adaptive resistance, and production of resistant phenotypes (persisters) to communal behaviour, as in swarming and the ultimate defence of a biofilm. A major part of all of these responses involves the use of antibiotic efflux transporters...
July 14, 2017: European Biophysics Journal: EBJ
https://www.readbyqxmd.com/read/28709374/nanoparticles-as-efflux-pump-and-biofilm-inhibitor-to-rejuvenate-bactericidal-effect-of-conventional-antibiotics
#3
REVIEW
Divya Gupta, Ajeet Singh, Asad U Khan
The universal problem of bacterial resistance to antibiotic reflects a serious threat for physicians to control infections. Evolution in bacteria results in the development of various complex resistance mechanisms to neutralize the bactericidal effect of antibiotics, like drug amelioration, target modification, membrane permeability reduction, and drug extrusion through efflux pumps. Efflux pumps acquire a wide range of substrate specificity and also the tremendous efficacy for drug molecule extrusion outside bacterial cells...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28705674/molecular-bases-of-antifungal-resistance-in-filamentous-fungi
#4
Cheshta Sharma, Anuradha Chowdhary
Invasive mould infections due to Aspergillus species, Fusarium spp., Scedosporium spp. and other filamentous fungi remain a significant cause of morbidity and mortality in immunocompromised patients. Antifungal therapy is required for successful patient management; however, limited antifungal drugs and emergence of drug resistance pose a challenge to the clinicians for the effective management of the disease. The evolution of multidrug resistant strains due to selective pressure and the intrinsically resistant pathogenic species are a major concern...
July 10, 2017: International Journal of Antimicrobial Agents
https://www.readbyqxmd.com/read/28700974/mechanism-of-berberine-mediated-fluconazole-susceptibility-enhancement-in-clinical-fluconazole-resistant-candida-tropicalis-isolates
#5
GaoXiang Shi, Jing Shao, TianMing Wang, DaQiang Wu, ChangZhong Wang
BACKGROUND: Candida tropicalis was one of the most common non-albicans Candida (NACA) species creating relatively high morbidity and mortality. We previously demonstrated that the antifungal effect of BBR in combination with FLC might be attributed to reactive oxygen species production, ergosterol content and efflux pump levels in a clinical C. tropicalis isolate. METHODS: we employed thirteen clinical C. tropicalis isolates as well as four standard reference strains to evaluate the antifungal activity of BBR in combination with FLC under planktonic and biofilm states by analyzing the mRNA expressions of ERG11, CDR1 and MDR1 by qRT-PCR...
July 9, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28646205/comparative-nanouplc-ms-e-analysis-between-magainin-i-susceptible-and-resistant-escherichia-coli-strains
#6
Marlon H Cardoso, Keyla C de Almeida, Elizabete de S Cândido, André M Murad, Simoni C Dias, Octávio L Franco
In recent years the antimicrobial peptides (AMPs) have been prospected and designed as new alternatives to conventional antibiotics. Indeed, AMPs have presented great potential toward pathogenic bacterial strains by means of complex mechanisms of action. However, reports have increasingly emerged regarding the mechanisms by which bacteria resist AMP administration. In this context, we performed a comparative proteomic study by using the total bacterial lysate of magainin I-susceptible and -resistant E. coli strains...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28621579/optimization-of-antimicrobial-photodynamic-therapy-in-biofilms-by-inhibiting-efflux-pump
#7
Tatiana Maria Starck Fogaça de Aguiar Coletti, Laura Marise de Freitas, Ana Marisa Fusco Almeida, Carla Raquel Fontana
BACKGROUND: One of the main mechanisms of microbial resistance is given by efflux pumps, which reduce the effectiveness of antimicrobials by decreasing their intracellular concentration. OBJECTIVE AND METHODS: Considering that efflux pump inhibitors are promising adjuvant molecules for antibiotics in infections, in this study, using XTT test and colony forming unit (CFU) counting, we evaluated the association between the pump inhibitor verapamil (VP) and the antimicrobial photodynamic therapy (aPDT) mediated by methylene blue (MB) in biofilms of Escherichia coli and Staphylococcus aureus to optimize the bacterial reduction...
July 2017: Photomedicine and Laser Surgery
https://www.readbyqxmd.com/read/28618136/amphiphilic-cargo-loaded-nanocarrier-enhances-antibiotic-uptake-and-perturbs-efflux-effective-synergy-for-mitigation-of-methicillin-resistant-staphylococcus-aureus
#8
Durairaj Thiyagarajan, Gopal Das, Aiyagari Ramesh
A pyridinium-amphiphile-loaded poly(lactic-co-glycolic acid) (PLGA) nanocarrier (C1-PNC) was developed as an adjuvant in order to break the resistance and restore the susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) cells to therapeutic antibiotics. Notably, against a clinical MRSA strain, C1-PNC was found to render 8- and 6-fold decreases in the minimum biofilm eradication concentration (MBEC90 ) of gentamicin and ciprofloxacin, respectively. Mechanistic studies on MRSA planktonic cells revealed that in the case of gentamicin, C1-PNC promotes enhanced cellular uptake of the antibiotic, whereas the propensity of C1-PNC to inhibit efflux pump activity could be leveraged to enhance cellular accumulation of ciprofloxacin, leading to effective killing of MRSA cells...
June 15, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28587519/inactivation-of-a-putative-efflux-pump-lmrb-in-streptococcus-mutans-results-in-altered-biofilm-structure-and-increased-exopolysaccharide-synthesis-implications-for-biofilm-resistance
#9
Jia Liu, Jianying Zhang, Lihong Guo, Wei Zhao, Xiaoli Hu, Xi Wei
Efflux pumps are a mechanism associated with biofilm formation and resistance. There is limited information regarding efflux pumps in Streptococcus mutans, a major pathogen in dental caries. The aim of this study was to investigate potential roles of a putative efflux pump (LmrB) in S. mutans biofilm formation and susceptibility. Upon lmrB inactivation and antimicrobial exposure, the biofilm structure and expression of other efflux pumps were examined using confocal laser scanning microscopy (CLSM) and qRT-PCR...
June 7, 2017: Biofouling
https://www.readbyqxmd.com/read/28584154/pa3225-is-a-transcriptional-repressor-of-antibiotic-resistance-mechanisms-in-pseudomonas-aeruginosa
#10
Clayton W Hall, Li Zhang, Thien-Fah Mah
The tssABC1 locus is part of the Hcp secretion island (HSI) -I type VI secretion system (T6SS) in Pseudomonas aeruginosa Previous work has implicated the tssC1 gene in P. aeruginosa biofilm-specific antibiotic resistance, and tssC1 is preferentially expressed in biofilms compared to planktonic cells. Using a DNA-dependent protein pulldown approach, we discovered PA3225, an uncharacterised LysR-type transcriptional regulator that specifically bound to the tssABC1 upstream regulatory region. Deletion of PA3225 led to a two-fold decrease in tssA1 expression in planktonic cells compared to wild-type, and tssA1 expression was slightly reduced in ΔPA3225 biofilms compared to wild-type biofilms...
June 5, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28536672/response-to-bile-salts-in-clinical-strains-of-acinetobacter-baumannii-lacking-the-adeabc-efflux-pump-virulence-associated-with-quorum-sensing
#11
Maria López, Lucia Blasco, Eva Gato, Astrid Perez, Laura Fernández-Garcia, Luis Martínez-Martinez, Felipe Fernández-Cuenca, Jesús Rodríguez-Baño, Alvaro Pascual, German Bou, Maria Tomás
Introduction:Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies analyzing the molecular characteristics involved in the response to bile salts in clinical strains of A. baumannii are scarce...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28534862/differences-in-gene-expression-profiles-between-early-and-late-isolates-in-monospecies-achromobacter-biofilm
#12
Signe M Nielsen, Rikke L Meyer, Niels Nørskov-Lauritsen
Bacteria of genus Achromobacter are emerging pathogens in cystic fibrosis (CF) capable of biofilm formation and development of antimicrobial resistance. Evolutionary adaptions in the transition from primary to chronic infection were assessed by transcriptomic analysis of successive isolates of Achromobacter xylosoxidans from a single CF patient. Several efflux pump systems targeting antimicrobial agents were upregulated during the course of the disease, whereas all genes related to motility were downregulated...
May 19, 2017: Pathogens
https://www.readbyqxmd.com/read/28486078/characterization-of-clinically-isolated-antibiotic-resistant-salmonella-typhimurium-exposed-to-subinhibitory-concentrations-of-ceftriaxone-and-ciprofloxacin
#13
Jeongjin Kim, Juhee Ahn
This study was designed mainly to assess the phenotypic properties of clinically isolated Salmonella Typhimurium exposed to ceftriaxone and ciprofloxacin. The antibiotic susceptibility, β-lactamase activity, efflux activity, bacterial motility, biofilm-forming ability, and gene expression were determined in S. Typhimurium ATCC 19585 and S. Typhimurium CCARM 8009 when exposed to subinhibitory concentrations of ceftriaxone and ciprofloxacin. S. Typhimurium CCARM 8009 was highly resistant to ampicillin, kanamycin, penicillin G, and streptomycin, showing minimum inhibitory concentration values of more than 512 μg/ml, while S...
May 9, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
https://www.readbyqxmd.com/read/28476775/defining-genetic-fitness-determinants-and-creating-genomic-resources-for-an-oral-pathogen
#14
Ajay M Narayanan, Matthew M Ramsey, Apollo Stacy, Marvin Whiteley
Periodontitis is a microbial infection that destroys the structures that support the teeth. Although it is typically a chronic condition, rapidly progressing, aggressive forms are associated with the oral pathogen Aggregatibacter actinomycetemcomitans One of this bacterium's key virulence traits is its ability to attach to surfaces and form robust biofilms that resist killing by the host and antibiotics. Though much has been learned about A. actinomycetemcomitans since its initial discovery, we lack insight into a fundamental aspect of its basic biology, as we do not know the full set of genes that it requires for viability (the essential genome)...
July 15, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28437232/epidemiological-physiological-and-molecular-characteristics-of-a-brazilian-collection-of-carbapenem-resistant-acinetobacter-baumannii-and-pseudomonas-aeruginosa
#15
Vanessa Cordeiro Dias, Juliana Alves Resende, André Netto Bastos, Lucas Quinet De Andrade Bastos, Victor Quinet De Andrade Bastos, Ricardo Villela Bastos, Cláudio Galuppo Diniz, Vânia Lúcia Da Silva
Nonfermenting Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii are widespread in the environment and are increasingly associated with nosocomial infections, often associated with multidrug-resistance phenotypes. This study aimed to evaluate epidemiological, physiological, and molecular characteristics of carbapenem resistance in P. aeruginosa and A. baumannii. In total, 63 nonreplicated strains (44 A. baumannii and 19 P. aeruginosa) were isolated from hospitalized patients. Antimicrobial resistance patterns, biocide tolerance, oxidative stress, hemolytic activity, and biofilm formation were assessed...
February 24, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
https://www.readbyqxmd.com/read/28436748/disruption-of-tetr-type-regulator-aden-by-mobile-genetic-element-confers-elevated-virulence-in-acinetobacter-baumannii
#16
Rajagopalan Saranathan, Sudhakar Pagal, Ajit R Sawant, Archana Tomar, M Madhangi, Suresh Sah, Annapurna Satti, K P Arunkumar, K Prashanth
Acinetobacter baumannii is an important human pathogen and considered as a major threat due to its extreme drug resistance. In this study, the genome of a hyper-virulent MDR strain PKAB07 of A. baumannii isolated from an Indian patient was sequenced and analyzed to understand its mechanisms of virulence, resistance and evolution. Comparative genome analysis of PKAB07 revealed virulence and resistance related genes scattered throughout the genome, instead of being organized as an island, indicating the highly mosaic nature of the genome...
April 24, 2017: Virulence
https://www.readbyqxmd.com/read/28348056/analysis-of-shigella-flexneri-resistance-biofilm-formation-and-transcriptional-profile-in-response-to-bile-salts
#17
Kourtney P Nickerson, Rachael B Chanin, Jeticia R Sistrunk, David A Rasko, Peter J Fink, Eileen M Barry, James P Nataro, Christina S Faherty
The Shigella species cause millions of cases of watery or bloody diarrhea each year, mostly in children in developing countries. While many aspects of Shigella colonic cell invasion are known, crucial gaps in knowledge regarding how the bacteria survive, transit, and regulate gene expression prior to infection remain. In this study, we define mechanisms of resistance to bile salts and build on previous research highlighting induced virulence in Shigella flexneri strain 2457T following exposure to bile salts...
June 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28289081/light-modulates-metabolic-pathways-and-other-novel-physiological-traits-in-the-human-pathogen-acinetobacter-baumannii
#18
Gabriela L Müller, Marisel Tuttobene, Matías Altilio, Maitena Martínez Amezaga, Meaghan Nguyen, Pamela Cribb, Larisa E Cybulski, María Soledad Ramírez, Silvia Altabe, María Alejandra Mussi
Light sensing in chemotrophic bacteria has been relatively recently ascertained. In the human pathogen Acinetobacter baumannii, light modulates motility, biofilm formation, and virulence through the blue-light-sensing-using flavin (BLUF) photoreceptor BlsA. In addition, light can induce a reduction in susceptibility to certain antibiotics, such as minocycline and tigecycline, in a photoreceptor-independent manner. In this work, we identified new traits whose expression levels are modulated by light in this pathogen, which comprise not only important determinants related to pathogenicity and antibiotic resistance but also metabolic pathways, which represents a novel concept for chemotrophic bacteria...
May 15, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28275296/effect-of-biofilm-formation-by-clinical-isolates-of-helicobacter-pylori-on-the-efflux-mediated-resistance-to-commonly-used-antibiotics
#19
Bahareh Attaran, Tahereh Falsafi, Nassim Ghorbanmehr
AIM: To evaluate the role of biofilm formation on the resistance of Helicobacter pylori (H. pylori) to commonly prescribed antibiotics, the expression rates of resistance genes in biofilm-forming and planktonic cells were compared. METHODS: A collection of 33 H. pylori isolates from children and adult patients with chronic infection were taken for the present study. The isolates were screened for biofilm formation ability, as well as for polymerase chain reaction (PCR) reaction with HP1165 and hp1165 efflux pump genes...
February 21, 2017: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/28270804/eradication-and-sensitization-of-methicillin-resistant-staphylococcus-aureus-to-methicillin-with-bioactive-extracts-of-berry-pomace
#20
Serajus Salaheen, Mengfei Peng, Jungsoo Joo, Hironori Teramoto, Debabrata Biswas
The therapeutic roles of phenolic blueberry (Vaccinium corymbosum) and blackberry (Rubus fruticosus) pomace (commercial byproduct) extracts (BPE) and their mechanism of actions were evaluated against methicillin resistant Staphylococcus aureus (MRSA). Five major phenolic acids of BPE, e.g., protocatechuic, p. coumaric, vanillic, caffeic, and gallic acids, as well as crude BPE completely inhibited the growth of vegetative MRSA in vitro while BPE+methicillin significantly reduced MRSA biofilm formation on plastic surface...
2017: Frontiers in Microbiology
keyword
keyword
116780
1
2
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"