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Polysaccharide klebsiella

Anna Mularski, Jonathan Wilksch, Eric Hanssen, Jian Li, Takehiro Tomita, Sacha James Pidot, Tim Stinear, Frances Separovic, Dick Strugnell
Atomic force microscopy measurements of capsule thickness revealed that that the wild-type Klebsiella pneumoniae AJ218 capsular polysaccharides were rearranged by exposure to colistin. The increase in capsule thickness measured near minimum inhibitory/bactericidal concentration (MIC/MBC) is consistent with the idea that colistin displaces the divalent cations that cross-bridge adjacent lipopolysaccharide (LPS) molecules through the capsule network. Cryo-electron microscopy demonstrated that the measured capsule thickness at near MIC/MBC of 1...
October 17, 2016: European Biophysics Journal: EBJ
Kwan Soo Ko
No abstract text is available yet for this article.
October 7, 2016: Virulence
Lei Yu, Qing-Wen Tang, Yu-Jia Zhang, Rong-Ping Chen, Xin Liu, Wei-Chuan Qiao, Wen-Wei Li, Hong-Hua Ruan, Xin Song
In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses...
October 7, 2016: Scientific Reports
L Kristopher Siu, Yu-Kuo Tsai, Jung-Chung Lin, Te-Li Chen, Chang-Phone Fung, Feng-Yee Chang
In this study, a novel colloidal gold-based immunochromatographic strip (ICS) containing anti-K. pneumoniae capsular polysaccharide polyclonal antibodies was developed to specifically detect K. pneumoniae serotypes K1 and K2. Capsular polysaccharide K1 and K2 antigens were first used to produce polyclonal anti-K1 or -K2 antibodies. Reference strains with different serotypes, non-typable K. pneumoniae strains, and other bacterial species were then used to assess the sensitivity and specificity of these test strips...
October 5, 2016: Journal of Clinical Microbiology
Tolani F Olonisakin, Huihua Li, Zeyu Xiong, Elizabeth J K Kochman, Minting Yu, Yanyan Qu, Mei Hulver, Jay K Kolls, Claudette St Croix, Yohei Doi, Minh-Hong Nguyen, Robert M Q Shanks, Rama K Mallampalli, Valerian E Kagan, Anuradha Ray, Roy L Silverstein, Prabir Ray, Janet S Lee
Klebsiella pneumoniae remains an important cause of intrapulmonary infection and invasive disease worldwide. Klebsiella pneumoniae can evade serum killing and phagocytosis primarily through the expression of a polysaccharide capsule, but its pathogenicity is also influenced by host factors. We examined whether CD36, a scavenger receptor that recognizes pathogen and modified-self ligands, is a host determinant of Klebsiella pneumoniae pathogenicity. Despite differences in serum sensitivity and virulence of three distinct Klebsiella pneumoniae (hypermucoviscous K1, research K2, carbapenemase-producing ST258) strains utilized, the absence of CD36 significantly increased host susceptibility to acute intrapulmonary infection by K...
September 28, 2016: Journal of Infectious Diseases
Monica Benincasa, Cristina Lagatolla, Lucilla Dolzani, Annalisa Milan, Sabrina Pacor, Gianfranco Liut, Alessandro Tossi, Paola Cescutti, Roberto Rizzo
Biofilm matrices of two Klebsiella pneumoniae clinical isolates, KpTs101 and KpTs113, were investigated for their polysaccharide composition and protective effects against antimicrobial peptides. Both strains were good biofilm producers, with KpTs113 forming flocs with very low adhesive properties to supports. Matrix exopolysaccharides were isolated and their monosaccharide composition and glycosidic linkage types were defined. KpTs101 polysaccharide is neutral and composed only of galactose, in both pyranose and furanose ring configurations...
August 10, 2016: Microorganisms
Adeyemi Ojutalayo Adeeyo, Agbaje Lateef, Evariste Bosco Gueguim-Kana
Exopolysaccharide (EPS) production by a strain of Lentinus edodes was studied via the effects of treatments with ultraviolet (UV) irradiation and acridine orange. Furthermore, optimization of EPS production was studied using a genetic algorithm coupled with an artificial neural network in submerged fermentation. Exposure to irradiation and acridine orange resulted in improved EPS production (2.783 and 5.548 g/L, respectively) when compared with the wild strain (1.044 g/L), whereas optimization led to improved productivity (23...
2016: International Journal of Medicinal Mushrooms
Chii-Lan Lin, Fei-Hsu Chen, Li-Yueh Huang, Jen-Chang Chang, Jiun-Han Chen, Yu-Kuo Tsai, Feng-Yee Chang, Jung-Chung Lin, L Kristopher Siu
The capsular polysaccharides in different serotypes of Klebsiella pneumoniae (KP) coded by the (CPS) gene cluster are characterized by a conserved and a hyper-variable region. We performed a virulence study by switching genes in the highly conserved region of the CPS cluster between strains. Six genes in the CPS conserved region in serotype K20, including galF, acidPPc, wzi, wza, wzb and wzc, were knocked out and replaced by the homologous genes from serotype K1. Compared to the parental K20 strain, the mutants showed a decline in lethality (LD50) in mice from 10-fold to > 10(5)-fold and were categorized in terms of the effect on virulence as low (L) for galF and acidPPC, moderate (M) for wzi, and high (H) for wza, wzb and wzc...
August 26, 2016: Virulence
Chun-Ru Hsu, Chun-Hsing Liao, Tzu-Lung Lin, Han-Ru Yang, Feng-Ling Yang, Pei-Fang Hsieh, Shih-Hsiung Wu, Jin-Town Wang
Klebsiella pneumoniae can cause community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) is important for its virulence. Among 79 capsular (K) types discovered thus far, K57 is often associated with PLA. Here, we report the identification of a K57 variant. Cps gene locus sequencing revealed differences between the K57 reference strain 4425/51 (Ref-K57) and a variant, the PLA isolate A1142. While Ref-K57 cps contained orf13 encoding a putative acetyltransferase, the insertion of a putative transposase-encoding gene at this position was detected in A1142...
2016: Scientific Reports
Taesoo Kwon, Young-Hee Jung, Sanghyun Lee, Mi-Ran Yun, Won Kim, Dae-Won Kim
BACKGROUND: Klebsiella pneumoniae subsp. pneumoniae KP617 is a pathogenic strain that coproduces OXA-232 and NDM-1 carbapenemases. We sequenced the genome of KP617, which was isolated from the wound of a Korean burn patient, and performed a comparative genomic analysis with three additional strains: PittNDM01, NUHL24835 and ATCC BAA-2146. RESULTS: The complete genome of KP617 was obtained via multi-platform whole-genome sequencing. Phylogenetic analysis along with whole genome and multi-locus sequence typing of genes of the Klebsiella pneumoniae species showed that KP617 belongs to the WGLW2 group, which includes PittNDM01 and NUHL24835...
2016: Gut Pathogens
Nawapan Pongsapipatana, Piyanat Damrongteerapap, Sudathip Chantorn, Wilawan Sintuprapa, Suttipun Keawsompong, Sunee Nitisinprasert
Gene encoding for β-mannanase (E.C from Klebsiella oxytoca KUB-CW2-3 was cloned and expressed by an E. coli system resulting in 400 times higher mannanase activities than the wild type. A 3314bp DNA fragment obtained revealed an open reading frame of 1164bp, namely kman-2, which encoded for 387 amino acids with an estimated molecular weight of 43.2kDa. It belonged to the glycosyl hydrolase family 26 (GH26) exhibited low similarity of 50-71% to β-mannanase produced by other microbial sources. Interestingly, the enzyme had a broad range of substrate specificity of homopolymer of ivory nut mannan (6%), carboxymethyl cellulose (30...
July 2016: Enzyme and Microbial Technology
Paola Cescutti, Gianluigi De Benedetto, Roberto Rizzo
Klebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy-seven different K antigens have been described and they are the basis for K serotyping. Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid medium, where it formed floating biofilms (flocs)...
July 22, 2016: Carbohydrate Research
Chen-Hsiang Lee, I-Ling Chen, Seng-Kee Chuah, Wei-Chen Tai, Chia-Chi Chang, Fang-Ju Chen, Jung-Fu Chen
Klebsiella pneumoniae (KP), with production of abundant capsular polysaccharide (CPS), is capable of causing invasive syndrome. Environmental glucose stimuli may increase CPS biosynthesis. We aimed to investigate the relationship between glycemic control and KP-mediated invasive syndrome in diabetic patients and the effect of glucose on CPS biosynthesis. Diabetic patients with community-acquired KP bacteremia were included to study the risk factors of invasive syndrome. KP-M1, a serotype-K1 KP clinical isolate, was used to examine the CPS biosynthesis and cps gene expression, and the effect of exogenous glucose on bacterial phagocytosis and killing...
October 2, 2016: Virulence
Anna Mularski, Jonathan J Wilksch, Eric Hanssen, Richard A Strugnell, Frances Separovic
Time-resolved AFM images revealed that the antimicrobial peptide (AMP) caerin 1.1 caused localised defects in the cell walls of lysed Klebsiella pneumoniae cells, corroborating a pore-forming mechanism of action. The defects continued to grow during the AFM experiment, in corroboration with large holes that were visualised by scanning electron microscopy. Defects in cytoplasmic membranes were visualised by cryo-EM using the same peptide concentration as in the AFM experiments. At three times the minimum inhibitory concentration of caerin, 'pores' were apparent in the outer membrane...
June 2016: Biochimica et Biophysica Acta
Yanfei Kang, Pingfang Tian, Tianwei Tan
Klebsiella pneumoniae is of great attractiveness because it naturally produces a series of bulk chemicals such as 1,3-propanediol, 2,3-butanediol and 3-hydroxypropionic acid. Although this species has been fueled in recent years, its pathogenicity is considered an obstacle hindering industrial applications. Here we portray a picture of the virulence factors, including pili, receptors, capsular polysaccharides, lipopolysaccharides, and newly identified virulence factors. This review covers aspects of virulence genes, proteins, metabolic activities, as well as the mechanisms underlying infection and immune responses...
October 4, 2015: Wei Sheng Wu Xue Bao, Acta Microbiologica Sinica
Evan Mann, Evan Mallette, Bradley R Clarke, Matthew S Kimber, Chris Whitfield
Export of the Escherichia coli serotype O9a O-antigenic polysaccharides (O-PS) involves an ATP-binding cassette (ABC) transporter. The process requires a non-reducing terminal residue, which is recognized by a carbohydrate-binding module (CBM) appended to the C terminus of the nucleotide-binding domain of the transporter. Here, we investigate the process in Klebsiella pneumoniae serotype O12 (and Raoultella terrigena ATCC 33257). The O12 polysaccharide is terminated at the non-reducing end by a β-linked 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) residue...
April 29, 2016: Journal of Biological Chemistry
Miguel A Ares, José L Fernández-Vázquez, Roberto Rosales-Reyes, Ma Dolores Jarillo-Quijada, Kristine von Bargen, Javier Torres, Jorge A González-Y-Merchand, María D Alcántar-Curiel, Miguel A De la Cruz
Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial infections. Main virulence determinants of K. pneumoniae are pili, capsular polysaccharide, lipopolysaccharide, and siderophores. The histone-like nucleoid-structuring protein (H-NS) is a pleiotropic regulator found in several gram-negative pathogens. It has functions both as an architectural component of the nucleoid and as a global regulator of gene expression. We generated a Δhns mutant and evaluated the role of the H-NS nucleoid protein on the virulence features of K...
2016: Frontiers in Cellular and Infection Microbiology
Kuo-Ming Yeh, Sheng-Kung Chiu, Chii-Lan Lin, Li-Yueh Huang, Yu-Kuo Tsai, Jen-Chang Chang, Jung-Chung Lin, Feng-Yee Chang, Leung-Kei Siu
BACKGROUND: The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. METHOD: To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver...
2016: Gut Pathogens
Sebastien Breurec, Benedicte Melot, Bruno Hoen, Virginie Passet, Kinda Schepers, Sylvaine Bastian, Sylvain Brisse
We report a case of pyogenic liver abscess caused by community-acquired Klebsiella quasipneumoniae subsp. quasipneumoniae. The infecting isolate had 2 prominent features of hypervirulent K. pneumoniae strains: the capsular polysaccharide synthesis region for K1 serotype and the integrative and conjugative element ICEKp1, which encodes the virulence factors yersiniabactin, salmochelin, and RmpA.
March 2016: Emerging Infectious Diseases
Franco Baldi, Salvatore Daniele, Michele Gallo, Stefano Paganelli, Dario Battistel, Oreste Piccolo, Claudia Faleri, Anna Maria Puglia, Giuseppe Gallo
Silver nanoparticles (AgNPs), embedded into a specific exopolysaccharide (EPS), were produced by Klebsiella oxytoca DSM 29614 by adding AgNO3 to the cultures during exponential growth phase. In particular, under aerobic or anaerobic conditions, two types of silver nanoparticles, named AgNPs-EPS(aer) and the AgNPs-EPS(anaer), were produced respectively. The effects on bacterial cells was demonstrated by using Escherichia coli K12 and Kocuria rhizophila ATCC 9341 (ex Micrococcus luteus) as Gram-negative and Gram-positive tester strains, respectively...
April 2016: Biometals: An International Journal on the Role of Metal Ions in Biology, Biochemistry, and Medicine
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