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klebsiella pneumoniae capsule

Scott D Kobayashi, Adeline R Porter, Brett Freedman, Ruchi Pandey, Liang Chen, Barry N Kreiswirth, Frank R DeLeo
Carbapenem-resistant Klebsiella pneumoniae is a problem worldwide. A carbapenem-resistant K. pneumoniae lineage classified as multilocus sequence type 258 (ST258) is prominent in the health care setting in many regions of the world, including the United States. ST258 strains can be resistant to virtually all clinically useful antibiotics; treatment of infections caused by these organisms is difficult, and mortality is high. As a step toward promoting development of new therapeutics for ST258 infections, we tested the ability of rabbit antibodies specific for ST258 capsule polysaccharide to enhance human serum bactericidal activity and promote phagocytosis and killing of these bacteria by human neutrophils...
March 13, 2018: MBio
Andrés E Marcoleta, Macarena A Varas, Javiera Ortiz-Severín, Leonardo Vásquez, Camilo Berríos-Pastén, Andrea V Sabag, Francisco P Chávez, Miguel L Allende, Carlos A Santiviago, Octavio Monasterio, Rosalba Lagos
Multiresistant and invasive hypervirulent Klebsiella pneumoniae strains have become one of the most urgent bacterial pathogen threats. Recent analyses revealed a high genomic plasticity of this species, harboring a variety of mobile genetic elements associated with virulent strains, encoding proteins of unknown function whose possible role in pathogenesis have not been addressed. K. pneumoniae virulence has been studied mainly in animal models such as mice and pigs, however, practical, financial, ethical and methodological issues limit the use of mammal hosts...
2018: Frontiers in Cellular and Infection Microbiology
Dong Wei, Yuki Yuminaga, Jiping Shi, Jian Hao
OBJECTIVES: To investigate the outcomes of capsule lost on cell transformation efficiency and chemicals (1,3-propanediol, 2,3-butanediol, and 2-ketogluconic acid) production by Klebsiella pneumoniae. RESULTS: The cps gene cluster showed low sequence homology with pathogenic strains. The wza is a highly conserved gene in the cps cluster that encodes an outer membrane protein. A non-capsulated mutant was constructed by deletion of wza. Phenotype studies demonstrated that non-capsulated cells were less buoyant and easy to sediment...
February 10, 2018: Biotechnology Letters
Barbara Corelli, Ana S Almeida, Fabiane Sonego, Virginia Castiglia, Cindy Fevre, Sylvain Brisse, Philippe J Sansonetti, Régis Tournebize
Rhinoscleroma is a human specific chronic granulomatous infection of the nose and upper airways caused by the gram-negative bacterium Klebsiella pneumoniae subsp. rhinoscleromatis. Although considered a rare disease, it is endemic in low-income countries where hygienic conditions are poor. A hallmark of this pathology is the appearance of atypical foamy monocytes called Mikulicz cells. However, the pathogenesis of rhinoscleroma remains poorly investigated. Capsule polysaccharide (CPS) is a prominent virulence factor in bacteria...
January 30, 2018: PLoS Neglected Tropical Diseases
V Nordberg, K Jonsson, C G Giske, A Iversen, O Aspevall, B Jonsson, A Camporeale, M Norman, L Navér
OBJECTIVE: To analyse Klebsiella pneumoniae (KP) isolates from an outbreak of Extended-Spectrum β-Lactamase (ESBL)-producing KP and Escherichia coli (ESBL-EC) among infants admitted to neonatal intensive care units (NICUs) and to determine the duration of the intestinal colonization. METHODS: A prospective cohort study of intestinal ESBL-KP/ ESBL-EC colonized neonates after a five-month outbreak in two NICUs. Whole genome sequencing (WGS), multilocus sequence typing (MLST), core genome MLST, pulsed-field electrophoresis (PFGE) and PCR for blaCTX-M were performed on the first isolates...
January 8, 2018: Clinical Microbiology and Infection
Rambha K Shah, Zhao H Ni, Xiao Y Sun, Guo Q Wang, Fan Li
Klebsiella pneumoniae strains that are commonly recognized by clinicians and microbiologists are termed as classical K. pneumoniae (cKP). A strain with capsule-associated mucopolysaccharide web is known as hypervirulent K. pneumoniae (hvKP) as it enhances the serum resistant and biofilm production. Aim is to determine and correlate various virulence genes, ESBL, serum bactericidal effect and biofilm formation of clinical isolated cKP and hvKP from respiratory tract infected patients. A total of 96 K. pneumoniae strains were isolated from sputum of respiratory tract infected patients...
December 4, 2017: Polish Journal of Microbiology
Wei Zhao, Qing Tian, Yan Luo, Yin Wang, Ze-Xiao Yang, Xue-Ping Yao, Jian-Guo Cheng, Xin Zhou, Wu-You Wang
Klebsiella pneumoniae is an important pathogen commonly associated with opportunistic infections. In this study, lung pathogenic K. pneumoniae (LPKP) was isolated and identified from suppurative pneumoniae in forest musk deer by conventional methods and by 16S ribosomal RNA sequence analysis. Median lethal dose and histopathologic analysis were used to demonstrate pathogenicity of the organism in mice. Furthermore, a draft genome of LPKP was sequenced, and its virulence genes were detected. One hundred and twenty-two virulence genes encoded determinant of capsule polysaccharide (CPS), lipopolysaccharide, fimbriae, outer membrane proteins, iron acquisition, and urease...
December 2017: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
Jane F Turton, Zoë Payne, Amy Coward, Katie L Hopkins, Jack A Turton, Michel Doumith, Neil Woodford
PURPOSE: Klebsiella pneumoniae is a concern because of its multidrug resistance and the ability of hypervirulent types, especially capsular type K1-clonal complex 23 (K1-CC23), to cause community-acquired, life-threatening infections. Hypervirulent types carry an array of virulence genes including rmpA/rmpA2, coding for capsule up-regulation. We sought to identify isolates carrying these elements among submissions to the UK national reference laboratory during 2016. METHODOLOGY: Virulence elements and carbapenemase genes were sought by PCR or from whole genome sequences...
January 2018: Journal of Medical Microbiology
David A Rosen, Joy Twentyman, David A Hunstad
The bacterial second messenger bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) has been shown to influence the expression of virulence factors in certain pathogenic bacteria, but little is known about its activity in the increasingly antibiotic-resistant pathogen Klebsiella pneumoniae Here, the expression in K. pneumoniae of a heterologous diguanylate cyclase increased the bacterial c-di-GMP concentration and attenuated pathogenesis in murine pneumonia. This attenuation remained evident in mice lacking the c-di-GMP sensor STING, indicating that the high c-di-GMP concentration exerted its influence not on host responses but on bacterial physiology...
February 2018: Infection and Immunity
Halit Kuş, Uğur Arslan, Hatice Türk Dağı, Duygu Fındık
Klebsiella pneumoniae is an opportunistic pathogen that commonly affects immunosuppressed patients and causes nosocomial infections. K.pneumoniae has a variety of virulence factors, especially capsule polysaccharide, hypermucoviscosity (HV), fimbriae, toxins and determinants for iron acquisition. The aim of this study was to detect the virulence factors in K.pneumoniae strains isolated from nosocomial infections in two years. Fifty three K.pneumoniae strains isolated from the samples of patients with nosocomial infections in the Medical Microbiology Laboratory of Selcuk University Faculty of Medicine Hospital between 2011 and 2013 were included in the study...
October 2017: Mikrobiyoloji Bülteni
Fiorella Krapp, Andrew R Morris, Egon A Ozer, Alan R Hauser
Two types of Klebsiella pneumoniae (KP) strains are currently emerging: hypervirulent (hvKP) strains and carbapenem-resistant (CR-KP) strains. To date, these two strain types rarely overlap. Recent reports, however, suggest that CR-KP strains are increasing in virulence. hvKP strains frequently present as highly invasive infections, such as necrotizing skin and soft tissue infections (NSSTI). To examine whether CR-KP strains with features of hvKP were present in our U.S. hospital, we retrospectively identified four cases of CR-KP NSSTI diagnosed between January 2012 and January 2016...
October 19, 2017: Scientific Reports
I Russel Lee, Ethel Sng, Kok-Onn Lee, James S Molton, Monica Chan, Shirin Kalimuddin, Ezlyn Izharuddin, David C Lye, Sophia Archuleta, Yunn-Hwen Gan
The major risk factor for Klebsiella liver abscess (KLA) is type 2 diabetes mellitus (DM), but the immunological mechanisms involved in the increased susceptibility are poorly defined. We investigated the responses of neutrophils and peripheral blood mononuclear cells (PBMCs) to hypervirulent Klebsiella pneumoniae (hvKP), the causative agent of KLA. DNA and myeloperoxidase levels were elevated in the plasma of KLA patients compared to uninfected individuals indicating neutrophil activation, but diabetic status had no effect on these neutrophil extracellular trap (NET) biomarkers in both subject groups...
2017: Frontiers in Cellular and Infection Microbiology
Martha Lorena Ostria-Hernandez, Karla Cecilia Juárez-de la Rosa, Patricia Arzate-Barbosa, Antonino Lara-Hernández, Fuminori Sakai, J Antonio Ibarra, Graciela Castro-Escarpulli, Jorge E Vidal
BACKGROUND: Klebsiella pneumoniae (Kpn) strains are a leading cause of hospital-acquired infections, including ventilator-associated pneumonia. Resistance to antibiotics, biofilm formation, and the production of certain fimbriae play an important role in the pathogenesis. AIM: We investigated the genetic relatedness, antibiotic resistance, virulence potential, and ability to form biofilms of Kpn strains isolated from hospital-acquired infections (n = 76). Strains were isolated at three major hospitals serving the largest metropolitan urban area in Mexico City, Mexico...
September 15, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
Michelle Palacios, Christopher A Broberg, Kimberly A Walker, Virginia L Miller
Klebsiella pneumoniae is considered a significant public health threat because of the emergence of multidrug-resistant strains and the challenge associated with treating life-threatening infections. Capsule, siderophores, and adhesins have been implicated as virulence determinants of K. pneumoniae, yet we lack a clear understanding of how this pathogen causes disease. In a previous screen for virulence genes, we identified a potential new virulence locus and constructed a mutant (smr) with this locus deleted...
July 2017: MSphere
Yee-Huang Ku, Yin-Ching Chuang, Chi-Chung Chen, Mei-Feng Lee, Yan-Chang Yang, Hung-Jen Tang, Wen-Liang Yu
Klebsiella pneumoniae (KP) resistance to broad-spectrum cephalosporin (BSC) in meningitis is important because of limited therapeutic options. To investigate the antibiotic resistance, virulence and epidemiology of KP in meningitis, we conducted a retrospective study for 33 non-metastatic isolates, including primary meningitis (n = 20) and post-craniotomy meningitis (n = 13) collected from 1999 to 2013. BSC resistance was found in 9 (27.3%) isolates, all from post-craniotomy meningitis, harboring bla SHV-5 (n = 6), bla CMY-2 (n = 2), bla DHA-1 (n = 2), and bla TEM-1B (n = 1)...
July 26, 2017: Scientific Reports
C Vuotto, F Longo, C Pascolini, G Donelli, M P Balice, M F Libori, V Tiracchia, A Salvia, P E Varaldo
AIMS: Multidrug-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. Nonenzymatic antibiotic resistance is related to nonexpression or mutation of porins (OmpK35 and OmpK36), and efflux pump (acrB) overexpression. The aim of this study was to analyse some virulence factors of K...
July 21, 2017: Journal of Applied Microbiology
Baharak Babouee Flury, Valentina Donà, Niccolò Buetti, Hansjakob Furrer, Andrea Endimiani
BACKGROUND: We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland. METHODS: Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates. RESULTS: Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases...
September 2017: Journal of Global Antimicrobial Resistance
Edward H Wood, Matthew A Powers, Darius M Moshfeghi
In this retrospective report, the authors describe a rare case of spontaneous globe rupture from Klebsiella pneumoniae endophthalmitis in a middle-aged man with poorly controlled type 2 diabetes mellitus. There have been only four previously reported cases of spontaneous globe rupture from endophthalmitis. Out of the now five reported cases, all have been due to endogenous endophthalmitis, four have been due to gram-negative bacteria, and three have been due to K. pneumoniae. K. pneumoniae, especially the hypermucoid variant with a protective polysaccharide capsule, is an emerging pathogen with remarkable virulence...
July 1, 2017: Ophthalmic Surgery, Lasers & Imaging Retina
Pei-Fang Hsieh, Hsiao-Hsuan Lin, Tzu-Lung Lin, Yi-Yin Chen, Jin-Town Wang
Two Klebsiella bacteriophages K5-2 and K5-4, which are able to infect and grow on either capsular types K30/K69 and K5 or K8 and K5 of Klebsiella strains, were isolated and characterized. Each phage contained two open reading frames (ORFs), which encoded two putative capsule depolymerases, respectively. The first ORF encoded tail fiber proteins, which have K30/K69 depolymerase and K8 depolymerase activities. The second ORF encoded hypothetical proteins, which are almost identical in amino acid sequences, and have K5 depolymerase activity...
July 4, 2017: Scientific Reports
Lingling Zhan, Shanshan Wang, Yinjuan Guo, Ye Jin, Jingjing Duan, Zhihao Hao, Jingnan Lv, Xiuqin Qi, Longhua Hu, Liang Chen, Barry N Kreiswirth, Rong Zhang, Jingye Pan, Liangxing Wang, Fangyou Yu
Hypervirulent and multidrug resistant Klebsiella pneumoniae strains pose a significant threat to the public health. In the present study, 21 carbapenem-resistant K. pneumoniae isolates (CRKP) were determined by the string test as hypermucoviscous K. pneumoniae (HMKP), with the prevalence of 15.0% (21/140) among CRKP, and 1.1% (21/1838) among all K. pneumoniae isolates. Among them, 7 (33.3%), and 1 (4.76%) isolate belonged to capsular serotype K20 and K2 respectively, while 13 (61.9%, 13/21) weren't successfully typed by capsular serotyping...
2017: Frontiers in Cellular and Infection Microbiology
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