scholarly journals Genomic organization and regulation of cps cluster that is involved in synthesis of capsular polysaccharide as a virulence factor of Klebsiella pneumoniae.

1994 ◽  
Vol 49 (3/4) ◽  
pp. 455-463 ◽  
Author(s):  
Yoshichika ARAKAWA
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Factor ◽  
Capsular Polysaccharide ◽  
Genomic Organization

scholarly journals Microbiological characteristics of hypermucoviscous Klebsiella pneumoniae isolates from different body fluids

2017 ◽  
Vol 11 (09) ◽  
pp. 672-678
Author(s):  
Xiumei Xiao ◽  
Bei Yao ◽  
Qingtao Zhou ◽  
Jie Zhang
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Factor ◽  
Medical Records ◽  
Capsular Polysaccharide ◽  
Body Fluids ◽  
Microbiological Characteristics ◽  
Group 2 ◽  
Challenging Situation ◽  
Sequence Types ◽  
Group 1

Introduction: Reports of hypermucoviscous Klebsiella pneumoniae (hvKP) isolated from fluids other than blood or abscess are rare. The aim of the study was to compare clinical and microbiological characteristics of hvKP found in blood or abscess fluid with those isolated from other loci. Methodology: A total of 24 non-repetitive hvKP isolates were collected from January 2013 to June 2014 from patients with hvKP infections. There were 15 in Group 1 (fluid other than blood or abscess) and 9 in Group 2 (blood or abscess fluid). Medical records of all patients were reviewed. Capsular polysaccharide (CPS) typing, virulence factor determination, and multilocus sequence typing (MLST) of hvKP isolates were performed. Results: Seventeen sequence types (STs) and 6 capsular serotypes were identified. Type K2CC65 was most commonly identified in Group 1 and type K2CC86 in Group 2. Deletion of pLVPK-derived loci were found in K2 and non-K1/K2 hvKP strains. Two virulent genes, fimH and ycfM, were identified more frequently in Group 2 than in Group 1. There was no difference in the frequency of other virulent genes or serotypes in the two groups. Two imipenem resistant hvKP isolates (cr-hvKP) were found in non-blood or abscess samples. Conclusions: hvKP isolated from different body fluids had similar clinical and microbiological characteristics. cr-hvKP identified in non-blood or abscess samples should raise our attention to the challenging situation and management of hvKP infection.

scholarly journals The PTS Components in Klebsiella pneumoniae Affect Bacterial Capsular Polysaccharide Production and Macrophage Phagocytosis Resistance

2021 ◽  
Vol 9 (2) ◽  
pp. 335
Author(s):  
Novaria Sari Dewi Panjaitan ◽  
Yu-Tze Horng ◽  
Chih-Ching Chien ◽  
Hung-Chi Yang ◽  
Ren-In You ◽  
...  
Keyword(s):  
Survival Rate ◽  
Klebsiella Pneumoniae ◽  
Laser Scanning ◽  
Bacterial Resistance ◽  
Capsular Polysaccharide ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Intracellular Bacteria ◽  
Wild Type ◽  
Macrophage Phagocytosis

Capsular polysaccharide (CPS) is a crucial virulence factor for Klebsiella pneumoniae infection. We demonstrated an association of CPS production with two phosphoenolpyruvate:carbohydrate phosphotransferase systems (PTSs). Deficiency of crr, encoding enzyme IIA of PTS, in K. pneumoniae enhanced the transcriptional activities of galF, wzi and gnd, which are in the cps gene cluster, leading to high CPS production. A crr mutant exhibited a higher survival rate in 1% hydrogen peroxide than the wild-type. The crr mutant showed less sensitivity to engulfment by macrophage (RAW 264.7) than the wild-type by observing the intracellular bacteria using confocal laser scanning microscopy (CLSM) and by calculating the colony-forming units (CFU) of intracellular bacteria. After long-term incubation, the survival rate of the intracellular crr mutant was higher than that of the wild-type. Deficiency of crr enhanced the transcriptional activities of etcABC which encodes another putative enzyme II complex of a PTS. Deletion of etcABC in the crr mutant reduced CPS production and the transcriptional activities of galF compared to those of the crr mutant. These results indicated that one PTS component, Crr, represses CPS production by repressing another PTS component, EtcABC, in K. pneumoniae. In addition, PTS plays a role in bacterial resistance to macrophage phagocytosis.

scholarly journals Phage Resistance Is Associated with Decreased Virulence in KPC-Producing Klebsiella pneumoniae of the Clonal Group 258 Clade II Lineage

2021 ◽  
Vol 9 (4) ◽  
pp. 762
Author(s):  
Lucia Henrici De Angelis ◽  
Noemi Poerio ◽  
Vincenzo Di Pilato ◽  
Federica De Santis ◽  
Alberto Antonelli ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Parental Strain ◽  
Bacterial Infections ◽  
Capsular Polysaccharide ◽  
Galleria Mellonella ◽  
Bacterial Pathogen ◽  
Phage Resistance ◽  
Infection Model ◽  
Lytic Phage ◽  
Susceptible Host

Phage therapy is now reconsidered with interest in the treatment of bacterial infections. A major piece of information for this application is the definition of the molecular targets exploited by phages to infect bacteria. Here, the genetic basis of resistance to the lytic phage φBO1E by its susceptible host Klebsiella pneumoniae KKBO-1 has been investigated. KKBO-1 phage-resistant mutants were obtained by infection at high multiplicity. One mutant, designated BO-FR-1, was selected for subsequent experiments, including virulence assessment in a Galleria mellonella infection model and characterization by whole-genome sequencing. Infection with BO-FR-1 was associated with a significantly lower mortality when compared to that of the parental strain. The BO-FR-1 genome differed from KKBO-1 by a single nonsense mutation into the wbaP gene, which encodes a glycosyltransferase involved in the first step of the biosynthesis of the capsular polysaccharide (CPS). Phage susceptibility was restored when BO-FR-1 was complemented with the constitutive wbaP gene. Our results demonstrated that φBO1E infects KKBO-1 targeting the bacterial CPS. Interestingly, BO-FR-1 was less virulent than the parental strain, suggesting that in the context of the interplay among phage, bacterial pathogen and host, the emergence of phage resistance may be beneficial for the host.

scholarly journals Amino Acid Substitutions of MagA in Klebsiella pneumoniae Affect the Biosynthesis of the Capsular Polysaccharide

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e46783 ◽  
Author(s):  
Tzu-Lung Lin ◽  
Feng-Ling Yang ◽  
An-Suei Yang ◽  
Hung-Pin Peng ◽  
Tsung-Lin Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Amino Acid Substitutions

scholarly journals Development of a new trend conjugate vaccine for the prevention of Klebsiella pneumoniae

2012 ◽  
Vol 4 (1) ◽  
pp. 33 ◽  
Author(s):  
Tarek A. Ahmad ◽  
Medhat Haroun ◽  
Ahmed A. Hussein ◽  
El Sayed H. El Ashry ◽  
Laila H. El-Sayed
Keyword(s):  
Klebsiella Pneumoniae ◽  
Respiratory Diseases ◽  
Capsular Polysaccharide ◽  
Outer Membrane Proteins ◽  
Immunological Methods ◽  
Easy Method ◽  
O Antigen ◽  
Bacterial Endotoxins ◽  
Tract Infections ◽  
Limited Spectrum

<em>Klebsiella pneumoniae</em> is a major cause of nosocomial pneumonia, septicemia and urinary tract infections, especially in newborns, blood cancer patients, and other immunocompromised candidates. The control of <em>K. pneumoniae</em> is a complicated issue due to its tight pathogenesis. Immuno-prophylactic preparations, especially those directed toward the <em>bacterium</em> O-antigen, showed to be the most successful way to prevent the infection incidence. However, all previously proposed preparations were either of limited spectrum or non-maternal, and hence not targeting the main <em>Klebsiella</em> patients. Moreover, all preparations were directed only to prevent the respiratory diseases due to that pathogen. This article addresses the development of a method originally used to purify the non-capsular bacterial- endotoxins, as a new and easy method for vaccine production against <em>K. pneumoniae</em>. The application of this method was preceded by a biotechnological control of capsular polysaccharide production in <em>K. pneumoniae</em>. The new produced natural conjugate between the bacterial O-antigen and its outer membrane proteins was evaluated by physicochemical and immunological methods to investigate its purity, integrity, safety and immunogenicity. It showed to be pure, stable, safe for use, and able to elicit a protective immunoglobulin titer against different <em>Klebsiella</em> infections. This immune-response proved to be transferable to the offspring of the vaccinated experimental rabbits via placenta.

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