Comparison of wild-type and nifV mutant molybdenum-iron proteins of nitrogenase from Klebsiella pneumoniae by ENDOR spectroscopy

1990 ◽  
Vol 112 (2) ◽  
pp. 651-657 ◽  
Author(s):  
Anne E. True ◽  
Paul McLean ◽  
Mark J. Nelson ◽  
W. H. Orme-Johnson ◽  
Brian M. Hoffman
Keyword(s):  
Klebsiella Pneumoniae ◽  
Wild Type ◽  
Iron Proteins ◽  
Endor Spectroscopy

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 Detection of Polymorphism in the Gene blaKPC2 of Local Klebsiella pneumoniae Isolated from Iraqi Patients

2017 ◽  
Vol 11 (1) ◽  
pp. 26-33
Author(s):  
Saadi Abd-Alkareem Jasim ◽  
Mohammed Maaroof ◽  
Najwa Ahmed
Keyword(s):  
Environmental Management ◽  
Klebsiella Pneumoniae ◽  
Dna Sequences ◽  
Microscopic Examination ◽  
Gene Bank ◽  
Bacterial Isolates ◽  
Wild Type ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Severe Infections

Carbapenemases are clinically important because they destroy and may confer a resistance to carbapenems, severe infections caused by carbapenemase producers is associated with increased mortality. To achieve this goal, 180 samples were collected from different clinical sources included 92 urine, 33 smears of wounds, 13 smears of burns and 42 sputum. The samples were taken from patients attended Al-Yarmouk Teaching Hospital and Ibin Baladi Hospital in Baghdad Governorate. Diagnosis of bacterial isolates was done depending upon the microscopic examination, the cultured characteristics and biochemical tests. DNA extracted from 84 samples. Accordingly, detection of blaKPC2 gene was conducted by using specific primers for amplification of blaKPC2 gene. Moreover, the sequencing of 910 bp for blaKPC2 gene was performed by the biotechnology lab. at the National Instrumentation Center for Environmental Management (NICEM). Such test has been implanted by using 3730XL as a DNA sequences. The obtained results were analyzed by blast at the National Center Biotechnology Information (NCBI) and detect polymorphism in blaKPC2 based on the Bio Edit. Consequently, 94 variations between 47 transversions, 43 transitions and 4 deletions nucleotide were noticed. In a sense the test showed 79% under sequence ID gb|CP009872.1| from 3037673 -3038166 number of nucleotide from K. pneumoniae subsp. pneumoniae strain KPNIH30 of Gene Bank, score (329) and expect 5e-86 with the wild type of blaKPC2 gene from Gene Bank. Finally, the results illustrated polymorphism between local strains of

scholarly journals A Novel Cecropin D-Derived Short Cationic Antimicrobial Peptide Exhibits Antibacterial Activity Against Wild-Type and Multidrug-Resistant Strains of Klebsiella pneumoniae and Pseudomonas aeruginosa

2020 ◽  
Vol 16 ◽  
pp. 117693432093626
Author(s):  
Iván Darío Ocampo-Ibáñez ◽  
Yamil Liscano ◽  
Sandra Patricia Rivera-Sánchez ◽  
José Oñate-Garzón ◽  
Ashley Dayan Lugo-Guevara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Health Concern ◽  
Wild Type ◽  
Cationic Antimicrobial Peptide ◽  
Promising Alternative ◽  
Resistant Strains

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

The metallo-sulphur centres of the nitrogenase MoFe protein (Kp1) from wild-type and mutant strains of Klebsiella pneumoniae.

1993 ◽  
Vol 51 (1-2) ◽  
pp. 348
Author(s):  
B.E. Smith ◽  
M. Buck ◽  
K.Y. Faridoon ◽  
C.A. Gormal ◽  
B.D. Howes ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Wild Type ◽  
Mofe Protein ◽  
Mutant Strains

scholarly journals Role of Lung Epithelial Cells in Defense against Klebsiella pneumoniae Pneumonia

2002 ◽  
Vol 70 (3) ◽  
pp. 1075-1080 ◽  
Author(s):  
Guadalupe Cortés ◽  
Dolores Álvarez ◽  
Carles Saus ◽  
Sebastián Albertí
Keyword(s):  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Type Strain ◽  
Pathogenic Bacteria ◽  
Wild Type Strain ◽  
Capsular Polysaccharide ◽  
Defense Mechanism ◽  
Lung Epithelial Cells ◽  
Wild Type ◽  
Lung Epithelial

ABSTRACT The airway epithelium represents a primary site for the entry of pathogenic bacteria into the lungs. It has been suggested for many respiratory pathogens, including Klebsiella pneumoniae, that adhesion and invasion of the lung epithelial cells is an early stage of the pneumonia process. We observed that poorly encapsulated K. pneumoniae clinical isolates and an isogenic unencapsulated mutant invaded lung epithelial cells more efficiently than highly encapsulated strains independent of the K type. By contrast, the unencapsulated mutant was completely avirulent in a mouse model of pneumonia, unlike the wild-type strain, which produced pneumonia and systemic infection. Furthermore, the unencapsulated mutant bound more epithelially produced complement component C3 than the wild-type strain. Our results show that lung epithelial cells play a key role as a host defense mechanism against K. pneumoniae pneumonia, using two different strategies: (i) ingestion and control of the microorganisms and (ii) opsonization of the microorganisms. Capsular polysaccharide avoids both mechanisms and enhances the virulence of K. pneumoniae.

The metallo-sulphur centres of the nitrogenase MoFe protein (Kp1) from wild-type and mutant strains of Klebsiella pneumoniae.

1993 ◽  
Vol 51 (1-2) ◽  
pp. 357
Author(s):  
B.E. Smith ◽  
M. Buck ◽  
K.Y. Faridoon ◽  
C.A. Gormal ◽  
B.D. Howes ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Wild Type ◽  
Mofe Protein ◽  
Mutant Strains
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