2.Isolation of Klebsiella pneumoniae from Sungai Skudai and in silico analysis of putative dehalogenase protein
Nur Aina Jamil ; Roswanira Abdul Wahab ; Amir Husni Mohd Shariff ; Fahrul Huyop
Malaysian Journal of Microbiology 2021;17(3):294-304
Aims:
The surplus use of herbicide Dalapon® contains 2,2-dichloropropionic acid (2,2-DCP) poses great danger to
human and ecosystem due to its toxicity. Hence, this study focused on the isolation and characterization of a
dehalogenase producing bacteria from Sungai Skudai, Johor, capable of utilizing 2,2-DCP as a carbon source and in
silico analysis of its putative dehalogenase.
Methodology and results:
Isolation of the target bacteria was done by using 2,2-DCP-enriched culture as the sole
carbon source that allows a bacterium to grow in 20 mM of 2,2-DCP at 30 °C with the corresponding doubling time of
8.89 ± 0.03 h. The isolated bacterium was then designated as Klebsiella pneumoniae strain YZ based on biochemical
tests and basic morphological examination. The full genome of K. pneumoniae strain KLPN_25 (accession number:
RRE04903) which obtained from NCBI database was screened for the presence of dehalogenase gene, assuming both
strains YZ and KLPN_25 were the same organisms. A putative dehalogenase gene was then identified as type II
dehalogenase from the genome sequence of strain KLPN_25. The protein structure of the type II dehalogenase of
KLPN_25 strain was then pairwise aligned with the crystal structure of L-2-haloacid dehalogenase (L-DEX)
Pseudomonas sp. strain YL as the template, revealing the existence of conserved amino acids residues, uniquely known
to participate in the dehalogenation mechanism. The finding thus implies that the amino acid residues of type II
dehalogenase possibly shares similar catalytic functions with the L-DEX.
Conclusion, significance and impact of the study
In conclusion, this study confirmed the presence of new
dehalogenase from the genus Klebsiella with potential to degrade 2,2-DCP from the river water. The structural
information of type II dehalogenase provides insights for future work in designing haloacid dehalogenases.
Klebsiella pneumoniae--isolation &
;
purification
;
Computer Simulation
;
Molecular Dynamics Simulation
6.Isolation of a methane-utilizing Klebsiella sp. strain and its application for detecting methane.
Jun ZHENG ; Jun GUO ; Yujun WANG ; Yujing YANG ; Jinmei PANG ; Suping YANG ; Gengui ZHAO ; Chuan DONG
Chinese Journal of Biotechnology 2009;25(5):695-700
We have isolated a strain C611 that used methane as the sole carbon sources for growth from paddy soil in Taiyuan of Shanxi province. Based on the physiological characteristics and 16S rDNA sequence analysis, we identified the strain as Klebsiella sp.. We used statistic-based experimental design (RSM) to optimize the culture conditions for C611 strain. The optimum conditions were as follows: temperature of 24.4 degrees C, inoculum volume of 6.7% and methane content of 25%. We studied the response time and the relationship between consumption of dissolved oxygen and methane gas contents with PVA-H3BO3 immobilized cell of C611 using electrochemical method. The response time was no more than 100 s of this reaction system, and the linear range of detection of methane content was from 0 to 10%. The standard gas sample 3% methane was measured by this method with the mean content value of 3.09%, RSD of 3.48%, and the relative error of 3%. Hence, it has the potential in developing biosensor for methane.
Environmental Monitoring
;
methods
;
Klebsiella
;
isolation & purification
;
metabolism
;
Methane
;
analysis
;
metabolism
;
Soil Microbiology
7.Multiplex PCR for Rapid Detection of Genes Encoding Class A Carbapenemases.
Sang Sook HONG ; Kyeongmi KIM ; Ji Young HUH ; Bochan JUNG ; Myung Seo KANG ; Seong Geun HONG
Annals of Laboratory Medicine 2012;32(5):359-361
In recent years, there have been increasing reports of KPC-producing Klebsiella pneumoniae in Korea. The modified Hodge test can be used as a phenotypic screening test for class A carbapenamase (CAC)-producing clinical isolates; however, it does not distinguish between carbapenemase types. The confirmation of type of CAC is important to ensure optimal therapy and to prevent transmission. This study applied a novel multiplex PCR assay to detect and differentiate CAC genes in a single reaction. Four primer pairs were designed to amplify fragments encoding 4 CAC families (SME, IMI/NMC-A, KPC, and GES). The multiplex PCR detected all genes tested for 4 CAC families that could be differentiated by fragment size according to gene type. This multiplex PCR offers a simple and useful approach for detecting and distinguishing CAC genes in carbapenem-resistant strains that are metallo-beta-lactamase nonproducers.
Bacterial Proteins/*genetics/metabolism
;
DNA Primers/metabolism
;
Databases, Genetic
;
Humans
;
Klebsiella Infections/microbiology
;
Klebsiella pneumoniae/genetics/isolation & purification/metabolism
;
*Multiplex Polymerase Chain Reaction
;
beta-Lactamases/*genetics/metabolism
8.A case of Klebsiella pneumoniae outbreak in a newborn intensive care unit.
Gui-Ping LI ; Jiong ZHOU ; Xiao-Jun MA ; Hong-Li SUN ; Hui WANG ; Ying-Chun XU
Acta Academiae Medicinae Sinicae 2008;30(5):540-542
OBJECTIVETo investigate and take a case study on a Klebsiella pneumoniae outbreak in a newborn intensive care unit (NICU).
METHODSUsing epidemiological investigation method to cultivate bacilli and detect the homology.
RESULTSKlebsiella pneumonia was detected in 4 NICU patients. Based on environmental sample analyses, four Klebsiella pneumonia strains were identified and confirmed to be highly homologous. The outbreak was effectively controlled after the strict implementation of hand hygiene practice and environment disinfection.
CONCLUSIONKlebsiella pneumonia outbreak in NICU may be caused by the route of hand transmission.
Cross Infection ; epidemiology ; microbiology ; Disease Outbreaks ; Female ; Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Klebsiella Infections ; epidemiology ; microbiology ; Klebsiella pneumoniae ; genetics ; isolation & purification ; Male
9.Characteristics of urinary tract infection in kidney transplant recipients and non-recipient patients.
Siteng CHEN ; Lixin YU ; Wenfeng DENG ; Yun MIAO ; Rumin LIU ; Guirong YE
Journal of Zhejiang University. Medical sciences 2016;45(2):201-207
OBJECTIVETo compare the characteristics of urinary tract infection (UTI) between kidney transplant recipients and non-recipient patients.
METHODSForty-nine kidney transplant recipients with UTI (69 episodes) and 401 non-recipient patients with UTI (443 episodes) admitted in Nanfang Hospital from January 2003 to August 2014 were enrolled in the study. The characteristics of UTI were compared between two groups.
RESULTSIn both groups of UTI, female patients comprised a greater proportion (63.3% and 58.6%) and Escherichia coli was the most common pathogen isolated (37.7% and 34.1%). However, the infection rate of Klebsiella pneumonia in recipients was higher than that in non-recipients (11.6% vs 3.2%, P= 0.001), while the infection rate of Candida albicans was lower (1.5% vs 11.3%, P=0.008) than that in non-recipients. Recipients were likely to develop antibiotic resistance and with a higher recurrence rate than non-recipient patients (38.8% vs 16.7%, P<0.001). Compared to non-recipient UTI patients, the symptoms of urinary irritation in recipient UTI patients were more common. There was higher percentage of neutrophil granulocyte (72.65% ± 1.90% vs 68.59% ± 0.73%, P=0.048), lower proportion of lymphocytes (17.73% ± 1.27% vs 21.28% ± 0.61%, P=0.037), and less platelets [(187.64 ± 10.84) × 10(9)/L vs (240.76 ± 5.26) × 10(9)/L, P<0.01] in recipients than in non-recipient UTI patients.
CONCLUSIONThese results indicate that the characteristics of UTI in kidney transplantation recipients and non-recipients patients are different.
Candida albicans ; isolation & purification ; Escherichia coli ; isolation & purification ; Female ; Humans ; Kidney Transplantation ; Klebsiella pneumoniae ; isolation & purification ; Male ; Transplant Recipients ; Urinary Tract Infections ; epidemiology ; pathology
10.Evaluation of the Phoenix Automated Microbiology System for Detecting Extended-Spectrum beta-Lactamase in Escherichia coli, Klebsiella species and Proteus mirabilis.
Kyo Kwan LEE ; Sung Tae KIM ; Ki Suk HONG ; Hee Jin HUH ; Seok Lae CHAE
The Korean Journal of Laboratory Medicine 2008;28(3):185-190
BACKGROUND: The aim of this study was to compare the BD Phoenix (Beckton Dickinson Diagnostic Systems, USA) extended-spectrum beta-lactamase (ESBL) test with the Clinical and Laboratory Standards Institute (CLSI) ESBL phenotypic confirmatory test by disk diffusion (CLSI ESBL test) in Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and Proteus mirabilis. METHODS: We tested 224 clinical isolates of E. coli, K. pneumoniae, K. oxytoca and P. mirabilis during May 2006 to March 2007. These isolates were examined by the Phoenix and the CLSI ESBL tests simultaneously. For the isolates showing discordant results between the two tests, boronic acid disk test was performed to differentiate AmpC beta-lactamase and ESBL. RESULTS: Among the 224 clinical isolates, 75 and 79 isolates were positive for ESBL by CLSI ESBL test and Phoenix test, respectively. Having detected 4 more isolates as ESBL-producers, Phoenix test showed a 98.2% agreement with a 100% sensitivity and 97.3% specificity compared with CLSI ESBL test. Among the four false positive isolates, three were AmpC-positive but ESBL-negative. CONCLUSIONS: The BD Phoenix ESBL test was sensitive and specific, and can be used as a rapid and reliable method to detect ESBL production in E. coli, Klebsiella species, and P. mirabilis.
Automation
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Bacterial Proteins/classification/*metabolism
;
Disk Diffusion Antimicrobial Tests
;
Escherichia coli/drug effects/*enzymology/isolation & purification
;
Humans
;
Klebsiella/*enzymology
;
Klebsiella oxytoca/drug effects/enzymology/isolation & purification
;
Klebsiella pneumoniae/drug effects/enzymology/isolation & purification
;
*Microbial Sensitivity Tests
;
Proteus mirabilis/drug effects/*enzymology/isolation & purification
;
Reagent Kits, Diagnostic
;
Sensitivity and Specificity
;
beta-Lactamases/classification/*metabolism