1.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
5.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
6.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.Prevalence of Carbapenem-Resistant Klebsiella Pneumoniae (CRKP) and the Distribution of Class 1 Integron in Their Strains Isolated from a Hospital in Central China.
Qin OU ; Wenfang LI ; Bei LI ; Chunfang YU
Chinese Medical Sciences Journal 2017;32(2):107-102
Objective The aim of our study is to investigate the prevalence of Carbapenem-resistant Klebsiella pneumoniae (CRKP) and the genetic characteristics of the class 1 integron in CRKP on multi-drug resistance.Methods Clinical Klebsiella pneumoniae strains were collected from multiple departments of a hospital in central China. CRKP strains were identified among the isolates, and antibiotics susceptibility of CRKP strains was analyzed. The polymerase chain reaction (PCR) was adopted to amplify the class 1 integron variable area. The integron genetic structure was analyzed with enzyme digestion and DNA sequencing technology. The relation between class 1 integron and drug resistance was analyzed statistically.Results Totally 955 strains of Klebsiella pneumoniae were isolated from varied sites of the hospital, and 117(12.3%) of them were identified as CRKP, with a separation rate of 8.9% (26/292) in 2013, 11.3% (38/336) in 2014 and 16.2% (53/327) in 2015, which shows an increasing trend by year. 44.4% (52/117) of CRKP strains were separated from specimen of ICU, and 61.5% (72/117) were from sputum. Over 95% CRKP strains were resistant to ampicillin/sulbactam, aztreonam, imipenem, meropenem, ceftazidme, cefotaxime, cefepime,and piperacillin, while relatively low resistant rates were found in tigecycline (12.8%) and colistin (35.9%). The class 1 integron was detected in 77.8% (91/117) of CRKP strains. Class 1 integron of CRKP was significantly correlated with the antibiotic resistance to the tobramycin, gentamicin and amikacin (all P<0.01). The gene cassette analysis of variable area of class 1 integron showed that aadA2 accounts for 64.8% (59/91), aacA4-catB8-aadA1 23.1% (21/91), and aadA2-dfrA25 12.1% (11/91).Conclusions CRKP has an increasing trend in a clinical setting in China, and most of them were resistant to multiple antibiotics. Class 1 integron in CRKP has strong ability to capture the genes resistant to aminoglycosides antibiotics from environment, with the aadA2 gene as the most popular one.
Anti-Bacterial Agents
;
pharmacology
;
Carbapenems
;
pharmacology
;
Drug Resistance, Bacterial
;
Integrons
;
Klebsiella pneumoniae
;
drug effects
;
genetics
;
isolation & purification
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.Pathologic bacterial distribution and antibiotic resistance in induced sputum of infants aged from 1 to 3 months with lower respiratory tract infection.
Man-Feng ZUO ; He-Lin LIU ; Mu-Liang ZHU ; Qiong-Zhang SHU ; Ling JIANG
Chinese Journal of Contemporary Pediatrics 2014;16(12):1226-1230
OBJECTIVETo investigate the pathologic bacterial distribution and their antibiotic resistance in infants aged from 1 to 3 months with lower respiratory tract infection, so as to provide instructions for clinical application of antibiotics.
METHODSInduced sputum was extracted from 622 cases of hospitalized infants aged from 1 to 3 months with lower respiratory tract infection between January 2013 and December 2013, and microbial sensitivity test was performed with agar diffusion sensitivity test.
RESULTSA total of 379 (60.9%) strains of bacteria were isolated from induced sputum in the 622 infants. The Gram-negative strains were detected in 325 strains (85.8%), and the Gram-positive strains were found in 50 strains (13.2%) in the 379 strains. The others were Fungal strains (4 strains, 1.1%). The Gram-negative bacteria included Escherichia coli (31.1%) and Klebsiella pneumoniae (18.2%), with extended-spectrum β-lactamases (ESBLs) production of 48.3% and 52.2% respectively. The average rate of antibiotic resistance for ESBLs-producing bacteria was 53%. ESBLs-producing bacteria were highly resistant (100%) to ampicillin and cefotaxime, but sensitive to carbapenems. Staphylococcus aureus (10.0%) was the dominant bacteria in Gram-positive bacteria. A lower proportion of methicillin-resistant Staphylococcus aureus (1.8%) was observed, however the resistance rate of methicillin-resistant Staphylococcus aureus to β-lactam antibiotics were 100%.
CONCLUSIONSEscherichia coli and Klebsiella pneumoniae are the main pathogenic bacteria causing lower respiratory tract infection in infants aged from 1 to 3 months. ESBLs-producing bacteria accounted for over 48%, and the antibiotic resistance rate were more than 53% in these infants. These results provide a basis for the first empirical clinical use of antimicrobial in infants with lower respiratory tract infection.
Drug Resistance, Bacterial ; Escherichia coli ; isolation & purification ; Female ; Humans ; Infant ; Klebsiella pneumoniae ; isolation & purification ; Male ; Respiratory Tract Infections ; drug therapy ; microbiology ; Sputum ; microbiology