scholarly journals Characterization of Klebsiella pneumoniae associated with cattle infections in southwest China using multi-locus sequence typing (MLST), antibiotic resistance and virulence-associated gene profile analysis

2018 ◽  
Vol 49 ◽  
pp. 93-100 ◽  
Author(s):  
Fangjun Cheng ◽  
Zhangcheng Li ◽  
Shimei Lan ◽  
Wei Liu ◽  
Xiaoyan Li ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Southwest China ◽  
Profile Analysis ◽  
Multi Locus Sequence Typing ◽  
Gene Profile ◽  
Cattle Infections

Characterization of Pasteurella multocida associated with ovine pneumonia using multi-locus sequence typing (MLST) and virulence-associated gene profile analysis and comparison with porcine isolates

2017 ◽  
Vol 204 ◽  
pp. 180-187 ◽  
Author(s):  
Andrés García-Alvarez ◽  
Ana Isabel Vela ◽  
Elvira San Martín ◽  
Fernando Chaves ◽  
José Francisco Fernández-Garayzábal ◽  
...  
Keyword(s):  
Pasteurella Multocida ◽  
Profile Analysis ◽  
Multi Locus Sequence Typing ◽  
Gene Profile

scholarly journals Monitoring of Non-β-Lactam Antibiotic Resistance-Associated Genes in ESBL Producing Enterobacterales Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 884
Author(s):  
Pottathil Shinu ◽  
Rajesh Bareja ◽  
Anroop B. Nair ◽  
Vashishth Mishra ◽  
Snawar Hussain ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
North India ◽  
Gene Profile ◽  
Chain Reaction ◽  
Extended Spectrum ◽  
Lactam Antibiotic ◽  
Polymerase Chain ◽  
Genetic Context

Genetic context of extended spectrum β-Lactamase (ESBL) producing Enterobacterales and its association with plasmid mediated quinolone resistance (PMQR), aminoglycoside modifying enzymes (AME) and Trimethoprim/Sulfamethoxazole (TMP-SMX) resistance is little known from North India. Therefore, the current study was aimed to investigate the frequency of Non-β-Lactam antibiotic resistance associated genes in extended spectrum β-Lactamase producing Enterobacterales. For this study, Non-Duplicate phenotypically confirmed ESBL producing Enterobacterales isolates (N = 186) were analyzed for ESBLs, PMQRs, AMEs and TMP-SMX resistance genes using polymerase chain reaction (PCR). PCR detected presence of PMQR genes in 81.29% (N = 139) of ESBL isolates (N = 171), AME genes in 60.82% and TMP-SMX resistance genes in 63.74% of the isolates. Molecular characterization of ESBL producing Enterobacterales showed 84.79% blaTEM followed by 73.68% blaCTX-M, 43.86% blaSHV, 19.88% blaPER and 9.94% blaVEB, respectively. Analysis of PMQR genes revealed 77.7% aac(6′)-lb-cr the most commonly detected gene followed by 67.63% oqxB, 62.59% oqxA, 43.17% qnrB, 19.42% qnrD, 18.7% qnrS, 9.35% qnrA, 3.6% qepA and 2.88% qnrC, respectively. Analysis of AMEs gene profile demonstrated 81.73% aac(6′)-Ib, the most frequently encountered gene followed by 46.15% aph(3′)-Ia, 44.23% ant(3”)-Ia, respectively. A 100% prevalence of sul1, followed by dfrA (54.63%) and sul2 (15.74%) was observed. In summary, prevalence of ESBL-Producing genes (particularly blaTEM and blaCTX-M) along with PMQR, AMEs, and TMP-SMX resistant genes may potentially aid in the transfer of antimicrobial resistance among these strains.

Virulence characterization of Klebsiella pneumoniae and its relation with ESBL and AmpC beta-lactamase associated resistance

2020 ◽  
Author(s):  
Elghar Soltani ◽  
Alka Hasani ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Tahereh Pirzadeh ◽  
Mahin Ahangar Oskouee ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Disk Diffusion Method ◽  
Extended Spectrum Beta Lactamase ◽  
Virulence Trait ◽  
Polymerase Chain

Background and Objectives: Trend analysis reveals that Klebsiella pneumoniae has witnessed a steep enhancement in the antibiotic resistance and virulence over the last few decades. The present investigation aimed at a comprehensive approach investigating antibiotic susceptibility including, extended spectrum beta-lactamase (ESBL) and AmpC β-lactamase (AmpC) resistance and the prevalence of virulence genes among the K. pneumoniae isolates. Materials and Methods: Sixty-one K. pneumoniae isolates were obtained from various clinical infections. Antimicrobial susceptibility was performed by disk diffusion method. The Mast® D68C test detected the presence of ESBLs and AmpCs phenotypically, and later presence of ESBL and AmpC genes was observed by polymerase chain reaction (PCR). Multi- plex-PCR was performed to investigate various virulence genes. CMY-2   Results: Amongst 61 K. pneumoniae isolates, 59% were observed as ESBL and 14.7% as AmpC producers. All ESBL   CTX-M-15   producers were positive for bla   CTX-M-15   , while bla   CTX-M-14   was observed in 54.1% isolates. The frequency of AmpC genes was   CMY-2   as follows: bla   CMY-2   (60.7%) and bla   DHA-1   (34.4%). The most frequent virulence genes were those encoding enterobactin and   DHA-1   lipopolysaccharide. Presence of mrkD was associated with bla   CMY-2   DHA-1   gene, while bla   significantly (p≤0.05) correlated   DHA-1   with the presence of iutA and rmpA virulence genes. bla   positive isolates had urine as a significant source, while bla   positive isolates were mainly collected from wound exudates (p≤0.05). Conclusion: Our results highlight that ESBL and AmpC production along with a plethora of virulence trait on K. pneumoni- ae should be adequately considered to assess its pathogenesis and antibiotic resistance.  

Detection of NDM-1 producing Klebsiella pneumoniae ST15 and ST147 in Iran during 2019–2020

2021 ◽  
Author(s):  
Zohreh Riahi Rad ◽  
Zahra Riahi Rad ◽  
Hossein Goudarzi ◽  
Mehdi Goudarzi ◽  
Hesam Alizade ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Molecular Typing ◽  
Susceptibility Testing ◽  
Carbapenem Resistance ◽  
Gram Negative Bacteria ◽  
Broth Microdilution ◽  
Gram Negative ◽  
Beta Lactamases

AbstractCarbapenems are employed to treat infections caused by Gram-negative bacteria including Klebsiella pneumoniae. This research is aimed to perform phenotypic detection of β-lactamases and molecular characterization of NDM-1 positive K. pneumoniae isolates. Another objective is to investigate NDM-1 producing K. pneumoniae among children in Iran. From 2019 to 2020, altogether 60 K. pneumoniae isolates were acquired from various patients in certain Iranian hospitals. Antimicrobial susceptibility testing was performed by disk diffusion and broth microdilution methods. In addition, mCIM and eCIM were used to confirm the production of carbapenemases and metallo-beta-lactamases (MBLs), respectively. Detection of resistance genes namely, blaNDM-1, blaIMP, blaVIM, blaKPC, blaOXA-48-like, blaCTX-M, blaSHV, blaTEM, and mcr-1 was performed by PCR and confirmed by DNA sequencing. Multilocus sequence typing (MLST) was employed to determine the molecular typing of the strains. According to the findings, the highest rate of carbapenem resistance was detected against doripenem 83.3% (50). Moreover, 31.7% (19) were resistant to colistin. Further to the above, altogether 80% (48) were carbapenemase-producing isolates and among them 46.7% (28) of the isolates were MBL and 33.3% (20) isolates were serine β-lactamase producer. According to the PCR results, 14 isolates produced blaNDM-1. Remarkably, four blaNDM-1 positive isolates were detected in children. In addition, these isolates were clonally related as determined by MLST (ST147, ST15). Altogether ten blaNDM-1 positive isolates were ST147 and four blaNDM-1 positive isolates were ST15. Based on the results, the emergence of NDM-producing K. pneumoniae among children is worrying and hence, it is necessary to develop a comprehensive program to control antibiotic resistance in the country.

Applications of SIMS to electronic materials and devices

1992 ◽  
Vol 50 (2) ◽  
pp. 1682-1683
Author(s):  
S.F. Corcoran
Keyword(s):  
Depth Distribution ◽  
Secondary Ion Mass Spectrometry ◽  
Semiconductor Device ◽  
Electronic Materials ◽  
Profile Analysis ◽  
Semiconductor Industry ◽  
Small Diameter ◽  
Depth Resolution ◽  
Detection Sensitivity

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.

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