scholarly journals Wild-type cutoff for Apramycin against Escherichia coli

2020 ◽  
Author(s):  
Xiuying Zhang ◽  
Yuqi Yang ◽  
Tianshi Xiao ◽  
Jiarui Li ◽  
Ping Cheng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Wild Type ◽  
Research Papers ◽  
E Coli ◽  
Antibacterial Susceptibility

Abstract Background Apramycin is used exclusively for the treatment of Escherichia coli ( E.coli ) infections in swine around the world since the early 1980s. Recently, many research papers have demonstrated that apramycin has obvious in vitro activity against multidrug-resistant Enterobacteriaceae isolated in hospitals. Therefore, ensuring the proper use of apramycin in veterinary clinics is of great significance of public health. The objectives of this study were to develop a wild-type cutoff for apramycin against E.coli using a statistical method recommended by Clinical and Laboratory Standards Institute (CLSI) and to investigate the prevalence of resistance genes that confer resistance to apramycin in E. coli . Results Antibacterial susceptibility testing of 1230 E.coli clinical isolates from swine were determinded by broth microdilution testing according to the CLSI document M07-A9. A total number of 310 E.coli strains from different minimum inhibitory concentration (MIC) subsets (0.5-256 µg/mL) were conveniently selected for the detection of resistance genes ( aac(3)-IV ; npmA ; apmA ) in E. coli by PCR. The percentage at each MIC (0.5, 1, 2, 4, 8, 16, 32, 64, 128, and 256 µg/mL) was 0.08%, 0.08%, 0.16%, 2.93%, 31.14%, 38.86%, 12.85%, 2.03%, 1.46%, and 10.41%. The MIC 50 and MIC 90 were 16 and 64 µg/mL. All the 310 E.coli isolates were negative for npmA and apmA gene, and only the aac(3)-IV gene was detected in this study. Conclusions The wild-type cutoff for apramycin against E.coli was defined as 32 µg/mL. The prevelance of aac(3)-IV gene mainly concentrated in these MIC subsets ‘MIC ≥ 64 µg⁄ mL’, which indicates that the wild-type cutoff established in our study is reliable. The wild-type cutoff offers interpretion criteria of apramycin susceptibility testing of E.coli .

scholarly journals Wild-type cutoff for Apramycin against Escherichia coli

2020 ◽  
Author(s):  
Yuqi Yang ◽  
Tianshi Xiao ◽  
Jiarui Li ◽  
Ping Cheng ◽  
Fulei Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Wild Type ◽  
Research Papers ◽  
E Coli ◽  
The World

Abstract Background：Apramycin is used exclusively for the treatment of Escherichia coli (E.coli) infections in swine around the world since the early 1980s. Recently, many research papers have demonstrated that apramycin has significant in vitro activity against multidrug-resistant E.coli isolated in hospitals. Therefore, ensuring the proper use of apramycin in veterinary clinics is of great significance of public health. The objectives of this study were to develop a wild-type cutoff for apramycin against E.coli using a statistical method recommended by Clinical and Laboratory Standards Institute (CLSI) and to investigate the prevalence of resistance genes that confer resistance to apramycin in E. coli.Results: Apramycin susceptibility testing of 1230 E.coli clinical isolates from swine were determinded by broth microdilution testing according to the CLSI document M07-A9. A total number of 310 E.coli strains from different minimum inhibitory concentration (MIC) subsets (0.5-256 µg/mL) were selected for the detection of resistance genes (aac(3)-IV; npmA; apmA) in E. coli by PCR. The percentage of E. coli isolates at each MIC (0.5, 1, 2, 4, 8, 16, 32, 64, 128, and 256 µg/mL) was 0.08%, 0.08%, 0.16%, 2.93%, 31.14%, 38.86%, 12.85%, 2.03%, 1.46%, and 10.41%. The MIC50 and MIC90 were 16 and 64 µg/mL. All the 310 E.coli isolates were negative for npmA and apmA gene, and only the aac(3)-IV gene was detected in this study.Conclusions: The wild-type cutoff for apramycin against E.coli was defined as 32 µg/mL. The prevelance of aac(3)-IV gene mainly concentrated in these MIC subsets ‘MIC ≥ 64 µg⁄ mL’, which indicates that the wild-type cutoff established in our study is reliable. The wild-type cutoff offers interpretion criteria of apramycin susceptibility testing of E.coli.

scholarly journals Wild-type cutoff for Apramycin against Escherichia coli

2020 ◽  
Author(s):  
Yuqi Yang ◽  
Tianshi Xiao ◽  
Jiarui Li ◽  
Ping Cheng ◽  
Fulei Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Wild Type ◽  
Research Papers ◽  
E Coli ◽  
The World

Abstract Background：Apramycin is used exclusively for the treatment of Escherichia coli (E.coli) infections in swine around the world since the early 1980s. Recently, many research papers have demonstrated that apramycin has significant in vitro activity against multidrug-resistant E.coli isolated in hospitals. Therefore, ensuring the proper use of apramycin in veterinary clinics is of great significance of public health. The objectives of this study were to develop a wild-type cutoff for apramycin against E.coli using a statistical method recommended by Clinical and Laboratory Standards Institute (CLSI) and to investigate the prevalence of resistance genes that confer resistance to apramycin in E. coli.Results: Apramycin susceptibility testing of 1230 E.coli clinical isolates from swine were determinded by broth microdilution testing according to the CLSI document M07-A9. A total number of 310 E.coli strains from different minimum inhibitory concentration (MIC) subsets (0.5-256 µg/mL) were selected for the detection of resistance genes (aac(3)-IV; npmA; apmA) in E. coli by PCR. The percentage of E. coli isolates at each MIC (0.5, 1, 2, 4, 8, 16, 32, 64, 128, and 256 µg/mL) was 0.08%, 0.08%, 0.16%, 2.93%, 31.14%, 38.86%, 12.85%, 2.03%, 1.46%, and 10.41%. The MIC50 and MIC90 were 16 and 64 µg/mL. All the 310 E.coli isolates were negative for npmA and apmA gene, and only the aac(3)-IV gene was detected in this study.Conclusions: The wild-type cutoff for apramycin against E.coli was defined as 32 µg/mL. The prevelance of aac(3)-IV gene mainly concentrated in these MIC subsets ‘MIC ≥ 64 µg⁄ mL’, which indicates that the wild-type cutoff established in our study is reliable. The wild-type cutoff offers interpretion criteria of apramycin susceptibility testing of E.coli.

scholarly journals In Vitro Antimicrobial Activity of Various Cefoperazone/Sulbactam Products

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 77
Author(s):  
Ming-Jen Sheu ◽  
Chi-Chung Chen ◽  
Ying-Chen Lu ◽  
Bo-An Su ◽  
Chun-Cheng Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
The Other ◽  
In Vitro Activity ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Multidrug Resistant Organisms

This study aims to assess the in vitro activity of different samples of cefoperazone/sulbactam (CFP/SUL) against multidrug-resistant organisms (MDROs). Clinical isolates of extended-spectrum β-lactamase (ESBL)-Escherichia coli, ESBL-Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii (CR-AB), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA) were collected. The minimum inhibitory concentration (MIC) and time-killing methods were used to assess and compare the in vitro activities of different samples of cefoperazone/sulbactam (CFP/SUL) against these MDROs. For ESBL-E. coli, ESBL-K. pneumoniae, and CR-PA, product C had smaller variations than product A and B (p < 0.05). For CR-AB, product B had the largest variation compared to the other two products (p < 0.05). In the time-killing studies, significant differences among the products when used at 16/16 µg/mL were noted for ESBL-E. coli, ESBL-K. pneumoniae, and CR-AB isolates. In conclusion, this study demonstrated the significantly different activity of different products of CFP/SUL against MDROs.

scholarly journals Antimicrobial and Transconjugants Characteristics of Sul3 Positive Escherichia Coli Isolated from Animals in Nanning, Guangxi Province

2020 ◽  
Author(s):  
Zheng Li ◽  
Yunru Chen ◽  
Geyin Zhang ◽  
Qingmei Li ◽  
Junying Sun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Multidrug Resistant ◽  
E Coli ◽  
Ceftriaxone Sodium ◽  
Numerous Type ◽  
Multiple Resistance Genes ◽  
Term Monitoring

Abstract Background: Sulfonamides is the second most popular antibiotic in many countries, which leads to the widespread emergence of sulfonamides resistance. Sul3 is a late sulfanilamide resistance gene, whose research is relatively little. Result: 46 sul3 positive E. coli strains were separated. A total of 12 ST types were observed, and 1 of those was previously unknown type. The ST350 is the most numerous type. All isolates were multidrug-resistant E. coli, with high antimicrobial rates to penicillin, ceftriaxone sodium, streptomycin, tetracycline, ciprofloxacin, gatifloxacin and chloramphenicol (100%, 73.9%, 82.6%, 100%, 80.4%, 71.7% and 97.8%), and with at least 3 resistance genes in addition to sul3. The plasmids transfered from 3 sul3-positive isolates to C600, the most of which brought 7 antibiotic resistance and increased resistance genes to C600. The transferred sul3 gene and the plasmid that carries it could be stably inherited in the recipient bacteria for at least 20 days. Those plasmids had no effect on the growth of the recipient bacteria, but it would greatly reduce (at least 60 time) the in vitro competitiveness of the strains. Conclusions: In Nanning, these sul3-positive Escherichia coli have strong antimicrobial resistance, and the plasmid carrying sul3 has the ability to transfer multiple resistance genes, so long-term monitoring is necessary. Since the transferred plasmid will greatly reduce the in vitro competitiveness of the strain, we can consider limiting the spread of antimicrobial in this respect.

scholarly journals In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaitlin S. Witherell ◽  
Jason Price ◽  
Ashok D. Bandaranayake ◽  
James Olson ◽  
Douglas R. Call
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
E Coli ◽  
Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

scholarly journals Enhancement of the Efficiency of Secretion of Heterologous Lipase in Escherichia coli by Directed Evolution of the ABC Transporter System

2005 ◽  
Vol 71 (7) ◽  
pp. 3468-3474 ◽  
Author(s):  
Gyeong Tae Eom ◽  
Jae Kwang Song ◽  
Jung Hoon Ahn ◽  
Yeon Soo Seo ◽  
Joon Shick Rhee
Keyword(s):  
Escherichia Coli ◽  
Directed Evolution ◽  
Abc Transporter ◽  
Microtiter Plate ◽  
Single Amino Acid ◽  
Wild Type ◽  
E Coli ◽  
Single Amino Acid Change ◽  
Secretion Efficiency

ABSTRACT The ABC transporter (TliDEF) from Pseudomonas fluorescens SIK W1, which mediated the secretion of a thermostable lipase (TliA) into the extracellular space in Escherichia coli, was engineered using directed evolution (error-prone PCR) to improve its secretion efficiency. TliD mutants with increased secretion efficiency were identified by coexpressing the mutated tliD library with the wild-type tliA lipase in E. coli and by screening the library with a tributyrin-emulsified indicator plate assay and a microtiter plate-based assay. Four selected mutants from one round of error-prone PCR mutagenesis, T6, T8, T24, and T35, showed 3.2-, 2.6-, 2.9-, and 3.0-fold increases in the level of secretion of TliA lipase, respectively, but had almost the same level of expression of TliD in the membrane as the strain with the wild-type TliDEF transporter. These results indicated that the improved secretion of TliA lipase was mediated by the transporter mutations. Each mutant had a single amino acid change in the predicted cytoplasmic regions in the membrane domain of TliD, implying that the corresponding region of TliD was important for the improved and successful secretion of the target protein. We therefore concluded that the efficiency of secretion of a heterologous protein in E. coli can be enhanced by in vitro engineering of the ABC transporter.

scholarly journals Molecular survey of mcr1 and mcr2 plasmid mediated colistin resistance genes in Escherichia coli isolates of animal origin in Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kayhan Ilbeigi ◽  
Mahdi Askari Badouei ◽  
Hossein Vaezi ◽  
Hassan Zaheri ◽  
Sina Aghasharif ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Companion Animals ◽  
Multidrug Resistant ◽  
Animal Origin ◽  
Colistin Resistance ◽  
E Coli ◽  
High Level ◽  
Farming Industry

Abstract Objectives The emergence of colistin-resistant Enterobacteriaceae from human and animal sources is one of the major public health concerns as colistin is the last-resort antibiotic for treating infections caused by multidrug-resistant Gram-negative bacteria. We aimed to determine the prevalence of the prototype widespread colistin resistance genes (mcr-1 and mcr-2) among commensal and pathogenic Escherichia coli strains isolated from food-producing and companion animals in Iran. Results A total of 607 E. coli isolates which were previously collected from different animal sources between 2008 and 2016 used to uncover the possible presence of plasmid-mediated colistin resistance genes (mcr-1 and mcr-2) by PCR. Overall, our results could not confirm the presence of any mcr-1 or mcr-2 positive E. coli among the studied isolates. It is concluded that despite the important role of food-producing animals in transferring the antibiotic resistance, they were not the main source for carriage of mcr-1 and mcr-2 in Iran until 2016. This study suggests that the other mcr variants (mcr-3 to mcr-9) might be responsible for conferring colistin resistance in animal isolates in Iran. The possible linkage between pig farming industry and high level of mcr carriage in some countries needs to be clarified in future prospective studies.

scholarly journals Tetracycline Susceptibility Testing and Resistance Genes in Isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus Complex from a U.S. Military Hospital

2009 ◽  
Vol 53 (6) ◽  
pp. 2693-2695 ◽  
Author(s):  
Kevin S. Akers ◽  
Katrin Mende ◽  
Heather C. Yun ◽  
Duane R. Hospenthal ◽  
Miriam L. Beckius ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Tetracycline Resistance ◽  
Acinetobacter Calcoaceticus ◽  
Multidrug Resistant ◽  
Military Hospital ◽  
Tetracycline Resistance Genes ◽  
Testing Method

ABSTRACT Infections with multidrug-resistant Acinetobacter baumannii-Acinetobacter calcoaceticus complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes tetA, tetB, and tetA(39) were present in the isolates.

Antibiotic Resistance Profile of Commensal Escherichia coli Isolated from Broiler Chickens in Qatar

2017 ◽  
Vol 81 (2) ◽  
pp. 302-307 ◽  
Author(s):  
Nahla O. Eltai ◽  
Elmoubasher A. Abdfarag ◽  
Hamad Al-Romaihi ◽  
Eman Wehedy ◽  
Mahmoud H. Mahmoud ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Broiler Chickens ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Test Method ◽  
Health Concern ◽  
E Coli ◽  
Extended Spectrum ◽  
Stewardship Program

ABSTRACT Antibiotic resistance (AR) is a growing public health concern worldwide, and it is a top health challenge in the 21st century. AR among Enterobacteriaceae is rapidly increasing, especially in third-generation cephalosporins and carbapenems. Further, strains carrying mobilized colistin resistance (mcr) genes 1 and 2 have been isolated from humans, food-producing animals, and the environment. The uncontrolled use of antibiotics in food-producing animals is a major factor in the generation and spread of AR. No studies have been done to evaluate AR in the veterinary sector of Qatar. This study aimed at establishing primary baseline data for the prevalence of AR among food-producing animals in Qatar. Fecal samples (172) were obtained from two broiler farms and one live bird market in Qatar, and 90 commensal Escherichia coli bacteria were isolated and subjected to susceptibility testing against 16 clinically relevant antibiotics by using the E-test method. The results found that 81 (90%) of 90 isolates were resistant to at least one antibiotic, 14 (15.5%) of 90 isolates were colistin resistant, 2 (2.2%) of 90 isolates were extended-spectrum β-lactamase producers, and 2 (2.2%) of 90 isolates were multidrug resistant to four antibiotic classes. Extended-spectrum β-lactamase–producing E. coli and colistin-resistant isolates were confirmed by using double-disc susceptibility testing and PCR, respectively. Such a high prevalence of antibiotic-resistant E. coli could be the result of a long application of antibiotic treatment, and it is an indicator of the antibiotic load in food-producing animals in Qatar. Pathogens carrying AR can be easily transmitted to humans through consumption of undercooked food or noncompliance with hygiene practices, mandating prompt development and implementation of a stewardship program to control and monitor the use of antibiotics in the community and agriculture.

scholarly journals In Vivo Titration of Mitomycin C Action by Four Escherichia coli Genomic Regions on Multicopy Plasmids

2001 ◽  
Vol 183 (7) ◽  
pp. 2259-2264 ◽  
Author(s):  
Yan Wei ◽  
Amy C. Vollmer ◽  
Robert A. LaRossa
Keyword(s):  
Escherichia Coli ◽  
Mitomycin C ◽  
Transcriptional Activation ◽  
Efflux Pump ◽  
Wild Type ◽  
Potent Inducer ◽  
E Coli ◽  
Genomic Regions

ABSTRACT Mitomycin C (MMC), a DNA-damaging agent, is a potent inducer of the bacterial SOS response; surprisingly, it has not been used to select resistant mutants from wild-type Escherichia coli. MMC resistance is caused by the presence of any of four distinctE. coli genes (mdfA, gyrl, rob, andsdiA) on high-copy-number vectors. mdfAencodes a membrane efflux pump whose overexpression results in broad-spectrum chemical resistance. The gyrI (also called sbmC) gene product inhibits DNA gyrase activity in vitro, while the rob protein appears to function in transcriptional activation of efflux pumps. SdiA is a transcriptional activator of ftsQAZ genes involved in cell division.

Sign in / Sign up

Export Citation Format

Share Document