scholarly journals Colistin-resistant Escherichia coli clinical isolate harbouring the mcr-1 gene in Ecuador

2016 ◽  
Vol 144 (14) ◽  
pp. 2967-2970 ◽  
Author(s):  
D. ORTEGA-PAREDES ◽  
P. BARBA ◽  
J. ZURITA
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Clinical Isolate ◽  
Inhibitory Concentration ◽  
Resistance Mechanism ◽  
Sequence Type ◽  
Colistin Resistance ◽  
Gram Negative ◽  
E Coli ◽  
Commensal Strain

SUMMARYColistin resistance mediated by the mcr-1 gene has been reported worldwide, but to date not from the Andean region, South America. We report the first clinical isolate of Escherichia coli harbouring the mcr-1 gene in Ecuador. The strain was isolated from peritoneal fluid from a 14-year-old male with acute appendicitis, and subjected to molecular analysis. The minimum inhibitory concentration of colistin for the strain was 8 mg/ml and it was susceptible to carbapenems but resistant to tigecycline. The strain harboured mcr-1 and blaCTX-M-55 genes and was of sequence type 609. The recognition of an apparently commensal strain of E. coli harbouring mcr-1 serves as an alert to the presence in the region of this recently described resistance mechanism to one of the last line of drugs available for the treatment of multi-resistant Gram-negative infections.

scholarly journals First Report of the mcr-1 colistin Resistance Gene Identified in Escherichia coli Isolated from a Clinical Sample in Naples in 2020

2020 ◽  
Author(s):  
BIAGIO SANTELLA ◽  
CARLA ZANNELLA ◽  
CHIARA DEL VECCHIO ◽  
ANNALISA CHIANESE ◽  
VERONICA FOLLIERO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Clinical Sample ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Colistin Resistance ◽  
Gram Negative ◽  
E Coli ◽  
Carbapenem Resistant

Abstract Background: The emergence of a novel plasmid-mediated colistin resistance mechanism, encoded by the mcr-1 gene, represents a major public health concern. The mechanism of resistance to colistin, mediated by plasmids, is a serious problem, both for its ability to be transferred to other species, and for infections caused by carbapenem-resistant Gram-negative, in which colistin is used as an antimicrobial drug of last line for the treatment of these infections. The present study highlights the first isolation and genetic evaluation of detecting plasmid-mediated resistance to colistin in a multidrug-resistant (MDR) Escherichia coli (E. coli) isolated from a clinical sample in the metropolitan city of Naples, Italy. Results: Colistin-resistant E. coli isolate was identified in August 2020 from the blood culture of a male patient with multiple comorbidities. The minimum inhibitory concentration (MIC) of colistin was 8 mg/L. In addition to colistin, the isolate was resistant to third-generation cephalosporins (cefotaxime and ceftazidime), penicillin (amoxicillin and piperacillin), aminoglycosides (gentamicin and tobramycin), and fluoroquinolones (ciprofloxacin and levofloxacin). However, it showed susceptibility to carbapenems (ertapenem, imipenem, and meropenem), tetracyclines (tigecycline), and piperacillin-tazobactam. The results of the PCR confirmed the presence of the mcr-1 resistance gene. Conclusion: This study confirms the presence of resistance to colistin mediated by the mcr-1 gene in a clinical isolate of E. coli. Although resistance to colistin caused by the mcr-1 gene is not common in our region, it should not be ignored. Therefore, further surveillance studies are recommended to monitor the spread of plasmid-mediated colistin resistance genes in Gram-negative MDR bacteria.

scholarly journals Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Neonatal Meningitis ◽  
E Coli ◽  
Drug Candidates ◽  
Metabolic Genes ◽  
Genetic Mechanisms ◽  
Cell Stress Response

Abstract Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.

scholarly journals Heterogeneous and Flexible Transmission ofmcr-1in Hospital-AssociatedEscherichia coli

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Yingbo Shen ◽  
Zuowei Wu ◽  
Yang Wang ◽  
Rong Zhang ◽  
Hong-Wei Zhou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Gram Negative Bacteria ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Genes Encoding

ABSTRACTThe recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route ofmcr-1amongEnterobacteriaceaespecies in clinical settings is largely unknown. Here, we present a comprehensive genomic analysis ofEscherichia coliisolates collected in a hospital in Hangzhou, China. We found thatmcr-1-carrying isolates from clinical infections and feces of inpatients and healthy volunteers were genetically diverse and were not closely related phylogenetically, suggesting that clonal expansion is not involved in the spread ofmcr-1. Themcr-1gene was found on either chromosomes or plasmids, but in most of theE. coliisolates,mcr-1was carried on plasmids. The genetic context of the plasmids showed considerable diversity as evidenced by the different functional insertion sequence (IS) elements, toxin-antitoxin (TA) systems, heavy metal resistance determinants, and Rep proteins of broad-host-range plasmids. Additionally, the genomic analysis revealed nosocomial transmission ofmcr-1and the coexistence ofmcr-1with other genes encoding β-lactamases and fluoroquinolone resistance in theE. coliisolates. These findings indicate thatmcr-1is heterogeneously disseminated in both commensal and pathogenic strains ofE. coli, suggest the high flexibility of this gene in its association with diverse genetic backgrounds of the hosts, and provide new insights into the genome epidemiology ofmcr-1among hospital-associatedE. colistrains.IMPORTANCEColistin represents one of the very few available drugs for treating infections caused by extensively multidrug-resistant Gram-negative bacteria. The recently emergentmcr-1colistin resistance gene threatens the clinical utility of colistin and has gained global attention. Howmcr-1spreads in hospital settings remains unknown and was investigated by whole-genome sequencing ofmcr-1-carryingEscherichia coliin this study. The findings revealed extraordinary flexibility ofmcr-1in its spread among genetically diverseE. colihosts and plasmids, nosocomial transmission ofmcr-1-carryingE. coli, and the continuous emergence of novel Inc types of plasmids carryingmcr-1and newmcr-1variants. Additionally,mcr-1was found to be frequently associated with other genes encoding β-lactams and fluoroquinolone resistance. These findings provide important information on the transmission and epidemiology ofmcr-1and are of significant public health importance as the information is expected to facilitate the control of this significant antibiotic resistance threat.

Serum Inhibitory and Bactericidal Activity of Ciprofloxacin following Intravenous Administration

DICP ◽  
1989 ◽  
Vol 23 (6) ◽  
pp. 456-460
Author(s):  
Michael N. Dudley ◽  
Hilary D. Mandler ◽  
Kenneth H. Mayer ◽  
Stephen H. Zinner
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Minimum Inhibitory Concentration ◽  
Bactericidal Activity ◽  
Resistant Strain ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
E Coli ◽  
Dose Levels

Serum inhibitory and bactericidal titers were measured in nine healthy volunteers following single iv doses of ciprofloxacin 100, 150, and 200 mg. The median peak serum bactericidal titer (5 minutes following completion of a 30-minute infusion) against two highly susceptible strains of Escherichia coli ranged between 1:64 and 1:1024 and titers exceeded 1:8 for six hours for all dose levels. The bactericidal titers against two strains of Pseudomonas aeruginosa and a methicillin-resistant strain of Staphylococcus aureus were considerably lower, the median peak being 1:2 at all dose levels. Measured inhibitory and bactericidal titers at five minutes and one hour postinfusion were significantly greater than those predicted (measured serum ciprofloxacin concentration to minimum inhibitory concentration [MIC] or minimum bactericidal concentration [MBC]) for only one strain of E. coli. Intravenous doses of ciprofloxacin 100–200 mg produce high and sustained serum bactericidal titers against highly susceptible bacteria; considerably lower levels of activity are seen against bacteria having higher MICs and MBCs but still considered susceptible to the drug.

scholarly journals Heterogeneous Absorption of Antimicrobial Peptide LL37 inEscherichia coliCells Enhances Population Survivability

2018 ◽  
Author(s):  
Mehdi Snoussi ◽  
John Paul Talledo ◽  
Nathan-Alexander Del Rosario ◽  
Bae-Yeun Ha ◽  
Andrej Košmrlj ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mathematical Model ◽  
Minimum Inhibitory Concentration ◽  
Cell Density ◽  
Inhibitory Concentration ◽  
Single Cell Level ◽  
Cell Level ◽  
E Coli ◽  
Rapid Absorption ◽  
Growing Population

AbstractAntimicrobial peptides (AMPs) are broad spectrum antibiotics that selectively target bacteria. Here we investigate the activity of human AMP LL37 againstEscherichia coliby integrating quantitative, population and single-cell level experiments with theoretical modeling. Our data indicate an unexpected, rapid absorption and retention of a large number of LL37 byE. colicells upon the inhibition of their growth, which increases the chance of survival for the rest of population. Cultures with high-enough cell density exhibit two distinct subpopulations: a non-growing population that absorb peptides and a growing population that survive owing to the sequestration of the AMPs by others. A mathematical model based on this binary picture reproduces the rather surprising behaviors ofE. colicultures in the presence of LL37, including the increase of the minimum inhibitory concentration with cell density (even in dilute cultures) and the extensive lag in growth introduced by sub-lethal dosages of LL37.

scholarly journals Determination of the carbapenem resistance in Escherichia coli isolated from samples obtained from Shahrekord hospitals and determination of their minimum inhibitory concentration

2019 ◽  
Vol 21 (6) ◽  
pp. 280-283
Author(s):  
Farshad Kakian ◽  
Behnam Zamanzad ◽  
Abolfazle Gholipour ◽  
Kiarash Zamanzad
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Test Strip ◽  
Major Step ◽  
Accurate Identification ◽  
E Coli ◽  
Tract Infections

Background and aims: Carbapenems are the final-line treatments for multidrug-resistant, gram-negative infections. The patterns of resistance to carbapenems among hospital bacterial pathogens vary widely across different hospitals in a country. Considering that Escherichia coli is one of the most important causes of nosocomial infections, it is essential to study its drug resistance. Methods: In this descriptive-analytical study, a total of 80 samples of E. coli isolated from inpatients with urinary tract infections (UTIs) were collected in different wards (i.e., women, urology, infectious, and ICU) of Shahrekord hospitals. After the diagnosis and confirmation of bacteria by standard bacteriological methods, their sensitivity to imipenem and meropenem was investigated by the antibiogram (diskdiffusion) method. Then, the minimum inhibitory concentration (MIC) was determined by the E-test strip according to the Clinical and Laboratory Standards Institute (CLSI) standard. Results: In this study, resistance to meropenem and imipenem by antibiogram (disc diffusion) was observed in 21 (25.26%) and 20 (25%) of the isolates, respectively. Twenty isolates had MIC ≥4 μg/mL for meropenem, 13 isolates demonstrated MIC≥4 μg/mL for imipenem, and 14 isolates had 1≤MIC<4 μg/mL and were semi-sensitive. Conclusion: In general, E. coli had significant resistance to carbapenems. Therefore, rapid and accurate identification of these strains can be a major step to the treatment and control of these strains and prevention of the spread of the resistance.

scholarly journals Adaptation of Esherichia coli to Antiobiotic Cycling via Single Nucleotide Polymorphisms

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Samuel Hager ◽  
Ellen Jensen ◽  
Timothy Johnson ◽  
David Mitchell
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Nalidixic Acid ◽  
Inhibitory Concentration ◽  
Acid Resistance ◽  
Penicillin G ◽  
Single Nucleotide ◽  
E Coli ◽  
Esherichia Coli ◽  
Nalidixic Acid Resistance

Bacteria are quick to adapt and evolve, especially under the effects of selective pressures from chemical antibiotics. In addition, bacteria may develop resistance to antibiotics from multiple classes simultaneously, making their eradication from the human body particularly challenging. This study aims to demonstrate that bacterial multiple-drug resistance can be developed and retained in a laboratory setting. Escherichia coli B was grown in tryptic soy broth in the presence of a small, increasing concentration of streptomycin. This exposure resulted in a strain of E. coli, which had an increased minimum inhibitory concentration (MIC) towards streptomycin, or “resistance.” This resistant strain was then grown in like manner in nalidixic acid and then penicillin G. The result was a strain that became resistant to streptomycin and nalidixic acid, and increasingly resistant to nalidixic acid after penicillin G exposure. Additionally, the bacteria retained resistance to streptomycin and nalidixic acid even after exposure to those chemicals ceased. Genome sequencing and comparison to E. coli B reference strain REL606 revealed the emergence of point mutations with each exposure to an antibiotic. Of particular interest is a mutation associated with the appearance of nalidixic acid resistance. Base pair 4,553,488 was changed from adenine to guanine, resulting in a change from aspartate to glycine in the protein helicase. Previous studies have not indicated mutations to this locus as nalidixic acid resistance conferring. Thus, this mutation may be a novel mutation conferring E. coli B nalidixic acid resistance. Since the region of the mutated helicase is functionally undefined, a mechanism is not apparent. Further research needs to be done to confirm this hypothesis and illuminate a mechanism. KEYWORDS: Bacteria; Escherichia coli; Evolution; Antibiotic Resistance; Nalidixic Acid; Streptomycin; Point Mutation; Single-nucleotide Polymorphism; Helicase; Minimum Inhibitory Concentration

scholarly journals AKTIVITAS ANTIBAKTERI EKSTRAK BIJI JERUK SIAM (Citrus reticulata) PADA BAKTERI Escherichia coli

2020 ◽  
Vol 7 (2) ◽  
pp. 289-295
Author(s):  
Mohammad Arfi Setiawan ◽  
Mita Dewi Retnoningrum ◽  
Febriyandhi Yahya ◽  
Resa Ragil Andika ◽  
Dyan Hatining Ayu Sudarni
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Seed Extract ◽  
Nutrient Agar ◽  
Citrus Reticulata ◽  
E Coli ◽  
Mic Minimum Inhibitory Concentration ◽  
Paper Disc

Antibacterial Activity of Citrus seed (Citrus reticulata) Extract on Escherichia coli Indonesian agriculture provides a resource of medicinal plants whose potential needs to be explored in order to benefit society. One of them is the use of Siam orange seeds (Citrus reticulata) which has the potential for the production of antibacterial compounds. This study aims to test the antibacterial activity of the ethanol and n-hexane extract of orange seeds. The extract was obtained through maceration techniques using ethanol and n-hexane as solvents. The antibacterial activity test of orange seeds against Escherichia coli used the paper disc diffusion method with nutrient agar (NA) media. The concentration of orange seed extract for the determination of MIC (Minimum Inhibitory Concentration) was 0.5, 2, 8, 10, 20 mg mL-1. The results showed that the ethanol and n-hexane extract of orange seeds had antibacterial activity against E. coli. However, the ethanol extract had a higher antibacterial effect than the n-hexane orange seed extract. From the results of this study, it is hoped that the waste of orange seeds will provide beneficial contribution for pharmaceutical development. Pertanian Indonesia memiliki sumber tanaman obat yang perlu digali potensinya agar bermanfaat bagi masyarakat. Salah satunya pemanfaatan biji jeruk siam (Citrus reticulata) yang berpotensi menghasilkan senyawa antibakteri. Penelitian ini bertujuan untuk menguji aktivitas antibakteri ekstrak etanol dan n-heksana biji jeruk. Ekstrak diperoleh melalui teknik maserasi menggunakan pelarut etanol dan n-heksana. Uji aktivitas antibakteri biji jeruk terhadap Escherichia coli menggunakan metode difusi paper disc dengan media nutrient agar (NA). Konsentrasi ekstrak biji jeruk untuk penentuan MIC (Minimum Inhibitory Concentration) adalah 0,5, 2, 8, 10, 20 mg mL-1. Hasil penelitian menunjukkan bahwa ekstrak etanol dan n-heksana biji jeruk memiliki aktivitas antibakteri terhadap E. coli. Namun, ekstrak etanol memiliki efek antibakteri yang lebih tinggi dibandingkan ekstrak biji jeruk n-heksana. Dari hasil penelitian ini, limbah biji jeruk diharapkan dapat memberikan kontribusi bermanfaat bagi pengembangan farmasi.

scholarly journals Colistin resistance prevalence in Escherichia coli from domestic animals in intensive breeding farms of Jiangsu Province, China

2018 ◽  
Author(s):  
X. Zhang ◽  
B. Zhang ◽  
Z. Yu ◽  
Y. Guo ◽  
J. Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Safety Issue ◽  
Resistance Mechanism ◽  
Domestic Animals ◽  
Jiangsu Province ◽  
Resistant Bacteria ◽  
Colistin Resistance ◽  
E Coli ◽  
Chromogenic Agar ◽  
Breeding Farms

AbstractThe global dissemination of colistin resistance has received a great deal of attention. Recently, the plasmid-mediated colistin resistance encoded by mcr-1 and mcr-2 genes in Escherichia coli (E.coli) strains from animals, food, and patients in China have been reported continuously. To make clear the colisin resistance and mcr gene spread in domestic animals in Jiangsu Province, we collected fecael swabs from pigs, chicken and cattle at different age distributed in intensive feeding farms. The selected chromogenic agar and mcr-PCR were used to screen the colisin resistance and mcr gene carriage. Colistin resistant E.coli colonies were identified from 54.25 % (440/811) pig faecal swabs, from 35.96 % (443/1232) chicken faecal swabs, and 26.92 % (42/156) from cattle faecal swabs. Of all the colisin resistant E.coli colonies, the positive amplifications of mcr-1 were significantly higher than mcr-2. The mcr-1 prevalence was 68.86 % (303/440) in pigs, 87.58 % (388/443) in chicken, and 71.43 % (30/42), compared with 46.82 % (206/440) in pigs, 14.90 % (66/443) in chicken, and 19.05 % (8/42) in cattle of prevalence of mcr-2. Co-occurrence of mcr-1 and mcr-2 was identified in 20 % (88/440) in pigs, 7.22 % (32/443) in chickens, and in 9.52 % (4/42) cattle. These data indicate that mcr was the most important colistin resistance mechanism. Interventions and alternative options are necessary to minimise further dissemination of mcr between food-producing animals and human.IMPORTANCEColistin is recognized one of the last defence lines for the treatment of highly resistant bacteria, but the emergence of resistance that conferred by a transferable plasmid-mediated mcr genes to this vital antibiotic is extremely disturbing. Here, we used E. coli as an index to monitor drug resistance in domestic animals (pigs, chicken and cattle). It was found that the colistin resistance widely occurred at all ages of domestic animals and the mcr-dependent mechanism dominated in E.coli. We also found that the elder and adult animals were a reservoir of resistant strains, suggesting a potential food safety issue and greater public health problems.

Minimum Inhibitory Concentration (MIC) versus Minimum Biofilm Eliminating Concentration (MBEC) in Evaluation of Antibiotic Sensitivity of Gram-negative Bacilli Causing Peritonitis

2004 ◽  
Vol 24 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Farshad Sepandj ◽  
Howard Ceri ◽  
Allan Gibb ◽  
Ronald Read ◽  
Merle Olson
Keyword(s):  
Escherichia Coli ◽  
Peritoneal Dialysis ◽  
Minimum Inhibitory Concentration ◽  
Antibiotic Susceptibility ◽  
Inhibitory Concentration ◽  
Antibiotic Sensitivity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Planktonic State

Objective Minimum inhibitory concentration (MIC) and minimum biofilm eliminating concentration (MBEC) results were compared to determine changes in the pattern of antibiotic sensitivity of gram-negative bacilli from the planktonic to the biofilm phase of growth. Methodology The MIC and MBEC assays were conducted on stored isolates obtained from patients presenting with peritoneal dialysis-related gram-negative peritonitis with Escherichia coli or Pseudomonas. Results The antibiotic sensitivities of planktonic organisms tested by the MIC assays were significantly higher than the antibiotic sensitivities of the same organisms in their biofilm state, as tested by the MBEC assays. Conclusions In their biofilm state, gram-negative bacteria are much less susceptible to antibiotics compared to their antibiotic susceptibility in the planktonic state.

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