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

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.

2020 ◽  
Vol 44 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Shiva Mirkalantari ◽  
Faramarz Masjedian ◽  
Gholamreza Irajian ◽  
Emmanuel Edwar Siddig ◽  
Azam Fattahi

Abstract Background Escherichia coli accounts for 70–95% of community-acquired urinary tract infections (UTIs). Recently, there has been an increase in the prevalence of extended-spectrum β-lactamase (ESBL) in the community which required an accurate identification for better management. Therefore, the current study was performed to determine the antimicrobial resistance pattern, investigate ESBL phenotypes and genotypes (blaCTX-M, bla TEM and bla SHV genes) and determine the phylogenetic groups among ESBL-positive isolates from outpatients. Methods One hundred and eighty-three positive urine samples were collected from 4450 outpatient clinic attendees. Antibiotic susceptibility was determined and ESBL phenotype screening was carried out using disk diffusion agar and combination disk techniques, respectively. The assessment of the presence of the blaCTX-M, bla TEM and blaSHV genes and phylogenetic grouping were performed using the polymerase chain reaction (PCR) method. Results Out of 183 E. coli isolates, 59 (32.2%) showed a positive ESBL phenotype. The prevalence of ESBL-producing E. coli was higher in males (57.4%). Fifty-seven of the ESBL-producing strains carried at least one of the β-lactamase genes (bla CTX-M, bla TEM, bla SHV). Phylotyping of multi-drug resistant isolates indicated that the isolates belonged to B2, A and D phylogroups. Analysis of resistance patterns among these phylogroups revealed that 74.4%, 55.3% and 29.7% of the isolates in the B2 group were resistant to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Most of the strains in the phylogroup B2 carried the bla CTX-M gene. Conclusions All the ESBL-producing isolates were placed in one of the four phylogenetic groups. The presence of CTX-M and resistance to quinolones were more frequent in B2 strains than in non-B2 strains.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdulkader Masri ◽  
Naveed Ahmed Khan ◽  
Muhammad Zarul Hanifah Md Zoqratt ◽  
Qasim Ayub ◽  
Ayaz Anwar ◽  
...  

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.


2020 ◽  
Author(s):  
Mohammad Hasan Namaei ◽  
Hengameh Hamzei ◽  
Marzie Moghanni ◽  
Azadeh Ebrahimzadeh

Abstract Background: Urinary Tract Infection (UTI) is the most common bacterial infection in the world. E. coli is the predominant Pathogen. This study evaluates the prevalence of ESBL in E. colis isolated from patients with urinary tract infections with phenotypic and genotypic methods.Methods: This descriptive-analytical study was done on 155 isolates of E. coli isolated from patients with urinary tract infection who had received the study consent. After accurate identification of E. coli strains. ESBL production for Escherichia coli isolates which are resistant to ceftriaxone or ceftazidime was evaluated by CDT method. TEM, SHV and CTX-M genes were identified by PCR.Results: The results showed that 30 strains from 155 strains of E. coli had ESBL. Strains of ESBL producer were more in males was lower in educated persons. 38.9% of ESBL producer had antibiotic use, 29.9% -producing Escherichia hospitalization and 31.6% uti history. The highest level of drug allergy in the ESBL was related to nitrofurantoin, and the highest resistance was related to cefazolin, co-trimoxazole. The CTX-M and the CTX-M15 gene were found in 92.7% and 57.1% of cases, respectively; also the SHV and TEM genes were not found in any of ESBL-producing Escherichia coli strains. Most therapeutic response in patients was related to cefexime, ciprofloxacin and nitrofurantoin 27.4%, 26% 21.9%, respectively.Conclusion: This study showed that the history of antibiotic use, hospitalization, uti related to increase of ESBL-producing in E. coli isolates., the CTMX-M gene is the most common gene in ESBL-producing E. coli strains.


DICP ◽  
1989 ◽  
Vol 23 (6) ◽  
pp. 456-460
Author(s):  
Michael N. Dudley ◽  
Hilary D. Mandler ◽  
Kenneth H. Mayer ◽  
Stephen H. Zinner

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.


2018 ◽  
Author(s):  
Mehdi Snoussi ◽  
John Paul Talledo ◽  
Nathan-Alexander Del Rosario ◽  
Bae-Yeun Ha ◽  
Andrej Košmrlj ◽  
...  

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.


2019 ◽  
Vol 21 (2) ◽  
pp. 80-85
Author(s):  
Farshad Kakian ◽  
Behnam Zamzad ◽  
Abolfazl Gholipour ◽  
Kiarash Zamanzad

Background and aims: Klebsiella is an opportunistic organism that is the cause of severe diseases such as pneumonia, septicemia, and urinary tract infections (UTIs). In addition, high antibiotic resistance has challenged the treatment of this bacterium. However, carbapenem antibiotics are considered as the therapeutic agents for selecting the treatment of penicillin- and cephalosporin-resistant gram-negative bacterial infections. The present study aimed to determine the resistance and minimum inhibitory concentration (MIC) of meropenem and imipenem. Methods: A total of 80 Klebsiella spp isolated from UTIs were collected in various educational wards (i.e., urology, obstetrics, and gynecology, as well as the units of infectious diseases, internal medicine, and intensive care) in different hospitals of Shahrekord. The isolates were then identified by using biochemical tests. Further, disc diffusion method was employed to determine the antibiotic resistance. Furthermore, MIC was estimated by the Epsilon-test strip. Moreover, P=Q=0.50, an error of 0.05, and an accuracy of 0.11 were considered for determining the sample size (n=80). Results: Based on the results of disc diffusion method, 24 strains were resistant to meropenem and imipenem. Additionally, the MIC was 24 (30%) by the E-test. In addition, 24 isolates had a MIC of ≥4 μg/mL for meropenem and imipenem and thus were resistant while 18 isolates were found to have a MIC of 1≤ MIC<4 μg/mL and therefore, were considered semi-sensitive (P<0.001). Conclusion: In general, Klebsiella strains were found to be resistant to meropenem and imipenem. Therefore, rapid and accurate identification of these strains and the selection of appropriate antibiotics can help quickly eradicate the infections caused by these bacteria. Accordingly, a waste of time, the consumption of medication, or even an increased resistance are prevented.


2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Samuel Hager ◽  
Ellen Jensen ◽  
Timothy Johnson ◽  
David Mitchell

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


2020 ◽  
Vol 7 (2) ◽  
pp. 289-295
Author(s):  
Mohammad Arfi Setiawan ◽  
Mita Dewi Retnoningrum ◽  
Febriyandhi Yahya ◽  
Resa Ragil Andika ◽  
Dyan Hatining Ayu Sudarni

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.


2016 ◽  
Vol 144 (14) ◽  
pp. 2967-2970 ◽  
Author(s):  
D. ORTEGA-PAREDES ◽  
P. BARBA ◽  
J. ZURITA

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.


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