scholarly journals Evaluation of Two Phenotypic Methods for the Detection of Plasmid-Mediated AmpC β-Lactamases among Enterobacteriaceae Isolates

2021 ◽  
Author(s):  
Ronni Mol P ◽  
Khalid Mubarak Bindayna ◽  
Ganesan Shanthi
Keyword(s):  
Test Performance ◽  
Boronic Acid ◽  
Clinical Laboratory ◽  
Cost Effective ◽  
Tertiary Hospital ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Polymerase Chain ◽  
Phenotypic Methods

Abstract Objectives AmpC β-lactamases are cephalosporinases that confer resistance to cephalothin, cefazolin, cefoxitin, penicillin, and β-lactamase inhibitor-β-lactam combinations. Even though the AmpC resistance is reported, but the accurate occurrence of AmpC β-lactamases in Enterobacteriaceae members is still unknown. Techniques to identify AmpC producers are still evolving but not yet optimized for the clinical laboratory. Here we aimed to compare the test performance of two different phenotypic methods, that is inhibitor-based assay using boronic acid and disk approximation test for AmpC detection in Enterobacteriaceae isolates from a tertiary hospital microbiology laboratory. Materials and Methods The study includes 137 nonrepeat Enterobacteriaceae strains. Bacterial isolates, that yielded a zone diameter of less than 18 mm for cefoxitin by disk diffusion method were considered potential AmpC producers and further confirmed by phenotype methods—inhibitor-based assay using boronic acid and disk approximation test. A multiplex polymerase chain reaction was used to detect the most common plasmid-mediated AmpC genes: ACC, FOX, MOX, DHA, CIT, and EBC. Results Of the 137 clinical isolates, 58 (42.33%) were cefoxitin resistant, while 53.4 and 18.9% of the cefoxitin-resistant isolates were positive by inhibitor-based assay and disk approximation test. Multiplex PCR detected 42 (30.6%) isolates with AmpC genes. Of the 42 isolates, the inhibitor-based assay detected 25 (59.5%) isolates, while the disk approximation test detected nine (21.4%) isolates. Conclusion Our findings suggest that inhibitor-based assay using boronic acid can be used for the detection of the isolates that harbor AmpC β-lactamases. This method is cost-effective, simple to perform, and easy to interpret. Thus AmpC detection as a routine in clinical laboratories can help in appropriate therapeutic intervention and improved infection control.

scholarly journals Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Raw Milk Cheese

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

scholarly journals Detection of plasmid-mediated qnr genes among the quinolone-resistant Escherichia coli isolates in Iran

2014 ◽  
Vol 8 (07) ◽  
pp. 818-822 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mohammad Zibaei ◽  
Younes Soleimani-Asl
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Quinolone Resistance ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Tract Infections

Introduction: Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. Methodology: A total of 140 Escherichia coli isolates were collected between March and October 2012 from urinary tract infections in Khorram Abad, Iran. All isolates were tested for quinoloe resistance using the disk diffusion method. Also, all quinolone-resistant isolates were screened for the presence of the qnrA and qnrB genes by polymerase chain reaction. Minimum inhibitory concentrations (MICs) of ciprofloxacin for the qnr-positive isolates were determined. Results: One hundred sixteen (82.8%) of 140 Escherichia coli isolates were nalidixic acid-resistant; among them, 14 (12.1%) and 9 (7.8%) were qnrA and qnrB-positive, respectively. Two quinolone-resistant isolates harbored both qnrA and qnrB. Among 63 ciprofloxacin-resistant isolates, 14 (22.2%) and 9 (14.3%) were found to carry qnrA and qnrB genes, respectively. The ciprofloxacin MIC range was 0.25–512 μg/mL for 23 qnr-positive Escherichia coli isolates, 18 of which had MICs values of 4–512 μg/mL. Conclusion: Our study shows that the frequency of plasmid-mediated quinolone resistance genes among E. coli isolates in Iran is high.

Ceftazidime – Avibactam susceptibility among carbapenem-resistant Enterobacterales in a pilot study in Turkey

2021 ◽  
Author(s):  
Hasan Selcuk Ozger ◽  
Ebru Evren ◽  
Serap Suzuk Yildiz ◽  
Cigdem Erol ◽  
Fatma Bayrakdar ◽  
...  
Keyword(s):  
Practical Method ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Drug Resistant ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Therapeutic Choice ◽  
Polymerase Chain

AbstractThis study aimed to detect carbapenemase genes and to determine the in vitro susceptibility of Ceftazidime-Avibactam (CZA) in Enterobacterales isolates. Carbapenemase genes were detected by polymerase chain reaction. CZA sensitivity of isolates was evaluated with broth microdilution (BMD) and disk diffusion methods. A total of 318 carbapenem-resistant Enterobacterales isolates were included. Most of the isolates (n = 290, 91.2%) were identified as Klebsiella pneumoniae. The most common carbapenemase type was OXA-48 (n = 82, 27.6%). CZA susceptibility was evaluated in 84 isolates with OXA-48 and KPC carbapenemase activity. Both BMD and disk diffusion methods revealed that 95.2% of the isolates were sensitive to CZA; whereas, 4 (4.76%) isolates were resistant to CZA. Among colistin resistant isolates, 96.5% (n = 80) of them were susceptible to CZA. Our study demonstrated high in vitro efficacy of CZA in Enterobacterales isolates producing OXA-48 carbapenemase. High susceptibility rates against colistin resistant isolates which generally are also pan drug resistant, makes CZA a promising therapeutic choice for difficult-to-treat infections. Due to its high correlation with the BMD, disk diffusion method is a suitable and more practical method in detecting CZA in vitro activity.

scholarly journals Molecular Characterization of Carbapenemase-Producing Escherichia coli and Salmonella in children with diarrhea in rural Burkina Faso

2020 ◽  
Author(s):  
Rene DEMBELE ◽  
Issiaka Soulama ◽  
Wendpoulomdé A. D. Kaboré ◽  
Ali Konaté ◽  
Assèta Kagambèga ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Treatment Options ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Resistance Rates ◽  
Encoding Genes

Abstract Background: In recent years, carbapenemase-producing Enterobacterales (CPE) resistance to antibiotics has dramatically increased leading to limitations of their treatment options. In the present study, we investigated the occurrence of carbapenemase-producing Escherichia coli and Salmonella in rural Burkina Faso. Methods: Salmonella isolates were serotyped according to the Kauffman White scheme. Diarrheagenic Escherichia coli (DEC) strains was identified using 16-plex Polymerase Chain Reaction (PCR), whereas antibiotic susceptibility was realized using the disk diffusion method. Furthermore, multiplex PCR assays were carried out using oligonucleotides to detect the presence of genes of the blaKPC, blaVIM, blaIMP, blaTEM, blaSHV, blaOXA and blaCTX-M types in all E. coli and Salmonella strains.Results: The study highlighted high resistance rates of the identified bacteria to common antibiotics. Likewise, two strains of E. coli were imipenem resistant with carbapenemase-encoding genes. The genes detected were Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2) reaching a rate of 40% each in E. coli strains. However, no Salmonella carbapenemases blaKPC, blaVIM or blaIMP were detected.Conclusions: This study showed that for a real-time infection control and prompt application of antimicrobial chemotherapy, characterization of carbapenemase-producing Enterobacterales in patients is crucial.

scholarly journals Detection of Ampicillin Resistance Encoding Gene of Escherichia coli from Chickens in Bandung and Purwakarta

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Kuntum Khoirani ◽  
Agustin Indrawati ◽  
Surachmi Setiyaningsih
Keyword(s):  
Diffusion Method ◽  
Antibiotics Resistance ◽  
Test Results ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Encoding Gene ◽  
Almost All

The purpose of this study was to test the resistance and to detect antibiotic resistence encoding gene in E. coli bacteria from chickens in Bandung and Purwakarta livestock. 18 E. coli isolates were tested for antibiotics resistance using the disk diffusion method. Isolates that were categorized as resistant and intermediate to antibiotics, then polymerase chain reaction was utilized to detect the resistent coding gene. The test results showed that all E. coli isolates from chickens in Bandung and Purwakarta were resistant to ampicillin (100%). E. coli isolates were still sensitive to chloramphenicol (11.1%) and gentamicin (22.2%). The gene encoding for ampC resistance from the test were in the amount of 77.7%. Sensitivity test results and detection of resistance coding gene showed that almost all isolates were resistant to ampicillin antibiotics and E. coli isolates were still sensitive to chlorampenicol and gentamicin. 

scholarly journals Detection of integron genes in the plasmid DNA of multidrug resistant Pseudomonas aeruginosa isolated from surgical wounds of some patients in Benin City, Nigeria

2021 ◽  
Vol 37 (2) ◽  
pp. 95-102
Author(s):  
A.O Eremwanarue ◽  
H.O Shittu ◽  
E Igiehon ◽  
E.R Oijagbe
Keyword(s):  
Polymerase Chain Reaction ◽  
Pseudomonas Aeruginosa ◽  
Plasmid Dna ◽  
Pcr Amplification ◽  
Opportunistic Pathogen ◽  
Diffusion Method ◽  
Bacterial Cells ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Polymerase Chain

Pseudomonas aeruginosa is an opportunistic pathogen with the capability to cause serious surgical wound infections and remains a major healthcare problem. Plasmid is an extra chromosomal material in bacterial cells and confers resistance to the cell against many antibiotics. Genetic elements such as integron are implicated in conferring multidrug resistance (MDR) to P. aeruginosa . This study aims at investigating the occurrence of integron genes (int1, int2, int3) in the plasmid DNA and their ability to cause MDR in P. aeruginosa . In total, 284 different wound swabs were collected, P. aeruginosa isolated and screened using standard laboratory methods. Antibiotics susceptibility tests were carried out using Kirby-Bauer disk diffusion method. Polymerase chain reaction (PCR) was also carried out using P. aeruginosa plasmid DNA as a template to detect the presence/absence of the integron genes using different pairs of specific primers. The results reveal that 34 (54.8%) of the microbes isolated were P. aeruginosa . Most of the isolates showed notable resistance to antibiotics, most notably against Ceftazidime, Augmentin, Cefixime and Gentamicin . Eleven isolates harbors the plasmid DNA . PCR amplification showed that 6 (54.5%) of the P. aeruginosa isolates harbor integron class 1 genes, non harbors the integron class 2 genes while 3 (27.3%) possess the integron class 3 genes. The isolates with these genes were highly resistant to most of the antibiotics used. int1 gene was prevalent then int3. Keywords: Antimicrobial, Wound infection, Integron, Polymerase chain reaction, Plasmid DNA

Prevalence of SHV-extended spectrum β-lactamase producing carbapenem –resistantKlebsiellapneumoniae among patients with lower respiratory tractinfections in Babylon Province-Iraq.

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Fatima Moeen Abbas
Keyword(s):  
Resistance Rate ◽  
Combination Method ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Tract Infections ◽  
Positive Results

This study was carried out to screen the prevalence of Klebsiella pneumoniae isolated from patients with lower respiratory tract infections in Babylon province.From December,2015 to the end of March,2016,a total of 100 sputum samples were collected from patients visited or hospitalized Merjan Teaching Hospital and Al- Hashimya General Hospital. Fifteenth (65%) isolates were identified as Klebsiellapneumoniae. All bacterial isolates were evaluated for extended spectrum β-lactamase (ESBL) production phenotypically using disk combination method. Eleven (73.3%) isolates were detected as ESBL-producers. Kirby-Bauer disk diffusion method was employed to determine resistance profile of ESBLs-positive isolates. Higher rates of resistance were observed for ampicillin and piperacillin antibiotics with (81.8%) and (72.7%) resistance rate, respectively, while the lowest rate was noticed for imipenem antibiotic (14.28%). Carbapenem-resistant isolates were investigated for blaSHV gene by Polymerase Chain Reaction (PCR) method, 2 (100%) isolates gave positive results.

Cost-Effectiveness of Nasopharyngeal Carcinoma Screening with Epstein-Barr Virus Polymerase Chain Reaction or Serology in High-Incidence Populations Worldwide

2020 ◽  
Author(s):  
Jacob A Miller ◽  
Quynh-Thu Le ◽  
Benjamin A Pinsky ◽  
Hannah Wang
Keyword(s):  
Cost Effectiveness ◽  
Epstein Barr Virus ◽  
Cost Effective ◽  
Chain Reaction ◽  
Men And Women ◽  
Barr Virus ◽  
Screening Strategies ◽  
High Incidence ◽  
Polymerase Chain ◽  
Epstein Barr

Abstract Background The incidence of endemic Epstein-Barr Virus (EBV)-associated nasopharyngeal carcinoma (NPC) varies considerably worldwide. In high-incidence regions, screening trials have been conducted. We estimated the mortality reduction and cost-effectiveness of EBV-based NPC screening in populations worldwide. Methods We identified 380 populations in 132 countries with incident NPC and developed a decision-analytic model to compare ten unique onetime screening strategies to no screening for men and women at age 50 years. Screening performance and the stage distribution of undiagnosed NPC were derived from a systematic review of prospective screening trials. Results Screening was cost-effective in up to 14.5% of populations, depending on the screening strategy. These populations were limited to East Asia, Southeast Asia, North Africa, or were Asian, Pacific Islander, or Inuit populations in North America. A combination of serology and nasopharyngeal polymerase chain reaction (PCR) was most cost-effective, but other combinations of serologic and/or plasma PCR screening were also cost-effective. The estimated reduction in NPC mortality was similar across screening strategies. For a hypothetical cohort of patients in China, 10-year survival improved from 71.0% (95%CI = 68.8%–73.0%) without screening to a median of 86.3% (range = 83.5%–88.2%) with screening. This corresponded to a median 10-year reduction in NPC mortality of 52.9% (range= 43.1%–59.3%). Screening interval impacted absolute mortality reduction and cost-effectiveness. Conclusions We observed decreased NPC mortality with EBV-based screening. Screening was cost-effective in many high-incidence populations and could be extended to men and women as early as age 40 years in select regions. These findings may be useful when choosing among local public health initiatives.

scholarly journals Development of a Genoserotyping Method for Salmonella Infantis Detection on the Basis of Pangenome Analysis

2020 ◽  
Vol 9 (1) ◽  
pp. 67
Author(s):  
Seung-Min Yang ◽  
Jiwon Baek ◽  
Eiseul Kim ◽  
Hyeon-Be Kim ◽  
Seyoung Ko ◽  
...  
Keyword(s):  
Public Health ◽  
Polymerase Chain Reaction ◽  
Bacterial Species ◽  
Cost Effective ◽  
The Other ◽  
Gene Marker ◽  
Diagnostic Assay ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Substantial Economic Burden

In recent years, Salmonella Infantis has become a predominant serovariant in clinical and poultry isolates, thereby imposing a substantial economic burden on both public health and the livestock industry. With the aim of coping with the steep increase in serovar Infantis prevalence, a polymerase chain reaction (PCR)-based rapid and accurate diagnostic assay was developed in this study through pangenome profiling of 60 Salmonella serovars. A gene marker, SIN_02055, was identified, which is present in the S. Infantis genome but not in the pangenome of the other serovars. Primers specific to SIN_02055 were used to accurately detect serovar Infantis, and to successfully differentiate Infantis from the other 59 serovars in real-time PCR with a R2 of 0.999 and an efficiency of 95.76%. The developed method was applied to 54 Salmonella strains belonging to eight dominant serovars, and distinguished Infantis from the other seven serovars with an accuracy of 100%. The diagnostic primer set also did not show false positive amplification with 32 strains from eight non-Salmonella bacterial species. This cost-effective and rapid method can be considered an alternative to the classic serotyping using antisera.

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