scholarly journals Combinatorial Antimicrobial Susceptibility Testing Enabled by Non-Contact Printing

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 142 ◽  
Author(s):  
Adam S. Opalski ◽  
Artur Ruszczak ◽  
Yurii Promovych ◽  
Michał Horka ◽  
Ladislav Derzsi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Point Of Care ◽  
Antibiotic Susceptibility Testing ◽  
Contact Printing ◽  
Independence Model ◽  
Bliss Independence

We demonstrate the utility of non-contact printing to fabricate the mAST—an easy-to-operate, microwell-based microfluidic device for combinatorial antibiotic susceptibility testing (AST) in a point-of-care format. The wells are prefilled with antibiotics in any desired concentration and combination by non-contact printing (spotting). For the execution of the AST, the only requirements are the mAST device, the sample, and the incubation chamber. Bacteria proliferation can be continuously monitored by using an absorbance reader. We investigate the profile of resistance of two reference Escherichia coli strains, report the minimum inhibitory concentration (MIC) for single antibiotics, and assess drug–drug interactions in cocktails by using the Bliss independence model.

An automated and portable antimicrobial susceptibility testing system for urinary tract infections

Lab on a Chip ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 755-763
Author(s):  
Kuo-Wei Hsu ◽  
Wen-Bin Lee ◽  
Huey-Ling You ◽  
Mel S. Lee ◽  
Gwo-Bin Lee
Keyword(s):  
Urinary Tract ◽  
Minimum Inhibitory Concentration ◽  
Urinary Tract Infections ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Microfluidic System ◽  
Antimicrobial Susceptibility Testing ◽  
Testing System ◽  
Tract Infections

A portable, integrated microfluidic system capable of automatically conducting antimicrobial susceptibility testing (AST) and minimum inhibitory concentration (MIC) measurements using urine samples were developed.

A multiplexed nanoliter array-based microfluidic platform for quick, automatic antimicrobial susceptibility testing

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Mohammad Osaid ◽  
Yi-Sin Chen ◽  
Chih-Hung Wang ◽  
Anirban Sinha ◽  
Wen-Bin Lee ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Cells ◽  
Microfluidic Platform

A nanoliter array-based automatic microfluidic platform for performing rapid antimicrobial susceptibility testing using only ∼2000 bacterial cells was reported, and required 8–9 hours to determine the minimum inhibitory concentration value.

scholarly journals Susceptibility profile of Brazilian Rhodococcus equi isolates against azithromycin, clarithromycin and erythromycin

2015 ◽  
Vol 45 (4) ◽  
pp. 680-683
Author(s):  
Letícia Trevisan Gressler ◽  
Bibiana Petri da Silveira ◽  
Marcelo Luís Schwab ◽  
Agueda Castagna de Vargas ◽  
Luciana Pötter ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Rhodococcus Equi ◽  
Antimicrobial Susceptibility Testing ◽  
Microbiological Culture ◽  
Infection Treatment

Rhodococcus equi infection treatment is usually a macrolide (azithromycin - AZM, clarithromycin - CLR and erythromycin - ERY) and rifampicin combination. However, resistance cases have been reported, especially for ERY. In view of the need of a study about Brazilian isolates susceptibility profile, this study aimed to characterize the minimum inhibitory concentration (MIC) of the macrolides - AZM, CLR and ERY - against 44 R. equi isolates. It was found all isolates CLR and AZM sensitive; however, for ERY, 27% (12/44) were classified as intermediate sensitivity. R. equi Brazilian isolates used here showed a large susceptibility profile, except against ERY, for which it was observed some resistance evidence. In order to avoid failures in the equine rhodococcosis therapy it was highlighted the importance of microbiological culture and antimicrobial susceptibility testing in vitro before beginning treatment

scholarly journals Detection of Antibiotic Susceptibility by Colorimetric Minimum Inhibitory Concentration in Staphylococcal Isolates

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
B S Mahmoud ◽  
S A ElMasry ◽  
N A Fahim ◽  
O A Shaker ◽  
M A Abdelsattar
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Concentration ◽  
Tetrazolium Chloride ◽  
Wide Range ◽  
Agar Dilution

Abstract Background Staphylococcus species are implicated in a wide range of community and hospital-acquired infections, which necessitates rapid provision of antibiotic susceptibility results for patients at risk. The current study evaluated the usefulness of applying broth microdilution (BMD) and agar dilution methods for antimicrobial susceptibility testing of Staphylococci using tetrazolium salts as redox indicators. Methods Minimum inhibitory concentration (MICs) of eight antimicrobials representing different antibiotic classes as recommended by CLSI; vancomycin (VA), linezolid (LZD), oxacillin (OX), gentamicin (CN), tetracycline (TE), ciprofloxacin (CIP), erythromycin (E) and clindamycin (DA) was investigated for 80 isolates of Staphylococci by a modified BMD with the addition of dimethyl thiazole diphenyl tetrazolium bromide (MTT). As well as agar dilution with the addition of MTT & triphenyl tetrazolium chloride (TTC) at the standard bacterial concentration together with addition of MTT at an experimental bacterial concentration. Results BMD (MTT) showed the highest agreement regarding most antibiotics among different isolates in comparison with the standard BMD. All performed methods showed significant agreement except agar dilution (TTC) using TE, DA, E, and agar dilution (MTT 108) using DA as well as agar dilution (MTT 104) using E among S. aureus. Conclusions Colorimetric BMD was rapid, easy to interpret and showed the highest agreement with the standard BMD. Colorimetric agar dilution (MTT) was less tedious than BMD. The colorimetric MIC method using MTT may be a useful surrogate of antimicrobial susceptibility testing among Staphylococcus isolates.

Use of Linezolid to Treat MRSP Bacteremia and Discospondylitis in a Dog

2014 ◽  
Vol 50 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Jonathan D. Foster ◽  
Lauren A. Trepanier ◽  
Jennifer A. Ginn
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Thoracic Vertebrae ◽  
Antibiotic Susceptibility Testing ◽  
German Shepherd ◽  
Methicillin Resistant ◽  
German Shepherd Dog ◽  
Successful Resolution ◽  
Plasma Minimum

A 1.5 yr old male German shepherd dog was evaluated for recurrent intermittent episodes of fever and lethargy. Clinicopathologic abnormalities were suggestive of a discospondylitis at the seventh and eighth thoracic vertebrae. Blood and urine cultures yielded growth of methicillin-resistant Staphylococcus pseudintermedius (MRSP) that was resistant to all commonly used antibiotics. Extralabel antibiotic susceptibility testing demonstrated susceptibility of both blood and urine isolates to linezolid. The prescribed dose was extrapolated from pharmacokinetic (PK) studies and the isolate’s plasma minimum inhibitory concentration (MIC). Linezolid was administered for 23 wk and resulted in successful resolution of bacteremia, bacteriuria, and discospondylitis. When justified, linezolid should be considered to treat methicillin-resistant infections.

scholarly journals Phenotypical and Genotypical Comparison of Clostridium difficile Isolated from Clinical Samples: Homebrew DNA Fingerprinting versus Antibiotic Susceptibility Testing (AST) and Clostridial Toxin Genes

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Javid Sisakhtpour ◽  
Fatemeh Savaheli Moghadam ◽  
Sepideh Khodaparast ◽  
Nima Khoramabadi ◽  
Ashraf Mohabati Mobarez
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Dna Fingerprinting ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Antibiotic Susceptibility Testing ◽  
Anaerobic Culture ◽  
Toxin Genes

Background. Clostridium (Clostridioides) difficile is recognized as the major cause of healthcare antibiotic-associated diarrhea. We surveyed a molecular epidemiological correlation between the clinical isolates from two general hospitals in Iran through clustering toxigenic types and antibiotic susceptibility testing (AST) accuracy. Methods. Study population included 460 diarrhoeic specimens from inpatients with a history of antibiotic therapy. All samples underwent enriched anaerobic culture, confirmed by detection of gluD gene with PCR. Toxin status and AST were assessed by the disk diffusion method (DDM) and minimal inhibitory concentrations (MICs) of metronidazole, vancomycin, and rifampin. C. difficile outbreak was analyzed through conventional PCR by tracing toxin genes and Homebrew pulsed-field gel electrophoresis (PFGE) for characterizing isolates within our healthcare systems. Results. A total of 29 C. difficile strains were isolated by enriched anaerobic culture from the clinical samples. Among them, 22 (4.8%) toxigenic profiles yielded toxins A and B (tcdA, tcdB) and binary toxins (cdtA, cdtB). The minimum inhibitory concentration (MIC) was 18.1% and 9% for vancomycin and metronidazole, and all isolates were susceptible to rifampicin and its minimum inhibitory concentration was at <0.003 μg/mL. The most dominant toxigenic and antibiotic-resistant “pulsotype F” was detected through PFGE combined with multiple Clostridial toxigenic pattern and AST. Conclusions. DNA fingerprinting studies represent a powerful tool in surveying hypervirulent C. difficile strains in clinical settings. Resistance to vancomycin and metronidazole, as first-line antibiotics, necessitate accomplishment of proper control strategies and also prescription of tigecycline as a more appropriate option.

scholarly journals Antimicrobial Susceptibility Testing of Metronidazole and Clindamycin against Gardnerella vaginalis in Planktonic and Biofilm Formation

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Ting Li ◽  
Zhan Zhang ◽  
Fengjuan Wang ◽  
Yuanhui He ◽  
Xiaonan Zong ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Resistance Rate ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Lower Resistance ◽  
Antimicrobial Susceptibilities ◽  
Susceptibility Rate

Background. Bacterial vaginosis (BV), one of the most common vaginal ecosystem-related microbiologic syndromes, is the most common disorder in women of reproductive age. Gardnerella (G.) vaginalis is the predominant species causing this infection. Our aim was to compare the antimicrobial susceptibilities of metronidazole and clindamycin against G. vaginalis at planktonic and biofilm levels. Methods. From September 2019 to October 2019, we recruited a total of 10 patients with BV who underwent gynecological examinations at Beijing Obstetrics and Gynecology Hospital. G. vaginalis isolates were obtained from the vagina and identified using their characteristic colony morphology. Sequence data of clinical G. vaginalis isolates were confirmed by comparing 16S rDNA sequences. Subsequently, clinical isolates were evaluated for antimicrobial susceptibilities in vitro to metronidazole and clindamycin at planktonic and biofilm levels. The minimum inhibitory concentration (MIC) for metronidazole and clindamycin was evaluated by antimicrobial susceptibility testing. The minimum biofilm eradication concentration (MBEC) was evaluated by the biofilm inhibition assay. Results. Planktonic clinical isolates showed a significantly higher susceptibility rate (76.67%) and lower resistance rate (23.33%) to clindamycin than to metronidazole (susceptibility rate: 38.24%; resistance rate: 58.82%; P<0.05 for both). Furthermore, in comparison to planktonic isolates, the minimum inhibitory concentration (MIC) of metronidazole was significantly higher for biofilm-forming isolates (7.3 ± 2.6 μg/mL vs. 72.4 ± 18.3 μg/mL; P=0.005); the resistance rate was 27.3%, and the minimum biofilm eradication concentration (MBEC) was >128 μg/mL. Moreover, the MIC of clindamycin was higher too for biofilm-forming isolates (0.099 ± 0.041 μg/mL vs. 23.7 ± 9.49 μg/mL; P=0.034); the resistance rate was 27.3%, and the MBEC of clindamycin was 28.4 ± 6.50 μg/mL. Conclusion. Our results indicate that in comparison to metronidazole, clindamycin seems to be a better choice to tackle G. vaginalis as it exhibits a relatively higher susceptibility rate and lower resistance rate.

scholarly journals Renaissance of Conventional First-Line Antibiotics inSalmonella entericaClinical Isolates: Assessment of MICs for Therapeutic Antimicrobials in Enteric Fever Cases from Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Puspa Raj Khanal ◽  
Deepa Satyal ◽  
Anjeela Bhetwal ◽  
Anjila Maharjan ◽  
Shreena Shakya ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Blood Samples

Enteric fever caused bySalmonella entericais a life-threatening systemic illness of gastrointestinal tract especially in tropical countries. Antimicrobial therapy is generally indicated but resistance towards commonly used antibiotics has limited their therapeutic usefulness. Therefore, we aimed to determine the antimicrobial susceptibility pattern by minimum inhibitory concentration method of common therapeutic regimens againstSalmonella entericafrom enteric fever clinical cases.Salmonella entericaclinical isolates recovered from the patients with suspected enteric fever whose blood samples were submitted to microbiology laboratory of Manmohan Memorial Community Hospital, Kathmandu, from March 2016 to August 2016, were studied. These isolates were subjected to antimicrobial susceptibility testing against common therapeutic antimicrobials by Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of ciprofloxacin, azithromycin, chloramphenicol, and cefixime was determined by Agar dilution method based on the latest CLSI protocol. A total of 88 isolates ofSalmonella entericawere recovered from blood samples of enteric fever cases. Out of them, 74 (84.09%) wereSalmonellaTyphi and 14 (15.91%) wereSalmonellaParatyphi A. On Kirby-Bauer disk diffusion antimicrobial susceptibility testing, entire isolates were susceptible to cotrimoxazole, cefixime, ceftriaxone, azithromycin, and chloramphenicol. Sixty-four (72.7%)Salmonella entericaisolates were nalidixic acid resistant and nonsusceptible to ciprofloxacin and levofloxacin. On MIC determination, fourSalmonellaisolates were ciprofloxacin resistant with MIC 1 µg/ml and two isolates were ciprofloxacin intermediate with MIC 0.5 µg/ml. The MIC range of azithromycin was from 0.125 µg/ml to 2.0 µg/ml, whereas that for chloramphenicol was 2.0 µg/ml–8.0 µg/ml and for cefixime was 0.0075–0.5 µg/ml, respectively. Despite global surge of antimicrobial resistance amongSalmonella entericaclinical isolates, the level of drug resistance in our study was not so high. However, higher level of NARST strains limits therapeutic use of fluoroquinolones and necessitates the routine monitoring of such resistance determinants in order to effectively and rationally manage enteric fever cases.

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.

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