scholarly journals Recent Development of Rapid Antimicrobial Susceptibility Testing Methods through Metabolic Profiling of Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 311
Author(s):  
Chen Chen ◽  
Weili Hong

Due to the inappropriate use and overuse of antibiotics, the emergence and spread of antibiotic-resistant bacteria are increasing and have become a major threat to human health. A key factor in the treatment of bacterial infections and slowing down the emergence of antibiotic resistance is to perform antimicrobial susceptibility testing (AST) of infecting bacteria rapidly to prescribe appropriate drugs and reduce the use of broad-spectrum antibiotics. Current phenotypic AST methods based on the detection of bacterial growth are generally reliable but are too slow. There is an urgent need for new methods that can perform AST rapidly. Bacterial metabolism is a fast process, as bacterial cells double about every 20 to 30 min for fast-growing species. Moreover, bacterial metabolism has shown to be related to drug resistance, so a comparison of differences in microbial metabolic processes in the presence or absence of antimicrobials provides an alternative approach to traditional culture for faster AST. In this review, we summarize recent developments in rapid AST methods through metabolic profiling of bacteria under antibiotic treatment.

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3449
Author(s):  
Cristina-Mirabela Gaşpar ◽  
Ludovic Toma Cziszter ◽  
Cristian Florin Lăzărescu ◽  
Ioan Ţibru ◽  
Marius Pentea ◽  
...  

This study aimed to compare the antibiotic resistance levels of the indicator bacteria Escherichia coli in wastewater samples collected from two hospitals and two urban communities. Antimicrobial susceptibility testing was performed on 81 E. coli isolates (47 from hospitals and 34 from communities) using the disc diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. Ten antibiotics from nine different classes were chosen. The strains isolated from the community wastewater, compared to those from the hospital wastewater, were not resistant to gentamicin (p = 0.03), but they showed a significantly higher susceptibility—increased exposure to ceftazidime (p = 0.001). Multidrug resistance was observed in 85.11% of the hospital wastewater isolates and 73.53% of the community isolates (p > 0.05). The frequency of the presumed carbapenemase-producing E. coli was higher among the community isolates (76.47% compared to 68.09%) (p > 0.05), whereas the frequency of the presumed extended-spectrum beta-lactamase (ESBL)-producing E. coli was higher among the hospital isolates (21.28% compared to 5.88%) (p > 0.05). The antibiotic resistance rates were high in both the hospital and community wastewaters, with very few significant differences between them, so the community outlet might be a source of resistant bacteria that is at least as important as the well-recognised hospitals.


Lab on a Chip ◽  
2021 ◽  
Author(s):  
Mohammad Osaid ◽  
Yi-Sin Chen ◽  
Chih-Hung Wang ◽  
Anirban Sinha ◽  
Wen-Bin Lee ◽  
...  

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.


Author(s):  
Mustafa Ersal

Antimicrobial susceptibility testing can be used for prediction of therapeutic results, epidemiology and drug discovery. Microbial infections are an important problem which have developed resistance towards antimicrobial agents. Otherwise, efficacy of these agents is considerable with treatment failures associated with multidrug-resistant bacteria and it has become a global concern to public health. Therefore, explore the new antimicrobial agents and widely use of antimicrobial susceptibility need to be developed. There are many techniques for the determination of antimicrobial activity. Many of these techniques, which are applied to inhibit sensitive microorganisms, are based on diffusion-related methods in the solid or semi-solid production environment. Cross-streak among these techniques is an easy technique that allows for relatively rapid screening of cultures in research for the discovery of the new antibiotics. However, the biggest disadvantage of the Cross-streak test is the difficulty in obtaining quantitative data. Because the edges of the inhibition zone are usually very fuzzy and unclear. Some antimicrobial susceptibility testing techniques were standardized by Clinical Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) to determine the striking steps in this area. This testing procedure requires the use of specific test conditions and methods. In addition, the medium, incubation conditions and time are among these requirements. It is important to understand and develop the Cross-streak method from the currently used activity determination methods.


Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 288
Author(s):  
Britney Forsyth ◽  
Peter Torab ◽  
Jyong-Huei Lee ◽  
Tyler Malcom ◽  
Tza-Huei Wang ◽  
...  

Bloodstream infections are a significant cause of morbidity and mortality worldwide. The rapid initiation of effective antibiotic treatment is critical for patients with bloodstream infections. However, the diagnosis of bloodborne pathogens is largely complicated by the matrix effect of blood and the lengthy blood tube culture procedure. Here we report a culture-free workflow for the rapid isolation and enrichment of bacterial pathogens from whole blood for single-cell antimicrobial susceptibility testing (AST). A dextran sedimentation step reduces the concentration of blood cells by 4 orders of magnitude in 20–30 min while maintaining the effective concentration of bacteria in the sample. Red blood cell depletion facilitates the downstream centrifugation-based enrichment step at a sepsis-relevant bacteria concentration. The workflow is compatible with common antibiotic-resistant bacteria and does not influence the minimum inhibitory concentrations. By applying a microfluidic single-cell trapping device, we demonstrate the workflow for the rapid determination of bacterial infection and antimicrobial susceptibility testing at the single-cell level. The entire workflow from blood to categorical AST result can be completed in less than two hours.


2017 ◽  
Vol 22 (6) ◽  
pp. 662-674 ◽  
Author(s):  
Kenneth P. Smith ◽  
David L. Richmond ◽  
Thea Brennan-Krohn ◽  
Hunter L. Elliott ◽  
James E. Kirby

Antibiotic resistance is compromising our ability to treat bacterial infections. Clinical microbiology laboratories guide appropriate treatment through antimicrobial susceptibility testing (AST) of patient bacterial isolates. However, increasingly, pathogens are developing resistance to a broad range of antimicrobials, requiring AST of alternative agents for which no commercially available testing methods are available. Therefore, there exists a significant AST testing gap in which current methodologies cannot adequately address the need for rapid results in the face of unpredictable susceptibility profiles. To address this gap, we developed a multicomponent, microscopy-based AST (MAST) platform capable of AST determinations after only a 2 h incubation. MAST consists of a solid-phase microwell growth surface in a 384-well plate format, inkjet printing–based application of both antimicrobials and bacteria at any desired concentrations, automated microscopic imaging of bacterial replication, and a deep learning approach for automated image classification and determination of antimicrobial minimal inhibitory concentrations (MICs). In evaluating a susceptible strain set, 95.8% were within ±1 and 99.4% were within ±2, twofold dilutions, respectively, of reference broth microdilution MIC values. Most (98.3%) of the results were in categorical agreement. We conclude that MAST offers promise for rapid, accurate, and flexible AST to help address the antimicrobial testing gap.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lidvine Boland ◽  
Corentin Streel ◽  
Hélène De Wolf ◽  
Hector Rodriguez ◽  
Alexia Verroken

Abstract Background A bacteremia diagnosis with speeded-up identification and antimicrobial susceptibility testing (AST) is mandatory to adjust empirical broad-spectrum antibiotherapy and avoid the emergence of multi-resistant bacteria. Alfred 60AST (Alifax, Polverara, PD, Italy) is an innovative automated system based on light scattering measurements allowing direct AST from positive blood cultures with rapid results. In this study we aimed to evaluate the system’s performances and turnaround time (TAT) compared to routine AST. Methods The study was conducted during 2 non-consecutive 3-month periods at the microbiology laboratory of the Cliniques universitaires Saint-Luc. All blood cultures detected positive in the 0 AM–10 AM time frame with a pure Gram-positive cocci or Gram-negative bacilli stain were included for Alfred 60AST testing. Two customized EUCAST antibiotic panels were set up composed of 1) a “Gram-negative” panel including cefuroxime, ceftazidime Enterobacteriaceae, piperacillin-tazobactam Enterobacteriaceae, ciprofloxacine, and ceftazidime Pseudomonas 2) a “Gram-positive” panel including cefoxitin Staphylococcus aureus, cefoxitin coagulase-negative (CNS) Staphylococci and ampicillin Enterococci. Categorical agreement (CA), very major errors (VME), major errors (ME), minor errors (mE) and TAT to Alfred 60AST results were calculated in comparison with AST results obtained from direct testing on positive blood cultures with the Phoenix system (Becton Dickinson, Franklin Lakes, NJ, USA). Results Five hundred seventy and one hundred nine antibiotics were evaluated on respectively 166 Gram-negative bacilli and 109 Gram-positive cocci included in the studied population. During the first study period regarding Gram-negative strains a CA of 89.5% was obtained with a high rate of VME (19 and 15.4% respectively) for cefuroxime and piperacillin-tazobactam Enterobacteriaceae. Considering this, Alifax reviewed these antibiotics’ formulations improving Gram-negative bacilli total CA to 92.2% with no VME during the second study period. For Gram-positive cocci, total CA was 88.1% with 2.3% VME, 13.8% ME (mainly cefoxitin CNS) and 12% mE rates both study periods combined. Median TAT to AST results was 5 h with Alfred versus 12 h34 with Phoenix. Conclusion The Alfred 60AST system shows correct yet improvable microbiological performances and a major TAT reduction compared to direct automated AST testing. Clinical studies measuring the impact of the approach on antibiotic management of patients with bacteremia are recommended.


2020 ◽  
Vol 75 (11) ◽  
pp. 3230-3238
Author(s):  
Anna Åkerlund ◽  
Emma Jonasson ◽  
Erika Matuschek ◽  
Lena Serrander ◽  
Martin Sundqvist ◽  
...  

Abstract Objectives When bloodstream infections are caused by resistant bacteria, rapid antimicrobial susceptibility testing (RAST) is important for adjustment of therapy. The EUCAST RAST method, directly from positive blood cultures, was validated in a multi-laboratory study in Europe. Methods RAST was performed in 40 laboratories in northern Europe (NE) and 15 in southern Europe (SE) from clinical blood cultures positive for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Categorical results at 4, 6 and 8 h of incubation were compared with results for EUCAST standard 16–20 h disc diffusion. The method, preliminary breakpoints and the performance of the laboratories were evaluated. Results The total number of isolates was 833/318 in NE/SE. The number of zone diameters that could be read (88%, 96% and 99%) and interpreted (70%, 81% and 85%) increased with incubation time (4, 6 and 8 h). The categorical agreement was acceptable, with total error rates in NE/SE of 2.4%/4.9% at 4 h, 1.1%/3.5% at 6 h and 1.1%/3.3% at 8 h. False susceptibility at 4, 6 and 8 h of incubation was below 0.3% and 1.1% in NE and SE, respectively, and the corresponding percentages for false resistance were below 1.9% and 2.8%. After fine-tuning breakpoints, more zones could be interpreted (73%, 89% and 93%), with only marginally affected error rates. Conclusions The EUCAST RAST method can be implemented in routine laboratories without major investments. It provides reliable antimicrobial susceptibility testing results for relevant bloodstream infection pathogens after 4–6 h of incubation.


2020 ◽  
Vol 75 (9) ◽  
pp. 2485-2494 ◽  
Author(s):  
Jiayue Lu ◽  
Ning Dong ◽  
Congcong Liu ◽  
Yu Zeng ◽  
Qiaoling Sun ◽  
...  

Abstract Objectives To investigate the nationwide prevalence of mcr-1-positive Klebsiella pneumoniae (MCRPKP) strains among healthy adults in China and identify their phenotypic and genomic characterizations. Methods A total of 7401 rectal swab samples were collected from healthy individuals in 30 hospitals located in 30 provinces and municipalities of mainland China in 2016. Colistin-resistant bacteria were enriched in colistin-supplemented lysogeny broth. MCRPKP strains were isolated and characterized with MALDI-TOF MS, PCR analysis and antimicrobial susceptibility testing. The genomic characteristics of MCRPKP strains were determined by WGS and bioinformatics analysis. Results Seven MCRPKP strains and one mcr-1-positive Klebsiella variicola strain were selectively isolated from six locales (three from Henan and one from each of Tianjin, Jiangxi, Yunnan, Gansu and Tibet). Antimicrobial susceptibility testing results indicated that all mcr-1-positive strains were susceptible to meropenem, aztreonam and ceftazidime/avibactam. WGS analysis suggested these strains belonged to seven distinct STs: ST15, ST1425, ST1462, ST273, ST307, ST391 and ST37-SLV. mcr-1 genes were carried by diverse plasmids, including IncHI2 (n = 3), IncX4 (n = 2), IncHI2/IncN (n = 1), IncFIB (n = 1) and one other plasmid type. Two ST15 strains harboured both mcr-1 and mcr-8 genes, which has not been reported before. Conclusions Our data indicated a low prevalence of mcr-1-positive Klebsiella strains (0.11%, 8/7401) in healthy individuals in mainland China and most of these strains remained susceptible to clinically important antibiotics. The prevalence and coexistence of mcr-1 and mcr-8 in K. pneumoniae may further threaten public health through either the food chain or environmental routes.


2021 ◽  
Vol 11 (5) ◽  
pp. 41-52
Author(s):  
Stephen Mwisiya Mubita ◽  
Wila Simbile ◽  
Barbara Mulunda

Background: The ever-increasing magnitude of antimicrobial resistance encountered in human pathogens has led to limited treatment options for bacterial infections, consequently reducing antimicrobial efficacy while increasing treatment costs, morbidity, and mortality. In clinical setup, laboratory-based in vitro antimicrobial susceptibility testing is the cornerstone for guiding therapy and enables the monitoring of antimicrobial resistance trends. Aim: To characterize the distribution of bacteria isolated from various specimens and their antibiotic susceptibility profiles in Mary Begg Health facilities. Material & Methods: This was a retrospective, cross-sectional, quantitative, descriptive study that involved the review of 569 laboratory files from three Mary Begg Health facilities from the period of January 2019 to June 2020. A systematic random sampling method was used and SPSS version 21.0 was used for data analysis. Results: The distribution of bacteria based on Gram stain reaction found that most bacteria that were isolated were Gram negative bacilli, 79.5% (171/215). The most common bacterium isolated was Escherichia coli, 46.5% (100/215) followed by Staphylococcus aureus, 12.1% (26/215) and Klebsiella pneumoniae, 17 7.9% (17/215). The study found that E. coli was highly resistant to amoxicillin (95.0%), Ampicillin (90.0%) and Cotrimoxazole (77.0%), respectively. In contrast, E. coli was highly sensitive to Amikacin (96.0%), Ertapenem (91.0%) and Ceftriaxone (80.0%) S. aureus species isolated were sensitive to Gentamicin (65.4%) and Clindamycin (46.2%) but highly resistant to Cotrimoxazole (80.8%). Conclusion: The most frequent isolates were Escherichia coli followed by Staphylococcus aureus and majority of them were from urine specimens. Key words: Antimicrobial, Resistant, Antimicrobial Resistance, Antimicrobial susceptibility testing, Mary Begg Health services.


2019 ◽  
Vol 116 (21) ◽  
pp. 10270-10279 ◽  
Author(s):  
Hui Li ◽  
Peter Torab ◽  
Kathleen E. Mach ◽  
Christine Surrette ◽  
Matthew R. England ◽  
...  

Infectious diseases caused by bacterial pathogens remain one of the most common causes of morbidity and mortality worldwide. Rapid microbiological analysis is required for prompt treatment of bacterial infections and to facilitate antibiotic stewardship. This study reports an adaptable microfluidic system for rapid pathogen classification and antimicrobial susceptibility testing (AST) at the single-cell level. By incorporating tunable microfluidic valves along with real-time optical detection, bacteria can be trapped and classified according to their physical shape and size for pathogen classification. By monitoring their growth in the presence of antibiotics at the single-cell level, antimicrobial susceptibility of the bacteria can be determined in as little as 30 minutes compared with days required for standard procedures. The microfluidic system is able to detect bacterial pathogens in urine, blood cultures, and whole blood and can analyze polymicrobial samples. We pilot a study of 25 clinical urine samples to demonstrate the clinical applicability of the microfluidic system. The platform demonstrated a sensitivity of 100% and specificity of 83.33% for pathogen classification and achieved 100% concordance for AST.


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