scholarly journals Current and Emerging Methods of Antibiotic Susceptibility Testing

Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 49 ◽  
Author(s):  
Zeeshan A. Khan ◽  
Mohd F. Siddiqui ◽  
Seungkyung Park
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infection ◽  
Economic Burden ◽  
Antibiotic Susceptibility ◽  
Historical Perspective ◽  
Susceptibility Testing ◽  
Empirical Therapy ◽  
Pivotal Role ◽  
Disk Diffusion ◽  
Antibiotic Susceptibility Testing

Antibiotic susceptibility testing (AST) specifies effective antibiotic dosage and formulates a profile of empirical therapy for the proper management of an individual patient’s health against deadly infections. Therefore, rapid diagnostic plays a pivotal role in the treatment of bacterial infection. In this article, the authors review the socio-economic burden and emergence of antibiotic resistance. An overview of the phenotypic, genotypic, and emerging techniques for AST has been provided and discussed, highlighting the advantages and limitations of each. The historical perspective on conventional methods that have paved the way for modern AST like disk diffusion, Epsilometer test (Etest), and microdilution, is presented. Several emerging methods, such as microfluidic-based optical and electrochemical AST have been critically evaluated. Finally, the challenges related with AST and its outlook in the future are presented.

scholarly journals Antibiotic Susceptibility Testing, Plasmid Detection and Curing of Clinically Isolated Enterococcus Species

2019 ◽  
pp. 1-20 ◽  
Author(s):  
G. A. C. Ezeah ◽  
M. C. Ugwu ◽  
A. O. Ekundayo ◽  
O. F. Odo ◽  
O. C. Ike ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Plasmid Dna ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Resistance Pattern ◽  
Antibiotic Susceptibility Testing ◽  
Enterococcus Species ◽  
Transfer Resistance ◽  
Antibiotic Resistance Profile ◽  
Agarose Electrophoresis

Vancomycin resistant enterococci (VRE) are a major medical concern globally. Their significantly greater prevalence and the ability to transfer resistance to vancomycin from other bacteria made them an object of interest and intense research. The isolates of Enterococcus sp. were subjected to antibiotic susceptibility testing before curing. The three Enterococcus species exhibited different antibiotic resistance profile. Pre-curing antibiotic resistance of nosocomial isolates compared with community acquired isolates revealed that high percentage of the nosocomial isolates were resistant to antibiotics compared to community isolate. Post-curing antibiograms of the isolates showed different resistant and susceptibility pattern. Also, DNA plasmid pre-curing and post curing analysis of the isolates showed different resistance pattern. Six of the 15 representative isolates selected on the basis of their high pre-curing antibiotic resistance for plasmid analysis with 0.8% agarose electrophoresis were positive for plasmid DNA. Four (4) of the positive isolates (E. faecium, E. faecium, E. faecalis, and E. avium) had plasmid fragment of greater than 1000 bp while two (2) of them (E. faecalis and E. faecalis) had fragments of between 100 and 500 bp. The remaining nine (9) had no plasmid DNA. The study revealed the pathogenicity factors demonstrated with the enterococcal isolates.

scholarly journals A Multiplex Fluidic Chip for Rapid Phenotypic Antibiotic Susceptibility Testing

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Pikkei Wistrand-Yuen ◽  
Christer Malmberg ◽  
Nikos Fatsis-Kavalopoulos ◽  
Moritz Lübke ◽  
Thomas Tängdén ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibiotic Susceptibility ◽  
Bacterial Infections ◽  
Susceptibility Testing ◽  
Empirical Therapy ◽  
Automated Image Analysis ◽  
Antibiotic Susceptibility Testing ◽  
Content Type ◽  
Broad Spectrum Antibiotics ◽  
Severe Infections

ABSTRACT Many patients with severe infections receive inappropriate empirical treatment, and rapid detection of bacterial antibiotic susceptibility can improve clinical outcome and reduce mortality. To this end, we have developed a multiplex fluidic chip for rapid phenotypic antibiotic susceptibility testing of bacteria. A total of 21 clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were acquired from the EUCAST Development Laboratory and tested against amikacin, ceftazidime, and meropenem (Gram-negative bacteria) or gentamicin, ofloxacin, and tetracycline (Gram-positive bacteria). The bacterial samples were mixed with agarose and loaded in an array of growth chambers in the chip where bacterial microcolony growth was monitored over time using automated image analysis. MIC values were automatically obtained by tracking the growth rates of individual microcolonies in different regions of antibiotic gradients. Stable MIC values were obtained within 2 to 4 h, and the results showed categorical agreement with reference MIC values as determined by broth microdilution in 86% of the cases. IMPORTANCE Prompt and effective antimicrobial therapy is crucial for the management of patients with severe bacterial infections but is becoming increasingly difficult to provide due to emerging antibiotic resistance. The traditional methods for antibiotic susceptibility testing (AST) used in most clinical laboratories are reliable but slow with turnaround times of 2 to 3 days, which necessitates the use of empirical therapy with broad-spectrum antibiotics. There is a great need for fast and reliable AST methods that enable starting targeted treatment within a few hours to improve patient outcome and reduce the overuse of broad-spectrum antibiotics. The multiplex fluidic chip for phenotypic AST described in the present study may enable data on antimicrobial resistance within 2 to 4 h, allowing for an early initiation of appropriate antibiotic therapy.

scholarly journals Molecular characterization and antibiotic susceptibility ofVibrio choleraenon-O1

1995 ◽  
Vol 114 (1) ◽  
pp. 51-63 ◽  
Author(s):  
A. Dalsgaard ◽  
O. Serichantalergs ◽  
C. Pitarangsi ◽  
P. Echeverria
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Low Molecular Weight ◽  
Toxin Gene ◽  
Antibiotic Susceptibility Testing ◽  
Multiple Antibiotic Resistance ◽  
Heat Stable ◽  
Epidemiological Tool ◽  
Gene Status

SUMMARYA collection of 64 clinical and environmentalVibrio choleraenon-O1 strains isolated in Asia and Peru were characterized by molecular methods and antibiotic susceptibility testing. All strains were resistant to at least 1 and 80% were resistant to two or more antibiotics. Several strains showed multiple antibiotic resistance (≥ three antibiotics). Plasmids most often of low molecular weight were found in 21/64 (33%) strains. The presence of plasmids did not correlate with antibiotic resistance or influence ribotype patterns. In colony hybridization studies 63/64 (98%)V. choleraenon-O1 strains were cholera toxin negative, whereas only strains recovered from patients were heat-stable enterotoxin positive. Forty-sevenBglI ribotypes were observed. No correlation was shown between ribotype and toxin gene status. Ribotype similarity was compared by cluster analysis and two main groups of 13 and 34 ribotypes was found. Ribotyping is apparently a useful epidemiological tool in investigations ofV. choleraenon-O1 infections.

Hospital surveillance predicts community pneumococcal antibiotic resistance in Vietnam

2020 ◽  
Vol 75 (10) ◽  
pp. 2902-2906
Author(s):  
V T T Dai ◽  
J Beissbarth ◽  
P V Thanh ◽  
P T Hoan ◽  
H N L Thuy ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Vaccine Trial ◽  
Nationwide Survey ◽  
Surveillance Data ◽  
Antibiotic Prescribing ◽  
Antibiotic Susceptibility Testing ◽  
Population Demographics ◽  
Testing Data

Abstract Background In Vietnam, Streptococcus pneumoniae is a leading cause of disease, including meningitis. Antibiotics are available without physician prescription at community pharmacies and rates of antibiotic non-susceptibility are high. Appropriate treatment and antibiotic stewardship need to be informed by surveillance data. Objectives To report community-based pneumococcal antibiotic susceptibility testing data from children enrolled in a pneumococcal conjugate vaccine trial in Ho Chi Minh City [the Vietnam Pneumococcal Project (ViPP)] and compare these with published hospital-based data from the nationwide Survey of Antibiotic Resistance (SOAR) to determine whether hospital surveillance data provide an informative estimate of circulating pneumococcal resistance. Methods Pneumococcal isolates from 234 nasopharyngeal swabs collected from ViPP participants at 12 months of age underwent antibiotic susceptibility testing using CLSI methods and the data were compared with SOAR data. Results Antibiotic susceptibility testing identified penicillin-non-susceptible pneumococci in 93.6% of pneumococcus-positive ViPP swabs (oral, non-meningitis breakpoints). Non-susceptibility to erythromycin, trimethoprim/sulfamethoxazole, clindamycin and tetracycline also exceeded 79%. MDR, defined as non-susceptibility to three or more classes of antibiotic, was common (94.4% of swabs). Low or no resistance was detected for ceftriaxone (non-meningitis breakpoints), ofloxacin and vancomycin. Antibiotic non-susceptibility rates in ViPP and SOAR were similar for several antibiotics tested. Conclusions A very high proportion of pneumococci carried in the community are MDR. Despite wide disparities in population demographics between ViPP and SOAR, the non-susceptibility rates for several antibiotics were comparable. Thus, with some qualification, hospital antibiotic susceptibility testing data in Vietnam can inform circulating pneumococcal antibiotic non-susceptibility in young children, the group at highest risk of pneumococcal disease, to guide antibiotic prescribing and support surveillance strategies.

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