scholarly journals Salmonella spp. antibiotic susceptibility testing by the Kirby-Bauer disk diffusion method v1 (protocols.io.bpypmpvn)

protocols.io ◽  
2020 ◽  
Author(s):  
Enrique Delgado
Keyword(s):  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Antibiotic Susceptibility Testing ◽  
Salmonella Spp ◽  
Disk Diffusion Method

scholarly journals Standardization of Operator-Dependent Variables Affecting Precision and Accuracy of the Disk Diffusion Method for Antibiotic Susceptibility Testing

2015 ◽  
Vol 53 (12) ◽  
pp. 3864-3869 ◽  
Author(s):  
Michael Hombach ◽  
Florian P. Maurer ◽  
Tamara Pfiffner ◽  
Erik C. Böttger ◽  
Reinhard Furrer
Keyword(s):  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Antibiotic Susceptibility Testing ◽  
Content Type ◽  
E Coli ◽  
The Mean ◽  
Precision And Accuracy ◽  
Standard Deviations

Parameters like zone reading, inoculum density, and plate streaking influence the precision and accuracy of disk diffusion antibiotic susceptibility testing (AST). While improved reading precision has been demonstrated using automated imaging systems, standardization of the inoculum and of plate streaking have not been systematically investigated yet. This study analyzed whether photometrically controlled inoculum preparation and/or automated inoculation could further improve the standardization of disk diffusion. Suspensions ofEscherichia coliATCC 25922 andStaphylococcus aureusATCC 29213 of 0.5 McFarland standard were prepared by 10 operators using both visual comparison to turbidity standards and a Densichek photometer (bioMérieux), and the resulting CFU counts were determined. Furthermore, eight experienced operators each inoculated 10 Mueller-Hinton agar plates using a single 0.5 McFarland standard bacterial suspension ofE. coliATCC 25922 using regular cotton swabs, dry flocked swabs (Copan, Brescia, Italy), or an automated streaking device (BD-Kiestra, Drachten, Netherlands). The mean CFU counts obtained from 0.5 McFarland standardE. coliATCC 25922 suspensions were significantly different for suspensions prepared by eye and by Densichek (P< 0.001). Preparation by eye resulted in counts that were closer to the CLSI/EUCAST target of 108CFU/ml than those resulting from Densichek preparation. No significant differences in the standard deviations of the CFU counts were observed. The interoperator differences in standard deviations when dry flocked swabs were used decreased significantly compared to the differences when regular cotton swabs were used, whereas the mean of the standard deviations of all operators together was not significantly altered. In contrast, automated streaking significantly reduced both interoperator differences, i.e., the individual standard deviations, compared to the standard deviations for the manual method, and the mean of the standard deviations of all operators together, i.e., total methodological variation.

scholarly journals Preliminary Results on the Prevalence of Salmonella Spp. in Marine Animals Stranded in Sicilian Coasts: Antibiotic Susceptibility Profile and ARGs Detection in the Isolated Strains

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 930
Author(s):  
Delia Gambino ◽  
Sonia Sciortino ◽  
Sergio Migliore ◽  
Lucia Galuppo ◽  
Roberto Puleio ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Susceptibility ◽  
Antibiotic Resistance Genes ◽  
Diffusion Method ◽  
Salmonella Spp ◽  
Marine Animals ◽  
Disk Diffusion Method ◽  
Phenotypic Resistance ◽  
Low Prevalence

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.

scholarly journals Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp.

2011 ◽  
Vol 50 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Pirkko Kotilainen ◽  
Pauli Puukka ◽  
Ulla-Maija Nakari ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Agar Dilution ◽  
Campylobacter Spp

scholarly journals Antibiotic Susceptibility Pattern of Salmonella Enterica serovars Typhi and Paratyphi A Isolated From Patients Suspected of Enteric Fever

2020 ◽  
Vol 7 ◽  
pp. 31-36
Author(s):  
Dhirendra Niroula ◽  
Jyotsna Shrestha ◽  
Supriya Sharma ◽  
Anjana Singh
Keyword(s):  
Salmonella Enterica ◽  
Antibiotic Susceptibility ◽  
Enteric Fever ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Salmonella Spp ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
Microbiological Techniques

Objectives: The study aimed to assess the antibiotic susceptibility profile of Salmonella spp isolated from patients suspected of enteric fever. Methods: This cross-sectional prospective study was carried out from April to June, 2014among 484 patients clinically suspected of enteric fever visiting Bir Hospital, Kathmandu, Nepal. Blood sample collected from each patient was processed for culture in bile broth. Identification of Salmonella spp was done by conventional microbiological techniques including colony characteristics, Gram's staining and biochemical tests. Antibiotic susceptibility testing of identified isolates was done by Kirby-Bauer disk diffusion method following the 2014 CLS I guideline. Results: Out of 484 blood samples, 36 (7.43%) cases showed the growth of Salmonella spp; of which 27 (75%) were Salmonella enterica serovar Typhi (ST) and 9 (25%) were Salmonella enterica Paratyphi A (SPA). Among the Salmonella isolates, 5.55% were multidrug resistant and 41.66% were fluoroquinolone resistant. More than 80% of isolates were sensitive to chloramphenicol, amoxicillin, and cotrimoxazole whereas 58%, 50% and 6% of isolates were sensitive to fluoroquinolone antibiotics i.e. ciprofloxacin, ofloxacin and nalidixic acid respectively. All the isolates were susceptible to ceftazidime. All SPA and 89% of ST were sensitive to azithromycin. Conclusion: Higher percentage of susceptible isolates to chloramphenicol, cotrimoxazole, and amoxicillin suggests the reconsideration of these antibiotics for the treatment of enteric fever. Azithromycin can be considered as drug of choice for the treatment of enteric fever.  

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