| Research Title |
Vancomycin disk diffusion test for screening of vancomycin non-susceptible Staphylococcus aureus |
| Date of Distribution |
29 July 2014 |
| Conference |
| Title of the Conference |
the International Medical Sciences Conference 2014 (IMSC2014) and the 4th MT Symposium: Emerging diseases and public health concern in Asia-Pacific region on the Occasion of 36th Anniversary of the Faculty of Associated Medical Sciences |
| Organiser |
Faculty of Associated Medical Sciences , Khon Kaen University, Khon Kaen, Thailand 40002 |
| Conference Place |
Pullman Khon Kaen Raja Orchid Hotel |
| Province/State |
Khon Kaen, Thailand |
| Conference Date |
15 July 2014 |
| To |
17 July 2014 |
| Proceeding Paper |
| Volume |
2014 |
| Issue |
- |
| Page |
93 |
| Editors/edition/publisher |
Associate Prefessor Dr.Patcharee Jearanaikoon |
| Abstract |
Introduction: Detection of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) is currently problematic and still pending. Although the population analysis profile
with area under the curve (PAP-AUC) is the gold standard for detecting hVISA strains, this method is laborious and time-consuming. The aim of this study was to determine the performance of vancomycin disk diffusion test for detection of the in vitro induced and natural vancomycin non-susceptible isolates.
Methodology: A total of 216 MRSA isolates were classified for their susceptibility to vancomycin and confirmed by using a PAP-AUC method. The performance of 10, 15, 20 and 30 µg vancomycin disk diffusion test for detecting both induced and natural hVISA/VISA isolates were analyzed using the MedCal program version 10.2.0.0.
Results: The MRSA isolates were categorized into 3 groups including 140 VSSA (64.8%), 36 hVISA (16.7%) and 40 VISA (18.5%). The PAP-AUC ratios of VSSA, hVISA and VISA isolates were ranged 0.12-0.89, 0.90-1.29 and 1.35-3.91 respectively. The proper vancomycin disk for hVISA/VISA detection by vancomycin disk diffusion was 20 µg/disk testing on brain heart infusion agar plus 2% NaCl. Such conditions gave a high accuracy of 88.9 and 55.9% for induced and natural vancomycin non-susceptible isolates respectively at the cutoff-point ≤ 12 mm and ≤ 17 mm respectively. The 20 µg disks provided 71.4 and 66.7% sensitivity, 100 and 47.7% specificity, 100 and 25.3% PPV and 75 and 84.9% NPV respectively, when using a 1.0 McFarland inoculum and 24-hr incubation.
Conclusions: The results indicated that using 20 µg vancomycin disks testing with 1.0 McFarland of bacterial inoculum is simple for screening of hVISA/VISA and enable to obtain a primary result within 24 hours. However, confirmation test was still necessary.
Key words: Staphylococcus aureus; vancomycin resistance; hVISA; PAP-AUC
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หมายเหตุ
น.ส. วิลัดดา นามแสงแกง และ
น.ส. กาญจานา ดุจจานุทรรศน์
มีชื่อร่วมในการเขียนงาน
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| Author |
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| Peer Review Status |
มีผู้ประเมินอิสระ |
| Level of Conference |
นานาชาติ |
| Type of Proceeding |
Abstract |
| Type of Presentation |
Poster |
| Part of thesis |
true |
| Presentation awarding |
false |
| Attach file |
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| Citation |
0
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Publication
Journal Publication
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