Detection of heterogeneous, intermediate-vancomycin-resistant Staphylococcus aureus (hVISA) using low-concentration vancomycin disks.
نویسندگان
چکیده
Heterogeneous, intermediate-vancomycin-resistant Staphylococcus aureus (hVISA) represents a threat of an incurable infection since the first report in 1997. The method used to detect hVISA isolates is a population analysis profile (PAP); however, it is impractical for routine laboratory analysis. We therefore tested a simple, reliable and inexpensive method for the detection of hVISA. Eighteen isolates of hVISA and 22 of vancomycin-sensitive S. aureus (VSSA) were included. The organisms were tested by the disk diffusion method, using 15-microg vancomycin disks on four different media: Mueller-Hinton agar (MHA), MHA plus 2% NaCI (MHAS), Brain Heart Infusion agar (BHA), and BHA plus 2% NaCl (BHAS). In addition, two different inoculum sizes, bacterial suspensions adjusted to 0.5 and 2.0 McFarland, were tested. The inhibition zone was read independently by three medical technologists after incubation at 37 degrees C for 24 and 48 hours. The use of MHAS with an inoculum size of 2.0 McFarland and 48-hour incubation period yielded the highest sensitivity (94.4%), specificity (81.8%), positive predictive value (80.9%), and negative predictive value (94.7%). The disk diffusion test with 15-microg vancomycin disk is simple and may be used as a screening method for the detection of hVISA.
منابع مشابه
Performance of vancomycin and teicoplanin disk diffusion test in isogenic vancomycin non-susceptible Staphylococcus aureus.
INTRODUCTION Detection of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) is currently problematic. Although the population analysis profile with area under the curve (PAP-AUC) is the gold standard for detecting hVISA strains, this method is time consuming. This study aimed to induce vancomycin non-susceptible Staphylococcus aureus isolates in methicillin-resistant S. aureus...
متن کاملScreening and detection of heterogenous vancomycin intermediate Staphylococcus aureus in Hospital Kuala Lumpur Malaysia, using the glycopeptide resistance detection Etest and population analysis profiling
In a 3-month study done in Hospital Kuala Lumpur (HKL), 7 out of 320 methicillin resistant Staphylococcus aureus isolates were confirmed as heterogeneous vancomycin intermediate S. aureus (hVISA) using the glycopeptide resistance detection e-test and population analysis, giving a prevalence rate of 2.19%. This is the first report of hVISA in Malaysia.
متن کاملPrevalence of Vancomycin Resistance in Methicillin-Resistant Staphylococcus Aureus
Background & Aims: Staphylococcus aureus is one of the most common pathogens in nosocomial infections. Vancomycin is the most important therapeutic drug of choice for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains. Therefore, vancomycin-resistant Staphylococcus aureus (VRSA) or vancomycin-intermediate Staphylococcus aureus (VISA) strains are warning...
متن کاملThe incidence of heterogeneous vancomycin-intermediate Staphylococcus aureus correlated with increase of vancomycin MIC.
A total of 559 methicillin-resistant Staphylococcus aureus isolates were investigated for heterogeneous vancomycin-intermediate S. aureus (hVISA) by population analysis profile area under the curve. Our results suggested that the incidence of hVISA increased rapidly when vancomycin MIC shifted from 1 to 2 μg/mL, and at vancomycin MIC of 2 μg/mL, the incidence of hVISA was nearly 40%.
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ورودعنوان ژورنال:
- The Southeast Asian journal of tropical medicine and public health
دوره 37 4 شماره
صفحات -
تاریخ انتشار 2006