Correlation Between Sedimentation Plate and Surface Swab in the Isolation of Fungi from the Hospital Wards

Abstract

Periodic monitoring of fungi in the hospital wards is undertaken by various hospitals worldwide. The objective of this study was to compare the effectiveness of the sedimentation plate method with surface swab in the isolation of various fungi from some wards of Sultan Qaboos University Hospital (SQUH).Moistened swabs were used to swab surfaces of some articles and equipments found in some wards and the hospital kitchen. The swabs were subsequently inoculated onto Sabouraud dextrose agar. All growths were examined and identified. Penicillium and Aspergillus niger had distribution frequencies of 23.8 and 23.8%, respectively by sedimentation and 20 and 33.3%, respectively by surface swab. The total isolates by sedimentation for medical and kitchen were 44 and 56%, respectively by sedimentation, while 17.1 and 60% were by surface swab, respectively. The ICU had isolation rate of 22.8% by surface and no growth by sedimentation. Fusarium and Cladosporium species were isolated by surface method from medical and ICU, but could not be isolated by sedimentation method. A. candidius was isolated by sedimentation, but no growth was shown by surface method. It was concluded that no single method can isolate all the fungi from sources surveyed. It is recommended that the two methods be used in parallel when monitoring the degree of fungal load in the wards and hospital kitchen. However, it is necessary that this work be repeated with larger samples and at different periods of the year so as to evaluate conclusively the effectiveness of the two systems.