ABSTRACT
INTRODUCTION: Effective medications are becoming more necessary to combat the global rise in antimicrobial resistance. The findings that some flavonoids have antibacterial properties have urged interest in flavonoid research. The aim of this work was to investigate the inhibitory properties of fisetin, fisetinidin, 7,3`,4`-trihydroxyflavone (THF), and 7,3`,4`-trihydroxyflavonol (THF-) against selected pathogenic bacteria and fungi and to review the literature on relevant compounds. METHODS: An in vitro experiment was performed on 19 organisms (gram-positive, gram-negative, and yeast fungi) using varying concentrations (100-1000 ug/mL) of fisetin, fisetinidin, THF, and THF-. Using the agar well diffusion method. The in vitro activity of flavonoid compounds against gram-positive, gram-negative, and yeasts was assessed using a serial dilution of the four compounds against organism suspensions (50 µL of 0.5 McFarland). Inoculated agar plates were incubated aerobically at 37oC. The results of inhibition were recorded after 24, 48, and 72 hours. RESULTS: Various classes of flavonoids from different sources have been reviewed for their antimicrobial effects. They showed various inhibitory reactions against a plethora of gram-positive, gram-negative, and yeast organisms. In the present study, the selected four compounds have shown varying antibacterial effects, as have the reviewed flavonoids from the literature. With minimum inhibitory concentrations (MICs) ranging from 100 ug/mL to 1000 ug/mL, the substances fisetin, fisetinidin, THF, and THF- demonstrated inhibitory action against the examined species. The main activity was against Staphylococcus, Bacillus, Acinetobacter, Proteus, and Pseudomonas species. Fisetin and fisetinidin did not inhibit Escherichia coli, whereas THF and THF- exhibited inhibitory action. CONCLUSIONS: Flavonoids, a readily accessible dietary ingredient, remain a viable treatment option for infectious diseases. This study suggests that THF, THF-, fisetin, and fisetinidin may be helpful in stopping the growth of some pathogens, especially staphylococci. Improvements to flavonoids' pharmacokinetics and diffusion may encourage their use in therapy as an adjuvant to conventional medications.
ABSTRACT
OBJECTIVES: To isolate, identify, and determine the prevalence of Candida and other yeasts of clinical importance in Aseer region, Saudi Arabia. METHODS: This is a cross-sectional study involving retrospective analysis of 6100 samples submitted to the Microbiology Laboratory, Aseer Central Hospital, Abha, Saudi Arabia between 2011 and 2012, and prospective isolation and identification of 84 isolates recovered from various clinical specimens presented to the Microbiology Laboratory between 2012 and 2013 using the classic morphological schemes and the Vitek 2 automated system. RESULTS: The results of the retrospective analysis (2011-2012) indicated that of the 6100 various clinical specimens submitted to the routine microbiology analysis, 143 (2.35%) revealed the presence of Candida spp. The distribution of the 143 Candida spp according to specimens was as follows: urine 72%, sputum 10.5%, endotracheal tube 7%, blood 4.2%, catheter tip 2.1%, throat swab 2.1%, eye swab 0.7%, wound exudates 0.7%, and cerebrospinal fluid 0.7%. The results of the prospective study (2012-2013), which involved the identification of yeast recovered from 84 specimens indicated that Candida albicans 28.6% was the predominant species, followed by Candida parapsilosis 21.4%, Candida tropicalis 14.3%, and Candida lusitaniae 9.5%. CONCLUSIONS: Along with the commonly encountered Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida lusitaniae were detected with significant rates. Many other Candida species and some other pathogenic yeasts have been detected for the first time in the region. Urinary tract samples were the main source of Candida species.
