Prevalence of Antibiotic-Resistant Bacteria in Herbal Products
Authors: Brown, Joseph C.1; Jiang, Xiuping2
Source: Journal of Food Protection®, Volume 71, Number 7, July 2008 , pp. 1486-1490(5)
Key:
- Free Content
- New Content
- Subscribed Content
- Free Trial Content
Abstract:
The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 μg/ml) or tetracycline (16 μg/ml). Total bacterial counts ranged from <5 to 2.9 × 105 CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 × 102 CFU/g and 3.0 × 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 × 103 CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation.Document Type: Research article
Affiliations: 1: Department of Biological Sciences, Clemson University, Clemson, South Carolina 29634, USA 2: Department of Food Science & Human Nutrition, Clemson University, Clemson, South Carolina 29634, USA
Key:
- Free Content
- New Content
- Subscribed Content
- Free Trial Content

Click here for Page Help