INVESTIGATION OF THE MICROBIOLOGICAL QUALITY OF COMMERCIALLY SOLD HERBAL DRUGS DURING STORAGE

ABSTRACT

There are between 250,000 and 500,000 different plant species in the world. One to ten percent of these are consumed by both humans and other animal species as food, even employed for medical functions. Different parts of the plant like the roots, stem or leaves can be employed for this purpose. The aim of this investigation was to enumerate and isolate bacteria and fungi from different herbal samples during storage, characterize and identify bacterial and fungal, determine phenotypic virulent features of isolated bacteria and determine the antibiotic susceptibility profile of the bacterial isolates. Four samples of herbal medicines were obtained for this study. They were then transported to the microbiology laboratory for analysis and cultured on various medis using the pour plate method. Growth media like Nutrient agar, MacConkey agar, salmonella shigella agar, potato dextrose agar, mannitol agar were used to isolate the various microorganisms. A pure culture of the isolates were identified phenotypically. The pH of the samples was measured every 2 days consecutively for 7 days. The titratable acid, virulence factors and antibiotic sensitivity tests were carried out for all bacterial isolates. The organisms isolated were Staphylococcus xylosus, Corynebacteria sp, Moraxella catarrhalis, Staphylococcus cohnii, Neisseria sp, Bacillus subtiliis and Alkaligenes sp. The pH of sample C was seen to have increased by day 4 from 4.7 on day 0 and day 2 to 4.3 in day 4. Other samples showed a slight flunctuation in the pH. The titratable acidity results showed a variation in all samples with the exception of sample A. the isolates were susceptible to the antibiotics tested excluding Nesseira sp., which was resistant to all Gram negative antibiotics. This study shows that the shelf life of herbal drugs is narrow and cannot be used for a long period of time after opening. The use of natural preservatives should also be considered to increase the shelf life of these herbal products.