Antimicrobial Susceptibility Of Various Natural Extracts On Coliforms

Abstract

Coliforms are several types of bacteria that are found in the soil, on vegetation or on surface waters. The distribution of resistance to various antibiotics among coliforms in sewage, surface waters, and sea water was investigated. The incidence of resistant strains among isolates varied significantly among the water samples and there is no obvious connection with the water source or the level of pollution. The presence of fecal coliforms in the water often indicates recent contamination. That means higher risk of presence of pathogens. Coliforms were isolated from water samples and plated on Nutrient agar, Mac Conkeys agar plates and incubated at 37 o C for 24h and the colony morphology was noted. They were microscopically identified as Gram negative bacilli. A subculture stage confirmation was performed on EMB agar plate and a greenish metallic sheen was identified confirming the presence of coliforms. Antimicrobial activity was done with various aqueous natural extracts of turmeric, cinnamon, cardamom, garlic, ginger and cloves against coliforms. The aqueous extracts of turmeric (1.5cm) showed maximum antimicrobial susceptibility against coliforms followed by cloves (1.4cm), ginger (1.2cm), garlic (0.8cm), cinnamon (0.6cm), and cardamom (0.2cm) respectively. A similar study was done with antibiotics on coliforms, it was identified that norfloxacin (10mcg) showed a zone of inhibition 1.5cm, while gentamycin (10mcg) showed 1.3cm, streptomycin (10mcg) showed 1cm and vancomycin (30mcg) 0.3 cm. Natural products are a major source of new natural drugs and they can be used as an alternative medicine for treatment of various diseases. In comparison to the formulated drugs the herbs and spices have fewer side effects.