Isolation of pathogenic microorganisms from fresh fruits and screening the efficacy of different disinfectant solution against the pathogens

Abstract

Fruits are important parts of our daily diet to maintain a healthy life as they have potential nutritional values. But unfortunately, a number of foodborne diseases have been noticed due to the consumption of raw and contaminated fruits. The present study was carried out to isolate the pathogenic microorganisms from fruits sample and to determine the effects of some household cleaning methods including washing and various common chemical treatments for the removal of bacterial load. A conventional spread plate technique was performed for the detection of bacteria. Total heterotrophic bacteria, Escherichia coli, Staphylococcus spp. Salmonella spp. and Listeria spp. were found in 30 samples of 6 categories including Java apple (Syzygium cumini), Carambola (Averrhoa carambola), Indian gooseberry (Phyllanthus emblica), Olive (Olea europaea) Koromcha (Carissa carandas) and Pear (Pyrus). Tap water, hot water (50°C), 100 mg/L sodium hypochlorite (NaOCl), 50 mg/L calcium lactate, 4% acetic acid and 2 ml/L CleanAva were used as decontaminating agents. All samples were soaked in tested cleaning agents for 20 min at room temperature. All the tested solutions were found to be effective and reduced bacterial loads in fruits compared to the unwashed fruits samples (p<0.01). It was revealed, NaOCl, calcium lactate, acetic acid and CleanAva were more effective cleaning agents than water wash. Two to three log of bacterial load was reduced when samples were subjected to treat with decontaminating agents. Potable water, the types and concentration of the disinfectant solutions are important parameters for effective washing.