Isolation and Characterization of Faecal Coliforms in Street Vended Fruit Juices and Its Safety Evaluation: a Case Study of Bellary City, India

Aim: Present study was undertaken for detection, isolation, characterization of the possible sources of faecal coliforms in street vended fresh fruit juices sold along the road sides of Bellary city, India and assessed its safety for human consumption. Materials and Methods: The samples of orange fruit juices were collected from the four different public hot spot areas of the city and subjected them for Most Probable Number [MPN] test to estimate the coliform population in both water and food (juice) samples. The study was further extended for the isolation of coliforms by a selective solid media and then identified the presence of different types of Enterobacteria by using rapid biochemical tests. Results: Based on the MPN studies, juice sample-1 was found to be most contaminated with a count of 1, 40,000 coliforms/ 100 ml, sample -3 with a count of 1,10,000 coliforms/ 100 ml, sample-2 was 1,500 coliforms/100ml. The least count of only 400 coliforms/100ml was observed in sample-4. Where as, the water samples-1, 2 and 3 were also found to be totally contaminated with faecal coliforms with a count of 1,100 microbes per 100ml. But sample-4 contains only 28 microbes/ 100 ml. The colony characteristics, microscopic examination as well as rapid biochemical studies showed the presence of four different pathogenic coliforms in all four food and water samples. They are Klebsiella pneumoniae, Citrobacter freundii, Enterobacter aerogens and Escherichia coli. Conclusion: The MPN analysis showed high levels of contamination in first three fruit juices as well as water samples. This would be possible because of the poor quality of water used in juice preparation. Moreover, water is one of the major sources of sewage contamination.