Source of Klebsiella pneumoniae in Alfalfa and Mung Bean Sprouts and Attempts to Reduce Its Occurrence

Abstract Twenty lots of alfalfa seeds and 24 lots of mung beans were analyzed for Klebsiella pneumoniae; 40% of the alfalfa seeds and 67% of the mung bean samples were found to be positive. When sprouts were produced from these seeds using sterile water, sterile utensils and sanitized sprouting chambers, K. pneumoniae was isolated from 60% of alfalfa sprouts ranging in number from 2 × 10 3 to 3 × 10 5 CFU/g (median 2.2 × 10 4 CFU/g) and from 83% of the bean sprouts containing from 3 × 10 4 to 2 × 10 6 CFU/g (medium 6.5 × 10 5 CFU/g). When sprouts were produced from hypochlorite-treated seeds, over 90% of both types were free of Klebsiella. The sanitation process did not affect germination or organoleptic quality of the sprouts. Further improvement toward the production of Klebsiella-free sprouts could be achieved by treatment of the environmental air.