Cronobacter sakazakii in powdered infant formula on sale in Portugal and its behaviour at different temperatures after reconstitution.

摘要

Cronobacter sakazakii is an emerging foodborne pathogen which causes necrotizing enterocolitis, bacteraemia and, rarely, meningitis, especially in infants. The infection has commonly been associated with consumption of contaminated powdered infant formula (PIF). The frequency of disease is low, but its mortality rate is high. This study evaluated the presence of C. sakazakii in 58 PIF obtained from various retail establishments in the North of Portugal. The microbiological quality of these 58 PIF samples, namely the presence of C. sakazakii, counts of Enterobacteriaceae, coliforms, coagulase-positive staphylococci, and the presence of Salmonella spp., was evaluated. Results show that all the tested samples fulfilled the microbiological criteria of the EU (Regulation (EEC) 2073/2005). Growth of C. sakazakii in 2 of the PIF samples (a reconstituted milk and a weaning formula) at 4, 22 or 37 degrees C was evaluated. No significant differences in the growth rate (P > 0.05) in the 2 tested PIF samples were observed. Growth of the pathogen was prevented during storage of the reconstituted PIF samples at 4 degrees C; however, it was found that hazardous levels may be obtained in <4 h at 37 degrees C and in 8 h at 22 degrees C.