Cronobacter Support
05-15-2009, 07:46 PM
1st International Conference on Cronobacter Poster Abstract 34
Assessment of growth of Enterobacter sakazakii (Cronobacter spp) in reconstituted powdered infant food by using three chromogenic media
Enterobacter sakazakii (Cronobacter spp), is an emerging pathogen associated to neonatal cases of necrotizing enterocolitis and meningitis particularly related to consumption of contaminated powdered infant formula. In order to guarantee the safety of foods for infants and to reduce the risks of contamination by E. sakazakii (Cronobacter spp) it is necessary to introduce rigorous control measures at industrial, legislative and domestic levels; particularly, correct information regarding preparation, handling, and storage are required. The aim of this work was to assess how the growth of E. sakazakii (Cronobacter spp) in reconstituted powdered infant formula was affected by time, temperature and composition by comparing three commercial chromogenic media. Three different powdered infant food (infant milk powder, powdered infant milk for special medical purposes and powdered infant food manufactured from wheat) purchased from local markets were tested for presence of Enterobacteriaceae by ISO 21528-1:2000. Samples negative for Enterobacteriaceae were reconstituted according to instructions of manufacturer and inoculated with a 4-strain mixture of E. sakazakii (Cronobacter spp) at populations of ca. 850cfu/g, ca. 85cfu/g (to reproduce naturally contaminated products) and ca. 0,75cfu/g of powdered food, respectively. Each reconstituted and inoculated food was stored at: 4°C (that inhibit growth of E. sakazakii), 15°C (abuse temperature), room temperature, ca. 23-25°C (to simulate the wrong custom to hold unused reconstituted food without refrigeration). Populations were monitored at moment of inoculum (D0) and at 4 h, 24 h, 48 h, and 72 h by using, at the same time, three commercial chromogenic media: ESIA (Biolife), Compass agar (Biokar Diagnostic), Agar ChromoID Sakazakii-ESPM (Biomerieux). The data of this study indicate that all reconstituted infant food can support growth of E. sakazakii (Cronobacter spp) at three different storage temperatures; E. sakazakii (Cronobacter spp) survives for up 72 h a 4°C and increases of one log; the hang time for reconstituted infant food held at room temperature should be no longer than 4 h; all chromogenic media had a good performance.
Alfonsina Fiore and Laura Toti
Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, viale Regina Elena, Rome, Italy.
Assessment of growth of Enterobacter sakazakii (Cronobacter spp) in reconstituted powdered infant food by using three chromogenic media
Enterobacter sakazakii (Cronobacter spp), is an emerging pathogen associated to neonatal cases of necrotizing enterocolitis and meningitis particularly related to consumption of contaminated powdered infant formula. In order to guarantee the safety of foods for infants and to reduce the risks of contamination by E. sakazakii (Cronobacter spp) it is necessary to introduce rigorous control measures at industrial, legislative and domestic levels; particularly, correct information regarding preparation, handling, and storage are required. The aim of this work was to assess how the growth of E. sakazakii (Cronobacter spp) in reconstituted powdered infant formula was affected by time, temperature and composition by comparing three commercial chromogenic media. Three different powdered infant food (infant milk powder, powdered infant milk for special medical purposes and powdered infant food manufactured from wheat) purchased from local markets were tested for presence of Enterobacteriaceae by ISO 21528-1:2000. Samples negative for Enterobacteriaceae were reconstituted according to instructions of manufacturer and inoculated with a 4-strain mixture of E. sakazakii (Cronobacter spp) at populations of ca. 850cfu/g, ca. 85cfu/g (to reproduce naturally contaminated products) and ca. 0,75cfu/g of powdered food, respectively. Each reconstituted and inoculated food was stored at: 4°C (that inhibit growth of E. sakazakii), 15°C (abuse temperature), room temperature, ca. 23-25°C (to simulate the wrong custom to hold unused reconstituted food without refrigeration). Populations were monitored at moment of inoculum (D0) and at 4 h, 24 h, 48 h, and 72 h by using, at the same time, three commercial chromogenic media: ESIA (Biolife), Compass agar (Biokar Diagnostic), Agar ChromoID Sakazakii-ESPM (Biomerieux). The data of this study indicate that all reconstituted infant food can support growth of E. sakazakii (Cronobacter spp) at three different storage temperatures; E. sakazakii (Cronobacter spp) survives for up 72 h a 4°C and increases of one log; the hang time for reconstituted infant food held at room temperature should be no longer than 4 h; all chromogenic media had a good performance.
Alfonsina Fiore and Laura Toti
Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, viale Regina Elena, Rome, Italy.