Cronobacter Support
06-03-2009, 05:21 PM
1st International Conference on Cronobacter Poster Abstract 55
Biofilm formation by Cronobacter on infant feeding bottles and teats
Cronobacter (Enterobacter sakazakii), a relatively rare cause of neonatal infections, can form biofilms on different materials. Biofilms withstand nutrient deprivation, disinfectants, pH change and antibiotics to a greater extent than planktonic cells. The extent to which biofilm formation by Cronobacter strains NCIMB 5920 and 8272 occurs on feeding bottles (polycarbonate) and teats (silicone) was examined to determine the need for additional hygiene precautions. Infant feeding bottles and teats were cut in 10x10x0.5mm pieces and sterilised. Separate suspensions containing 104 cfu/ml of Cronobacter strains 5920 and 8272 were prepared in infant formula milk (IFM). Silicone and polycarbonate pieces were added to the suspensions and incubated at 22ºC for three days. The materials were then washed twice with phosphate buffered saline (PBS) and vortexed at maximum speed in PBS with antibumping granules for one minute to dislodge biofilm cells. Both PBS and IFM were diluted and plated on tryptone soya agar. Data were analysed using the independent t-test. Planktonic cell numbers from both strains of Cronobacter were higher than those of biofilms. There was a significant difference between the strains forming biofilms on silicone and polycarbonate surfaces. Strain 5920 showed greater variability than strain 8272, with a maximum of log 6.88 cfu/ml biofilm-forming cells on silicone surfaces. Strain 8272 was less variable; maximum cell numbers forming biofilms were log 6.36 cfu/ml on polycarbonate surfaces. Previous research showed that when grown in IFM, Cronobacter adheres strongly to different surfaces used for infant feeding preparation units and equipment. Our research showed that both strains 8272 and 5920 adhered and formed biofilms on polycarbonate and silicone from infant feeding bottles. Strain 5920 adhered and formed biofilm more readily on silicone, while strain 8272 adhered and formed biofilm more readily on polycarbonate. However, existing hygiene recommendations for sterilising feeding bottles should suffice.
Edita Custic, Sumeet Kaur and Jane P. Sutherland
Microbiology Research Unit, Department of Human Sciences, London Metropolitan University, 166 220 Holloway Road, London N7 8DB, UK.
Biofilm formation by Cronobacter on infant feeding bottles and teats
Cronobacter (Enterobacter sakazakii), a relatively rare cause of neonatal infections, can form biofilms on different materials. Biofilms withstand nutrient deprivation, disinfectants, pH change and antibiotics to a greater extent than planktonic cells. The extent to which biofilm formation by Cronobacter strains NCIMB 5920 and 8272 occurs on feeding bottles (polycarbonate) and teats (silicone) was examined to determine the need for additional hygiene precautions. Infant feeding bottles and teats were cut in 10x10x0.5mm pieces and sterilised. Separate suspensions containing 104 cfu/ml of Cronobacter strains 5920 and 8272 were prepared in infant formula milk (IFM). Silicone and polycarbonate pieces were added to the suspensions and incubated at 22ºC for three days. The materials were then washed twice with phosphate buffered saline (PBS) and vortexed at maximum speed in PBS with antibumping granules for one minute to dislodge biofilm cells. Both PBS and IFM were diluted and plated on tryptone soya agar. Data were analysed using the independent t-test. Planktonic cell numbers from both strains of Cronobacter were higher than those of biofilms. There was a significant difference between the strains forming biofilms on silicone and polycarbonate surfaces. Strain 5920 showed greater variability than strain 8272, with a maximum of log 6.88 cfu/ml biofilm-forming cells on silicone surfaces. Strain 8272 was less variable; maximum cell numbers forming biofilms were log 6.36 cfu/ml on polycarbonate surfaces. Previous research showed that when grown in IFM, Cronobacter adheres strongly to different surfaces used for infant feeding preparation units and equipment. Our research showed that both strains 8272 and 5920 adhered and formed biofilms on polycarbonate and silicone from infant feeding bottles. Strain 5920 adhered and formed biofilm more readily on silicone, while strain 8272 adhered and formed biofilm more readily on polycarbonate. However, existing hygiene recommendations for sterilising feeding bottles should suffice.
Edita Custic, Sumeet Kaur and Jane P. Sutherland
Microbiology Research Unit, Department of Human Sciences, London Metropolitan University, 166 220 Holloway Road, London N7 8DB, UK.