Bacterial Contamination of Infant Formula and Expressed Breast Milk

No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
There is a high mortality of infants in Sub-Saharan Africa and diarrhoeal illnesses contribute significantly to this mortality. Cases of diarrhoeal infection in children have been epidemiologically linked to the consumption of contaminated feeds. The aim of this study was to investigate bacterial contamination of prepared formula and expressed breast milk. Seventy-two samples of prepared formulae on lying-in wards and nurseries, Mother and Baby Unit (MBU) and medical children’s ward of Komfo Anokye Teaching Hospital and 34 samples of breast milk from lactating mothers on MBU were collected for the study. These milk samples were cultured for microbial contamination. Expressed breast milk samples (EBM) were stored at room temperature and cultured at zero (T0), three (T3), six (T6) and nine (T9) hours after collection to determine bacterial propagation over time. 85% (61/72) of the prepared formulae were contaminated primarily with Acinetobacter sp. (85.2%), Klebsiella pneumoniae (34.4%), Enterococcus sp. (18%) and Staphylococcus epidermidis (13.1%). Only 2 out of the 72 prepared formula had plate counts of bacteria greater than the maximum acceptable limit of 1.0 × 105 CFU/ml. Acinetobacter sp., Klebsiella pneumoniae, Enterococcus sp. and Bacillus sp. were the isolates from these two samples. Bacterial contamination was found in 97.1% (33/34) of EBM. The dominant bacteria isolated from EBM were Staphylococcus epidermidis (82.4%), Klebsiella pneumoniae (20.6%), Acinetobacter sp. (14.7%) and Staphylococcus aureus (10%). The numbers of organisms in EBM during the 9-hour period of storage were consistently low. The majority of EBM (85.3%) had plate counts of bacteria less than 1.0 × 105 CFU/ml. The findings indicate that control measures to eliminate microbial contamination of prepared formula on the wards were not adequate. However, safety of prepared formula could be assured as plate counts of organisms were less than the maximum acceptable limit of organisms. The results also demonstrate that it is possible to use EBM for baby’s consumption up to 6 hours of storage at room temperature (mean = 27.9OC). It is recommended that stringent measures should be put in place to ensure that health staff on the pediatric wards comply with basic principles of good hygiene. Mothers should be educated on the possibility of using unprocessed breast milk to feed babies up to 6 hours after expression if access to refrigeration is unavailable.
A Thesis submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirements for the Degree of Master of Science in Clinical Microbiology, August-2011