Fortifying fresh human milk with commercial powdered human milk fortifiers does not affect bacterial growth during 6 hours at room temperature.
OBJECTIVE
To evaluate the growth of resident aerobic mesophilic flora and added Enterobacter sakazakii in fresh, unfortified human milk; fresh human milk fortified with two commercial powdered fortifiers differing in iron content; and infant formula prepared from powder.


METHODS
Eight mothers provided preterm breast milk samples.


METHODS
Breast milk samples were divided into three aliquots: unfortified, fortified with fortifier containing 1.44 mg iron/14 kcal, and fortified with fortifier containing 0.4 mg iron/14 kcal. Aliquots of formula were prepared. Breast milk and formula aliquots were divided into two test samples. Half were inoculated with low amounts of E sakazakii; half were not. All test samples were maintained at room temperature (22 degrees C), serially diluted, and plated onto agars after 0, 2, 4, and 6 hours. Plates were incubated at 35 degrees C and enumerated.


METHODS
Data were analyzed using repeated measures analysis of variance. P<.05 was considered significant.


RESULTS
There were no differences in colony counts of aerobic bacteria among uninoculated or among inoculated human milk samples at any time; counts did not increase significantly over 6 hours. There were no differences in colony counts of E sakazakii among inoculated human milk samples at any time; counts did not increase significantly over 6 hours. Aerobic bacteria and E sakazakii colony counts from infant formula did not increase significantly over 6 hours.


CONCLUSIONS
During 6 hours at 22 degrees C, fresh human milk and formula had negligible bacterial growth; fortifying human milk with powdered fortifiers did not affect bacterial growth.
Telang
Sucheta
S
Department of Medicine, University of Louisville, Louisville, KY, USA.
Berseth
Carol Lynn
CL
Ferguson
Paul W
PW
Kinder
Julie M
JM
DeRoin
Mark
M
Petschow
Bryon W
BW
D000704:Analysis of Variance; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D044083:Cronobacter sakazakii / Q000254:growth & development* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005527:Food, Fortified; D006801:Humans; D041943:Infant Formula / Q000592:standards; D019266:Iron, Dietary / Q000008:administration & dosage*; D008895:Milk, Human / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors
D019266:Iron, Dietary