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. 1989 Jul;27(7):1560–1566. doi: 10.1128/jcm.27.7.1560-1566.1989

Is ingestion of milk-associated bacteria by premature infants fed raw human milk controlled by routine bacteriologic screening?

B J Law 1, B A Urias 1, J Lertzman 1, D Robson 1, L Romance 1
PMCID: PMC267615  PMID: 2768443

Abstract

Expressed human milk is often used to feed premature infants. Raw milk contains bacteria which may be a source of infection. Milk banks have developed screening programs which combine periodic quantitative milk cultures with arbitrary rules specifying limits of bacterial concentration. It is unknown whether such programs succeed in preventing infants from being fed milk containing bacteria. At the Health Sciences Centre (Winnipeg, Manitoba, Canada), milk is screened once weekly. When a woman's milk is found to have excess bacteria, it is discarded only if she is an unrelated donor (as opposed to an infant's mother). To assess the effectiveness of this screening program, we determined the frequency at which infants fed raw human milk were exposed to milk-associated bacteria and compared the bacterial contents of donor and maternal milk. From February 1986 to April 1987, all human milk fed to 98 premature infants during the first 2 weeks of feeding (n = 10,128 feeds) was cultured quantitatively. Among study infants, 100% were exposed at least once to coagulase-negative staphylococci, 41% were exposed to Staphylococcus aureus, and 64% were exposed to gram-negative bacilli. The proportions of feeds containing bacteria and the quantities (log10 CFU [mean +/- standard deviation]) ingested per positive feed were: 39% and 5.9 +/- 0.5 for coagulase-negative staphylococci; 2.4% and 5.1 +/- 1.0 for S. aureus; and 5.2% and 4.8 +/- 1.1 for gram-negative bacilli. There were no adverse events attributable to ingestion of milk-associated bacteria. Milk coagulase-negative staphylococcal isolates were multiply antibiotic susceptible, whereas infant isolates were antibiotic resistant. Donor milk was significantly less likely than maternal milk to contain coagulase-negative staphylococcal species in any quantity (40 versus 93% of samples, respectively [P < 0.001]) or in concentrations exceeding 10(8) CFU/liter (3 versus 27% of samples, respectively [P < 0.0001]). There was no difference between milk from either source in terms of S. aureus or gram-negative bacterial content (4 to 6%). These results suggest that the Health Sciences Centre screening program is effective in limiting the number of harmless coagulase-negative staphylococcal species but has no impact on the quantity of potentially pathogenic bacteria ingested by premature infants. Implications for screening donor milk are discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Asquith M. T., Pedrotti P. W., Stevenson D. K., Sunshine P. Clinical uses, collection, and banking of human milk. Clin Perinatol. 1987 Mar;14(1):173–185. [PubMed] [Google Scholar]
  2. Barlow B., Santulli T. V., Heird W. C., Pitt J., Blanc W. A., Schullinger J. N. An experimental study of acute neonatal enterocolitis--the importance of breast milk. J Pediatr Surg. 1974 Oct;9(5):587–595. doi: 10.1016/0022-3468(74)90093-1. [DOI] [PubMed] [Google Scholar]
  3. Björkstén B., Burman L. G., De Château P., Fredrikzon B., Gothefors L., Hernell O. Collecting and banking human milk: to heat or not to heat? Br Med J. 1980 Sep 20;281(6243):765–769. doi: 10.1136/bmj.281.6243.765. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Botsford K. B., Weinstein R. A., Boyer K. M., Nathan C., Carman M., Paton J. B. Gram-negative bacilli in human milk feedings: quantitation and clinical consequences for premature infants. J Pediatr. 1986 Oct;109(4):707–710. doi: 10.1016/s0022-3476(86)80246-3. [DOI] [PubMed] [Google Scholar]
  5. Carroll L., Osman M., Davies D. P. Does discarding the first few millilitres of breast milk improve the bacteriological quality of bank breast milk? Arch Dis Child. 1980 Nov;55(11):898–899. doi: 10.1136/adc.55.11.898. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Carroll L., Osman M., Davies D. P., McNeish A. S. Bacteriological criteria for feeding raw breast-milk to babies on neonatal units. Lancet. 1979 Oct 6;2(8145):732–733. doi: 10.1016/s0140-6736(79)90654-8. [DOI] [PubMed] [Google Scholar]
  7. Davidson D. C., Poll R. A., Roberts C. Bacteriological monitoring of unheated human milk. Arch Dis Child. 1979 Oct;54(10):760–764. doi: 10.1136/adc.54.10.760. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Donowitz L. G., Marsik F. J., Fisher K. A., Wenzel R. P. Contaminated breast milk: A source of Klebsiella bacteremia in a newborn intensive care unit. Rev Infect Dis. 1981 Jul-Aug;3(4):716–720. doi: 10.1093/clinids/3.4.716. [DOI] [PubMed] [Google Scholar]
  9. Eidelman A. I., Szilagyi G. Patterns of bacterial colonization of human milk. Obstet Gynecol. 1979 May;53(5):550–552. [PubMed] [Google Scholar]
  10. Evans T. J., Ryley H. C., Neale L. M., Dodge J. A., Lewarne V. M. Effect of storage and heat on antimicrobial proteins in human milk. Arch Dis Child. 1978 Mar;53(3):239–241. doi: 10.1136/adc.53.3.239. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Eyal F., Sagi E., Arad I., Avital A. Necrotising enterocolitis in the very low birthweight infant: expressed breast milk feeding compared with parenteral feeding. Arch Dis Child. 1982 Apr;57(4):274–276. doi: 10.1136/adc.57.4.274. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ford J. E., Law B. A., Marshall V. M., Reiter B. Influence of the heat treatment of human milk on some of its protective constituents. J Pediatr. 1977 Jan;90(1):29–35. doi: 10.1016/s0022-3476(77)80759-2. [DOI] [PubMed] [Google Scholar]
  13. Gransden W. R., Webster M., French G. L., Phillips I. An outbreak of Serratia marcescens transmitted by contaminated breast pumps in a special care baby unit. J Hosp Infect. 1986 Mar;7(2):149–154. doi: 10.1016/0195-6701(86)90057-5. [DOI] [PubMed] [Google Scholar]
  14. Hernandez J., Lemons P., Lemons J., Todd J. Effect of storage processes on the bacterial growth-inhibiting activity of human breast milk. Pediatrics. 1979 Apr;63(4):597–601. [PubMed] [Google Scholar]
  15. Jason J. M., Nieburg P., Marks J. S. Mortality and infectious disease associated with infant-feeding practices in developing countries. Pediatrics. 1984 Oct;74(4 Pt 2):702–727. [PubMed] [Google Scholar]
  16. Kliegman R. M., Pittard W. B., Fanaroff A. A. Necrotizing enterocolitis in neonates fed human milk. J Pediatr. 1979 Sep;95(3):450–453. doi: 10.1016/s0022-3476(79)80534-x. [DOI] [PubMed] [Google Scholar]
  17. Kovar M. G., Serdula M. K., Marks J. S., Fraser D. W. Review of the epidemiologic evidence for an association between infant feeding and infant health. Pediatrics. 1984 Oct;74(4 Pt 2):615–638. [PubMed] [Google Scholar]
  18. Liebhaber M., Lewiston N. J., Asquith M. T., Sunshine P. Comparison of bacterial contamination with two methods of human milk collection. J Pediatr. 1978 Feb;92(2):236–237. doi: 10.1016/s0022-3476(78)80014-6. [DOI] [PubMed] [Google Scholar]
  19. Paxson C. L., Jr, Cress C. C. Survival of human milk leukocytes. J Pediatr. 1979 Jan;94(1):61–64. doi: 10.1016/s0022-3476(79)80352-2. [DOI] [PubMed] [Google Scholar]
  20. Pitt J., Barlow B., Heird W. C. Protection against experimental necrotizing enterocolitis by maternal milk. I. Role of milk leukocytes. Pediatr Res. 1977 Aug;11(8):906–909. doi: 10.1203/00006450-197708000-00011. [DOI] [PubMed] [Google Scholar]
  21. Pittard W. B., 3rd, Anderson D. M., Cerutti E. R., Boxerbaum B. Bacteriostatic qualities of human milk. J Pediatr. 1985 Aug;107(2):240–243. doi: 10.1016/s0022-3476(85)80133-5. [DOI] [PubMed] [Google Scholar]
  22. Ryder R. W., Crosby-Ritchie A., McDonough B., Hall W. J., 3rd Human milk contaminated with Salmonella kottbus. A cause of nosocomial illness in infants. JAMA. 1977 Oct 3;238(14):1533–1534. [PubMed] [Google Scholar]
  23. Siimes M. A., Hallman N. A perspective on human milk banking, 1978. J Pediatr. 1979 Jan;94(1):173–174. doi: 10.1016/s0022-3476(79)80406-0. [DOI] [PubMed] [Google Scholar]
  24. Silverman W. A. Human milk banking practices. Pediatrics. 1971 Feb;47(2):456–459. [PubMed] [Google Scholar]
  25. Sosa R., Barness L. Bacterial growth in refrigerated human milk. Am J Dis Child. 1987 Jan;141(1):111–112. doi: 10.1001/archpedi.1987.04460010111040. [DOI] [PubMed] [Google Scholar]
  26. Stiver H. G., Albritton W. L., Clark J., Friesen P., White F. M. Nosocomial colonization and infection due to E. coli 0125:K70 epidemiologically linked to expressed breast-milk feedings. Can J Public Health. 1977 Nov-Dec;68(6):479–482. [PubMed] [Google Scholar]
  27. Williamson S., Hewitt J. H., Finucane E., Gamsu H. R. Organisation of bank of raw and pasteurised human milk for neonatal intensive care. Br Med J. 1978 Feb 18;1(6110):393–396. doi: 10.1136/bmj.1.6110.393. [DOI] [PMC free article] [PubMed] [Google Scholar]

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