Molecular Virology: Tables of
Antimicrobial Factors and Microbial Contaminants in Human Milk
Table 1: Antibacterial factors found in human milk
"Many cultures have considered that human milk has special medicinal and nutritional properties ... it is also used as a folk remedy for conjuntivitis ... This view is paralleled in the 18th Century London Pharmacopoeia which says, 'breast milk is an emollient and cool, and cureth Red Eye immediately.'"
- Singh, et al. (1981) J. Trop. Ped. 28: 35
| Factor | Shown in vitro to be active against |
|---|---|
| Secretory IgA | E. coli (also pili, capsular antigens, CFA1) including enteropathogenic strains, C. tetani, C. diphtheriae, K. pneumoniae, S. pyogenes, S. mutans, S. sanguins, S. mitis, S. agalactiae (group B streptococci), S. salvarius, S. pneumoniae (also capsular polysaccharides), C. burnetti, H. influenzae, H. pylori, S. flexneri, S. boydii, S. sonnei, C. jejuni, N. meningitidis, B. pertussis, S. dysenteriae, C. trachomatis, Salmonella (6 groups), S. minnesota, P. aeruginosa, L. innocua, Campylobacter flagelin, Y. enterocolitica, S. flexneri virulence plasmid antigen, C. diphtheriae toxin, E. coli enterotoxin, V. cholerae enterotoxin, C. difficile toxins, H. influenzae capsule, S. aureus enterotoxin F, Candida albicans*, Mycoplasma pneumoniae |
| IgG | E. coli, B. pertussis, H. influenzae type b, S. pneumoniae, S. agalactiae, N. meningitidis, 14 pneumoccoccal capsular polysaccharides, V. cholerae lipopolysaccharide, S. flexneri invasion plasmid-coded antigens, major opsonin for S. aureus |
| IgM | V. cholerae lipopolysaccharide, E. coli, S. flexneri |
| IgD | E. coli |
| Analogues of epithelial cell receptors (oligosaccharides and sialylated oligosaccharides***) |
S. pneumoniae, H. influenzae |
| Bifidobacterium bifidum growth factors (oligosaccharides, glycopeptides) Other Bifidobacteria growth factors (alpha-lactoglobulin, lactoferrin, sialyllactose) |
Enteric bacteria. Two infant Bifidobacteria species provide a lipophilic molecule which kills S. typhimurium. B. bifidum produces Bifidocin B which kills Listeria. B. longum produces protein BIF, which stops E. coli. |
| Carbohydrate | E. coli enterotoxin, E. coli, C. difficile toxin A |
| Cathelicidin (LL-37 peptide) | S. aureus, group A streptococcus, E. coli |
| Casein | H. influenzae |
| kappa-Casein** | H. pylori, S. pneumoniae, H. influenzae |
| Complement C1-C9 (mainly C3 and C4) |
Killing of S. aureus in macrophages, E. coli (serum-sensitive) |
| β-defensin-1 or -2 or neutrophil-α-defensin-1 or α-defensin-5 or -6 |
E. coli, P. aeruginosa, (some Candida albicans *) |
| Factor binding proteins (zinc, vitamin B12, folate) |
Dependent E. coli |
| Free secretory component** | E. coli colonization factor antigen 1 (CFA I) and CFA II, C. difficile toxin A, H. pylori, E. coli |
| Fucosylated oligosaccharides | E. coli heat stable enterotoxin, C. jejuni, E. coli |
| Ganglioside GM1 | E. coli enterotoxin, V. cholerae toxin, C. jejuni enterotoxin, E. coli |
| Ganglioside GM3 | E. coli |
| Glycolipid Gb3 | S. dysenterae toxin, shigatoxin of shigella and E. coli |
| Glycoproteins (mannosylated) | E. coli, E. coli CFA11, fimbrae |
| Glycoproteins (receptor- like)+ oligosaccharides |
V. cholerae |
| Glycoproteins (sialic acid -containing or terminal galactose) |
E. coli (S-fimbrinated) |
| alpha-Lactalbumin (variant) | S. pneumoniae |
| Lactoferrin** | E. coli, E. coli/CFA1 or S-fimbriae, Candida albicans*, Candida krusei*, Rhodotorula rubra*, H. influenzae, S. flexneri, Actinobacillus actinomycetemcomitans |
| Lactoperoxidase | Streptococcus, Pseudomonas, E. coli, S. typhimurium |
| Lewis antigens | S. aureus, C. perfringens |
| Lipids | S. aureus, E. coli, S. epidermis, H. influenzae, S. agalactiae, L. monocytogenes, N. gonorrhoeae, C. trachomatis, B. parapertusis heat-labile toxin, binds Shigella-like toxin-1 |
| Lysozyme | E. coli, Salmonella, M. lysodeikticus, S. aureus, P. fragi, growing Candida albicans* and Aspergillus fumigatus* |
| Milk cells (80% macrophages, 15% neutrophils, 0.3% B and 4% T lymphocytes) |
By phagocytosis and killing: E. coli, S. aureus, S. enteritidis By sensitised lymphocytes: E. coli By phagocytosis: Candida albicans*, E. coli Lymphocyte stimulation: E. coli K antigen, tuberculin Spontaneous monokines: simulated by lipopolysaccaride Induced cytokines: PHA, PMA + ionomycin Fibronectin helps in uptake by phagocytic cells. |
| Mucin (muc-1; milk fat globulin membrane) |
E. coli (S-fimbrinated) |
| Nonimmunoglobulin (milk fat, proteins) |
C. trachomatis, Y. enterocolitica |
| Phosphatidylethanolamine | H. pylori |
| (Tri to penta) phosphorylated beta-casein | H. influenzae |
| Sialyllactose | V. cholerae toxin, H. pylori |
| Sialyloligosaccharides on sIgA(Fc) |
E. coli (S-fimbrinated) adhesion |
| Soluble bacterial pattern recognition receptor CD14 | Bacteria (or LPS) activate this to induce immune response molecules from intestinal cells |
| Sulphatide (sulphogalactosylceramide) | S. typhimurium |
| Unidentified factors | S. aureus, B. pertussis, C. jejuni, E. coli, S. typhimurium, S. flexneri, S. sonnei, V. cholerae, L. pomona, L. hyos, L. icterohaemorrhagiae, C. difficile toxin B, H. pylori, C. trachomatis |
| Xanthine oxidase (with added hypoxanthine) |
E. coli, S. enteritidis |
| Factors found at low level in human milk | Shown in vitro to be active against |
| CCL28 (CC-chemokine) | Candida albicans*, P. aeruginosa, S. mutans, S. pyogenes, S. aureus, K. pneumonidae |
| Heparin | Chlamydia pneumoniae |
| RANTES (CC-chemokine) | E. coli, S. aureus, Candida albicans*, Cryptococcus neoformans* |
| Secretory leukocyte protease inhibitor (antileukocyte protease; SLPI) | E. coli, S. aureus, growing C. albicans* and A. fumigatus* |
* Fungi
** Contain fucosylated oligosaccharides. Stomach pepsin releases potent
antibacterial peptides.
*** One sialylated pentasaccharide (3'-sialyllactose-N-neotetraose; NE-1530) had
no beneficial effect on otitis media in phase-2 clinical trials
- Human milk contains nearly a thousand different oligosaccharides (determined by MALDI-mass spectrometry). Many have the potential to act as receptors for bacteria not listed in the table.
- Concentration of milk components in Breastfeeding: unravelling the mysteries of mother's milk (requires completion of free registration to Medscape)
- Various combinations of lysozyme, lactoferrin and SLPI have synergistic effect against E. coli.
Based on a table from the Proceedings of Breast Milk and Special Care Nurseries: Problems and Opportunities Conference. August 1995. Melbourne.
NB: A bibliography for this table is currently available.
