TABLE 3.
Number of putative virulence genes among different isolates of Bifidobacterium determined by BLAST analysis
| Virulence factora | No. of putative virulence genes in the indicated isolates in the following cladesb: |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clade I |
Clade II |
Clade III |
Clade IV |
||||||||||||
| B. breve (10) | B. breve (7) | B. longum subsp. infantis (14) | B. longum subsp. infantis (15) | B. longum subsp. infantis (13) | B. longum subsp. infantis (4) | B. longum subsp. longum (12) | B. longum subsp. longum (9) | B. longum subsp. longum (3) | B. longum subsp. longum (5) | B. longum subsp. longum (6) | B. longum subsp. longum (2) | B. longum subsp. longum (1) | B. animalis (11) | B. animalis (8) | |
| Target | |||||||||||||||
| Adherence | 7 | 7 | 7 | 4 | 4 | 3 | 5 | 7 | 5 | 6 | 4 | 4 | 4 | 8 | 9 |
| Invasion | 1 | 1 | 1 | ||||||||||||
| Toxin | 13 | 12 | 13 | 12 | 12 | 13 | 9 | 9 | 12 | 11 | 13 | 10 | 7 | 10 | 11 |
| Secretion | 8 | 8 | 6 | 5 | 4 | 6 | 10 | 4 | 5 | 6 | 5 | 7 | 2 | 7 | 8 |
| Defensive | |||||||||||||||
| Antiphagocytosis | 12 | 11 | 7 | 6 | 7 | 5 | 8 | 6 | 9 | 8 | 6 | 8 | 2 | 12 | 11 |
| Bile resistance | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Biofilm | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |||
| Stress | 4 | 4 | 5 | 3 | 3 | 3 | 4 | 4 | 3 | 3 | 3 | 3 | 4 | 4 | 4 |
| Immune evasion | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 1 | 1 | 1 | 3 | 2 | |
| Nonspecific | |||||||||||||||
| Iron uptake | 9 | 7 | 8 | 8 | 9 | 4 | 6 | 5 | 6 | 7 | 7 | 8 | 5 | 8 | 8 |
| Mg uptake | 1 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Enzyme | 2 | 1 | 1 | 1 | |||||||||||
| Exoenzyme | 1 | 1 | 1 | 1 | 1 | 1 | 1 | ||||||||
| Other | |||||||||||||||
| Reg. of VAGc | 2 | 2 | 2 | 1 | 1 | 1 | 2 | 1 | 2 | 1 | 1 | 1 | 1 | 2 | 2 |
| Regulation | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Efflux pumps | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| Signaling | 1 | 1 | 1 | 1 | 1 | ||||||||||
| Unclassified | 1 | 1 | 2 | 2 | 2 | 1 | 2 | 2 | 2 | 1 | 2 | 1 | 1 | 2 | 2 |
| Total | 64 | 61 | 59 | 49 | 49 | 43 | 51 | 44 | 51 | 51 | 47 | 49 | 31 | 63 | 64 |
Target, virulence factors promoting colonization of the host, invasion into host cells by surface components, and production of endo- or exotoxins; defensive, virulence factors helping bacteria to evade host defense, including capsules that protect them from opsonization and phagocytosis; nonspecific, virulence factors promoting sophisticated adaptation to the host environment, including iron-binding factors that compete with the host for iron and factors involving altered magnesium uptake protecting the integrity of proteins or membranes, enzymatic activity altering the host environment to enhance bacterial survival, and colonization; other includes signaling molecules involved in regulation of cellular functions, such as motility and cell-cell aggregation, among others.
Patient numbers are given in parentheses.
Reg. of VAG, regulation of virulence-associated genes.