bacteria are extremely numerous

Bacteria are extremely numerous

1030 vs 1010

bacteria humans

1014 vs 1013

bacterial cells in human cells in

a human body a human body

Bacteria can be extremely dangerous

• In the 19th Century 1 in 7 deaths was caused by a single bacterial lineage (Mycobacterium tuberculosis)

• TB still causes 1.7 million deaths annually

Bacteria evolve extremly rapidly

Bacterial genomes are small:

4,000,000 bp vs 2 * 3,000,000,000 bp

typical bacteria human

Bacterial replication

Bacterial sex

ACTTGCTTTCGACCCTAGGATTTTACTTCTTT

ACTTGCTTTCGACCCTTGGATTTTACTTCTTT

Point mutation

ACTTGCTTTCGACCCTAGGATTTTACTTCTTT

GACCTTAGCATTAT+

ACTTGCTTTCGACCTTAGCATTATACTTCTTT

Homologous recombination

Branch swapping algorithm

Node that will be transplanted

daughter

father

Salmonella enterica

Salmonella enterica

?

?

Genotype information Correct (%) Uncertainty removed (%)

Alleles 58 37

ST 40 10

Clonal complex (1) 42 13

Clonal complex (2) 42 13

Alleles plus ST 60 40

Alleles plus clonal complex 58 37

Assignment to sheep vs chicken vs cow.

Predicted host

Host

(n) Chicken Cow Sheep

Chicken 309 66% 14% 19%

Cattle 245 12% 50% 38%

Sheep 159 10% 36% 54%

~21 complex

518

43

300

302

368

44341

345 409

423

518 519

641262

274

275

369 621

642

722

487615

742

748752

719

712

21 434388

268

300300

302302

368368

44341

345 409

4444341341

345345 409409

423423

519519

635635

641641262

274

275

369 621

642262262

274274

275275

369369 621621

642642

722722

487487615615

742742

748748752752

719719

712712

2121

Chicken Ruminant

No. of descendent genotypes     1 (success) 0 (failure)

tbpB family 1 1 18

tbpB family 3 0 3

tbpB family 4 3 3

pgm 1 1

IS1106A 5 4

Translocation of opaJ 2 8

Translocation of opaA 1 4

Other opa changes 4 5

iga 1 1