. 2016 Apr 19;7(2):e00404-16. doi: 10.1128/mBio.00404-16

TABLE 2 .

Infectivity of the WT, ftsH(in), and ftsH(res) strains in mice

B. burgdorferi strain^a	No. of mice with reisolation from tissue/total assessed^b			No. infected/total
B. burgdorferi strain^a	Ear	Bladder	Joint	No. infected/total
A3-68-LS	5/5	5/5	5/5	5/5
ftsH(in)	0/5	0/5	0/5	0/5
ftsH(res)^b	5/5	5/5	5/5	5/5

The inocula for needle infection were 8 × 10³ spirochetes injected intraperitoneally and 2 × 10³ spirochetes injected subcutaneously.

Day 10 outgrowth was isolated from the ftsH(in) strain cultured in the absence of IPTG and designated the ftsH(res) strain. A spontaneous mutation in the lac operator sequence presumably allowed for resumption of FtsH production and cell growth.