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Table 2 Survival of recombinant E. coli within THP-1 cells

From: Characterization of Mce4A protein of Mycobacterium tuberculosis: role in invasion and survival

Recombinant E. coli used to infect THP-1 cells Colony forming units at different time points (% survival)
  t0 t3 t24
Vector only 1426 ± 112 376 ± 37.74
(26.3 ± 1.8)
6.6 ± 1.45
(0.46 ± 0.12)
pET28a/mce4A 3157 ± 37.17 1493 ± 90.07
(47.2 ± 2.7φφ)
556 ± 60.80
(18.3 ± 2.17θθ)
pET28a/mce1A 3596 ± 106.4 2209 ± 146.3
(61.5 ± 4.59**)
770.7 ± 59.05
(21.33 ± 1.09***)
  1. Survival was assayed as colony forming units per milliliter of lysate following lysis of the infected cells. Time points considered were as follows: t0 - 1 hour, t3 - 3 hours and t24 - 24 hours, post-infection. All values were normalised to t0 value taken as 100%. The significance was calculated using t test. Recombinant E. coli expressing Mce4A or Mce1A survived inside THP-1 cells at a significantly high CFU as compared to recombinant E. coli with vector alone.
  2. φφ, p < 0.005; **, p < 0.005; when t test applied to compare percentage survival of E. coli (pET28a) with percentage survival of E. coli (pET28a/mce4A) and E. coli (pET28a/mce1A) respectively at 3 h of incubation.
  3. θθ, p < 0.005; ***, p < 0.0005; t test applied to compare percentage survival of E. coli (pET28a) with percentage survival of E. coli (pET28a/mce4A) and E. coli (pET28a/mce1A) respectively at 24 h of incubation.