FIG 5.

Pyocyanin disables the infectivity of EBs. (A, B) Host cells were pretreated with 0.06, 1, and 8 μM pyocyanin or 0.5% DMSO for 1, 2, 3, or 4 h. Following washes, HeLa (A) and Hep2 (B) cells were inoculated with C. trachomatis L2 or C. pneumoniae AR39, respectively. Numbers of inclusions were quantified using immunofluorescence microscopy. (C to F) EBs were pretreated with 0.06, 1, and 8 μM pyocyanin or 0.5% DMSO for 1 h at indicated temperature. Following washes, EBs were added to cells. Numbers of inclusions formed by 36 hpi were quantified using immunofluorescence microscopy. (C, D) Percent inhibition of EB infectivity was calculated based on data in pyocyanin-treated samples relative to those of the DMSO-treated control. (E, F) Numbers of inclusions pretreated with 0.5% DMSO are presented. Asterisks indicate statistically significant difference between 4°C and 37 or 35°C (*, P < 0.05 by Student's t test).