RT Journal Article SR Electronic(1) A1 Miyazaki, Shuichi A1 Matsumoto, Tetsuya A1 Tateda, Kazuhiro A1 Ohno, Akira A1 Yamaguchi, KeizoYR 1995 T1 Role of exotoxin A in inducing severe Pseudomonas aeruginosa infections in mice JF Journal of Medical Microbiology, VO 43 IS 3 SP 169 OP 175 DO https://doi.org/10.1099/00222615-43-3-169 PB Microbiology Society, SN 1473-5644, AB Summary The effects of exotoxin A (EXA) from Pseudomonas aeruginosa on polymorphonuclear leucocytes (PMNLs) were studied in a mouse model and in vitro. P. aeruginosa PA103, which produced EXA, was 20 times more virulent for normal mice than was its EXA-deficient mutant, PA103-29. EXA was detected in the plasma of mice infected with P. aeruginosa PA103, and its presence correlated with increasing numbers of bacteria in the blood and internal organs. A monoclonal antibody (MAb) against EXA prevented the death of the mice if it was given simultaneously with, or 2 h before, infection with strain PA 103. The number of PMNLs in murine blood decreased by 50% within 30 min of intravenous injection of EXA, but this decrease was prevented by simultaneous or prior injection of MAb to the toxin. EXA inhibited in-vitro phagocytosis and killing of P. aeruginosa by human and murine PMNLs and decreased the number of the PMNLs by between 60 and 68%. Collectively, these results not only confirm that EXA. is toxic in vivo, but also suggest that this toxin accelerates the growth of virulent P. aeruginosa in mice., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-43-3-169