Assessing the effect of oral exposure to Paenibacillus alvei, a potential biocontrol agent, in male, non-pregnant, pregnant animals and the developing rat fetus

Paenibacillus alvei, a naturally occurring soil microorganism, may be used in the control and/or elimination of human/animal pathogens present on/within produce commodities associated with human consumption. The safety of oral exposure to P. alvei in male, nulliparous females, the pregnant dam and developing fetus was assessed. Adult male and female rats received a single oral dose (gavage) of P. alvei and tissues were collected at post exposure days 0, 3 and 14. To evaluate the effect of the test organism on fetal development, sperm positive female rats received the test organism every 3 days thereafter throughout gestation. As human exposure would be no more than 1 × 10³ CFU/ml the following dose levels were evaluated in both study phases: 0 CFU/ml tryptic soy broth (negative control); 1 × 10⁸ CFU/ml; 1 × 10⁴ CFU/ml or 1 × 10² CFU/ml. Neither sex specific dose-related toxic effects (feed or fluid consumption, body weight gain, and histopathology) nor developmental/reproductive effects including the number of implantations, fetal viability, fetal weight, fetal length and effects on ossification centers were observed. The test organism did not cross the placenta and was not found in the amniotic fluid.