Immunotoxic effect of herbicide simazine exposure in BALB/c mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To examine the effect of simazine on selected immune parameters in BALB/c mice.</p><p><b>METHODS</b>Simazine (90, 200, 400 mg/kg) was administrered by oral gavage for 21 days in adult BALB/c mice. The negative control group unith distilled water and positive control group administered with cyclophosphamide in abdominal cavity were also established. After the last simazine dose, the mice were sacrificed, and blood, spleens, and thymuses were collected and processed for detection. The relative weight of spleen and thymus was calculated. The rate of T cell in spleen and the concentration of IL-2, IL-4, IgG and IgM were detected by ELISA.</p><p><b>RESULTS</b>The weights of mice were decreased in 200 mg/kg and 400 mg/kg simazine groups. Thymus and spleen weights were decreased in 200 mg/kg and 400 mg/kg simazine groups compared with the negative control group. The concentration of IL-2, IL-4, IgG and IgM in serum of 200 mg/kg group were (108.50 +/- 3.20) pg/ml, (36.54 +/- 3.36) pg/ml, (46.25 +/- 7.41) μg/ml, (17.58 +/- 2.23) μg/ml respectively;The concentration of IL-2, IL-4, IgG and IgM in serum of 400 mg/kg group were (85.70 +/- 4.00) pg/ml, (35.92 +/- 2.29) pg/ml, (40.08 +/- 6.80) μg/ml, (11.92 +/- 3.23) μg/ml respectively (P < 0.05 or P < 0.01). These results were decreased significantly compared with negative group.</p><p><b>CONCLUSION</b>Simazine can inhibit the cellular immune function and the humoral immune function.</p>

Novel s-triazine-degrading bacteria isolated from agricultural soils of central Chile for herbicide bioremediation

s-Triazine-degrading bacterial strains were isolated from long-term simazine-treated agricultural soils of central Chile. The number of culturable heterotrophic bacteria of these agricultural soils (7 x 10(6) CFU/g of dry soil) was not affected by simazine application on field. The simazine-degrading bacterial strains P51, P52 and C53 were isolated by enrichment in minimal medium using simazine as the sole nitrogen source. Resting cells of strains P51 and P52 degraded >80 percent of simazine within 48 hrs, whereas strain C53 was able to remove >60 percent of the herbicide. The atzA and atzD genes of the s-triazine upper and lower catabolic pathways were detected in strains P51 and C53, while only atzD gene was observed in strain P52. To compare the bacterial 16S rRNA gene sequence structure, ARDRA were performed using the restriction enzymes Msp1 and Hha1. ARDRA indicated that strain P52 was a different ribotype than C53 and P51 strains. For further characterization the novel isolates were identified by 16S rRNA gene sequencing. Strains C53 and P51 belong to the genus Stenotrophomonas and the strain P52 belongs to the genus Arthrobacter . s -Triazine-degrading bacterial strains isolated from contaminated soils could be used as biocatalysts for bioremediation of these herbicides.