ABSTRACT Aims: Dickeya dadantii is a pathogenic bacterium causing bacterial soft rot disease in plants. The bacterium uses a homoserine lactone signal in its quorum sensing process to express the virulence factor genes. Anti-quorum sensing is a new approach to control plant pathogenic bacteria. The aims of this study are to characterize AHL-lactonase enzyme produced by Bacillus thuringiensis SGT3g and to determine its effectiveness in inhibiting virulence of D. dadantii. Methodology and results: Activity of AHL-lactonase was determined using Chromobacterium violaceum as a bacterial biosensor. The crude extract enzymes of AHL-lactonase on both as extracellular and intracellular enzymes were analyzed their enzyme activity of protein precipitation and dialysis products. The optimum activity of AHL-lactonase was found at 30 °C and pH 5-8. Bacillus thuringiensis SGT3g was capable to reduce soft rot symptom disease caused by D. dadantii on Phalaenopsis orchid leaves after 24 h of incubation. Conclusion, significance and impact study: Bacillus thuringiensis SGT3g was capable to degrade AHL signal of C. violaceum and D. dadantii. The activity AHL-lactonase of B. thuringiensis SGT3g had a wide range of pH and temperature. The lactonase could reduce soft rot symptom disease caused by D. dadantii without any growth inhibition of D. dadantii on orchid leaves. Bacillus thuringiensis SGT3g can be used as an alternative biopesticide to control phytopathogenic bacteria due to its capability to suppress bacterial pathogenic virulence.
Bacillus thuringiensis

The cases of morbidity and mortality of babies and toddlers are continue to occur because of negligence of the mothers in providing complete basic immunization to their babies. This study is a cross-sectional study that was conducted to identify the predisposing, enabling, and reinforcing factors that influence full basic immunization coverage. The study was performed on mothers who had 9-12 months old child spread in 22 villages, purposively selected through from 22 community health centers in Bangkalan District, Madura Island. 200 mothers were selected as the study's respondents. The data were collected through questionnaires and from the book of "Kesehatan Ibu dan Anak" (KIA). The result of the study was obtained using logistic regression statistical test and it showed that the factors that influenced of full basic immunization coverage in Bangkalan District, Madura Island, were family income as predisposing factor (OR=2.26; 95% CI= 1.14 to 4.51; p= 0.020); health facility as enabling factor (OR=3.03; 95% CI= 1.59 to 5.80; p= 0.001); and community leader support as reinforcing factor (OR=2.56; 95% CI= 1.33 to 4.92; p= 0.005).