Levels of Organochlorine Pesticides in Blood Plasma from Residents of Malaria-Endemic Communities in Chiapas, Mexico

Organochlorine (OC) pesticides have been extensively used for pest control in agriculture and against malaria vectors in the region of Soconusco, Chiapas, in southern Mexico. Our study aimed to identify whether the inhabitants of four Soconusco communities at different locations (i.e., altitudes) and with different history of use of OC pesticides, have been similarly exposed to residues of these pesticides. In particular, we analyzed the potential relationship between levels of OC pesticides in plasma and the age, gender, and residence of the study population (n = 60). We detected seven pesticides in total (gamma-HCH, beta-HCH, heptachlor, p,p'-DDE, p,p'-DDT, beta-endosulfan, endrin aldehyde). Of these, p,p'-DDE and beta-endosulfan were the most frequently found (in 98% and 38% of the samples, respectively). The low-altitude (60 years) had the highest p,p'-DDE level (56.94 +/- 57.81 mu g/L) of all age groups, while men had higher p,p'-DDE (34.00 +/- 46.76 mu g/L) than women. Our results demonstrate that residents of the Soconusco region are exposed to p,p'-DDE because of high exposure to DDT in the past and current environmental exposure to this DDT-breakdown product

Isolation and Molecular Identification of <i>Serratia</i> Strains Producing Chitinases, Glucanases, Cellulases, and Prodigiosin and Determination of Their Antifungal Effect against <i>Colletotrichum siamense</i> and <i>Alternaria alternata</i> In Vitro and on Mango Fruit

Microorganisms represent a viable option for the control of phytopathogens. From the surface of healthy mangoes, different bacteria were isolated. For all isolated bacterial strains, we determined their antimicrobial activity against a fungal strain that caused anthracnose in mangoes and against Alternaria alternata, both in the culture medium and directly on mangoes. The bacterial strains with the highest antifungal activity were identified by sequencing the 16s rRNA gene. Two species of Serratia were identified: marcescens and nematodiphila. Finally, the chitinolytic, glucanolytic, and cellulolytic activity and prodigiosin production of bacteria with antifungal activity was determined. Five fungal strains were isolated from mangoes with anthracnose. Only one strain was responsible for anthracnose in mangoes. This fungal strain was identified as Colletotrichum siamense. Against C. siamense and A. alternata in vitro and in mango selected strains of Serratia showed antifungal activity. Finally, the Serratia strains produced chitinases, glucanases, cellulases and prodigiosin, and the two S. marcescens strains did not produce hemolysins. The three Serratia strains isolated in this study can potentially be used in the biological control of anthracnose caused by C. siamense and A. alternata on mango

Isolation and Molecular Identification of Serratia Strains Producing Chitinases, Glucanases, Cellulases, and Prodigiosin and Determination of Their Antifungal Effect against Colletotrichum siamense and Alternaria alternata In Vitro and on Mango Fruit

Microorganisms represent a viable option for the control of phytopathogens. From the surface of healthy mangoes, different bacteria were isolated. For all isolated bacterial strains, we determined their antimicrobial activity against a fungal strain that caused anthracnose in mangoes and against Alternaria alternata, both in the culture medium and directly on mangoes. The bacterial strains with the highest antifungal activity were identified by sequencing the 16s rRNA gene. Two species of Serratia were identified: marcescens and nematodiphila. Finally, the chitinolytic, glucanolytic, and cellulolytic activity and prodigiosin production of bacteria with antifungal activity was determined. Five fungal strains were isolated from mangoes with anthracnose. Only one strain was responsible for anthracnose in mangoes. This fungal strain was identified as Colletotrichum siamense. Against C. siamense and A. alternata in vitro and in mango selected strains of Serratia showed antifungal activity. Finally, the Serratia strains produced chitinases, glucanases, cellulases and prodigiosin, and the two S. marcescens strains did not produce hemolysins. The three Serratia strains isolated in this study can potentially be used in the biological control of anthracnose caused by C. siamense and A. alternata on mango