Seasonal variations of Environmental parameters and their effect on the Brucella species in Iraqi animals soil

Abstract

The soils samples collected from animals soils from of different villages for the fourth season from middle,south and north of Babylon province, Iraq. for the fourth season from winter in February to Autumn in November, Theses samples included 10 sites in Winter, 32 sites in Spring,9 sites in Summer and 12 sites in Autumn, 2021. The samples was taken from the upper layer for bacteriological study and from the deepest layer (25-30 cm in depth) of the soil for environmental study, dried by air and sieved (to ~ 2 mm particle size) during the collecting the samples measured air temperature and soil temperature. This investigation aim to knowledge presence types of Brucella spp. in the animal's soils. Brucella is a gram-negative, intracellular, non-motile, none sporulating, non-toxigenic, no fermenting, and weakly acid-fast bacteria. The bacteria isolated from soil by Brucella agar base, PCR technique was used to diagnose the genus of Brucella and the gene used 16SrRNA. The results showed the presence of brucellosis in the soil and its percentage varies according to the seasons, where the highest percentage of brucellosis was in summer and the lowest in winter, and these percentages were related to seasonal environmental indicators. The presence of the most Brucella had the highest values of physical and chemical properties (Air and Soil temperature, pH, E.C TDS, Salinity, TOC) except for Toc is lower, while the percentages of the lowest Brucella had the lowest environmental indicators except for Toc. It was also noted that this low percentage of Brucella in the winter had the highest values of heavy elements (Cu, Fe,Cd) except for Pb has the lowest value, while the higher percentages in summer had the lowest value (Cu, Fe,Cd) except for Pb being high. The results revealed presence the bacteria in some the soil isolated samples and after senting these samples to DNA sequence noticed different species of bacteria. DNA sequencing for (B.melitensis, B. pseudogrignonensis, B.lupini and B.inopinata) strains include substituation mutation (transversion and transition) and at compared these results for genotype with phenotype that include ( Air and Soil temperature, pH, E.C TDS, Salinity, TOC) by statistical analysis that proportion of bacteria presence in summer is higher and the relation with environmental parameters include (Air and Soil temperature, pH, EC, TDS and Salinity) is high, except TOC is low while proportion of bacteria presence in Winter is lower while bacteria presence in winter is lower. This indicates to presence a relationship between the Brucella percentage with environmental parameters and heavy metals according to seasons.