This work was carried out to answer a question of multidrug resistance and fodder pesticide residue relations to increasing mastitis syndrome in cattle and buffalos in Egypt. For this, Milk of cattle and buffalos and fodder samples were collected from 3 different localities in El-Fayoum province.
Pesticide residues analysis was carried out using the modified QuEChERS method followed by liquid chromatography coupled to triple quadrupole tandem mass spectrometry (LC-MS/MS). The residue analysis revealed that about 85% of alfalfa fodder samples and 58% of milk samples were contaminated with pesticides in the valley applied pesticide in alfalfa fodder. The pesticides found in this study were chlorpyrifos, cyhalothrin, lufenuron, and malathion. Identification of bacterial isolates was carried out using conventional PCR. Their prevalence rates were as follows: Escherichia coli 4, 11, 15 (5, 10, 13.64%) in milk from the farm, non-pesticide applied, and pesticide applied villages, respectively. For the other microorganisms; Klebsiella 0, 2, 5 (0, 1.8, 4.5%), Staphylococcus aureus 6, 8, 18 (7.5, 7.3, 16.4%), and Streptococcus agalactiae 3, 7, 17 (3.75, 6.4, 15.5%). The isolation rates of these identified bacteria from each sampling point were found to be statistically significant using the Fischer Exact Probability test (P < 0.05). The results also showed that there was a multidrug resistance to nearly all tested antibiotics in bacteria isolated from milk collected from Ezbet Furqan. The antibiotic sensitivity pattern of bacterial isolates in milk samples collected from a dairy cow's farm in Fayoum province was higher when compared to that of Ezbet Barghout cows. In conclusion, there was a significant correlation between pesticide residues and multidrug resistance.