This study aims to assess the impact of the use of treated wastewater (without chlorination) in farming and dairy cattle breeding. Milk samples were collected from a farm in northeastern Algeria. The treated wastewater from the treatment plant is used on this farm for different activities. The results obtained show that the average contamination of milks with total flora is 3.7.105 CFU /ml. fecal coliforms are present at an average value of 1.5.103 CFU/ml. All of the samples (100%) were positive for the count of fecal enterococci with an average value of 2.5.10 CFU/ml. Fungal flora was present with an average value of 1.36,103 CFU/ml. Escherichia coli was isolated in 100% of the samples with high resistance rates for beta-lactam antibiotics. The results obtained for the search for pathogens belonging to the genus Staphylococcus show that 64% of the isolates were coagulase-negative Staphylococcus and 36% of the isolates were coagulase-positive. The study of Staphylococcus susceptibility/resistance to antibiotics revealed high frequencies of resistance, especially to beta-lactam antibiotics and macrolides. The bacteria tested show a majority resistance for Penicillin and Oxacillin (100%). These results reflect the microbiological risk that the consumption and marketing of this milk represents for the health of consumers and the need to implement preventive measures.
Keywords: Irrigation, Fecal coliforms, Escherichia coli, Staphylococcus sp, Antibiotic resistance. Microbiological risk