Molecular Detection and Characterization of Staphylococcus Aureus from Buffalo Milk in District Muzaffargarh

Milk is an important food component in our country and has great nutritious value. But contamination of milk makes it harmful for health. Staphylococcus aureus is a zoonotic pathogen which can cause a potential threat to the public health. The S. aureus associated infections affect the animal?s milk quality and quantity which create a burden on the economics industry.The main purpose of our research was to identify the rate of the possibility of the presence of Staphylococcus aureus in the available raw milk at Muzaffer Garh district. Total 100 samples were collected from different areas of district Muzaffargarh, such as Jutoi, Alipur, Kotadu, Murad Abad, Choak Qureshi, Ahmadpur, Ruhilan Wali, shahjamal, Khanpur and Muzaffargarh city. Isolation of S. aureus and the detection of S. aureus was performed by the used of biochemical and molecular tests from the collected samples. The samples were cultured on mannitol salt agar which contained a high concentration of salt which sport the growth of gram-positive bacteria (Staphylococcus and Micrococcaceae). Yellow zones appeared in 80 samples which indicated the presence of S. aureus and then detected by gram staining which showed 80/100(80%) positive results. S. aureus fermentation test showed 76/100(76%) positive results and other biochemical tests such as catalase test 63/100(63%), coagulase test 52/100(52%), methyl red (MR) test 42/100(42%), Voges Proskauer (VP) test 40/100(40%). Finally, the detected colonies were subculture and DNA was extracted from that bacterial culture. Molecular detection was done through PCR. To amplify the sequences of 16S rRNA gene, PCR assay was used which is considered to be the standard for detection of S. aureus by using the nuc gene 447bp. The PCR products were analyzed by the visualization of agarose gel electrophoresis. There were 11 samples out of 100 samples, showed positive results for the detection of S. aureus. Ten different areas of Muzaffargarh district showed the different tendency of the existence of S. aureus, such as S. aureus detected in raw milk of buffalo of Alipur 1/10(10%). The S. aureus existence in buffalo milk of Jutoi 2/10(20%), Murad Abad 1/10(10%), Ruhilan Wali 1/10(10%), city Muzaffargarh 2/10(20%), Khanpur 1/10(10%), Ahmadpur 1/10(20%), Shahjamal 1/10(10%) while samples collected from Kotadu and Choak Qureshi showed negative PCR results for S. aureus. This study indicated the potential of staphylococcal food poisoning and health risks in district Muzaffargarh. Poor hygienic conditions effect the bacterial growth and S. aureus availability also related to the hygienic conditions.