Vol. 12, Issue 1 (2023)

Author(s):
Dr. Sowjanya Priya Ronanki, P Ramya, A Jagadeesh Babu and B Sreedevi

Abstract:
A study was carried out in Tirupati city to assess the Proteus species contamination in raw milk and meat, meant for human consumption and molecularly characterised the virulent gene profile of the isolates. A total of 741 samples including 347 raw milk and 394 raw meat samples were aseptically collected from different sampling points of 50 different wards of Tirupati, Andhra Pradesh for a period of 4 weeks. Out of 741 milk and meat samples, 189 (25.5%) isolates were positive for Proteus spp. (163 (41.4%) are from meat samples and 26 (7.5%) are from milk samples) based on cultural and biochemical characteristics. The biochemically confirmed isolates (189) were screened by using genus specific PCR targeting 16S rRNA, 176 (93.1%) isolates were positive for genus specific gene of Proteus spp. (18 (69.2%) from milk samples and 158 (96.9%) from meat samples. Out of 176 Proteus spp. isolates 132 were confirmed as P. mirabilis (13 (50%) from milk and 119 (73%) from meat) by targeting ureR gene. Out of 176 Proteus spp. isolates 44 (25%) were confirmed as P. vulgaris (5 (19.2%) from milk and 39 (23.9%) from meat) by targeting urease C gene. The species confirmed isolates of P. mirabilis and P. vulgaris were screened for the presence of rsbA, zapA, ureC and hpmA virulent genes. 100% prevalence of rsbA and zapA genes were observed in P. mirabilis and P. vulgaris isolates of milk and meat samples. In multiplex PCR of ureC and hpmA, the prevalence of ureC gene is 100% and 92.44% and hpmA gene is 92.30% and 90.75%, respectively in milk and meat sample isolates of P. mirabilis. The prevalence of ureC gene of P. vulgaris is 100% and 82.05%and hpmA gene of P. vulgaris is 40% and 51.28%, respectively from milk and meat sample isolates.