title: Microbial based assay for specific detection of β-lactam group of antibiotics in milk.
abstract: The spore forming Bacillus cereus (66) was screened for the induction of β-lactamase in presence of an inducer using iodometric assay. A significant induction in marker enzyme was observed in B. cereus 66 at maximum residual limit (MRL) of penicillin, ampicillin, cloxacillin, amoxicillin, cefalexin, and cephazolin belonging to β-lactam group of antibiotics. A microbial based assay, where enzyme induction was optimized at pH 7.0, temperature 30°C, and whey powder (0.25%) after 4 h of incubation. The spore based assay was tested with milk samples spiked with 6 different β-lactam antibiotics. The results were 100 and 83.33% in correlation with microbial receptor and inhibition based assay, respectively. Overall, spore based assay can be a useful and cost effective tool for the specific detection of β-lactam group of antibiotics in milk.
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Sougata
authors.initials: S
authors.lastname: Das
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Raghu Hirikyathanahalli
authors.initials: RH
authors.lastname: Vishweswaraiah
authors.affiliation: The ICFAI University, Tripura, Kamalghat Sadar, Agarthala, 799210 West Tripura, India.
authors.forename: Lopamudra
authors.initials: L
authors.lastname: Haldar
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Manju
authors.initials: M
authors.lastname: Gaare
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Vinai Kumar
authors.initials: VK
authors.lastname: Singh
authors.affiliation: Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001 Haryana India.
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Puniya
keywords: Assay; Bacillus; Induction; Spore; β-lactam; β-lactamase