Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Identification of Enterotoxigenic Coagulase Negative Staphylococcus spp. Isolated from Bovine Milk and Milk Products of Southern Assam, India

Ananya Mohanta1, Pranab Behari Mazumder1*, Amitabh Bhattacharjee2 and Bishwakush Deb1

1Department of Biotechnology, Assam University Silchar, Silchar - 788011, India. 2Department of Microbiology, Assam University Silchar, Silchar - 788011, India.

Received on 06 December 2014 and accepted on 11 January 2015

 

ABSTRACT

Coagulase negative staphylococci (CNS) have been frequently isolated from milk and milk products but the pathogenicity of CNS has long been underrated.The objective of this study was to detect the presence of the classical enterotoxin genes sea,seb, sec in CNS and identify the strains that harboured these genes. 50 CNS isolates were selected for the present study. 27 out of these 50 isolates (54%) tested positive for the enterotoxin genes with sec being the most predominant followed by sea and seb. On the basis of their phenotypic characters, 5 representative isolates were selected for 16S r RNA gene sequencing for identification and their phylogenetic relationship was studied. The enterotoxin gene harbouring CNS strains were identified as Staphylococcus succinus, Staphylococcus sciuri, Staphylococcus kloosii and Staphylococcus saprophyticus. The present study confirms the enterotoxin producing capability of the coagulase negative group of Staphylococcus and emphasizes the need for their precise identification in order to devise appropriate measures in controlling the pathogens.

Keywords : Coagulase negative staphylococci, bovine milk, milk products, enterotoxin genes, 16S r RNA.