Tamilselvam Batcha - Streptococcus uberis internalizes and persists in bovine mammary epithelial cells

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      Publication Details (including relevant citation   information):

      Microb Pathog. 2006   Jun;40(6):279-85. Epub 2006 May 5.


      Streptococcus uberis is one of the most important emerging bovine   mastitis pathogens and chronic persistent intramammary infections   (IMI) are often described. To define the ability of S. uberis to   persist intracellularly, studies on time-dependent   internalization and survival of S. uberis strains in bovine   mammary epithelial cells were conducted. Two S. uberis strains   (UT366 and UT888) and a Staphylococcus aureus strain used as   positive control, all isolated from cows with clinical mastitis   were cocultured with bovine mammary epithelial cells (MAC-T) and   persistent survival in host epithelial cells for extended periods   (120 h) studied. Of S. uberis strains tested, UT366 showed   highest internalization values at 60 min of incubation whereas at   8 h of incubation the corresponding values for UT888 were the   highest. Of both strains of S. uberis tested, UT366 seems to   internalize bovine mammary cells more efficiently initially,   however, during the first 8 h, UT888 seems to survive   intracellularly better than UT366. Results showed that both S.   uberis strains could survive intracellularly up to 120 h without   apparent loss of host cells viability. S. aureus internalized   more efficiently than all strains tested and host cell death was   observed after 72 h of incubation. These results indicate that S.   uberis can survive within mammary epithelial cells for extended   time without apparent loss of host cells viability. Intracellular   persistence of S. uberis may be associated with the spread of the   infection to deeper tissues and development of persistent IMI.

      Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/16678381