Characterization of bacterial population of raw milk from bovine mastitis by culture-independent PCR–DGGE method

Abstract

Culture-independent PCR-DGGE fingerprinting was used to reveal the bacterial composition and diversity associated with raw milk of mastitis cows from Hokkaido, Japan for the first time. All the mastitis milk samples were diagnosed as solely infection by Coliforms using the classical microbiological method based on on-farm culturing. Our results revealed that the bovine mastitis-associated bacteria were host-specific because community structure varied between each sample. Klebsiella pseudomoniae, Lactococcus lactis Staphylococcus aureus and Escherichia sp were found to be the widely distributed species. Furthermore, more than one mastitis-causing pathogen was found to be present in some mastitis samples. These pathogens may not only act as etiology agents but also play a role in disrupting the natural microbial ecology in mastitis bovine. This finding highlights the limitation of the traditional identification and characterization strategy. Therefore, it is suggested that the methodology applied in this study might be a valuable addition to mastitis control and prevention.

Short communication: Genotypic and phenotypic identification of environmental streptococci and association of Lactococcus lactis ssp. lactis with intramammary infections among different dairy farms

“…Among this 18%, species of Enterococcus and Aerococcus have been well characterized in terms of incidence and role in bovine IMI; however, similar data for Lactococcus spp. are few (Malinowski et al, 2003;Kuang et al, 2009;Plumed-Ferrer et al, 2013). This lack of information could be attributed to limitations in routine procedures used to speciate environmental streptococci and streptococci-like bacteria.…”

Molecular characterization of intercellular adhesion gene in Staphylococcus aureus isolated from bovine mastitic milk

“…In India, mastitis costs approximately US$357 million per year (Vijayakumar 2003). Staphylococcus auerus is the prime etiological agent causing mastitis in bovines (Kalorey et al 2007;Kuang et al 2009). Besides the production of exotoxins and surface proteins (Oliveira et al 2011a;Fijalkowski et al 2011), the formation of highly organized multicellular complexes by bacteria, the biofilms, is increasingly being recognized as an important virulence factor in S. aureus (Oliveira et al 2006;Coelho et al 2011).…”

IgG-dependent aggregation of Staphylococcus aureus inhibits bacteriophage attack

“…aureus is an aggregating species, which easily forms clumps, biofilms, and abscesses. Bacteria growing in a biofilm or aggregate are more resistant to antimicrobial agents than planktonically growing bacteria of the same strain [5,6]; this resistance is at least in part a result of delayed penetration of antimicrobial agents through the biofilm or aggregate matrix [7][8][9]. In the context of mastitis, S. aureus is mainly located in clusters within the lactiferous ducts, in association with epithelial cells [10].…”