Biology Reference
In-Depth Information
Chapter 7
Staphylococcus aureus: Application of a Rapid
Test for Molecular Typing of Strains Isolated
from Bovine Mastitis
P. Cremonesi, V. Benedetti, G. Pisoni, P. Moroni, M. Luini, and B. Castiglioni
Abstract
Staphylococcus aureus
is the most important etiologic agent of conta-
gious mastitis able to produce a number of virulence factors that may play impor-
tant roles in the development of this disease. Recently, a rapid technique based on
the amplification of the 16S-23S rRNA intergenic space (RS-PCR) was developed
for
S. aureus
genotyping The aim of the present study was to characterize certain
strains collected from North Italy herds to verify the presence of a specific genotype
associated in Switzerland with severe clinical expression in the herd. In the 30
strains analyzed, our preliminary results showed the presence of four isolates
similar to Switzerland genotype B and the possibility to link an electrophoretic
profile to a specific pattern of virulence.
Keywords Genotyping • Mastitis •
Staphylococcus aureus
7.1
Introduction
Staphylococcus aureus
is one of the most important causes of clinical and subclini-
cal bovine mastitis and is associated with great economic losses in dairy herds.
Many
S. aureus
strains are able to produce a number of virulence factors that can
destroy and lyse host cellular membranes and cause diseases. These factors include
four distinct
leukocidins, six hemolysins, over 20 different
toxins, and three
P. Cremonesi (
*
) • B. Castiglioni
Istituto di Biologia e Biotecnologia Agraria, CNR, Milano, Italy
e-mail:
cremonesi@ibba.cnr.it
V. Benedetti • M. Luini
Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia (Sezione di Lodi), Lodi, Italy
G. Pisoni • P. Moroni
Dipartimento di Patologia Animale, Igiene e Sanit` Pubblica Veterinaria, Universit` degli Studi di
Milano, Milan, Italy
