2. It is a Gram-Positive bacterium.
It is an immobil, anaerobic and facultative organism.
Microscopic morphology: Spherical shape.
Biochemical characteristics: It is catalase positive and
oxidase negative bacterium.
This bacterium generate diseases like skin infections,
bacteremias, endocarditis, pneumonia and food poisoning.
3. The most notable virulence factors associated with this
microorganism are the heat-stable enterotoxins that
cause the sporadic food-poisoning syndrome or
foodborne outbreaks
Bacterial resistance:
Is the capacity of bacteria to
withstand the effetcs of Ab
or biocides that are intented
to kill or control them.
MRSA:
It is a strain of Staphylococcus
aureus that is resistant to
treatment with a common class
of antibiotics like penicilins and
cephalosporins.
Virulence factors:
Thermonuclease,
hyaluronidase, lipases, and
hemolysisn which are involved
in tissue invasion of the host.
The responsable for this
resistance is the mecA gene
4. The aim of this study was to determine the
enterotoxigenic potential of MDR S. aureus
isolated from dry catfish sold in some open
markets in Zaria, Nigeria
5. 1. Lisis celular de
globulos rojos y nuclear
de globulos blancos.
2. Con la utilización de
una RNAasa se elimina
el RNA
3. Remoción de
proteínas celulares por
medio de la
precipitación de sales
4. ADN genómico se
concentra y se
desaliniza con la
adición de isopropanol.
6. Tabla 1: Primers usados para detectar genes (enterotoxinas, mecA y 16S)
Fundamento PCR: La técnica involucra
dos primers, que son oligonucleótidos
que se unen a la molécula de ADN e
inician la secuencia. El producto de cada
ciclo sirve como molde para el siguiente y
cada vez se duplican las copias. Los
DNTp´s son los que determinan la
secuencia del ADN
7. Análisis de
huellas
genéticas en
muestras
forenses
Mutagénesis
in vitro.
Herramien-
ta de
análisis para
diferenciar
variaciones
alélicas.
Análisis en la
transcripción
de la
estructura del
ARN.
Clonación
directa
desde ADN
genómico y
cADN.
Análisis para
detectar
presencia de
agentes
infecciosos.
8. Fig. 1: Detección de las enterotoxinas de
S.aureus
Tres cepas diferentes mostraron bandas
correspondientes a los genes de las
enterotoxinas A, C, D y otras dos cepas
diferentes mostraron bandas correspondientes
a los genes de la enterotoxina B.
9. Fig. 2: Detección gen mecA y 16S rDNA.
Las 10 cepas dieron un resultado
positivo para el gen 16S rDNA, y solo 2
para el gen mecA.
10. Jaiswal M, Parveda
M, Amareshwari P,
Bhadoriya SS,
Rathore P, Yadav M,
Nair
AS.
All the isolates tested were positive
for 16S rDNA, confirming that they
belong to the same genus of
Staphylococcus. Unlike phenotypic
identification, 16S rDNA sequencing
provides accurate identification of
isolates with a typical phenotypic
characteristic
Varshney AK,
Mediavilla JR,
Robiou N, Guh A,
Wang X, Gialanella P,
Fries BC.
In this study, 40% of strains studied
were positive for two or more
staphylococcal enterotoxin genes.
All but one strain that showed
phenotypic resistance to multi
antibiotics carried genes for
enterotoxins whereas, those that
were phenotypically susceptible to
antibiotics tested did not show any
band for enterotoxin genes
Prabhu K, Rao S, Rao
V
We detected methicillin resistance
gene (mecA)
in two out the five MDR isolates
tested by PCR
11. In conclusion, these results should
make us have another perspective
of the diseases generated by this
bacterium, this is an example of a
big public health problem. We need
to prevent infections and make
more campaigns to promote and
prevent these diseases and make
people more aware
Detect the presence of resistant
bacterias is really important to know
which antibiotic we can use for the
treatment and is really important to
know the mechanism of virulence of
the bacteriums for example, in this
case, the enterotoxins of the
Staphylococcus aureus to understand
the way and the mechanism of the
disease.
