3. Introduction
Salmonella
Bacteria gram-negative
bacillus
Affects intestinal tract of humans and
other animals
invading the epithelial cells of the small
intestine and macrophages
Range from 0.7 to 1.5 µm
in diamater and from 2 to
5 µm in length.
They possess flagella
which project in all
directions and enable
them to move around.
Rod-shaped
Three-layers:
- outer membrane
- THIN peptidoglycan layer
- inner plasma membrane.
4. Salmonella
It has two species
Genus
Salmonella
bongori
Salmonella
enterica
• Enterica
• Salamae
• Arizonae
• Diarizonae
• houtenae
• indica
Belongs to the family
Enterobacteriaceae
5. Salmonella spreads by
• Via fecal-oral route when animals or
people pass stools
• Consuming food or drink products that
have been contaminated with bacteria
from the feces of infected people or
animals.
• Handling infected meat
• Cleaning up animal droppings and then
eating with your hands or putting your
hands in your mouth without washing
them.
• Salmonella bacteria are not spread by
coughing or sneezing
Salmonella produces
• Salmonellosis
• Thypoid fever
6. Historically the incidence of different
infectious diseases has been high in
Yunnan, one of the minority habitations
in China
The prevalence and incidence of S.
Paratyphi A in Yunnan since 2005 ranked
first in China where the average
incidence rate was ten times higher
compared to other provinces.
7. Multilocus sequence typing
(MLST) is suitable to study
the evolutionary relationships
of the pathogen.
We used PFGE and MLST including antibiotic susceptibility
tests to identify the characteristics and the molecular
features of S. Paratyphi A isolates.
Pulse-field gel electrophoresis
(PFGE) is used for pathogen
molecular typing and shows
high discriminatory power in
epidemiology investigations.
8. GENERAL OBJECTIVE
Study the characteristics of the molecular
epidemiology for S. Paratyphi A isolates in Yunnan
using pulsed-field gel electrophoresis (PFGE) and
the multilocus sequence typing (MLST)
9. Cepas Bacterianas
En el estudio se aislaron
• 349 cepas mediante hemocultivo
• 13 cepas del ambiente (agua
contaminada)
• 4 cepas de los alimentos
• Escherichia coli cepa ATCC
25922 sirvió como control.
Todas las bacterias fueron
identificadas como
Salmonella spp utilizando
Vitek Compact 2 , y lo
confirmaron con prueba
de aglutinación en suero
como S. Paratyphi A.
MATERIALES Y MÉTODOS
10. Se determinó la sensibilidad a los antimicrobianos de todas las cepas utilizando el método
de difusión en disco en agar Mueller-Hinton (MH)
Susceptibilidad
antimicrobiana
Los antibióticos utilizados fueron:
• Ampicilina (AMP)
• Cefotaxima (CTX)
• Ácido nalidíxico (NAL)
• Ciprofloxacina (CIP)
• Trimetoprim /sulfametoxazol (SMZ).
MATERIALES Y MÉTODOS
11. Pulsed-field gel
electrophoresis (PFGE)
• Is a highly discriminative molecular typing technique
that is used in epidemiological studies worldwide.
• By comparing the fingerprints of any two isolates,
one can investigate if they belong to the same strain
(i.e. the two isolates are clonal) or if they are
genetically unrelated.
• PFGE is based upon the variable migration of large
DNA restriction fragments in an electrical field of
alternating polarity.
MATERIALES Y MÉTODOS
12.
13. • Is a procedure for characterizing isolates of bacterial
species using the sequences of internal fragments of
(usually) seven house-keeping genes.
• Approximately 450-500 bp internal fragments of each
gene are used, as these can be accurately sequenced on
both strands using an automated DNA sequencer.
The multilocus sequence
typing (MLST)
MATERIALES Y MÉTODOS
17. AUTHORS WHAT THEY SAID YES OR NO
Goh et al., 2002
During the past few years, the isolation
rates of S. Paratyphi A has increased
throughout South Asia within creased
antimicrobial drug resistance YES
Didelot et al., 2007, 2011;
McClelland et al., 2004
Furthermore, several studies showed the
genomes of S. Paratyphi A were extremely
conserved YES
DISCUSSION
18. AUTHORS WHAT THEY SAID YES OR NO
Lu et al., 2006; Zhou et al.,
2006; Gong et al., 2006; Fu et
al., 2011
Additionally, nalidixic acid resistant
S.Paratyphi A were found highly prevalent
in Shenzhen, China ( Wu et al., 2010 ).
YES
Chandel et al., 2000 Chandel et al. found S. Paratyphi A
resistant to chloramphenicol and
cotrimoxazole increased in India and a
portion of the strains were resistant to
ciprofloxacin
NO
DISCUSSION
19. 1. Some bacteria such as salmonella have
evolved to avoid the effect of antibiotics but has
persisted their ability to be cloned and
transmitted in the middle
CONCLUSIONS
20. 2. The pharmaceutical laboratories have the task
of creating new drugs or methods to counter the
resistance of microorganisms as evidenced in
this case
CONCLUSIONS
21. 3. The bacterial strains could proliferate in
humans for bad manipulation of the food and
water, because they didn’t meet the
requirements of sanitation
CONCLUSIONS
22. 4. S. Paratyphi A could proliferate due to poor
infrastructure, waste like feces and urine
drained in the food crops. The majority of
diseases are caused by not have a proper water
supply system
CONCLUSIONS
