5. Shigella’s resistance 1930 – 1940
Sulfonamides 90 %
Acquisition
of plasmids
Chromosome
mutation
Shigella’s mechanisms
• Production of drug-
inactivating enzymes
• Struggle in the uptake of
the antimicrobial agent
• Less antimicrobial
accumulation
B lactamases
Cefalosporinases
Chloranphenicol
transferases
6. Uncommon in
other animal
species than
humans
Transmission mechanism
Person-to-person
Vehicles
The causative
organism is
frequently found in
water polluted
with human feces
•Diarrhea (often
containingbloodor
mucus)
•Abdominal pain or
cramps
•Fever
•Nausea and vomiting
Shigellosis
Symptoms
7. Objective
To check which organism was
responsible for dysentery
presented in SCWI`s children,
establish it’s transmision
mechanism, and analyze it´s
drug-resistance spectre for
selecting a treatment plan to
avoid it’s spread.
10. qIdentificación de Shigella
Sensititre GNID
32 pruebas bioquímicas con
señal fluorescente para detectar
crecimiento y actividad
enzimática correspondientes a
bacterias Gram -
Serotipificación
Slide
aglutination
Antígeno desconocido
Anticuerpo conocido
Carácterísticas moleculares de
superficie:
Ag K: Cápsula
Ag H: Flagelo
Ag O: Lipopolisacáridos
11. qTest de susceptibilidad
Sistema Vitek 2
64 pozos con sustrato de
prueba individual que
mide hidrólisis,
acidificación,
alcalinización, y
desarrollo en presencia
de sustancias inhibidoras
Pasos:
1. Inoculación
2. Sellado e
incubación
3. Lectura (15 min)
Resultado de
turbiedad
analizados por
Software
Antibióticos contra:
Enterobacterias,
bastones gram – no
fermentadores,
estafilococos,
estreptococos, S.
Pneumoniae,
enterococos.
12. Pfge (electroforesis en gel de campo pulsatil)
Separa fragmentos de DNA con
longitudes mayores a 30 Kb y 2Mb
Gel poroso de Agarosa al 1%
La dirección y la intensidad del campo
se cambia periódicamente (PULSO)
Separación de
moléculas según su
movilidad en un campo
eléctrico según la
carga y el peso Charles CantorDavid C. Schwartz
1984
17. Discussion
REFERENCE STATEMENT
DuPont HL, Levine MM,
Hornick RB, Formal SB.
“The onset of symptoms of
these ill persons occurred
after they stayed with Child
A, indicating this outbreak
was caused by secondary
person-to-person spread of
the Shigella, since as few as
10 Shigella organisms can
cause illnes.”
18. Discussion
REFERENCE STATEMENT
Mahoney FJ, Farley TA,
Burbank DF, Leslie NH,
McFarland LM.
“The case patientes were
only found at the rooms
where Child A have stayed
in, consistent with previous
investigation that duration
of diarrhea may have
increased the risk of
infection for other residents
within the same unit.”
19. Discussion
REFERENCE STATEMENT
Lew JF, Swerdlow DL,
Dance ME, Griffin PM,
Bopp CA, Gillenwater
MJ, et al.
“Multiple vehicles were
identified in the outbreak of
shigellosis caused by S.
felxneri in which food(s)
were implicated.”
20. REFERENCE STATEMENT
Varsano I, Eidlitz-
Marcus T, Nussinovitch
M, Elian I.
“… , the in vitro
antibiotics succeptibility
results were stll
guidelines for selecting
appropriate antibiotics
for treatment.”
Discussion
