Seminario nisseria final
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Transcript of Seminario nisseria final
LUIS DANIEL URIBE MONTOYAMANUELA ZAMBRANO SALDARRIAGA
INTRODUCTION
NEISSERIA
Is a large genus of bacteria that
colonize the mucosal
surfaces of many animals.
Neisseria species are Gram
negative bacteria included among the proteobacteria, a large group of Gram-negative
forms.
Of the 11 species that colonize
humans, only two are pathogens, N. meningitidis and N.
gonorrhoeae.
These two species produce meningitis and gonorrhea respectively.
N. gonorrhoeae has a size ranging between 0.6 and 1 micron in diameter , the average
size of 0.8 microns in diameter. Microorganisms are displayed by light microscopy as intracellular diplococci
within neutrophils.
NEISSERIA GONORRHOEAE
VIRULENCE FACTORS
It only affects
humans.Fimbriae:
high rate of antigenic variation
Can hidrolize
Iga.Leucocidinsβ -
lactamase
Resistance to ampicillin and
first generation cephalosporins
PILI
Penicilinase
PFGEThis electrophoresis use a different size camera, the traditional camera has two positive electrodes and two negatives, this one has four of each this kind of camera is useful for bigger DNA molecules.
OBJECTIVE
This study aimed to ascertain the molecular
epidemiology of circulating gonococci from remote
regional WA over the 3-year period from 2011 to 2013.
MATERIALES Y METODOS
POBLACIÓN
APROBACION ETICA
El estudio no requería aprobación ética porque solo se usaron bacterias, sin embargo “ Western Australian Health Department and the Queen Elizabeth II Medical Centre, Perth el de” manifestaron la aprobación.
VITEK 2
Sistema que utiliza tarjetas con reactivos colorimétricos, las que son inoculadas con la suspensión de un cultivo puro microbiano y el perfil de desarrollo es interpretado de forma automática. Existen 4 tipos:
GN – Bacilos Gram
negativos fermentadores
y no fermentadores
GP - Cocos y bacilos no
formadores de esporas Gram
positivos
YST – Levaduras y organismos
levaduriformes
BCL – Bacilos formadores de esporas Gram
positivos
En el estudio usaron el Vitek 2 para la identificación de colonias bacterianas de la N gonorrhoeae.
MALDI Se usó para la
identificación de colonias
bacterianas de N. gonorrhoeae
La tecnología MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time-of-Flight) examina los patrones de proteínas detectadas directamente de la bacteria intacta.
MALDI PROCEDIMIENTO
La muestra analizada se llama matriz.
La mezcla es aplicada a un plato de metal e irradiada con
una luz laser
La matriz absorbe el laser y vaporiza durante la ionización
Los campos electricos luego guían los iones y se separan
de acuerdo a su masa.
Finalmente la cantidadde cada ion es determinada
Se realiza la detección
PCR
Reacción enzimática in vitro que amplifica millones de veces una secuencia específica de ADN durante varios ciclos
repetidos en los que la secuencia blanco es copiada fielmente. Consiste en aumentar un segmento especifico de ADN usando
la polimerasa, obteniendo miles o millones de copias.
PCRPOSEE 3 PASOS BASICOS
HIBRIDACIÓN
DENATURACIÓN
SINTESIS
PFGE• Se utiliza una corriente eléctrica controlada con la finalidad de
separar biomoléculas según su tamaño y carga eléctrica a través de una matriz gelatinosa.
• Separación de grandes fragmentos de DNA induciendo su reorientación mediante cambios periódicos en el campo eléctrico.
PFGEPROCEDIMIENTO
Cuanto mayor sea el tamaño de los fragmentos a separar, mayor ha de ser la duración de los campos aplicados.
PFGESe diferencia de la electroforesis tradicional por su número de cámaras
Su utilidad es similar a la de la electrophoresis convencional con la salvedad de que los
fragmentos de DNA separados son de mayor tamaño.
SECUENCIACIÓNEs un conjunto de métodos y técnicas bioquímicas cuya finalidad es la determinación del orden de los nucleótidos (A, C, G y T) en un oligonucleótido de ADN.
APLICACIONES:• Procesos biológicos fundamentales• Investigación forense• Mutaciones somáticas• Proyecto genoma humano
SECUENCIACIÓN
TIPOS• Secuenciación por terminador-fluorescente• Secuenciación alelo-específica por bisulfito
Todos los aislamientos fueron confirmados como N. gonorrhoeae por ambos métodos fenotípicos y PCR.
No se identificó susceptibilidad reducida o resistencia a la ceftriaxona.
Se identificó resistencia a la penicilina con mayor frecuencia en aislamientos metropolitanas (23%) en comparación con los
aislados remota región (8%).
RESULTADOS
AUTHOR CITATION AGREED OR DISAGREED
Goire N, Lahra MM, Chen M, Donovan B, Fairley CK, Guy R, et al.
“Neisseria gonorrhoeae, the etiological agent of the sexually transmitted disease gonorrhoea, has emerged as a challenging pathogen due to its propensity to acquire resistance to a wide range of antimicrobial agents. With the world-wide spread of antimicrobial resistant strains, epidemiological surveillance has acquired new importance for the control of gonorrhea.”
AUTHOR CITATION AGREED OR DISAGREED
Speers DJ, Fisk RE, Goire N, Mak DB
“As a result, amoxycillin combined with probenecid remains successful for the empiric management of gonorrhoeae acquired locally in these remote regions.”
AUTHOR CITATION AGREED OR DISAGREED
Lahra MM.
“The remote and indigenous populations of Western Australia (WA), Australia’s largest state by area, have one of the highest notification rates of gonorrhoea in the world yet the circulating gonococci in these populations harbour very low levels of penicillin resistance.”
AUTHOR CITATION AGREED OR DISAGREED
Thakur SD, Levett PN, Horsman GB, Dillon JA.
“Therefore we classified our isolates based on the relatively more conserved tbpB gene as this was more likely to demonstrate linkages over time.”
DISCUSSION
The great diversity observed amongst the NG-MAST types in this study is most likely due to the hyper-variable nature of the target loci, especially the
porB locus, evolving under selection pressure over years.
The tbpB-group based classification identified the presence of four large clusters- namely tbpB-groups 29, 349, 1330 and 1749 which accounted for 67
% percent of all isolates in the study .
The constantly evolving NG-MAST loci are known to undergo changes to their porB and tbpB alleles over relatively short periods of time which would
explain their distribution over a wide range of PT.
MANUELA ZAMBRANO
PERSONAL CONCLUSIONS
This study show us how usefull are some tests as the PCR which is used for the information that it gave us about the batery and the PGFE which is a very specific test that allows the researchers to determinate the bacterian colonies that have a
bigger size DNA.
The preparation of the study takes a lot of importance in the field of public health since gonorrhea is an easily transmittable disease and its increasing the infected population, which is why an investigation about it can give the doctors many tools
for generate p&p campaigns and decrease the infected population.
LUIS DANIEL URIBE
PERSONAL CONCLUSIONS
This kind of investigations are essential for the correct understanding of how a bacteria can mutate and develop a new defense against drugs because this way
we can learn a correct form of treating it.
A correct understanding of how the bacteria propagates and how it interacts with the population of an specific area can hep us to develop more efficient p&p
control.