seminario biología molecular
TRANSCRIPT
Texto adicional Texto adicional
Texto adicional texto adicional
Texto adicional texto adicional
Erika Julieth Salazar JiménezAndrea Vanegas.Universidad Pontificia Bolivariana Facultad de Medicina3th Semester
Molecular analysis and antimicrobial resistance of Salmonella isolates recovered from raw meat
marketed in the area of ‘‘Grand Tunis’’, Tunisia
Abbassi-Ghozzi , A. Jaouani , S. Hammami , J. Martinez-Urtaza , A. Boudabous , M. Gtari ,*
Introduction
Salmonella
• Bacteria gram negative, anaerobic• Gender: Salmonella• Family: enterobacteriaceae
• Universal distribution zoonotic agent
• Is one of the most common cause of food borne infections ( principally animal products) to humans
• It can be transmitted by direct contact through fomites, but the most frequent cross-contamination during handling, processing or eating food, or water contaminated
Bacterial resistance
Mechanism by which bacteria can reduce part or all of the action of antimicrobial agents, generated by the indiscriminate and irrational use of these and the evolutionary pressure exerted on the therapeutic use.
Types of Bacterial resistance
• Intrinsic Resistance: develops naturally in the absence of selection pressure mechanism of antimicrobial (no prior exposure to antibiotics).
• Acdquire Resistance: From the genetic point of view, acquired resistance may be a temporary phenomenon (also called adaptive) as it depends on the growth conditions of the germ.
The relation between Salmonella / bacterial resistance is:
Salmonella are showingtrends toward increasing resistance to standard available therapiesin both developed and developing countries
Salmonella are showing trends toward increasing resistance to standard available therapiesin both developed and developing countries
Salmonella/Bacterial resistance
The objective of this study was to assess the genetic diversity and antimicrobial resistance of Salmonella in contaminated raw meat products.
Objective
Materiales y métodos
• De 315 muestras de carne cruda Se recolectaron 80 muestras con Salmonella provenientes principalmente del pollo (48.3%), carne de res ( 29.8%), carne picada (10.7%) y en cordero (6%)
• # de cepas : 33
• # Serotipos : 9
• Con predominancia en: salmonella typhimurium seguido de Salmonella Kentucky( demostró mayor resistencia bacteriana), Salmonella Suberu ,Salmonella Zanzibar, SalmonellaNewlands, Salmonella Orion, Salmonella Enteritidis, Salmonella Amsterdam y Salmonella Neumuenster.
• Se sometieron las muestras a métodos bacteriológicos y serológicos.
Materiales y métodos
• Serotipificación: detecta antígenos.
• Suceptibiidad antimicrobiana:los islotes fueron evaluados por suceptibilidad a 16 agentes antimicrobianos por difusión en disco del antimicrobiano se utilizaron los siguientes discos: amikacin, apramycin, amoxicilin- clavulanicacid, ampicilin, chloranphenicol,cefoperazone, ceftazidine, colistin,furazolidone, gentamicin, nalidixiz acid, neomycin, streptpmycin ( entre otros).
Materiales y métodos
• PFGE: La PFGE separa fragmentos cromosómicos que no pueden ser separados por el método convencional uni-direccional de electroforesis
Fundamento
¿Para que se realizó esta técnica?
Materiales y métodos
• Analisis de plasmidos: El análisis de plásmidos tiene como objetivos detectar su presencia y/o establecer la relación entre ellos. Tamaño, rango de hospedador (presencia en una o diferentes especies y géneros), número de copias por célula, capacidad de transferirse
Fundamento : cepa de bacterias-centrifugacion-extraccion del ADN plasmidico- purificación-electroforesis
Para que se realizó esta técnica?
Materiales y métodos
Tabla 1 Aislamiento de la frecuencia de Salmonella en muestras de alimentos.
Resultados
Resultados
tabla 2Distribución de los serotipos de Salmonella.
Resultados
Figura 1. representa un dendrograma basado en la combinación de losserotipos, los tipos de PFGE, perfiles de plásmidos y patrones de resistencia a antimicrobianos
DiscussionAUTOR QUE DIJO ESTA DE ACUERDO O NO
Rose BE, Hill WE, Umholtz R, Ransom GM, James WO.
Is common the contamination of paultry products with salmonella
si
Gatto AJ, Peter TM, Green J, Fisher IS, Gill ON, O’brien SJ, et al
Salmonella species are recognised as major foodborne pathogens in human worldwide
si
Zerrin A, Martin D, Cigdem BK, Sukufe D, Threlfall
The predominant serovars change overtime and differ from geographical area to another.
si
D’Aoust JY, Sewell AM, Daley E, Greco P and Setti I, Rodriguez-Castro A, Pata MP, Cadarso-Suarez C, Yacoubi B, Bensmael L, et al.
In a range of 28.8%-50% and almost 50% respectively of examinated islotes were antimicrobial resistant
si
Conclussions
• PFGE is very discriminative marker because it is very sensitive to the existing microvariation a collection of strains. It allows us to look at the number of genetic changes that reflects the difference between the patterns obtained. In addition to having utility in the analysis and comparison of isolates from different geographical areas and their evolution over time.
• This analysis could be used to modify therapies for salmonellosis or other infections incited by other pathogens analysed as this way.
• The food that doesn´t have a grate manipulation could became an important and dangerous carrier for pathogens like salmonella.
• Antimicrobial resistance, in this case the salmonellosis constitutes a serious public health problem that has affected the more developed countries to those that are not.
MARTINEZ S, Lina María. Biología molecular. 3 ed. Medellín: UPB. Fac. de Medicina
Bibliography
MEDINA, Jesús. Guía de antimicrobianos y tratamiento de las infecciones. 2 ed. Editorial Díaz de Santos.Pag.59
Jawetz, Melnick, Adelberg, MICROBIOLOGIA MÉDICA, Edition 18th. Manual moderno editorial
http://www.seimc.org/documentos/protocolos/microbiologia/cap18.htm
Andrea Vanegas
Erika Salazar
THANKS