Antimicrobial susceptibility and genetic similarity of ESBL-Positive Klebsiella

pneumoniae strainsAlicja Sekowska, Eugenia Gospodarek,

Dorota Kaminska

Valentina Ortega – Andrés Monsalve

K. Pneumoniae

• Name after Edwin Klebs (also known as Friedländer’s bacilo.)

• Enterobacteriaceae• Gramm negative• Moist Cultives• Inmunosupression • Causes infections such as Pneumonia

ESBL (Extended-spectrum beta-lactamase)

• ESBL: Enzymes that hidrolizes extended-spectrum cephalosporins with an oxyimino side chain. – TEM beta-lactamases (class A): Also responsible

for the ampicillin and penicillin resistance– SHV beta-lactamases (class A): 20% of the

plasmid-mediated ampicillin resistance– CTX-M beta-lactamases (class A)– OXA beta-lactamases (class D)

Introduction

•Klebsiella Pneumoniae is important to study because its rods can cause nosocomial infections especially at pediatric units.

•β-Lactamases (ESBL, AmpC, MBL, KPC) are the most frequent source of resistance to antibiotics.

•This bacteria is one of the most frequent ESBL producers.

•Treatment is really difficult because of the strains multidrug resistance. (Antibiotics not recommended in children.

General Objective

To evaluate antimicrobial susceptibility and genetic similarity of ESBL-positive K. Pneumoniae strains

isolated from colonization and infections from children.

Materiales y Métodos

28 cepas de K. Pneumoniae aisladas de 18 niños

Aislación e identificación usando métodos de rutina en el laboratorio

Suceptibilidad antimicrobiana de Gentamicina y Ciprofloxacina por Método de dilución en agar

La MIC para Imipenem y tigecycline fue determinada por Etest

Materiales y Métodos

Los “Breakpoints” de suceptibilidad de los AB fueron tomados de ECAST

Capacidad de producir ESBL determinada por 2 discos y el método EUCAST

Relación genética evaluada con PFGE usando enzima Xbal.

Conceptos

• PFGE: Para separar el ADN de acuerdo a su tamaño aplicando un campo electrico a un gel que periódicamente cambia de dirección

• MIC (minimum inhibitory concentration): Concentración mas baja de un antimicrobiano que inhibirá el crecimiento visible de un microorganismo después de la incubación nocturna.

Conceptos: Etest®

• Predefinido, gradiente estable de concentraciones de 15 antibioticos en un tiras de plástico.

• Sirve para determinar MIC.• Uso para determinar resistencia a un

antibiótico.• Corrobar.• Probar nuevos fármacos.

Resultados

Imipiden revelo alta actividad con MIC 50=o,19 mg/L ciprofloxacina reveló una baja actividad a MIC50=2 mg/L -16 mg/L

Resultados

De acuerdo a PFGE

• 7 cepas identicas (Grupo A)• 9 cepas estrechamente relacionadas(Grupo B)• 4 cepsas posiblemente relacionadas (Grupo C)• 8 cepas no relacionadas entre si (Grupo D)

6 cepas mostraron 95% de similaridad de acuerdo con el MAF.

DiscusiónBagattini et al.

In these studies, it can see the ability of strains with different resistance mechanisms to survive in the hospital environment. Also Differences between MIC values for antibiotics of K. pneumoniae strains isolated from the same patient may suggest that survival of strains in a human body facilitates development of drug resistance during antibiotic therapy.

Demirdag and Hosoglu [2], Dzierża -nowska et al. [3] and Ktari et al. [11]

The studies show that certain K. pneumoniae strains survive in the clinic environment in which colonised patients or patients infected with these bacilli stayed. From the results it was deduced that strains classified in the same group on the grounds of chromosomal DNA patterns can have different drug sensitivity profiles.

Mapa Conceptual

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