Detection of antibiotic resistance genes β-lactamics in bacterial strains isolated from Umbilical Cord Blood Units for transplant

Abstract

Introduction

Among the risks associated with hematopoietic stem cells transplantation of umbilical cord blood are bacterial infections. This becomes dangerous when bacterial sepsis is related to resistance to antibiotics commonly used to eliminate of this type infections. Among the widely used antibiotics are those of the β-lactam family. Among the genes responsible for the resistance are designated “bla genes” which encode for broad-spectrum lactamases. Its detection in the laboratory shown the importance in the manufacture of cord blood units.

Objective

To correlate the antibiotic resistance in bacterial contaminants isolated from Umbilical Cord Blood Units (UCBU), with detection of genes encoding resistance of β-lactamics antibiotics.

Materials and methods

Test of resistance to antibiotics was determined in 107 bacterial strains using disk diffusion method according to the recommendations of “The Clinical and Laboratory Standards Institute (CLSI)” and multiplex amplification by PCR of genes bla_TEM, bla_SHV and bla_CTX-M were performed in order to detect genetic elements associated to antimicrobial resistance tested.

Results

Broad-spectrum penicillins showed lower inhibitory activity on the tested strains. Gene detection by multiplex PCR of encoding antimicrobial resistance (β-lactamases) revealed the presence of bla_–HSV, bla_CTX-M and bla_–TEM genes in most strains tested even when these genes have been reported in Enterobacteriaceae family members.

Conclusions

The genotype detection encoding antibiotic resistance in isolates of UCBU clearly indicates the potential risk of sepsis difficult to eradicate in the patient, if present in a UCBU available for transplant. Additionally, the existence of these genes reveals horizontal transfer events of genetic material between bacteria. So the importance to realize this studies before transplant.