Bloodstream infections caused by multidrug-resistant gram-negative bacteria: epidemiological, clinical and microbiological features

Helena Ferreira Leal,Joice Neves Reis,Giulyana Evelyn Oliveira Silva,Jailton Azevedo,Ana Carolina Palmeira Arraes,Ana Verena Mendes,Edilane Lins Gouveia,Angelica Maria Lima Amorim,Ianick Souto Martins,Mitermayer Galvão Reis,Maria Goreth Barberino,Marcio De Oliveira Silva,Larissa Rangel Cabral De Roma

doi:10.1186/s12879-019-4265-z

Abstract

BackgroundBloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB).MethodsWe conducted a laboratory-based surveillance for gram-negative bacteremia over a 1-year period. The bacterial isolates were identified by MALDI-TOF/MS and the antimicrobial susceptibility testing was performed by VITEK®2. Resistance genes were identified through PCR assays.ResultsOf the 143 patients, 28.7% had infections caused by MDR-GNB. The risk factors for MDR bacteremia were male sex, age ≥ 60, previous antimicrobial use, liver disease and bacteremia caused by K. pneumoniae. K. pneumoniae was the most frequently observed causative agent and had the highest resistance level. Regarding the resistance determinants, SHV, TEM, OXA-1-like and CTX-M-gp1 were predominant enzymatic variants, whereas CTX-M-gp9, CTX-M-gp2, KPC, VIM, GES, OXA-48-like, NDM and OXA-23-like were considered emerging enzymes.ConclusionsHere we demonstrate that clinically relevant antibiotic resistance genes are prevalent in this setting. We hope our findings support the development of intervention measures by policy makers and healthcare professionals to face antibiotic resistance.

Highlights

Bloodstream infections (BSI) are associated with high morbidity and mortality
We found that the male sex, age ≥ 60, previous antimicrobial therapy, liver disease and bacteremia caused by K. pneumoniae were independent factors associated with multidrug resistance (MDR) infection
In summary, we found that the factors associated with MDR bacteremia were liver disease, male sex, age ≥ 60, previous therapeutic antimicrobial use and bacteremia caused by K. pneumoniae

Summary

Introduction

Bloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB). Bloodstream infections (BSI) are characterized as severe disorders since they are acute events and usually result in serious life-threatening organ dysfunctions, such as sepsis and septic shock [1, 2]. Sepsis is considered to be a public health issue and is a leading cause of mortality worldwide, being recently listed as a global health priority. Many studies tackling the antibiotic resistance rely on the problem of screening resistant isolates solely, which may substantially affect susceptibility reports, representing a strong bias towards resistance [18]

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