High frequency of colonization by diverse clones of beta-lactam-resistant Gram-negative bacilli in haemodialysis: different sources of transmission outside the renal unit?

Abstract

Introduction. While colonization by Staphylococcus aureus in haemodialysis patients has been assessed, knowledge about colonization by beta-lactam-resistant Gram-negative bacilli is still limited. Aim. To describe clinical and molecular characteristics in haemodialysis patients colonized by S. aureus (MSSA-MRSA) and beta-lactam-resistant Gram-negative bacilli in an ambulatory renal unit. Methodology. The study included patients with central venous catheters in an outpatient haemodialysis facility in Medellín, Colombia (October 2017–October 2018). Swab specimens were collected from the nostrils and skin around vascular access to assess colonization by S. aureus (MSSA-MRSA). Stool samples were collected from each patient to evaluate beta-lactam-resistant Gram-negative bacilli colonization. Molecular typing included PFGE, multilocus sequence typing (MLST), spa typing and enterobacterial repetitive intergenic consensus-PCR (ERIC). Clinical information was obtained from medical records and personal interview. Results. A total of 210 patients were included in the study. S. aureus colonization was observed in 33.8 % (n=71) of the patients, 4.8 % (n=10) of which were colonized by methicillin-resistant S. aureus . Stool samples were collected from 165 patients and of these 41.2 % (n=68) and 11.5 % (n=19) were colonized by extended-spectrum-beta-lactamase-producing (ESBL) and carbapenem-resistant bacilli, respectively. Typing methods revealed high genetic diversity among S. aureus and ESBL-producing Gram-negative bacilli (ESBL-GNB). Antibiotic use and hospitalization in the previous 6 months were observed in more than half of the studied population. Conclusion. The high colonization by ESBL-GNB in haemodialysis patients shows evidence for the need for stronger surveillance, not only for S. aureus but also for multidrug-resistant bacilli in order to avoid their spread. Additionally, the high genetic diversity suggests other sources of transmission outside the renal unit instead of horizontal transmission between patients.

High frequency of colonization by extended-spectrum beta-lactamase-producing Gram-negative bacilli in hemodialysis patients and their household contacts in Colombia: dissemination between the community and the hospital

“…The frequency of BR-GNB colonization in hemodialysis patients was similar to that reported in a previous study carried out in hemodialysis patients from the same renal unit, where 41.2% and 11.5% of patients were colonized by ESBL-producing and carbapenem-resistant Gram-negative, respectively [ 4 ]. Our results exceed the prevalence of BR-GNB reported in other studies, such as Wendt et al [ 18 ], of a kidney unit in Germany, where colonization by multi-resistant Gram-negative bacteria was 10.4%.…”

“…of patients colonized by ESBL-producing and carbapenem-resistant Gram-negative bacilli were reported, respectively [4]. Our results exceed the prevalence of BR-GNB reported in other studies, such as Wendt et al, of a kidney unit in Germany, where colonization by multi-resistant Gram-negative bacteria was 10.4%.…”

“…Hemodialysis patients were contacted by telephone from a cohort of a previous study in our research group, who presented previous colonization [ 4 ]. A visit to each home was arranged and, once informed consent had been provided, the clinical and epidemiological information was obtained using a form designed for this purpose.…”

“…Hemodialysis patients present specific clinical characteristics that favor high frequencies of colonization by BR-GNB, even higher than those reported for other bacteria of clinical importance such as Staphylococcus aureus , therefore increasing the risk of infection [ 4 ]. In addition, these patients constantly circulate between hospital and community environments, so they act as carriers of these bacteria for long periods, facilitating their transmission to people with whom they interact closely, such as members of their family and their contacts within the community [ 5 , 6 ].…”

“…Accordingly, hemodialysis patients and their household contacts are a model population to understand the behavior of the colonization of BR-GNB between the hospital environment and the community. Taking into account that Colombia is an endemic country for BR-GNB, and that, particularly in Medellín, colonization by these microorganisms in hemodialysis patients has been reported in up to 52.7% [ 4 ], this study aimed to determine the clinical and epidemiological characteristics of colonization by BR-GNB in hemodialysis patients and their household contacts, in order to reach an understanding of the behavior of colonization between the hospital and the community, and to identify prevention and control strategies to reduce the spread of resistant bacteria.…”