Interplay of nasal and rectal carriage of Staphylococcus aureus in intensive care unit patients

Abstract

The aim of this study was to investigate the relationship between nasal and rectal Staphylococcus aureus carriage in intensive care unit (ICU) patients and the occurrence of ICU-acquired infections related to S. aureus carriage. Three hundred and ninety-five patients admitted in ICU were screened for S. aureus nasal and rectal carriages and followed to record S. aureus infections during their stay. S. aureus strains were genotyped by arbitrarily primed PCR, spatyping, microarray and whole genome sequencing. At ICU admission, 112 of 363 (30.9%) patients carried S. aureus including 61 (16.8%) exclusive nasal carriers, 40 (11.0%) combined nasal and rectal carriers and 11 (3.0%) exclusive rectal carriers. The 152 S. aureus isolates from nasal and rectal swabs belonged to 19 clonal complexes (CCs). Patients colonized in both nose and rectum harboured different strains in at least 40% of cases according to arbitrarily primed PCR data. Nasal carriers of CC5 S. aureus had an increased risk of rectal carriage (RR = 1.85, P < .05). S. aureus nasal and rectal carriage was a risk factor of S. aureus ICU-acquired infection (RR = 4.04; 95%CI [1.38-11.76]). Incidence rates of endogenous ICU-acquired infections in exclusive nasal carriers, exclusive rectal carriers and in both nasal and rectal carriers were 0.08 (5/61), 0.09 (1/11) and 0.03 (1/40), respectively (p = 0.47). Rectal swabbing increased the detection of S. aureus carriage and revealed an important diversity of S. aureus strains in ICU patients. Further studies are needed to understand how S. aureus rectal carriage increases the risk of endogenous ICU-acquired infections.

Longitudinal whole-genome based comparison of carriage and infection associated Staphylococcus aureus in northern Australian dialysis clinics

“…Interestingly there is a report that PVL+ strains are easier to remove from carriage sites than PVL-strains [45]. Studies similar to ours, although smaller in scale and with mainly lower resolution genotyping, showed more frequent concordance between carriage strains and infection strains than we observed [46,47]. There have been implementations of S. aureus decolonisation in haemodialysis clients.…”

Staphylococcal trafficking and infection—from ‘nose to gut’ and back

“… 2006 ; Bhalla, Aron and Donskey 2007 ; van Belkum 2016 ; Gagnaire et al . 2017 , 2019 ). For instance, it was shown that diarrheal stools of patients colonized with MRSA have an important impact on the environmental contamination with these multiple drug-resistant variants, and it has even been evidenced that the intestinal tract could provide a potential reservoir for the much feared emergence of vancomycin-resistant S. aureus (Claassen-Weitz et al .…”

“…Importantly, this study documented endogenous infection in patients with both rectal and nasal carriage, or with rectal S. aureus carriage only (Gagnaire et al . 2019 ).…”

Comparative Microbiological and Whole-Genome Analysis of Staphylococcus aureus Populations in the Oro-Nasal Cavities, Skin and Diabetic Foot Ulcers of Patients With Type 2 Diabetes Reveals a Possible Oro-Nasal Reservoir for Ulcer Infection

“…The link between nasal colonization with S. aureus and endogenous infection risk is well documented (Wertheim et al, 2005;Sakr et al, 2018;Gagnaire et al, 2019). Researchers have also reported the recovery of identical S. aureus isolates from the nares and ulcers of 65% of 276 patients with DFUIs based on DNA microarray profiling and concluded that nasal S. aureus colonization may be a significant DFUI risk factor (Dunyach-Remy et al, 2017).…”