Frequency and co-colonization of vancomycin-resistant Enterococci and Candida in ICU-hospitalized children

The intestinal carrier status of Enterococcus spp. in children: clonal diversity and alterations in resistance phenotypes before and after admission to a pediatric intensive care unit

BACKGROUND

This study aimed to investigate the intestinal carrier status of Enterococcus spp. among children in a pediatric intensive care unit (PICU) and reveal the role of hospitalization in the alteration of resistance phenotypes and clonal diversity of the isolates during admission and discharge periods.

METHODS

Two separate stool samples were collected from hospitalized patients in the pediatric intensive care unit at admission and discharge times. The culture was done, and Enterococcus species were tested for antimicrobial susceptibility and carriage of vanA-D gene subtypes. Random Amplified Polymorphic DNA (RAPD)-PCR was used for a phylogenetic study to check the homology of pairs of isolates.

RESULTS

The results showed carriage of Enterococci at admission, discharge, and at both time points in 31%, 28.7%, and 40.1% of the cases, respectively. High frequencies of the fecal Enterococcus isolates with vancomycin-resistance (VR, 32.6% and 41.9%), high-level of gentamicin-resistance (HLGR, 25.6% and 27.9%), and multi-drug resistance phenotypes (MDR, 48.8% and 65.1%) were detected at admission and discharge times, respectively. Resistance to vancomycin, ampicillin, and rifampicin was higher among E. faecium, but resistance to ciprofloxacin was higher in E. faecalis isolates. The increased length of hospital stay was correlated with the carriage of resistant strains to vancomycin, ampicillin, and ciprofloxacin. While the homology of the isolates was low among different patients during hospitalization, identical (9%) and similar (21%) RAPD-PCR patterns were detected between pairs of isolates from each patient.

CONCLUSIONS

The high rate of intestinal carriage of VR, HLGR-, and MDR-Enterococci at admission and during hospitalization in the PICU, and the impact of increased length of hospital stay on the fecal carriage of the resistant strains show the importance of antibiotic stewardship programs to control their transmission and spread in children.

Intestinal colonization of vancomycin-resistant Enterococcus in children admitted to Mofid children's hospital intensive care unit at admission and at discharge

BACKGROUND

This study aimed to investigate the frequency of intestinal colonization by vancomycin-resistant Enterococcus (VRE) carrying vanA and vanB genes in patients at ICU admission and at discharge from ICU in Mofid children's Hospital, Tehran, Iran.

METHOD

Sampling was performed using rectal swabs and vancomycin susceptibility testing for Enterococcus spp. was carried out using a minimum inhibitory concentration (MIC) assay on Muller Hinton Agar (MHA) medium using an E-test kit. The molecular detection of VRE isolates was performed by the PCR method using the vanA and vanB resistance genes.

RESULTS

A total of 234 and 186 non-duplicate rectal swab samples were collected from patients at ICU admission and at discharge from ICU, respectively. Enterococcus spp. was detected in 34.6% (n = 81/234) of rectal swab samples collected from patients at ICU admission, of which 44.4% (n = 36/81) were VRE isolates. In contrast, the prevalence of Enterococcus spp. and VRE isolates among patients at discharge from ICU was 17.7% (n = 33/186) and 57.6% (n = 19/33), respectively. Out of 19 VRE isolated from patients at ICU admission, 4 (21%) and 1 (5.3%) contained vanA and vanB genes, respectively. In contrast, out of 36 VRE isolated from patients at discharge from ICU, 11 (30.5%) were positive for the vanA gene.

CONCLUSION

Results revealed that the prevalence of Enterococcus spp. among patients at ICU admission was high. However, VRE was frequently isolated from patients who were hospitalized for several days in ICUs. The implementation of proper infection control strategies and the use of suitable protocols to guide the appropriate prescribing of antibiotics are necessary.

Regulation of Resistance in Vancomycin-Resistant Enterococci: The VanRS Two-Component System

Vancomycin-resistant enterococci (VRE) are a serious threat to human health, with few treatment options being available. New therapeutics are urgently needed to relieve the health and economic burdens presented by VRE. A potential target for new therapeutics is the VanRS two-component system, which regulates the expression of vancomycin resistance in VRE. VanS is a sensor histidine kinase that detects vancomycin and in turn activates VanR; VanR is a response regulator that, when activated, directs expression of vancomycin-resistance genes. This review of VanRS examines how the expression of vancomycin resistance is regulated, and provides an update on one of the field's most pressing questions: How does VanS sense vancomycin?