Is it worth screening for vancomycin-resistant Enterococcus faecium colonization?: Financial burden of screening in a developing country

Cessation of Rectal Screening for Vancomycin-Resistant Enterococci: Experience from a Tertiary Care Hospital from Türkiye

OBJECTIVE

Here, we compared the impact of different polices on the epidemiology of Vancomycin-resistant Enterococcus faecium bloodstream infections (VRE-BSIs) in a tertiary care hospital including two hospital buildings (oncology and adult hospitals) in the same campus.

MATERIAL AND METHODS

All patients who were hospitalized in high-risk units were screened weekly for VRE colonization via rectal swab between January 2006 and January 2013. After January 2013, VRE screening was only performed in cases of suspicion of VRE outbreak and during point prevalence studies to evaluate the epidemiology of VRE colonization. Contact precautions were in place for all VRE-positive patients. The incidence density rates of hospital-acquired (HA)-VRE-BSIs were compared between two periods.

RESULTS

While the rate of VRE colonization was higher in the second period (5% vs. 9.5% (p < 0.01) for the adult hospital, and 6.4% vs. 12% (p = 0.02 for the oncology hospital), there was no increase in the incidence rate HA-VRE BSIs after the cessation of routine rectal screening in either of the hospitals.

CONCLUSION

Screening policies should be dynamic and individualized according to the epidemiology of VRE as well as the workforce and cost. Periodical rectal screening of VRE can be discontinued if suspicion of an outbreak can be carefully monitored.

Should Perirectal Swab Culture Be Performed in Cases Admitted to the Neonatal Intensive Care Unit? Lessons Learned from the Neonatal Intensive Care Unit

Serial perirectal swabs are used to identify colonization of multidrug-resistant bacteria and prevent spread. The purpose of this study was to determine colonization with carbapenem-resistant Enterobacterales (CRE) and vancomycin-resistant Enterococci (VRE). An additional purpose was to establish whether sepsis and epidemic associated with these factors were present in the neonatal intensive care unit (NICU), to which infants with hospital stays exceeding 48 h in an external healthcare center NICU were admitted. Perirectal swab samples were collected in the first 24 h by a trained infection nurse using sterile cotton swabs moistened with 0.9% NaCl from patients admitted to our unit after hospitalization exceeding 48 h in an external center. The primary outcome was positivity in perirectal swab cultures, and the secondary outcomes were whether this caused invasive infection and significant NICU outbreaks. A total of 125 newborns meeting the study criteria referred from external healthcare centers between January 2018 and January 2022 were enrolled. Analysis revealed that CRE constituted 27.2% of perirectal swab positivity and VRE 4.8%, and that one in every 4.4 infants included in the study exhibited perirectal swab positivity. The detection of colonization by these microorganisms, and including them within the scope of surveillance, is an important factor in the prevention of NICU epidemics.

Distinguishing Clinical Enterococcus faecium Strains and Resistance to Vancomycin Using a Simple In-House Screening Test

Vancomycin-resistant enterococci (VRE) are a major concern as microorganisms with antimicrobial resistance and as a public health threat contributing significantly to morbidity, mortality, and socio-economic costs. Among VREs, vancomycin-resistant Enterococcus faecium (VREfm) is frequently isolated and is resistant to many antibiotics used to treat patients with hospital-acquired infection. Accurate and rapid detection of VREfm results in effective antimicrobial therapy, immediate patient isolation, dissemination control, and appropriate disinfection measures. An in-house VREfm screening broth was developed and compared to the broth microdilution method and multiplex polymerase chain reaction for the detection of 105 enterococci, including 81 VRE isolates (61 E. faecium, 5 E. faecalis, 10 E. gallinarum, and 5 E. casseliflavus). Verification of this screening broth on 61 VREfm, 20 other VRE, and 24 non-VRE revealed greater validity for VREfm detection. The accuracy of this broth was 100% in distinguishing E. faecium from other enterococcal species. Our test revealed 93.3% accuracy, 97.5% sensitivity, and 79.2% specificity compared with broth microdilution and PCR detecting van genes. The kappa statistic to test interrater reliability was 0.8, revealing substantial agreement for this screening test to the broth microdilution method. In addition, the in-house VREfm screening broth produced rapid positivity after at least 8 h of incubation. Application of this assay to screen VREfm should be useful in clinical laboratories and hospital infection control units.

Molecular epidemiology of vancomycin-resistant Enterococcus faecium clinical isolates in a tertiary care hospital in southern Thailand: a retrospective study

Objective

Vancomycin-resistant enterococci are nosocomial pathogens that are responsible for commonly causing healthcare-associated infections, and they exhibit increased resistance to many antimicrobials, particularly to vancomycin. The epidemiological data available on vancomycin-resistant enterococci (VRE) in Thailand are inadequate.

Methods

Using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR), this study investigated genes that encode antimicrobial resistance and genetic relatedness to further understand VRE prevalence. Ninety VRE isolates were collected between 2011 and 2019 from a tertiary care hospital in southern Thailand. Antimicrobial susceptibility was determined using the disk diffusion method and E-test methods. Multiplex PCR was performed to detect the van gene and virulence genes.

Results

The study showed a high prevalence of diverse multidrug-resistant VRE strains. The prevalence of VRE infection was the highest in 2014 (28 isolates, 39.4%). VRE were mostly found in the urogenital tract (26 isolates, 28.9%), followed by the digestive tract (20%), body fluid, i.e., pancreatic cyst fluid, peritoneal dialysis fluid, Jackson–Pratt (JP) drain (20%), and blood specimens (10%). Patients in medical and surgical wards had 71.1% multi-drug-resistant and 28.9% extensively drug-resistant (XDR) VRE strains, respectively. The most prevalent antibiotic resistance was to ampicillin (74.4%). Susceptibility to gentamicin and meropenem were similar (7% and 10%, respectively). Four isolates (4.4%) were resistant to colistin. Only vanA was detected among the strains. The virulence gene test showed that the detection rates of enterococcal surface protein (esp) and hyaluronidase (hyl) genes were 91.1% and 5.6%, respectively. According to ERIC-PCR analysis, 51 of 90 strains had clonality, with a similarity rate of 95%.

Conclusions

We conclude that there is a need to implement infection control practices and active surveillance. Molecular techniques can effectively detect antibiotic-resistant genes, which would allow monitoring to control VRE infection in hospitals.

Real-time PCR for the rapid detection of vanA, vanB and vanM genes

BACKGROUND/PURPOSE

To evaluate the ability of quadruple Taqman probe real-time PCR to the detection of vanA, vanB and vanM in enterococcal isolates.

METHODS

A total of 343 strains, including 253 vancomycin-resistant enterococcus (VRE) strains and 90 non-VRE strains, were tested by both quadruple Taqman probe real-time PCR and gel-based PCR assay.

RESULTS

When differentiating among three genotypes of vanA, vanB and vanM in VRE strains, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy and consistency of the quadruple Taqman probe real-time PCR were all 100%. Minimum. Inhibitory concentration (MIC) results showed that there was a wide MIC range of vancomycin and teicoplanin for the strains that harboring vanA/vanM gene respectively or harboring vanA and vanM genes simultaneously. However, the VRE strains with vanB genotype all were sensitive to teicoplanin.

CONCLUSION

Considering the excellent PPV and low NPV, real-time PCR would be useful to monitor VRE-colonized or infected patients. However, further evaluation of the assay's performance in the clinical specimens is required, especially when considering that high level of PCR inhibitors present in these samples.

Evaluation of a matrix-assisted laser desorption ionization-time of flight mass spectrometry assisted, selective broth method to screen for vancomycin-resistant enterococci in patients at high risk

BACKGROUND

Bile esculin azide with vancomycin (BEAV) medium is a sensitive, but slightly less specific method for vancomycin-resistant enterococci (VRE) screening. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid method for identification of clinical pathogens. This study aimed to assess the performance of a novel combination screening test for VRE, using BEAV broth combined with MALDI-TOF MS.

MATERIALS AND METHODS

Clinical specimens were collected from patients at risk of VRE carriage, and tested by the novel combination method, using selective BEAV broth culture method followed by MALDI-TOF MS identification (SBEAVM). The reference method used for comparison was the ChromID VRE agar method.

RESULTS

A total of 135 specimens were collected from 78 patients, and 63 specimens tested positive for VRE positive using the ChromID VRE method (positive rate 46.7%). The sensitivity, specificity, positive predictive value, and negative predictive value of SBEAVM method after an incubation period of 28 hours were 93.7%, 90.3%, 89.4%, and 94.2%, respectively. The SBEAVM method when compared to the ChromID VRE method had a shorter turnaround time (29 vs. 48-72 hours) and lower laboratory cost ($2.11 vs. $3.23 per test).

CONCLUSIONS

This study demonstrates that SBEAVM is a rapid, inexpensive, and accurate method for use in VRE screening.

Vancomycin-resistant enterococci colonisation, risk factors and risk for infection among hospitalised paediatric patients: a systematic review and meta-analysis

The objective of this study was to estimate the rate and significance of colonisation with vancomycin-resistant enterococci (VRE) among hospitalised children. The PubMed and EMBASE databases were systematically searched (last accessed on 29 May 2016) to identify studies evaluating VRE colonisation of the gastrointestinal tract of hospitalised children in non-outbreak periods. Of 945 non-duplicate citations, 19 studies enrolling 20 234 children were included. The overall and paediatric intensive care unit (PICU) rate of VRE colonisation were both 5% [95% confidence interval (CI) 3-8% overall and 95% CI 2-9% in the PICU] but was 23% in haematology/oncology units (95% CI 18-29%). Studies that were exclusively performed in haematology/oncology units reported significantly higher rates compared with all other studies in the univariate and multivariate analyses (P = 0.001). Previous vancomycin [risk ratio (RR) = 4.34, 95% CI 2.77-6.82] or ceftazidime (RR = 4.15, 95% CI 2.69-6.40) use was a risk factor for VRE colonisation. Importantly, VRE colonisation increased the risk of subsequent VRE infection (RR = 8.75, 95% CI 3.19-23.97). In conclusion, a high rate of VRE colonisation was found among hospitalised children in institutions that performed targeted screening. Importantly, colonised children were almost 9 times more likely to develop subsequent VRE infection. Judicious use of specific antibiotics along with intensification of infection control measures should be considered in high-prevalence institutions. Also, the high incidence of VRE colonisation among children with haematological/oncological diseases identifies a high-risk population.

Detection of vancomycin-resistant enterococci (VRE) in stool specimens submitted for Clostridium difficile toxin testing

The aim of this study was to determine the association between Clostridium difficile (C. difficile) and vancomycin-resistant Enterococcus (VRE) and efficacy of screening stools submitted for C. difficile toxin assay for prevalence of VRE. Between April 2012 and February 2014, 158 stool samples submitted for C. difficile toxin to the Marmara University Microbiology Laboratory, were included in the study. Stool samples were analyzed by enzyme immuno assay test; VIDAS (bioMerieux, France) for Toxin A&B. Samples were inoculated on chromID VRE (bioMerieux, France) and incubated 24 h at 37 °C. Manuel tests and API20 STREP (bioMerieux, France) test were used to identify the Enterococci species. After the species identification, vancomycin and teicoplanin MIC's were performed by E test and molecular resistance genes for vanA vs vanB were detected by polymerase chain reaction (PCR). Of the 158 stool samples, 88 were toxin positive. The prevalence of VRE was 17%(n:19) in toxin positives however, 11.4% in toxin negatives(n:70). All VRE isolates were identified as Enterococcus faecium. These results were evaluated according to Fischer's exact chi-square test and p value between VRE colonization and C. difficile toxin positivity was detected 0.047 (p < 0.05). PPV and NPV were 79% and 47% respectively. In our study, the presence of VRE in C. difficile toxin positives is statistically significant compared with toxin negatives (p < 0.05). Screening for VRE is both additional cost and work load for the laboratories. Therefore VRE screening among C. difficile toxin positive samples, will be cost effective for determination of high risk patients in the hospitals especially for developing countries.

Epidemiology and cost implications of candidemia, a 6-year analysis from a developing country

Surveillance of candidemia is essential to monitor trends in species distribution and change in the incidence and antifungal resistance. In this study, we aimed to investigate prevalence, resistance rates, antifungal utilization and costs. A 6-year retrospective analysis of the data belonging to patients with candidemia hospitalized between 2010 and 2016 was performed. The annual usage of fluconazole and caspofungin and the usage of these antifungals in different units were described in defined daily doses (DDD) per 1000 patient days. In total, 351 patients of candidemia were included. Median age of the patients was 45 (0-88) and 55.1% of them were male. Overall, 48.1% of the candidemia episodes (169/351) were due to C. albicans, followed by C. parapsilosis (25.1%), C. glabrata (11.7%). Length of hospital stay was longer with a median of 20 days among patients with non-albicans candidemia. Presence of a central venous catheter was found to be an associated risk for candidemia caused by non-albicans strains. Annual incidence of candidemia increased from 0.10 to 0.30 cases/1000 patient days. Antifungal use was increased over years correlated with the cost paid for it. The policy against candidemia should be specified by each institution with respect to candidemia prevalence, resistance rates, antifungal use and costs.