Temporal and Geographic Variation in Antimicrobial Susceptibility and Resistance Patterns of Enterococci: Results From the SENTRY Antimicrobial Surveillance Program, 1997-2016

Analysis of molecular epidemiological characteristics and antimicrobial susceptibility of vancomycin-resistant and linezolid-resistant Enterococcus in China

BACKGROUND

This study investigates the distribution and characteristics of linezolid and vancomycin susceptibilities among Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and explores the underlying resistance mechanisms.

METHODS

A total of 2842 Enterococcus clinical isolates from patients were retrospectively collected, and their clinical data were further analyzed. The minimum inhibitory concentrations (MICs) of vancomycin and linezolid were validated by broth dilution method. The resistance genes optrA, cfr, vanA, vanB and vanM were investigated using polymerase chain reaction (PCR). Housekeeping genes and resistance genes were obtianed through whole-genome sequencing (WGS).

RESULTS

Of the 2842 Enterococcus isolates, 88.5% (2516) originated from urine, with E. faecium accounted for 60.1% of these. The vanA gene was identified in 27/28 vancomycin resistant Enterococcus (VRE) isolates, 4 of which carried both vanA and vanM genes. The remaining strain was vanM positive. The optrA gene was identified in all E. faecalis isolates among linezolid resistant Enterococcus (LRE). E. faecium showed a higher multiple antibiotic resistance index (MAR index) compared to E. faecalis. The multi-locus sequence typing (MLST) showed the sequence type of E. faecium mainly belongs to clonal complex (CC) 17, nearly E. faecalis isolates analyzed were differentiated into 7 characteristics of sequence types (STs), among which ST16 of CC16 were the major lineage.

CONCLUSION

Urine was the primary source of VRE and LRE isolates in this study. E. faecium showed higher levels of resistance compared to E. faecalis. OptrA gene was detected in 91.6% of LRE, which could explain linezolid resistance, and van genes were detected in all vancomycin resistant Enterococcus strains, while vanA was a key resistance mechanism in VRE identified in this study.

ESKAPE pathogens: antimicrobial resistance, epidemiology, clinical impact and therapeutics

The rise of antibiotic resistance and a dwindling antimicrobial pipeline have been recognized as emerging threats to public health. The ESKAPE pathogens - Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. - were initially identified as critical multidrug-resistant bacteria for which effective therapies were rapidly needed. Now, entering the third decade of the twenty-first century, and despite the introduction of several new antibiotics and antibiotic adjuvants, such as novel β-lactamase inhibitors, these organisms continue to represent major therapeutic challenges. These bacteria share several key biological features, including adaptations for survival in the modern health-care setting, diverse methods for acquiring resistance determinants and the dissemination of successful high-risk clones around the world. With the advent of next-generation sequencing, novel tools to track and combat the spread of these organisms have rapidly evolved, as well as renewed interest in non-traditional antibiotic approaches. In this Review, we explore the current epidemiology and clinical impact of this important group of bacterial pathogens and discuss relevant mechanisms of resistance to recently introduced antibiotics that affect their use in clinical settings. Furthermore, we discuss emerging therapeutic strategies needed for effective patient care in the era of widespread antimicrobial resistance.

Surveillance of vancomycin-resistant enterococci reveals shift in dominating clusters from vanA to vanB Enterococcus faecium clusters, Denmark, 2015 to 2022

BackgroundVancomycin-resistant enterococci (VRE) are increasing in Denmark and Europe. Linezolid and vancomycin-resistant enterococci (LVRE) are of concern, as treatment options are limited. Vancomycin-variable enterococci (VVE) harbour the vanA gene complex but are phenotypically vancomycin-susceptible.AimThe aim was to describe clonal shifts for VRE and VVE in Denmark between 2015 and 2022 and to investigate genotypic linezolid resistance among the VRE and VVE.MethodsFrom 2015 to 2022, 4,090 Danish clinical VRE and VVE isolates were whole genome sequenced. We extracted vancomycin resistance genes and sequence types (STs) from the sequencing data and performed core genome multilocus sequence typing (cgMLST) analysis for Enterococcus faecium. All isolates were tested for the presence of mutations or genes encoding linezolid resistance.ResultsIn total 99% of the VRE and VVE isolates were E. faecium. From 2015 through 2019, 91.1% of the VRE and VVE were vanA E. faecium. During 2020, to the number of vanB E. faecium increased to 254 of 509 VRE and VVE isolates. Between 2015 and 2022, seven E. faecium clusters dominated: ST80-CT14 vanA, ST117-CT24 vanA, ST203-CT859 vanA, ST1421-CT1134 vanA (VVE cluster), ST80-CT1064 vanA/vanB, ST117-CT36 vanB and ST80-CT2406 vanB. We detected 35 linezolid vancomycin-resistant E. faecium and eight linezolid-resistant VVEfm.ConclusionFrom 2015 to 2022, the numbers of VRE and VVE increased. The spread of the VVE cluster ST1421-CT1134 vanA E. faecium in Denmark is a concern, especially since VVE diagnostics are challenging. The finding of LVRE, although in small numbers, ia also a concern, as treatment options are limited.

The Impact of Enterococcus spp. in the Immunocompromised Host: A Comprehensive Review

The immunocompromised host is usually vulnerable to infectious diseases due to broad-spectrum treatments and immunological dysregulation. The Enterococcus genus consists of normal gut commensals, which acquire a leading role in infective processes among individuals with compromised immune systems. These microorganisms may express a potential virulence and resistance spectrum, enabling their function as severe pathogens. The Enterococcus spp. infections in immunocompromised hosts appear to be difficult to resolve due to the immunological response impairment and the possibility of facing antimicrobial-resistant strains. As regards the related risk factors, several data demonstrated that prior antibiotic exposure, medical device insertion, prolonged hospitalization and surgical interventions may lead to Enterococcus overgrowth, antibiotic resistance and spread among critical healthcare settings. Herein, we present a comprehensive review of Enterococcus spp. in the immunocompromised host, summarizing the available knowledge about virulence factors, antimicrobial-resistance mechanisms and host-pathogen interaction. The review ultimately yearns for more substantial support to further investigations about enterococcal infections and immunocompromised host response.

How New Regulation of Laboratory-Developed Antimicrobial Susceptibility Tests Will Affect Infectious Diseases Clinical Practice

Antimicrobial resistance (AMR) affects 2.8 million Americans annually. AMR is identified through antimicrobial susceptibility testing (AST), but current and proposed regulatory policies from the United States Food and Drug Administration (FDA) jeopardize the future availability of AST for many microorganisms. Devices that perform AST must be cleared by the FDA using their susceptibility test interpretive criteria, also known as breakpoints. The FDA list of breakpoints is relatively short. Today, laboratories supplement FDA breakpoints using breakpoints published by the Clinical and Laboratory Standards Institute, using legacy devices and laboratory-developed tests (LDTs). FDA proposes to regulate LDTs, and with no FDA breakpoints for many drug-bug combinations, the risk is loss of AST for key clinical indications and stifling innovation in technology development. Effective solutions require collaboration between manufacturers, infectious diseases clinicians, pharmacists, laboratories, and the FDA.

Genomic context as well as sequence of both psr and penicillin-binding protein 5 contributes to β-lactam resistance in Enterococcus faecium

Penicillin-binding protein 5 (PBP5) of Enterococcus faecium (Efm) is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in Efm clade B strains [ampicillin susceptible (AMP-S)], PBP5-S/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here, pbp5 deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.01-0.09 µg/mL for clade B and 0.12-0.19 µg/mL for clade A strains; in situ complementation restored parental AMP MICs. Using D344SRF (lacking ftsW/psr/pbp5), constructs with ftsWA/psrA (from a clade A1 strain) cloned upstream of pbp5-S and pbp5-S/R alleles resulted in modest increases in MICs to 3-8 µg/mL, while high MICs (>64 µg/mL) were seen using pbp5 from A1 strains. Next, using ftsW ± psr from clade B and clade A/B and B/A hybrid constructs, the presence of psrB, even alone or in trans, resulted in much lower AMP MICs (3-8 µg/mL) than when psrA was present (MICs >64 µg/mL). qRT PCR showed relatively greater pbp5 expression (P = 0.007) with pbp5 cloned downstream of clade A1 ftsW/psr (MIC >128 µg/mL) vs when cloned downstream of clade B ftsW/psr (MIC 4-16 µg/mL), consistent with results in western blots. In conclusion, we report the effect of clade A vs B psr on AMP MICs as well as the impact of pbp5 alleles from different clades. While previously, Psr was not thought to contribute to AMP MICs in Efm, our results showed that the presence of psrB resulted in a major decrease in Efm AMP MICs.

IMPORTANCE

The findings of this study shed light on ampicillin resistance in Enterococcus faecium clade A strains. They underscore the significance of alterations in the amino acid sequence of penicillin-binding protein 5 (PBP5) and the pivotal role of the psr region in PBP5 expression and ampicillin resistance. Notably, the presence of a full-length psrB leads to reduced PBP5 expression and lower minimum inhibitory concentrations (MICs) of ampicillin compared to the presence of a shorter psrA, regardless of the pbp5 allele involved. Additionally, clade B E. faecium strains exhibit lower AMP MICs when both psr alleles from clades A and B are present, although it is important to consider other distinctions between clade A and B strains that may contribute to this effect. It is intriguing to note that the divergence between clade A and clade B E. faecium and the subsequent evolution of heightened AMP MICs in hospital-associated strains appear to coincide with changes in Pbp5 and psr. These changes in psr may have resulted in an inactive Psr, facilitating increased PBP5 expression and greater ampicillin resistance. These results raise the possibility that a mimicker of PsrB, if one could be designed, might be able to lower MICs of ampicillin-resistant E. faecium, thus potentially resorting ampicillin to our therapeutic armamentarium for this species.

An essential protease, FtsH, influences daptomycin resistance acquisition in Enterococcus faecalis

Daptomycin is a last-line antibiotic commonly used to treat vancomycin-resistant Enterococci, but resistance evolves rapidly and further restricts already limited treatment options. While genetic determinants associated with clinical daptomycin resistance (DAPR) have been described, information on factors affecting the speed of DAPR acquisition is limited. The multiple peptide resistance factor (MprF), a phosphatidylglycerol-modifying enzyme involved in cationic antimicrobial resistance, is linked to DAPR in pathogens such as methicillin-resistant Staphylococcus aureus. Since Enterococcus faecalis encodes two paralogs of mprF and clinical DAPR mutations do not map to mprF, we hypothesized that functional redundancy between the paralogs prevents mprF-mediated resistance and masks other evolutionary pathways to DAPR. Here, we performed in vitro evolution to DAPR in mprF mutant background. We discovered that the absence of mprF results in slowed DAPR evolution and is associated with inactivating mutations in ftsH, resulting in the depletion of the chaperone repressor HrcA. We also report that ftsH is essential in the parental, but not in the ΔmprF, strain where FtsH depletion results in growth impairment in the parental strain, a phenotype associated with reduced extracellular acidification and reduced ability for metabolic reduction. This presents FtsH and HrcA as enticing targets for developing anti-resistance strategies.

In Vitro Antibacterial Activity of Ceftobiprole and Comparator Compounds against Nation-Wide Bloodstream Isolates and Different Sequence Types of MRSA

Bloodstream infections by bacteria, especially multidrug-resistant bacteria, remain a worldwide public health concern. We evaluated the antibacterial activity of ceftobiprole and comparable drugs against different bloodstream isolates and different sequence types of methicillin-resistant Staphylococcus aureus (MRSA) in China. We found that MRSA, methicillin-susceptible Staphylococcus aureus (MSSA), and methicillin-susceptible coagulase-negative Staphylococcus (MSCNS) displayed ceftobiprole sensitivity rates of >95%, which are similar to the rates for linezolid, daptomycin, and vancomycin. Of the tested MRCNS strains, 90.4% were sensitive to ceftobiprole. The sensitivities of ST59, ST398, and ST22 MRSA to ceftobiprole were higher than that of ST239. Ceftobiprole's MIC50/90 value against Enterococcus faecalis was 0.25/2 mg/L, whereas Enterococcus faecium was completely resistant to this drug. Ceftobiprole exhibited no activity against ESBL-positive Enterobacterales, with resistance rates between 78.6% and 100%. For ESBL-negative Enterobacterales, excluding Klebsiella oxytoca, the sensitivity to ceftobiprole was comparable to that of ceftazidime, ceftriaxone, and cefepime. The MIC50/90 value of ceftobiprole against Pseudomonas aeruginosa was 2/16 mg/L, and for Acinetobacter baumannii, it was 32/>32 mg/L. Thus, ceftobiprole shows excellent antimicrobial activity against ESBL-negative Enterobacterales and Pseudomonas aeruginosa (comparable to that of ceftazidime, ceftriaxone, and cefepime); however, it is not effective against ESBL-positive Enterobacterales and Acinetobacter baumannii. These results provide important information to clinicians.

Antibiotic Resistance to Molecules Commonly Prescribed for the Treatment of Antibiotic-Resistant Gram-Positive Pathogens: What Is Relevant for the Clinician?

Antibiotic resistance in Gram-positive pathogens is a relevant concern, particularly in the hospital setting. Several antibiotics are now available to treat these drug-resistant pathogens, such as daptomycin, dalbavancin, linezolid, tedizolid, ceftaroline, ceftobiprole, and fosfomycin. However, antibiotic resistance can also affect these newer molecules. Overall, this is not a frequent phenomenon, but it is a growing concern in some settings and can compromise the effectiveness of these molecules, leaving few therapeutic options. We reviewed the available evidence about the epidemiology of antibiotic resistance to these antibiotics and the main molecular mechanisms of resistance, particularly methicillin-resistant Sthaphylococcus aureus, methicillin-resistant coagulase-negative staphylococci, vancomycin-resistant Enterococcus faecium, and penicillin-resistant Streptococcus pneumoniae. We discussed the interpretation of susceptibility tests when minimum inhibitory concentrations are not available. We focused on the risk of the emergence of resistance during treatment, particularly for daptomycin and fosfomycin, and we discussed the strategies that can be implemented to reduce this phenomenon, which can lead to clinical failure despite appropriate antibiotic treatment. The judicious use of antibiotics, epidemiological surveillance, and infection control measures is essential to preserving the efficacy of these drugs.

Concerning emergence of a new vancomycin-resistant Enterococcus faecium strain ST1299/CT1903/vanA at a tertiary university centre in South Germany

BACKGROUND

vanB-carrying vancomycin-resistant Enterococcus faecium (VREfm) of the sequence types 80 (ST80) and ST117 have dominated Germany in the past. In 2020, our hospital witnessed a sharp increase in the proportion of vanA-positive VREfm.

AIM

To attempt to understand these dynamics through whole-genome sequencing (WGS) and analysis of nosocomial transmissions.

METHODS

At our hospital, the first VREfm isolate per patient, treated during 2020, was analysed retrospectively using specific vanA/vanB PCR, WGS, multi-locus sequence typing (MLST), and core-genome (cg) MLST. Epidemiologic links between VRE-positive patients were assessed using hospital occupancy data.

FINDINGS

Isolates from 319 out of 356 VREfm patients were available for WGS, of which 181 (56.7%) fulfilled the ECDC definition for nosocomial transmission. The high load of nosocomial cases is reflected in the overall high clonality rate with only three dominating sequence (ST) and complex types (CT), respectively: the new emerging strain ST1299 (100% vanA, 77.4% CT1903), and the well-known ST80 (90.0% vanB, 81.0% CT1065) and ST117 (78.0% vanB, 65.0% CT71). The ST1299 isolates overall, and the subtype CT1903 in particular, showed high isolate clonality, which demonstrates impressively high spreading potential. Overall, 152 out of 319 isolates had an allelic cgMLST difference of ≤3 to another, including 91 (59.6%) ST1299. Occupancy data identified shared rooms (3.7%), shared departments (6.2%), and VRE-colonized prior room occupants (0.6%) within 30 days before diagnosis as solid epidemiological links.

CONCLUSION

A new emerging VREfm clone, ST1299/CT1903/vanA, dominated our institution in 2020 and has been an important driver of the increasing VREfm rates.

Profiling Antibiotic Susceptibility among Distinct Enterococcus faecalis Isolates from Dental Root Canals

Enterococcus faecalis, a leading multi-resistant nosocomial pathogen, is also the most frequently retrieved species from persistently infected dental root canals, suggesting that the oral cavity is a possible reservoir for resistant strains. However, antimicrobial susceptibility testing (AST) for oral enterococci remains scarce. Here, we examined the AST profiles of 37 E. faecalis strains, including thirty-four endodontic isolates, two vanA-type vancomycin-resistant isolates, and the reference strain ATCC-29212. Using Etest gradient strips and established EUCAST standards, we determined minimum inhibitory concentrations (MICs) for amoxicillin, vancomycin, clindamycin, tigecycline, linezolid, and daptomycin. Results revealed that most endodontic isolates were susceptible to amoxicillin and vancomycin, with varying levels of intrinsic resistance to clindamycin. Isolates exceeding the clindamycin MIC of the ATCC-29212 strain were further tested against last-resort antibiotics, with 7/27 exhibiting MICs matching the susceptibility breakpoint for tigecycline, and 1/27 reaching that of linezolid. Both vanA isolates confirmed vancomycin resistance and demonstrated resistance to tigecycline. In conclusion, while most endodontic isolates remained susceptible to first-line antibiotics, several displayed marked intrinsic clindamycin resistance, and MICs matched tigecycline's breakpoint. The discovery of tigecycline resistance in vanA isolates highlights the propensity of clinical clone clusters to acquire multidrug resistance. Our results emphasize the importance of implementing AST strategies in dental practices for continued resistance surveillance.

Association between ratio of area under the concentration-time curve to minimum inhibitory concentration of vancomycin and clinical outcomes in Enterococcus faecium bacteremia

The purpose of this study was to evaluate the relationship between the treatment resolution of Enterococcus faecium bacteremia and the pharmacodynamic targets of vancomycin. This is a retrospective single-center cohort study involving patients with E. faecium bacteremia on vancomycin therapy hospitalized between January 2010 and December 2021. The average vancomycin area under the concentration-time curve (AUC)0 -24 was computed using the Bayesian approach. The minimum inhibitory concentration (MIC) was determined using the broth microdilution method, and The AUC24/MIC value over the initial 24-48 h of therapy was calculated. We assessed 30-day mortality, as the primary outcome. Classification and regression tree analysis (CART) was used to identify the vancomycin AUC24/MIC target associated with 30-day mortality. Eighty-seven patients with E. faecium bacteremia were included in this study, with 14 (16.1%) being non-survivors. In the CART analysis, vancomycin AUC/MIC ≥414.3 was associated with a higher treatment success. In multivariate analysis, an AUC/MIC ≥414.3 was a significant factor for treatment success (adjusted odds ratio = 17.5, 95% confidence interval, 3.7-83.9). Our findings suggest that a target vancomycin AUC/MIC ≥414.3 is a good prognostic indicator and could be useful for treatment monitoring of E. faecium bacteremia.

Oritavancin in vitro activity against Gram-positive organisms from European medical centers: a 10-year longitudinal overview from the SENTRY Antimicrobial Surveillance Program (2010-2019)

To assess oritavancin in vitro activity against clinically relevant Gram-positive pathogens in European (EU) hospitals, a total of 51,531 consecutive and unique clinical isolates collected in 2010-2019 were evaluated. All isolates were tested by CLSI broth microdilution methods. The key resistance phenotypes differed considerably between Eastern Europe (E-EU) and Western Europe (W-EU), respectively: methicillin-resistant (MR) Staphylococcus aureus 27.7%/22.9%; multidrug resistant (MDR) S. aureus, 19.7%/15.2%; MR coagulase-negative staphylococci, 77.3%/61.9%; vancomycin-resistant enterococci (E. faecium), 44.2%/20.9%; and MDR E. faecium, 63.8%/55.4%. There were no substantive differences in oritavancin minimum inhibitory concentration (MIC) values for the different species/organism groups over time or by EU region. Oritavancin inhibited 99.9% and 99.1% of all S. aureus and coagulase-negative staphylococci at 0.12 mg/L, respectively, and all isolates of E. faecalis and E. faecium at ≤0.5 mg/L. Oritavancin susceptibility rates against β-hemolytic and Viridans group streptococci isolates were 98.1% and 99.4%, respectively. Oritavancin had potent activity in vitro against this contemporary collection of European Gram-positive isolates from 2010 to 2019.

Vancomycin resistant enterococcus risk factors for hospital colonization in hematological patients: a matched case-control study

BACKGROUND

Vancomycin-resistant enterococcus (VRE) was the fastest growing pathogen in Europe in 2022 (+ 21%) but its clinical relevance is still unclear. We aim to identify risk factors for acquired VRE rectal colonization in hematological patients and evaluate the clinical impact of VRE colonization on subsequent infection, and 30- and 90-day overall mortality rates, compared to a matched control group.

METHODS

A retrospective, single center, case-control matched study (ratio 1:1) was conducted in a hematological department from January 2017 to December 2020. Case patients with nosocomial isolation of VRE from rectal swab screening (≥ 48 h) were matched to controls by age, sex, ethnicity, and hematologic disease. Univariate and multivariate logistic regression compared risk factors for colonization.

RESULTS

A total of 83 cases were matched with 83 controls. Risk factors for VRE colonization were febrile neutropenia, bone marrow transplant, central venous catheter, bedsores, reduced mobility, altered bowel habits, cachexia, previous hospitalization and antibiotic treatments before and during hospitalization. VRE bacteraemia and Clostridioides difficile infection (CDI) occurred more frequently among cases without any impact on 30 and 90-days overall mortality. Vancomycin administration and altered bowel habits were the only independent risk factors for VRE colonization at multivariate analysis (OR: 3.53 and 3.1; respectively).

CONCLUSIONS

Antimicrobial stewardship strategies to reduce inappropriate Gram-positive coverage in hematological patients is urgently required, as independent risk factors for VRE nosocomial colonization identified in this study include any use of vancomycin and altered bowel habits. VRE colonization and infection did not influence 30- and 90-day mortality. There was a strong correlation between CDI and VRE, which deserves further investigation to target new therapeutic approaches.

Volatile anesthetic isoflurane exposure facilitates Enterococcus biofilm infection

Enterococcus faecalis (E. faecalis) is one of the major pathogenic bacteria responsible for surgical site infections. Biofilm infections are major hospital-acquired infections. Previous studies suggested that ions could regulate biofilm formation in microbes. Volatile anesthetics, frequently administered in surgical setting, target ion channels. Here, we investigated the role of ion channels/transporters and volatile anesthetics in the biofilm formation by E. faecalis MMH594 strain and its ion transporter mutants. We found that a chloride transporter mutant significantly reduced biofilm formation compared to the parental strain. Downregulation of teichoic acid biosynthesis in the chloride transporter mutant impaired biofilm matrix formation and cellular adhesion, leading to mitigated biofilm formation. Among anesthetics, isoflurane exposure enhanced biofilm formation in vitro and in vivo. The upregulation of de novo purine biosynthesis pathway by isoflurane exposure potentially enhanced biofilm formation, an essential process for DNA, RNA, and ATP synthesis. We also demonstrated that isoflurane exposure to E. faecalis increased cyclic-di-AMP and extracellular DNA production, consistent with the increased purine biosynthesis. We further showed that isoflurane enhanced the enzymatic activity of phosphoribosyl pyrophosphate synthetase (PRPP-S). With the hypothesis that isoflurane directly bound to PRPP-S, we predicted isoflurane binding site on it using rigid docking. Our study provides a better understanding of the underlying mechanisms of E. faecalis biofilm formation and highlights the potential impact of an ion transporter and volatile anesthetic on this process. These findings may lead to the development of novel strategies for preventing E. faecalis biofilm formation and improving patient outcomes in clinical settings.

Antimicrobial Resistance Patterns of Staphylococcus aureus and Enterococcus Species at the Ethiopian Public Health Institute, Ethiopia: A Five-Year Retrospective Analysis

Purpose

The study aimed to investigate the antimicrobial resistance patterns of Staphylococcus aureus and Enterococcus species isolated from clinical specimens over a period of five years, including resistance to methicillin and vancomycin.

Patients and Methods

Bacterial identification and antimicrobial susceptibility testing reports from 2017 to 2021 at the Ethiopian Public Health Institute were used for this retrospective study. The organisms were identified using either BD Phoenix M50, Vitek 2 compact, or conventional biochemical methods, whichever was available at the time of testing. The antimicrobial susceptibility profiles of the isolates were determined using either Kirby-Bauer disc diffusion, BD phoenix M50, or Vitek 2 compact. WHONET software was used to analyze the antimicrobial resistance patterns of both organisms. The p-values of ≤0.05 were considered statistically significant.

Results

During the study period, a total of 315 Staphylococcus aureus and 92 Enterococcus species were isolated. Out of 315 Staphylococcus aureus isolates, 27% and 5.1% were methicillin and vancomycin resistant, respectively. Staphylococcus aureus showed very high resistance to Penicillin G (86.7%). Out of 92 Enterococcus species recovered, 8.7% were vancomycin-resistant. Enterococcus species showed very high resistance to Penicillin G (71.4%) and tetracyclines (83.3%). Methicillin-resistant Staphylococcus aureus shows 100% resistance to penicillin followed by ciprofloxacin (50%), erythromycin (45.6%), and tetracycline (44.2%) and lower resistance to vancomycin (18.8%). All vancomycin-resistant isolates of both organisms were fully resistant (100%) to all antibiotics tested, except for linezolid and daptomycin, to which they were susceptible.

Conclusion

This study found a high prevalence of methicillin and vancomycin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus species between 2017 and 2021. However, there were no statistically significant changes in the prevalence of these organisms during the study period. This suggests that larger and more representative nationwide data is needed to show trends of these pathogens.

CHROMAgar™ LIN-R as an efficient screening tool to assess the prevalence of linezolid-resistant enterococci in German hospital patients-a multicentre study approach, 2021-2022

BACKGROUND

In recent years, an increasing number of linezolid-resistant enterococci (LRE) was recognized at the German National Reference Centre (NRC) for Enterococci. National guidelines on infection prevention recommend screening for LRE in epidemiologically linked hospital settings without referring to a reliable and rapid diagnostic method. Since 2020, CHROMAgar™ provide a chromogenic linezolid screening agar, LIN-R, suitable to simultaneously screen for linezolid-resistant staphylococci and enterococci.

OBJECTIVES

To assess the applicability of CHROMAgar™ LIN-R in clinical settings for detecting LRE directly from patient material and to infer prevalence rates of LRE amongst German hospital patients.

METHODS

During the 3-month trial period, clinical samples were plated on CHROMAgar™ LIN-R. Antimicrobial susceptibility testing was performed using VITEK2 or disc diffusion. At the NRC, linezolid resistance was determined by broth microdilution, multiplex-PCR for cfr/optrA/poxtA and by a restriction-based assay for 23S rDNA mutations.

RESULTS

The 12 participating study sites used 13 963 CHROMAgar™ LIN-R plates during the study period. Of 442 presumptive LRE, 192 were confirmed by phenotypic methods. Of these, 161 were received by the NRC and 121 (75%) were verified as LRE. Most of LR-E. faecium 53/81 (65%) exhibited a 23S rRNA gene mutation as the sole resistance-mediating mechanism, whereas optrA constituted the dominant resistance trait in LR-E. faecalis [39/40 (98%)]. Prevalence of LRE across sites was estimated as 1% (ranging 0.18%-3.7% between sites).

CONCLUSIONS

CHROMAgar™ LIN-R represents a simple and efficient LRE screening tool in hospital settings. A high proportion of false-positive results demands validation of linezolid resistance by a reference method.

Impact of a new hospital with close to 100% single-occupancy rooms on environmental contamination and incidence of vancomycin-resistant Enterococcus faecium colonization or infection: a genomic surveillance study

BACKGROUND

Vancomycin-resistant Enterococcus faecium (VRE) is a leading cause of nosocomial infection, driven by its ability to spread between patients and persist in the hospital environment.

AIM

To investigate the impact of a long-established cardiothoracic hospital moving to new premises with close to 100% single-occupancy rooms on the rates of environmental contamination and infection or colonization by VRE.

METHODS

Prospective environmental surveillance for VRE was conducted at five time-points between April and November 2019, once in the original building, and four times in the new building. Incidence rate ratios (IRRs) of VRE infection/colonization were determined for the one-year period before and after the hospital move, and compared to a nearby hospital.

FINDINGS

In the original location, the first environmental screen found 29% VRE positivity. The following four screens in the new location showed a significant reduction in positivity (1-6%; P<0.0001). The VRE infection/colonization rates were halved in the new location (IRR: 0.56; 95% confidence interval: 0.38-0.84), compared to the original location, contrasting with an increase in a nearby hospital (1.62; 1.17-2.27) over the same time-period. Genomic analysis of the environmental isolates was consistent with reduced transmission in the new hospital.

CONCLUSION

The use of single-occupancy rooms was associated with reduced environmental contamination with VRE, and lower transmission and isolation of VRE from clinical samples. The cost-effectiveness of single-occupancy room hospitals in reducing healthcare-associated infections should be reassessed in the context of operational costs of emerging pandemic and increasing antimicrobial resistance threats.

The use of aminopenicillins in animals within the EU, emergence of resistance in bacteria of animal and human origin and its possible impact on animal and human health

Aminopenicillins have been widely used for decades for the treatment of various infections in animals and humans in European countries. Following this extensive use, acquired resistance has emerged among human and animal pathogens and commensal bacteria. Aminopenicillins are important first-line treatment options in both humans and animals, but are also among limited therapies for infections with enterococci and Listeria spp. in humans in some settings. Therefore, there is a need to assess the impact of the use of these antimicrobials in animals on public and animal health. The most important mechanisms of resistance to aminopenicillins are the β-lactamase enzymes. Similar resistance genes have been detected in bacteria of human and animal origin, and molecular studies suggest that transmission of resistant bacteria or resistance genes occurs between animals and humans. Due to the complexity of epidemiology and the near ubiquity of many aminopenicillin resistance determinants, the direction of transfer is difficult to ascertain, except for major zoonotic pathogens. It is therefore challenging to estimate to what extent the use of aminopenicillins in animals could create negative health consequences to humans at the population level. Based on the extent of use of aminopenicillins in humans, it seems probable that the major resistance selection pressure in human pathogens in European countries is due to human consumption. It is evident that veterinary use of these antimicrobials increases the selection pressure towards resistance in animals and loss of efficacy will at minimum jeopardize animal health and welfare.

ESKAPE and Beyond: The Burden of Coinfections in the COVID-19 Pandemic

The ESKAPE group constitute a threat to public health, since these microorganisms are associated with severe infections in hospitals and have a direct relationship with high mortality rates. The presence of these bacteria in hospitals had a direct impact on the incidence of healthcare-associated coinfections in the SARS-CoV-2 pandemic. In recent years, these pathogens have shown resistance to multiple antibiotic families. The presence of high-risk clones within this group of bacteria contributes to the spread of resistance mechanisms worldwide. In the pandemic, these pathogens were implicated in coinfections in severely ill COVID-19 patients. The aim of this review is to describe the main microorganisms of the ESKAPE group involved in coinfections in COVID-19 patients, addressing mainly antimicrobial resistance mechanisms, epidemiology, and high-risk clones.

The Challenge of Emerging Resistant Gram-Positive Pathogens in Hip and Knee Periprosthetic Joint Infections

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An increase in resistant bacterial pathogens has occurred over the last 4 decades.

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Careful patient selection and improving or correcting risk factors for periprosthetic joint infection (PJI) before elective surgical treatment are strongly recommended.

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Appropriate microbiological methods, including those used to detect and grow Cutibacterium acnes, are recommended.

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Antimicrobial agents used in the prevention or management of infection should be selected appropriately and the duration of therapy should be carefully considered in order to mitigate the risk of developing bacterial resistance.

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Molecular methods including rapid polymerase chain reaction (PCR) diagnostics, 16S sequencing, and/or shotgun and/or targeted whole-genome sequencing are recommended in culture-negative cases of PJI.

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Expert consultation with an infectious diseases specialist (if available) is recommended to assist with the appropriate antimicrobial management and monitoring of patients with PJI.

Effectiveness and Safety of Linezolid Versus Vancomycin, Teicoplanin, or Daptomycin against Methicillin-Resistant Staphylococcus aureus Bacteremia: A Systematic Review and Meta-Analysis

Vancomycin (VCM) and daptomycin (DAP) are standard therapies for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, despite concerns regarding clinical utility and growing resistance. Linezolid (LZD) affords superior tissue penetration to VCM or DAP and has been successfully used as salvage therapy for persistent MRSA bacteremia, indicating its utility as a first-choice drug against MRSA bacteremia. In a systematic review and meta-analysis, we compared the effectiveness and safety of LZD with VCM, teicoplanin (TEIC), or DAP in patients with MRSA bacteremia. We evaluated all-cause mortality as the primary effectiveness outcome, clinical and microbiological cure, hospital length of stay, recurrence, and 90-day readmission rates as secondary effectiveness outcomes, and drug-related adverse effects as primary safety outcomes. We identified 5328 patients across 2 randomized controlled trials (RCTs), 1 pooled analysis of 5 RCTs, 1 subgroup analysis (1 RCT), and 5 case-control and cohort studies (CSs). Primary and secondary effectiveness outcomes were comparable between patients treated with LZD versus VCM, TEIC, or DAP in RCT-based studies and CSs. There was no difference in adverse event incidence between LZD and comparators. These findings suggest that LZD could be a potential first-line drug against MRSA bacteremia as well as VCM or DAP.

Multisite Detection of Tn1549-Mediated vanB Vancomycin Resistance in Multidrug-Resistant Enterococcus faecalis ST6 in Texas and Florida

In the United States, vanB-mediated resistance in enterococci is rare. We characterized three sequence type (ST) 6, vancomycin-resistant Enterococcus faecalis isolates causing bacteremia in unique patients in spatiotemporally distinct settings. Isolates were recovered between 2018 and 2020 in two cities in the United States (Houston, TX; Miami, FL). The isolates harbored the vanB operon on a chromosomally located Tn1549 transposon, and epidemiological data suggested multiple introductions of the vanB gene cluster into ST6 E. faecalis.

Preoperative oral fluoroquinolone antibiotics in elective colorectal surgery to prevent surgical site infections: a systematic review and meta-analysis

BACKGROUND

Preoperative treatment with oral neomycin combined with erythromycin or metronidazole is recommended to decrease the risk of surgical site infections (SSIs) in elective colorectal surgery. However, oral neomycin is not commercially available in Canada, and therefore it is not routinely used. Fluoroquinolones are widely available and have excellent activity against aerobic Gram-negative bacteria. The aim of this systematic review was to identify, critically appraise and summarize the evidence on the efficacy and safety of preoperative use of oral fluoroquinolone antibiotics for the prevention of SSIs in adult patients undergoing elective colorectal resection.

METHODS

Following Cochrane guidelines, we included English-language randomized controlled trials (RCTs) comparing oral fluoroquinolones plus routine preoperative intravenous antibiotics against intravenous antibiotics alone from MEDLINE (Ovid), Embase (Ovid), the Cochrane Central Register of Controlled Trials( Ovid) and ClinicalTrials.gov.

RESULTS

We included 3 RCTs (1136 patients). Risk of bias was uncertain in 2 trials and high in 1 trial. Preoperative oral fluoroquinolones led to significantly decreased total SSIs (risk ratio [RR] 0.43, 95% confidence interval [CI] 0.32-0.57, I ² = 0%), superficial incisional (RR 0.38, 95% CI 0.22-0.68, I ² = 32%), deep incisional (RR 0.19, 95% CI 0.06-0.65, I ² = 0%) and organ/space SSIs (RR 0.34, 95% CI 0.12-0.90, I ² = 33%). There was also a significant reduction in anastomotic leaks (RR 0.22, 95% CI 0.06-0.87, I ² = 0%). No antibiotic-related adverse events were reported.

CONCLUSION

This review suggests that preoperative oral fluoroquinolones with intravenous antibiotics are superior to intravenous antibiotics alone for preventing SSIs after colorectal surgery. If neomycin is unavailable, oral fluoroquinolones should be considered as a reasonable alternative. Future trials are required to further compare the relative efficacy of oral antibiotic regimens.

Diverse Enterococcus faecalis strains show heterogeneity in biofilm properties

Biofilm formation is important for Enterococcus faecalis to cause healthcare-associated infections. It is unclear how E. faecalis biofilms vary in parameters such as development and composition. To test the hypothesis that differences in biofilms exist among E. faecalis strains, we evaluated in vitro biofilm formation and matrix characteristics of five genetically diverse E. faecalis lab-adapted strains and clinical isolates (OG1RF, V583, DS16, MMH594, and VA1128). Biofilm formation of all strains was repressed in TSB+10% FBS. However, DMEM+10% FBS enhanced biofilm formation of clinical isolate VA1128. Crystal violet staining and fluorescence microscopy of biofilms grown on Aclar membranes demonstrated differences between OG1RF and VA1128 in biofilm development over a 48-h time course. None of the biofilms were dispersed by single treatments of sodium (meta)periodate, DNase, or Proteinase K alone, but the biofilm biomass of both OG1RF and DS16 was partially removed by a sequential treatment of sodium (meta)periodate and DNase. Reversing the treatment order was not effective, suggesting that the extracellular DNA targeted by DNase was obscured by carbohydrates that are susceptible to sodium (meta)periodate degradation. Fluorescent staining of biofilm matrix components further demonstrated that more carbohydrates bound by wheat germ agglutinin comprise OG1RF biofilms compared to VA1128 biofilms. This study highlights the existence of heterogeneity in biofilm properties among diverse E. faecalis strains, which may have implications for the design of novel anti-biofilm treatment strategies.

Investigation of a vanA linezolid- and vancomycin-resistant Enterococcus faecium outbreak in the Southwest Indian Ocean (Reunion Island)

INTRODUCTION

Dual resistance to linezolid and glycopeptides is a milestone reached by certain extensively drug-resistant (XDR) enterococci. This paper describes the molecular and epidemiological investigations of a linezolid-resistant and vancomycin-resistant Enterococcus faecium (E. faecium) (LVREf) outbreak in the French overseas territory of Reunion Island (Indian Ocean).

METHODS

All vancomycin-resistant Enterococcus (VRE) isolates detected on Reunion Island between 2015 and 2019 were included in the study. The VRE isolates were phenotypically characterised and genetically explored by whole-genome sequencing (WGS).

RESULTS

Sixteen vancomycin-resistant E. faecium (VREf) isolates were retrieved between 2015 and 2019. Seven isolates obtained in 2019 were involved in the outbreak. These seven LVREf isolates from the 2019 outbreak at the University Hospital of Reunion Island (UHRI) were suspected to be related to a linezolid-susceptible VREf strain imported from India. An epidemiological link was highlighted for six of the seven outbreak cases. All the LVREf outbreak isolates were obtained from rectal swabs (colonisation) and resistant to vancomycin (MIC > 128 mg/L) and linezolid (MIC 8-32 mg/L); one isolate was also resistant to daptomycin (MIC 8 mg/L). The seven outbreak isolates were positive for the vanA and optrA genes and belonged to ST761.

CONCLUSIONS

These results argue for the strict application of control and prevention measures for VRE clones at high risk of spread, particularly in areas such as Reunion Island where the risk of importation from the Indian subcontinent is high. The regional spread of optrA linezolid-resistance genes in VRE isolates is a matter of concern, due to possibility of treatment failure.

Carbapenemase-producing Enterobacterales and vancomycin-resistant Enterococcus faecium carriage in patients who have traveled in foreign countries: A single center 5-year prospective study

BACKGROUND

Numerous patients carrying carbapenemase-producing Enterobacterales (CPE) and/or vancomycin-resistant Enterococcus faecium (VRE) in France have previously travelled abroad. The risk of spreading CPE/VRE by patients who have stayed abroad without hospitalization is underexplored. This prompted us to screen and isolate all patients who travelled abroad in the previous 12 months upon admission to our hospital. Our aim was to evaluate the efficiency of this CPE/VRE-related risk policy.

METHODS

From 2014 to 2018, patients who had travelled abroad in the previous year before their admission underwent microbiological screening and were pre-emptively isolated. Contact precautions were verified and CPE/VRE cross-transmission events investigated.

RESULTS

Among 1,780 screened patients, 59 (3.3%) were colonized with CPE and/or VRE, of whom 17 (29.3%) were not hospitalized abroad. Nine generated 18 readmissions. No episodes of CPE/VRE cross-transmission were related to patients with a stay abroad without hospitalization, whereas 2 patients hospitalized abroad generated one episode each, despite implementation of contact precautions reaching values from 73.6% to 87.5%.

DISCUSSION

Throughout 17 admissions and 18 readmissions, patients who stayed abroad without hospitalization represented a true risk of spreading CPE/VRE, without generating cross-transmission.

CONCLUSIONS

Our strategy of CPE/VRE-related risk policy is successful.

Antimicrobial Susceptibility Testing for Enterococci

Enterococci are major, recalcitrant nosocomial pathogens with a wide repertoire of intrinsic and acquired resistance determinants and the potential of developing resistance to all clinically available antimicrobials. As such, multidrug-resistant enterococci are considered a serious public health threat. Due to limited treatment options and rapid emergence of resistance to all novel agents, the clinical microbiology laboratory plays a critical role in deploying accurate, reproducible, and feasible antimicrobial susceptibility testing methods to guide appropriate treatment of patients with deep-seated enterococcal infections. In this review, we provide an overview of the advantages and disadvantages of existing manual and automated methods that test susceptibility of Enterococcus faecium and Enterococcus faecalis to β-lactams, aminoglycosides, vancomycin, lipoglycopeptides, oxazolidinones, novel tetracycline-derivatives, and daptomycin. We also identify unique problems and gaps with the performance and clinical utility of antimicrobial susceptibility testing for enterococci, provide recommendations for clinical laboratories to circumvent select problems, and address potential future innovations that can bridge major gaps in susceptibility testing.

Antimicrobial Resistance Patterns of Bacterial and Fungal Isolates in COVID-19

Background: The pattern of bacterial infection in coronavirus disease 2019 (COVID-19) patients differ worldwide. Objectives: This study aimed to determine the patterns of bacterial infections and the antibiotic resistance profile by VITEK 2 (bioMérieux, France) in the culture of blood samples from hospitalized patients with COVID-19. Methods: This retrospective descriptive cross-sectional was conducted on a total of 25 patients with critical COVID-19 admitted to Imam Reza Hospital in Mashhad, Iran, during the first three COVID-19 peaks (2019 - 2020). Results: Among Gram-positive bacteria, two strains isolated from Staphylococcus aureus were methicillin-resistant S. aureus at a concentration of > 2 μg/mL. Enterococcus was vancomycin-resistant Enterococcus at a concentration of higher than 4 μg/mL (the minimum inhibitory concentration [MIC] ≥ 32). Among Gram-negative bacteria, three strains of Acinetobacter baumannii complex were extensively drug-resistant. Conclusions: There is evidence of the remarkable increase of various antibiotics’ MIC during the COVID-19 pandemic, which highlights the impact of the use of steroids on the risk of developing antimicrobial resistance during the COVID-19 pandemic.

A comprehensive review on genomics, systems biology and structural biology approaches for combating antimicrobial resistance in ESKAPE pathogens: computational tools and recent advancements

In recent decades, antimicrobial resistance has been augmented as a global concern to public health owing to the global spread of multidrug-resistant strains from different ESKAPE pathogens. This alarming trend and the lack of new antibiotics with novel modes of action in the pipeline necessitate the development of non-antibiotic ways to treat illnesses caused by these isolates. In molecular biology, computational approaches have become crucial tools, particularly in one of the most challenging areas of multidrug resistance. The rapid advancements in bioinformatics have led to a plethora of computational approaches involving genomics, systems biology, and structural biology currently gaining momentum among molecular biologists since they can be useful and provide valuable information on the complex mechanisms of AMR research in ESKAPE pathogens. These computational approaches would be helpful in elucidating the AMR mechanisms, identifying important hub genes/proteins, and their promising targets together with their interactions with important drug targets, which is a crucial step in drug discovery. Therefore, the present review aims to provide holistic information on currently employed bioinformatic tools and their application in the discovery of multifunctional novel therapeutic drugs to combat the current problem of AMR in ESKAPE pathogens. The review also summarizes the recent advancement in the AMR research in ESKAPE pathogens utilizing the in silico approaches.

Aminopenicillins for treatment of ampicillin-resistant enterococcal urinary tract infections

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

The purpose of this review is to describe the theory behind and data supporting use of aminopenicillins in the treatment of ampicillin-resistant enterococcal urinary tract infections.

SUMMARY

Aminopenicillin concentrations in the urine may be high enough to achieve bacterial eradication and clinical cure for infections affecting the lower genitourinary tract, even in the context of in vitro resistance based on established susceptibility breakpoints. A literature search was conducted to identify original research articles describing the use of aminopenicillins in the treatment of urinary tract infections caused by ampicillin-resistant Enterococcus species. Three published retrospective cohort studies were identified, all of which reported that aminopenicillins had similar rates of clinical cure as other antibiotic classes prescribed for the treatment of enterococcal urinary tract infections.

CONCLUSION

Both pharmacokinetic/pharmacodynamic principles and limited retrospective clinical data support the use of aminopenicillins in the treatment of lower urinary tract infections caused by Enterococcus species, even when the isolates have a minimum inhibitory concentration that exceeds the susceptibility breakpoint.

The occurrence of antibiotic-resistant bacteria on the clothes of nursery teachers in daycare centres

AIMS

Childcare facilities act as microenvironments that facilitate and promote the selection, spread, and transmission of antibiotic-resistant microorganisms in the community. We focused on the study of antimicrobial resistance and genetic predispositions for β-lactamase production in bacterial isolates from nursery teachers' clothing.

METHODS AND RESULTS

Antimicrobial resistance of bacterial strains belonging to Enterobacteriaceae, Enterococcus, Staphylococcus spp., Pseudomonas spp. and Bacillus spp. isolated from 80 samples of nursery teachers' clothing was determined. The selected ESβL genes were found in 30 (44.1%) of 68 strains examined. The CTX-M type ESβL determinants were detected in 15.4%, 71.5%, and 42.5% of the Enterobacteriaceae, Pseudomonas, and Bacillus isolates, respectively. The OXA-type coding genes were detected only in strains of the genera Pseudomonas (57.1%) and Bacillus (48.6%). Thus, most B. cereus strains were sensitive to the recommended antibiotics used to treat infections caused by these bacteria. Methicillin resistance was phenotypically confirmed in 27 (14.6%) of 185 staphylococcal isolates. Four isolates (2.2%) were identified as MRSA. Vancomycin resistance was not observed in any of the staphylococcal and enterococci strains.

CONCLUSIONS

This study has shown that potential pathogens have been isolated from the clothing of nursery teachers, posing a risk of transmission to children. These clothes should be maintained and properly laundered to avoid cross-contamination and the spread of multidrug-resistant (MDR) bacteria in childcare centres.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides insight into the route of transmission of MDR microorganisms through the clothing of nursery teachers, to which greater importance should be given in the future. Proper procedures for the cleaning and use of clothing in daycare centres should be clarified and standardised.

Molecular Epidemiology of Vancomycin-Resistant Enterococci Bloodstream Infections in Germany: A Population-Based Prospective Longitudinal Study

Vancomycin-resistant enterococci (VRE) pose a public health challenge worldwide. While VRE bloodstream infections (VREBI) increase in Germany and Europe, population-based molecular data are scarce. We aimed to analyze the molecular epidemiology, demographic aspects, and geographical distribution of VREBI in the German Federal State of North-Rhine-Westphalia (NRW), located in the German-Dutch-Belgian border area, representing over 20% of Germany's population. VREBI isolates were collected from hospitals across NRW between 2016 and 2019. Demographic data were gathered and anonymized upon sample collection. Multilocus sequence typing (MLST) and identification of glycopeptide resistance were carried out. Epidemiological analysis and geographical mapping were performed. Single VREBI isolates from 755 patients were analyzed. In total, 38.9% were female, and 80.0% were aged ≥ 60 years. The VREBI incidence per 100,000 inhabitants nearly tripled, from 0.52 (2016) to 1.48 (2019), particularly in male patients aged ≥ 50 years. The proportion of vanB reached 83% (n = 202/243) in 2018, overtaking vanA as the predominant glycopeptide resistance determinant, detected in close relation with ST117 isolates. The proportion of MLST sequence type (ST) 117 peaked in 2018, at 78.2% (n = 190/243). The major role of these emerging strains in invasive infections in central Europe requires novel strategies for their diagnosis, treatment, and prevention.

Impact of single-room contact precautions on acquisition and transmission of vancomycin-resistant enterococci on haematological and oncological wards, multicentre cohort-study, Germany, January-December 2016

BackgroundEvidence supporting the effectiveness of single-room contact precautions (SCP) in preventing in-hospital acquisition of vancomycin-resistant enterococci (haVRE) is limited.AimWe assessed the impact of SCP on haVRE and their transmission.MethodsWe conducted a prospective, multicentre cohort study in German haematological/oncological departments during 2016. Two sites performed SCP for VRE patients and two did not (NCP). We defined a 5% haVRE-risk difference as non-inferiority margin, screened patients for VRE, and characterised isolates by whole genome sequencing and core genome MLST (cgMLST). Potential confounders were assessed by competing risk regression analysis.ResultsWe included 1,397 patients at NCP and 1,531 patients at SCP sites. Not performing SCP was associated with a significantly higher proportion of haVRE; 12.2% (170/1,397) patients at NCP and 7.4% (113/1,531) patients at SCP sites (relative risk (RR) 1.74; 95% confidence interval (CI): 1.35-2.23). The difference (4.8%) was below the non-inferiority margin. Competing risk regression analysis indicated a stronger impact of antimicrobial exposure (subdistribution hazard ratio (SHR) 7.46; 95% CI: 4.59-12.12) and underlying disease (SHR for acute leukaemia 2.34; 95% CI: 1.46-3.75) on haVRE than NCP (SHR 1.60; 95% CI: 1.14-2.25). Based on cgMLST and patient movement data, we observed 131 patient-to-patient VRE transmissions at NCP and 85 at SCP sites (RR 1.76; 95% CI: 1.33-2.34).ConclusionsWe show a positive impact of SCP on haVRE in a high-risk population, although the observed difference was below the pre-specified non-inferiority margin. Importantly, other factors including antimicrobial exposure seem to be more influential.

Update on activity of dalbavancin and comparators against clinical isolates of Gram-positive pathogens from Europe and Russia (2017-2018), and on clonal distribution of MRSA

BACKGROUND

Gram-positive pathogens remain a major cause of healthcare- and community-associated infections. In particular, the dissemination of methicillin-resistant staphylococci, as methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE), have significantly reduced the therapeutic options, making the management of these infections even more challenging. Dalbavancin is a second-generation lipoglycopeptide approved for the treatment of moderate to severe acute bacterial skin and skin structure infections (ABSSSIs) caused by Gram-positive organisms, showing a bactericidal effect and a low propensity towards the selection of resistance over time.

AIM

This study aimed to evaluate the antimicrobial activity of dalbavancin and other comparators against recent clinical isolates of Gram-positive pathogens obtained from different sources and from several European countries, including countries of southern and eastern Europe and Russia, where resistance rates are typically high. This study also aimed to describe the clonal relationship of MRSA strains circulating in southern and eastern Europe and Russia.

RESULTS

A total of 1478 isolates were collected. Study results demonstrated the excellent and stable activity of dalbavancin against Gram-positive microorganisms, including MRSA. Interestingly, dalbavancin has retained unaltered MIC₅₀ and MIC₉₀ values over the years and seemed to have a low propensity in selecting resistance mechanisms.

CONCLUSIONS

Our data supported the potential efficacy of dalbavancin against Gram-positive bacteria and uncommon Gram-positive pathogens in patients with ABSSSIs. Of note, few CoNS isolates were resistant to dalbavancin and susceptible to vancomycin, pointing out the importance of testing the susceptibility to dalbavancin before its administration for CoNS infections.

Replacement of Enterococcus faecalis by Enterococcus faecium as the predominant enterococcus in UK bacteraemias

Objectives

To review temporal changes in the proportions of different Enterococcus species recorded in two UK bacteraemia surveillance systems. Antibiotic resistance trends were also considered.

Methods

We reviewed data for enterococci from 2001 to 2019 in: (a) the BSAC Resistance Surveillance Programme, which collected up to 7–10 bloodstream enterococci every year from each of 23–39 hospitals in the UK and Ireland and tested these centrally; and (b) PHE bacteraemia surveillance, using routine results from NHS microbiology laboratories in England.

Results

BSAC surveillance, based upon 206–255 enterococci each year (4486 in total), indicated that the proportion of Enterococcus faecium rose from 31% (212/692) in the period 2001–3 to 51% (354/696) in the period 2017–19, balanced by corresponding falls in the proportion of Enterococcus faecalis. PHE surveillance provided a larger dataset, with >5000 enterococcus reports per year; although its identifications are less precise, it too indicated a rise in the proportion of E. faecium. BSAC surveillance for E. faecium indicated no consistent trends in resistance to ampicillin (≥86% in all years), vancomycin (annual rates 19%–40%) or high-level resistance to gentamicin (31%–59%). Resistance to vancomycin remained <4% in E. faecalis in all years, whilst high-level resistance to gentamicin fell, perhaps partly reflecting the decline of two initially prevalent gentamicin- and ciprofloxacin-resistant clones.

Conclusions

Both surveillance systems indicate a growing proportion of E. faecium in enterococcal bloodstream infections. This is important because fewer therapeutic options remain against this frequently multiresistant species than against E. faecalis.

Phenotypic and genotypic characterization of antimicrobial resistance in clinical isolates of Vibrio cholerae over a decade (2002-2016)

PURPOSE

Emergence and spread of resistance among Vibrio cholerae have become a global public health problem. In India, no consolidated data is available on antimicrobial susceptibility patterns and antibiotic resistance genes.

METHODS

A total of 110 representative isolates obtained over a period of 14 years were included. Antimicrobial susceptibility was tested by disc diffusion and micro broth dilution. Presence of 13 antimicrobial resistance genes was ascertained by using PCR.

RESULTS

Antimicrobial resistance fluctuated for most of the antibiotics. Resistance to cotrimoxazole in our study was 92.72% and the SXT element was present in all isolates. Resistance to nalidixic acid, tetracycline, and cefotaxime was found to be 98.18%, 7.27%, and 10.9% respectively. Resistance to ampicillin saw a fluctuating trend with a recent fall. Resistance to ciprofloxacin and azithromycin was 12.72% and 29% by MIC. bla_TEM was the most common ESBL gene (94.5%). Other were bla_CMY (26.36%) and bla_NDM (2.7%). We report bla_CTX-M-15 and bla_OXA-48 and ermB for the first time in the world. Newer antimicrobials like prulifloxacin and rifaximin were tested for the first time from India.

CONCLUSIONS

Our study has shown very high levels of resistance to older antibiotics and the emergence of resistance to some of the newer classes of antibiotics. There is an urgent need for increased surveillance studies, rational use of the antimicrobials and preventive measures to control the disease.

Perfil bacteriano del shock séptico en una unidad de cuidados intensivos de la altitud del seguro social del Perú

Conocer el perfil bacteriano del shock séptico permitirá una adecuada elección de antibióticos empíricos. Objetivos: a) Describir el perfil bacteriano del shock séptico en una unidad de cuidados intensivos de la altitud. b) Conocer la localización de los cultivos positivos. c) Identificar la sensibilidad y el mecanismo de resistencia bacteriana. d) Encontrar diferencias de los perfiles bacterianos de la altitud. Estudio retrospectivo transversal. Realizado en una unidad de cuidados intensivos a 3,250 “msnm”. Se incluyeron los cultivos positivos y antibiogramas de residentes de la altitud con shock séptico extraídos antes del inicio de los antibióticos durante 7 años. 1,212 muestras. Escherichia coli (18.48%). Las bacterias gramnegativas presentaron sensibilidad para colistina (94-99%) el principal mecanismo de resistencia fue betalactamasa de espectro extendido (43-91%). Staphylococcus aureus (22.19%). Las bacterias grampositivas presentaron sensibilidad para tigecilina, linezolid (100%) y vancomicina (36-100%) el principal mecanismo de resistencia fue ampicilina/sulbactam resistente productor de betalactamasa (50-97%) y meticilino resistente (87-100%). En Conclusión. - a) Escherichia coli la gramnegativa más frecuente y Staphylococcus aureus el grampositivo. b) El cultivo más frecuente provenía del tracto respiratorio inferior. c) De las gramnegativas, Pseudomona aeruginosa mostro elevada sensibilidad para colistina, el resto también para tigecilina. El mecanismo de resistencia más frecuente fue betalactamasa de espectro extendido. Las Bacterias grampositivas tienen una elevada sensibilidad para tigecilina, linezolid y vancomicina. Su mecanismo de resistencia más frecuente fue ampicilina/sulbactam resistente. d) No encontramos diferencias de los perfiles bacterianos informados en la altitud. Recomendamos confirmar los resultados de sensibilidad “in vitro” de Tigeciclina.

Hospital-acquired infections caused by enterococci: a systematic review and meta-analysis, WHO European Region, 1 January 2010 to 4 February 2020

BackgroundHospital-acquired infections (HAI) caused by Enterococcus spp., especially vancomycin-resistant Enterococcusspp. (VRE), are of rising concern.AimWe summarised data on incidence, mortality and proportion of HAI caused by enterococci in the World Health Organization European Region.MethodsWe searched Medline and Embase for articles published between 1 January 2010 and 4 February 2020. Random-effects meta-analyses were performed to obtain pooled estimates.ResultsWe included 75 studies. Enterococcus spp. and VRE accounted for 10.9% (95% confidence interval (CI): 8.7-13.4; range: 6.1-17.5) and 1.1% (95% CI: 0.21-2.7; range: 0.39-2.0) of all pathogens isolated from patients with HAI. Hospital wide, the pooled incidence of HAI caused by Enterococcus spp. ranged between 0.7 and 24.8 cases per 1,000 patients (pooled estimate: 6.9; 95% CI: 0.76-19.0). In intensive care units (ICU), pooled incidence of HAI caused by Enterococcus spp. and VRE was 9.6 (95% CI: 6.3-13.5; range: 0.39-36.0) and 2.6 (95% CI: 0.53-5.8; range: 0-9.7). Hospital wide, the pooled vancomycin resistance proportion among Enterococcus spp. HAI isolates was 7.3% (95% CI: 1.5-16.3; range: 2.6-11.5). In ICU, this proportion was 11.5% (95% CI: 4.7-20.1; range: 0-40.0). Among patients with hospital-acquired bloodstream infections with Enterococcus spp., pooled all-cause mortality was 21.9% (95% CI: 15.7-28.9; range: 14.3-32.3); whereas all-cause mortality attributable to VRE was 33.5% (95% CI: 13.0-57.3; range: 14.3-41.3).ConclusionsInfections caused by Enterococcus spp. are frequently identified among hospital patients and associated with high mortality.

Development and Validation of a Tool for the Prediction of Vancomycin-Resistant Enterococci Colonization Persistence-the PREVENT Score

Vancomycin-resistant enterococci (VRE) are nosocomial pathogens with increasing prevalence worldwide. Extensive hygiene measures have been established to prevent infection transmission in hospitals. Here, we developed a predictive score system (the predictive vancomycin-resistant enterococci [PREVENT] score) to identify the clearance or persistence in patients with a history of VRE carrier status at readmission. Over a cumulative 3-year period, patients with a positive VRE carrier status were included. The study population was recruited in two successive time periods and separated into training data for predictive score development and validation data for evaluation of the predictive power. The risk factors for persistent VRE colonization were analyzed in a univariable analysis before development of a logistic regression model based on the potential risk factors. The score points were determined proportionally to the beta coefficients of the logistic regression model. The data from 448 (79%) patients were used as the training data, and those from 119 (21%) as the validation data. Multivariable analysis revealed the following variables as independent risk factors: age of ≥60 years, hemato-oncological disease, cumulative antibiotic treatment for >4 weeks, and a VRE infection. The resulting logistic regression model exhibited an acceptable area under the curve (AUC) of 0.81 (95% confidence interval [CI], 0.72 to 0.91). The predictive score system had a sensitivity of 82% (95% CI, 65 to 93%) and a specificity of 77% (95% CI, 66 to 85%). The developed predictive score system is a useful tool to assess the VRE carrier status of patients with a history of VRE colonization. On the basis of this risk assessment, more focused and cost-effective infection control measures can be implemented. IMPORTANCE Given the increasing relevance of VRE as nosocomial pathogens worldwide, infection prevention and control measures, including patient isolation and contact precautions, are indispensable to avoid their spread in the hospital setting. In this study, we developed and validated the PREVENT score, a tool for rapid risk assessment of VRE persistence in patients with a history of previous VRE colonization. The score is designed to be easily performed, employing clinical information available in a regular admission setting and immediately providing information to inform the decision of whether to adopt patient isolation and contact precautions during the hospital stay. After validation, the score was shown to accurately identify patients with persistent VRE colonization upon admission, representing a suitable option as (i) a complementary method yielding preliminary results significantly more quickly than culture-based VRE detection techniques and (ii) an alternative strategy for VRE detection in settings in which microbiological VRE screening is not routinely performed due to limited resources.

Genetic features of the poxtA linezolid resistance gene in human enterococci from France

OBJECTIVES

To describe the prevalence of poxtA among clinical linezolid-resistant enterococci (LRE) collected in France from 2016 to 2020 and to extensively characterize its genetic supports and environments.

METHODS

All LRE clinical isolates received at the National Reference Centre for Enterococci from French hospitals between 2016 and 2020 were included. LRE isolates were screened for linezolid resistance genes (cfr-like, optrA and poxtA) by real-time PCR and phenotypically characterized. A collection of 11 representative poxtA-positive isolates (10 Enterococcus faecium and 1 Enterococcus faecalis) underwent WGS by hybrid assembly combining short-read (Illumina MiSeq) and long-read (MinION) approaches. Transferability of poxtA was attempted by filter-mating experiments.

RESULTS

Out of 466 LRE received at the National Reference Centre for Enterococci over the period, 47 (10.1%) were poxtA-positive, including 42 E. faecium. The 11 isolates characterized by WGS were confirmed to be epidemiologically unrelated by core genome analysis and eight different STs were assigned to E. faecium isolates. The poxtA gene was found to be plasmid carried and flanked by IS1216E transposase genes in all isolates and frequently linked with fexB, tet(M) and tet(L). A total of seven distinct poxtA-harbouring plasmids were obtained after hybrid assembly and plasmid transfer of poxtA was successful in three cases. For the two poxtA/optrA-positive isolates, those genes were carried by different plasmids.

CONCLUSIONS

The poxtA gene has been circulating among clinical enterococci in France since at least 2016, mostly in E. faecium and independently from optrA. The poxtA-carrying plasmids often co-carried resistance genes to phenicols and tetracyclines, and could have been co-selected through their veterinary use.

Performance of commercial methods for linezolid susceptibility testing of Enterococcus faecium and Enterococcus faecalis

BACKGROUND

Linezolid-resistant enterococci (LRE) causing infections that are challenging to treat are rising, highlighting the need for reliable screening of LRE clinical isolates.

OBJECTIVES

To evaluate the ability of the broth microdilution (BMD) method for LRE detection and to assess the performance of seven commercially available techniques for linezolid susceptibility testing.

METHODS

A collection of 100 clinical isolates (80 Enterococcus faecium and 20 Enterococcus faecalis), including 20 optrA-positive isolates, 17 poxtA-positive isolates and 1 optrA/poxtA-positive E. faecium isolate, were studied. MICs were determined after 18 h [Day 1 (D1)] and 42 h [Day 2 (D2)] of incubation and interpreted following EUCAST and CLSI guidelines, which currently provide different interpretative breakpoints. Performance of commercial techniques was compared with BMD results.

RESULTS

MIC50/D1 and MIC50/D2 were both 8 mg/L, while MIC90/D1 and MIC90/D2 were 16 and 32 mg/L, respectively. MICD1 values for poxtA-positive isolates were lower than those for optrA-positive isolates. Proportions of susceptible isolates at D1 and D2 were 48% and 41%, respectively, according to EUCAST breakpoints and 35% and 13%, respectively, according to CLSI criteria (the proportions of isolates categorized as intermediate following CLSI recommendations were 13% and 28% at D1 and D2, respectively). Percentage susceptibility assessed by the commercially available techniques was always higher. The four commercial methods allowing MIC determination provided an overall essential agreement of ≥90% at D1. Categorical agreement and error rates were generally improved at D2.

CONCLUSIONS

Non-automated methods (Sensititre and UMIC) and, to a lesser extent, gradient strip Etest appear to show an acceptable correlation with the BMD reference method for the detection of isolates with low MICs of linezolid after prolonged incubation.

Structural basis of ABCF-mediated resistance to pleuromutilin, lincosamide, and streptogramin A antibiotics in Gram-positive pathogens

Target protection proteins confer resistance to the host organism by directly binding to the antibiotic target. One class of such proteins are the antibiotic resistance (ARE) ATP-binding cassette (ABC) proteins of the F-subtype (ARE-ABCFs), which are widely distributed throughout Gram-positive bacteria and bind the ribosome to alleviate translational inhibition from antibiotics that target the large ribosomal subunit. Here, we present single-particle cryo-EM structures of ARE-ABCF-ribosome complexes from three Gram-positive pathogens: Enterococcus faecalis LsaA, Staphylococcus haemolyticus VgaALC and Listeria monocytogenes VgaL. Supported by extensive mutagenesis analysis, these structures enable a general model for antibiotic resistance mediated by these ARE-ABCFs to be proposed. In this model, ABCF binding to the antibiotic-stalled ribosome mediates antibiotic release via mechanistically diverse long-range conformational relays that converge on a few conserved ribosomal RNA nucleotides located at the peptidyltransferase center. These insights are important for the future development of antibiotics that overcome such target protection resistance mechanisms.

Sex differences in vancomycin-resistant enterococci bloodstream infections-a systematic review and meta-analysis

Background

Vancomycin-resistant enterococci (VRE) have emerged in the healthcare setting worldwide. Infections with these pathogens, i.e., bloodstream infections (BSI), are accompanied with an impaired patient outcome. Diverse factors comprising patient characteristics, therapeutic strategies, and infection control measures are positively or negatively associated with VRE BSI occurrence. However, whether sex-specific differences influence the frequency of VRE BSI is yet unknown.

The aim of this systematic review was to comprehensively summarize and analyze sex prevalence in VRE BSI patients.

Main text

A systematic search for relevant articles was conducted in PubMed and Web of Science. After screening for eligibility, data extraction from included articles and risk of bias assessment were processed. The prevalence of male/female sex in VRE BSI patients and 95% CI were calculated for each study and summarized as pooled estimated effect.

In total, nine articles met the inclusion criteria. Risk of bias assessment resulted in low (six studies) to moderate bias (three studies). The pooled prevalence of male patients suffering from VRE BSI was 59% resulting in a 1.4 male/female prevalence ratio.

Conclusions

Current literature suggests sex differences with male preference (59%) in the distribution of VRE BSI cases. Further primary studies should address the question of male-specific factors favoring the enhanced frequency of VRE BSI.

Antimicrobial susceptibility of bacteremic vancomycin-resistant Enterococcus faecium to eravacycline, omadacycline, lipoglycopeptides, and other comparator antibiotics: Results from the 2019-2020 Nationwide Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

Multicenter surveillance of antimicrobial susceptibility was performed for 235 vancomycin-resistant Enterococcus faecium (VREfm) isolates from 18 Taiwanese hospitals. The minimum inhibitory concentrations (MICs) of eravacycline, omadacycline, lipoglycopeptides, and other comparator antibiotics were determined using the broth microdilution method. Nearly all isolates of VREfm were not susceptible to teicoplanin, dalbavancin, and telavancin, with susceptibility rates of 0.5%, 1.7% and 0.5%, respectively. Tigecycline and eravacycline were active against 93.2% and 89.7% of the VREfm isolates, respectively. Moreover, the susceptibility rates of quinupristin/dalfopristin, tedizolid, and linezolid were 59.1%, 84.2%, and 77.4%, respectively. Additionally, 94% of the VREfm isolates were classified as susceptible to daptomycin, and the MICs of omadacycline required to inhibit VREfm growth by 50% and 90% were 0.12 and 0.5 mg/L, respectively. Susceptibility rates of VREfm isolates to synthetic tetracyclines and daptomycin were slightly lower and to oxazolidinone-class antibiotics were much lower in Taiwan than those in other parts of the world. Continuous monitoring of VREfm resistance to novel antibiotics, including synthetic tetracyclines, oxazolidinone-class antibiotics, and daptomycin, is needed in Taiwan.

Vancomycin-resistant enterococci and coagulase-negative staphylococci prevalence among patients attending at Felege Hiwot Comprehensive Specialized Hospital, Bahir Dar, Ethiopia

Background

Vancomycin resistant enterococci (VRE) and vancomycin resistance coagulase negative staphylococci (VRCoNS) are common pathogens causing difficult to treat health care associated infections (HAI). Hence, the World Health Organization listed VRE as one of the high priority pathogens for new antibiotic discovery and antimicrobial resistance surveillance. Despite this, data on the prevalence of VRE and VRCoNS in Ethiopia is scarce. Thus, the present study determined prevalence of VRE and VRCoNS among patients attending Felege-Hiwot comprehensive specialized hospital, Ethiopia.

Methods

A hospital based cross-sectional study was conducted on 384 patients selected conveniently from February to March 2020. Data on demographic and clinical variables were collected using a structured questionnaire by face-to-face interview. Simultaneously urine, venous blood and wound swab were collected and processed following standard bacteriological technique. Antimicrobial susceptibility test was performed by minimum inhibitory concentration method using E-test for vancomycin and Kirby-Bauer disc diffusion method for other classes of antibiotics. Data was entered and analyzed using SPSS version 23. Logistic regression was performed to identify factors associated with VRE infection. P. value < 0.05 was considered as statistically significant.

Results

The prevalence of enterococci and CoNS were 6.8% and 12% respectively. The prevalence of VRE was 34.61% (9/26), while all CoNS (46 isolates) were susceptible to vancomycin. The majority (66.7%) of VRE was isolated from blood samples. Furthermore all VRE (100%), 58.8% of vancomycin susceptible enterococci and 45.7% of CoNS were multidrug resistant (MDR). Having educational level of secondary school and below (AOR = 12.80, CI = 1.149–142.5), previous exposure to catheterization (AOR = 56.0, CI = 4.331–724.0) and previous antibiotic use practice (AOR = 26.25, CI = 3.041–226.2) were a significant associated explanatory factor for VRE infection.

Conclusions

The prevalence of vancomycin resistance enterococci, which is also multidrug resistant, was significantly high. Though no vancomycin resistance CoNS detected, the MDR level of CoNS was high. Thus to limit enterococci and CoNS infections and MDR development, focused infection prevention measures should be implemented.

Mobile genetic elements beyond the VanB-resistance dissemination among hospital-associated enterococci and other Gram-positive bacteria

An increasing resistance to vancomycin among clinically relevant enterococci, such as Enterococcus faecalis and Enterococcus faecium is a cause of a great concern, as it seriously limits treatment options. The vanB operon is one of most common determinants of this type of resistance. Genes constituting the operon are located in conjugative transposons, such as Tn1549-type transposons or, more rarely, in ICEEfaV583-type structures. Such elements show differences in structure and size, and reside in various sites of bacterial chromosome or, in the case of Tn1549-type transposons, are also occasionally associated with plasmids of divergent replicon types. While conjugative transposition contributes to the acquisition of Tn1549-type transposons from anaerobic gut commensals by enterococci, chromosomal recombination and conjugal transfer of plasmids appear to represent main mechanisms responsible for horizontal dissemination of vanB determinants among hospital E. faecalis and E. faecium. This review focuses on diversity of genetic elements harbouring vanB determinants in hospital-associated strains of E. faecium and E. faecalis, the mechanisms beyond vanB spread in populations of these bacteria, and provides an overview of the vanB-MGE distribution among other enterococci and Gram-positive bacteria as potential reservoirs of vanB genes.

Excellent performance of CHROMagarTM LIN-R to selectively screen for linezolid-resistant enterococci and staphylococci

The increasing number of nosocomial pathogens with resistances against last resort antibiotics like linezolid leads to a pressing need for the reliable detection of these drug-resistant bacteria. National guidelines on infection prevention, e.g., in Germany, have already recommend screening for linezolid-resistant bacteria, although a corresponding screening agar medium has not been provided. In this study we analyzed the performance and reliability of a commercial, chromogenic linezolid screening agar. The medium was capable to predict more than a hundred linezolid-resistant isolates of E. faecium, E. faecalis, S. aureus, S. epidermidis, and S. hominis with excellent sensitivity and specificity. All isolates were collected at the National Reference Centre between 2010 and 2020.

Risk factors and outcomes associated with vancomycin-resistant Enterococcus faecium and ampicillin-resistant Enterococcus faecalis bacteraemia: A 10-year study in a tertiary-care centre in Mexico City

OBJECTIVES

We sought to identify risk factors associated with vancomycin-resistant Enterococcus faecium (VRE) and ampicillin-resistant Enterococcus faecalis (ARE) bacteraemia, predictors of 30-day mortality, and 90-day recurrence-free survival according to resistance.

METHODS

We evaluated clinical records of patients with E. faecalis and E. faecium bacteraemia (2007-2017). We performed bivariate and multivariate logistic regression analyses to identify factors associated with VRE and ARE bacteraemia and predictors of 30-day mortality. A Kaplan-Meier estimate of 90-day recurrence-free survival was done.

RESULTS

We identified 192 and 147 E. faecium and E. faecalis bacteraemia episodes, respectively, of which 55.7% of E. faecium were VRE (94% vanA) and 12.2% of E. faecalis were ARE. Factors related to VRE bacteraemia were previous hospitalisation (aOR, 80.18, 95% CI 1.81-634), history of central venous catheter (aOR, 11.15, 95% CI 2.48-50.2) and endotracheal cannula use (aOR, 17.91, 95% CI 1.22-262.82). There was higher attributable mortality to VRE (28%, 95% CI 14-68%; P < 0.001) and ARE (10%, 95% CI 0.1-36%; P = 0.58) compared with their susceptible counterparts. APACHE II (aOR, 1.45, 95% CI 1.26-1.66) and history of chemotherapy (aOR, 3.52, 95% CI 1.09-11.39) were predictors of E. faecium bacteraemia 30-day mortality. We could not recognise any factor related to ARE bacteraemia or E. faecalis 30-day mortality.

CONCLUSION

History of hospitalisation and invasive device use were related to VRE bacteraemia. APACHE II and history of chemotherapy were predictors of mortality. We could not identify factors related to ARE or predictors of mortality.