Nosocomial ventriculitis caused by a meticillin- and linezolid-resistant clone of Staphylococcus epidermidis in neurosurgical patients

Does selective digestive decontamination (SDD) increase antibiotic resistance? Long-term comparison of two intensive care units (with and without SDD) of the same tertiary hospital

PURPOSE

The aim of this study was to to compare the antimicrobial resistance rate and its relationship with the antibiotic consumption in two separate Intensive Care Units (ICUs) of the same hospital, one with and other without selective decontamination of the digestive tract (SDD).

METHODS

We performed a retrospective study in the two ICUs of the Araba University Hospital. Trauma and neurosurgical patients are admitted to the SDD-ICU, and general digestive surgery patients go to the no SDD-ICU. From 2014 to 2018 we analyzed the number of isolates, and the bacterial resistance trends of 47 antimicrobial-microorganism combinations. Additionally, antimicrobial consumption was estimated in both ICUs. Resistance rates were also compared with those reported in ENVIN-HELICS Spanish national registry.

RESULTS

In the ICU with SDD protocol, there was a significant decrease in the resistance of E. coli to amoxicillin/clavulanic acid and in the resistance of E. faecalis to high concentration of gentamycin and high concentration of streptomycin. A significant increase of resistance of Staphylococcus coagulasa negative (CoNS) to linezolid in the no SDD-ICU was also detected. Overall, the level of resistance in the SDD-ICU was lower or of the same order than in the ICU without SDD and that reported in the Spanish national registry.

CONCLUSIONS

SDD had neither a clinically relevant impact on emergence and spread of resistance, nor in the overall systemic antimicrobial use. The patient type rather than the SDD protocol showed to condition the ecology and therefore, the resistance rate in the ICUs.

Escalation of antimicrobial resistance among MRSA part 2: focus on infections and treatment

INTRODUCTION

MRSA is associated with causing a variety of infections including skin and skin structure infections, catheter and device-related (e.g. central venous catheter, prosthetic heart valve) infections, infectious endocarditis, blood stream infections, bone, and joint infections (e.g. osteomyelitis, prosthetic joint, surgical site), central nervous system infections (e.g. meningitis, brain/spinal cord abscess, ventriculitis, hydrocephalus), respiratory tract infections (e.g. hospital-acquired pneumonia, ventilator-associated pneumonia), urinary tract infections, and gastrointestinal infections. The emergence and spread of multidrug resistant (MDR) MRSA clones has limited therapeutic options. Older agents such as vancomycin, linezolid and daptomycin and a variety of newer MRSA antimicrobials and combination therapy are available to treat serious MRSA infections.

AREAS COVERED

The authors discuss infections caused by MRSA as well as common older and newer antimicrobials and combination therapy for MRSA infections. A literature search of MRSA was performed via PubMed (up to September 2022), using the keywords: antimicrobial resistance; β-lactams; multidrug resistance, Staphylococcus aureus, vancomycin; glycolipopeptides.

EXPERT OPINION

Innovation, discovery, and development of new and novel classes of antimicrobial agents are critical to expand effective therapeutic options. The authors encourage the judicious use of antimicrobials in accordance with antimicrobial stewardship programs along with infection-control measures to minimize the spread of MRSA.

Detection of the optrA Gene Among Polyclonal Linezolid-Susceptible Isolates of Enterococcus faecalis Recovered from Community Patients

Dispersion of transferable oxazolidinone resistance genes among enterococci poses a serious problem to human health. Prompt detection of bacteria carrying these genes is crucial to avoid their spread to multidrug-resistant bacteria. The aim of the study was to describe the presence of optrA-positive isolates among enterococci in a Spanish hospital, and to determine their genetic context and location through whole genome sequencing. All enterococci recovered in a Spanish hospital (Hospital El Bierzo; HEB) from February to December 2018 (n = 443), with minimal inhibitory concentrations (MICs) to linezolid (LZD) ≥4 mg/L, were tested by polymerase chain reaction for the presence of cfr, optrA, and poxtA transferable genes. Only four Enterococcus faecalis isolates (0.9%) had LZD MICs ≥4 mg/L and none of them was positive for cfr or poxtA genes. However, the optrA gene was detected in three isolates collected from urine samples of community patients, whose genomes were sequenced and subjected to bioinformatics analysis. These isolates belonged to different clones: ST7, ST480, and ST585. In these three isolates, the optrA gene was located on plasmids, associated with IS1216 in different arrays. In one isolate, the optrA plasmid coexists with a second plasmid, which carried multiple resistance genes for different classes of antibiotics. Detection of optrA-positive E. faecalis isolates in the community is a matter of concern. The spread of these bacteria into hospital settings, particularly in those, such as the HEB, where vancomycin-resistant enterococci are endemic, should be avoided, to preserve the efficacy of the last-resort oxazolidinones.

Cerebrospinal fluid drainage-related ventriculitis due to multidrug-resistant microorganisms

INTRODUCTION

The aim of the study was to analyze the clinical and microbiological characteristics of adult patients with cerebrospinal fluid (CSF) drainage-related ventriculitis.

METHODS

Retrospective study from January 2010 to June 2019 performed in the Complexo Hospitalario Universitario de Vigo (Spain). Cases of CSF drainage-related ventriculitis in patients ≥18-year-old were gathered. Clinical characteristics of patients, type of drainage devices, management and microbiological isolates were analyzed.

RESULTS

Ninety-one episodes of CSF drainage-related ventriculitis were identified. The most frequent organisms isolated were Gram-positive cocci (65%), mainly Staphylococcus epidermidis (48%). Multidrug-resistant microorganisms were detected in 21 episodes (23%). In multivariate analysis, the independent factors related with multidrug-resistant ventriculitis were the length of hospital stay >14 days (HR 6.7; 95%CI 1.75-25.86, p=0.006) and previous antimicrobial therapy (HR 5.58; 95%CI 1.44-21.65, p=0.013).

CONCLUSIONS

Our study shows a large number of drainage-related ventriculitis episodes caused by multidrug-resistant organisms and reinforce the importance of a judicious use of antibiotics.

Comparative Proteomic Analysis Reveals Antibacterial Mechanism of Patrinia scabiosaefolia Against Methicillin Resistant Staphylococcus epidermidis

Purpose

As a kind of opportunist pathogen, Staphylococcus epidermidis (MRSE) can cause nosocomial infections and easily evolve into resistant bacteria. Among these, methicillin-resistant Staphylococcus epidermidis (MRSE) exhibit significantly higher rates. Our previous study showed that Patrinia scabiosaefolia (PS) possessed strong antibacterial activity against MRSE. However, the mechanism of PS against MRSE is not clear.

Methods

Here, a tandem mass tag-based (TMT) proteomic analysis was performed to elucidate the potential mechanism of PS against MRSE. We compared the differential expression proteins of MRSE under PS stress.

Results

Based on a fold change of >1.2 or < 1/1.2 (with p value set at <0.05), a total of 248 proteins (128 up-regulated proteins, 120 down-regulated proteins) were identified. Bioinformatic analysis showed that proteins including arginine deiminase (arcA), ornithine carbamoyltransferase (arcB) and carbamate kinase (arcC), serine–tRNA ligase (serS), phenylalanine–tRNA ligase beta and subunit (pheT), DltD (dlt), d-alanyl carrier protein (dlt), accumulation-associated protein (SasG), serine-aspartate repeat-containing protein C (SdrC) and hemin transport system permease protein HrtB (VraG) played important roles in mechanism of PS against MRSE.

Conclusion

In summary, these results indicated that arginine deiminase pathway (ADI) pathway, protein synthesis, cell wall synthesis, biofilm formation and uptake of iron were related to mechanisms of PS against MRSE. Our findings provide an insight into the the mechanism of PS against MRSE, and may be valuable in offering new targets to develop more anti-MRSE drugs.

Combined antibiotic stewardship and infection control measures to contain the spread of linezolid-resistant Staphylococcus epidermidis in an intensive care unit

Background

The unrestricted use of linezolid has been linked to the emergence of linezolid-resistant Staphylococcus epidermidis (LRSE). We report the effects of combined antibiotic stewardship and infection control measures on the spread of LRSE in an intensive care unit (ICU).

Methods

Microbiological data were reviewed to identify all LRSE detected in clinical samples at an ICU in southwest Germany. Quantitative data on the use of antibiotics with Gram-positive coverage were obtained in defined daily doses (DDD) per 100 patient-days (PD). In addition to infection control measures, an antibiotic stewardship intervention was started in May 2019, focusing on linezolid restriction and promoting vancomycin, wherever needed. We compared data from the pre-intervention period (May 2018–April 2019) to the post-intervention period (May 2019–April 2020). Whole-genome sequencing (WGS) was performed to determine the genetic relatedness of LRSE isolates.

Results

In the pre-intervention period, LRSE were isolated from 31 patients (17 in blood cultures). The average consumption of linezolid and daptomycin decreased from 7.5 DDD/100 PD and 12.3 DDD/100 PD per month in the pre-intervention period to 2.5 DDD/100 PD and 5.7 DDD/100 PD per month in the post-intervention period (p = 0.0022 and 0.0205), respectively. Conversely, vancomycin consumption increased from 0.2 DDD/100 PD per month to 4.7 DDD/100 PD per month (p < 0.0001). In the post-intervention period, LRSE were detected in 6 patients (4 in blood cultures) (p = 0.0065). WGS revealed the predominance of one single clone.

Conclusions

Complementing infection control measures by targeted antibiotic stewardship interventions was beneficial in containing the spread of LRSE in an ICU.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00970-3.

Cerebrospinal fluid drainage-related ventriculitis due to multidrug-resistant microorganisms

INTRODUCTION

The aim of the study was to analyze the clinical and microbiological characteristics of adult patients with cerebrospinal fluid (CSF) drainage-related ventriculitis.

METHODS

Retrospective study from January 2010 to June 2019 performed in the Complexo Hospitalario Universitario de Vigo (Spain). Cases of CSF drainage-related ventriculitis in patients ≥18-year-old were gathered. Clinical characteristics of patients, type of drainage devices, management and microbiological isolates were analyzed.

RESULTS

Ninety-one episodes of CSF drainage-related ventriculitis were identified. The most frequent organisms isolated were Gram-positive cocci (65%), mainly Staphylococcus epidermidis (48%). Multidrug-resistant microorganisms were detected in 21 episodes (23%). In multivariate analysis, the independent factors related with multidrug-resistant ventriculitis were the length of hospital stay >14 days (HR 6.7; 95%CI 1.75-25.86, p=0.006) and previous antimicrobial therapy (HR 5.58; 95%CI 1.44-21.65, p=0.013).

CONCLUSIONS

Our study shows a large number of drainage-related ventriculitis episodes caused by multidrug-resistant organisms and reinforce the importance of a judicious use of antibiotics.

Linezolid for the treatment of postneurosurgical infection caused by methicillin-resistant Staphylococcus

Background

Postneurosurgical infection (PNSI) is a major problem. Linezolid is a bacteriostatic oxazolidinone antibiotic with a highly activity against Gram-positive cocci resistant to methicillin and a good cerebrospinal fluid penetration. The purpose of this study is to evaluate the efficacy of linezolid in the treatment of PNSI caused by methicillin-resistant Staphylococcus (MRS).

Methods

We conducted an observational study for all patients over 14 years old and diagnosed with MRS PNSI. Demographic, clinical, and laboratory information were collected prospectively.

Results

A total of 10 patients with PNSI (6 meningitis, 2 ventriculitis, and 2 subdural empyema) received linezolid. MRS isolated was Staphylococcus aureus in seven cases and Staphylococcus epidermidis in three cases. All isolated microorganisms were susceptible to vancomycin (minimum inhibitory concentration (MIC) = 2 mg/L) and linezolid (MIC = 1). The rate of microbiologic efficacy was 100% for patients with meningitis or ventriculitis. In the case of subdural empyema, focal infection had improved between 14 and 18 days. No adverse effects occurred during this study.

Conclusion

Our results suggest that linezolid as an alternative to vancomycin for the treatment of PNSI caused by MRS with a high rate of efficacy.

Long-term endemic situation caused by a linezolid- and meticillin-resistant clone of Staphylococcus epidermidis in a tertiary hospital

BACKGROUND

Linezolid (LZD)-resistant Staphylococcus epidermidis (LRSE) are increasing, and are mainly associated with outbreaks in hospital wards with high LZD consumption.

AIM

To investigate the frequency of LRSE in a tertiary hospital in the context of LZD use.

METHODS

The frequency of LRSE and the data on LZD usage [expressed as defined daily dose (DDD) per 100 patient-days], from 2011 to 2017, were analysed retrospectively. Selected LRSE were typed by pulsed-field gel electrophoresis (PFGE) and screened for transferable LZD resistance genes. Representative isolates were typed by multi-locus sequence typing, and ribosomal mechanisms of LZD resistance were investigated.

FINDINGS

In total, 435 LRSE were detected, with frequencies ranging from 13.56% to 32.93% in the intensive care unit (ICU) where LZD consumption was high (6.34-8.10 DDDs), and from 2.48 to 6.80% in the remaining wards where LZD use was considerably lower (0.63-2.49 DDDs). The first 44 LRSE isolates recovered (June 2013-June 2014) were closely related according to PFGE patterns, and all except one were resistant to meticillin due to mecA production. Selected isolates belonged to ST2, carried SCCmec III, and had the G2576T mutation in the V domain of each of the six copies of the 23S rRNA gene. Five of the 44 isolates (11.36%) were positive for the cfr gene.

CONCLUSION

An ST2 LZD- and meticillin-resistant clone was found in the ICU and also in wards with low consumption of LZD. This highlights the need to implement and maintain infection control measures as well as antimicrobial stewardship programmes in all hospital units in order to preserve the efficacy of LZD.

Clinical Outcomes Associated With Linezolid Resistance in Leukemia Patients With Linezolid-Resistant Staphylococcus epidermidis Bacteremia

Background

Coagulase-negative staphylococci, including Staphylococcus epidermidis, are the most common cause of bloodstream infection in cancer patients. Linezolid resistance is increasingly identified in S. epidermidis, but whether such resistance alters the clinical course of S. epidermidis infections is unknown. The purpose of this study was to assess the clinical impact of linezolid resistance in leukemia patients with S. epidermidis bloodstream infection.

Methods

This was a retrospective, single-center cohort study of all adult leukemia patients with S. epidermidis bacteremia treated with empiric linezolid between 2012 and 2015. The primary end point was adverse clinical outcome on day 3, defined as a composite of persistent bacteremia, fever, intensive care unit admission, or death. Fourteen- and 30-day mortality were also assessed.

Results

Eighty-two unique leukemia patients with S. epidermidis were identified. Linezolid resistance was identified in 33/82 (40%). Patients with linezolid-resistant S. epidermidis were significantly more likely to have persistent bacteremia (41% vs 7%; adjusted relative risk [aRR], 5.15; 95% confidence interval [CI], 1.63–16.30; P = .005); however, adverse short-term clinical outcomes overall were not more common among patients with linezolid-resistant S. epidermidis (61% vs 33%; aRR, 1.46; 95% CI, 0.92–2.32; P = .108). No differences were observed in 14- or 30-day mortality.

Conclusions

Leukemia patients with linezolid-resistant S. epidermidis bacteremia who were treated with linezolid were significantly more likely to have persistent bacteremia compared with those with linezolid-sensitive isolates. Interventions to limit the clinical impact of linezolid-resistant S. epidermidis are warranted.