A Review of Combination Antimicrobial Therapy for Enterococcus faecalis Bloodstream Infections and Infective Endocarditis

The protective effect of Ambrosia maritima versus vitamin D3 against gentamicin-induced acute cortical kidney injury in adult male albino rats: Histological and immunohistochemical study

Gentamicin (GM) is a broad-spectrum antibiotic widely used for severe bacterial infections, but itis associated with acute nephrotoxicity. Ambrosia maritima L. is an annual herbaceous plant that has avariety of medicinal and antioxidant activities. Vitamin D3 is involved in a multitude of biological functions and essential antioxidant pathways. This study aims to investigate the protective effects of Damsissa (Ambrosia maritima) versus vitamin D3 against GM-induced nephrotoxicity using 72 male rats that were randomly divided into six groups: control, Damsissa (100 mg/kg/day), vitamin D3 (1000 IU/kg/day), GM(100 mg/kg/day for 7 days), GM + Damsissa, and GM + vitamin D3. Renal function, oxidative stress biomarkers (MDA, CAT, SOD, GSH), cytokine levels (IL-1β, IL-6, TNF-α, IL-4), and gene expression (Caspase-3, Keap1, PPARγ, Nrf2) were assessed. Histopathological and ultrastructural kidney analyses were conducted using H&E, Masson's trichrome, PCNA staining, and transmission electron microscopy. Blood samples were tested for renal and liver markers (creatinine, BUN, AST, ALT). Damsissa enhanced survival rates, returned the renal indices to near normal, and ameliorated pathological changes based on immunohistopathological and ultrastructural results. They further reduced pro-inflammatory cytokine production, optimized oxidative stress markers, and normalized gene expression levels. Both treatments exhibited abundant antioxidant and anti-inflammatory effects, which remarkably reduced GM-induced acute kidney injury. These results suggest that both Damsissa and vitamin D3 may exert protective effects against drug-induced nephrotoxicity.

Tetracyclines at subinhibitory concentrations are lethal for NADH peroxidase-deficient mutants of Enterococcus faecium

OBJECTIVES

Tigecycline is a bacteriostatic antibiotic member of the glycylcycline family that inhibits protein synthesis. Tigecycline is a last-line treatment for infections caused by MDR pathogens like vancomycin-resistant Enterococcus faecium (VR-Efm). We recently explored oxidative stress defences in E. faecium and we here aimed to assess their role in antibiotic resistance.

METHODS

Antibiotic susceptibility was evaluated in mutants deficient in primary oxidative stress defences by monitoring bacterial survival after a 24 h treatment. Hydrogen peroxide (H2O2) levels were quantified to link bacterial survival to oxidative stress.

RESULTS

Unexpectedly, tigecycline and other tetracyclines were lethal for VR-Efm AUS0004 mutants deficient in NADH peroxidase (Npr) at concentrations below their MICs. Lethality seemed to correlate with increased H2O2 accumulation in the Δnpr mutant. H2O2 production in Efm AUS0004 was mainly mediated by lactate oxidase Lox1, whereas Lox2 and pyruvate oxidase (Pox) had minor or no roles. Tigecycline was not lethal for a ΔnprΔlox1 double mutant, suggesting lethality results from both antibiotic effect and peroxide accumulation.

CONCLUSIONS

This study might pave the way to develop strategies aimed at potentiating tigecycline action by increasing endogenous H2O2 production and/or impairing H2O2 detoxification, potentially improving treatment efficiencies for VR-Efm infections with this last-line antibiotic.

Management of Enterococcus faecalis biofilms: a combinatorial approach with phytochemical

The rapid emergence of antimicrobial resistance in Enterococcus faecalis infections was primarily due to their robust biofilm formation, highlighting the urgent need for meaningful strategies. Since combinatorial application of natural phytochemical often offer promising outcomes in dealing with microbial infections, present study indicated the pharmacological, antimicrobial and antibiofilm potential of combinatorial strategies of natural phytochemical involving cuminaldehyde and thymoquinone against E. faecalis. Towards this direction, in silico analysis suggested that both compounds could show favourable oral bioavailability and high GI absorption, with a considerable solubility and drug-likeness profiles. Furthermore, in vitro antimicrobial assay indicated that the minimum inhibitory concentrations (MIC) of cuminaldehyde and thymoquinone were found to be 500 µg/mL and 30 µg/mL, respectively against E. faecalis. Thereafter, the fractional inhibitory concentration (FIC) index score of 0.73 indicated an additive effect prevailed between cuminaldehyde and thymoquinone, enhancing their antimicrobial potential. Thereafter, sub-MIC doses of cuminaldehyde (40 µg/mL) and thymoquinone (8 µg/mL) were selected to assess their antibiofilm potential. Though the compounds were able to show antibiofilm activity separately, their combination was significantly more effective, reduced biofilm formation by approximately 80%, and decreased production of extracellular polymeric substance (EPS) and protein content by ~ 76% and ~ 70%, respectively. Further studies revealed that the antibiofilm activity of the test compounds could likely to be attributed to the accumulation of reactive oxygen species (ROS) and enhancement of membrane permeability. Taken together, all this experimental observation revealed that combination of these natural compounds could potentially improve the treatment outcomes of biofilm-borne infections of E. faecalis.

Treatment of Complicated Gram-Positive Bacteremia and Infective Endocarditis

The Gram-positive cocci Staphylococcus aureus, Streptococcus spp., and Enterococcus spp. are the most frequent causative organisms of bloodstream infections and infective endocarditis. "Complicated bacteremia" is a term used in S. aureus bloodstream infections and originally implied the presence of metastatic infectious foci (i.e. complications of S. aureus bacteremia). These complications demand longer antimicrobial treatment durations and, frequently, interventional source control. Several risk factors for the incidence of bacteremia complications have been identified and are often used for the definition of complicated bacteremia. Here, we discuss management and diagnostic approaches and treatment options for patients with complicated bacteremia, with particular focus on infective endocarditis. We also summarize the available evidence regarding imaging modalities and the choice of antimicrobial mono- or combination therapy according to resistance patterns for these pathogens as well as treatment durations and optimized application routes. Finally, we synopsize current and future areas of research in complicated bacteremia and infective endocarditis.

From Isolation to Application: Utilising Phage-Antibiotic Synergy in Murine Bacteremia Model to Combat Multidrug-Resistant Enterococcus faecalis

Enterococcus species, natural inhabitants of the human gut, have become major causes of life-threatening bloodstream infections (BSIs) and the third most frequent cause of hospital-acquired bacteremia. The rise of high-level gentamicin resistance (HLGR) in enterococcal isolates complicates treatment and revives bacteriophage therapy. This study isolated and identified forty E. faecalis clinical isolates, with 30% exhibiting HLGR. The HLGR5 isolate, resistant to fosfomycin, vancomycin, and linezolid, was used to isolate the vB_EfaS_SZ1 phage from effluent water. This phage specifically lysed 42% of HLGR isolates. vB_EfaS_SZ1 demonstrated beneficial traits, including thermal stability, acid-base tolerance, a short latent period, and a large burst size. The phage genome comprises a 40,942 bp linear double-stranded DNA with 65 open reading frames (ORFs). The genome closely resembled Enterococcus phages, classifying it within the Efquatrovirus genus. Phage-antibiotic synergy was assessed using checkerboard assays and time-killing analyses, revealing enhanced bacteriolytic activity of ampicillin and fosfomycin, with significant reductions in minimum inhibitory concentration values. In a mouse bacteremia model, phage-antibiotic combinations significantly reduced E. faecalis liver burden compared to monotherapies. Histopathological analysis confirmed therapeutic synergy, showing reduced inflammation and improved hepatocyte regeneration. These findings underscore the potential of phage vB_EfaS_SZ1 as an adjunct to antibiotic therapy for resistant enterococcal bacteremia.

The Combination of Phage Therapy and β-Lactam Antibiotics for the Effective Treatment of Enterococcus faecalis Infections

A phage-antibiotic synergy could be an alternative in urinary tract infection (UTI) therapy, as it leads to the elimination of bacteria and to the reduction in variants resistant to phages and antibiotics. The aims of the in vitro study were to determine whether phages vB_Efa29212_2e and vB_Efa29212_3e interact synergistically with selected antibiotics in the treatment of E. faecalis infections, to optimize antibiotic concentrations and phage titers for the most effective combinations, and to assess their impact on the number of spontaneous resistant variants and on the phages' reproductive cycles. The modified double-layer disc diffusion method, checkboard, time-kill assays, one-step growth method and the double agar overlay plaque assay were implemented. Synergistic interactions were most often observed after the combined action of phages 2e or 3e and β-lactam antibiotics on E. faecalis strains. The beneficial effects depended on the bacterial strain, phage and antibiotic used. The lowest minimum inhibitory concentration (MIC50) values of the antibiotics were recorded, after the application of low titers of phage 2e, and high titers of phage 3e. The combined use of the tested agents resulted in a significant reduction in the number of resistant variants and had an impact on the reproductive cycle of the tested phages, e.g., a 50% increase in burst size, and a 5 min reduction in the latency period of 2e were observed. The study confirmed beneficial interactions between phages and β-lactam antibiotics against E. faecalis growth.

Antibiotics' resistance profile of pathogens isolated from fish products sold in the city of Bangangté, Cameroon: Aqueous extracts from spices' formulations used as accompanying soup of braised fish as antimicrobial alternative

The present study aimed to evaluate the antimicrobial activity of aqueous extracts of the mixture of spices used as accompanying soup of braised fish against multidrug resistant (MDR) bacteria isolated from raw and braised fish collected in the city of Bangangté, Cameroon. A survey was conducted in the city of Bangangté to diagnose the braising fish processes. Pathogens were isolated from raw and braised fish samples collected in fish farms and selling points, and their susceptibility to 16 commonly used antibiotics was tested using the Kirby-Bauer disk diffusion method. The aqueous extracts of spices' formulations used as accompanying soup of braised fish were tested against MDR isolates using the well diffusion method. The results revealed that 13 spices are used in the preparation of accompanying soups of braised fish. Three formulations were identified with mbongo, clove and prekeses as the main differential spices. These formulations were either heated at 100 °C/30 min (process 1) or not (process 2) before being served to consumers'. Fifty-five strains belonging to six species (Salmonella Typhi, Salmonella Paratyphi, Escherichia coli, Escherichia vulneralis, Staphylococcus aureus and Staphylococcus spp.) were isolated from the different samples. Forty-four isolates were resistant to several antibiotics with Multiple Antibiotic Resistance indexes ranging from 0.18 to 0.81. The aqueous extracts of all the formulations were active against the MDR isolates independent of the formulation and preparation process, with inhibition diameters varying significantly (p < 0.05) from one isolate to another. Heated extracts were less active than the unheated ones and the most active extract was from the formulation including clove. The strains E. coli and E. vulneralis were most resistant to the different extracts whereas S. Typhi, S. aureus, Staphylococcus spp. and S. Paratyphi A, were more sensitive. This study evidenced that fish products from Bangangté city contain MDR pathogens and demonstrated that the formulations of spices used as accompanying soup for braised fish are active against these MDR pathogens. It suggests their potential use as strategy to combat the antimicrobial resistance phenomena associated to foodborne gastroenteritis pathogens. It also suggests that more attention should be paid to the use of antibiotics in fish farming activities.

Conjugation of Polycationic Peptides Extends the Efficacy Spectrum of β-Lactam Antibiotics

Antibiotic-resistant enterococci represent a significant global health challenge. Unfortunately, most β-lactam antibiotics are not applicable for enterococcal infections due to intrinsic resistance. To extend their antimicrobial spectrum, polycationic peptides are conjugated to examples from each of the four classes of β-lactam antibiotics. Remarkably, the β-lactam-peptide conjugates gained an up to 1000-fold increase in antimicrobial activity against vancomycin-susceptible and vancomycin-resistant enterococci. Even against β-lactam-resistant Gram-negative strains, the conjugates are found to be effective despite their size exceeding the exclusion volume of porins. The extraordinary gain of activity can be explained by an altered mode of killing. Of note, the conjugates showed a concentration-dependent activity in contrast to the parent β-lactam antibiotics that exhibited a time-dependent mode of action. In comparison to the parent β-lactams, the conjugates showed altered affinities to the penicillin-binding proteins. Furthermore, it is found that peptide conjugation also resulted in a different elimination route of the compounds when administered to rodents. In mice systemically infected with vancomycin-resistant enterococci, treatment with a β-lactam-peptide conjugate reduced bacterial burden in the liver compared to its originator. Therefore, peptide modification of β-lactam antibiotics represents a promising platform strategy to broaden their efficacy spectrum, particularly against enterococci.

Transcatheter aortic valve implantation (TAVI) prostheses in vitro - biofilm formation and antibiotic effects

Background

Transcatheter aortic valve implantation (TAVI) is a percutaneous catheter-based treatment of aortic stenosis as an alternative to open heart valve surgery. In cases of TAVI endocarditis, the treatment possibilities may be limited as surgical removal of the infected valve may be associated with a high risk in elderly, comorbid or frail patients. The propensity of bacteria to form a biofilm on foreign material is assumed to be of importance part of the disease process in TAVI endocarditis, but no studies on biofilm formation on TAVI valves have been conducted. We hypothesize that Staphylococcus aureus and Enterococcus faecalis biofilm formation on TAVI valves may have an impact on antibiotic tolerance and non-surgical cure rates.

Methods

TAVI valves (pieces including part of the metal frame, approximately 1 cm wide) were exposed to either species in vitro in LB-Krebs Ringer medium at 37 °C, with the bacterial count being assessed by culturing of sonicated TAVI pieces and broth at 0, 4, 18 and 24 h after bacterial exposure. Scanning electron microscopy (SEM) was performed. Effects of ampicillin, gentamicin, moxifloxacin, rifampicin (for S. aureus), and ceftriaxone (for E. faecalis) at 5 times minimal inhibitory concentration were tested alone and in combination with ampicillin. Antibiotics were added to biofilm aged 0 or 24 h and the effects assessed.

Results

Exposure for 15 min established attachment to all of valve pieces. SEM findings were consistent with biofilm formation and suggested lower amounts of bacteria on the metal compared to the tissue part of the TAVI valves. The number of bacteria attached to the TAVI valves increased until 24 h of incubation from less than 10^1 to a level of approximately 10^9 CFU/g. The bacteria became more tolerant to antibiotics on the TAVI valves over time, with the bactericidal effect against 24-h old biofilm being significantly less effective than against 0-h old biofilm depending on antibiotic.

Conclusions

The results indicate that bacteria can adhere to metal and tissue parts of the TAVI valves within minutes after an exposure which is comparable to transient bacteremia in vivo, and that the bacteria rapidly gain biofilm properties, associated with significantly reduced antibiotic effect.

Update on the epidemiology, diagnosis, and management of infective endocarditis: A review

Despite advancements in the diagnosis and treatment of infective endocarditis (IE), the burden of IE has remained relatively high over the past decade. With an ageing population and an increasing proportion of healthcare-associated IE, the epidemiology of IE has undergone significant changes. Staphylococcus aureus has evolved as the most common causative microorganism, even in most low- and middle-income countries. Several imaging modalities and novel microbiological tests have emerged to facilitate the diagnosis of IE. Outpatient parenteral antibiotic treatment and oral step-down antibiotic treatment have become new trends for the management of IE. Early surgical intervention, particularly within seven days, should be considered in cases of IE with appropriate surgical indications. We comprehensively review the updated epidemiology, microbiology, diagnosis, and management of IE.

Activity of the Caged Xanthone Morellic Acid against Vancomycin-Resistant Enterococcus Infection by Targeting the Bacterial Membrane

Vancomycin-resistant Enterococcus (VRE) is an important nosocomial opportunistic pathogen that is associated with multidrug resistance. Here, we demonstrate that morellic acid inhibits VRE by restoring its sensitivity to vancomycin and ampicillin with low drug resistance and efficient biofilm clearance effects. Morellic acid binds to inner membrane phospholipids, such as phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) of VRE, such that the fluidity and proton-motive force (PMF) interfere with the damaged inner membrane, causing intracellular reactive oxygen species (ROS) accumulation and bacterial death. Transcriptional analyses supported this effect on inner membrane-related pathways such as fatty acid biosynthesis and glycerophospholipid metabolism. Moreover, morellic acid significantly eliminated residual bacteria in the spleen, liver, kidneys, and abdominal effusion in mice. Our findings indicate the potential applications of morellic acid as an antibacterial agent or adjuvant for treating VRE infections.

Synthesis, Physicochemical Characterization, and Antimicrobial Evaluation of Halogen-Substituted Non-Metal Pyridine Schiff Bases

Four synthetic Schiff bases (PSB1 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-dibromophenol], PSB2 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-diiodophenol], PSB3 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-iodophenol], and PSB4 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-chloro-6-iodophenol]) were fully characterized. These compounds exhibit an intramolecular hydrogen bond between the hydroxyl group of the phenolic ring and the nitrogen of the azomethine group, contributing to their stability. Their antimicrobial activity was evaluated against various Gram-negative and Gram-positive bacteria, and it was found that the synthetic pyridine Schiff bases, as well as their precursors, showed no discernible antimicrobial effect on Gram-negative bacteria, including Salmonella Typhi (and mutant derivatives), Salmonella Typhimurium, Escherichia coli, and Morganella morganii. In contrast, a more pronounced biocidal effect against Gram-positive bacteria was found, including Bacillus subtilis, Streptococcus agalactiae, Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus haemolyticus. Among the tested compounds, PSB1 and PSB2 were identified as the most effective against Gram-positive bacteria, with PSB2 showing the most potent biocidal effects. Although the presence of reactive oxygen species (ROS) was noted after treatment with PSB2, the primary mode of action for PSB2 does not appear to involve ROS generation. This conclusion is supported by the observation that antioxidant treatment with vitamin C only partially mitigated bacterial inhibition, indicating an alternative biocidal mechanism.

Epidemiological trends and susceptibility patterns of bloodstream infections caused by Enterococcus spp. in six German university hospitals: a prospectively evaluated multicentre cohort study from 2016 to 2020 of the R-Net study group

PURPOSE

To analyse recent epidemiological trends of bloodstream infections (BSI) caused by Enterococcus spp. In adult patients admitted to tertiary care centres in Germany.

METHODS

Epidemiological data from the multicentre R-NET study was analysed. Patients presenting with E. faecium or E. faecalis in blood cultures in six German tertiary care university hospitals between October 2016 and June 2020 were prospectively evaluated. In vancomycin-resistant enterococci (VRE), the presence of vanA/vanB was confirmed via molecular methods.

RESULTS

In the 4-year study period, 3001 patients with BSI due to Enterococcus spp. were identified. E. faecium was detected in 1830 patients (61%) and E. faecalis in 1229 patients (41%). Most BSI occurred in (sub-) specialties of internal medicine. The pooled incidence density of enterococcal BSI increased significantly (4.0-4.5 cases per 10,000 patient days), which was primarily driven by VRE BSI (0.5 to 1.0 cases per 10,000 patient days). In 2020, the proportion of VRE BSI was > 12% in all study sites (range, 12.8-32.2%). Molecular detection of resistance in 363 VRE isolates showed a predominance of the vanB gene (77.1%).

CONCLUSION

This large multicentre study highlights an increase of BSI due to E. faecium, which was primarily driven by VRE. The high rates of hospital- and ICU-acquired VRE BSI point towards an important role of prior antibiotic exposure and invasive procedures as risk factors. Due to limited treatment options and high mortality rates of VRE BSI, the increasing incidence of VRE BSI is of major concern.

Infective endocarditis with metastatic infections in a renal transplant recipient: a case report

BACKGROUND

Infective endocarditis is an uncommon but well-known post-transplant complication with significant morbidity and mortality. It has been observed to be about 171 times more common in solid organ transplant patients than in the general population. With the increasing rate of end-stage kidney disease, the higher demand for kidney transplantation with better graft survival, and life expectancy rates, more transplant recipients may develop infective endocarditis as a late post-transplant complication. Prompt diagnosis of infective endocarditis is therefore necessary to avert graft loss and other life-threatening outcomes.

CASE PRESENTATION

We present a case of a 52-year-old African patient who had a live donor kidney transplant 18 months prior to presentation and had been on oral tacrolimus 5 mg every morning/4.5 mg every evening, mycophenolic acid (MPA) 720 mg twice daily, and oral prednisolone 10 mg daily as maintenance immunosuppressive medications. Regarding the above immunosuppressive medications, he had been in good health and had a functioning transplant graft. He presented with a resolving right thigh swelling, recurrence of fever, new onset left hemiplegia, and seizures. Enterococcus faecalis infective endocarditis was diagnosed with metastatic brain abscesses, which was treated with intravenous vancomycin and gentamycin for 5 weeks. There are very few reported cases of infective endocarditis due to Enterococcus faecalis, and this case is unique because the initial presentation was pyomyositis.

CONCLUSION

Infective endocarditis with septic embolization to the brain should be considered in kidney transplant recipients with pyomyositis and multiple rim-enhancing lesions, especially in the late post-transplant period with Enterococcal spp. as an emerging cause of infective endocarditis in kidney transplant recipients. Clinicians will need to have a high index of suspicion to aid early diagnosis with appropriate treatment to prevent adverse outcomes.

A Rhein-Based Derivative Targets Staphylococcus aureus

The rise in antibiotic-resistant bacteria highlights the need for novel antimicrobial agents. This study presents the design and synthesis of a series of rhein (RH)-derived compounds with improved antimicrobial properties. The lead compound, RH17, exhibited a potent antibacterial activity against Staphylococcus aureus (S. aureus) isolates, with minimum inhibitory concentrations (MICs) ranging from 8 to 16 μg/mL. RH17 disrupted bacterial membrane stability, hindered metabolic processes, and led to an increase in reactive oxygen species (ROS) production. These mechanisms were confirmed through bacterial growth inhibition assays, membrane function assessments, and ROS detection. Notably, RH17 outperformed the parent compound RH and demonstrated bactericidal effects in S. aureus. The findings suggest that RH17 is a promising candidate for further development as an antimicrobial agent against Gram-positive pathogens, addressing the urgent need for new therapies.

Biofilm-specific determinants of enterococci pathogen

Amongst all Enterococcus spp., E. faecalis and E. faecium are most known notorious pathogen and their biofilm formation has been associated with endocarditis, oral, urinary tract, and wound infections. Biofilm formation involves a pattern of initial adhesion, microcolony formation, and mature biofilms. The initial adhesion and microcolony formation involve numerous surface adhesins e.g. pili Ebp and polysaccharide Epa. The mature biofilms are maintained by eDNA, It's worth noting that phage-mediated dispersal plays a prominent role. Further, the involvement of peptide pheromones in regulating biofilm maintenance sets it apart from other pathogens and facilitating the horizontal transfer of resistance genes. The role of fsr based regulation by regulating gelE expression is also discussed. Thus, we provide a concise overview of the significant determinants at each stage of Enterococcus spp. biofilm formation. These elements could serve as promising targets for antibiofilm strategies.

Clinical profile, microbiology and outcomes in infective endocarditis treated with aortic valve replacement: a multicenter case-control study

BACKGROUND

Aortic valve infective endocarditis (IE) is associated with significant morbidity and mortality. We aimed to describe the clinical profile, risk factors and predictors of short- and long-term mortality in patients with aortic valve IE treated with aortic valve replacement (AVR) compared with a control group undergoing AVR for non-infectious valvular heart disease.

METHODS

Between January 2008 and December 2013, a total of 170 cases with IE treated with AVR (exposed cohort) and 677 randomly selected non-infectious AVR-treated patients with degenerative aortic valve disease (controls) were recruited from three tertiary hospitals with cardiothoracic facilities across Scandinavia. Crude and adjusted hazard ratios (HR) were estimated using Cox regression models.

RESULTS

The mean age of the IE cohort was 58.5 ± 15.1 years (80.0% men). During a mean follow-up of 7.8 years (IQR 5.1-10.8 years), 373 (44.0%) deaths occurred: 81 (47.6%) in the IE group and 292 (43.1%) among controls. Independent risk factors associated with IE were male gender, previous heart surgery, underweight, positive hepatitis C serology, renal failure, previous wound infection and dental treatment (all p < 0.05). IE was associated with an increased risk of both short-term (≤ 30 days) (HR 2.86, [1.36-5.98], p = 0.005) and long-term mortality (HR 2.03, [1.43-2.88], p < 0.001). In patients with IE, chronic obstructive pulmonary disease (HR 2.13), underweight (HR 4.47), renal failure (HR 2.05), concomitant mitral valve involvement (HR 2.37) and mediastinitis (HR 3.98) were independent predictors of long-term mortality. Staphylococcus aureus was the most prevalent microbe (21.8%) and associated with a 5.2-fold increased risk of early mortality, while enterococci were associated with the risk of long-term mortality (HR 1.78).

CONCLUSIONS

In this multicenter case-control study, IE was associated with an increased risk of both short- and long-term mortality compared to controls. Efforts should be made to identify, and timely treat modifiable risk factors associated with contracting IE, and mitigate the predictors of poor survival in IE.

Characterization and Anti-Biofilm Activity of Lytic Enterococcus Phage vB_Efs8_KEN04 against Clinical Isolates of Multidrug-Resistant Enterococcus faecalis in Kenya

Enterococcus faecalis (E. faecalis) is a growing cause of nosocomial and antibiotic-resistant infections. Treating drug-resistant E. faecalis requires novel approaches. The use of bacteriophages (phages) against multidrug-resistant (MDR) bacteria has recently garnered global attention. Biofilms play a vital role in E. faecalis pathogenesis as they enhance antibiotic resistance. Phages eliminate biofilms by producing lytic enzymes, including depolymerases. In this study, Enterococcus phage vB_Efs8_KEN04, isolated from a sewage treatment plant in Nairobi, Kenya, was tested against clinical strains of MDR E. faecalis. This phage had a broad host range against 100% (26/26) of MDR E. faecalis clinical isolates and cross-species activity against Enterococcus faecium. It was able to withstand acidic and alkaline conditions, from pH 3 to 11, as well as temperatures between -80 °C and 37 °C. It could inhibit and disrupt the biofilms of MDR E. faecalis. Its linear double-stranded DNA genome of 142,402 bp contains 238 coding sequences with a G + C content and coding gene density of 36.01% and 91.46%, respectively. Genomic analyses showed that phage vB_Efs8_KEN04 belongs to the genus Kochikohdavirus in the family Herelleviridae. It lacked antimicrobial resistance, virulence, and lysogeny genes, and its stability, broad host range, and cross-species lysis indicate strong potential for the treatment of Enterococcus infections.

Native Infective Endocarditis: A State-of-the-Art-Review

Native valve infective endocarditis (NVE) is a global phenomenon, defined by infection of a native heart valve and involving the endocardial surface. The causes and epidemiology of the disease have evolved in recent decades, with a doubling of the average patient age. A higher incidence was observed in patients with implanted cardiac devices that can result in right-sided infection of the tricuspid valve. The microbiology of the disease has also changed. Previously, staphylococci, which are most often associated with health-care contact and invasive procedures, were the most common cause of the disease. This has now been superseded by streptococci. While innovative diagnostic and therapeutic strategies have emerged, mortality rates have not improved and remain at 30%, which is higher than that for many cancer diagnoses. The lack of randomized trials and logistical constraints impede clinical management, and long-standing controversies such as the use of antibiotic prophylaxis persist. This state of the art review addresses clinical practice, controversies, and strategies to combat this potentially devastating disease. A multidisciplinary team will be established to provide care for patients with presumptive NVE. The composition of the team will include specialists in cardiology, cardiovascular surgery, and infectious disease. The prompt administration of combination antimicrobial therapy is essential for effective NVE treatment. Additionally, a meticulous evaluation of each patient is necessary in order to identify any indications for immediate valve surgery. With the intention of promoting a more comprehensive understanding of the procedural management of native infective endocarditis and to furnish clinicians with a reference, the current evidence for the utilization of distinct strategies for the diagnosis and treatment of NVE are presented.

Phenomics and genomic features of Enterococcus avium IRMC1622a isolated from a clinical sample of hospitalized patient

BACKGROUND

Enterococcus avium (E. avium) is a Gram-positive nosocomial pathogen that is commonly isolated from the alimentary tract. The objective of this functional genomics study was to identify the resistant genes by analyzing the genome of E. avium IRMC1622a, a type of bacteria found in feces collected from a patient at a Saudi Arabian tertiary hospital.

METHODS

The bacterial strain IRMC1622a was identified by 16 S rRNA sequencing as Enterococcus sp. The resistance phenomics were performed using VITEK® 2, and morphological analysis was achieved using a scanning electron microscope (SEM). Finally, the whole bacterial genome of the bacterial strain IRMC1622a was subjected to sequencing during October 2023 using Oxford Nanopore long-read sequencing technology, and mining for resistant genes.

RESULTS

The results of antimicrobial resistant phenomics indicated that the IRMC1622a strain was sensitive to all tested antimicrobial agents except for erythromycin, and the same result was confirmed by genomic analysis in addition to other classes of antibiotics. SEM showed E. avium IRMC1622a is ovoid shape, in single cells (L 1.2797 ± 0.1490 µm), in pairs (L 1.7333 ± 0.1054 µm), and in chains (L 2.44033 ± 0.1978 µm). The E. avium IRMC1622a genome has 14 (in CARD) antimicrobial resistance genes that were identified with several mechanisms of antimicrobial resistance, such as the efflux pump and conferring antibiotic resistance. The present study revealed that the E. avium IRMC1622a genome contains a high number of genes associated with virulence factors, and 14 matched pathogenic protein families and predicted as human pathogen (probability score 0.855). We report two (ISEnfa4 and ISEfa5) mobile genetic elements for the first time in the E. avium genome.

CONCLUSIONS

The study concludes that E. avium IRMC1622a is susceptible to all tested antibacterials except erythromycin. The IRMC1622a has 14 genes encoding antimicrobial resistance mechanisms, including the efflux pump and conferring antibiotic resistance. This could indicate a potential rise in E. avium resistance in healthcare facilities. These observations may raise concerns regarding E. avium resistance in healthcare. We need more research to understand the pathophysiology of E. avium, which leads to hospital-acquired infections.

Risk Factors for 30-Day Mortality in Nosocomial Enterococcal Bloodstream Infections

Enterococci commonly cause nosocomial bloodstream infections (BSIs), and the global incidence of vancomycin-resistant enterococci (VRE) BSIs is rising. This study aimed to assess the risk factors for enterococcal BSIs and 30-day mortality, stratified by Enterococcus species, vancomycin resistance, and treatment appropriateness. We conducted a retrospective cohort study (2014-2021) including all hospitalized adult patients with at least one blood culture positive for Enterococcus faecalis or Enterococcus faecium. We included 584 patients with enterococcal BSI: 93 were attributed to vancomycin-resistant E. faecium. The overall 30-day mortality was 27.5%; higher in cases of BSI due to vancomycin-resistant E. faecium (36.6%) and vancomycin-sensitive E. faecium (31.8%) compared to E. faecalis BSIs (23.2%) (p = 0.016). This result was confirmed by multivariable Cox analysis. Independent predictors of increased mortality included the PITT score, complicated bacteremia, and age (HR = 1.269, p < 0.001; HR = 1.818, p < 0.001; HR = 1.022, p = 0.005, respectively). Conversely, male gender, consultation with infectious disease (ID) specialists, and appropriate treatment were associated with reduced mortality (HR = 0.666, p = 0.014; HR = 0.504, p < 0.001; HR = 0.682, p = 0.026, respectively). In conclusion, vancomycin-resistant E. faecium bacteremia is independently associated with a higher risk of 30-day mortality.

Caffeic acid phenethyl ester attenuates Enterococcus faecalis infection in vivo: antioxidants and NF-κB have a protective role against stomach damage

The mammalian gastrointestinal tract hosts a significant microbial symbiont community, an intriguing feature of this complex organ system. This study aimed to investigate the anti-inflammatory, antioxidant, and protective effects of caffeic acid phenethyl ester (CAPE) against Enterococcus faecalis infection in the stomach at a dose of 106 CFU in Swiss mice. A total of 30 mice were randomly assigned to three groups of ten mice each. Group I was the negative control, Group II was infected orally with E. faecalis for 18 days, and Group III was infected with E. faecalis and treated with CAPE orally at a daily dose of 4 mg/kg for 18 days. We assessed the antioxidant activities of stomach homogenate and the immunohistochemical expressions of the transcription factor nuclear factor kappa B (NF-κB) and proliferating cell nuclear antigen (PCNA). Histopathological examination was performed on the stomachs of all mice. Group II had decreased levels of antioxidant activity and positive expressions of NF-κB and PCNA. Histological observations revealed an increase in mucosal and glandular thickness compared with Group I. Group III, treated with CAPE, showed a significant increase in antioxidant activities and a significant decrease in NF-κB and PCNA immunoreactivities compared with Group II. In addition, Group III showed restoration of the normal thickness of the non-glandular and glandular parts of the stomach. Our results revealed that E. faecalis infection has damaging effects on the stomach and proved that CAPE has promising protective, anti-inflammatory, and antioxidant effects against E. faecalis. Further studies may investigate the potential therapeutic effects of CAPE against E. faecalis infection.

Triggered Release of Ampicillin from Metallic Implant Coatings for Combating Periprosthetic Infections

Periprosthetic infections caused by Staphylococcus aureus (S. aureus) pose unique challenges in orthopedic surgeries, in part due to the bacterium's capacity to invade surrounding bone tissues besides forming recalcitrant biofilms on implant surfaces. We previously developed prophylactic implant coatings for the on-demand release of vancomycin, triggered by the cleavage of an oligonucleotide (Oligo) linker by micrococcal nuclease (MN) secreted by the Gram-positive bacterium, to eradicate S. aureus surrounding the implant in vitro and in vivo. Building upon this coating platform, here we explore the feasibility of extending the on-demand release to ampicillin, a broad-spectrum aminopenicillin β-lactam antibiotic that is more effective than vancomycin in killing Gram-negative bacteria that may accompany S. aureus infections. The amino group of ampicillin was successfully conjugated to the carboxyl end of an MN-sensitive Oligo covalently integrated in a polymethacrylate hydrogel coating applied to titanium alloy pins. The resultant Oligo-Ampicillin hydrogel coating released the β-lactam in the presence of S. aureus and successfully cleared nearby S. aureus in vitro. When the Oligo-Ampicillin-coated pin was delivered to a rat femoral canal inoculated with 1000 cfu S. aureus, it prevented periprosthetic infection with timely on-demand drug release. The clearance of the bacteria from the pin surface as well as surrounding tissue persisted over 3 months, with no local or systemic toxicity observed with the coating. The negatively charged Oligo fragment attached to ampicillin upon cleavage from the coating did diminish the antibiotic's potency against S. aureus and Escherichia coli (E. coli) to varying degrees, likely due to electrostatic repulsion by the anionic surfaces of the bacteria. Although the on-demand release of the β-lactam led to adequate killing of S. aureus but not E. coli in the presence of a mixture of the bacteria, strong inhibition of the colonization of the remaining E. coli on hydrogel coating was observed. These findings will inspire considerations of alternative broad-spectrum antibiotics, optimized drug conjugation, and Oligo linker engineering for more effective protection against polymicrobial periprosthetic infections.

Enterococcal Infective Endocarditis - Post discharge treatment with continuous benzylpenicillin and ceftriaxone: A retrospective cohort study

BACKGROUND

Enterococcal Infective Endocarditis (EIE) is usually treated with the combination of penicillin/ampicillin with gentamicin or ampicillin with ceftriaxone. To enable prolonged outpatient treatment, a combination of benzylpenicillin and ceftriaxone has been suggested. This study aimed to describe the incidence and characteristics of EIE and to determine the outcome of EIE cases treated with benzylpenicillin and ceftriaxone.

METHODS

This was a retrospective single-center study including all patients diagnosed with infective endocarditis (IE) during 2016-2021, comparing EIE with IE caused by other pathogens. We described the outpatient treatment of patients with EIE, comparing those treated of benzylpenicillin - ceftriaxone with other regimes.

RESULTS

Among 222 patients with IE, 44 (20%) were diagnosed with EIE. Those were older, had a male predominance (p = 0.035), and were more disabled (p = 0.004). The incidence of EIE reached 30% towards the last year, becoming the leading etiology. Twenty-six patients received outpatient treatment, five of whom were discharged with benzylpenicillin and ceftriaxone. Adding patients from this cohort to the scarce data available, revealed similar recurrence and mortality rates compared to other treatment regimes.

CONCLUSIONS

EIE is becoming a more frequent cause of IE, involving older, more disabled patients with male predominance. Our experience and existing literature suggest that the combination of benzylpenicillin and ceftriaxone is as safe as more conventional regimes, although further research is needed.

Comparison of efficacy and safety between daptomycin plus β-lactam and daptomycin monotherapy for bloodstream infections due to gram-positive cocci: A systematic review and meta-analysis

Objectives

We performed a comprehensive systematic review and meta-analysis to evaluate the clinical or microbiological outcomes and safety of a combination of daptomycin (DAP) and β-lactams compared to DAP monotherapy in patients with blood stream infection (BSI) due to gram-positive cocci (GPC).

Methods

We searched Scopus, PubMed, EMBASE, CINAHL, and Ityuushi databases up to January 30, 2023. Outcomes included all-cause mortality, clinical failure, and creatine phosphokinase (CPK) elevation.

Results

Six cohorts or case-control studies fulfilled the inclusion criteria and were included in the final meta-analysis. Combination therapy of DAP and β-lactams significantly reduced the mortality and clinical failure rate for all BSI due to GPC compared with the DAP monotherapy (mortality, odds ratio [OR] = 0.63, 95 % confidence interval [CI] = 0.41-0.98; clinical failure, OR = 0.42, 95 % CI = 0.22-0.81). In contrast, no significant difference was noted in the incidence of CPK elevation between the two groups (OR = 0.85, 95 % CI = 0.39-1.84).

Conclusion

Altogether, combination therapy of DAP and β-lactams can improve the prognosis for patients with BSI due to GPC compared with DAP alone. Therefore, it should be considered as an option for the empirical treatment of BSI caused by GPC.

Differential in vitro susceptibility to ampicillin/ceftriaxone combination therapy among Enterococcus faecalis infective endocarditis clinical isolates

OBJECTIVES

To investigate the genomic diversity and β-lactam susceptibilities of Enterococcus faecalis collected from patients with infective endocarditis (IE).

METHODS

We collected 60 contemporary E. faecalis isolates from definite or probable IE cases identified between 2018 and 2021 at the University of Pittsburgh Medical Center. We used whole-genome sequencing to study bacterial genomic diversity and employed antibiotic checkerboard assays and a one-compartment pharmacokinetic-pharmacodynamic (PK/PD) model to investigate bacterial susceptibility to ampicillin and ceftriaxone both alone and in combination.

RESULTS

Genetically diverse E. faecalis were collected, however, isolates belonging to two STs, ST6 and ST179, were collected from 21/60 (35%) IE patients. All ST6 isolates encoded a previously described mutation upstream of penicillin-binding protein 4 (pbp4) that is associated with pbp4 overexpression. ST6 isolates had higher ceftriaxone MICs and higher fractional inhibitory concentration index values for ampicillin and ceftriaxone (AC) compared to other isolates, suggesting diminished in vitro AC synergy against this lineage. Introduction of the pbp4 upstream mutation found among ST6 isolates caused increased ceftriaxone resistance in a laboratory E. faecalis isolate. PK/PD testing showed that a representative ST6 isolate exhibited attenuated efficacy of AC combination therapy at humanized antibiotic exposures.

CONCLUSIONS

We find evidence for diminished in vitro AC activity among a subset of E. faecalis IE isolates with increased pbp4 expression. These findings suggest that alternate antibiotic combinations against diverse contemporary E. faecalis IE isolates should be evaluated.

A Case of Enterococcal Patent Ductus Arteriosus-associated Endarteritis in a Preterm Neonate

INTRODUCTION

The persistent patency of the ductus arteriosus frequently occurs in premature neonates and can cause infective endocarditis (IE) or ductal endarteritis (DE) during sepsis. Even though neonatal IE and DE are believed to be a rare eventuality, their incidence has been increasing in the last decades due to the improved survival of even more preterm babies, favored by highly invasive procedures and therapies. In parallel, antimicrobial resistance is another rising problem in neonatal intensive care units, which frequently compels to treat infections with broad-spectrum or last generation antibiotics.

CASE PRESENTATION

We report the case of a preterm neonate affected by patent ductus arteriosus-associated DE that followed an episode of sepsis caused by a high-level aminoglycoside-resistant enterococcus. The neonate was successfully treated with the synergistic combination of ampicillin and cefotaxime.

DISCUSSION

IE and patent ductus arteriosus-associated DE are rising inside neonatal intensive care units and neonatologists should be aware of these conditions. Enterococcal IE and patent ductus arteriosus-associated DE sustained by high-level aminoglycoside-resistant strains can be successfully treated with the synergistic combination of ampicillin and cefotaxime even in preterm neonates.

From Polymeric Nanoformulations to Polyphenols-Strategies for Enhancing the Efficacy and Drug Delivery of Gentamicin

Gentamicin is an essential broad-spectrum aminoglycoside antibiotic that is used in over 40 clinical conditions and has shown activity against a wide range of nosocomial, biofilm-forming, multi-drug resistant bacteria. Nevertheless, the low cellular penetration and serious side effects of gentamicin, as well as the fear of the development of antibacterial resistance, has led to a search for ways to circumvent these obstacles. This review provides an overview of the chemical and pharmacological properties of gentamicin and offers six different strategies (the isolation of specific types of gentamicin, encapsulation in polymeric nanoparticles, hydrophobization of the gentamicin molecule, and combinations of gentamicin with other antibiotics, polyphenols, and natural products) that aim to enhance the drug delivery and antibacterial activity of gentamicin. In addition, factors influencing the synthesis of gentamicin-loaded polymeric (poly (lactic-co-glycolic acid) (PLGA) and chitosan) nanoparticles and the methods used in drug release studies are discussed. Potential research directions and future perspectives for gentamicin-loaded drug delivery systems are given.

State-of-the-Art Review: Persistent Enterococcal Bacteremia

Persistent enterococcal bacteremia is a commonly encountered and morbid syndrome without a strong evidence base for optimal management practices. Here we highlight reports on the epidemiology of enterococcal bacteremia to better describe and define persistent enterococcal bacteremia, discuss factors specific to Enterococcus species that may contribute to persistent infections, and describe a measured approach to diagnostic and therapeutic strategies for patients with these frequently complicated infections. The diagnosis of persistent enterococcal bacteremia is typically clinically evident in the setting of repeatedly positive blood culture results; instead, the challenge is to determine in an accurate, cost-effective, and minimally invasive manner whether any underlying nidus of infection (eg, endocarditis or undrained abscess) is present and contributing to the persistent bacteremia. Clinical outcomes for patients with persistent enterococcal bacteremia remain suboptimal. Beyond addressing host immune status if relevant and pursuing source control for all patients, management decisions primarily involve the selection of the proper antimicrobial agent(s). Options for antimicrobial therapy are often limited in the setting of intrinsic and acquired antimicrobial resistance among enterococcal clinical isolates. The synergistic benefit of combination antimicrobial therapy has been demonstrated for enterococcal endocarditis, but it is not clear at present whether a similar approach will provide any clinical benefit to some or all patients with persistent enterococcal bacteremia.

Characterization of Prescribing Practices for Uncomplicated Streptococcal and Enterococcal Bacteremias: The NARRATE Study

Background

Bloodstream infections (BSIs) rank among the top causes of death in North America. Despite the prevalence of these infections, there remain significant practice variations in the prescribing of antibiotics.

Objective

To investigate current prescribing practices for management of uncomplicated streptococcal and enterococcal BSIs.

Methods

A retrospective cohort study was conducted using charts for patients admitted to an acute care centre in British Columbia between November 16, 2019, and October 20, 2020. Adult patients (≥ 18 years of age) with a diagnosis of uncomplicated streptococcal or enterococcal BSI were included. Patients were excluded if they had polymicrobial bacteremia or deep-seated infection or had been admitted for no more than 48 hours. The primary outcomes were duration of antibiotic therapy (IV and oral) and time to appropriate oral therapy for treatment of BSI. The secondary outcomes were observed rates of re-initiation of antibiotics and readmission with recurrent BSI. Descriptive statistics were calculated and regression analysis was performed for the primary and secondary outcomes.

Results

A total of 96 patients met the inclusion criteria. The median total duration of therapy for uncomplicated streptococcal and enterococcal BSI was about 2 weeks. Streptococcus pneumoniae BSIs were associated with a significantly shorter duration of IV therapy and were more likely to be associated with transition to oral antibiotics. No recurrent BSIs were observed in patients for whom therapy was transitioned to oral antibiotics.

Conclusions

Further study is warranted to explore shorter duration of antibiotic therapy and transition to oral therapy as treatment approaches for uncomplicated streptococcal and enterococcal BSI. Other outcomes of interest for future research include determining the optimal time for transition to oral therapy.

Septic Embolic Encephalitis Following Cardiac Valve Replacement

This paper presents a detailed case study of a 48-year-old male who underwent ascending aortic aneurysm repair with a bioprosthetic valve five years prior and subsequently developed septic embolic encephalitis, an infrequent yet critical complication following cardiac valve replacement. The patient exhibited an array of initial symptoms, including generalized weakness, fatigue, fevers, chills, diarrhea, and altered mentation. Microbiological analysis of blood cultures revealed the presence of Enterococcus, and echocardiogram examination demonstrated vegetation on the prosthetic valve. To assess disease progression, diagnostic imaging, including CT scans and MRIs, was conducted at various time points. The imaging results unveiled several abnormalities, including subarachnoid and parenchymal bleeding, cortical infarcts, cerebritis, and meningitis. Additionally, splenic and renal infarcts were observed through an abdominal CT scan. This case report accentuates the paramount role of diagnostic imaging in corroborating suspected septic embolic encephalitis while underscoring the significance of appropriate management of patients with a history of cardiac valve replacement, thereby emphasizing the urgency of timely intervention.

[Study of the growth temperature of ocular surface microorganisms in norm and in infectious keratitis]

Standard bacteriological examinations, which involve culturing microorganisms at 37 °C, are commonly used in clinical practice for diagnosing infectious diseases. However, the growth temperature of microorganisms on the ocular surface (OS) during infectious keratitis (IK) may not coincide with the laboratory standard, which is due to the characteristic features of heat exchange in the eye.

PURPOSE

This exploratory study examines the distribution and properties of OS microorganisms isolated under different temperature cultivation conditions in patients with IK and healthy volunteers without ophthalmic pathology.

MATERIAL AND METHODS

Fifteen participants were divided into two groups. Group 1 (n=10) consisted of patients with signs of unilateral infectious keratitis, while group 2 (n=5) served as the control group. A novel microbiological method was employed to isolate pure cultures of microorganisms. This method involved cultivating microorganisms at two temperature regimes (37 °C and 24 °C) and subsequently identifying them using biochemical, immunological, and physicochemical techniques, including mass spectrometry. Scanning electron microscopy (SEM) with lanthanide staining used as the reference method. The temperature status of the ocular surface was assessed using non-contact infrared thermography.

RESULTS

The study demonstrated the presence of psychrotolerant microorganisms on the ocular surface, which exhibited growth at a relatively low temperature of 24 °C. These psychrotolerant microorganisms were found to be isolated from the ocular surface displaying signs of temperature dysregulation. Among such microorganisms are Acinetobacter lwoffii, Achromobacter xylosoxidans, Bacillus licheniformis, Enterococcus faecalis, Klebsiella oxytoca, Klebsiella pneumoniae, Micrococcus luteus, Pseudomonas luteola, Streptococcus spp.

CONCLUSION

When identifying the causative agent of infectious keratitis, it is crucial to consider the divergence of growth temperature of ocular surface microorganisms. The presence of psychrotolerant microorganisms on the ocular surface, which can effectively grow at room temperature, should be taken into account, especially in cases of temperature dysregulation.

Thiazolopyrimidinone Derivative H5-23 Enhances Daptomycin Activity against Linezolid-Resistant Enterococcus faecalis by Disrupting the Cell Membrane

The increasing emergence and dissemination of multidrug-resistant (MDR) Gram-positive pathogens pose a serious threat to global public health. Previous reports have demonstrated that the compound H5-23, which has a thiazolopyrimidinone core structure, exhibited antibacterial activity against Staphylococcus epidermidis in vitro. However, the antibacterial activity in vivo and mechanism of action of H5-23 against MDR bacteria have not been fully studied. In this study, we report that H5-23 has wide-spectrum antibacterial activity against Gram-positive bacteria. When combined with daptomycin (DAP), H5-23 demonstrates enhanced antimicrobial activity, effectively killing both planktonic and persister cells, as well as eradicating biofilm formation by linezolid-resistant Enterococcus faecalis. The development of resistance shows that H5-23 has a low propensity to induce antibiotic resistance compared to that of linezolid in vitro. Mechanistic studies reveal that H5-23 increases membrane permeability and disrupts membrane integrity, resulting in increased production of reactive oxygen species (ROS), metabolic perturbations, and ultimately cell death. Additionally, we demonstrate the synergistic antibacterial effect of H5-23 combined with DAP in a murine model. These findings suggest that H5-23 is a promising antimicrobial agent and provides a potential strategy for enhancing the efficacy of DAP in combating multidrug-resistant E. faecalis.

Phage Therapy, a Salvage Treatment for Multidrug-Resistant Bacteria Causing Infective Endocarditis

Infective endocarditis (IE) is defined as an infection of the endocardium, or inner surface of the heart, most frequently affecting the heart valves or implanted cardiac devices. Despite its rarity, it has a high rate of morbidity and mortality. IE generally occurs when bacteria, fungi, or other germs from another part of the body, such as the mouth, spread through the bloodstream and attach to damaged areas in the heart. The epidemiology of IE has changed as a consequence of aging and the usage of implantable cardiac devices and heart valves. The right therapeutic routes must be assessed to lower complication and fatality rates, so this requires early clinical suspicion and a fast diagnosis. It is urgently necessary to create new and efficient medicines to combat multidrug-resistant bacterial (MDR) infections because of the increasing threat of antibiotic resistance on a worldwide scale. MDR bacteria that cause IE can be treated using phages rather than antibiotics to combat MDR bacterial strains. This review will illustrate how phage therapy began and how it is considered a powerful potential candidate for the treatment of MDR bacteria that cause IE. Furthermore, it gives a brief about all reported clinical trials that demonstrated the promising effect of phage therapy in combating resistant bacterial strains that cause IE and how it will become a hope in future medicine.

Combinatorial efficacy of Manuka honey and antibiotics in the in vitro control of staphylococci and their small colony variants

Introduction

Staphylococci are among the list of problematic bacteria contributing to the global antibiotic resistance (ABR) crisis. Their ability to adopt the small colony variant (SCV) phenotype, induced by prolonged antibiotic chemotherapy, complicates staphylococcal infection control options. Novel and alternative approaches are needed to tackle staphylococcal infections and curb ABR. Manuka honey (MH), a non-antibiotic alternative is recognized for its unique antibacterial activity based on its methylglyoxal (MGO) component.

Methods

In this study, MH (MGO 830+) was tested in combination with gentamicin (GEN), rifampicin (RIF), or vancomycin (VA) against staphylococcal wildtype (WT) and SCVs. To our knowledge, there are no current studies in the literature documenting the effects of MH on staphylococcal SCVs. While Staphylococcus aureus is well-studied for its international ABR burden, limited data exists demonstrating the effects of MH on S. epidermidis and S. lugdunensis whose pathogenic relevance and contribution to ABR is also rising.

Results & discussion

The three staphylococci were most susceptible to RIF (0.06-0.24 μg/ml), then GEN (0.12-0.49 μg/ml), and lastly VA (0.49-0.96 μg/ml). The MICs of MH were 7%, 7-8%, and 6-7% (w/v), respectively. Fractional inhibitory concentration (FIC) evaluations showed that the combined MH + antibiotic effect was either additive (FICI 1-2), or partially synergistic (FICI >0.5-1). While all three antibiotics induced SCVs in vitro, stable SCVs were observed in GEN treatments only. The addition of MH to these GEN-SCV-induction analyses resulted in complete suppression of SCVs (p<0.001) in all three staphylococci, suggesting that MH's antibacterial properties interfered with GEN's SCV induction mechanisms. Moreover, the addition of MH to growth cultures of recovered stable SCVs resulted in the inhibition of SCV growth by at least 99%, indicating MH's ability to prevent subsequent SCV growth. These in vitro analyses demonstrated MH's broad-spectrum capabilities not only in improving WT staphylococci susceptibility to the three antibiotics, but also mitigated the development and subsequent growth of their SCV phenotypes. MH in combination with antibiotics has the potential to not only resensitize staphylococci to antibiotics and consequently require less antibiotic usage, but in instances where prolonged chemotherapy is employed, the development and growth of SCVs would be hampered, providing a better clinical outcome, all of which mitigate ABR.

Effect of antibiotic prophylaxis in the prognosis of Post-neurosurgical meningitis patients

AIMS

To evaluate the effect of antibiotic prophylaxis(AP) in the prognosis of Post-neurosurgical meningitis(PNM) patients.

METHODS

A cohort analysis was performed using the clinical database in Beijing Tiantan Hospital and Capital Medical University. Data were collected on patients with the diagnosis of PNM (n = 3931) during 2012.01 to 2022.04. The microbial distribution, types of AP, and 42 and 90 days survival analysis of AP patients were evaluated using probable statistical methods. Independent risk factors for mortality were established by constructing a logistic regression analysis.

RESULT

A total of 1,190 patients were included in this study, Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus occupied the highest proportion. Of them, 929 cases received AP, cefuroxime and ceftriaxone are the most frequent used antibiotics. In addition, We found that PNM patients without AP significantly increased the 42 days and 90 days all-cause mortality rates. The use of different levels of AP did not improve patient outcomes, and ICU admission and assisted mechanical ventilation (AMV) were identified as independent mortality risk factors for PNM patient received AP.

CONCLUSIONS

AP plays an important role in the prognosis of PNM patients and has a significant function in improving prognosis. The prevention of PNM with antibiotics prior to neurosurgery should be emphasized in clinical practice, and appropriate selection of antibiotics is necessary to prevent the occurrence of infection and inhibit the emergence of antibiotic-resistant bacteria.

Microbiologic diagnostics and pathogen spectrum in infective endocarditis of surgically treated patients: a five-year, retrospective, monocentric study

PURPOSE

The spectrum of causative organisms in infective endocarditis (IE) has changed significantly in the last decades. Reliable pathogen detection is crucial for appropriate antimicrobial therapy for IE. The aim of the study was to evaluate the diagnostic value of microbiological methods for detecting the causative microorganism of IE and to analyze the spectrum of pathogens.

METHODS

A total of 224 cases (211 unique patients, some with multiple surgeries) were included into this retrospective study. Patients were diagnosed with IE according to the modified Duke criteria from January 2016 to July 2021 and underwent heart valve surgery in a tertiary hospital. Pathogen detection was performed by blood culture, microbiological culture and 16S rDNA PCR of explanted heart valve material.

RESULTS

A causative pathogen of IE was detected in 95.5% (n = 214) of cases. Blood cultures were positive in 83.3%, while a pathogen in the examined heart valve samples was identified in 32.6% by culture and in 88.2% by 16S rDNA PCR. A microorganism was identified by 16S rDNA PCR in 61.1% of blood culture negative cases but only in 19.4% by heart valve culture. The most common pathogens were Staphylococcus aureus (27%), viridans group streptococci (20%), enterococci (19%) and coagulase-negative staphylococci (CoNS 8%). Cutibacterium acnes (7%) was detected in prosthetic valve IE cases only.

CONCLUSION

Blood culture as a comparatively non-invasive and straightforward technique remains an important and reliable method for initial detection of the causative organism in IE. Diagnostic stewardship programs should broadly emphasize proper collection of blood cultures, particularly sampling prior to any antibiotic treatment. Additionally, molecular testing using 16S rDNA tissue PCR can be used with culture techniques to increase the diagnostic yield, especially in the case of a negative blood culture.

Short report: impact of selective reporting of antibiotic susceptibility testing on antibiotic use in patients with bloodstream infection with Enterococcus faecalis

INTRODUCTION

Bloodstream infections with Enterococcus faecalis are associated with relevant morbidity and mortality. Targeted antimicrobial therapy is essential. The choice of an adequate treatment may be challenging when susceptibility testing offers different options. Selective reporting of antibiotic susceptibility test results might lead to a more tailored antibiotic therapy and could therefore be an important antimicrobial stewardship program intervention. The aim of this study was to analyse whether the introduction of selective reporting of antibiotic test results leads to a more targeted antibiotic therapy in patients with bloodstream infection with Enterococcus faecalis.

METHODS

This study was performed as a retrospective cohort study at the University Hospital Regensburg, Germany. All patients with blood cultures positive for Enterococcus faecalis between March 2003 and March 2022 were analysed. In February 2014 selective reporting of antibiotic susceptibility test results omitting sensitivity results for agents not recommended was introduced.

RESULTS

263 patients with blood cultures positive for Enterococcus faecalis were included. After introduction of selective reporting of antibiotic tests (AI) significantly more patients received ampicillin than before introduction of selective reporting (BI) (9.6% BI vs. 34.6% AI, p < 0.001).

CONCLUSION

Selective reporting of antibiotic susceptibility test results led to a significantly higher use of ampicillin.

Assessment of Bacterial Infections and Antibiotic Regimens in Intravenous Drug Users

Bacterial infections in people who inject drugs (PWID) are a significant cause of hospitalizations and increased morbidity in this group. In this review, we evaluated bacterial trends in the most common infections and appropriate empiric antibiotic coverage. Articles from PubMed and Google Scholar were curated in a Google document with shared access. Discussion and development of the paper were achieved over Zoom meetings. The common infections in PWID were skin and soft tissue infections (SSTIs), infective endocarditis, septic arthritis, osteomyelitis, and bloodstream infections (BSIs). The presence of comorbidities increased susceptibility to bacterial infections. Staphylococcus aureus was the predominant species in all the infections and included methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). The current standard of antibiotic use for Staphylococcus species was found to be sufficient. The gram-negative bacillus Serratia marcescens was prevalent in PWID as a causative agent of septic arthritis, osteomyelitis, and infective endocarditis. Its treatment required a combination of β-lactam and either a fluoroquinolone or an aminoglycoside for a prolonged duration. Streptococci were commonly implicated in SSTIs and BSIs. The appropriate response was seen with β-lactam antibiotics. In PWID, Enterococcus and Pseudomonas were implicated in infective endocarditis of native and prosthetic valves. The former being difficult to treat, a new strategy of using dual β-lactam antibiotics was found to be supported by clinical data. Anti-pseudomonal antibiotics can be avoided in other infections seen in this group, as their prevalence was low. PWID, especially those with comorbidities, have an increased risk of acquiring infections with difficult-to-treat microbes. Therefore, empiric antibiotic treatment should be relevant to the infection, for which bacterial trends and antibiotic susceptibility must be reassessed periodically.

Interest in the combination of antimicrobial therapy for orthopaedic device-related infections due to Enterococcus spp

INTRODUCTION

The objective of this study was to evaluate the management of orthopaedic device-related infections (ODRIs) due to Enterococcus spp.

MATERIALS AND METHODS

We performed a retrospective cohort study in a French tertiary university hospital. Patients with prosthetic joint- or osteosynthesis-associated infections caused by enterococci from 2013 to 2020 were included. Patients who died within 5 days after surgery; who were in palliative care; or who had osteosynthesis of the hand, foot or vertebra were excluded.

RESULTS

Thirty-six patients were included, with 24 in the arthroplasty group and 12 in the osteosynthesis material group. Most infections were polymicrobial (63.9%, n = 23). Debridement, antibiotics and implant retention (DAIR) was performed in 30.6% (n = 11), withdrawal of material in 16.7% (n = 6), one-stage exchange in 30.6% (n = 11) and two-stage exchange in 22.2% of cases (n = 8). The antibiotic regimen was amoxicillin in 41.6% (n = 15), rifampicin in 27.8% (n = 10), linezolid in 25% (n = 9) and/or fluoroquinolones in 30.6% (n = 11). Clinical success at 1 year was 67% (18/27). The only variable statistically associated with a decreased risk of clinical failure was a duration of antibiotic therapy of 12 weeks (p = 0.04). Patients with a lower body mass index and age tended to decrease the risk of clinical failure (p = 0.05 and 0.06 respectively).

CONCLUSIONS

The management of enterococcal ODRIs is complex, and ODRI patients are at high risk for relapse. In our small study, a better outcome was not demonstrated for patients with combination therapy and rifampicin use. Further studies are needed to improve the medico-surgical strategy for treating these infections.

The association of infectious diseases consultation and 30-day mortality rates among veterans with enterococcal bacteraemia: a propensity score-matched retrospective cohort study

OBJECTIVES

Infectious disease consultation (IDC) has been associated with improved outcomes in several infections, but the benefit of IDC among patients with enterococcal bacteraemia has not been fully evaluated.

METHODS

We performed a 1:1 propensity score-matched retrospective cohort study evaluating all patients with enterococcal bacteraemia at 121 Veterans Health Administration acute-care hospitals from 2011 to 2020. The primary outcome was 30-day mortality. We performed conditional logistic regression to calculate the OR to determine the independent association of IDC and 30-day mortality adjusted for vancomycin susceptibility and the primary source of bacteraemia.

RESULTS

A total of 12,666 patients with enterococcal bacteraemia were included; 8400 (63.3%) had IDC, and 4266 (36.7%) did not have IDC. Two thousand nine hundred seventy-two patients in each group were included after propensity score matching. Conditional logistic regression revealed that IDC was associated with a significantly lower 30-day mortality rate compared with patients without IDC (OR = 0.56; 95% CI, 0.50-0.64). The association of IDC was observed irrespective of vancomycin susceptibility, and when the primary source of bacteraemia was a urinary tract infection, or from an unknown primary source. IDC was also associated with higher appropriate antibiotic use, blood culture clearance documentation, and the use of echocardiography.

DISCUSSION

Our study suggests that IDC was associated with improved care processes and 30-day mortality rates among patients with enterococcal bacteraemia. IDC should be considered for patients with enterococcal bacteraemia.

Combined effect of apigenin and reduced graphene oxide against Enterococcus faecalis biofilms

PURPOSE

Enterococcus faecalis (E. faecalis) is one of the major microorganisms that causes failure of endodontic treatment. This study aimed to investigate the antibacterial activity of apigenin and its synergistic effect with reduced graphene oxide (RGO) in treating E. faecalis biofilms.

METHODS

The antibacterial activities were characterized by viability analysis including colony forming units and confocal laser scanning microscopy (CLSM) analyses. The effect on biofilm biomass was measured using a crystal violet staining method. Live and dead bacteria bio-volumes were determined by CLSM analysis, and the morphology of E. faecalis biofilm after treatment with apigenin and apigenin + RGO was observed by scanning electron microscopy (SEM).

RESULTS

The viability of E. faecalis in biofilms decreased by apigenin treatment in a dose-dependent manner. While apigenin alone did not significantly affect the biofilm biomass, apigenin + RGO reduced the biomass in an apigenin concentration-dependent manner. Likewise, the bio-volume of live bacteria decreased and the bio-volume of dead bacteria increased in apigenin-treated biofilms. According to SEM images, apigenin + RGO-treated samples showed less E. faecalis in biofilms than apigenin-only treated samples.

CONCLUSION

The results suggested that the combined use of apigenin and RGO could be a potential strategy for effective endodontic disinfection.

The Role of Platelets in Infective Endocarditis

Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation. In this review, we will analyze the key role of platelets in the physiopathology of endocarditis and in the formation of vegetation, depending on the bacterial species. We provide a comprehensive outline of the involvement of platelets in the host immune response, investigate the latest developments in platelet therapy, and discuss prospective research avenues for solving the mechanistic enigma of bacteria-platelet interaction for preventive and curative medicine.

Essential Oil of Lavandula officinalis: Chemical Composition and Antibacterial Activities

The purpose of this study was to determine the chemical composition of the essential oil of Lavandula officinalis from Morocco using the GC-MS technique and assess the antibacterial effects against seven pathogenic bacteria strains isolated from the food origins of Salmonella infantis, Salmonella kentucky, Salmonella newport, three serotypes of Escherichia coli (O114H8K11, O127K88ac, O127H40K11) and Klebsiella. Tests of sensitivity were carried out on a solid surface using the Disc Diffusion Method. Results showed that E. coli and S.newport were sensitive to Lavandula officinalis essential oil. Minimum inhibitory concentrations (MIC) were determined using the method of agar dilution. The antibacterial results showed that four strains (three serotypes of E. coli, and S. newport) were remarkedly sensitive to Lavandula officinalis essential oil, giving MIC values of 88.7 µg/mL and 177.5 µg/mL. The molecular docking of the main oil products with the E. coli target protein 1VLY, showed that eucalyptol and linalyl acetate bind efficiently with the active site of the target protein. In particular, eucalyptol showed a higher activity than gentamicin used as positive control with a binding energy of -5.72 kcal/mol and -5.55 kcal/mol, respectively.

A universal strategy for the construction of polymer brush hybrid non-glutaraldehyde heart valves with robust anti-biological contamination performance and improved endothelialization potential

With the intensification of the aging population and the development of transcatheter heart valve replacement technology (THVR), clinical demand for bioprosthetic valves is increasing rapidly. However, commercial bioprosthetic heart valves (BHVs), mainly manufactured from glutaraldehyde cross-linked porcine or bovine pericardium, generally undergo degeneration within 10-15 years due to calcification, thrombosis and poor biocompatibility, which are closely related to glutaraldehyde cross-linking. In addition, endocarditis caused by post-implantation bacterial infection also accelerates the failure of BHVs. Herein, a functional cross-linking agent bromo bicyclic-oxazolidine (OX-Br) has been designed and synthesized to crosslink BHVs and construct a bio-functionalization scaffold for subsequent in-situ atom transfer radical polymerization (ATRP). The porcine pericardium cross-linked by OX-Br (OX-PP) exhibits better biocompatibility and anti-calcification property than the glutaraldehyde-treated porcine pericardium (Glut-PP) as well as comparable physical and structural stability to Glut-PP. Furthermore, the resistance to biological contamination especially bacterial infection of OX-PP along with anti-thrombus and endothelialization need to be enhanced to reduce the risk of implantation failure due to infection. Therefore, amphiphilic polymer brush is grafted to OX-PP through in-situ ATRP polymerization to prepare polymer brush hybrid BHV material SA@OX-PP. SA@OX-PP has been demonstrated to significantly resist biological contamination including plasma proteins, bacteria, platelets, thrombus and calcium, and facilitate the proliferation of endothelial cells, resulting in reduced risk of thrombosis, calcification and endocarditis. Altogether, the proposed crosslinking and functionalization strategy synergistically achieves the improvement of stability, endothelialization potential, anti-calcification and anti-biofouling performances for BHVs, which would resist the degeneration and prolong the lifespan of BHVs. The facile and practical strategy has great potential for clinical application in fabricating functional polymer hybrid BHVs or other tissue-based cardiac biomaterials. STATEMENT OF SIGNIFICANCE: Bioprosthetic heart valves (BHVs) are widely used in valve replacements for severe heart valve disease, and clinical demand is increasing year over year. Unfortunately, the commercial BHVs, mainly cross-linked by glutaraldehyde, can serve for only 10-15 years because of calcification, thrombus, biological contamination, and difficulties in endothelialization. Many studies have been conducted to explore non-glutaraldehyde crosslinkers, but few can meet high requirements in all aspects. A new crosslinker, OX-Br, has been developed for BHVs. It can not only crosslink BHVs but also serve as a reactive site for in-situ ATRP polymerization and construct a bio-functionalization platform for subsequent modification. The proposed crosslinking and functionalization strategy synergistically achieves the high requirements for stability, biocompability, endothelialization, anti-calcification, and anti-biofouling propeties of BHVs.

Stability of Ampicillin plus Ceftriaxone Combined in Elastomeric Infusion Devices for Outpatient Parenteral Antimicrobial Therapy

Currently, ampicillin plus ceftriaxone (AC) is one of the preferred treatments for Enterococcus faecalis infective endocarditis. However, there is a lack of stability data for the combination of both drugs in elastomeric devices, so the inclusion of AC in Outpatient Parenteral Antimicrobial Therapy (OPAT) programs is challenging. The objective of the study was to determine the stability of AC in elastomeric pumps when stored at 8 ± 2 °C, 25 ± 2 °C, 30 ± 2 °C and 37 ± 2 °C using LC-MS/MS. The combination was diluted in 0.9% sodium chloride and the final concentrations were ampicillin 24 g/L plus ceftriaxone 8 g/L. Physical and chemical stability were evaluated at 12, 20, 24, 36 and 48 h after preparation. Stability was met at each time point if the percentage of intact drug was ≥90% of its respective baseline concentration and color and clearness remained unchanged. The drug combination was stable for 48 h when it was kept at 8 ± 2 °C. At 25 ± 2 °C and 30 ± 2 °C, they were stable for 24 h of storage. At 37 ± 2 °C, the stability criterion was not met at any time point. These results prove that AC could be included in OPAT programs using elastomeric infusion devices for the treatment of E. faecalis infections.

Pharmacokinetic/Pharmacodynamic Index Linked to In Vivo Efficacy of the Ampicillin-Ceftriaxone Combination against Enterococcus faecalis

Combination therapy with ampicillin plus ceftriaxone (AMP+CRO) is the first-line therapy for treating severe infections due to Enterococcus faecalis. However, the pharmacokinetic/pharmacodynamic (PK/PD) index linked to the in vivo efficacy of the combination is not yet defined, hindering dose optimization in the clinic. Because classical PK/PD indices are not directly applicable to antimicrobial combinations, two novel indices were tested in the optimized murine model of infection by E. faecalis to delineate the potentiation of AMP by CRO: the time above the CRO threshold (T_>threshold) and the time above the AMP instantaneous MIC (T_>MICi). The potential clinical relevance was evaluated by simulating human doses of AMP and CRO. Hill's equation fitted well the exposure-response data in terms of T_>threshold, with a CRO threshold of 1 mg/L. The required exposures were 46%, 49%, and 52% for stasis and 1- and 2-log₁₀ killing, respectively. Human ceftriaxone doses of 2 g every 12 h (q12h) would reach the target in >90% of strains with thresholds ≤64 mg/L. The AMP T_>MICi index also fitted well, and the required exposures were 37%, 41%, and 46% for stasis and 1- and 2-log₁₀ killing, respectively. In humans, the addition of CRO would allow use of lower AMP doses to reach the same T_>MICi and to treat strains with higher MICs. This is the first report of the PK/PD indices and required magnitudes linked to AMP+CRO against E. faecalis; these results can be used as the basis to guide the design of clinical trials to improve combined therapy against enterococci.

Native and Prosthetic Simultaneously Double Valve Infective Endocarditis with Enterococcus faecalis-Case-Based Review

Infective endocarditis is a severe infective heart disease, commonly involving native or prosthetic valves. It frequently presents with univalvular involvement and simultaneous double valve or multivalvular involvement is rarely described. The third leading cause of infective endocarditis worldwide is Enterococcus faecalis, which is associated with high mortality rates despite important advances in antimicrobial therapy. It develops secondary to enterococcal bacteremia, with its origin from the gastrointestinal or genitourinary tract and predominantly affecting the elderly population with multiple comorbidities. Clinical presentation is usually less typical, and the treatment is challenging. It can be marked by antibiotic resistance, side effects, and subsequent complications. Surgical treatment can be considered if deemed appropriate. To the best of our knowledge, we present the first case-based narrative review of Enterococcus faecalis double valve endocarditis involving both the aortic native and prosthetic mitral valve, highlighting the clinical characteristics, treatment, and complications of this condition.

Evaluation of resazurin microplate method for rapid detection of vancomycin and linezolid resistance in Enterococcus faecalis and Enterococcus faecium clinical isolates

BACKGROUND

Vancomycin and linezolid resistance among enterococci is an increasing problem due to a lack of alternative antibiotics. Early identification of vancomycin-resistant and linezolid-resistant strains can help prevent the spread of resistance to these antibiotics. Hence, early, rapid and accurate detection of vancomycin and linezolid resistance is critical.

OBJECTIVES

The resazurin microplate method (RMM) was developed for detecting vancomycin and linezolid susceptibility among Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) clinical isolates, and its performance was further evaluated.

METHODS

A total of 209 non-duplicate clinical isolates and three strains from the faeces of domestic animals, including 142 E. faecalis (71 linezolid non-susceptible and 71 linezolid susceptible) and 70 E. faecium (23 vancomycin non-susceptible, 23 vancomycin susceptible, 12 linezolid non-susceptible and 12 linezolid susceptible), were tested using RMM.

RESULTS

The susceptibility of E. faecium to vancomycin was detected within 5 h, with high susceptibility (23/23) and specificity (23/23). The susceptibility of E. faecalis and E. faecium to linezolid was detected within 4 h, with specificities of 98.59% and 100% and susceptibilities of 94.37% and 58.33% for E. faecalis and E. faecium, respectively.

CONCLUSIONS

RMM had a good positive predictive value for the detection of vancomycin-non-susceptible E. faecium and linezolid-non-susceptible E. faecalis. It thus has the potential to become an alternative method for the rapid screening of these resistant pathogens in clinical practice.