Genomic Characterization of a Vancomycin-Resistant Strain of Enterococcus faecium Harboring a rep2 Plasmid.

Purpose: In China, vancomycin-resistant enterococci (VRE) was not a common occurrence, and research on the genetic context and transmission mechanism of vanA-plasmid was scarce. The aim of this study was to molecularly characterise a vancomycin-resistant Enterococcus faecium isolate from a bloodstream infection and determine the genetic environment and delivery pattern of the plasmid carrying vancomycin-resistant gene. Materials and Methods: In May 2022, a vancomycin-resistant strain of Enterococci was identified during routine screening for VRE bacteria at the First Affiliated Hospital, Zhejiang University School of Medicine. Utilizing matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), the isolate was accurately identified. Antimicrobial susceptibility and whole-genome sequencing (WGS) were employed to perform phenotypic and genomic analysis, respectively. Further bioinformatics analyses was carried out to characterize the vanA-bearing plasmid. Results: The antimicrobial susceptibility test showed that SJ2 strain was resistant to multiple antimicrobials, including ampicillin, benzylpenicillin, ciprofloxacin, erythromycin, levofloxacin, streptomycin, and vancomycin. Whole-genome analysis revealed that SJ2 strain carries several antimicrobial resistance genes and virulence determinants. MLST analysis found that SJ2 strain belongs to an unknown ST type. Plasmid analysis confirmed that the vanA gene was located on a variant of ~50 kb rep2 plasmid. Conclusion: Our study found that vanA-bearing rep2 plasmid is a potential source of dissemination and outbreak, and continuous surveillance is necessary to control its spread in Hangzhou, China.

Effect of nisin and p-coumaric acid on autoinducer-2 activity, biofilm formation, and sprE expression of Enterococcus faecalis.

Quorum sensing (QS) is an inter- and intracellular communication mechanism that regulates gene expression in response to population size. Autoinducer-2 (AI-2) signaling is a QS signaling molecule common to both Gram-negative and Gram-positive bacteria. Enterococcus faecalis is one of the leading causes of nosocomial infections worldwide. There has been an increasing interest in controlling infectious diseases through targeting the QS mechanism using natural compounds. This study aimed to investigate the effect of nisin and p-coumaric acid (pCA), on biofilm formation and AI-2 signaling in E. faecalis. Their effect on the expression of the QS-regulated virulence encoding gene sprE was also investigated. Nisin exhibited a MIC ranging from 0.25 to 0.5 mg/mL, while the MIC of pCA was 1 mg/mL. The luminescence-based response of the reporter strain Vibrio harveyi BB170 was used to determine AI-2 activity in E. faecalis strains. Nisin was not effective in inhibiting AI-2 activity, while pCA reduced AI-2 activity by ≥ 60%. Moreover, pCA and nisin combination showed higher inhibitory effect on biofilm formation of E. faecalis, compared to the treatment of pCA or nisin alone. qRT-PCR analysis showed that nisin alone and the combination of nisin and pCA, at their MIC values, led to a 32.78- and 40.22-fold decrease in sprE gene expression, respectively, while pCA alone did not have a significant effect. Considering the demand to explore new therapeutic avenues for infectious bacteria, this study was the first to report that pCA can act like a quorum sensing inhibitor (QSI) against AI-2 signaling in E. faecalis.

Comparative evaluation of antibacterial efficacy of nonsteroidal anti-inflammatory medications and proton-pump inhibitor against Enterococcus faecalis: An in vitro study.

Aim: The present in vitro experimental study was undertaken to evaluate and compare the antimicrobial activity of triple antibiotic paste (TAP), diclofenac, and proton-pump inhibitor (PPI) against the microorganism Enterococcus faecalis. Materials and Methods: Three medicaments were selected for the study, TAP, diclofenac, and PPI. The experimental groups for the test were as follows: Part 1 - Group 1: TAP, Group 2: diclofenac, and Group 3: PPI; Part 2 - Group 1: TAP + PPI and Group 2: diclofenac + PPI. An agar well diffusion test was used to determine the efficacy of the experimental medicaments against E. faecalis (ATCC 29212). The diameter of inhibition zones was measured in millimeters using an inhibition zone measuring scale and the results were recorded. Statistical Analysis: The statistical analysis was done using an analysis of variance and an unpaired t-test. P value was set at < 0.05. Results: There was a significant difference in the diameter of growth inhibition zones, with the greatest diameter noted for TAP + PPI followed by diclofenac sodium (DS) + PPI, TAP, DS, and PPI. Conclusions: The antimicrobial effectiveness of TAP + PPI was found to be superior to all other medicaments (DS + PPI, TAP, DS, and PPI).

Prevalence of antimicrobial resistance in fecal Escherichia coli and Enterococcus spp. isolates from beef cow-calf operations in northern California and associations with farm practices.

Antimicrobials are necessary for the treatment of bacterial infections in animals, but increased antimicrobial resistance (AMR) is becoming a concern for veterinarians and livestock producers. This cross-sectional study was conducted on cow-calf operations in northern California to assess prevalence of AMR in Escherichia coli and Enterococcus spp. shed in feces of beef cattle of different life stages, breeds, and past antimicrobial exposures and to evaluate if any significant factors could be identified that are associated with AMR status of the isolates. A total of 244 E. coli and 238 Enterococcus isolates were obtained from cow and calf fecal samples, tested for susceptibility to 19 antimicrobials, and classified as resistant or non-susceptible to the antimicrobials for which breakpoints were available. For E. coli, percent of resistant isolates by antimicrobial were as follows: ampicillin 100% (244/244), sulfadimethoxine 25.4% (62/244), trimethoprim-sulfamethoxazole 4.9% (12/244), and ceftiofur 0.4% (1/244) while percent of non-susceptible isolates by antimicrobial were: tetracycline 13.1% (32/244), and florfenicol 19.3% (47/244). For Enterococcus spp., percent of resistant isolates by antimicrobial were as follows: ampicillin 0.4% (1/238) while percent of non-susceptible isolates by antimicrobial were tetracycline 12.6% (30/238) and penicillin 1.7% (4/238). No animal level or farm level management practices, including antimicrobial exposures, were significantly associated with differences in isolate resistant or non-susceptible status for either E. coli or Enterococcus isolates. This is contrary to the suggestion that administration of antibiotics is solely responsible for development of AMR in exposed bacteria and demonstrates that there are other factors involved, either not captured in this study or not currently well understood. In addition, the overall use of antimicrobials in this cow-calf study was lower than other sectors of the livestock industry. Limited information is available on cow-calf AMR from fecal bacteria, and the results of this study serve as a reference for future studies to support a better understanding and estimation of drivers and trends for AMR in cow-calf operations.

Heat-Killed Enterococcus faecalis Inhibit FL83B Hepatic Lipid Accumulation and High Fat Diet-Induced Fatty Liver Damage in Rats by Activating Lipolysis through the Regulation the AMPK Signaling Pathway.

Continuous consumption of high-calorie meals causes lipid accumulation in the liver and liver damage, leading to non-alcoholic fatty liver disease (NAFLD). A case study of the hepatic lipid accumulation model is needed to identify the mechanisms underlying lipid metabolism in the liver. In this study, the prevention mechanism of lipid accumulation in the liver of Enterococcus faecalis 2001 (EF-2001) was extended using FL83B cells (FL83Bs) and high-fat diet (HFD)-induced hepatic steatosis. EF-2001 treatment inhibited the oleic acid (OA) lipid accumulation in FL83B liver cells. Furthermore, we performed lipid reduction analysis to confirm the underlying mechanism of lipolysis. The results showed that EF-2001 downregulated proteins and upregulated AMP-activated protein kinase (AMPK) phosphorylation in the sterol regulatory element-binding protein 1c (SREBP-1c) and AMPK signaling pathways, respectively. The effect of EF-2001 on OA-induced hepatic lipid accumulation in FL83Bs enhanced the phosphorylation of acetyl-CoA carboxylase and reduced the levels of lipid accumulation proteins SREBP-1c and fatty acid synthase. EF-2001 treatment increased the levels of adipose triglyceride lipase and monoacylglycerol during lipase enzyme activation, which, when increased, contributed to increased liver lipolysis. In conclusion, EF-2001 inhibits OA-induced FL83B hepatic lipid accumulation and HFD-induced hepatic steatosis in rats through the AMPK signaling pathway.

Elimination of Enterococcus faecalis from root canal system using laser-activated nanoparticles: a systematic review.

Elimination of Enterococcus faecalis is vital during root canal treatment. Owing to their antimicrobial properties, laser-activated nanoparticles (NPs) have been used in root canal irrigation in the recent past. The aim of this review is to conduct a qualitative analysis of the published data evaluating the antibacterial efficacy of laser-activated nanoparticles in the elimination of E. faecalis from the root canal system. Considering all the papers published till August 2022, a search of the databases PubMed, SCOPUS, and EBSCOhost was conducted. All the articles that were published in English were included. The review process was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. The risk of bias was assessed after the extraction of the data. After screening the distinguished 51 studies according to the inclusion criteria, five in vitro studies were included for the systematic review. A systematic review of the selected studies showed a positive impact on E. faecalis load reduction following irrigation with nanoparticles irradiated using lasers. Laser-activated nanoparticles have shown superior antibacterial efficacy compared to conventional irrigation techniques and may be used as an alternative for root canal disinfection.

Treatment and outcome of gram-positive bacteremia in patients receiving extracorporeal membrane oxygenation.

BACKGROUND: While guidance exists for management of blood stream infections with various invasive devices, there are currently limited data to guide antibiotic selection and duration for bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO). OBJECTIVE: To evaluate the treatment and outcomes of thirty-six patients with Staphylococcus aureus and Enterococcus bacteremia on ECMO support. METHODS: Blood culture data was retrospectively analyzed from patients with Staphylococcus aureus bacteremia (SAB) or Enterococcus bacteremia who underwent ECMO support between March 2012 and September 2021 at Brooke Army Medical Center. RESULTS: Of the 282 patients who received ECMO during this study period, there 25 (9%) patients developed Enterococcus bacteremia and 16 (6%) developed SAB. SAB occurred earlier in ECMO as compared to Enterococcus (median day 2 IQR (1-5) vs. 22 (12-51), p = 0.01). The most common duration of antibiotics was 28 days after clearance for SAB and 14 days after clearance for Enterococcus. 2 (5%) patients underwent cannula exchange with primary bacteremia, and 7 (17%) underwent circuit exchange. 1/3 (33%) patients with SAB and 3/10 (30%) patients with Enterococcus bacteremia who remained cannulated after completion of antibiotics had a second episode of SAB or Enterococcus bacteremia. CONCLUSION: This single center case series is the first to describe the specific treatment and outcomes of patients receiving ECMO complicated by SAB and Enterococcus bacteremia. For patients who remain on ECMO after completion of antibiotics, there is a risk of a second episode of Enterococcus bacteremia or SAB.

Multicenter Clinical Evaluation of ETEST Eravacycline for Susceptibility Testing of Enterobacteriaceae and Enterococci.

Eravacycline (ERV) (brand name Xerava [Tetraphase]) is a new tetracycline-class antibacterial that has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for treatment of complicated intra-abdominal infections (cIAIs). ETEST is a gradient diffusion method that represents a simple alternative to the broth microdilution (BMD) method for performing antimicrobial susceptibility testing (AST). A multicenter evaluation of the performance of the new ETEST ERV (bioMérieux) in comparison with BMD was conducted following FDA and International Standards Organization (ISO) recommendations, using FDA- and EUCAST-defined breakpoints. Clinical isolates of Enterobacteriaceae (n = 542) and Enterococcus spp. (n = 137) were included. Based on the BMD reference method, 92 Enterobacteriaceae isolates and 9 enterococcal isolates were nonsusceptible to ERV according to the FDA breakpoints, while 7 Escherichia coli isolates and 3 Enterococcus sp. isolates were classified as ERV resistant according the EUCAST breakpoints. Referring to FDA performance criteria, the ETEST ERV demonstrated 99.4% and 100.0% essential agreement (EA), 98.0% and 94.9% categorical agreement (CA), very major error (VME) rates of 5.4% and 33.33%, and major error (ME) rates of 1.3% and 3.1% with clinical and challenge isolates, respectively, of Enterobacteriaceae and Enterococcus spp. According to EUCAST breakpoints, E. coli and Enterococcus sp. isolate results also met ISO acceptance criteria for EA and CA (EA of 99.0% and 100.0%, respectively, and CA of 100.0% for both), without any VMEs or MEs. In conclusion, we report that ETEST ERV represents an accurate tool for performing ERV AST of Enterobacteriaceae and Enterococcus sp. isolates.

Plasmid-Associated Bacteriocin Produced by Pediococcus pentosaceus Isolated from Smoked Salmon: Partial Characterization and Some Aspects of his Mode of Action.

Strain ST3Ha, isolated from commercially available smoked salmon, was identified as Pediococcus pentosaceus based on biochemical and physiological tests and 16S rRNA sequencing. Strain ST3Ha produces a class IIa bacteriocin active against lactic acid bacteria, Listeria monocytogenes and Enterococcus faecalis. The antimicrobial peptide was inactivated by proteolytic enzymes, confirming his proteinaceous nature, but was not affected when treated with α-amylase, SDS, Tween 20, Tween 80, urea, and EDTA. No change in activity was recorded after 2 h at pH values between 2.0 and 9.0 and after treatment at 100 °C for 120 min or 121 °C for 15 min. The mode of action against Listeria ivanovii subsp. ivanovii ATCC 19119 and E. faecalis ATCC 19443 was bactericidal, resulting in cell lyses and enzyme leakage. The highest level of activity (1.6 × 106 AU/mL) was recorded when cells were grown at 37 °C or 30 °C in MRS broth (pH 6.5). Antimicrobial peptide ST3Ha adsorbs at high levels to the sensitive test organisms on strain-specific manner and depending on incubation temperature, environmental pH, and presence of supplemented chemicals. Based on PCR analysis, P. pentosaceus ST3Ha harbor a 1044-bp plasmid-associated fragment corresponding in size to that recorded for pediocin PA-1. Sequencing of the fragment revealed a gene identical to pedB, reported for pediocin PA-1. The combined application of the low levels (below MIC) of ciprofloxacin and bacteriocin ST3Ha results in the synergetic effect in the inhibition of L. ivanovii subsp. ivanovii ATCC 19119. Expressed by P. pentosaceus ST3Ha, bacteriocin was characterized as low cytotoxic, a characteristic relevant for its application in food industry and/or in human and veterinary medical practices.

Enterococcus moraviensis EMo 1-1Nik of horse origin:characteristics and potential bacteriocin-producing strain.

Nowadays, developed more precisious identification techniques have allowed to validate newer enterococcal species. Among them, the species Enterococcus moraviensis was also validated, at first from surface waters. However, in this study, characteristics and potential to bacteriocin production by the strain E. moraviensis EMo 1-1Nik isolated from buccal mucosa of Slovak warm-blood horse breed has been studied. BLASTn analysis allotted this strain to the species E. moraviensis with percentage identity BLASTn 16S rRNA sequence in the strain up to 100% (99.93% similarity with E. moraviensis NR113937.1). The strain EMo 1-1Nik has been provided with GenBank accession number MW326085. It is hemolysis-negative (γ-hemolysis), deoxyribonuclease-negative and gelatinase-negative; absent of virulence factor genes, low-grade biofilm-positive (0.133 ± 0.36), mostly susceptible to tested antibiotics. Moreover, 60% of EMo1-1Nik colonies were found as bacteriocin-producing against the principal indicator Enterococcus avium EA5. The concentrated substance (CS, pH 4.5) of EMo1-1Nik showed the inhibitory activity against EA5 strain (800 AU/mL); CSs with pH 6.3 and 7.3 reached inhibitory activity 100 AU/mL against EA5 strain. CS was thermo-stable and it does not lost activity after enzymes treatment. Oppositelly, EMo 1-1Nik was susceptible to Mundticin EM 41/3 (800 AU/mL) produced by horse fecal strain E. mundtii EM 41/3 and enterocins (up to 51 200 AU/mL). In spite of the preliminary results, it has been shown a potential to produce bacteriocin substance of the safe strain E. moraviensis EMo1-1Nik. The additional studies are in processing.

Role of microbial microbes in arsenic bioaccumulation and biotransformation in mice.

Although gut microbes can affect the accumulation and metabolism of arsenic (As), the microbes contributing to these processes remain largely unknown. Therefore, this study aimed to investigate the bioaccumulation and biotransformation of arsenate [As(V)] and arsenobetaine (AsB) in mice with a disordered gut microbiome. We used cefoperazone (Cef) to construct a mouse model of gut microbiome disruption along with 16S rRNA sequencing to elucidate the effect of gut microbiome destruction on the biotransformation and bioaccumulation of As(V) and AsB. This revealed the role of specific bacteria in As metabolism. Gut microbiome destruction increased the bioaccumulation of As(V) and AsB in various organs and reduced the excretion of As(V) and AsB in the feces. Further, gut microbiome destruction was found to be important for the biotransformation of As(V). Interference with Cef can significantly decrease Blautia and Lactobacillus while increasing Enterococcus, leading to increase As accumulation in mice and enhanced methylation. We also identified Lachnoclostridium, Erysipelatoclostridium, Blautia, Lactobacillus, and Enterococcus as biomarkers involved in As bioaccumulation and biotransformation. In conclusion, specific microbes can increase As accumulation in the host, exacerbating its potential health risks.

Vancomycin and Linezolid-Resistant Enterococcus Isolates from a Tertiary Care Center in India.

INTRODUCTION: There is increasing development of antibiotic resistance among the Enterococcus species. OBJECTIVES: This study was performed to determine prevalence and characterize the vancomycin-resistant and linezolid-resistant enterococcus isolates from a tertiary care center. Moreover, the antimicrobial susceptibility pattern of these isolates was also determined. MATERIALS AND METHODS: A prospective study was performed in Medical College, Kolkata, India, over a period of two years (from January 2018 to December 2019). After obtaining clearance from the Institutional Ethics Committee, Enterococcus isolates from various samples were included in the present investigation. In addition to the various conventional biochemical tests, the VITEK 2 Compact system was used to identify the Enterococcus species. The isolates were tested for antimicrobial susceptibility to different antibiotics using the Kirby-Bauer disk diffusion method and VITEK 2 Compact to determine the minimum inhibitory concentration (MIC). The Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines were used to interpret susceptibility. Multiplex PCR was performed for genetic characterization of the vancomycin-resistant Enterococcus isolates and sequencing was performed for characterization of the linezolid-resistant Enterococcus isolates. RESULTS: During the period of two years, 371 isolates of Enterococcus spp. were obtained from 4934 clinical isolates showing a prevalence of 7.52%. Among these isolates, 239 (64.42%) were Enterococcus faecalis, 114 (30.72%) Enterococcus faecium, and others were Enterococcus durans, Enterococcus casseliflavus, Enterococcus gallinarum, and Enterococcus avium. Among these, 24 (6.47%) were VRE (Vancomycin-Resistant Enterococcus) of which 18 isolates were Van A type and six isolates of Enterococcus casseliflavus and Enterococcus gallinarum were resistant VanC type. There were two linezolid-resistant Enterococcus, and they were found to have the G2576T mutation. Among the 371 isolates, 252 (67.92%) were multi-drug resistant. CONCLUSION: This study found an increasing prevalence of vancomycin-resistant Enterococcus isolates. There is also an alarming prevalence of multidrug resistance among these isolates.

Genetic and Probiotic Characteristics of Urolithin A Producing Enterococcus faecium FUA027.

Enterococcus faecium FUA027 transforms ellagic acid (EA) to urolithin A (UA), which makes it a potential application in the preparation of UA by industrial fermentation. Here, the genetic and probiotic characteristics of E. faecium FUA027 were evaluated through whole-genome sequence analysis and phenotypic assays. The chromosome size of this strain was 2,718,096 bp, with a GC content of 38.27%. The whole-genome analysis revealed that the genome contained 18 antibiotic resistance genes and seven putative virulence factor genes. E. faecium FUA027 does not contain plasmids and mobile genetic elements (MGEs), and so the transmissibility of antibiotic resistance genes or putative virulence factors should not occur. Phenotypic testing further indicated that E. faecium FUA027 is sensitive to clinically relevant antibiotics. In addition, this bacterium exhibited no hemolytic activity, no biogenic amine production, and could significantly inhibit the growth of the quality control strain. In vitro viability was >60% in all simulated gastrointestinal environments, with good antioxidant activity. The study results suggest that E. faecium FUA027 has the potential to be used in industrial fermentation for the production of urolithin A.

Identification of Multiple Iron Uptake Mechanisms in Enterococcus faecalis and Their Relationship to Virulence.

Among the unfavorable conditions bacteria encounter within the host is restricted access to essential trace metals such as iron. To overcome iron deficiency, bacteria deploy multiple strategies to scavenge iron from host tissues, with abundant examples of iron acquisition systems being implicated in bacterial pathogenesis. Yet the mechanisms utilized by the major nosocomial pathogen Enterococcus faecalis to maintain intracellular iron balance are poorly understood. In this study, we conducted a systematic investigation to identify and characterize the iron acquisition mechanisms of E. faecalis and to determine their contribution to virulence. Bioinformatic analysis and literature surveys revealed that E. faecalis possesses three conserved iron uptake systems. Through transcriptomics, we discovered two novel ABC-type transporters that mediate iron uptake. While inactivation of a single transporter had minimal impact on the ability of E. faecalis to maintain iron homeostasis, inactivation of all five systems (Δ5Fe strain) disrupted intracellular iron homeostasis and considerably impaired cell growth under iron deficiency. Virulence of the Δ5Fe strain was generally impaired in different animal models but showed niche-specific variations in mouse models, leading us to suspect that heme can serve as an iron source to E. faecalis during mammalian infections. Indeed, heme supplementation restored growth of Δ5Fe under iron depletion and virulence in an invertebrate infection model. This study revealed that the collective contribution of five iron transporters promotes E. faecalis virulence and that the ability to acquire and utilize heme as an iron source is critical to the systemic dissemination of E. faecalis.

Incidence of Breast Cancer and Enterococcus Infection: A Retrospective Analysis.

Background: Enterococci role in the microbiome remains controversial, and researches regarding enterococcal infection (EI) and its sequelae are limited. The gut microbiome has shown to play an important role in immunology and cancer. Recent data have suggested a relationship between the gut microbiome and breast cancer (BC). Methods: Patients in a Health Insurance Portability and Accountability Act (HIPAA) compliant national database (2010 - 2020) were used for this retrospective study. International Classification of Disease (ICD) Ninth and Tenth Codes, Current Procedural Terminology (CPT), and National Drug Codes were used to identify BC diagnosis and EI. Patients were matched for age, sex, Charlson comorbidity index (CCI), antibiotic treatment, obesity, and region of residence. Statistical analyses were implemented to assess significance and estimate odds ratio (OR). Results: EI was associated with a decreased incidence of BC (OR = 0.60, 95% confidence interval (CI): 0.57 - 0.63) and the difference was statistically significant (P < 2.2 × 10-16). Treatment for EI was controlled for in both EI and noninfected populations. Patients with a prior EI and treated with antibiotics were compared to patients with no history of EI and received antibiotics. Both populations subsequently developed BC. Results remained statistically significant (P < 2.2 × 10-16) with an OR of 0.57 (95% CI: 0.54 - 0.60). In addition to standard matching protocol, obesity was controlled for in both groups by exclusively containing obese patients, but one group with prior EI and the other without. In obese patients, a lower incidence of BC was shown in the infected group compared to the noninfected group. Results were statistically significant (P < 2.2 × 10-16) with an OR of 0.56 (95% CI: 0.53 - 0.58). Age of BC diagnosis with and without a prior EI was analyzed and demonstrated increased BC incidence with increasing age in both groups, but less in the EI group. Incidence of BC based on region was analyzed, which showed lower BC incidence across all regions in the EI group. Conclusion: This study shows a statistically significant correlation between EI and decreased incidence of BC. Further exploration is needed to identify and understand not only the role of enterococcus in the microbiome, but also the protective mechanism(s) and impact of EI on BC development.

The association of infectious diseases consultation and 30-day mortality rates among veterans with enterococcal bacteremia: 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 bacteremia has not been fully evaluated. METHODS: We performed a 1:1 propensity-score matched retrospective cohort study evaluating all patients with enterococcal bacteremia 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 odds ratio (OR) to determine the independent association of IDC and 30-day mortality adjusted for vancomycin susceptibility and the primary source of bacteremia. RESULTS: 12,666 patients with enterococcal bacteremia were included. 8,400 (63.3%) had IDC and 4,266 (36.7%) did not have IDC. 2,972 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 to 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 bacteremia 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. CONCLUSIONS: Our study suggests that IDC was associated with improved care processes and 30-day mortality rates among patients with enterococcal bacteremia. IDC should be considered for patients with enterococcal bacteremia.

Genome sequence and probiotic potential of newly isolated Enterococcus durans strain MN187066.

Enterococci are commensals of the human intestinal tract. Their use as probiotics is supported by their ability to confer several health benefits and eliminate foodborne pathogens but is controversial due to the presence of virulence and antibiotic resistance traits. To use them as probiotics requires thorough research to establish their safety. Here we sequenced the whole genome of a newly isolated Enterococcus durans MN187066 and used a suite of bioinformatics tools to analyze its beneficial probiotic traits as well as antimicrobial resistance and virulence genes. The whole genome had a length of 2 978,152 bp, and an average G + C content of 37.88%. The bopABCD genes involved in biofilm formation were annotated in the genome. However, further analysis showed that these genes are mostly helpful in strengthening their colonization and establishment in the gastrointestinal tract. Also, we identified secondary metabolite gene clusters and the bacteriocins Enterolysin A and Enterocin P. We also identified repUS15 and rep1 replicons and genes that were associated with antimicrobial resistance and virulence. Nevertheless, vancomycin resistance genes were not detected. Our results show that the E. durans strain MN187066 can be considered a non-toxigenic strain and produces beneficial metabolites that are critical for their success as probiotics.

Freeze dried probiotic carrot juice powder for better storage stability of probiotic.

Probiotic strains isolated from Gundruk- a traditional Indian fermented food-and fermented carrot juice, were evaluated for their probiotic properties and analyzed probiotic properties such as lactic acid production, NaCl tolerance, and acid tolerance for all the isolated strains. Most isolated strains were susceptible to antibiotics, and cell-free extracts showed potential antioxidant activity and observed antagonistic properties against foodborne pathogens such as Salmonella typhi ATCC 6539, Escherichia coli ATCC 25922, Shigella ATCC 12022, and Staphylococcus ATCC 29213. The isolate Enterococcus faecalis(K13), was incorporated in carrot juice and microencapsulated by freeze-drying and spray drying. Gum Arabic and maltodextrin were used as coating materials. The physicochemical properties, such as bulk density, moisture content, water activity and color of the powders, and the survivability of probiotic bacteria, were studied on storage. The freeze-dried probiotic formulation is suggested over spray-dried formulation for further use, since it had good storage stability up to one month (6-7 Log CFU/g).

Antimicrobial and cleaning effects of ultrasonic-mediated plasma-loaded microbubbles on Enterococcus faecalis biofilm: an in vitro study.

BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently isolated bacteria from teeth with root canal treatment failure. This study aims to evaluate the disinfection effect of ultrasonic-mediated cold plasma-loaded microbubbles (PMBs) on 7d E. faecalis biofilm, the mechanical safety and the mechanisms. METHODS: The PMBs were fabricated by a modified emulsification process and the key reactive species, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated. The 7d E. faecalis biofilm on human tooth disk was constructed and divided into the following groups: PBS, 2.5%NaOCl, 2%CHX, and different concentrations of PMBs (108 mL-1, 107 mL-1). The disinfection effects and elimination effects were verified with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Microhardness and roughness change of dentin after PMBs treatment were verified respectively. RESULTS: The concentration of NO and H2O2 in PMBs increased by 39.99% and 50.97% after ultrasound treatment (p < 0.05) respectively. The CLSM and SEM results indicate that PMBs with ultrasound treatment could remove the bacteria and biofilm components effectively, especially those living in dentin tubules. The 2.5% NaOCl presented an excellent effect against biofilm on dishes, but the elimination effect on dentin tubules is limited. The 2% CHX group exhibits significant disinfection effect. The biosafety tests indicated that there is no significant changes on microhardness and roughness after PMBs with ultrasound treatment (p > 0.05). CONCLUSION: PMBs combined with ultrasound treatment exhibited significant disinfection effect and biofilm removal effect, the mechanical safety is acceptable.

Chicken Enterococcus faecalis-induced immunoglobulin Y as a prophylactic and therapeutic agent against streptococcosis in red tilapia (Oreochromis hybrid).

Background and Aim: Streptococcosis is a common bacterial disease in red tilapia, in which Enterococcus faecalis infection has not been widely reported. This study aimed to evaluate the efficacy of pellets that contain chicken E. faecalis-induced immunoglobulin Y (IgY) to treat and prevent streptococcosis in red tilapia. Materials and Methods: We conducted a 28-day study for immunoprophylaxis and immunotherapy, each using four groups with two replications: Healthy control fish (KS), non-IgY pellets (PA and TA), pellets with 25% egg yolk containing E. faecalis-induced IgY (PB and TB), and pellets with 50% egg yolk containing E. faecalis-induced IgY(PC and TC). Indirect enzyme-linked immunosorbent assay was performed on prototype pellets produced with an IgY suspension at 1.63 mg/mL as the standard optical density curve. For the immunoprophylaxis study, pellets of 3% of the average body weight of the experimental fish (0.50 g per fish per day) were given daily until day 14 before the challenge test with E. faecalis (2.1 × 109 Colony-forming unit/mL peroral) on day 15. The data from the observation period on days 15-28 were analyzed. For the immunotherapy study, pellets of 3% of the average body weight (0.50 g per fish per day) were given daily for 21 days (days 8-28) 7 day spost-infection. The data from the immunotherapy study were collected during the observation period on days 8-28. Statistical analysis was performed on non-specific immune variables: Total leukocytes, monocytes, lymphocytes, neutrophils, phagocytic activity, and macrophage capacity; and the semi-quantitative distribution of melanomacrophage centers (MMCs) in the lymphoid organs, such as spleen and liver. Photomacrographic data were analyzed descriptively and qualitatively by comparing the healing process and clinical signs found between experiments in the immunotherapy study. Results: The pellet with 50% egg yolk with an IgY at 2.43 mg/g pellet, 3% of body weight once daily, was the best formula on experimental fish. The administration of this formulation can also increase non-specific immunity and the distribution of MMCs in the spleen and liver with a survival rate of 55% for 14 days of challenge period in the immunoprophylaxis study and 70% for 21 days of therapy period in the immunotherapy study. Conclusion: Immunoglobulin Y can be a prophylactic and therapeutic agent against streptococcal infections caused E. faecalis in red tilapia with an optimum dosage of 2.43 mg/g pellet.