Search

Enterococcus faecalis and Enterococcus faecium are frequent causes of healthcare-associated infections. Antimicrobial-resistant enterococci pose a serious public health threat, particularly vancomycin-resistant enterococci (VRE), for which treatment options are limited. The Centers for Disease Control and Prevention's Division of Healthcare Quality Promotion Sentinel Surveillance system conducted surveillance from 2018 to 2019 to evaluate antimicrobial susceptibility profiles and molecular epidemiology of 205 E. faecalis and 180 E. faecium clinical isolates collected from nine geographically diverse sites in the United States. Whole genome sequencing revealed diverse genetic lineages, with no single sequence type accounting for more than 15% of E. faecalis or E. faecium . Phylogenetic analysis distinguished E. faecium from 19 E. lactis (previously known as E. faecium clade B). Resistance to vancomycin was 78.3% among E. faecium , 7.8% among E. faecalis , and did not occur among E. lactis isolates. Resistance to daptomycin and linezolid was rare: E. faecium (5.6%, 0.6%, respectively), E. faecalis (2%, 2%), and E. lactis (5.3%, 0%). All VRE harbored the vanA gene. Three of the seven isolates that were not susceptible to linezolid harbored optrA , one chromosomally located and two on linear plasmids that shared a conserved backbone with other multidrug-resistant conjugative linear plasmids. One of these isolates contained optrA and vanA co-localized on the linear plasmid. By screening all enterococci, 20% of E. faecium were predicted to harbor linear plasmids, whereas none were predicted among E. faecalis or E. lactis . Continued surveillance is needed to assess the future emergence and spread of antimicrobial resistance by linear plasmids and other mechanisms.IMPORTANCEThis work confirms prior reports of E. faecium showing higher levels of resistance to more antibiotics than E. faecalis and identifies that diverse sequence types are contributing to enterococcal infections in the United States. All VRE harbored the vanA gene. We present the first report of the linezolid resistance gene optrA on linear plasmids in the United States, one of which co-carried a vanA cassette. Additional studies integrating epidemiological, antimicrobial susceptibility, and genomic methods to characterize mechanisms of resistance, including the role of linear plasmids, will be critical to understanding the changing landscape of enterococci in the United States., Competing Interests: The authors declare no conflict of interest.

Enterococcus species are a normal flora of animals and humans. However, life-threatening opportunistic infections can be caused by antimicrobial resistant strains. Fecal (n = 42) and feed (n = 8) samples were obtained from a mink farm and cultured for the enumeration and detection of erythromycin-resistant (a macrolide; ERYr)- and tetracycline-resistant (TETr) enterococci. ERYr and TETr enterococci were detected from all fecal (mean concentrations = 6 and 7 logs, respectively) and feed (mean concentrations = 5 and 4 logs, respectively) samples. While Enterococcus faecalis and Enterococcus faecium were detected at equal proportions among the fecal TETr isolates, E. faecium predominated among ERYr fecal isolates. All ERYr and 90% of the TETr isolates (n = 50) were multidrug resistant (resistant to three or more antimicrobial classes). Among ERYr isolates, while 83% of E. faecalis (n = 12) were positive for erm(B), 58% of E. faecium (n = 38) isolates were positive for msr(C). Among ERYr isolates, tet(M) was detected from 92% of E. faecalis (n = 12) and 97% of E. faecium (n = 38) isolates. Conversely, however, erm(B) was detected in 18% of E. faecalis (n = 22) and 33% of E. faecium (n = 27) TETr isolates. Our study provides a baseline for future efforts to reduce antimicrobial resistance and improve antimicrobial stewardship in commercial mink production facilities. [ABSTRACT FROM AUTHOR]

Dalbavancin and comparators were susceptibility tested against 8643 Gram-positive bacteria from 74 hospitals located in Europe and the United States by broth microdilution method. The most common organisms were Staphylococcus aureus (45.2%), Enterococcus faecalis (12.2%), and Staphylococcus epidermidis (8.9%), but rank order varied markedly by geographic region. Dalbavancin demonstrated potent activity and broad spectrum, with MIC90 values of 0.03 mg/L for Staphylococcus aureus, β-haemolytic streptococci, and viridans group streptococci; 0.06 mg/L for Enterococcus faecalis and Staphylococcus epidermidis; and 0.12 mg/L for vancomycin-susceptible Enterococcus faecium. All organisms, except vancomycin-resistant enterococci and 1 Staphylococcus haemolyticus isolate, were inhibited at ≤ 0.25 mg/L of dalbavancin. [ABSTRACT FROM AUTHOR]

Enterococcus faecalis and faecium with resistance to daptomycin and/or linezolid are emerging globally. We present the genomic characterization of daptomycin- and linezolid-resistant E. faecalis and E. faecium surveillance isolates from the United States, 2013–2016. Daptomycin resistance was low among E. faecalis (2/364, 0.5%) and E. faecium (17/344, 5%). The majority (71%, 12/17) of daptomycin-resistant E. faecium isolates belonged to the emerging ST736 clone and contained mutations in liaFSR and cls previously associated with resistance. However, 1/2 E. faecalis and 3/17 E. faecium did not contain these mutations previously associated with daptomycin resistance. Linezolid resistance was rare among E. faecalis (1/364, 0.3%) and E. faecium (2/344, 0.6%). These two E. faecium isolates, one of which was also resistant to daptomycin and vancomycin, contained the 23S rRNA nucleotide mutation (G2576T) associated with linezolid resistance. Long-read sequencing revealed the linezolid-resistant E. faecalis isolate contained chromosomal- and plasmid-encoded copies of optrA. The chromosomal optrA was located on the recently described Tn 6674 multiresistance transposon. The second copy of optrA was encoded on an ∼65 kb mosaic plasmid, with component regions sharing high sequence identity to optrA -encoding multiresistance plasmids of animal origin. The optrA -encoding plasmid contained open reading frames predicted to encode proteins associated with a pheromone-responsive plasmid transfer system, and filter mating experiments confirmed the plasmid was conjugative. Continued surveillance of enterococci is necessary to assess the prevalence and trends of daptomycin and linezolid resistance in the United States, characterize resistance mechanisms and how they transfer, and monitor for emerging sequence types associated with resistance. [ABSTRACT FROM AUTHOR]

Objectives: To assess activity of the combination of ceftriaxone and ampicillin against clinical isolates of ampicillin-susceptible Enterococcus faecium.Methods: Ampicillin-susceptible E. faecium (n = 29) and Enterococcus faecalis (n = 10) collected from locations in the USA and France were used for this analysis. Susceptibility testing was performed by gradient diffusion strip (GDS) and broth microdilution (BMD). Synergy with the combination of ceftriaxone and ampicillin was assessed in all isolates using GDS crossing and double disc diffusion methods. Selected isolates (nine E. faecium and three E. faecalis) were assessed for synergy in time-kill studies using ampicillin alone and in combination with ceftriaxone.Results: In isolates of E. faecium, the median (range) ampicillin MIC by BMD was 0.5 (0.25-4) mg/L and by GDS it was 2 (1-8)  mg/L. In E. faecalis, the median (range) ampicillin MIC by BMD was 0.5 (0.5-1) mg/L and by GDS it was 2 (0.75-3) mg/L. A total of 24/29 (82.8%) isolates of E. faecium displayed synergy by GDS and 22/29 (75.9%) by double disc diffusion. Seven of 10 (70%) isolates of E. faecalis displayed synergy by GDS and 4/10 (40%) by double disc diffusion. Time-kill studies found synergy in 3/9 (33.3%) E. faecium and 3/3 (100%) E. faecalis.Conclusions: In contrast to the demonstrated synergy in time-kill models of ceftriaxone and ampicillin for E. faecalis, this combination does not appear to provide uniform synergy in E. faecium. Antagonism was not observed. Clinical correlation is necessary and caution should be used when considering ampicillin and ceftriaxone for the treatment of infections caused by ampicillin-susceptible E. faecium. [ABSTRACT FROM AUTHOR]

Ceftobiprole medocaril, the prodrug of ceftobiprole, is an advanced-generation cephalosporin that is approved in many European and non-European countries for the treatment of adults with hospital-acquired pneumonia (excluding ventilator-associated pneumonia) and community-acquired pneumonia and is currently being evaluated in a global phase 3 clinical trial of patients with Staphylococcus aureus bacteremia. This study investigated the in vitro activity of ceftobiprole and comparators against a total of 5466 gram-positive and -negative isolates from bloodstream infections (BSIs) that were collected in the United States during 2016 and 2017 as part of the SENTRY Antimicrobial Surveillance Program. Ceftobiprole was highly active (isolates were >99% susceptible) against S. aureus (including methicillin-resistant S. aureus), coagulase-negative staphylococci, Enterococcus faecalis , streptococci, and non–extended-spectrum β-lactamase (non-ESBL) phenotype Enterobacteriaceae. As expected, lower activities were observed against Enterococcus faecium , ESBL-phenotype Enterobacteriaceae , Pseudomonas aeruginosa , and Acinetobacter baumannii. These results support further clinical evaluation of ceftobiprole for the treatment of BSIs caused by susceptible organisms. [ABSTRACT FROM AUTHOR]

Aim and objective: The aim and objective of present study are to prepare and characterize Pluronic F-127 coated colloidal silver nanoparticles and to evaluate its cytocompatibility and anti-microbial efficacy in comparison to 5.25% NaOCl. Materials and Methodology: The cytocompatibility was evaluated on L929 human fibroblast cell line by MTT assay at five different concentrations of Pluronic F-127 coated colloidal silver nanoparticles [0.01μg/mL; 0.1μg/mL; 1μg/mL; 10μg/mL; 100μg/mL] and antimicrobial activity was evaluated by Agar well diffusion method on Enterococcus faecalis (ATCC 29212) using 100μL Pluronic F-127 coated colloidal silver nanoparticles [as test solution], 100μL 5.25%NaOCl [as standard solution], 100μL water [as control]. Statistical Analysis: Statistical analysis was performed using one way analysis of variance (ANOVA), followed by Dunnett's multiple comparison test (Graph Pad Prism, Version 6, Graph Pad Software Inc., La Jolla, USA). Results: The values with p < 0.05 were considered significant. MTT assay showed Pluronic F-127 coated colloidal silver nanoparticles are more cytocompatible on healthy fibroblast cells. In antimicrobial activity there is more significant difference among groups. Conclusion: Pluronic F-127 coated colloidal silver nanoparticles showed more zone of inhibition compared to NaOCl. Pluronic F-127 coated colloidal silver nanoparticles proved to be more cytocompatible and has highest antimicrobial activity compared to NaOCl. [ABSTRACT FROM AUTHOR]

BACKGROUND: Enterohemorrhagic Escherichia coli (EHEC) is still a major foodborne bacterial infectious agent in the USA and causes both diarrheal disease and hemolytic uremic syndrome (HUS). As antibiotic therapy is not an option, appropriate antimicrobial or inhibitor against EHEC colonization/infections is urgently needed. OBJECTIVE: Develop an appropriate natural antimicrobial and stimulate host defense to control foodborne illnesses with EHEC. METHOD: We investigated the role of chokeberry (Aronia melanocarpa) pomace (byproducts) extract (CPE) on growth and survival of EHEC EDL-933, probiotics specifically Lactobacillus, and other common gut bacterial flora including Streptococcus thermophilus, Enterococcus faecalis and Bacillus subtilis. We also tested the effects of CPE on physicochemical properties, host cells-EHEC interactions, and expression of various virulence genes of EHEC. RESULTS: The growth of EHEC EDL-933 was reduced by 4 logs in the presence of 0.5 mg GAE/mL CPE at 5 hr while this concentration promoted the growth of Lactobacillus and common gut bacterial flora, S. thermophillus, E. faealis and B. subtilis. The abilities of EHEC to attach and invade host intestinal epithelial (INT-407) cells were also reduced significantly (p < 0.05) which was supported by alternation physiological properties of EHEC and virulence genes expression. CONCLUSION: These results suggest that CPE has the potential to be an effective therapeutic/preventive for EHEC EDL-933 without affecting the common gut microflora and probiotics. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the antimicrobial activity of sodium and calcium hypochlorite utilising reciprocating instrumentation. Sixty root canals were inoculated with E. faecalis for 14 days. Samples were divided into six groups according to decontamination protocol: G1: no treatment, G2: distilled water, G3: 2.5% sodium hypochlorite, G4: 2.5% calcium hypochlorite, G5: 5.25% sodium hypochlorite and G6: 5.25% calcium hypochlorite. Instrumentation was performed with Wave One reciprocating system (Dentsply Sirona Endodontics, York, PA, USA) in groups G2 to G6. Colony‐forming units (CFUs) counting was performed and the data were subjected to Anova and Tukey (α  =  0.05). Group 1 and 2 showed the highest mean contamination, with a significant difference between them (P < 0.05). Groups 3, 4, 5 and 6 showed the lowest contamination means with no significant difference between them (P < 0.05). Sodium and calcium hypochlorite, in association with reciprocating instrumentation, can be an effective decontamination protocol in root canals infected with E. faecalis. [ABSTRACT FROM AUTHOR]

Objectives: The in vitro activity of oritavancin was assessed against clinically relevant Gram-positive pathogens causing infections in cancer patients in European and US hospitals.Methods: A total of 1357 Gram-positive cocci (GPC) were included. Isolates were predominantly from bloodstream infections (54.6%). The most frequently isolated GPC were Staphylococcus aureus (43.6%), CoNS (14.4%) and Enterococcus spp. (22.0%).Results: Oritavancin (99.8% susceptible) showed modal MIC, MIC50 and MIC90 results of 0.015, 0.015-0.03 and 0.06 mg/L, respectively, when tested against S. aureus, regardless of methicillin susceptibility or geographical region. CoNS isolates from the USA demonstrated an MIC90 of oritavancin (MIC90, 0.12 mg/L) that was slightly higher than that for isolates from European countries (MIC90 0.06 mg/L). Oritavancin inhibited all Enterococcus faecalis and Enterococcus faecium, including VRE, at ≤ 0.25 mg/L. Oritavancin exhibited MIC50 results of 0.03 and 0.008-0.015 mg/L when tested against isolates of β-haemolytic streptococci and viridans group streptococci, respectively, regardless of geographical region.Conclusions: Oritavancin had potent activity in vitro against this contemporary collection of European and US GPC isolates from cancer patients. [ABSTRACT FROM AUTHOR]

Background: Combat-related extremity wound infections can complicate the recovery of injured military personnel. The Enterococcus genus contains both commensal and pathogenic bacteria found in many combat wounds. We describe the patient population susceptible to Enterococcus infection, the characteristics of Enterococcus spp. isolated from combat-related wounds, and the microbiological profile of Enterococcus-positive wounds.Methods: Patient and culture data were obtained from the Trauma Infectious Disease Outcomes Study. Subjects were divided into a case group with enterococcal extremity wound infections and a comparator group with wound infections caused by other micro-organisms.Results: Case and comparator subjects had similar patterns of injury and infection. Case subjects had higher Injury Severity Scores (33 vs. 30; p < 0.001), longer hospitalization at U.S. facilities (55 vs. 40 days; p = 0.004), and required more large-volume blood transfusions (>20 units) within 24 h post-injury (53% vs. 30%; p < 0.001). Approximately 60% of case subjects had three or more infections, and 91% had one or more polymicrobial infections, compared with 43% and 50%, respectively, in the comparator group. The thigh was the most common site of Enterococcus spp. isolation, contributing 50% of isolates. Enterococcus faecium was the predominant species isolated from case-group infections overall (66%), as well as in polymicrobial infections (74%). Frequent co-colonizing microbes in polymicrobial wound infections with Enterococcus were other ESKAPE pathogens (64%) (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae [and Escherichia coli], Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and fungi (35%).Conclusions: The specific pathogenicity of Enterococcus relative to other pathogens in polymicrobial wounds is unknown. Identifying strain-specific outcomes and investigating the interactions of Enterococcus strains with other wound pathogens could provide additional tools and strategies for infection mitigation in combat-related wounds. [ABSTRACT FROM AUTHOR]

Aim: This study investigated the sealing ability produced by AH Plus (Dentsply DeTrey, Konstaz, Germany), EndoSequence BC sealer (Brasseler USA, Savannah, GA, USA), GuttaFlow (Coltène/ Whaledent, Altstätten, France) and MTA Fillapex (Angelus, Londrina, Brazil). Methdos: A total of forty-six single-root human canines were prepared and randomly divided into four experimental groups (n=10): MTA Fillapex, EndoSequence BC Sealer, AH Plus or GuttaFlow. Teeth with intact crowns served as negative controls (n=3) and teeth filled with only gutta-percha served as positive controls (n=3). Teeth were mounted in a two-chamber apparatus and exposed to Enterococcus faecalis. The number of days over a 60-days period was recorded for the appearance of turbidity in the lower chamber. Kaplan- Meier method was used to estimate the survival curves. The nonparametric log-rank test was used to compare the survival curves using a significance level of 0.05. Results: The results at the end of the observation time were further analyzed by chi-square testing. All positive controls leaked within 24 h, whereas none of the negative controls leaked after 60 days. EndoSequence BC Sealer and MTA Fillapex had significant less bacterial leakage (P<0.05) than the other tested sealers. No significant difference between AH Plus and GuttaFlow was observed (P>0.05). Conclusion: In conclusion, calcium-silicate based root canal sealers promoted improved sealing ability when compared to other endodontic sealers. [ABSTRACT FROM AUTHOR]

Faecal pollution of water and the resulting potential presence of human enteric pathogens is a predominant threat to public health. Microbiological water quality can be assessed by the detection of standard faecal indicator bacteria (SFIB) such as E. coli or certain Enterococcus species. In recent years, isothermal amplification methods have become a useful alternative to polymerase chain reaction (PCR), allowing molecular diagnostics with simple or no instrumentation. In this study, a novel screening method for the molecular detection of Enterococcus spp. by loop-mediated isothermal amplification (LAMP) is described. A set of six specific LAMP primers was designed to amplify a diagnostic fragment of the Enterococcus 23S rRNA gene, which is present in several enterococcal species targeted by quantitative PCR (qPCR), which is the standard technique recommended by the US Environmental Protection Agency. Sensitivity and specificity tests were performed using a set of 30 Enterococcus and non-target bacterial reference strains. It is shown that LAMP is equally sensitive and even more specific than the qPCR assay. A dilution series of Enterococcus faecalis DNA revealed that the LAMP method can reliably detect 130 DNA target copies per reaction within 45 min. Additionally, enterococci isolated from Austrian surface waterbodies, as well as a set of DNA extracts from environmental waters, were tested. Contingency analysis demonstrated a highly significant correlation between the results of the developed LAMP assay and the reference qPCR method. Furthermore, a simple staining procedure with a fluorescence dye demonstrated the identification of amplified products by eye. In conclusion, this method is an important component for the efficient screening and testing of water samples in low-resource settings lacking sophisticated laboratory equipment and highly trained personnel, requiring only a simple heating block. [ABSTRACT FROM AUTHOR]

Abstract: Antibiotic-resistant enterococci are important opportunistic pathogens and have been recovered from retail tomatoes. However, it is unclear where and how tomatoes are contaminated along the farm-to-fork continuum. Specifically, the degree of pre-harvest contamination with enterococci is unknown. We evaluated the prevalence, diversity and antimicrobial susceptibilities of enterococci collected from tomato farms in the Mid-Atlantic United States. Tomatoes, leaves, groundwater, pond water, irrigation ditch water, and soil were sampled and tested for enterococci using standard methods. Antimicrobial susceptibility testing was performed using the Sensititre microbroth dilution system. Enterococcus faecalis isolates were characterized using amplified fragment length polymorphism to assess dispersal potential. Enterococci (n = 307) occurred in all habitats and colonization of tomatoes was common. Seven species were identified: Enterococcus casseliflavus, E. faecalis, Enterococcus gallinarum, Enterococcus faecium, Enterococcus avis, Enterococcus hirae and Enterococcus raffinosus. E. casseliflavus predominated in soil and on tomatoes and leaves, and E. faecalis predominated in pond water. On plants, distance from the ground influenced presence of enterococci. E. faecalis from samples within a farm were more closely related than those from samples between farms. Resistance to rifampicin, quinupristin/dalfopristin, ciprofloxacin and levofloxacin was prevalent. Consumption of raw tomatoes as a potential exposure risk for antibiotic-resistant Enterococcus spp. deserves further attention. [Copyright &y& Elsevier]

Two novel gull-specific quantitative PCR (qPCR) assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR green assay targeting Streptococcus spp. (gull3) and a hydrolysis TaqMan assay targeting Catellicoccus marimammalium (gull4). The objectives of this study were to compare the host specificity of a previous C. marimammalium qPCR assay (gull2) with that of the new markers and to examine the presence of the three gull markers in environmental water samples from different geographic locations. Most of the gull fecal samples tested (n = 255) generated positive signals with the gull2 and gull4 assays (i.e., >86%), whereas only 28% were positive with gull3. Low prevalence and abundance of tested gull markers (0.6 to 15%) were observed in fecal samples from six nonavian species (n = 180 fecal samples), whereas the assays cross-reacted to some extent (13 to 31%) with other (nongull) avian fecal samples. The gull3 assay was positive against fecal samples from 11 of 15 avian species, including gull. Of the presumed gull-impacted water samples (n = 349), 86%, 59%, and 91% were positive with the gull2, the gull3, and the gull4 assays, respectively. Approximately 5% of 239 non-gull-impacted water samples were positive with the gull2 and the gull4 assays, whereas 21% were positive witg the gull3 assay. While the relatively high occurrence of gull2 and gull4 markers in waters impacted by gull feces suggests that these assays could be used in environmental monitoring studies, the data also suggest that multiple avian-specific assays will be needed to accurately assess the contribution of different avian sources in recreational waters [ABSTRACT FROM AUTHOR]

Abstract: This study updates the activity of telavancin against Gram-positive pathogens collected from USA hospitals (2007–2009). Telavancin (MIC50/90, 0.12/0.25 μg/mL) was active against coagulase-negative staphylococci and methicillin-resistant Staphylococcus aureus (100% susceptible), for which only daptomycin (MIC50/90, 0.25/0.5 μg/mL; 99% susceptible) and quinupristin/dalfopristin (MIC50/90, ≤0.25–0.5/0.5 μg/mL; 99% susceptible) exhibited similar activity. Telavancin (MIC50/90, 0.25/0.5 μg/mL) inhibited 96.5% of Enterococcus faecalis at the Food and Drug Administration breakpoint (MIC, ≤1 μg/mL), where ampicillin (99.9% susceptible), daptomycin (99.9% susceptible), and linezolid (100% susceptible) also demonstrated high-level coverage. Telavancin inhibited, respectively, 100.0% and 91.7% of VanB-phenotype E. faecalis and E. faecium at ≤1 μg/mL, whereas it was less active against VanA strains. Telavancin was uniformly active against Streptococcus pneumoniae and resistant subsets, and demonstrated good potency (MIC90, 0.06-0.12 μg/mL) against other streptococci, regardless of resistance to other drugs. This assessment reveals potent activity of telavancin against Gram-positive isolates collected from USA hospitals with no evidence of emergence of resistance. [Copyright &y& Elsevier]

Aims: The contribution of dogs and cats as reservoirs of antimicrobial resistant enterococci remains largely undefined. This is increasingly important considering the possibility of transfer of bacteria from companion animals to the human host. In this study, dogs and cats from veterinary clinics were screened for the presence of enterococci. Methods and Results: A total of 420 enterococci were isolated from nasal, teeth, rectal, belly and hindquarters sites of 155 dogs and 121 cats from three clinics in Athens, GA. Eighty per cent (124 out of 155) of the dogs and 60% (72 out of 121) of the cats were positive for enterococci. From the total number of dog samples ( n = 275), 32% ( n = 87) were from hindquarter, 31% ( n = 86) were rectal, and 29% ( n = 79) were from the belly area. The majority of isolates originated from rectal samples (53 out of 145; 37%) from cats. The predominant species identified was Enterococcus faecalis (105 out of 155; 68%) from dogs and E. hirae (63 out of 121; 52%) from cats. Significantly more E. faecalis were isolated from rectal samples than any other enterococcal species ( P < 0·05) for both dogs and cats suggesting site specific colonization of enterococcal species. The highest levels of resistance were to ciprofloxacin in E. faecium (9 out of 10; 90%), chloramphenicol resistance in E. faecalis (17 out of 20; 85%) and gentamicin resistance in E. faecalis (19 out of 24; 79%) from dog samples and nitrofurantoin resistance in E. faecium (15 out of 19; 79%) from cats. Multi-drug resistance (MDR) (resistance ≥2 antimicrobials) was observed to as few as two and as many as eight antimicrobials regardless of class. Conclusion: This study demonstrated that dogs and cats are commonly colonized with antimicrobial resistant enterococci. Significance and Impact of the Study: Dogs and cats may act as reservoirs of antimicrobial resistance genes that can be transferred from pets to people. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the study was to evaluate the clonality of 21 strains of Enterococcus faecalis associated with arthritis and amyloid arthropathy by multilocus sequence typing (MLST). The strains originated from five countries. Fifteen of the 21 strains demonstrated the same sequence type, ST82, including a reference amyloid arthropathy strain from the Netherlands. Some of the demonstrated sequence types (ST36, ST59 and ST82) have also been described from human clinical samples while other types are reported for the first time. The results confirm previous observations that outbreaks of amyloid arthropathy seem to be clonally related and indicate a wide distribution of the predominant sequence type which was demonstrated in four countries in Europe and in the USA. [Copyright &y& Elsevier]

The limited host range of Enterococcus faecalis may reduce its clonal diversity and thereby increase its geographic sharing of ribotype patterns. Such sharing would be advantageous for bacterial source tracking (BST). We determined the geographic sharing of ribotype patterns in 752 Ent. faecalis isolates obtained primarily from wastewater treatment plants in Delaware (15 locations; 490 isolates), Georgia (2 locations; 48 isolates), Idaho (1 location; 118 isolates), New York (2 locations; 48 isolates), and Puerto Rico (2 locations; 48 isolates). Isolates were ribotyped with a RiboPrinter. When pooled across all locations and analyzed at a similarity index of 100% and a tolerance level of 1.00%, the 752 Ent. faecalis isolates yielded 652 different ribotypes, of which 429 (66%) were unshared. Even when the matching criterion was relaxed by decreasing the tolerance level from 1% to 10% or lowering the similarity cutoff from 100% to 90%, half or almost half of the ribotypes were unshared. A Mantel test of zero correlation showed no statistically significant correlation between ribotype patterns and geographic distance among the 32 samples (one location at one time) at either the 1.00% (P = 0.91) or 10.00% (P = 0.83) tolerance levels. Therefore, the percentage of ribotype patterns shared between two locations did not increase as the distance between locations decreased. In the case of BST, a permanent host origin database sufficiently large to encompass these ribotype patterns would be time-consuming and expensive to construct. [ABSTRACT FROM AUTHOR]

Background. Nosocomial bloodstream infections (BSIs) are important causes of morbidity and mortality in the United States. Methods. Data from a nationwide, concurrent surveillance study (Surveillance and Control of Pathogens of Epidemiological importance [SCOPE]) were used to examine the secular trends in the epidemiology and micro- biology of nosocomial BSIs. Results. Our study detected 24,179 cases of nosocomial BSI in 49 US hospitals over a 7-year period from March 1995 through September 2002 (60 cases per 10,000 hospital admissions). Eighty-seven percent of BSIs were monomicrobial. Gram-positive organisms caused 65% of these BSIs, gram-negative organisms caused 25%, and fungi caused 9.5%. The crude mortality rate was 27%. The most-common organisms causing BSIs were coagulase- negative staphylococci (CoNS) (31% of isolates), Staphylococcus aureus (20%), enterococci (9%), and Candida species (9%). The mean interval between admission and infection was 13 days for infection with Escherichia coil, 16 days for S. aureus, 22 days for Candida species and Klebsiella species, 23 days for enterococci, and 26 days for Acinetobacter species. CoNS, Pseudomonas species, Enterobacter species, Serratia species, and Acinetobacter species were more likely to cause infections in patients in intensive care units (P < .001). In neutropenic patients, infections with Candida species, enterococci, and viridans group streptococci were significantly more common. The proportion of S. aureus isolates with methicillin resistance increased from 22% in 1995 to 57% in 2001 (P< .001, trend analysis). Vancomycin resistance was seen in 2% of Enterococcus faecalis isolates and in 60% of Enterococcus faecium isolates. Conclusion, in this study, one of the largest multicenter studies performed to date, we found that the proportion of nosocomial BSIs due to antibiotic-resistant organisms is increasing in US hospitals. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize the antibiotic resistance profiles of Enterococcus species isolated from fresh produce harvested in the southwestern United States. Among the 185 Enterococcus isolates obtained, 97 (52%) were Enterococcus faecium, 38 (21%) were Enterococcus faecalis, and 50 (27%) were other Enterococcus species. Of human clinical importance, E. faecium strains had a much higher prevalence of resistance to ciprofloxacin, tetracycline, and nitrofurantoin than E. faecalis. E. faecalis strains had a low prevalence of resistance to antibiotics used to treat E. faecalis infections of both clinical and of agricultural relevance, excluding its intrinsic resistance patterns. Thirty-four percent of the isolates had multiple-drug- resistance patterns, excluding intrinsic resistance. Data on the prevalence and types of antibiotic resistance in Enterococcus species isolated from fresh produce may be used to describe baseline antibiotic susceptibility profiles associated with Enterococcus spp. isolated from the environment. The data collected may also help elucidate the role of foods in the transmission of antibiotic-resistant strains to human populations. [ABSTRACT FROM AUTHOR]

Presents a study that described the variations within the structure of the pathogenicity island in vancomycin-resistant isolates on Enterococcus faecalis in the U.S. Comparison of the nucleotide sequences coding for the cytolysin operon and a surface protein in two strains of E. faecalis; Similarities in the nucleotide sequences of the genome of E. faecalis isolates; Examination of the traits found in the pathogenicity island of E. faecalis.

Presents a study that characterized the current water quality at the Meadows of Garnet Canyon and in the lower elevations of Cascade Creek in Grand Teton National Park, Wyoming. Evaluation of water quality; Water quality in the backcountry of Grand Teton National Park; Information on Streptococcus faecalis.

Enterococci with high-level resistance to gentamicin account for 55% of clinical isolates of enterococci found in patients at the Ann Arbor Veterans Administration Medical Center. We prospectively studied cultures obtained from all 100 patients hospitalized from 1 December 1985 through 23 January 1986 on the surgical and thoracic intensive care units and a general medical floor. Ten patients' cultures grew colonies of gentamicin-resistant enterococci--six after admission to the intensive care units and four after hospitalization on the medical ward. The initial sites of colonization were the rectal and perineal areas in seven patients, sternal wound in one, urine in one, and the rectal and perineal areas as well as urine after Foley catheter insertion in one. Nine patients died and three of the deaths were associated with enterococcal infection. The acquisition of resistant strains was associated with previous and more frequent exposure to antimicrobial agents, and with geographic clustering of patients. Resistant enterococci were isolated from the hands of hospital personnel and were frequently isolated from environmental surfaces. Nosocomial acquisition and interhospital spread of gentamicin-resistant enterococci was shown to have occurred when plasmid content was used as an epidemiologic marker. [ABSTRACT FROM AUTHOR]

This study updates dalbavancin activity against contemporary (2017–2019) isolates of indicated species/groups (n = 16,451). Isolates from 71 hospitals were tested by broth microdilution method. All isolates were susceptible to dalbavancin. Dalbavancin MIC 50/90 values remained stable for Staphylococcus aureus, vancomycin-susceptible Enterococcus faecalis , β-hemolytic streptococci, and Streptococcus anginosus group since its clinical approval. • This study updates dalbavancin activity against current isolates of indicated species. • Isolates from 71 US hospitals were tested by broth microdilution method. • All isolates were susceptible to dalbavancin. • Dalbavancin MIC 50/90 values remained stable for all groups since its clinical approval. [ABSTRACT FROM AUTHOR]

Studies evaluating large series of pediatric patients with bloodstream infections (BSIs) are scarce. We evaluated the frequency and antimicrobial susceptibility of organisms isolated from pediatric patients with BSI and therapeutic options for BSI caused by multidrug-resistant (MDR) organisms. A total of 2423 organisms were consecutively collected from 33 US medical centers between 2014 and 2018, and susceptibility was tested by reference broth microdilution methods. Isolates with an extended-spectrum β-lactamase phenotype were screened for β-lactamase genes. Overall, 40.2% of organisms were Gram-negative bacteria, 57.0% Gram-positives, and 2.8% Candida spp. The 5 most common organisms were Staphylococcus aureus (26.0%), Escherichia coli (13.0%), coagulase-negative staphylococci (8.3%), Enterococcus faecalis (7.1%), and Klebsiella pneumoniae (6.9%). Among S. aureus , 26.0% were oxacillin-resistant and 99.8% were susceptible to ceftaroline (MIC 50/90 , 0.25/0.5 mg/L). Enterobacterales and Pseudomonas aeruginosa isolates combined represented >85% of Gram-negative bacteria, and all isolates (100.0%) were susceptible to ceftazidime-avibactam. [ABSTRACT FROM AUTHOR]

For the foreseeable future, conventional small molecule antibiotics will continue to be the predominant treatment option due to wide patient coverage and low costs. Today, however, there is already a significant portion of patients that fail to respond to small molecule antibiotics and, according to the Centers for Disease Control and Prevention, this number is poised to increase in the coming years. Therefore, this rise in drug resistant bacteria must be countered with the development of nontraditional therapies. We propose a measure based on the re-engagement of the immune system toward pathogenic bacteria by grafting bacterial cell surfaces with immunogenic agents. Herein, we describe a class of cell wall analogues that selectively graft bacterial cell surfaces with epitopes that promote their opsonization. More specifically, synthetic analogues of peptidoglycan conjugated to haptens were designed to be incorporated by the cell wall biosynthetic machinery into live Enterococcus faecium . E. faecium is a formidable human pathogen that poses a considerable burden to healthcare and often results in fatalities. We showed that treatment of E. faecium and vancomycin-resistant strains with the cell wall analogues led to the display of haptens on the cell surface, which induced the recruitment of antibodies existing in the serum of humans. These results demonstrate the feasibility in using cell wall analogues as the basis of a class of bacterial immunotherapies against dangerous pathogens.

Oxazolidinones are one of the most important antimicrobials potentially active against glycopeptide- and β-lactam-resistant Gram-positive pathogens. Linezolid-the first oxazolidinone to be approved for clinical use in 2000 by the US Food and Drug Administration-and the newer molecule in the class, tedizolid, inhibit protein synthesis by suppressing the formation of the 70S ribosomal complex in bacteria. Over the past two decades, transferable oxazolidinone resistance genes, in particular cfr and optrA , have been identified in Firmicutes isolated from healthcare-related infections, livestock, and the environment. Our goals in this study were to investigate the genetic contexts and the transferability of the cfr and optrA genes and examine genomic features, such as antimicrobial resistance genes, plasmid incompatibility types, and CRISPR-Cas defenses of a linezolid-resistant Enterococcus faecalis isolated in feces from a healthy pig during an antimicrobial surveillance program for animal production in Brazil. The cfr gene was found to be integrated into a transposon-like structure of 7,759 nt flanked by IS 1216E and capable of excising and circularizing, distinguishing it from known genetic contexts for cfr in Enterococcus spp., while optrA was inserted into an Inc18 broad host-range plasmid of >58 kb. Conjugal transfer of cfr and optrA was shown by filter mating. The coexistence of cfr and optrA in an E. faecalis isolated from a healthy nursery pig highlights the need for monitoring the use of antibiotics in the Brazilian swine production system for controlling spread and proliferation of antibiotic resistance., (Copyright © 2020 Almeida, Gaca, Bispo, Lebreton, Saavedra, Silva, Basílio-Júnior, Zorzi, Filsner, Moreno and Gilmore.)

High-level aminoglycoside resistance was noted in 30.0% of Enterococcus faecalis and 25.2% of Enterococcus faecium isolates. Only 3.3% and 2.1% of E. faecalis isolates had elevated daptomycin MIC (≥2 mg/liter) and vancomycin resistance, respectively. In contrast, 37.4% to 40.3% of E. faecium isolates exhibited these phenotypes. Tedizolid inhibited 98.9% to 100.0% of enterococci causing serious invasive infections, including resistant subsets. Oxazolidinone resistance was mainly driven by G2576T; however, optrA and poxtA genes were also detected, including poxtA in the United States and Turkey., (Copyright © 2020 American Society for Microbiology.)

Background Oritavancin (ORI) is a potent lipoglycopeptide with desirable PK/PD parameters for treating serious gram-positive infections. This study assessed the activity of ORI against Staphylococcus aureus (SA), Enterococcus faecalis (EF), and E. faecium (EFM) causing bloodstream infection (BSI), including infective endocarditis (IE) and daptomycin (DAP)- susceptible dose-dependent (SDD) vancomycin-resistant (VRE) subsets. We also evaluated the longitudinal activity of ORI. Methods A total of 5,469 SA, 1,157 EF, and 721 EFM were recovered from BSI in 35 US sites (2011–2018). Subsets of SA isolates causing IE (84) and EFM displaying DAP-SDD-VRE phenotypes (230) were included. Identification was confirmed by MALDI-TOF MS and isolates were tested for susceptibility (S) according to CLSI. Results Overall, ORI showed similar MIC50 (0.03 mg/L) and MIC90 results (0.06 mg/L) against MRSA and MSSA (figure) and the SA EC subset (41.7% MRSA; data not shown). Similar findings were noted for ORI tested against EF DAP-S (MIC50/90, 0.015/0.06 mg/L) and DAP-SDD (MIC50/90, 0.015/0.06 mg/L). ORI MIC values against DAP- and VAN-S EFM (MIC50/90, ≤0.008/0.015 mg/L) were at least 8-fold lower than those from DAP-SDD-VRE isolates (MIC50/90, 0.06/0.12 mg/L; 31.9% of all EFM), and all EFM were inhibited by ORI at ≤0.25 mg/L. The longitudinal analysis showed MRSA rates varying from 39.7% (2017) to 46.8% (2011), while the annual ORI MIC50 and MIC90 results were 0.015–0.06 mg/L and 0.03–0.12 mg/L, respectively, against MRSA during the 8-year period. ORI yearly MIC50 and MIC90 results were 0.015–0.03 mg/L and 0.03–0.12 mg/L against EF, respectively. MIC50 and MIC90 results of 0.008–0.03 mg/L and 0.03–0.12 mg/L, respectively, were obtained for ORI against the DAP-SDD EF subset each year. ORI MIC50 and MIC90 results of 0.03–0.06 and 0.06–0.12 mg/L were obtained annually against DAP-SDD-VRE (EFM), respectively. Conclusion ORI showed a potent activity against this collection of isolates causing BSI and IE in the USA, including resistant subsets requiring higher dosage regimens when treating serious infections. In addition, ORI maintained a stable potency throughout the 8-year study period with no apparent temporal trends. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Summary: Infections caused by multidrug-resistant Gram-positive bacteria represent a major public health burden, not just in terms of morbidity and mortality, but also in terms of increased expenditure on patient management and implementation of infection control measures. Staphylococcus aureus and Enterococcus spp. are established pathogens in the hospital environment, and their frequent multidrug resistance complicates therapy. The archetypal hospital “superbug”, methicillin-resistant S. aureus (MRSA), regularly attracts mass-media interest and, in many countries, there is political pressure to reduce MRSA infection rates, with some progress now being made in the United Kingdom and the United States. To compound these established problems, we have witnessed the emergence and spread of virulent clones of MRSA in the community, and of Clostridium difficile in hospitals. Multidrug-resistant Streptococcus pneumoniae clones are major community pathogens in many parts of the world, but are now being challenged by new conjugate vaccines. Using combinations of molecular epidemiological tools, which characterize the resistant isolates and their resistance determinants, scientists can track highly successful bacterial strains at local, national, and international levels. These methods have provided new insights into the evolution of key pathogens, and this information may aid the design of control strategies and vaccines. In addition, the development of new antimicrobials including oxazolidinones, lipopeptides, glycylcyclines, ketolides, and new generations of fluoroquinolones, antistaphylococcal b-lactams, and glycopeptides must remain a high priority for the continued effective treatment of infections caused by resistant strains. So far, resistance to these newer agents is identified rarely in surveillance programs, but occasional reports of resistance causing therapeutic failure (e.g., with linezolid, daptomycin, telithromycin, or newer fluoroquinolones) give cause for concern. The emergence of antibiotic resistance is inevitable, but we must seek to decrease its impact and prolong the effectiveness of the agents available to us. [Copyright &y& Elsevier]

Mitral valve aneurysm is a rare cause of mitral regurgitation, and is usually associated with aortic valve endocarditis. Prompt diagnosis and early surgical treatment can prevent complications such as embolization and rupture of the aneurysm. The authors report a case of aortic valve endocarditis and mitral valve aneurysm in a patient who initially presented with urinary tract infection.