Search Results (299)

Vancomycin-resistant enterococci (VRE) are a major cause of healthcare-associated infections (HAIs). However, the clinical significance of VRE colonization and the subsequent risk of VRE infection in hospitalized patients are not fully established. Prolonged hospital stays have been observed in neonates colonized by VRE. The mortality rate in pediatric patients with VRE infections ranges from 0% to 42% in both endemic and outbreak settings, often occurring in VRE-colonized neonates. Host and bacterial factors associated with a worse outcome are not fully understood yet. We describe an outbreak of VRE colonization in 21 newborns admitted to our neonatal intensive care unit in January 2024. Microbiological analyses on rectal swabs were performed using molecular testing and culture. Results: In January, VRE was first detected in the urine culture of a 3-week-old patient, followed by a subsequent positive rectal swab result. In accordance with our infection control policy, all the NICU patients were tested, leading to the identification of another 12 colonized patients. The implementation of molecular testing led to rapid VRE identification and the subsequent isolation of colonized neonates, which promptly contained the outbreak. The median time from NICU admission to colonization was 34 (6–37) days. Only one patient developed a CVC-related bloodstream infection, which was successfully treated with linezolid and CVC removal. No VRE-related deaths occurred, even among three patients who underwent abdominal surgery (one gastroschisis, one incarcerated abdominal hernia, and one umbilical hernia) and one patient with necrotizing enterocolitis. Our data show a low infection rate (4%) among VRE-colonized patients (4%) during a NICU outbreak. The rapid identification of multidrug-resistant genes by molecular testing may be implemented in specific settings to enable timely patient identification, adopt infection control measures, and administer appropriate antimicrobial therapy. Full article

This study investigates the occurrence, antimicrobial resistance (AMR) profiles, virulence factors, and plasmid composition of Enterococcus species isolated from salad ingredients in the United Arab Emirates (UAE). Four hundred salad vegetable items collected from local markets, over ten months through 2023, were screened, yielding an Enterococcus detection rate of 85.5% (342/400). E. casseliflavus was the most commonly identified species (50%), followed by E. faecium (20%) and E. faecalis (16%). Among 85 Enterococcus isolates tested for antimicrobial susceptibility, 55.3% displayed resistance to at least one agent, with 18.8% classified as multidrug-resistant (MDR). All isolates were not resistant to ampicillin, linezolid, teicoplanin, tigecycline, and high-level gentamicin. Intrinsic phenotypic resistance to vancomycin was found in E. gallinarum and E. casseliflavus, while low-level (<5%) ciprofloxacin and erythromycin resistance was sporadically detected in E. faecium and E. faecalis. Whole-genome sequencing (WGS) of 14 isolates (nine E. faecium, four E. faecalis, and one E. casseliflavus) unveiled a complex resistome. We report the first detection in salad vegetables of vancomycin resistance genes (vanC, vanXY-C2) in a vancomycin-susceptible E. faecalis isolate. Identifying tetM, ermB, and optrA genes in the studied isolates further underscored emerging resistance to tetracyclines, macrolides, and oxazolidinones. Concurrently, virulence gene analysis revealed 74 putative virulence factors, with E. faecalis harboring a higher diversity of biofilm-related and exoenzyme-encoding genes. One E. faecalis strain carried the cytolysin cluster (cylI, cylS, cylM), highlighting its pathogenic potential. Plasmid profiling identified 19 distinct plasmids, ranging from 3845 bp to 133,159 bp. Among the genome-sequenced isolates, mobilizable plasmids (47.3%) commonly carried AMR genes, especially tet(L) and tet(M), whereas conjugative plasmids (10.5%) did not harbor resistance determinants. These findings highlight that salad vegetables can still harbor and potentially transmit Enterococcus strains with clinically relevant resistance determinants and virulence traits. Enhancing foodborne AMR surveillance with WGS and targeted interventions is key to controlling its spread in the food. Full article

Background: Antimicrobial resistance (AMR) has become a serious global challenge in the 21st century. Poultry, including turkeys, are a vital source of animal-derived protein worldwide. Commensal bacterial strains in poultry can act as reservoirs for AMR, making monitoring them crucial for both veterinary and public health. Enterococcus species are emerging pathogens, particularly in severe nosocomial infections. Methods: This study aimed to assess the resistance profiles of commensal Enterococcus strains isolated (n = 470) from large-scale turkey flocks in Hungary. From each animal, two swab samples were collected: one from the oropharyngeal region near the tracheal entrance and one from the cloaca. The samples were subsequently processed, and the minimum inhibitory concentration (MIC) was determined following the Clinical and Laboratory Standards Institute (CLSI) guidelines. The tested antibiotics included amoxicillin, amoxicillin–clavulanic acid, imipenem, neomycin, doxycycline, florfenicol, tylosin, enrofloxacin, potentiated sulfonamide, vancomycin, ceftriaxone, spectinomycin, tiamulin, lincomycin, and colistin. The dilution range for MIC determination was set between 512 and 0.001 µg/mL. Results: Resistance to amoxicillin, a first-line treatment for Enterococcus infections, was low (11.1%). However, high resistance levels were observed for tylosin (62.6%), florfenicol (51.1%), doxycycline (48.7%), and enrofloxacin (45.5%). Notably, vancomycin resistance reached 15.5%, a finding consistent with global trends. Compared to human-derived Enterococcus data, resistance to aminopenicillins was significantly lower in turkey isolates, while neomycin resistance levels were comparable to those observed in human E. faecalis strains. Conclusions: The findings underscore the necessity of continuous surveillance of AMR trends in poultry production. While amoxicillin remains an effective treatment, the presence of multidrug-resistant strains and vancomycin-resistant isolates raises concerns regarding the potential dissemination of resistance genes. Future studies should incorporate next-generation sequencing to elucidate the genetic mechanisms underlying resistance. Additionally, integrating antibiotic usage data from farms may provide further insights into resistance dynamics. Strengthening antibiotic stewardship programs and fostering collaboration between veterinary and human medicine are crucial steps in addressing AMR under the One Health framework. Full article

Linezolid-non-susceptible Enterococcus faecalis (LNSEf) has emerged as a critical clinical concern worldwide, yet data from Latin American settings remain scarce. This study aimed to investigate the molecular epidemiology and mechanisms underlying LNSEf in a Mexican tertiary care university hospital, focusing on clinical correlates and clonal relationships. A total of 392 non-duplicated E. faecalis isolates were collected over 12 months, of which 24 with minimum inhibitory concentrations ≥4 µg/mL underwent whole-genome sequencing to identify specific resistance determinants (optrA, cfrA, 23S rRNA mutations) and to perform multilocus sequence typing (MLST) and phylogenetic analyses. Of the 392 isolates, 6.12% showed linezolid non-susceptibility, predominantly linked to plasmid- or chromosomally encoded optrA; only two isolates carried cfrA. No mutations were detected in 23S rRNA domain V or ribosomal proteins L3/L4. Clinically, LNSEf strains were associated with immunosuppression, previous surgical interventions, and prolonged hospital stays. Although most LNSEf isolates retained susceptibility to ampicillin, vancomycin, and daptomycin, they exhibited high rates of resistance to other antibiotic classes, particularly aminoglycosides and fluoroquinolones. These findings underscore the emergence of LNSEf in this region, highlighting the need for robust genomic surveillance, strict infection control, and judicious antimicrobial stewardship to curb further dissemination. Full article

Background: Vancomycin-resistant enterococci (VRE) rectal colonization represents a critical risk factor for subsequent bloodstream infections (BSIs), posing a serious concern in healthcare settings. This study aims to investigate the association between the presence of VRE in rectal swabs and the occurrence of BSIs, highlighting the challenges of rapid detection and patient care implications in an infectious disease hospital setting. Methods: We performed a retrospective analysis of cultural rectal swab screening and molecular assays (MAs) for VRE detection between January 2020 and December 2023. All adult patients admitted with at least one rectal swab screening performed during hospitalization were included. All blood cultures that yielded VRE were identified, and the first Enterococcus-positive blood sample for each patient with at least one prior rectal swab per year was analyzed. Results: The results showed a 15.4% positivity rate for VRE in cultural screening, predominantly Enterococcus faecium. MA showed a higher prevalence of 49.4%, with a significant discordance between MA rectal swab screening and cultural testing. Patients with VRE intestinal colonization by E. faecium were significantly more likely to develop E. faecium BSI, with a risk ratio of 9.78 (p < 0.001). Conclusions: The study identified a strong correlation between VRE rectal colonization and the risk of developing BSI, emphasizing the need for effective screening and infection control measures. The results support the inclusion of molecular testing in VRE detection protocols and highlight the importance of ongoing surveillance for antimicrobial resistance. Full article

Background/Objectives: Vancomycin-resistant enterococci (VRE) are one of the leading causes of antibiotic-resistant infections in the hospital setting worldwide, and this has become a major issue, because most patients infected with this strain are difficult to treat. Multiplex real-time polymerase chain reaction (RT PCR) is an advantageous technique that can amplify multiple targets in a single reaction, and can be used to quickly detect specific targets in VRE within two hours, starting from suspected colonies of bacterial cultures, without sample preparation. Methods: In this study, we selected the glycopeptide/vancomycin resistance genes that are most common in clinical settings, vanA and vanB, in combination with the species markers ddl_faecium and ddl_faecalis for the most common VRE species—Enterococcus faecium and Enterococcus faecalis. Results: DNA from forty clinical VRE strains was prepared using a fast and economic heat lysis method, and a multiplex real-time PCR assay was optimized and carried out subsequently. The results were in concordance with the results from recombinase polymerase amplification (RPA) of the same VRE samples. Conclusions: Multiplex RT PCR and RPA for VRE detection proffers a second method for the confirmation of vancomycin resistance, and it can be developed as a fast screening assay for patients before admission into high-risk settings. Full article

Background/Objectives: Enterococcus is one of the major nosocomial pathogens. The present status of antimicrobial resistance determinants and virulence factors was analyzed for current Enterococcus causing infectious diseases in Bangladesh. Methods: Clinical isolates of Enterococcus recovered from various specimens in a tertiary care hospital were analyzed. Antimicrobial susceptibility was measured by a broth microdilution test, and resistance genes/virulence factors were detected by uniplex/multiplex PCR, along with sequencing analysis as required. The sequence type (ST) of E. faecalis and E. faecium was identified based on a multilocus sequence typing (MLST) scheme. Results: For a one-year period, a total of 143 isolates (135 E. faecalis, 7 E. faecium, and 1 E. hirae) were collected. Although all E. faecalis isolates were susceptible to penicillin, high resistance rates were noted against erythromycin (87%) and levofloxacin (62%). High-level resistance to gentamicin was detected in 30% of E. faecalis and 86% of E. faecium. Vancomycin resistance due to vanA was identified in one isolate each of E. faecalis (ST1912, CC116) and E. faecium (ST80, CC17). Three E. faecalis isolates (2.2%) with ST32 or ST1902 were resistant to linezolid, harboring optrA-fexA. Conclusions: The present study identifies the vancomycin-resistant Enterococcus harboring vanA from humans in Bangladesh and shows the potential spread of optrA in multiple lineages of E. faecalis. Full article

Background/Objective: Vancomycin-resistant enterococci (VRE), particularly Enterococcus faecium (VREfm), are significant healthcare-associated infections, especially bloodstream infections (BSIs). Method: This study explored the genotypic and phenotypic characteristics of 29 VREfm isolates causing BSIs in Thailand. Bacterial species, sequence types (STs), virulence genes, and vancomycin antimicrobial-resistance genes were identified by multiplex PCR, multilocus sequence typing, and whole-genome sequencing (WGS). Antibiotic susceptibility was determined by disk diffusion, while an E-test or broth microdilution were used for daptomycin, teicoplanin, linezolid, and tigecycline. Biofilm formation was assessed using a microtiter plate assay. Results: All isolates harbored the vanA gene and exhibited resistance to ampicillin, erythromycin, norfloxacin, vancomycin, and rifampin. Resistance to ciprofloxacin, tigecycline, and nitrofurantoin was widespread as well. All isolates remained susceptible to chloramphenicol and linezolid. The majority of isolates belonged to clonal complex 17, with ST17 being predominant (21/29, 72.4%), followed by ST80 (6/29, 20.7%), ST761 (1/29, 3.4%), and ST117 (1/29, 3.4%). WGS analysis confirmed the presence of various antimicrobial resistance genes, including aac(6′)-Ii, ant-Ia, erm(B), and vanA. Additionally, virulence genes such as acm (collagen adhesin) and esp (enterococcal surface protein), which are involved in biofilm formation, were detected. Conclusion: This study provides insights into the genomic characteristics and clonal dissemination of invasive VREfm in Thailand, which is crucial for infection control and public health surveillance. Full article

Background: Antimicrobial resistance (AMR) is an escalating global health threat, projected to cause over 40 million deaths by 2050. ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are major contributors to nosocomial infections and AMR. We evaluated the epidemiology and AMR prevalence of ESKAPE pathogens at the University Hospital in Palermo between January 2018 and July 2023, analyzing factors associated with mortality in patients with positive blood cultures. Methods: Microbiological data from all specimen types were collected using the Business Intelligence system Biwer, excluding duplicates. We assessed the prevalence and trends of ESKAPE isolates and AMR over time. Clinical data from hospital discharge forms were used to evaluate factors associated with mortality in patients with ESKAPE-positive blood cultures. Differences in AMR prevalence between blood and non-blood isolates were examined. Results: A total of 11,607 specimens from 4916 patients were analyzed. Most patients were admitted to Internal Medicine (19.4%), the ICU (13.2%), and General Surgery (9.9%). Additionally, 21.5% of the specimens were collected from ICU-admitted patients. Blood cultures accounted for 14.3% of the specimens, urine for 25.3%, respiratory secretions for 22.1%, and skin and mucosal swabs for 20.9%. The prevalence of all isolates increased progressively, peaking in 2021. The vancomycin-resistant E. faecium prevalence was 19.4%, with a significant upward trend, while oxacillin-resistant S. aureus prevalence was 35.0%, showing a significant decline. A. baumannii exhibited high resistance to all antibiotics tested except for colistin and cefiderocol. Carbapenemase resistance was 55.0% in K. pneumoniae, 20.4% in P. aeruginosa, and 4.6% in Enterobacter spp. P. aeruginosa showed a significant decrease in meropenem resistance. K. pneumoniae and A. baumannii bloodstream infections were linked to higher mortality risk. Full article

Complex wounds pose a significant healthcare challenge due to their susceptibility to infections and delayed healing. This study focuses on developing electrospun polycaprolactone (PCL) nanofiber membranes coated with Type I collagen derived from bovine skin and functionalized with silver nanoparticles (AgNPs) to address these issues. The collagen coating enhances biocompatibility, while AgNPs synthesized through chemical reduction with sodium citrate provide broad-spectrum antimicrobial properties. The physical properties of the membranes were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results showed the formation of nanofibers without defects and the uniform distribution of AgNPs. A swelling test and contact angle measurements confirmed that the membranes provided an optimal environment for wound healing. In vitro biological assays with murine 3T3 fibroblasts revealed statistically significant (p ≤ 0.05) differences in cell viability among the membranes at 24 h (p = 0.0002) and 72 h (p = 0.022), demonstrating the biocompatibility of collagen-coated membranes and the minimal cytotoxicity of AgNPs. Antibacterial efficacy was evaluated against Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Vancomycin-resistant Enterococcus (VRE), with the significant inhibition of biofilm formation observed for VRE (p = 0.006). Overall, this novel combination of collagen-coated electrospun PCL nanofibers with AgNPs offers a promising strategy for advanced wound dressings, providing antimicrobial benefits. Future in vivo studies are warranted to further validate its clinical and regenerative potential. Full article

Linezolid is an oxazolidinone antibiotic and is considered a last-resort treatment option for serious infections caused by problematic Gram-positive pathogens, including vancomycin-resistant enterococci. The present study aimed to explore the linezolid resistance mechanisms and genomic characteristics of two vancomycin-susceptible Enterococcus faecalis isolates from Bulgaria. The strains designated Efs2503-bg (inpatient from Pleven) and Efs966-bg (outpatient from Varna) were recovered from wounds in 2018 and 2023, respectively. Antimicrobial susceptibility testing, whole-genome sequencing, multilocus sequence typing, and phylogenomic analysis based on 332 linezolid-resistant E. faecalis genomes were performed. Efs2503-bg was high-level resistant to linezolid (MIC > 256 mg/L) and displayed the G2576T mutation affecting three of the four 23S rDNA loci. Efs966-bg (MIC = 8 mg/L) carried a plasmid-located optrA determinant surrounded by fexA and ermA. No mutations in the genes encoding for ribosomal proteins L3, L4, and L22 were detected. The isolates belonged to the sequence types ST6 (Efs2503-bg) and ST1102 (Efs966-bg). Phylogenomic analysis revealed that Efs2503-bg and Efs966-bg are genetically distinct, with a difference of 12,051 single-nucleotide polymorphisms. To our knowledge, this is the first report of linezolid-resistant enterococci in Bulgaria. Although the global incidence of linezolid-resistant enterococci is still low, their emergence is alarming and poses a growing clinical threat to public health. Full article

A chemical investigation of the soft coral Lobophytum sp. and the sponge Xestospongia sp. from the South China Sea led to the isolation of five steroids, including two new compounds (1 and 4) and one known natural product (3). Compounds 1–3 were derived from the soft coral Lobophytum sp., while 4 and 5 were obtained from the sponge Xestospongia sp. The structures of these compounds were determined by extensive spectroscopic analysis, the time-dependent density functional theory–electronic circular dichroism (TDDFT-ECD) calculation method, and comparison with the spectral data previously reported in the literature. The antibacterial and anti-inflammatory activities of isolated compounds were evaluated in vitro. Compounds 1–3, 4, and 5 exhibited weak antibacterial activity against vancomycin-resistant Enterococcus faecium G1, Streptococcus parauberis KSP28, Photobacterium damselae FP2244, Lactococcus garvieae FP5245, and Pseudomonas aeruginosa ZJ028. Moreover, compound 3 showed significant anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells, with an IC₅₀ value of 13.48 μM. Full article

Background/Objectives: The growing resistance of bacteria to antibiotics is a serious problem in health care. The present study aims to assess the drug resistance of Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis and Streptococcus pneumoniae isolated from infections in a multispecialty hospital over a 6-year period. Methods: Identification and antimicrobial susceptibility testing were performed using the VITEK^®2 automated system (Biomerieux). Results and Conclusions: Based on data from the analyzed hospital, MRSA strains were the etiological factor of 18–28% of S. aureus infections. In each year from 2017 to 2022, the percentage of MSSA strains steadily exceeded the number of MRSA strains. The MRSA strains isolated show significant sensitivity to antibiotic groups other than β-lactams, such as aminoglycosides, tetracyclines, cotrimoxazole, linezolid and vancomycin. Ciprofloxacin is the antibiotic to which S. aureus displays the second-highest resistance, after methicillin. In the case of MRSA strains, almost 100% lack of sensitivity to quinolines was found. An increase in the number of infections caused by strains of the Enterococcus genus was observed. For E. faecium strains, the percentage of vancomycin-resistant strains reached as much as 41% in 2018. Among the resistant strains in E. faecalis, VREs (Vancomycin-Resistant Enterococci) slightly predominate, while GREs (Glycopeptide-Resistant Enterococci) are much more prevalent in E. faecium. The data show that the percentage of S. pneumoniae strains insensitive to ampicillin ranged from 6% to 17%. In 2017, the percentage of strains resistant to this antibiotic reached 17%, while in 2022, their share decreased to 9%. In 2021–2022, the percentage of strains resistant to erythromycin was as high as 33%. This resistance is related to the MLS (macrolides, lincosamides, streptogramines B) mechanism. An increase in S. pneumoniae resistance to 100% was observed in 2017 and 2019. In the analyzed six-year period, from 2020 (beginning of the pandemic), in some groups of antibiotics, a significant increase in consumption in DDD/100 person-days was recorded. This is most visible in the case of fluoroquinolones. The analysis carried out will increase the effectiveness of empirical therapy in the hospital and the prudent use of antibiotics to limit the selection of multidrug-resistant strains. Full article

Background/Objectives: Antimicrobial resistance (AMR) in Enterococcus species from poultry production represents a significant public health threat due to the potential transmission of AMR through the food chain. This study aimed to examine the relative prevalence, resistance patterns, and mannitol fermentation capacity of Enterococcus isolates from various poultry production systems in Spain over a seven-year period (2017–2023). Methods: A total of 215 Enterococcus isolates were analyzed. Phenotypic assessments were conducted to determine resistance rates and metabolic capacities, while genotypic characterization focused on detecting vancomycin-resistance genes (vanA, vanB, vanC, and vanD). Results: Enterococcus faecalis (62.3%) and Enterococcus faecium (29.77%) were the predominant species, primarily isolated from broilers (74.88%), with the highest frequency observed in one-week-old chicks (31.16%). High resistance rates to tetracyclines and streptogramins were identified, while resistance to vancomycin (0.47%) and tigecycline (3.03%) was low. Interestingly, a significant reduction in tetracyclines resistance was shown in this period for Enterococcus faecalis (from 100% to 70% (2017–2023) and Enterococcus faecium (from 100% to 40% (2018–2023)). Multidrug resistance (MDR) was detected in 26.98% of isolates. Mannitol fermentation tests revealed high metabolic capacity in Enterococcus faecalis (99.25%) and Enterococcus faecium (96.88%), associated with adaptability and virulence potential. Genotypic analysis showed a very low prevalence of vanB and vanC genes. Conclusions: These findings highlight the critical need for targeted surveillance and intervention strategies in poultry production to mitigate the risks posed by MDR Enterococcus to public health. Full article

Microorganisms, including pathogens that cause skin, respiratory, and urinary tract infections, are widespread in our environment. Despite routine cleaning with bleach and disinfectants, the transmission of pathogens still occurs, leading to potential infectious diseases. This study aimed to determine the antibacterial effect of two coating formulas against common environmental pathogens like Escherichia coli, Staphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa, Salmonella sp., vancomycin-resistant Enterococcus faecium, and Klebsiella pneumoniae. The antibacterial coatings exhibited efficacy against these pathogens, with a bacterial reduction rate (R) greater than two, even after prolonged bleach cleaning. However, UV exposure may affect the efficacy of such coatings. The antibacterial coatings can eliminate the need for repetitive consumption of toxic detergents and reduce cleaning manpower, making them an environmentally friendly product for safety control and infection prevention. Full article