Search Results (1,331)

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by barrier dysfunction and susceptibility to Staphylococcus aureus colonization. Biofilm formation modifies antibiotic resistance and the host immune response. This longitudinal study analyzed antimicrobial susceptibility and biofilm formation in 136 S. aureus isolates obtained over 18 months from lesional, nonlesional, and nasal samples of 26 pediatric patients with moderate-to-severe AD. Antimicrobial susceptibility testing was determined by the disk diffusion method, and biofilm production was quantified using a crystal violet microtiter assay. Clinical parameters, including disease severity, treatment response, and the administration of dilute bleach baths, were evaluated in relation to bacterial characteristics. Overall, 60.2% of isolates exhibited moderate-to-strong biofilm production, significantly associated with severe AD at baseline (p = 0.01), lack of clinical improvement (p = 0.04), and persistent moderate-to-severe disease (p = 0.01). Resistance rates for penicillin, gentamicin, clindamycin, and erythromycin exceeded 15%. Isolates from patients using dilute bleach baths showed greater resistance to ciprofloxacin (p < 0.0001) and exhibited constitutive or inducible macrolide–lincosamide–streptogramin B (MLS_B) resistance, with ermA detected in 80% of inducible cases. In conclusion, S. aureus biofilm formation is linked to disease severity and treatment failure in pediatric AD, underscoring the importance of culture-guided, targeted therapeutic strategies. Full article

Background: Vancomycin is a critically important antimicrobial in human medicine, and vancomycin-non-susceptible enterococci represent a One Health concern when animal reservoirs contribute to the wider resistance ecology. We aimed to characterize vancomycin non-susceptibility among poultry-derived Enterococcus spp. from Hungary, using a combined phenotypic–genomic approach. Methods: Following a phenotypic pre-screen with antimicrobials authorized for poultry, 218 isolates with elevated minimum inhibitory concentrations (MICs) were selected for extended broth microdilution testing including vancomycin. Vancomycin susceptibility was interpreted using Clinical and Laboratory Standards Institute (CLSI) clinical breakpoints and European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cut-off values (ECOFFs). Whole-genome sequencing was performed on a targeted multidrug resistant (MDR) subset (n = 42), enriched for elevated or borderline vancomycin MICs and stratified by region and host species (chicken, turkey), and resistance determinants were annotated against the Comprehensive Antibiotic Resistance Database (CARD) using stringent similarity/coverage thresholds. Results: Among the 218 pre-screened isolates (126 from chickens; 92 from turkeys), 196 (89.9%) met MDR criteria. For vancomycin, 15.6% of isolates were resistant and 9.2% intermediate by CLSI, while EUCAST ECOFF classification placed 34.9% in the non-wild-type group. The vancomycin MIC distribution was right shifted, with high-end MICs observed. In the sequenced subset, vancomycin-associated determinants consistent with the vanC pathway (including regulatory and auxiliary components) were detected in five isolates. Beyond vancomycin-related determinants, the WGS subset harbored common resistance genes consistent with the observed multidrug-resistant phenotypes. Conclusions: Vancomycin non-susceptibility was detected among pre-screened poultry-derived Enterococcus isolates in Hungary, and genomic analysis revealed vanC-associated and other peptide antibiotic resistance signatures. These findings support targeted One Health surveillance integrating MIC distributions with genomic resistance determinants in food animal reservoirs. Full article

Understanding antimicrobial resistance (AMR) within a One Health framework requires examining how human–animal–environment interactions shape bacterial populations, and captive wildlife offers a unique context to explore these dynamics. This study aimed to characterise the phenotypic resistance and virulence profiles of Escherichia coli isolated from faecal samples of captive non-domestic felids housed in a wildlife sanctuary in the United Kingdom and evaluate the influence of captive conditions in E. coli traits. A total of 41 faecal samples were collected from 36 animals representing 11 non-domestic felid species, from which it was possible to obtain 108 E. coli isolates identified using IMViC testing. The isolates were characterised regarding their susceptibility to 12 antibiotics by disc diffusion and screened for the phenotypic expression of six virulence factors, including protease, DNase, gelatinase, lecithinase, haemolysins, and biofilm formation. The highest resistance rates were observed for tetracycline (19.4%) and ampicillin (10.2%), while isolates presented complete susceptibility regarding half of the tested antibiotics. Also, 9.3% of the isolates presented a multidrug-resistant profile. Biofilm formation was the only virulence factor expressed by the isolates under study (8.3%). Significant associations were detected between resistance outcomes and levels of human proximity and enclosure type. These findings suggest that captivity-related factors may influence AMR profiles in wild felids and highlight the importance of continued AMR surveillance and appropriate management practices to reduce selective pressures in captive wildlife. Full article

Background/Objectives: Reverse total shoulder arthroplasty (RTSA), a commonly performed procedure in elderly patients with osteoarthritis, is frequently complicated by postoperative infections—primarily caused by Cutibacterium acnes and coagulase-negative staphylococci (CoNS)—which remain a major clinical challenge. While standard antiseptic skin protocols can reduce the bacterial load at the surgical site, they often fail to achieve complete eradication, particularly with C. acnes, a resident species of the shoulder microbiome. Recent evidence indicates that intraoperative povidone–iodine irrigation is effective in significantly decreasing microbial burden; however, a thorough characterization of the virulence factors of the isolated strains remains essential. Methods: A total of 187 clinical strains isolated immediately after RTSA were characterized with respect to their antibiotic resistance profiles and biofilm-forming capacity, and the impact of intraoperative povidone–iodine irrigation on the reduction in bacteria that express these virulence traits was evaluated. Results: Of the 120 C. acnes isolates, 97.67% were susceptible to the tested antimicrobial agents, while only 3.33% exhibited resistance, specifically to clindamycin. In contrast, 53% of CoNS isolates were classified as susceptible, whereas the remaining 47% demonstrated multidrug resistance. Biofilm production was detected in 24% (29/120) of C. acnes and 39% (25/64) of CoNS isolates, with a statistically significant reduction observed after irrigation only for C. acnes. No association was found between biofilm formation and clindamycin resistance in C. acnes, likely due to the low number of resistant isolates. Conversely, among CoNS, a correlation was observed, with the 17.2% of biofilm-producing strains also exhibiting resistance to antimicrobial agents. Conclusions: Notwithstanding the presence of these virulence factors, povidone–iodine irrigation proved effective in substantially reducing the number of bacterial isolates recovered at the surgical site without selecting for strains with enhanced pathogenicity. Notably, the majority of resistant bacteria were detected prior to intraoperative irrigation. This intraoperative procedure may be a key approach to reducing prosthetic joint infections frequently caused by more virulent pathogens, which are unlikely to be selected following this disinfection strategy. Full article

In recent decades, the burden of TB has been gradually declining; however, with the emergence of COVID-19 and ongoing political conflicts, including the war in Ukraine, the proper functioning of healthcare services and TB control programs has been jeopardized. Recently, research has emphasized the importance of hematological parameters associated with inflammation, which can be easily analyzed through routine blood tests. Combining these parameters may have predictive value for various diseases, including pulmonary tuberculosis and even help monitor the effectiveness of treatment. Since there is no single hematological or inflammatory biomarker that provides precise and dynamic information about the success or failure of treatment, identifying individual markers or sets of biomarkers with higher sensitivity and specificity is essential. This is particularly important since sputum culture conversion at two months remains insufficiently sensitive and microscopy conversion has limited sensitivity and specificity in detecting treatment failure. Also, the analysis of the impact of the standard directly observed treatment, short-course regimen on pathogenic mechanisms also focuses on how it influences the interaction between inflammation and oxidative tissue degradation, by measuring plasma levels of glutathione. Utilizing a combination of hematological, inflammatory, and antioxidant biomarkers offers significant insights into systemic inflammatory responses in pulmonary tuberculosis patients, both before commencing treatment and during the entire duration of antituberculosis therapy. Combining different inflammatory parameters into a multiple biomarker can significantly enhance the accuracy of predicting prognosis and response to antibiotic chemotherapy. Identifying an optimal combination of biomarkers with predictive value is crucial for assessing treatment response and evaluating the effectiveness of anti-TB medication. Rather than developing or testing a composite prediction model, this review summarizes reported performance metrics from individual studies and highlights priorities for future prospective validation of integrated biomarker panels. Full article

Objectives: Respiratory syncytial virus (RSV) is a leading cause of hospitalization for acute lower respiratory tract infections (ALRIs) in children, with bacterial coinfection complicating diagnosis and often driving antibiotic overuse. This study aimed to develop and validate a clinical prediction model using common laboratory biomarkers to enable early, accurate identification of clinically significant bacterial coinfection in children with RSV infection. Methods: A single-center, retrospective cohort study was conducted at Fujian Children’s Hospital, enrolling 518 hospitalized children with RSV infection, which was confirmed via targeted next-generation sequencing (tNGS). Patients were randomly divided into a training set (n = 363) and a test set (n = 155) at a 7:3 ratio. The primary outcome, bacterial coinfection, was defined by a composite reference standard integrating etiological evidence from tNGS with clinical, inflammatory, and imaging data, and adjudicated by a blinded expert panel. LASSO regression identified independent predictors, followed by multivariable logistic regression modeling. Model performance was assessed via discrimination (AUC), calibration (Hosmer–Lemeshow test), and clinical utility (Decision Curve Analysis) in both sets. Results: Neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), and serum amyloid A (SAA) were selected as predictors. The model achieved an AUC of 0.832 (95% CI: 0.788–0.875) in the training set and 0.811 (95% CI: 0.737–0.885) in the test set, with well-calibrated predictions (p > 0.05). Decision curve analysis demonstrated net clinical benefit across 10–80% threshold probabilities. A nomogram was developed for practical application. Conclusions: This study established a model integrating NLR, CRP, and SAA. It offers a reliable tool for the early detection of bacterial coinfection in RSV-infected children, enabling targeted antibiotic stewardship and improving clinical outcomes. Full article

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become one of the most serious problems confronting modern healthcare, particularly in intensive care units where patients are highly susceptible, procedures are frequent, and antibiotic exposure is often prolonged. In this review, carbapenem resistance in K. pneumoniae is presented not as a fixed feature of individual bacteria, but as a process that is constantly changing and closely interconnected. We bring together evidence showing how the spread of successful bacterial lineages, the exchange of resistance genes, and gradual genetic adjustment combine to drive both the rapid spread and the long-lasting presence of resistance. A major focus is placed on mobile genetic elements, including commonly encountered plasmid backbones, transposons, and insertion sequences that carry carbapenemase genes such as blaKPC, blaNDM, and blaOXA-48-like. These elements allow resistance genes to move easily between bacteria and across different biological environments. The human gut plays a particularly important role in this process. Its microbial community serves as a largely unseen reservoir where resistance genes can circulate and accumulate well before infection becomes clinically apparent, making prevention and control more difficult. This review also discusses the key biological factors that shape resistance levels, including carbapenemase production, changes in the bacterial cell membrane, and systems that expel antibiotics from the cell, and explains how these features work together. Advances in molecular testing have made it possible to identify resistance more quickly, supporting earlier clinical decisions and infection control measures. Even so, current tests remain limited by narrow targets and may miss low-level carriage, hidden genetic reservoirs, or newly emerging resistance patterns. Finally, we look ahead to approaches that move beyond detection alone, emphasizing the need for integrated surveillance, thoughtful antibiotic use, and coordinated system-wide strategies to lessen the impact of CRKP. Full article

Background/Objectives: Infection prevention and control (IPC) programs combine pathogen-targeted measures (e.g., admission screening) with hospital-wide standard precautions (e.g., hand hygiene, HH). We assessed temporal associations between screening, HH, antimicrobial stewardship (AMS), and hospital-level outcomes in a tertiary paediatric hospital. Methods: This study was a retrospective hospital-wide ecological time-series at the Children’s Memorial Health Institute. Annual aggregate data: 2011–2024 for screening, colonisation, and healthcare-associated infections (HAIs) with alert pathogens; 2016–2024 for antibiotic consumption (ATC J01, systemic antibacterials). Process indicators: number of screening tests and alcohol-based hand rub (ABHR) consumption per 1000 patient-days (PD). Outcomes: colonisations/HAIs per 1000 PD and defined daily doses (DDD) per 1000 PD overall and by class. Trends used linear regression and Spearman’s rank correlation. Results: Screening intensity increased from 39 to 150/1000 PD (slope +8.3/year; R² = 0.90; p < 0.001). Detected colonisation rose (2.5 → peak 8.05/1000 PD in 2023; slope +0.39; R² = 0.81; p < 0.001), while multidrug-resistant-organism (MDRO)-attributable HAIs remained low/stable (0.27–0.62/1000 PD; slope −0.014; p = 0.023). ABHR consumption increased from 26.1 to 78.0 L/1000 PD in 2020 (p < 0.001) and partially normalised to 60.0 in 2024 (>2 × baseline). Overall ATC J01 showed no long-term linear trend (~278–356 DDD/1000 PD; +2.57/year; p = 0.46), but class mix shifted: carbapenems, fluoroquinolones, and amoxicillin–clavulanate decreased; third/fourth-generation cephalosporins, piperacillin/tazobactam, and glycopeptides increased. Conclusions: In this tertiary paediatric setting, expansion of risk-based admission screening and sustained implementation of horizontal IPC measures were accompanied by increased detection of colonisation with alert pathogens, while MDRO-attributable HAIs remained low and stable at the hospital level. Over the same period, AMS activity coincided with a redistribution in antibiotic class use without a clear long-term reduction in total antibiotic consumption. These hospital-level findings are descriptive and hypothesis-generating; causal inference is limited by the ecological study design, and the heterogeneous, multispecialty structure of a tertiary paediatric centre. Full article

Mycoplasma synoviae (MS) is a major pathogen threatening China’s poultry industry, causing severe economic losses, and clarifying its epidemiology is pivotal for disease control and flock purification. In this study, a total of 3215 chicken samples collected from 643 broiler farms across 15 provinces in China in 2024 were analyzed. PCR detected 14% positivity (450 samples), and 18 isolates obtained from these positive samples (4.0% isolation rate). Multilocus sequence typing (MLST, 7 housekeeping genes) and neighbor-joining phylogenetic analysis (integrating 425 reference sequences from public databases) identified 13 distinct sequence types (STs), demonstrating considerable genetic diversity among circulating MS strains. Pathogenicity assessment of the five isolates revealed that the infected chickens exhibited varying degrees of infectious synovitis, while no respiratory signs were observed. In addition, antimicrobial susceptibility testing against 10 commonly used antibiotics was conducted on the 18 strains, providing urgently needed guidance for rational drug use in the clinical treatment of both breeder and broiler flocks. This large-scale epidemiological study yields crucial insights into the current prevalence and genetic diversity of MS in China and lays a scientific foundation for formulating targeted prevention strategies and optimizing management practices. Full article

Methicillin-resistant coagulase-negative staphylococci (MRCoNS) are a major cause of infectious diseases, owing to their ability to form biofilms and colonize community and hospital environments. MRCoNS strains were identified using biochemical tests, an MALDI-TOF MS analyzer, and PCR-based 16S rRNA gene confirmation. This study was designed to assess antibiotic resistance and biofilm-forming capacity and to determine the presence of the mecA, mecC, agrA, srtA, icaABCD, bap, fnbAB, and clfAB genes in MRCoNS isolates. From patients undergoing random screening during hospitalization in the Orthopedics Clinic in Slovakia, 28 strains of MRCoNS were identified: S. epidermidis (n = 10), S. hominis (n = 8), S. haemolyticus (n = 4), S. lugdunensis (n = 3), while S. simulans, S. pasteuri, and S. warneri were detected only once. The highest rates of resistance were observed for ampicillin, oxacillin, rifampicin, trimethoprim (100%), and erythromycin (62%). The mecA gene was detected in 12 analyzed isolates. In 12 isolates, MDR, strong efflux pump activity, and strong or moderate biofilm formation were simultaneously detected. Our findings highlight the problems posed by biofilm-forming, resistant CoNS in hospitalized patients and the importance of diagnostics, separation, rapid treatment, and proper hospital hygiene. Full article

Pathogens that have developed resistance to antibiotics pose a threat to public health. The primary goal in preventing foodborne infections is to inhibit the growth of and, subsequently, eliminate antibiotic-resistant pathogens at every stage from production to consumption. Escherichia coli, which has acquired resistance to most known antibiotics, is frequently found in chicken meat. In many countries, due to unregulated antibiotic use in poultry farming, poor hygiene in slaughterhouses, or cross-contamination, extended-spectrum beta-lactamase (ESBL)-producing E. coli has been identified as the causative agent in poultry-associated food poisoning. The need for more effective antimicrobial agents against this pathogen, which is resistant to existing antibiotics, has led to increased attention being paid to postbiotics produced by lactic acid bacteria, particularly bacteriocins. This study aimed to determine the antimicrobial effects of postbiotics obtained from kefir-derived Lactiplantibacillus plantarum and Lactococcus lactis against ESBL-positive E. coli. To achieve this, E. coli strains were isolated from raw chicken meat samples collected from the market using culture-based methods, and their antimicrobial resistance profiles were determined using the disk diffusion method. The ESBL positivity of the isolates was assessed using the double-disk synergy test. The antimicrobial activities of the postbiotics against the identified ESBL-positive E. coli strains were tested using the macro-dilution method to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. ESBL-positive E. coli was detected in 48% of raw chicken meat samples. The antimicrobial effects of postbiotics were examined by disk diffusion, and postbiotics produced by 18 Lb. plantarum strains and 20 Lc. lactis strains showed strong antimicrobial activity. Significant differences in the antimicrobial effects of postbiotics were observed between the two species. Lb. plantarum postbiotics exhibited both bacteriostatic (concentration 60%) and bactericidal (concentration 80%) effects on ESBL-positive E. coli strains, whereas Lc. lactis postbiotics showed only bacteriostatic effects (80% concentration). Postbiotics derived from probiotic bacteria offer promising effects against multidrug-resistant E. coli due to their heat resistance, activity across different pH values, strong antimicrobial effects, affordability, and ease of production. Full article

The human skin microbiome has gained considerable attention as a resource for the development of innovative probiotics for cosmetic purposes or promoting skin health. However, the evaluation of new probiotic strains to ensure their “generally recognized as safe” (GRAS) status remains challenging. Here, we have subjected the annotated draft genome sequences of four human skin-derived bacterial strains, namely Bacillus subtilis MBF10-19J, Micrococcus luteus MBF05-19J, Staphylococcus hominis MBF12-19J, and Staphylococcus warneri MBF02-19J, to bioinformatic analyses to detect the genes associated with important probiotic traits, as well as undesirable characteristics such as antibiotic resistance, virulence factors, and toxic metabolites. Each bacterium harbors at least one type of adhesin-encoding gene, while only S. hominis MBF12-19J and S. warneri MBF02-19J contain the putative genes encoding enzymes for metabolism improvement. In vitro assays, including antibiotic susceptibility and antimicrobial activity testing, revealed strain-specific safety characteristics that complement the genomic findings. With regard to antibiotic resistance determinants, S. hominis MBF12-19J showed the most favorable profile, S. warneri MBF02-19J and M. luteus MBF05-19J appeared suitable when used with appropriate caution, and B. subtilis MBF10-19J exhibited amoxicillin resistance, i.e., warrants careful evaluation. Further in vivo validation is needed to determine whether these strains do indeed comply with GRAS evaluation frameworks. Full article

Background/Objectives: Syndromic multiplex PCR assays such as BIOFIRE FilmArray^® Pneumonia (PN) panel enable rapid and simultaneous detection of bacterial and viral pathogens in respiratory specimens, improving diagnostic accuracy and patient management in lower respiratory tract infections (LRTIs). Methods: In this retrospective observational study, PN panel results in 410 bronchoalveolar lavage (BAL) samples from hospitalized patients with suspected pneumonia were analyzed and compared with those obtained using the conventional culture (CC) method. Results: The PN panel showed an overall positivity rate of 54%, detecting bacteria in 39.0% of samples, viruses in 7.1%, and atypical bacteria in 2.2%. Using the conventional culture (CC) method, 33.9% of samples tested positive. Overall, 83 (20.2%) samples that were positive by the PN panel were negative by CC, whereas only 14 specimens (3.4%) were positive by CC and negative by PN panel. The most frequently detected pathogen by both the PN panel and CC was Staphylococcus aureus (n = 67, 16.34% for PN; n = 40, 9.76% for CC). Regarding diagnostic performance, the PN panel demonstrated a sensitivity of 89.02%, a specificity of 97.86%, and an overall accuracy of 97.63%. Lower sensitivity values were observed only for the Enterobacter cloacae complex (57.14%) and the Klebsiella pneumoniae group (75%). Specificity exceeded 92% for all bacterial targets. Conclusions: The PN panel confirms enhanced pathogen detection and a shortened time-to-result. It serves as a valuable adjunct for the timely diagnosis of LRTIs, supporting antimicrobial stewardship through more precise and appropriate antibiotic selection. Full article

Identifying pathogens causing periprosthetic joint infection (PJI) is a challenge for clinicians. We aimed to evaluate the application of metagenomic next-generation sequencing (mNGS) to identify pathogens in PJI. A prospective analysis was conducted of patients diagnosed PJI between 2022 and 2024 at twelve hospitals in Taiwan. Both conventional bacterial culture (CMT) and mNGS of joint fluid and debrided tissue were performed. Demographic characteristics, laboratory results and clinical outcomes were collected. The diagnostic performance of these two methods was analyzed. A total of 42 patients with a mean age of 67.9 years were enrolled in analysis. The knee was the most common joint involved (69.1%). A high proportion of patients (78.6%) received prior antibiotics within the two weeks at sample collection. mNGS identified pathogens in 28 out of 42 patients (66.7%), whereas CMT yielded positive results in 12 out of 42 patients (28.6%) (McNemar’s test, p = 0.01). Staphylococcus species was the most common genus detected (n = 11), followed by Cutibacterium (n = 4). Other detected genera included Escherichia, Mycobacterium, Enterobacter, Klebsiella (n = 2 each), Acinetobacter, and Corynebacterium (n = 1 each). Our results support the idea that mNGS could serve as a valuable diagnostic tool for PJI in addition to traditional culture methods. Full article

Bifidobacterium animalis subsp. lactis is a widely used probiotic, yet its efficacy is highly strain-specific, and growing antibiotic resistance necessitates rigorous safety evaluations. We used whole-genome sequencing and in vitro assays to characterize the safety and probiotic traits of infant feces-sourced strain BD1, which shows preliminary mood-modulating and anti-inflammatory potential. The BD1 genome showed a favorable safety profile. VFDB analysis identified 139 low-similarity homologs, with no major toxins detected. Only four chromosomally encoded antibiotic resistance genes were found; phenotypic testing confirmed resistance solely to tetracycline and mupirocin. Although the tetracycline resistance gene tet(W) was identified in genomic island GI01, the absence of associated mobile genetic elements results in a negligible risk of its mobilization. Functional annotation highlighted a dominant metabolic capacity for carbohydrate and amino acid metabolism. BD1 is rich in CAZymes, enabling superior utilization of diverse substrates (starch, sucrose, galactose). Enrichment in lipid metabolism pathways (glycerolipid, sphingolipid) further suggests potential for enhancing fermented product flavor. In vitro assessment demonstrated moderate gastrointestinal tolerance and strong bile salt tolerance. Surface properties showed pronounced cell surface hydrophobicity and confirmed biofilm-forming potential. In conclusion, BD1 exhibits robust safety, metabolic versatility, and strong probiotic characteristics, supporting its development as a functional probiotic strain. Full article