Background/Objectives: Wastewaters containing antibiotics pose risks to human health and soil ecosystems. In this study, the white-rot fungus Coriolopsis gallica (a basidiomycete exhibiting high laccase production) was used for the biotransformation of three antibiotics (50 mg L−1): tetracycline, chloramphenicol, and sulfanilamide. Methods: The biotransformation process was investigated in liquid and solid media using high-performance liquid chromatography (HPLC) and the bacterial growth inhibition agar well diffusion method, respectively. Results: Among the three antibiotics tested, tetracycline showed the highest biotransformation efficiency, achieving a 100% removal rate in the liquid medium and a 100% decrease in the growth inhibition of Escherichia coli in the solid medium. Chloramphenicol and sulfanilamide were partially removed (20% and 16%, respectively) after 12 days of treatment in more than one step without the loss of their antibacterial activities. The presence of these antibiotics in the culture medium of C. gallica enhanced laccase activity, indicating that this ligninolytic enzyme might participate in the biotransformation process. Conclusions: Thus, the results reported in this article extend our knowledge of the catalytic potential of C. gallica and give further perspectives for its application in the biodegradation of antibiotics. To the best of our knowledge, this is the first study wherein C. gallica was used for the treatment of tetracycline, chloramphenicol, and sulfanilamide.

Background/Objectives: Chitosan-based films incorporating green-synthesized silver nanoparticles AgNPs) or copper oxide nanoparticles (CuONPs) were developed to compare their selective antimicrobial action for topical applications. While AgNPs are known for broad-spectrum activity, this study hypothesized that CuONPs would exhibit superior, targeted efficacy against the acne-associated bacterium Cutibacterium acnes. Methods: Nanoparticles were synthesized using Camellia sinensis extract and characterized. Antimicrobial activity was evaluated using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. Chitosan films containing AgNPs or CuONPs were further tested for selective antimicrobial activity and fibroblast cytocompatibility. Results: AgNPs showed strong activity against Escherichia coli and Staphylococcus aureus (MIC = 15 µg/mL) but were less effective against C. acnes (MIC = 125 µg/mL). In contrast, CuONPs demonstrated selective efficacy against C. acnes (MIC = 62 µg/mL; MBC = 125 µg/mL). When incorporated into chitosan films, AgNPs@CHI inhibited E. coli (35 mm halo) and S. aureus (30 mm), whereas CuONPs@CHI were selectively effective against C. acnes (45 mm). All films preserved fibroblast viability above the 70% ISO 10993-5 threshold. Conclusions: CuONPs@CHI films validated selective anti-C. acnes performance, highlighting their promise for targeted anti-acne therapies, while AgNPs@CHI films served as effective broad-spectrum antimicrobial barriers.revealed that AgNPs were potent against Escherichia coli and Staphylococcus aureus (MIC = 15 µg/mL) but less effective against C. acnes (MIC = 125 µg/mL). Conversely, CuONPs demonstrated a marked selective advantage against C. acnes (MIC = 62 µg/mL; MBC = 125 µg/mL). When incorporated into chitosan films, AgNPs@CHI films inhibited E. coli (35 mm halo) and S. aureus (30 mm), whereas CuONPs@CHI films were selectively effective only against C. acnes (45 mm), confirming the targeted performance. All films maintained fibroblast viability above the 70% ISO 10993-5 cytotoxicity threshold. These findings validate the selective action of CuONPs@CHI films, positioning them as a promising biomaterial for targeted anti-acne therapies, while AgNPs@CHI films serve as effective broad-spectrum antimicrobial barriers.

Background: The intestinal tract is a host to a high number of diverse bacteria, and the presence of multidrug-resistant (MDR) Enterobacterales strains acts as a reservoir and a source of infection. The interactions between the intestinal microbiome and colonizer Enterobacterales strains influence long-lasting colonization. Aims: In this narrative review, we summarize available data about the intestinal colonization of MDR Enterobacterales strains and correlations between colonization and the intestinal microbiome. Results: Several endogenous and exogenous factors influence the intestinal colonization of MDR Enterobacterales strains. On the gut microbiome level, the intestinal microbial community is composed of the Lachnospiraceae family (e.g., Lachnoclostridium, Agathobacter, Roseburia, Tyzzerella), which indicates a protective role against colonizer MDR Enterobacterales strains; by contrast, a high abundance of Enterobacterales correlates with the colonization of MDR Enterobacterales strains. In specific patient groups, striking differences in microbiome composition can be detected. Among hematopoietic stem-cell-transplanted patients colonized by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales, a greater abundance of Bifidobacterium, Blautia, Clostridium, Coprococcus, L-Ruminococcus, Mogibacteriaceae, Peptostreptococceae and Oscillospira was observed compared to patients not colonized by ESBL-producing strains, who had a greater abundance of Actinomycetales. In liver transplant patients, a reduction in the alpha-diversity of the intestinal microbiome in fecal samples correlates with the carriage of MDR Enterobacterales. Conclusions: Intestinal colonization with MDR Enterobacterales is a multifactorial process that involves the MDR strain (e.g., its plasmids, fimbria), host and mucosal factors (e.g., IgA and defensin) and exogenous factors (e.g., use of antibiotics, hospitalization). On the gut microbiome level, the Lachnospiraceae family is dominant among intestines not colonized by MDR strains, but a high abundance of Enterobacterales was correlated with colonization with MDR Enterobacterales strains.

Background/Objectives: The present study investigates the antifungal potential of 1,5-diarylidene-4-piperidones. Methods: These compounds were synthesized via Claisen–Schmidt condensation, and their antifungal efficacy was tested against Cryptococcus neoformans, a yeast recently qualified as a critical priority pathogen by the World Health Organization, through determination of their minimum inhibitory concentration (MIC). We designed and synthesized a series of piperidones to explore structure–activity relationships. Results: Systematic modification of the substituent pattern revealed that tetrabutoxy groups exhibited potent activity (MIC of 7.8 µM), surpassing standard antifungals like fluconazole. The selectivity index (SI) values confirmed their safety profile across various human cells. Docking analysis demonstrated that these compounds target sterol 14-demethylase, suggesting potential inhibition of ergosterol synthesis as a mechanism of action. Interestingly, the compounds also demonstrated broad-spectrum activity against other pathogenic yeasts and fungi, including Candida and Aspergillus species, and against fluconazole-resistant strains. Conclusions: These findings underscore the potential of 1,5-diarylidene-4-piperidones as promising antifungal candidates with a favorable safety profile.

Introduction: Septic arthritis of the knee caused by the combination of Rothia mucilaginosa and Erysipelothrix rhusiopathiae is extremely rare. E. rhusiopathiae is a rare zoonotic pathogen that primarily affects individuals with occupational exposure to animals, while R. mucilaginosa can cause severe infections, particularly in immunocompromised patients. Case Presentation: A 59-year-old male underwent right knee arthroscopy in 2019 due to meniscal degeneration. Two weeks later, activity-related pain appeared. Magnetic resonance imaging showed proliferative synovitis, and joint aspiration revealed the presence of E. rhusiopathiae, which was treated with ciprofloxacin. As inflammation persisted, arthroscopic synovectomy was performed. Cultures revealed R. mucilaginosa and E. rhusiopathiae, prompting treatment with vancomycin and clindamycin. Despite repeated synovectomies, symptoms remained. After knee trauma in 2023, infection recurred. A two-stage total knee arthroplasty was performed in early 2024. At this time, another pathogen was isolated. At 12-month follow-up, the patient’s function and alignment had improved significantly. Conclusions: The described case highlights the importance of anamnesis, early diagnostics, and knowledge about the possible resistances of rare pathogens to ensure appropriate treatment of the illness.

Background/Objectives: Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections in both community and hospital settings worldwide. Antimicrobial-resistant UPEC strains pose a significant challenge for effective antibiotic therapy. In this study, 50 bacterial isolates recovered from urine samples of patients attended in different sectors of a public hospital in Rio de Janeiro over five months were analyzed to assess antimicrobial resistance and virulence profiles through broad gene screening. Methods: Biofilm production was assessed using a semi-quantitative adherence assay. PCR was employed to investigate 27 resistance genes, 6 virulence genes, sequence types (STs), and phylogroups. Susceptibility to 25 antimicrobial agents was determined by disk diffusion testing. Furthermore, the pathogenic potential was evaluated in vivo using the Tenebrio molitor larvae infection model. Results: Most UPEC isolates were moderate or strong biofilm producers (41/50; 82%). The sul1 and sul2 resistance genes were the most frequently detected (58%). Two virulence gene patterns were identified: fyuA, iutA, fimH, cnf1 and fyuA, iutA, fimH (13 isolates; 26%). ST131 and ST73 were the most common sequence types (16% each), and phylogroup B2 was the most prevalent (50%). Thirty isolates (60%) were multidrug-resistant, most of which belonged to phylogroup B2. UPEC exhibited dose-dependent lethality, causing 100% mortality at 2.6 × 108 CFU/mL within 24 h. Conclusions: These findings reinforce the urgent need for surveillance strategies and effective antimicrobial stewardship in clinical practice.

Background/Objectives: Extended-Spectrum Beta-Lactamase-producing Escherichia coli (ESBL-E. coli) are widely circulating in livestock of low- and middle-income countries. However, the drivers of their circulation remain largely unknown. Small-scale farms in Peru exhibit an unusually high prevalence of fecal carriage of ESBL-E. coli in their livestock. The objective of this study was to compare the prevalence of ESBL-E. coli fecal carriage in dairy cows, pigs, and poultry in the Lima and Ica regions of Peru and to identify the drivers associated with the observed prevalence at the farm level. Methods: We compared the prevalence of fecal carriage of ESBL-E. coli isolated from dairy cattle (N = 244 animals; 25 farms), pigs (N = 261; 25), and laying hens (N = 255; 10). We also administrated questionnaires to 59 farmers regarding their socioeconomic status, husbandry practices, animal diseases, and antibiotic use. Results: All but one of the 60 farms sampled had at least one animal carrying ESBL-E. coli. A statistically higher prevalence of ESBL-E. coli was estimated in dairy cows (75%) and pigs (61%) from Lima compared to laying hens from Ica (34%). Our statistical analyses (Poisson generalized linear models) using two variable selection approaches revealed that the prevalence of ESBL-E. coli was lower in farms raising laying hens, when farmers oversaw both animal husbandry and healthcare, and in farms with a lower number of gastrointestinal outbreaks in the last semester. Socio-economic features of farmers and self-reporting antibiotic use varied across farms (i.e., highest antibiotic use over the last semester was reported among pig farmers (96%), followed by laying hen (70%) and dairy cattle farmers (50%)), but these factors were not associated with the prevalence of ESBL-E. coli. Conclusions: Despite a relatively low number of farms sampled, our findings suggest that the widespread circulation of ESBL-E. coli among livestock in Peru could be mainly associated with unknown species-specific drivers, independently of the socioeconomic status of farmers and antibiotic use. Therefore, our study calls for future research to identify the specific drivers promoting the high prevalence of ESBL-E. coli among cattle and pigs in Peru.

Background/Objectives: The presence of multi-drug-resistant (MDR) bacteria in healthy individuals poses a significant public health concern, as these strains may contribute to or even facilitate the dissemination of antibiotic resistance genes (ARGs) and virulence factors. In this study, we investigated the genomic features of antimicrobial-producing Escherichia coli strains from the gut microbiota of healthy individuals in Singapore. Methods: Using a large-scale screening approach, we analyzed 3107 E. coli isolates from 109 fecal samples for inhibitory activity against E. coli DH5α and performed whole-genome sequencing on 37 representative isolates. Results: Our findings reveal genetically diverse strains, with isolates belonging to five phylogroups (A, B1, B2, D, and F) and 23 unique sequence types (STs). Bacteriocin gene clusters were widespread (92% of isolates carried one or more bacteriocin gene clusters), with colicins and microcins dominating the profiles. Notably, we identified an hcp-et3-4 gene cluster encoding an effector linked to a Type VI secretion system. Approximately 40% of the sequenced isolates were MDR, with resistance for up to eight antibiotic classes in one strain (strain D96). Plasmids were the primary vehicles for ARG dissemination, but chromosomal resistance determinants were also detected. Additionally, over 55% of isolates were classified as potential extraintestinal pathogenic E. coli (ExPEC), raising concerns about their potential pathogenicity outside the intestinal tract. Conclusions: Our study highlights the co-occurrence of bacteriocin genes, ARGs, and virulence genes in gut-residing E. coli, underscoring their potential role in shaping microbial dynamics and antibiotic resistance. While bacteriocin-producing strains show potential as probiotic alternatives, careful assessment of their safety and genetic stability is necessary for therapeutic applications.

Background/Objectives: Veillonella species are Gram-negative, non-motile, non-fermentative, obligate anaerobic cocci. They are typically considered commensals of the oral cavity, respiratory tract, genitourinary tract, and gastrointestinal tract. It may be a rare cause of dental infections and discitis/spondylodiscitis. Methods: We report the case of an 80-year-old patient diagnosed with discitis caused by Veillonella parvula, isolated from blood. In addition, we performed a comprehensive literature review summarizing all reported cases of discitis or spondylodiscitis caused by Veillonella species. Results: In our case, antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method. Based on the results, the patient was treated with amoxicillin/clavulanate, which led to a favourable clinical outcome. A review of the literature revealed that, to date, only 14 cases of spondylodiscitis or discitis caused by Veillonella spp. have been reported. Potential risk factors for Veillonella spp. bacteremia were identified in only 9 cases. The most commonly affected site was the lumbar or lumbosacral spine. Magnetic resonance imaging was consistently regarded as the diagnostic gold standard. Most patients presented with localized pain. The overall therapeutic approach generally consisted of an initial course of intravenous antibiotics, typically ceftriaxone administered either as monotherapy or in combination with metronidazole, followed by an oral regimen with amoxicillin/clavulanate, given alone or alongside metronidazole. Conclusions: Spondylodiscitis due to V. parvula remains extremely rare. Although antimicrobial susceptibility patterns remain heterogeneous, beta-lactams, particularly amoxicillin/clavulanate, appear effective in most cases, and treatment regimens typically involve an initial intravenous phase followed by oral therapy.

Background/Objectives: The rise in urinary tract infections caused by multidrug-resistant (MDR) bacteria presents a serious public health challenge across the Balkans, a region already burdened by aging populations, healthcare resource limitations, and fragmented antimicrobial surveillance systems. Methods: This review explores the epidemiology, risk factors, and consequences of MDR UTIs, particularly in the context of the COVID-19 pandemic, which significantly accelerated antimicrobial resistance (AMR) due to widespread, inappropriate antibiotic use. Results: The paper discusses region-specific data on resistance trends, highlights the gaps in diagnostic infrastructure, and evaluates emerging clinical strategies including antimicrobial stewardship (AMS), rapid diagnostic technologies, novel antibiotics, and non-antibiotic alternatives such as bacteriophage therapy and vaccines. Conclusions: Policy recommendations are provided to strengthen surveillance, promote evidence-based treatment, and ensure equitable access to diagnostic and therapeutic tools. A multidimensional and regionally coordinated response is essential to curb the MDR UTI burden and safeguard public health across the Balkans.