Search Results (230)

A 61-year-old woman developed prosthetic valve infective endocarditis after osteomyelitis caused by extensively drug-resistant (XDR) Acinetobacter baumannii. Moreover, a systematic descriptive review of published case reports was performed to describe the main features, treatment, and outcomes of this condition. Methods: Apart from the description of our case, a PubMed and Embase literature review was conducted up to January 2026 using the terms “A. baumannii” AND (“infective endocarditis” OR “endocarditis” OR “valvular infection”). We included clinical cases of IE caused by A. baumannii published as full-text articles in English. Results: After orthopedic osteosynthesis surgery following a femur fracture, our patient developed osteomyelitis by XDR A. baumannii and was treated for a short period of time. Later, prosthetic aortic valve endocarditis was diagnosed. Despite treatment with cefiderocol and eravacycline, she died. An additional 18 clinical cases of IE by A. baumannii were identified from the literature, bringing the total to 19 cases. IE affected prosthetic valves in nine cases, native valves in nine and involved a right atrial mass in one. Twelve cases were caused by MDR or XDR A. baumannii. Mortality occurred more frequently in cases not treated with surgery (9/13, 69%) compared to those treated with surgery (1/6, 16.7%). However, given the very small sample size, these data should be interpreted with caution. Conclusion: This case, together with previously reported observations, highlights the severity of EI by A. baumannii and the need of multidisciplinary management. Full article

Background/Objectives: The frequent use of antibiotics has led to increasing drug resistance in Aeromonas hydrophila; therefore, there is an urgent need to develop novel antimicrobial agents to prevent and control bacterial diseases in aquaculture. Allicin E (ALE) is derived from garlic (Allium sativum L.), a plant extensively used in traditional medicine for treating infections. This study aimed to evaluate the potential of ALE against A. hydrophila, a major aquaculture pathogen, by investigating its antibacterial efficacy, mechanisms of action, and in vivo protective effects. Methods: The minimum inhibitory and bactericidal concentrations (MIC/MBC) were determined by broth microdilution. Antibacterial mechanisms were investigated through ROS detection, electron microscopy, fluorescent staining, and content leakage measurement. In vivo efficacy was evaluated in Carassius auratus gibelio by monitoring survival rates and bacterial loads, analyzing immune and antioxidant biomarkers, and histopathological analysis after A. hydrophila challenge. Results: ALE exhibited potent antibacterial activity (MIC = MBC = 8 μg/mL), achieving complete bacterial elimination within 1 h and showing a low resistance propensity. Mechanistically, ALE induced ROS accumulation, causing oxidative damage that disrupted membrane integrity and facilitated the leakage of cellular contents. In vivo, ALE significantly enhanced fish survival, reduced bacterial loads, modulated inflammatory cytokines, boosted antioxidant enzyme activities (SOD and CAT), and alleviated tissue damage. Conclusions: ALE possesses potent in vitro antibacterial activity and exerts an inhibitory effect on bacteria-induced inflammatory responses, effectively combating A. hydrophila through a multi-target mechanism and enhancing host resistance. Full article

Background/Objectives: The rise in healthcare-associated infections caused by multidrug-resistant (MDR) bacteria in hospitals, particularly in intensive care units, has resulted in increased rates of morbidity and mortality, escalating costs, and has become a significant public health concern. In our Intensive Care Unit, we address healthcare-associated infections caused by multidrug-resistant bacteria, with a specific focus on those listed in the WHO 2024 List of Critically and Highly Prioritized Pathogens. Methods: Over the course of 1 year, from 1 January to 31 December 2024, we monitored the prevalence of healthcare-associated infections in the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital, Romania, and the antibiotic susceptibility of the isolated bacteria. Results: The majority of infections were caused by pathogens in the ESKAPEE group. The most frequently isolated microorganism was Klebsiella pneumoniae (36.8%), followed by Acinetobacter baumannii (24.5%), classified as a critical priority by the WHO in 2024. Most positive samples for critical priority pathogens, including Klebsiella pneumoniae and Acinetobacter baumannii, as well as all MRSA strains (high priority), were obtained from tracheal aspirates collected from intubated and mechanically ventilated patients. A significant proportion of the isolated bacteria were multidrug-resistant, including extensively drug-resistant and pan-drug-resistant strains. Conclusions: The increase in antibiotic and antimicrobial resistance among hospital strains raises serious concerns about limited treatment options. Full article

Wildlife can serve as a potential reservoir and spreader of resistant and pathogenic bacteria. Raptors, occupying the ecological position of apex or mesopredators, integrate exposure across different habitats and therefore serve as bioindicators of environmental dissemination of pathogens. In this study, we isolated 54 Escherichia coli (E. coli) strains from feces sampled from 64 raptors admitted to a wildlife rescue center in Central Italy. Phenotypic antimicrobial susceptibility testing was conducted, followed by molecular screening for resistance genes. Additionally, the presence of intestinal E. coli pathotypes, including STEC, EHEC, EPEC, ETEC, EAEC, EIEC, and NTEC, was evaluated through virulence gene analysis. Results indicated notable resistance to commonly used antimicrobials, with the highest percentages observed for ampicillin (40.74%), fluoroquinolones (31.48%), and tetracycline (25.93%). Molecular analysis of phenotypically resistant isolates identified the presence of several resistance genes, including bla_TEM (13 isolates), bla_CTX-M (4 isolates), bla_CMY-2 (3 isolates), bla_SHV (1 isolate), tet(A) (9 isolates), tet(B) (4 isolates), cat1 (1 isolate), and cmlA (2 isolates). Furthermore, 29.63% of isolates were classified as multidrug-resistant (MDR) and 7.41% as extensively drug-resistant (XDR). Regarding virulence profiles, one isolate harboring eaeA, escV, and astA genes was classified as atypical EPEC, while 27.78% isolates had only the astA gene, preventing precise pathotype assignment. These findings highlight the circulation of antimicrobial-resistant and potentially pathogenic E. coli strains within raptor populations in Central Italy, emphasizing the zoonotic potential and reaffirming the role of raptors as bioindicators within a One Health approach. Full article

Background: Antimicrobial resistance is a threat that increases morbidity and mortality. This cross-sectional study aimed to describe the profile of priority antimicrobial-resistant pathogens and to analyze the behavior of multidrug-resistant tuberculosis (MDR-TB) in the Santiago de Cali District, Colombia. Methods: researchers compiled information from data provided by healthcare institutions, the National Public Health Surveillance System, and laboratory-based surveillance using the World Health Organization’s WHONET v.5.6 software. Univariate statistical analysis described trends in pathogen resistance, and multivariate analysis analyzed the behavior of MDR-TB. Results: Among Gram-negative bacteria, high levels of carbapenem resistance were observed in A. baumannii (84% aztreonam resistance) and in K. pneumoniae (63%). P. aeruginosa exhibited elevated multidrug resistance, consistent with extensive antimicrobial selective pressure. MDR-TB exhibited a high burden of resistance, reaching 96%, with projections indicating a potential increase driven by monoresistance and resistance to rifampicin. Patients with drug-resistant tuberculosis who were HIV-positive or experiencing homelessness had a significantly higher likelihood of hospitalization (OR 5.59; 95% CI 3.09–10.11 and OR 2.94; 95% CI 1.48–5.81, respectively) and mortality (OR 3.34; 95% CI 1.72–6.49 and OR 2.59; 95% CI 1.16–5.79, respectively). Conclusions: The expansion of resistance mechanisms suggests sustained selective pressure, underscoring the need for strategies to optimize antibiotics. Full article

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB), as a critical-priority pathogen among extensively drug-resistant (XDR) bacteria, influences healthcare-associated infections in China. Sulbactam–durlobactam (SUL-DUR) is recommended as a first-line agent for managing CRAB infections by the 2024 Infectious Diseases Society of America (IDSA) guidelines, but the usage of SUL-DUR for CRAB bloodstream infections (BSIs) has never been described in China. Methods: The present study aims to report five critically ill ICU patients recently treated in our center with CRAB BSIs who were successfully treated with SUL-DUR. Relevant literature and current guidelines are being briefly reviewed to provide a novel and promising clinical paradigm for managing BSI caused by CRAB. Findings: Use of SUL-DUR marked a definitive turning point in all five patients’ clinical trajectories. Conclusions: Our real-world evidence confirms SUL-DUR’s efficacy as a first-line agent for confirmed CRAB BSI cases and the definitive salvage therapy agent, impels a re-evaluation of the current clinical therapeutic spectrum for CRAB infection. Full article

In the last three decades, 2-oxazolidinones have emerged as an important class of inhibitors of bacterial protein synthesis, effective in the treatment of multidrug-resistant (MDR) bacterial infections. From a public health perspective, the importance of 2-oxazolidinones is related to the treatment of tuberculosis (TB), primarily MDR-TB and extensively drug-resistant XDR-TB. Linezolid, the first oxazolidinone antibiotic approved by FDA, is still used in therapy despite common adverse events, such as myelosuppression and serotonergic toxicity, as well as the increasing percentage of linezolid-resistant bacteria (Staphylococcus aureus, enterococci and methicillin-resistant S. aureus). Tedizolid phosphate was the second commercially available oxazolidinone antibiotic approved, followed by other oxazolidinones (contezolid, radezolid, ranbezolid, sutezolid, delpazolid, cadazolid, TBI-233 and MK-7762) that are in clinical study. Contezolid is approved in China and cadazolid has entered phase III clinical trials. This comprehensive review intends to provide an overview of the compounds belonging to this class already in use in therapy and/or clinical studies and to portray the most significant and recent outcomes regarding new oxazolidinones under study. Three literature databases, i.e., PubMed/MEDLINE, Google Scholar and Scopus, were used for the literature search, particularly focusing on the last five years, and screened using different keywords. The design of new drugs belonging to this class may be of considerable interest to researchers and clinicians, contributing to the discovery of new antibiotics that retain antibacterial activity but have fewer side effects. Full article

Background: Infected pancreatic necrosis (IPN) is a serious complication of moderate-to-severe acute pancreatitis (AP), associated with high morbidity, intensive care unit (ICU) admission, organ failure, and mortality. Initial management relies on antibiotics and drainage of walled-off necrosis (WON). In the context of increasing multidrug-resistant (MDR) bacteria, identifying risk factors for MDR emergence is crucial. The impact of fungal infections (FIs) on outcomes also remains unclear. This study aimed to identify risk factors associated with the emergence of MDR bacteria and FIs during intervention for IPN. Methods: This retrospective study included 71 consecutive patients undergoing intervention for suspected IPN or symptomatic WON. Results: At first intervention, IPN was confirmed in 52 patients (73%), MDR bacteria in 19 (27%), extensively drug-resistant (XDR) bacteria in 4 (5.6%), and FI in 21 (30%). After all interventions, MDR/XDR bacteria and fungi were detected in 25 (35%)/11 (15.5%) and 42 (59%) patients, respectively. Independent risk factors for MDR emergence were the number of antibiotic changes (b, 1.70; 95% CI 1.18–2.43; p = 0.004) and need for nutritional support (NS) (b, 5.69; 95% CI 1.52–20.50; p = 0.010). No independent factor was associated with FI. The 180-day mortality did not differ across groups. The 90-day cumulative ICU admission rate was higher in IPN vs. non-IPN (63.1% vs. 29.4%, p = 0.030) and in MDR vs. non-MDR (72.2% vs. 37.1%, p = 0.005). Conclusions: Antibiotic changes and NS were independently associated with MDR emergence in IPN. No independent factors were linked to FI. ICU admission was significantly higher in IPN and MDR cases. Full article

In recent years, silver nanoparticles have emerged as potent antimicrobial agents capable of combating extensively drug-resistant pathogenic bacteria that pose serious health risks. The primary aim of our research was to explore the green synthesis of AgNPs using Candida glabrata as an antibacterial agent. A single clinical isolate of Candida glabrata was re-examined via traditional yeast identification methods. Biosynthesis of AgNPs was accomplished by incubating Candida glabrata cell-free supernatant with silver nitrate. AgNP formation was verified by UV-Vis spectroscopy, and the XRD technique assessed the physical properties of the lyophilized AgNPs. EDX and SEM provided insights into the AgNPs’ composition, shape, and size. The antibacterial efficacy was evaluated against pathogenic bacteria through the Agar Well Diffusion method. The formation of AgNPs was evidenced by a shift in color to dark brown. The formation of AgNPs at an absorbance wavelength of 430 nm revealed a polycrystalline structure with an average crystal size of 21.91 nm. The silver constituted 29.50% of the composition and indicated a spherical shape with sizes ranging from 74.96 to 100.40 nm. Significant antimicrobial activity was obtained against pathogenic bacteria. Hence, the proposed research highlights a single-step, cost-effective, and environmentally friendly AgNP synthesis approach that exhibits considerable antibacterial properties. Full article

Antimicrobial resistance in urinary tract infections (UTIs) poses a critical public health challenge, yet comparative data between outpatient and inpatient settings remain limited, particularly in Latin America. This study characterized the epidemiology, microbiology, and resistance patterns of UTIs in northwestern Mexico. A retrospective analysis of 1041 patients with UTI (May–November 2024) was conducted. Microorganism identification and antimicrobial susceptibility were determined using the MicroScan WalkAway system in accordance with CLSI guidelines. Results: Outpatients accounted for 80.5% of cases and inpatients for 19.4%, with a 3.1% mortality rate. Escherichia coli predominated (62.9%), with a significant association with outpatients (p = 0.02), whereas Enterobacter cloacae, Acinetobacter spp., Candida tropicalis, and C. albicans were associated with inpatients (p < 0.05). Pediatric patients exhibited distinctive microbiological profiles: Pseudomonas aeruginosa (9.7% vs. 2.1%, p = 0.032), Enterococcus faecalis (33.3% vs. 16.2%, p = 0.001), and Staphylococcus epidermidis (26.6% vs. 6.5%, p = 0.027) were significantly more prevalent than in adults. Multidrug resistance (MDR) was detected in 27.1% of isolates, and extensive drug resistance (XDR) in 3.2%. XDR was associated with Gram-positive bacteria (12.2% vs. 1.4%, p < 0.001). Carbapenem-resistant Enterobacteriaceae (CRE) were identified in 0.9% (7/772) of cases, with 42.9% occurring in outpatients. Hospitalization (OR: 2.01; 95% CI: 1.43–2.83), surgical services (OR: 1.41; 95% CI: 1.02–1.97), and recent surgery (OR: 2.37; 95% CI: 1.04–5.39) were independent predictors of MDR/XDR infections. Conclusions: These findings demonstrate the emergence of CRE within the community and distinctive pediatric resistance patterns, underscoring the need for tailored antimicrobial stewardship strategies in this region. Full article

Extensively drug-resistant (XDR) bacteria pose a serious global public health threat due to their high levels of resistance to multiple classes of antibiotics. This study aimed to characterize bacterial isolates obtained from clinical samples, evaluate their antibiotic resistance patterns, and investigate the antimicrobial and anticancer potential of essential oils (EOs) and their nanoemulsions (NEs). A total of 175 bacterial isolates were collected from various clinical sources, identified, and subjected to antibiotic susceptibility testing using both conventional methods and the VITEK^® 2 system. Among these, nine isolates were identified as extensively drug-resistant. Among the tested EOs, carvacrol exhibited the strongest antibacterial activity, with minimum inhibitory concentrations (MICs) ranging from 14 to 35 µg/mL, compared to 8 to 19 µg/mL for meropenem. To enhance its stability and efficacy, carvacrol nanoemulsions (CANE) were prepared via ultrasonication and characterized using zeta potential measurements, which indicated a positive surface charge of +14.2 mV, while dynamic light scattering (DLS) analysis revealed a narrow size distribution with a mean hydrodynamic diameter of 411.3 nm. High-resolution transmission electron microscopy (HR-TEM) showed spherical droplets ranging from 18 to 144 nm in size, with an average diameter of 69 ± 28 nm. The nanoemulsion formulation significantly enhanced antibacterial activity, with MICs reduced to 11 ± 0.0–23 ± 0.21 µg/mL, compared to 14 ± 0.13–35 ± 0.11 µg/mL for pure carvacrol oil. Gas chromatography–mass spectrometry (GC–MS) analysis identified major active constituents, including thymol, methoxyphenyl, estragole, and D-limonene, which are likely contributors to the observed antimicrobial and anticancer effects. In addition, carvacrol nanoemulsions demonstrated potent cytotoxicity against multiple human cancer cell lines (HepG2, MCF-7, PC-3, and Caco-2) while showing minimal toxicity toward normal cells. Confocal microscopy further confirmed apoptosis induction in treated cancer cells, suggesting a mitochondria-mediated apoptotic pathway. In conclusion, this study highlights the strong therapeutic potential of essential oils—particularly carvacrol and its nanoemulsion formulation—as dual-action agents exhibiting broad-spectrum antibacterial activity against XDR pathogens and selective cytotoxicity against cancer cells. Full article

Background/Objectives: Colistin (polymyxin E) has re-emerged as a last-hope treatment against MDR Gram-negative pathogens due to the development of extensively drug-resistant Gram-negative bacteria. Unfortunately, rapid global resistance towards colistin has emerged, which represents a major public health concern. In this context (CBD), a lipophilic molecule derived from Cannabis sativa, exhibits antimicrobial activity mainly against Gram-positive bacteria but is generally ineffective against Gram-negative species. However, synergistic antibacterial activity between CBD and polymyxin B has been reported. The objective of this work is to analyze the colistin–CBD synergy against clinically relevant Gram-negative isolates displaying diverse mechanisms of colistin resistance and to explore the basis of the possible mechanism of action involved in the first steps of this synergy. Methods: Microbiological assays, minimal inhibitory concentration, cell culture, synergy tests by checker board and time kill, biofilm inhibition evaluation by crystal violet and MTT, SEM (scanning electron microscopy), molecules interaction analysis by nuclear magnetic resonance (NMR). Results: The colistin–CBD combination displayed synergy in colistin resistant Gram-negative bacteria and also disrupted preformed biofilms and killed bacteria within them. Time-kill assays revealed rapid bactericidal activity and SEM showed mild surface alterations on bacterial outer membranes after sublethal colistin monotherapy. Furthermore, a series of sequential treatment assays on colistin-resistant Escherichia coli showed that simultaneous exposure to both compounds was required for activity, as introducing a washing step between treatments abolished the antibacterial effect. In order to obtain deeper insight into this mechanism, NMR analyses were performed, revealing specific molecular interactions between CBD and colistin molecules. Conclusions: These results provide evidence for the first time that both molecules engage through a specific and structurally meaningful interaction and only display synergy when acting together on colistin-resistant bacteria. Full article

Background: Carbapenem-resistant Enterobacterales and difficult-to-treat resistance (DTR) Pseudomonas aeruginosa are a growing public health issue. Cefiderocol demonstrated activity against β-lactamase-producing Gram-negative bacteria (GNB). However, bone PharmacoKinetics (PK) data is lacking. Here, we report a case of post-traumatic chronic osteomyelitis caused by extensively drug-resistant (XDR) Pseudomonas aeruginosa which was successfully treated with cefiderocol. Moreover, we conducted a non-systematic review of the available literature. Case Report: We described the case of a 64-year-old man who was admitted to a traumatology ward after a work accident caused crushing of his left foot. Microbiological tests on intraoperative biopsies demonstrated XDR P. aeruginosa and K. oxytoca. Despite the administrations of different antibiotics regimens and multiple surgical revisions, the patient developed chronic osteomyelitis. To prevent amputation, cefiderocol was prescribed for six weeks, resulting in a complete clinical resolution of osteomyelitis. Review of the Literature: We performed a non-systematic review of the literature searching the public databases PubMed and Google Scholar. We identified nine case reports. In most patients (60%) the cause of osteomyelitis was post-surgical, and all the reported cases were healthcare associated. Osteomyelitis treatment required both antimicrobial therapy and surgery in all the cases described. Cefiderocol was often prescribed in association with other antibiotics (70%). Clinical cure was described in all the reported cases. Conclusions: This study highlights that cefiderocol is safe and efficacious to treat osteomyelitis caused by carbapenem-resistant GNB. However, evidence is limited to a few case reports. Full article

Antibiotics have revolutionized medicine and animal production, yet their extensive use has accelerated the emergence and spread of antimicrobial resistance (AMR). Beyond clinical contexts, livestock and aquaculture are now recognized as major contributors to the global resistome. This review synthesizes evidence across cattle, poultry, swine, sheep and goats, and aquaculture, highlighting how antimicrobial usage shapes resistance at the human–animal–environment interface. A substantial proportion of administered drugs is excreted unmetabolized, leading to the accumulation of unmetabolized antimicrobial residues, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs) in soils, manures, waters, sediments, and air. These reservoirs function as long-term sources and dissemination pathways through runoff, leaching, bioaerosols, effluents, and biological vectors. Despite different production systems, similar ARG families dominate, particularly those conferring resistance to tetracyclines, sulfonamides, and β-lactams. Mobile genetic elements and co-selectors such as heavy metals, disinfectants, and microplastics reinforce their persistence. Aquaculture, where water serves both as habitat and vector, emerges as a critical hotspot, while small ruminant systems remain under-researched despite their importance in many low- and middle-income countries. This synthesis highlights convergent patterns across sectors: antimicrobial use drives ARG enrichment; manures, litters, sediments, and effluents act as persistent reservoirs; and dissemination routes connect farms, ecosystems, and human populations. Within a One Health framework, mitigation requires preventive strategies—vaccination, biosecurity, and optimized waste management—supported by harmonized stewardship policies and integrated environmental surveillance. Full article

Introduction: Carbapenem-resistant Gram-negative bacteria (CR-GNB) are rapidly spreading pathogens that increase morbidity and mortality in hospital settings and significantly restrict available treatment options worldwide. The lack of molecular epidemiological data and the limited use of next-generation sequencing (NGS) in South Lebanon have hindered comprehensive surveillance efforts. This study represents the first molecular characterization of CR-GNB in this region. Methods: A total of 477 clinical Gram-negative bacterial isolates were collected from intensive care unit (ICU) patients admitted to various hospitals in South Lebanon in 2023. Of these, 131 CR-GNB were subjected to whole-genome sequencing using the Illumina MiSeq platform. K-mer-based species identification, multilocus sequence typing (MLST), antimicrobial resistance (AMR) gene profiling, and plasmid analysis were performed using multiple bioinformatic tools. Phylogenetic analysis was conducted using SaffronTree. Results: K-mer-based identification revealed that the predominant species among CR-GNB isolates were Pseudomonas spp. and Escherichia coli (26.7% each), followed by Klebsiella pneumoniae (19.8%), Acinetobacter baumannii (17.6%), Proteus mirabilis (4.6%), Enterobacter cloacae (2.3%), Achromobacter spp. (1.5%), and Citrobacter freundii (0.8%). Based on antimicrobial susceptibility testing, isolates were classified as follows: 0.8% as pan drug-resistant (PDR), 40.5% as extensively drug-resistant (XDR), and 52.7% as multidrug-resistant (MDR) and 6.1% as antimicrobial-resistant (AMR). All isolates harbored AMR genes, with the following distribution: 2% bla_VIM, 5% bla_NDM-1, 27% bla_NDM-5, 65% bla_OXA-type, and 1% bla_DIM-1. Plasmid-associated AMR genes were detected in 58% of isolates; among these, 96% carried Inc-family plasmids, 57% Col plasmids, and 11% replication-associated elements (rep). Phylogenetic analysis demonstrated that certain isolates exhibited both hospital-specific and shared genetic profiles, indicating widespread dissemination across multiple healthcare facilities, as well as evidence of local emergence and ongoing transmission. Conclusions: The high prevalence of CR-GNB harboring resistance genes and plasmids underscores the urgent need for NGS-based genomic surveillance in South Lebanon. Implementing such strategies is essential for tracking resistance genes, identifying clonal outbreaks, and guiding effective infection control interventions to mitigate the spread of CR-GNB. Full article