Search Results (151)

Introduction: Urinary tract infections (UTIs) caused by carbapenem-resistant pathogens are increasingly common and pose serious treatment challenges due to limited antibiotic options and high complication rates. Identifying patients at risk is essential for guiding empirical therapy and improving outcomes. The primary objective of this study was to identify risk factors associated with carbapenem-resistant (CR) UTIs by comparing them with carbapenem-susceptible (CS) UTIs. Secondary objectives included analyzing the types of microorganisms involved in both groups, their antibiotic susceptibility profiles, and the presence of carbapenemase enzymes among CR UTI cases. Method: We conducted a retrospective case-control study involving 127 hospitalized patients with UTIs caused by CR microorganisms and 91 patients with UTIs caused by multidrug-resistant (MDR) strains that retain susceptibility to carbapenems, admitted between 1 October 2023, and 31 March 2025. Results: In univariate analysis, CR UTI patients had significantly higher rates of neoplasia, neurological disorders, urosepsis at admission, septic shock, the presence of urinary catheters at diagnosis, permanent nephrostomy catheters, hospitalizations within the past 180 days, previous antibiotic exposure including carbapenems, and recent urological procedures. Multivariate analysis revealed four independent risk factors for CR UTIs: neoplasia (OR = 2.152; 95% CI: 1.044–4.436; p = 0.038), neurological disorders (OR = 7.427; 95% CI: 2.804–19.674; p < 0.0001), antibiotic use in the previous 180 days (OR = 2.792; 95% CI: 1.487–5.396; p = 0.001), and prior carbapenem treatment OR = 10.313; 95% CI: 1.277–83.248; p = 0.029). Most of the isolated organisms belonged to the Enterobacterales genus, with Klebsiella spp. and Pseudomonas aeruginosa being the most common pathogens in CR UTIs, accounting for over 90% of cases. Among patients tested for carbapenemase production, all but one tested positive for at least one carbapenemase. Conclusions: Neoplasia, neurological disorders, recent antibiotic therapy, and prior carbapenem use were significantly associated with increased risk of developing CR UTIs. Klebsiella spp. and Pseudomonas aeruginosa were the predominant causative organisms, with New Delhi metallo-β-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) being the most frequently identified resistance mechanisms. Full article

Micro-organisms are abundant in nature and can also be found in hospital settings, causing high rates of infections. This study aimed to identify bacteria isolated from a veterinary hospital, as well as to perform antimicrobial susceptibility testing using the disk diffusion method (Kirby–Bauer), biofilm production tests using 96-well polystyrene microtiter plates and crystal violet dye, and genetic analysis of the ica operon of Staphylococcus isolates. Three collections were made from eleven surfaces and objects in the hospital’s non-critical areas (general areas) and critical areas (surgical center), totaling thirty-three samples. A total of 66 different bacterial isolates were obtained, with 77% (51/66) Gram-positive and 23% (29/66) Gram-negative. Resistance profiles were found for multidrug-resistance (MDR), methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), and other unidentified species of methicillin-resistant coagulase-negative (MRCNS) and extended-spectrum beta-lactamase (ESBL), as well as biofilm production rates of 57% (38/66) of the isolates. Analysis of the operon genes for Staphylococcus sp. showed divergence in some samples when compared to the phenotypic test performed. In summary, there is a high presence of micro-organisms with resistance and virulence factors spread throughout the various areas of the veterinary hospital. Full article

Background/Objectives. Multi-drug-resistant (MDR) microorganisms pose a significant challenge in healthcare settings, particularly with beta-lactam-resistant Gram-negative bacteria and glycopeptide-resistant enterococci. Culture represents the most reliable technique in determining their presence within surveillance swabs. However, it requires a long time-to-result (TTR) and shows low sensitivity. Molecular techniques integrate diagnostic procedures, allowing TTR reduction and precise identification of genes. Methods. During our usual surveillance campaign, we had the opportunity to evaluate the Allplex Entero-DR assay (Seegene Inc., Seoul, Republic of Korea) and the Entero-DR Plus assay (Arrow Diagnostics srl, Genova, Italy) molecular kits for the detection of extended-β-lactamases (ESBL), carbapenem- and vancomycin-resistant genes, as well as Acinetobacter spp. and Pseudomonas aeruginosa spp. identification directly from rectal swabs. A comparison between these tests and the culture-based routine completed the study. Results. The analysis included 300 rectal swabs from the University Hospital Policlinico (Catania, Italy). One hundred and eighty-eight samples (62.6%) resulted as positive for at least one Allplex™ target, reaching optimal sensitivity and negative predictive value (100%). Our results underlined the ubiquitous blaCTX-M and van genes presence and demonstrated the diffusion of double-carbapenemases genes and metallo-β-lactamases-producing strains. In our epidemiological setting, few data were collected about carbapenem-resistant P. aeruginosa and Acinetobacter spp., which require further evaluations on simultaneous respiratory colonization and higher sample numbers. Conclusions. Our analysis highlighted the importance of combining conventional and advanced diagnostic methods in investigating MDR pathogens. The right approach should be based on the prevalence and variability of resistance mechanisms within a specific epidemiological area. Remarkably, molecular screenings may exclude negative samples within high-risk areas due to a significant negative predictive value. Full article

Extremophilic microorganisms offer an untapped potential for producing unique bioactive metabolites with therapeutic applications. In the current study, bacterial isolates were obtained from samples collected from Chamalang cave located in Kohlu District, Balochistan, Pakistan. The cave-derived isolate C1 (Rhodococcus jialingiae) exhibits prominent antibacterial activity against multidrug-resistant pathogens (MDR), including Escherichia coli, Staphylococcus aureus, and Micrococcus luteus. It also demonstrates substantial antioxidant activity, with 71% and 58.39% DPPH radical scavenging. Optimization of physicochemical conditions, such as media, pH, temperature, and nitrogen and carbon sources and concentrations substantially enhanced both biomass and metabolite yields. Optimal conditions comprise specialized media, a pH of 7, a temperature of 30 °C, peptone (1.0 g/L) as the nitrogen source, and glucose (0.5 g/L) as the carbon source. HPLC and QTOF-MS analyses uncovered numerous metabolites, including a phenolic compound, 2-[(E)-3-hydroxy-3-(4-methoxyphenyl) prop-2-enoyl]-4-methoxyphenolate, Streptolactam C, Puromycin, and a putative aromatic polyketide highlighting the C1 isolate chemical. Remarkably, one compound (C₁₄H₃₆N₇) demonstrated a special molecular profile, signifying structural novelty and warranting further characterization by techniques such as ¹H and ¹³C NMR. These findings highlight the biotechnological capacity of the C1 isolate as a source of novel antimicrobials and antioxidants, linking environmental adaptation to metabolic potential and supporting natural product discovery pipelines against antibiotic resistance. Full article

Objectives: Cefideroccol (FDC) is a siderophore cephalosporin with potent antibacterial activity against a wide range of Gram-negative multidrug-resistant (MDR) microorganisms. We investigated the anti-biofilm capacity of FDC against clinical strains. Methods: This multicenter study was conducted on 28 selected strains of MDR Gram-negative bacilli isolated from clinical samples of Pseudomonas aeruginosa (n = 5), Acinetobacter baumannii (n = 11), and Klebsiella pneumoniae (n = 12). We first determined the minimum inhibitory concentration (MIC) of each strain using the microdilution method. We also defined the minimum biofilm inhibitory concentration (MBIC) as a ≥50% reduction in tetrazolium salt (XTT) (as recommended in the 2017 Spanish Microbiology Protocols [SEIMC] for the microbiological diagnosis of infections related to the formation of biofilms). We also analyzed the reduction in the following biofilm variables after an 8 mg/mL FDC treatment: the CFU count, the cell viability, the biomass, the metabolic activity, and extracellular α or β polysaccharides. Results: The MIC₅₀ and MBIC₅₀ of FDC were 0.5 mg/L and 64 mg/L, respectively. We observed a mean (SD) fold increase in the susceptibility to FDC between planktonic and sessile cells for P. aeruginosa, A. baumannii, and K. pneumoniae of 9.60 (0.55), 6.27 (2.28), and 6.25 (2.80), respectively. When 8 mg/mL of FDC was tested, we observed that the best median (IQR) percentage reductions were obtained for cell viability and the extracellular matrix (73.1 [12.4–86.5] and 79.5 [37.3–95.5], respectively), particularly for P. aeruginosa. The lowest percentage reduction rates were those obtained for biomass. Conclusions: We demonstrated that the susceptibility to FDC was significantly reduced when strains were in a biofilm state. The best percentage reduction rates for all biofilm-defining variables were observed for P. aeruginosa. Our results need to be validated using a larger collection of clinical samples. Full article

Objectives: The global rise in multidrug resistance underscores the urgent need for the development of novel and effective antimicrobial agents. Semi-organic iodine-containing complexes, owing to their unique properties, low likelihood of resistance development, and stability under various conditions, represent a promising avenue for the design of new therapeutic strategies. This study describes the synthesis of semi-organic iodine-containing complexes and the in vitro evaluation of their impact on antibiotic susceptibility modulation in the multidrug-resistant pathogenic microorganisms S. aureus and E. coli. Methods: The physicochemical properties of the semiorganic compounds were characterized using UV-Vis spectroscopy, potentiometric, and titrimetric methods. Evaluation of antimicrobial activity was obtained according to CLSI protocols. The impact of semiorganic compounds on the in vitro susceptibility of MDR strains was evaluated by the disk diffusion method. Results: This study evaluated the effects of iodine-containing complexes KC-270 and KC-271 on the antibiotic susceptibility of Staphylococcus aureus BAA-39 and Escherichia coli BAA-196. The most pronounced effect was observed with KC-270 applied during the lag phase, which enhanced the activity of several antibiotics and, in some cases, restored susceptibility. KC-271 exhibited a weaker and more limited impact. The findings suggest that KC-270 has potential as a modulator of antibiotic susceptibility, particularly when administered at early stages of bacterial growth. Conclusions: The results support the ability of amino acid-based iodine coordination compounds to influence the antibiotic susceptibility of pathogenic bacteria, highlighting their potential as adjuvant agents to improve the effectiveness of current antimicrobial therapies. However, although changes in susceptibility were detected, neither compound fully eliminated resistance in the multidrug-resistant strains, indicating the necessity for further research into their mechanisms of action and possible synergistic interactions with antibiotics. Full article

Staphylococcus saprophyticus (S. saprophyticus) is an opportunistic coagulase-negative staphylococcus (CoNS) known to cause urinary tract infections in humans and is increasingly recognized in veterinary medicine. The aim of this study was to provide an epidemiological characterization of S. saprophyticus strains and to identify potential virulence factors that may contribute to interspecies transmission. This research is particularly important, as companion animals represent an understudied reservoir of this microorganism, and their role in the spread of resistant pathogens remains insufficiently understood. A total of 61 S. saprophyticus strains isolated from humans, dogs, and cats were analyzed. Identification was performed using MALDI-TOF MS and confirmed by PCR targeting the hrcA gene. Antimicrobial susceptibility was assessed using the disk diffusion and broth microdilution methods, while resistance genes were detected by PCR. The blaZ and mecA genes were present in all strains; additionally, the majority harbored the resistance genes ermA, ermB, tetM, and tetK. Multidrug resistance (MDR) was identified in 21/61 strains (34.4%). Biofilm-forming capacity was temperature-dependent, with the strongest biofilm production observed at 37 °C (70.5%). At 38 °C and 39 °C, the proportion of strong biofilm producers decreased to 50.8% and 52.5%, respectively. All tested strains demonstrated pathogenic potential in the Galleria mellonella larvae infection model, with the highest mortality recorded for selected feline and canine strains. These findings indicate that S. saprophyticus strains from both humans and companion animals possess notable virulence and multidrug resistance. The detection of genotypically and phenotypically resistant strains in animals highlights their potential role as reservoir for zoonotic transmission. Full article

The emergence of multidrug-resistant (MDR) bacteria and biofilm-associated infections has created a significant hurdle for conventional antibiotics, prompting the exploration of alternative strategies. Photodynamic therapy (PDT), a technique that utilizes photosensitizers activated by light to produce ROS, has emerged as a beacon of hope in the fight against MDR microorganisms. Among the natural photosensitizers, hypocrellins (A and B) have shown remarkable potential with their dual-mode photodynamic action, generating ROS via both Type I (electron transfer) and Type II (singlet oxygen) pathways. This unique action disrupts bacterial biofilms and inactivates MDR pathogens. The amphiphilic nature of hypocrellins further enhances their promise, enabling deep biofilm penetration and ensuring potent antibacterial effects even in hypoxic environments, surpassing the capabilities of synthetic photosensitizers. This study critically examines the antimicrobial properties of hypocrellin-based PDT, emphasizing its mechanisms, advantages over traditional antibiotics, and effectiveness against MDR pathogens. Comparative analysis with other photosensitizers, the role of nanotechnology-enhanced delivery systems, and future clinical applications are explored. Its combination with nanotechnology enhances therapeutic outcomes, providing a viable alternative to conventional antibiotics. Further clinical research is essential to optimize its application and integration into antimicrobial treatment protocols. Full article

Ventilator-associated pneumonia (VAP) develops in patients who stay on mechanical ventilation for more than 48 h. In the presence of causative pathogens, the patient develops clinical signs such as purulent tracheal discharge, fever, and respiratory distress. A prospective observational study was carried out in the Intensive Care Unit (ICU) of Max Healthcare Centre, New Delhi, from 2020 to 2023. The study comprised 70 samples from patients diagnosed with VAP. This study thoroughly examined VAP-associated microorganisms and resistance in the hospital ICU. Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa were the most commonly reported pathogens. Significant drug resistance was seen in P. aeruginosa, K. pneumoniae, A. baumannii and Staphylococcus aureus. The heatmap also supported the antibiotic resistance data patterns obtained from conventional and automated systems of determination. Notably, Serratia marcescens, Escherichia coli, Klebsiella pneumoniae, Ralstonia insidiosa, and Ralstonia mannitolilytica, showed 60 to 100% of resistance to a number of antibiotics. Among all VAP patients, 31.42% early-onset and 68.57% late-onset VAP cases were detected. Out of 70 patients, 43 patients died (mortality rate 61.4%); majority of them suffered from late-onset VAP. The study goal was to describe the antibiotic resistance patterns and microbial ecology of the pathogens that were isolated from VAP patients. According to the heatmap analysis, a varied VAP microbiome with high prevalences of MDR in A. baumannii, P. aeruginosa, K. pneumoniae, and S. aureus was identified. To address the increasing prevalence of MDR VAP, the study highlights the critical need for improved VAP monitoring, strong infection control, and appropriate antibiotic usage. Full article

The rapid emergence of multidrug-resistant (MDR) bacterial pathogens poses a critical threat to global health, creating an urgent need for novel antimicrobial agents. In this study, we evaluated a small library of natural and semisynthetic phytocannabinoids against a broad panel of MDR Gram-positive bacterial strains, evidencing very good activity in the low µM range. We provide evidence of the antibacterial activity of the two separated enantiomers of cannabidiol, offering novel insights into the stereochemical aspects of their bioactivity. To investigate the possible molecular targets and clarify the mechanism of action, we employed Inverse Virtual Screening (IVS), a computational approach optimized for predicting potential protein–ligand interactions, on three selected MDR bacterial species. Interestingly, key targets belonging to important bacterial metabolic pathways and defense mechanisms were retrieved, and the results were used to rationalize the observed biological activities. To the best of our knowledge, this study marks the first application of IVS to microorganisms, offering a novel strategy for identifying bacterial protein targets. The results pave the way for future experimental validation, structure-based drug design, and the development of novel antibacterial agents. Full article

Objectives: Fosfomycin is an old antibiotic that has recently gained attention owing to its preserved activity against multidrug-resistant (MDR) bacteria. Data on its use in real life are limited. Thus, we evaluated the efficacy and safety of fosfomycin disodium in the context of our hospital clinical practice. Methods: Single-center, retrospective, observational study on 56 patients who received fosfomycin disodium from September 2016 to July 2023, focusing on clinical and microbiological outcomes and adverse events. Results: Included in this study were 56 patients. Fosfomycin disodium was administered for a median duration of 10 days [5–13.5] and was always used in combination with other antibiotics, more frequently with meropenem (16 cases, 28.6%) and colistin (11 cases, 19.6%). It was mostly used for treating pneumonia (41%), followed by bloodstream infections (19.6%), urinary tract infections (16.1%), bone infections (16.1%), and surgical site infections (7.1%). The most common isolated pathogen was Pseudomonas aeruginosa (17%), and polymicrobial infections were detected in 18 patients (32%). Among the isolated bacteria, 36 (44.4%) were MDR. The complete resolution, defined as the disappearance of symptoms, eradication of the causative microorganism, and decrease in CRP levels, was achieved in 39% of cases. During treatment, we observed electrolyte imbalances, in particular a decrease in serum potassium (0.6 mEq/L [0.3–1.1]), calcium (0.7 mEq/L [0.3–1.1]) and magnesium levels (0.3 mg/dL [0.20–0.48]), and an increase in serum sodium levels (4 mEq/dL [2–7]). Changes in potassium and sodium levels were more pronounced in patients with prior kidney dysfunction and heart failure, respectively, and in patients receiving fosfomycin diluted with saline compared with 5% glucose solution (p = 0.04). Conclusions: Fosfomycin is effective in treating complicated infections in comorbid patients when combined with other antimicrobials. During treatment, major electrolyte imbalances occur that require careful monitoring and correction, especially in patients with prior kidney disease. Full article

The objective of this study was to determine the epidemiological, clinical, and laboratory characteristics of newborns with sepsis in northwestern Mexico, identify the microorganisms causing early- and late-onset sepsis, and assess antimicrobial resistance. Additionally, it sought to associate neonatal characteristics with antimicrobial resistance or mortality. A retrospective study was conducted from August 2021 to April 2023, during which 8382 neonatal clinical records were analyzed to collect epidemiological, clinical, and laboratory characteristics, as well as microorganisms isolated from neonates and their antimicrobial resistance profiles. Of these, 314 neonates with sepsis were included. The incidence of neonatal sepsis was 4% (314/8382), and the mortality was 12.7% (40/314); late-onset sepsis (65.3%) was more frequent than early-onset sepsis (34.7%). Staphylococcus epidermidis was the most frequently isolated bacterium in neonates with sepsis (both early- and late-onset). Gram-positive bacteria, such as Staphylococcus hominis and Enterococcus faecium, were associated with early-onset sepsis, whereas fungi, particularly Candida albicans, were associated with late-onset sepsis. Of the microorganisms, 52.6% were multidrug resistant (MDR), 10.8% were extensively drug resistant (XDR), and 5.5% were pan-drug resistant (PDR). Low birth weight, prematurity, cesarean section, mechanical ventilation, tachycardia, and low hemoglobin and platelet levels, among others, were associated with XDR or MDR microorganisms. In contrast, low birth weight, mechanical ventilation, stroke, unexpected delivery, respiratory distress, tachycardia, convulsive crisis, high procalcitonin, urea, and AST/TGO levels, among others, were associated with mortality. The incidence, types of sepsis, antimicrobial resistance, and associations identified in this study will aid in diagnosing neonatal sepsis earlier and may reduce mortality in our region. Full article

This study examines temporal patterns in pathogens isolated from prosthetic joint infection (PJI) cases and antimicrobial resistance patterns at a Romanian orthopedic center. We have conducted a retrospective cohort study that included 674 patients undergoing hip or knee replacement revision surgery between January 2016 and December 2023. From these, 102 confirmed PJI cases requiring surgical intervention were selected for analysis. We isolated 27 microorganisms from acute PJI cultures and 82 from chronic PJIs. Staphylococcus epidermidis (33 cases, 30.3%; 95% CI 22.0–40.3) was the predominant pathogen, with coagulase-negative Staphylococci (22 cases, 20.18%; 95% CI 0.9–41.3) and Enterobacteriaceae (13 cases, 11.9%; 95% CI 6.4–18.3) also prevalent. Methicillin resistance was identified in 43.6% of coagulase-negative staphylococci and 45.5% of Staphylococcus aureus isolates. All Gram-positive isolates remained susceptible to vancomycin, linezolid, and tigecycline. Among Gram-negative bacilli, Klebsiella oxytoca and Proteus mirabilis showed resistance to third-generation cephalosporins, with phenotypic profiles suggestive of extended-spectrum β-lactamase (ESBL) production. All Escherichia coli, Enterobacter spp., and Citrobacter freundii strains were fully susceptible to tested agents, while Pseudomonas aeruginosa exhibited reduced susceptibility to ciprofloxacin, aztreonam, and imipenem. Among the isolated strains, 47 were multidrug-resistant (MDR), with Staphylococcus aureus accounting for the highest MDR count, including methicillin resistance. The distribution of microorganism types and MDR strains remained consistent throughout the study period, with no significant association between infection type and MDR strain presence or between infection site and microorganism presence except for a strong association between MDR strains and the type of microorganism (p < 0.05). The microbial profile and resistance patterns in PJIs have remained stable over eight years. Our observations do not suggest that MDR PJIs are more commonly acute cases, contrary to what has been highlighted in previous reports. The ongoing prevalence of MDR strains underscores the importance of targeted antimicrobial treatments based on local susceptibility profiles. Full article

Currently, multidrug-resistant (MDR) bacteria are a global problem, which requires modern approaches and effective pharmaceutical agents. Substances isolated from nature sources have a strong potential in combating highly virulent and antibiotic-resistant microorganisms, including within the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). One of these substances is mangiferin, the bioactive compound obtained from parts of Mangiferin indica L. Mangiferin has a low aqueous solubility, which causes low activity and requires additional modification or delivery system to increase its concentration in the cell. Many studies show that it has multiple biological effects and can be used as an antioxidant or an anticancer agent, and it can exhibit antibacterial properties. Extracts obtained from plant parts show high efficacy in low doses against the ESKAPE group and other strains. This makes mangiferin a possible candidate as a strong agent against bacterial infections. The mechanisms underlying the action of mangiferin on bacterial cells are poorly understood. This review summarizes studies confirming the antibacterial properties of mangiferin both in its native form and using delivery systems. Full article

One of the most urgent threats to public health worldwide is the ongoing rise of multidrug-resistant (MDR) bacterial strains. Among the most critical pathogens are MDR-Klebsiella pneumoniae strains. The lack of new antibiotics has led to an increased need for non-antibiotic antimicrobial therapies. Photodynamic therapy (PDT) has become increasingly significant in treating MDR bacteria. PDT uses photosensitizer compounds (PS) that generate reactive oxygen species (ROS) when activated by light. These ROS produce localized oxidative stress, damaging the bacterial envelope. A downside of PDT is the limited bioavailability of PSs in vivo, which can be enhanced by conjugating them with carriers like nanoparticles (NPs). Zinc nanoparticles possess antibacterial properties, decreasing the adherence and viability of microorganisms on surfaces. The additive or synergistic effect of the combined NP-PS could improve phototherapeutic action. Therefore, this study evaluated the effectiveness of the copper(I)-based PS CuC1 compound in combination with Zinc Oxide NP, ZnONP, to inhibit the growth of both MDR and sensitive K. pneumoniae strains. The reduction in bacterial viability after exposure to a PS/NP mixture activated by 61.2 J/cm² of blue light photodynamic treatment was assessed. The optimal PS/NP ratio was determined at 2 µg/mL of CuC1 combined with 64 µg/mL of ZnONP as the minimum effective concentration (MEC). The bacterial gene response aligned with a mechanism of photooxidative stress induced by the treatment, which damages the bacterial cell envelope. Additionally, we found that the PS/NP mixture is not harmful to mammalian cells, such as Hep-G2 and HEK-293. In conclusion, the CuC1/ZnONP combination could effectively aid in enhancing the antimicrobial treatment of infections caused by MDR bacteria. Full article