Search Results (723)

Background: Antimicrobial resistance coupled with the lack of new antibiotics calls for the responsible use of antibiotics, including old antimicrobials. Aminoglycosides are effective against bacteria in acute appendicitis, a common intra-abdominal infection. Their use has been discouraged recently, but their place in therapy is based on studies performed in the era of lower resistance rates, and with multiple dosing regimens. Methods: In a prospective randomized open-label study, we compared the efficacy and safety of gentamicin in one daily dose and metronidazole (GTM+MZ) to ertapenem (ETP) and to cefuroxime with metronidazole (CXM+MZ) in adult patients surgically treated for acute appendicitis. Efficacy was assessed via the duration of antibiotic treatment and hospital stay, c-reactive protein (CRP) dynamics, and post-operative complications. Nephrotoxicity was assessed with urine biomarkers. Statistical analysis comprised mixed-model analysis of variance (ANOVA) with the missing-data-imputation method and linear mixed model (LMM). Results: One hundred-and-sixty-six patients were included in this study. There were no significant differences among the three groups in the durations of treatment and lengths of stay (p = 0.093, p = 0.222). CRP level was the lowest (p = 0.003) in the ETP group. There were five complications during hospitalization, with two of them classified as infectious. Both occurred in the GTM+MZ group; however, the difference was not statistically significant (p = 0.330). No difference was found in complications in the month following the operation (p = 0.763). Biomarkers indicating kidney injury showed the same trend in all three groups. Conclusions: Our results suggest the use of once-daily dose of gentamicin following an appendectomy for acute appendicitis. Gentamicin may be used to decrease selective pressure of other antimicrobials. Full article

Objectives: Acute peritonitis remains a critical condition with high mortality rates, further complicated by the rising antibiotic resistance. This study aimed to investigate the therapeutic potential of Chlorella vulgaris (CHL), both alone and in combination with standard antibiotic therapy (SFT), in a rat model of cecal ligation and puncture (CLP)-induced peritonitis. Methods: Seventy (70) male Wistar albino rats were divided into seven groups (n = 10): Control, Peritonitis Control, Low-dose CHL (CHL I) (150 mg/kg), High-dose CHL (CHL II) (300 mg/kg), the standard first-line therapy group (SFT) (Ceftriaxone + Metronidazole), SFT + CHL I, and SFT + CHL II. Following CLP-induced peritonitis, treatments were administered for 7 days. Peritoneal tissues were evaluated histopathologically and immunohistochemically for TNF-α, IL-1β, IL-10, and iNOS expression. Total Antioxidant Status (TAS) and Total Oxidant Stress (TOS) were measured to assess the oxidative stress. Results: Histopathological analysis showed that CLP-induced severe inflammatory damage was significantly reduced in all treatment groups, with the most prominent recovery observed in the SFT + CHL II group. CHL treatment led to a significant decrease in pro-inflammatory markers (TNF-α, IL-1β, iNOS) compared to the peritonitis control group (PC) (p < 0.05). Furthermore, CHL administration significantly improved the oxidative balance by increasing TAS and reducing TOS levels. Conclusions: Chlorella vulgaris exhibits significant anti-inflammatory, antioxidant, and immunomodulatory properties in experimental peritonitis. When used as an adjunct to standard antibiotic therapy, high-dose CHL provides synergistic effects that contribute to limiting tissue damage and controlling systemic inflammation. These findings suggest that CHL may be a promising supportive agent in the clinical management of acute peritonitis. Full article

Background/Objectives: To prevent surgical site infections, it is important to consider the concentration of the administered antibiotic in the target compartment. We measured the concentrations of cefuroxime and metronidazole in peritoneal fluid with the microdialysis technique in patients undergoing surgery for secondary peritonitis (7 patients) and for inflammatory bowel disease (11 patients). Methods: All patients received 1.5 g of cefuroxime and 0.5 g of metronidazole every 8 h during the postoperative period for at least 72 h. Microdialysates covering 8-h intervals were collected, and the concentration of cefuroxime and metronidazole was measured using liquid chromatography–mass spectrometry. Results: For metronidazole, a concentration of ≥4 μg/mL was reached in all but one sample, corresponding to the minimal inhibitory concentration (MIC) for most anaerobic bacteria strains. For cefuroxime, a value of ≥4 μg/mL was reached in 88% and 93% of the samples in the peritonitis group and the IBD group, respectively, corresponding to the MIC values for most Gram-negative bacteria, and a value of ≥16 μg/mL, corresponding to the MIC value for more resistant bacteria, was reached in only 40% and 23% of the samples, respectively. Conclusions: Our results show that the peritoneal microdialysis method is feasible for studying the diffusion of antibiotics into the peritoneal cavity. Measuring the accumulative concentration of antibiotics in the peritoneal fluid corresponding to the drug administration interval may provide important information to consider alongside traditional pharmacodynamic parameters and may be relevant to achieving an optimal therapeutic effect. Full article

Helicobacter pylori (H. pylori) is the primary etiological agent for chronic gastritis, peptic ulcers, and gastric adenocarcinoma. The alarming rise in multidrug-resistant (MDR) strains, particularly against clarithromycin (CLR), metronidazole (MNZ), and levofloxacin (LVX), has severely compromised standard therapies. Thus, there is an urgent clinical need for novel antimicrobial agents that operate through distinct mechanisms to bypass resistance pathways and mitigate gastric cancer risk. We designed and synthesized a series of antimicrobial peptides, focusing on the proteolytically stable all-D-amino acid enantiomer, DT7-3, derived from a probiotic-sourced template. Minimum inhibitory concentrations (MICs) were determined against standard strains and 11 clinical MDR isolates via the broth microdilution method. Antimicrobial mechanisms were elucidated using scanning electron microscopy (SEM) for morphology, fluorescence-based assays for anti-adhesion activity, and real-time qPCR to quantify virulence gene expression (babA, ureA, and vacA). Biocompatibility was assessed using defibrinated sheep erythrocytes, gastric epithelial cells (GES-1), and representative beneficial gut microbiota. Analysis of the clinical isolates revealed resistance rates of 63.6% for CLR/LVX and 81.8% for MNZ, with 54.5% identified as MDR. DT7-3 exhibited superior potency (MIC 1–32 µg/mL) against all strains, significantly outperforming its L-enantiomer counterparts. Mechanistic studies unveiled a “triple-hit” mechanism: (1) rapid membrane disruption; (2) potent inhibition of bacterial adhesion to host cells (~60% reduction at 0.5 × MIC); (3) significant downregulation of critical virulence factors (babA, ureA, and vacA). Furthermore, DT7-3 showed an excellent safety profile, with negligible hemolysis (<5% at 32 µg/mL) and minimal cytotoxicity toward GES-1 cells, yielding a high selectivity index (SI, MHC/MIC) > 32 relative to mammalian cells. Crucially, DT7-3 showed high selectivity for the pathogen over beneficial gut microbiota (MIC > 128 µg/mL, SI > 16). Crucially, DT7-3 maintained potent bactericidal activity (MIC ≤ 16 µg/mL) even under cholesterol-enriched conditions. The engineered D-peptide DT7-3 is a potent candidate for combating MDR H. pylori. Its multifaceted mechanism, targeting bacterial viability while suppressing core virulence factors, positions it as a robust lead compound for next-generation eradication therapies aimed at reducing the burden of H. pylori-associated diseases. Full article

Background/Objectives: Although triple antibiotic paste is effective in managing infected primary teeth, its incomplete removability from tooth structure remains a major limitation, prompting the search for alternative drug-delivery systems. The aim of this study was to obtain a multi-antibiotic porous composite system for tailored drug delivery, to develop a formulation strategy, and to characterize the physicochemical properties and drug release. Methods: The developed composites consisted of a porous composite matrix (PCM; chitosan/bioactive filler) and two or three antibiotics (ciprofloxacin [CIP], metronidazole [MET], clindamycin [CLI]). Three methods of incorporating antibiotics were used: applying an antibiotic solution to the stabilized PCM; introducing an antibiotic solution into the polymer matrix; and introducing an antibiotic into the polymer matrix as nanoparticles. The physicochemical properties of the composites, including microstructure, compressive strength, and swelling, were assessed. The antibiotic release profile was assessed for up to 168 h. Results: The most advantageous method for introducing MET and CLI, in terms of release profile, was applying them to the PCM surface, whereas ciprofloxacin exhibited stable release when incorporated directly into the polymer matrix and entrapped during the stabilization process. The composites with nanoparticles, including MET or CIP, did not release any active substances during the experimental period. Conclusions: The results demonstrate that the developed formulation strategy enables the production of composites that rapidly release substantial amounts of the active substances within a short time frame and maintain their concentration for an extended period, which may be beneficial for the treatment of bacterial infections. Full article

Antimicrobial resistance (AMR) emerges and circulates across interconnected human, animal, food, and environmental reservoirs; however, food fermentation systems remain underexplored as indicators of local AMR pressure, even though artisanal dairy fermentations may function as natural sentinels of AMR. In this study, we used an artisanal dairy fermentation chain as a One Health model to investigate whether environmentally exposed lactobacilli can reflect stage-associated shifts in resistance. A total of 1.085 isolates representing 16 Lactobacillus species were recovered from the same artisanal dairy matrix at two fermentation stages: day 5 (“Tyrovolia”; n = 518) and day 30 (“Kopanisti”; n = 567). Susceptibility to 14 antibiotics was evaluated by broth micro-dilution, and L. acidophilus was further screened for selected resistance genes. Overall resistance increased significantly from 69.88% (362/518) at day 5 to 77.25% (438/567) at day 30 (p = 0.0059), while multidrug resistance rose from 37.57% to 60.73% of resistant isolates (p < 0.001). Across the 224 species–antibiotic combinations examined, 129 (57.58%) showed an increased upper MIC limit at day 30, and resistance increased significantly for 9 of the 14 antibiotics tested, with the largest rises observed for metronidazole (RR = 7.67), chloramphenicol (RR = 5.74), quinupristin/dalfopristin (RR = 4.11), vancomycin (RR = 2.78), and trimethoprim (RR = 2.43). In contrast, erythromycin and oxytetracycline resistance declined significantly at the ripened stage. In L. acidophilus, 21 resistance genes were detected in 14/70 day-5 isolates and 19 genes in 13/71 day-30 isolates, but marked genotype–phenotype discordance was observed, including matrix-dependent expression patterns for tetM, ermB, and blaTEM. Collectively, these findings show that environmentally exposed artisanal dairy fermentations can enrich resistance phenotypes and may serve as sensitive sentinels of AMR dynamics at the human–animal–environment interface. Full article

Resistance surveillance programmes are essential for choosing the most appropriate eradication therapy for the stomach pathogen Helicobacter pylori. This study aimed to determine H. pylori antimicrobial resistance rates in Ireland. H. pylori was cultured from patients attending four gastroenterology clinics from 2018 to 2023. Antimicrobial susceptibility testing (AST) was performed using Etests for metronidazole, clarithromycin, levofloxacin, amoxicillin, tetracycline and rifampicin and resistance classified using EUCAST guidelines. Resistance rates were compared between H. pylori treatment-naïve and previously treated patients (primary and secondary resistance, respectively). Samples from 138 culture-positive patients (mean age 49.4 ± 15.7 years, 47.1% female) were analysed. A total of 28.7% of isolates from treatment-naïve patients were susceptible to all antimicrobials tested. Primary resistance rates to metronidazole, clarithromycin, levofloxacin, amoxicillin, tetracycline and rifampicin were 44.3%, 36.5%, 18.3%, 14.6%, 9.6% and 9.6%, respectively. Primary dual resistance to clarithromycin and metronidazole was 22.6% and primary multidrug resistance was 13.0%. Secondary resistance rates were significantly higher than primary resistance rates for clarithromycin, metronidazole, dual resistance to clarithromycin and either amoxicillin, metronidazole or levofloxacin, and multidrug resistance. Female sex and older age were associated with increased risk of resistance. H. pylori resistance rates were high in our cohort. Clarithromycin-based triple therapy should no longer be used in Ireland in the absence of pre-treatment AST. Resistance to amoxicillin, tetracycline and rifampicin should be monitored closely. Full article

Background/Objectives: Butyricimonas species constitute a genus of Gram-negative, anaerobic bacteria that are part of the human gut microbiota. Infections caused by these organisms are extremely rare in clinical practice. While uncommon in the general population, their occurrence is higher among immunocompromised individuals or patients with significant underlying health conditions. This review aims to compile and analyze all reported cases of human Butyricimonas infections, focusing on epidemiology, microbiological characteristics, antimicrobial resistance patterns, treatment strategies, and associated mortality. Methods: This review was conducted using data retrieved from the PubMed/MEDLINE and Scopus databases. Results: A total of 14 publications described Butyricimonas infections affecting 14 patients. The mean age of those affected was 66.46 years, and 10 (71.4%) were male. The most frequently reported predisposing factor was a history of malignancy, observed in almost one-third of cases (30.8%). Clinically, fever, organ dysfunction, and shock were the most common presentations (fivecases), followed by sepsis and the need for ICU in fourpatients. In vitro studies indicated that the isolates were generally susceptible to carbapenems and metronidazole, with only high resistance levels observed to penicillin. Among the antimicrobial therapies used, carbapenems were the most commonly administered (50%), followed by piperacillin/tazobactam (41.7%) and metronidazole (33.3%). The overall mortality rate across the cohort was 16.7%, with infection-attributable deaths representing 8.3% of cases. Conclusions: Given the potential of Butyricimonas species to cause severe infections, clinicians should consider this organism in patients presenting with unexplained bacteremia or intra-abdominal infections, particularly in the setting of mucosal disruption or immune dysfunction. Full article

Antimony oxide nanoparticles (Sb₂O₃ NPs) were synthesized via a chemical vapor deposition (CVD) method and systematically characterized to evaluate their multifunctional performance. Powder X-ray diffraction (PXRD) confirmed the formation of an orthorhombic Sb₂O₃ phase with an average crystallite size of 53.50 nm, while SEM analysis revealed elongated nanostructures with diameters in the range of 20–100 nm. The stoichiometric composition of Sb₂O₃ (Sb:O ≈ 2:3) was verified by EDAX, and optical studies indicated a direct band gap of 3.10 eV. The electrochemical sensing capability of Sb₂O₃ NPs was investigated using a modified nickel mesh electrode for the detection of Metronidazole (MTZ) in 0.1 N KOH. The presence of Sb₂O₃ NPs resulted in an additional irreversible reduction peak at −0.14 V, confirming enhanced electrocatalytic activity toward MTZ, along with excellent cycling stability (94.36% retention after 10 cycles). In addition, the photocatalytic performance of Sb₂O₃ NPs was evaluated through the degradation of Acid Orange (AO) dye under UV-Vis irradiation, achieving a degradation efficiency of 73.31%. These results demonstrate that Sb₂O₃ nanoparticles are promising multifunctional materials for environmental remediation and electrochemical sensing applications, highlighting their potential for industrial implementation. Full article

Background and Objectives: Anal fissures are a common condition in the general population, for which there are multiple treatment options. It is essential to select the most appropriate treatment for the right patient. This study aimed to observe and evaluate the effect of topical antibiotherapy, which is widely used in the management of wounds and chronic infections, on the healing of acute and chronic anal fissures. Materials and Methods: Hospital records of 625 individuals diagnosed with an anal fissure were reviewed. Previous treatments, including 0.4% glyceryl trinitrate and 5% lidocaine, were recorded. A total of 118 patients were included: 49 patients who received additional topical metronidazole due to inflammation, induration and minimal purulent discharge, in the absence of an abscess; and 69 uncomplicated patients who received only standard treatment, as per the exclusion criteria. Results: The mean age of the participants was 41.06 ± 10.70 years. No significant differences were found between the groups regarding age or sex (p = 0.616 and p = 0.665, respectively). However, prior treatment history and mucosal healing differed significantly between the two groups (p = 0.001 and p = 0.024, respectively). There were no significant differences in follow-up intervals, additional treatment requirements or improvement in VAS scores (p = 0.546, 0.904 and 0.154, respectively). Conclusions: Topical metronidazole may be associated with improved mucosal healing in selected patients with acute anal fissures presenting with clinical features such as local inflammation, minimal discharge or incision-related changes. However, the observed benefit does not appear to be uniform across all patients, and, in the absence of microbiological data, the extent of microbial involvement remains uncertain. Accordingly, topical metronidazole may be considered for carefully selected cases of acute anal fissure based on clinical judgement, while avoiding routine or indiscriminate antibiotic use. Full article

Bacterial vaginosis (BV), the most common lower genital tract infection among women of childbearing age, is characterized by a decline in Lactobacillus populations and the excessive proliferation of anaerobic bacteria. Clinically, metronidazole remains the first-line therapeutic agent. However, the increasing recurrence rate has become an urgent clinical challenge. An important factor of BV recurrence is the persistent presence of Gardnerella biofilms, which enhances pathogenic resistance to antibiotics. In contrast, a healthy vaginal microbiome, predominated by Lactobacillus, exerts protective effects by producing antimicrobial compounds that inhibit BV pathogen colonization and restore microbial homeostasis. Given this, Lactobacillus preparations have gained widespread attention for their adjunctive therapeutic potential in BV management. Accordingly, in this study, we selected two extensively investigated Lactobacillus species, Lactobacillus crispatus and Lactobacillus rhamnosus, to evaluate their inhibitory capacity against Gardnerella biofilms. Our findings suggest that hydrogen peroxide and D-lactic acid are prominent bioactive components involved in the inhibition of Gardnerella biofilm formation by these Lactobacillus species, though the potential contribution of bacteriocins and other uncharacterized factors cannot be excluded. Notably, this inhibitory activity is not accompanied by alterations to the composition of pre-formed biofilms. This study clarifies the anti-biofilm mechanism of specific Lactobacillus, providing a valuable reference for future research on probiotic-based strategies for the treatment of BV. Full article

Giardiasis, caused by Giardia duodenalis, is a common gastrointestinal infection. This study aimed to evaluate the effects of Hedera helix leaf extract (HLE) and HLE-loaded chitosan nanoparticles (HLE-CsNPs) against Giardia duodenalis isolates from individuals with gastrointestinal issues, using an experimental rat model. Stool samples from 147 participants were analyzed for Giardia duodenalis, with positive samples further characterized by nested PCR-RFLP, revealing a 4.8% prevalence, all belonging to assemblage B. Ten groups of male albino rats were used to evaluate the antigiardial activity of various treatments. This included five non-infected groups [one untreated and four treated with HLE, HLE-CsNPs, CsNPs, and metronidazole (MTZ)] and five infected groups [one untreated and four similarly treated]. Treatment efficacy was assessed using parasite counts, intestinal histopathology, CD117 immunohistochemistry, and markers of liver and kidney function. HLE-CsNPs markedly reduced Giardia cysts by 88.8%, approaching the 99.2% reduction achieved by MTZ, while also improving intestinal architecture and reducing inflammation. Importantly, HLE and HLE-CsNPs provided superior protection for the liver and kidneys compared to MTZ. In conclusion, HLE-CsNPs exhibited significant antigiardial activity and organ protection in rats, suggesting a potential alternative treatment for Giardia duodenalis isolated from individuals with gastrointestinal issues. Full article

Objectives: The present study evaluated the efficacy of a preparation based on bacterial lysates of Streptococcus oralis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum in the treatment of experimental periodontitis in rats, compared to metronidazole. Methods: Twenty female Wistar rats were used, divided into three groups: control, bacterial lysates and metronidazole, administered for 10 days by oral lavage/gavage. Periodontitis was induced by ligatures contaminated with bacterial suspensions (10⁹ CFU/mL) for 4 weeks. Lysates were obtained by culturing bacterial strains, centrifugation, washing, heat inactivation, ultrasonication and filtration. The evaluations included biocompatibility on HGF-1 fibroblasts, microbiological stability, clinical parameters, hematological, biochemical and histopathological analyses. Results: The lysates demonstrated the absence of cytotoxicity (cell viability 90–100%) and significant antimicrobial effect at the optimal concentration (2 × 10⁹ CFU/mL equivalent). Both treatments significantly reduced periodontal inflammation, with no statistical differences between them. Systemic immunoinflammatory indices (SII, SIRI, AISI) increased comparably, demonstrating controlled immune mobilization, and ALT was maintained within physiological limits. Histopathological examination revealed a reduction in inflammatory infiltrate, connective tissue reorganization and bone regeneration in both treated groups. Conclusions: Bacterial lysates represent a viable therapeutic alternative with comparable efficacy to metronidazole, favorable safety profile and immunomodulatory potential in the treatment of periodontitis. Full article

This work reports the elaboration and testing of polydimethylsiloxane/titanium dioxide (PDMS/TiO₂) polymer nanocomposites, focusing on producing and combining TiO₂ nanoparticles with a polymer matrix through an ex situ route. By mixing the inherent flexibility of PDMS with the unique properties of nanoparticles, the nanocomposites aim to enhance mechanical stability, optical response, and photocatalytic activity. X-ray diffraction (XRD) confirmed the successful incorporation of TiO₂ into the PDMS matrix. UV–visible spectroscopy monitored photocatalytic performance using metronidazole as a model pollutant under 365 nm irradiation. Kinetic analysis revealed degradation and showed that the reaction rate constant (k) increased with TiO₂ loading, reaching a maximum of 0.0019 min⁻¹ for the 6 wt.% composite. These findings indicate that while the reaction kinetics are slower than those of free powders, the PDMS/TiO₂ nanocomposites provide a viable, recoverable, and flexible solution for environmental remediation applications. Future efforts will target improved durability, broadened visible light absorption, and process optimization for scalable fabrication. Full article

Objective: To evaluate the clinical and microbiological effects of antimicrobial underwear as an adjunct to standard treatment in women with acute vaginitis. Methods: Sixty reproductive-age women with acute vaginitis received a 7-day intravaginal regimen of metronidazole and miconazole. Participants were assigned either to a group wearing antimicrobial underwear or to a control group wearing non-antimicrobial underwear. Vaginal symptoms and culture results were assessed before and after treatment. Results: The antimicrobial-underwear group showed significant improvement in vaginal symptoms, including discharge (96.7%→6.9% vs. 72.5%→27.5%; p < 0.001), pruritus (37.5% vs. 68.4%; p = 0.044), odor (19.6% vs. 53.8%; p = 0.016), and irritation (36.4% vs. 75%; p = 0.013). Dyspareunia was similar between groups. While no microbiological change was observed in controls (p = 0.950), negative cultures increased from 40% to 80% in the antimicrobial-underwear group (p = 0.018), with marked reductions in Candida spp., Gardnerella vaginalis, E. coli, and Klebsiella spp. Conclusions: Antimicrobial underwear, when used in conjunction with standard treatment, can enhance symptom relief and maintain genital hygiene. By improving the vulvovaginal microenvironment, antimicrobial textiles can reduce moisture and the persistence of pathogens. Full article