Search Results (934)

Cefepime-enmetazobactam is a novel β-lactam/β-lactamase inhibitor combination showing good activity against multidrug-resistant (MDR) Gram-negative bacteria producing a variety of β-lactamases. In this systematic review, we aimed to evaluate the available data on resistance to this drug. We performed a thorough search of four databases (Embase, PubMed, Scopus, and Web of Science), as well as backward citation searching, to identify studies containing data on resistance to cefepime-enmetazobactam. The data were extracted and analyzed according to the breakpoints established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Food and Drug Administration (FDA), or the specific breakpoints reported by the authors of the respective studies. Analysis based on the type of lactamases produced by the isolates was also performed. Ten studies reported in vitro susceptibility testing and mechanisms of antimicrobial resistance. The total number of isolates was 15,408. The activity of cefepime-enmetazobactam against β-lactamase-producing isolates was variable. The resistance of the studied extended-spectrum β-lactamase (ESBL)-producing and ampicillin C β-lactamase (AmpC)-producing isolates was low (0–2.8% and 0%, respectively). The resistance was higher among oxacillinase-48 β-lactamase (OXA-48)-producing and Klebsiella pneumoniae carbapenemase (KPC)-producing isolates (3.4–13.2% and 36.7–57.8%, respectively). High resistance was noted among metallo-β-^lactamase (MBL)-producing isolates (reaching 87.5% in one study), especially those producing New Delhi metallo-β-lactamase (NDM) and Verona integron-encoded metallo-β-lactamase (VIM), which had the highest rates of resistance. The high activity of cefepime-enmetazobactam against Enterobacterales and selected lactose non-fermenting Gram-negative pathogens, including ESBL-producing and AmpC-producing isolates, makes it a potential carbapenem-sparing agent. The drug should be used after in vitro antimicrobial susceptibility testing in patients with infections caused by OXA-48, KPC, and MBL-producing isolates. Full article

Background: The COVID-19 pandemic has profoundly altered the clinical and microbiological landscape of respiratory tract infections (RTIs), potentially reshaping pathogen distribution and antimicrobial resistance (AMR) profiles across care settings. Objectives: The objective of this study was to assess temporal trends in respiratory bacterial pathogens, antimicrobial resistance, and polymicrobial infections across three pandemic phases—pre-COVID (2018–2019), COVID (2020–2022), and post-COVID (2022–2024)—in hospitalized and ambulatory patients. Methods: We retrospectively analyzed 1827 respiratory bacterial isolates (hospitalized patients, n = 1032; ambulatory patients, n = 795) collected at a tertiary care center in Northern Italy. Data were stratified by care setting, anatomical site, and pandemic phase. Species identification and susceptibility testing followed EUCAST guidelines. Statistical analysis included chi-square and Fisher’s exact tests. Results: In hospitalized patients, a significant increase in Pseudomonas aeruginosa (from 45.5% pre-COVID to 58.6% post-COVID, p < 0.0001) and Acinetobacter baumannii (from 1.2% to 11.1% during COVID, p < 0.0001) was observed, with 100% extensively drug-resistant (XDR) rates for A. baumannii during the pandemic. Conversely, Staphylococcus aureus significantly declined from 23.6% pre-COVID to 13.7% post-COVID (p = 0.0012). In ambulatory patients, polymicrobial infections peaked at 41.2% during COVID, frequently involving co-isolation of Candida spp. Notably, resistance to benzylpenicillin in Streptococcus pneumoniae reached 80% (4/5 isolates) in hospitalized patients during COVID, and carbapenem-resistant P. aeruginosa (CRPA) significantly increased post-pandemic in ambulatory patients (0% pre-COVID vs. 23.5% post-COVID, p = 0.0014). Conclusions: The pandemic markedly shifted respiratory pathogen dynamics and resistance profiles, with distinct trends observed in hospital and community settings. Persistent resistance phenotypes and frequent polymicrobial infections, particularly involving Candida spp. in outpatients, underscore the need for targeted surveillance and antimicrobial stewardship strategies. Full article

Polymicrobial biofilms involving fungal and bacterial species are increasingly recognized as contributors to persistent infections, particularly in the oral cavity. Candida albicans and Aggregatibacter actinomycetemcomitans are two commensals that can turn into opportunistic pathogens and are able to form robust biofilms. Objectives: This study aimed to assess the interaction dynamics between these two microorganisms and to evaluate their susceptibility to fluconazole and azithromycin in single- and mixed-species forms. Methods: Biofilm biomass was quantified using crystal violet assays, while biofilm cell viability was assessed through CFU enumeration (biofilm viability assay). To assess the resistance properties of single versus mixed-species coincubations, we applied the antimicrobial susceptibility test (AST) to each drug, and analysed spatial organization with confocal laser scanning microscopy, using PNA-FISH. Results: The results indicated that both species can coexist without significant mutual inhibition. However, a non-reciprocal synergism was also observed, whereby mixed-species biofilm conditions promoted the growth of A. actinomycetemcomitans, while C. albicans growth remained stable. As expected, antimicrobial tolerance was elevated in mixed cultures, likely due to enhanced extracellular matrix production and potential quorum-sensing interactions, contributing to increased resistance against azithromycin and fluconazole. Conclusions: This study provides novel insights into previously rarely explored interactions between C. albicans and A. actinomycetemcomitans. These findings underscore the importance of investigating interspecies interactions within polymicrobial biofilms, as understanding their mechanisms, such as quorum-sensing molecules and metabolic cooperation, can contribute to improved diagnostics and more effective targeted therapeutic strategies against polymicrobial infections. Full article

Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) is eroding therapeutic options for urinary tract infections. We isolated a multidrug-resistant strain from the urine of a chronically bacteriuric patient and confirmed its identity by Vitek-2 and MALDI-TOF MS. Initial disk-diffusion profiling against 48 antibiotics revealed susceptibility to only 5 agents. One month later, repeat testing showed that tetracycline alone remained active, highlighting the strain’s rapidly evolving resistome. Given the scarcity of drug options, we performed an “aromatogram” with seven pure essential oils, propolis, and two commercial phytotherapeutic blends. Biomicin Forte^® produced a 30 mm bactericidal halo, while thyme, tea tree, laurel, and palmarosa oils yielded clear inhibition zones of 11–22 mm. These in vitro data demonstrate that carefully selected plant-derived products can target CR-Kp where conventional antibiotics fail. Integrating aromatogram results into One Health’s stewardship plans may therefore help preserve last-line antibiotics and provide adjunctive options for persistent urinary infections. Full article

This study explores the potential of biodegradable Bioglass 45S5 formulations as a dual-function approach for preventing and treating Staphylococcus aureus infections in orthopaedic surgery while addressing the growing concern of antimicrobial resistance (AMR). The research focuses on the development and characterisation of antibiotic-loaded BG45S5 formulations, assessing parameters such as drug loading efficiency, release kinetics, antimicrobial efficacy, and dissolution behaviour. Key findings indicate that the F2l-BG45S5-T-T-1.5 and F2l-BG45S5-T-V-1.5 formulations demonstrated controlled antibiotic release for up to seven days, with size distributions of D(10): 7.11 ± 0.806 µm, 4.96 ± 0.007 µm; D(50): 25.34 ± 1.730 µm, 25.20.7 ± 0.425 µm; and D(90): 53.7 ± 7.95 µm, 56.10 ± 0.579 µm, respectively. These formulations facilitated hydroxyapatite formation on their surfaces, indicative of osteogenic potential. The antimicrobial assessments revealed zones of inhibition against methicillin-susceptible Staphylococcus aureus (MSSA, ATCC-6538) measuring 20.3 ± 1.44 mm and 24.6 ± 1.32 mm, while for methicillin-resistant Staphylococcus aureus (MRSA, ATCC-43300), the inhibition zones were 21.6 ± 1.89 mm and 22 ± 0.28 mm, respectively. Time-kill assay results showed complete bacterial eradication within eight hours. Additionally, biocompatibility testing via MTT assay confirmed cell viability of >75%. In conclusion, these findings highlight the promise of antibiotic-loaded BG45S5 as a multifunctional biomaterial capable of both combating bone infections and supporting bone regeneration. These promising results suggest that in vivo studies should be undertaken to expedite these materials into clinical applications. Full article

The ATP-binding cassette transporter ABCG2 plays a critical role in drug pharmacokinetics and multidrug resistance in cancer therapy. Two common nonsynonymous polymorphisms, rs2231137 (V12M) and rs2231142 (Q141K), are associated with altered ABCG2 function, drug response, and disease susceptibility. However, the functional impact of their haplotype remains poorly understood. In this study, we established Flp-In™-293 cell lines stably expressing ABCG2 (12M/141K) and systematically compared their expression and drug resistance profiles with those of cells expressing ABCG2 (12V/141Q) (WT), ABCG2 (12M/141Q), and ABCG2 (12V/141K). The mRNA of ABCG2 (12M/141K) was expressed at levels comparable to those of the other variants in cells. Cells expressing ABCG2 (12M/141K) exhibited significantly higher resistance to mitoxantrone (10.7-fold) and SN-38 (5.99-fold) than the mock cells. While ABCG2 (12M/141Q) conferred the highest resistance among the tested variants, the ABCG2 (12M/141K) haplotype showed a trend toward higher mitoxantrone resistance than the ABCG2 (12V/141Q) (WT) (p = 0.066), suggesting a haplotype-specific effect. These findings provide novel insights into haplotype-based modulation of ABCG2 function and its contribution to multidrug resistance, with potential implications for optimizing personalized chemotherapy strategies. Full article

Invasive infections with rare yeasts are increasing worldwide and are associated with higher mortality rates due to their resistance to antifungal drugs. Accurate antifungal susceptibility testing (AFST) is crucial for proper management of rare yeast infections. We performed AFST of 74 Candida kefyr isolates by Etest, EUCAST-based MICRONAUT-AM assay (MCN-AM) and reference Clinical and Laboratory Standards Institute broth microdilution method (CLSI). Essential agreement (EA, ±1 two-fold dilution), categorical agreement (CA), major errors (MEs) and very-major errors (VmEs) were determined using epidemiological cut-off values of ≤1.0 µg/mL, ≤0.03 µg/mL, ≤0.5 µg/mL and ≤1 µg/mL, defining wild-type isolates for fluconazole, voriconazole, micafungin and amphotericin B (AMB), respectively. Results for AMB susceptibility were correlated with ERG2/ERG3 mutations and total-cell sterols. CA of ≥97% was recorded between any two methods while EA varied between 72 and 82%, 87 and 92%, and 49 and 76% for fluconazole, voriconazole and micafungin, respectively. For AMB, CAs between CLSI and Etest; CLSI and MCN-AM; MCN-AM and Etest were 95% (4 ME, 0 VmE), 96% (3 ME, 0 VmE) and 99%, respectively, while EA varied from 32% to 69%. Non-synonymous ERG2/ERG3 mutations and no ergosterol were found in seven of eight isolates of non-wild types for AMB by Etest. Our data show that Etest, CLSI and MCN-AM methods are suitable for AFST of C. kefyr for fluconazole, voriconazole and micafungin. Excellent CAs for AMB between Etest and MCN-AM with concordant sterol profiles but not with CLSI suggest that Etest is also an excellent alternative for the detection of C. kefyr isolates with reduced susceptibility to AMB. Full article

Background: Salmonella infections pose a serious threat to both animal and human health worldwide. Notably, there is an increasing trend in the resistance of Salmonella to fluoroquinolones, the first-line drugs for clinical treatment. Methods: Utilizing Salmonella Typhimurium CICC 10420 as the test strain, ciprofloxacin was used for in vitro induction to develop the drug-resistant strain H1. Changes in the minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined using the broth microdilution method. Transcriptomic and metabolomic analyses were conducted to investigate alterations in gene and metabolite expression. A combined drug susceptibility test was performed to evaluate the potential of exogenous metabolites to restore antibiotic susceptibility. Results: The MICs of strain H1 for ofloxacin and enrofloxacin increased by 128- and 256-fold, respectively, and the strain also exhibited resistance to ceftriaxone, ampicillin, and tetracycline. A single-point mutation of Glu469Asp in the GyrB was detected in strain H1. Integrated multi-omics analysis showed significant differences in gene and metabolite expression across multiple pathways, including two-component systems, ABC transporters, pentose phosphate pathway, purine metabolism, glyoxylate and dicarboxylate metabolism, amino sugar and nucleotide sugar metabolism, pantothenate and coenzyme A biosynthesis, pyrimidine metabolism, arginine and proline biosynthesis, and glutathione metabolism. Notably, the addition of exogenous glutamine, in combination with tetracycline, significantly reduced the resistance of strain H1 to tetracycline. Conclusion: Ciprofloxacin-induced Salmonella resistance involves both target site mutations and extensive reprogramming of the metabolic network. Exogenous metabolite supplementation presents a promising strategy for reversing resistance and enhancing antibiotic efficacy. Full article

Background/Objectives: The beneficial and multifaceted effects of Sideritis scardica Griseb. extracts are attributed to the presence of polyphenolic compounds, particularly phenolic acids. Methods: The research was carried out for S. scardica herb of different origins (Albania, Bulgaria, North Macedonia, and Türkiye). Identification of compounds was performed using the HPLC/ESI-QTOF-MS method; phenolic acids and flavonoids were determined spectrophotometrically. The antioxidant activity of methanol extracts from studied herbs was determined using the Folin–Ciocalteu, DPPH, and FRAP methods, and the antimicrobial activity was evaluated using the broth microdilution method in accordance with the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Results: We demonstrated the presence 18–20 active compounds, depending on the origin of the raw material, with verbascoside being the predominant compound in all samples. The raw material was characterized by significant polyphenol content and high antioxidant activity. DPPH tests revealed the highest antioxidant activity, ranging from 86.5% to 87.9%, in samples from Bulgaria, North Macedonia, and Türkiye, and the latter showed the strongest antimicrobial activity, particularly against Gram-positive pathogens and Candida spp. Conclusions: This research is the first report comparing the chemical composition and biological activity of S. scardica raw material of different origins. Our findings indicate that S. scardica herb extracts have significant phytotherapeutic potential, although this varies depending on the origin of the raw material, and point to the need for further research on this plant material, particularly in terms of the level of active compounds and their possible synergistic effects with conventional drugs, as well as the need for standardization. Full article

Beach Sand Mycobiome is currently among the most important health challenges for viticulture in the world. Remarkably, the study of fungal communities in coastal beach sand and recreational waters remains underexplored despite their potential implications for human health. This research aimed to assess the prevalence of fungal species and the antifungal susceptibility profiles of fungi recovered from the beaches of the Persian Gulf and the Sea of Oman. Sand and seawater samples from 39 stations distributed within 13 beaches along the coastline were collected between May and July 2023. The grown isolates were identified at the species level based on morphological characteristics and DNA sequencing. Antifungal susceptibility testing was performed according to the Clinical Laboratory Standards Institute guidelines. Of 222 recovered isolates, 206 (92.8%) filamentous fungi and 16 (7.2%) yeast strains were identified. Sand-recovered fungi comprised 82.9%, while water-originated fungi accounted for 17.1%. The DNA sequencing technique categorized 191 isolates into 13 genera and 26 species. The most recovered genus was Aspergillus (68.9%), and Aspergillus terreus sensu stricto was the commonly identified species (26.14%). Voriconazole was the most effective antifungal drug against Aspergillus species. Research on fungal contamination levels at these locations could provide a foundation for establishing regulatory frameworks to diminish fungal risks, thereby enhancing public health protection. The ecological significance of fungal communities in sandy beaches to human infections remains to be explored, and earlier reports in the literature may motivate researchers to focus on detecting this mycobiome in natural environments where further investigation is warranted. Ultimately, our discovery serves as a reminder that much remains to be learned about pathogenic fungi and underscores the need for vigilance in areas where emerging pathogens have not yet been identified. Full article

Background/Objectives: All current FDA-approved antibody–drug conjugates (ADCs) are single-target and single-payload molecules that have limited efficacy in patients due to drug resistance. Therefore, our goal was to generate a novel ADC that was less susceptible to single points of resistance to reduce the likelihood of patient relapse. Methods: We developed a dual-targeting, dual-payload ADC by conjugating a bispecific EGFR x cMET antibody to two payloads (MMAF and SN38) that had separate mechanisms of action using a novel tri-functional linker. This dual-payload ADC was tested for potency and efficacy in dividing and nondividing in vitro cell models using multiple tumor cell types. Efficacy of the dual-payload ADC was confirmed using in vivo models. Results: Our ADC with dual MMAF and SN38 payloads was more efficacious in inhibiting cell proliferation than single-payload ADCs across multiple cancer cell lines. In addition, the dual-payload molecule inhibited nondividing cells, which were more resistant to traditional ADC payloads. The dual-payload ADC also exhibited more potent tumor growth inhibition in vivo compared to that of single-payload ADCs. Conclusions: Overall, the bispecific antibody conjugated with both the MMAF and SN38 payloads inhibited tumor growth more strongly than ADCs conjugated with MMAF or SN38 alone. Developing dual-payload ADCs could limit the impact of acquired resistance in patients as well as lower the effective dose of each payload. Full article

Background/Objectives: Hot-melt extrusion (HME) has gained prominence for the manufacture of sustained-release oral dosage forms, yet the application of wax-based matrices and their resilience to alcohol-induced dose dumping (AIDD) remains underexplored. This study aimed to develop and characterise wax-based sustained-release felodipine formulations, with a particular focus on excipient functionality and robustness against AIDD. Methods: Felodipine sustained-release formulations were prepared via HME using Syncrowax HGLC as a thermally processable wax matrix. Microcrystalline cellulose (MCC) and lactose monohydrate were incorporated as functional fillers and processing aids. The influence of wax content and filler type on mechanical properties, wettability, and drug release behaviour was systematically evaluated. Ethanol susceptibility testing was conducted under simulated co-ingestion conditions (4%, 20%, and 40% v/v ethanol) to assess AIDD risk. Results: MCC-containing tablets demonstrated superior sustained-release characteristics over 24 h, showing better wettability and disintegration. In contrast, tablets formulated with lactose monohydrate remained structurally intact during dissolution, overly restricting drug release. This limitation was effectively addressed through granulation, where reduced particle size significantly improved surface accessibility, with 0.5–1 mm granules achieving a satisfactory release profile. Ethanol susceptibility testing revealed divergent behaviours between the two filler systems. Unexpectedly, MCC-containing tablets showed suppressed drug release in ethanolic media, likely resulting from inhibitory effect of ethanol on filler swelling and disintegration. Conversely, formulations containing lactose monohydrate retained their release performance in up to 20% v/v ethanol, with only high concentrations (40% v/v) compromising matrix drug-retaining functionality and leading to remarkably increased drug release. Conclusions: This study highlights the pivotal role of excipient type and constitutional ratios in engineering wax-based sustained-release formulations. It further contributes to the understanding of AIDD risk through in vitro assessment and offers a rational design strategy for robust, alcohol-resistant oral delivery systems for felodipine. Full article

Background/Objectives: Tuberculosis (TB) remains a major public health challenge in Davao City, Philippines, with persistent issues in both disease burden and treatment outcomes. Understanding the risk factors for TB and its unsuccessful treatment is essential for guiding effective interventions. This study aimed to evaluate the association of sociodemographic and clinical factors with TB occurrence and to identify predictors of unsuccessful TB treatment outcomes among patients in Davao City. Methods: A retrospective cohort study was conducted using data from 521 patients diagnosed with drug-susceptible TB at Davao Chest Center between January 2021 and May 2024. The sociodemographic and clinical profiles of the patients were described using descriptive statistics. Chi-square tests were used to assess the associations between sociodemographic and clinical variables with TB risk and treatment outcomes. Results: The patient cohort was predominantly aged 31–50 years (n = 201, 38.58%), male (n = 284, 54.51%), and married (n = 285, 54.70%), with most residing in Districts I and II (n = 98, 38% each), and had no previous TB treatment (n = 344, 66.03%). Among the 456 patients assessed for comorbidities, 56.14% (n = 256) had at least one comorbidity. Evaluation of the risk factors for TB occurrence among the study population revealed that comorbidity status was not significantly associated with an increased risk of TB diagnosis (p = 0.682). However, among patients diagnosed with TB, the presence of comorbidities was significantly associated with unsuccessful treatment outcomes (p = 0.003). Conclusions: Although sociodemographic factors did not significantly influence TB risk or treatment outcomes, the presence of comorbidities was a significant predictor of unsuccessful TB treatment. These findings highlight the importance of integrating comorbidity management with TB care to improve treatment success in high-burden urban settings. Full article

Background: Accurate and rapid diagnosis of drug-resistant tuberculosis is essential for initiating appropriate treatment and preventing the transmission of these strains. This study compares phenotypic and genotypic methods of drug susceptibility testing for Mycobacterium tuberculosis (M. tuberculosis). Methods: Resistance to first-line drugs, as well as resistance to second-line drugs (fluoroquinolones and aminoglycosides), was assessed using the Löwenstein–Jensen medium phenotypic method and the GenoType MTBDRplus genotypic method and analyzed. Results: The phenotypic resistance rate was 84.85% for INH (n = 56), 46.97% for RIF (n = 31), 48.48% for STR (n = 32), and 30.30% for EMB (n = 20). Of the MDR-TB isolates (n = 29), 41.37% were resistant to fluoroquinolones (n = 12) and 31.03% were resistant to both fluoroquinolones and injectable aminoglycosides, being classified as XDR-TB (n = 9). In addition, 22.73% of the MDR-TB isolates were resistant to all four first-line drugs (n = 15). The overall concordance between the line probe assay method and phenotypic testing was 94.74% for RIF and 95.16% for INH. Discordances were identified in three cases for RIF and two cases for INH, where isolates were reported as susceptible by GenoType MTBDRplus, but phenotypically resistant. Conclusions: Genotypic testing using GenoType MTBDRplus provides rapid and accurate results, but some cases of phenotypic resistance are not detected by this method. The results highlight the importance of using combined phenotypic and genotypic methods for accurate diagnosis of MDR-TB, as well as the need to integrate genomic sequencing to improve diagnostic accuracy. Full article

The Stability Toolkit for the Appraisal of Bio/Pharmaceuticals’ Level of Endurance (STABLE) is introduced and proposed as a comprehensive tool and software to evaluate the stability of active pharmaceutical ingredients (APIs) under various stress conditions. In the pharmaceutical industry, stability testing is a critical step in the drug development process, ensuring the quality, safety, and efficacy of APIs. Traditional stability tests—such as real-time, accelerated, and forced degradation testing—often face challenges, including inconsistent interpretation and implementation across different regions and organizations. STABLE addresses these challenges by providing a standardized and holistic approach to assessing drug stability across five key stress conditions: oxidative, thermal, acid-catalyzed hydrolysis, base-catalyzed hydrolysis, and photostability. Beyond its role as an evaluation tool, STABLE also serves as a practical guide for chemists, encouraging a more complete and thoughtful approach to stability studies. While many investigations focus solely on acid- and base-catalyzed hydrolysis, other critical conditions—such as photostability—are often underexplored or entirely omitted. By highlighting the importance of evaluating all relevant degradation pathways, STABLE promotes more robust and informed stability testing protocols. The index utilizes a color-coded scoring system to quantify and compare stability, facilitating consistent assessments across different APIs. This paper discusses the methodology of STABLE, including the scoring system and specific criteria applied under each condition. This tool is introduced to reflect intrinsic degradation susceptibility under forced conditions. The software is freely available as an open-source tool at bit.ly/STABLE2025, enabling broader accessibility and implementation across the pharmaceutical research community. Full article