Synthesis of 1-(2-Hydroxyphenyl)- and (3,5-Dichloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic Acid Derivatives as Promising Scaffolds for the Development of Novel Antimicrobial and Anticancer Agents.

Increasing antimicrobial resistance among Gram-positive pathogens and pathogenic fungi remains one of the major public healthcare threats. Therefore, novel antimicrobial candidates and scaffolds are critically needed to overcome resistance in Gram-positive pathogens and drug-resistant fungal pathogens. In this study, we explored 1-(2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid and its 3,5-dichloro-2-hydroxyphenyl analogue for their in vitro antimicrobial activity against multidrug-resistant pathogens. The compounds showed structure-dependent antimicrobial activity against Gram-positive pathogens (S. aureus, E. faecalis, C. difficile). Compounds 14 and 24b showed promising activity against vancomycin-intermediate S. aureus strains, and favorable cytotoxic profiles in HSAEC-1 cells, making them attractive scaffolds for further development. 5-Fluorobenzimidazole, having a 3,5-dichloro-2-hydroxyphenyl substituent, was found to be four-fold, and hydrazone, with a thien-2-yl fragment, was two-fold stronger than clindamycin against methicillin resistant S. aureus TCH 1516. Moreover, hydrazone, bearing a 5-nitrothien-2-yl moiety, showed promising activity against three tested multidrug-resistant C. auris isolates representing major genetic lineages (MIC 16 µg/mL) and azole-resistant A. fumigatus strains harboring TR34/L98H mutations in the CYP51A gene. The anticancer activity characterization demonstrated that the 5-fluorobenzimidazole derivative with a 3,5-dichloro-2-hydroxyphenyl substituent showed the highest anticancer activity in an A549 human pulmonary cancer cell culture model. Collectively these results demonstrate that 1-(2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives could be further explored for the development of novel candidates targeting Gram-positive pathogens and drug-resistant fungi.

Synthesis and Development of N-2,5-Dimethylphenylthioureido Acid Derivatives as Scaffolds for New Antimicrobial Candidates Targeting Multidrug-Resistant Gram-Positive Pathogens.

The growing antimicrobial resistance to last-line antimicrobials among Gram-positive pathogens remains a major healthcare emergency worldwide. Therefore, the search for new small molecules targeting multidrug-resistant pathogens remains of great importance. In this paper, we report the synthesis and in vitro antimicrobial activity characterisation of novel thiazole derivatives using representative Gram-negative and Gram-positive strains, including tedizolid/linezolid-resistant S. aureus, as well as emerging fungal pathogens. The 4-substituted thiazoles 3h, and 3j with naphthoquinone-fused thiazole derivative 7 with excellent activity against methicillin and tedizolid/linezolid-resistant S. aureus. Moreover, compounds 3h, 3j and 7 showed favourable activity against vancomycin-resistant E. faecium. Compounds 9f and 14f showed broad-spectrum antifungal activity against drug-resistant Candida strains, while ester 8f showed good activity against Candida auris which was greater than fluconazole. Collectively, these data demonstrate that N-2,5-dimethylphenylthioureido acid derivatives could be further explored as novel scaffolds for the development of antimicrobial candidates targeting Gram-positive bacteria and drug-resistant pathogenic fungi.

Synthesis of Novel Aminothiazole Derivatives as Promising Antiviral, Antioxidant and Antibacterial Candidates.

It is well-known that thiazole derivatives are usually found in lead structures, which demonstrate a wide range of pharmacological effects. The aim of this research was to explore the antiviral, antioxidant, and antibacterial activities of novel, substituted thiazole compounds and to find potential agents that could have biological activities in one single biomolecule. A series of novel aminothiazoles were synthesized, and their biological activity was characterized. The obtained results were compared with those of the standard antiviral, antioxidant, antibacterial and anticancer agents. The compound bearing 4-cianophenyl substituent in the thiazole ring demonstrated the highest cytotoxic properties by decreasing the A549 viability to 87.2%. The compound bearing 4-trifluoromethylphenyl substituent in the thiazole ring showed significant antiviral activity against the PR8 influenza A strain, which was comparable to the oseltamivir and amantadine. Novel compounds with 4-chlorophenyl, 4-trifluoromethylphenyl, phenyl, 4-fluorophenyl, and 4-cianophenyl substituents in the thiazole ring demonstrated antioxidant activity by DPPH, reducing power, FRAP methods, and antibacterial activity against Escherichia coli and Bacillus subtilis bacteria. These data demonstrate that substituted aminothiazole derivatives are promising scaffolds for further optimization and development of new compounds with potential influenza A-targeted antiviral activity. Study results could demonstrate that structure optimization of novel aminothiazole compounds may be useful in the prevention of reactive oxygen species and developing new specifically targeted antioxidant and antibacterial agents.

Synthesis, Biological Activity, and Molecular Modelling Studies of Naphthoquinone Derivatives as Promising Anticancer Candidates Targeting COX-2.

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-associated mortalities worldwide. Therefore, it is crucial to develop a novel therapeutic option targeting localized and metastatic NSCLC. In this paper, we describe the synthesis and biological activity characterization of naphthoquinone derivatives bearing selective anticancer activity to NSCLC via a COX-2 mediated pathway. The biological evaluation of compounds 9−16 showed promising structure-dependent anticancer activity on A549 cells in 2D and 3D models. Compounds were able to significantly (p < 0.05) reduce the A549 viability after 24 h of treatment in comparison to treated control. Compounds 9 and 16 bearing phenylamino and 4-hydroxyphenylamino substituents demonstrated the most promising anticancer activity and were able to induce mitochondrial damage and ROS formation. Furthermore, most promising compounds showed significantly lower cytotoxicity to non-cancerous Vero cells. The in silico ADMET properties revealed promising drug-like properties of compounds 9 and 16. Both compounds demonstrated favorable predicted GI absorption values, while only 16 was predicted to be permeable through the blood−brain barrier. Molecular modeling studies identified that compound 16 is able to interact with COX-2 in arachidonic acid site. Further studies are needed to better understand the safety and in vivo efficacy of compounds 9 and 16.

The Feasibility of Ibrexafungerp for the Treatment of Fungal Infections in Patients with Hematological Malignancies.

Invasive fungal diseases (IFD) remain a major cause of morbidity and mortality in hematological patients, especially those undergoing hematopoietic stem cell transplantation (HSCT). Despite relatively high incidence, diagnosis and treatment remain a challenge due to non-specific manifestation and limited antifungal armamentarium. A first-in-class triterpenoid antifungal ibrexafungerp that acts by inhibiting the glucan synthase enzyme in the fungal cell wall was recently approved by the USA Food and Drug Administration for the treatment of vaginal yeast infections. Preclinical data show activity against numerous fungi species, including azole- and echinocandin-resistant strains. Preliminary data from ongoing phase 3 studies in IFD have been encouraging, but the role of ibrexafungerp in hematological patients who develop fungal infections has not yet been described. Herein, we discuss the feasibility of oral ibrexafungerp-based antifungal therapy for adult patients with hematological malignancies who have either undergone HSCT or received treatment with a novel targeted therapy agent. We present four clinical cases where ibrexafungerp alone or in combination with other antifungal agents was successfully employed for the management of refractory fungal infection. We describe real-life experiences showing the potential clinical implementation of ibrexafungerp for patients with hematological malignancies for the first time, and provoke future discussion.

Focused multivector ultraviolet (FMUV) technology rapidly eradicates SARS-CoV-2 in-vitro: Implications for hospital disinfection of COVID-19 environments.

Focused Multivector Ultraviolet technology rapidly killed the SARS-CoV-2 coronavirus in-vitro. Plates were inoculated with a mean of greater than 106 plaque forming units of USA-WA1 Washington index patient strain of SARS-CoV-2 and exposed to ultraviolet, resulting in mean reductions of 99.99% within 30 seconds, 99.999% within 60 seconds, and 99.9999% within 90 seconds. These results support the effectiveness of Focused Multivector Ultraviolet technology for SARS-CoV-2 disinfection.

Assessing the Feasibility of a Focused Multivector Ultraviolet System Between Surgery Cases with a Parallel Protocol for Enhanced Disinfection Capabilities.

A focused multivector ultraviolet (FMUV) light system was used in a parallel process with manual chemical disinfection during operating room (OR) turnovers to assess the impact on cleaning time. The average time to disinfect an OR using only chemical wipes and mops was 19.0 minutes (n = 68); for the FMUV process, the average time was 18.8 minutes (n = 61). The mean cleaning times were equivalent within a 7% margin (P < .17), and total turnover time was not significantly affected.

Assessment of focused multivector ultraviolet disinfection withshadowless delivery using 5-point multisided sampling ofpatientcare equipment without manual-chemical disinfection.

BACKGROUND: The aim of this study was to evaluate the performance of a focused multivector ultraviolet (FMUV) system employing shadowless delivery with a 90-second disinfection cycle for patient care equipment inside and outside the operating room (OR) suite without manual-chemical disinfection. METHODS: A 5-point multisided sampling protocol was utilized to measure the microbial burden on objects inside and outside the OR environment in a 3-phase nonrandomized observational study. Surface sampling was performed pre- and postdisinfection in between cases (IBCs) to assess the performance of manual-chemical disinfection. FMUV system performance was separately assessed pre- and postdisinfection before the first case and IBCs. Additionally, visibly clean high-touch objects were sampled outside the OR, and the microbial burden reductions after FMUV disinfection were quantified without manual-chemical disinfection. RESULTS: Manual-chemical disinfection reduced the active microbial burden on sampled objects IBCs by 52.8%-90.9% (P < .05). FMUV reduced the active microbial burden by 92%-97.7% (P < .0001) before the firstcase and IBCs combined, and 96.3%-99.6% (P < .0001) on objects outside the OR without chemical disinfection. CONCLUSIONS: Five-point multisided sampling proved effective for assessing disinfection performance on all exterior sides of equipment. FMUV produced significant overall reductions of the microbial burden on patient care equipment in all study phases and independent of manual cleaning and chemical disinfection.

Bone and joint infections caused by mucormycetes: A challenging osteoarticular mycosis of the twenty-first century.

Osteomyelitis and arthritis caused by mucormycetes are rare diseases that rank among the most challenging complications in orthopedic and trauma surgery. The aim of this work is to review the epidemiological, clinical, diagnostic, and therapeutic aspects of the osteoarticular mucormycosis with particular emphasis on high-risk patients. A systematic review of osteoarticular mucormycosis was performed using PUBMED and EMBASE databases from 1978 to 2014. Among 34 patients with median age 41 (0.5-73 years), 24 (71%) were males. While 12 (35%) were immunocompromised patients, 14 (41%) had prior surgery, and seven (21%) suffered trauma. Other underlying conditions included diabetes mellitus, hematological malignancies, transplantation, and corticosteroid therapy. The median diagnostic delay from onset of symptoms and signs was 60 (10-180) days. The principal mechanism of the infection was direct inoculation (n = 19; 56%), and in immunocompromised patients was usually hematogenous disseminated. The long bones were infected by trauma or surgery, while a wide variety of bones were involved by hematogenous dissemination. Combined surgery and amphotericin B treatment were implemented in 28 (82%) and eight (23%) had an unfavorable outcome. Osteoarticular mucormycosis occurs most frequently after trauma or surgical procedures. These infections are progressively destructive and more virulent in individuals with impaired immune systems. Early diagnosis, timely administration of amphotericin B, control of underlying conditions, and surgical debridement of infected tissue are critical for successful management of osteoarticular mucormycosis.

Aspergillus arthritis: analysis of clinical manifestations, diagnosis, and treatment of 31 reported cases.

Aspergillus arthritis is a debilitating form of invasive aspergillosis. Little is known about its epidemiology, clinical manifestations, laboratory features, treatment, and prognosis. Cases of Aspergillus arthritis were reviewed in the English literature from 1967 through 2015 for variables of arthritis with Aspergillus spp. recovered from joint and/or adjacent bone, underlying conditions, symptoms, signs, inflammatory biomarkers, diagnostic imaging, management, and outcome. Among 31 evaluable cases, 87% were males and 13% pediatric. Median age was 50 y (range 1-83 y). Seventeen (55%) patients were immunosuppressed with such conditions as hematological malignancies (26%), corticosteroids (39%), and/or transplantation (26%). Approximately one-half (52%) of patients had hematogenous seeding of the joint, and more than 80% had de novo infection with no prior antifungal therapy. Oligoarticular infection (2-3 joints) occurred in 45% and contiguous osteomyelitis was present in 61%. Clinical manifestations included pain (87%), edema (26%), and limited function (23%), with knees (35%), intervertebral discs (26%), and hips (16%) being most commonly infected. Aspergillus fumigatus constituted 77% of cases followed by Aspergillus flavus in 13%, Aspergillus niger in 3%, and not specified in 7%. Median ESR was 90 mm/hr and median CRP was 3.6 mg/dl. Median synovial fluid WBC was 17,200/µL (7,300-128,000) with 72% PMNs (range 61-92). Osteolysis occurred in 35%, and soft-tissue extension 47%. Nineteen patients (61%) were managed with combined medical and surgical therapy, 10 (32%) with medical therapy only, and 2 (6%) surgery only. Amphotericin B and itraconazole were the most frequently used agents with median duration of therapy of 219 days (range 30-545). Surgical interventions included debridement in 61%, drainage 19%, and amputation 6%. Complete or partial response was achieved in 71% and relapse occurred in 16%. Medical therapy was reinstituted with successful outcome in these patients. Overall survival was 65%. Aspergillus arthritis mainly develops as a de novo infection involving knees and intervertebral disks in immunocompromised patients with localizing symptoms. Contiguous osteomyelitis is frequently observed. Diagnosis is established by synovial fluid culture. Aspergillus arthritis is therapeutically challenging with most patients undergoing surgery and protracted antifungal therapy.

Osteoarticular Infections Caused by Non-Aspergillus Filamentous Fungi in Adult and Pediatric Patients: A Systematic Review.

Osteoarticular mycoses due to non-Aspergillus moulds are uncommon and challenging infections. A systematic literature review of non-Aspergillus osteoarticular mycoses was performed using PUBMED and EMBASE databases from 1970 to 2013. Among 145 patients were 111 adults (median age 48.5 [16-92 y]) and 34 pediatric patients (median age 7.5 [3-15 y]); 114 (79.7%) were male and 88 (61.9%) were immunocompromised. Osteomyelitis was due to direct inoculation in 54.5%. Trauma and puncture wounds were more frequent in children (73.5% vs 43.5%; P = 0.001). Prior surgery was more frequent in adults (27.7% vs 5.9%; P = 0.025). Vertebral (23.2%) and craniofacial osteomyelitis (13.1%) with neurological deficits predominated in adults. Lower limb osteomyelitis (47.7%) and knee arthritis (67.8%) were predominantly seen in children. Hyalohyphomycosis represented 64.8% of documented infections with Scedosporium apiospermum (33.1%) and Lomentospora prolificans (15.8%) as the most common causes. Combined antifungal therapy and surgery was used in 69% of cases with overall response in 85.8%. Median duration of therapy was 115 days (range 5-730). When voriconazole was used as single agent for treatment of hyalohyphomycosis and phaeohyphomycosis, an overall response rate was achieved in 94.1% of cases. Non-Aspergillus osteoarticular mycoses occur most frequently in children after injury and in adults after surgery. Accurate early diagnosis and long-course therapy (median 6 mo) with a combined medical-surgical approach may result in favorable outcome.

Role of NADPH oxidase versus neutrophil proteases in antimicrobial host defense.

NADPH oxidase is a crucial enzyme in mediating antimicrobial host defense and in regulating inflammation. Patients with chronic granulomatous disease, an inherited disorder of NADPH oxidase in which phagocytes are defective in generation of reactive oxidant intermediates (ROIs), suffer from life-threatening bacterial and fungal infections. The mechanisms by which NADPH oxidase mediate host defense are unclear. In addition to ROI generation, neutrophil NADPH oxidase activation is linked to the release of sequestered proteases that are posited to be critical effectors of host defense. To definitively determine the contribution of NADPH oxidase versus neutrophil serine proteases, we evaluated susceptibility to fungal and bacterial infection in mice with engineered disruptions of these pathways. NADPH oxidase-deficient mice (p47(phox-/-)) were highly susceptible to pulmonary infection with Aspergillus fumigatus. In contrast, double knockout neutrophil elastase (NE)(-/-)×cathepsin G (CG)(-/-) mice and lysosomal cysteine protease cathepsin C/dipeptidyl peptidase I (DPPI)-deficient mice that are defective in neutrophil serine protease activation demonstrated no impairment in antifungal host defense. In separate studies of systemic Burkholderia cepacia infection, uniform fatality occurred in p47(phox-/-) mice, whereas NE(-/-)×CG(-/-) mice cleared infection. Together, these results show a critical role for NADPH oxidase in antimicrobial host defense against A. fumigatus and B. cepacia, whereas the proteases we evaluated were dispensable. Our results indicate that NADPH oxidase dependent pathways separate from neutrophil serine protease activation are required for host defense against specific pathogens.

Pathogenesis of Aspergillus fumigatus and the kinetics of galactomannan in an in vitro model of early invasive pulmonary aspergillosis: implications for antifungal therapy.

BACKGROUND: Little is known about the pathogenesis of invasive pulmonary aspergillosis and the relationship between the kinetics of diagnostic markers and the outcome of antifungal therapy. METHODS: An in vitro model of the human alveolus, consisting of a bilayer of human alveolar epithelial and endothelial cells, was developed. An Aspergillus fumigatus strain expressing green fluorescent protein was used. Invasion of the cell bilayer was studied using confocal and electron microscopy. The kinetics of culture, polymerase chain reaction, and galactomannan were determined. Galactomannan was used to measure the antifungal effect of macrophages and amphotericin B. A mathematical model was developed, and results were bridged to humans. RESULTS: A. fumigatus penetrated the cellular bilayer 14-16 h after inoculation. Galactomannan levels were inextricably tied to fungal invasion and were a robust measure of the antifungal effect of macrophages and amphotericin B. Neither amphotericin nor macrophages alone was able to suppress the growth of A. fumigatus; rather, the combination was required. Monte Carlo simulations showed that human dosages of amphotericin B of at least 0.6 mg/kg were required to achieve adequate drug exposure. CONCLUSIONS: This model provides a strategy by which relationships among pathogenesis, immunological effectors, and antifungal drug therapy for invasive pulmonary aspergillosis may be further understood.

Antifungal efficacy of caspofungin (MK-0991) in experimental pulmonary aspergillosis in persistently neutropenic rabbits: pharmacokinetics, drug disposition, and relationship to galactomannan antigenemia.

The antifungal efficacy, pharmacokinetics, and safety of caspofungin (CAS) were investigated in the treatment and prophylaxis of invasive pulmonary aspergillosis due to Aspergillus fumigatus in persistently neutropenic rabbits. Antifungal therapy consisted of 1, 3, or 6 mg of CAS/kg of body weight/day (CAS1, CAS3, and CAS6, respectively) or 1 mg of deoxycholate amphotericin B (AMB)/kg/day intravenously for 12 days starting 24 h after endotracheal inoculation. Prophylaxis (CAS1) was initiated 4 days before endotracheal inoculation. Rabbits treated with CAS had significant improvement in survival and reduction in organism-mediated pulmonary injury (OMPI) measured by pulmonary infarct score and total lung weight (P < 0.01). However, animals treated with CAS demonstrated a paradoxical trend toward increased residual fungal burden (log CFU per gram) and increased serum galactomannan antigen index (GMI) despite improved survival. Rabbits receiving prophylactic CAS1 also showed significant improvement in survival and reduction in OMPI (P < 0.01), but there was no effect on residual fungal burden. In vitro tetrazolium salt hyphal damage assays and histologic studies demonstrated that CAS had concentration- and dose-dependent effects on hyphal structural integrity. In parallel with a decline in GMI, AMB significantly reduced the pulmonary tissue burden of A. fumigatus (P < or = 0.01). The CAS1, CAS3, and CAS6 dose regimens demonstrated dose-proportional exposure and maintained drug levels in plasma above the MIC for the entire 24-h dosing interval at doses that were > or =3 mg/kg/day. As serial galactomannan antigen levels may be used for therapeutic monitoring, one should be aware that profoundly neutropenic patients receiving echinocandins for aspergillosis might have persistent galactomannan antigenemia despite clinical improvement. CAS improved survival, reduced pulmonary injury, and caused dose-dependent hyphal damage but with no reduction in residual fungal burden or galactomannan antigenemia in persistently neutropenic rabbits with invasive pulmonary aspergillosis.