Proven anti-virulence therapies in combating methicillin- and vancomycin-resistant Staphylococcus aureus infections.

Introduction: Despite years of efforts to develop new antibiotics for eradicating multidrug-resistant (MDR) and multi-virulent Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Staphylococcus aureus (VRSA) infections, treatment failures and poor prognoses in most cases have been common. Therefore, there is an urgent need for new therapeutic approaches targeting virulence arrays. Our aim is to discover new anti-virulence therapies targeting MRSA and VRSA virulence arrays. Methodology: We employed phenotypic, molecular docking, and genetic studies to screen for anti-virulence activities among selected promising compounds: Coumarin, Simvastatin, and Ibuprofen. Results: We found that nearly all detected MRSA and VRSA strains exhibited MDR and multi-virulent profiles. The molecular docking results aligned with the phenotypic and genetic assessments of virulence production. Biofilm and hemolysin productions were inhibited, and all virulence genes were downregulated upon treatment with sub-minimum inhibitory concentration (sub-MIC) of these promising compounds. Ibuprofen was the most active compound, exhibiting the highest inhibition and downregulation of virulence gene products. Moreover, in vivo and histopathological studies confirmed these results. Interestingly, we observed a significant decrease in wound area and improvements in re-epithelialization and tissue organization in the Ibuprofen and antimicrobial treated group compared with the group treated with antimicrobial alone. These findings support the idea that a combination of Ibuprofen and antimicrobial drugs may offer a promising new therapy for MRSA and VRSA infections. Conclusion: We hope that our findings can be implemented in clinical practice to assist physicians in making the most suitable treatment decisions.

Monoclonal Gammopathy of Clinical Significance (MGCS) and Related Disorders: A Review and the Role of Imaging.

The term monoclonal gammopathy of clinical significance (MGCS) refers to a group of symptomatic monoclonal gammopathies that do not meet the diagnostic criteria for malignant plasma cell disorders, such as multiple myeloma or Waldenström macroglobulinemia. These symptoms are attributable to the paraneoplastic effects of monoclonal immunoglobulins that occur through diverse mechanisms. The presence of symptoms distinguishes MGCS from monoclonal gammopathy of undetermined significance, which lacks significant symptomatic presentation. The presentations of MGCS are manifold, adding to the diagnostic challenge. Clinical suspicion is key for accurate and timely diagnosis. Radiologic imaging can provide pivotal information to guide the diagnosis. In this review, we discuss MGCS from a radiology perspective and highlight pertinent imaging features associated with the disorders.

Influence of Connector Design on Displacement and Micromotion in Tooth-Implant Fixed Partial Dentures Using Different Lengths and Diameters: A Three-Dimensional Finite Element Study.

The literature presents insufficient data evaluating the displacement and micromotion effects resulting from the combined use of tooth-implant connections in fixed partial dentures. Analyzing the biomechanical behavior of tooth-implant fixed partial denture (FPD) prothesis is vital for achieving an optimum design and successful clinical implementation. The objective of this study was to determine the relative significance of connector design on the displacement and micromotion of tooth-implant-supported fixed dental prostheses under occlusal vertical loading. A unilateral Kennedy class I mandibular model was created using a 3D reconstruction from CT scan data. Eight simulated designs of tooth-implant fixed partial dentures (FPDs) were split into two groups: Group A with rigid connectors and Group B with non-rigid connectors. The models were subjected to a uniform vertical load of 100 N. Displacement, strain, and stress were computed using finite element analysis. The materials were defined as isotropic, homogeneous, and exhibiting linear elastic properties. This study focused on assessing the maximum displacement in various components, including the bridge, mandible, dentin, cementum, periodontal ligament (PDL), and implant. Displacement values were predominantly higher in Group B (non-rigid) compared to Group A (rigid) in all measured components of the tooth-implant FPDs. Accordingly, a statistically significant difference was observed between the two groups at the FPD bridge (p value = 0.021 *), mandible (p value = 0.021 *), dentin (p value = 0.043 *), cementum (p value = 0.043 *), and PDL (p value = 0.043 *). Meanwhile, there was an insignificant increase in displacement values recorded in the distal implant (p value = 0.083). This study highlighted the importance of connector design in the overall stability and performance of the prosthesis. Notably, the 4.7 mm × 10 mm implant in Group B showed a displacement nearly 92 times higher than its rigid counterpart in Group A. Overall, the 5.7 mm × 10 mm combination of implant length and diameter showcased the best performance in both groups. The findings demonstrate that wider implants with a proportional length offer greater resistance to displacement forces. In addition, the use of rigid connection design provides superior biomechanical performance in tooth-implant fixed partial dentures and reduces the risk of micromotion with its associated complications such as ligament overstretching and implant overload, achieving predictable prognosis and enhancing the stability of the protheses.

Influence of Capsicum chinense concentration and salt varieties on the quality attributes of Kilishi, a sundried beef jerky.

The impact of Capsicum chinense concentration and salt varieties on cholesterol oxides, physicochemical properties, microbial profiles and organoleptic attributes of Kilishi, a sundried beef jerky, was assessed. Kilishi (KL) was prepared from sundried strips of Biceps femoris and marinated with either 2 % Sodium chloride (NaCl) + 7 % fresh Capsicum chinense (CC) (KL-1), 1 % NaCl + 1 % Potassium chloride (KCl) + 7 % CC (KL-2), 1 % NaCl + 1 % Potassium citrate (C6H5K3O7) + 7 % CC (KL-3), 1 % NaCl + 14 % CC (KL-4), 1 % KCl + 14 % CC (KL-5) or 1 % C6H5K3O7 + 14 % CC (KL-6), and stored at 29 ± 1 °C for 90 d. The partial or total replacement of NaCl lowered (P < 0.05) the Na content in KL. The KL samples treated with 14 % CC had lower (P < 0.05) 25-hydroxy cholesterol, cholesta-3,5-dien-7-one, carbonyl, pH, malondialdehyde, and lightness and greater (P < 0.05) redness and Lactobacillus counts than those treated with 7 % CC. The chemical composition, sensory scores and water activity were unaffected by the additives. The taste, flavor, and overall acceptance scores of KL decreased (P < 0.05) after 30 days of storage. The substitution of KCl and C6H5K3O7 for NaCl and the increase in CC concentration from 7 to 14 % lowered the Na content and selected cholesterol oxides, respectively, without impairing the organoleptic traits of Kilishi.

Are positional screws superior to lag screws in fixation of medial malleolar fractures? A randomized controlled trial.

PURPOSE: There is no consensus about the best fixation method for medial malleolar fractures. This study was conducted to compare the clinical and radiological results of positional (fully threaded) screws and lag (partially threaded) screws when used to fix medial malleolar fractures. METHODS: This prospective, randomized clinical trial included 68 patients with closed isolated medial malleolar fractures. Each study arm included 34 patients who were randomly treated with either fully threaded screws (FT group) or partially threaded screws (PT group). Patients were evaluated radiologically for union and clinically using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot score. RESULTS: After a 12-month follow-up, the mean AOFAS ankle hindfoot score was 92.1 ± 3.5 in the FT group and 91.8 ± 5.4 in the PT group. Union was achieved in the FT group after a mean of 6.2 ± 1.3 weeks and after a mean of 6.5 ± 1.5 weeks in the PT group. CONCLUSION: Both fully threaded and partially threaded screws yielded good comparable clinical and radiological outcomes when used to fix isolated medial malleolar fractures.

Comparative Study Between Single-limb Versus One-and-a-Half Hip Spica Cast in Fracture Femur in Young Children.

INTRODUCTION: Femoral fractures account for ∼1% to 2% of all pediatric bone injuries and are a common occurrence in children. The conservative approach, employing either a single or one-and-a-half spica casts, has been traditionally favored, yielding satisfactory outcomes in select cases. This study aims to compare both procedures regarding functional and radiologic outcomes, complications, and parents' satisfaction. METHODS: In this randomized controlled trial, we enrolled 84 pediatric patients, aged between 2 and 6 years, presenting with femoral fractures. Participants were randomly allocated into 2 groups; one receiving single-limb spica cast fixation (n=42) and the other receiving one-and-a-half spica cast fixation (n=42). We assessed postprocedural functional and radiologic outcomes. Other evaluations focused on parental ease in maintaining hygiene for the casted child, the child's mobility capabilities including standing and crawling, and the incidence of skin complications. RESULTS: No significant variance was observed between the 2 groups concerning the time to bone union, and the overall complication rates. Parental satisfaction was notably higher in the single-limb spica group, particularly regarding the ease of maintaining hygiene for the casted child and the child's mobility while encased in the cast (P<0.001). Furthermore, a significant correlation was identified between the one-and-a-half spica application and the increased occurrence of skin pressure ulcers (P<0.001). CONCLUSION: Both single-limb and one-and-a-half spica cast applications demonstrated comparable results in functional and radiologic outcomes, as well as in complication rates. However, parents favored the single-limb method due to its facilitation of a more manageable lifestyle for both the child and their parents. These considerations suggest that the single-limb hip spica cast fixation may be preferable in managing pediatric femoral fractures. LEVEL OF EVIDENCE: Level II.

Recent advances in nano-based drug delivery systems for treatment of liver cancer.

Liver cancer is one of the aggressive primary tumors as evident by high rate of incidence and mortality. Conventional treatments (e.g. chemotherapy) suffer from various drawbacks including wide drug distribution, low localized drug concentration, and severe off-site toxicity. Therefore, they cannot satisfy the mounting need for safe and efficient cancer therapeutics, and alternative novel strategies are needed. Nano-based drug delivery systems (NDDSs) are among these novel approaches that can improve the overall therapeutic outcomes. NDDSs are designed to encapsulate drug molecules and target them specifically to liver cancer. Thus, NDDSs can selectively deliver therapeutic agents to the tumor cells and avoid distribution to off-target sites which should improve the safety profile of the active agents. Nonetheless, NDDSs should be well designed, in terms of the preparing materials, nanocarriers structure, and the targeting strategy, in order to accomplish these objectives. This review discusses the latest advances of NDDSs for cancer therapy with emphasis on the aforementioned essential design components. The review also entails the challenges associated with the clinical translation of NDDSs, and the future perspectives towards next-generation NDDSs.

The characteristics of frozen-thawed rooster sperm using various intracellular cryoprotectants.

Cryopreservation of rooster semen is essential for conserving genetic resources, genetic improvement, and increasing productivity. However, the nature of avian sperm presents a global issue in ensuring superior frozen semen for artificial insemination. Thus, the present study aimed to evaluate the impact of using dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), and ethylene glycol (EG) as cryoprotectants on post-thawed sperm motility, quality, antioxidant indicators, and fertilizing capacity. Twice a week, fresh semen ejaculates were collected from 15 adult roosters and immediately evaluated to constitute a pool from clean and qualified samples. The pooled semen was further diluted at a ratio of 1:2 (v/v) with an extender and then subjected to a freezing protocol in a liquid nitrogen vapor after adding a cryoprotectant solution containing 6% of either DMA, DMSO, or EG, respectively. After thawing, characteristics of sperm motion, quality, antioxidants, and fertilizing ability were evaluated and compared to fresh and cooled semen as controls. The results demonstrated that semen cooling negatively affected some parameters of sperm motility, quality, antioxidant biomarkers, and fertility. In comparison to the DMSO and EG groups, employing DMA considerably (P < 0.05) raised the percentages of sperm progressive motility, viability, plasma membrane intactness, and DNA integrity. The DMA group showed a significant increase in the catalase and glutathione reduced antioxidant enzyme activity and a reduction in nitric oxide and lipid peroxidation. After artificial insemination, the DMA and DMSO groups exhibited considerably (P < 0.05) better rates of hatchability and fertility than the EG group. It is concluded that freezing extenders containing 6% DMA is better than DMSO or EG to improve the post thaw semen quality and fertility in chickens.

Translational modeling-based evidence for enhanced efficacy of standard-of-care drugs in combination with anti-microRNA-155 in non-small-cell lung cancer.

BACKGROUND: Elevated microRNA-155 (miR-155) expression in non-small-cell lung cancer (NSCLC) promotes cisplatin resistance and negatively impacts treatment outcomes. However, miR-155 can also boost anti-tumor immunity by suppressing PD-L1 expression. Therapeutic targeting of miR-155 through its antagonist, anti-miR-155, has proven challenging due to its dual molecular effects. METHODS: We developed a multiscale mechanistic model, calibrated with in vivo data and then extrapolated to humans, to investigate the therapeutic effects of nanoparticle-delivered anti-miR-155 in NSCLC, alone or in combination with standard-of-care drugs. RESULTS: Model simulations and analyses of the clinical scenario revealed that monotherapy with anti-miR-155 at a dose of 2.5 mg/kg administered once every three weeks has substantial anti-cancer activity. It led to a median progression-free survival (PFS) of 6.7 months, which compared favorably to cisplatin and immune checkpoint inhibitors. Further, we explored the combinations of anti-miR-155 with standard-of-care drugs, and found strongly synergistic two- and three-drug combinations. A three-drug combination of anti-miR-155, cisplatin, and pembrolizumab resulted in a median PFS of 13.1 months, while a two-drug combination of anti-miR-155 and cisplatin resulted in a median PFS of 11.3 months, which emerged as a more practical option due to its simple design and cost-effectiveness. Our analyses also provided valuable insights into unfavorable dose ratios for drug combinations, highlighting the need for optimizing dose regimens to prevent antagonistic effects. CONCLUSIONS: This work bridges the gap between preclinical development and clinical translation of anti-miR-155 and unravels the potential of anti-miR-155 combination therapies in NSCLC.

Femoral Lengthening in Children with Congenital Femoral Deficiency: A Systematic Review.

BACKGROUND: Congenital femoral deficiency (CFD) presents a significant challenge in pediatric orthopaedics, characterized by a spectrum of congenital anomalies ranging from mild femoral shortening to complete absence of the proximal femur and hip joint. This review aims at reviewing the latest concepts of femoral limb lengthening modalities in treating CFD, to explore the efficacy, complications, and long-term outcomes of various surgical techniques. METHODS: A comprehensive search of the literature was performed for clinical studies involving lengthening in patients with proximal focal femoral deficiency (PFFD) in several databases. RESULTS: We analyze the evolution of limb lengthening procedures, from the Wagner and Ilizarov methods to the latest advancements in distraction osteogenesis, and assess their role in addressing the functional needs of patients. We also analyze the possible risk factors for the occurrence of complications with each method and alternatives to avoid them. CONCLUSION: The review highlights the importance of individualized treatment plans, considering factors such as the degree of femoral deficiency and the potential for achieving a functional limb length; however, it requires a multidisciplinary approach and careful preoperative planning to optimize patient outcomes. The review underlines the need for ongoing research to refine surgical techniques and to compare them and improve the quality of life for individuals with PFFD. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.

Mucosal immunization with ChAd-SARS-CoV-2-S prevents sequential transmission of SARS-CoV-2 to unvaccinated hamsters.

COVID-19 vaccines have successfully reduced severe disease and death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Nonetheless, COVID-19 vaccines are variably effective in preventing transmission and symptomatic SARS-CoV-2 infection. Here, we evaluated the impact of mucosal or intramuscular vaccine immunization on airborne infection and transmission of SARS-CoV-2 in Syrian hamsters. Immunization of the primary contact hamsters with a mucosal chimpanzee adenoviral-vectored vaccine (ChAd-CoV-2-S), but not intramuscular messenger RNA (mRNA) vaccine, reduced infectious virus titers ~100-fold and 100,000-fold in the upper and lower respiratory tract of the primary contact hamster following SARS-CoV-2 exposure. This reduction in virus titer in the mucosal immunized contact animals was sufficient to eliminate subsequent transmission to vaccinated and unvaccinated hamsters. In contrast, sequential transmission occurred after systemic immunization with the mRNA vaccine. Thus, immunization with a mucosal COVID-19 vaccine protects against cycles of respiratory transmission of SARS-CoV-2 and can potentially limit the community spread of the virus.

Catalytic reduction of toxic dyes over nickel oxide nanoparticles supported on CMK-3 catalyst.

In the current paper, a NiO nanoparticles-loaded mesoporous carbon (CMK-3) catalyst, denoted as NiO/CMK-3, has been successfully synthesized using a facile strategy. The as-prepared material has been characterized through XRD, Raman spectroscopy, low-temperature N2 physisorption measurements, FTIR, FE-SEM, TEM, and XPS. The as-fabricated NiO/CMK-3 catalyst manifested a superior activity in the NaBH4-assisted reduction of methylene blue (MB) dye to its colorless leuco form. Remarkably, over 99% of 25 mg L-1 MB was reduced by 7.5 mM/L NaBH4 using 0.1 g L-1 NiO/CMK-3 within 3 min at room temperature. Furthermore, the kinetics study confirmed the appropriateness of the pseudo-first-order kinetic model for elucidating the kinetics of MB reduction by the catalyst. Importantly, the NiO/CMK-3 catalyst maintained almost constant catalytic activity even after 5 times of reuse in MB reduction, demonstrating its superior stability and reusable ability. So, NiO/CMK-5 appears as a promising heterogeneous catalyst for the effective remediation of dye-containing wastewater.

SARS-CoV-2-associated lymphopenia: possible mechanisms and the role of CD147.

T lymphocytes play a primary role in the adaptive antiviral immunity. Both lymphocytosis and lymphopenia were found to be associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While lymphocytosis indicates an active anti-viral response, lymphopenia is a sign of poor prognosis. T-cells, in essence, rarely express ACE2 receptors, making the cause of cell depletion enigmatic. Moreover, emerging strains posed an immunological challenge, potentially alarming for the next pandemic. Herein, we review how possible indirect and direct key mechanisms could contribute to SARS-CoV-2-associated-lymphopenia. The fundamental mechanism is the inflammatory cytokine storm elicited by viral infection, which alters the host cell metabolism into a more acidic state. This "hyperlactic acidemia" together with the cytokine storm suppresses T-cell proliferation and triggers intrinsic/extrinsic apoptosis. SARS-CoV-2 infection also results in a shift from steady-state hematopoiesis to stress hematopoiesis. Even with low ACE2 expression, the presence of cholesterol-rich lipid rafts on activated T-cells may enhance viral entry and syncytia formation. Finally, direct viral infection of lymphocytes may indicate the participation of other receptors or auxiliary proteins on T-cells, that can work alone or in concert with other mechanisms. Therefore, we address the role of CD147-a novel route-for SARS-CoV-2 and its new variants. CD147 is not only expressed on T-cells, but it also interacts with other co-partners to orchestrate various biological processes. Given these features, CD147 is an appealing candidate for viral pathogenicity. Understanding the molecular and cellular mechanisms behind SARS-CoV-2-associated-lymphopenia will aid in the discovery of potential therapeutic targets to improve the resilience of our immune system against this rapidly evolving virus.

Genomic Biomarkers to Predict Response to Atezolizumab Plus Bevacizumab Immunotherapy in Hepatocellular Carcinoma: Insights from the IMbrave150 Trial.

Introduction: Combination immunotherapy, exemplified by atezolizumab plus bevacizumab, has become the standard of care for inoperable hepatocellular carcinoma (HCC). However, the lack of predictive biomarkers and limited understanding of response mechanisms remain a challenge. Methods: Using data from the IMbrave150plus cohort, we applied an immune signature score (ISS) predictor to stratify HCC patients treated with atezolizumab plus bevacizumab or with sorafenib alone into potential high and low response groups. By applying multiple statistical approaches including a Bayesian covariate prediction algorithm, we refined the signature to 10 key genes (ISS10) for clinical use while maintaining similar predictive power to the full model. We further validated ISS10 in an independent HCC cohort treated with nivolumab plus ipilimumab. Results: The study identified a significant association between the ISS and treatment response. Among patients classified as high responders, those treated with the atezolizumab plus bevacizumab combination exhibited improved overall and progression-free survival as well as better objective response rate compared to those treated with sorafenib. We also observed a significant correlation between ISS10 and response to nivolumab plus ipilimumab treatment. Analysis of immune cell subpopulations revealed distinct characteristics associated with ISS subtypes. In particular, the ISS10 high subtype displayed a more favorable immune environment with higher proportions of anti-tumor macrophages and activated T-cells, potentially explaining its better response. Conclusions: Our study suggests that ISS and ISS10 are promising predictive biomarkers for enhanced therapeutic outcomes in HCC patients undergoing combination immunotherapy. These markers are crucial for refining patient stratification and personalized treatment approaches to advance the effectiveness of standard-of-care regimens.

Severe febrile neutropenia and pancytopenia in a patient with advanced hepatocellular carcinoma treated with atezolizumab and bevacizumab: a case report.

Background: Immune checkpoint inhibitors (ICIs), agents that stimulate T-cell function, have become the standard first-line treatment for unresectable hepatocellular carcinoma (HCC). However, they may also cause immune-related adverse events (irAEs), which are rare and have not been extensively reported. Here, we describe a case of severe febrile neutropenia and pancytopenia after atezolizumab plus bevacizumab (atezo/bev) therapy and its treatment course. Case Description: The combination of atezo/bev was initiated as the first-line treatment for a man in his early 50s, who was diagnosed with unresectable HCC. The first treatment cycle was administered in the outpatient setting, and the patient developed a fever of 39.0 ℃ 10 days after therapy initiation. He presented 5 days later with persistent fever as well as a headache, vomiting, chills, generalized pain, fatigue, mild abdominal discomfort, and a burning rash present on his neck and face. Complete blood counts showed severe neutropenia [absolute neutrophil count (ANC) of 90 cells/µL], leukopenia [white blood cell (WBC) count 500 cells/µL], thrombocytopenia [platelet count (PC) 18,000 cells/µL], and mild anemia (hemoglobin level 12.6 gm/dL). Imaging findings showed colitis on computed tomography (CT). Atezo/bev therapy was discontinued. Treatment plan constituted of cefepime and filgrastim, a recombinant form of the naturally occurring granulocyte colony-stimulating factor (G-CSF) for febrile neutropenia, metronidazole for colitis, and intravenous methylprednisolone for immune-related toxicities. The patient fully recovered after 4 days of admission. Conclusions: In conclusion, we observed temporary severe febrile neutropenia and pancytopenia during systemic immunotherapy in a patient with unresectable HCC. Healthcare providers should consider hematological irAEs (hem-irAEs) in patients after the administration of ICIs.

The preventive effects of diosmin alone or combined with irinotecan on 1,2-dimethylhydrazine-induced colon cancer in rats.

OBJECTIVE: Colorectal cancer, one of the most frequently diagnosed cancers worldwide, has a high mortality rate. Thus, our research aims to examine the preventive effects of diosmin (DIO) alone and in conjunction with the anti-cancer drug irinotecan (camptothecin-11, CPT-11), on 1,2-dimethylhydrazine (DMH)-induced colon cancer (CC) in male Wistar rats. MATERIALS AND METHODS: Fifty adult male Wistar rats were categorized into five groups. Group I (Normal) received saline 0.9 orally % as a vehicle once a week for 14 weeks. Group II (DMH) received DMH (20 mg/kg/week) orally dissolved in 0.9% saline for 14 weeks and 1% carboxymethylcellulose (CMC) every other day for the final 10 weeks. Group III (DMH+DIO) received DMH orally for 14 weeks and DIO (10 mg/kg, suspended in 1% CMC) every other day for the final 10 weeks. Group IV (DMH+CPT-11) received DMH orally for 14 weeks and intraperitoneal injection of CPT-11 (3 mg/kg) twice a week for the final 10 weeks. Group V (DMH+DIO+CPT-11) orally received DMH for 14 weeks and both DIO and CPT-11. RESULTS: All treated groups showed a significant reduction (p<0.05) in their elevated serum malondialdehyde levels and significant amelioration (p<0.05) of their lowered activities of colon glutathione-S-transferase (GST) and glutathione reductase (GR) as well as serum glutathione level (GSH). In addition, simultaneous treatment with DIO and CPT-11 led to a significant decrease (p<0.05) in the elevated serum levels of carcinoembryonic antigen (CEA) in rats administered with DMH, as well as a reduction in the colon expression levels of the inflammatory mediator (NF-κB), cell proliferator protein (Ki-67), and proapoptotic protein (p53). CONCLUSIONS: These findings suggest DIO, CPT-11, and their combination have anticarcinogenic effects against DMH-induced CC by suppressing oxidative stress, simulating the antioxidant defense system, attenuating the inflammatory effects, and reducing cell proliferation.

Self-assembled monovalent lipidated mannose ligand as a standalone nanoadjuvant.

Subunit vaccines require an immunostimulant (adjuvant) and/or delivery system to induce immunity. However, currently, available adjuvants are either too dangerous in terms of side effects for human use (experimental adjuvants) or have limited efficacy and applicability. In this study, we examined the capacity of mannose-lipopeptide ligands to enhance the immunogenicity of a vaccine consisting of polyleucine(L15)-antigen conjugates anchored to liposomes. The clinically tested Group A Streptococcus (GAS) B-cell epitope, J8, combined with universal T helper PADRE (P) was used as the antigen. Six distinct mannose ligands were incorporated into neutral liposomes carrying L15PJ8. While induced antibody titers were relatively low, the ligand carrying mannose, glycine/lysine spacer, and two palmitic acids as liposomal membrane anchoring moieties (ligand 3), induced significantly higher IgG titers than non-mannosylated liposomes. The IgG titers were significantly enhanced when positively charged liposomes were employed. Importantly, the produced antibodies were able to kill GAS bacteria. Unexpectedly, the physical mixture of only ligand 3 and PJ8 produced self-assembled nanorods that induced antibody titers as high as those elicited by the lead liposomal formulation and antigen adjuvanted with the potent, but toxic, complete Freund's adjuvant (CFA). Antibodies produced upon immunization with PJ8 + 3 were even more opsonic than those induced by CFA + PJ8. Importantly, in contrast to CFA, ligand 3 did not induce observable adverse reactions or excessive inflammatory responses. Thus, we demonstrated that a mannose ligand, alone, can serve as an effective vaccine nanoadjuvant.

Colistin-resistance genes in Escherichia coli isolated from patients with urinary tract infections.

BACKGROUND: The incidence of antimicrobial resistance is alarmingly high because it occurs in humans, environment, and animal sectors from a "One Health" viewpoint. The emergence of plasmid-carried mobile colistin-resistance (MCR) genes limits the efficacy of colistin, which is the last-line treatment for multidrug resistance (MDR) against gram-negative infections. OBJECTIVES: The current study aimed to investigate emergence of colistin-resistance (MCR 1-5) genes in E. coli isolated from patients with urinary tract infections (UTIs) in Jordan. METHODS: E. coli (n = 132) were collected from urine specimens. The E. coli isolated from human UTI patients were examined the resistance to colistin based on the presence of MCR (1-5). All isolates were tested against 20 antimicrobials using the standard disk diffusion method. The broth microdilution technique was used to analyze colistin resistance. In addition, the MCR (1-5) genes were detected using multiplex PCR. RESULTS: Out of the 132 isolates, 1 isolate was colistin-resistant, having a minimum inhibitory concentration of 8 µg/mL and possessing MCR-1. All the E. coli isolates showed high resistance to penicillin (100%), amoxicillin (79.55%), cephalexin (75.76%), nalidixic acid (62.88%), tetracycline (58.33%), or cefepime (53.79). CONCLUSION: To our knowledge, this is the first report on the presence of plasmid-coded MCR-1 in E. coli from a patient with UTIs in Jordan. This is a problematic finding because colistin is the last-line drug for the treatment of infections caused by MDR gram-negative bacteria. There is a crucial need to robustly utilize antibiotics to control and prevent the emergence and prevalence of colistin-resistance genes.