Antimicrobial therapy during cancer treatment: Beyond antibacterial effects

Developing Advanced Antibacterial Alginic Acid Biomaterials through Dual Functionalization

This paper delves into the intersection of biomaterials and antibacterial agents, highlighting the importance of alginic acid-based biomaterials. We investigate enhancing antibacterial properties by functionalizing alginic acid with an ionic liquid and a potent chelating agent, tris(hydroxypyridinone) (THP). Initial functionalization with the ionic liquid markedly improves the material's antibacterial efficacy. Subsequent functionalization with THP further enhances this activity, reducing the minimum inhibitory concentration from 6 to 3 mg/mL. Notably, the newly developed dual-functionalized materials exhibit no cytotoxic effects at the concentrations tested, underscoring their potential for safe and effective antibacterial applications. These findings highlight the promising role of dual-functionalized alginic acid biomaterials in developing advanced antibacterial treatments.

The role of intratumoral microorganisms in the progression and immunotherapeutic efficacy of head and neck cancer

The effectiveness of cancer immunization is largely dependent on the tumor’s microenvironment, especially the tumor immune microenvironment. Emerging studies say microbes exist in tumor cells and immune cells, suggesting that these microbes can affect the state of the immune microenvironment of the tumor. Our comprehensive review navigates the intricate nexus between intratumoral microorganisms and their role in tumor biology and immune modulation. Beginning with an exploration of the historical acknowledgment of microorganisms within tumors, the article underscores the evolution of the tumor microenvironment (TME) and its subsequent implications. Using findings from recent studies, we delve into the unique bacterial compositions across different tumor types and their influence on tumor growth, DNA damage, and immune regulation. Furthermore, we illuminate the potential therapeutic implications of targeting these intratumoral microorganisms, emphasizing their multifaceted roles from drug delivery agents to immunotherapy enhancers. As advancements in next-generation sequencing (NGS) technology redefine our understanding of the tumor microbiome, the article underscores the importance of discerning their precise role in tumor progression and tailoring therapeutic interventions. The review culminates by emphasizing ongoing challenges and the pressing need for further research to harness the potential of intratumoral microorganisms in cancer care.

Gut microbiota reshapes cancer immunotherapy efficacy: Mechanisms and therapeutic strategies

Gut microbiota is essential for maintaining local and systemic immune homeostasis in the presence of bacterial challenges. It has been demonstrated that microbiota play contrasting roles in cancer development as well as anticancer immunity. Cancer immunotherapy, a novel anticancer therapy that relies on the stimulation of host immunity, has suffered from a low responding rate and incidence of severe immune-related adverse events (irAEs). Previous studies have demonstrated that the diversity and composition of gut microbiota were associated with the heterogeneity of therapeutic effects. Therefore, alteration in microbiota taxa can lead to improved clinical outcomes in immunotherapy. In this review, we determine whether microbiota composition or microbiota-derived metabolites are linked to responses to immunotherapy and irAEs. Moreover, we discuss various approaches to improve immunotherapy efficacy or reduce toxicities by modulating microbiota composition.

Total Bio-Based Material for Drug Delivery and Iron Chelation to Fight Cancer through Antimicrobial Activity

Bacterial involvement in cancer's development, along with their impact on therapeutic interventions, has been increasingly recognized. This has prompted the development of novel strategies to disrupt essential biological processes in microbial cells. Among these approaches, metal-chelating agents have gained attention for their ability to hinder microbial metal metabolism and impede critical reactions. Nanotechnology has also contributed to the antibacterial field by offering various nanomaterials, including antimicrobial nanoparticles with potential therapeutic and drug-delivery applications. Halloysite nanotubes (HNTs) are naturally occurring tubular clay nanomaterials composed of aluminosilicate kaolin sheets rolled multiple times. The aluminum and siloxane groups on the surface of HNTs enable hydrogen bonding with biomaterials, making them versatile in various domains, such as environmental sciences, wastewater treatment, nanoelectronics, catalytic studies, and cosmetics. This study aimed to create an antibacterial material by combining the unique properties of halloysite nanotubes with the iron-chelating capability of kojic acid. A nucleophilic substitution reaction involving the hydroxyl groups on the nanotubes' surface was employed to functionalize the material using kojic acid. The resulting material was characterized using infrared spectroscopy (IR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM), and its iron-chelating ability was assessed. Furthermore, the potential for drug loading-specifically, with resveratrol and curcumin-was evaluated through ultraviolet (UV) analysis. The antibacterial assay was evaluated following CLSI guidelines. The results suggested that the HNTs-kojic acid formulation had great antibacterial activity against all tested pathogens. The outcome of this work yielded a novel bio-based material with dual functionality as a drug carrier and an antimicrobial agent. This innovative approach holds promise for addressing challenges related to bacterial infections, antibiotic resistance, and the development of advanced therapeutic interventions.

Synchronous anal mucinous adenocarcinoma and anal tuberculosis presenting as chronic anal fistula: Challenging management

Metachronous anal tuberculosis to an anal adenocarcinoma is an exceptional condition. The aim of our study was to report management of the first case of synchronized anal canal adenocarcinoma and anal canal tuberculosis and report our multidisciplinary approach. A 71-year-old man was admitted for non-healing anal fistula. Rectal examination at supine position showed an ulcerative growth at the medio-superior quadrant on a radius of 2cm from the anal verge. Digital rectal examination assessed no tumor in the anorectum. Biopsy of fistulae confirmed diagnosis of anal mucinous adenocarcinoma with coexisting anal tuberculosis. Further exploration confirmed diagnosis with no distal metastasis, no active pulmonary tuberculosis and no immunodepression. Adjuvant anti-bacillary chemotherapy was initiated 1 month prior to adjuvant radio-chemotherapy. Patient was re-admitted at the 6th week following the last dose of radio-chemotherapy for surgery. On long-term evaluation at 10 months, the patient reported absence of symptoms with weight gain. Association of both entities is rare. Chronic inflammatory damage may possibly initiate a sequence of metaplasia and dysplasia, resulting in neoplastic transformation. Anal canal adenocarcinoma treatment follows same guidelines as rectal cancer. Extra-pulmonary tuberculosis treatment follows anti-bacillary protocol with consequent side effects. Therefore, our case is a unique clinical challenge for physicians. Management decision was multidisciplinary process. Their pathophysiology relationship is yet to be understood. Moreover, each entity has defined and individual therapeutic protocols and indications. All this taken into consideration, such case presents a clinical and therapeutic challenge for physicians.

Exploring antibiotic resistance with chemical tools

Antibiotic resistance is an enormous problem that is accountable for over a million deaths annually, with numbers expected to significantly increase over the coming decades. Although some of the underlying causes leading up to antibiotic resistance are well understood, many of the molecular processes involved remain elusive. To better appreciate at a molecular level how resistance emerges, customized chemical biology tools can offer a solution. This Feature Article attempts to provide an overview of the wide variety of tools that have been developed over the last decade, by highlighting some of the more illustrative examples. These include the use of fluorescent, photoaffinity and activatable antibiotics and bacterial components to start to unravel the molecular mechanisms involved in resistance. The antibiotic crisis is an eminent global threat and requires the continuous development of creative chemical tools to dissect and ultimately counteract resistance.

Tigecycline reduces tumorigenesis in colorectal cancer via inhibition of cell proliferation and modulation of immune response

BACKGROUND

and Purpose: Colorectal cancer (CRC) is one of the cancers with the highest incidence in which APC gene mutations occur in almost 80% of patients. This mutation leads to β-catenin aberrant accumulation and an uncontrolled proliferation. Apoptosis evasion, changes in the immune response and microbiota composition are also events that arise in CRC. Tetracyclines are drugs with proven antibiotic and immunomodulatory properties that have shown cytotoxic activity against different tumor cell lines.

EXPERIMENTAL APPROACH

The effect of tigecycline was evaluated in vitro in HCT116 cells and in vivo in a colitis-associated colorectal cancer (CAC) murine model. 5-fluorouracil was assayed as positive control in both studies.

KEY RESULTS

Tigecycline showed an antiproliferative activity targeting the Wnt/β-catenin pathway and downregulating STAT3. Moreover, tigecycline induced apoptosis through extrinsic, intrinsic and endoplasmic reticulum pathways converging on an increase of CASP7 levels. Furthermore, tigecycline modulated the immune response in CAC, reducing the cancer-associated inflammation through downregulation of cytokines expression. Additionally, tigecycline favored the cytotoxic activity of cytotoxic T lymphocytes (CTLs), one of the main immune defenses against tumor cells. Lastly, the antibiotic reestablished the gut dysbiosis in CAC mice increasing the abundance of bacterial genera and species, such as Akkermansia and Parabacteroides distasonis, that act as protectors against tumor development. These findings resulted in a reduction of the number of tumors and an amelioration of the tumorigenesis process in CAC.

CONCLUSION AND IMPLICATIONS

Tigecycline exerts a beneficial effect against CRC supporting the use of this antibiotic for the treatment of this disease.

'Click' synthesized calcium-chitosan-triazole nanocomplex from CaC2 as an efficient drug carrier, antimicrobial and antioxidant polymer

A calcium-chitosan-triazole nanocomplex (Ca@CS-Tz) was synthesized via the robust copper catalyzed azide-alkyne cycloaddition using calcium carbide (CaC2) as an in-situ source of acetylene. The nanocomplex was characterized by various techniques and it was proved to be an efficient drug carrier with satisfactory antimicrobial and antioxidant properties. Quercetin loaded nanocomplex (encapsulation efficiency- 68.2 ± 1.0 %) was studied for targeted drug release and the drug release after 120 h was found to be 80.7 ± 0.8 % and 8.69 ± 0.5 % at pH 5.0 and 7.4 respectively. On biological evaluation, the nanocomplex showed enhanced antimicrobial activity against gram-negative bacteria Escherichia coli (E. coli), gram-positive bacteria Bacillus subtilis (B. subtilis) and a fungi Aspergillus niger (A. niger). Moreover, the synthesized Ca@CS-Tz nanocomplex also exhibited significant antioxidant property. Herein, the novel results corresponding to the antimicrobial effect on A. niger and drug delivery studies performed using our previously synthesized chitosan triazole (CS-triazole) derivative have also been reported. Finally, the results of the present study were compared to the results obtained to our previously reported derivative. The incorporation of calcium ions into CS-triazole can lead to the utilization of this complex in various other biomedical applications e.g. bone tissue engineering.

The Lung Microbiota and Lung Cancer: A Growing Relationship

Simple Summary

In the past few years, the microbiota has emerged as a major player in cancer management. The efficacy of chemotherapy or immunotherapy may be influenced by the concomitant use of antibiotics before, during, or shortly after treatment with immune checkpoint inhibitors. Despite this, the mechanism linking the microbiota, host immunity, and malignancies are not clear, and the role of microbiota manipulation and analyses in cancer management is underway. In this manuscript, we discuss the role of the microbiota in the initiation, progression, and treatment outcomes of lung cancer.

Abstract

The lung is home to a dynamic microbial population crucial to modulating immune balance. Interest in the role of the lung microbiota in disease pathogenesis and treatment has exponentially increased. In lung cancer, early studies suggested an important role of dysbiosis in tumor initiation and progression. These results have helped accelerate research into the lung microbiota as a potential diagnostic marker and therapeutic target. Microbiota signatures could represent diagnostic biomarkers of early-stage disease. Lung microbiota research is in its infancy with a limited number of studies and only single-center studies with a significant methodological variation. Large, multicenter longitudinal studies are needed to establish the clinical potential of this exciting field.

Piperacillin/Tazobactam and Meropenem Use Increases the Risks for Acute Graft Rejection Following First Kidney Transplantation

Many broad-spectrum antibiotics (BSA) alter the intestinal microbiome that regulates adaptive immune responses. We hypothesized that BSA use before and early after kidney transplant may affect acute graft rejection (AGR). We carried out a retrospective cohort study on all patients who underwent kidney transplants in our institution. Patient demographics, clinical data, diagnosis, and treatment history were collected. Antibiotic use within 2 months prior to transplant and during the hospital admissions for transplant, as well as antibiotic types were recorded. A total of 357 consecutive first transplants were included for analysis. Median age was 52 years (range 7–76). A total of 67 patients received living donor and 290 deceased donor kidneys. A total of 19 patients received BSA within two months prior to transplant and 55 patients during the hospital admission for the transplant. With a median follow-up of 1270 days, 38 episodes of biopsy-proven AGR were recorded. There was no difference in the AGR rates during the first year between patients who received BSA and those who did not. However, the use of piperacillin/tazobactam or meropenem (PM) was associated with increased risks for the development of AGR, irrespective of the source of the donor grafts. Time to development of AGR was also shorter. Our data, therefore, suggest that the use of PM BSA prior to and immediately after kidney transplant increases the risks for AGR.

The interplay between anticancer challenges and the microbial communities from the gut

Cancer being an increasing burden on human health, the use of anticancer drugs has risen over the last decades. The physiological effects of these drugs are not only perceived by the host's cells but also by the microbial cells it harbors as commensals, notably the gut microbiota. Since the early '50 s, the cytotoxicity of anticancer chemotherapy was evaluated on bacteria revealing some antimicrobial activities that result in an established perturbation of the gut microbiota. This perturbation can affect the host's health through dysbiosis, which can lead to multiple complications, but has also been shown to have a direct effect on the treatment efficiency.We, therefore, conducted a review of literature focusing on this triangular relationship involving the microbial communities from the gut, the host's disease, and the anticancer treatment. We focused specifically on the antimicrobial effects of anticancer chemotherapy, their impact on mutagenesis in bacteria, and the perspectives of using bacteria-based tools to help in the diagnostic and treatment of cancer.

To study the contributing factors and outcomes of Clostridioides difficile infection in patients with solid tumors

Background

Clostridioides difficile infection (CDI) is a considerable healthcare burden, and now identified as the leading cause of acquired diarrheal illness in patients receiving antibiotics. Patients with malignancies are more prone to acquire CDI, owing to their frequent exposure to risk factors.

Objective

This study aims to investigate the factors affecting the outcome of Clostridioides Difficile Infection in patients with solid tumors at our community healthcare center.

Methods

This is a retrospective study that included a total of 59 patients with solid tumors who were hospitalized for Clostridioides difficile infection.

Results

The median age of the study population was 79 years with 39 males and 20 females. The patients had a diagnosis of a malignancy involving the following sites: prostate (25), lung (19), colon (7), bladder (4), breast (3), and renal (1). There were 52 cases of first time and 7 cases of recurrent CDI admissions. 40 patients were detected to have CDI at presentation while 19 patients were diagnosed with CDI after admission. CDI was categorized as follows: non-severe (29), severe (28), and very severe (2). There were 33 patients on chemotherapy and 20 patients undergoing radiotherapy. Twenty-seven patients had a recent history of cancer care-related procedures or interventions. Twenty-nine patients were from either a rehabilitation center or a long-term nursing care facility. There were 39 recent hospitalizations with 29 patients receiving antibiotics. Almost half of the patients were on proton pump inhibitors (29) and 12 were on steroids (20.3%) at the time of developing CDI. Patients with a high-risk qSOFA score of 2 or more (p-value = 0.008) or a high white blood cell count of >15 × 10⁹/L (p-value = 0.016) at the time of admission were found to have higher in-hospital mortality. Critical care data suggested that 9 patients required intensive care, 7 patients required vasopressor support, and 6 needed mechanical ventilation. Patients were treated with either vancomycin alone (13), or metronidazole alone (25), or combination therapy with vancomycin + metronidazole (21). The median duration of hospital stay was 6 days with 11 fatalities (18.64%).

Conclusions

CDI causes significant morbidity in patients with malignancies. A high qSOFA score and leukocytosis are significantly associated with high morbidity and thus should be used to prioritize and intensify inpatient care of these patients.

Fine-tuning of the pharmacological potential of novel thiazolium ionic liquids by anion alteration

A novel series of thiazolium ionic liquids (TILs) bound to chloride (2a-c), tetrafluoroborate (BF4) (3a-c), and bis-(trifluoromethanesulfonimide) (Tf2N) anions (4a-c) was synthesized and their physicochemical characteristics were investigated using various microanalytical techniques. The pharmacological potential of the new TILs was assessed as chemotherapeutic agents for bacterial infections and ovarian cancer (SKOV-3). Notably, ILs with the same cations become more bactericidal upon their binding with the strongest chaotropic anion (TN2f). The in vitro toxicity of the TILs toward ovarian carcinoma cell lines (SKOV-3) and normal human skin fibroblast cells (HSF) revealed that all tested TILs have the capacity to induce a dose- and time-dependent decline in SKOV-3 cell viability, with Tf2N-linked TILs (4a-c) having a preferable efficacy. In addition, the new compounds showed excellent selectivity for cancer cells (SKOV-3) over healthy cells (HSF). [iPBzTh][Tf2N] (4b) is the most cytotoxic and specific one and may act as a promising anti-ovarian cancer agent.

Antibiotics to modify sickle cell disease vaso-occlusive crisis?

Despite the availability of hydroxyurea, the clinical use of the medication among patients with sickle cell disease (SCD) remains low in the United States. Given the high healthcare utilization cost, SCD requires new therapeutic approaches. Recent studies demonstrated bacterial overgrowth and dysbiosis-related intestinal pathophysiological changes in SCD. Intestinal microbes regulate neutrophil ageing. Aged and activated neutrophils contribute to the pathogenesis of vaso-occlusive crisis (VOC) in SCD. In this paper, we will review the pre-clinical and clinical data on how antibiotics might reduce the intestinal microbial density and influence the course of VOC. Based on these observations, we will discuss rationales for and potential challenges to antibiotic-based therapeutic approaches that may modify the clinical course of VOC in SCD.