Ceragenins exhibit bactericidal properties that are independent of the ionic strength in the environment mimicking cystic fibrosis sputum.

The purpose of the work was to investigate the impact of sodium chloride (NaCl) on the antimicrobial efficacy of ceragenins (CSAs) and antimicrobial peptides (AMPs) against bacterial and fungal pathogens associated with cystic fibrosis (CF) lung infections. CF-associated bacterial (Pseudomonas aeruginosa, Ochrobactrum spp., and Staphylococcus aureus), and fungal pathogens (Candida albicans, and Candida tropicalis) were used as target organisms for ceragenins (CSA-13 and CSA-131) and AMPs (LL-37 and omiganan). Susceptibility to the tested compounds was assessed using minimal inhibitory concentrations (MICs) and bactericidal concentrations (MBCs), as well as by colony counting assays in CF sputum samples supplemented with various concentrations of NaCl. Our results demonstrated that ceragenins exhibit potent antimicrobial activity in CF sputum regardless of the NaCl concentration when compared to LL-37 and omiganan. Given the broad-spectrum antimicrobial activity of ceragenins in the microenvironments mimicking the airways of CF patients, ceragenins might be promising agents in managing CF disease.

Antibiotic-Resistant Strains of Helicobacter pylori in 50 Antibiotic Treatment-Naive Children in Northeast Poland Diagnosed by Gastric or Duodenal Biopsy Between February 2019 and May 2022.

BACKGROUND In recent years, an increasing prevalence of Helicobacter pylori resistance to antibiotics has been observed. The aim of this study was to assess antibiotic resistance of Helicobacter pylori in previously untreated children from northeast Poland. MATERIAL AND METHODS Inclusion criteria comprised suspicion of Helicobacter pylori infection based on the presence of Helicobacter pylori antigen in the stool and/or characteristic macroscopic lesions seen on esophagogastroduodenoscopy. Samples of the gastric and/or duodenal mucosa were collected from 82 children with a median age of 13 years (range 3-17) during esophagogastroduodenoscopy between February 2019 and May 2022. The material was cultured, and positive Helicobacter pylori strains were tested for drug resistance to amoxicillin, metronidazole, and clarithromycin using the quantitative antibiotic concentration gradient stripe method E-test. RESULTS Based on biopsy culture, Helicobacter pylori infection was confirmed in 50 (61%) children. Helicobacter pylori resistance was most common to clarithromycin (n=19; 38%), followed by metronidazole (n=15; 30%), and the least frequent to amoxicillin (n=13; 26%). The resistance to 1 antibiotic was found in 14 children (28%). Double-drug resistance was noted in 3 children (6%) and triple drug resistance in 9 children (18%). In the whole group, 24 children (48%) were susceptible to all 3 antibiotics. CONCLUSIONS In this study, conducted for the first time in treatment-naïve children in northeast Poland, we found a high proportion of Helicobacter pylori strains resistant to at least 1 antibiotic. Our results may help in the appropriate choice of antibiotics for treatment of Helicobacter pylori in our region.

Cathelicidin LL-37 in Health and Diseases of the Oral Cavity.

The mechanisms for maintaining oral cavity homeostasis are subject to the constant influence of many environmental factors, including various chemicals and microorganisms. Most of them act directly on the oral mucosa, which is the mechanical and immune barrier of the oral cavity, and such interaction might lead to the development of various oral pathologies and systemic diseases. Two important players in maintaining oral health or developing oral pathology are the oral microbiota and various immune molecules that are involved in controlling its quantitative and qualitative composition. The LL-37 peptide is an important molecule that upon release from human cathelicidin (hCAP-18) can directly perform antimicrobial action after insertion into surface structures of microorganisms and immunomodulatory function as an agonist of different cell membrane receptors. Oral LL-37 expression is an important factor in oral homeostasis that maintains the physiological microbiota but is also involved in the development of oral dysbiosis, infectious diseases (including viral, bacterial, and fungal infections), autoimmune diseases, and oral carcinomas. This peptide has also been proposed as a marker of inflammation severity and treatment outcome.

Biocompatible Materials in Otorhinolaryngology and Their Antibacterial Properties.

For decades, biomaterials have been commonly used in medicine for the replacement of human body tissue, precise drug-delivery systems, or as parts of medical devices that are essential for some treatment methods. Due to rapid progress in the field of new materials, updates on the state of knowledge about biomaterials are frequently needed. This article describes the clinical application of different types of biomaterials in the field of otorhinolaryngology, i.e., head and neck surgery, focusing on their antimicrobial properties. The variety of their applications includes cochlear implants, middle ear prostheses, voice prostheses, materials for osteosynthesis, and nasal packing after nasal/paranasal sinuses surgery. Ceramics, such as as hydroxyapatite, zirconia, or metals and metal alloys, still have applications in the head and neck region. Tissue engineering scaffolds and drug-eluting materials, such as polymers and polymer-based composites, are becoming more common. The restoration of life tissue and the ability to prevent microbial colonization should be taken into consideration when designing the materials to be used for implant production. The authors of this paper have reviewed publications available in PubMed from the last five years about the recent progress in this topic but also establish the state of knowledge of the most common application of biomaterials over the last few decades.

Nanomechanical Hallmarks of Helicobacter pylori Infection in Pediatric Patients.

BACKGROUND: the molecular mechanism of gastric cancer development related to Helicobacter pylori (H. pylori) infection has not been fully understood, and further studies are still needed. Information regarding nanomechanical aspects of pathophysiological events that occur during H. pylori infection can be crucial in the development of new prevention, treatment, and diagnostic measures against clinical consequences associated with H. pylori infection, including gastric ulcer, duodenal ulcer, and gastric cancer. METHODS: in this study, we assessed mechanical properties of children's healthy and H. pylori positive stomach tissues and the mechanical response of human gastric cells exposed to heat-treated H. pylori cells using atomic force microscopy (AFM NanoWizard 4 BioScience JPK Instruments Bruker). Elastic modulus (i.e., the Young's modulus) was derived from the Hertz-Sneddon model applied to force-indentation curves. Human tissue samples were evaluated using rapid urease tests to identify H. pylori positive samples, and the presence of H. pylori cells in those samples was confirmed using immunohistopathological staining. RESULTS AND CONCLUSION: collected data suggest that nanomechanical properties of infected tissue might be considered as markers indicated H. pylori presence since infected tissues are softer than uninfected ones. At the cellular level, this mechanical response is at least partially mediated by cell cytoskeleton remodeling indicating that gastric cells are able to tune their mechanical properties when subjected to the presence of H. pylori products. Persistent fluctuations of tissue mechanical properties in response to H. pylori infection might, in the long-term, promote induction of cancer development.

Biofilm Growth Causes Damage to Silicone Voice Prostheses in Patients after Surgical Treatment of Locally Advanced Laryngeal Cancer.

Voice prosthesis implantation with the creation of a tracheoesophageal fistula is the gold standard procedure for voice rehabilitation in patients after a total laryngectomy. All patients implanted with a voice prosthesis (VP) have biofilms of fungi and bacteria grow on their surface. Biofilm colonization is one of the main reasons for VP degradation that can lead to VP dysfunction, which increases the high risk of pneumonia. In a 20-month evaluation period, 129 cases of prostheses after replacement procedures were investigated. Microbiological examination of the biofilms revealed that there were four of the most common fungi species (Candida spp.) and a large variety of bacterial species present. We studied the relationship between the time of proper function of Provox VP, the microorganism composition of the biofilm present on it, and the degradation level of the silicone material. Evaluation of the surface of the removed VP using an atomic force microscope (AFM) has demonstrated that biofilm growth might drastically change the silicone's mechanical properties. Changes in silicone stiffness and thermal properties might contribute to the failure of VP function. Our data can serve in future studies for the development of methods to prevent or inhibit biofilm formation on the VP surface that would translate to an increase in their durability and safety.

Quantification of Synergistic Effects of Ceragenin CSA-131 Combined with Iron Oxide Magnetic Nanoparticles Against Cancer Cells.

BACKGROUND: Therapeutic efficiency of ceragenins against cancers may be limited by lack of their hemocompatibility when high concentrations of molecules are required to reach a desired result. Synergistic effects observed upon administration of anticancer agents and metal nanoparticles may provide an opportunity to limit toxicity of immobilized ceragenins on the surface of metal nanoparticles and to improve their therapeutic efficiency at the same time. The aim of present work is to investigate the anticancer activities and hemocompatibility of nanoformulations consisting of ceragenin CSA-131 united with aminosilane-modified iron oxide-based magnetic nanoparticles (MNP) and prepared by 1) covalent bonding (MNP@CSA-131) or 2) by combining CSA-131 with MNP in 1:1 ratio (CSA-131 + MNP). Possible synergistic interactions between CSA-131 and magnetic nanoparticles were also quantified. METHODS: MNP@CSA-131 and CSA-131+MNP were tested in vitro against selected lung and colon cancer cells using colorimetric, fluorimetric and flow cytometry methods. RESULTS: Performed analysis demonstrates that MNP-based nanosystems significantly improve the killing efficiency of tested ceragenin, decreasing the viability of extra 1.37±4.72% to 76.07±15.30% cancer cells when compared to free CSA-131. Quantification of synergistic effects indicates the favorable interactions between CSA-131 and magnetic nanoparticles (CI < 1 for all tested doses), revealing at the same time a reduction in effective doses of ceragenin from 1.17 ± 0.61 to 34.57 ± 12.78 times when combined with MNP. We demonstrate that both MNP@CSA-131 and CSA-131+MNP induce significantly apoptosis of cancer cells and prevent the division of colon cancer cells even at relatively low doses of the active compound (10 µg/mL). Importantly, combining CSA-131 with MNP decreases the hemolytic activity of free ceragenin 4.72 to 7.88 times, which indicates a considerable improvement of hemotoxicity profile. CONCLUSION: Comparative analyses have revealed that both developed CSA-containing nanoformulations due to the utility of synergistic interactions between MNP and CSA-131, which are effective against lung and colon cancer cells. This indicates the new directions in preparation of MNP-based therapeutics, which are relatively easy to synthetize, cost-effective and safe when intravenously administrated.

Nanoantibiotics containing membrane-active human cathelicidin LL-37 or synthetic ceragenins attached to the surface of magnetic nanoparticles as novel and innovative therapeutic tools: current status and potential future applications.

Nanotechnology-based therapeutic approaches have attracted attention of scientists, in particular due to the special features of nanomaterials, such as adequate biocompatibility, ability to improve therapeutic efficiency of incorporated drugs and to limit their adverse effects. Among a variety of reported nanomaterials for biomedical applications, metal and metal oxide-based nanoparticles offer unique physicochemical properties allowing their use in combination with conventional antimicrobials and as magnetic field-controlled drug delivery nanocarriers. An ever-growing number of studies demonstrate that by combining magnetic nanoparticles with membrane-active, natural human cathelicidin-derived LL-37 peptide, and its synthetic mimics such as ceragenins, innovative nanoagents might be developed. Between others, they demonstrate high clinical potential as antimicrobial, anti-cancer, immunomodulatory and regenerative agents. Due to continuous research, knowledge on pleiotropic character of natural antibacterial peptides and their mimics is growing, and it is justifying to stay that the therapeutic potential of nanosystems containing membrane active compounds has not been exhausted yet.

Conventional and molecular methods in the diagnosis of community-acquired diarrhoea in children under 5 years of age from the north-eastern region of Poland.

OBJECTIVES: The purpose of this study was to determine the main causative agents of community-acquired acute diarrhoea in children using conventional methods and PCR. METHODS: Stool samples were collected from 100 children under 5 years of age with acute diarrhoea during the autumn-winter period of 2010-2011. Rotaviruses and adenoviruses were detected by the stool antigen immunoassay, and Salmonella spp, Campylobacter spp, Shigella spp, Yersinia enterocolitica, Yersinia pseudotuberculosis, Clostridium difficile, enterotoxigenic Bacteroides fragilis (ETBF), and diarrhoeagenic Escherichia coli were detected by culture methods and PCR. RESULTS: Overall, enteropathogens were identified in 73% of the children. Bacteria, viruses, and mixed infections were noted in 37%, 24%, and 12% of diarrhoeal cases, respectively. The most common enteric pathogens were rotaviruses (31%), followed by C. difficile (17%), Campylobacter jejuni (13%), Salmonella spp (11%), and atypical enteropathogenic Escherichia coli (aEPEC) strains (10%). Compared with culture methods, PCR increased the overall detection frequency of the bacterial enteropathogens by 4%. CONCLUSIONS: The high prevalence of Campylobacter jejuni suggests that the number of campylobacteriosis cases in Poland may be underestimated; this pathogen should be investigated routinely in children with diarrhoea. Moreover, C. difficile might be considered a causative or contributing agent of diarrhoea in 14.8% of children aged >1 year.

[Clostridium difficile toxin A and other enteropathogens in stool specimens of children hospitalized due to acute diarrhoea]. / Toksyna A Clostridium difficile i inne enteropatogeny w kale dzieci hospitalizowanych z powodu ostrej biegunki.

A total of 74 fresh stool specimens obtained from children with acute diarrhoea (43) and without diarrhoea (31) were examined simultaneously for bacteria pathogens (culture methods) and for Clostridium difficile toxin A (Oxoid Toxin A Kits) and enteric viruses (only diarrhoeal samples) (Slidex Rota-Adeno Kits; bioMçrieux). One (49%) or dual with C. difficile (23%) enteric pathogens associated with community-acquired diarrhoea (58% bacteria and 14% viruses) in 31 (72%) children were recognized. Clostridium difficile associated diarrhoea (CDAD) (18,6%) and Salmonella enterica subsp. enterica serovar Enteritidis (16,3%) the most commonly were observed. Children were considered to have CDAD if they met special criteria such as the positive test for C. difficile toxin A, the presence of diarrhoea for at least 2 days and no other documented enteric pathogens. It was be found that antibiotic usage in the previous 3 weeks as a main risk factor for CDAD not be frequent (only 2/8 CDAD). The frequency of C. difficile toxin A detection in the diarrhoeal stool specimens from children treated or not treated with antibiotics was comparable (p>0,05); this same observed when stool specimens from children without diarrhoea were tested. The frequency of toxin A detection in stool specimens from children with acute diarrhoea (41,9%) and without diarrhoea (54,8%) was comparable (p>0,05) also. In conclusion, we recommended detection of toxin A by C. difficile toxin A Test as the rapid screening in diarrhoeal stool specimens only because the high predictive value of a negative test and the high sensitivity for CDAD with special criteria were found.