Antibiotics Gentamicin Research Articles

Microneedles based on hyaluronic acid-polyvinyl alcohol with antibacterial, anti-inflammatory, and antioxidant effects promote diabetic wound healing

Diabetic wound healing has become one of the major clinical burdens due to uncontrolled bacterial growth and an increase in the risk of various microbial infections. Despite excellent antioxidant properties, the poor aqueous solubility of resveratrol (RES) hampers its applicability. In this study, we proposed a novel multifunctional microneedle patch loaded with RES-encapsulated polymeric micelles. Resveratrol micelles (RES MC) were loaded in the microneedle tip, while the base part was coated with the antibiotic gentamicin (GEN) to promote wound healing. The microneedle tip composed of sodium hyaluronate (HA) could effectively deliver the anti-inflammatory and antioxidant RES MC. Furthermore, the base of the microneedle patch composed of polyvinyl alcohol (PVA) offered excellent flexibility, releasing GEN and providing resistance to bacterial contamination, thereby further promoting wound repair. In vitro antibacterial experiments indicated that the bactericidal rate reached 99 %. Further, the wound healing rate was recorded as 86.05 % on the 11th day of diabetes wound treatment. Together, the multifunctional microneedle patch with excellent biocompatibility exhibited anti-inflammatory, antioxidant, and antibacterial effects on the wound healing process, potentiating its efficacy in the treatment of diabetic wounds.

Stress granules formation in HEI-OC1 auditory cells and in H4 human neuroglioma cells secondary to cisplatin exposure

Abstract Stress granules (SGs) are highly dynamic micromolecular membraneless condensates that generate in cells subjected to stress. Formed from pools of untranslating messenger ribonucleoproteins (RNP), SGs dynamics constitute vital processes essential for cell survival. Here, we investigate whether established cytotoxic agents, such as the platinum-based chemotherapeutic agent cisplatin and the aminoglycoside antibiotic gentamicin, elicit SG formation in the House Ear Institute-Organ of Corti-1 (HEI-OC1) auditory cell line, H4 human neuroglioma cells and HEK-293T human embryonic kidney cells. Cells were treated with cisplatin or gentamicin for specific durations at designated concentrations. SG formation was assessed using immunocytochemistry and live cell imaging. Levels of essential proteins involved in SG assembly were evaluated using immunoblotting. We observed cisplatin-associated SG assembly in HEI-OC1 and H4 cells via confocal microscopy through antibody colabeling of G3BP1 with PABP or Caprin1. While maintaining an unchanged pattern of expression of main constituent SG proteins, cisplatin-related SGs in H4 cells persisted for at least 12 h after drug removal. Cells subjected to gentamicin exposure did not exhibit SGs. Our findings offer insights into subcellular mechanisms related to cisplatin-associated cytotoxicity, highlighting the need for future studies to further investigate this stress-response mechanism.

Bactericidal and Synergistic Effects of Lippia origanoides Essential Oil and Its Main Constituents against Multidrug-Resistant Strains of Acinetobacter baumannii.

Bacterial resistance in Acinetobacter baumannii is a significant public health challenge, as these bacteria can evade multiple antibiotics, leading to difficult-to-treat infections with high mortality rates. As part of the search for alternatives, essential oils from medicinal plants have shown promising antibacterial potential due to their diverse chemical constituents. This study evaluated the antibacterial, antibiofilm, and synergistic activities of the essential oil of Lippia origanoides (EOLo) and its main constituents against multidrug-resistant clinical isolates of A. baumannii. Additionally, the antibacterial and antibiofilm potential of a nanoemulsion containing carvacrol (NE-CAR) was assessed. EOLo was extracted through hydrodistillation, and its components were identified via gas chromatography coupled with mass spectrometry. The A. baumannii isolates (n = 9) were identified and tested for antimicrobial susceptibility using standard disk diffusion methods. Antibacterial activity was determined by broth microdilution, while antibiofilm activity was measured using colorimetric methods with crystal violet and scanning electron microscopy. Synergism tests with antibiotics (meropenem, ciprofloxacin, gentamicin, and ampicillin+sulbactam) were performed using the checkerboard method. The primary constituents of EOLo included carvacrol (48.44%), p-cymene (14.58%), and thymol (10.16%). EOLo, carvacrol, and thymol demonstrated significant antibacterial activity, with carvacrol showing the strongest effect. They were also effective in reducing biofilm formation, as was NE-CAR. The combinations with antibiotics revealed significant synergistic effects, lowering the minimum inhibitory concentration of the tested antibiotics. Therefore, this study confirms the notable antibacterial activity of the essential oil of L. origanoides and its constituents, especially carvacrol, suggesting its potential as a therapeutic alternative for A. baumannii infections.

Galangin prevents gentamicin-induced nephrotoxicity by modulating oxidative damage, inflammation and apoptosis in rats.

The well-known antibiotic gentamicin (GEN) works well against a variety of pathogenic bacteria, nevertheless its therapeutic use might be limited by the possibility of nephrotoxicity. The naturally occurring flavonoid galangin (GAL) has several interesting anti-inflammatory and antioxidant properties. The present study evaluated the nephroprotective effect of GAL on GEN-induced renal injury. Rats received GAL for 14 days and GEN from day 8 to day 14. There was a significant increase in serum urea and creatinine along with several histopathological changes in the kidney following GEN administration. GEN-treated rats also showed increased levels of kidney MDA and NO, and decreased GSH content and activities of antioxidant enzymes. Rats received GEN also demonstrated increased NF-κB p65, iNOS, TNF-α, IL-1β and IL-6 levels in the kidney. GAL remarkably prevented tissue injury, attenuated MDA and NO levels, improved antioxidants, and decreased levels of inflammatory mediators in the kidney of GEN-treated rats. Furthermore, GEN-administrated rats exhibited increased Bax and caspase-3 with concomitant decline in Bcl-2 levels in the kidney, an effect that GAL attenuated. In conclusion, GAL prevents GEN-induced nephrotoxicity by attenuating oxidative stress, inflammation, and apoptosis and augmenting antioxidant defense, suggesting its therapeutic potential against drug nephrotoxicity.

Aqueous electrophoretic deposition of yttrium-doped nanobioactive glass/collagen/chitosan orthopedic coatings on 316L SS

The current study used yttrium-doped nanobioactive glass (Y-nBG), based on 62 SiO2 – (33 – x) CaO – 5 P2O5 – x Y2O3 mole % system (x = 0 and 3 mol %), collagen, and chitosan composites for coating 316L stainless steel (316L SS) using aqueous electrophoretic deposition (EPD) technique. The corresponding coated samples are encoded as SS/Col-Chit, SS/BG-Y0/Col-Chit, and SS/BG-Y3/Col-Chit, respectively. Physicochemical characterization implied TGA, FTIR, SEM-EDX, contact angle, adhesion strength and in vitro bioactivity in SBF were performed. Following SBF immersion, FTIR and SEM-EDX investigations were also carried out. Furthermore, the coatings were loaded with gentamicin drug; the drug-release profile and mechanism were evaluated. The antibacterial efficacy of the composite coatings was also assessed. The results showed the formation of homogeneous coatings with good adhesion strength, 1.39 MPa, 0.55 MPa, and 0.81 MPa, and enhanced the wettability by decreasing the contact angle 36⁰, 22⁰ and 12⁰ for SS/Col-Chit, SS/BG-Y0/Col-Chit and SS/BG-Y3/Col-Chit coatings, respectively. In vitro bioactivity of coatings containing nBG revealed apatite formation after immersion in SBF. Furthermore, the antibiotic gentamicin showed a sustained release profile over time by diffusion mechanisms based on the Higuchi, Fickian, and Weibull models. As well, all coatings containing drugs have an antibacterial effect. Overall, these findings suggested that the prepared coatings have potential applications as orthopedic and dental implants.

A Study of the Characteristics and Properties of P. aeruginosa Isolated from Different Sources and their Resistance to Antibiotics

Pseudomonas aeruginosa, a common opportunistic bacterium, is a major source of human surface infections. Infections with these bacteria are difficult to cure and cause significant economic implications. Objectives The current study looked at the antibiotic resistance patterns of P. aeruginosa isolated from burns, wound swabs, and urinary tract infections that were referred to Iraq Hospitals' emergency health care units. From October 2022 to May 2023, 180 swabs were collected from burn and wound patients (110 burns, 67 wounds, and 3 urinary tract infections) of both sexes, (80) males and (100) females, aged 1-72 years, at Baghdad government hospitals: Ghazi Al-Hariri Hospital, Central Laboratories, Specialized Burns Hospital, and Yarmouk Hospital. Results:(180) diagnostic swabs from patients with burns and wound infections of both sexes, (80) males and (100) females, aged 1–72 years. The current study found 25(31.25) more P. aeruginosa positive cases in males than females, with 29(29) out of 54 positive cases. The study discovered that the age group 21-30 years had the highest rate of bacterial infection, followed by the age groups 11-20 and 1-10, with 11 (20.37%), 10 (18.51%), and 10 (18.51%), respectively. According to the current study's findings, the antibiotics Amikacin, Gentamicin, Ceftazidime, Cefepime, Netilmicin, and Tobramycin showed the highest resistance rates (81.4%, 81.4%, 79.6%, 72.2%, 74%, and 79.6%, respectively).The test findings showed that 52 isolates (96%) produced pyrocyanin and hemolysins. Bacterial colonies were white to gray with a sticky feel. All isolates exhibited β-hemolysis.Alkaline protease production All isolates exhibited a translucent halo surrounding the bacterial colonies.Lipase production All isolates exhibited a hazy halo surrounding the development zone of P.aeruginosa colonies. The current study discovered that the antibiotics Amikacin, Gentamicin, Ceftazidime, Cefepime, Netilmicin, and Tobramycin were the most resistant in cases of burn and wound patients, as well as urinary tract infections in Iraq.

Urinary tract infection pathogens diagnosed in Basra city hospitals

Background. Urinary tract infection (UTI) is the growth of pathological bacteria within the urinary tract, and is one of the most common types of bacterial infections worldwide. Bacterial resistance to antibiotics is a major public health concern. Antibiotic-resistant bacterial infections exacerbate the situation in developed, developing and underdeveloped countries. Objective. The aim of this research is to identify the frequency of different bacterial pathogens and their sensitivity to different types of antibiotics in patients suffering from UTI in Basra city hospitals. Method. This cross-sectional study included 505 samples positive for bacterial growth. It was conducted by data extraction from hospital laboratory records, where information was obtained about bacterial examination of urine samples taken from patients with urinary tract infection. The samples were cultured and antibiotic sensitivity was tested by laboratory workers, in order to determine the appropriate treatment for patients. Results and conclusions. The average age of patients was 43.5 years, of whom (60.4%) were females. The most common bacteria was Escherichia coli (40.6%). In antibiotic susceptibility testing process, gentamicin (5.7%), ciprofloxacin (4.7%), trimethoprim (4.7%), trimethoprim/sulfamethoxazole (4.1%), and cefepime (3.9%) were the most frequently used antibiotics, while cefotetan (0.06%), ampicillin-sulbactam (0.09%), mupirocin (0.2%), cefazolin (0.2%), fosfomycin and amoxicillin (0.2%) were the least used. The highest sensitivity shown by cultured bacteria was to linezolid (95.5%), ertapenem (91.7%), teicoplanin (79.4%), nitrofurantoin (75.2%) and amikacin (72.4%). The highest resistance shown by cultured bacteria was to cefazolin (100%), oxacillin (94.6%), fusidic acid (91.2%), ampicillin (90.4%), and amoxicillin (88.2%).

A multifunctional hydrogel dressing loaded with antibiotics for healing of infected wound

Wound bacterial infections can significantly delay the healing process and even lead to fetal sepsis. There is a need for multifunctional dressings that possess antibacterial property, tissue adhesive property, self-healing capability, and biocompatibility to effectively treat bacteria-infected wound. In this study, we report a dual dynamically crosslinked hydrogel, OHA-PBA/PVA/Gen, which incorporates the antibiotic gentamicin (Gen) as a dynamic crosslinker. The hydrogel is formed through the formation of Schiff base bonds between phenylboronic acid-grafted oxidized hyaluronic acid (OHA-PBA) and Gen, as well as boronic acid ester bonds between OHA-PBA and polyvinyl alcohol (PVA). This unique composition imparts tissue adhesiveness, injectability and self-healing property to the hydrogel. The hydrogel also exhibits pH-responsive antibiotic release behavior due to the acid-responsive dissociation of Schiff base bonds. As a result, it demonstrates strong antibacterial activity against both Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli through contact killing and diffusion killing mechanisms. Importantly, the OHA-PBA/PVA/Gen hydrogel avoids incorporation of toxic small molecular crosslinking agents, and all the components of the hydrogel are biocompatible, ensuring its biosafety. In a S. aureus-infected wound mouse model, this hydrogel effectively eradicated bacteria and promoted angiogenesis, leading to significantly accelerated wound healing. These results highlight the potential of the dual dynamically crosslinking hydrogel OHA-PBA/PVA/Gen as a multifunctional wound dressing for the treatment of bacteria-infected wound.

Isolation of Pathogenic Cronobacter Species as Bacteriological Risks Indicator in Powdered Infant Formula Available to Deprived Infants in Lagos Metropolis, Nigeria.

Powdered infant formula (PIF) is rich in nutrients that support the survival and growth of bacteria that trigger food safety disorders in deprived infants through life-threatening illnesses. The study aims to examine and identify the incidence of pathogenic bacteria of concern in PIF upon reconstitution in lukewarm water. A total of 172 samples consisting of 38 brands of PIF available in the Lagos metropolis were sampled, suspended in water (10g in 100mL), and bacteria strains were isolated using combinational enrichment and selective culture techniques. Pure bacterial strains were characterized and identified based on their physiology and 16S rRNA gene sequence homology. While 85 bacterial strains were isolated from the enriched culture system, 20 strains were selectively isolated based on tolerance to sodium deoxycholate. Approximately 13% of the selected bacteria were identified as Cronobacter spp., exhibiting virulence traits including extracellular protease production, coagulation and proteolysis of casein, haem-agglutination, and β-haemolysis of human blood. Approximately 82% of the Cronobacter strains tolerated NaCl (10%) and bile salt; and exhibited resistance to cefotaxime, ceftriaxone, gentamicin, and Amoxicillin-clavulanic acid antibiotics. The presence of Cronobacter spp. in 13% of the PIF brands available to infants calls for concern about the safety of deprived infants that might be fed with such PIF. Consequently, PIF safety alerts need to be activate while further studies on critical points at which the pathogens get introduced to the PIFs need to be identified.

Assessment of the potential susceptibility of planktonic cells and bacterial biofilms by diosgenin

Bacterial biofilms are formed by a complex community of microorganisms, held together by a matrix that provides structural support and stability to microbial communities, making infections associated with biofilms more difficult to treat. In the face of growing research in the health area in search of antibiotics with action against biofilms, natural products present an effective alternative strategy. In this context, the aim of this study was to evaluate bacterial biofilm formation, assess the susceptibility of planktonic cells to diosgenin, and examine its efficacy on inhibiting and treating biofilms. The broth microdilution method was used to determine the Minimum Inhibitory Concentration (MIC). Six bacterial strains were tested: Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 9027, Pseudomonas aeruginosa 24, Enterococcus faecalis INCQS 0017, Enterococcus faecalis INCQS 00018, and Enterococcus faecalis INCQS 654. The crystal violet method was employed to evaluate the potential of diosgenin in biofilm inhibition and eradication. Chlorhexidine gluconate served as a reference standard for the antibiofilm assays, along with the antibiotics norfloxacin, ampicillin, and gentamicin. MIC determination revealed that diosgenin exhibited intrinsic antimicrobial activity, with an MIC of 406 μg/mL against S. aureus ATCC 25923. The antibiofilm activity showed significant inhibition for E. faecalis 17 and moderate inhibition against E. faecalis 654 and S. aureus 25923. Furthermore, diosgenin effectively eradicated preformed biofilms of S. aureus 25923 and P. aeruginosa 9027, indicating its ability to interfere with biofilm biomass. These results suggest that diosgenin not only inhibits bacterial biofilm formation but also eradicates established biofilms, highlighting it as a promising candidate for the development of products aimed at combating bacterial biofilms.

Photocatalysis Inhibits the Emergence of Multidrug-Resistant Bacteria in an Antibiotic-Resistant Bacterial Community in Aquatic Environments.

Bacterial antibiotic resistance has recently attracted increasing amounts of attention. Here, an artificially antibiotic-resistant bacterial community (ARBC) combined with five different constructed antibiotic-resistant bacteria (ARB) with single antibiotic resistance, namely, kanamycin (KAN), tetracycline (TET), cefotaxime (CTX), polymyxin B (PB), or gentamicin (GEM), was studied for the stress response to photocatalysis. With photocatalytic inactivation, the transfer and diffusion of antibiotic resistance genes (ARGs) in the ARBC decreased, and fewer multidrug-resistant bacteria (MDRB) emerged in aquatic environments. After several days of photocatalytic inactivation or Luria broth cultivation, >90% ARB were transformed to antibiotic-susceptible bacteria by discarding ARGs. Bacteria with double antibiotic resistance were the dominant species (99%) of residual ARB. The changes in ARG abundance varied, decreasing for the GEM and TET resistance genes and increasing for the KAN resistance genes. The change in the antibiotic resistance level was consistent with the change in ARG abundance. Correspondingly, point mutations occurred for the KAN, CTX and PB resistance genes after photocatalytic inactivation, which might be the reason why these genes persisted longer in the studied ARBC. In summary, photocatalytic inactivation could reduce the abundance of some ARGs and inhibit the emergence of MDRB as well as block ARG transfer in the bacterial community in aquatic environments. This work highlights the advantages of long-term photocatalytic inactivation for controlling antibiotic resistance and facilitates a better understanding of bacterial communities in real aquatic environments.

The effect of combinations of a glyphosate-based herbicide with various clinically used antibiotics on phenotypic traits of Gram-negative species from the ESKAPEE group

The emission of glyphosate and antibiotic residues from human activities threatens the diversity and functioning of the microbial community. This study examines the impact of a glyphosate-based herbicide (GBH) and common antibiotics on Gram-negative bacteria within the ESKAPEE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli). Ten strains, including type and multidrug-resistant strains for each species were analysed and eight antibiotics (cefotaxime, meropenem, aztreonam, ciprofloxacin, gentamicin, tigecycline, sulfamethoxazole-trimethoprim, and colistin) were combined with the GBH. While most combinations yielded additive or indifferent effects in 70 associations, antagonistic effects were observed with ciprofloxacin and gentamicin in five strains. GBH notably decreased the minimum inhibitory concentration of colistin in eight strains and displayed synergistic activity with meropenem against metallo-β-lactamase (MBL)-producing strains. Investigation into the effect of GBH properties on outer membrane permeability involved exposing strains to a combination of this GBH and vancomycin. Results indicated that GBH rendered strains sensitive to vancomycin, which is typically ineffective against Gram-negative bacteria. Furthermore, we examined the impact of GBH in combination with three carbapenem agents on 14 strains exhibiting varying carbapenem-resistance mechanisms to assess its effect on carbapenemase activity. The GBH efficiently inhibited MBL activity, demonstrating similar effects to EDTA (ethylenediaminetetraacetic acid). Chelating effect of GBH may have multifaceted impacts on bacterial cells, potentially by increasing outer membrane permeability and inactivating metalloenzyme activity.

THE EFFECT OF THE ANTIBIOTIC GENTAMICIN ON THE STAGES OF ONTOGENESIS IN CHICKEN EGGS

Introduction: Various studies have shown that the effects of the action of drugs, in addition to having positive effects, they can also provoke negative effects in different organs of the body, where by giving more doses in some cases it can exceed the therapeutic limit and become toxic and produce pathological effects in both experimental animals and humans. Uncontrolled use and drug overdose can lead to macroscopic histopathological changes and give teratogenic, mutagenic and carcinogenic effects. Purpose of the paper: This paper aims to study the effects of some drugs at different stages of embryonic development in chicken eggs. The research of this paper will consist of the toxic effect of drugs and macroscopic and microscopic histopathological changes in certain stages of embryonic development of chicken eggs. Material and method: In the study, fertilized chicken eggs were taken and incubated in the incubator for 21 days of incubation. The eggs were treated with the antibiotic gentamicin at certain stages of embryonic development. The eggs hatched on day thirteen, day fifteen, eighteen and day twentyone. Using the stereomicroscope with the macroscopic and microscopic method were analyzed ontogenetic changes in certain stages of embryonic development. Results: The given dose of the antibiotic gentamicin can have negative effects in certain stages of embryonic development in chicken eggs. The dose given in ampullary form in certain quantities to chicken eggs has inhibited and stagnated the processes of embryonic development at different stages compared to control eggs. Conclusion: The given dose of gentamicin can stagnate embryonic development in certain stages and can provoke changes in certain stages of embryonic development. This phenomenon encourages us to do even more detailed research in this direction to see the effect of the given dose and to analyze what consequences it can provoke overdoses at different stages of embryonic development and within the organism. The lethal dose applied at certain stages of ontogenesis may have lethal consequences for the chick embryo at certain stages of embryonic development.

The in vitro Antimicrobial Effects of Hydrolysable and Condensed Tannin Extracts on Escherichia coli Isolated from Pathological Samples of Deceased Poultry

Abstract Colibacillosis, caused by avian pathogenic Escherichia coli (APEC), is one of the most prevalent and economically damaging bacterial diseases affecting poultry globally. Managing colibacillosis is difficult and frequently ineffective because APEC strains have developed widespread resistance to antibiotics, and the strict regulations and public concerns towards using antimicrobial agents in poultry further complicate the situation. This study aimed to evaluate the antibacterial properties of hydrolysable (sweet chestnut extract) and condensed (quebracho extract) tannins on Escherichia coli (E. coli) isolates from poultry, exploring their potential as antibiotic alternatives in managing colibacillosis. E. coli was isolated from the internal organs of deceased poultry across 18 farms, including layers, broilers, and broiler breeders. Each isolate was assessed for the presence of APEC strain predictors (virulence genes iutA, hlyF, iss, iroN, and ompT), antimicrobial resistance to 14 antibiotics using the disc diffusion method, and the presence of resistance genes for specific antibiotics (ampicillin, gentamicin, tetracycline, and quinolones). Out of 43 isolates, 27 (62.8%) were classified as APEC, 30 (69.8%) showed resistance to three or more antibiotic classes, and 32 (74.4%) carried at least one AMR gene. The minimum inhibitory concentrations (MICs) for the hydrolysable tannins from sweet chestnut extract (Castanea sativa Mill.) (SwCh) ranged from 0.5 to 3 mg/mL, while for the condensed tannins from quebracho extract (Schinopsis lorentzii) (Que), the MICs ranged from 1.5 to 4.5 mg/mL. The results indicate that both hydrolysable and condensed tannins possess significant in vitro antimicrobial activity against APEC, offering a potentially valuable alternative for controlling colibacillosis in the poultry industry.

Phytochemical Screening and Biological Activity (Antioxidant and Antibacterial) of Punica granatum Fruit peel extract Cultivated in Sa'dah Governorate-Yemen

Punica granatum (Pomegranate) is a valuable source of secondary plant metabolism compounds (SMs) that are widely used in the pharmaceutical, cosmetics, and food industries. The phytochemical screening illustrates that the Sa’dah P. granatum cultivar peel ethanol extract containsvarious beneficial components, including Flavonoids, Alkaloids, Steroids, Phenols, and Tannins. Moreover, the Sa’dah P. granatum cultivar peel ethanol extract (1.3 μg/ml) exhibited significant antioxidant activity compared to low concentrations of ascorbic acid (0.4, 0.6, 0.8, and 1 μg/ml). Furthermore, the Sa’dah P. granatum cultivar peel ethanol extract displays potent antibacterial activities against selected pathogenic bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) compared to two nominated antibiotics (Ampicillin and Gentamicin). This remarkable performance can be attributed to the presence of phenols and flavonoid compounds, which exhibit high antioxidant activity.

Facile and convenient electrochemical syntheses of novel multifunctional (catalytic, antioxidant and in vivo antimicrobial) phosphorylated chitosan derivatives

The electrochemical coupling of N-protected chitosan with diphenylphosphine oxide was recognized as new facile, fast, and convenient route to phosphorylated chitosans. The reaction affords low substituted (capable of self-assembling into nanoparticles), moderately substituted (water soluble) or highly substituted (soluble in both water and toluene) polymeric chitosan phosphonates. The degree of substitution can be adjusted by simply increasing the triphenylphosphine oxide/chitosan ratio. Highly substituted polymers (CH-P0.70) are efficient homogeneous catalysts towards the model reaction of monoglyceride synthesis (ca. 100% yield in 3 h). The phosphorylated chitosans are also efficient antioxidants. Their antioxidant effect increases with an increase in their degree of substitution. CH-P0.70 exhibits an antioxidant activity comparable to that of the natural antioxidant ascorbic acid. Remarkably, the highly substituted species is characterized by a strong in vivo antibacterial effect which is even more pronounced than that of the commercial antibiotics ampicillin and gentamicin. Moreover, the obtained phosphorylated chitosan CH-P0.70 demonstrates neither acute nor subacute in vivo toxicity.

Molecular detection of avian pathogenic Escherichia coli (APEC) in broiler meat from retail meat shop

Avian pathogenic Escherichia coli (APEC) is a major bacterial pathogen responsible for the most widespread form of colibacillosis, resulting in substantial economic losses within the poultry sector and posing a potential public health risk. From July to September 2021, our study investigated the antibiotic resistance pattern of Escherichia coli (E. coli) and the presence of virulence-associated genes (iucD, iutA, iss, and ompT) linked to APEC using 105 broiler meat samples comprising liver, thigh, and breast muscle, in Chitwan, Nepal. E. coli was isolated and identified by culturing samples on MacConkey's agar, Eosin-methylene blue (EMB) agar and performing different biochemical tests. Antibiotic resistance patterns of E. coli were determined by the Kirby-Bauer disc diffusion method. Following the isolation of E. coli, the molecular detection of APEC was performed using conventional polymerase chain reaction (PCR). Out of the 105 samples analyzed, 61 (58.1 %) tested positive for E. coli. In antibiotic susceptibility test (AST), gentamicin and tetracycline exhibited the highest resistance rates, with 90.2 % and 67.2 %, respectively and 29.5 % of the E. coli isolates displayed multidrug-drug resistance. Out of 61 confirmed E. coli isolates, iutA was detected in 47 (77.0 %) samples, iucD in 46 (75.4 %), iss in 53 (86.8 %), and ompT in 39 (63.9 %) samples. This study reports the occurrence of MDR E. coli in meat samples, together with virulence genes associated with APEC which poses a public health threat. Continuous surveillance is vital for monitoring APEC transmission within poultry farms, coupled with efforts to raise awareness of food safety among consumers of broiler meat.

Preparation and Characterization of Oxide Nanotubes on Titanium Surface for Use in Controlled Drug Release Systems.

Preventing or treating infections at implantation sites where the risk of bacterial contamination is high requires the development of intelligent drug delivery systems. The objective of this work was to develop a production method and characterization of fourth-generation oxide nanotubes on titanium grade 4 surface as a potential drug carrier. This study focused on the anodizing process; physico-chemical characterization using FE-SEM, EDS, and FTIR; in vitro corrosion resistance in an artificial saliva solution; and determining the drug release kinetics of gentamicin sulfate using UV-VIS. The anodizing process was optimized to produce fourth-generation oxide nanotubes in a fluoride-free electrolyte, ensuring rapid growth and lack of order. Results showed that the length of the oxide nanotubes was inversely proportional to the anodizing voltage, with longer nanotubes formed at lower voltages. The nanotubes were shown to have a honeycomb structure with silver particles co-deposited on the surface for antibacterial properties and were capable of carrying and releasing the antibiotic gentamicin sulfate in a controlled manner, following Fick's first law of diffusion. The corrosion resistance study demonstrates that the oxide nanotubes enhance the corrosion resistance of the titanium surface. The oxide nanotubes show promise in enhancing osseointegration and reducing post-implantation complications.

Mechanical Properties, Drug Release, Biocompatibility, and Antibacterial Activities of Modified Emulsified Gelatin Microsphere Loaded with Gentamicin Composite Calcium Phosphate Bone Cement In Vitro.

Bone defects are commonly addressed with bone graft substitutes; however, surgical procedures, particularly for open and complex fractures, may pose a risk of infection. As such, a course of antibiotics combined with a drug carrier is often administered to mitigate potential exacerbations. This study involved the preparation and modification of emulsified (Em) crosslinking-gelatin (gel) microspheres (m-Em) to reduce their toxicity. The antibiotic gentamicin was impregnated into gel microspheres (m-EmG), which were incorporated into calcium phosphate bone cement (CPC). The study investigated the effects of m-EmG@CPC on antibacterial activity, mechanical properties, biocompatibility, and proliferation and mineralization of mouse progenitor osteoblasts (D1 cells). The average size of the gel microspheres ranged from 22.5 to 16.1 μm, with no significant difference between the groups (p > 0.05). Most of the oil content within the microspheres was transferred through modification, resulting in reduced cytotoxicity. Furthermore, antibiotic-impregnated m-EmG did not compromise the intrinsic properties of the microspheres and exhibited remarkably antibacterial effects. After combining with CPC (m-EmG@CPC), the microspheres did not significantly hinder the CPC reaction and produced the main product, hydroxyapatite (HA). However, the compressive strength of the largest microsphere content of 0.5 wt.% m-EmG in CPC decreased significantly from 59.8 MPa of CPC alone to 38.7 MPa of 0.5m-EmG@CPC (p < 0.05). The 0.5m-EmG@CPC composite was effective against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in drug release and antibacterial tests. Compared with m-EmG alone, the 0.5m-EmG@CPC composite showed no toxicity to mouse fibroblast cells (L929). Additionally, the proliferation and mineralization of mouse osteoblastic osteoprogenitor cells (D1 cells) did not have a negative impact on the 0.5m-EmG@CPC composite over time in culture compared with CPC alone. Results suggest that the newly developed antibacterial 0.5m-EmG@CPC composite bone cement did not negatively affect the performance of osteoprogenitor cells and could be a new option for bone graft replacement in surgeries.

Antibiotic dip and irrigation solutions confer increased antimicrobial efficacy of inflatable penile prosthesis hydrophilic surfaces compared with 0.05% chlorhexidine gluconate.

Chlorhexidine gluconate (CHG) (0.05%) has recently been suggested as both a dip for the hydrophilic surface and an irrigation solution in the setting of penile prosthesis (PP) surgery. The study sought to compare the antimicrobial efficacy of 0.05% CHG with vancomycin and gentamicin (VG) antibiotics as dip and/or irrigation solutions in the setting of a hydrophilic PP surface in vitro. Sterile PPs with a hydrophilic coating were obtained. A series of experiments were performed to evaluate the efficacy of normal saline (NS), 0.05% CHG, or VG as dip and/or irrigation solutions to reduce methicillin-sensitive Staphylococcus aureus adhesion to PP surfaces. The 8-mm discs from PPs were incubated in 105colony-forming units/mL of methicillin-sensitive S aureus for 48hours, plated, and counted. Disc-diffusion tests were conducted by suspending 6-mm discs for 2minutes in NS, 0.05% CHG, or VG, then placing them coated side down onto plates streaked with the following organisms: methicillin-sensitive S aureus, S epidermidis, Enterococcus, and Escherichia coli. After 24hours of growth, zones of inhibition were measured. We found average bacterial counts (colony-forming units/mL) and zones of inhibition (mm) following a series of treatment protocols of PP discs. PP discs dipped in VG reduced bacterial adhesion to the implant surface >0.05% CHG (~5.5 log vs ~1.5 log; P < .01). Discs irrigated with either 0.05% CHG or NS removed all dip solution adsorbed to the hydrophilic surface, allowing bacterial growth. VG irrigation adsorbed to the hydrophilic surface even after 0.05% CHG or NS dips, reducing bacterial adherence (~3 log). Dipping and irrigating discs with VG was most effective in reducing adherent bacteria (~5.5 log) and was the only irrigation that showed antimicrobial activity. VG, when used both as a prophylactic dip and as an intraoperative irrigation solution for hydrophilic penile implant surfaces, has improved efficacy to 0.05% CHG and NS. This is the first study to compare the use of VG, 0.05% CHG, and NS as prophylactic dips and intraoperative irrigations for hydrophilic penile implant surfaces. Limitations include the use of in vitro studies, which serve as a proxy for in vivo practices and may not be entirely accurate nor translatable clinically. We demonstrated the superior efficacy of VG as a combined dip and irrigation solution for hydrophilic penile implant surfaces compared with 0.05% CHG.