Fabrication and application of targeted ciprofloxacin nanocarriers for the treatment of chronic bacterial prostatitis.

Pathogenic bacteria cause chronic bacterial prostatitis (CBP). CPB is characterized by urinary tract infection and persistence of pathogenic bacteria in prostatic secretion. Owing to poor blood supply to the prostate gland and limited drug penetration, CBP treatment is difficult. Transferosomes are ultradeformable vesicles for nanocarrier applications, which have become an important area of nanomedicine. Such carriers are specifically targeted to the pathological area to provide maximum therapeutic efficacy. It consists of a lipid bilayer soybean lecithin phosphatidylcholine (PC), an edge activator Tween 80 with various ratios, and a chloroform/methanol core. Depending on the lipophilicity of the active substance, it can be encapsulated within the core or among the lipid bilayer. Due to their exceptional flexibility, which enables them to squeeze themselves through narrow pores that are significantly smaller than their size, they can be a solution. One formulation (Cipro5 PEG) was selected for further in vitro analysis and was composed of phosphatidylcholine (PC), Tween 80, and polyethylene glycol-6 stearate (PEG-6 stearate) in a ratio of 3:3:1 in a chloroform/methanol mixture (1:2 v/v). In vitro, the results showed that PEGylated transferosomes had faster drug release, higher permeation, and increased bioavailability. The transferosomes were quantified with a particle size of 202.59 nm, a zeta potential of-49.38 mV, and a drug entrapment efficiency of 80.05%. The aim of this study was to investigate drug targeting. Therefore, Monoclonal antibody IgG was coupled with Cipro5 PEG, which has specificity and selectivity for conjugated nanoparticles. In vivo, a total of twenty-five adult Wistar rats were obtained and randomly divided into 5 groups, each of 5 rats at random: the control group, blank group, positive control group, Cipro 5PEG group, and Cipro 5PEG coupled with IgG antibody group. The cytokines levels (IL-1ß, IL-8, and TNF-α) in the serum were detected by analysis kits. Compared with the control group, treatment with Cipro 5PEG coupled with the IgG antibody could significantly inhibit cytokines, according to histological analysis. Cipro 5PEG, coupled with the IgG antibody group, reduced prostate tissue inflammation. Hence, our results show a promising approach to delivering antibiotics for the targeted therapy of CBP.

Studying the viability and growth kinetics of vancomycin-resistant Enterococcus faecalis V583 following femtosecond laser irradiation (420-465 nm).

Enterococcus faecalis is among the most resistant bacteria found in infected root canals. The demand for cutting-edge disinfection methods has rekindled research on photoinactivation with visible light. This study investigated the bactericidal activity of femtosecond laser irradiation against vancomycin-resistant Enterococcus faecalis V583 (VRE). The effect of parameters such as wavelength and energy density on the viability and growth kinetics of VRE was studied to design an optimized laser-based antimicrobial photoinactivation approach without any prior addition of exogenous photosensitizers. The most effective wavelengths were 430 nm and 435 nm at a fluence of 1000 J/cm2, causing a nearly 2-log reduction (98.6% and 98.3% inhibition, respectively) in viable bacterial counts. The colony-forming units and growth rate of the laser-treated cultures were progressively decreased as energy density or light dose increased at 445 nm but reached a limit at 1250 J/cm2. At a higher fluence of 2000 J/cm2, the efficacy was reduced due to a photobleaching phenomenon. Our results highlight the importance of optimizing laser exposure parameters, such as wavelength and fluence, in bacterial photoinactivation experiments. To our knowledge, this is the first study to report an optimized wavelength for the inactivation of VRE using visible femtosecond laser light.

Probiotics mixture and taurine attenuate L-arginine-induced acute pancreatitis in rats: Impact on transient receptor potential vanilloid-1 (TRPV-1)/IL-33/NF-κB signaling and apoptosis.

Acute pancreatitis (AP) is an inflammatory disorder of acinar cells. It may develop into severe chronic pancreatitis with a significant mortality rate. The current study aimed to assess the therapeutic effect of a Lactobacillus (LAB) mixture against rat AP. Six groups were created including control, taurine (300 mg/kg; i.p.) for 7 days, LAB mixture for 7 days, L-arginine (2.5 g/kg; i.p.) 2 doses with 1 h interval on 1st day, L-arginine+taurine, and L-arginine+LAB. Serum amylase and lipase activities were measured. Pancreatic tissue was used for histopathological examination, oxidative stress biomarkers including malondialdehyde (MDA) and reduced glutathione (GSH), and inflammatory biomarkers including myeloperoxidase (MPO) and interleukin (IL)-33 assessment. qRT-PCR was used for transient receptor potential vanilloid-1 (TRPV-1) investigation and Western blot analysis for measuring nuclear factor kappa-B (NF-κBp65) and the apoptosis biomarker; caspase-3. Taurine and LAB reduced lipase and significantly ameliorated induced oxidative stress by normalizing MDA and GSH contents. They counteracted inflammation by reducing MPO, IL-33, NF-κBp65, and TRPV-1. In addition, taurine and LAB counteracted apoptosis as proved by reduced caspase-3 expression. Taken together, these findings indicate that taurine and the use LAB mixture can mitigate AP by L-arginine via influencing TRPV-1/IL-33/NF-κB signaling together with exhibiting potent antioxidant and anti-inflammatory effects.

Genome sequencing of Enterococcus faecium NT04, an oral microbiota revealed the production of enterocin A/B active against oral pathogens.

Objective: This study aimed to isolate and investigate a bacterium from an Egyptian adult's healthy oral cavity, focusing on its probiotic properties, especially its antagonistic activity against oral pathogens. Methods: The isolated bacterium NT04 using 16S rRNA gene sequencing, was identified as Enterococcus faecium. In this study, the whole genome of Enterococcus faecium NT04 was sequenced and annotated by bioinformatics analysis tools. Results: Numerous genes encoding the production of diverse metabolic and probiotic properties, such as bacteriocin-like inhibitory substances (Enterocin A and B), cofactors, antioxidants, and vitamins, were confirmed by genomic analysis. There were no pathogenicity islands or plasmid insertions found. This strain is virulent for host colonization rather than invasion. Conclusion: Genomic characteristics of strain NT04 support its potentiality as an anti-oral pathogen probiotic candidate.

Antimicrobial and antivirulence saponins of Mimusops laurifolia leaves.

Mimusops laurifolia is a native species restricted to the Red Sea mountains and Gulf of Aden. Its leaves contain saponins with wide range of biological activities. The presented research aimed to prepare saponins-rich extract from n-butanol fraction of M. laurifolia leaves and screen it for promising antimicrobial activities. Minimum inhibitory concentration (MIC) of the prepared saponins against Candida albicans, and their potential anti-pathogenic and antivirulence effects were determined. Different concentrations of the saponins-rich extract were investigated for their antimicrobial potential, particularly against C. albicans, using the agar well diffusion method. To assess the potential antivirulence and antipathogenic effects, we carried out molecular docking of the bioactive saponins against four key enzymes in C. albicans, which are involved in virulence and/or pathogenicity. Different concentrations of the investigated mixture showed notable antifungal activity against C. albicans with an MIC value of 6.4 µg ml-1. Docking analysis of the investigated saponins showed their affinity toward the docked enzymes, particularly saponin 1 with secreted aspartic proteinase 3 and saponin 6 with secreted aspartic proteinase 5. Thereafter, the stability of these two protein-ligand interactions was investigated using molecular dynamics (MD) simulation. The molecular interactions between saponins and the enzymes' active sites were analyzed and discussed.

Irinotecan-gut microbiota interactions and the capability of probiotics to mitigate Irinotecan-associated toxicity.

BACKGROUND: Irinotecan is a chemotherapeutic agent used to treat a variety of tumors, including colorectal cancer (CRC). In the intestine, it is transformed into SN-38 by gut microbial enzymes, which is responsible for its toxicity during excretion. OBJECTIVE: Our study highlights the impact of Irinotecan on gut microbiota composition and the role of probiotics in limiting Irinotecan-associated diarrhea and suppressing gut bacterial ß-glucuronidase enzymes. MATERIAL AND METHODS: To investigate the effect of Irinotecan on the gut microbiota composition, we applied 16S rRNA gene sequencing in three groups of stool samples from healthy individuals, colon cancer, and Irinotecan treated patients (n = 5/group). Furthermore, three Lactobacillus spp.; Lactiplantibacillus plantarum (L. plantarum), Lactobacillus acidophilus (L. acidophilus), Lacticaseibacillus rhamnosus (L. rhamnosus) were used in a single and mixed form to in-vitro explore the effect of probiotics on the expression of ß-glucuronidase gene from E. coli. Also, probiotics were introduced in single and mixed forms in groups of mice before the administration of Irinotecan, and their protective effects were explored by assessing the level of reactive oxidative species (ROS) as well as studying the concomitant intestinal inflammation and apoptosis. RESULTS: The gut microbiota was disturbed in individuals with colon cancer and after Irinotecan treatment. In the healthy group, Firmicutes were more abundant than Bacteriodetes, which was the opposite in the case of colon-cancer or Irinotecan treated groups. Actinobacteria and Verrucomicrobia were markedly present within the healthy group, while Cyanobacteria were noted in colon-cancer and the Irinotecan-treated groups. Enterobacteriaceae and genus Dialister were more abundant in the colon-cancer group than in other groups. The abundance of Veillonella, Clostridium, Butryicicoccus, and Prevotella were increased in Irinotecan-treated groups compared to other groups. Using Lactobacillus spp. mixture in mice models significantly relieved Irinotecan-induced diarrhea through the reduction of both ß-glucuronidase expression and ROS, in addition to guarding gut epithelium against microbial dysbiosis and proliferative crypt injury. CONCLUSIONS: Irinotecan-based chemotherapy altered intestinal microbiota. The gut microbiota participates greatly in determining both the efficacy and toxicity of chemotherapies, of which the toxicity of Irinotecan is caused by the bacterial ß-glucuronidase enzymes. The gut microbiota can now be aimed and modulated to promote efficacy and decrease the toxicity of chemotherapeutics. The used probiotic regimen in this study lowered mucositis, oxidative stress, cellular inflammation, and apoptotic cascade induction of Irinotecan.

Perceptions, Knowledge, and Experiences of Using Face Masks among Egyptian Healthcare Workers during the COVID-19 Pandemic: A Cross-Sectional Study.

Using face masks appropriately is important for preventing the community spread of respiratory infections. A cross-sectional study was conducted to evaluate the knowledge level and experience of using face masks between healthcare teams to protect them and limit the spread of COVID-19 infection. A structured questionnaire was distributed to 228 healthcare members in July-December 2021. It was divided into two sections and consisted of 29 questions for a total possible score of 0 to 29. The first section was related to perceptions and knowledge about face masks (13 items); the second was related to the experience of using face masks (16 items). The average score of this questionnaire was 23.21/29 with respect to the knowledge about face masks and their proper use techniques. The healthcare team studied had satisfactory knowledge about face mask use techniques, and the study shed light on their unsatisfactory practices. Following instructions is very vital to protecting the person wearing the mask and preventing the spread of infection during health care by blocking droplets produced by speaking or coughing. Providing the healthcare teams with knowledge and experience about how to use face masks during the pandemic is critical to increase their awareness and practice in using face masks and prevent the infection from spreading.

Tunable femtosecond laser suppresses the proliferation of breast cancer in vitro.

Worldwide, the most frequently diagnosed cancer is female breast cancer, and it poses a serious global health threat. Traditional cancer therapies are associated with various side effects, so developing better therapies for breast cancer is necessary, such as laser therapy which could be a promising treatment option. The aim of the current study was to investigate the femtosecond laser irradiation effect on breast cancer using T47D cell line as an in vitro model. Cells were seeded at a density of 5 × 104 cells/well in 96-well plates and incubated overnight. After that, the cells were exposed to femtosecond laser irradiation at various wavelengths falling in the UV, visible, and IR ranges for 3, 5, or 10 min and at a constant power of 100 mW. Cell viability was measured directly and 24 h after femtosecond laser irradiation using MTT assay. When using different femtosecond laser irradiation parameters, especially the 380 and 400 nm femtosecond laser irradiation, there was significant inhibition of breast cancer cell growth, either directly or 24 h after femtosecond laser exposure. Also, 420 and 440 nm significantly affected the viability of the cells. It was also observed that increasing exposure time enhances the observed effect, so 10 min exposure time was the best time of exposure. However, 700, 720, 750, and 780 nm did not significantly affect the cells viability with different exposure times. It was possible to conclude from the aforementioned results that femtosecond laser irradiation exerted a significant anticancer effect against T47D cells. Consequently, the femtosecond laser could be used successfully for breast cancer management.

The Outcomes of COVID-19 Patients with Spontaneous Intracerebral Hemorrhage Comorbidity and the Efficacy of Enoxaparin in Decreasing the Mortality Rate in Them: Single Egyptian Center Report.

Patients with neurological comorbidities are more likely to develop severe COVID-19. We aimed to detect the outcomes of COVID-19 patients with spontaneous intracerebral hemorrhage comorbidity and the role of enoxaparin in decreasing the mortality rate in these cases, even though enoxaparin is a potential cause of intracerebral hemorrhage. The patients were checked on to detect surveillance outcomes, the relationship between mortality and patient characteristics, and the relationship between enoxaparin and study outcomes. Chest condition and GCS improved in 67.9% of participants. Hematoma course increased in 49.1%. Midline-shift, brain-edema, and COVID symptoms improved in 67.9%. There was a non-significant difference in mortality regarding age and gender. There was a significant difference in mortality regarding treatment with enoxaparin; 75% of the patients who did not receive enoxaparin died. 92.6% of the patients who showed decreases in hematoma course were administered enoxaparin. 76.9% of the patients who showed increases in hematoma-course were administered enoxaparin. Most of the patients who were admitted to the neurosurgical unit with spontaneous intracerebral hemorrhage acquired the COVID-19 infection. Most of the cases included in this study did not progress to severe cases. The dying patients showed deterioration in both neurological and COVID-19 symptoms. The anticoagulant properties of enoxaparin given earlier before and throughout the infection can considerably reduce mortality in COVID-19 individuals with spontaneous intracerebral hemorrhage. It is recommended to use enoxaparin for cases with spontaneous intracerebral hemorrhage and COVID-19 regardless of hematoma size because the rate of improvement was greater than the mortality rate after using enoxaparin in this study.

The Antimicrobial Effect of Gold Quantum Dots and Femtosecond Laser Irradiation on the Growth Kinetics of Common Infectious Eye Pathogens: An In Vitro Study.

We studied the antimicrobial effect of gold quantum dots (AuQDs), femtosecond laser irradiation, and the combined effect of laser irradiation and AuQD treatment against common infectious eye pathogens. The INSPIRE HF100 laser system (Spectra Physics) provided a femtosecond laser, which was pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics), while a Quanta-Ray nanosecond Nd: YAG laser (Spectra-Physics) was used to precisely synthesize 7.8, 8.7, and 11.6 nm spherical AuQDs. Then, the in vitro growth kinetics and growth rate analysis of E. coli, methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, and Candida albicans (treated with the AuQDs, femtosecond laser irradiation, or combined laser and AuQDs treatment) was measured. The biocompatibility of the AuQDs with the retinal epithelial cell lines (ARPE-19) and their toxicity to the cells was assayed. The results showed that (1) in vitro irradiation using a 159 J/cm2 energy density obtained from the 400 nm femtosecond laser suppressed the growth of each of the five pathogens. (2) Similarly, treatment with the AuQDs was antimicrobial against the four bacteria. The AuQDs with an average size of 7.8 nm were more highly antimicrobial and biocompatible and were less cytotoxic than the larger AuQD sizes. (3) The combined femtosecond laser irradiation and AuQD treatment was more highly antimicrobial than each treatment alone. (4) The AuQD treatment did not impair the rate of wound closure in vitro. These findings suggest that combined femtosecond laser irradiation and AuQD treatment is significantly antimicrobial against Candida albicans, Gram-positive L. monocytogenes, S. aureus, and E. faecalis, as well as Gram-negative E. coli. The nontoxicity and biocompatibility of the AuQD particles tested suggest that this form of treatment may be clinically viable.

Preparation of zinc oxide nanoparticles using laser-ablation technique: Retinal epithelial cell (ARPE-19) biocompatibility and antimicrobial activity when activated with femtosecond laser.

The unusual physical, chemical, and biological features of nanoparticles have sparked considerable attention in the ophthalmological applications. This study reports the synthesis and characterization of zinc oxide nanoparticles (ZnONPs) using laser-ablation at 100 mJ with different ablation times. The synthesized ZnONPs were spherical with an average size of 10.2 nm or 9.8 nm for laser ablation times of 20 and 30 min, respectively. The ZnONPs were screened for their antimicrobial activity against ophthalmological bacteria, methicillin-resistant S. aureus (MRSA) and Pseudomonas aeruginosa. The significant decrease in bacterial growth was observed after treatment with ZnONPs in combination with 400 nm femtosecond laser irradiation. ZnONPs were investigated for their antioxidant activity and biocompatibility towards retinal epithelial cells (ARPE-19). ZnONPs showed moderate antioxidant and free radical scavenging activity. ZnONPs prepared with an ablation time of 20 min were safer and more biocompatible than those prepared with an ablation time of 30 min, which were toxic to ARPE-19 cells with LC50 (11.3 µg/mL) and LC90 (18.3 µg/mL). In this study, laser ablation technique was used to create ZnONPs, and it was proposed that ZnONPs could have laser-activated antimicrobial activity for ophthalmological applications.

Side Effects and Efficacy of COVID-19 Vaccines among the Egyptian Population.

BACKGROUND: Knowledge about a vaccine's side effects and efficacy is important to improving public vaccine acceptance. This study aimed to detect the safety and efficacy of vaccines among the Egyptian population. METHODOLOGY AND RESULTS: Data was collected using an online survey from participants who took two doses of the BBIBP-CorV, ChAdOx1, or BNT162 vaccines. Pain at the vaccine injection site, muscle pain, fatigue, dizziness, fever, and headache were the most common side effects after the first and second doses. The number pf side effects was higher in ChAdOx1 than in BNT162 and BBIBP-CorV. Most of the side effects started on the first day after vaccination and persisted for 1-2 days. Vaccinated people with past coronavirus infections before vaccination developed better antibodies than those who were only vaccinated. The side-effect severity was greater after the first dose of BBIBP-CorV and ChAdOx1 than after the second dose, but in contrast, the side-effect severity was greater after the second dose of BNT162 vaccine than after the first dose. ChAdOx1 was more effective than BBIBP-CorV, and one dose of ChAdOx1 produced an immune response similar to that of two doses of BBIBP-CorV. CONCLUSIONS: Coronavirus vaccines were well-tolerated, safe, and produced an immune response against the virus in most cases. Most postvaccine side effects were mild to moderate, which indicated the building of immunity by the body for protection.

Metabolomic profiling and antioxidant potential of three fungal endophytes derived from Artemisia annua and Medicago sativa.

In this work, three fungal endophytes identified as Aspergillus terreus (AFL, AFSt and AFR), were studied for their antioxidant potential. LC-MS-based metabolomics, followed by multivariate statistical analysis were then applied to comprehensively profile their extracts. The three fungal endophytes revealed interesting antioxidant potential, in particular, the strain isolated from the Artemisia annua leaves (AFL), which was rich in different types of phenolic metabolites. Additionally, all fungal-derived ethyl acetate extracts showed potent inhibition against the prooxidant xanthine oxidase. Multivariate analysis (PCA and PLS-DA) demonstrated a unique chemical fingerprint for each strain, where phenolics, coumarins, and polyketides were the discriminative metabolites of the three fungal strains. The present findings highlighted the power of metabolomics in the chemotaxonomical classification of closely related strains. It also asserted the role of fungal endophytes in the management of oxidative stress, particularly when they are utilized in the production of fermented food products.

Genomic analysis of Enterococcus durans NT21, a putative bacteriocin-producing isolate.

Enterococcus species are a long-standing and non-pathogenic commensal bacterium, representing an important part of the normal. Enterococcus durans is a rarely isolated species from animals and humans, and it was a tiny constituent of human oral cavity and animal intestinal flora, as well as animal-derived foods, particularly dairy products. This study evaluated the security of our strain E. durans NT21 by using whole-genome sequencing (WGS), physicochemical features, and antimicrobial activity. The complete genomic of our strain Enterococcus durans NT21was sequenced and analyzed by using several bioinformatics tools to identify bacteriocin genes, virulence genes, antibiotic resistance genes, Crispr-Cas and pathogenicity islands. The results showed that our strain NT21 lacks the presence of virulence genes, pathogenicity islands, plasmids and has only two antibiotic resistance genes. On the other hand, it produces three bacteriocin-like inhibitory substances (Enterolysin A, P and L50a). It has six gene-encoded Crisper-Cas and one cluster Crispr-Cas gene. According to our findings, E. durans NT21 is a possible probiotic strain that is safe for both human and animal use.

Efficacy of Ceftazidime and Cefepime in the Management of COVID-19 Patients: Single Center Report from Egypt.

The purpose of this study was to explore the value of using cefepime and ceftazidime in treating patients with COVID-19. A total of 370 (162 males) patients, with RT-PCR-confirmed cases of COVID-19, were included in the study. Out of them, 260 patients were treated with cefepime or ceftazidime, with the addition of steroids to the treatment. Patients were divided into three groups: Group 1: patients treated with cefepime (124 patients); Group 2: patients treated with ceftazidime (136 patients); Group 3 (control group): patients treated according to the WHO guidelines and the Egyptian COVID-19 management protocol (110 patients)/ Each group was classified into three age groups: 18-30, 31-60, and >60 years. The dose of either cefepime or ceftazidime was 1000 mg twice daily for five days. Eight milligrams of dexamethasone were used as the steroidal drug. Careful follow-ups for the patients were carried out. In vitro and in silico Mpro enzyme assays were performed to investigate the antiviral potential of both antibiotics. The mean recovery time for Group 1 was 12 days, for Group 2 was 13 days, and for Group 3 (control) was 19 days. No deaths were recorded, and all patients were recovered without any complications. For Group 1, the recovery time was 10, 12, and 16 days for the age groups 18-30, 30-60, and >60 years, respectively. For Group 2, the recovery time was 11, 13, and 15 days for the age groups 18-30, 30-60, and >60 years, respectively. For Group 3 (control), the recovery time was 15, 16, and 17 days for the age groups 18-30, 30-60, and >60 years, respectively. Both ceftazidime and cefepime showed very good inhibitory activity towards SARS CoV-2's Mpro, with IC50 values of 1.81 µM and 8.53 µM, respectively. In conclusion, ceftazidime and cefepime are efficient for the management of moderate and severe cases of COVID-19 due to their potential anti-SARS CoV-2 activity and low side effects, and, hence, the currently used complex multidrug treatment protocol can be replaced by the simpler one proposed in this study.

Role of repeating quarantine instructions and healthy practices on COVID-19 patients and contacted persons to raise their awareness and adherence to quarantine instructions.

OBJECTIVE: This study aimed to develop a model evaluating the role of repeating quarantine instructions and healthy practices among COVID-19 patients and contact persons at-home quarantine and to evaluate the instructions' adequacy in decreasing the rate of disease spread with better clinical outcomes. METHODS: A structured questionnaire was distributed to COVID-19 patients (mild and moderate cases isolated at home) and contacting persons during May and June 2020. Data were collected using a structured online survey collected every five days for three times from each participant. The questionnaire was divided into three sections, consisting of 35 questions for a total possible score of 0 to 35. RESULTS: A total of 150 valid participant's responses out of 304 participants were obtained. Among the150 total participants, 88 were infected with COVID-19, and 62 were contacting with COVID-19 patients. The improvement in the score of awareness and adherence to instructions for the infected patients and their contacts was significantly high in the third questionnaire than in the second and the first questionnaire. The people who live in cities followed the instructions provided at the home quarantine better than those who live in the country. The city patients improved in symptoms better than the country patients. Also, patients followed the instructions better than their contacts. City females adhered to the instructions better than city males. Young people had high awareness score than older people. City people are committed to taking both immune boosters supplements as prophylaxis or prescribed medications on time for treatment more than country people. CONCLUSION: This study offers useful insights into factors associated with the role of repeating quarantine instructions and healthy practices to overcome the COVID-19 pandemic. So, repeating the instructions is important to increase adherence to the instructions, decrease the rate of disease progression and decrease the spread of the infection.

The antimicrobial effect of 400 nm femtosecond laser and silver nanoparticles on gram-positive and gram-negative bacteria.

Silver nanoparticles are well-known for their antimicrobial effect. However, they are potentially toxic in high doses. We explored the possibility of enhancing the bactericidal effect of low concentrations of silver nanoparticles with blue light femtosecond laser irradiation, since such concentrations are less toxic. The growth dynamics of Pseudomonas aeruginosa, Listeria monocytogenes and methicillin-resistant Staphylococcus aureus grown in pre-synthesized silver nanoparticles were measured with or without pre-irradiation with 50 mW and 400 nm femtosecond laser irradiation. With each bacterium, combined treatment with laser and silver nanoparticles significantly reduced bacterial growth, indicating that this form of treatment could be beneficial in the ongoing efforts to reduce the deleterious effects of antibiotic resistant Gram-positive and Gram-negative bacteria. The combined treatment was more antimicrobial than treatment with silver nanoparticles alone or photo-irradiation alone. P. aeruginosa and L. monocytogenes were more susceptible to the bactericidal effects of silver nanoparticles, and the combination of laser treatment and silver nanoparticles than MRSA.

The effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus: An in vitro study.

We investigated the effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus. In order to improve laser-based antimicrobial therapy and develop a clinically viable modality, various laser parameters such as laser light wavelength, laser power, exposure time, and energy density were studied. The INSPIRE HF100 laser system (Spectra Physics) provided the femtosecond laser light, which was pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics). The survival of the bacterial cells was monitored after irradiation by determination of growth rate using optical density, which is a rapid, simple, and reliable method. The growth rate of laser-exposed cultures was compared to control cultures. Fifteen minutes of exposure to femtosecond laser radiation with a wavelength of 390 nm and 400 nm at an average power of 50 mW was enough to significantly reduce bacterial viability, with a lag in the growth phase of 5 h longer than the control culture (P < 0.0001 by ANOVA and Tukey test).

Antimicrobial Activity of Cationic Poly(3-hexylthiophene) Nanoparticles Coupled with Dual Fluorescent and Electrochemical Sensing: Theragnostic Prospect.

Designing therapeutic and sensor materials to diagnose and eliminate bacterial infections remains a significant challenge for active theragnostic nanoprobes. In the present work, fluorescent/electroactive poly(3-hexylthiophene) P3HT nanoparticles (NPs) stabilized with quaternary ammonium salts using cetyltrimethylammonium bromide (CTAB), (CTAB-P3HT NPs) were prepared using a simple mini-emulsion method. The morphology, spectroscopic properties and electronic properties of CTAB-P3HT NPs were characterized by DLS, zeta potential, SEM, TEM, UV-vis spectrophotometry, fluorescence spectroscopy and electrochemical impedance spectroscopy (EIS). In an aqueous solution, CTAB-P3HT NPs were revealed to be uniformly sized, highly fluorescent and present a highly positively charged NP surface with good electroactivity. Dual detection was demonstrated as the binding of the bacteria to NPs could be observed by fluorescence quenching as well as by the changes in EIS. Binding of E. coli to CTAB-P3HT NPs was demonstrated and LODs of 5 CFU/mL and 250 CFU/mL were obtained by relying on the fluorescence spectroscopy and EIS, respectively. The antimicrobial activity of CTAB-P3HT NPs on bacteria and fungi was also studied under dark and nutritive conditions. An MIC and an MBC of 2.5 µg/mL were obtained with E. coli and with S. aureus, and of 0.312 µg/mL with C. albicans. Additionally a good biocompatibility toward normal human cells (WI38) was observed, which opens the way to their possible use as a therapeutic agent.

Purification and characterization of bacteriocins-like inhibitory substances from food isolated Enterococcus faecalis OS13 with activity against nosocomial enterococci.

Nosocomial infections caused by enterococci are an ongoing global threat. Thus, finding therapeutic agents for the treatment of such infections are crucial. Some Enterococcus faecalis strains are able to produce antimicrobial peptides called bacteriocins. We analyzed 65 E. faecalis isolates from 43 food samples and 22 clinical samples in Egypt for 17 common bacteriocin-encoding genes of Enterococcus spp. These genes were absent in 11 isolates that showed antimicrobial activity putatively due to bacteriocins (three from food, including isolate OS13, and eight from clinical isolates). The food-isolated E. faecalis OS13 produced bacteriocin-like inhibitory substances (BLIS) named enterocin OS13, which comprised two peptides (enterocin OS13α OS13ß) that inhibited the growth of antibiotic-resistant nosocomial E. faecalis and E. faecium isolates. The molecular weights of enterocin OS13α and OS13ß were determined as 8079 Da and 7859 Da, respectively, and both were heat-labile. Enterocin OS13α was sensitive to proteinase K, while enterocin OS13ß was resistant. Characterization of E. faecalis OS13 isolate revealed that it belonged to sequence type 116. It was non-hemolytic, bile salt hydrolase-negative, gelatinase-positive, and sensitive to ampicillin, penicillin, vancomycin, erythromycin, kanamycin, and gentamicin. In conclusion, BLIS as enterocin OS13α and OS13ß represent antimicrobial agents with activities against antibiotic-resistant enterococcal isolates.