Resistant Strains Of Bacteria Research Articles

Chemoenzymatic Modification of Daptomycin: Aromatic Group Installation on Trp1.

Daptomycin is a cyclic lipodepsipeptide antibiotic used to treat infections caused by Gram-positive pathogens, including multi-drug resistant strains such as methicillin-resistant Staphylococcus au-reus (MRSA) and vancomycin-resistant enterococci (VRE). The emergence of daptomycin-resistant bacterial strains has renewed interest in generating daptomycin analogs. Previous studies have shown that replacing the tryptophan of daptomycin with aromatic groups can generate analogs with enhanced potency. Additionally, we have demonstrated that aromatic prenyltransferases can attach diverse groups to the tryptophan of daptomycin. Here, we report the use of the prenyltransferase CdpNPT to derivatize the tryptophan of daptomycin with a library of benzylic and heterocyclic pyrophosphates. An analytical-scale study revealed that CdpNPT can transfer various aromatic groups onto daptomycin. Subsequent scaled-up and purified reactions indicated that the enzyme can attach aromatic groups to N1, C2, C5 and C6 positions of Trp1 of daptomycin. In vitro antibacterial activity assays using six of these purified compounds identified aromatic substituted daptomycin analogs show potency against both daptomycin-susceptible and resistant strains of Gram-positive bacteria. These findings suggest that installing aromatic groups on the Trp1 of daptomycin can lead to the generation of potent daptomycin analogs.

Antibiotic Resistance Profiles in Eye Infections: A Local Concern with a Retrospective Focus on a Large Hospital in Northern Italy.

The emergence of antibiotic resistance poses a significant threat to public health worldwide, affecting various medical fields, including ophthalmology. Eye infections, ranging from conjunctivitis to more severe conditions like keratitis, are commonly treated with antibiotics. However, the misuse and overuse of these drugs have led to the development of resistant strains of bacteria, allowing traditional treatments ineffective. This paper aims to examine the current situation of antibiotic resistance in eye infections globally, with a specific focus on a large group of hospitals located in Milan (Italy) with considerable experience in cataract and cornea surgery as well as in retinopathy. The results of the study show the prevalence of Gram-positives in the tested samples and a low resistance of fluoroquinolones and glycopeptides. The results also highlight the need to implement sample collection methods for ocular infections, as the quantity of positive samples is rather low compared to the total number of samples. In conclusion, the study, although with limited data, shows that resistance to aminoglycosides and cephalosporins is a situation to be monitored. These data also show the critical need to improve and guide the biological sample collection modalities in order to make the diagnosis more reliable.

Cold Plasma Deposition of Tobramycin as an Approach to Localized Antibiotic Delivery to Combat Biofilm Formation.

Hospital-acquired infections (HAIs) remain a significant factor in hospitals, with implant surfaces often becoming contaminated by highly resistant strains of bacteria. Recent studies have shown that electrical plasma discharges can reduce bacterial load on surfaces, and this approach may help augment traditional antibiotic treatments. To investigate this, a cold atmospheric plasma was used to deposit tobramycin sulphate onto various surfaces, and the bacterial growth rate of K. pneumoniae in its planktonic and biofilm form was observed to probe the interactions between the plasma discharge and the antibiotic and to determine if there were any synergistic effects on the growth rate. The plasma-deposited tobramycin was still active after passing through the plasma field and being deposited onto titanium or polystyrene. This led to the significant inhibition of K. pneumoniae, with predictable antibiotic dose dependence. Separate studies have shown that the plasma treatment of the biofilm had a weak antimicrobial effect and reduced the amount of biofilm by around 50%. Combining a plasma pre-treatment on exposed biofilm followed by deposited tobramycin application proved to be somewhat effective in further reducing biofilm growth. The plasma discharge pre-treatment produced a further reduction in the biofilm load beyond that expected from just the antibiotic alone. However, the effect was not additive, and the results suggest that a complex interaction between plasma and antibiotic may be at play, with increasing plasma power producing a non-linear effect. This study may contribute to the treatment of infected surgical sites, with the coating of biomaterial surfaces with antibiotics reducing overall antibiotic use through the targeted delivery of therapeutics.

The Antimicrobial and Antibiofilm Abilities of Fish Oil Derived Polyunsaturated Fatty Acids and Manuka Honey.

Both honey and fish oil have been historically used in medicine and identified as having antimicrobial properties. Although analyses of the substances have identified different components within them, it is not fully understood how these components interact and contribute to the observed effect. With the increase in multi-drug resistant strains of bacteria found in infections, new treatment options are needed. This study aimed to assess the antimicrobial abilities of fish oil components, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and derived resolvins (RvE1, RvD2, and RvD3), as well as two varieties of manuka honey, against a panel of medically relevant microorganisms and antimicrobial resistant organisms, such as Methicillin Resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Escherichia coli. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were identified; further minimum biofilm eradication concentrations (MBEC) were investigated for responsive organisms, including S. aureus, E. coli, Staphylococcus epidermidis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Concurrent with the existing literature, manuka honey was found to be a broad-spectrum antimicrobial with varied potency according to methylglyoxal content. DHA and EPA were both effective against Gram-positive and negative bacteria, but some drug-resistant strains or pathogens were not protected by a capsule. Only E. coli was inhibited by the resolvins.

Exploring the biogenic peptide’s potential in combating bacterial zoonosis: application and future prospect – a review

Abstract Worldwide, microbial infections have a serious impact because they cause infectious diseases, death, and significant economic losses. Zoonosis is now a major public health issue on a global scale because of the fast expansion of human exploitation of nature and animal husbandry. Notably, in the past 30 years, over 30 novel human infections have been discovered, 75% of which fall under the category of zoonosis. Resistant strains have emerged as a result of improper use of antibiotics and insufficient infection management posing a serious risk to both public health and the global economy. As alternatives, antimicrobial peptides are showing good results. The majority of living things use antibacterial peptides (ABPs) as a key part of their natural defenses against invading infections. These peptides are cationic, amphipathic, and relatively tiny with varied sequences, structures, and lengths. For the delivery of these efficacious biological peptides, nanoparticles are providing opportunities for effective, safe, and viable delivery. An innovative method of treating infectious diseases is demonstrated by nanoparticles and antibacterial peptides. When ABPs are combined with carrier nanoparticles to optimize distribution, their half-life may be increased, allowing for lower dosages and ultimately lower toxicity. For biological applications, ABPs and nanoparticle conjugates have become effective methods, enabling the treatment, prevention of disease, and detection. More than 50 peptide medications have been made available for purchase on the market as of 2018. Around 25 billion USD is spent on peptide medications each year, including ABPs. But still, there is a gap in the distribution of these ABPs as an alternative to synthetic antibiotics. It might be due to the high cost of these goods. Thus, scientists, researchers, and commercializing companies should work together so that these ABPs with a safe delivery system should be available in the market to combat resistant strains of bacteria. In doing so, we draw attention to the significant advancements made in the field as well as the difficulties still encountered in developing imaging species, active therapies, and nano-drug delivery systems that are functionalized with peptides and proteins for clinical use.

Levofloxacin loaded chitosan and poly-lactic-co-glycolic acid nano-particles against resistant bacteria: Synthesis, characterization and antibacterial activity

BackgroundWith the global increase in antibacterial resistance, the challenge faced by developing countries is to utilize the available antibiotics, alone or in combination, against resistant bacterial strains. We aimed to encapsulate the levofloxacin (LVX) into polymeric nanoparticles using biodegradable polymers i.e. Chitosan and PLGA, estimating their physicochemical characteristics followed by functional assessment as nanocarriers of levofloxacin against the different resistant strains of bacteria isolated from biological samples collected from tertiary care hospital in Lahore, Pakistan. MethodsLVX-NPs were synthesized using ion gelation and double emulsion solvent-evaporation method employing chitosan (CS) and poly-lactic-co-glycolic acid (PLGA), characterized via FTIR, XRD, SEM, and invitro drug release studies, while antibacterial activity was assessed using Kirby-Bauer disc-diffusion method. ResultsData revealed that the levofloxacin-loaded chitosan nanoparticles showed entrapment efficiency of 57.14% ± 0.03 (CS-I), 77.30% ± 0.08(CS-II) and 87.47% ± 0.08 (CS-III). The drug content, particle size, and polydispersity index of CS-I were 52.22% ± 0.2, 559 nm ± 31 nm, and 0.030, respectively, whereas it was 66.86% ± 0.17, 595 nm ± 52.3 nm and 0.057, respectively for CS-II and 82.65% ± 0.36, 758 nm ± 24 nm and 0.1, respectively for CS-III. The PLGA-levofloxacin nanoparticles showed an entrapment efficiency of 42.80% ± 0.4 (PLGA I) and 23.80% ± 0.4 (PLGA II). The drug content, particle size and polydispersity index of PLGA-I were 86% ± 0.21, 92 nm ± 10 nm, and 0.058, respectively, whereas it was 52.41% ± 0.45, 313 nm ± 32 nm and 0.076, respectively for PLGA-II. The XRD patterns of both polymeric nanoparticles showed an amorphous nature. SEM analysis reflects the circular-shaped agglomerated nanoparticles with PLGA polymer and dense spherical nanoparticles with chitosan polymer. The in-vitro release profile of PLGA-I nanoparticles showed a sustained release of 82% in 120 h and it was 58.40% for CS-III. Both types of polymeric nanoparticles were found to be stable for up to 6 months without losing any major drug content. Among the selected formulations, CS-III and PLGA-I, CS-III had better antibacterial potency against gram+ve and gram-ve bacteria, except for K. pneumonia, yet, PLGA-I demonstrated efficacy against K. pneumonia as per CSLI guidelines. All formulations did not exhibit any signs of hemotoxicity, nonetheless, the CS-NPs tend to bind on the surface of RBCs. ConclusionThese data suggested that available antibiotics can effectively be utilized as nano-antibiotics against resistant bacterial strains, causing severe infections, for improved antibiotic sensitivity without compromising patient safety.

Antibiotic use in the Northern Irish sheep flock: What lessons can be learnt from medicine records and farmer attitudes to improve stewardship of these essential medicines?

Stewardship of antibiotics used in livestock production has come under increasing scrutiny, from both the animal welfare point of view and due to concerns that antibiotic use in livestock may pose a risk to human health through selection pressure to drive development of antibiotic resistant strains of bacteria. Despite this concern, however, antibiotic consumption in the sheep sector is currently poorly described. This study determines the range and quantities of antibiotics used in the Northern Irish (NI) sheep flock as well as exploring drivers for their use. A mixed-methods approach was utilised, with an anonymous online scoping survey, analysis of the medicine records from 52 NI sheep farms and semi-structured interviews undertaken with 27 farmers. Eighteen farmers contributed both records and participated in interviews. Veterinary medicine records were derived from two sources: on-farm medicine books (seven) or veterinary practice sales data (51). As six of these farmers provided information from both sources a total of 52 unique farms participated. Overall, antibiotic use in sheep on the 52 farms sampled was low, with a median value of 11.35 mgPCU−1 (mean 13.63 mgPCU−1, sd 10.7; range 0–45.29 mgPCU−1), with all farms below 50 mgkg−1. Critically important antibiotics accounted for 0.21% of all antibiotics purchased. Lameness was the main driver of antibiotic use identified by this study. Others included a range of prophylactic treatments such as oral antibiotics to prevent watery mouth, injectable antibiotics to prevent abortion and following assisted lambing. Farmers acknowledged some of these uses had become habitual over time. The veterinary medicine sales records demonstrated significant sales of antibiotics not authorised for use in sheep, on an ongoing, rather than case-by-case, basis. Farmers were positive about their veterinarian’s ability and knowledge to improve flock welfare and productivity, but were unwilling to pay for this advice. However, veterinarians may have facilitated weak medicine stewardship through a failure to adequately challenge farmers seeking antibiotics. Farmers did not maintain accurate or up-to-date on farm medicine or production records in the majority of cases. Despite this lack of on-farm recording, veterinary sales records can be studied in consultation with farmers to provide veterinarians with a farm-specific insight into antibiotic use and related attitudes and behaviours. Farmers and veterinarians can then identify areas and behaviours to target collaboratively, improving antibiotic and wider medicine stewardship, whilst simultaneously improving flock health and productivity.

The Use of Conjugated Gold Nanorods with Reduced Toxicity in Photothermal Therapy for MRSA

AbstractMethicillin‐resistant Staphylococcus aureus (MRSA) is one of the deadliest pathogenic bacteria. Using photothermal therapy (PTT) to eradicate MRSA bacteria easily and effectively, it has directed this bacterium to be destroyed. Gold nanorods (AuNRs), which are nanoparticles that provide PPT, were synthesized and removed from the CTAB molecule reduce the toxic effect caused by CTAB. Subsequently, mercaptophenylboronic acid (MFBA) coated AuNRs were synthesized and used in photothermal therapy to develop a targeting agent to selectively eliminate MRSA. A decrease in cytotoxic effect of CTAB@AuNRs after conjugation with MFBA was also demonstrated by the MTS cell viability test. We found that at the end of 48 hours and 72 hours of interaction, IC50 values of MFBA@ AuNR increased by approximately 50 % compared to CTAB@AuNR. Also, it shows that the cytotoxicity of AuNRs conjugated with MFBA was reduced. Herein, photothermal efficiency was achieved with MFBA@AuNRs targeting MRSA. The purpose of using and modifying gold nanorods is to reduce the toxicity of AuNRs and to examine their efficacy on resistant pathogenic bacteria strains by taking advantage of photothermal therapy properties.

Novel Insights into the Antimicrobial Resistance and Strategies to Curb the Menace

Antibiotics are an essential part of modern healthcare, revolutionizing medicine and saving countless lives worldwide. However, the emergence of antimicrobial resistance (AMR) is a growing concern, with the potential to cause a public health crisis in the future. The aim of this review article is to provide an overview of the microbial and anthropogenic factors contributing to AMR, as well as the consequences of inaction to address the AMR crisis. We searched various international databases such as PubMed, Scopus, ScienceDirect and Google Scholar using “Antimicrobial Resistance”,” Superbug”, “Antibiotic Stewardship”, “One Health’ and “Surveillance” as search keywords in different combinations. We have thoroughly discussed the causes of AMR, such as the overuse and misuse of antibiotics, and the development of resistant strains of bacteria. We have also suggested possible interventions to combat AMR, such as the one health approach, antibiotic stewardship protocols, and the application of artificial intelligence in drug design. Additionally, we have explored the benefits of traditional ethnic medicinal practices in therapy. In conclusion, this review article emphasized the urgent need for a comprehensive and strategic plan to address the issue of AMR. Further in-depth research and novel approaches can mitigate the growing menace of AMR and safeguard both human and animal populations.

Clinical microbiota isolated from the uterine contents of sows in postpartum endometritis

Currently, diseases of the reproductive organs remain an urgent problem in pig breeding enterprises with intensive reproduction of livestock. Among them, the most common is postpartum endometritis. According to a number of researchers, the incidence of acute forms of endometritis in sows is 37.6-70.6%, while the prevalence of chronic forms is at the level of 21-27%. This type of pathology is the cause of morbidity and death of piglets from gastrointestinal diseases, and is also the cause of impaired reproductive function and infertility in sows, which leads to premature retirement from the herd. This type of pathology causes considerable harm in the development of the pig breeding sector and causes great economic damage. In pig breeding enterprises, the main therapeutic and preventive solution to this problem is the use of antibiotics and other chemotherapeutic preparations. Nevertheless, it is worth noting that their use is most often carried out uncontrollably and unreasonably, due to this, there is an increase in the number of resistant strains of bacteria, which poses a direct threat to animal and human health. The paper presents the results of the conducted studies, which made it possible to identify the types of bacteria involved in the etiology and pathogenesis of postpartum endometritis and the formation of the symptom complex of postpartum endometritis of sows. Based on the data obtained, it will be possible to further optimize the strategy of therapeutic measures to combat pathogenic microflora.

Synthesis of ZnO and PEG-ZnO nanoparticles (NPs) with controlled size for biological evaluation.

The objective of this research was to produce the smallest possible ZnO nanoparticles through an adapted wet chemical process and subsequently, to fabricate a core-shell structure utilizing polyethylene glycol (PEG) as the shell component. The synthesis, size, and shape of the NPs were confirmed using advanced techniques. The resulting clustered NPs were round and had a size of 9.8 nm. Both plain and core-shell NPs were tested for their antibacterial properties against multi-drug resistant bacteria strains (E. cloacae, E. amnigenus, S. flexneri, S. odorifacae, Citrobacter, and E. coli), with concentrations of 500, 1000, and 1500 μg ml-1 used for testing. Both types of NPs demonstrated antibacterial activity against the tested pathogens, with the core-shell NPs being more effective. The synthesized NPs were biocompatible with human red blood cells, with a low level of hemolysis observed. The biocompatibility of the core-shell NPs was significantly enhanced by the presence of the PEG added as the shell. In addition, their effectiveness as photosensitizers for cancer treatment via photodynamic therapy (PDT) was evaluated. MTT assay was used to evaluate the cytotoxicity of ZnO and PEG-ZnO, and the results showed that these NPs were able to generate ROS inside tumor cells upon irradiation, leading to apoptosis and cell death, making them a promising candidate for PDT.

Knowledge, attitude, and practice toward antibiotic use and antibiotic resistance among 2nd-year medical students: A cross-sectional study

Background: Antibiotics are probably one of the most successful forms of chemotherapy in the history of medicine. Their use has significantly reduced the mortality and morbidity associated with infectious disease. The irrational and overuse of antibiotics clearly drive the evolution of resistance. Epidemiological studies have demonstrated that a direct relationship between antibiotic consumption and the emergence and dissemination of resistant bacteria strains leads to increased mortality. Aims and Objective: The aims and objectives of the study are to evaluate knowledge, attitude, and practice toward antibiotic use and its resistance. Materials and Methods: After getting approval of the Ethics Committee of Mysore Medical College and Research Institute, Mysore, and obtaining written informed consent from 2nd-year medical undergraduates studying in Mysore Medical College and Research Institute, a self-administered, structured, and pre-tested questionnaire was used. The questionnaire was adopted from previously conducted similar studies and modified to fit with the current setup. Results: 64% of the students agree that antibiotics are inappropriate for use in viral infections, 58.4% of the participants disagreed on the safety of antibiotic usage, while 67.8% marked a negative response, when asked if they share the antibiotics with family members. Conclusion: More emphasis should be given on topic-like antibiotic usage and its resistance during UG teaching program, which goes a long way and help in reduction of antibacterial resistance development.

Antibacterial activity of five selected ethno-medicinal plants against extreme multi-drug resistance strains of pseudomonas aeruginosa and Staphylococcus aureus

Emergence of multidrug resistance strains of different kinds of virulent pathogens to various antibiotics worldwide had become one of the most concerning public health issues in Nigeria. This research is aimed at evaluating the antibacterial activity of five selected ethno-medicinal plants against multi-drug resistant strains of Pseudomonas aeruginosa and Staphylococcus aureus. Ficus sycomorus, Vitex doniana, Jatropha curcas, Acacia nilotica and Prosopis africana leafs were extracted using chloroform, to get the crude extracts of the various plants material. Exactly 150 clinical and environmental samples each, was collected for the isolation of Pseudomonas aeruginosa and Staphylococcus aureus each. The antibiogram profile and resistance level of the isolated strains was ascertained using the standard disc diffusion bioassay. Multi-drug resistance genes; BLA-TEM, BLA-SHV and CTX-M presence were evaluated and also served as another form of selection protocol for extremely resistant strains of the selected pathogenic bacterial species. In-vitro and in-vivo bioassay was done to evaluate the antimicrobial potential of the plants extracts on the most resistant strains of the two pathogenic bacteria. Tannins, saponin, alkaloids, flavonoids, phenols, terpenoids, quinones, phytosterols and phlobatanins were found present in these plants extracts. Eleven Pseudomonas aeruginosa and four Staphylococcus aureus extreme multi-drug resistance strains were successfully isolated and identified. The in-vitro bioassay reveals that F. sycomorus and J. curcas extracts has the highest antimicrobial activity against the various multi-drug resistant strains, while A. nilotica extract also maintains some level of activity against the resistant strains. The in-vivo bioassay reconfirmed the antibacterial effects of the three most active plants mentioned above, against all the resistant bacteria. Decoction of the three most active plants extracts also proves effective on the resistant strains of both bacteria, than the individual extracts. F. sycomorus, J. curcas and A. nilotica plant extracts could provide an alternative active pharmaceutical agents against multidrug resistant strains of Pseudomonas aeruginosa and Staphylococcus aureus.

Antibiotics resistance as a major public health concern: A pharmaco-epidemiological study to evaluate prevalence and antibiotics susceptibility-resistance pattern of bacterial isolates from multiple teaching hospitals

BackgroundMulti Drugs Resistance (MDR) is among the most worrisome healthcare issues resulting from inappropriate and indiscriminate utilization of antimicrobial agents which has compromised the efficacy and reliability of antimicrobial agents (AMAs). This has not only put a huge burden on the health care system but also is a major cause of morbidity and mortality. This project was designed to evaluate the prevalence of various microbial strains among patients admitted to various teaching hospitals and to assess their susceptibility and resistance towards clinically approved antibiotics. MethodsThe study was conducted during August 2021-February 2022 to determine the prevalence of common resistant strains of bacteria and to analyze their susceptibility pattern to the commonly prescribed antibiotics using standard procedures. One hundred and thirty biological samples including urine, blood, cerebrospinal fluid (CSF), wound swabs, pus and sputum were collected from the site of infection from the patients admitted at different wards of North West General Hospital (NWGH), Peshawar, Pakistan, Khyber Teaching Hospital (KTH), Peshawar Pakistan, and Hayat Abad Medical Complex (HMC) Peshawar Pakistan. Samples were collected and cultured following standard hospital procedures. The cultured samples were subjected to identification procedures including Gram staining, morphological characterization of bacterial colonies and biochemical assessments. The identified bacteria were tested for their susceptibility using Kirby-Bauer disc diffusion method. The diameter of Inhibitory Zones (DIZ) was analyzed following Clinical and Laboratory Standards Institute (CLSI) criteria. Minimum Inhibitory Concentrations (MICs) were evaluated using agar dilution method. Antimicrobials sensitivity were presented as antibiogram following CLSI M39 standard. ResultsA total of one hundred and thirty biological samples were collected, out of which one hundred and nine samples were positive for bacterial growth and were further processed for detailed analysis. The frequency and type of bacteria isolated from various cultures indicated that Gram negative bacteria (n = 92/109) were more dominant than Gram-positive (n = 17/109) pathogens. The most prevalent bacteria isolated was Escherichia coli (29.35 %), followed by Staphylococcus aureus (15.59 %), and Klebsiella spp, (12.84 %). In addition, other pathogens including, Enterobacter spp, Citrobacter spp, and Acinetobacter spp. showed a prevalence of 9.175 %, 8.25 %, and 5.50 % respectively. As indicated in the antbiogram, several organisms exhibited considerble decline in the sensitivies towards various antibiotics. A high percentage of resistance was observed against some antibiotics including trimethoprim, co-trimoxazole, amoxicillin/clavulanate, ciprofloxacin, piperacillin/tazobactam, cefotaxime and ceftazidime. ConclusionThe prevalence of resistant strains of pathogens is increasing day by day, while the antibiotics commonly prescribed against them are losing their efficacy, which is pushing the world to the era of pre-antibiotics. Unfortunately, the discovery of novel antibiotics is limited and researchers speculate that the is pushing towards pre-antibiotics era. Subsequently, efforts must be directed towards ensuring rational antibiotics use to prevent emergence of MDR pathogens. Our findings indicated that Gram negative bacteria including Escherichia coli was most prevalent. Other bacterial strains including S. aureus, Klebsiella spp, Enterobacter spp, Citrobacter spp, and Acinetobacter spp. were found among the causative agents. Unfortunately, considerable decline in the sensitivities of various bacterial isolated were observed towards the tested antibiotics. Previous studies reported the high prevalence of E. coli and S. aureus in clinical samples of Pakistani hospitals including hospitals in Peshawar and thus our findings are in agreement with the previous reports. Pharmacists being experts can play their role by promoting the optimal use of antimicrobial agents and educating healthcare professionals, patients and the public.

Two–step pulsed laser ablation for preparation NiO@ZnO core-shell nanostructure and evaluation of their antibacterial activity

The excessive use of antibiotics led to the appearance of many strains of resistant bacteria, so it became necessary to use new antibacterial techniques. The aim of this work is the synthesis of novel core–shell NPs (NiO@ZnO) for antibacterial applications. A novel NiO@ZnO core–shell nanomaterial with a nanosize and uniform shape has been synthesised using the two-step pulsed laser ablation in liquid (PLAL) method. The first step is the laser ablation of the nickel target and the production of NiO NPs (core) colloidal, followed by the second step, the ablation of ZnO (shell) inside NiO NPs colloidal. The transmission electron microscopy results approve the formation of NiO@ZnO core–shell NPs with an average particle size of 54.4 nm for NiO particles and 60.7 nm for the NiO@ZnO core–shell. The antibacterial activity was examined against the pathogenic bacterial strains E. coli and S. aureus. We found that in the case of NiO, the inhibition rates were 62.4 and 59.2% for E. coli and S. aureus, respectively. While with NiO@ZnO NPs, this result was improved to 74.8% for E. coli and 71.2% for S. aureus. So, it was found that using the core–shell NPs increased the antibacterial activity of NPs, and the use of NiO NPs and core approved their effect as antibacterial agents due to their special properties. This behaviour is primarily because of the accumulation of the NiO@ZnO NPs on the surface of the bacteria, which leads to cytotoxic bacteria and a relatively increased ZnO, causing cell death. Furthermore, the use of a NiO@ZnO core–shell material will inhibit the bacteria from nourishing themselves on the culture medium. Therefore, core shelling metal oxides with another metal oxide or other material improves their antibacterial activity compared with using them alone.

Development, validation, and implementation of an ultratrace analysis method for the determination of moenomycin A, in aquatic animal products.

Moenomycin A, an antimicrobial growth promoter widely used as an additive in aquaculture feedstuffs, has been restricted for use in the European Union and China due to its potential risk of promoting resistant strains of pathogenic bacteria and causing residues in aquatic animal products. Although methods for analyzing moenomycin A in feedstuffs have been developed, no established method exists for aquatic matrices. In this study, we present, for the first time, a sensitive and validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of moenomycin A in aquatic animal products. Samples were extracted using methanol and purified with the QuEChERS method employing C18 sorbent. The aliquot was dried under a nitrogen stream, reconstituted with methanol-water solvent, and analyzed by HPLC-MS/MS. The developed method exhibited good linearity (r2 > 0.995) over a wide concentration range (1-100μg/L) and a low limit of detection (1µg/kg). Average recoveries ranged between 70 and 110% at spiked concentrations of 1, 50, and 100μg/kg, with associated intra- and inter-day relative standard deviations of 1.25 to 7.32% (n = 6) and 2.91 to 10.08% (n = 3), for different representative aquatic animal production, respectively. To the best of our knowledge, this is the first reported HPLC-MS/MS method for the quantification of moenomycin A in aquatic animal products. The new approach was effectively employed in the analysis of moenomycin A across various aquatic samples.

Pandemics of Sexually Transmitted Infections (STIs): Clinical Use of Ezrin Peptide Therapy in Russia to Treat and Prevent Candida, Chlamydia, Trichomonas vaginalis, Syphilis, HPV and Herpes (HSV-1 & 2)

There is a global problem of increasing incidence and prevalence of sexually transmitted infection (affecting more than ten percent of the world population), and there is a growing problem of drug and vaccine resistant infections: human ezrin peptide therapy presents a novel solution. This review summarizes the results of 17 clinical trials on the use of human ezrin peptide one (HEP-1 “Gepon”), a 14 amino acid adaptive immunity amplifying peptide registered as a pharmaceutical, which has been in use in the Russian Federation since 2001, for the treatment of a broad spectrum of sexually transmitted diseases caused by infections of bacteria, viruses, fungi and protozoans. HEP-1 and RepG3 (a derivative of HEP-1) have also been successfully used to treat SARS-CoV-2 infection. The high prevalence of chlamydia, candida, Trichomonas vaginalis, Herpes (HSV-1 & HSV-2), Human Papilloma Virus (HPV) are the result of pandemics of sexually transmitted infections (STIs) that are generally increasing world-wide, particularly in women. Although treatments or vaccines are available for the various infections, the current medical interventions have not significantly reduced the growing problem. Multi-drug resistant bacterial & viral strains, and increasing sexual promiscuity are adding to the problem, so new solutions are required. In the Russian Federation, human ezrin peptide therapy with HEP-1 (brand name “Gepon”) is used to treat candida, chlamydia, Trichomonas vaginalis, herpes, and HPV infection. In addition HEP-1 (Gepon) has been shown to be effective in combination with antibiotics, for the treatment of Syphilis. Ezrin peptides induce biological responses in patients to achieve the same or better treatment results than anti-biotic, anti-fungal, anti-viral and anti-protozoan pharmaceuticals, as well as enhancing adaptive protective immune responses like a vaccine. Ezrin peptides can be used as a post-infection vaccination strategy against re-infection. Human Ezrin Peptides can also overcome the rapidly growing problem of drug resistant strains of bacteria, protozoa and viruses. In addition, ezrin peptides amplify adaptive immune responses while simultaneously inhibiting expression of IL-1b, IL-6, IL-8 and TNFa, quickly supressing mucosal inflammation. Human Ezrin Peptides also stimulate fibroblasts to repair damaged tissues.

Plasmid and Cell Envelope Characterization of <i>Vibrio alginolyticus</i> Isolated from Infected Tiger Prawn,<i>Penaeus monodon</i>

It has been reported that indiscriminate use of antibacterial compounds in aquaculture has resulted in an increase in populations of antibiotic resistant strains of bacteria. In the present study, Vibrio alginolyticus isolated from infected Penaeus monodon has been found resistant to Furoxone (30 g), Ampicillin (10 g), Cloxacillin (1 g), Bacitracin (10 units), Penicillin (10 units) and Oxytetracycline (30 pg) by antibiotic sensitivity test, suggesting the restricted prophylactic use of antibiotics in shrimp aquaculture industry. As an approach towards differentiation and identification of bacterial strain, the plasmid characterization of V. alginolyticus by restriction enzyme analysis was carried out which revealed the presence of 6.3 kb and 0.8 kb DNA fragments by Hind lil and a 7. 9 kb DNA fragment by EcoRI enzymes. The cell envelope characterization of V. alginolyticus by SOS-PAGE showed the presence of 12 protein bands in the range of 29 to 112.20 kD. The preliminary information on the cell envelope characterization may help in studies relating towards development of immunostimulant against vibriosis.

Repurposing of waste ammonium sulfate as S,N-doped carbon quantum dots: A sensitive and selective fluorescent probe for the determination of tetracycline

BackgroundCurrently, many types of pharmaceuticals are used to treat disease and bacterial infections. Tetracycline (TC) is a widely applied human and veterinary medicine. However, the widespread usage and lack of awareness in the management of TC lead to its unavoidable discharge into the environment. The consequences include the proliferation of resistant strains of bacteria and adverse impacts on nontarget organisms and microbial ecosystems, which means that TC is an emerging substance of concern and that it is crucial to develop determination platforms with cost-effective and fast-response features. MethodsCarbon quantum dots (CQDs) have received tremendous attention owing to their great performance in fluorescent probing. In the present work, ammonium sulfate-doped carbon quantum dots (S,NCQDs) are fabricated through a facile hydrothermal synthesis pathway. Significant FindingsThe results illustrate that the S,NCQDs exhibit sensitive determination ability toward tetracycline via a static quenching mechanism and possess several superior features, including a rapid response, good sensitivity and stability, broad linear detection range (1–100 μM), and low LOD value (0.1203 μM), when applied in the determination of TC. Additionally, the application of S,NCQDs valorizes ammonium sulfate waste from semiconductor manufactory waste and has great potential in fluorescence sensing.

Quantitative proteomics reveals unique responses to antimicrobial treatments in clinical Pseudomonas aeruginosa isolates.

Epidemic strains of Pseudomonas aeruginosa often have increased levels of antibiotic resistance, and these resistance phenotypes are difficult to predict. We used quantitative proteomics to compare the responses of laboratory strain PAO1 and two isolates of the Liverpool epidemic strain (LES) to four antibiotics and hydrogen peroxide. The majority of proteome changes were unique to either one isolate or treatment, but smaller groups of proteins were differentially abundant in more than one sample. Proteins in these shared adaptive responses represent promising avenues for further investigation to understand the contribution of these proteins to resistance and their potential as targets for novel treatments. We observed the largest overlap between the proteome profiles of PAO1 challenged with tobramycin and hydrogen peroxide, and our data support previous work suggesting a role for heat shock protein IbpA in response to tobramycin. Our proteome profiling uncovered extensive changes in LESB58 in response to carbenicillin, with more than 1,000 proteins significantly changed in abundance. This included unique changes in the abundance of proteins involved in cell wall synthesis and division. We used phase contrast microscopy to check for corresponding changes in cell morphology and show that LESB58 maintained shorter cell lengths under treatment with β-lactams. We propose that the ability to maintain the processes of cell wall synthesis and division through changes in protein abundances contributes to the high levels of β-lactam resistance in LESB58. IMPORTANCE Pseudomonas aeruginosa is an important pathogen often associated with hospital-acquired infections and chronic lung infections in people with cystic fibrosis. P. aeruginosa possesses a wide array of intrinsic and adaptive mechanisms of antibiotic resistance, and the regulation of these mechanisms is complex. Label-free quantitative proteomics is a powerful tool to compare susceptible and resistant strains of bacteria and their responses to antibiotic treatments. Here we compare the proteomes of three isolates of P. aeruginosa with different antibiotic resistance profiles in response to five challenge conditions. We uncover unique and shared proteome changes for the widely used laboratory strain PAO1 and two isolates of the Liverpool epidemic strain of P. aeruginosa, LESlike1 and LESB58. Our data set provides insight into antibiotic resistance in clinically relevant Pseudomonas isolates and highlights proteins, including those with uncharacterized functions, which can be further investigated for their role in adaptive responses to antibiotic treatments.