Screening of Anti-Infectives against Leishmania donovani

Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC50) were obtained using the broth dilution method. The IC50’s of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC50 = 0.089 μg/ml), gentamicin (IC50 = 8.1 μg/ml), amodiaquine (IC50 = 138 μg/ml) and the two standard drugs: Amphotericin B (IC50 = 6.3 μg/ml) and Pentamidine (IC50 = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.

Analysis of the Clinical Value of Surgical Treatment and Postoperative Anti-Infection Treatment of Acute Suppurative Appendicitis

Objective: To explore the clinical value of surgical treatment and postoperative anti-infection treatment for acute suppurative appendicitis. Methods: A total of 116 patients with acute suppurative appendicitis were enrolled in this study. The collection period was from December 2021 to December 2023. The patients were randomly grouped into a control group (surgical treatment) and an observation group (surgical treatment and postoperative anti-infection treatment), of 58 patients each. At the end of the treatment, the results of each index of the two groups were compared. Results: The length of hospitalization time, exhaust time, and incidence of complications in the observation group were shorter than those of the control group (P < 0.05). The total effective rate of the observation group was higher than that of the control group (P < 0.05). Conclusion: It is crucial to perform anti-infective treatment promptly after surgical treatment in patients with acute suppurative appendicitis. It can effectively prevent the occurrence of complications and improve the clinical efficacy. Hence, it is worthy of research and promotion.

Anti-infective therapy durations predict psychological stress and laparoscopic surgery quality in pelvic abscess patients

BACKGROUND The degree of psychological stress and the difficulty and efficacy of laparoscopic surgery differ in patients with pelvic abscesses after different durations of antiinfection treatment.AIM To compare and analyse the effects of different durations of anti-infective therapy on patients’preoperative psychological stress level and the clinical efficacy of laparoscopic surgery in patients with pelvic abscesses to offer a reference for the selection of therapy plans.METHODS A total of 100 patients with pelvic abscesses who were admitted to the Department of Gynecology of Suzhou Ninth Hospital affiliated to Soochow University(Suzhou Ninth People's Hospital)from January 2018 to December 2022 were retrospectively enrolled.According to the different durations of antiinfective therapy,they were divided into Group S(50 patients,received antiinfective therapy for 24-48 h)and Group L(50 patients,received anti-infective therapy for 48-96 h).Baseline data,state-trait anxiety score at admission and before surgery,self-rating anxiety scale(SAS)+self-rating depression scale(SDS)score,surgery time,adhesion grading score,intraoperative blood loss,presence or absence of intraoperative intestinal injury,ureteral injury or bladder injury,postoperative body temperature,length of hospital stay,and presence or absence of recurrence within 3 mo after surgery,chronic pelvic pain,incision infection,dysmenorrhea,menstrual disorder or intestinal obstruction were compared between the S group and the L group.RESULTS There was no significant difference in the background data between the S group and the L group(P<0.05).There was no significant difference in the state-trait anxiety score or SAS+SDS score between the S group and the L group on admission(P<0.05).The state-trait anxiety score and SAS+SDS score of the S group were lower than those of Group L after receiving different durations of anti-infective therapy(P<0.05).There was no significant difference in the incidence of intestinal,ureteral or bladder injury between the S group and the L group(P<0.05).The surgery time of Group S was shorter than that of Group L,and the adhesion score and intraoperative blood loss volume were lower than those of Group L(P<0.05).There was no significant difference in the incidence of incision infection,dysmenorrhea,menstrual disorder or intestinal obstruction between the S group and the L group(P<0.05).The postoperative body temperature of Group S was lower than that of Group L(P<0.05),and the hospital stay was shorter than that of Group L(P<0.05).The incidences of recurrence and chronic pelvic pain within 3 mo after surgery were lower than that of Group L(P<0.05).CONCLUSION Twenty-four to forty-eight hours of anti-infective therapy is better than 48-96 h of anti-infective therapy for patients with pelvic abscesses because the degree of psychological stress is lower,which is more conducive to achieving better outcomes after laparoscopic surgery.

Bioactivities,Mechanisms,Production,and Potential Application of Bile Acids in Preventing and Treating Infectious Diseases

Infectious diseases are a global public health problem,with emerging and re-emerging infectious diseases on the rise worldwide.Therefore,their prevention and treatment are still major challenges.Bile acids are common metabolites in both hosts and microorganisms that play a significant role in controlling the metabolism of lipids,glucose,and energy.Bile acids have historically been utilized as first-line,valuable therapeutic agents for related metabolic and hepatobiliary diseases.Notably,bile acids are the major active ingredients of cow bezoar and bear bile,which are commonly used traditional Chinese medicines(TCMs)with the therapeutic effects of clearing heat,detoxification,and relieving wind and spasm.In recent years,the promising performance of bile acids against infectious diseases has attracted attention from the scientific community.This paper reviews for the first time the biological activities,possible mechanisms,production routes,and potential applications of bile acids in the treatment and prevention of infectious diseases.Compared with previous reviews,we comprehensively summarize existing studies on the use of bile acids against infectious diseases caused by pathogenic microorganisms that are leading causes of global morbidity and mortality.In addition,to ensure a stable supply of bile acids at affordable prices,it is necessary to clarify the biosynthesis of bile acids in vivo,which will assist scientists in elucidating the accumulation of bile acids and discovering how to engineer various bile acids by means of chemosynthesis,biosynthesis,and chemoenzymatic synthesis.Finally,we explore the current challenges in the field and recommend a development strategy for bile-acid-based drugs and the sustainable production of bile acids.The presented studies suggest that bile acids are potential novel therapeutic agents for managing infectious diseases and can be artificially synthesized in a sustainable way.

Cytocompatibility with osteogenic cells and enhanced in vivo anti-infection potential of quaternized chitosan-loaded titania nanotubes

Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan （hydroxypropyltrimethyl ammonium chloride chitosan, HACC）, could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes （NT-H）. The titanium implant （Ti）, nanotubes without polymer loading （NT）, and nanotubes loaded with chitosan （NT-C） were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methiciUin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.

Study on Anti-infection Effect of Polysaccharide from Agaricus blazei Murrill on Mice

In order to study the anti-infection effect of phoshporylated Agaricus blazei polysaccharide on mice, mice were drenched phoshporylated A. blazei polysaccharide for 14 d, and an A. blazei polysaccharide control group and a blank control group were also set. The mice in all the three groups were infected with Escherichia coli on the 15 th day and the 29 th day of the experiment, the body weight of the mice in each group was recorded, as well as the spleen index on the 29 th day of infection and the 36 th day of the experiment, and the anti- E. coli titer in serum was also detected. The results showed that phoshporylated A. blazei polysaccharide could promote and maintain the development of spleen, and improve the immune response of organisms, thereby resisting bacterial infection. Furthermore, phoshporylated A. blazei polysaccharide has better immunoregulation and anti-infection effects than A. blazei polysaccharide, and could play an important role in veterinary clinical treatment and prevention and control of diseases as a immunologic adjuvant or immunopotentiator.

Observations on the Preventive Effects of Anti-infective Treatment on Wound Infection in Emergency Surgery

Objective:To explore the preventive effects of anti-infective treatment on wound infection in emergency surgical trauma.Methods:180 patients in our hospital from 2019 to June to May 2020 were selected as subjects.The 180 patients were randomly divided into two groups.The control group had 90 cases and adopted the conventional treatment method,and the experimental group received anti-infective treatment.The wound healing,infection status,and patient satisfaction of the two groups of patients were analyzed.Results:The wound healing,infection status,and patient satisfaction of the experimental group were better than those of the control group.Conclusion:The application of anti-infective treatment to the prevention of wound infection in emergency surgical trauma can reduce the infection rate of the patients'incision and promote the recovery of patients.It is suitable for clinical applications.

Chemical constituents and theiranti-infective activity of Paeonia suffruticosa

Objective:Research the chemical constituents of Paeonia suffruticosa that are responsible for its anti-infective properties.Methods:Several column chromatographic methods were used to purify the chemical constituents from P.suffruticosa,including medium pressure liquid chromatography,Sephadex LH-20,and normal silica gel.A disc diffusion method was used to screen for antibacterial activity,and their anti-virulence activity was assessed on the type III secretion system(T3SS)of Salmonella pathogenicity island 1(SPI-1)in Salmonella enterica serovar Typhimurium UK-1 g 8956 by SDS-PAGE and western blots.Results:Twenty-one compounds were identified.Compounds 7,8 and 17 showed moderate activity against S.aureus ATCC25923,compounds 8,9 and 10 showed weak activities against B.subtilis ACCC11060.Meanwhile,phenols(14-18)and flavonoids(20 and 21)inhibited T3SS protein secretion of S.typhimurium without affecting bacterial growth.Furthermore,a strong inhibitory effect was observed for 17 and 20 on SPI-1 mediated invasion of HeLa cells.Additionally,no toxicity was observed for these compounds.Conclusion:P.suffruticosa has anti-infective properties due in part to the fact that phenols and flavonoids can block the secretion of T3SS-associated protein effectors.

Postpartum ovarian vein thrombosis after cesarean section and vaginal delivery:Two case reports

BACKGROUND Postpartum ovarian vein thrombosis(POVT)is a rare puerperal complication.It is easily missed or misdiagnosed due to its insidious onset and lack of specific clinical symptoms and signs.This paper reports two patients who developed right ovarian vein thrombosis after cesarean section and vaginal delivery,respectively.CASE SUMMARY Case 1 was a 32-year-old female who underwent a cesarean section in labor at 40 wk of gestation due to fetal distress.The patient was persistently febrile after the operation and escalated antibiotic treatment was ineffective.POVT was diagnosed by abdominal computed tomography(CT)and was treated by increasing the dose of low molecular weight heparin(LMWH).Case 2 was a 21-year-old female with a spontaneous vaginal delivery at 39 wk of gestation.The patient developed fever and abdominal pain 3 days after delivery.POVT was promptly identified by abdominal CT,and the condition was quickly controlled after treatment with LMWH and antibiotics.CONCLUSION These two cases occurred after cesarean section and vaginal delivery,respectively.The diagnosis was mainly based on imaging examination due to the unspecific clinical symptoms and signs,the CT scan provided an especially high diagnostic value.Comparing these two cases,escalating antibiotics alone did not provide significant therapeutic benefit,but the early escalation of anticoagulant dosage seemed to shorten the disease course.Therefore,early diagnosis by CT followed by aggressive anticoagulation might have a positive effect on improving the prognosis of the disease.

Recovery rates of combination antibiotic therapy using in vitro microdialysis simulating in vivo conditions

Microdialysis is a technique used to measure the unbound antibiotic concentration in the interstitial spaces, the target site of action. In vitro recovery studies are essential to calibrating the microdialysis system for in vivo studies. The effect of a combination of antibiotics on recovery into microdialysate requires investigation. In vitro microdialysis recovery studies were conducted on a combination of vancomycin and tobramycin, in a simulated in vivo model. Comparison was made between recoveries for three different concentrations and three different perfusate flow rates. The overall relative recovery for vancomycin was lower than that of tobramycin. For tobramycin, a concentration of 20μg/mL and flow rate of 1.0μL/min had the best recovery. A concentration of 5.0μg/mL and flow rate of 1.0μL/min yielded maximal recovery for vancomycin. Large molecular size and higher protein binding resulted in lower relative recoveries for vancomycin. Perfusate flow rates and drug concentrations affected the relative recovery when a combination of vancomycin and tobramycin was tested. Low perfusate flow rates were associated with higher recovery rates. For combination antibiotic measurement which includes agents that are highly protein bound, in vitro studies performed prior to in vivo studies may ensure the reliable measurement of unbound concentrations.

Low eradication rate of Helicobacterpyloriwith triple 7-14 days and quadriple therapy in Turkey

AIM:The eradication rate of Helicobacter pylori (H pylori) shows variation among countries and regimens of treatment. We aimed to study the eradication rates of different regimens in our region and some factors affecting the rate of eradication. METHODS:One hundred and sixty-four H pylori positive patients (68 males,96 females;mean age:48±12 years) with duodenal or gastric ulcer without a smoking history were included in the study.The patients were divided into three groups according to the treatment regimens.Omeprazole 20mg,clarithromycin 500mg,amoxicillin 1g were given twice daily for 1 week (Group Ⅰ) and 2 weeks (Group Ⅱ). Patients in Group Ⅲ received bismuth subsitrate 300mg, tetracyline 500mg and metronidazole 500mg four times daily in addition to Omeprazole 20mg twice daily.Two biopsies each before and after treatment were obtained from antrum and corpus,and histopathologically evaluated. Eradication was assumed to be successful if no H pylorus was detected from four biopsy specimens taken after treatment.The effects of factors like age,sex,H pylori density on antrum and corpus before treatment,the total H pylori density,and the inflammation scores on the rate of H pylori eradication were evaluated. RESULTS:The overall eradication rate was 42%.The rates in groups Ⅱ and Ⅲ were statistically higher than that in group Ⅰ (P<0.05).The rates of eradication were 24.5%, 40.7% and 61.5% in groups Ⅰ,Ⅱ and Ⅲ,respectively.The eradication rate was negatively related to either corpus H pylori density or total H pylori density (P<0.05).The median age was older in the group in which the eradication failed in comparison to that with successful eradication (55 yr vs 39 yr,P<0.001).No correlation between sex and H pylori eradication was found. CONCLUSION:Our rates of eradication were significantly lower when compared to those reported in literature.We believe that advanced age and high H pylori density are negative predictive factors for the rate of H pylori eradication.

Screening strategies for quorum sensing inhibitors in combating bacterial infections

Interference with quorum sensing(QS)represents an antivirulence strategy with a significant promise for the treatment of bacterial infections and a new approach to restoring antibiotic tolerance.Over the past two decades,a novel series of studies have reported that quorum quenching approaches and the discovery of quorum sensing inhibitors(QSIs)have a strong impact on the discovery of anti-infective drugs against various types of bacteria.The discovery of QSI was demonstrated to be an appropriate strategy to expand the anti-infective therapeutic approaches to complement classical antibiotics and antimicrobial agents.For the discovery of QSIs,diverse approaches exist and develop in-step with the scale of screening as well as specific QS systems.This review highlights the latest findings in strategies and methodologies for QSI screening,involving activity-based screening with bioassays,chemical methods to seek bacterial QS pathways for QSI discovery,virtual screening for QSI screening,and other potential tools for interpreting QS signaling,which are innovative routes for future efforts to discover additional QSIs to combat bacterial infections.

Cefoperazone-sulbactam and ornidazole for Gardnerella vaginalis bloodstream infection after cesarean section:A case report

BACKGROUND Gardnerella vaginalis(G.vaginalis)is a facultative anaerobic bacteria known to cause bloodstream infections.However,cases are very rare in clinics.There is very limited clinical experience in the treatment of bloodstream infections caused by G.vaginalis.Therefore,there is an urgent need for effective antibacterial drugs to treat patients with bloodstream infections caused by G.vaginalis.CASE SUMMARY A woman who underwent a cesarean section presented with a sudden onset of high fever 1-d post-surgery.The blood cultures suggested an infection due to G.vaginalis,and treatment with cefoperazone-sulbactam was started.After 5 d of treatment,there was a decrease in the hemogram;however,the temperature and C-reactive protein levels remained high.Based on clinical experience and a review of literature,the treatment was modified to include ornidazole in combination with cefoperazone-sulbactam.Following a week of treatment,the temperature,hemogram and C-reactive protein levels returned to normal,and blood cultures turned negative,suggesting a therapeutic effect of the combination treatment.CONCLUSION This case highlighted the effective use of cefoperazone-sulbactam combined with ornidazole for bloodstream infection caused by G.vaginalis following a cesarean section.

Self-enhanced photothermal-chemodynamic antibacterial agents for synergistic anti-infective therapy

Cu_(2-x)S nanostructures have been intensively studied as outstanding chemodynamic therapy(CDT)and good photothermal therapy(PTT)antibacterial agents due to their highly efficient Cu(Ⅰ)-initiated Fenton-like catalytic activity and good photothermal conversion property.However,they still suffer from shortage of Cu(Ⅰ)supply in the long-term and comparatively low inherent photothermal conversion efficiency.Herein,we constructed a self-enhanced synergistic PTT/CDT nanoplatform(Cu_(1.94)S@MPN)by coating Cu_(1.94)S nanoparticles with Fe(Ⅲ)/tannic acid based metal-polyphenol networks(MPN).Activated by the acidic bacterial infection microenvironment,Cu_(1.94)S@MPN could be decomposed to continuously release Cu(Ⅱ),Fe(Ⅲ)ions and tannic acid.As the result of tannic acid-involved Cu and Fe redox cycling,Cu(Ⅰ)/Fe(Ⅱ)-rich CDT could be achieved through the highly accelerated catalytic Fenton/Fenton-like reactions.More importantly,experimental results demonstrated that Cu_(1.94)S@MPN exhibited both excellent photothermal antibacterial and photothermal-enhanced CDT properties to eradicate bacteria in vitro and in vivo.Overall,this novel nanotherapeutics has great potential to become a clinic candidate for anti-infective therapy in future.

Effects of All-trans Retinoic Acid (ATRA) against Bacterial Infection in Chickens

In order to investigate the effects of all-trans retinoic acid （ATRA） against bacterial infection in chickens, 35 3-day-old AA broiler chickens were fed adaptively for two days and randomly divided into five groups, including Escherichia coli experimental group （ group 1 ）, Escherichia coli control group （group 2）, blank control group （ group 3 ）, PasteureUa experimental group （ group 4）, and PasteureUa control group （ group 5 ）. At 5 days of age, the chickens in group 1 and group 4 were drenched with 5 p.mol/kg ATRA for seven consecutive days according to their weight; the chickens in group 2, group 3 and group 5 were drenched with an equal volume of dimethyl sulfoxlde （DMSO）. The clinical symptoms and weight changes in each group were observed and recorded. Seven days later, the chickens were euthanized and dissected to determine the immune organ indexes. The results showed that there were significant differences in body weight between ATRA-administrated chickens and non-administrated chickens after bacterial infection （P 〈 0.05 ） ; moreover, the immune organ indexes of ATRA-administrated chickens exhibited significant differences compared with control group （P 〈 0.05 ）, indicating that ATRA could promote the development of immune organs of poultry, thereby enhancing the body immunity against bacterial infection.

Pharmacokinetic and pharmacodynamic considerations of antimicrobial drug therapy in cancer patients with kidney dysfunction

Patients with cancer have a high inherent risk of infectious complications.In addition,the incidence of acute and chronic kidney dysfunction rises in this population.Antiinfective drugs often require dosing modifications based on an estimate of kidney function,usually the glomerular filtration rate(GFR).However,there is still no preferential GFR formula to be used,and in acute kidney injury there is always a considerable time delay between true kidney function and estimated GFR.In most cases,the anti-infective therapy should start with an immediate and high loading dose.Pharmacokinetic as well as pharmacodynamic principles must be applied for further dose adjustment.Anti-infective drugs with time-dependent action should be given with the target of high trough concentrations(e.g.,beta lactam antibiotics,penems,vancomycin,antiviral drugs).Anti-infective drugs with concentration-dependent action should be given with the target of high peak concentrations(e.g.,aminoglycosides,daptomycin,colistin,quinolones).Our group created a pharmacokinetic database,called NEPharm,hat serves as a reference to obtain reliable dosing regimens of anti-infective drugs in kidney dysfunction as well as renal replacement therapy.To avoid the risk of either too low or too infrequent peak concentrations,we prefer the eliminated fraction rule for dose adjustment calculations.

Germline Deletion of the Expression of a Human Bispecific Mucosal Immunoglobulin: Genetic Predisposition to Cancer and Communicable Diseases Predominantly among African-Americans

In a previous report we had reported on the discovery of a novel bispecific immunoglobulin expressed by colonic epithelial cells as they transform into immunomimetic cells during exfoliation (Albaugh et al. (2020) Open Journal of Preventive Medicine, 10, 126-150). Colonic cells isolated from 0.5 gm aliquots of fresh stools (SCSR-10, Fecal Cell Isolation Kit, NonInvasive Technologies, Elkridge, MD) preserved at room temperature for up to one week, with viability of >85% were used to determine the number of cells expressing this novel bispecific immunoglobulin. Over the course of this period (18 years) we recognized that these cells opened the opportunity to investigate the expression of cell membrane biomarkers. As the applications grew, we introduced a new terminology, termed COPROCYTOBIOLOGY*. In this study, we surveyed a cohort of 58 free-living adults for the expression of the newly discovered bi-specific chimeric antibody. Almost all of the subjects showed a strong signal during flow-cytometric evaluation of their stool samples;averaging around 65%. However, two subjects exhibited a total loss of this signal and both these individuals were of African-American lineage (one male and one female). These cells upon culturing in vitro remained defective in contrast to the rest of the group where their progeny continued to generate the antibody. We propose that this signals the existence of a germ-line deletion of the gene for which a novel test (MEDISHIELD†) is suggested. This syndrome may be associated with a lack of response to prophylactic vaccines involving m-RNA.

Clinical analysis of 198 cases of western medicine adverse reaction

Objective: To discuss the clinical symptoms of western medicine adverse reaction, and to provide basis for clinical rational drug use. Methods: Clinical data of 198 patients with adverse drug reactions were retrospectively analyzed in our hospital. Adverse reactions clinical manifestations, the types of drugs and the route of medication were summarized. Results: The first two common adverse reactions were anti-infective drugs and cardiovascular system drugs respectively. In-tramuscular injection and intravenous administration were two main routes of medication for adverse drug reactions. The main clinical symptoms of adverse reactions were digestive tract and anaphylactic shock etc. After treatment, 184 patients recovered and 14 patients got better. Conclusions: In order to reduce the incidence of adverse reactions as far as possible, clinicians should do a good job of rational use of drugs and attach importance to the safety of drug use. Adverse reactions monitoring can reduce the occurrence of adverse reactions and ensure the safety of clinical treatment.

Natural medicine can substitute antibiotics in animal husbandry:protective effects and mechanisms of rosewood essential oil against Salmonella infection

Aniba rosaeodora essential oil(RO) has been traditionally used in natural medicine as a substitute for antibiotics due to its notable antidepressant and antibacterial properties. Salmonella, a prevalent pathogen in foodborne illnesses, presents a major challenge to current antibiotic treatments. However, the antibacterial efficacy and mechanisms of action of RO against Salmonella spp. remain underexplored. This study aims to elucidate the chemical composition of RO, evaluate its antibacterial activity and mechanisms against Salmonella in vitro, and further delineate its anti-inflammatory mechanisms in vivo during Salmonella infection. Gas chromatography-mass spectrometry(GC-MS) was utilized to characterize the chemical constituents of RO. The antibacterial activity of RO was assessed using minimal inhibitory concentration(MIC) and time-kill assays. Various biochemical assays were employed to uncover the potential bactericidal mechanisms. Additionally, mouse and chick models of Salmonella infection were established to investigate the prophylactic effects of RO treatment. RO exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacteria, with an MIC of 4 mg·mL^(-1) for Salmonella spp. RO treatment resulted in bacterial damage through the disruption of lipid and purine metabolism. Moreover, RO reduced injury and microbial colonization in infected mice and chicks. RO treatment also modulated the host inflammatory response by inhibiting proinflammatory pathways. In conclusion, our findings demonstrate that RO is effective against Salmonella infection, highlighting its potential as an alternative to antibiotics for antibacterial therapy.

Self-assembly multifunctional DNA tetrahedron for efficient elimination of antibiotic-resistant bacteria

Antibiotic resistance is a major challenge in the clinical treatment of bacterial infectious diseases.Herein,we constructed a multifunctional DNA nanoplatform as a versatile carrier for bacteria-specific delivery of clinical antibiotic ciprofloxacin(CIP)and classic nanoantibiotic silver nanoparticles(AgNP).In our rational design,CIP was efficiently loaded in the self-assembly double-bundle DNA tetrahedron through intercalation with DNA duplex,and single-strand DNA-modified AgNP was embedded in the cavity of the DNA tetrahedron through hybridization.With the site-specific assembly of targeting aptamer in the well-defined DNA tetrahedron,the bacteria-specific dual-antibiotic delivery system exhibited excellent combined bactericidal properties.With enhanced antibiotic accumulation through breaking the out membrane of bacteria,the antibiotic delivery system effectively inhibited biofilm formation and promoted the healing of infected wounds in vivo.This DNAbased antibiotic delivery system provides a promising strategy for the treatment of antibiotic-resistant infections.