Utilizing the photodynamic properties of curcumin to disrupt biofilms in Cutibacterium acnes: A promising approach for treating acne.

BACKGROUND: The treatment of acne vulgaris is often challenging due to the antibiotic resistance frequently observed in Cutibacterium acnes (C.acnes), a prevalent bacterium linked to this condition. OBJECTIVE: The objective of this research was to examine the impact of curcumin photodynamic therapy (PDT) on the survival of C.acnes and activity of biofilms produced by this microorganism. METHODS: Following the Clinical and Laboratory Standards Institute (CLSI) guidelines, we assessed the drug sensitivity of 25 clinical C.acnes strains to five antibiotics (erythromycin, clindamycin, tetracycline, doxycycline, minocycline) and curcumin by implementing the broth microdilution technique. In addition, we established C.acnes biofilms in a laboratory setting and subjected them to curcumin-PDT(curcumin combined with blue light of 180 J/cm2). Afterwards, we evaluated their viability using the XTT assay and observed them using confocal laser scanning microscopy. RESULTS: The result revealed varying resistance rates among the tested antibiotics and curcumin, with erythromycin, clindamycin, tetracycline, doxycycline, minocycline, and curcumin exhibiting resistance rates of 72 %, 44 %, 36 %, 28 %, 0 %, and 100 %, respectively. In the curcumin-PDT inhibition tests against four representative antibiotic-resistant strains, it was found that the survival rate of all strains of planktonic C. acnes was reduced, and the higher the concentration of curcumin, the lower the survival rate. Furthermore, in the biofilm inhibition tests, the vitality and three-dimensional structure of the biofilms were disrupted, and the inhibitory effect became more significant with higher concentrations of curcumin. CONCLUSION: The results emphasize the possibility of using curcumin PDT as an alternative approach for the treatment of C.acnes, especially in instances of antibiotic-resistant variations and infections related to biofilms.

[Investigation of the Efficacy of Cinnamaldehyde, Cannabidiol and Eravacycline in a Malaria Model]. / Sitma Modelinde Cinnamaldehyde, Cannabidiol ve Eravacycline'in Etkinliginin Arastirilmasi.

In this study, it was aimed to investigate the antimalarial activity of cinnamaldehyde (CIN) and cannabidiol (CBD) which have shown various biological activities such as potent antimicrobial activity and eravacycline (ERA), a new generation tetracycline derivative, in an in vivo malaria model. The cytotoxic activities of the active substances were determined by the MTT method against L929 mouse fibroblasts and their antimalarial activity were determined by the four-day test in an in vivo mouse model. In this study, five groups were formed: the CIN group, the CBD group, the ERA group, the chloroquine group (CQ) and the untreated group (TAG). 2.5 x 107 parasites/mL of P.berghei-infected erythrocyte suspension was administered IP to all mice. The determined doses of active substances were given to the mice by oral gavage in accordance with the four-day test and the parasitemia status in the mice was controlled for 21 days with smear preparations made from the blood taken from the tail end of the mice. The IC50 values, which express the cytotoxic activity values of the active substances were determined as 27.55 µg/mL, 16.40 µM and 48.82 µg/mL for CIN, CBD and ERA, respectively. The mean parasitemia rate in untreated mice was 33% on day nine and all mice died on day 11. On the ninth day, when compared with the TAG group, no parasites were observed in the CIN group, while the average parasitemia was 0.08% in the CBD group and 17.8% in the ERA group. Compared to the mice in the TAG group, the life expectancy of the other groups was prolonged by eight days in the CIN group, 12 days in the CBD group and eight days in the ERA group. It has been determined that all three active subtances tested in this study suppressed the development of Plasmodium parasites in an in vivo mouse model and prolonged the life span of the mice. It is thought that the strong antimalarial activity of CIN and CBD shown in the study and the possible positive effect of ERA on the clinical course can be improved by combining them with the existing and potential antimalarial molecules.

Evaluation of disk diffusion method for testing the rifampicin, erythromycin, and tetracycline susceptibility of Clostridioides (prev. Clostridium) difficile.

INTRODUCTION: Antimicrobial resistance (AMR) is one of the greatest threats to animal and public health. Clostridioides (prev. Clostridium) difficile is a major burden to healthcare and a relevant AMR gene reservoir. Despite the known importance of AMR in C. difficile epidemiology and treatment, antimicrobial susceptibility testing for this pathogen is still based on the determination of the minimal inhibitory concentration (MIC) by the agar dilution method, which is technically demanding and labor-intensive. In this study, the disk diffusion method was used to evaluate the susceptibility of C. difficile to erythromycin, rifampicin, and tetracycline. MATERIAL AND METHODS: A total of 155 isolates isolated between 2011 and 2022 from humans and animals in Brazil were simultaneously tested using the disk diffusion method and the epsilometer test (Etest) for these three antimicrobials on Brucella blood agar supplemented with vitamin K and hemin. RESULTS: The results suggest that disk diffusion can be an interesting routine tool to identify erythromycin- and rifampicin-resistant C. difficile isolates (≥20 mm cut-off) and wild type (WT) strains (≥28 mm). However, the disk diffusion protocol tested in this study does not seem suitable for tetracycline because of the common misclassification of resistant strains.

Tea polyphenols and catechins postpone evolution of antibiotic resistance genes and alter microbial community under stress of tetracycline.

Relying on the high mobility of water flow, the dissemination of antibiotic resistance genes (ARGs) in the water tends to be exacerbated and enlarged. It caused negative impacts on a wider scope of the environment. The ARGs dissemination monitoring and the methods efficiently reducing their concentration in water became the focus of interest. Green chemicals with antibacterial effects such as tea polyphenols (TPs) and catechins (CA) have been considered as auxiliary disinfectants for ARGs removal in the water environment. However, the antibacterial performance of TPs and CA under the stress of external antibiotics still lacks sufficient research. The results show that more operational taxonomic units can be observed in water samples with TPs and CA than in those without the ingredients under pressure of tetracycline. An unexpected increase along with the increase of ARGs concentrations and the diversity of microbial communities under the low-concentration TPs or CA (1 mg/L). Besides, under the stress of tetracycline, the inhibition of TPs was detected to be strengthened for increase of inti1 and tetC but weakened towards for the increase of tetA. Whilst CA substantially diminished abundances of tetC and tetA under tetracycline pressure. This research demonstrated that TPs and CA are able to assuage development of ARGs under the pressure of antibiotic in water system.

Evaluation of efflux pump inhibitory activity of some plant extracts and using them as adjuvants to potentiate the inhibitory activity of some antibiotics against Staphylococcus aureus.

Background: Antibiotic-resistant pathogens became a real global threat to human and animal health. This needs to concentrate the efforts to minimize and control these organisms. Efflux pumps are considered one of the important strategies used by bacteria to exclude harmful materials from the cell. Inhibition of these pumps can be an active strategy against multidrug resistance pathogens. There are two sources of efflux pump inhibitors that can be used, chemical and natural inhibitors. The chemical origin efflux pump inhibitors have many toxic side effects while the natural origin is characterized by a wide margin of safety for the host cell. Aim: In this study, the ability of some plant extracts like (propolis show rosemary, clove, capsaicin, and cumin) to potentiate the inhibitory activity of some antibiotics such as (ciprofloxacin, erythromycin, gentamycin, tetracycline, and ampicillin) against Staphylococcus aureus pathogen were tested. Methods: Efflux pump inhibitory activity of the selected plant extracts was tested using an ethidium bromide (EtBr) accumulation assay. Results: The results have shown that Propolis has a significant synergistic effect in combination with ciprofloxacin, erythromycin, and gentamycin. While it has no effect with tetracycline or ampicillin. Also, no synergic effect was noticed in a combination of the minimum inhibitory concentration for the selected plant extracts (rosemary, clove, capsaicin, and cumin) with any of the tested antibiotics. Interestingly, according to the results of the EtBr accumulation assay, Propolis has potent inhibitory activity against the S. aureus (MRS usa300) pump system. Conclusion: This study suggests that Propolis might act as a resistance breaker that is able to restore the activity of ciprofloxacin, erythromycin, and gentamycin against S. aureus strains, in case of the efflux-mediated antimicrobial resistance mechanisms.

Efficacy and safety of high-dose esomeprazole-amoxicillin dual therapy for Helicobacter pylori rescue treatment: a multicenter, prospective, randomized, controlled trial.

BACKGROUND: High-dose dual therapy (HDDT) with proton pump inhibitors (PPIs) and amoxicillin has attracted widespread attention due to its favorable efficacy in eradicating Helicobacter pylori (H. pylori). This study aimed to compare the efficacy and safety of high-dose PPI-amoxicillin dual therapy and bismuth-containing quadruple therapy for H. pylori rescue treatment. METHODS: This was a prospective, randomized, multicenter, non-inferiority trial. Patients recruited from eight centers who had failed previous treatment were randomly (1:1) allocated to two eradication groups: HDDT (esomeprazole 40 mg and amoxicillin 1000 mg three times daily; the HDDT group) and bismuth-containing quadruple therapy (esomeprazole 40 mg, bismuth potassium citrate 220 mg, and furazolidone 100 mg twice daily, combined with tetracycline 500 mg three times daily; the tetracycline, furazolidone, esomeprazole, and bismuth [TFEB] group) for 14 days. The primary endpoint was the H. pylori eradication rate. The secondary endpoints were adverse effects, symptom improvement rates, and patient compliance. RESULTS: A total of 658 patients who met the criteria were enrolled in this study. The HDDT group achieved eradication rates of 75.4% (248/329), 81.0% (248/306), and 81.3% (248/305) asdetermined by the intention-to-treat (ITT), modified intention-to-treat (MITT), and per-protocol (PP) analyses, respectively. The eradication rates were similar to those in the TFEB group: 78.1% (257/329), 84.2% (257/305), and 85.1% (257/302). The lower 95% confidence interval boundary (-9.19% in the ITT analysis, - 9.21% in the MITT analysis, and -9.73% in the PP analysis) was greater than the predefined non-inferiority margin of -10%, establishing a non-inferiority of the HDDT group vs. the TFEB group. The incidence of adverse events in the HDDT group was significantly lower than that in the TFEB group (11.1% vs. 26.8%, P  < 0.001). Symptom improvement rates and patients' compliance were similar between the two groups. CONCLUSIONS: Fourteen-day HDDT is non-inferior to bismuth-containing quadruple therapy, with fewer adverse effects and good treatment compliance, suggesting HDDT as an alternative for H. pylori rescue treatment in the local region. TRIAL REGISTRATION: Clinicaltrials.gov, NCT04678492.

GC/MS Composition and Resistance Modulatory Inhibitory Activities of Three Extracts of Lemongrass: Citral Modulates the Activities of Five Antibiotics at Sub-Inhibitory Concentrations on Methicillin-Resistant Staphylococcus aureus.

We investigated whether three extractable fractions of lemongrass (Cymbopogon citratus): aqueous and ethanol extracts and lemongrass essential oil exhibited any antimicrobial resistance modulatory effects if used in combination with selected antibiotics ampicillin, tetracycline, streptomycin, cefloxacin and amoxicillin on methicillin-resistant Staphylococcus aureus (MRSA). MRSA growth inhibition (zones of inhibition) was greatest for the lemongrass oil at concentrations of 1, 2, 5, 10 and 20 % (wt/vol). The MIC for lemongrass oil was 0.5 mg/mL, while it was 4 mg/mL for both the aqueous and ethanol extracts. Evaluation of extracts for antibacterial resistance modifying activities when used in combination with either of the five antibiotics at sub-inhibitory concentrations, showed that lemongrass oil highly potentiated the activities of three antibiotics; amoxicillin, streptomycin and tetracycline. The ethanol extract enhanced the activity of tetracycline and ampicillin, while the aqueous extract only increased the activity of tetracycline against MRSA. The activity of cefloxacin with the extracts was either indifferent. Analysis of the lemongrass oil by GC/MS showed the prominence of three compounds: the two isomers neral and geranial of citral and, the acetate geranyl acetate, which together made up 94 % of the composition. The compounds were also observed in the ethanol and water extracts but to a lesser extent when analyzed by HPLC-UV (λ 233 nm). Our study confirms the antibacterial properties of the extracts especially, lemongrass oil. It also demonstrates that lemongrass oil potentiates the activities of three antibiotics against the biofilm-forming MRSA. This biocidal, anti-biofilm disruption and antibiotic potentiating abilities are mainly attributable to citral and geranyl acetate, further evidence of lemongrass oil as a very useful source of phytochemicals, especially citral for the fight against antibiotic resistance.

Increased Prevalence of Minocycline-Resistant Staphylococcus epidermidis with tet(M) by Tetracycline Use for Acne Treatment.

Staphylococcus epidermidis, a major skin bacterium, can cause opportunistic infections. Use of antimicrobial agents against Cutibacterium acnes for acne treatment becomes a risk factor for emergence of antimicrobial-resistant skin bacteria. In this study, the impact of antimicrobial treatment of acne vulgaris on S. epidermidis antimicrobial resistance was assessed. A total of 344 S. epidermidis strains isolated from patients with acne vulgaris who visited hospital (165 strains) and dermatological clinics (179 strains), respectively, were analyzed. Except for doxycycline, the resistance rates were higher in strains isolated from patients who had used antimicrobials for acne treatment than in those isolated from patients who had not used antimicrobials. The prevalence rates of strains with erm(C) from patients who used macrolides and clindamycin (hospital, 78.0%; clinics, 61.3%) and those of strains with tet(M) from patients who used tetracyclines (hospital, 27.5%; clinics, 42.4%) were significantly higher than those of strains from patients who did not use antimicrobials (p < 0.05). All strains with erm(A) (8/8) and 91.7% strains with erm(C) (156/170) showed high-level resistance to macrolides and clindamycin (MIC ≥256 µg/mL). Furthermore, almost all strains with tet(M) showed resistance to minocycline. Our results showed that the use of antimicrobials for acne treatment may lead to an increased prevalence of antimicrobial-resistant S. epidermidis. In particular, the emergence of minocycline-resistant strains with tet(M) owing to the use of tetracyclines (doxycycline and minocycline) is a critical issue. Appropriate antimicrobial use for acne treatment may be an important strategy to prevent the emergence of antimicrobial-resistant skin bacteria.

Direct Detection of Antibiotic Resistance in Chinese Helicobacter pylori Clinical Isolates by Sequencing-Based Approach.

Objective: The detection of Helicobacter pylori mutations that result in antimicrobial resistance can serve as a guideline of antimicrobial therapeutics and probably prevent the failure of clinical treatments. Evaluating the potential of Sanger sequencing to identify genetically resistant determinants in Helicobacter pylori clinical isolates will be important. Methods: 180 cultured strains have been tested using agar dilution for antibiotic susceptibility. NCBI BLAST was used to perform genotypic analysis on the sequencing data. Sanger sequencing was evaluated as an alternative method to detect resistant genotypes and susceptibility. Results: By the conventional E-test, resistance to levofloxacin, amoxicillin, metronidazole, and clarithromycin was 67.3%, 15.1%, 96.4%, and 25.5%, respectively. In contrast, tetracycline had no resistance. Resistance to multiple drugs was observed in 8.12% of the strains. The genetic determinants of resistance to CLA was 23s rRNA, the determinants of resistance to amoxicillin was Pbp1, the determinants of resistance to metronidazole was rdxA, and the determinants of resistance to levofloxacin were GyrA and GyrB. However, there was no association of resistance in tetracycline. Conclusion: We found increased rates of metronidazole antibiotic resistance, highlighting the necessity for alternative therapies and periodic evaluation. Sanger sequencing has proved to be highly effective and holds the potential to be implemented in policies catering to local treatments.

Rescuing Tetracycline Class Antibiotics for the Treatment of Multidrug-Resistant Acinetobacter baumannii Pulmonary Infection.

Acinetobacter baumannii causes high mortality in ventilator-associated pneumonia patients, and antibiotic treatment is compromised by multidrug-resistant strains resistant to ß-lactams, carbapenems, cephalosporins, polymyxins, and tetracyclines. Among COVID-19 patients receiving ventilator support, a multidrug-resistant A. baumannii secondary infection is associated with a 2-fold increase in mortality. Here, we investigated the use of the 8-hydroxyquinoline ionophore PBT2 to break the resistance of A. baumannii to tetracycline class antibiotics. In vitro, the combination of PBT2 and zinc with either tetracycline, doxycycline, or tigecycline was shown to be bactericidal against multidrug-resistant A. baumannii, and any resistance that did arise imposed a fitness cost. PBT2 and zinc disrupted metal ion homeostasis in A. baumannii, increasing cellular zinc and copper while decreasing magnesium accumulation. Using a murine model of pulmonary infection, treatment with PBT2 in combination with tetracycline or tigecycline proved efficacious against multidrug-resistant A. baumannii. These findings suggest that PBT2 may find utility as a resistance breaker to rescue the efficacy of tetracycline-class antibiotics commonly employed to treat multidrug-resistant A. baumannii infections. IMPORTANCE Within intensive care unit settings, multidrug-resistant (MDR) Acinetobacter baumannii is a major cause of ventilator-associated pneumonia, and hospital-associated outbreaks are becoming increasingly widespread. Antibiotic treatment of A. baumannii infection is often compromised by MDR strains resistant to last-resort ß-lactam (e.g., carbapenems), polymyxin, and tetracycline class antibiotics. During the on-going COVID-19 pandemic, secondary bacterial infection by A. baumannii has been associated with a 2-fold increase in COVID-19-related mortality. With a rise in antibiotic resistance and a reduction in new antibiotic discovery, it is imperative to investigate alternative therapeutic regimens that complement the use of current antibiotic treatment strategies. Rescuing the efficacy of existing therapies for the treatment of MDR A. baumannii infection represents a financially viable pathway, reducing time, cost, and risk associated with drug innovation.

Gentamicin Susceptibility in Neisseria gonorrhoeae and Treatment Outcomes for Urogenital Gonorrhea After 25 Years of Sustained Gentamicin Use in Malawi.

BACKGROUND: Gentamicin has been used for the treatment of gonorrhea in Malawi since 1993. However, declining clinical cure rates have been suspected. We evaluated current Neisseria gonorrhoeae susceptibility to gentamicin in vitro and clinically. METHODS: Men with acute urethritis were recruited at the Bwaila District Hospital STI Clinic in Lilongwe, Malawi, between January 2017 and August 2019. All men provided urethral swabs for etiological testing at enrollment and test of cure (TOC), 1 week later, using Gram-stained microscopy and culture. We used Etest to determine minimum inhibitory concentrations (MICs) of gentamicin, azithromycin, cefixime, ceftriaxone, ciprofloxacin, and spectinomycin; disc diffusion for tetracycline susceptibility; and whole-genome sequencing (WGS) to verify/refute treatment failure. RESULTS: Among 183 N. gonorrhoeae culture-positive men enrolled, 151 (82.5%) had a swab taken for TOC. Of these 151 men, 16 (10.6%) had a positive culture at TOC. One hundred forty-one baseline isolates were tested for gentamicin susceptibility using Etest: 2 (1.4%), MIC = 2 µg/mL; 111 (78.7%), MIC = 4 µg/mL; and 28 (19.9%), MIC = 8 µg/mL. All isolates were susceptible to azithromycin, cefixime, ceftriaxone, and spectinomycin, whereas 63.1% had intermediate susceptibility or resistance to ciprofloxacin. Almost all (96.1%) isolates were resistant to tetracycline. All examined isolates cultured at TOC (n = 13) had gentamicin MICs ≤8 µg/mL. Ten men had pretreatment and posttreatment isolates examined by whole-genome sequencing; 2 (20%) were verified new infections (4119 and 1272 single-nucleotide polymorphisms), whereas 8 (80%) were confirmed treatment failures (0-1 single-nucleotide polymorphism). CONCLUSIONS: Gentamicin MICs poorly predict gonorrhea treatment outcome with gentamicin, and treatment failures are verified with gonococcal strains with in vitro susceptibility to gentamicin. The first-line treatment of gonorrhea in Malawi should be reassessed.

Mechanochemical-Assisted Extraction and Hepatoprotective Activity Research of Flavonoids from Sea Buckthorn (Hippophaë rhamnoides L.) Pomaces.

Pomaces of sea buckthorn berry were usually side-products during the processing of juice. Due to a lack of an economical and effective extraction method, it was typically recognized as waste. For the purpose of resource utilization, the mechanochemical-assisted extraction (MCAE) method was applied to develop an ecofriendly extraction method and product with better pharmacology activity. The parameters were investigated through response surface methodology (RSM) design experiments. The processing conditions were optimized as follows: amount of Na2CO3 40%, ball-to-material rate 29:1 g/g, milling speed 410 rpm, milling time 24 min, extraction temperature 25 °C, extraction time 20 min and the solid-to-solution ratio 1:10 g/mL. Under these conditions, the yields of flavonoids from sea buckthorn pomaces were 26.82 ± 0.53 mg/g, which corresponds to an increase of 2 times in comparison with that extracted by the heat reflux extraction method. Meanwhile, the hepatoprotective activity of sea buckthorn pomaces extracts was studied by the liver injury induced by ip injection of tetracycline. Biochemical and histopathological studies showed that biomarkers in serum and liver of nonalcoholic fatty liver disease (NAFLD) mice were significantly ameliorated when sea buckthorn flavonoids extracted by MCAE were used. Altogether, these results demonstrate that, as a green and efficient extraction, MCAE treatment could increase the extraction yield of sea buckthorn flavonoids, meanwhile it could exhibit significant activity of improving liver function. This research provided a new way to use pomaces of sea buckthorn as a functional food. It also has great value on the comprehensive utilization of nature's resources.

Fate of antibiotic resistance genes and metal resistance genes during the thermophilic fermentation of solid and liquid swine manures in an ectopic fermentation system.

Environmental pollution due to resistance genes from livestock manure has become a serious issue that needs to be resolved. However, little studies focused on the removal of resistance genes in simultaneous processing of livestock feces and urine. This study investigated the fate of antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and class 1 integron-integrase gene (intI1) during thermophilic fermentation of swine manure in an ectopic fermentation system (EFS), which has been regarded as a novel system for efficiently treating both feces and urine. The abundances of MRGs and tetracycline resistance genes were 34.44-97.71% lower in the EFS. The supplementation of heavy metals significantly increased the abundance of intI1, with the enhancement effect of copper being more prominent than that of zinc. The highest abundances of resistance genes and intI1 were observed at high Cu levels (A2), indicating that Cu can increase the spreading of resistance genes through integrons. Network analysis revealed the co-occurrence of ARGs, MRGs, and intI1, and these genes potentially shared the same host bacteria. Redundancy analysis showed that the bacterial community explained most of the variations in ARGs, and environmental factors had influences on ARGs abundances by modulating the bacterial community composition. The decreased Sphingomonas, Comamonas, Acinetobacter, Lactobacillus, Bartonella, Rhizobium, and Bacteroides were mainly responsible for the reduced resistance genes. These results demonstrate that EFS can reduce resistance genes in simultaneous processing of livestock feces and urine.

Study on the mechanisms of the cross-resistance to TET, PIP, and GEN in Staphylococcus aureus mediated by the Rhizoma Coptidis extracts.

The purpose of this study was focused on the mechanisms of the cross-resistance to tetracycline (TET), piperacillin Sodium (PIP), and gentamicin (GEN) in Staphylococcus aureus (SA) mediated by Rhizoma Coptidis extracts (RCE). The selected strains were exposed continuously to RCE at the sublethal concentrations for 12 days, respectively. The susceptibility change of the drug-exposed strains was determined by analysis of the minimum inhibitory concentration. The 16S rDNA sequencing method was used to identify the RCE-exposed strain. Then the expression of resistant genes in the selected isolates was analyzed by transcriptome sequencing. The results indicated that RCE could trigger the preferential cross-resistance to TET, PIP, and GEN in SA. The correlative resistant genes to the three kinds of antibiotics were upregulated in the RCE-exposed strain, and the mRNA levels of the resistant genes determined by RT-qPCR were consistent with those from the transcriptome analysis. It was suggested from these results that the antibacterial Traditional Chinese Medicines might be a significant factor of causing the bacterial antibiotic-resistance.

Design, synthesis and drug resistance reversal potential of novel curcumin mimics Van D: Synergy potential of curcumin mimics.

Being crucial part of plant-based novel discovery of drug from natural resources, a study was done to explore the antibacterial potential of curcumin mimics in combination with antibiotics against multidrug resistant isolates of Pseudomonas aeruginosa. The best candidate Van D, a curcumin mimics reduced the MIC of tetracycline (TET) up to 16 folds against multidrug resistant clinical isolates. VanD further inhibited the efflux pumps as evident by ethidium bromide efflux and by in-silico docking studies. In another experiment, it was also found that Van D inhibits biofilm synthesis. This derivative kills the KG-P2, an isolate of P. aeruginosa in a time dependent manner, the post-antibiotic effect (PAE) of tetracycline was extended as well as mutant prevention concentration (MPC) of TET was also decreased. In Swiss albino mice, Van D reduced the proinflammatory cytokines concentration. In acute oral toxicity study, this derivative was well tolerated and found to be safe up to 1000 mg/kg dose. To the best of our knowledge, this is the first report on curcumin mimics as synergistic agent via inhibition of efflux pump.

Empiric Versus Clarithromycin Resistance-Guided Therapy for Helicobacter pylori Based on Polymerase Chain Reaction Results in Patients With Gastric Neoplasms or Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: A Randomized Controlled Trial.

INTRODUCTION: We investigated to compare the effect of empirical therapy vs clarithromycin resistance-guided tailored therapy (tailored therapy) for eradication of Helicobacter pylori. METHODS: In this prospective, single center, open-label randomized controlled trial, we enrolled 72 patients with H. pylori infection from January 2019 through June 2019 in Korea. The patients were randomly assigned to both groups received empirical (n = 36) or tailored therapy (n = 36). Empirical therapy was defined as triple therapy with esomeprazole, amoxicillin, and clarithromycin for 10 days irrespective of clarithromycin resistance. Tailored therapy was triple or quadruple therapy with esomeprazole, metronidazole, tetracycline, and bismuth for 10 days based on genotype markers of resistance determined by gastric biopsy. Resistance-associated mutations in 23S rRNA were confirmed by multiplex polymerase chain reaction. Eradication status was assessed by C-urea breath test, and the primary outcome was eradication rates. RESULTS: H. pylori was eradicated in 27 patients (75.0%), given empirical therapy and 32 patients (88.9%) treated with tailored therapy (P = 0.136) in intention-to-treat analysis. In per protocol analysis, the eradication rate was 97.0% and 81.8% in tailoredvs empirical groups (P = 0.046). Although clarithromycin-resistant H. pylori was eradicated in 3/9 (33.3%) with empirical therapy, it was treated in 11/12 (91.7%) with tailored therapy (P = 0.009). There was no difference in compliance between 2 groups. The rate of adverse events of the tailored group was higher than that of the empirical group (P = 0.036) because quadruple therapy had more side effects than those of triple therapy (P = 0.001). DISCUSSION: Tailored therapy based on polymerase chain reaction is a good alternative to increase eradication rates in a region of high prevalence of clarithromycin resistance (see Visual Abstract, Supplementary Digital Content 1, http://links.lww.com/CTG/A342).

Calcium Supplement by Tetracycline guided amorphous Calcium Carbonate potentiates Osteoblast promotion for Synergetic Osteoporosis Therapy.

Background: The calcium supplement is a clinically approved approach for osteoporosis therapy but usually requires a large dosage without targetability and with poor outcome. This modality is not fully explored in current osteoporosis therapy due to the lack of proper calcium supplement carrier. Methods: In this study, we constructed a tetracycline (Tc) modified and simvastatin (Sim) loaded phospholipid-amorphous calcium carbonate (ACC) hybrid nanoparticle (Tc/ACC/Sim). Results: The resulted Tc/ACC/Sim was able to enhance its accumulation at the osteoporosis site. Most importantly, the combination of calcium supplement and Sim offered synergetic osteoblast promotion therapy of osteoporosis with advanced performance than non-targeted system or mono therapy. Conclusion: This platform provides an alternative approach to stimulate bone formation by synergetic promotion of osteoblast differentiation using calcium supplement and Sim.

Genome-wide effect of tetracycline, doxycycline and 4-epidoxycycline on gene expression in Saccharomyces cerevisiae.

Tetracycline (Tet) and derivative chemicals (e.g., doxycycline or Dox) have gained widespread recognition for their antibiotic properties since their introduction in the late 1970s, but recent work with these chemicals in the lab has shifted to include multiple techniques in all genetic model systems for the precise control of gene expression. The most widely used Tet-modulated methodology is the Tet-On/Tet-Off gene expression system. Tet is generally considered to have effects specific to bacteria; therefore, it should have few off-target effects when used in eukaryotic systems, and a previous study in the yeast Saccharomyces cerevisiae found that Dox had no effect on genome-wide gene expression as measured by microarray. In contrast, another study found that the use of Dox in common cell lines and several model organisms led to mitonuclear protein imbalance, suggesting an inhibitory role of Dox in eukaryotic mitochondria. Recently, a new Dox derivative, 4-epidoxycycline (4-ED) was developed that was shown to have less off-target consequences on mitochondrial health. To determine the best tetracycline family chemical to use for gene expression control in S. cerevisiae, we performed RNA sequencing (RNA-seq) on yeast grown on standard medium compared with growth on media supplemented with Tet, Dox or 4-ED. We found each caused dozens of genes to change expression, with Dox eliciting the greatest expression responses, suggesting that the specific tetracycline used in experiments should be tailored to the specific gene(s) of interest when using the Tet-On/Tet-Off system to reduce the consequences of confounding off-target responses.

Optimizing the MIC breakpoints of amoxicillin and tetracycline for antibiotic selection in the rescue therapy of H. pylori with bismuth quadruple regimen.

PURPOSE: H. pylori with triple-drug resistance (TR) to clarithromycin, metronidazole, and levofloxacin limits the success of rescue therapy. We aimed to identify the optimal breakpoints of antibiotic minimal inhibitory concentration (MIC) to predict the success of rescue therapy for TR H. pylori infection. METHODS: We consecutively enrolled 430 patients with at least one course of failed H. pylori eradications to receive an H. pylori culture for antibiotic MIC test. Seventy-three (17%) had TR H. pylori infection (MIC of clarithromycin > 0.5, levofloxacin > 1, and metronidazole > 8 mg/L, respectively). Sixty-nine cases with TR H. pylori infection received rescue therapy with either ATBP (amoxicillin, tetracycline, bismuth, and PPI) or MTBP (metronidazole, tetracycline, bismuth and PPI) for 7-14 days. Fourteen patients with positive 13C-urea breath test after the first rescue therapy were retreated with a crossover second rescue therapy. RESULTS: The MTBP regimen had higher eradication success than the ATBP regimen as the first rescue therapy for TR H. pylori (intent-to-treat (ITT) analysis, 70.3 vs. 46.9%, p = 0.048; per protocol (PP) analysis, 78.8% vs. 51.7%, p = 0.025). For MTBP regimen, tetracycline MIC ≤ 0.094 mg/L (p < 0.001) with a 14-day treatment duration (p = 0.037) could predict eradication success with 100% accuracy. For the ATBP regimen, amoxicillin MIC selected as ≤ 0.032 mg/L could optimally determine eradication success (72.2 vs. 33.3%, p = 0.025). CONCLUSION: Optimizing the MIC breakpoints of amoxicillin and tetracycline resistance better predicts the outcome of bismuth quadruple therapy. Further prospective studies using the revised MIC breakpoints to select antibiotics are warranted.

Establishment of tetracycline-regulated bimolecular fluorescence complementation assay to detect protein-protein interactions in Candida albicans.

To visualize protein-protein interactions in Candida albicans with the bimolecular fluorescence complementation (BiFC) approach, we created a Tet-on system with the plasmids pWTN1 and pWTN2. Both plasmids bear a hygromycin B-resistant marker (CaHygB) that is compatible with the original Tet-on plasmid pNIM1, which carries a nourseothricin-resistant marker (CaSAT1). By using GFPmut2 and mCherry as reporters, we found that the two complementary Tet-on plasmids act synergistically in C. albicans with doxycycline in a dose-dependent manner and that expression of the fusion proteins, CaCdc11-GFPmut2 and mCherry-CaCdc10, derived from this system, is septum targeted. Furthermore, to allow detection of protein-protein interactions with the reassembly of a split fluorescent protein, we incorporated mCherry into our system. We generated pWTN1-RN and pNIM1-RC, which express the N-terminus (amino acids 1-159) and C-terminus (amino acids 160-237) of mCherry, respectively. To verify BiFC with mCherry, we created the pWTN1-CDC42-RN (or pWTN1-RN-CDC42) and pNIM1-RC-RDI1 plasmids. C. albicans cells containing these plasmids treated with doxycycline co-expressed the N- and C-terminal fragments of mCherry either N-terminally or C-terminally fused with CaCdc42 and CaRdi1, respectively, and the CaCdc42-CaRdi1 interaction reconstituted a functional form of mCherry. The establishment of this Tet-on-based BiFC system in C. albicans should facilitate the exploration of protein-protein interactions under a variety of conditions.