Enhanced Inhibition of Drug-Resistant Escherichia coli by Tetracycline Hydrochloride-Loaded Multipore Mesoporous Silica Nanoparticles.

Drug-resistant bacterial infections exhibit a major threat to public health. Thus, exploring a novel antibacterial with efficient inhibition is urgently needed. Herein, this paper describes three types of MSNs (MSNs-FC2-R1, MSNs-FC2-R0.75, MSNs-FC2-R0.5) with controllable pore size (4-6 nm) and particle size (30-90 nm) that were successfully prepared. The MSNs were loaded with tetracycline hydrochloride (TCH) for effective inhibition of Escherichia coli (ATCC25922) and TCH-resistant Escherichia coli (MQ776). Results showed that the loading capacity of TCH in three types of MSNs was as high as over 500 mg/g, and the cumulative release was less than 33% in 60 h. The inhibitory rate of MSNs-FC2-R0.5 loaded with TCH against E. coli and drug-resistant E. coli reached 99.9% and 92.9% at the concentration of MIC, respectively, compared with the other two types of MSNs or free TCH. Modified MSNs in our study showed a great application for long-term bacterial growth inhibition.

Synergistic Effect of Co-Delivering Ciprofloxacin and Tetracycline Hydrochloride for Promoted Wound Healing by Utilizing Coaxial PCL/Gelatin Nanofiber Membrane.

Combining multiple drugs or biologically active substances for wound healing could not only resist the formation of multidrug resistant pathogens, but also achieve better therapeutic effects. Herein, the hydrophobic fluoroquinolone antibiotic ciprofloxacin (CIP) and the hydrophilic broad-spectrum antibiotic tetracycline hydrochloride (TH) were introduced into the coaxial polycaprolactone/gelatin (PCL/GEL) nanofiber mat with CIP loaded into the PCL (core layer) and TH loaded into the GEL (shell layer), developing antibacterial wound dressing with the co-delivering of the two antibiotics (PCL-CIP/GEL-TH). The nanostructure, physical properties, drug release, antibacterial property, and in vitro cytotoxicity were investigated accordingly. The results revealed that the CIP shows a long-lasting release of five days, reaching the releasing rate of 80.71%, while the cumulative drug release of TH reached 83.51% with a rapid release behavior of 12 h. The in vitro antibacterial activity demonstrated that the coaxial nanofiber mesh possesses strong antibacterial activity against E. coli and S. aureus. In addition, the coaxial mats showed superior biocompatibility toward human skin fibroblast cells (hSFCs). This study indicates that the developed PCL-CIP/GEL-TH nanofiber membranes hold enormous potential as wound dressing materials.

Activated Carbon Fiber Cloth/Biomimetic Apatite: A Dual Drug Delivery System.

A biomaterial that is both bioactive and capable of controlled drug release is highly attractive for bone regeneration. In previous works, we demonstrated the possibility of combining activated carbon fiber cloth (ACC) and biomimetic apatite (such as calcium-deficient hydroxyapatite (CDA)) to develop an efficient material for bone regeneration. The aim to use the adsorption properties of an activated carbon/biomimetic apatite composite to synthetize a biomaterial to be used as a controlled drug release system after implantation. The adsorption and desorption of tetracycline and aspirin were first investigated in the ACC and CDA components and then on ACC/CDA composite. The results showed that drug adsorption and release are dependent on the adsorbent material and the drug polarity/hydrophilicity, leading to two distinct modes of drug adsorption and release. Consequently, a double adsorption approach was successfully performed, leading to a multifunctional and innovative ACC-aspirin/CDA-tetracycline implantable biomaterial. In a second step, in vitro tests emphasized a better affinity of the drug (tetracycline or aspirin)-loaded ACC/CDA materials towards human primary osteoblast viability and proliferation. Then, in vivo experiments on a large cortical bone defect in rats was carried out to test biocompatibility and bone regeneration ability. Data clearly highlighted a significant acceleration of bone reconstruction in the presence of the ACC/CDA patch. The ability of the aspirin-loaded ACC/CDA material to release the drug in situ for improving bone healing was also underlined, as a proof of concept. This work highlights the possibility of bone patches with controlled (multi)drug release features being used for bone tissue repair.

Knowledge, attitudes and practices of animal farm owners/workers on antibiotic use and resistance in Amhara region, north western Ethiopia.

Inappropriate use of antibiotics in animal and human plays a role in the emergence and spread of bacteria resistant to antibiotics which threatens human health significantly. Although extensive use of these antibiotics could contribute to the development of drug resistance, information on the knowledge, attitude and practice of antimicrobial resistance and use among animal farm owners/workers in north western Ethiopia is rare. The objective of the present study was to assess knowledge, attitude and practice of animal farm owner/workers towards antibiotic resistance and use in Amhara regional state north western Ethiopia. A cross sectional study was conducted in selected cities of Amhara regional state from January to February, 2020. Data was collected from 91 participants using structured questionnaire and analyzed using SPSSS version 23. The results showed that 96.7% of respondents gave antibiotics to treat their livestock from different sources. Most of the respondents bought their antibiotics from private pharmacies without prescription and the most frequently mentioned antibiotics used to treat animal diseases was tetracycline (76.9%), followed by ampicillin (72.5%). Although, 90.1% of the animal farm owners heard about antibiotics and antibiotic resistance from different sources, they did not know the factors contributing to the transmission of resistant bacteria to humans and the impact of antibiotic resistance on human and animals' health. Using the mean score 4.44 ± 0.15 as the cut-off, half of the animal farm owners/workers had good knowledge about antimicrobial resistance and use. 52.5% of animal farm owners/workers had positive attitudes towards wise antibiotic use and resistance with a mean score of 28.4 ± 0.5. However, 52.75% participants had poor practice with the mean score of practice 4.95 ± 0.17. Better knowledge, positive attitudes and better practices on antibiotic use and resistance were associated with farm owners/workers who engaged in higher education. Although poor awareness on antimicrobial resistance was perceived by 76.9% of respondents as very important factors that contribute to increasing antibiotic resistance, increasing the use of complementary treatments was perceived by the majority of respondents as very important strategies that contribute to reduce antibiotic use and resistance. The current study disclosed that there is low level of awareness among animal farm owners about the correct use of antibiotics and resistance. It is necessary to raise awareness, develop and implement interventions to reduce antimicrobial use and antibiotic resistance in the study area.

Comparative study of cefixime and tetracycline as an evaluation policy driven by the antibiotic resistance crisis in Indonesia.

Antibiotic resistance is a serious threat that occurs globally in the health sector due to increased consumption of inappropriate antibiotics. Guidelines for prescribing antibiotics for ARTIs have been issued in general practice to promote rational antibiotic prescribing. This study was conducted to compare the effectiveness of cefixime and tetracycline as a solution to improve monitoring of appropriate antibiotic use in the treatment of ARTIs. All stock isolates were rejuvenated first, and cultured on standard media and Kirby-Bauer disc diffusion method was used for susceptibility testing in accordance with the Clinical and Laboratory Standard Institute's (CLSI) recommendations. Identification of bacteria from a single isolate was carried out to determine which bacteria were resistant to cefixime and tetracycline. A total of 466 single isolates of bacteria were analyzed, which showed a percentage of resistance to cefixime 38.0%, and tetracycline 92.86%. Bacterial isolates were resistant to cefixime and tetracycilne was a genus of Haemophilus, Streptococcus, Corynebacterium, Staphylococcus, and bordetella. Cefixime compared to tetracycline was proven to be superior in terms of the effectiveness of ARIs treatment.

Two Different 1-Week Quadruple Therapies Given Back-to-Back Consecutive Therapy for Difficult-to-Treat Helicobacter pylori Infection: A Pilot Study.

INTRODUCTION: We aim to evaluate the efficacy of 2 different 1-week quadruple therapies given back-to-back consecutive therapy in patients with difficult-to-treat Helicobacter pylori infection. METHODS: Patients with proven H. pylori infection were recruited after >3 failed standard quadruple eradication. They received consecutive therapy consisting of esomeprazole 40 mg or rabeprazole 20 mg twice daily, amoxicillin 1,000 mg twice daily, tetracycline 500 mg 4 times daily, and furazolidone 100 mg 3 times daily for the first 7 days, followed by colloidal bismuth pectin 200 mg twice daily in place of furazolidone 100 mg for another 7 days. Eradication rates, treatment-emergent adverse events (TEAEs), and compliance were assessed. RESULTS: Sixty-five patients were enrolled. The mean number of previous eradications was 3.6 (range: 3-7). The intention-to-treat and per-protocol eradication rates were 90.8% (59/65) and 95.1% (58/61). In total, 23.4% (15/64) of patients experienced drug-related TEAEs. No serious adverse events were observed. None of the patients required treatment for TEAEs, and 95.3% (61/64) showed good compliance. Overall, 51 patients (78.5%) were with the available antimicrobial susceptibility testing results. The resistance rates to clarithromycin, metronidazole, levofloxacin, and amoxicillin were 60.8% (31/51), 100% (51/51), 70.6% (36/51), and 2.0% (1/51), respectively. No resistance was detected to either furazolidone or tetracycline. However, in 54.9% of patients (28/51), H. pylori was resistant to 3 antibiotics (metronidazole, levofloxacin, and clarithromycin). DISCUSSION: Consecutive therapy, including amoxicillin, tetracycline, and furazolidone, achieved a good eradication rate (>90%), with desirable compliance and tolerability in difficult-to-treat H. pylori infection.

Pleurodesis with povidone iodine in patients with malignant pleural effusion in a tertiary center in Nigeria.

INTRODUCTION: malignant pleural effusion occurs as a consequence of a primary or metastatic malignant process involving the pleura. The aim of pleurodesis is to prevent re-accumulation of the effusion and avoid the need for repeated hospitalization. Povidone iodine has been used in other climes for pleurodesis with good results. The aim of this study is to assess the efficacy and safety of povidone iodine in producing pleurodesis as compared to tetracycline. METHODS: the study is a prospective experimental study. The patients are randomized into two groups A (tetracycline-control) and B (povidone iodine). All patients are assessed with chest X-ray after 1 week and 1 month. The responses were ascribed as complete, partial or failure. RESULTS: thirty patients were recruited into this study, 15 patients in each group A (tetracycline) and B (povidone iodine). The mean age was 45.7±14.24 years. The commonest primary malignancy was Breast cancer (70%) followed by bronchogenic cancer (10%). Seventy three (73%) of the patients in this study had complete response and in 7% pleurodesis failed whilst 20% has partial response. In the povidone group the success rate was 93.4% and in the tetracycline group was 93.3% with a p-value of 0.716. There was no statistical difference in the responses based on the agents used. CONCLUSION: malignant pleural effusion is a devastating condition as it heralds the end-of-life processes of a primary malignancy. Povidone iodine is a safe, cheap, effective, widely available and effective pleurodesing agent for use in patients with malignant pleural effusion.

Formulation, Evaluation, and Clinical Assessment of Novel Solid Lipid Microparticles of Tetracycline Hydrochloride for the Treatment of Periodontitis.

The novel solvent-free process to formulate long-acting microparticles of tetracycline hydrochloride (TH) using hot melt extrusion granulation process coupled with size reduction using comil for the treatment of periodontitis was investigated using hydrogenated castor oil (HCO) as hydrophobic matrix former. The microparticles were characterized for micromeritics, drug diffusion, SEM studies, and stability analysis by DSC, FTIR, and proton NMR. Xanthan gum gel was used as delivery vehicles to administer microparticles inside periodontal pockets. The microparticles were sterilized using gamma radiation; delivery vehicle was sterilized using gamma radiation and autoclave process. Microparticles were evaluated for microbial load as per compendial guidelines. Optimized composition was evaluated for clinical parameters such as plaque index, gingival index, probing pocket depth, and clinical attachment level. Based on the statistical analysis of the data, the micromeritic properties and drug diffusion profiles vary based on the concentration of HCO in the formulation. SEM images reflect the surface properties prior and post drug diffusion studies, which indicates that release takes place predominantly by diffusion of TH through HCO matrix. DSC studies indicate no change in the respective spectra of initial and stability samples. FTIR studies indicate possibility of hydrogen bonding. Proton NMR data suggests characteristic peaks of TH being retained in the stability samples, indicating stable composition. Gamma radiation has led to significant reduction in viscosity of xanthan gum solution over autoclave. Clinical studies indicated statistical improvements in the formulation compared to baseline results, indicating the efficacy of the formulation in the treatment of periodontitis.

Poultry Ownership and Genetic Antibiotic Resistance Determinants in the Gut of Preschool Children.

Zoonotic transmission is likely a pathway for antibiotic resistance. Data from a randomized trial of pediatric antibiotic administration were secondarily evaluated to determine if poultry ownership was significantly associated with the presence of gut genetic antibiotic resistance determinants among 118 children in Burkina Faso. Antimicrobial resistance (AMR) determinants were classified using DNA sequencing. We measured the relationship between genetic resistance determinants and chicken ownership using a logistic regression model adjusted for confounding variables. Children in households reporting poultry ownership had four times the odds of tetracycline resistance determinants in the gut compared with those without household poultry (odds ratio [OR]: 4.08, 95% CI: 1.08-15.44, P = 0.04). There was no statistically significant difference found for other antibiotic classes. Understanding the origins of antibiotic resistance may help spur the development of interventions to combat the global AMR crisis.

Controlled release of tetracycline hydrochloride from poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin nanofibers.

Development of drug delivery systems is an extensively researched area in biomedical field. In recent years, there is an increasing interest on fabrication of biocompatible nanofibrous drug delivery systems. In the present study, poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin nanofibrous membranes were fabricated for the controlled delivery and release of tetracycline hydrochloride (TCH) antibiotic. Poly(ω-pentadecalactone-co-ε-caprolactone) content provides an originality to the membrane, since it has been synthesized enzymatically previously. Varied amounts of tetracycline hydrochloride including poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin (1:1, v:v) binary polymer blend was electrospun and characterizations (morphological and molecular structure, wettability characteristics, and thermal behavior) were applied to investigate the incorporation of drug molecule. Afterwards, in vitro drug release studies were carried out and mathematical modelling was applied to drug release data in order to clarify the transport mechanism of drug. TCH release profile comprised of an initial burst release in first hour and followed by a sustained release through 14 days which allowed sufficient antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. The presented drug delivery system may be applied as an antibacterial wound dressing device for skin infections.

European Registry on Helicobacter pylori management: Single-capsule bismuth quadruple therapy is effective in real-world clinical practice.

BACKGROUND: There has been resurgence in the use of bismuth quadruple therapy (proton pump inhibitor, bismuth, tetracycline and metronidazole) for treating Helicobacter pylori infection thanks to a three-in-one single-capsule formulation. OBJECTIVE: To evaluate the effectiveness and safety of the single-capsule bismuth quadruple therapy. METHODS: Data were collected in a multicentre, prospective registry of the clinical practice of gastroenterologists on the management of H. pylori infection, where patients were registered at the Asociación Española de Gastroenterologia REDCap database on an electronic case report form until January 2020. Effectiveness by modified intention-to-treat and per-protocol as well as multivariable analysis were performed. Independent factors evaluated were: age, gender, indication, compliance, proton pump inhibitor dose and treatment line. RESULTS: Finally, 2100 patients were prescribed single-capsule bismuth quadruple therapy following the technical sheet (i.e., three capsules every 6 h for 10 days). The majority of these patients were naive (64%), with an average age of 50 years, 64% women and 16% with peptic ulcer. An overall modified intention-to-treat effectiveness of 92% was achieved. Eradication was over 90% in first-line treatment (95% modified intention-to-treat, n = 1166), and this was maintained as a rescue therapy, both in second (89% modified intention-to-treat, n = 375) and subsequent lines of therapy (third to sixth line: 92% modified intention-to-treat, n = 236). Compliance was the factor most closely associated with treatment effectiveness. Adverse events were generally mild to moderate, and 3% of patients reported a severe adverse event, leading to discontinuation of treatment in 1.7% of cases. CONCLUSIONS: Single-capsule bismuth quadruple therapy achieved H. pylori eradication in approximately 90% of patients in real-world clinical practice, both as a first-line and rescue treatment, with good compliance and a favourable safety profile.

Oral Tetracyclines and Acne: A Systematic Review for Dermatologists.

Oral tetracyclines are the most widely prescribed systemic antibiotic for acne. Synthesis of efficacy and safety of traditional and novel oral tetracyclines is highly informative to clinical practice. We conducted a systematic search of PubMed to identify large interventional and observational studies utilizing oral tetracyclines as an acne treatment. We identified 13 articles meeting inclusion for this review, which represented 226,019 pediatric and adult acne patients. Oral tetracyclines that were included in this systematic review were sarecycline (a novel narrow-spectrum tetracycline), doxycycline, minocycline, and tetracycline. Based on shared and divergent outcome measures, different oral tetracyclines were variably effective against facial acne. Sarecycline also demonstrated efficacy in truncal acne. Members of the oral tetracycline class also differed in their ability to minimize antibiotic resistance and gut dysbiosis. J Drugs Dermatol. 2020;19:11(Suppl):s4-11.

Intramuscular injection of tetracycline decreased gut microbial diversity in mouse.

Antibiotics contribute a lot to human beings and can kill bacteria effectively. However, more and more studies show that antibiotics can disturb the intestinal microbial community. It has been widely reported that oral antibiotics can reduce the diversity of intestinal microflora, but the effect of intramuscular injection on intestinal microflora is less studied. In this study, we sequenced the intestinal microflora of mice treated with tetracycline by 16SrRNA method, and found that intramuscular injection of tetracycline (TET) can also reduce the intestinal microbial richness of mice. In addition, the results showed that within a certain range (3 mg), with the increase of TET injection concentration, the wind of intestinal microflora in mice decreased significantly. When the injection concentration reached saturation, although the amount of TET injection was increased, the degree of intestinal flora affected was not increased. The results showed that the degree of diversity decrease was in direct proportion to the amount of tetracycline injection in the saturated concentration, but not positively related to the high amount of TET injection after exceeding the saturated concentration.

Long-Term Patient Experience with Tetracycline Injections for Festoons.

BACKGROUND: The purpose of this study was to evaluate the long-term patient experience with tetracycline injections for treatment of festoons. METHODS: Charts of all patients undergoing tetracycline injection for treatment of lower eyelid festoons at the Cole Eye Institute, Cleveland Clinic, between 2008 and 2018 were identified using billing records. Patients were invited to participate in a questionnaire based on the FACE-Q checklist, a previously validated questionnaire for studying cosmetic procedure outcomes. Data from the questionnaire were summarized with size, mean, and frequency. RESULTS: One hundred two patients who received tetracycline injection during the study period were identified and 61 responses were obtained. The average follow-up time after injection was 3.6 years. Of 61 respondents, 36 (59 percent) noted improvement in their festoons after treatment, and 27 of 33 (82 percent) noted that improvement occurred within 2 months of treatment. Overall, 40 of 60 respondents (67 percent) would consider repeating tetracycline treatment. The most common adverse effects included discomfort (18 percent), swelling (15 percent), and bruising (13 percent). There was no statistically significant difference in questionnaire responses between men and women, except that men were more likely to consider repeated injection (92 percent versus 58 percent; p = 0.005). CONCLUSION: Tetracycline injection appears to improve festoons in a majority of patients, with an acceptable side-effect profile, although more data are needed to determine the optimal dose and frequency and to identify possible rare and/or significant side effects.

Interventions for preventing ophthalmia neonatorum.

BACKGROUND: Ophthalmia neonatorum is an infection of the eyes in newborns that can lead to blindness, particularly if the infection is caused by Neisseria gonorrhoeae. Antiseptic or antibiotic medication is dispensed into the eyes of newborns, or dispensed systemically, soon after delivery to prevent neonatal conjunctivitis and potential vision impairment. OBJECTIVES: 1. To determine if any type of systemic or topical eye medication is better than placebo or no prophylaxis in preventing ophthalmia neonatorum. 2. To determine if any one systemic or topical eye medication is better than any other medication in preventing ophthalmia neonatorum. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, LILACS, and three trials registers, date of last search 4 October 2019. We also searched references of included studies and contacted pharmaceutical companies.  SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials of any topical, systemic, or combination medical interventions used to prevent ophthalmia neonatorum in newborns compared with placebo, no prophylaxis, or with each other. DATA COLLECTION AND ANALYSIS: We used standard methods expected by Cochrane. Outcomes were: blindness or any adverse visual outcome at 12 months, conjunctivitis at 1 month (gonococcal (GC), chlamydial (CC), bacterial (BC), any aetiology (ACAE), or unknown aetiology (CUE)), and adverse effects.  MAIN RESULTS: We included 30 trials with a total of 79,198 neonates. Eighteen studies were conducted in high-income settings (the USA, Europe, Israel, Canada), and 12 were conducted in low- and middle-income settings (Africa, Iran, China, Indonesia, Mexico). Fifteen of the 30 studies were quasi-randomised. We judged every study to be at high risk of bias in at least one domain. Ten studies included a comparison arm with no prophylaxis. There were 14 different prophylactic regimens and 12 different medications in the 30 included studies. Any prophylaxis compared to no prophylaxis  Unless otherwise indicated, the following evidence comes from studies assessing one or more of the following interventions: tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%. None of the studies reported data on the primary outcomes: blindness or any adverse visual outcome at any time point. There was only very low-certainty evidence on the risk of GC with prophylaxis (4/5340 newborns) compared to no prophylaxis (5/2889) at one month (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.24 to 2.65, 3 studies). Low-certainty evidence suggested there may be little or no difference in effect on CC (RR 0.96, 95% CI 0.57 to 1.61, 4874 newborns, 2 studies) and BC (RR 0.84, 95% CI 0.37 to 1.93, 3685 newborns, 2 studies). Moderate-certainty evidence suggested a probable reduction in risk of ACAE at one month (RR 0.65, 95% 0.54 to 0.78, 9666 newborns, 8 studies assessing tetracycline 1%, erythromycin 0.5%, povidone-iodine 2.5%, silver nitrate 1%, colostrum, bacitracin-phenacaine ointment). There was only very low-certainty evidence on CUE  (RR 1.75, 95% CI 0.37 to 8.28, 330 newborns, 1 study). Very low-certainty evidence on adverse effects suggested no increased nasolacrimal duct obstruction (RR 0.93, 95% CI 0.68 to 1.28, 404 newborns, 1 study of erythromycin 0.5% and silver nitrate 1%) and no increased keratitis (single study of 40 newborns assessing silver nitrate 1% with no events).    Any prophylaxis compared to another prophylaxis Overall, evidence comparing different interventions did not suggest any consistently superior intervention. However, most of this evidence was of low-certainty and was extremely limited. AUTHORS' CONCLUSIONS: There are no data on whether prophylaxis for ophthalmia neonatorum prevents serious outcomes such as blindness or any adverse visual outcome. Moderate-certainty evidence suggests that the use of prophylaxis may lead to a reduction in the incidence of ACAE in newborns but the evidence for effect on GC, CC or BC was less certain. Comparison of individual interventions did not suggest any consistently superior intervention, but data were limited. A trial comparing tetracycline, povidone-iodine (single administration), and chloramphenicol for GC and CC could potentially provide the community with an effective, universally applicable prophylaxis against ophthalmia neonatorum.

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.

Synergistic Effect of a Pleuromutilin Derivative with Tetracycline against Streptococcus suis In Vitro and in the Neutropenic Thigh Infection Model.

Tetracycline (TET) has been widely used in the treatment of Streptococcus suis (S. suis) infection. However, it was found that the efficacy of many antibiotics in S. suis decreased significantly, especially tetracycline. In this study, GML-12 (a novel pleuromutilin derivative) was used in combination with TET against 12 S. suis isolates. In the checkerboard assay, the TET/GML-12 combination exhibited synergistic and additive effects against S. suis isolates (n = 12). In vitro time-killing assays and in vivo therapeutic experiments were used to confirm the synergistic effect of the TET/GML-12 combination against S. suis strains screened based on an FICI ≤ 0.5. In time-killing assays, the TET/GML-12 combination showed a synergistic effect or an additive effect against three isolates with a bacterial reduction of over 2.4-log10 CFU/mL compared with the most active monotherapy. Additionally, the TET/GML-12 combination displayed potent antimicrobial activity against four isolates in a mouse thigh infection model. These results suggest that the TET/GML-12 combination may be a potential therapeutic strategy for S. suis infection.

Bismuth quadruple regimen with tetracycline or doxycycline versus three-in-one single capsule as third-line rescue therapy for Helicobacter pylori infection: Spanish data of the European Helicobacter pylori Registry (Hp-EuReg).

BACKGROUND: Different bismuth quadruple therapies containing proton-pump inhibitors, bismuth salts, metronidazole, and a tetracycline have been recommended as third-line Helicobacter pylori eradication treatment after failure with clarithromycin and levofloxacin. AIM: To evaluate the efficacy and safety of third-line treatments with bismuth, metronidazole, and either tetracycline or doxycycline. METHODS: Sub-study with Spanish data of the "European Registry on H pylori Management" (Hp-EuReg), international multicenter prospective non-interventional Registry of the routine clinical practice of gastroenterologists. After previous failure with clarithromycin- and levofloxacin-containing therapies, patients receiving a third-line regimen with 10/14-day bismuth salts, metronidazole, and either tetracycline (BQT-Tet) or doxycycline (BQT-Dox), or single capsule (BQT-three-in-one) were included. Data were registered at AEG-REDCap database. Univariate and multivariate analyses were performed. RESULTS: Four-hundred and fifty-four patients have been treated so far: 85 with BQT-Tet, 94 with BQT-Dox, and 275 with BQT-three-in-one. Average age was 53 years, 68% were women. Overall modified intention-to-treat and per-protocol eradication rates were 81% (BQT-Dox: 65%, BQT-Tet: 76%, BQT-three-in-one: 88%) and 82% (BQT-Dox: 66%, BQT-Tet: 77%, BQT-three-in-one: 88%), respectively. By logistic regression, higher eradication rates were associated with compliance (OR = 2.96; 95% CI = 1.01-8.84) and no prior metronidazole use (OR = 1.96; 95% CI = 1.15-3.33); BQT-three-in-one was superior to BQT-Dox (OR = 4.46; 95% CI = 2.51-8.27), and BQT-Tet was marginally superior to BQT-Dox (OR = 1.67; 95% CI = 0.85-3.29). CONCLUSION: Third-line H pylori eradication with bismuth quadruple treatment (after failure with clarithromycin and levofloxacin) offers acceptable efficacy and safety. Highest efficacy was found in compliant patients and those taking 10-day BQT-three-in-one or 14-day BQT-Tet. Doxycycline seems to be less effective and therefore should not be recommended.

Generation and characterization of U937-TR: a platform cell line for inducible gene expression in human macrophages.

Monocytes and macrophages are involved in a wide range of biological processes and parasitic diseases. The characterization of the molecular mechanisms governing such processes usually requires precise control of the expression of genes of interest. We implemented a tetracycline-controlled gene expression system in the U937 cell line, one of the most used in vitro models for the research of human monocytes and macrophages. Here we characterized U937-derived cell lines in terms of phenotypic (morphology and marker expression) and functional (capacity for phagocytosis and for Leishmania parasite hosting) changes induced by phorbol-12-myristate-13-acetate (PMA). Finally, we provide evidence of tetracycline-inducible and reversible Lamin-A gene silencing of the PMA-differentiated U937-derived cells.