Integrating bacterial molecular genetics with chemical biology for renewed antibacterial drug discovery.

The application of dyes to understanding the aetiology of infection inspired antimicrobial chemotherapy and the first wave of antibacterial drugs. The second wave of antibacterial drug discovery was driven by rapid discovery of natural products, now making up 69% of current antibacterial drugs. But now with the most prevalent natural products already discovered, ∼107 new soil-dwelling bacterial species must be screened to discover one new class of natural product. Therefore, instead of a third wave of antibacterial drug discovery, there is now a discovery bottleneck. Unlike natural products which are curated by billions of years of microbial antagonism, the vast synthetic chemical space still requires artificial curation through the therapeutics science of antibacterial drugs - a systematic understanding of how small molecules interact with bacterial physiology, effect desired phenotypes, and benefit the host. Bacterial molecular genetics can elucidate pathogen biology relevant to therapeutics development, but it can also be applied directly to understanding mechanisms and liabilities of new chemical agents with new mechanisms of action. Therefore, the next phase of antibacterial drug discovery could be enabled by integrating chemical expertise with systematic dissection of bacterial infection biology. Facing the ambitious endeavour to find new molecules from nature or new-to-nature which cure bacterial infections, the capabilities furnished by modern chemical biology and molecular genetics can be applied to prospecting for chemical modulators of new targets which circumvent prevalent resistance mechanisms.

Synthesis and biological evaluation of novel 1,2,3,4-tetrahydro-ß-carboline derivatives as potential antibacterial agents.

The quest for novel antibacterial agents is imperative in the face of escalating antibiotic resistance. Naturally occurring tetrahydro-ß-carboline (THßC) alkaloids have been highlighted due to their significant biological derivatives. However, these structures have been little explored for antibacterial drugs development. In this study, a series of 1,2,3,4-THßC derivatives were synthesized and assessed for their antibacterial prowess against both gram-positive and gram-negative bacteria. The compounds exhibited moderate to good antibacterial activity, with some compounds showing superior efficacy against gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), to that of Gentamicin. Among these analogs, compound 3k emerged as a hit compound, demonstrating rapid bactericidal action and a significant post-antibacterial effect, with significant cytotoxicity towards human LO2 and HepG2 cells. In addition, compound 3k (10 mg/kg) showed comparable anti-MRSA efficacy to Ciprofloxacin (2 mg/kg) in a mouse model of abdominal infection. Overall, the present findings suggested that THßC derivatives based on the title compounds hold promising applications in the development of antibacterial drugs.

Phytochemical Screening and Antibacterial Activity of Commercially Available Essential Oils Combinations with Conventional Antibiotics against Gram-Positive and Gram-Negative Bacteria.

The present study aims to evaluate the antibacterial activity of five commercially available essential oils (EOs), Lavender (LEO), Clove (CEO), Oregano (OEO), Eucalyptus (EEO), and Peppermint (PEO), against the most-known MDR Gram-positive and Gram-negative bacteria-Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853)-alone and in various combinations. Gas Chromatography-Mass Spectrometry (GC-MS) analysis established their complex compositions. Then, their antibacterial activity-expressed as the inhibition zone diameter (IZD) value (mm)-was investigated in vitro by the diffusimetric antibiogram method, using sterile cellulose discs with Ø 6 mm impregnated with 10 µL of sample and sterile borosilicate glass cylinders loaded with 100 µL; the minimum inhibitory concentration (MIC) value (µg/mL) for each EO was calculated from the IZD values (mm) measured after 24 h. The following EO combinations were evaluated: OEO+CEO, CEO+EEO, CEO+PEO, LEO+EEO, and EEO+PEO. Then, the influence of each dual combination on the activity of three conventional antibacterial drugs-Neomycin (NEO), Tetracycline (TET), and Bacitracin (BAC)-was investigated. The most active EOs against S. aureus and E. coli were LEO and OEO (IZD = 40 mm). They were followed by CEO and EEO (IZD = 20-27 mm); PEO exhibited the lowest antibacterial activity (IZD = 15-20 mm). EEO alone showed the highest inhibitory activity on P. aeruginosa (IZD = 25-35 mm). It was followed by CEO, LEO, and EEO (IZD = 7-11 mm), while PEO proved no antibacterial action against it (IZD = 0 mm). Only one synergic action was recorded (OEO+CEO against P. aeruginosa); EEO+PEO revealed partial synergism against S. aureus and CEO+PEO showed additive behavior against E. coli. Two triple associations with TET showed partial synergism against E. coli, and the other two (with NEO and TET) evidenced the same behavior against S. aureus; all contained EEO+PEO or CEO+PEO. Most combinations reported indifference. However, numerous cases involved antagonism between the constituents included in the double and triple combinations, and the EOs with the strongest antibacterial activities belonged to the highest antagonistic combinations. A consistent statistical analysis supported our results, showing that the EOs with moderate antibacterial activities could generate combinations with higher inhibitory effects based on synergistic or additive interactions.

Preparation of mesoporous silica/hydroxyapatite loaded quercetin nanoparticles and research on its antibacterial properties.

In this study, amino-functionalized mesoporous silica/hydroxyapatite nanoparticles (MSNS/HAP) with the property of acid dissociation have been prepared as a traditional Chinese medicine monomer carriers to improve the drug loading rate and antibacterial properties of antimicrobial quercetin (QUE) in vitro. The experimental results confirm that the drug loading rate of MSNs/HAP is 28.94 %, which is about 3.6 times higher than that of aminated mesoporous sililca nanoparticles (MSNs). The drug release of QUE on MSNs/HAP is pH-sensitive in phosphate buffered saline (pH=4.0-7.4). The above fabricated traditional Chinese medicine monomer modified nanocomposites (QUE@MSNs/HAP) displays concentration-dependent inhibitory effect, which shows better antibacterial effect than free QUE. The minimum inhibitory concentration for two tested bacteria, Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli), is 256 mg·L -1. In summary, QUE@MSNs/HAP have successfully prepared, which not only improves the bio-availability of QUE, but also has acid-sensitive drug release properties. Compared with free QUE, its antibacterial performance significantly enhances, which provides a theoretical basis for the application of Chinese medicine molecules in bacterial treatment.

Effectiveness of prophylactic antibacterial drugs for patients with liver cirrhosis and upper gastrointestinal bleeding: a systematic review and meta-analysis.

Background: Prophylactic antibacterial drugs are used for patients with liver cirrhosis and upper gastrointestinal bleeding, and independent studies have concluded that they can decrease the rate of infection, mortality, and rebleeding in these diseases. However, no comprehensive assessment of this effect has been reported in recent years and available data pertaining to the prognostic implications of diverse categories of antibiotic prophylaxis in individuals afflicted with cirrhosis are notably limited. The objective of this article is to assess the clinical effectiveness of prophylactic antibacterial drugs for patients with liver cirrhosis and upper gastrointestinal bleeding. Methods: Relevant randomized controlled studies and cohort studies which examined the value of prophylactic antibacterial drugs for patients with liver cirrhosis and upper gastrointestinal bleeding were retrieved via Cochrane Library, EMBASE, MedLine, and Web of Science. The search period was from database inception until 30 April 2023. Summing up the relevant data, the dichotomous variable was statistically analysed using the relative risk (RR) value and its 95% confidence interval (CI) and the continuous variable using the mean difference (MD) value and its 95% CI. All analyses were performed using Revman 5.4 software. The study has been registered on the PROSPERO website under registration number CRD42022343352. Results: Twenty-six studies (18 RCTs and 8 cohort studies, including 13,670 participants) were included to evaluate the effect of antibacterial prophylaxis versus no antibacterial prophylaxis or placebo. Prophylactic antibiotics reduced mortality rates (RR 0.66, 95% CI 0.51-0.83), infection rates (RR 0.41, 95% CI 0.35-0.49), rebleeding rates (RR 0.42, 95% CI 0.31-0.56), and length of hospital stay (MD -5.29, 95% CI -7.53, -3.04). Subgroup analysis revealed that the prophylactic administration of quinolone antimicrobials demonstrated the most favorable efficacy, followed by cephalosporins. Both interventions were effective in averting infections frequently observed in patients with liver cirrhosis and upper gastrointestinal bleeding. Conclusion: Based on our investigation, the prophylactic antibacterial drugs confers noteworthy advantages in patients afflicted by liver cirrhosis with upper gastrointestinal bleeding. It has been associated with reductions in mortality, infection incidence, rebleeding occurrences, and the duration of hospitalization. Among prophylactic antibacterial options, quinolones emerged as the foremost choice, with cephalosporins ranking closely thereafter. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022343352, identifier CRD42022343352.

Consumption of non-antibacterial drugs may have negative impact on Helicobacter pylori colonization in the stomach.

Background: Nineteen non-antibacterials were examined to show that their consumption for treatment of other diseases may inhibit Helicobacter pylori. Four antibiotics were used for comparison. Materials and methods: Agar dilution method was used to examine the susceptibility of 20 H. pylori isolates to 4 antibiotics; metronidazole (MTZ), clarithromycin (CLR), amoxicillin (AMX), tetracycline (TET) and 19 non-antibacterials; proton pump inhibitors (PPIs), H2-blockers, bismuth subsalicylate (BSS), antifungals, statins, acetaminophen (ACE), aspirin (ASA), B-vitamins (B-Vits; Vit B1, Vit B6 and Vit Bcomplex) and vitamin C (Vit C). Blood agar plates were prepared with different concentrations of drugs and spot-inoculated with bacterial suspensions. Plates were incubated at 37 °C under microaerobic conditions and examined after 3-5 days. The isolate #20 that was mucoid and resistant to 19 drugs, including MTZ and SMV was tested against combined MTZ (8 µg/mL) and SMV (100 µg/mL). Results were analyzed statistically. Results: Minimum inhibitory concentrations (MICs, µg/mL) of drugs and the frequency of susceptible H. pylori were determined as MTZ (8, 80%), CLR (2, 90%), AMX (1, 100%), TET (0.5, 70%), PPIs (8-128, 80%), H2-blockers (2000-8000, 75-80%), BSS (15, 85%), antifungals (64-256, 30-80%), statins (100-250, 35-90%), ACE (40, 75%), ASA (800, 75%), B-Vits (5000-20000, 80-100%) and Vit C (2048, 85%). Susceptibility of H. pylori isolates to 16 out of 19 non-antimicrobials (75-100%) was almost similar to those of antibiotics (70-100%) (P-value >0.05). The highest susceptibility rate (100%) belonged to Vit B1, Vit B6 and AMX. Out of 20 H. pylori isolates, 17 (85%) were susceptible to ≥13 non-antimicrobials and 3 (15%) were susceptible to < 13 (P-value <0.05). Mucoid H. pylori showed susceptibility to combination of MTZ and SMV. Conclusions: Most of non-antibacterials inhibited H. pylori isolates, similar to antibiotics but their MICs exceeded those of antibiotics and their plasma concentrations. At low plasma concentration, non-antimicrobials may act as weak antibacterials, antibiotic adjuvants and immunostimulators.

A systematic review of peptide nucleic acids (PNAs) with antibacterial activities: Efficacy, potential and challenges.

Peptide nucleic acids (PNAs) are synthetic molecules that are like DNA/RNA, but with different building blocks. PNAs target and bind to mRNAs and disrupt the function of a targeted gene, hence they have been studied as potential antibacterials. The aim of this systematic review was to provide an in-depth analysis of the current status of PNAs as antibacterial agents, define the characteristics of the effective PNA constructs, and address the gap in advancing PNAs to become clinically competent agents. Following the PRISMA model, four electronic databases were searched: Web of Science, PubMed, SciFinder and Scopus. A total of 627 articles published between 1994 and 2023 were found. After screening and a rigorous selection process using explicit inclusion and exclusion criteria, 65 scientific articles were selected, containing 656 minimum inhibitory concentration (MIC) data. The antibacterial activity of PNAs was assessed against 20 bacterial species. The most studied Gram-negative and Gram-positive bacteria were Escherichia coli (n=266) and Staphylococcus aureus (n=53), respectively. In addition, the effect of PNA design, including construct length, binding location, and carrier agents, on antibacterial activity was shown. Finally, antibacterial test models to assess the inhibitory effects of PNAs were examined, emphasising gaps and prospects. This systematic review provides a comprehensive assessment of the potential of PNAs as antibacterial agents and offers valuable insights for researchers and clinicians seeking novel therapeutic strategies in the context of increasing rates of antibiotic-resistant bacteria.

Synthesis, spectroscopic characterization, and antibacterial activity of chalcone (2E)-1-(3'-aminophenyl)-3-(4-dimethylaminophenyl)-prop-2-en-1-one against multiresistant Staphylococcus aureus carrier of efflux pump mechanisms and ß-lactamase.

BACKGROUND: The bacterium Staphylococcus aureus has stood out for presenting a high adaptability, acquiring resistance to multiple drugs. The search for natural or synthetic compounds with antibacterial properties capable of reversing the resistance of S. aureus is the main challenge to be overcome today. Natural products such as chalcones are substances present in the secondary metabolism of plants, presenting important biological activities such as antitumor, antidiabetic, and antimicrobial activity. OBJECTIVES: In this context, the aim of this work was to synthesize the chalcone (2E)-1-(3'-aminophenyl)-3-(4-dimethylaminophenyl)-prop-2-en-1-one with nomenclature CMADMA, confirm its structure by nuclear magnetic resonance (NMR), and evaluate its antibacterial properties. METHODS: The synthesis methodology used was that of Claisen-Schmidt, and spectroscopic characterization was performed by NMR. For microbiological assays, the broth microdilution methodology was adopted in order to analyze the antibacterial potential of chalcones and to analyze their ability to act as a possible inhibitor of ß-lactamase and efflux pump resistance mechanisms, present in S. aureus strain K4100. RESULTS: The results obtained show that CMADMA does not show direct antibacterial activity, expressing a MIC of ≥1024 µg/mL, or on the enzymatic mechanism of ß-lactamase; however, when associated with ethidium bromide in efflux pump inhibition assays, CMADMA showed promising activity by reducing the MIC of the bromide from 64 to 32 µg/mL. CONCLUSION: We conclude that the chalcone synthesized in this study is a promising substance to combat bacterial resistance, possibly acting in the inhibition of the QacC efflux pump present in S. aureus strain K4100, as evidenced by the reduction in the MIC of ethidium bromide.

Sputum bacterial culture and drug resistance of 475 patients with pneumonia / 公共卫生与预防医学

Objective To understand the distribution and drug resistance of pathogenic bacteria in sputum culture of pneumonia, and to provide evidence for the rational application of clinical antibacterial drugs . Methods The clinical data of 475 patients with positive sputum bacterial culture admitted to department of respiratory medicine of Neijiang Hospital of Traditional Chinese Medicine from May 2020 to May 2023 were collected. The types and drug resistance of pathogenic bacteria isolated from sputum culture were statistically analyzed . Results A total of 539 strains of pathogenic bacteria were isolated from the sputum culture of 475 patients with pneumonia, including 344 strains (63.82%) of Gram-negative bacteria [mainly Klebsiella pneumoniae (79 strains, 14.66%)] and 195 strains (36.18%) of Gram-positive bacteria [mainly Streptococcus pneumoniae (70 strains, 12.99%)]. Klebsiella pneumoniae was highly sensitive to aztreonam, levofloxacin, amikacin, imipenem, and ertapenem, with the sensitivity rates of 94.67%, 92.41%, 94.87%, 96.00% and 98.67% respectively. Streptococcus pneumoniae was absolutely sensitive to teicoplanin, vancomycin and linezolid, and was highly sensitive to cefpirome, levofloxacin, imipenem and ertapenem, with the sensitivity rates of 94.29%, 91.43%, 97.14% and 98.48%. Conclusions The common pathogenic bacteria of patients with pneumonia in Neijiang Hospital of Traditional Chinese Medicine include Klebsiella pneumoniae and Streptococcus pneumoniae. Various pathogenic bacteria have different degrees of resistance to common antibacterial drugs. It is necessary to combine with the types and drug susceptibility results of pathogenic bacteria for the rational application of antibacterial drugs.

Functionalized Calixarenes as Promising Antibacterial Drugs to Face Antimicrobial Resistance.

Since the discovery of polyphenolic resins 150 years ago, the study of polymeric compounds named calix[n]arene has continued to progress, and those skilled in the art perfectly know now how to modulate this phenolic ring. Consequently, calix[n]arenes are now used in a large range of applications and notably in therapeutic fields. In particular, the calix[4]arene exhibits multiple possibilities for regioselective polyfunctionalization on both of its rims and offers researchers the possibility of precisely tuning the geometry of their structures. Thus, in the crucial research of new antibacterial active ingredients, the design of calixarenes finds its place perfectly. This review provides an overview of the work carried out in this aim towards the development of intrinsically active prodrogues or metallic calixarene complexes. Out of all the work of the community, there are some excellent activities emerging that could potentially place these original structures in a very good position for the development of new active ingredients.

Bacteria-Targeting Nanosilver-Based Antibacterial Drugs for Efficient Treatment of Drug-Resistant Bacterial-Infected Keratitis.

Keratitis caused by drug-resistant bacteria is a severe condition that can lead to corneal perforation and even blindness, making effective treatment a top priority amid growing antibiotic resistance. Eye drops for anti-inflammatory treatment necessitate frequent administration of high doses throughout every day due to bacterial resistance resulting from antibiotic overuse and the low bioavailability of drugs. To overcome these issues, an antibacterial nanocomposite is prepared via conjugating random copolymers of galactose and 3-(acrylamide)phenylboronic acid to the surface of silver nanoparticles. The customized nanocomposites trigger specific binding to bacteria, resulting in excellent retention of the drug on the ocular surface, resulting in rapid and powerful killing of bacteria and inhibition of bacterial proliferation. Due to its superior drug delivery capabilities to the ocular surface, the functionalized nanocomplex markedly amplifies the anti-inflammatory efficacy, even at low doses. This effect is achieved by impeding immune cell infiltration and diminishing the synthesis of inflammatory mediators and cytokines, thereby suggesting enhanced healing properties for corneal inflammation. This study demonstrates a promising nanocomposite which is an effective and safe antibacterial strategy for bacterial keratitis with favorable prognostic and clinical conversion potential.

Distribution and Antibiotic Resistance Analysis of Blood Culture Pathogens in a Tertiary Care Hospital in China in the Past Four Years.

Purpose: This study aimed to investigate the antibiotic resistance patterns and clinical distribution of blood culture-positive isolates at Suining Central Hospital between 2018 and 2021. The findings of this study can provide a basis for ensuring rational and effective use of antibiotic therapy in clinical settings. Methods: This retrospective study analyzed the data of 3660 non-repeating strains that tested positive for clinical blood culture, collected from the microbiology laboratory of Suining Central Hospital between January 2018 and December 2021. The identification of bacterial species and their antibiotic resistance patterns were analyzed. Results: The study found that 76.7% of the bacterial strains identified were Gram-negative bacteria, while 23.3% were Gram-positive bacteria. Escherichia coli (44.8%), Klebsiella spp. (19.2%), Staphylococcus aureus (9.2%), Enterococcus spp. (5.3%), and Enterobacter spp. were the top five bacterial ratios observed. These bacteria were detected most frequently in the Digestion Center, intensive care unit (ICU), Neurology Center, Urology Department, and Hematology Department. Among the Staphylococcus spp., methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCNS) were detected at rates of 39.3% and 71.8%, respectively. However, no vancomycin- or linezolid-resistant staphylococci were identified. Enterococcus faecalis showed higher susceptibility to most antibiotic than Enterococcus faecium, except for tetracycline. The resistance rates of E. coli and Klebsiella spp. to meropenem and imipenem were low, but the resistance rates for other antibiotic were above 40%. Conclusion: The results of this study show a rising incidence of bacterial antibiotic resistance in positive blood culture specimens at Suining Central Hospital. Clinicians should carefully consider the importance of blood culture antibiotic susceptibility testing to ensure effective treatment. The Department of Microbiology at Suining Central Hospital should regularly analyze the distribution of pathogenic bacteria and antibiotic resistance in blood cultures to ensure the most effective treatment possible.

Increased Incidence and Risk Factors of Infections by Extended-Spectrum ß-Lactamase-Producing Enterobacterales During the COVID-19 Pandemic: A Retrospective Case-Control Study.

Purpose: To investigate changes in the incidence of infections by extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) and analyzed whether there was an association between endogenous changes in the organism due to COVID-19 infection and the infections by ESBL-E. Patients and Methods: The study was a single-center retrospective case-control design. A total of 107 patients infected by ESBL-E during the COVID-19 pandemic were selected as the case group, while 214 uninfected patients selected by 1:2 propensity score matching (PSM) acted as the control group. Univariate analysis, LASSO logistic regression, and multivariate logistic regression were used to determine the risk factors for ESBL-E infection. An interrupted time series was used to analyze the changes in the incidence of ESBL-E infections in hospitalized patients during the COVID-19 pandemic. Results: The incidence of infection with ESBL-E showed a significant increase during COVID-19 (3.42 vs 4.92 per 1000 patients, p = 0.003). The incidence of ESBL-E infections increased at an average rate of 0.45 per 1000 patients per week compared to the pre-pandemic period (p = 0.022). Multivariate logistic regression analysis showed that a length of hospitalization ≥ 15 days (OR: 2.98 (1.07-8.28), chronic kidney disease (OR: 4.25 (1.32-13.70), white blood cell (WBC) > 9.5×10^9/L (OR: 3.04 (1.54-6.01), use of hormonal drugs (OR: 2.38 (1.04-5.43), antibacterial drug use 1 type (OR: 5.38 (2.04-14.21), antibacterial drug use 2 types (OR: 23.05 (6.71-79.25) and antibacterial drug use ≥ 3 types (OR: 88.35 (8.55-912.63) were independent risk factors for infection with ESBL-E, while chronic obstructive pulmonary disease (COPD) was a protective factor (OR: 0.14 (0.03-0.66). COVID-19 was not an independent risk factor for infection by ESBL-E. Conclusion: During the COVID-19 pandemic, the incidence of infections by ESBL-E increased significantly. Increased exposure to traditional risk factors were the main reasons, however, COVID-19 was not an independent risk factor for ESBL-E infection.

Effects of the pharmaceutical formulation of topical medications on corneal epithelial healing after phototherapeutic keratectomy.

PURPOSE: To determine the effect of the formulation of topical medications on the healing of corneal epithelial cells after phototherapeutic keratectomy (PTK). STUDY DESIGN: Retrospective cohort study. METHODS: We studied 271 eyes of 189 consecutive patients (aged 67.6 ± 11.8 years) who had undergone PTK for granular corneal dystrophy (n = 140), band keratopathy (n = 47), or lattice corneal dystrophy (n = 2). Postoperatively, generic or brand-named levofloxacin, 0.1% betamethasone, or 0.1% bromfenac sodium hydrate was applied topically. Patients were examined on postoperative days 1, 2, and 5 and weekly thereafter. The time to re-epithelialization was assessed by use of Kaplan-Meier and Cox proportional hazards analyses. RESULTS: The time to re-epithelialization was significantly longer with generic 0.5% levofloxacin, at 8.2 ± 3.5 days, than with 0.5% Cravit (levofloxacin), at 6.7 ± 3.5 days (P = 0.018), or with 1.5% Cravit, at 6.3 ± 2.6 days (P = 0.000). In addition, the time to re-epithelialization was significantly longer with generic 0.1% betamethasone (Sanbetason), at 7.3 ± 3.4 days, than with brand-name 0.1% betamethasone (Rinderon), at 6.1 ± 2.5 days (P = 0.0002). The Cox proportional hazards model indicated that the use of generic formulations for levofloxacin eye drops and 0.1% betamethasone was a significant factor that delayed corneal re-epithelialization (hazard ratio [HR] = 0.72, P = 0.002 and HR = 0.77, P = 0.006, after adjustment for age). Re-epithelialization was significantly shorter in band keratopathy than in corneal dystrophy (HR = 1.56, P = 0.004). No other factors, including age, bandage contact lens, and diabetes mellitus, were significantly associated with time to re-epithelialization. CONCLUSION: Corneal epithelial healing can be significantly affected by different antibacterial or steroid eye drops. Clinicians need to be aware that a generic formulation may affect corneal epithelial healing.

Liposomal Forms of Fluoroquinolones and Antifibrotics Decorated with Mannosylated Chitosan for Inhalation Drug Delivery.

The severe course of COVID-19 leads to the long-terming pulmonary diseases, such as bacterial pneumonia and post-COVID-19 pulmonary fibrosis. Thus, the essential task of biomedicine is a design of new effective drug formulations, including those for inhalation administration. In this work, we propose an approach to the creation of lipid-polymer delivery systems for fluoroquinolones and pirfenidone based on liposomes of various compositions decorated with mucoadhesive mannosylated chitosan. A generalizing study on the physicochemical patterns of the interactions of drugs with bilayers of various compositions was carried out, and the main binding sites were identified. The role of the polymer shell in the stabilization of vesicles and the delayed release of the contents has been demonstrated. For the liquid-polymer formulation of moxifloxacin, a prolonged accumulation of the drug in lung tissues was found after a single endotracheal administration to mice, significantly exceeding the control intravenous and endotracheal administration of the drug.

Long Term Characteristics of Clinical Distribution and Resistance Trends of Carbapenem-Resistant and Extended-Spectrum ß-Lactamase Klebsiella pneumoniae Infections: 2014-2022.

Purpose: Through long-term and large sample size statistical analysis, we revealed the pattern of Klebsiella pneumoniae (KP) infection and drug resistance and provided epidemiological data for the treatment and prevention and control of multidrug-resistant bacterial infection in our hospital. Patients and Methods: Strains were identified using the BD PhoenixTM100 system, minimal inhibitory concentration of antibiotics were determined by the broth method, and data were statistically analyzed using WHONET 5.6 and SPSS27.0. Results: The isolation rate of KP from Enterobacteriaceae (26.2%, 4547/17358) in our hospital showed an increasing annual trend, ranking second only to Escherichia coli. Carbapenem-resistant KP (CRKP) accounted for the highest proportion of carbapenem-resistant Enterobacteriaceae (72.2%, 431/597), showing an upward trend. Infected patients had a male-to-female ratio of approximately 2:1 and were mainly >60 years of age (66.2%), with intensive care units being the most commonly distributed department. Sputum was the most common specimen type (74.0%). Compared with spring and summer, autumn and winter were the main epidemic seasons for KP and extended-spectrum ß-lactamase KP (ESBL-KP). The resistance rate of KP to common antibiotics was low, but all showed an increasing trend each year. ESBL-KP was >90% resistant to piperacillin, amoxicillin/clavulanic acid, and cefotaxime and less resistant to other common antibiotics, but showed an increasing trend in resistance to most antibiotics. CRKP resistance to common antibiotics was high, with resistance rates >90%, excluding amikacin (64.1%), gentamicin (87.4%), cotrimoxazole (44.3%), chloramphenicol (13.6%), and tetracycline (30.5%). Conclusion: KP in our hospital mainly caused pulmonary infection in older men, which occurred frequently in autumn and winter, and the isolation and drug resistance rates showed an increasing trend. Age over 70 years, admission to intensive care unit, and urinary tract infection were found to be the risk factors for CRKP and ESBL-KP-resistance.

Comparison of the therapeutic effects of different antibacterial drugs combined in the treatment of adult brucellosis patients / 中华地方病学杂志

Objective:To compare the efficacy of different antibacterial drugs combined in the treatment of adult brucellosis patients.Methods:Using a prospective design, 60 adult brucellosis patients admitted to the Affiliated Hospital of Jining Medical University from January 2018 to December 2021 were selected as the study subjects. They were randomly divided into an observation group ( n = 30) and a control group ( n = 30) using a random number table method. The observation group was treated with rifampicin combined with minocycline, and the control group was given rifampicin combined with doxycycline. The course of treatment in both groups was 6 weeks. The efficacy and clinical symptom disappearance time between the two groups, as well as the blood white blood cell count (WBC), alanine aminotransferase (ALT) levels, and serum interferon-γ (IFN-γ), interleukin-4 (IL-4) and interleukin-10 (IL-10) levels before and after treatment, and the occurrence of adverse reactions were compared. Results:The total effective rate of the observation group (96.67%, 29/30) was higher than that of the control group (73.33%, 22/30), with a statistically significant difference (χ 2 = 4.71, P = 0.030). The disappearance time of joint pain, hyperhidrosis, gastrointestinal reactions, and fever in the observation group were shorter than those in the control group, and the differences were statistically significant ( P < 0.05). After treatment, the blood WBC and ALT levels in both groups decreased compared to before treatment ( P < 0.05). After treatment, the blood WBC and ALT levels in the observation group were lower than those in the control group ( P < 0.001). The levels of serum IFN-γ and IL-10 were both decreased after treatment compared to before treatment in two groups, while IL-4 level increased compared to before treatment ( P < 0.05). The levels of serum IFN-γ and IL-10 in the observation group were lower than those of the control group, while IL-4 level was higher than that of the control group ( P < 0.001). The incidence of adverse reactions in the observation group (13.33%, 4/30) was lower than that in the control group (36.67%, 11/30), and the difference was statistically significant (χ 2 = 4.36, P = 0.037). Conclusion:The combination of rifampicin and minocycline in the treatment of adult brucellosis patients has good efficacy and can reduce serum IFN-γ and IL-10 levels and increase IL-4 level with few adverse reactions.

Optimization strategy of antibiotic dosing regimen in intensive care unit patients with augmented renal clearance / 中国临床药理学与治疗学

The incidence of augmented renal clearance (ARC) in intensive care patients (ICU) is exceptionally high, and these patients are often co-morbid with infection. The occurrence of ARC will significantly increase the clearance rate of antibiotics, making it difficult for conventional doses to reach effective therapeutic concentrations and affect the patient's anti-infective treatment effect and prognosis. It can be seen that it is crucial to formulate a reasonable dosing regimen for ICU patients with ARC. Regrettably, few reports in China about the adjustment strategy of antibiotic dosing regimens for ARC patients. Therefore, this article reviews the domestic and foreign literature for reference to provide evidence for medical personnel to adjust the dose of antibacterial drugs for such patients.

An LC-MS/MS method for the simultaneous determination of 18 antibacterial drugs in human plasma and its application in therapeutic drug monitoring.

Antimicrobial resistance (AMR) is a major threat to global health due to the wide use of antibacterial drugs. Multiple studies show that the pharmacokinetic/pharmacodynamic (PK/PD) studies of antibiotics are an approach to prevent/delay AMR. The pharmacokinetic parameters of antibiotics are the basis of PK/PD studies, and therapeutic drug monitoring (TDM) is the key method to obtain pharmacokinetic information. We developed an ultra-performance liquid chromatography-tandem mass spectrometry to determine 18 antibacterial drugs (piperacillin, cefazolin, cefuroxime, cefoperazone, ceftriaxone, cefepime, aztreonam, meropenem, imipenem, levofloxacin, moxifloxacin, azithromycin, clindamycin, tigecycline, linezolid, vancomycin, voriconazole and caspofungin) in human plasma for practical clinical usage. Samples were prepared using protein precipitation with methanol. Chromatographic separation was accomplished in 6 min on a BEH C18 column (2.1 × 100 mm, 1.7 µm) using a gradient elution of acetonitrile and 0.1% formic acid in water at a flow rate of 0.3 ml/min. The electrospray ionization source interface was operated in the positive and negative ionization modes. Inter- and intra-day precision, accuracy, recovery, matrix effect, and stability were validated according to the Food and Drug Administration guidance. The correlation coefficients of calibration curves were all greater than 0.99. The accuracies of the 18 antibacterial drugs ranged from 89.1% to 112.4%. The intra-day precision of the analytes ranged from 1.4% to 9.3% and the inter-day precision from 2.1% to 7.2%. The matrix effects ranged from 93.1% to 105.8% and the extraction recoveries ranged between 90.1% and 109.2%. The stabilities of the 18 antibacterial drugs in plasma were evaluated by analyzing three different concentrations following storage at three storage conditions. All samples displayed variations less than 15.0%. The validated method was successfully applied to routine clinical TDM for 231 samples.

[Rapid screening of 14 antibacterial drugs in anti-acne cosmetics using ion mobility spectrometry coupled with solid-phase extraction].

The main methods currently used to detect illegally added chemicals in cosmetics include thin-layer chromatography, high performance liquid chromatography (HPLC), gas chromatography (GC), and liquid chromatography-mass spectrometry (LC-MS). Compared with other analytical techniques, these methods have the advantages of high sensitivity, specificity, and accuracy, all of which are required in practical detection work. However, they also present a number of limitations, such as long analysis times and requirements for skilled operators and strictly controlled laboratory environments. Supervision, a growing trend in market surveillance, requires rapid and effective methods to screen illegally added chemicals. The suspected samples are sealed for some time and then sent to the laboratory for further testing. Ion mobility spectrometry (IMS) is a new type of trace gas separation technology that was developed in recent years. The principle behind IMS is the separation and characterization of chemical species based on differences in the migration speed of their gas-phase ions under an electric field. As this technology has the advantages of miniaturization, easy operation, and quick responses, it is widely used in food and drug quality testing, as well as other related fields. However, it is rarely used in cosmetic detection, likely because the cosmetics matrix is highly complex, which can interfere with ion determination. Thus, optimizing the pretreatment process of cosmetics for IMS is important. In this work, solid-phase extraction (SPE) is combined with IMS to establish a method for the rapid screening of 14 antibacterial drugs in anti-acne cosmetics. The IMS detection parameters, sample extraction conditions, and SPE clean-up conditions (SPE column, type of leachate, type and volume of eluent) were studied and optimized in detail. The sample was extracted with 80%(v/v) acetonitrile aqueous solution (containing 0.2% (mass fraction) trichloroacetic acid), loaded onto an activated Oasis® MCX SPE column, leached with 3.0 mL of methanol, and eluted with 1.0 mL of 2% ammonia methanol solution. The eluate was then directly injected into the IMS instrument. The IMS parameters were as follows: positive ion source voltage=2200 V, transfer tube voltage=8000 V, inlet temperature=180 ℃, transfer tube temperature=180 ℃, ion gate voltage=50 V, gate voltage pulse width=85 µs, and migration gas flow rate=1.2 L/min. The migration times for the 14 antibacterial drugs ranged from 11 to 17 ms, and the detection limits for the target compounds ranged from 0.2 to 1.2 µg/g. Owing to the narrow linear range of IMS, a quantitative method employing HPLC was also established to optimize the SPE pretreatment step and verify the positive samples. Chromatographic separation was conducted on a Phenomenex Luna C18 column (250 mm×4.6 mm, 5 µm), with a column flow rate of 1.0 mL/min and gradient elution with mobile phases A (0.01 mol/L potassium dihydrogen phosphate adjusted to pH 4.0 with phosphoric acid) and B (acetonitrile). The column temperature was set to 35 ℃, and the injection volume was fixed at 5 µL. A total of 25 cosmetics samples were screened, and one positive sample was found to be consistent with the results of HPLC. The proposed method is fast, simple, and efficient, and it can be used for the rapid screening of the 14 antibacterial drugs in anti-acne cosmetics. Pretreatment can significantly reduce the influence of the cosmetic matrices on the determination results, improve instrument sensitivity, and effectively decrease the occurrence rate of false positives and negatives. The technique developed in this work can improve the efficiency of screening for illegally added chemicals and expand the applications of IMS for detecting various chemicals in complex matrices, such as cosmetics.