Azithromycin reduces hemoglobin-induced innate neuroimmune activation.

Neonatal intraventricular hemorrhage (IVH) releases blood products into the lateral ventricles and brain parenchyma. There are currently no medical treatments for IVH and surgery is used to treat a delayed effect of IVH, post-hemorrhagic hydrocephalus. However, surgery is not a cure for intrinsic brain injury from IVH, and is performed in a subacute time frame. Like many neurological diseases and injuries, innate immune activation is implicated in the pathogenesis of IVH. Innate immune activation is a pharmaceutically targetable mechanism to reduce brain injury and post-hemorrhagic hydrocephalus after IVH. Here, we tested the macrolide antibiotic azithromycin, which has immunomodulatory properties, to reduce innate immune activation in an in vitro model of microglial activation using the blood product hemoglobin (Hgb). We then utilized azithromycin in our in vivo model of IVH, using intraventricular blood injection into the lateral ventricle of post-natal day 5 rat pups. In both models, azithromycin modulated innate immune activation by several outcome measures including mitochondrial bioenergetic analysis, cytokine expression and flow cytometric analysis. This suggests that azithromycin, which is safe for neonates, could hold promise for modulating innate immune activation after IVH.

Biodegradation of COVID19 antibiotic; azithromycin and its impact on soil microbial community in the presence of phenolic waste and with temperature variation.

The increase in using antibiotics, especially Azithromycin have increased steadily since the beginning of COVID19 pandemic. This increase has led to its presence in water systems which consequently led to its presence upon using this water for irrigation. The aim of the present work is to study the impact of irrigation using Azithromycin containing water on soil microbial community and its catabolic activity in the presence of phenolic wastes as compost. Wild berry, red grapes, pomegranate, and spent tea waste were added to soil and the degradation was monitored after 5 and 7 days at ambient and high temperatures. The results obtained show that at 30 °C, soil microbial community collectively was able to degrade Azithromycin, while at 40 °C, addition of spent tea as compost was needed to reach higher degradation. To ensure that the degradation was biotic and depended on degradation by indigenous microflora, a 25 kGy irradiation dose was used to kill the microorganisms in the soil and this was used as negative control. The residual antibiotic was assayed using UV spectroscopy and High Performance Liquid Chromatography (HPLC). Indication of Azithromycin presence was studied using Fourier Transform Infrared Spectroscopy (FTIR) peaks and the same pattern was obtained using the 3 used detection methods, the ability to assign the peaks even in the presence of soil and not to have any overlaps, gives the chance to study this result in depth to prepare IR based sensor for quick sensing of antibiotic in environmental samples.

Ciprofloxacin- and azithromycin-resistant bacteria in a wastewater treatment plant.

The occurrence of antibiotic-resistant bacteria (ARB) in wastewater treatment plants (WWTPs) has become an occupational and environmental concern. WWTPs are engineered systems that treat wastewater to meet public health standards before release into the environment. The residuals, as either effluent or solids, are then discharged or beneficially recycled into the environment. Since these wastes contain a diverse array of microorganisms, some of which are resistant to commonly used antibiotics, there is a potential for these organisms to spread in the environment via residual recycling and effluent discharge. Human infections with ARB are increasing, and it is not well known how the interaction between humans and the environment plays a role in this process. WWTP workers, who are on the front lines, may come into direct contact with materials containing these microbes. This study aimed to determine the number of ARB present in both air and sewage sludges in a WWTP using nonselective media supplemented with two antibiotics (ciprofloxacin and azithromycin). The densities of total heterotrophic bacteria, ciprofloxacin-resistant bacteria, and azithromycin-resistant bacteria were 7.82 × 105 - 4.7 × 109, 7.87 × 103 - 1.05 × 108, and 2.27 × 105 - 1.16 × 109 CFU/g, respectively. The prevalence [(concentration on medium with antibiotics/concentration on medium without antibiotics) × 100] of ciprofloxacin-resistant bacteria in treated sludge was twice as low as in digested sludge and approximately three times lower than in raw sludge. For azithromycin, the prevalence of resistant bacteria in treated sludge was about the same in digested and nearly twice lower than in raw sludge. Despite a marked reduction in the mean prevalence of resistant bacteria in dewatered treated sludge for both antibiotics, these differences were not significant. The highest prevalence of antibiotic resistance was observed for azithromycin. Similarly, the prevalence of airborne azithromycin-resistant bacteria inside the belt filter press room (BFPR) was nearly seven times higher than the prevalence of airborne ciprofloxacin-resistant bacteria. These concentrations of ARB were not negligible and may represent an exposure pathway for some workers in WWTPs.

Zwitterionic meso-silica/polypeptide hybrid nanoparticles for efficient azithromycin delivery and photodynamic therapy for synergistic treatment of drug-resistant bacterial infection.

The treatment of drug-resistant bacterial infections attributed to the overuse of antibiotics still remains a serious challenge globally. Herein, zwitterionic charge switchable meso-silica/polypeptide hybrid nanoparticles (MSPNs) were prepared for the synergistic chemo-photodynamic therapy in the treatment of drug-resistant bacterial infections. Subsequently, azithromycin (AZT) and methylene blue (MB) were loaded in the MSPNs to form the combined chemo-photodynamic therapeutic nanoparticles (MSPNs-AZT/MB) for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Remarkably, the as-prepared MSPNs-AZT/MB exhibited a negative surface charge of -5.2 mV at physiological pH while switching into positive surface charge of 24.7 mv in an acidic environment, leading to enhanced binding with bacterial surface. The lipase-triggered AZT release up to 77.9 % was achieved, and the loaded MB demonstrated efficient singlet oxygen (1O2) generation for photodynamic therapy. The in vitro experimental results displayed an excellent antibacterial effect against MRSA in both planktonic and biofilm phenotypes. Additionally, the as-prepared MSPNs-AZT/MB exhibited synergistic and enhanced antibacterial infection effect up to 94 % comparing to monotherapy in a mice model. Considering the above advantages, the as-prepared combined chemo-photodynamic therapeutic nanoparticles showed promising biocompatibility and clinical potential for the efficient therapy of drug-resistant bacteria.

Combination effect of azithromycin with TCM preparation Xiyanping injection against Klebsiella pneumoniae infection in rats.

BACKGROUND: Klebsiella pneumoniae is known as one of the most principal opportunistic human pathogens. Although antibiotics such as the first-line agent azithromycin (AZM) usually are efficient for the treatment of K. pneumonia-related infections, growing threat from antibiotic resistance has become a major challenge. Various preparations based on traditional Chinese medicine (TCM) clinical experience have been developed to help combat such a global public health threat, including Xiyanping injection (XYP) that is made from the natural product andrographolide with potent heat-clearing and toxin-resolving functions. PURPOSE: The present study aimed to demonstrate the therapeutic potential, as well as the action of mechanism of AZM in combination with XYP against K. pneumonia infection in rats. METHODS: Pneumonia model of K. pneumoniae infection in rats was established and subjected to various treatments. The lung histopathological lesions were evaluated. ELISA and Griess techniques were used to determine the level of crucial cytokines. The protein expressions of MAPKs and NF-κB pathways were analyzed by Western blotting. RESULTS: The combination in vivo could significantly inhibit the proliferation of K. pneumoniae in lung, improve the pathological changes of lung and reduce inflammatory factors in lung homogenate and bronchoalveolar lavage fluid, mainly by inactivating MAPKs and NF-κB signaling pathways. Combination therapy caused one-fold increase in apparent distribution volume of AZM in rats after multiple dosing, along with a significant increase of AZM level in lungs but obvious decrease in livers. CONCLUSION: The combination therapy of AZM and XYP showed increased antibacterial and anti-inflammatory properties, indicating that it might be used to treat K. pneumoniae infection.

Case Report: Whole-Genome Sequencing of Serially Collected Haemophilus influenzae From a Patient With Common Variable Immunodeficiency Reveals Within-Host Evolution of Resistance to Trimethoprim-Sulfamethoxazole and Azithromycin After Prolonged Treatment With These Antibiotics.

We report within-host evolution of antibiotic resistance to trimethoprim-sulfamethoxazole and azithromycin in a nontypeable Haemophilus influenzae strain from a patient with common variable immunodeficiency (CVID), who received repeated or prolonged treatment with these antibiotics for recurrent respiratory tract infections. Whole-genome sequencing of three longitudinally collected sputum isolates during the period April 2016 to January 2018 revealed persistence of a strain of sequence type 2386. Reduced susceptibility to trimethoprim-sulfamethoxazole in the first two isolates was associated with mutations in genes encoding dihydrofolate reductase (folA) and its promotor region, dihydropteroate synthase (folP), and thymidylate synthase (thyA), while subsequent substitution of a single amino acid in dihydropteroate synthase (G225A) rendered high-level resistance in the third isolate from 2018. Azithromycin co-resistance in this isolate was associated with amino acid substitutions in 50S ribosomal proteins L4 (W59R) and L22 (G91D), possibly aided by a substitution in AcrB (A604E) of the AcrAB efflux pump. All three isolates were resistant to aminopenicillins and cefotaxime due to TEM-1B beta-lactamase and identical alterations in penicillin-binding protein 3. Further resistance development to trimethoprim-sulfamethoxazole and azithromycin resulted in a multidrug-resistant phenotype. Evolution of multidrug resistance due to horizontal gene transfer and/or spontaneous mutations, along with selection of resistant subpopulations is a particular risk in CVID and other patients requiring repeated and prolonged antibiotic treatment or prophylaxis. Such challenging situations call for careful antibiotic stewardship together with supportive and supplementary treatment. We describe the clinical and microbiological course of events in this case report and address the challenges encountered.

Extensively drug-resistant (XDR) Neisseria gonorrhoeae causing possible gonorrhoea treatment failure with ceftriaxone plus azithromycin in Austria, April 2022.

We describe a gonorrhoea case with ceftriaxone plus high-level azithromycin resistance. In April 2022, an Austrian heterosexual male was diagnosed with gonorrhoea after sexual intercourse with a female sex worker in Cambodia. Recommended treatment with ceftriaxone (1 g) plus azithromycin (1.5 g) possibly failed. Worryingly, this is the second strain in an Asian Neisseria gonorrhoeae genomic sublineage including high-level azithromycin-resistant strains that developed ceftriaxone resistance by acquisition of mosaic penA-60.001. Enhanced resistance surveillance and actions are imperative to prevent spread.

Study Effect of Azithromycin and Doxycycline in Mucus Producing and Inflammatory Signaling Pathways of Allergic Asthma.

Asthma is a respiratory disease; involving millions of people worldwide. The main cause of asthma is allergy and immune response dysregulation. The effects of azithromycin and doxycycline as asthma-controlling drugs were evaluated in this study. Mice asthma model was produced and asthmatic mice were treated with azithromycin (75 mg/kg, orally) and doxycycline (20 mg/kg, orally). Eosinophils and neutrophils count, interleukin (IL)-4, IL-5, IL-12, IL-13, and total immunoglobulin E (IgE) levels were measured. Histological study and evaluating the genes expression of Muc5ac, Muc5b, IL-33, COX2, MYD88, and TRAF6 were performed. Azithromycin and doxycycline did not affect eosinophil and neutrophil percentage, IL-4, IL-5, IL-12, and total IgE levels, peribronchial and perivascular inflammation, goblet cell hyperplasia, and gene expression of MYD88, TRAF6, and COX2. Treatment with azithromycin significantly decreased IL-13 level, mucus secretion, and gene expression of IL-33, Muc5ac, and Muc5b; compared to the non-treated asthma group. Azithromycin administration controls mucus secretion and inflammation. Azithromycin therapy and not doxycycline might be an effective adjuvant option in asthma with reducing mucus in the airway.

Spectinomycin, gentamicin, and routine disc diffusion testing: An alternative for the treatment and monitoring of multidrug-resistant Neisseria gonorrhoeae?

INTRODUCTION: Neisseria gonorrhoeae is a major concern of public health due to its extraordinary capacity to develop and acquire resistance to different antimicrobials used to treat gonorrhoea. Limited treatment options and uncontrolled transmission have raised the need to assess the antimicrobial susceptibility profile of the isolates and to establish affordable alternatives for laboratory diagnosis. OBJECTIVES: This study aimed to (i) determine the susceptibility profile of 336 clinical isolates of N. gonorrhoeae to ceftriaxone, azithromycin, ciprofloxacin, spectinomycin and gentamicin by the gold standard agar dilution method; (ii) assess the agreement among agar dilution and disc diffusion results for ciprofloxacin, azithromycin, ceftriaxone, spectinomycin and gentamicin. RESULTS: All isolates were susceptible to ceftriaxone and spectinomycin. The levels of resistance to azithromycin and ciprofloxacin were 3.9% and 35.1%, respectively. Intermediate susceptibility to gentamicin was observed in 19.4% of isolates. There was 100% agreement between methods for spectinomycin and ceftriaxone, 99.7% for ciprofloxacin, and 85.7% for azithromycin. For gentamicin, there was 86.3% agreement between agar dilution and disc diffusion, resulting in intermediate susceptible by one method and susceptible by the other method, defined as minor errors. The discordance among agar dilution and disc diffusion results is acceptable for ciprofloxacin, ceftriaxone and spectinomycin as per CLSI M23-Ed4. CONCLUSIONS: Spectinomycin and gentamicin can be considered in some cases as options for the treatment of gonorrhoea in Brazil. Disc diffusion can be an alternative method in routine testing with comparable accuracy to agar dilution.

Markedly Increasing Antibiotic Resistance and Dual Treatment of Neisseria gonorrhoeae Isolates in Guangdong, China, from 2013 to 2020.

The emergence of multidrug resistance in Neisseria gonorrhoeae is concerning, especially the cooccurrence of azithromycin resistance and decreased susceptibility to extended-spectrum cephalosporin. This study aimed to confirm the antibiotic resistance trends and provide a solution for N. gonorrhoeae treatment in Guangdong, China. A total of 5,808 strains were collected for assessment of antibiotic MICs. High resistance to penicillin (53.80 to 82%), tetracycline (88.30 to 100%), ciprofloxacin (96 to 99.8%), cefixime (6.81 to 46%), and azithromycin (8.60 to 20.03%) was observed. Remarkably, spectinomycin and ceftriaxone seemed to be the effective choices, with resistance rates of 0 to 7.63% and 2.00 to 16.18%, respectively. Moreover, the rates of azithromycin resistance combined with decreased susceptibility to ceftriaxone and cefixime reached 9.28% and 8.64%, respectively. Furthermore, genotyping identified NG-STAR-ST501, NG-MAST-ST2268, and MLST-ST7363 as the sequence types among representative multidrug-resistant isolates. Evolutionary analysis showed that FC428-related clones have spread to Guangdong, China, which might be a cause of the rapid increase in extended-spectrum cephalosporin resistance currently. Among these strains, the prevalence of N. gonorrhoeae was extremely high, and single-dose ceftriaxone treatment might be a challenge in the future. To partially relieve the treatment pressure, a susceptibility test for susceptibility to azithromycin plus extended-spectrum cephalosporin dual therapy was performed. The results showed that all the representative isolates could be effectively killed with the coadministration of less than 1 mg/liter azithromycin and 0.125 mg/liter extended-spectrum cephalosporin, with a synergistic effect according to a fractional inhibitory concentration (FIC) of <0.5. In conclusion, dual therapy might be a powerful measure to treat refractory N. gonorrhoeae in the context of increasing antibiotic resistance in Guangdong, China.

Azithromycin and Ciprofloxacin Treatment Outcomes During an Outbreak of Multidrug-Resistant Shigella sonnei Infections in a Retirement Community-Vermont, 2018.

BACKGROUND: In 2018, the Centers for Disease Control and Prevention and the Vermont Department of Health investigated an outbreak of multidrug-resistant Shigella sonnei infections in a retirement community that offered a continuum of care from independent living through skilled nursing care. The investigation identified 24 culture-confirmed cases. Isolates were resistant to trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone, and had decreased susceptibility to azithromycin and ciprofloxacin. METHODS: To evaluate clinical and microbiologic response, we reviewed inpatient and outpatient medical records for treatment outcomes among the 24 patients with culture-confirmed S. sonnei infection. We defined clinical failure as diarrhea (≥3 loose stools per day) for ≥1 day after treatment finished, and microbiologic failure as a stool culture that yielded S. sonnei after treatment finished. We used broth microdilution to perform antimicrobial susceptibility testing, and whole genome sequencing to identify resistance mechanisms. RESULTS: Isolates contained macrolide resistance genes mph(A) and erm(B) and had azithromycin minimum inhibitory concentrations above the Clinical and Laboratory Standards Institute epidemiological cutoff value of ≤16 µg/mL. Among 24 patients with culture-confirmed Shigella infection, 4 were treated with azithromycin; all had clinical treatment failure and 2 also had microbiologic treatment failure. Isolates were susceptible to ciprofloxacin but contained a gyrA mutation; 2 patients failed treatment with ciprofloxacin. CONCLUSIONS: These azithromycin treatment failures demonstrate the importance of clinical breakpoints to aid clinicians in identifying alternative treatment options for resistant strains. Additionally, these treatment failures highlight a need for comprehensive susceptibility testing and systematic outcome studies, particularly given the emergence of multidrug-resistant Shigella among an expanding range of patient populations.

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.

Circulation of multi-drug-resistant Shigella sonnei and Shigella flexneri among men who have sex with men in Barcelona, Spain, 2015-2019.

BACKGROUND: In high-income countries, shigellosis is mainly found in travellers to high-risk regions or in men who have sex with men (MSM). This study investigated the genomic characteristics and the features of antimicrobial resistance of MSM-associated Shigella flexneri and Shigella sonnei circulating in Barcelona, Spain, elucidating their connectivity with contemporaneous Shigella spp. from other countries. METHODS: Antimicrobial susceptibility, whole-genome sequencing, genomic characterization and phylogenetic analysis were performed in MSM-associated Shigella spp. recovered from 2015 to 2019. Reference genomes of MSM-associated Shigella spp. were included for contextualization and to determine their connection with international outbreaks. RESULTS: In total, 44 S. flexneri and 26 S. sonnei were identified among MSM. Overall, 80% showed resistance to azithromycin, 65.7% showed resistance to trimethoprim-sulphamethoxazole and 32.8% showed resistance to ciprofloxacin; 27.1% were resistant to all three antimicrobials. mphA and/or ermB, and qnrS and mutations in the quinolone resistance determining regions were found in the azithromycin- and ciprofloxacin-resistant isolates, respectively. Additionally, two isolates carried blaCTX-M-27. Single-nucleotide-polymorphism-based analysis revealed that the isolates were organized into different lineages, most of which were closely related to dominant MSM-associated lineages described previously in the UK and Australia. CONCLUSIONS: This study investigated the circulation of lineages of S. flexneri and S. sonnei among MSM in Spain that were mainly resistant to first-/second-line oral treatments, and closely related to dominant MSM-associated lineages described previously in the UK and Australia. These data reinforce the urgent need for the implementation of public health measures focusing on the early detection and prevention of transmission of this emerging pathogen, which is contributing to the antimicrobial resistance crisis in sexually transmitted infections.

What's left in the cupboard? Older antimicrobials for treating gonorrhoea.

BACKGROUND: Neisseria gonorrhoeae has developed resistance to all antimicrobials used to treat gonorrhoea, with even ceftriaxone being undermined. It is therefore important to examine any potential to redeploy older antimicrobials routinely used for other infections to treat ceftriaxone-resistant gonococcal infections. OBJECTIVES: We examined the susceptibility of N. gonorrhoeae to aztreonam, chloramphenicol, co-trimoxazole, fosfomycin, piperacillin/tazobactam and rifampicin. METHODS: N. gonorrhoeae isolates (n = 94) were selected to include a range of antimicrobial susceptibilities: 58 were collected in the Gonococcal Resistance to Antimicrobials Surveillance Programme; 17 were clinical isolates referred to the PHE reference laboratory; and 19 were control strains. MICs were determined by agar dilution for the six study antimicrobials and for ceftriaxone and azithromycin as comparators. RESULTS: There was correlation between piperacillin/tazobactam and ceftriaxone MICs, but all five isolates with high ceftriaxone MICs (>0.5 mg/L) were inhibited by piperacillin/tazobactam at 0.06-0.5 mg/L. Aztreonam MICs for ceftriaxone-resistant isolates exceeded those of ceftriaxone. Among non-ß-lactams, fosfomycin and co-trimoxazole had low, tightly clustered MICs, suggesting widespread susceptibility, rifampicin split the collection into highly susceptible and highly resistant groups and chloramphenicol had a wide MIC distribution. CONCLUSIONS: Although unsuitable for empirical use, piperacillin/tazobactam, fosfomycin, co-trimoxazole, rifampicin and, possibly, chloramphenicol could be considered for individual patients with ceftriaxone-resistant gonococcal infection once MICs are known. Wider surveillance of the susceptibility of N. gonorrhoeae to these agents is needed, along with clinical trials and the establishment of clinical breakpoints for N gonorrhoeae.

Background review for the '2020 European guideline for the diagnosis and treatment of gonorrhoea in adults'.

Gonorrhoea is a major public health concern globally. Increasing incidence and sporadic ceftriaxone-resistant cases, including treatment failures, are growing concerns. The 2020 European gonorrhoea guideline provides up-to-date evidence-based guidance regarding the diagnosis and treatment of gonorrhoea. The updates and recommendations emphasize significantly increasing gonorrhoea incidence; broad indications for increased testing with validated and quality-assured nucleic acid amplification tests (NAATs) and culture; dual antimicrobial therapy including high-dose ceftriaxone and azithromycin (ceftriaxone 1 g plus azithromycin 2 g) OR ceftriaxone 1 g monotherapy (ONLY in well-controlled settings, see guideline for details) for uncomplicated gonorrhoea when the antimicrobial susceptibility is unknown; recommendation of test of cure (TOC) in all gonorrhoea cases to ensure eradication of infection and identify resistance; and enhanced surveillance of treatment failures when recommended treatment regimens have been used. Improvements in access to appropriate testing, test performance, diagnostics, antimicrobial susceptibility surveillance and treatment, and follow-up of gonorrhoea patients are essential in controlling gonorrhoea and to mitigate the emergence and/or spread of ceftriaxone resistance and multidrug-resistant and extensively drug-resistant gonorrhoea. This review provides the detailed background, evidence base and discussions, for the 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults (Unemo M, et al. Int J STD AIDS. 2020).

A novel virtual screening procedure identifies Pralatrexate as inhibitor of SARS-CoV-2 RdRp and it reduces viral replication in vitro.

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus poses serious threats to the global public health and leads to worldwide crisis. No effective drug or vaccine is readily available. The viral RNA-dependent RNA polymerase (RdRp) is a promising therapeutic target. A hybrid drug screening procedure was proposed and applied to identify potential drug candidates targeting RdRp from 1906 approved drugs. Among the four selected market available drug candidates, Pralatrexate and Azithromycin were confirmed to effectively inhibit SARS-CoV-2 replication in vitro with EC50 values of 0.008µM and 9.453 µM, respectively. For the first time, our study discovered that Pralatrexate is able to potently inhibit SARS-CoV-2 replication with a stronger inhibitory activity than Remdesivir within the same experimental conditions. The paper demonstrates the feasibility of fast and accurate anti-viral drug screening for inhibitors of SARS-CoV-2 and provides potential therapeutic agents against COVID-19.

Potential clinical use of azithromycin against gastroenteritis-causing pathogens other than Campylobacter.

The activity of azithromycin against enteritis-producing agents other than Campylobacter spp. was studied. The susceptibility to azithromycin, through gradient test, of 88 clinical isolates (51 Salmonella spp., 23 Aeromonas spp., 10 Shigella sonnei and 4 Yersinia enterocolitica) for one year was studied prospectively. The results were compared with the activity of ampicillin, trimethoprim-sulfamethoxazole and ciprofloxacin by microdilution. For azithromycin, the minimum inhibitory concentration (MIC) 50 and MIC90 were 4 and 12 mg/l, respectively. Six (6.8%) isolates were simultaneously resistant to ampicillin, trimethoprim- sulfamethoxazole and ciprofloxacin, and 3 (50%) of them presented a MIC >256 mg/l. Azithromycin may be a good empirical therapeutic option for the treatment of bacterial enteritis.

External quality assessment (EQA) of Neisseria gonorrhoeae antimicrobial susceptibility testing in primary laboratories in Germany.

BACKGROUND: Worldwide, an increase in antimicrobial resistance (AMR) of Neisseria gonorrhoeae has been observed. Until now, no protocol for an external quality assessment (EQA) has been available for Germany. The German gonococcal resistance network (GORENET) performed an EQA of primary laboratories in Germany in order to assess quality of antibiotic susceptibility testing, to gain information about laboratory procedures and to assess the impact of these procedures on test results. METHODS: Laboratories assessed drug susceptibility to cefixime, ceftriaxone, azithromycin, penicillin and ciprofloxacin for five N. gonorrhoeae strains, using their standard laboratory protocols. Minimal inhibitory concentrations (MICs) were compared to World Health Organisation (WHO) consensus results (or, if not available, reference laboratory results), while deviation by +/- one doubling dilution was accepted. Data on laboratory procedures were collected via a standardised questionnaire. Generalized linear models and conditional inference trees (CTREE) were used to assess relationships between laboratory procedures and testing outcomes. RESULTS: Twenty-one primary laboratories participated in the EQA in June 2018. 96% of ciprofloxacin MICs were reported within accepted deviations, as well as 88% for cefixime, 85% for ceftriaxone, 79% for penicillin and 70% for azithromycin. The use of interpretation standards and general laboratory procedures like agar base, incubation settings or the use of control strains strongly differed between laboratories. In statistical analysis, incubation time of cultures < 24 h was associated with correct measurements. Additionally, a 5% CO2 concentration was associated with correct results regarding azithromycin compared to 3%. CTREE analysis showed that incubation time, humidity and CO2 concentration had the greatest influence on the average deviation from consensus results. CONCLUSIONS: In conclusion, we report the development of a protocol for N. gonorrhoeae antimicrobial susceptibility testing in Germany. While testing results were in accordance with the expected consensus results in 70-96%, depending on the antibiotic agent, laboratory methodology was heterogeneous and may significantly affect the testing quality. We therefore recommend the development of a standard operating procedure (SOP) for N. gonorrhoeae susceptibility testing in Germany.

Clinical Pharmacology Perspectives on the Antiviral Activity of Azithromycin and Use in COVID-19.

Azithromycin (AZ) is a broad-spectrum macrolide antibiotic with a long half-life and a large volume of distribution. It is primarily used for the treatment of respiratory, enteric, and genitourinary bacterial infections. AZ is not approved for the treatment of viral infections, and there is no well-controlled, prospective, randomized clinical evidence to support AZ therapy in coronavirus disease 2019 (COVID-19). Nevertheless, there are anecdotal reports that some hospitals have begun to include AZ in combination with hydroxychloroquine or chloroquine (CQ) for treatment of COVID-19. It is essential that the clinical pharmacology (CP) characteristics of AZ be considered in planning and conducting clinical trials of AZ alone or in combination with other agents, to ensure safe study conduct and to increase the probability of achieving definitive answers regarding efficacy of AZ in the treatment of COVID-19. The safety profile of AZ used as an antibacterial agent is well established.1 This work assesses published in vitro and clinical evidence for AZ as an agent with antiviral properties. It also provides basic CP information relevant for planning and initiating COVID-19 clinical studies with AZ, summarizes safety data from healthy volunteer studies, and safety and efficacy data from phase II and phase II/III studies in patients with uncomplicated malaria, including a phase II/III study in pediatric patients following administration of AZ and CQ in combination. This paper may also serve to facilitate the consideration and use of a priori-defined control groups for future research.