A phase II, multicenter, nonblinded, randomized controlled trial for evaluating protective effects of ABPC/SBT plus, azithromycin versus erythromycin, in pregnant women with pPROM occurring at <28 weeks of gestation on the development of BPD in neonates: Study protocol.

This is a protocol for PPROM-AZM Study, phase II, nonblinded, randomized controlled trial. Bronchopulmonary dysplasia (BPD) at a postmenstrual age of 36 weeks (BPD36) is often observed in infants with preterm premature rupture of the membranes (pPROM). A regimen of ampicillin (ABPC) intravenous infusion for 2 days and subsequent amoxicillin (AMPC) oral administration for 5 days plus erythromycin (EM) intravenous infusion for 2 days followed by EM oral administration for 5 days is standard treatment for pPROM. However, the effect on the prevention of moderate/severe BPD36 using the standard treatment has not been confirmed. Recently, it is reported that ampicillin/sulbactam (ABPC/SBT) plus azithromycin (AZM) was effective for the prevention of moderate/severe BPD36 in pPROM patients with amniotic infection of Ureaplasma species. Therefore, our aim is to evaluate the occurrence rate of the composite outcome of "incidence rate of either moderate/severe BPD36 or intrauterine fetal death, and infantile death at or less than 36 weeks 0 days" comparing subjects to receive ABPC/SBT for 14 days plus AZM for 14 days (intervention group) and those to receive ABPC/SBT for 14 days plus EM for 14 days (control group), in a total of 100 subjects (women with pPROM occurring at 22-27 weeks of gestation) in Japan. The recruit of subjects was started on April 2022, and collection in on-going. We also investigate the association between the detection of Ureaplasma species and occurrence of BPD36. In addition, information on any adverse events for the mother and fetus and serious adverse events for infants are collected during the observation period. We allocate patients at a rate of 1:1 considering two stratification factors: onset of pPROM (22-23 or 24-27 weeks) and presence/absence of a hospital policy for early neonatal administration of caffeine. Trial registration: The trial number in the Japan Registry of Clinical Trials is jRCTs031210631.

A novel 12-membered ring non-antibiotic macrolide EM982 attenuates cytokine production by inhibiting IKKß and IκBα phosphorylation.

Antimicrobial resistance poses a serious threat to human health worldwide and its incidence continues to increase owing to the overuse of antibiotics and other factors. Macrolide antibiotics such as erythromycin (EM) have immunomodulatory effects in addition to their antibacterial activity. Long-term, low-dose administration of macrolides has shown clinical benefits in treating non-infectious inflammatory respiratory diseases. However, this practice may also increase the emergence of drug-resistant bacteria. In this study, we synthesized a series of EM derivatives, and screened them for two criteria: (i) lack of antibacterial activity and (ii) ability to suppress tumor necrosis factor-α (TNF-α) production in THP-1 cells stimulated with lipopolysaccharide. Among the 37 synthesized derivatives, we identified a novel 12-membered ring macrolide EM982 that lacked antibacterial activity against Staphylococcus aureus and suppressed the production of TNF-α and other cytokines. The effects of EM982 on Toll-like receptor 4 (TLR4) signaling were analyzed using a reporter assay and Western blotting. The reporter assay showed that EM982 suppressed the activation of transcription factors, NF-κB and/or activator protein 1 (AP-1), in HEK293 cells expressing human TLR4. Western blotting showed that EM982 inhibited the phosphorylation of both IκB kinase (IKK) ß and IκBα, which function upstream of NF-κB, whereas it did not affect the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and c-Jun N-terminal kinase, which act upstream of AP-1. These results suggest that EM982 suppresses cytokine production by inhibiting phosphorylation of IKKß and IκBα, resulting in the inactivation of NF-κB.

Erythromycin mediates co-flocculation between cyanobacterium Synechocystis sp. PCC 6803 and filamentous fungi in liquid cultivation without organic compounds.

Photoautotrophic cyanobacteria assimilate the greenhouse gas carbon dioxide as their sole carbon source for producing useful bioproducts. However, harvesting the cells from their liquid media is a major bottleneck in the process. Thus, an easy-to-harvest method, such as auto-flocculation, is desirable. Here, we found that cyanobacterium Synechocystis sp. PCC 6803 co-flocculated with a natural fungal contamination in the presence of the antibiotic erythromycin (EM) but not without EM. The fungi in the co-flocculated biomass were isolated and found to consist of five species with the filamentous Purpureocillium lilacinum and Aspergillus protuberus making up 71% of the overall fungal population. The optimal co-cultivation for flocculation was an initial 5 mg (fresh weight) of fungi, an initial cell density of Synechocystis of 0.2 OD730, 10 µM EM, and 14 days of cultivation in 100 mL of BG11 medium with no organic compound. This yielded 248 ± 28 mg/L of the Synechocystis-fungi flocculated biomass from 560 ± 35 mg/L of total biomass, a 44 ± 2% biomass flocculation efficiency. Furthermore, the EM treated Synechocystis cells in the Synechocystis-fungi flocculate had a normal cell color and morphology, while those in the axenic suspension exhibited strong chlorosis. Thus, the occurrence of the Synechocystis-fungi flocculation was mediated by EM, and the co-flocculation with the fungi protected Synechocystis against the development of chlorosis. Transcriptomic analysis suggested that the EM-mediated co-flocculation was a result of down-regulation of the minor pilin genes and up-regulation of several genes including the chaperone gene for pilin regulation, the S-layer protein genes, the exopolysaccharide-polymerization gene, and the genes for signaling proteins involved in cell attachment and abiotic-stress responses. The CuSO4 stress can also mediate Synechocystis-fungi flocculation but at a lower flocculation efficiency than that caused by EM. The EM treatment may be applied in the co-culture between other cyanobacteria and fungi to mediate cell bio-flocculation.

Whole-Cell Configuration of the Patch-Clamp Technique in the hERG Channel Assay.

In vitro electrophysiological safety studies have become an integral part of the drug development process because, in many instances, compound-induced QT prolongation has been associated with a direct block of human ether-a-go-go-related gene (hERG) potassium channels or their native current, the rapidly activating delayed rectifier potassium current (IKr ). Therefore, according to the ICH S7B guideline, the in vitro hERG channel patch-clamp assay is commonly used as an early screen to predict the ability of a compound to prolong the QT interval prior to first-in-human testing. The protocols described in this article are designed to assess the effects of acute or long-term exposure to new chemical entities on the amplitude of IKr in HEK293 cells stably transfected with the hERG channel (whole-cell configuration of the patch-clamp technique). Examples of results obtained with moxifloxacin, terfenadine, arsenic, pentamidine, erythromycin, and sotalol are provided for illustrative purposes. © 2024 Wiley Periodicals LLC. Basic Protocol: Measurement of the acute effects of test items in the hERG channel test Alternate Protocol: Measurement of the long-term effects of test items in the hERG channel test.

Immunologic effect and clinical impact of erythromycin in septic patients: A randomized clinical trial.

To investigate the potential regulatory effect of erythromycin added to standard care in septic patients on sepsis biomarkers and clinical outcome. It was a single-blind randomized trial including critical septic patients. The primary endpoint was the change in the TNF/IL-10 ratio between days 0 and 6. Changes in other biomarkers, vasopressor use, and 28-day mortality were secondary endpoints. One hundred and ten patients were examined (erythromycin group, n = 55 versus placebo group, n = 55). Clinical features of the groups were well matched. Erythromycin addition had no beneficial effects on the TNF/IL-10 ratio or mortality (51% vs. 47%, p = 0.62). Both groups' serum TNF/IL-10 ratios did not significantly rise (from 0.48 [0.34-1.18] to 0.59 [0.21-1.10] vs. 0.65 [0.25-1.14] to 0.93 [0.24-1.88] in the erythromycin and placebo groups, respectively; p values = 0.86 and 0.12). Serum Procalcitonin (PCT) and CRP dropped considerably in the Erythromycin group, whereas only PCT showed a drop in the placebo group. On day 6, the non-survivors' serum TNF/IL-10 ratio was lower than that of the survivors (0.55 [0.17-1.04] vs 1.08 [0.4-2.28], p = 0.029). Neither the pro/anti-inflammatory imbalance nor the mortality were impacted by the addition of erythromycin to standard care in septic patients (ClinicalTrials.gov ID: NCT04665089 (11/12/2020)).

Epitranscriptional m6A modification of rRNA negatively impacts translation and host colonization in Staphylococcus aureus.

Macrolides, lincosamides, and streptogramin B (MLS) are structurally distinct molecules that are among the safest antibiotics for prophylactic use and for the treatment of bacterial infections. The family of erythromycin resistance methyltransferases (Erm) invariantly install either one or two methyl groups onto the N6,6-adenosine of 2058 nucleotide (m6A2058) of the bacterial 23S rRNA, leading to bacterial cross-resistance to all MLS antibiotics. Despite extensive structural studies on the mechanism of Erm-mediated MLS resistance, how the m6A epitranscriptomic mark affects ribosome function and bacterial physiology is not well understood. Here, we show that Staphylococcus aureus cells harboring m6A2058 ribosomes are outcompeted by cells carrying unmodified ribosomes during infections and are severely impaired in colonization in the absence of an unmodified counterpart. The competitive advantage of m6A2058 ribosomes is manifested only upon antibiotic challenge. Using ribosome profiling (Ribo-Seq) and a dual-fluorescence reporter to measure ribosome occupancy and translational fidelity, we found that specific genes involved in host interactions, metabolism, and information processing are disproportionally deregulated in mRNA translation. This dysregulation is linked to a substantial reduction in translational capacity and fidelity in m6A2058 ribosomes. These findings point to a general "inefficient translation" mechanism of trade-offs associated with multidrug-resistant ribosomes.

The erythromycin polyketide compound TMC-154 stimulates ROS generation to exert antibacterial effects against Streptococcus pyogenes.

The erythromycin polyketide compound TMC-154 is a secondary metabolite that is isolated from the rhizospheric fungus Clonostachys rogersoniana associated with Panax notoginseng, which possesses antibacterial activity. However, its antibacterial mechanism has not been investigated thus far. In this study, proteomics coupled with bioinformatics approaches was used to explore the antibacterial mechanism of TMC-154. KEGG pathway enrichment analysis indicated that eight signaling pathways were associated with TMC-154, including oxidative phosphorylation, cationic antimicrobial peptide (CAMP) resistance, benzoate degradation, heme acquisition systems, glycine/serine and threonine metabolism, beta-lactam resistance, ascorbate and aldarate metabolism, and phosphotransferase system (PTS). Cell biology experiments confirmed that TMC-154 could induce reactive oxygen species (ROS) generation in Streptococcus pyogenes; moreover, TMC-154-induced antibacterial effects could be blocked by the inhibition of ROS generation with the antioxidant N-acetyl L-cysteine. In addition, TMC-154 combined with ciprofloxacin or chloramphenicol had synergistic antibacterial effects. These findings indicate the potential of TMC-154 as a promising drug to treat S. pyogenes infections. SIGNIFICANCE: Streptococcus pyogenes is a nearly ubiquitous human pathogen that causes a variety of diseases ranging from mild pharyngitis and skin infection to fatal sepsis and toxic heat shock syndrome. With the increasing incidence of known antibiotic resistance, there is an urgent need to find novel drugs with good antibacterial activity against S. pyogenes. In this study, we found that TMC-154, a secondary metabolite from the fungus Clonostachys rogersoniana, inhibited the growth of various bacteria, including Staphylococcus aureus, S. pyogenes, Streptococcus mutans, Pseudomonas aeruginosa and Vibrio parahemolyticus. Proteomic analysis combined with cell biology experiments revealed that TMC-154 stimulated ROS generation to exert antibacterial effects against S. pyogenes. This study provides potential options for the treatment of S. pyogenes infections in the future.

Fate-Mapping of Yolk Sac-Derived Macrophages.

To better understand the distinct functions of yolk-sac-derived tissue-resident macrophages (TRMs) and bone-marrow-derived macrophages in homeostasis and disease, it is important to trace the ontogeny of these cells. The majority of TRMs originate from erythro-myeloid progenitors (EMPs). EMPs develop into pre-macrophages (pMacs), which can be detected starting at embryonic developmental day (E)9.0, and which give rise to all TRM during early development. pMacs start expressing the gene Cx3cr1, allowing us to genetically target the early yolk-sac wave of pMacs and their progeny. Here, we describe the protocol for the identification of yolk sac-derived TRMs utilizing in utero labelling of the inducible fate mapping Cx3cr1CreERT; Rosa26LSL-eYFP mouse model.

Modular Drug-Loaded Nanocapsules with Metal Dome Layers as a Platform for Obtaining Synergistic Therapeutic Biological Activities.

Multifunctional drug-loaded polymer-metal nanocapsules have attracted increasing attention in drug delivery due to their multifunctional potential endowed by drug activity and response to physicochemical stimuli. Current chemical synthesis methods of polymer/metal capsules require specific optimization of the different components to produce particles with precise properties, being particularly complex for Janus structures combining polymers and ferromagnetic and highly reactive metals. With the aim to generate tunable synergistic nanotherapeutic actuation with enhanced drug effects, here we demonstrate a versatile hybrid chemical/physical fabrication strategy to incorporate different functional metals with tailored magnetic, optical, or chemical properties on solid drug-loaded polymer nanoparticles. As archetypical examples, we present poly(lactic-co-glycolic acid) (PLGA) nanoparticles (diameters 100-150 nm) loaded with paclitaxel, indocyanine green, or erythromycin that are half-capped by either Fe, Au, or Cu layers, respectively, with application in three biomedical models. The Fe coating on paclitaxel-loaded nanocapsules permitted efficient magnetic enhancement of the cancer spheroid assembly, with 40% reduction of the cross-section area after 24 h, as well as a higher paclitaxel effect. In addition, the Fe-PLGA nanocapsules enabled external contactless manipulation of multicellular cancer spheroids with a speed of 150 µm/s. The Au-coated and indocyanine green-loaded nanocapsules demonstrated theranostic potential and enhanced anticancer activity in vitro and in vivo due to noninvasive fluorescence imaging with long penetration near-infrared (NIR) light and simultaneous photothermal-photodynamic actuation, showing a 3.5-fold reduction in the tumor volume growth with only 5 min of NIR illumination. Finally, the Cu-coated erythromycin-loaded nanocapsules exhibited enhanced antibacterial activity with a 2.5-fold reduction in the MIC50 concentration with respect to the free or encapsulated drug. Altogether, this technology can extend a nearly unlimited combination of metals, polymers, and drugs, thus enabling the integration of magnetic, optical, and electrochemical properties in drug-loaded nanoparticles to externally control and improve a wide range of biomedical applications.

Prevalence of Clostridioides difficile in dogs (Canis familiaris) with gastrointestinal disorders in Rio de Janeiro.

Clostridioides difficile infections (CDI) have a high morbidity and mortality rate and have always been considered a nosocomial disease. Nonetheless, the number of cases of community-acquired CDI is increasing, and new evidence suggests additional C. difficile reservoirs exist. Pathogenic C. difficile strains have been found in livestock, domestic animals, and meat, so a zoonotic transmission has been proposed. OBJECTIVE: The goal of this study was to isolate C. difficile strains in dogs at a veterinary clinic in Rio de Janeiro, Brazil, and characterize clinical and pathological findings associated with lower gastrointestinal tract disorders. METHODS: Fifty stool samples and biopsy fragments from dogs were obtained and cultured in the CDBA selective medium. All suggestive C. difficile colonies were confirmed by MALDI-TOF MS and PCR (tpi gene). Vancomycin, metronidazole, moxifloxacin, erythromycin, and rifampicin were tested for antibiotic susceptibility. Biofilm, motility assays, and a PCR for the toxins (tcdA, tcdB, and cdtB), as well as ribotyping, were also performed. RESULTS: Blood samples and colonic biopsy fragments were examined in C. difficile positive dogs. Ten animals (20%) tested positive for C. difficile by using stool samples, but not from biopsy fragments. Most C. difficile strains were toxigenic: six were A+B+ belonging to RT106; two were A+B+ belonging to RT014/020; and two were A-B- belonging to RT010. All strains were biofilm producers. In the motility test, 40% of strains were as motile as the positive control, CD630 (RT012). In the disc diffusion test, two strains (RT010) were resistant to erythromycin and metronidazole; and another to metronidazole (RT014/020). In terms of C. difficile clinicopathological correlations, no statistically significant morphological changes, such as pseudomembranous and "volcano" lesions, were observed. Regarding hematological data, dogs positive for C. difficile had leucopenia (p = 0.02) and lymphopenia (p = 0.03). There was a significant correlation between senility and the presence of C. difficile in the dogs studied (p = 0,02). CONCLUSIONS: Although C. difficile has not been linked to canine diarrheal disorders, it appears to be more common in dogs with intestinal dysfunctions. The isolation of ribotypes frequently involved in human CDI outbreaks around the world supports the theory of C. difficile zoonotic transmission.

Mechanistic insights into Fe3O4-modified biochar relieving inhibition from erythromycin on anaerobic digestion.

Anaerobic digestion (AD) of antibiotic manufacturing wastewater to degrade residual antibiotics and produce mixture of combustible gases has been investigated actively in the past decades. However, detrimental effect of residual antibiotic to microbial activities is commonly faced in AD process, leading to the reduction of treatment efficiency and energy recovery. Herein, the present study systematically evaluated the detoxification effect and mechanism of Fe3O4-modified biochar in AD of erythromycin manufacturing wastewater. Results showed that Fe3O4-modified biochar had stimulatory effect on AD at 0.5 g/L erythromycin existence. A maximum methane yield of 327.7 ± 8.0 mL/g COD was achieved at 3.0 g/L Fe3O4-modified biochar, leading to the increase of 55.7% compared to control group. Mechanistic investigation demonstrated that different levels of Fe3O4-modified biochar could improve methane yield via different metabolic pathways involved in specific bacteria and archaea. Low levels of Fe3O4-modified biochar (i.e., 0.5-1.0 g/L) led to the enrichment of Methanothermobacter sp., strengthening the hydrogenotrophic pathway. On the contrary, high levels of Fe3O4-modified biochar (2.0-3.0 g/L) favored the proliferation of acetogens (e.g., Lentimicrobium sp.) and methanogen (Methanosarcina sp.) and their syntrophic relations played vital role on the simulated AD performance at erythromycin stress. Additionally, the addition of Fe3O4-modified biochar significantly decreased the abundance of representative antibiotic resistant genes (ARGs), benefiting the reduction of environmental risk. The results of this study verified that the application of Fe3O4-modified biochar could be an efficient approach to detoxify erythromycin on AD system, which brings high impacts and positive implications for biological antibiotic wastewater treatment.

The Strength of hERG Inhibition by Erythromycin at Different Temperatures Might Be Due to Its Interacting Features with the Channels.

Erythromycin is one of the few compounds that remarkably increase ether-a-go-go-related gene (hERG) inhibition from room temperature (RT) to physiological temperature (PT). Understanding how erythromycin inhibits the hERG could help us to decide which compounds are needed for further studies. The whole-cell patch clamp technique was used to investigate the effects of erythromycin on hERG channels at different temperatures. While erythromycin caused a concentration-dependent inhibition of cardiac hERG channels, it also shifted the steady-state activation and steady-state inactivation of the channel to the left and significantly accelerated the onset of inactivation at both temperatures, although temperature itself caused a profound change in the dynamics of hERG channels. Our data also suggest that the binding pattern to S6 of the channels changes at PT. In contrast, cisapride, a well-known hERG blocker whose inhibition is not affected by temperature, does not change its critical binding sites after the temperature is raised to PT. Our data suggest that erythromycin is unique and that the shift in hERG inhibition may not apply to other compounds.

Erythromycin Attenuates Hyperoxia Induced Lung Injury by Enhancing GSH Expression and Inhibiting Expression of Inflammatory Cytokines.

Introduction: Oxidative stress and inflammation have proven to be key factors contributing to the occurrence of BPD. Erythromycin has been shown to be effective in treating the redox imbalance seen in many non-bacterial infectious chronic inflammatory diseases. Methods: Ninety-six premature rats were randomly divided into air + saline chloride group, air + erythromycin group, hyperoxia + saline chloride group and hyperoxia + erythromycin group. Lung tissue specimens were collected from 8 premature rats in each group on days 1, 7 and 14, respectively. Results: Pulmonary pathological changes in premature rats after hyperoxia exposure were similar to those of BPD. Hyperoxia exposure induced high expression of GSH, TNF-α, and IL-1ß. Erythromycin intervention caused a further increase in GSH expression and a decrease in TNF-α and IL-1ß expression. Conclusion: GSH, TNF-α and IL-1ß are all involved in the development of BPD. Erythromycin may alleviate BPD by enhancing the expression of GSH and inhibiting the release of inflammatory mediators.

Enzymology of assembly line synthesis by modular polyketide synthases.

Modular polyketide synthases (PKSs) run catalytic reactions over dozens of steps in a highly orchestrated manner. To accomplish this synthetic feat, they form megadalton multienzyme complexes that are among the most intricate proteins on earth. Polyketide products are of elaborate chemistry with molecular weights of usually several hundred daltons and include clinically important drugs such as erythromycin (antibiotic), rapamycin (immunosuppressant) and epothilone (anticancer drug). The term 'modular' refers to a hierarchical structuring of modules and domains within an overall assembly line arrangement, in which PKS organization is colinearly translated into the polyketide structure. New structural information obtained during the past few years provides substantial direct insight into the orchestration of catalytic events within a PKS module and leads to plausible models for synthetic progress along assembly lines. In light of these structural insights, the PKS engineering field is poised to enter a new era of engineering.

Concurrent infections of Streptococcus iniae and Aeromonas veronii in farmed Giant snakehead (Channa micropeltes).

The giant snakehead, Channa micropeltes, is an increasingly important economic freshwater fish in Thailand and other regions of Asia. Presently, giant snakehead are cultured under intensive aquaculture conditions, leading to high stress and conditions favouring disease. In this study, we reported a disease outbreak in farmed giant snakehead with a cumulative mortality of 52.5%, continuing for 2 months. The affected fish exhibited signs of lethargy, anorexia and haemorrhage of the skin and eyes. Further bacterial isolations revealed two different types of colonies on tryptic soy agar: small white, punctate colonies of gram-positive cocci and cream-coloured, round and convex colonies of rod-shaped gram-negative bacteria. Additional biochemical and species-specific PCR analysis based on 16S rRNA confirmed the isolates as Streptococcus iniae and Aeromonas veronii. Multilocus sequence analysis (MLSA) placed the S. iniae isolate into a large clade of strains from clinically infected fish worldwide. Gross necropsy findings showed liver congestion, pericarditis and white nodules in the kidney and liver. Histologically, the affected fish showed focal to multifocal granulomas with inflammatory cell infiltration in kidney and liver, enlarged blood vessels with mild congestion within the meninges of the brain and severe necrotizing and suppurative pericarditis with myocardial infarction. Antibiotic susceptibility tests revealed that S. iniae was sensitive to amoxicillin, erythromycin, enrofloxacin, oxytetracycline, doxycycline and resistant to sulfamethoxazole-trimethoprim, while the A. veronii was susceptible to erythromycin, enrofloxacin, oxytetracycline, doxycycline, sulfamethoxazole-trimethoprim and resistant to amoxicillin. Conclusively, our findings highlighted the natural concurrent bacterial infections in cultured giant snakehead, which support the implementation of appropriate treatment and control strategies.

Protective Effect of Erythromycin Pre-adaptation on Focal Cerebral Ischemia in Rats and its Changes in TNF-α and nNOS.

Context: Ischemic stroke accounts for 85% of all types of stroke. Ischemic preconditioning can provide protection against cerebral ischemic injury. Erythromycin can induce ischemic preconditioning in brain tissue. Objective: The study intended to investigate the protective effects of erythromycin preconditioning on infarct volume after focal cerebral ischemia in rats and on the expression of tumor necrosis factor-alpha (TNF-α) and neuronal nitric oxide synthases (nNOS) in rat-brain tissue. Design: The research team performed an animal study. Setting: The study took place in the Department of Neurosurgery at the First Hospital of China Medical University in Shenyang, China. Animals: The animals were 60 healthy male Wistar rats, aged 6 to 8 weeks and weighing 270 to 300 g. Intervention: The research team randomly divided the rats into a control group in simple randomization and intervention groups preconditioning them according to their body weights using different concentrations of erythromycin-5, 20, 35, 50, and 65 mg/kg, with 10 rats in each group. The team induced focal cerebral ischemia and reperfusion using a modified, longa-wire embolization method. The control group, also 10 rats, received an injection intramuscularly of normal saline. Outcome Measures: The research team: (1) calculated the volume of cerebral infarction using triphenyltetrazolium chloride (TTC) staining with image analysis software and (2) investigated the effects of erythromycin preconditioning on the expression of TNF-α and nNOS mRNA and protein in the rat-brain tissue using real-time polymerase chain reaction (PCR) and Western blot. Results: Erythromycin preconditioning reduced the volume of cerebral infarction after induction of cerebral ischemia, showing a U-shaped, dose-response relationship, and the cerebral infarction volume significantly decreased in the 20-, 35-, and 50-mg/kg erythromycin preconditioning groups (P < .05). Erythromycin preconditioning at 20-, 35-, and 50-mg/kg significantly down-regulated the mRNA and protein expression of TNF-α in the rat-brain tissue (P < .05), with the 35-mg/kg erythromycin preconditioning group having the most significant downregulation. Erythromycin preconditioning at 20-, 35-, and 50-mg/kg upregulated the mRNA and protein expression of nNOS in the rat-brain tissue (P < .05), with the 35-mg/kg erythromycin preconditioning group having the most significant upregulation of the mRNA and protein of nNOS. Conclusions: Erythromycin preconditioning had a protective effect against focal cerebral ischemia in rats, and the best protective effect occurred for the 35-mg/kg preconditioning. The reason may be related to the fact that erythromycin preconditioning significantly upregulated nNOS and downregulated TNF-α in the brain tissue.

Antibacterial, Antioxidant and Nutraceutical Potential of New Culinary-Medicinal Mushroom Russula lakhanpalii (Agaricomycetes) from India.

Russula lakhanpalii is a wild edible mushroom, collected from Pedkhal block of Pauri Garhwal, India. The nutritional composition, antioxidant activity (AOA), and antibacterial activity (ABA) of R. lakhanpalii were analyzed for the first time in this study. Dried fruiting bodies of R. lakhanpalii were reported to contain 17.7% ash, 10% crude fiber, 13.4% protein, 30.9% carbohydrate, and 5% unsaturated lipids. In addition, 10.22-72.56% DPPH scavenging activity also confirmed the good antioxidant nature of R. lakhanpalii. The methanolic extract of R. lakhanpalii fruiting bodies inhibited the growth of five pathogenic bacteria in vitro; Klebsiella pneumoniae (MTCC 4030), Micrococcus luteus (MTCC 1809), Staphylococcus aureus (MTCC 1144), Escherichia coli (MTCC 68), and Streptococcus pneumoniae (MTCC 655). The maximum and minimum zone of inhibitions (ZOIs) reported were 17.8 ± 1.04 mm (K. pneumoniae) and 11.16 ± 0.76 mm, (E. coli), respectively. The noticeable feature of the extract was the inhibition of erythromycin-resistant E. coli and M. luteus by it, which were resistant to 15 µg/disc concentration of erythromycin. Dietary components, antibacterial and antioxidant potentials of R. lakhanpalii suggested its nutraceutical and medicinal applications.

Erythromycin Improves the Quality of Esophagogastroduodenoscopy in Upper Gastrointestinal Bleeding: A Network Meta-Analysis.

BACKGROUND/AIM: Upper gastrointestinal bleeding (UGIB) usually requires esophagogastroduodenoscopy (EGD) for diagnostic and-potentially-therapeutic purposes. However, blood within the gastric lumen may hinder the procedure. Administration of prokinetics like erythromycin has shown efficacy. This network meta-analysis investigates the efficacy of this intervention prior to EGD. METHODS: We performed a systematic literature search of Embase, PubMed/Medline, and other databases through March 8, 2022 to include randomized controlled trials (RCTs) comparing prokinetic use in EGD for UGIB. We used the DerSimonian-Laird approach to pool data and compare outcomes including need for repeat endoscopy and blood transfusion. Pooled prevalence of proportional outcomes, 95% confidence interval (CI), and p-values were calculated. RESULTS: We included eight RCTs with four distinct intervention groups (erythromycin, placebo to erythromycin, nasogastric (NG) lavage and NG lavage + erythromycin) published between 2002 and 2020 with a total of 721 patients (mean age 60.0 ± 3.1 years; 73.2% male). The need for second look endoscopy was significantly lower with erythromycin than placebo (relative risk: 0.42, CI 0.22-0.83, p = 0.01). Using the frequentist approach, the combination of NG lavage and erythromycin (92.2) was rated highest, followed by erythromycin alone (73.1) for higher rates of empty stomach. Erythromycin was rated highest for lower need for packed red blood cell transfusion (72.8) as well as mean endoscopy duration (66.0). CONCLUSION: Erythromycin improved visualization at EGD, reduced requirements for blood transfusion and repeat EGD, and shortened hospital stay. The combination of erythromycin and NG lavage showed reduced mortality.

Cellular Stress-Induced Metabolites in Escherichia coli.

Escherichia coli isolates commonly inhabit the human microbiota, yet the majority of E. coli's small-molecule repertoire remains uncharacterized. We previously employed erythromycin-induced translational stress to facilitate the characterization of autoinducer-3 (AI-3) and structurally related pyrazinones derived from "abortive" tRNA synthetase reactions in pathogenic, commensal, and probiotic E. coli isolates. In this study, we explored the "missing" tryptophan-derived pyrazinone reaction and characterized two other families of metabolites that were similarly upregulated under erythromycin stress. Strikingly, the abortive tryptophanyl-tRNA synthetase reaction leads to a tetracyclic indole alkaloid metabolite (1) rather than a pyrazinone. Furthermore, erythromycin induced two naphthoquinone-functionalized metabolites (MK-hCys, 2; and MK-Cys, 3) and four lumazines (7-10). Using genetic and metabolite analyses coupled with biomimetic synthesis, we provide support that the naphthoquinones are derived from 4-dihydroxy-2-naphthoic acid (DHNA), an intermediate in the menaquinone biosynthetic pathway, and the amino acids homocysteine and cysteine. In contrast, the lumazines are dependent on a flavin intermediate and α-ketoacids from the aminotransferases AspC and TyrB. We show that one of the lumazine members (9), an indole-functionalized analogue, possesses antioxidant properties, modulates the anti-inflammatory fate of isolated TH17 cells, and serves as an aryl-hydrocarbon receptor (AhR) agonist. These three systems described here serve to illustrate that new metabolic branches could be more commonly derived from well-established primary metabolic pathways.

Protocols for genetic labeling and tracing of Staphylococcus xylosus during tumor progression.

Intratumor microbiota is a dynamic cancer component that can be carried over by metastatic tumor cells to distal organs. This protocol was developed to genetically label Staphylococcus xylosus and trace the recombinant strain in vivo in the tumor. We optimized the recombination-based gene replacement protocol to insert a GFP-Erythromycin resistant protein (Erm) cassette. The inserted cassette facilitates the tracking of the recombinant strain, allowing a sensitive interrogation of microbial dynamics with high temporal and spatial resolution. For complete details on the use and execution of this protocol, please refer to Fu et al. (2022).