Erythromycin Research Articles

AcrB-TolC efflux system is essential for macrolide resistance in Helicobacter pylori

The prevalence of Helicobacter pylori strains resistant to macrolide is increasing worldwide. Macrolide molecules can be generally extruded by the AcrB-TolC system in bacteria. The H. pylori 26695 genome was assessed for putative translocases and the outer membrane efflux of AcrB (HP607) and TolC (HP605) proteins. We investigated the role of the AcrB-TolC efflux system in macrolide resistant (M-R) H. pylori. Both acrB- and tolC-mutant M-R strains were constructed from M-R strains by insertional inactivation of the acrB and tolC genes. The minimal inhibition concentrations (MICs) of erythromycin (EM) and clarithromycin (CLR) were determined by an agar dilution assay. To investigate the efflux ability of macrolides, intracellular accumulation of radiolabeled EM in the H. pylori 26695 strain, M-R strain, and acrB- and tolC-mutant M-R strains was measured by a liquid scintillation counter. For Post antibiotic effect (PAE), EM-treated H. pylori was diluted 1000-fold to remove antimicrobial activity. After additional 24 hours incubation, the CFU was measured. The decrease in the levels of resistance to EM and CLR was 32-fold higher for the acrB- and tolC-mutant M-R strains than the M-R strains. The intracellular EM concentration significantly increased in the acrB- and tolC-mutant M-R strains than the H. pylori 26695 and M-R strains. Diluted acrB, and tolC M-R mutant H. pylori after EM treatment was markedly reduced compared to M-R H. pylori. Our result showed that the M-R mechanism of H. pylori is significantly associated with AcrB-TolC efflux system.

Preparation, Characteristics, and Controlled Release Efficiency of the Novel PCL-PEG/EM Rod Micelles

In order to achieve sustained and controlled release of the hydrophobic cargoes, improve the bioavailability, and reduce the side effects of antibiotics, the model drug erythromycin (EM) was used to prepare polycaprolactone-polyethylene glycol (PCL-PEG)/EM micelles. PCL-PEG, a biocompatible and biodegradable amphiphilic polymer, was used as carrier material of micelles to optimize the formulation and preparation process by orthogonal design. The morphology, stability, drug loading, and encapsulation efficiency and the in vitro release behavior of the micelles were investigated. In addition, activity assays of anti-Staphylococcus aureus were performed. The results indicated that PCL-PEG/EM were rod-like micelles with an average particle size of 220 ± 2.6 nm and a zeta potential of +19 mV. The average drug loading and encapsulation efficiency were approximately 6.5% and 97.0%, respectively. The micelles were stable in the serum within three days. At the effective concentration of the drug, the formulation indicated no apparent toxicity to the cells. The micelles were able to rapidly enter Staphylococcus aureus (S. aureus) and to provide sustained release cargoes that effectively inhibited S. aureus proliferation. The present study provided a new platform for the rational and effective use of hydrophobic antibiotics to treat infections.

1236. Update on the In Vitro Activity of Ceftaroline against Staphylococcus aureus from United States (US) Medical Centers Stratified by Infection Type (2018-2020)

1236. Update on the In Vitro Activity of Ceftaroline against Staphylococcus aureus from United States (US) Medical Centers Stratified by Infection Type (2018-2020)

1240. Ceftobiprole Activity against Drug-Resistant Staphylococcus aureus Clinical Isolates Collected in the United States from 2016 through 2020

BackgroundMultidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA) present significant treatment challenges and can cause serious morbidity and mortality. Ceftobiprole, the active moiety of the prodrug ceftobiprole medocaril, is an advanced cephalosporin approved in many European and other countries for the treatment of adults with community- and hospital-acquired pneumonia, excluding ventilator-associated pneumonia. Ceftobiprole is currently in phase 3 clinical development to support a New Drug Application in the United States for acute bacterial skin and skin structure infections and S. aureus bacteremia. Here, the activity of ceftobiprole and comparators was evaluated against recent MDR S. aureus and MRSA clinical isolates.Methods13,868 S. aureus isolates were collected from patients with various infection types at 34 US medical centers from 2016–2020. Susceptibility to ceftobiprole and comparator agents was tested by CLSI methods. Current CLSI and EUCAST interpretive criteria were applied (Table). Isolates were categorized as MDR if they were non-susceptible (NS; CLSI criteria) to ≥3 of the following antimicrobials: clindamycin (CM), daptomycin (DAP), erythromycin (ERY), gentamicin (GM), levofloxacin (LEV), linezolid (LZD), tetracycline (TET), tigecycline (TGC), trimethoprim-sulfamethoxazole (TMP-SMX), or vancomycin (VAN). Isolates displaying oxacillin MIC values ≥4 mg/L were categorized as MRSA.ResultsCeftobiprole was more active than ceftaroline (CPT) against MRSA (99.2% susceptible [S] versus 94.0% S, respectively) (Table). Ceftobiprole maintained activity against 88.0% of the CPT-NS isolates, but CPT was only active against 6.5% of the ceftobiprole-NS isolates. Ceftobiprole was also highly active (97.7–100.0% S) against isolates NS to CM, DAP, ERY, GM, LEV, LZD, TET, TGC, or TMP-SMX. No VAN-NS isolates were detected. Importantly, ceftobiprole was more active (97.7% S) than CPT (83.0% S) against the subset of MDR-MRSA isolates.Conclusion Conclusions: Ceftobiprole was highly active in vitro against MRSA and MDR S. aureus collected at US medical centers during 2016–2020. These results support the further development of ceftobiprole to treat S. aureus infections in the US. Disclosures Leonard R. Duncan, PhD, AbbVie (formerly Allergan) (Research Grant or Support)Basilea Pharmaceutica International, Ltd. (Research Grant or Support)Cipla Therapeutics (Research Grant or Support)Cipla USA Inc. (Research Grant or Support)Department of Health and Human Services (Research Grant or Support, Contract no. HHSO100201600002C)Shionogi (Research Grant or Support) Kamal Hamed, MD, MPH, Basilea Pharmaceutica International, Ltd (Employee)Department of Health and Human Services (Research Grant or Support, Contract no. HHSO100201600002C) Jennifer Smart, PhD, Basilea Pharmaceutica International, Ltd. (Employee)Department of Health and Human Services (Research Grant or Support, Contract no. HHSO100201600002C) Michael A Pfaller, MD, Basilea Pharmaceutica International, Ltd. (Research Grant or Support)Cidara Therapeutics, Inc. (Research Grant or Support)Department of Health and Human Services (Research Grant or Support, Contract no. HHSO100201600002C)Pfizer, Inc. (Research Grant or Support) Helio S. Sader, MD, PhD, FIDSA, AbbVie (formerly Allergan) (Research Grant or Support)Basilea Pharmaceutica International, Ltd. (Research Grant or Support)Cipla Therapeutics (Research Grant or Support)Cipla USA Inc. (Research Grant or Support)Department of Health and Human Services (Research Grant or Support, Contract no. HHSO100201600002C)Melinta Therapeutics, LLC (Research Grant or Support)Nabriva Therapeutics (Research Grant or Support)Pfizer, Inc. (Research Grant or Support)Shionogi (Research Grant or Support)Spero Therapeutics (Research Grant or Support)

Obesogenic effect of erythromycin on Caenorhabditis elegans through over-eating and lipid metabolism disturbances

Environmental obesogens contributed significantly to the obesity prevalence. Recently, antibiotics joined the list of environmental obesogens, while the underlying mechanisms remained to be explored. In the present study, effects of erythromycin (ERY), one widely used macrolide antibiotic, were measured on C. elegans to investigate the obesogenic mechanism. Results showed that ERY at 0.1 μg/L significantly increased the fat content by 17.4% more than the control and also stimulated triacylglycerol (TAG) levels by 25.7% more than the control. Regarding the obesogenic mechanisms, ERY provoked over-eating by stimulation on the pharyngeal pumping and reduction on the satiety quiescence percentage and duration. Such effects were resulted from stimulation on the neurotransmitters including serotonin (5-HT), dopamine (DA) and acetylcholine (ACh). The nervous responses involved the up-regulation of Gsα (e.g., ser-7, gsa-1, acy-1 and kin-2) signaling pathway and the down-regulation of TGFβ (daf-7) but not via cGMP-dependent regulations (e.g., egl-4). Moreover, ERY stimulated the activities of fatty acid synthase (FAS) and glycerol-3-phosphateacyl transferases (GPAT) that catalyze lipogenesis, while ERY inhibited those of acyl-CoA synthetase (ACS), carnitine palmitoyl transferase (CPT) and acyl-CoA oxidase (ACO) that catalyze lipolysis. The unbalance between lipogenesis and lipolysis resulted in the fat accumulation which was consistent with up-regulation on mgl-1 and mgl-3 which are the down-steam of TGFβ regulation. Such consistence supported the close connection between nervous regulation and lipid metabolism. In addition, ERY also disturbed insulin which connects lipid with glucose in metabolism.

Formulation and Evaluation of Throat Paint of Erythromycin Estolate

The research work was aimed at developing and optimizing erythromycin estolate throat paint solution for improved bioavailability in the oral delivery of based throat paint is prepared by unique method. Potassium iodide, glycerol has been selected based on mouth paint, mucoadhesive strength, and the drug the medication with the goal of treating wooping cough. Erythromycin estolateis released in vitro. A 32factorial prototype was used to preparation the throat paint at concentration of potassium iodide and glycerol was used as an independent variable released in vitro and permeated by percentage.For throat paint, the percentage of mucoadhesion, product consistency,releaseof drugs in vitro, and percentage of rest from permeation were calculated. With mucoadhesive strength, percentage permeation and in-vitro drug releaseperformance, formula f9 has been optimized. Studies of FTIR and have characterised throat paint. Study of stability revealed stable formulation was found.

Optimization of Bi2O3/TS-1 preparation and photocatalytic reaction conditions for low concentration Erythromycin wastewater treatment based on artificial neural network

At present, it is a challenge to degrade antibiotics of low concentrations in wastewater environment, highly effective and eco-friendly photocatalytic processes were considered promising technologies for this degradation. In this work, Bi2O3-loaded titanium silicalite-1 molecular sieve (Bi2O3/TS-1) composites were prepared and used to degrade low-concentration erythromycin (ERM) in wastewater. The content of active components and the dose of photocatalyst are key operating parameters with major effects on photocatalytic efficiency. The optimal parameters (Bi content and photocatalyst dose) were determined through artificial neural network simulating the relationship between key operating parameters and removal efficiency (RE). The maximum RE (98.02%) was measured under optimal operating parameters (Bi % = 5.5%, catalyst dosage = 0.6 g/L). The effects of water quality parameters (such as pH and ERM concentration) were also studied under optimal experimental conditions. Artificial intelligence was used in this work to achieve optimal control of catalyst preparation and photocatalytic reaction conditions. This study provides a useful strategy for the preparation of nanocatalysts and the practical application of high-efficiency photocatalytic reactions.

Dissemination of antibiotic resistance under antibiotics pressure during anaerobic co-digestion of food waste and sludge: Insights of driving factors, genetic expression, and regulation mechanism

This study revealed the effects and regulation mechanisms on antibiotic resistance genes (ARGs) dissemination during anaerobic co-digestion (AcoD) of food waste and sludge under the exposure of tetracycline, sulfamethoxazole (SMZ) and erythromycin (ERY). Results indicated antibiotics significantly increased the abundance of ARGs, and selectively enriched integron gene, suggesting antibiotics promoted the dissemination of ARGs. Procrustes analysis indicated that bacterial community, integrons and physicochemical properties displayed significant correlations with ARGs, and they respectively contributed 10.61%, 6.94% and 2.97% of explanations on ARGs variation. Especially, the maximum combined contribution (48.6%) of bacterial community and integrons, implying their significances on ARGs alteration. Metatranscriptomic analysis further demonstrated antibiotics upregulated the expressions of total ARGs and virulence factors, raising potential risks. The proposed mechanisms for ARGs dissemination facilitated by antibiotics might be attributed to the changes of ARGs-regulated functions for inducing DNA/cell damage and DNA conjugation during AcoD.

Erythromycin reduces nasal inflammation by inhibiting immunoglobulin production, attenuating mucus secretion, and modulating cytokine expression

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) share some similar pathological mechanisms. In current study, we intend to investigate the impact of AR on CRS. In addition, we explored the efficacy of erythromycin (EM) treatment on CRS mice with or without AR (CRSwoAR, CRSwAR). Study subjects were divided into control, CRSwoAR, and CRSwAR groups. Experimental mice were divided similarly into control, CRSwoAR, and CRSwAR groups. In addition, CRS mice were treated with EM at 0.75, 7.5, or 75 mg/kg or with dexamethasone (Dex) at 1 mg/kg. In our results, allergy exacerbates inflammation that was evident in nasal histology and cytokine expression both in patients and in mice with CRS. Dex 1 mg/kg, EM 7.5 or 75 mg/kg treatments significantly inhibited serum IgE and IgG2a in CRS mice. EM-treated CRS mice had significantly elevated IL-10 levels and had a reversal of Th-1/Th-2 cytokine expression in nasal-associated lymphoid tissue. MUC5AC expressions were significantly reduced in the 7.5 or 75 mg/kg EM-treated mice compared with untreated mice. EM showed inhibitions on immunoglobulin production and mucus secretion stronger than Dex. We concluded that comorbid AR enhanced inflammation of CRS. EM and Dex treatments showed similar anti-inflammatory effects on CRS but through partly different mechanisms.

Waterborne Isolates of Campylobacter jejuni Are Able to Develop Aerotolerance, Survive Exposure to Low Temperature, and Interact With Acanthamoeba polyphaga.

Campylobacter jejuni is regarded as the leading cause of bacterial gastroenteritis around the world. Even though it is generally considered to be a sensitive microaerobic pathogen, it is able to survive in the environment outside of the intestinal tract of the host. This study aimed to assess the impact of selected environmental parameters on the survival of 14 C. jejuni isolates of different origins, including 12 water isolates. The isolates were tested for their antibiotic resistance, their ability to survive at low temperature (7°C), develop aerotolerance, and to interact with the potential protozoan host Acanthamoeba polyphaga. The antibiotic susceptibility was determined by standard disk diffusion according to EUCAST. Out of the 14 isolates, 8 were resistant to ciprofloxacin (CIP) and 5 to tetracycline (TET), while only one isolate was resistant to erythromycin (ERY). Five isolates were resistant to two different antibiotic classes. Tetracycline resistance was only observed in isolates isolated from wastewater and a clinical sample. Further, the isolates were tested for their survival at 7°C under both aerobic and microaerobic conditions using standard culture methods. The results showed that under microaerobic conditions, all isolates maintained their cultivability for 4 weeks without a significant decrease in the numbers of bacteria and variation between the isolates. However, significant differences were observed under aerobic conditions (AC). The incubation led to a decrease in the number of cultivable cells, with complete loss of cultivability after 2 weeks (one water isolate), 3 weeks (7 isolates), or 4 weeks of incubation (6 isolates). Further, all isolates were studied for their ability to develop aerotolerance by repetitive subcultivation under microaerobic and subsequently AC. Surprisingly, all isolates were able to adapt and grow under AC. As the last step, 5 isolates were selected to evaluate a potential protective effect provided by A. polyphaga. The cocultivation of isolates with the amoeba resulted in the survival of about 40% of cells treated with an otherwise lethal dose of gentamicin. In summary, C. jejuni is able to adapt and survive in a potentially detrimental environment for a prolonged period of time, which emphasizes the role of the environmental transmission route in the spread of campylobacteriosis.

Antibiotic resistance of Aeromonas spp. isolated from diseased walking catfish (Clarias sp.)

Abstract. Mulia DS, Isnansetyo A, Pratiwi R, Asmara W. 2021. Antibiotic resistance of Aeromonas spp. isolated from diseased walking catfish (Clarias sp.). Biodiversitas 22: 4839-4846. Aeromonas spp. is known to be pathogenic to freshwater fish, including catfish. Antibiotics are often used to overcome bacterial attacks. However, the indiscriminate use of antibiotics, especially at incorrect doses and frequencies, could result in the emergence of resistant bacteria. The presence of resistance genes is also suspected to trigger the resistance potential of Aeromonas sp. against antibiotics. The objective of this study is to characterize the resistance genes of Aeromonas spp. isolated from diseased walking catfish (Clarias sp.). Ten Aeromonas spp. were isolated from infected walking catfish cultivated in Java. The resistance genes assessed included tetA, strA-strB, and qnrA. The antibiotics tested consisted of ampicillin (AMP), erythromycin (ERY), oxytetracycline (OXT), kanamycin (KAN), enrofloxacin (ENRO), and chloramphenicol (CHL). Results showed that some Aeromonas spp. had at least one out of the three genes assessed (i.e., tetA and strA-strB) but none had the qnrA gene. Aeromonas spp. were sensitive to KAN, ENRO, and CHL but resistant to AMP, ERY, and OXT. Thus, KAN, ENRO, and CHL are effective antibiotics for treating fish infected with Aeromonas spp.

Erythromycin stimulates rather than inhibits methane production in anaerobic digestion of antibiotic fermentation dregs

Erythromycin fermentation dregs (EFD) as one kind of organic-rich biosolid was of great potential for methane production. However, the influence of residual erythromycin (ERY) on the anaerobic digestion process of EFD remains unclear. In this study, a batch test was conducted with different ERY concentrations to investigate its effects on methanogenesis. The antibiotic resistance genes and microbial community composition were analyzed to explore the potential mechanism. The results showed that more than 80% of ERY was removed after 30 days digestion. Furthermore, 100, 200 and 300 mg/L of ERY presented no significant effect on the performance of anaerobic digestion. Instead, a high concentration of ERY (500 mg/L) increased 13% rather than inhibited the methane yields. Moreover, the proliferation of the methylase gene (e.g., ermA/T) was promoted under the high pressure of ERY. The relative abundance of acetogenic bacteria (Sedimentibacter) and mixotrophic archaea (Methanosarcina) were enhanced, indicating that their syntrophic association would play the dominant role in the stimulating effects of methanogenesis.

Cross-sectional study on the drug utilization and evaluation indicator of antibiotics used in pediatric population

BackgroundThe lack of medication standards is a serious problem in paediatrics mainly because of age-related differences in organ development and physiological functions in children. Consequently, dosage measurement becomes inaccurate. For this reason, methods for evaluating and monitoring rational paediatric medications should be developed. Drug use indicators, such as those similar to the drug utilisation index (DUI) based on the Anatomical Therapeutic Chemical/Defined Daily Dose (DDD) and widely used for the assessment of appropriate dosage in adults, should be explored in terms of their applicability to children.MethodsA total of 5,538 prescriptions of antibiotics selected from a general teaching hospital were included. Drug, dose, frequency and treatment duration were obtained from each prescription. The prescription daily dose (PDD) of each antibiotic drug was calculated as the average of the daily doses. Underdose and overdose were determined in terms of the PDD/DDD ratio for each prescription. Children’s DUI (cDUI) was explored in terms of the appropriate dosage for children as follows: the meaning of children’s DDD (cDDD) and the evaluation of paediatric drug dosage.ResultsThe top five antibiotics and their utilisation rates were as follows: cefmetazole sodium injection (18.47 %), erythromycin lactobionate injection (15.07 %), amoxicillin/clavulanate potassium injection (10.72 %), ceftriaxone sodium injection (9.50 %) and azithromycin dry suspension (8.02 %). The ratio of cDUI and PDD/cDDD was mostly not close to 1.ConclusionsThe establishment of a cDUI system is an effective means of paediatric dosage evaluation. In addition to DDDs, cDUI and PDD/cDDD should be used to analyse the utilisation of antibiotics in children.

How anammox process resists the multi-antibiotic stress: Resistance gene accumulation and microbial community evolution

The effects of multiple antibiotics on the anaerobic ammonia oxidation (anammox) process were investigated. The resistance of the anammox system to high-concentration antibiotics was also demonstrated through gradual acclimation experiments. Inhibition of the anammox process (R1) occurred when the concentrations of erythromycin (ERY), sulfamethoxazole (SMX) and tetracycline (TC) were 0.1, 5.0 and 0.1 mg L−1, respectively. The nitrogen removal efficiency (NRE) of R1 was reduced from 97.2% to 60.7% within 12 days and then recovered to 88.9 ± 9.5% when the nitrogen loading declined from 4.52 ± 0.69 to 2.11 ± 0.58 kg N m−3 d−1. Even when the concentrations of ERY, SMX and TC were as high as 1.0, 15.0 and 1.0 mg L−1, respectively, R1 maintained stable operation. The increases in the abundance of antibiotic resistance genes (ARGs) and in extracellular polymeric substances (EPS) content showed that the anammox process alleviated stress from multiple antibiotics mainly by producing ARGs and secreting EPS. The molecular docking simulation results illustrated the potential binding sites between ammonium transporter and different antibiotics. The upregulation of functional gene expression and the stable abundance of Candidatus Kuenenia in R1 compared with that in the control suggested that the R1 reactor generally maintained more stable long-term operation. This work provides a new understanding of the application of the anammox process to treat wastewater containing multiple antibiotics.

EVALUATION OF THE IN VITRO ACTIVITY OF CEFTAROLINE AND COMPARATORS AGAINST STREPTOCOCCUS PNEUMONIAE ISOLATES FROM THE UNITED STATES: RESULTS FROM 10 YEARS OF THE AWARE SURVEILLANCE PROGRAM (2011-2020)

TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: Ceftaroline (CPT) is a broad-spectrum cephalosporin with activity against S. pneumoniae (SPN), including ceftriaxone-resistant and multidrug-resistant (MDR) strains. CPT fosamil is approved for clinical use in the United States (US) to treat community-acquired bacterial pneumonia (CABP). We evaluated trends in SPN antimicrobial susceptibility in US hospitals during 2011-2020. METHODS: 7,901 isolates were consecutively collected (1 per patient) from 28 medical centers and tested for susceptibility to CPT and comparator agents using CLSI broth microdilution methods. Resistant subgroups included isolates that were nonsusceptible (NS) to penicillin (PEN), ceftriaxone (CRO), amoxicillin-clavulanate (AMX-CLA), erythromycin (ERY), clindamycin (CLI), tetracycline (TET), and levofloxacin (LEV) as well as MDR (NS to ≥3 classes of agents) and extensively drug resistant (XDR; NS to ≥5 classes). Selected isolates were serotyped. RESULTS: CPT inhibited 99.99% of SPN isolates at ≤0.5 mg/L (only 1 isolate had a CPT MIC of 1 mg/L) and remained active against all SPN-resistant subgroups, including AMX-CLA-NS (8.9% at ≥4 mg/L), PEN-NS (6.2% at ≥4 mg/L), and CRO-NS (5.1% at ≥2 mg/L). CPT activity remained stable against all R subgroups each year. In general, susceptibility to PEN, CRO, AMX-CLA, CLI, trimethoprim-sulfamethoxazole, and tetracycline (TET) increased from 2011 to 2015 and remained relatively stable from 2016 to 2020. Similarly, MDR and XDR rates decreased from 2011 to 2015 and remained stable in 2016-2020. Susceptibility to ERY oscillated from 52.2% (2014) to 56.4% (2011) and LEV was very active during the study period (98.9-100.0%S). MDR rates varied from 23.7% in 2011 to 16.2% in 2020 (19.7% overall), and XDR rates varied from 13.3% in 2011 to 1.8% in 2019 (6.1% overall). Against MDR isolates (n=1,555), CPT (MIC50/90, 0.06/0.25 mg/L; 99.9%S), LEV (MIC50/90, 1/1 mg/L 98.1%S), linezolid (LZD; MIC50/90, 1/1 mg/L; 100.0%S), and vancomycin (VAN; MIC50/90, 0.25/0.5 mg/L, 100.0%S) were the most active agents. All XDR isolates were susceptible to CPT (MIC50/90, 0.12/0.25 mg/L), LZD (MIC50/90, 0.5/1 mg/L), and VAN (MIC50/90, 0.25/0.5 mg/L), and 97.5% were susceptible to TIG (MIC50/90, ≤0.03/0.06 mg/L). The CPT-NS isolate was isolated in 2014 and had multiple substitutions in the penicillin binding proteins (PBP), mainly PBP2x, when compared with reference sequences. The CPT-NS isolate also showed 31 amino acid alterations in MurM. CONCLUSIONS: CPT demonstrated potent and consistent (2010-2020) activity against SPN, including several resistant phenotypes and the less susceptible serotypes. SPN susceptibility to many antibiotics increased from 2011 to 2015 but remained stable in 2016-2020. CLINICAL IMPLICATIONS: Increases in susceptibility rates could be related to the anti-pneumococcal vaccine PVC-13 introduced in 2010. Continued surveillance is crucial since resistance clones not covered by the vaccine may expand. DISCLOSURES: my employer received research support relationship with AbbVie Please note: 2020-2022 Added 04/20/2021 by Cecilia Carvalhaes, source=Web Response, value=Grant/Research Support No relevant relationships by Mariana Castanheira, source=Web Response no disclosure on file for Rodrigo Mendes;Research Contractor relationship with Allergan Please note: $1001 - $5000 by Helio Sader, source=Web Response, value=Grant/Research Support Research Contractor relationship with AbbVIe (formerly Allergan) Please note: Ongoing Added 04/15/2021 by Helio Sader, source=Web Response, value=Grant/Research Supportemployer received grant/research support relationship with Allergan/ Abbvie Please note: 2020-2022 Added 04/20/2021 by Dee Shortridge, source=Web Response, value=Grant/Research Support No relevant relationships by Streit Streit, source=Web Response

The effects of the antibiotic erythromycin on Oryzias javanicus in gender perspective

Erythromycin (ERY) is an antibiotic that is widely prescribed in human and veterinary medicine to treat several bacterial infections. This antibiotic was reported to have various effects on aquatic environments. This study aimed to evaluate whether there is a difference in sensitivity to ERY between male and female Oryzias javanicus. The experimental fish were exposed to ERY (2 mg/L) for 96 hours. In this experiment, each experimental unit used five fish with five replications. Male and female animals were kept in different containers during the experiment The parameters measured were oxygen consumption and survival rate. The oxygen consumption of male and female of O. javanicus before the experiment began showed a statistically significant difference (p <0.05). The average oxygen consumption of female O. javanicus was 0.752 mgO2/g body weight/hour, while the average oxygen consumption of males was 0.474 mgO2/g body weight/hour. After exposure to ERY, the oxygen consumption of male O. javanicus was reduced to 0.353 mgO2/g body weight/hour. In contrast, there was 100% mortality of the female O. javanicus by the end of the experiment. After exposure to ERY, the percent mortality of male and female O. javanicus were statistically no different (p <0.05). Males were not more resistant to ERY than females. This study concluded that there was no difference in sensitivity to ERY between male and female O. javanicus.

Genotypic and phenotypic characteristics of Streptococcus pneumoniae from community-acquired pneumonia patients and healthy asymptomatic participants in Sichuan province, China

BackgroundStreptococcus pneumoniae (S. pneumoniae) is the common cause of community-acquired pneumonia (CAP) and is also found in the upper respiratory tract of healthy people. Hence, the study aimed to compare the serotypes, virulence/pili genes, and antibiotic susceptibility of S. pneumoniae from healthy asymptomatic participants and CAP patients.MethodsStreptococcus pneumoniae were retrospectively collected from health asymptomatic participants and CAP patients in Sichuan, China. The serotypes were tested by multiplex polymerase chain reaction (PCR) or Quellung reaction. Antibiotic susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S. pneumoniae was analyzed by multilocus sequence typing (MLST). Additionally, the presence of virulence/pili genes were detected using PCR.ResultsA total of 83 pneumococcal isolates were collected in the current study. Of these, 52 and 31 isolates were from healthy asymptomatic participants and CAP patients, respectively. Most of S. pneumoniae were resistant to erythromycin (ERY), clindamycin (CLI), tetracycline (TET) and trimethoprim-sulfamethoxazole (SXT). 90.4% isolates were classified as multidrug resistant (MDR). The predominant serotypes were 3, 19F and 19A in the CAP carriers, whereas 3, 6 and 19F were the main serotypes among the asymptomatic carriers. The overall coverage rates of pneumococcal conjugate vaccine (PCV) 10 and PCV13 serotypes were 34.9% and 66.3%, respectively. The predominant sequence types (STs) were ST271, ST320, and ST3397. There were significant differences in some resistance and virulence characteristics between CAP patients and asymptomatic carriers. Additionally, clonal complex (CC) 271 strains had higher percentage in resistance to cefuroxime (CXM) and cefotaxime (CEF), meropenem (MER) and cefepime (CFP), which mainly carried the rlrA and sipA genes.ConclusionsHigh coverage rate of PCV13 and high prevalence of MDR indicated the necessity to expand immunization with PCV13 and rationally use the antibiotics in Sichuan, China. Importantly, long-term surveillance should be conducted to assess effectiveness brought by vaccines. Our findings may supply new guidance for developing new pneumococcal vaccines.

Enhancing the hydrophilicity and biofoulant removal ability of a PVDF ultrafiltration membrane via π-π interactions as measured by AFM

Antibiotics are commonly used as inhibitors to terminate protein formation in the biotechnology and pharmaceutical industries; however, due to the large difference in molecular weight between antibiotics and proteins, it is hard to remove them simultaneously through ultrafiltration or nanofiltration. In this work, a novel membrane with nanoscale pores and anti-protein adsorption was developed to reject antibiotics and reduce protein adhesion. Amphiphiles consisting of hydrophobic and hydrophilic moieties were synthesized from a poly(styrene-alt-maleic anhydride) (SMA) copolymer with a 2-hydroxyethyl acrylate (HEA) monomer to enhance the hydrophilicity of polyvinylidene difluoride (PVDF) membranes. A series of SMAs with different polystyrene molar ratios (maleic acid/styrene (m/s) = 1:1, 1:2 and 1:3) was synthesized in this study, and the bonding force between the amphiphiles and PVDF, namely, π-π interactions between styrene molecules and the C–F bonds of PVDF, was evaluated. The π-π interaction between the amphiphiles and the PVDF membrane was determined via atomic force microscopy (AFM) repulsive force measurements for the first time in this work. The repulsive force increased significantly from -5.9 ± 1.0 nN to −18.3 ± 0.8 nN as the m/s ratio increased to 1:3, indicating that the π-π interaction was enhanced as the proportion of polystyrene in the SMA-HEA copolymer increased, resulting in tight attachment. Furthermore, the amphiphile-modified membrane demonstrated better hydrophilicity than the pristine PVDF membrane, and the water contact angle (WCA) decreased considerably from 104° (PVDF) to 55° (m/s = 1:2, P2000-600). The pure water flux recovery rate of P2000-600 improved by approximately 10%, and antibiotic rejections of 92.8%, 99.9% and 97.1% for tetracycline (TC), chloramphenicol (CL) and erythromycin (EM), respectively, were observed during the 7-h filtration process, indicating that P2000-600 can effectively remove antibiotics from water. In addition, P2000-600 also displayed good restriction of bovine serum albumin (BSA) adsorption at 28.4 ± 8.1 μg/cm2 under static adsorption processes and BSA rejection of nearly 90% during the three-cycle filtration.

Assessment of toxicity and kinetic effects of erythromycin on activated sludge consortium by fast respirometry method

Background: The present study aimed to assess the acute impact of erythromycin (ERY) as an inhibitor on peptone mixture utilization of activated sludge (AS) consortium. Methods: For this purpose, the inhibition of oxygen consumption was used based on the ISO 8192:2007 procedure. In this method, the AS consortium (10-day age) was extracted from lab-scale membrane bioreactor, then, percentage inhibition for total, heterotrophic, and nitrifying microorganisms, in separate batch respirometric tests were calculated in the absence and presence of N-allylthiourea (ATU) as a specific Nitrification inhibitor. Results: The obtained data showed that the height of oxygen uptake rate (OUR) profiles and amount of oxygen consumption reduced with increasing ERY dose. The half-maximal effective concentration (EC50) of ERY for heterotrophic and nitrifier microorganisms were 269.4 and 1243.1 mg/L, respectively. In Run 1, the kinetic coefficients bH, fA,H, YH, and µH were calculated as 2.61 d-1, 0.44, 0.4945 mg VSS/mg COD, and 0.047 d-1, respectively. Also, for maximum ERY concentration (1000 mg/L), the kinetic coefficients bH., fA,H, YH, and µH were calculated as 2.27 d-1, 0.3, 0.4983 mg VSS/mg COD, and 0.0049 d-1, respectively. Conclusion: The findings showed that the inhibitory impact of ERY was observed as a decrease in the amount of oxygen consumption by OUR profiles in rapid respirometric method (ISO 8192), which offered a novel insight for the acute inhibitory impact of this antibiotic. Also, chemical oxygen demand (COD) as an overall substrate parameter is most helpful in interpreting the behavior and the metabolic functions of AS systems.

Evaluating the effect of microalga Haematococcus pluvialis bioaugmentation on aerobic membrane bioreactor in terms of performance, membrane fouling and microbial community structure

In this study, considering the enhancement potential of microalgae and MBRs for wastewater treatment, the microalgae Haematococcus pluvialis, which is a freshwater species of Chlorophyta with a high capacity to synthesize astaxanthin, was bioaugmented into an aerobic MBR to investigate its potential on treatment of antibiotics in wastewater, reducing membrane biofouling, and impact on the microbial community structure. For this purpose, two control MBRs, with and without antibiotics, alongside an MBR bioaugmented with H. pluvialis, were set under mesophilic conditions, using inoculum from a local wastewater treatment facility and synthetic wastewater. The common antibiotics sulfamethoxazole (SMX), tetracycline (TET) and erythromycin (ERY) were selected to investigate removal efficiencies by Haematococcus pluvialis in an MBR for this study. In the bioaugmented reactor, membrane biofouling was delayed by 33% and chemical oxygen demand removal increased by 6%. The highest removal of antibiotics was observed for TET with a 20% enhancement from 69.75% (C2) to 89.73% (HP). The results also suggested that H. pluvialis reconstructed indigenous and biofilm microbial communities in MBR. The biodegradation network was modified and the relative abundance of Proteobacteria increased, while Firmicutes and Bacteroidetes were significantly reduced.