Combined toxicity of spiramycin and amoxicillin was tested in Microcystis aeruginosa. The respective 50% effective concentrations (EC50mix) expressed in toxic unit (TU) values were 1.25 and 1.83 for spiramycin and amoxicillin mixed at 1:7 and 1:1, suggesting an antagonistic interaction at the median effect level. Deviations from the prediction of concentration addition (CA) and independent action (IA) models further indicated that combined toxicity of two antibiotics mixed at 1:1 varied from synergism to antagonism with increasing test concentration. Both the EC50mix of 0.86 (in TU value) and the deviation from two models manifested a synergistic interaction between spiramycin and amoxicillin mixed at 7:1. At an environmentally relevant concentration of 800ngL(-1), combined effect of mixed antibiotics on algal growth changed from stimulation to inhibition with the increasing proportion of higher toxic component (spiramycin). Chlorophyll-a content and expression levels of psbA, psaB, and rbcL varied in a similar manner as growth rate, suggesting a correlation between algal growth and photosynthesis under exposure to mixed antibiotics. The stimulation of microcystin-production by mixed antibiotics was related with the elevated expression of mcyB. The mixture of two target antibiotics with low proportion of spiramycin (<50%) could increase the harm of M. aeruginosa to aquatic environments by stimulating algal growth and production and release of microcystin-LR at their current contamination levels.
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http://dx.doi.org/10.1016/j.jhazmat.2014.07.002 | DOI Listing |
Prev Vet Med
December 2024
Veterinary Epidemiology Unit, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium. Electronic address:
Animals (Basel)
September 2023
Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, 80137 Naples, Italy.
ACS Omega
April 2023
Istanbul Aydin University, Application and Research Center for Advanced Studies, Sefakoy, Kucukcekmece, Istanbul 34295, Turkey.
Recent studies have shown that plastic particles can sorb antibiotics, and these sorption properties have been examined in various studies; however, the possible mechanism responsible for the interactions requires a deeper investigation in terms of further interaction with living systems. Moreover, the usage of disposable surgical masks and plastic bottles has increased the plastic pollution risk for living systems like humans. Therefore, this study aimed to examine the sorption characteristics between antibiotics (amoxicillin and spiramycin) and plastic particles from surgical masks and plastic bottles through batch sorption experiments.
View Article and Find Full Text PDFMicrob Genom
January 2023
Institut Pasteur, Université Paris Cité, Biodiversity and Epidemiology of Bacterial Pathogens, Paris, France.
Antimicrobial therapy is important for case management of diphtheria, but knowledge on the emergence of multidrug-resistance in is scarce. We report on the genomic features of two multidrug-resistant toxigenic isolates sampled from wounds in France 3 years apart. Both isolates were resistant to spiramycin, clindamycin, tetracycline, kanamycin and trimethoprim-sulfamethoxazole.
View Article and Find Full Text PDFJ Clin Exp Dent
October 2022
Biomedical Stomatology Research Group, Universidad de Antioquia U de A, Medellín, Colombia.
Background: Patients with odontogenic infections are commonly prescribed antimicrobials on an experiential base without knowing the precise microorganisms implicated. The aim of this systematic scoping review is to evaluate the prevalence and proportions of antimicrobial-resistant species in patients with odontogenic infections.
Material And Methods: A systematic scoping review of scientific evidence was accomplished involving different databases.
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