The First Report on Pharmacokinetic/Pharmacodynamic Study of Trimethoprim/Sulfamethoxazole against Staphylococcus aureus with a Neutropenic Murine Thigh Infection Model

Chemotherapy ◽  
2019 ◽  
Vol 64 (5-6) ◽  
pp. 224-232
Author(s):  
Mao Hagihara ◽  
Hideo Kato ◽  
Shinya Uchida ◽  
Rieko Yamashita ◽  
Shimako Tanaka ◽  
...  

Introduction: With an increase in the incidence of Staphylococcus aureus infections in the healthcare settings and in the community, trimethoprim/sulfamethoxazole (TMP/SMX) has been suggested as a convenient treatment option. However, the appropriate dosage regimen of TMP/SMX is unclear. Objective: This study aimed to examine the pharmacokinetics/pharmacodynamics (PK/PD) of TMP/SMX against S. aureus using a neutropenic murine thigh infection model. Methods: Five S. aureus isolates with TMP/SMX (1:5 fixed ratio) minimum inhibitory concentrations (MICs) of 0.032–64 μg/mL were tested. The antimicrobial efficacy of TMP/SMX (1–689 mg/kg/day: dose shown as SMX dosage) was calculated as the change in bacterial density after 24 h of treatment. The plasma concentrations of TMP/SMX were detected using high-performance liquid chromatography. Results: After TMP/SMX single dose (130 mg/kg), the half-life, area under the blood concentration curve (AUC0–∞), and the protein binding ratio of SMX were 1.5 h, 718.2 μg h/mL, and 73.0 ± 8.3%, respectively. The free AUC/MIC and free %time (%T) above the MIC of SMX were better correlated with the in vivo antimicrobial activity than Cmax/MIC (free AUC/MIC, R2 = 0.69; free %T > MIC, R2 = 0.71; free Cmax/MIC, R2 = 0.53). The distributed doses (2–3 times per day) of TMP/SMX (130, 260, and 390 mg/kg/day) showed higher antimicrobial activity than the single dosage. However, TMP/SMX did not show its antimicrobial activity at <100% free %T > MIC. Conclusions: The TMP/SMX treatment demonstrated that the free AUC/MIC of SMX was the better predictor of the PK/PD index of TMP/SMX.

2019 ◽  
Vol 70 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Gergely Sámuel Bartha ◽  
Gergő Tóth ◽  
Péter Horváth ◽  
Eszter Kiss ◽  
Nóra Papp ◽  
...  

Introduction Several Aristolochia species were used as medicinal herb across Europe and in recent years, their antimicrobial activity has also been investigated. Materials and methods In this study, A. clematitis was selected to evaluate the aristolochic acids I and II (AA I and AA II) concentrations and the antimicrobial activity of methanol, hexane, butanol, and ethyl acetate extracts of the root, stem, leaf, root, and fruit. AA I and AA II contents were measured by a validated high-performance liquid chromatography–ultraviolet method. Results Each fraction of the plant contained AA I and AA II and the root was found to have the highest contents of AA I (1.09%) and AA II (0.7454%). The minimum inhibitory concentrations of all extracts were determined by standard microdilution method. The fruit’s extracts showed the most efficient antimicrobial effect against both methicillin sensitive and resistant Staphylococcus aureus strains. Conclusion Correlation between the AA I and AA II concentrations and the antimicrobial effect was not found.


2019 ◽  
Vol 39 (12) ◽  
pp. 954-960
Author(s):  
Heidy C. Dos Santos ◽  
Dielson S. Vieira ◽  
Sandra M. Yamamoto ◽  
Mateus M. Costa ◽  
Maria C.A. Sá ◽  
...  

ABSTRACT: The indiscriminate use of antibiotics in the treatment of caprine mastitis causes the appearance of resistant microorganisms, besides leaving residues in milk, putting at risk to human health. In this way, propolis is an alternative in the treatment of diseases because it has antimicrobial activity, mainly because of the presence of flavonoids in its composition. The aim of this study was to evaluate the antimicrobial potential of propolis to Staphylococcus spp. Isolated from cases of goat mastitis and qualify the crude ethanoic extract by high performance liquid chromatography (HPLC). In this study, the minimum bactericidal concentration values of propolis extracts in ethanol, ethyl acetate and hexane showed that the best concentrations capable of promoting the highest mortality of the isolates of Staphylococcus spp. from mastitis in goats, were 6250, 3125 and 1562.5μg/mL, respectively. By the microplate adherence test, it was found that 20.78% isolates were not able to form biofilm, 14.70% were classified as moderate and 64.70% were weak and none as a strong biofilm producer. Propolis in its different diluents was able to affect the formation of biofilm and showed a pronounced marked antimicrobial activity against Staphylococcus spp. strains and may be indicated for use in in vivo studies.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2319
Author(s):  
Klara Lalouckova ◽  
Lucie Mala ◽  
Petr Marsik ◽  
Eva Skrivanova

Ultra-high performance liquid chromatography/mass spectrometry showed soyasaponin I and the isoflavones daidzein, genistein, and glycitein to be the main components of the methanolic extract of the Korean soybean fermented product doenjang, which is known to be a rich source of naturally occurring bioactive substances, at average contents of 515.40, 236.30, 131.23, and 29.00 ng/mg, respectively. The antimicrobial activity of the methanolic extract of doenjang against nine Staphylococcusaureus strains was determined in vitro by the broth microdilution method to investigate its potential to serve as an alternative antibacterial compound. The results suggest that the extract is an effective antistaphylococcal agent at concentrations of 2048–4096 µg/mL. Moreover, the tested extract also showed the ability to inhibit the growth of both methicillin-sensitive and methicillin-resistant animal and clinical S. aureus isolates. The growth kinetics of the chosen strains of S. aureus at the minimum inhibitory concentration of the methanolic extract of doenjang support the idea that the tested extract acts as an antibacterial compound. To the best of our knowledge, this is the first report on the antistaphylococcal action of the methanolic extract of doenjang thus, additional studies including in vivo testing are necessary to confirm this hypothesis.


Author(s):  
C.A. Moran ◽  
J. Apajalahti ◽  
A. Yiannikouris ◽  
S. Ojanperä ◽  
H. Kettunen

SummaryA pilot study was conducted to evaluate the suitability of hepatic aflatoxin (AFB1) concentration as a biomarker to assess the in vivo efficacy of a mycotoxin binder in poultry when AFB1 dietary concentrations are low. Diets containing low doses of AFB1 without or with Mycosorb® (MTB), a mycotoxin binder, were fed to broilers from 7 to 21 days of age. The accumulation of AFB1 in liver was measured by high performance liquid chromatography with a detection limit of 5 ng/kg liver. In response to 10 and 50 µg AFB1/kg feed, hepatic AFB1 accumulation was 27 and 145 ng AFB1/kg liver, respectively. At each dietary concentration of AFB1, the inclusion of 5 g MTB/kg of feed reduced (P < 0.1 for 10 μg AFB1/kg feed and P < 0.05 for 50 μg AFB1/kg feed) hepatic AFB1 accumulation by at least 50%. These results suggest that hepatic AFB1 concentration is a suitable biomarker for evaluating mycotoxin binder efficacy in poultry fed the EU maximum dietary concentration of 10 µg of AFB1/kg feed.


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