scholarly journals In vitro postantibiotic effects following multiple exposures of cefotaxime, ciprofloxacin, and gentamicin against Escherichia coli in pooled human cerebrospinal fluid and Mueller-Hinton broth.

1993 ◽  
Vol 37 (5) ◽  
pp. 1154-1157 ◽  
Author(s):  
J A Karlowsky ◽  
G G Zhanel ◽  
R J Davidson ◽  
S R Zieroth ◽  
D J Hoban
Keyword(s):  
Escherichia Coli ◽  
Cerebrospinal Fluid ◽  
Multiple Exposures ◽  
Human Cerebrospinal Fluid ◽  
Mueller Hinton ◽  
Mueller Hinton Broth

In vitro Time Kill of Trimethoprim/Sulfamethoxazole against Stenotrophomonas maltophilia versus Escherichia coli using Cation Adjusted Muller Hinton Broth and ISO-Sensitest Broth

2022 ◽  
Author(s):  
Maxwell J. Lasko ◽  
Matthew L. Gethers ◽  
Jennifer L. Tabor-Rennie ◽  
David P. Nicolau ◽  
Joseph L. Kuti
Keyword(s):  
Escherichia Coli ◽  
Stenotrophomonas Maltophilia ◽  
E Coli ◽  
Optimal Dosing ◽  
Mueller Hinton ◽  
Colony Forming Units ◽  
Time Kill ◽  
Pharmacodynamic Data ◽  
Mueller Hinton Broth

Trimethoprim/sulfamethoxazole (TMP/SMZ) is considered the treatment of choice for infections caused by Stenotrophomonas maltophilia , but limited pharmacodynamic data are available to support current susceptibility breakpoints or guide optimal dosing. Time-kill studies using a TMP/SMZ concentration of 4/40 μg/mL were conducted to compare 4 S. maltophilia with 4 Escherichia coli having the same MICs (0.25/4.75-4/76 μg/mL) in cation adjusted Mueller Hinton Broth (CAMHB) and ISO-Sensitest™ broth (ISO). With the exception of the resistant isolates (4/76 μg/mL), which resulted in regrowth approaching control, TMP/SMZ displayed significantly greater killing for E. coli compared with S. maltophilia at each MIC. Against E. coli , mean changes at 24 hour were -4.49, -1.73, -1.59, and +1.83 log 10 colony forming units (CFU) for isolates with MICs of 0.25/4.75, 1/19, 2/39, and 4/74 μg/mL, respectively. The f AUC/MIC required for stasis, 1-log 10 , and 2-log 10 CFU reductions were 40.7, 59.5, and 86.3, respectively. In contrast, TMP/SMZ displayed no stasis or CFU reductions against any S. maltophilia regardless of MIC, and no pharmacodynamic thresholds were quantifiable. Observations were consistent in both CAMHB and ISO broth. These data add increasing evidence that current TMP/SMZ susceptibility breakpoints against S. maltophilia should be reassessed.

scholarly journals In Vitro Activities of Daptomycin against 2,789 Clinical Isolates from 11 North American Medical Centers

2001 ◽  
Vol 45 (6) ◽  
pp. 1919-1922 ◽  
Author(s):  
Arthur L. Barry ◽  
Peter C. Fuchs ◽  
Steven D. Brown
Keyword(s):  
Clinical Isolates ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Medical Centers ◽  
Mueller Hinton ◽  
Calcium Cations ◽  
Important Exception ◽  
Mueller Hinton Broth

ABSTRACT The in vitro activity of daptomycin is affected by the concentration of calcium cations in the test medium. Mueller-Hinton broth is currently adjusted to contain 10 to 12.5 mg of magnesium per liter and 20 to 25 mg of calcium per liter, but for testing of daptomycin, greater concentrations of calcium (50 mg/liter) are recommended to better resemble the normal concentration of ionized calcium in human serum. Two levels of calcium were used for broth microdilution tests of 2,789 recent clinical isolates of gram-positive bacterial pathogens. MICs of daptomycin were two- to fourfold lower when the broth contained additional calcium. For most species, however, the percentages of strains that were inhibited by 2.0 μg of daptomycin per ml were essentially identical with the two broth media. Enterococci were the important exception; i.e., 92% were inhibited when tested in calcium-supplemented broth but only 35% were inhibited by 2.0 μg/ml without the additional calcium. This type of information should be considered when selecting criteria for defining in vitro susceptibility to daptomycin.

Effect of Ethanol/Trisodium Citrate Lock on Microorganisms Causing Hemodialysis Catheter-Related Infections

2007 ◽  
Vol 8 (4) ◽  
pp. 262-267 ◽  
Author(s):  
T.A. Takla ◽  
S.A. Zelenitsky ◽  
L.M. Vercaigne
Keyword(s):  
In Vitro Study ◽  
Trisodium Citrate ◽  
Methicillin Resistant ◽  
Hemodialysis Catheter ◽  
E Coli ◽  
Lock Solution ◽  
Mueller Hinton ◽  
Mueller Hinton Broth ◽  
Made In

Purpose This in vitro study tested the effectiveness of a novel 30% ethanol/4% trisodium citrate (TSC) lock solution against the most common pathogens causing hemodialysis catheter-related infections. Methods Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillin-sensitive S. aureus (MSSA) (n=8), methicillin-resistant Staphylococcus epidermidis (MRSE) (n=8), Pseudomonas aeruginosa (n=4) and Escherichia coli (n=4) were tested in duplicate. Bacterial suspensions of each isolate were made in a control solution of normal saline and Mueller-Hinton broth (MHB), and in a lock solution of ethanol 30%, TSC 4% and MHB. Suspensions were incubated at 37 °C for 48 h. Colony counts were determined from samples collected at t=0 h (before exposure to the ethanol/TSC lock), t=1 h (one hour after exposure to the ethanol/TSC lock), t=24 h and t=48 h. To confirm the absence of viable organisms in the lock solution, the remaining volume at 48 h was filtered through a 0.45 μm filter. The filter was rinsed with 15 mL sterile water and plated on tryptic soy agar (TSA). Results All controls demonstrated significant growth over 48 h. In the lock solutions, initial inocula were reduced to 0 viable colonies by t=1 h (6-log kill), and there was no growth at t=24 and 48 h. Filtering of lock solutions also showed no growth. These results were consistent among duplicates of all isolates. Conclusions The 30% ethanol/4% TSC lock solution consistently eradicated MRSA, MSSA, MRSE, P. aeruginosa and E. coli within 1 h of exposure. Experiments are currently underway to test this novel lock solution on preventing biofilm production by these pathogens.

scholarly journals Efeito antimicrobiano do extrato de Cranberry sobre micro-organismos causadores de infecção urinária

2016 ◽  
Vol 11 (31) ◽  
pp. 113-122
Author(s):  
Carla Franco Porto Belmont Souza ◽  
Luiz Eduardo Souza da Silva Irineu ◽  
Renan Silva De Souza ◽  
Renato da Silva Teixeira ◽  
Ivina Sanches Pereira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Proteus Mirabilis ◽  
Enterococcus Faecium ◽  
Vaccinium Macrocarpon ◽  
Mueller Hinton

A resistência microbiana tem se mostrado um problema de proporções mundiais, causando estado de morbidade e mortalidade em diversos pacientes. Em vista disso, tem crescido a busca por métodos alternativos naturais de profilaxia. A investigação clínica sugere que o Extrato de Cranberry está entre as melhores propostas de prevenção natural. O Cranberry (Vaccinium macrocarpon) é um fruto que tem crescido comercialmente pelo sabor e propriedades benéficas à saúde. Dentre as formas comercializadas estão: o suco, o chá e as cápsulas contendo o extrato seco. A ação desta planta está relacionada ao tratamento de doenças do trato urinário, por possuir substâncias que inibem a adesão bacteriana ao epitélio do trato urinário, dificultando sua proliferação e reprodução. Dentre todas as infecções relacionadas à assistência a saúde, a Infecção do Trato Urinário é a mais frequentemente associada a procedimentos invasivos. Se não for tratada, pode resultar em complicações como pielonefrite aguda, bacteremia e pionefrose. Portanto, cranberry pode ser uma nova alternativa para o combate das infecções uroepiteliais, por ser um produto natural de preço acessível, e com formas de comercialização diversificada, ao contrário dos antimicrobianos convencionais, que por sua vez são caros e podem acabar causando resistência nos micro-organismos. Este trabalho teve como objetivo avaliar in vitro a atividade antimicrobiana do extrato de Cranberry, adquirido em farmácia de manipulação, sobre 8 micro-organismos isolados de infecções urinárias. As cepas utilizadas, adquiridas da coleção da FIOCRUZ, foram: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Serratia marscecens, Staphylococcus aureus, Enterococcus faecalis e Enterococcus faecium. No estudo, foram utilizados o caldo Mueller Hinton (MH), Extrato de Cranberry e as bactérias patogênicas. O ensaio foi realizado em triplicata, com o uso de um controle de crescimento dos micro-organismos e o experimento para avaliação do crescimento bacteriano na presença do extrato. A turbidez foi medida com o auxílio de um espectrofotômetro, no comprimento de onda de 600 nm, antes e após 24 horas de incubação à 37 ºC. O procedimento forneceu a Densidade Ótica, do qual possibilitou a identificação da inibição microbiana. Para análise estatística foi utilizado o Teste t de Student. O Extrato de Cranberry apresentou atividade antimicrobiana sobre as bactérias Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Serratia marscecens e Enterococcus faecalis (p < 0,05), confirmando seu efeito benéfico em infecções urinárias. No entanto, não teve efeito inibitório significativo sobre Pseudomonas aeruginosa, Proteus mirabilis e Enterococcus faecium (p > 0,05).

scholarly journals Analysis of Paradoxical Efficacy of Carbapenems against Carbapenemase-Producing Escherichia coli in a Murine Model of Lethal Peritonitis

2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Ariane Roujansky ◽  
Victoire de Lastours ◽  
François Guérin ◽  
Françoise Chau ◽  
Geoffrey Cheminet ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Benefit ◽  
Content Type ◽  
Potential Clinical Benefit ◽  
Mueller Hinton ◽  
Zinc Depletion ◽  
Bacterial Fitness ◽  
Subinhibitory Concentrations

ABSTRACT The clinical benefit of carbapenems against carbapenemase-producing Enterobacteriaceae (CPE) remains in question. MICs of imipenem (IMP) and ertapenem (ERT) against isogenic derivatives of the wild-type strain Escherichia coli CFT073 producing KPC-3, OXA-48, or NDM-1 were 0.25, 2, 16, and 64 mg/liter for IMP and 0.008, 0.5, 8, and 64 mg/liter for ERT, respectively. Swiss ICR-strain mice with peritonitis were treated for 24 h with IMP or ERT. Despite a limited duration of time during which free antibiotic concentrations were above the MIC (down to 0% for the NDM-1-producing strain), IMP and ERT significantly reduced bacterial counts in spleen and peritoneal fluid at 24 h (P < 0.005) and prevented mortality. Several possible explanations were investigated. Addition of 4% albumin or 50% normal human serum did not modify IMP activity. Bacterial fitness of resistant strains was not altered and virulence did not decrease with resistance. In the presence of subinhibitory concentrations of ERT, growth rates of OXA-48, KPC-3, and NDM-1 strains were significantly decreased and filamentation of the NDM-1 strain was observed. The expression of blaNDM-1 was not decreased in vivo compared to in vitro. No zinc depletion was observed in infected mice compared with Mueller-Hinton broth. In conclusion, a paradoxical in vivo efficacy of IMP and ERT against highly resistant carbapenemase-producing E. coli was confirmed. Alternative mechanisms of antibacterial effects of subinhibitory concentrations of carbapenems may be involved to explain in vivo activity. These results are in agreement with a potential clinical benefit of carbapenems to treat CPE infections, despite high carbapenem MICs.

scholarly journals Antimicrobial susceptibility pattern of Corynebacterium striatum.

1996 ◽  
Vol 40 (11) ◽  
pp. 2671-2672 ◽  
Author(s):  
L Martínez-Martínez ◽  
A Pascual ◽  
K Bernard ◽  
A I Suárez
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Pattern ◽  
Beta Lactams ◽  
Antimicrobial Susceptibility Pattern ◽  
Mueller Hinton ◽  
Corynebacterium Striatum ◽  
Mueller Hinton Broth

The in vitro activities of 16 antimicrobial agents against 86 strains of Corynebacterium striatum were evaluated by microdilution using cation-adjusted Mueller-Hinton broth. MICs at which 90% of strains were inhibited were 0.06 microgram/ml for teicoplanin, 1 microgram/ml for vancomycin, 0.03 to 8 micrograms/ml for beta-lactams, 8 micrograms/ml for sparfloxacin, 16 micrograms/ml for ciprofloxacin, 16/304 micrograms/ml for co-trimoxazole (trimethoprim-sulfamethoxazole), 64 micrograms/ml for tetracycline, 128 micrograms/ml for gentamicin, and > 128 micrograms/ml for amikacin, erythromycin, and rifampin.

scholarly journals PSV-41 Antibacterial activity of ferulic acid and sodium chlorate against Escherichia coli F18 and K88 during incubations with porcine fecal bacteria

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 296-297 ◽  
Author(s):  
Claudio Arzola ◽  
Elizabeth Latham ◽  
Robin Anderson ◽  
Jaime Salinas-Chavira ◽  
Yamicela Castillo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ferulic Acid ◽  
Sodium Chlorate ◽  
Fecal Bacteria ◽  
Aerobic Incubation ◽  
E Coli ◽  
Mueller Hinton ◽  
Fecal Suspension ◽  
Porcine Feces ◽  
Mueller Hinton Broth

Abstract The influence of ferulic acid (FA) and sodium chlorate (SC) was evaluated in two trials on the growth of Escherichia coli F18 and K88 (F18 and K88) incubated with porcine fecal bacteria. Treatments were 2 levels of FA (0 and 5 mg/mL) and 2 levels of SC (0 and 10 mM/mL). In trial one, ½-strength Mueller Hinton broth mixed with porcine feces (0.5% w/v) was inoculated with a novobiocin and naladixic acid resistant F18-strain. This fecal suspension was transferred to tubes (3/treatment) and anaerobically incubated at 39 oC for enumeration at 0, 6 and 24 h using MacConkey agar supplemented with novobiocin and naladixic acid with aerobic incubation at 37 oC. An interaction (FA x SC) at 6 and 24 h was observed (P &lt; 0.01). At 6 h of incubation, SC alone or combined with FA had the lowest counts (P &lt; 0.05); FA alone was lower than control but higher than SC or SC+FA (P &lt; 0.05). At 24 h, FA alone or combined with SC had the lowest counts (P &lt; 0.05); SC was lower than control but higher than FA or SC+FA (P &lt; 0.05). In trial 2 were used the same procedures of trial 1, except that K88 was used. There was an interaction at 6 h (P &lt; 0.01) where the lowest counts were in FA+SC (P &lt; 0.05). SC alone or FA alone were lower than control but higher than SC+FA (P &lt; 0.05). There was no interaction at 24 h (P = 0.16), where FA reduced the K88 counts (P &lt; 0.01), however it was not affected by SC (P = 0.12). In conclusion, SC reduced E. coli counts; however, at 24 h of incubation greater reductions were observed when FA alone or combined with SC was added into the incubation fluid with porcine feces.

Activity of Amikacin, Gentamicin and Kanamycin against Pseudomonas Aeruginosa

1976 ◽  
Vol 4 (3) ◽  
pp. 165-175 ◽  
Author(s):  
Jose Ximenes ◽  
Orlando Natale Bassoi ◽  
Jairo Perche de Menezes ◽  
Wilson Fry
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Half Life ◽  
Intramuscular Injection ◽  
Saline Solution ◽  
Serum Levels ◽  
Post Dose ◽  
Mueller Hinton ◽  
Single Intramuscular Injection ◽  
Mueller Hinton Broth

The activity of amikacin, gentamicin and kanamycin was tested in vitro against clinical isolates of Pseudomonas aeruginosa. Concentrations of the antibiotics in serum and in saline solution were prepared according to serum levels produced in volunteers 15 minutes, 1, 2, and 6 hours after a single intramuscular injection of 500 mg amikacin, 80 mg gentamicin and 500 mg kanamycin. Following isolation of the Pseudomonas strains in cultures, they were incubated and seeded in Mueller-Hinton broth, then 107 dilutions of the organisms were kept in contact with the prepared antibiotic solutions in serum and in saline solution for three hours, the approximate half-life of the antibiotics in serum. Amikacin was active at concentrations seen six hours post-dose, inhibiting growth in a total of 72·5% of seeded plates. Gentamicin was active for only two hours and inhibited growth in 2·5% of the plates. Kanamycin showed no anti-pseudomonal activity.

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