Aminoglycosides plus beta-lactams against gram-negative organisms: Evaluation of in vitro synergy and chemical interactions

1986 ◽  
Vol 80 (6) ◽  
pp. 126-137 ◽  
Author(s):  
Helen Giamarellou
Keyword(s):  
Beta Lactams ◽  
Chemical Interactions ◽  
Gram Negative ◽  
Gram Negative Organisms

scholarly journals In Vitro Activity of the Histatin Derivative P-113 against Multidrug-Resistant Pathogens Responsible for Pneumonia in Immunocompromised Patients

2005 ◽  
Vol 49 (3) ◽  
pp. 1249-1252 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Wojciech Kamysz ◽  
Giuseppina D'Amato ◽  
Carmela Silvestri ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Vitro Activity ◽  
Immunocompromised Patients ◽  
In Vitro Activity ◽  
Beta Lactams ◽  
Gram Negative ◽  
Resistant Strains ◽  
Multidrug Resistant Pathogens ◽  
Gram Negative Organisms

ABSTRACT The in vitro activity of the histatin derivative P-113, alone or combined with eight antibiotics, was investigated against multidrug-resistant strains isolated from clinical specimens of immunocompromised patients with pneumonia. The gram-negative isolates were susceptible to P-113. S. aureus showed less susceptibility. Synergy was demonstrated when P-113 was combined with beta-lactams against gram-negative organisms.

scholarly journals INCREASED RESISTANCE TO INFECTION AND ACCOMPANYING ALTERATION IN PROPERDIN LEVELS FOLLOWING ADMINISTRATION OF BACTERIAL LIPOPOLYSACCHARIDES

1956 ◽  
Vol 104 (3) ◽  
pp. 383-409 ◽  
Author(s):  
Maurice Landy ◽  
Louis Pillemer
Keyword(s):  
Defense Mechanisms ◽  
Bacterial Species ◽  
Complex Nature ◽  
Gram Negative ◽  
Resistance To Infection ◽  
Bacterial Lipopolysaccharides ◽  
Gram Negative Organisms ◽  
Incomplete Picture ◽  
Time Of Administration

It has been shown that injection of lipopolysaccharides, derived from a variety of Gram-negative bacterial species, evokes in mice a rapidly developing rise in resistance to infection with Gram-negative pathogens. This is accompanied by an elevation in properdin titer, at times to levels 2 to 3 times the normal. The rate, magnitude, and duration of these responses are dependent on many factors, the most important of which are the quantity and timing of the lipopolysaccharide administered. The increased resistance to infection evoked in mice by lipopolysaccharides was effective against infections produced by endotoxin-bearing organisms-bacterial species highly susceptible in vitro to the bactericidal action of the properdin system. Properdin titers of mice prior to infection provide an incomplete picture of the subsequent reaction of the host to the infective agent. Following infection with Gram-negative organisms, properdin levels accurately reflect the bacteriologic course and outcome of the infection. Thus, in control animals, properdin titers progressively declined and the animals died, while in mice appropriately treated with lipopolysaccharide, properdin levels were either maintained in the normal range or increased, depending on the dose and time of administration of lipopolysaccharide; this was always accompanied by successful management of the infection. The complex nature of the alterations produced in the host by lipopolysaccharides is stressed. It is pointed out that the increase in the ability of the host to cope with Gram-negative infections may be the result of stimulation of other defense mechanisms, in addition to the properdin system.

Rifampicin

1970 ◽  
Vol 8 (3) ◽  
pp. 11-12
Keyword(s):  
Messenger Rna ◽  
Viral Infections ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
Low Concentrations ◽  
Resistant Mutants ◽  
Gram Negative Organisms

Rifampicin (Rifadin-Lepetit; Rimactane-Ciba) is a semi-synthetic antibiotic derived from Streptomyces mediterranei which inhibits the synthesis of bacterial messenger-RNA. In vitro it is active against Gram-positive organisms and mycobacteria in low concentrations (0.0002 – 0.5 mcg/ml); and against Gram-negative organisms in higher concentrations (1 – 10 mcg/ml). Drug-resistant mutants readily emerge if rifampicin is used alone.1 It is already established as an important agent in the treatment of tuberculosis. Its usefulness in other bacterial and in viral infections is uncertain.

scholarly journals 2214. Comparison of Cefepime–Zidebactam (WCK 5222), Ceftazidime–Avibactam, and Ceftolozane–Tazobactam Tested Against Gram-Negative Organisms Causing Pneumonia in United States Hospitals in 2018

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S755-S755 ◽  
Author(s):  
Helio S Sader ◽  
Cecilia G Carvalhaes ◽  
Rodrigo E Mendes ◽  
Mariana Castanheira ◽  
Robert K Flamm
Keyword(s):  
Therapeutic Option ◽  
High Dose ◽  
Gram Negative ◽  
E Coli ◽  
Highly Active ◽  
Medical Centers ◽  
Carbapenem Resistant ◽  
Gram Negative Organisms ◽  
Dual Mechanism

Abstract Background Zidebactam (ZID) is a bicyclo-acyl hydrazide antibiotic with a dual mechanism of action: selective Gram-negative PBP2 binding and β-lactamase inhibition. We evaluated the frequency and antimicrobial susceptibility (S) of Gram-negative bacilli (GNB) isolated from patients with pneumonia in US hospitals. Methods All 3,086 clinical isolates were consecutively collected from patients hospitalized with pneumonia (1/patient) in 29 US medical centers in 2018, and the GNB (n = 2,171) were S tested against cefepime (FEP)-ZID (1:1 ratio) and comparators by reference broth microdilution methods. The FEP S breakpoint of ≤8 mg/L (CLSI, high dose) was applied to FEP-ZID for comparison purposes. An FEP-ZID S breakpoint of ≤64 mg/L has been proposed for non-fermentative GNB based on pharmacokinetic/pharmacodynamic target attainment and was applied. Enterobacterales (ENT) isolateswere screened for β-lactamase genes by whole-genome sequencing. Results GNB represented 70.3% of the collection, and the most common GNB were P. aeruginosa (PSA; 34.9% of GNB), K. pneumoniae (10.9%), E. coli (9.7%), S. marcescens (7.7%), and S. maltophilia (XM; 6.4%). FEP-ZID was highly active against PSA (MIC50/90, 2/8 mg/L; 98.8% and 99.9% inhibited at ≤8 and ≤16 mg/L, respectively; highest MIC, 32 mg/L), including resistant subsets (table). Among comparators, colistin (99.6%S), ceftazidime–avibactam (CAZ-AVI; 95.2%S), and ceftolozane–tazobactam (C-T; 94.5%S) were the most active compounds against PSA. FEP-ZID inhibited all ENT at ≤4 mg/L, including ESBL-producers (MIC90, 0.25 mg/L) and carbapenem-resistant ENT (MIC90, 4 mg/L). The most active comparators against ENT were CAZ-AVI (99.9%S), amikacin (98.5%S), and meropenem (MEM; 98.3%S). FEP-ZID inhibited 75.0% and 97.9% of XM isolates at ≤8 and ≤16 mg/L, respectively (highest MIC, 64 mg/L). The only other compounds active against XM were co-trimoxazole (MIC50/90, ≤0.12/2 mg/L; 95.7%S) and levofloxacin (MIC50/90, 1/2 mg/L; 70.7%S). FEP-ZID inhibited 71.0% and 98.9% of A. baumannii isolates at ≤8 and ≤64 mg/L,, respectively. Conclusion FEP-ZID showed potent in vitro activity against GNB causing pneumonia in US hospitals and may represent a valuable therapeutic option for these difficult-to-treat infections Disclosures All authors: No reported disclosures.

scholarly journals Photochemical inactivation of pathogenic bacteria in human platelet concentrates

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2698-2706 ◽  
Author(s):  
L Lin ◽  
H Londe ◽  
JM Janda ◽  
CV Hanson ◽  
L Corash
Keyword(s):  
Platelet Function ◽  
Pathogenic Bacteria ◽  
Uv Light ◽  
Platelet Concentrates ◽  
Gram Positive ◽  
Plasma Protein Concentration ◽  
Transfusion Therapy ◽  
Gram Negative ◽  
Gram Negative Organisms

Abstract Platelet concentrates (PC) may be infrequently contaminated with low levels of bacteria that can cause septicemia and death in patients receiving transfusion therapy. We evaluated the efficacy of a photochemical decontamination (PCD) technique using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA) to inactivate bacteria in standard therapeutic PC. Twelve phylogenetically distinct pathogenic bacteria, 5 gram-positive and 7 gram-negative organisms, were seeded into PC to a final challenge dose ranging from 10(5) to 10(7) colony- forming units (CFU)/mL. Contaminated PC were treated with 8-MOP (5 micrograms/mL) and 5 J/cm2 of UVA, a PCD treatment regimen found to adequately preserve in vitro platelet function. Greater than 10(5) CFU/mL of all 5 gram-positive (Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Listeria monocytogenes, and Corynebacterium minutissimum) and 2 of the gram-negative (Escherichia coli and Yersinia enterocolitica) organisms were inactivated. The remaining 5 gram-negative organisms were more resistant, with less than 10(1) to 10(3.7) CFU/mL inactivated under these conditions. The inactivation efficiency for this resistant group of gram-negative organisms was improved when PC were resuspended in a synthetic storage medium with reduced plasma protein concentration (15%) and an increased 8-MOP concentration (23.4 micrograms/mL). Illumination with 3 J/cm2 of UVA in this system inactivated greater than 10(5) CFU/mL of 4 resistant gram-negative organisms (Salmonella choleraesuis, Enterobacter cloacae, Serratia marcescens, and Klebsiella pneumoniae) and 10(4.1) CFU/mL of the most resistant gram-negative organism (Pseudomonas aeruginosa). This level of PCD treatment did not adversely affect in vitro platelet function. These results demonstrate that PCD using 8-MOP (5 to 23.4 micrograms/mL) effectively inactivated high levels of pathogenic bacteria in PC with adequate preservation of in vitro platelet properties.

scholarly journals In Vitro Activity of Ceftaroline against 623 Diverse Strains of Anaerobic Bacteria

2010 ◽  
Vol 54 (4) ◽  
pp. 1627-1632 ◽  
Author(s):  
D. M. Citron ◽  
K. L. Tyrrell ◽  
C. V. Merriam ◽  
E. J. C. Goldstein
Keyword(s):  
Soft Tissue ◽  
Broad Spectrum ◽  
Anaerobic Bacteria ◽  
Soft Tissue Infections ◽  
Good Activity ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Amoxicillin Clavulanate ◽  
Gram Negative Organisms

ABSTRACT The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and four comparator antimicrobials were determined against anaerobic bacteria. Against Gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin-clavulanate and four to eight times greater than that of ceftriaxone. Against Gram-negative organisms, ceftaroline showed good activity against β-lactamase-negative strains but not against the members of the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft tissue infections.

Comparative in vitro Activity of Cef epime and Four Extended-Spectrum Beta-Lactams on 1,251 Aminoglycoside-Resistant Gram-Negative Hospital Strains

Chemotherapy ◽  
1992 ◽  
Vol 38 (4) ◽  
pp. 225-231
Author(s):  
Raymond Vanhoof ◽  
Eric Nulens ◽  
Henry-Jean Nyssen ◽  
Eleonora Hannecart-Pokorni
Keyword(s):  
Vitro Activity ◽  
In Vitro Activity ◽  
Beta Lactams ◽  
Gram Negative ◽  
Extended Spectrum

scholarly journals In Vitro and Bactericidal Activities of ABT-492, a Novel Fluoroquinolone, against Gram-Positive and Gram-Negative Organisms

2004 ◽  
Vol 48 (7) ◽  
pp. 2771-2777 ◽  
Author(s):  
Laurel S. Almer ◽  
Jennifer B. Hoffrage ◽  
Erika L. Keller ◽  
Robert K. Flamm ◽  
Virginia D. Shortridge
Keyword(s):  
Bactericidal Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
The Family ◽  
Comparable Activity ◽  
Bactericidal Activities ◽  
Gram Negative Organisms

ABSTRACT In vitro activities of ABT-492, ciprofloxacin, levofloxacin, trovafloxacin, moxifloxacin, gatifloxacin, and gemifloxacin were compared. ABT-492 was more potent against quinolone-susceptible and -resistant gram-positive organisms, had activity similar to that of ciprofloxacin against certain members of the family Enterobacteriaceae, and had comparable activity against quinolone-susceptible, nonfermentative, gram-negative organisms. Bactericidal activity of ABT-492 was also evaluated.

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