scholarly journals Sub-minimal inhibitory concentrations of cefmetazole enhance serum bactericidal activity in vitro by amplifying poly-C9 deposition.

1992 ◽  
Vol 89 (4) ◽  
pp. 1198-1207 ◽  
Author(s):  
J E Schweinle ◽  
M Nishiyasu
Keyword(s):  
Bactericidal Activity ◽  
Minimal Inhibitory Concentrations ◽  
Serum Bactericidal Activity

scholarly journals Pharmacokinetics of sparfloxacin and serum bactericidal activity against pneumococci.

1996 ◽  
Vol 40 (3) ◽  
pp. 776-779 ◽  
Author(s):  
M Trautmann ◽  
M Ruhnke ◽  
K Borner ◽  
J Wagner ◽  
P Koeppe
Keyword(s):  
Bactericidal Activity ◽  
Geometric Mean ◽  
Clinical Situation ◽  
In Vitro Activity ◽  
Serum Bactericidal Activity ◽  
Time Period ◽  
Quinolone Antibiotics ◽  
Humoral Antibodies ◽  
Bactericidal Activities

Sparfloxacin, a new fluorinated quinolone, exhibits higher in vitro activity against pneumococci than do ciprofloxacin and ofloxacin. Since up to 30% of cases of pneumococcal pneumonia are associated with bacteremia, and since an increasing percentage of pneumococci are resistant against penicillin, we studied the serum bactericidal activity of sparfloxacin against pneumococci in eight healthy, middle-aged volunteers. Pharmacokinetics in serum and urine after a 400-mg oral dose of sparfloxacin were comparable to those described by other authors. Inhibitory and bactericidal activities in serum were measured for four pneumococcal isolates representing penicillin-susceptible (one isolate), intermediately resistant (two isolates), and highly resistant (one isolate) strains. Geometric mean inhibitory titers ranged between 1:2.4 and 1:6.3 and bactericidal titers ranged between 1:1.3 and 1:3.6 during a time period of 1 to 6 h after drug intake. Although such titers were not sufficient to predict a clinical response based on previous pharmacodynamic studies using quinolone antibiotics, data obtained with volunteers may only partially reflect the clinical situation in which a rise of humoral antibodies directed against pneumococcal antigens may help to reinforce the bactericidal action of the antibiotic.

Cefminox: correlation between in-vitro susceptibility and pharmacokinetics and serum bactericidal activity in healthy volunteers

1994 ◽  
Vol 33 (1) ◽  
pp. 91-101 ◽  
Author(s):  
L. Aguilar ◽  
C. Esteban ◽  
J. Frias ◽  
I. Pérez-Balcabao ◽  
A. J. Carcas ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Bactericidal Activity ◽  
In Vitro Susceptibility ◽  
Serum Bactericidal Activity

scholarly journals Naturally Acquired Passive Protective Activity against Neisseria meningitidis Group C in the Absence of Serum Bactericidal Activity

2004 ◽  
Vol 72 (10) ◽  
pp. 5903-5909 ◽  
Author(s):  
Jo Anne Welsch ◽  
Dan Granoff
Keyword(s):  
Bactericidal Activity ◽  
Geometric Mean ◽  
Antibody Concentration ◽  
Protective Activity ◽  
Serum Samples ◽  
Antibody Avidity ◽  
Serum Bactericidal Activity ◽  
Infant Rat

ABSTRACT The hallmark of immunity to meningococcal disease is a bactericidal titer in serum of ≥1:4 measured with human complement, but this threshold titer may underestimate the extent of protection. We used the infant rat model of meningococcal bacteremia to measure group C passive protective activity in serum samples from 91 unimmunized adults living in California. A total of 35 sera (38.5%) had passive protective activity. Sera with complement-mediated bactericidal titers of ≥1:4 were 3.4-fold more likely to confer protection (89%) than nonbactericidal sera (26%; P < 0.0001). Thus, bactericidal titers of ≥1:4 are a marker of protection, but this threshold lacks sensitivity for predicting protective activity. We investigated the 73 sera with bactericidal titers of <1:4 to determine the basis of protective activity. The 19 sera with protective activity had a higher geometric mean group C anticapsular antibody concentration (0.72 μg/ml) than the 54 sera that lacked protective activity (0.16 μg/ml; P < 0.001). Thus, protective activity in the absence of bactericidal activity was associated with higher concentrations of anticapsular antibodies, but not all sera with anticapsular antibodies conferred protection. Of 18 nonbactericidal sera with anticapsular antibody concentrations between 0.31 and 0.99 μg/ml, the 11 sera that conferred protection had a higher mean antibody avidity constant (21.9 nM−1) than the 7 nonprotective sera (14.6 nM−1; P < 0.03). Thus, in sera with titers of <1:4, protective activity is associated with higher-avidity group C anticapsular antibodies, which are present in concentrations insufficient to elicit complement-mediated bacteriolysis in vitro but sufficient to confer protection in an in vivo bacteremia model.

scholarly journals Functional and Transcriptional Adaptations of Blood Monocytes Recruited to the Cystic Fibrosis Airway Microenvironment In Vitro

2021 ◽  
Vol 22 (5) ◽  
pp. 2530
Author(s):  
Bijean D. Ford ◽  
Diego Moncada Giraldo ◽  
Camilla Margaroli ◽  
Vincent D. Giacalone ◽  
Milton R. Brown ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Bactericidal Activity ◽  
Scavenger Receptor ◽  
Receptor Expression ◽  
Blood Monocytes ◽  
Bacterial Killing ◽  
Blood Neutrophils ◽  
Vitro Model

Cystic fibrosis (CF) lung disease is dominated by the recruitment of myeloid cells (neutrophils and monocytes) from the blood which fail to clear the lung of colonizing microbes. In prior in vitro studies, we showed that blood neutrophils migrated through the well-differentiated lung epithelium into the CF airway fluid supernatant (ASN) mimic the dysfunction of CF airway neutrophils in vivo, including decreased bactericidal activity despite an increased metabolism. Here, we hypothesized that, in a similar manner to neutrophils, blood monocytes undergo significant adaptations upon recruitment to CFASN. To test this hypothesis, primary human blood monocytes were transmigrated in our in vitro model into the ASN from healthy control (HC) or CF subjects to mimic in vivo recruitment to normal or CF airways, respectively. Surface phenotype, metabolic and bacterial killing activities, and transcriptomic profile by RNA sequencing were quantified post-transmigration. Unlike neutrophils, monocytes were not metabolically activated, nor did they show broad differences in activation and scavenger receptor expression upon recruitment to the CFASN compared to HCASN. However, monocytes recruited to CFASN showed decreased bactericidal activity. RNASeq analysis showed strong effects of transmigration on monocyte RNA profile, with differences between CFASN and HCASN conditions, notably in immune signaling, including lower expression in the former of the antimicrobial factor ISG15, defensin-like chemokine CXCL11, and nitric oxide-producing enzyme NOS3. While monocytes undergo qualitatively different adaptations from those seen in neutrophils upon recruitment to the CF airway microenvironment, their bactericidal activity is also dysregulated, which could explain why they also fail to protect CF airways from infection.

scholarly journals A Prospective Open-Label Multicentre Trial on the Use of 1 G, Once Daily Ceftriaxone in Lower Respiratory Tract Infections

1994 ◽  
Vol 5 (suppl c) ◽  
pp. 3C-8C ◽  
Author(s):  
Donald E Low ◽  
Lionel A Mandell
Keyword(s):  
Respiratory Tract ◽  
Treatment Failure ◽  
Lower Respiratory Tract ◽  
Study Drug ◽  
Open Label ◽  
In Vitro Susceptibility ◽  
Once Daily ◽  
Minimal Inhibitory Concentrations ◽  
Tract Infections

This prospective. single open-label sludy was conducted in 14 Canadian centres to assess lhe efncacy of I g, once a day intravenous ceftriaxone treatment administered for a minimum of three days in patients with lower respiratory tract infection. There were 137 patients enrolled. Age varied between 19 and 95 years (mean 68 years). Mosl patients (91 %) were diagnosed with community acquired pneumonia without bacteremia. Most of the cases (82%) were defined as modcralc or severe. Patients received ceftriaxone treatment for an average or five days. Macrolidcs or metronidazole were administered concomitantly wilh ceftriaxone in 34 patienls (25%). After a minimum of three days of ceftriaxone treatment. 59 palicnls (43%) were switched to oral antibiotics. Favourable treatment outcome was found in 92.9% and treatment failure (including relapse of infection) in 7.1 % o lpalicnls. Evaluable patients accounted for 91 % of patients enrolled in the study. Clinical cure and clinical improvement were achieved in 64.6 and 28.3% of the evaluable patients. respectively. Relapse of infection occurred in two patients (1.8%). and treatment failure was recorded in six cases (5.3%). Twelve patients (8.8%) died clue to reasons unrelated to the sludy treatment. Three adverse event (hives, diarrhea and phlebitis at the injection site) were possibly related to the study drug. A cross-Canada in vitro susceptibility surveillance study of bacterial pathogens. frequently the cause of pneumonia. found ceftriaxone to have minimal inhibitory concentrations in 90% of isolates that would support such a dosing regimen. with the exception of Enterobacter species. These rcsults support the use of 1 g, once daily ceftriaxone for the empirical treatment of pneumonia in those patients requiring hospitalization.

scholarly journals A molecular architectural design that promises potent antimicrobial activity against multidrug-resistant pathogens

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Bing Yuan ◽  
Jiaojiao Liu ◽  
Zhixiong Deng ◽  
Lin Wei ◽  
Wenwen Li ◽  
...  
Keyword(s):  
Architectural Design ◽  
Building Blocks ◽  
Multidrug Resistant ◽  
In Vitro Cytotoxicity ◽  
Antimicrobial Drugs ◽  
Minimal Inhibitory Concentrations ◽  
Antimicrobial Efficiency ◽  
Multidrug Resistant Pathogens

AbstractAddressing the devastating threat of drug-resistant pathogens requires the discovery of new antibiotics with advanced action mechanisms and/or novel strategies for drug design. Herein, from a biophysical perspective, we design a class of synthetic antibacterial complexes with specialized architectures based on melittin (Mel), a natural antimicrobial peptide, and poly(ethylene glycol) (PEG), a clinically available agent, as building blocks that show potent and architecture-modulated antibacterial activity. Among the complexes, the flexibly linear complex consisting of one Mel terminally connected with a long-chained PEG (e.g., PEG12k–1*Mel) shows the most pronounced improvement in performance compared with pristine Mel, with up to 500% improvement in antimicrobial efficiency, excellent in vitro activity against multidrug-resistant pathogens (over a range of minimal inhibitory concentrations of 2–32 µg mL−1), a 68% decrease in in vitro cytotoxicity, and a 57% decrease in in vivo acute toxicity. A lipid-specific mode of action in membrane recognition and an accelerated “channel” effect in perforating the bacterial membrane of the complex are described. Our results introduce a new way to design highly efficient and low-toxicity antimicrobial drugs based on architectural modulations with clinically available agents.

scholarly journals Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 591
Author(s):  
Bożena Grimling ◽  
Bożena Karolewicz ◽  
Urszula Nawrot ◽  
Katarzyna Włodarczyk ◽  
Agata Górniak
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Ratio ◽  
Scanning Calorimetry ◽  
Minimal Inhibitory Concentrations ◽  
Dissolution Tests ◽  
Effective Combination ◽  
The Impact ◽  
High Molecular Weight Chitosan

Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole–chitosan solid mixtures (CL–CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole–chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.

Sign in / Sign up

Export Citation Format

Share Document