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.

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 In Vitro Activity of Tebipenem, a New Oral Carbapenem Antibiotic, against β-Lactamase-Nonproducing, Ampicillin-Resistant Haemophilus influenzae

2010 ◽  
Vol 54 (9) ◽  
pp. 3970-3973 ◽  
Author(s):  
Kozue Kishii ◽  
Naoko Chiba ◽  
Miyuki Morozumi ◽  
Akiko Ono ◽  
Takashi Ida ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Bactericidal Activity ◽  
Gene Mutations ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Oral Antibiotics ◽  
Pcr Identification ◽  
Minimal Concentration ◽  
Carbapenem Antibiotic

ABSTRACT In vitro activity of tebipenem, a new oral carbapenem antibiotic, against clinical Haemophilus influenzae isolates was compared with those of 8 reference agents. Isolates were classified into 6 resistance classes after PCR identification of β-lactamase genes and ftsI gene mutations. For all isolates, the minimal concentration at which 90% of isolates were inhibited was lower for tebipenem than for the reference oral antibiotics, except for cefditoren. Tebipenem also showed excellent bactericidal activity against β-lactamase-nonproducing, ampicillin-resistant isolates.

scholarly journals 688. In Vitro Activity of Eravacycline, a New Tetracycline Analog, and Comparators Against the Six Most Commonly Isolated Ribotypes of Clostridioides difficile

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S312-S313 ◽  
Author(s):  
Eugenie Basseres ◽  
Julie Miranda ◽  
Anne J Gonzales-Luna ◽  
Travis J Carlson ◽  
Tasnuva Rashid ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Large Collection ◽  
In Vitro Susceptibility ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Abdominal Infections ◽  
Insight Into

Abstract Background Eravacycline is a novel, tetracycline class antibacterial indicated for the treatment of complicated intra-abdominal infections in adults. In clinical trials, patients given eravacycline had a low likelihood of developing Clostridioides difficile infection (CDI). We hypothesized this was likely due, in part, to the in vitro susceptibility of eravacycline to C. difficile. The purpose of this study was to test the in vitro susceptibility of eravacycline vs. comparators on contemporary clinical isolates representing common ribotypes, including isolates with decreased susceptibility to metronidazole and vancomycin. Methods Two hundred and thirty-four isolates from our biobank were selected from the six most common ribotypes (F001, F002, F014-020, F027, F106, and F255). Minimum inhibitory concentrations (MIC) at 24 hours were measured according to CLSI guidelines for eravacycline, vancomycin, metronidazole and fidaxomicin. MICs results were tabulated and are presented as the geometric mean by ribotype. Results Geometric MIC results are shown in Table 1. Eravacycline was the most potent antimicrobial tested followed by fidaxomicin, metronidazole, and vancomycin. Results were consistent amongst all ribotypes, including isolates with reduced susceptibility to vancomycin and metronidazole. Conclusion Eravacycline displayed potent in vitro activity against a large collection of clinical C. difficile isolates. These data provide insight into why patients given eravacycline had a low likelihood of developing CDI and support further research to better understand the use of eravacycline to prevent or potentially treat patients with CDI. Disclosures All authors: No reported disclosures.

scholarly journals Comparison of In Vitro Activity of Liposomal Nystatin againstAspergillus Species with Those of Nystatin, Amphotericin B (AB) Deoxycholate, AB Colloidal Dispersion, Liposomal AB, AB Lipid Complex, and Itraconazole

1999 ◽  
Vol 43 (5) ◽  
pp. 1264-1266 ◽  
Author(s):  
Karen L. Oakley ◽  
Caroline B. Moore ◽  
David W. Denning
Keyword(s):  
Amphotericin B ◽  
Aspergillus Terreus ◽  
Antifungal Agents ◽  
Geometric Mean ◽  
Colloidal Dispersion ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Lipid Complex

ABSTRACT We compared the in vitro activity of liposomal nystatin (Nyotran) with those of other antifungal agents against 60Aspergillus isolates. Twelve isolates were itraconazole resistant. For all isolates, geometric mean (GM) MICs (micrograms per milliliter) were 2.30 for liposomal nystatin, 0.58 for itraconazole, 0.86 for amphotericin B (AB) deoxycholate, 9.51 for nystatin, 2.07 for liposomal AB, 2.57 for AB lipid complex, and 0.86 for AB colloidal dispersion. Aspergillus terreus (GM, 8.72 μg/ml; range, 8 to 16 μg/ml) was significantly less susceptible to all of the polyene drugs than all other species (P = 0.0001).

scholarly journals In Vitro Activities of Terbinafine againstAspergillus Species in Comparison with Those of Itraconazole and Amphotericin B

2001 ◽  
Vol 45 (6) ◽  
pp. 1882-1885 ◽  
Author(s):  
Caroline B. Moore ◽  
Caroline M. Walls ◽  
David W. Denning
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Geometric Mean ◽  
Vitro Activity ◽  
Clinical Correlation ◽  
In Vitro Activity

ABSTRACT Compared with the in vitro activities of itraconazole (geometric mean MIC [GM], 0.56 μg/ml) and amphotericin B (GM, 0.66 μg/ml), the in vitro activity of terbinafine was inferior againstAspergillus fumigatus (GM, 19.03 μg/ml) (P < 0.05) and superior against A. flavus(GM, 0.10 μg/ml), A. terreus (GM, 0.16 μg/ml), andA. niger (GM, 0.19 μg/ml). Clinical correlation is required, as trailing endpoints are problematic.

scholarly journals Attenuated Vancomycin Bactericidal Activity against Staphylococcus aureus hemB Mutants Expressing the Small-Colony-Variant Phenotype

2008 ◽  
Vol 52 (4) ◽  
pp. 1533-1537 ◽  
Author(s):  
Brian T. Tsuji ◽  
Christof von Eiff ◽  
Pamela A. Kelchlin ◽  
Alan Forrest ◽  
Patrick F. Smith
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Pharmacodynamic Model ◽  
Small Colony Variant ◽  
Variant Phenotype ◽  
Small Colony ◽  
Bactericidal Activities

ABSTRACT The in vitro bactericidal activities of vancomycin against Staphylococcus aureus hemB mutants displaying the small-colony-variant phenotype and their parental strains were evaluated. Vancomycin killing activities against hemB mutants were markedly attenuated, demonstrating approximately 50% less effect, a result which was well described by a Hill-type pharmacodynamic model.

scholarly journals In Vitro Activity of Ceftaroline against Community-Associated Methicillin-Resistant, Vancomycin-Intermediate, Vancomycin-Resistant, and Daptomycin-Nonsusceptible Staphylococcus aureus Isolates

2010 ◽  
Vol 54 (7) ◽  
pp. 3027-3030 ◽  
Author(s):  
Louis Saravolatz ◽  
Joan Pawlak ◽  
Leonard Johnson
Keyword(s):  
Staphylococcus Aureus ◽  
Treatment Option ◽  
Bactericidal Activity ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Methicillin Resistant ◽  
Vancomycin Resistant

ABSTRACT This study assessed the in vitro activities of ceftaroline and five comparator agents against a collection of Staphylococcus aureus isolates. Ceftaroline demonstrated potent activity against community-associated methicillin-resistant S. aureus (CA-MRSA) isolates and showed bactericidal activity against vancomycin-intermediate S. aureus (VISA), vancomycin-resistant S. aureus (VRSA), heteroresistant VISA (hVISA), and daptomycin-nonsusceptible S. aureus (DNSSA) isolates. Ceftaroline may represent a bactericidal treatment option for infections caused by these pathogens.

scholarly journals Comparative bactericidal activity of ceftazidime against isolates of Pseudomonas aeruginosa as assessed in an in vitro pharmacodynamic model versus the traditional time-kill method.

1997 ◽  
Vol 41 (11) ◽  
pp. 2527-2532 ◽  
Author(s):  
M Manduru ◽  
L B Mihm ◽  
R L White ◽  
L V Friedrich ◽  
P A Flume ◽  
...  
Keyword(s):  
Bactericidal Activity ◽  
Drug Exposure ◽  
Growth Conditions ◽  
Pharmacodynamic Model ◽  
Drug Concentrations ◽  
Bactericidal Activities ◽  
Time Kill ◽  
In Vivo Pharmacokinetics

Bactericidal activity, historically assessed by in vitro tests which employ fixed drug concentrations, may also be evaluated in in vitro pharmacodynamic models in which in vivo pharmacokinetics and bacterial growth conditions can be simulated. However, systematic comparisons between the two methods are lacking. We evaluated the bactericidal activities of ceftazidime, at two different concentration/MIC ratios (C/MICs), against 10 clinical isolates of Pseudomonas aeruginosa in a two-compartment model with continuous-infusion conditions and a 2-h half-life. These values were compared to those determined by traditional 24-h time-kill (TTK) methods at the same C/MICs. Bactericidal activities were compared by using area under the colony count-time curves. Antibiotic exposure (area under the drug concentration-time curve) was also evaluated. Although bactericidal activity appeared greater by the TTK method (P = 0.05), when it was normalized for drug exposure, these differences disappeared (P = 0.2). This disparity was likely due to differences in drug exposure in the TTK method and in the peripheral compartment of the model (site of bacteria) over the first 8 h of the experiment, during which the antibiotic accumulated to target concentrations. This suggests that the bactericidal effects with constant antibiotic concentrations are similar in the two methods; however, this may not hold true with fluctuating drug concentrations. Further, results from the pharmacodynamic model may theoretically be more relevant, as in vivo pharmacokinetics and bacterial growth conditions call be more faithfully simulated.

scholarly journals Bacteriostatic and bactericidal activities of Acalypha indica L. plant leave extracts on bacteria shigella disenteriae type 1 in vitro

2021 ◽  
Vol 8 (6) ◽  
pp. 304-309
Author(s):  
Abdul Majid ◽  
Frans Salesman
Keyword(s):  
Experimental Study ◽  
Bactericidal Activity ◽  
Pathogenic Bacteria ◽  
Shigella Dysenteriae ◽  
Herbal Extract ◽  
Bactericidal Activities ◽  
Acalypha Indica ◽  
Shigella Dysenteriae Type

This study aimed to analyze the bacteriostatic and bactericidal activity of Acalypha indica L. extract against Shigella dysenteriae type 1 bacteria in vitro. This research is a laboratory experimental study consisting of six concentration treatments, namely: (K = 0/ml, P1 = 100/ml, P2 = 200/ml, P3 = 400/ml, P4 = 800/ml, P5 = 1600 mg/ml ), and five replications each. The results showed that the herbal extract of Acalypha indica L. was bacteriostatic (inhibiting) at a concentration of 400 mg/mm, and bactericidal (killing) the bacteria Shigella dysenteriae type 1, which was tested in vitro at a concentration of at least 800 mg/ml. It is necessary to study the effect of Acalypha indica L. herbal extract from Timor in the serum of Rattus norwegicus against bacteria that cause bloody diarrhea (EHEC O157:H7, and Shigella dysenteriae type 1), MRSA bacteria, and other pathogenic bacteria.

scholarly journals Meningococcal Polysaccharide AO-Acetylation Levels Do Not Impact the Immunogenicity of the Quadrivalent Meningococcal Tetanus Toxoid Conjugate Vaccine: Results from a Randomized, Controlled Phase III Study of Healthy Adults Aged 18 to 25 Years

2013 ◽  
Vol 20 (10) ◽  
pp. 1499-1507 ◽  
Author(s):  
Socorro Lupisan ◽  
Kriengsak Limkittikul ◽  
Nestor Sosa ◽  
Pornthep Chanthavanich ◽  
Véronique Bianco ◽  
...  
Keyword(s):  
Conjugate Vaccine ◽  
Bactericidal Activity ◽  
Tetanus Toxoid ◽  
Geometric Mean ◽  
Phase Iii ◽  
Controlled Study ◽  
Rabbit Serum ◽  
Vaccine Response ◽  
Serum Bactericidal Activity ◽  
Phase Iii Study

ABSTRACTIn this study, we compared the immunogenicities of two lots of meningococcal ACWY-tetanus toxoid conjugate vaccine (MenACWY-TT) that differed in serogroup A polysaccharide (PS)O-acetylation levels and evaluated their immunogenicities and safety in comparison to a licensed ACWY polysaccharide vaccine (Men-PS). In this phase III, partially blinded, controlled study, 1,170 healthy subjects aged 18 to 25 years were randomized (1:1:1) to receive one dose of MenACWY-TT lot A (ACWY-A) (68%O-acetylation), MenACWY-TT lot B (ACWY-B) (92%O-acetylation), or Men-PS (82%O-acetylation). Immunogenicity was evaluated in terms of serum bactericidal activity using rabbit complement (i.e., rabbit serum bactericidal activity [rSBA]). Solicited symptoms, unsolicited adverse events (AEs), and serious AEs (SAEs) were recorded. The immunogenicities, in terms of rSBA geometric mean titers, were comparable for both lots of MenACWY-TT. The vaccine response rates across the serogroups were 79.1 to 97.0% in the two ACWY groups and 73.7 to 94.1% in the Men-PS group. All subjects achieved rSBA titers of ≥1:8 for all serogroups. All subjects in the two ACWY groups and 99.5 to 100% in the Men-PS group achieved rSBA titers of ≥1:128. Pain was the most common solicited local symptom and was reported more frequently in the ACWY group (53.9 to 54.7%) than in the Men-PS group (36.8%). The most common solicited general symptoms were fatigue and headache, which were reported by 28.6 to 30.3% and 26.9 to 31.0% of subjects, respectively. Two subjects reported SAEs; one SAE was considered to be related to vaccination (blighted ovum; ACWY-B group). The level of serogroup A PSO-acetylation did not affect vaccine immunogenicity. MenACWY-TT (lot A) was not inferior to Men-PS in terms of vaccine response and was well tolerated.

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