Category Archives: Antimicrobial activity

Antimicrobial activity of ceftriaxone compared: DISCUSSION part 2

Because the time-kill kinetic method is considered to be more sensitive than simple mic-mbc methodology for evaluating antimicrobial activity, it is possible to observe wide differences in the killing kinetics among strains with similar mics. Since there was no difference in the extent of killing at 6 or 24 h, the extrapolated results from the convenience plot of 6 h time-kill tested at mbc levels … Continue reading

Antimicrobial activity of ceftriaxone compared: DISCUSSION part 1

The re I ationships between serum protein bind I ng and the distribution of beta-I actam anfibiotics has been exfensively studied and reviewed over the past two decades. The differences in serum protein binding between ceftriaxone and cefotaxime have been esfablished. Methodology has been developed to compare the pharmacokinetics of antibiotics that differ in protein binding. Protein binding may be of importance in antibacterial chemotherapy … Continue reading

Antimicrobial activity of ceftriaxone compared: RESULTS

The susceptibility data of the bacterial strains in broth and broth with serum albumin are shown in Table 1. A marked effect of serum albumin on the mic90 and mbc90 was noted. The ceftriaxone MIC90 and MBC90 increased eightfold in the presence of serum albumin. The mic90 of cefotaxime and cefotaxime/desacetylcefotaxime were virtually unaffected by the addition of serum albumin. There were minor differences in the … Continue reading

Antimicrobial activity of ceftriaxone compared: MATERIALS AND METHODS part 2

For minimum bactericidal concentration (mbc) determinations, duplicate 0.01 mL samples were removed from each well without growth and dispensed by spread г ng across the surface of nutrient agar plates. Results were recorded after incubation of plates for 18 h at 35°C. The initial inocula were determined and ranged from 3 to 4×105 colony-forming units (cfu)/mL. The mbc was detined as the lowest concentration producing … Continue reading

Antimicrobial activity of ceftriaxone compared: MATERIALS AND METHODS part 1

One hundred and twenty-one bacteremic isolates of nonpseudomonal Gram-negative bacilli (77 Escherichia coli, 18 Klebsiella pneumoniae, four Klebsiella oxytoca, five Proteus mirabilis, four Citrobacter freundii, nine Enterobacter cloacae and four Enterobacter aerogenes) were used. The isolates were from a stock culture col г ection, and antimicrobial sensitivities were determined us г ng the MicroScan system (Travenol Labo tatories, New Jersey) with break point minimum inhibitory … Continue reading

Antimicrobial activity of ceftriaxone compared

Third-generation cephalosporins are often used in the therapy of serious nosocomial Gram-negative bacterial infections. Ceftriaxone and cefotaxime are similar in antibacterial spectrum and resistance to beta- I actamases, but differ markedly in se rum protein bind i ng and elimination half- I ife (ceftriaxone: 95% protein bound, elimination half- I ife of 8.8 h versus cefotaxime: 35%, 1.2 h). It has been suggested that serum … Continue reading