The effect of ceftriaxone on the anaerobic bacterial flora and the bacterial enzymatic activity in the intestinal tract

Abstract

The normal flora of the intestinal tract, mainly consisting of anaerobic bacteria, protects the host against colonization by pathogenic microorganisms. Antimicrobial treatment with ceftriaxone may influence the colonic microflora and as a consequence, the protective effect. Ten healthy volunteers received 1 g of ceftriaxone intramuscularly for five days. This resulted in a significant decrease (p less than 0.05) of the mean cultural counts (+/- SEM) of total anaerobes from 10.67 (0.11) (prior to treatment) to 9.02 (0.45) and 8.97 (0.46) at days 3 and 5, respectively (during treatment). After treatment (days 10 and 15-19), the cultural counts of anaerobes returned to 10.17 (0.16) and 10.44 (0.18), respectively. Bacterial enzymes may serve as an indicator of protective microflora. beta- aspartylpeptidase and deoxycholate hydrolase activity was determined in faecal supernatants of the volunteers and compared with anaerobic culturing. Both enzymatic activities show a significant correlation with the total number of anaerobes present at day 3 of deftriaxone treatment. At day 5 and 8 only beta-aspartylpeptidase showed significant correlations with cultural counts of total anaerobes, Bacteroides spp. or bifidobacteria. At day 15 to 19 (ten to 14 days after treatment) beta-aspartylpeptidase showed only a significant correlation with the number of Bacteroides spp. This indicates that changes in the indigenous bacterial flora during and shortly after treatment with ceftriaxone can be monitored by determination of beta-aspartylpeptidase. Recovery of the intestinal flora is difficult to assess in this manner.

Bile Acid Metabolism by Colonic Bacteria in Continuous Culture: Effects of Starch and pH

“…deoxycholic and lithocholic acid [11,12], In numerous experimental studies, secondary bile acids have been shown to be potent pro moters of colorectal cancer [6,7,13,14], Bacterial BA metabolism in the human large intestine, however, may be influenced by dietary components. Dietary fiber has been shown to reduce fecal concentrations of sec ondary BA, an effect which was mostly attrib uted to the bulking effect of fiber [15][16][17], Malabsorbed starch, however, may act in a different way. In a previous study, we have shown in healthy volunteers that during acarbose-induced starch malabsorption, less sec ondary BA were excreted in feces whereas total BA excretion remained unchanged [18], In an in vitro study using fecal batch cultures, degradation of primary to secondary BA was inhibited when starch was present in the me dia [19], To study the mechanisms of this inhibition, we have now measured BA metab olism in continuous cultures of mixed fecal bacteria.…”

Comparative Effects of Single-Dose Ceftriaxone Versus Three Oral Antibiotic Regimens on Stool Colonization by Resistant Bacilli in Children

“…18,26 -28 Moreover, the high clearance of ceftriaxone through the bile relative to other extended-spectrum cephalosporins results in substantial exposure of the normal enteric flora to drug in vivo and subsequent reduction of colonization resistance. 20,29 These properties presumably account for observations repeatedly reported by others of the overgrowth of cephalosporin-resistant bacilli in the stool after ceftriaxone administration. 20,22,30,31 The prevalence of resistant fecal Gram-negative bacteria in our ceftriaxone-treated subjects was not detectably different than that noted after exposure to cefprozil and amoxicillin.…”

Healthy individuals possess circulating antibodies against their indigenous faecal microflora as well as against allogenous faecal microflora: an immunomorphometrical study

“…Serum antibodies of IgA, IgG and IgM isotype were measured against the bacteria in the 'washed faeces' of the other seven volunteersby indirect immunofluorescence as described previously [14]. Instead of several serum dilutions, however, we tested only the 1:16 serum 275 10 HYG 111 276 H. Z. APPERLOO-RENKEMA AND OTHERS dilution that was used in the absorption. As a positive control we assessed the presence of antibodies in the serum of each volunteer against his own microflora without previous absorption of antibacterial antibodies.…”

“…Apart from analysis by culturing, the composition of faecal flora can be studied indirectly, in several ways by determining microflora associated characteristics (MACs) [8]. These MACs involve the presence of bacterial enzymes [9] or their products [10].…”