In vitro activity of rifaximin against bacterial enteropathogens causing diarrhoea in children under 5 years of age in Ifakara, Tanzania (original) (raw)
Related papers
Rifaximin, a non-absorbable rifamycin derivative, has published clinical efficacy in the alleviation of symptoms in patients with irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) is associated with the pathogenesis of IBS. This study describes for the first time the antimicrobial effect of rifaximin against SIBO microorganisms from humans. Fluid was aspirated from the third part of the duodenum from 567 consecutive patients; quantitative cultures diagnosed SIBO in 117 patients (20.6%). A total of 170 aerobic microorganisms were isolated and the in vitro efficacy of rifaximin was studied by (i) minimum inhibitory concentration (MIC) testing by a microdilution technique and (ii) time–kill assays using bile to simulate the small intestinal environment. At a breakpoint of 32 g/mL, rifaximin inhibited in vitro 85.4% of Escherichia coli, 43.6% of Klebsiella spp., 34.8% of Enterobacter spp., 54.5% of other Enterobacteriaceae spp., 82.6% of non-Enterobacteriaceae Gram-negative spp., 100% of Enterococcus faecalis, 100% of Enterococcus faecium and 100% of Staphylococcus aureus. For the time–kill assays, 11 E. coli, 15 nonE. coli Gram-negative enterobacteria and three E. faecalis isolates were studied. Rifaximin produced a >3 log 10 decrease in the starting inoculum against most of the tested isolates at 500 g/mL after 24 h of growth. The results indicate that rifaximin has a potent effect on specific small bowel flora associated with SIBO. This conclusion should be regarded in light of the considerable time–kill effect at concentrations lower than those achieved in the bowel lumen after administration of conventional doses in humans.
Antimicrobial Agents and Chemotherapy
Diarrhea in children is often caused by enteropathogen infections that might benefit from early empirical antibiotic therapy. However, when the definition of the pathogen requires sophisticated laboratory studies, the etiology of enteritis is not known early in illness. Empirical therapy may be dangerous if the child is infected with a Shiga toxin-producing Escherichia coli (STEC) strain because antimicrobials may increase Shiga toxin (Stx) release, resulting in increased risk of microangiopathic hemolytic anemia with acute renal failure (hemolytic-uremic syndrome [HUS]) and death. There is a need for antimicrobials that would be effective against multiple bacterial enteropathogens yet not induce Stx release or increase the risk of HUS. Rifaximin has been evaluated in adults for treatment of bacterial enteritis and has a good record for safety and efficacy, but it has not been evaluated extensively in children with gastroenteritis. We therefore evaluated rifaximin's potential fo...
Rifaximin: a unique gastrointestinal-selective antibiotic for enteric diseases
Current Opinion in Gastroenterology, 2010
Purpose of review-Rifaximin is gaining attention for its potential activity in a multitude of gastrointestinal diseases. We review the unique pharmaceutical properties of this antibiotic and the published evidence in the literature regarding the use of rifaximin for different gastrointestinal disorders. Recent findings-Rifaximin is a gastrointestinal-selective antibiotic with a broad spectrum of antimicrobial activity, an excellent safety profile, minimal drug interactions, and negligible impact on the intestinal microbiome. Rifaximin is currently approved in the United States for the treatment of travelers' diarrhea caused by noninvasive diarrheagenic Escherichia coli and is approved in more than 30 other countries for a variety of gastrointestinal disorders. Considerable research with this medication has been conducted for the treatment and prevention of travelers' diarrhea, the treatment of portal systemic encephalopathy, Clostridium difficile infection, small bowel intestinal overgrowth, irritable bowel syndrome, inflammatory bowel disease, pouchitis, and colonic diverticular disease. Summary-Rifaximin is effective for the treatment of travelers' diarrhea and can be considered as the treatment of choice for uncomplicated travelers' diarrhea. When invasive travelers' diarrhea pathogens are suspected, an alternative antibiotic should be administered. Rifaximin appears promising as a chemoprophylaxis for travelers' diarrhea and as a treatment of portal systemic encephalopathy. This antibiotic may be effective for other gastrointestinal diseases, but more welldesigned clinical studies are needed to confirm its efficacy for these off-label indications. Future studies will determine whether the development of significant bacterial resistance will limit rifaximin use.
Rifaximin treatment for acute recurrent diarrhea in children with genitourinary disorders
Current Therapeutic Research-clinical and Experimental, 1998
This study was undertaken to investigate the suitability of rlf" for short-term treatment of acute bacterial diarrhea in children receiving long-term prophylactic therapy for urinary tract infections. Using a 2:l ratio, 46 children (mean age, 4.9 years) were consecutively assigned to receive either rlfazimin oral suspension (n = 30) or oral rehydration (control group, n = 16) for a mazimum of 6 days. After 6 days, in the rifazimln groups, 15 patients (50.0%) were cllnitally cured, 13 (43.3%) improved, and 2 (6.7%) had an lnsufflcient outcome. In the control group, 6 patients (31.2%) were clinically cured after 4 days, 2 patients (12.6%) improved after 5 days, 4 (26.0%) had a sufficient outcome, and 5 (31.2%) had an insufficient outcome. Stools normalized rapidly during treatment with rifazlnun-formed stools were detected in 24 children (80.0%) on treatment day 1. Only 2 patients still had watery stools after 6 days of treatment. In the control group, patients' stools normalized after 4 days ln 7 children (43.8%) and after 5 days in 2 (12.6%); stools had not normalized by the end of the 5-day period in the remaining 7 patients (43.8%). Overall, a quick and statistically significant remission of fever and other clinical symptoms was seen with rlfazimin. In the control group, symptoms were reduced more slowly. No adverse events, withdrawals, or dropouts occurred in the rifazlmin group. The rapidity, effectiveness, and safety of rifazlmln suggest that it is suitable for the treatment of acute recurrent episodes of diarrhea ln children periodically undergoing prophylactic therapy for other genitourinary pathologic conditions. Keg loor&: acute recurrent bacterlsl diarrhea, pediatrics, nonabsorbable antimlcroblals, rlfazimin.
Rifaximin: beyond the traditional antibiotic activity
Rifaximin is a non-systemic oral antibiotic derived from rifampin and characterized by a broad spectrum of antibacterial activity against Gram-positive and-negative, aerobic and anaerobic bacteria. Rifaximin was first approved in Italy in 1987 and afterwards in many other worldwide countries for the treatment of several gastrointestinal diseases. This review updates the pharmacology and pharmacodynamics of rifaximin highlighting the different actions, beyond its antibacterial activity, such as alteration of virulence, prevention of gut mucosal adherence and bacterial translocation. Moreover, rifaximin exerts some anti-inflammatory effects with only a minimal effect on the overall composition of the gut microbiota. All these properties make rifaximin a good candidate to treat various gastrointestinal diseases.
Revista de Gastroenterología de México (English Edition), 2016
Background: Bacterial resistance may hamper the antimicrobial management of acute gastroenteritis. Bacterial susceptibility to rifaximin, an antibiotic that achieves high fecal concentrations (up to 8,000 g/g), has not been evaluated in Mexico. Objective: To determine the susceptibility to rifaximin and other antimicrobial agents of enteropathogenic bacteria isolated from patients with acute gastroenteritis in Mexico. Material and methods: Bacterial strains were analyzed in stool samples from 1,000 patients with diagnosis of acute gastroenteritis. The susceptibility to rifaximin (RIF) was tested by microdilution (< 100, < 200, < 400 and < 800 g/ml) and susceptibility to chloramphenicol (CHL), trimethoprim-sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), fosfomycin (FOS), ampicillin (AMP) and ciprofloxacin (CIP) was tested by agar diffusion at the concentrations recommended by the Clinical & Laboratory Standards Institute and the American Society for Microbiology.