| 1. |
- Adamsson, I, et al.
(författare)
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Microbial ecology and treatment of Helicobacter pylori infections : Review
- 2000
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Ingår i: Journal of chemotherapy. - 1120-009X .- 1973-9478. ; 12:1, s. 5-16
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Forskningsöversikt (refereegranskat)abstract
- The aims of the present study were to investigate the ecological disturbances caused by four different anti-H. pylori regimens, to compare different methods for diagnosing H. pylori, and to study the genetic variability of H. pylori. The patients included in the study were all treated at the Center of Gastroenterology, Huddinge University Hospital, Karolinska Institute. All patients were H. pylori-positive before entering the study, confirmed by rapid urease test, histology, culture and urea breath test or PCR. Treatment regimens included in the study were omeprazole alone (OP), in combination with amoxicillin (OA), in combination with amoxicillin and metronidazole (OAM) and in combination with clarithromycin and metronidazole (OCM). Samples from the mouth (saliva and dental plaque), stomach (biopsies from the gastric mucosa in the corpus and in the antrum) and the intestine (feces) were collected before, during and after treatment. The oral microflora was challenged by the three treatment regimens including antimicrobial agents, with the emergence of resistant streptococci and staphylococci in the OCM group. Bacterial strains in the gastric mucosa increased in numbers during treatment in all treatment groups, probably due to the pH rise, which provides a better environment for the commensal microflora. This overgrowth was especially pronounced during treatment with omeprazole alone (OP), possibly due to the fact that a concomitant suppression exerted by the antimicrobial agents occurred in the other treatment groups. H. pylori was, on the other hand, suppressed during treatment in all treatment groups, possibly due to a direct effect of omeprazole and to the colonization resistance expressed by the normal microflora, An emergence of resistant commensal strains in the gastric mucosa was seen in the OCM and the OAM groups. The intestinal microflora was most altered in the OAM and the OCM groups, with persistent disturbances in the OCM group 4 weeks after treatment. The frequency of resistant Enterococcus spp, (OCM), Enterobacteriaceae spp, (OA and OAM) and Bacteroides spp, (OCM) was increased during and after treatment. Different detection methods for H. pylori were compared and PCR was shown to have higher sensitivity than other routine diagnostic tests. The patients in the present study seemed to be colonized with a single strain of H. pylori. Treatment failures in patients treated with OAM were caused by recrudescence. These four patients with relapsing H. pylori infection, were shown to be reinfected with the original H. pylori strain, indicating that H. pylori escapes treatment by a thus far unknown mechanism.
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| 2. |
- Edlund, Charlotta, et al.
(författare)
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Comparative effects of moxifloxacin and clarithromycin on the normal intestinal microflora
- 2000
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 32:1, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- Twelve healthy male subjects age range 24-40 y participated in the investigation. The trial was divided into 2 35-d periods. The 2 treatment regimens were: (i) 1 x 400 mg moxifloxacin tablet in the morning and 1 placebo tablet in the evening for 7 d; and (ii) 1 x 500 mg clarithromycin tablet in the morning and 1 x 500 mg clarithromycin tablet in the evening for 7 d. Each subject received firstly 1 treatment regimen and secondly the other treatment regimen. The wash-out period was 6 weeks between the two treatment regimens. Moxifloxacin caused significant decreases of enterococci and enterobacteria during the administration period while the numbers of staphylococci, streptococci, Bacillus and Candida were not affected. No impact on peptostreptococci, lactobacilli, Veillonella, Bacteroides or fusobacteria was observed, while bifidobacteria and clostridia decreased during moxifloxacin administration. The microflora was normalized after 35 d. Clarithromycin caused significant reduction of Escherichia coli while the numbers of enterococci, Enterobacter, Citrobacter, Klebsiella and Pseudomonas increased markedly. No significant changes in the numbers of staphylococci, streptococci, Bacillus and Candida were noticed. In the anaerobic microflora bifidobacteria, lactobacilli and clostridia were suppressed, while no changes in peptostreptococci, Veillonella, Bacteroides and fusobacteria were found. The microflora was normalized in all volunteers after 35 d.
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| 3. |
- Edlund, Charlotta, et al.
(författare)
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Effect on the human normal microflora of oral antibiotics for treatment of urinary tract infections
- 2000
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 46, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- Oral administration of antibiotics for treatment of urinary tract infections (UTIs) can cause ecological disturbances in the normal intestinal microflora. Poorly absorbed drugs can reach the colon in active form, suppress susceptible microorganisms and disturb the ecological balance. Suppression of the normal microflora may lead to reduced colonization resistance with subsequent overgrowth of pre-existing, naturally resistant microorganisms, such as yeasts and Clostridium difficile. New colonization by resistant potential pathogens may also occur and may spread within the body or to other patients and cause severe infections. It is therefore important to learn more about the ecological effects of antibacterial agents on the human microflora. The impact on intestinal microorganisms of oral antibiotics used for the treatment of UTIs is reviewed here. Ampicillin, amoxycillin and co-amoxiclav suppress both the aerobic and anaerobic intestinal microflora with overgrowth of ampicillin-resistant Enterobacteriaceae. Pivmecillinam also affects the intestinal microflora, suppressing Escherichia coli, but does not have a major effect on the anaerobic microflora. Several orally administered cephalosporins, such as cefixime, cefpodoxime, cefprozil and ceftibuten, reduce the number of Enterobacteriaceae and increase the number of enterococci. Colonization with C. difficile has also been observed. Fluoroquinolones eliminate or strongly suppress intestinal Enterobacteriaceae, but affect enterococci and anaerobic bacteria only slightly. When antimicrobial agents are prescribed for the treatment of UTIs, not only the antimicrobial spectrum of the agent but also the potential ecological disturbances, including the risk of emergence of resistant strains, should be considered.
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| 4. |
- Edlund, Charlotta, et al.
(författare)
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Pharmacokinetics and comparative effects of telithromycin (HMR 3647) and clarithromycin on the oropharyngeal and intestinal microflora
- 2000
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 46:5, s. 741-749
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Tidskriftsartikel (refereegranskat)abstract
- The pharmacokinetics in plasma and saliva of a new ketolide, telithromycin (HMR 3647), and the effect on the normal oropharyngeal and intestinal microflora were studied in healthy volunteers and compared with those of clarithromycin. Ten subjects received 800 mg telithromycin perorally once daily and 10 other subjects received 500 mg clarithromycin bid for 10 days. Blood, saliva and faecal specimens were collected at defined intervals before, during and after administration for pharmacokinetic and microbiological analyses. In subjects receiving telithromycin, the mean C(max), AUC and C(24) (24 h) in saliva exceeded the values obtained from plasma, while saliva and serum pharmacokinetic parameters were in the same range for the clarithromycin group. The quantitative ecological disturbances in the normal microflora during administration of telithromycin were moderate and comparable to those associated with clarithromycin administration. No overgrowth of yeasts or Clostridium difficile occurred. Emergence of resistant strains was seen in both treatment groups. Administration of both telithromycin and clarithromycin was associated with significant increases in MICs for intestinal Bacteroides isolates, which persisted 2 weeks after discontinuation of treatment. In addition, a significant emergence of highly clarithromycin-resistant a-haemolytic streptococci, intestinal enterococci and Enterobacteriaceae was detected at day 10 in the clarithromycin group. In conclusion, administration of telithromycin resulted in high drug levels in saliva, which indicates a good therapeutic profile for throat infections. Telithromycin seems to have a more favourable ecological profile compared with clarithromycin in terms of resistance development in the normal microflora.
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| 5. |
- Lund, Bodil, et al.
(författare)
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Impact on human intestinal microflora of an Enterococcus faecium probiotic and vancomycin
- 2000
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 32:6, s. 627-632
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were to evaluate the impact of a fermented milk product containing viable Enterococcus faecium on human intestinal microflora and to evaluate any risk of development of vancomycin-resistant enterococci (VRE). Twenty Danish and 20 Swedish healthy volunteers were given 150 mi of the fermented mill;. product once daily, equivalent to a daily dose of 4.5 x 10(9) to 7.5 x 10(9) CFU E. faecium, for 10 d. Half of the volunteers also received 125 mg vancomycin orally q.i.d. for 10 d. Faecal samples were collected on day 0 before intake, on day 10 directly after end of intake and on day 31, 3 weeks after the end of the experiment. There,Fas a significant increase in the total number of enterococci on day 10 (p < 0.01) in the group receiving only the E. faecium supplement, but 3 weeks later the level was as before intake. In the vancomycin group, the total number of enterococci was reduced on day 10 (p < 0.01) but had increased on day 31 (p < 0.01) in relation to day 0. In none of the Swedish and 4 of the Danish volunteers, VRE were sporadically detected, but without relation to intake of the probiotic or vancomycin. In healthy young Danish individuals the VRE carrier rate tended to be higher than previously found.
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| 6. |
- Oh, H, et al.
(författare)
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Ecological disturbances in intestinal microflora caused by clinafloxacin, an extended-spectrum quinolone
- 2000
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Ingår i: Infection. Zeitschrift für Klinik und Therapie der Infektionen. - : Springer Science and Business Media LLC. - 0300-8126 .- 1439-0973. ; 28:5, s. 272-277
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Tidskriftsartikel (refereegranskat)abstract
- Background: The quinolones developed over the past few years have enhanced in vitro activity and a broader spectrum of antimicrobial activity compared to ma ny other antimicrobial agents including the older quinolones. The present study focuses on the effect of clinafloxacin, a member of the new broad-spectrum quinolone class of antibiotics, on the normal intestinal microflora. Subjects and Methods: A total of it healthy volunteers received clinafloxacin orally, zoo mg twice daily for 7 days. Fecal specimens were collected at defined intervals before, during and after the administration in order to study the effect of clinafloxacin on the intestinal microflora and to correlate this effect with fecal clinafloxacin concentrations. Intestinal microorganisms isolated before, during and 2 weeks after clinafloxacin administration were tested for their suseptibility to clinafloxacin. Results: Oral administration of clinafloxacin resulted in high drug levels in feces (mean value 176.2 mg/kg on day 7) and pronounced ecological disturbances. The aerobic microflora was eradicated in 11 of the 12 subjects and the anaerobic microflora was strongly suppressed during administration. There was a significant emergence of clinafloxacin-resistant Bacteroides spp, strains (MIC greater than or equal to 4 mg/ml) during administration. The elevated MIC values still remained 2 weeks after discontinuation of the antibiotic (p < 0.001). Conclusion: The emergence of clinafloxacin-resistant Bacteroides spp. demonstrates the necessity of restricting prescription for particular indications in order to preserve the efficacy of the highly active broad-spectrum quinolones.
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