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Biomedical subjects

V Korten

Publications and source records attributed to V Korten.

13 recordsLinked to original sources

Influence of oral glycopeptides on the fecal flora of human volunteers: selection of highly glycopeptide-resistant enterococci.

Changes in fecal flora were evaluated in 22 healthy volunteers administered oral vancomycin or teicoplanin in 1989-1991 in Belgium. Evaluation of 5 colonies per subject revealed no glycopeptide-resistant enterococci in the predominant flora before glycopeptide administration; however, large numbers (mostly Enterococcus faecium) emerged by the end of the study in 14 (64%) of the subjects. Pediococci and lactobacilli also increased in number. In 1992, 40 healthy volunteers and 33 cancer patients were evaluated by plating stool samples directly onto selective media containing vancomycin; low numbers of vancomycin-resistant enterococci (< 50 cfu/g) were found in 11 (28%) of the 40 and 4 (12%) of the 33 samples, respectively. DNA restriction fragment length polymorphism analysis showed that most isolates were different, but all contained vanA in Tn1546-like elements. These results indicate that vanA and Tn1546-like elements were common in Belgium as early as 1989 and that community-based individuals in that location likely form a major reservoir for glycopeptide-resistant enterococci.

Adult

Antimicrobial prophylaxis in management of urinary tract stones by extracorporeal shock-wave lithotripsy: is it necessary?

OBJECTIVES: In a prospective randomized study, we evaluated the incidence of urinary tract infections following extracorporeal shock-wave lithotripsy (ESWL) and the necessity of prophylactic antibiotic administration in patients treated with this modality. METHODS: A total of 360 consecutive patients with renal and ureteric stones who had sterile urine before ESWL treatment and did not have any increased risk of infection received either a single dose of 400 mg of ofloxacin or no prophylaxis. Patients were followed by simple urine analysis and urine cultures together, with clinical evaluations. RESULTS: Only 3 patients (0.8%) had positive urine cultures at 1 week after ESWL. Two of these patients were in the antibiotic prophylaxis group. CONCLUSIONS: The incidence of urinary tract infections after ESWL is extremely low, provided that patients have sterile urine before ESWL, and prophylactic antibiotics are not required.

Adult

DU-6859a, a new fluoroquinolone agent. Comparative in vitro activity against enteric pathogens and multiresistant outpatient Escherichia coli.

The activity of DU-6859a, a new fluoroquinolone antimicrobial agent, was compared with that of ciprofloxacin by agar dilution susceptibility testing against enteric pathogens and multiresistant Escherichia coli. The results indicate that DU-6859a inhibits most of these organisms at concentrations similar to those of ciprofloxacin. DU-6859a showed increased activity compared to ciprofloxacin against Campylobacter species isolates.

Anti-Infective Agents

Comparative in vitro activity of DU-6859a, a new fluoroquinolone agent, against gram-positive cocci.

The in vitro activity of DU-6859a (DU), a new fluoroquinolone agent, was evaluated against 233 gram-positive cocci and was compared with those of ciprofloxacin, vancomycin, nafcillin, and ampicillin. The MICs of DU for 90% of the staphylococci tested were < or = 0.06 microgram/ml. All of the groups A and B and viridans group streptococci were inhibited by < or = 0.125 microgram of DU per ml, which was 32-fold more active than ciprofloxacin. On the basis of MICs for 90% of the strains tested, DU was 32- and 16-fold more active than ciprofloxacin against Enterococcus faecalis and Enterococcus faecium, respectively. The bactericidal activity of DU was demonstrated by time-kill techniques against all ciprofloxacin-susceptible enterococci. DU shows promise for the treatment of infections with gram-positive cocci and warrants further evaluation by in vitro and in vivo studies.

Anti-Bacterial Agents

Analysis by PCR and direct DNA sequencing of gyrA mutations associated with fluoroquinolone resistance in Enterococcus faecalis.

A region of gyrA, the gene encoding subunit A of DNA gyrase, that is known to be associated with resistance was amplified and sequenced from 16 Enterococcus faecalis and Enterococcus faecium isolates. Six ciprofloxacin-resistant clinical isolates (MICs of ciprofloxacin, 32 to 64 micrograms/ml) and one multistep resistant laboratory mutant of E. faecalis (MIC of ciprofloxacin, 128 micrograms/ml) contained a change from serine to arginine or to isoleucine at codon 83 or a change from glutamic acid to lysine or to glycine at codon 87 (Escherichia coli GyrA coordinates); these changes have been associated with fluoroquinolone resistance in other species. No difference in the region studied was found in two ciprofloxacin-resistant E. faecium isolates (MICs, 32 micrograms/ml) or in four laboratory derived, spontaneous ciprofloxacin-resistant mutants of E. faecalis (MICs, 8 to 16 micrograms/ml), suggesting that other mechanisms may be responsible for fluoroquinolone resistance in some enterococci.

Amino Acid Sequence

Treatment of intracranial abscesses: experience with sulbactam/ampicillin.

In an open prospective study, the efficacy of sulbactam/ampicillin (50 and 100 mg/kg, respectively, qid) was evaluated in 21 patients with intracranial abscess(es). Sixteen patients had cerebral, 3 epidural, and 2 cerebellar abscesses. Multiple lesions were found in 7 patients. Sixteen patients underwent surgical intervention, others were treated with antibiotic alone. The mean duration of antibiotic therapy (+/- SD) was 48 +/- 10 days (range 26-65 days). The mean duration of follow-up after completion of therapy (+/- SD) was 6 +/- 2.4 months. All patients had at least some reduction in size of abscess(es) within 3 weeks of the initiation of therapy as monitored by computerized tomography. Seventeen patients were cured, three patients died due to causes unrelated to their infection. One patient was reoperated since no clear improvement either clinically or radiologically was observed 18 days after the first operation. Side effects of sulbactam/ampicillin were minor and transient. Results obtained in this study indicate that sulbactam/ampicillin can be used in the treatment of intracranial abscesses, alone or with surgical intervention.

Adolescent

Impact of the fluoroquinolones on gastrointestinal flora.

A number of studies have been performed to evaluate the effect of the fluoroquinolones on gastrointestinal flora. The fluoroquinolones have only slight or no effect on the oropharyngeal flora, except when Neisseria, Haemophilus or Branhamella spp. are present. Studies have consistently shown that Gram-negative facultative bacteria of the lower intestinal flora are strongly suppressed during administration of these agents. Total faecal anaerobes are generally unchanged. The effect of the fluoroquinolones on Gram-positive bacteria is more variable with mild to moderate suppression reported with some agents. In view of the high faecal concentrations of the fluoroquinolones, the general lack of effect on anaerobes is surprising; it may be attributable to the large number of microorganisms found in faeces and faecal binding of the fluoroquinolones. Several recent studies suggest that the effects of some fluoroquinolones on faecal anaerobes and Gram-positive cocci may be more profound in certain patient populations such as bone marrow transplant recipients and patients undergoing gastrointestinal surgery. Colonisation with yeasts and the emergence of resistant bacterial strains have been reported during or after fluoroquinolone administration in some studies. Future studies will need to investigate the effect of the newer agents with greater activity against anaerobes and Gram-positive cocci on the gastrointestinal flora and to continue surveillance for resistant organisms.

Anti-Infective Agents

Subcutaneous nodules caused by Pseudomonas aeruginosa: healing without incision and drainage.

In a patient with multiple myeloma, numerous indurated, subcutaneous nodules and pyomyositis due to Pseudomonas aeruginosa were noted. These lesions resolved with ciprofloxacin plus ceftazidime therapy without surgical incision and drainage. Despite another course of cancer chemotherapy after total disappearance, there were no recurrences at the end of 3 months. Quinolones initially combined with other antipseudomonal beta-lactam agents may be the drugs of choice in the management of patients with subcutaneous nodules caused by P. aeruginosa.

Amikacin

[Group B streptococcal endocarditis].

In this article, a case of group B streptococcal endocarditis in a diabetic patient, taking immunosuppressive therapy because of dermatomyositis is reported.

Dermatomyositis

[Shigella serotypes and drug resistance patterns of strains isolated in Etimesgut, Turkey, in 1987].

Drug resistance patterns of shigella strains were investigated in a prospective manner in Etimesgut district during a period of 1 year. Thirty strains shigella were isolated, belonged to three subgroups with preponderance of Sh. flexneri (70%), followed by Sh. sonnei (27%) and Sh. boydii (3%). The resistance was highest with streptomycin (80%), followed by trimethoprim-sulfamethoxazole (TMP-SMZ) (53%) and ampicillin (43%). Only three strains (10%) were sensitive to all eight antibiotics tested. Sixteen (53%) were resistant to three or more antibiotics. The data showed an increase in resistance to the commonly used antimicrobial agents--namely IMP-SMZ and ampicillin. IMP-SMZ is no longer the drug of choice in severe shigellosis, at least in this region of Turkey.

Ampicillin Resistance