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Biomedical subjects

R Vanhoof

Publications and source records attributed to R Vanhoof.

At least 55 records · Page 3Linked to original sources

In-vitro activity of 21 antimicrobial agents against Neisseria gonorrhoeae in Brussels.

The minimum inhibitory concentrations (MIC) of 21 antimicrobial agents was measured for 80 strains of Neisseria gonorrhoeae isolated in Brussels in 1978. Bimodal distributions were found for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin. Of the strains, 17.5% were relatively resistant to penicillin G (MIC greater than 0.08 microgram/ml) 27.5% to ampicillin (MIC greater than 0.16 microgram/ml), 23.8% to amoxycillin, and 43.3% to carbenicillin. Cefotaxime was the most active antibiotic, with MICs in the nanogram range; 3.8% and 5% of the strains were relatively resistant to cephaloridine and cephalexin respectively, but no strains were resistant to cefazolin, cefuroxime, or cefotaxime. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than 1 microgram/ml) was found in 6.3%, 2.5%, 5%, and 51.3% of the strains respectively. A very good correlation was present between chloramphenicol and thiamphenicol, with 16.3% and 10% of relatively resistant strains respectively. Only two isolates showed an MIC greater than 1.25 microgram/ml for rifampicin, and 10% of the strains needed greater than or equal to 12 microgram/ml of spectinomycin for complete inhibition of growth. A very high energy was found for the 20 : 1 combination of sulphamethoxazole and trimethoprim, with only one isolate resistant to this combination. None of the strains tested produced beta-lactamase.

Anti-Bacterial Agents↗

Cefotaxime therapy of serious infections with multiresistant gram-negative bacilli.

33 patients with serious gram-negative bacillary infections were treated with cefotaxime. In patients with normal renal function the dose varied between 1.5 to 4 g/day. 17 patients had urinary tract infections, 5 respiratory tract infections, 1 combined urinary tract infection and respiratory tract infection, and 10 miscellaneous infections. 16 patients had septicemia. 25 infections were due to pathogens resistant in vitro to ampicillin, cephalothin, gentamicin and/or tobramycin. 15 infections had failed to respond to ampicillin, cefazolin, gentamicin or tobramycin therapy. 32/33 patients responded favourably to cefotaxime (cure or improvement) but 4 patients developed superinfection with cefotaxime-resistant bacteria. No evidence of nephrotoxicity was observed except for a transient moderate rise in creatinine in one patient.

Adult↗

[Cefotaxime in the treatment of severe infections due to multiresistant Gram-negative bacilli (author's transl)].

Cefotaxime was used to treat 33 patients with serious Gram-negative bacillary infections. The dosage varied between 1.5 g and 4 g/day in patients without renal failure. Eighteen patients had urinary tract infections, 6 had pulmonary infections and 10 had miscellaneous infections. Sixteen patients were also bacteremic. Twenty-five infections were due to pathogens resistant to ampicillin, cephalothin, gentamicin and/or tobramycin, in vitro. Fifteen infections had failed to resolve during ampicillin, cefazolin, gentamicin or tobramycin therapy. Thirty-two patients responded favourably (cure or improvement). Four patients developed superinfection with cefotaxime-resistant bacteria. One patient developed mild reversible renal insufficiency. Cefotaxime is a very active cephalosporin with potential use in serious multi-resistant enterobacteria infections.

Acinetobacter Infections↗

Bacteriostatic and bactericidal activities of 24 antimicrobial agents against Campylobacter fetus subsp. jejuni.

The bacteriostatic and bactericidal activities of 24 antimicrobial agents were tested with the Dynatech MIC 2000 system against 86 strains of Campylobacter fetus subsp. jejuni from human sources. The penicillins (penicillin G, ampicillin, amoxycillin, carbenicillin) had poor activity. Ampicillin and amoxycillin were equally active. Cefotaxime revealed a rather good activity. Erythromycin, gentamicin, tobramycin, amikacin, and furazolidone were the most active compounds. Two strains (2.3%) were resistant to erythromycin. One strain (1.2%) was completely resistant to tobramycin. The tetracyclines (tetracyline, doxycycline, minocycline) were generally effective, but 8% of the strains were totally resistant to them. Minocycline was the most active. Chloramphenicol, thiamphenicol, and clindamycin had good activity. The bacteriostatic and bactericidal distributions for colistin, nalidixic acid, and metronidazole were broad.

Anti-Bacterial Agents↗

Clinical and pharmacological evaluation of different preparations of oral erythromycin.

The activity of erythromycin stearate in respiratory tract infections was evaluated. This study involved 269 out-patients. Of these, 76 satisfied the strict criteria for detailed bacteriological study with positive cultures of a known pathogen before treatment and bacteriological follow-up after treatment. The results of erythromycin stearate were good against the haemolytic streptococcal infections. The activity of this antibiotic was shown to be insufficient against Haemophilus influenzae. A second clinical trial with 20 patients with acute exacerbations of chronic bronchitis demonstrated quite good activity from erythromycin ethylsuccinate and no intolerance when administered in a dose of 1 g q.i.d. The administration of 1 g of the ethylsuccinate immediately after a meal gave a peak serum concentration after 60 min of 3.36 micrograms/ml. Blood levels on the fourth day of this treatment showed some accumulation, concentrations of greater than 4 micrograms/ml being found at 30, 60 and 90 min after the dose. With its good absorption, its lack of toxicity and its reputation for good diffusion into bronchial secretions, we consider that erythromycin ethylsuccinate should have a major place in the treatment of respiratory tract infections.

Administration, Oral↗

Amoxicillin entry into human cerebrospinal fluid: comparison with ampicillin.

The entry of amoxicillin and ampicillin into cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twelve volunteers received 33 mg of amoxicillin per kg intravenously over 30 min and nine volunteers received 33 mg of ampicillin per kg. The CSF specimens were sampled at 1, 2, and 4 h after the beginning of the infusion. Blood samples were obtained at the end of the infusion and at 45, 60, 90, 120, 180, and 240 min after the beginning of the infusion. Amoxicillin and ampicillin were both detected in the CSF. Ampicillin tended to give higher CSF levels than amoxicillin, although the difference was small. Serum concentrations of ampicillin equaled those of amoxicillin.

Adult↗

Susceptibility of Campylobacter fetus subsp. jejuni to twenty-nine antimicrobial agents.

The activity of 29 antimicrobial agents was tested against 95 strains of Campylobacter fetus subsp. jejuni isolated from human stools. Furazolidone and gentamycin were the most active agents. The tetracyclines, erythromycin, and chloramphenicol were very active against most of the strains, but with each antibiotic a few resistant strains were found. The penicillins were relatively inactive, and the cephalosporins tested were only active against occasional strains.

Anti-Bacterial Agents↗

In-vitro activity of antimicrobial agents against Neisseria gonorrhoeae in Brussels.

The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents against 104 strains of Neisseria gonorrhoeae isolated in the Brussels area between January and October 1976 have been measured. The MICs for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin showed a bimodal distribution. The second modus strains of cephalexin (MIC = 6.25 microgram/ml) were relatively resistant to penicillin G (MIC greater than or equal to 0.08 microgram/ml). About 51% of all strains were relatively resistant to penicillin G, 40.5% to ampicillin (MIC greater than or equal to 0.16 microgram/ml), 46% to amoxycillin, and 47.5% to carbenicillin. For cephalexin and cephaloridine, 25% and 8.5% respectively of all strains were relatively resistant (MIC greater than 3.12 microgram/ml). For cefazolin all MICs fell into a range of 0.097--3.12 microgram/ml. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than or equal to 1 microgram/ml) was found in 9.5%, 7%, 6%, 36.5%, and 71% respectively of all isolates. No strains were resistant to rifampicin. For chloramphenicol and thiamphenicol the MICs ranged from 0.39 to 12.5 microgram/ml and from 0.195 to 3.12 microgram/ml respectively. The results for sulphamethoxazole, trimethoprim, and the combination of sulphamethoxazole and trimethoprim in a 20:1 ratio are given and discussed. The fractional inhibitory concentration (FIC) indices have also been calculated. No beta-lactamase-producing strains were found, and a contingency coefficient C has been determined for all the pairs of antibiotics investigated.

Anti-Bacterial Agents↗

Moxalactam therapy of serious infections.

Twenty-four patients were treated with moxalactam for 25 serious infections. Nineteen patients were septicemic and 18 presented severe underlying diseases considered to impair the normal response to bacterial pathogens. All of the pathogens had MICs of less than 12 mg/l except one Pseudomonas aeruginosa strain with an MIC of 32 mg/l. The dosage ranged from 3 to 12 g/day; the route of administration was either i.v. or i.m. The duration of treatment was six to 26 days. Six patients had urinary tract infections (three bacteremia), four had pulmonary abscesses (two bacteremia), five had septic thrombophlebitis (five bacteremia) and ten had miscellaneous infections (nine bacteremia). Twenty-two (92%) patients responded favourably. Four patients (16.6%) developed superinfections due to organisms highly resistant to moxalactam: three Streptococcus faecalis, one Bacteroides fragilis and one Aspergillus flavus. Tolerance was good. Nine moderate adverse reactions were observed: three cases of transient eosinophilia, two of phlebitis, three hepatic enzyme alterations and one rash. Moxalactam kinetics were measured in serum from 15 patients with normal renal function after receiving 1 g i.v. over 30 min. The mean peak level after the infusion was 82.8 +/- 12.1 (SE) mg/l; the mean trough level 8 h later was 6.2 +/- 1.7 (SE) mg/l. The serum half-life was 2.6 +/- 0.6 (SE) h for the beta phase. Plasma clearance was 76.8 +/- 8.2 ml/min. Moxalactam was found to be highly effective in the therapy of life-threatening infections.

Adult↗

The comparative activity of pefloxacin, enoxacin, ciprofloxacin and 13 other antimicrobial agents against enteropathogenic microorganisms.

In this study, we compared the activity of pefloxacin, enoxacin and ciprofloxacin against 269 enteropathogenic strains (Campylobacter jejuni, enteropathogenic Escherichia coli, Salmonella typhi, Shigella spp., Vibrio cholerae and Yersinia enterocolitica) with that of rosoxacin, flumequin, nifuroxazide, erythromycin, chloramphenicol, ampicillin, cefotaxime, tetracycline, amikacin, netilmicin, sulfamethoxazole, trimethoprim and co-trimoxazole. Pefloxacin, enoxacin and ciprofloxacin were always among the most active compounds. Furthermore, resistant strains or strains with elevated MIC values were not found. The MIC90 value for these three compounds was less than or equal to 0.25 mg/l, except for C. jejuni where it was 0.3 mg/l and 1.4 mg/l for pefloxacin and enoxacin, respectively.

Animals↗

In vitro study on the antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae from Belgium collected during winter 1998-1999.

A total of 205 isolates of Streptococcus pneumoniae obtained from 10 different centres were included in this study. The susceptibilities to penicillin, ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, grepafloxacin, levofloxacin, trovafloxacin, erythromycin, clarithromycin, miocamycin, clindamycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 16.1% [6.8% intermediate (0.12-1 microgram/mL) and 9.3% high-level (> or = 2 micrograms/mL)], cefotaxime insusceptibility (> or = 1 microgram/mL) 12.7%, ciprofloxacine insusceptibility (> or = 2 micrograms/mL) 15.6% with 1.5% of high level resistance (> or = 4 micrograms/mL), erythromycin insusceptibility (> or = 0.5 microgram/mL) 36.1% and tetracycline insusceptibility (> or = 4 micrograms/mL) 22.9%. Decreased susceptibility to cefotaxime was found in 78.8% of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (> or = 0.5 microgram/mL) and trovafloxacin (> or = 1 microgram/mL). Compared to the 1996-1997 surveillance, penicillin, cefotaxime and erythromycin insusceptibility rose by 3.8%, 5.2% and 5.0% respectively, while tetracycline insusceptibility decreased with 8.2%. MICs of all beta-lactams rose with those of penicillin for penicillin-insusceptible isolates. Amoxicillin +/- clavulanate, cefotaxime and imipenem were generally 1, 1 and 5 doubling dilutions respectively more potent than penicillin on these isolates. Penicillin, ampicillin and cefuroxime were equally active while cefaclor was generally 5 dilutions less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin +/- clavulanate and imipenem. The penicillin-insusceptible isolates were 36.4%, 27.3% and 3.0% co-insusceptible to erythromycin, erythromycin plus tetracycline and tetracycline respectively. A subpopulation of 52 isolates obtained from children aged < or = 3 years was also studied. Compared to the other isolates we found a statistically significant increase in insusceptibility for penicillin, cefaclor, cefuroxime, erythromycin, clarithromycin and tetracycline while a significant decrease was found for ciprofloxacin.

Adolescent↗

Study of the in vitro activity of amoxicillin/clavulanic acid and other beta-lactam antibiotics against Escherichia coli isolated from urine specimens.

A total of 205 serial, unduplicated urinary isolates of Escherichia coli was collected from June through August 1998 in 2 community and 3 hospital laboratories. By using the NCCLS broth microdilution technique, their in vitro susceptibility to ampicillin, amoxicillin/clavulanic acid, cefuroxime, cefuroxime axetil, ticarcillin/clavulanic acid and piperacillin/tazobactam was determined. One hundred and twenty isolates were from hospitalised patients, 85 from ambulatory, 129 community acquired and 76 nosocomial. Half of the nosocomial isolates were obtained from naturally produced and half from alternatively produced urine specimens. In general, the highest susceptibility rates, following NCCLS criteria, were found for piperacillin/tazobactam (93.2%) followed by cefuroxime (92.2%) and amoxicillin/clavulanic acid (82.9%). Ampicillin showed a clear bimodal distribution with a clear peak for the resistant population. The highest degree of ampicillin resistance was found in nosocomial isolates. Overall, ampicillin showed the lowest degree of susceptibility. Most of the ampicillin resistant isolates remained susceptible to piperacillin/tazobactam, cefuroxime and amoxicillin/clavulanic acid. In general, the community acquired isolates had higher susceptibility rates than the nosocomial isolates.

Amoxicillin-Potassium Clavulanate Combination↗

Comparative in vitro activity of temocillin and other antimicrobial agents against Enterobacteriaceae isolated from patients admitted to five Belgian hospitals.

Temocillin, a methoxy-derivative of the broad-spectrum penicillin, ticarcillin, has been introduced into clinical practice in Belgium in 1988. Since then, not many surveys of its in vitro activity have been published. This study addresses this issue in a prospective collection of 300 consecutive Gram-negative isolates originating from in-patients in five general hospitals throughout Belgium. In addition to temocillin, seven common antibiotics were tested: amoxicillin-clavulanate, piperacillin-tazobactam, cefotaxime, aztreonam, meropenem, ciprofloxacin and amikacin. Meropenem appeared to exhibit the best activity overall, whereas amoxicillin-clavulanate scored the worst. Cumulative MIC plot for two subsets of organisms are given: temocillin, meropenem and cefotaxime are the most active on E. coli and Klebsiella spp., while a significant percentage is resistant to ciprofloxacin and amoxicillin-clavulanate. In the group of inducible Enterobacteriaceae, temocillin, meropenem and amikacin are the most active drugs, while the activity of amoxicillin-clavulanate, piperacillin-tazobactam, cefotaxime and ciprofloxacin is largely decreased. Taking this well preserved in vitro activity of temocillin into account, and looking at its convenient pharmacokinetics and low cost of acquisition, this drug may prove a useful alternative in the treatment of severe nosocomial infections.

Anti-Bacterial Agents↗

High prevalence of penicillin resistance and comparative in vitro activity of various antibiotics in clinical isolates of streptococcus pneumoniae isolated in the Province of Hainaut during winter 2004.

A total of 154 isolates of Streptococcus pneumoniae obtained from 8 different centres in the province of Hainaut were included in this study. The susceptibilities to penicillin, amoxicillin, cefuroxime, ciprofloxacin, moxifloxacin, erythromycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 32.5% (23.4% intermediate and 9.1% high-level). The other insusceptibility rates were as follows: amoxicillin 1.9% [0% Resistance (R)], cefuroxime 23.4% (R 22.1%), ciprofloxacin 9.1% (R 1.3%), erythromycin 39.6% (R 38.3%), and tetracycline 31.8% (R 30.5%). No decreased susceptibility was found for moxifloxacin. MICs of amoxicillin, cefuroxime, erythromycin and tetracycline rose with those of penicillin for penicillin-insusceptible isolates. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin (94%), while moxifloxacin and ciprofloxacin kept an activity on 100% and 92% of these isolates respectively. Phenotypes with triple or quadruple insusceptibility were present in 31.2% of the isolates. Penicillin-insusceptible isolates showed a co-insusceptibility of 36.7% to erythromycin, 30.0% to tetracycline and 3.3% to ciprofloxacin.

Adolescent↗