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H Colding

Publications and source records attributed to H Colding.

At least 19 recordsLinked to original sources
PubMed1997

Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time.

No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study to determine the influences of medium, inoculum density, and incubation time. Seven media were investigated and were primarily evaluated on the basis of their abilities to support growth both semiquantitatively and qualitatively; Iso-Sensitest agar supplemented with 10% horse blood was found to be well suited for the purpose; this was closely followed by Mueller-Hinton agar with 10% horse blood, Mueller-Hinton with 10% sheep blood, and finally, 7% lysed horse blood agar. Investigations of two inoculum densities and two incubation times resulted in recommendations for the use of 10(9) CFU/ml (10[6] CFU/spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase. Consequently, susceptibility testing of all H. pylori strains is recommended in order to survey the development of resistance, and in our hands the described methodology was relatively easy to perform and the results were easy to read.

Animals↗
PubMed1996

Comparison of ribotyping and genome fingerprinting of Pseudomonas aeruginosa isolates from cystic fibrosis patients.

Forty Pseudomonas aeruginosa strains, previously characterized by pulsed-field gel electrophoresis, were ribotyped with EcoRI, BamHI, ClaI, and PvuII. Ribotyping with PvuII proved to be as discriminatory as pulsed-field gel electrophoresis with XbaI or DraI while EcoRI and BamHI were not. ClaI contributed further ribotypes, some of which might be due to a transposable element.

Bacteriological Techniques↗
PubMed1995

Ribotyping on small-sized spirochetes isolated from subgingival plaque.

In the present study DNA restriction patterns and corresponding ribotypes of 17 subgingival small-sized spirochetes (1:2:1 and 2:4:2 isolates), 2 Treponema socranskii strains and two Treponema denticola strains were examined. Purified chromosomal DNA was digested by BamHI, HindIII, PstI and ClaI. The DNA fragments were separated in a horizontal slab of 0.7% agarose containing ethidium bromide and transferred by nylon membranes. Hybridization was carried out with digoxigenin-labelled copy DNA of 16S and 23S ribosomal RNA from Escherichia coli. Depending on the restriction endonuclease used, up to 4 distinct bands were observed for the 2:4:2 isolates and the T. denticola strains. For each of the endonucleases used, identical band patterns were always observed for this group of isolates, and these patterns differed persistently from the T. denticola strains. For the 1:2:1 strains, up to 11 distinct bands were observed after digestion with HindIII, whereas a maximum of 6 bands were observed when PstI or ClaI was used. By using ClaI, the examined 1:2:1 isolates were separated into 8 groups, whereas PstI and HindIII separated these isolates into 5 groups. The ribotyping showed that the tested 1:2:1 spirochetes were more heterogeneous than the 2:4:2 spirochetes examined.

Bacterial Typing Techniques↗
PubMed1995

Restriction fragment length polymorphism of rRNA genes for molecular typing of members of the family Legionellaceae.

Typing of Legionella pneumophila remains important in the investigation of outbreaks of Legionnaires' disease and in the control of organisms contaminating hospital water. We found that the discriminatory power of a nonradioactive ribotyping method could be improved by combining results obtained with four restriction enzymes (HindIII, NciI, ClaI, and PstI). Fifty-eight clinical and environmental L. pneumophila strains including geographically unrelated as well as epidemiologically connected isolates were investigated. Epidemiologically related strains had the same ribotypes independent of the combinations of enzymes used. Some strains belonging to the same serogroup were assigned to different ribotypes, and some ribotypes contained members of different serogroups, indicating, as others have found, that serogroup and genotype are not always related. The discriminatory power of the method was estimated by calculating an index of discrimination (ID) for individual enzymes and combinations thereof. The combined result with all four enzymes was highly discriminatory (ID = 0.97), but results for three enzymes also yielded ID values acceptable for epidemiological purposes. In addition, the testing of 27 type strains and 6 clinical isolates representing Legionella species other than L. pneumophila indicated that ribotyping might be of value for species identification within this genus, as previously suggested.

Bacterial Typing Techniques↗
PubMed1994

Ribotyping for differentiating Flavobacterium meningosepticum isolates from clinical and environmental sources.

On the basis of DNA-DNA hybridization data, two main genomic relatedness groups (I and II) have been reported for a geographically varied collection of 52 strains of Flavobacterium meningosepticum. Herein, we have shown that genomic group II can be further divided into four subgroups (II:1 to II:4). To examine the taxonomic relevance of the ribosomal patterns of the 52 F. meningosepticum strains, the patterns were compared with existing DNA-DNA hybridization data with restriction enzymes PstI and HindIII. Ribotyping of the 52 F. meningosepticum strains showed banding patterns that could identify them correctly to one of the five genomic groups or subgroups. To assess the value of ribotyping for the interpretation of epidemiological data, the discriminatory power of the method was investigated for the 52 F. meningosepticum strains. With one to four restriction enzymes (PstI, HindIII, ClaI, EcoRI), a discriminatory index of 0.95 to 0.97 was found. The value of ribotyping in an epidemiological setting was assessed for three clinical isolates of F. meningosepticum from an outbreak of meningitis and bacteremia in the neonatal intensive care unit, Rigshospitalet, Copenhagen, Denmark. The three clinical isolates were shown to belong to the same ribotype, characteristic of genomic subgroup II:1. This ribotyping method will prove to be a useful tool for epidemiological studies concerning F. meningosepticum in the future.

Bacteremia↗
PubMed1992

Enzymuria in neonates receiving continuous intravenous infusion of gentamicin.

Urinary excretion of the tubular enzymes NAG and AAP was investigated during gentamicin treatment of 105 newborn infants. The values found for NAG and AAP show a significant positive correlation. The urinary excretion of NAG was on the average 92% higher during gentamicin treatment as compared with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP as an index of nephrotoxicity. The changes in NAg and AAP within treatment periods were studied. During gentamicin treatment an insignificant average increase in the urinary excretion of NAG occurred, whereas a significant decrease was found during non-treatment periods. A significant negative correlation was found between urinary excretion of NAG and birth weight/gestational age. The long-term effect of the higher excretion of NAG and AAP in newborn and adult patients during aminoglycoside treatment is unknown.

Acetylglucosaminidase↗
PubMed1989

Auditory function after continuous infusion of gentamicin to high-risk newborns.

Audiometry was performed at four years of age in 69 of 105 surviving children who had received continuous intravenous infusion of gentamicin during neonatal intensive care. A hearing loss of 20 dB was found in 2 of them (3%), corresponding to that shown in other studies of survivors following neonatal intensive care. Free field audiometry performed in another 7 children and questionnaires returned from 13 of the remaining 29 gave no suspicion of hearing loss. Thus there is no indication that continuous 24 hours intravenous infusion of gentamicin causes more hearing impairment than intermittent intravenous or intramuscular administration.

Audiometry↗
PubMed1988

Stability of ampicillin, piperacillin, cefotaxime, netilmicin and amikacin in an L-amino acid solution prepared for total parenteral nutrition of newborn infants.

The stability of ampicillin, piperacillin and cefotaxime, alone or in combination with either netilmicin or amikacin, was tested by microbiological methods at 29 degrees C (ampicillin, also at 22 degrees C) in an L-amino acid solution specially prepared for newborn infants. In the case of ampicillin, the mean concentration had dropped to 84% of the initial value after 24 hours. This fall is acceptable. Piperacillin and cefotaxime were stable. Admixture of netilmicin or amikacin did not affect the activity of ampicillin, piperacillin and cefotaxime. The concentrations of netilmicin and amikacin were stable for 24 hours. Combination with ampicillin, piperacillin or cefotaxime did not affect the activity of either aminoglycoside. The antibiotics investigated could therefore be used in our TPN infusion system.

Amikacin↗
PubMed1984

[Erythromycin].

Explore the source record for details and available documents.

Drug Resistance, Microbial↗
PubMed1984

Continuous intravenous infusion of ampicillin and gentamicin during parenteral nutrition to 36 newborn infants using a dosage schedule.

Ampicillin and gentamicin were given continuously i.v. to 36 newborn infants using a dosage schedule and the results were compared with those obtained in an earlier study including 88 infants who received individually calculated dosages. With the dosage schedule the variation in the serum concentrations of antibiotics was smaller in the same child throughout the treatment course, but greater between the infants. The 95% limits for the serum concentrations of antibiotics were, however, nearly the same in the two treatment groups, and the use of a dosage schedule is therefore recommended. Serum gentamicin concentration should be assayed about 3 half lives (18 hours) after beginning the treatment, and dosage adjustment be made if the serum gentamicin concentration is outside 3-5 micrograms/ml.

Ampicillin↗
PubMed1983

Kinetics and dose calculations of ampicillin and gentamicin given as continuous intravenous infusion during parenteral nutrition in 88 newborn infants.

Ampicillin and gentamicin were administered continuously intravenously to 88 newborn infants using individually calculated dosages. For infants with a mean value of plasma clearance of the antibiotics, it was calculated that the serum ampicillin and gentamicin concentrations would be between 35-55 and 3-5 micrograms/ml, respectively, using the dosages for intermittent treatment. These dosages are therefore recommended as fixed dosages for continuous intravenous infusion initiated by a bolus dosage. Serum gentamicin concentration should be assayed about three half-lives after start of infusion and the dosage adjusted for values outside 3-5 micrograms/ml.

Ampicillin↗
PubMed1982

Continuous intravenous infusion of ampicillin and gentamicin during parenteral nutrition in 88 newborn infants.

Ampicillin and gentamicin were dissolved once a day in an L-amino acid solution especially prepared for parenteral nutrition of newborn infants and infused continuously to 88 infants in whom septicaemia was suspected or had been proved. The mean dosages were 162 and 5.3 mg/kg per 24 hours respectively, and the 95% limits for the serum concentrations were 11-133 and 1.3-7.4 micrograms/ml. The treatment results were at least as good as with intermittent intramuscular or intravenous administration. This new mode of giving antibiotics is less painful to the babies and easier for the nurses.

Ampicillin↗
PubMed1982

Administration of gentamicin and ampicillin by continuous intravenous infusion to newborn infants during parenteral nutrition.

Gentamicin and ampicillin were dissolved in an L-amino acid solution especially prepared for newborn infants and infused intravenously over 24 h in 7 babies with serious neonatal surgical problems. Serum concentrations of the antibiotics were maintained rather constant and well above the minimal inhibitory concentration for most bacterial strains. One very sick newborn infant died with overwhelming Klebsiella pneumoniae septicemia. No signs of renal toxicity or ototoxicity were found. The serum amino acids remained within the normal range, except in 1 child with cytomegalovirus infection and liver insufficiency.

Amino Acids↗
PubMed1978

Stability of antibiotics and amino acids in two synthetic L-amino acid solutions commonly used for total parenteral nutrition in children.

The stability and interaction at 29 degrees C of ampicillin, carbenicillin, gentamicin, and polymyxin B were examined in a common electrolyte solution, invertose darrow, and in two synthetic l-amino acid solutions, one commercial (vamin with fructose; Vitrum) and the other a neonatal preparation modified for use in newborn infants. The concentration of amino acids was measured before and after the addition of these antibiotics. The concentration of antibiotics was measured over a 24-h period with a microbiological method. The concentration of ampicillin in invertose darrow fell 52%, and in vamin with fructose it fell 69%, whereas in the neonatal preparation the fall was only 22%. The concentration of carbenicillin in vamin with fructose fell 37%, and in the neonatal preparation it fell 31%. The combination of ampicillin or carbenicillin with gentamicin or polymyxin B did not influence the activity of the penicillins. The concentration of gentamicin and polymyxin B was unchanged in all solutions over a 24-h period. With the exception of cystine, the concentration of all amino acids remained constant after 24 h in the neonatal preparation with and without the different combinations of antibiotics. For cystine there was a fall of 20 to 30%.

Amino Acids↗