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P Sandven

Publications and source records attributed to P Sandven.

At least 55 records · Page 3Linked to original sources
PubMed1987

Evaluation of two vacuum bottle blood culture media--supplemented peptone broth and brain heart infusion broth.

A new blood culture medium (brain heart infusion broth) (BHI) from Terumo was compared with a commonly used blood culture medium, supplemented peptone broth (Becton Dickinson) (SPB). Blood from patients with suspected bacteraemia was simultaneously cultured in the two media, approximately five ml of blood in each bottle. Both bottles were incubated aerobically at 37 degrees C for 7 days. A total of 3724 paired blood cultures (sets) were processed. Altogether 340 (9.1%) of the blood culture sets were positive. Of these, 233 were positive in both media, 51 in the SPB medium only and 56 in the BHI medium only. Despite the similar overall results, Streptococcus spp. and anaerobic bacteria were detected more frequently in the SPB bottles and Enterobacteriaceae more frequently in the BHI bottles.

Bacteria, Anaerobic↗
PubMed1985

Effect of aerobic and anaerobic atmosphere on the detection of micro-organisms from blood cultures.

Blood from patients with suspected bacteraemia was simultaneously cultured in two Vacutainer blood culture bottles containing 45 ml of supplemented peptone broth (Becton Dickinson), five ml of blood in each bottle. The cultures were incubated at 37 degrees C for seven days. One of the bottles was vented and the other unvented. A total of 3958 blood culture sets were processed during the 20-month period of the study. Altogether 438 (11%) of the blood culture sets were positive. Of the 438 isolates, 317 (72%) were detected in both bottles, 61 (14%) in the vented bottle and 60 (14%) in the unvented bottle. A total of 60 (14%) isolates would not have been detected if only five ml of blood had been cultured. Only minor differences in the isolation rates of different bacterial and fungal species from the vented and unvented bottles were found. The results indicate that aerobic incubation of Vacutainer bottles with supplemented peptone broth is sufficient in routine diagnostic work.

Aerobiosis↗
PubMed1984

Effect of temperature on the survival of Neisseria meningitidis.

The effect of different temperatures and variations in temperature on the survival of Neisseria meningitidis in modified Stuart transport medium and in human cerebrospinal fluid (CSF) has been investigated. The meningococcal strains examined died quickly during storage at 37 degrees C, while storage at 4 degrees C and 22 degrees C caused only a moderate decrease in their viability. Short periods of temperature variations during storage at 22 degrees C in transport medium were found to be harmful only when the specimens were kept at -20 degrees C for these short periods. According to our results, 37 degrees C storage temperature cannot be recommended for specimens such as those examined. As 4 degrees C may be harmful to H. influenzae one cannot generally recommend keeping specimens from meningitis patients in refrigerator until analyzed. Room temperature therefore seems preferable. Specimens inoculated onto growth-supporting media should of course contrarily be incubated at 35-37 degrees C.

Cerebrospinal Fluid↗
PubMed1984

External quality assessment for clinical microbiological laboratories in Norway 1983.

The external quality assessment scheme for clinical microbiology (EQA-M) used in Norway in 1983 is described and the results are evaluated. Altogether three distributions, each consisting of 3--4 simulated clinical specimens, were carried out. All specimens were distributed as "open" tests (identifiable by the participants as EQA-M tests), but two were also simultaneously distributed as "blind" tests (not identifiable by the participants as EQA-M tests). The EQA-M in 1983 has revealed some problem areas concerning the isolation, identification and reporting procedures, the more important being: The clinical information given seems often to be ignored The reported priorities of different microorganisms recovered from one specimen often seem to be accidental rather than the results of thorough considerations The isolation rates of Shigella sp and Yersinia enterocolitica from faecal specimens are too low A great number of laboratories seem to overestimate the quantities of bacteria in dip-slide cultures.

Clinical Laboratory Techniques↗
PubMed1983

The diagnosis of meningococcal disease by culture. Some points of practical importance.

Meningococcal disease has been a serious problem in Norway for nearly a decade. A nation-wide study of this disease revealed that almost 40% of all cases in clinical practice remained without a microbiological diagnosis. In the hope that this situation can be improved, a brief review is given of information available in the literature concerning collection and handling of microbiological specimens from patients with possible systemic meningococcal disease.

Bacteriological Techniques↗
PubMed1983

External quality assessment for clinical microbiological laboratories in Norway 1982. 1. Evaluation of the identifications of 24 bacterial strains.

The first general external quality assessment (EQA) for clinical microbiological laboratories in Norway was carried out in 1982. Fifteen of 16 county and regional laboratories participated. Twenty-four pure cultures of different bacterial species were distributed by post. The distribution was "open" in the sense that the participants were aware of the cultures being part of the assessment. The strains had to be treated as routine clinical specimens. The bacterial identifications, the identification methods and the antibiotic sensitivity pattern had to be reported. The mean number of erroneous identifications was 2.7 (11.3%). Eleven strains were correctly identified by all laboratories, whereas four strains were misidentified by four to seven laboratories, accounting for approximately 50% of all misidentifications. All laboratories used "rapid" biochemical methods when identifying Gram-negative rods, mainly the "Three-tube method" and API 20E. Five laboratories used only one method, 10 used a combination of two or three methods. The use of more than one method did not give any substantial advantage. The accuracy of the "rapid" biochemical methods was approximately 88%, contrasting to approximately 96-98% when scientifically evaluated. The necessity of developing a permanent EQA scheme for microbiological laboratories is emphasized and a possible design for this is discussed.

Bacteria↗
PubMed1983

External quality assessment for clinical microbiological laboratories in Norway 1982. 2. Evaluation of the antibiotic sensitivity test results.

An external quality assessment for microbiology included antibiotic sensitivity testing of the 24 bacterial strains submitted. The number of antibiotics selected when sensitivity testing bacteria from different sources varied considerably between the laboratories. The discrepancy between actually reported sensitivity groups and the sensitivity groups calculated on the basis of the reported inhibition zones using the recommended regression lines was as great as 7% of a total of 1922 tests. This was mainly due to the use of outdated zone size break-points, indicating that information concerning changing recommendations may be inadequate. Discrepancies between the results reported by the laboratories and the results of a microdilution method giving the minimal inhibitory concentration for six antibiotics were recorded in 18.6% of the tests. Approximately one third of these discrepancies were characterized as "major" or "very major".

Clinical Laboratory Techniques↗
PubMed1982

Improved medium for the transportation of gonococcal specimens.

A modification of Stuart medium, denominated SIFF transport medium, was compared with Stuart (Ringertz's modification), Amies and SBL transport media for its ability to preserve viability of gonococci during transport. The SIFF medium was superior both when using laboratory strains of Neisseria gonorrhoeae and when using clinical specimens. The new transport medium distinguishes itself mainly by an increased osmotic pressure and by its starch content.

Culture Media↗
PubMed1981

The importance of blood volume cultured on detection of bacteraemia.

The effect of culturing 2 and 5 ml of blood in 18 ml of supplemented peptone broth I (SPB I) and 45 ml of supplemented broth II (SPB II) respectively, was compared. A total of 204 isolates were recovered from 78 patients. There were 136 isolates recovered from both the 45 and the 18 ml tubes. 20 isolates from the 18 ml tube only and 48 isolates from the 45 ml tube only. Both Gram-negative bacilli and Gram-positive cocci were recovered more frequently from the 45 ml tube than from the 18 ml tube (p less than 0.05). From patients with two or more positive blood cultures the diagnosis of bacteraemia would not have been made in 5 out of 53 patients (9.4%) if only the small culture tube had been used.

Blood↗
PubMed1980

An in vitro evaluation of two commercial blood culture media--supplemented peptone broth and supplemented tryptone soya broth.

Two commercial blood culture--supplemented peptone broth and supplemented tryptone soya broth--were compared by an in vitro method. The two media were inoculated with microorganisms suspended in fresh human blood in an attempt to mimic the clinical situation. The two media differed completely in their ability to support the growth of Neisseria meningitidis and Neisseria gonorrhoeae. Macroscopic evaluation of the blood culture medium during the incubation period was difficult when using supplemented tryptone soya broth in contrast to supplemented peptone broth. The former medium remained turbid whether microorganisms were growing or not. No other important differences between the two media were detected. Our findings indicate a need for both in vitro and in vivo studies to evaluate blood culture media and also a need for quality control of microbiological diagnostic devices before they are released for clinical use.

Blood↗
PubMed1980

Comparative in vitro activity of tobramycin and gentamicin on three different media.

The minimal inhibitory concentration for tobramycin and gentamicin against 488 clinical isolates of Enterobacteriaceae, Staphylococcus aureus and Pseudomonas spp. were obtained on three different solid media. The results obtained on Antibiotic Sensitivity Medium AB Biodisk (PDM) were markedly different from the results obtained on Mueller-Hinton (MH) and Diagnostic Sensitivity Test Agar Oxoid (DST). It was shown that tobramycin was significantly disfavored relative to gentamicin by PDM agar compared to MH and DST agar.

Anti-Bacterial Agents↗
PubMed1980

Effect of atmosphere of incubation on the growth of Neisseria meningitidis in a blood culture medium.

Seven strains of Neisseria meningitidis have been grown in a commercial blood culture medium (supplemented peptone broth, Beckton-Dickinson) under five different atmospheric conditions (anaerobic, transiently vented, permanently vented in air, in 5% CO2 in air, and in air with agitation). Macroscopic evaluation was not a quick and reliable method to discover growth with this medium. With transient venting and under anaerobic conditions macroscopic growth was not detected at all and a loss in viability was observed. It is therefore recommended that frequent subcultures should be performed if meningococcal bacteraemia is suspected. Preliminary data indicate that agitation in air induces a more rapid growth than stationary incubation.

Bacteriological Techniques↗