PubMed Health⌕ Search

Biomedical subjects

M Steinbakk

Publications and source records attributed to M Steinbakk.

At least 19 recordsLinked to original sources
PubMed2006

European Committee on Antimicrobial Susceptibility Testing (EUCAST) Technical Notes on antimicrobial susceptibility testing.

The main objectives of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are to harmonise breakpoints for antimicrobial agents in Europe, and to act as the breakpoint committee for the European Medicines Agency (EMEA) during the registration of new antimicrobial agents. Detailed EUCAST procedures for harmonising and setting breakpoints for antimicrobial agents are available on the EUCAST website. Beginning with the current issue, a series of EUCAST Technical Notes will be published in CMI, based on the rationale documents produced by EUCAST for each of the antimicrobial agents studied, with the aim of highlighting important background information underlying decisions on breakpoints made by EUCAST.

Advisory Committees↗
PubMed2001

[Can disinfectants contribute to antibiotic resistance?].

BACKGROUND: Disinfectants are widely used in medicine, veterinary medicine, and the food processing industry. Increasingly, disinfectants are included in consumer products. Broad-scale use of antiseptics and disinfectants may have detrimental ecological consequences, for instance the development of antimicrobial resistance. MATERIAL AND METHODS: We give an overview of the correlation between the use of certain antiseptics and disinfectants, bacterial resistance to these agents, and antibiotic resistance. RESULTS: The mechanisms of antibiotic and biocide resistance share many common characteristics. There are links between disinfectant resistance and antibiotic resistance. Some biocides have the ability to select for antibiotic resistant mutants and vice versa. Resistance genes are often located on transferable genetic elements that facilitate horizontal gene transfer between microorganisms. Antibiotic resistance and disinfectant resistance may be stabilized and maintained even in the absence of a direct selective pressure. Higher incidence of bacteria resistant to certain disinfectants have been reported in environments where such agents are frequently used compared to environments where they are not in regular use. Increased domestic usage of non-antibiotic antimicrobial agents may select for antibiotic-resistant bacteria of clinical significance. INTERPRETATION: The use of antiseptics and disinfectants should be restricted to products and areas where they have an essential and documented effect.

Animals↗
PubMed2000

Mycobacterium interjectum: a new pathogen in humans?

Molecular genetic techniques have increased the number of species recognized within the genus Mycobacterium. The clinical significance of these is uncertain and their pathogenic potential has still to be proven. We describe here a case of mycobacterial lymphadenitis in a Swedish boy, which supports the role of M. interjectum as a human pathogen.

Child, Preschool↗
PubMed1999

A Norwegian nosocomial outbreak of methicillin-resistant Staphylococcus aureus resistant to fusidic acid and susceptible to other antistaphylococcal agents.

In Norway, infections caused by methicillin resistant Staphylococcus aureus (MRSA) are still uncommon. From December 1993 to January 1997, MRSA was isolated from 22 people in Oslo county; 17 patients and five carriers (healthcare workers). A cluster of ten people (five patients and five healthcare workers) were associated with an outbreak at two hospitals in Oslo. The five patients were all admitted to the same intensive care unit (ICU) at Ullevål University Hospital between May-July 1995 (they were not transferred from abroad) and treated for acute neurological lesions. After surgery, four of them (one died) were transferred to another hospital for rehabilitation and training. The presence of MRSA was discovered in the patients and the five healthcare workers during the 10 months June 1995-March 1996. All cluster strains showed an unusual antibiotic resistance pattern in vitro, with a relatively low degree of methicillin resistance, resistance to fusidic acid, but sensitivity to all other anti-staphylococcal agents. A clonal spread of this fusidic acid resistant MRSA was supported by strain typing using pulsed-field gel electrophoresis (PFGE), which showed that all ten cluster strains belonged to one type or its subtype.

Adolescent↗
PubMed1999

Identification of clinical isolates of Mycobacterium spp. by sequence analysis of the 16S ribosomal RNA gene. Experience from a clinical laboratory.

Twenty-one mycobacterial type strains and 334 clinical isolates of mycobacteria were identified by standardized sequence analysis using part of the gene encoding 16S rRNA. Apart from two clinical isolates, the resulting sequences corresponded to previously published sequences. The results of the molecular determinations of the type strains completely overlapped the identities obtained using conventional techniques (cultural characteristics, biochemical tests, commercial DNA probes, and gas chromatographic lipid profiles). Of 323 isolates conventionally identified as slow-growing mycobacteria, 318 (98.5%) were identified to the same species or group level by 16S rDNA sequence analysis, while 6 of the 11 strains of rapid growers obtained a corresponding identity with the two approaches. The sequencing protocol combined with a few cultural characteristics (i.e. growth rate, pigmentation and susceptibility testing) offers a rapid, reliable and usually definite identification of mycobacterial isolates.

Amino Acid Sequence↗
PubMed1998

[Methicillin resistant yellow staphylococci].

The incidence of methicillin-resistant Staphylococcus aureus in Norway is extremely low. Isolation of such strains is nearly always associated with import. From December 1993 to January 1997 at the Ullevål University Hospital Department of Medical Microbiology, methicillin-resistant Staphylococcus aureus was isolated from 22 persons in Oslo (17 patients and five healthy carriers). A cluster of ten infected persons was detected (five patients and five carriers (nurses)) who were infected with strains showing an unusual antibiotic resistance pattern. All of the cluster strains except for beta-lactams were resistant to fucidic acid and sensitive to other antistaphylococcal agents. The cluster was associated with two hospitals. The five patients were all admitted to the same intensive care unit during the period May to July 1995. Four of the five patients (one died) were referred to the same department in a long-term care hospital for rehabilitation and training. Problems concerning epidemiological investigation and control are discussed.

Adolescent↗
PubMed1998

Constant low rate of fungemia in norway, 1991 to 1996. The Norwegian Yeast Study Group.

Since 1991 information on yeast isolates from blood cultures has been recorded prospectively from all microbiological laboratories (5 university and 16 county or local hospital laboratories) in Norway (population, 4.3 million). From 1991 to 1996 a total of 571 episodes of fungemia in 552 patients occurred (1991, 109 episodes; 1992, 81 episodes; 1993, 93 episodes; 1994, 89 episodes; 1995, 98 episodes; and 1996, 101 episodes). The fungemia rates per 10,000 patient days were 0.29 in 1991 and 0.27 in 1996. The average rates for the years 1991 to 1996 were 0.37 for the university laboratories and 0.20 for the other laboratories. These rates are low compared to the rate (0. 76) in five Dutch university hospitals in 1995 and the rate (2.0) in Iowa in 1991. The four most frequently isolated species were Candida albicans (66%), Candida glabrata (12.5%), Candida parapsilosis (7.6%), and Candida tropicalis (6.4%). The incidences of both C. albicans (range, 63 to 73%) and C. glabrata (range, 8.4 to 15.7%) varied somewhat throughout this period, but no significant increase or decrease was noted. MICs of amphotericin B, flucytosine, and fluconazole were determined for 89% of the isolates. All were susceptible to amphotericin B, and only 29 (5.6%) strains had decreased susceptibility to flucytosine. All C. albicans isolates were susceptible to fluconazole. The percentage of yeast isolates with decreased susceptibility to fluconazole (MICs, >/=16 microgram/ml) did increase, from 9.6% in 1991 and 1992 to 12.2% in 1994, 16.1% in 1995, and 18.6% in 1996. This was largely due to increases in the percentages of resistant C. glabrata and Candida krusei strains in the last 2 years. Compared to the incidence in other countries, it is remarkable that Norway has such a low and constant incidence of fungemia. A possible reason for this difference might be a restricted antibiotic use policy in Norway.

Adult↗
PubMed1995

[Proper use of antibiotics--what is that?].

Antibiotics are one of the cornerstones of modern medicine. During the last 20 years there has been an alarming world-wide spread of multiple-resistant bacteria. One of the main reasons is the overuse of all types of antibiotics, especially broad-spectrum drugs. This paper gives general advice on antibiotic therapy in Norway. We adovcate the use of drugs with little ecological impact, such as the penicillins. Whenever possible, empiric treatment with macrolides, tetracyclines cefalosporines, imipenem and fluoroquinolones should be avoided.

Anti-Bacterial Agents↗
PubMed1995

[The end of antibiotics? Increasing bacterial resistance in global and Norwegian perspective].

During the last 20 years there has emerged a growing world-wide problem with regard to multidrug-resistant microbes. The most serious examples so far are vancomycin-resistant strains of Enterococcus faecium, totally resistant isolates of Mycobacterium tuberculosis and multiple-resistant Staphylococcus aureus and Streptococcus pneumoniae. With the exception of some few strains of methicillin-resistant S. aureus and vancomycin-resistant enterococci, such bacteria have not been found in Norway. In this article we discuss possible ways of preventing further selection and spread of multiple-resistant microbes. We stress the importance of infection control programmes and restrictive use of antibiotics.

Communicable Disease Control↗
PubMed1995

The leucocyte protein L1 (calprotectin): a putative nonspecific defence factor at epithelial surfaces.

The L1 protein occurs at high concentrations in neutrophils, monocytes, certain reactive tissue macrophages, squamous mucosal epithelia, and reactive epidermis. It constitutes in fact about 60% of the neutrophilic cytosol protein fraction. The two L1 chains (L1H and L1L) are referred to by a bewildering collection of names, various authors having different preferences (MRP-8 and MRP-14; CFA or calgranulin A and B). The most recent proposal is calprotectin because of its calcium-binding properties and antimicrobial effect shown in vitro. L1 belongs to the S-100 protein family and may be involved in the regulation of keratinocyte proliferation and differentiation. It exists at high levels in blood and interstitial tissue fluid in several infectious, inflammatory, and malignant disorders, and it is released abundantly in foci of granulocytes and macrophages. The C-terminal sequence of the L1H chain has been shown to be identical to the N-terminus of peptides known as neutrophil immobilizing factors. Such an activity of L1 could be important for the accumulation of vital granulocytes, while L1 released from neutrophils, macrophages and epithelial cells might exert antimicrobial activity, perhaps by depriving microorganisms of zinc. The minimum inhibitory concentrations of L1 in vitro were found to be 4-32 mg/l for Candida albicans, 64 mg/l for Staphylococcus aureus, 64-256 mg/l for S. epidermidis, and 256 mg/ml for Escherichia coli and Klebsiella spp. Killing was observed at 2-4 times higher concentrations. In patients with HIV infection, those who developed oral candidiasis had significantly lower parotid L1 levels than those who did not (67 micrograms/l vs. 216 micrograms/l).

AIDS-Related Opportunistic Infections↗
PubMed1995

Alterations in mucosal morphology and permeability, but no bacterial or endotoxin translocation takes place after intestinal ischemia and early reperfusion in pigs.

Ischemia and reperfusion of the gut may be an important etiological factor in the development of multiple organ failure. We have used a hemorrhagic and a superior mesenteric artery (SMA) occlusion shock model in pigs to estimate the effect of ischemia and reperfusion on intestinal morphology, mucosal permeability, and the occurrence of bacterial or endotoxin translocation. Mucosal ulceration and necrosis were found in the SMA shock model, while the morphological changes were less pronounced in the hemorrhagic shock model. Scanning electron microscopy showed shrinkage of the villi and plugging of the colonic crypts in both shock models. Enterocyte cell kinetics was investigated using 5-bromo-2'-deoksyuridine (BrdU) incorporation and immunovisualization by anti-BrdU antibodies. Cell renewal was almost completely lost from the jejunum to the rectum in both shock models. Intramucosal pH was measured using a tonometer placed in the terminal ileum. Segments of intestinal mucosa were mounted in Ussing chambers, and permeability was measured using radiolabeled probe molecules of differing molecular weights. Augmented molecular flux of inulin (M(r) 5.000) and mannitol (M(r) 182) and loss of short circuit current (Isc) and transepithelial potential difference (PD) were found in mucosae from both shock models. Endotoxin was demonstrated in the ascitic fluid in both shock models; 9.5 (2.7-14.3) (median and 95% confidence interval) EU/mL in the SMA occlusion model and 16.0 (4.9-29.4) EU/mL in the hemorrhagic shock model), but the levels were not significantly higher than in the control model 6.5 (4.3-34.0) EU/mL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Bacteriological examination of bronchial aspirates obtained via fiberoptic bronchoscopy].

We present the bacteriological findings in 329 aspirates from fiberoptic bronchoscopy. Quantitative cultures were not performed. 92 of the patients had radiologically confirmed pneumonia, 58 possibly had infectious bronchitis or pneumonia which was not verified radiologically, 154 had other pulmonary diseases and 25 had no verified pulmonary disease. 13% of aspirates contained no bacterial isolates and 33% revealed growth of multiple bacteria, classified as "normal pharyngeal flora". Among the 54% with specified bacterial findings the most frequent bacteria were viridans streptococci, staphylococci, Haemophilus influenzae, and Streptococcus pneumoniae. The differences in bacterial flora between the patient groups were only minimal. Klebsiella and Escherichia coli were the only bacteria indicating presence of pneumonia. S pneumoniae were found more frequently among patients with no signs of infection. Bronchial aspirates obtained with a fiberbronchoscope may give false positive results and are of limited value in diagnosing pneumonia. However, the presence of gram negative intestinal rods may indicate bacterial respiratory infection in hospitalized patients. Improving sampling and culture techniques can possibly improve the value of bacteriological findings.

Bacterial Infections↗
PubMed1991

C-reactive protein: a new rapid assay for managing infectious disease in primary health care.

Quantitative C-reactive protein (CRP) measurement has become increasingly valuable as a test for rapid diagnosis of infections in hospital medicine. CRP has not obtained the same importance in primary health care. This has, at least partly, been due to methodological difficulties, with no simple or rapid tests with quantitative results available. A new immunometric semi-quantitative assay, NycoCard CRP, has recently been developed. CRP was analysed at the local health centres by the new assay in 288 consultations where patients came because of infections. Parallel CRP values were obtained by an established reference method. The two procedures had an acceptable correlation (r = 0.85). The primary care doctors also registered the clinical information they obtained from each CRP result. CRP was helpful in indicating the presence, or absence of bacterial infection in more than half the consultations due to new infections. CRP was thought to yield more clinical information than the erythrocyte sedimentation rate in almost every case.

Blood Sedimentation↗
PubMed1990

Antimicrobial actions of calcium binding leucocyte L1 protein, calprotectin.

The calcium binding L1 protein was found to inhibit growth of blood culture isolates of Candida spp and cerebrospinal fluid isolates of Cryptococcus neoformans. Minimum inhibitory concentrations (MIC) were 4-128 mg/l, and concentrations 2-4 times the MIC were fungicidal. Blood culture isolates of Escherichia coli, Klebsiella spp, Staphylococcus aureus, and Staphylococcus epidermidis had MIC values of 64-256 mg/l. Antibacterial activity was strongly influenced by the nature of the culture medium. In view of the biological activity of L1, the name calprotectin is proposed to describe this antimicrobial protein with calcium binding properties.

Antifungal Agents↗
PubMed1990

Intestinal microbial conversion of cholesterol to coprostanol in man. Influence of antibiotics.

The intestinal microbial conversion of cholesterol to coprostanol has been measured in groups of healthy subjects before, during and after they received the antibiotics ampicillin, bacitracin, clindamycin, co-trimoxazole, doxycycline, erythromycin, metronidazole, nalidixic acid, ofloxacin or vancomycin orally for 6 days. Before they received antibiotics, the subjects demonstrated two distinct patterns of cholesterol conversion. One pattern was characterised by extensive conversion of cholesterol, the other by little or no conversion. Intake of bacitracin, clindamycin, erythromycin, metronidazole and vancomycin significantly reduced the conversion to coprostanol. In the groups receiving ampicillin or doxycycline, marked reductions were found in most of the subjects. No alterations were found in the groups receiving co-trimoxazole, nalidixic acid or ofloxacin. In 6 subjects no conversion of cholesterol to coprostanol was found up to 5 weeks after the end of the antibiotic intake. We conclude that orally given antibiotics may cause alterations in the intestinal conversion of cholesterol, reflecting changes in the anaerobic, Gram-positive component of the gut flora.

Adult↗
PubMed1990

Detection of serum antibodies against Borrelia burgdorferi with some commercially available serological tests.

Sixty-three sera were analysed for antibodies against Borrelia burgdorferi with an in-house indirect immunofluorescence assay. Thirty-nine sera were positive (titer greater than or equal to 256), seven borderline (titer 128) and 17 negative (titer less than or equal to 64). These results were compared with results obtained with four different commercial assays for detection of such antibodies. Indirect immunofluorescence tests yielded most positive results. The flagellin ELISA test detected antibodies in patients with erythema chronicum migrans (ECM) more often than the other test systems. Sera from patients with acrodermatitis chronica atrophicans (ACA) were positive in all systems. The serological diagnosis of borreliosis is difficult and direct methods for detecting the presence of the microbe are highly needed.

Antibodies, Bacterial↗
PubMed1987

In vitro activity of ceftazidime, cefotaxime and gentamicin against 11,521 clinical isolates of bacteria.

The in vitro activity of ceftazidime has been compared with those of another third-generation cephalosporin, cefotaxime, and the aminocyclitol aminoglycoside, gentamicin. A total of 11,521 clinical isolates of aerobic bacteria were employed, and an agar diffusion method was used for sensitivity testing. The MIC-values were calculated from regression lines. The mean inhibition zones for ceftazidime against Gram-positive organisms were significantly less than those against Gram-negative isolates (23 mm vs. 33 mm, p less than 0.0001). Cefotaxime inhibited 74.0%, gentamicin 66.3% and ceftazidime 20.4% of the Gram-positive isolates at a concentration of less than or equal to 2 mg/ml. Ceftazidime and cefotaxime were equally active against fermentative Gram-negative rods, inhibiting 92.7% of each of these isolates at 2 mg/l. Against Ps. aeruginosa, ceftazidime (MIC90 2.2 mg/l) was found to be almost as active as gentamicin (MIC90 1.2 mg/l), and far more active than cefotaxime (MIC90 434 mg/l). Gentamicin was the most active agent against Acinetobacter sp. (MIC90 6.0 mg/l), followed by ceftazidime (MIC90 18 mg/l) and cefotaxime (MIC90 83 mg/l).

Bacteria, Aerobic↗