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Biomedical subjects

K Bergh

Publications and source records attributed to K Bergh.

At least 19 recordsLinked to original sources
PubMed2005

Outbreak of methicillin-resistant Staphylococcus aureus in two nursing homes in Central Norway.

Until recently, infections with methicillin-resistant Staphylococcus aureus (MRSA) have mainly been associated with hospital outbreaks in Norway. However, increasingly cases are contracted outside hospitals. This paper reports the first two outbreaks of MRSA in two nursing homes in central Norway, affecting 23 residents and five staff members. Pulsed-field gel electrophoresis analysis showed that all strains from nursing home A were identical and that the strains from nursing home B were genotypically similar with one or two band differences. Multi-locus sequence typing (MLST) showed that the strains from the two nursing homes belong to clonal complex 45, with each strain being a single-locus variant of sequence type 45 (ST 45), a well-known European epidemic strain. No evident source of the two outbreaks was found, and there was no obvious connection between the two outbreaks. The latter is also supported by the minor differences observed by MLST, suggesting a connection at some time in the past. The outbreaks led to a heavier workload and economic strain on both nursing homes. The outbreak in nursing home A was brought to an end, whereas two residents remained colonized in nursing home B despite several eradication attempts. These outbreaks show the potential for MRSA spread in a nursing home. If the prevalence of MRSA in Norway continues to increase, nursing home staff and residents may have to be included in the groups to be screened for MRSA upon hospital admission.

Aged↗
PubMed2005

Ruptured abdominal aortic aneurysm secondary to tuberculous spondylitis.

A 69-year-old man was admitted with low back pain and signs of nerve root compression. A computed tomography (CT) scan showed abscess formation in the left psoas region, spondylodiscitis L3-L4 and a ruptured abdominal aortic aneurysm. The aortic aneurysm was replaced with a bifurcated vascular graft. One week later, laminectomy at the L4-level was done. In a small abscess, Mycobacterium bovis was found. The condition was considered to be a mycobacterial spondylitis secondary to BCG instillations of the urinary bladder for carcinoma. The patient received antituberculous medication for 9 months. Subsequently bone transplantation and internal fixation of the spine became necessary. Three years after surgery he is in good condition and there are no signs of graft infection on CT. Spondylitis and mycotic aortic aneurysm should be kept in mind in patients who have been treated for carcinoma of the bladder with BCG instillations.

Aged↗
PubMed2004

Distribution of PFGE types of invasive Norwegian group B streptococci in relation to serotypes.

BACKGROUND & OBJECTIVES: Pulsed-field gel electrophoresis (PFGE) has been used for characterisation of group B streptococci, non-typeable by serotyping. We wanted to compare PFGE with serotyping in order to see the how well the method discriminates between epidemiological unrelated strains. METHODS: A total of 78 epidemiological unrelated invasive GBS strains were examined by PFGE using SmaI digested chromosomal DNA. Of these, 11 were nontypeable (NT) with regard to capsular polysaccharide (CPS) serotype. PFGE patterns were analyzed and classified in a dendrogram. RESULTS: 75 strains were typeable by PFGE, and a total of 62 restriction profiles were identified. At an 85 per cent similarity level, 53 different PFGE patterns were identified. Within each serotype, PFGE patterns differed considerably, the largest degree of heterogeneity observed among type IV, Ia, and II strains. Serotype Ib, III, and V strains were more homogeneous. Strains with identical macrorestriction profiles belonged to the same CPS type, but varied with regard to serosubtypes. Any strain among the ones investigated showing a greater than 88 per cent similarity to a restriction profile in the database, could correctly be ascribed to a particular CPS type. Of the 11 NT strains 10 restriction profiles were found, two of which were identical to the PFGE profile for a cluster of type V strains, and one profile were identical to the profile showed by a cluster of 5 type Ib strains. INTERPRETATION & CONCLUSION: PFGE is a useful technique for classifying strains that are non-typeable by conventional serotyping.

Electrophoresis, Gel, Pulsed-Field↗
PubMed2004

Detection of group B streptococci (GBS) in vaginal swabs using real-time PCR with TaqMan probe hybridization.

BACKGROUND & OBJECTIVES: Implementation of a screening based strategy for the prevention of perinatal group B streptococcus (GBS) disease is anticipated to increase the demand of fast laboratory techniques. The aim of the present study was to develop a real-time PCR method for the specific detection of GBS in vaginal swabs. METHODS: Based on partial sequencing of the sip gene, primers and a TaqMan hybridization probe were constructed for a real-time PCR assay. The performance of the assay was tested on 100 consecutive vaginal specimens submitted to the laboratory for culture. Lysis of bacteria and DNA extraction was performed by lysozyme, mutanolysin, proteinase K and Quiagen spin columns. PCR was performed using LightCycler. Highly purified DNA from GBS was used as positive control. RESULTS: Of the 100 samples investigated, 25 were positive by culture (16 abundant/moderate growth, 6 sparse growth and 3 after enrichment only). At a cut-off of 12 fg per reaction (corresponding to 4 bacterial cells), PCR was positive in 32 samples. A complete concordance was noted between PCR positivity and abundant/moderate and sparse growth by culture. One of 3 samples that were positive by culture only after enrichment was negative in PCR. On the other hand, 8 samples were positive by PCR and negative by culture. INTERPRETATION & CONCLUSION: The real-time PCR assay was sensitive and rapid and enabled detection of GBS in less than 2 h after collection. Due to the rapidity of the assay by which results could be obtained, the assay harbors the potential for intrapartum detection of GBS.

Base Sequence↗
PubMed2002

Low prevalence of Bartonella henselae infections in Norwegian domestic and feral cats.

Bartonella henselae is the causative agent of cat scratch disease (CSD). This clinical entity is very rarely encountered in human medical practice in Norway. B. henselae infections including bacteraemia in cats have been frequently reported. The objective of the present study was to investigate the seroprevalence rate and the degree of B. henselae bacteraemia in Norwegian domestic and feral cats. One hundred cats investigated at a small animal veterinary practice in the middle of Norway were included in the study. Blood collected in Isolator blood-lysis tubes and lysates of erythrocytes after freezing and thawing were cultured. PCR analysis of whole blood was also performed. Serology was performed by indirect fluorescence assay (IFA) and enzyme immunoassay (EIA) using immobilised B. henselae Houston-1 strain as antigen. None of the 100 cats investigated was found to be bacteraemic. All 100 cats were seronegative when analysed by IFA; one cat was positive by EIA. The discrepancy between IFA and EIA of this particular cat is probably due to cross-reactive antibodies. Contrary to findings reported from several geographic regions, B. henselae infections in Norwegian cats appear to be virtually absent. This in turn may explain why CSD has not been reported in human medical practice in Norway.

Animals↗
PubMed2002

Spread of methicillin-resistant Staphylococcus aureus in a neonatal intensive unit associated with understaffing, overcrowding and mixing of patients.

Over the period May-June 1999, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) was registered in eight newborns in a neonatal intensive care unit (NICU) at the Department of Pediatrics, Ullevål University Hospital (UUH) in Oslo. Seven were infected or colonized with an indistinguishable strain, detected at the NICU, and one patient with a slightly different PFGE type (i.e. a subtype) was registered at the outpatient clinic. The MRSA strains resembled the sensitive, inbred 'Norwegian type' described four years earlier at UUH, showing a relatively low and heterogenic methicillin resistance (MIC 12-96 mg/L), and susceptibility to most other anti-staphylococcal agents. Before and during the outbreak, there was high activity, understaffing, overcrowding and a mix of patients; 42% of the staff were relatively untrained, and up to 62% (during weekends) were extra nursing staff, partly from other Scandinavian countries. All cases were isolated (air and contact isolation), and all other patients and personnel were treated as being exposed to MRSA (isolated from other departments) until the last patient had been identified, disinfection of all rooms was complete, and all screening samples from staff and other patients were negative. The NICU and the delivery suite were closed for one week for disinfection and screening. The outbreak ended after 34 days. Since then, two years later, no further cases have been detected in the NICU or the delivery suite.

Cross Infection↗
PubMed2001

Outbreak of methicillin-resistant Staphylococcus aureus in a Norwegian hospital.

Methicillin-resistant Staphylococcus aureus (MRSA) occurred sporadically in Norwegian hospitals in the 1960s and 1970s, but disappeared in the late 1970s for unknown reasons. Only 1 outbreak has subsequently been reported. We describe herein a second outbreak in a different hospital, this time featuring a more resistant strain. Staff and patients were screened immediately after detection of the first MRSA isolate. Colonized and infected patients were nursed using contact precautions, and the staff were not allowed to work until 3 nose samples were MRSA-negative. We treated colonized persons with topical administration of mupirocin to the nostrils and a chlorhexidine body wash. The outbreak affected 7 patients and 5 healthcare workers. Pulsed-field gel electrophoresis proved all isolates to be of the same type, and the MRSA phage type was M3. There was no sign of transmission of MRSA after contact precautions were implemented. MRSA was eradicated in 4 of the patients and all 5 healthcare workers. One patient died and 1 was still colonized 3 y after onset of the outbreak. Contact precautions proved to be sufficient to prevent transmission of MRSA.

Adult↗
PubMed2001

Peritoneal dialysis-associated peritonitis caused by Dermabacter hominis.

Dermabacter hominis was the cause of a peritoneal dialysis-associated peritonitis. D. hominis was identified by phenotypic criteria and by sequencing the 16S rRNA gene. Clinical cure was achieved with cefuroxime treatment despite the isolate's reduced susceptibility to this drug (MIC, 12 mg/liter) on in vitro testing. The successful treatment was probably due to the high concentrations attained by intraperitoneal administration of the drug.

Actinomycetales↗
PubMed2000

The inflammatory response following treatment of abdominal aortic aneurysms: a comparison between open surgery and endovascular repair.

OBJECTIVES: to compare the inflammatory response following endovascular and conventional AAA repair. DESIGN: prospective study. PATIENTS AND METHODS: ten patients were selected for open surgery (OPEN) and ten for endovascular (ENDO) AAA repair. Leukocytes, platelets, myeloperoxidase, lactoferrin, beta-thromboglobulin, C-reactive protein (CRP), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha) and complement activation products were measured before, during and after surgery. RESULTS: in the OPEN group the median hospital stay was longer (6 vs. 12 days, p=0.001) and more patients required transfusion (p=0.02). IL-6 and CRP increased postoperatively, most in OPEN (p<0.01). Platelet counts decreased after the first angiography in ENDO (p<0.01) and before aortic cross-clamping in OPEN (p<0.05). The decrease was larger in OPEN (p=0.02). Leukocyte counts decreased after the first angiography in ENDO, and thereafter increased (p=0.001). An equivalent increase was observed in OPEN after declamping (p=0.001). Leukocyte and platelet degranulation products increased after the first angiography in ENDO and after declamping in OPEN. Changes in complement activation products were small. TNF-alpha did not change significantly. CONCLUSION: endovascular AAA repair caused significant leukocyte and platelet activation. Based on the timing of activation this could be caused by radiographic contrast media.

Acute-Phase Reaction↗
PubMed2000

Cancellous bone as an antibiotic carrier.

We compared the release characteristics of antibiotics from in vivo and in vitro processed morselized cancellous bone. The bone was impregnated with 7 antibiotics and compressed into a wire-mesh cylinder. In vitro, the bone was processed by daily transfer of the cylinder with its contents into test tubes with broth. The amount of antibiotic eluted from the bone was measured after 1, 3 and 7 days. In vivo, the cylinder was implanted intramuscularly in the interscapular region in rats. After 1, 3 and 7 days, the cylinder was removed and the amount of antibiotic eluted in broth was measured. The results showed that morselized cancellous bone can act as a carrier of antibiotics in vitro and in vivo. The elution profiles of netilmicin-, vancomycin-, clindamycin- and rifampicin-impregnated cancellous bone processed in vitro and in vivo were similar.

Animals↗
PubMed2000

Role of L-selectin in leukocyte sequestration in lung capillaries in a rabbit model of endotoxemia.

After a variety of pathophysiologic stimuli, neutrophils accumulate in lung capillaries and contribute to the pathogenesis of acute lung injury. Lung neutrophil sequestration has previously been attributed to mechanical retention of stiffened neutrophils, but L-selectin-mediated leukocyte/endothelial interaction may be an essential step. We investigated the effect of the anti-L-selectin antibody HuDreg 200 on leukocyte sequestration and microhemodynamics in alveolar capillaries in a model of acute endotoxemia. We used in vivo fluorescence microscopy to analyze kinetics of fluorescently labeled red and white blood cells in alveolar capillary networks of the rabbit lung. Investigations were performed over 2 h after an intravenous infusion of 0.2 ml/kg body weight (bw) NaCl, 2 mg/kg bw HuDreg 200, 20 microg/kg bw lipopolysaccharide (LPS) of Escherichia coli 0111:B4, or the combination of HuDreg 200 and LPS, respectively. Infusion of LPS induced leukocyte sequestration in alveolar capillaries, which was accompanied by a reduction of alveolar capillary perfusion and functional capillary density. These effects could be completely blocked by pretreatment of animals with HuDreg 200. We conclude that L-selectin-mediated leukocyte/endothelial interaction is a necessary prerequisite for leukocyte sequestration in alveolar capillaries in this model. Impaired alveolar capillary perfusion appeared to result directly from capillary leukocyte sequestration.

Acute Disease↗
PubMed2000

Lack of effect of anti-C5a monoclonal antibody on endothelial injury by gas bubbles in the rabbit after decompression.

Previous studies have shown that gas bubbles activate the complement system in vitro, generating C5a. The effect of anti-C5a monoclonal antibody 4B1C11 in preventing endothelial damage caused by decompression in the pulmonary artery of the rabbit was examined. The endothelial response was measured using tension measurements in the blood vessel wall. The mean bubble count for all rabbits (n = 24) was 4.2+/-3.1 bubbles x cm(-2), and ranged from 0 to 15 bubbles x cm(-2). Animals with many bubbles showed significantly more vascular damage than those with fewer bubbles. Anti-C5a monoclonal antibody could not prevent endothelial damage than that occurred after exposure to this level of gas bubbles. The maximum number of gas bubbles present is important for the endothelial damage. We speculate that the endothelial damage observed was mainly mechanical. A possible beneficial effect of anti-C5a antibody can thus be masked at a high degree of bubble generation. This study, together with a previous paper, demonstrates that gas bubbles cause endothelial damage from decompression both in the pig and in the rabbit.

Acetylcholine↗
PubMed1999

Heparin-coated cardiopulmonary bypass equipment. I. Biocompatibility markers and development of complications in a high-risk population.

OBJECTIVES: 1. To study possible clinical benefits of heparin-coated cardiopulmonary bypass in patients with a broad range of preoperative risk factors. 2. To evaluate the correlation between the terminal complement complex and clinical outcome. 3. To identify clinical predictors of complement activation and correlates of granulocyte activation during cardiac surgery. METHODS: Blood samples from adults undergoing elective cardiac surgery with Duraflo II heparin-coated (n = 81) or uncoated (n = 75) cardiopulmonary bypass sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill) were analyzed for activation of complement (C3 activation products, terminal complement complex), granulocytes (myeloperoxidase, lactoferrin), and platelets (beta-thromboglobulin) by enzyme immunoassays. Preoperative risk was assessed by means of the "Higgins' score." Complications (cardiac, renal, pulmonary, gastrointestinal, and central nervous system dysfunction, infections, death) were registered prospectively. Data were analyzed by analysis of variance, logistic regression, and linear regression. RESULTS AND CONCLUSIONS: Sixty-seven percent of the patients had predefined risk factors. Complications developed in 53 patients (34%), equivalently with and without heparin-coated bypass sets (P =. 44-.82), despite a significant reduction in complement and granulocyte activation by heparin coating. No clear-cut relationship between the terminal complement complex and outcome was found, even if it was significant in the models for renal and central nervous system dysfunction and infections (P =.006). The Higgins' score was significantly related to complement activation (P <.05). Approximately 50% of the variation in granulocyte activation was explained by complement (P </=.01) and platelet activation (P <.05), heparin/protamine dose ratio (P =.02), duration of cardiopulmonary bypass (P <.01), and gender (P <.05). Therefore measures reducing complement activation alone will not necessarily reduce granulocyte activation sufficiently for clinical significance.

Aged↗
PubMed1999

Heparin-coated cardiopulmonary bypass equipment. II. Mechanisms for reduced complement activation in vivo.

OBJECTIVE: Our objective was to study mechanisms for reduced complement activation by heparin coating of cardiopulmonary bypass equipment in clinical heart surgery. METHODS: Adults undergoing elective coronary artery bypass grafting were randomized to cardiopulmonary bypass with Duraflo II heparin-coated (n = 15) or uncoated (n = 14) sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill). Blood samples were analyzed with the use of enzyme immunoassays for C1rs-C1 inhibitor complexes and the activation products Bb, C4bc, C3bc, C5a-desArg, and the terminal complement complex. Data were compared by repeated-measures analysis of variance. RESULTS: C1 was activated during bypass, and increases in C1rs-C1 inhibitor complexes were larger with heparin coating (P =.03). C4bc increased after administration of protamine, without intergroup differences (P =.69). Bb (P =.22) and C5a-desArg (P =.13) tended to increase less with heparin coating. Formation of C3bc (P =.03) and the terminal complement complex (P <.01) was significantly reduced with heparin coating. C5a-desArg increased 2-fold during bypass, whereas the terminal complement complex increased 10- to 20-fold. Maximal terminal complement complex concentrations were significantly correlated to maximal Bb and C3bc (R = 0.6, P <.001), but not to C1rs-C1 inhibitor complexes or C4bc (R < 0.05, P >.8). CONCLUSIONS: C1 activation during bypass was increased by heparin coating, but further classical pathway activation was held in check until administration of protamine. Heparin coating significantly inhibited C3bc and terminal complement complex formation. Terminal complement complex concentrations were related to alternative pathway activation and may be useful for evaluation of differences in bypass circuitry. Increases and intergroup differences in terminal complement complex concentrations were much larger than those in C5a-desArg.

Anticoagulants↗
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

Complement activation in patients with systemic lupus erythematosus without nephritis.

OBJECTIVE: To study the association between disease activity and complement activation prospectively in patients with systemic lupus erythematosus (SLE). PATIENTS AND METHODS: Twenty-one SLE patients were examined monthly for 1 yr. Disease activity, autoantibodies, conventional complement tests and the following complement activation products were investigated: C1rs-C1inh complexes, C4bc, Bb, C3a, C3bc, C5a and the terminal SC5b-9 complement complex (TCC). RESULTS: Modest variation in disease activity was noted. None of the patients had nephritis. Flare was observed at 27 visits. Four patients had anti-C1q antibodies in conjunction with modestly low C1q concentrations. The complement parameters were rather constant during the observation period. Slightly to moderately decreased C4 (0.05-0.10 g/l) was found in 10 patients and severely decreased C4 (<0.05 g/l) in seven patients. Decreased C4 was not associated with increased complement activation. Complement activation products were either normal or slightly elevated. TCC was the only activation product correlating significantly with score for disease activity at flare. None of the variables tested predicted flares. CONCLUSION: Complement tests are of limited importance in routine examination of SLE without nephritis, although TCC is suggested to be one of the most sensitive markers for disease activity.

Adult↗
PubMed1999

Adsorption and release of antibiotics from morselized cancellous bone. In vitro studies of 8 antibiotics.

We studied the basic release patterns of antibiotics from cancellous bone in vitro. Antibiotic-impregnated bone was compressed into a wire-mesh cylinder and the release of antibiotic was assessed by two different in vitro methods: agar diffusion and broth elution. The zones of inhibition were measured on seeded agar and the amounts of antibiotics released in elution tubes were assessed by a bioassay. The study continued for 21 days with daily transfer of the cylinders. The results indicated that benzylpenicillin, dicloxacillin, cephalotin, netilmicin, clindamycin, vancomycin, ciprofloxacin and rifampicin were adsorbed to cancellous bone in vitro. Compared to broth elution, agar diffusion showed a prolonged period of release, owing to the small amounts of antibiotic leaking out of the cylinder into the agar. The betalactams had antibacterial activity in broth for a shorter time than the other antibiotics. The release patterns of the betalactams were similar, in spite of their differences in thermal stability. Only rifampicin showed a concentration higher than MIC for longer than 21 days.

Adsorption↗