Biomedical subjects

B P Berdal

Publications and source records attributed to B P Berdal.

At least 19 recordsLinked to original sources

PubMed1996

[Bacteremia in the county of Ribe].

The Department of Microbiology at the Central Hospital of Esbjerg, established in 1987, serves the five hospitals in Ribe county, Denmark. From early on, the department has endeavoured to guide the hospital's antimicrobial policy. In order to investigate whether this involvement had any measurable impact on the antimicrobial resistance pattern in our region, we compared the resistance patterns of 212 strains isolated from the blood of bacteraemic patients in 1988 to those of 317 strains isolated in 1992. No increase in antibiotic resistance was revealed. This is noteworthy since new specialties have been established at the Central Hospital during this period, with an increased number of patients requiring antimicrobial therapy. It is important to survey the antibiotic resistance pattern closely, and that this is done locally.

Anti-Bacterial Agents↗

PubMed1995

Screening urine samples by leukocyte esterase test and ligase chain reaction for chlamydial infections among asymptomatic men.

Urine samples from 358 asymptomatic males were screened for urethral inflammation by the leukocyte esterase (LE) test and for Chlamydia trachomatis by the ligase chain reaction (LCR). LE and LCR positivity rates were 7.5% (27 of 358 samples) and 2.8% (10 of 358 samples), respectively. Eight of the 10 LCR-positive samples were detected by the LE screening test. The urine LE prescreening test in combination with the LCR assay may be a reasonable approach for genitourinary chlamydial disease control.

Bacteriological Techniques↗

PubMed1994

[Acute bronchitis in adults. Clinical findings, microorganisms and use of antibiotics].

Among 72 adult patients with a diagnosis of acute bronchitis, serological investigation established the presence of an aetiologic agent in 29 (40%). Influenza virus was the most common pathogen. Seven patients had bacterial infection, caused by pneumococci in four patients and Mycoplasma pneumoniae in three. Five of the patients had pneumonia as diagnosed by radiography, and mycoplasmal aetiology was established in one of these. Altogether, 11 patients either had bacterial infection or radiographic pneumonia. Although the doctors' recording of wheezes was strongly associated with prescription of antibiotics (p < 0.0001), wheezes were heard only in two of the 11 patients with pneumonia or bacterial infection, compared with 30 of the 61 patients with viral or unspecified bronchitis. The median value of C-reactive protein (CRP) was 52 mg/l in the 11 patients, significantly higher than < 11 mg/l in the 61 other patients (p < 0.0001). The corresponding values for erythrocyte sedimentation rate were 45 and 14 mm/h (p < 0.0005). The results indicate that certain patients with acute bronchitis should be treated with antibiotics, and that the erythrocyte sedimentation rate and the CRP-test may be useful in detecting which patients this applies to.

Acute Disease↗

PubMed1994

Detection of Chlamydia pneumoniae in clinical specimens by polymerase chain reaction using nested primers.

A nested primers strategy was used to develop a two-step PCR test for the direct species-specific detection of the 16s rRNA gene of Chlamydia pneumoniae. This test was applied to 58 nasopharyngeal or oropharyngeal swab specimens collected from patients in studies of community-acquired pneumonia and in a local outbreak of respiratory disease. Twelve patients (21%) showed evidence of Chlamydia pneumoniae infection in serological tests (7/56; 13%), culture (8/58; 14%) or PCR (10/58; 17%). Nested PCR but not single-step PCR was found to be as sensitive as culture or serology for detection of infection with this organism. In summary, nested PCR can be useful in direct testing of clinical specimens for Chlamydia pneumoniae, making additional DNA purification steps unnecessary.

Amino Acid Sequence↗

PubMed1993

[Chlamydia pneumoniae--pathogenesis and perspectives].

Chlamydia pneumoniae, a Gram-negative bacterium, formerly named TWAR but identified as a distinct species since 1988, is now considered to be the most common agent of chlamydial infection in Scandinavia. C pneumoniae has a different tissue trophism from that of Chlamydia trachomatis, since C pneumoniae may infect bronchi and lungs, macrophages, monocytes, and endothelial cells. C pneumoniae, like other chlamydiae, has a slow, intracellular life cycle. An absence of reaction from the host cells, combined with scant tissual reaction owing to the low endotoxic activity of chlamydial lipopolysaccharide, may help to explain the usually discreet clinical picture. Atherosclerosis and coronary heart disease may follow chronic lung infection, and acute pneumonic episodes can trigger myocardial infarct. Asymptomatic infection with C pneumoniae is widespread. Intriguing diagnostic questions are the possible existence of a non-pathogenic carrier state, and the conceivable sensitization of the host with respect to a heterotypic, secondary chlamydial infection by, for example, C trachomatis, giving rise to an aggravated clinical picture. Early antibiotics are indicated to avoid the development of chronic disease.

Cardiovascular Diseases↗

PubMed1993

Detection of Chlamydia trachomatis in the urine of young Norwegian males by enzyme immunoassay.

First-void urine samples from 392 Norwegian military conscripts were investigated for the presence of Chlamydia trachomatis by enzyme immunoassay (EIA) on day 1 and day 5 after collection. Positive samples were subsequently investigated by direct immunofluorescence (IF) microscopy for the presence of chlamydial elementary bodies (EBs) in the urine pellet, and urethral swab material taken from the EIA-positive individuals was cultured. 4.8% (19/392) of the urine samples were EIA-positive on day 1, and 5.4% (21/392) were positive on day 5, with a combined total of 6.6% (26/392). Twenty-four of the 26 urine samples were confirmed as positive on IF microscopy. Urethral swabs were taken from 21 EIA-positive individuals. Six of the swabs were positive on cell culture, whereas nine were positive on IF microscopy of swab material, suggesting that these techniques perform better in symptomatic cases than in male Chlamydia trachomatis carriers. In the urine samples a notable discrepancy in EIA results was seen when the same refrigerated samples were retested on day 5 compared to day 1. This discrepancy was probably due to storage-related factors.

Adult↗

PubMed1993

Susceptibility pattern of Scandinavian Francisella tularensis isolates with regard to oral and parenteral antimicrobial agents.

Some recently introduced antimicrobial agents have only been incompletely evaluated for use in Francisella tularensis infections. The present study evaluated the susceptibility pattern of Scandinavian human, rodent, and hare F. tularensis isolates with respect to a selection of traditional as well as recently introduced antimicrobial agents. All strains were resistant to the following beta-lactams: penicillin, cephalexin, cefuroxime, ceftazidime, aztreonam, imipenem, and meropenem with minimal inhibitory concentrations > 32 mg/l. Against macrolides, a mixed susceptibility/resistance pattern appeared. All strains were susceptible to gentamicin, chloramphenicol, doxycycline, and four quinolones. Since the quinolones showed the lowest MIC values, and in addition give a good intracellular penetration, we conclude that future drugs to consider against tularemia should definitely include this group of antibiotics. The outpatient mode of antibiotic treatment is especially relevant as the Scandinavian variant of F. tularensis infection is nonlethal, usually pustuloglandular, and not septicemic. Therefore, oral drugs must be sought, and the quinolone group also satisfies this requirement.

Administration, Oral↗

PubMed1992

Spread of subclinical Chlamydia pneumoniae infection in a closed community.

Chlamydia pneumoniae infections may spread subclinically. The present investigation took place in a military setting. Sera drawn when the conscripts had entered their military service 2 months previously had been kept frozen and were available. In a camp with 500 people, 35 (7%) developed clinical symptoms of pneumonia. The infection was serologically verified with C. pneumoniae-specific micro-immunofluorescence technique. Of 40 healthy controls, 21 turned out to fulfil the serological criteria of infection, thus, representing subclinical cases. These 21 cases, when extrapolated to the whole camp, equalled a rate of 49% which, added to the 7% of pneumonic cases, gave a total infection rate of 56%. Pre-existing IgG antibodies were demonstrated in 10% of the pneumonic cases, 48% of the subclinical cases, and 89% of the non-infected, healthy controls. Without the access to pre-epidemic sera permitting us to establish 4-fold titre rises, the spread of subclinical C. pneumoniae infection would have been noted at 5%, and not 49% as here demonstrated.

Adult↗

PubMed1992

Pneumonia--a clinical or radiographic diagnosis? Etiology and clinical features of lower respiratory tract infection in adults in general practice.

Etiology and clinical manifestations have been studied in 153 adult patients with lower respiratory tract infection, and the results are presented according to clinical and radiographic diagnosis. Laboratory investigations revealed that bacterial infection, mycoplasma and chlamydia included, occurred as often in 22 patients whose clinical diagnoses of pneumonia were not evident radiographically, as in 20 patients with radiographic pneumonia. In the latter group significantly higher values of erythrocyte sedimentation rate and C-reactive protein were demonstrated. The most common pathogen was influenzavirus A, followed by respiratory syncytial virus, Streptococcus pneumoniae, and Mycoplasma pneumoniae. Chlamydia pneumoniae infection was found in 3 patients with radiographic pneumonia. The study supports the traditional view that patients with a positive chest radiograph as a rule present more serious manifestations of lower respiratory tract pathology than patients with a normal radiograph. However, as only 1/9 patients with pneumococcal infection and 2/7 with mycoplasmal infection had radiographic evidence of pneumonia, radiography alone did not seem to offer sufficient information for selecting patients for antibacterial therapy.

Adult↗

PubMed1992

Observations on Pseudomonas aeruginosa proteolytic and toxic activity in experimentally infected rats.

To bypass natural resistance against Pseudomonas aeruginosa infection, a granuloma pouch model to be experimentally infected was established in rats. This experimental model also permitted easy collection of wound exudate. In general, the animals either died or became very ill and were consequently sacrificed within the first 12 days, or they (6 of 16) survived in good condition after 20 days. The virulence of recently isolated strains compared to twelve-months old subcultures of the same strains showed no major differences in clinical pattern. In the first seven days following the start of the infection, all animals presented a fall of elastase activity in the wound exudate. Toxin A was present in the exudate, sometimes in relatively high levels, but there was no correlation between toxin level and the clinical development. As a rule, spontaneous rupture of the granuloma pouch, apparently unrelated to the concentrations of either elastase or toxin A in the exudate, was beneficial to survival. In the present experimental infectious context, neither P. aeruginosa elastase nor toxin A seemed to play any isolated lethal nor pathogenetic role.

Animals↗

PubMed1991

[Early serological diagnosis of nephropathia epidemica].

The viral disease nephropathia epidemica is probably more common throughout Norway than previously reported. Since 1986, outbreaks of the disease have been registered every year but in different regions of the country. Very few cases have been reported in certain counties in spite of the presence of a small rodent reservoir for this zoonosis. Nephropathia epidemica may be underdiagnosed, since the disease is not equally well recognized in all parts of Norway. However, effective and reliable serological diagnostic tests are now available which use a single serum sample taken early in the acute phase of the disease. Test results are available at a time when they can help the physician to make an early diagnosis. This should lead to a more effective and rational treatment of these patients.

Enzyme-Linked Immunosorbent Assay↗

PubMed1991

Rapid identification of Legionella pneumophila zinc metalloprotease using chromogenic detection.

Strains of Legionella spp. produce extracellular proteases than can be detected using synthetic chromogenic peptides. Chromogenic tri- and tetrapeptides show a high degree of sensitivity, specificity and reagent stability when linked to para-nitroaniline (pNA). For example, SucOMe-Arg-Pro-Tyr.pNa (S-2586) is specifically hydrolysed by proteases of Legionella pneumophila and some other Legionella species. A paper disc method to sample protease directly from agar plates has been used to evaluate chromogenic peptides as reagents for diagnostic purposes. Strains of Legionella spp., Pseudomonas spp. and Enterobacteriaceae were examined, together with a recombinant Escherichia coli strain containing the cloned 38 kDa zinc metalloprotease from L. pneumophila, S-2586 was hydrolysed by 282 out of 283 L. pneumophila strains, and by the recombinant E. coli. Two of the six strains representing other Legionella species, and 22 of the 50 strains from the Pseudomonas group were also positive. No reaction was seen with any of the Enterobacteriaceae strains. Although there was functional homology between proteases from several bacterial groups, the high prevalence of S 2586-hydrolysing proteases within L. pneumophila indicates a potential usefulness for phenotypic identification.

Bacterial Proteins↗

PubMed1991

Antigenic variation among strains of Chlamydia pneumoniae.

The antigenic profiles of six strains of Chlamydia pneumoniae were analyzed by the microimmunofluorescence test (MIF) and immunoblotting with human serum and murine monoclonal antibody. MIF-derived antibody titers in serum samples from culture-positive patients were four- to eightfold higher against autologous isolate antigen than they were against the prototype antigen strain TW-183. Sera of patients with respiratory illness that were culture negative and complement fixation positive for Chlamydia spp. produced higher titers by MIF against a strain of C. pneumoniae isolated in the area than they did against TW-183. For two of five cases, the criteria for establishing the diagnosis of acute infection were met only with use of the antigen from the local strain; TW-183 was inadequate for this purpose. Immunoblot profiles revealed antigenic differences between strains that varied with the human serologic response; i.e., unique antigens were recognized by the sera of some individuals and not by the sera of others. Using the reactivity of a genus-specific monoclonal antibody against a major outer membrane protein, we found that strain CWL-011, isolated in Atlanta, Ga., may possess a major outer membrane protein with a molecular mass between those of C. trachomatis L2 and other C. pneumoniae strains. These data provide evidence of several new and unique serotypes of C. pneumoniae and suggest that the serologic diagnosis of C. pneumoniae infection may require the use of antigens from more than one strain of this species.

Antibodies, Bacterial↗

PubMed1991

Chlamydia pneumoniae respiratory tract infection: the interpretation of high titres in the complement fixation test.

Sera from 5 acute respiratory disease patients from Northern Norway presenting with high chlamydia complement fixation (CF) titres, were analyzed for Chlamydia pneumoniae-specific IgG and IgM in a micro-immunofluorescence (micro-IF) test that included antigens from the prototype strain TW 183, and a Norwegian isolate, FML 10. The patients were confirmed to have had C. pneumoniae infection based on serologic findings. This establishes the clinical significance of early CF results in this geographical area. However, different micro-IF titres against the 2 C. pneumoniae isolates tested suggest antigenic variability among the species.

Adolescent↗

PubMed1990

[Biological weapons--conventions and history].

The UN Convention of 10 April 1972 bans the development, production and storage of biological weapons. Prohibition of their use was already covered by the 1925 Geneva Protocol. Pursuant to Article XII of the 1972 Convention, two follow-up conferences have been held, in 1980 and 1986, and an expert meeting in Geneva in 1987. As a result, the parties to the Convention have agreed to the exchange of equipment, materials and scientific information relevant to biological weapons, open publication of research, and exchange of scientists. Historically, the spread of infections has often been attempted in warfare. Presently, the very rapid development of biotechnology creates a diffuse situation, where the development of biological weapons is quite conceivable. This indicates that our national preparedness concept will have to include preparedness against biological warfare for several more decades.

Biological Warfare↗

PubMed1990

Legionella antibodies in human and animal populations in Kenya.

Using a microagglutination method, domestic and wild animal sera, together with human patient and healthy blood donor sera, have been analysed for titres against various Legionella species, comprising fourteen different serogroups. Generally, the level of moderately elevated titres, i.e. greater than or equal to 64, was low for all the aforementioned serum groups. Within the domesticated animals, cattle, pigs and dogs presented a much lower prevalence in Kenya than found elsewhere, whereas it was the other way round for goats. Human sera, either from patients or from healthy donors, did not react against L. pneumophila serogroups 1, 6, or 3, which in that sequence are the most common L. pneumophila serogroups in Europe, and in other geographic areas where legionellosis is common. High titres of greater than or equal to 256 against L. pneumophila serogroup 6 (two cattle) or against L. bozemanii strain Mi-15 (two cattle, one dog) indicate that although the epidemiological picture may be different from other parts of the world, Legionella infections exist in Kenya as well.

Agglutination Tests↗

PubMed1989

[Drinking water for tourists in the Tropics].

The modern Norwegian tourist may need a simple and rapid procedure to ensure that water is potable. Convenient available products for such include chemicals and microfilters. We describe and comment on the chemicals currently available in Norway. We have also evaluated a series of portable filters. The microfilters reduced the number of microbes quite efficiently. Some also had good flow capacity, and can certainly be recommended as useful traveller's equipment.

Disinfectants↗

PubMed1989

Pseudomonas aeruginosa extracellular toxicity in infant mice and the protective effect of antitoxin A.

The toxin A-content of crude extracellular preparations from Pseudomonas aeruginosa has been measured by ELISA. Using infant mice as test animal, the toxicity of these preparations was evaluated. The LD 50 in infant mice was determined at 80 ng of purified toxin A in saline. With ten microliters of rabbit antitoxin A serum given together with purified toxin, the LD 50 increased to 2,500 ng. Generally there was no correlation between the LD 50 of the extracellular preparations, their quantity of toxin A as measured by ELISA, and the protective effect of antitoxin A.

ADP Ribose Transferases↗