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P Sandven

Publications and source records attributed to P Sandven.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the nitrate-based colorimetric method for testing the susceptibility of Mycobacterium tuberculosis to streptomycin and ethambutol in liquid cultures.

OBJECTIVES: To evaluate the inexpensive colorimetric nitrate reductase-based antibiotic susceptibility (CONRAS) assay for testing the susceptibility of Mycobacterium tuberculosis to streptomycin and ethambutol in liquid cultures, and to compare the CONRAS test with the manual mycobacteria growth indicator tube (MGIT) test, using the radiometric BACTEC 460TB method as reference. METHODS: A total of 89 M. tuberculosis isolates were tested for susceptibility to streptomycin and ethambutol using the CONRAS and manual MGIT methods and the results were compared with BACTEC 460TB. Isolates with discrepant results between the CONRAS test and BACTEC 460TB were analysed using the agar proportion method, Etest and mutation analysis of genes involved in resistance to streptomycin and ethambutol. RESULTS: The agreement between the CONRAS test and BACTEC 460TB was 88% for streptomycin and 84% for ethambutol. The corresponding agreement of the manual MGIT test with BACTEC 460TB was 89 and 80%, respectively. There was good agreement for streptomycin and moderate agreement for ethambutol between the CONRAS and manual MGIT tests on one hand and BACTEC 460TB on the other (CONRAS test, kappa(streptomycin) 0.74 and kappa(ethambutol) 0.59, P < 0.001; manual MGIT test, kappa(streptomycin) 0.77 and kappa(ethambutol) 0.50, P < 0.001). CONCLUSIONS: There is good agreement for the two non-radiometric liquid culture methods (CONRAS and manual MGIT) compared with BACTEC 460TB for the detection of streptomycin resistance. Further standardization is needed for testing of ethambutol resistance using the CONRAS and manual MGIT assays.

Antitubercular Agents↗
PubMed2005

Resistance of multidrug-resistant strains of Mycobacterium tuberculosis from the Archangel oblast, Russia, to second-line anti-tuberculosis drugs.

Multidrug-resistant tuberculosis has become common all over the world, necessitating the inclusion of second-line drugs in treatment regimens. In the present study, the susceptibility of a selection of multidrug-resistant strains of Mycobacterium tuberculosis isolated in the Archangel oblast, Russia, to second-line anti-tuberculosis drugs was analysed. Susceptibility testing of 77 Mycobacterium tuberculosis strains was performed by the Bactec method using the following recommended drug concentrations: capreomycin 1.25 microg/ml; ethionamide 1.25 microg/ml; kanamycin 5 microg/ml; and ofloxacin 2 microg/ml. The majority of strains (92.2%) were resistant to ethionamide. High rates of drug resistance were also found for capreomycin (42.9%) and kanamycin (41.6%), while nearly all strains (98.7%) were susceptible to ofloxacin. The high rates of resistance to ethionamide, capreomycin, and kanamycin show the real burden of drug resistance in the region and pose a serious problem for the treatment of patients with multidrug-resistant tuberculosis.

Antitubercular Agents↗
PubMed2005

Tuberculosis in contacts need not indicate disease transmission.

BACKGROUND: Traditional contact investigation is an important tool for controlling tuberculosis. It may also help to indicate drug susceptibility patterns when Mycobacterium tuberculosis cultures are not available. Such investigations often underestimate the degree of transmission found by genotyping, but overestimation may also occur. This report is the result of a routine successive DNA restriction fragment length polymorphism (RFLP) analysis of M tuberculosis isolated in Norway. METHOD: Fifteen immigrants belonging to the same community were notified with tuberculosis during February to September 2003. The mycobacterial isolates were analysed by RFLP. RESULTS: All 15 patients had social contact with each other and 13 belonged to the same church community. A total of 14 cultures were positive for M tuberculosis. Among these isolates, six different genotypes were found. Five patients had not acquired the infection from the putative source. CONCLUSIONS: Reactivation of tuberculosis may occur in contacts during the development of an outbreak. In such situations, traditional contact investigations may overestimate the rate of transmission found by genotyping of M tuberculosis. When cultures are unavailable and presumed drug susceptibility patterns are based on that of contacts, such overestimation may lead to incorrect treatment of a patient. Contact investigations must be combined with genotyping of M tuberculosis to conclude how tuberculosis is transmitted. This is especially important in persons with several risk factors for infection.

Adolescent↗
PubMed2005

[Impact of drug resistance of the causative agent on the outcomes of treatment for pulmonary tuberculosis in the Arkhangelsk Region].

The present study was undertaken to assess the results of treatment in patients with pulmonary tuberculosis in the Arkhangelsk Region in 1999 and to analyze the results of treatment in relation to the infection with Mycobacterium tuberculosis with different profiles of sensitivity to antituberculous drugs. The outcomes of treatment were assessed in relation to the infection with Mycobacterium tuberculosis with different profiles of sensitivity to antituberculous drugs in 76 patients to whom the BACTEC test was applied. Beneficial effects of therapy were recorded in 150 (63.9%) of the 235 new cases. In 29 (12.3%) patients, it ended in death, ineffective treatment was recorded in 20 (8.5%) first detected patients; 29 (12.3%) new cases discontinued treatment; the result of therapy was unknown in 7 (3.0%). There was a low efficiency of chemotherapy (26.2%), its inefficiency in 24 (39.4%) patients; treatment was discontinued in 18 (29.5%) cases and its outcome was unknown in 1 (1.6%) patient. Resistance to one antituberculous agent timely used in the effective chemotherapy regimen did not affect the outcome of treatment. The spread of drug resistance in pulmonary tuberculosis in the Arkhagelsk Region directly affects the outcome of the disease.

Antibiotics, Antitubercular↗
PubMed2004

Impact of drug-resistant Mycobacterium tuberculosis on treatment outcome of culture-positive cases of tuberculosis in the Archangel oblast, Russia, in 1999.

The objective of this study was to evaluate the outcome of treatment of culture-positive cases of tuberculosis registered in Archangel, Russia, in 1999, and to analyse the influence of Mycobacterium tuberculosis drug resistance on treatment outcome. The outcome of tuberculosis treatment was evaluated for 235 new and 61 previously treated culture-positive cases diagnosed in 1999. Of the 235 new cases, there were 150 (63.8%) cases of treatment completion, 20 (8.5%) cases of treatment failure, 29 (12.3%) cases of death during treatment, and 29 (12.3%) cases in which the patient failed to pick up medications for at least 2 consecutive months. The outcome in 7 (3%) cases was unknown, as the patients were transferred outside the oblast region. Among the 61 previously treated cases, the rate of treatment completion was low (26.2%), and rates of treatment failure (23%) and failure to pick up medications for at least 2 consecutive months (29.5%) were high. The relation between the susceptibility pattern of the infecting strain as determined by the Bactec method and tuberculosis treatment outcome was analysed for 76 patients. The majority (69%) of patients infected with drug-susceptible strains was cured. A large proportion (58.8%) of patients infected with Mycobacterium tuberculosis resistant to more than two drugs did not respond to treatment, i.e. the treatment failed or the patients died. The high rates of death (16.7%) and failure (66.7%) among patients infected with multidrug-resistant strains illustrate the negative impact of multidrug resistance on the outcome of tuberculosis treatment. Pan-resistance was significantly associated with treatment failure (P<0.001). The spread of resistant Mycobacterium tuberculosis has a serious negative impact on the outcome of tuberculosis treatment in Archangel, Russia.

Antitubercular Agents↗
PubMed2003

Rapid colorimetric method for testing susceptibility of Mycobacterium tuberculosis to isoniazid and rifampin in liquid cultures.

We have developed a rapid colorimetric method for testing the susceptibility of M. tuberculosis to isoniazid (INH) and rifampin (RIF) based on incorporation of nitrate in broth cultures containing growth supplements. The performance of this colorimetric nitrate reductase-based antibiotic susceptibility (CONRAS) test was compared with that of the radiometric BACTEC 460TB system in determining the susceptibilities of 74 M. tuberculosis strains to INH and RIF. By using the BACTEC 460TB system as the "gold standard," the sensitivity (i.e., the ability to detect true drug resistance) and specificity (i.e., the ability to detect true drug susceptibility) of the CONRAS test were 100 and 95% for INH and 94 and 100% for RIF, respectively. The repeatability of the CONRAS test was excellent (for INH, kappa = 1 and P < 0.001; for RIF, kappa = 0.88 and P < 0.001). For the majority of strains, results were obtained within 5 days. The CONRAS test is rapid, accurate, and inexpensive and is an adequate alternative, particularly for resource-poor countries.

Antitubercular Agents↗
PubMed2003

Risk factors for recent transmission of Mycobacterium tuberculosis.

In recent decades, the decline of tuberculosis has stopped in Western Europe, mainly due to increased immigration from high-prevalence countries. The objective of the current study was to identify risk factors for developing tuberculosis following recent infection, in order to better target interventions. Strains from 861 culture-positive cases, diagnosed in Norway in 1994-1999, were analysed by use of restriction fragment length polymorphism (RFLP). A cluster was defined as two or more isolates with identical RFLP patterns. Risk factors for being part of a cluster were identified by univariate and multivariate analysis. A total of 134 patients were part of a cluster. These constituted 5% Asian-born, 18% Norwegian-born, 24% European-born and 29% African-born patients. Four independent risk factors for being part of a cluster were identified: being born in Norway, being of young age, being infected with an isoniazid-resistant strain and being infected with a multidrug-resistant strain. Transmission of tuberculosis may be further reduced by improving case management, contact tracing, preventive treatment, screening of immigrants and access to health services for the foreign-born population.

Adolescent↗
PubMed2003

Drug susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones: first experience with a quality control panel in the Nordic-Baltic collaboration.

In the first attempt to establish a quality assurance programme for susceptibility testing of Mycobacterium tuberculosis to fluoroquinolones, 20 strains with different fluoroquinolone susceptibility patterns were distributed by the Supranational Reference Laboratory in Stockholm to the other mycobacterial reference laboratories of the Nordic and Baltic countries. Susceptibility testing to fluoroquinolones was performed according to routine procedures in each laboratory. Results were compared to sequence analysis of the gyrA gene and minimal inhibitory concentration determination. Most laboratories found identical susceptibility patterns. The two resistant strains were correctly identified by all laboratories, but three laboratories each falsely reported one susceptible strain as resistant. These results indicate that the participating laboratories yield reliable results in detection of fluoroquinolone-resistant strains, although the need for a standardised quality assurance programme for drug susceptibility testing for fluoroquinolones is stressed by the strains falsely reported as resistant.

Antitubercular Agents↗
PubMed2002

Do HIV-seropositive patients become colonised with drug-resistant microorganisms?

The aim of the present study was to investigate whether HIV-infected patients, a group that is supposedly at risk for infection with antibiotic-resistant microbes, really does so, and to assess possible risk factors for acquiring these organisms. During the period from January 1998 to July 1999, samples of normal flora were obtained from 107 HIV-infected patients attending an outpatient clinic in Oslo, Norway. The samples were cultured for Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli, coagulase-negative staphylococci and Candida spp., and the resulting isolates were tested for antimicrobial susceptibility. The patients studied represented all stages of HIV infection, from recently infected to severely immunocompromised. Samples were taken at one, two or three time-points to determine whether antimicrobial resistance in colonising microorganisms increases over time. Antimicrobial resistance was linked primarily to antimicrobial prophylaxis, but it did not increase during the observation period. The level of a patient's immunodeficiency and the consequently intensified medical care was also of some importance. Even though about 50% of the patients were receiving antimicrobial agents at the time of sampling, the level of resistance found in these patients was very similar to that found in other patient groups in Norway; except for Candida albicans isolates, which were less susceptible to fluconazole. Overall, antimicrobial resistance was uncommon in the HIV-seropositive patients studied, a finding that is probably related to the overall low prevalence of antimicrobial resistance in the general population in Norway.

Adult↗
PubMed2002

[Drug resistance in Mycobacteria tuberculosis in the Barents region of Russia and Norway].

The paper considers drug resistance in Mycobacterium tuberculosis (MBT) in the Barents region of Russia and Norway. Along with a rise in tuberculosis morbidity, there has been recently an increase in the number of patients isolating MBT that are resistant to antituberculous agents. The most dangerous trend is an increase in MDR of MBT strains. In the north-west of Russia there are high MBT drug resistance rated as compared to Norway. There are differences in the determination of drug resistance by the absolute concentration method and by the BACTEC method.

Antitubercular Agents↗
PubMed2002

Drug resistance of Mycobacterium tuberculosis strains isolated from patients with pulmonary tuberculosis in Archangels, Russia.

SETTING: The Archangels oblast, Russia, 1998-2000. OBJECTIVE: To study Mycobacterium tuberculosis resistance to anti-tuberculosis drugs in the Archangels oblast, and to reveal risk factors for the development of drug-resistant tuberculosis. DESIGN: The drug susceptibility of strains isolated from 119 patients with pulmonary tuberculosis was studied using the BACTEC method. Medical records of the patients were reviewed, retrospectively, to identify factors associated with drug resistance. RESULTS: Sixty-seven strains (56.3%) were resistant to at least one anti-tuberculosis drug. The highest rates of resistance were observed for streptomycin and isoniazid: respectively 40.4% and 66.7% of strains isolated from newly and previously treated patients were resistant to streptomycin, and respectively 37.1% and 73.3% of strains isolated from newly and previously treated patients were resistant to isoniazid. Thirty of the 119 strains (25.2%) were multidrug-resistant. Multidrug resistance was four times higher among previously treated patients than among new patients. A history of previous or interrupted treatment for tuberculosis and being female were significantly associated with drug resistance. CONCLUSION: Drug-resistant tuberculosis is an important problem in the Archangels oblast, Russia. The spread of drug resistance is attributed to several risk factors. Being female and evidence of previous treatment for tuberculosis are risk factors for the development of drug-resistant tuberculosis in the Archangels oblast. Patients with drug-resistant tuberculosis also showed a higher risk of interrupting their treatment.

Adolescent↗
PubMed2001

Yeast colonization in surgical patients with intra-abdominal perforations.

A prospective study was conducted to determine (i) the degree of yeast colonization in surgical patients with intra-abdominal perforations and (ii) whether the frequency of colonization is different in patients with a complicated postoperative course than in patients recovering uneventfully. A total of 1,496 specimens taken per- and post-operatively from the mouth, stomach, feces, urine, trachea, and abdomen of 109 surgical patients with intra-abdominal perforations were examined. Yeast was recovered from 98 (90%) of the patients and from 634 (42%) of the specimens. Approximately 70% of the specimens from the mouth and stomach, 47% of fecal specimens, and 31% of abdominal specimens were positive for yeast. A total of 42 patients had a complicated postoperative course. The majority of these patients were colonized with yeast at multiple body sites: yeast was recovered on one or more occasions from two or more body sites in 90% and from three or more body sites in 71%. Many of the patients with an uncomplicated postoperative course also were colonized: yeast was recovered from two or more body sites in 69% and from three or more body sites in 34%. The results of this study indicate that treatment recommendations based on yeast colonization will expose a large number of patients to unnecessary or even harmful antifungal treatment. This does not mean that yeast colonization is insignificant; however, more accurate criteria and methods based on prospective clinical studies are needed to detect patients at risk of developing severe Candida infection.

Adolescent↗
PubMed2001

Molecular epidemiology of Mycobacterium tuberculosis in Norway.

The incidence of tuberculosis in Norway is one of the lowest in the world, and approximately half of the cases occur in first- and second-generation immigrants. In the present study, the genetic diversity of 92% of all strains of Mycobacterium tuberculosis isolated in Norway in 1994 to 1998 was assessed using restriction fragment length polymorphism (RFLP) analysis, with the insertion sequence IS6110 and the repetitive element DR as probes, to determine the degree of active transmission between patients. The DR probe was used as a secondary molecular marker to support or rule out clustering of strains with fewer than five copies of IS6110. After exclusion of 20 cultures representing laboratory contamination, 573 different IS6110 patterns were found among the 698 strains analyzed. Of these 573 patterns, 542 were observed only once and 31 were shared by 2 to 14 isolates. Among 81 strains (11.5%) carrying fewer than five copies of IS6110, 56 RFLP patterns were found when the results of both the IS6110 and DR methods were combined. Among the 698 strains, 570 were considered to be independent cases. A total of 14.5% of the native Norwegians and 19.7% of the foreign patients were part of a cluster. Thus, the degree of recent transmission of tuberculosis in Norway is low and the great majority of the cases are due to reactivation of previous disease. Transmission between immigrants and native Norwegians is uncommon. Two outbreaks, one among native Norwegians and one mainly among immigrants, have been ongoing for several years, indicating that, even in a low-incidence country such as Norway, with a good national program for tuberculosis surveillance, certain transmission chains are difficult to break.

Adolescent↗
PubMed2001

[Molecular epidemiology of Mycobacterium tuberculosis in the Barents Sea region of Russia and Norway].

The paper shows how to detect an epidemiological chain of spread of tuberculosis in the Barents Sea Region. RFLP typing of Mycobacterium tuberculosis strains may serve as an important tool in detecting an infection source and drawing up epidemiological chains of tuberculosis spread. Cross infection may occur in tuberculosis cure hospitals, which shows it necessary to delimit fluxes of tuberculosis patients into health care facilities.

Adult↗
PubMed1999

Importance of selective media for recovery of yeasts from clinical specimens.

We compared the recovery of yeasts from clinical specimens cultured on routine bacteriological media to the recovery of yeast from specimens cultured on a selective fungal medium (Sabouraud agar). The use of Sabouraud agar was especially important in cases of mixed cultures, since in such cases yeast was recovered on bacteriological media from only 50% of 44 yeast-positive pus specimens and from 22. 5% of 22 yeast-positive throat specimens. The use of a selective fungal medium is therefore necessary to ensure the detection of yeast in specimens containing a mixture of bacteria and yeasts. As a result, clinicians must request yeast isolation when clinically indicated, and the microbiological laboratory must add a selective fungal medium when clinically significant yeasts are likely to be encountered. It is also important that selective fungal media be used in clinical studies of yeast infections.

Bacteria↗
PubMed1999

Detection of fluconazole-resistant Candida strains by a disc diffusion screening test.

A commercial disc diffusion test has been evaluated as a screening method for the detection of Candida species with decreased susceptibility to fluconazole. A total of 1,407 Candida strains of different species were tested, and the results were compared with the MIC results. The recently published National Committee for Clinical Laboratory Standards breakpoint criteria have been used. Isolates were classified as susceptible if the MIC for the isolates was </=8 microg/ml, susceptible-dose dependent (S-DD) if the MIC was 16 to 32 microg/ml, and resistant if the MIC was >/=64 microg/ml. All 77 resistant strains and 121 of 122 S-DD strains had fluconazole zone diameters of </=21 mm, and most of the strains (91%) had zone diameters of </=15 mm. It was not possible to distinguish between resistant and S-DD strains by the disc test. Among a total of 1,208 strains found to be susceptible by the microdilution method, 49 (4. 1%) yielded fluconazole zone sizes of </=21 mm and would have been misclassified as resistant or S-DD strains on the basis of the disc test. For the majority (86%) of these 49 strains the fluconazole MIC was 8 microg/ml. The fluconazole disc test is recommended as a simple and reliable screening test for the detection of Candida strains with decreased susceptibility to fluconazole. Fluconazole MICs should be determined for strains found to be resistant by the disc test. The reason for confirmatory testing is twofold: to determine if isolates are resistant or S-DD, since the disc test does not make this distinction, and to identify fluconazole-susceptible strains that are found to be falsely resistant by the fluconazole disc test.

Antifungal Agents↗