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B Olsson-Liljequist

Publications and source records attributed to B Olsson-Liljequist.

At least 19 recordsLinked to original sources
PubMed2004

Effect of clonal and serotype-specific properties on the invasive capacity of Streptococcus pneumoniae.

The present study compares the molecular epidemiology of Streptococcus pneumoniae causing invasive disease and carriage, respectively, in one geographic area (Stockholm, Sweden) during a specific point in time (the year 1997). A total of 273 invasive isolates (257 from adults and 16 from children) obtained from the 2 major hospitals in Stockholm, as well as 246 nasopharyngeal isolates recovered from children attending 16 day-care centers in the Stockholm area, were analyzed by serotyping, molecular typing (by pulsed-field gel electrophoresis and multilocus sequence typing), and antibiotic susceptibility testing. Of the 34 different serotypes plus nontypeable strains identified in the present study, 12 were never found among the 246 colonizing isolates, whereas only 3 were never found among the 273 invasive isolates. The isolates formed 2 major classes: 1 class that was found mainly among invasive isolates (type 1, 4, 7F, and 9V isolates) and was clonally highly related and 1 class that caused invasive disease but was also common in carriage (including type 6A, 6B, 14, and 19F isolates) and was genetically more diverse. Clones were found that belonged to the same serotype but had different abilities to cause invasive disease. Also, isolates belonging to the same clone were found, although they had different capsules because of serotype switch, and were found to have the same disease potential. Hence, properties associated with a particular clonal type, in addition to capsular serotype, are likely to be important for the potential of pneumococci to cause invasive disease.

Adult↗
PubMed2004

Penetration of fusidic acid and rifampicin into cerebrospinal fluid in low-grade inflammatory meningitis caused by Staphylococcus epidermidis.

Cerebrospinal fluid (CSF) concentration-time curves of rifampicin and fusidic acid were studied in a patient with post-operative meningitis caused by Staphylococcus epidermidis. The patient was treated with this combination of antimicrobial agents because of a severe hypersensitivity reaction to vancomycin. Peak CSF concentrations of rifampicin exceeded the MIC by > 60-fold, while those of fusidic acid just reached the MIC. CSF concentrations of fusidic acid were relatively stable within the range reported for patients with uninflamed meninges, but serum levels were surprisingly low. An increase in the metabolism of fusidic acid induced by rifampicin cannot be excluded.

Anti-Bacterial Agents↗
PubMed2004

Report on the first PVL-positive community acquired MRSA strain in Latvia.

Infections by community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) have been reported worldwide. Here we present characterisation of the first CA-MRSA isolated in Latvia. A PVL-positive ST30-MRSA-IV strain was isolated from a nasal swab and the central venous catheter of a patient with fever and multiple organ failure. The PFGE pattern of this strain was identical to pattern SE00-3 of MRSA isolated in Sweden from 29 patients during 2000-2003. This strain is related to the South Pacific area, and its appearance in Sweden and Latvia demonstrates its global spread.

Bacterial Toxins↗
PubMed2003

Evaluation of a cefoxitin 30 microg disc on Iso-Sensitest agar for detection of methicillin-resistant Staphylococcus aureus.

OBJECTIVES: To evaluate the performance of a cefoxitin 30 microg disc on Iso-Sensitest agar, using a semi-confluent inoculum and overnight incubation at 35-36 degrees C, for detection of methicillin-resistant Staphylococcus aureus (MRSA). METHODS: A total of 457 S. aureus, including 190 MRSA of several defined PFGE types and a number of low-level resistant isolates, were tested with a cefoxitin 30 microg disc on Iso-Sensitest agar, using a semi-confluent inoculum and overnight incubation at 35-36 degrees C. This method was compared with the standard SRGA (Swedish Reference Group for Antibiotics) method (oxacillin 1 microg disc on Iso-Sensitest agar supplemented with 5% defibrinated horse blood, confluent growth and 24 h incubation in ambient air at 30 degrees C). RESULTS: The cefoxitin method was excellent, with a sensitivity of 100% and a specificity of 99% using an interpretative zone diameter of S > or = 29 mm and R < 29 mm. Its performance was much better than the SRGA method, which with this collection of difficult strains had a sensitivity of only 78% using the current breakpoint of S > or = 12 mm. CONCLUSION: We suggest that the cefoxitin method should replace that currently recommended by the SRGA for the detection of MRSA, and that it would fit well into BSAC methodology.

Agar↗
PubMed2003

Clonality among ampicillin-resistant Enterococcus faecium isolates in Sweden and relationship with ciprofloxacin resistance.

OBJECTIVE: To investigate clonal relationships in a nationwide sample of human Enterococcus faecium isolates. METHODS: Biochemical fingerprinting (PhP (PhenePlate) typing) was used to compare 180 fecal ampicillin-resistant E. faecium (ARE) isolates with 169 matched fecal ampicillin-susceptible E. faecium (ASE) isolates from patients in 23 hospitals, collected in 1998, and to study 39 fecal ARE isolates from non-hospitalized individuals collected in 1998, and five ARE and 29 ASE isolates from the early 1990s. Representative ARE and ASE isolates were subjected to pulsed-field gel electrophoresis (PFGE) analysis of genomic DNA and sequencing of the regions encoding the fluoroquinolone targets of the enzymes GyrA and ParC. RESULTS: Both PhP and PFGE results showed a higher homogeneity among ARE than among ASE isolates (P < 0.001). One PhP type (FMSE1) comprised 73% of the hospital ARE isolates (53% of ARE isolates from non-hospitalized individuals, and four of five ARE isolates from the early 1990s), but only 1% of the ASE isolates. PFGE of the hospital E. faecium isolates revealed that 23 of the 25 ARE isolates and one of the 22 ASE isolates were of one dominating type. High-level resistance to ciprofloxacin (MIC > 16 mg/L) was present in 91% of ARE isolates, whereas only low-level resistance (MIC 4-16 mg/L; 35% of isolates) was found among ASE isolates. One mutation in parC (codon 80) and one of two mutations in gyrA (codons 83 or 87) were detected in all ARE isolates tested with high-level ciprofloxacin resistance, but were lacking in ARE and ASE isolates with low-level ciprofloxacin resistance. CONCLUSION: Most ARE isolates in Sweden were clonally related. High-level ciprofloxacin resistance was found in ARE isolates of PhP type FMSE1 as well as in other PhP types, but never in ASE isolates.

Ampicillin↗
PubMed2003

Clonal analysis of Streptococcus pneumoniae nonsusceptible to penicillin at day-care centers with index cases, in a region with low incidence of resistance: emergence of an invasive type 35B clone among carriers.

The nasopharyngeal carriage rate of potential respiratory pathogens was studied in 36 index children with a pneumococci nonsusceptible to penicillin (PNSP), in 595 healthy children, and in 123 personnel at 16 day-care centers (DCCs) with index cases in the Stockholm area, an urban area with a low incidence of antibiotic resistant pneumococci, during the winter of 1997-1998. The spread and clonality of PNSP, Haemophilus influenzae and Moraxella catarrhalis, were studied by analyzing antibiotic susceptibility and serotype, and for PSNP also by using pulsed-field electrophoresis (PFGE) and multilocus sequence typing (MLST). In contrast to the low carriage rate found among the adult contacts (2%), 40% of the children harbored pneumococci, of which 20% were PNSP. Nasopharyngeal colonization decreased with age. The 49 PNSP isolates consisted of 20 clones, of which 10 could be identified in more than one child attending the same or different DCCs. In five DCCs, we observed a spread of PNSP from the index case. A novel PNSP clone of type 35B, found to cause invasive disease in several states in the United States, was found to emerge among several carriers at two DCCs . A high proportion of PNSP isolates were multiresistant to antibiotics (34%), which has implications for treatment regimens, even in a country like Sweden where the proportion of PNSP currently is low (3-4%). One PNSP clone of type 9V found among the carriers, has been shown to cause invasive disease in Sweden as well as in other countries, suggesting that one reason for the occurrence of invasive PNSP clones may be their ability to colonize and spread among healthy carriers. Other internationally spread antibiotic resistant pneumococcal clones found were of types 9V, 19F, and 23F.

Anti-Bacterial Agents↗
PubMed2002

Antibiotic prescription practices, consumption and bacterial resistance in a cross section of Swedish intensive care units.

BACKGROUND: The purpose of this work was to study usage of antibiotics, its possible determinants, and patterns of bacterial resistance in Swedish intensive care units (ICUs). METHODS: Prospectively collected data on species and antibiotic resistance of clinical isolates and antibiotic consumption specific to each ICU in 1999 were analyzed together with answers to a questionnaire. Antibiotic usage was measured as defined daily doses per 1000 occupied bed days (DDD1000). RESULTS: Data were obtained for 38 ICUs providing services to a population of approximately 6 million. The median antibiotic consumption was 1257 DDD1000 (range 584-2415) and correlated with the length of stay but not with the illness severity score or the ICU category. Antibiotic consumption was higher in the ICUs lacking bedside devices for hand disinfection (2193 vs. 1214 DDD1000, p=0.05). In the ICUs with a specialist in infectious diseases responsible for antibiotic treatment the consumption pattern was different only for use of glycopeptides (58% lower usage than in other ICUs: 26 vs. 11 DDD1000,P=0.02). Only 21% of the ICUs had a written guideline on the use of antibiotics, 57% received information on antibiotic usage at least every 3 months and 22% received aggregated resistance data annually. Clinically significant antimicrobial resistance was found among Enterbacter spp. to cephalosporins and among Enterococcus spp. to ampicillin. CONCLUSIONS: Availability of hand disinfection equipment at each bed and a specialist in infectious diseases responsible for antibiotic treatment were factors that correlated with lower antibiotic consumption in Swedish ICUs, whereas patient-related factors were not associated with antibiotic usage.

Adult↗
PubMed2002

Clonal spread among Swedish children of a Staphylococcus aureus strain resistant to fusidic acid.

An increased incidence of fusidic acid-resistant Staphylococcus aureus strains causing superficial infections among children in Sweden has been noted since the mid-1990s. Based on routine susceptibility testing data from 10 laboratories representing 8/21 Swedish counties during 1990-2001, the increase was first demonstrated in southern Sweden and subsequently became apparent throughout the country. Epidemiological typing using pulsed-field gel electrophoresis of recent isolates of fusidic acid-resistant S. aureus from 11 laboratories representing 8/21 Swedish counties revealed a high degree of similarity of band patterns, indicating a clonal relationship. Data from 1 of the laboratories demonstrated a close connection between this clone and impetigo. Sales statistics showed a pronounced increase in the use of fusidic acid ointments in the 0-12 y age group from 1998 onwards. There was, however, no statistically significant correlation between sales of fusidic acid ointments and resistance among S. aureus strains to fusidic acid.

Administration, Topical↗
PubMed2001

Antimicrobial susceptibility of Mycobacterium marinum determined by E-test and agar dilution.

Mycobacterium marinum is recognized as a cutaneous pathogen requiring antibiotic treatment. We compared the E-test with a reference agar dilution method for susceptibility testing of M. marinum to amikacin, ciprofloxacin, clarithromycin, doxycycline, rifampicin, trimethoprim-sulfamethoxazole and ethambutol. MICs obtained after 6 d showed agreement between the E-test and agar dilution within +/- 2 dilutions in 95% of all cases for amikacin, ciprofloxacin, doxycycline and rifampicin. Inhibitory concentrations of trimethoprim-sulfamethoxazole were difficult to define using the E-test because of gradually decreased growth in the presence of increasing concentrations. For clarithromycin, results were generally 1-3 dilution steps lower with the E-test and for ethambutol they were often > 3 dilution steps lower. These differences always appeared in the low MIC range and did not affect the categorization of the strains as susceptible to these 2 antimicrobial agents. All strains were interpreted as susceptible to all tested antibiotics, except for doxycycline, according to recommended breakpoints. Overall, our results suggest that the E-test can be considered an alternative for susceptibility testing of certain antibacterial agents against M. marinum.

Anti-Bacterial Agents↗
PubMed2001

Changes in serotype distribution may hamper efficacy of pneumococcal conjugate vaccines in children.

During the last 10 y we have observed an increased incidence of pneumococcal bacteremia in Sweden. In order to study the serotype distribution over time we collected 1136 invasive pneumococcal isolates from 1987, 1992 and 1997 from Swedish microbiological laboratories. Currently, new pneumococcal conjugate vaccines are being considered for introduction in the general childhood vaccination program in several countries, including Sweden. We studied the potential vaccine coverage rate for the new conjugate vaccines among our Swedish invasive isolates. We found that the serotype distribution fluctuated with time and observed a surprisingly low potential coverage rate for the 7-valent vaccine in Sweden, in contrast to other countries. Therefore we argue that pneumococcal conjugate vaccines have to be tailored to suit current, local serotype patterns and most likely will need to be changed over time.

Adolescent↗
PubMed2000

Epidemiology and ecology of enterococci, with special reference to antibiotic resistant strains, in animals, humans and the environment. Example of an ongoing project within the European research programme.

The objectives of the present study are to generate knowledge of the ecology and epidemiology of enterococci in the food chain by studying the following: (1) the population structure (in measures of abundance, number of vancomycin resistant strains, antibiotic resistance patterns, diversity, and stability) among enterococcal populations in different geographical regions and in different links of the food chain (2) possible transmission of strains through the food chain and between hospital environments and the food chain (3) the association between vancomycin resistance and individual strains of enterococci and (4) the diversity of the drug resistance genes in enterococci. So far, 1578 samples have been collected from different countries within the EU (Sweden, Denmark, UK and Spain), and from different habitats (pig farms, carcasses in slaughter houses, soil, manure, water, sewage, and humans). Total and vancomycin resistant enterococcal populations in each sample have been enumerated and more than 12000 isolates have been characterised by phenotyping. Representative isolates are further species identified and characterised by genotyping and MIC determination and from antibiotic resistant isolates the resistance genes are characterised.

Animals↗
PubMed1999

[Fluoroquinolone resistance of human pathogenic bacteria. Resistant E coli now appearing in Sweden].

Fluoroquinolone-resistance is a growing international problem. Warnings have earlier been issued concerning the risk of resistance development due to excessive fluoroquinolone prescription. The development of resistance among E. coli strains isolated from primary care patients with UTI is now apparent in Sweden. So far the majority of these strains manifest only low-level resistance. However, in view of the risk of high-level resistance developing among these strains further exposed to fluoroquinolones, it is important to think twice before prescribing these drugs.

Anti-Infective Agents↗
PubMed1999

[Development of resistant Helicobacter pylori in Sweden. Tendency toward increasing resistance to clarithromycin].

This study was designed to investigate the development of antibiotic resistance in Swedish H pylori isolated 1990-96. A total of 415 isolates collected from 10 clinical microbiology laboratories were examined. Three different methods of susceptibility testing were compared: agar dilution, the E-test and disc diffusion. None of the isolates was resistant to ampicillin or tetracycline, but approximately 30 per cent were resistant to metronidazole. An increase in resistance to clarithromycin was noted during 1996 (9% resistant strains), though the significance of this finding needs further investigation. The comparison of susceptibility tests suggested disc diffusion to be of doubtful value, but the E-test to be appropriate for testing H pylori. However, the number of isolates resistant to metronidazole was higher with the E-test than with agar dilution. The value of testing susceptibility to metronidazole is discussed.

Anti-Bacterial Agents↗
PubMed1999

Antimicrobial susceptibility of equine isolates of Actinobacillus spp. and identification of beta-lactamases in some strains.

A total number of 149 Actinobacillus strains isolated from clinical samples (73 strains) and from the oral cavity of healthy horses (76 strains) were tested for their susceptibility to 17 antimicrobial substances. The antibiograms were generally very similar between the various strains and no differences could be clearly correlated to either phenotype or source of isolates. However, when tested against penicillin, ampicillin, trimethoprim-sulfa, and streptomycin, small groups of strains with what appeared to be acquired resistance could be identified. Eight of the penicillin-resistant strains were found to produce beta-lactamase. The beta-lactamases appeared to be bound tightly to the cell wall, thereby frustrating further characterization by isoelectric focusing. Plasmids of approximately 3 kb were found in four out of seven beta-lactamase-producing strains submitted to plasmid analysis.

Actinobacillus↗
PubMed1999

Near absence of vancomycin-resistant enterococci but high carriage rates of quinolone-resistant ampicillin-resistant enterococci among hospitalized patients and nonhospitalized individuals in Sweden.

Rates of colonization with enterococci with acquired resistance to vancomycin (vancomycin-resistant enterococci [VRE]) and ampicillin (ampicillin-resistant enterococci [ARE]) were determined by using fecal samples from 670 nonhospitalized individuals and 841 patients in 27 major hospitals. Of the hospitalized patients, 181 (21.5%) were carriers of ARE and 9 (1.1%) were carriers of VRE. In univariate analyses, length of hospital stay (odds ratio [OR], 4.6; 95% confidence interval [CI], 2.5 to 8.9) and antimicrobial therapy (OR, 4.7; 95% CI, 3.3 to 6.7) were associated with ARE colonization, as were prior treatment with penicillins (OR, 3.1; 95% CI, 1.8 to 5. 5), cephalosporins (OR, 2.9; 95% CI, 1.7 to 5.0), or quinolones (OR, 2.7; 95% CI, 1.5 to 4.7). In logistic regression analysis, antimicrobial therapy for at least 5 days was independently associated with ARE carriage (adjusted OR, 3.8; 95% CI, 2.6 to 5.4). Over 90% of the ARE isolates were fluoroquinolone resistant, whereas 14% of the ampicillin-susceptible Enterococcus faecium isolates were fluoroquinolone resistant. ARE carriage rates correlated with the use of fluoroquinolones (P = 0.04) but not with the use of ampicillin (P = 0.68) or cephalosporins (P = 0.40). All nine VRE isolates were E. faecium vanB and were found in one hospital. Seven of these isolates were related according to their types as determined by pulsed-field gel electrophoresis. Among the nonhospitalized individuals, the ARE carriage rate was lower (6%; P < 0.05), and only one person, who had recently returned from Africa, harbored VRE (E. faecium vanA). The absence of VRE colonization in nonhospitalized individuals reflects an epidemiological situation in Sweden radically different from that in countries in continental Europe where glycopeptides have been widely used for nonmedical purposes.

4-Quinolones↗
PubMed1997

[A handling program for resistant pneumococci. Physicians sometimes neglect mandatory notification].

Streptococcus pneumoniae infections belong to the leading worldwide causes of illness and death among young children, people with underlying debilitating medical conditions, and the elderly. Following early documentation of infections due to pneumococcal strains with reduced penicillin susceptibility in Australia in 1967, and of infections due to penicillin-resistant strains in South Africa in 1978, pneumococcal resistance to penicillin and other antibiotics has progressed rapidly and is now a global problem. In Sweden, notification of the occurrence of pneumococci with a minimum inhibitory concentration (MIC) > or = 0.5 mg/L for penicillin G (PcG) has been mandatory for general practitioners (GPs) and clinical microbiological laboratories since 1 January 1996. In 1996, 1,057 cases of infection by such pneumococci were reported by microbiological laboratories, but only 262 cases by GPs. With a view to minimising the impact of pneumococci with reduced penicillin susceptibility in Sweden, the National Board of Health and Welfare set up a working group of experts in November 1994. To reduce the transmission of such bacteria in the community, the working group introduced a control programme which includes the isolation of day-care children under six years of age carrying pneumococci with PcG-MICs > or = 0.5 mg/L. An enquiry among the 25 regional centres for infectious disease control in the country to ascertain compliance in the different counties of Sweden showed the programme to have been adhered to in a majority of counties, although many had chosen alternative measures to deal with the problem.

Disease Notification↗