| 1. |
- Berglund, Torsten, et al.
(författare)
-
One year of Neisseria gonorrhoeae isolates in Sweden : the prevalence study of antibiotic susceptibility shows relation to the geographic area of exposure
- 2002
-
Ingår i: International Journal of STD and AIDS (London). - : SAGE Publications. - 0956-4624 .- 1758-1052. ; 13:2, s. 109-114
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare epidemiological data with antibiotic susceptibility patterns, so as to characterize the risk of infection with a highly resistant Neisseria gonorrhoeae strain. N. gonorrhoeae strains isolated in Sweden from February 1998 through January 1999 were tested for antibiotic susceptibility. Epidemiological data were received from each clinician reporting a case of gonorrhoea and these data were linked to the N. gonorrhoeae strains. A total of 348 N. gonorrhoeae isolates, representing 89% of all Swedish cases diagnosed during the 12-month period, were tested for antibiotic susceptibility. Of all isolates, 24% were β-lactamase-producing, and 18% had decreased susceptibility to ciprofloxacin (MIC>0.064 mg/l). All isolates were fully susceptible to ceftriaxone and spectinomycin. More than 99% of the isolates were fully susceptible to azithromycin. The antibiotic susceptibility varied with the places where patients were exposed to infection. When exposed in Asia, 63% of the isolates showed reduced susceptibility to ciprofloxacin, compared with 0-8.5% of the isolates from patients exposed in other places (RR=8.5, P<0.001). Ciprofloxacin cannot be recommended as the first choice of treatment if the place of exposure was in Asia.
|
|
| 2. |
- Bäckman, Anders, et al.
(författare)
-
Complete Sequence of a β-Lactamase-Encoding Plasmid in Neisseria meningitidis
- 2000
-
Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 44:1, s. 210-212
-
Tidskriftsartikel (refereegranskat)abstract
- Identical β-lactamase-encoding (TEM-1) plasmids were found in two different clinical Neisseria meningitidis strains. They were completely sequenced (5,597 bp) and designated pAB6. The plasmid is almost identical to Neisseria gonorrhoeae plasmid pJD5 (5,599 kb) and may have been picked up from a gonococcus in vivo.
|
|
| 3. |
|
|
| 4. |
- Clarke, S. C., et al.
(författare)
-
Analysis of PorA variable region 3 in meningococci : implications for vaccine policy?
- 2003
-
Ingår i: Vaccine. - 0264-410X .- 1873-2518. ; 21:19-20, s. 2468-2473
-
Tidskriftsartikel (refereegranskat)abstract
- Outer membrane protein (OMP) vaccines are being developed against Neisseria meningitidis serogroup B which may provide protection against common circulating serotypes and serosubtypes in some countries. However, limited data is available in Europe from genosubtyping meningococci. We therefore undertook a retrospective analysis of the three main variable regions, VR1, VR2 as well as VR3, of the porA gene from N. meningitidis isolated from different countries, mainly from Scotland and Sweden. Analysis of this gene showed that, amongst 226 strains studied, there were a total of 78 different strains. No new VR1 or VR2 alleles were found but five new VR3 alleles are described. Our data indicates the importance of analysing the VR3 region of PorA in addition to VR1 and VR2 and also highlights, in general terms, the need for genosubtyping meningococci. Such analyses have major implications for the design of new meningococcal vaccines.
|
|
| 5. |
- Dahle, Charlotte, 1956-, et al.
(författare)
-
Methods of choice for diagnostic antinuclear antibody (ANA) screening : Benefit of adding antigen-specific assays to immunofluorescence microscopy
- 2004
-
Ingår i: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411 .- 1095-9157. ; 22:3, s. 241-248
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives. To evaluate and compare the performances of three enzyme-immunoassays (EIAs) and a double radial immunodiffusion (DRID) test in addition to immunofluorescence (IF) microscopy for routine laboratory screening of patient sera sent for antinuclear antibody (ANA) analysis. Methods. 3079 consecutive patient sera sent for routine testing of ANA were analysed by IF microscopy on HEp-2 cells (IF-ANA), three different ANA-EIAs, and a DRID test for antibodies against extractable nuclear antigens. The IF-ANA and DRID tests were regarded as reference methods. Results. By IF-ANA and/or DRID, 375 sera (12%) turned out ANA-positive. A further 171 sera (6%) were positive by EIA, but could not be confirmed either by IF microscopy or DRID. 32 of the 375 ANA-positive (9%) sera were negative by IF microscopy, but had precipitating antibodies against Ro/SS-A (52 and/or 60 kD). Conclusions. Different assays for ANA analysis give overlapping results to a certain extent, but are by no means interchangeable. Thus, different ANA tests reflect different aspects of these autoantibodies. The diagnostic utility of ANA testing still mainly refers to IF-microscopy and precipitin tests. IF-ANA should not be abandoned as the golden standard in clinical routine, until diagnostic and classification criteria for systemic lupus erythematosus and other systemic inflammatory autoimmune diseases have been revised. However, in addition we strongly advocate that a specific test for anti-Ro/SS-A antibodies is always included.
|
|
| 6. |
- Falk, Lars, et al.
(författare)
-
Genotyping of Chlamydia trachomatis would improve contact tracing
- 2003
-
Ingår i: Sexually Transmitted Diseases. - : Ovid Technologies (Wolters Kluwer Health). - 0148-5717 .- 1537-4521. ; 30:3, s. 205-210
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The reported number of genital Chlamydia trachomatis infections has increased 15% annually since 1997 in Sweden. Inaccurate partner notification might be one reason.Goal: The goals were to determine if genotyping of C trachomatis would improve partner notification and to study the duration of infection.Study Design: Sexual networks were constructed. C trachomatis isolates from 231 individuals attending the Örebro STD clinic during 1 year were typed by sequencing of the omp1 gene.Results: All individuals were traced and diagnoses were established in 30 of 161 networks. More than one genotype was seen in seven networks. The mean duration of C trachomatis infection in each network was calculated to be 23 weeks.Conclusion: Genotyping could be a useful tool in partner notification when there are discrepant or uncommon genotypes. Limited clinic catchment areas create information difficulties that obstruct accurate contact tracing.
|
|
| 7. |
|
|
| 8. |
- Forsum, Urban, 1946-, et al.
(författare)
-
Methods in molecular biology
- 2004
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- An accessible introduction to how genomics has and will provide novel methods for bacterial investigation and advance our understanding and knowledge of bacterial pathogenicity. The authors critically evaluate the applications of genomics to diagnostic bacteriology, highlighting both current and likely future uses, describing real-time PCR methods, and outlining the promise of microarrays in clinical bacteriology. Their discussion examines in detail genomic approaches to antibacterial discovery, the nature of pathogenicity, the discovery of new pathogens, the exploration of the concept of clonality in bacteria, and bacterial taxonomics.
|
|
| 9. |
|
|
| 10. |
- Garpenholt, Ö., et al.
(författare)
-
Invasive disease due to Haemophilus influenzae type b during the first six years of general vaccination of Swedish children
- 2000
-
Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227 .- 0000-0000. ; 89:4, s. 471-474
-
Tidskriftsartikel (refereegranskat)abstract
- Since 1992-93 vaccination against Haemophilus influenzae type b (Hib) has been included in the general Swedish childhood vaccination programme. The aim of the present study is to describe the epidemiology, identify and describe vaccine failures and calculate vaccine effectiveness during the first 6 y after introduction of vaccination against Hib. Laboratory reports of blood and cerebrospinal isolates to the Swedish Institute for Infectious Disease Control were used as the source for identifying the patients. Additional information was subsequently obtained from physicians and parents of children who had developed the disease during the study period. Vaccine failures were identified and vaccine effectiveness calculated. During the study period, 152 cases of invasive H. influenzae were identified in the age group 0-14 y. During the 6-y period, 6 true vaccine failures, 6 apparent vaccine failures and 1 possible vaccine failure were found in nearly two million vaccinated child-years. The effectiveness of the Hib vaccination in the birth cohort of children 1993 to 1997 in Sweden was calculated to be 96.1% (95% confidence interval 94.2-97.5). The study supports earlier studies from several countries that conjugated Hib vaccination introduced in general childhood vaccination programs is effective and substantially decreases suffering from invasive Hib diseases.
|
|
| 11. |
- Gharizadeh, Baback, et al.
(författare)
-
Multiple group-specific sequencing primers for reliable and rapid DNA sequencing
- 2003
-
Ingår i: Molecular and Cellular Probes. - 0890-8508 .- 1096-1194. ; 17:4, s. 203-210
-
Tidskriftsartikel (refereegranskat)abstract
- Pyrosequencing™ technology is a bioluminometric DNA sequencing method that employs a cascade of four enzymes to deliver sequence signals. To date this technology has been limited to the sequencing of short stretches of DNA. As an improvement to this technique, we have introduced a bacterial group-specific, multiple sequencing primer approach that circumvents sequencing of less informative semi-conservative regions of the 16S rRNA gene. This new approach is suitable for challenging templates, improving sequence data quality, avoiding sequencing of non-specific amplification products, lessening sequencing time, and moreover, this strategy should open the way for many new applications in the future. The group-specific, multiple sequencing primers can be applied in the Sanger dideoxy sequencing method as well. In addition, we have improved the chemistry of the Pyrosequencing system enabling sequencing of longer stretches of DNA, which allows numerous new applications.
|
|
| 12. |
|
|
| 13. |
- Hansson, L. Å., et al.
(författare)
-
The immunological role of breast feeding
- 2001
-
Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 12:s14, s. 15-19
-
Tidskriftsartikel (refereegranskat)
|
|
| 14. |
- Heikkinen, Terho, et al.
(författare)
-
Schould healthy children be vaccinated against influenza?
- 2006
-
Ingår i: European Journal of Pediatrics. - : Springer Science and Business Media LLC. - 0340-6199 .- 1432-1076. ; 165:4, s. 223-228
-
Tidskriftsartikel (refereegranskat)abstract
- Influenza is often regarded as an illness of the elderly portion of the population because most of the excess mortality associated with influenza epidemics occurs in that age group. However, evidence derived from a large number of clinical studies carried out in different countries and various settings has clearly demonstrated that the burden of influenza is also substantial in children. The attack rates of influenza during annual epidemics are consistently highest in children, and young children are hospitalized for influenza-related illnesses at rates comparable to those for adults with high-risk conditions. Especially among children younger than 3 years of age, influenza frequently predisposes the patient to bacterial complications such as acute otitis media. Children also serve as the main transmitters of influenza in the community. A safe and effective vaccine against influenza has been available for decades, but the vaccine is rarely used even for children with high-risk conditions. Despite several existing problems related to influenza vaccination of children, the current evidence indicates that the advantages of vaccinating young children would clearly outweigh the disadvantages. Considering the total burden of influenza in children, children younger than 3 years of age should be regarded as a high-risk group for influenza, analogously with the age-based definition of high risk among persons 65 years of age or older. Annual influenza vaccination should be recommended to all children from 6 months to 3 years of age.
|
|
| 15. |
- Issa, Mohamed, et al.
(författare)
-
Neisseria meningitidis serogroup W-135 isolated from healthy carriers and patients in Sudan after the Hajj in 2000
- 2003
-
Ingår i: Scandinavian Journal of Infectious Diseases. - 0036-5548 .- 1651-1980. ; 35:4, s. 230-233
-
Tidskriftsartikel (refereegranskat)abstract
- The first epidemic in the world of meningococcal disease due to serogroup W-135 was reported during the Hajj in 2000, with subsequent spread. The aims of the present study were to investigate whether the Hajj 2000 Neisseria meningitidis serogroup W-135 had also been carried to Sudan in the eastern part of the African meningitis belt, by examining healthy Sudanese pilgrims (Hajj 2000) and members of their families, and whether the strain was causing meningitis. The phenotypic character of W-135 meningococci from Sudanese carriers (n = 5) and patients (n = 2) 1 y later was similar to W-135 strains associated with Hajj 2000. The present study, using the combination of the 2 molecular techniques; sequencing of the porA gene for variable regions (VR1, VR2 and VR3) and pulsed-field gel electrophoresis of the entire genome (using SpeI and NheI), shows that the Hajj 2000 serogroup W-135 clone (P1.5,2,36-2 of the ET-37 complex) most probably was introduced into Sudan, by pilgrims returning from the Hajj 2000. This strain has not been diagnosed before in Sudan. Close epidemiological surveillance is required to identify a possible new emerging meningitis epidemic.
|
|
| 16. |
- Issa, Mohamed, et al.
(författare)
-
PCR of Cerebrospinal Fluid for Diagnosis of Bacterial Meningitis During Meningococcal Epidemics : an Example from Sudan
- 2003
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 35:10, s. 719-723
-
Tidskriftsartikel (refereegranskat)abstract
- Meningococcal disease is feared due to its rapid progression and high case fatality rate, especially in the African meningitis belt, where epidemics of meningococcal meningitis appear cyclically. Culture, direct microscopy and antigen detection are the basic methods for diagnosis and species identification of bacterial meningitis. These methods are known to have limitations, especially in developing countries. The aim of the present study was to document the application of PCR technology for the diagnosis of bacterial meningitis in cerebrospinal fluid (CSF) samples (n = 52) collected during epidemics in Sudan. In the application of PCR for detection of the causative agent of bacterial meningitis (based on the 16S rRNA gene), bacterial DNA was identified in 49 samples. Common bacterial species causing bacterial meningitis could be detected in 31 of the CSF samples (27 meningococci), while 18 contained DNA, mainly from normally contaminating bacteria. A specific PCR for group A meningococci (based on the sacC gene) was positive in 27 of the CSF samples. The results show that PCR technology is a sharpedged tool for confirmation of a diagnosis of meningococcal meningitis and for obtaining a direct genogrouping of group A meningococci in CSF. It is important to stress the use of direct and specific PCRs to avoid interference by contaminating bacteria, a great problem in samples from areas in the meningitis belt.
|
|
| 17. |
- Jacobsson, Susanne, et al.
(författare)
-
Molecular characterisation of group A Neisseria meningitidis isolated in Sudan 1985–2001
- 2003
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 111:11, s. 1060-1066
-
Tidskriftsartikel (refereegranskat)abstract
- A total of 33 group A Neisseria meningitidis (Mc) isolates, collected in Sudan between 1985 and 2001, were studied in order to describe the changes over time in a country within the meningitis belt of Africa. The isolates were characterised by traditional phenotypic methods (serogrouping, serotyping, serosubtyping and antibiogram) and molecular techniques (genosubtyping, pulsed-field gel electrophoresis [PFGE] with restriction endonucleases SpeI and NheI, and multilocus sequence typing [MLST]). Three clones of group A Mc were identified: one before 1988 (sulphadiazine sensitive, serotype 4, genosubtype P1.7,13-1,35-1, sequence type 4 [ST-4]); another during and after the 1988 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-5); and a third causing the 1999 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-7). The first clone showed major differences compared to the other two. The second and third clones had many similarities with differences in only a single gene (pgm) in the MLST (47 of the 450 bp) but significant other differences according to the PFGE patterns. Within the clones, genosubtyping and MLST gave identical information (except one base substitution in the aroE gene in one isolate). However, the PFGE patterns showed changes over time within the clones, where SpeI revealed somewhat more diversity than NheI.
|
|
| 18. |
- Jacobsson, Susanne, 1974-, et al.
(författare)
-
Sequence constancies and variations in genes encoding three new meningococcal vaccine candidate antigens
- 2006
-
Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 24:12, s. 2161-2168
-
Tidskriftsartikel (refereegranskat)abstract
- By the strategy “reverse vaccinology” a number of new antigens have been identified in Neisseria meningitidis, which are potential candidates for a highly needed broad-spectrum meningococcal vaccine. In the present study we examined the prevalence, sequence constancies and variations of the genes encoding three of these new antigens designated, genome-derived neisserial antigen (GNA) 1870, GNA1946 and GNA2132. All three genes were present in all N. meningitidis isolates tested. Concerning gna1870, three major variants of the gene sequences and deduced amino acid sequences were identified and 56% of the deduced amino acids were conserved in all isolates. In gna1946, 98% of the deduced amino acids were conserved and in gna2132, 54% of the deduced amino acids were conserved. Based on gene prevalence and conservation, all three antigens are promising candidates for an effective meningococcal vaccine against all N. meningitidis irrespective of serogroup.
|
|
| 19. |
- Jurstrand, Margaretha, et al.
(författare)
-
Characterization of Chlamydia trachomatis omp1 genotypes among sexually transmitted disease patients in Sweden
- 2001
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 39:11, s. 3915-3919
-
Tidskriftsartikel (refereegranskat)abstract
- A method for detection and genotyping of genital Chlamydia trachomatis infections based on omp1 gene amplification and sequencing was developed. DNA was extracted from urogenital or urine samples using a Chelex-based method, and an approximately 1,100-bp-long fragment from the omp1 gene was directly amplified and sequenced. Genotyping was performed by BLAST similarity search, and phylogenetic tree analysis was used to illustrate the evolutionary relationships between clinical isolates and reference strains. The method was used to determine the genotypes of C. trachomatis in 237 positive urogenital and/or urine specimens collected at a Swedish sexually transmitted disease clinic during 1 year. The most common genotypes corresponded to serotypes E (47%) and F (17%). The omp1 gene was highly conserved for genotype E (106 of 112 samples without any mutation) and F (41 of 42 samples without any mutation) strains but appear slightly less conserved for genotypes G (n = 6) and H (n = 6), where the sequences displayed one to four nucleotide substitutions relative to the reference sequence. Genotyping of samples collected at the follow-up visit indicated that two patients had become reinfected, while three other patients suffered treatment failure or reinfection. One woman appeared to have a mixed infection with two different C. trachomatis strains. This omp1 genotyping method had a high reproducibility and could be used for epidemiological characterization of sexually transmitted Chlamydia infections.
|
|
| 20. |
- Muyldermans, G, et al.
(författare)
-
External quality assessment for molecular detection of Bordetella pertussis in European laboratories.
- 2005
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 43:1, s. 30-35
-
Tidskriftsartikel (refereegranskat)abstract
- Although the PCR for the detection of Bordetella pertussis is routinely performed in diagnostic laboratories, no quality assessment program has so far been described. We report on the results obtained with two external quality assessment proficiency panels sent to European laboratories. The first proficiency panel contained a series of dilutions of three previously characterized B. pertussis clinical isolates and two negative controls. No false-positive results were reported by six laboratories providing seven data sets. The reported limits of detection of the three B. pertussis strains varied between 4 and 4,000, 9 and 9,000, and 3 and 30,000 CFU/ml, respectively. The second proficiency panel, composed of a series of dilutions of reference strains of B. pertussis, B. holmesii, B. hinzii, and B. bronchiseptica, as well as negative controls, was sent to nine laboratories. One laboratory reported a negative result for a sample and reported a B. parapertussis-positive sample to be positive for B. pertussis. By using the B. pertussis-specific target gene pertactin, one laboratory detected B. pertussis with 100% specificity. All other laboratories, which used IS481-based assays, reported positive results for the samples containing B. holmesii and B. bronchiseptica, species that have occasionally been recovered from human respiratory samples. These data show that the choice of the target gene is particularly critical for the species specificity of B. pertussis PCR assays.
|
|
| 21. |
- Mölling, Paula, et al.
(författare)
-
Comparison of Serogroup W-135 Meningococci Isolated in Sweden during a 23-Year Period and Those Associated with a Recent Hajj Pilgrimag
- 2001
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 39:7, s. 2695-2699
-
Tidskriftsartikel (refereegranskat)abstract
- An outbreak of serogroup W-135 meningococcal disease was reported among pilgrims returning from the annual hajj (pilgrimage to Mecca) in mid-March 2000. Molecular characterization was used to investigate the similarity of the hajj-associated W-135 strains with those isolated in Sweden during a 23-year period (1978 to 2000). The same hajj-associated genosubtype, genosubtype P1.5,2,36b, has been documented in Sweden since 1979, while pulsed-field gel electrophoresis and the sulfadiazine resistance of the W-135 isolates indicated that the outbreak was probably due to a new clone of W-135 meningococci.
|
|
| 22. |
- Mölling, Paula, et al.
(författare)
-
Direct and Rapid Identification and Genogrouping of Meningococci and porA Amplification by LightCycler PCR
- 2002
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 40:12, s. 4531-4535
-
Tidskriftsartikel (refereegranskat)abstract
- Invasive meningococcal infections are usually diagnosed by culture. This approach is far from optimal due to, e.g., treatment with precollection antibiotics. Molecular-genetics methods are therefore recognized as important tools for optimal laboratory confirmation of meningococcal infections as well as characterization of meningococci (Mc). The aims of the present study were to develop real-time PCRs for identification and genogrouping (A, B, C, Y, and W-135) of Mc and porA amplification that further can be used for subsequent genosubtyping. In a first run Mc were identified. In a second run they were genogrouped and porA genes were amplified. All the Mc isolates (n = 71) but one and cerebrospinal fluid samples (n = 11) tested gave the expected positive results. The specificity, inter- and intra-assay variations, and effects of different amounts of DNA on the melting temperatures were also explored. The LightCycler PCR system was found to effectively detect and characterize Mc in a few hours. This testing, including the DNA sequencing of the porA gene to reveal the genosubtype, does not take more than a working day, and the results can be compared to those from culturing with phenotypic analysis, which takes at least a few days.
|
|
| 23. |
- Mölling, P, et al.
(författare)
-
Genosubtyping by sequencing group A, B and C meningococci : a tool for epidemiological studies of epidemics, clusters and sporadic cases
- 2000
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 108:7-8, s. 509-516
-
Tidskriftsartikel (refereegranskat)abstract
- Genosubtyping, by sequencing variable regions (VRs) 1, 2 and 3 of the porA gene, was evaluated as a tool to detect clonality of isolates in meningococcal epidemics in Africa and clusters of disease in Sweden. All 63 examined meningococcal isolates were successfully genosubtyped. The isolates belonging to group A type 4 with genosubtype P1.20,9,35a showed little heterogeneity in African epidemics in 1988 and onwards. In Sweden, two meningococcal clones of group B type 15, with genosubtypes P1.7,16,35 and P1.7,16f,35, dominated during two clusters of meningococcal disease in 1995–96 and in sporadic cases thereafter. The characterisation of group C meningococci isolated during 1992 in Sweden indicated a cluster (type 2a with genosubtype P1.5a,10d,36b) connected with a discotheque visit. Two variants of VR2 (10p and 25b), not previously described, were found among the examined isolates. Nucleotide sequence analysis of VRs in the porA gene proved a valuable epidemiological tool since almost all isolates could be genosubtyped, in contrast to the phenotypic methods presently used.
|
|
| 24. |
- Nicolas, P., et al.
(författare)
-
Pharyngeal carriage of serogroup W135 Neisseria meningitidis in Hajjees and their family contacts in Morocco, Oman and Sudan
- 2005
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 113:3, s. 182-186
-
Tidskriftsartikel (refereegranskat)abstract
- In 2000 the global outbreak that began in Saudi Arabia was caused by a W135:2a:P1.5,2 strain of Neisseria meningitidis belonging to the ET-37 complex and to ST-11. There was concern that introduction of this epidemic clone (EC) might lead to a wave of outbreaks in the African meningitis belt. The WHO therefore initiated studies of meningococcal carriage among pilgrims and their family contacts in Morocco, Oman and Sudan, 3 to 12 months after the Hajj 2000. In Morocco, 1186 persons were swabbed 3 times. Ninety-five meningococcal strains were isolated from 2.7% of the specimens. Pulsed-field gel electrophoresis showed that 32 (33.6%) were identical with the EC. In Sudan, 5 strains identical with the EC were obtained after sampling 285 persons. In Oman, among 18 meningococcal strains isolated from 399 subjects, 11 (61.1%) belonged to the EC. The important pharyngeal carriage of W135 (EC) and its role in the 2001–2002 outbreaks in Burkina Faso argues for the necessity of reinforcing surveillance, and adapting and planning responses in Africa and the Middle East using the most appropriate vaccine.
|
|
| 25. |
|
|
| 26. |
- Olcén, Per, 1943-, et al.
(författare)
-
Isolation, culture, and identification of meningococci from clinical specimens.
- 2001
-
Ingår i: Renal Cancer : Methods and Protocols. - Linköping : Linköpings universitet. - 9780896038288 - 0896038289 ; , s. -403
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Because renal cancer can be managed successfully only when localized, there is a great need to develop new treatments for patients with advanced or metastatic disease. In Renal Cancer: Methods and Protocols, Jack H. Mydlo, MD, and a panel of leading clinicians and researchers review every aspect of the latest surgical, medical, and immunological therapies that can be used in the diagnosis and treatment of renal cancer. These broadly experienced investigators also present a practical account of their best basic research methods, including the use of reverse transcriptase PCR combined with genomic hybridization, cadherin, and metalloproteinase expression to reveal important factors in the detection, staging, aggressiveness, and treatment of this disease. Gene therapy, the generation of monoclonal antibodies, and the use of interferon alpha, GM-CSF, and IL-6 are also discussed. In vivo assays are provided for analyzing angiogenesis, anti-angiogenesis, and general renal tumor biology as a prelude to human clinical trials. Comprehensive and pioneering, Renal Cancer: Methods and Protocols offers urologists, medical oncologists, laboratory investigators, and pathologists a practical collection of the major cutting-edge techniques and therapies for renal cancer today, together with a view of the highly promising future of gene therapy.
|
|
| 27. |
- Orvelid, Paula, et al.
(författare)
-
PCR Identification of the Group A Neisseria Meningitidis Gene in Cerebrospinal Fluid
- 1999
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 31:5, s. 481-483
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to develop a PCR method for direct identification of Neisseria meningitidis serogroup A in cerebrospinal fluid. The assay makes use of unique sites within the gene cassette responsible for expression of the (α1→6)-linked N-acetyl-D-mannosamine-1-phosphate serogroup A capsule. A total of 67 different N. meningitidis strains and 12 clinical samples of CSF, culture positive for N. meningitidis, were examined. All the strains and samples of N. meningitidis serogroup A were correctly identified by an amplified PCR product of 519 bp. The PCR method for identification is specific for the group A gene of N. meningitidis. The assay may contribute to reducing recurrent, devastating epidemics of meningococcal infection by providing a diagnostic tool for grouping in developing countries where problems with false negative cultures are common and vaccination against serogroup A meningococci may be required.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Silfverdal, Sven Arne, et al.
(författare)
-
Protective effect of breastfeeding : an ecologic study of Haemophilus influenzae meningitis and breastfeeding in a Swedish population
- 1999
-
Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 28:1, s. 152-156
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In Orebro County, Sweden, a 2.5-fold increase in the incidence of Haemophilus influenzae (HI) meningitis was found between 1970 and 1980. In a case-control study of possible risk factors for invasive HI infection conducted in the same area, 1987-1992, breastfeeding was found to be a strong protective factor. MATERIAL AND METHODS: In order to study the relation between incidence rates of HI meningitis between 1956-1992 and breastfeeding rates in the population an ecologic study was performed. RESULTS: A strong (negative) correlation between breastfeeding and incidence of HI infection 5 to 10 years later (rho(xy) (s) approximately -0.6) was seen, whereas no relation seems to exist for the time lag 15 years and beyond. The correlation for contemporary data was intermediate. There were similar results for the breastfeeding proportions at 2, 4 as well as 6 months of age. DISCUSSION: Our ecologic data are consistent with results from our case-control study. The time-lag for the delayed effect on the population level could be estimated although sparse data make the estimates vulnerable to sampling fluctuations. Limitations with ecologic studies are discussed. CONCLUSION: There seems to be an association between high breastfeeding rate in the population and a reduced incidence of HI meningitis 5 to 10 years later. These results do have implications on strategies for breastfeeding promotion, especially in countries where Hib vaccination is too costly and not yet implemented.
|
|
| 31. |
|
|
| 32. |
- Strålin, Kristoffer, 1969-, et al.
(författare)
-
Antibody response to the patient's own Haemophilus influenzae isolate can support the aetiology in lower respiratory tract infections
- 2004
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 112:4-5, s. 299-303
-
Tidskriftsartikel (refereegranskat)abstract
- In order to understand the clinical importance of Haemophilus influenzae isolated from sputum samples, an indirect immunofluorescence (IF) assay was developed, using the patient's own isolate as the antigen. The method was tested on samples from six patients with lower respiratory tract infection (LRTI) and H. influenzae isolated from blood (n=2), sputum (n=3) or both (n=1), and on two healthy adults with H. influenzae isolated from the nasopharynx. Between acute and convalescent sera, a four-fold IgG antibody increase was achieved in five of six LRTI patients, including the three blood culture-positive patients. One LRTI patient and the two asymptomatic carriers showed stable antibody levels against their own isolate. Although small, the study indicates that indirect IF can be a promising tool for determining whether a H. influenzae strain represents the probable cause of infection or just a strain colonising the airways. More extensive studies should be performed in order to establish the usefulness of the assay.
|
|
| 33. |
- Strålin, Kristoffer, 1969-, et al.
(författare)
-
Comparison of two urinary antigen tests for establishment of pneumococcal etiology of adult community-acquired pneumonia
- 2004
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 42:8, s. 3620-3625
-
Tidskriftsartikel (refereegranskat)abstract
- The Binax NOW immunochromatographic test (ICT) detecting the pneumococcal C polysaccharide and a serotype-specific latex agglutination (LA) test detecting 23 pneumococcal capsular antigens were evaluated for establishing pneumococcal etiology in community-acquired pneumonia (CAP) by use of nonconcentrated urine. ICT was considered to be strongly positive for result lines at least as intense as the control line and weakly positive for less intense result lines. When 215 adult CAP patients were tested, strong ICT, weak ICT, and LA positivity were found in 28, 24, and 16 patients, respectively; of these patients, 13 (46%), 6 (25%), and 13 (81%), respectively, had pneumococcal bacteremia and 27 (96%), 17 (71%), and 15 (94%), respectively, had Streptococcus pneumoniae isolated from blood, sputum, and/or nasopharynx. Among 108 controls tested, 2 (1.9%) were weakly ICT positive. When weak positivity was considered negative, the sensitivity of ICT decreased from 79% (19 of 24) to 54% (13 of 24), while the specificity increased from 83% (158 of 191) to 92% (176 of 191); no controls were false positive. The sensitivity and specificity of LA were 54% (13 of 24) and 98% (188 of 191), respectively. Eight of nine LA serotypes corresponded to culture serotypes. In conclusion, using nonconcentrated urine and dividing ICT-positive results into strongly and weakly positive results is a suitable way of performing ICT. While weak ICT positivity should be interpreted with caution, strong ICT positivity and LA positivity should be considered supportive of pneumococcal etiology in adult CAP. As such, these assays might have implications for antibiotic use in CAP. LA has promising potential for pneumococcal serotyping, although further evaluation is required.
|
|
| 34. |
- Strålin, Kristoffer, 1969-, et al.
(författare)
-
Design of a multiplex PCR for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and Chlamydophila pneumoniae to be used on sputum samples
- 2005
-
Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 113:2, s. 99-111
-
Tidskriftsartikel (refereegranskat)abstract
- A multiplex PCR (mPCR) was developed for simultaneous detection of specific genes for Streptococcus pneumoniae (lytA), Mycoplasma pneumoniae (P1), Chlamydophila pneumoniae (ompA), and Haemophilus influenzae (16S rRNA, with verification PCR for P6). When the protocol was tested on 257 bacterial strains belonging to 37 different species, no false negatives and only one false positive were noted. One Streptococcus mitis out of thirty was positive for lytA. In a pilot application study of 81 sputum samples from different patients with suspected lower respiratory tract infection (LRTI), mPCR identified S. pneumoniae in 25 samples, H. influenzae in 29, M. pneumoniae in 3, and C. pneumoniae in 1. All samples culture positive for S. pneumoniae (n=15) and H. influenzae (n=15) were mPCR positive for the same bacteria. In a pilot control study with nasopharyngeal swabs and aspirates from 10 healthy adults, both culture and mPCR were negative. No PCR inhibition was found in any of the mPCR-negative sputum or nasopharyngeal samples. Whether all samples identified as positive by mPCR are truly positive in an aetiological perspective regarding LRTI remains to be evaluated in a well-defined patient material. In conclusion, the mPCR appears to be a promising tool in the aetiological diagnostics of LRTI.
|
|
| 35. |
- Strålin, Kristoffer, 1969-, et al.
(författare)
-
Etiologic diagnosis of adult bacterial pneumonia by culture and PCR applied to respiratory tract samples
- 2006
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 44:2, s. 643-645
-
Tidskriftsartikel (refereegranskat)abstract
- Respiratory culture and multiplex PCR for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, and Chlamydophila pneumoniae were applied to sputum, nasopharyngeal swabs, and nasopharyngeal aspirates from 235 adult patients with community-acquired pneumonia and 113 controls. Both culture and multiplex PCR performed well with the different samples and appear to be useful as diagnostic tools.
|
|
| 36. |
- Strålin, Kristoffer, 1969-, et al.
(författare)
-
Evaluation of a multiplex PCR for bacterial pathogens applied to bronchoalveolar lavage.
- 2006
-
Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 28, s. 568-575
-
Tidskriftsartikel (refereegranskat)abstract
- The present study assessed the diagnostic usefulness of a multiplex PCR (mPCR) for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and Chlamydophila pneumoniae applied to bronchoalveolar lavage (BAL). Fibreoptic bronchoscopy was performed on 156 hospitalised adult patients with lower respiratory tract infection (LRTI) and 36 controls. BAL fluid was analysed with bacterial culture and mPCR. By conventional diagnostic methods, S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae were aetiological agents in 14, 21, 3.2 and 0% of the LRTI patients, respectively. These pathogens were identified by BAL mPCR in 28, 47, 3.2 and 0.6% of cases, respectively, yielding sensitivities of 86% for S. pneumoniae, 88% for H. influenzae, 100% for M. pneumoniae and 0% for C. pneumoniae, and specificities of 81, 64, 100 and 99% for S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae, respectively. Of the 103 patients who had taken antibiotics prior to bronchoscopy, S. pneumoniae was identified by culture in 2.9% and by mPCR in 31%. Among the controls, mPCR identified S. pneumoniae in 11% and H. influenzae in 39%. In lower respiratory tract infection patients, bronchoalveolar lavage multiplex PCR can be useful for identification of Streptococcus pneumoniae, Mycoplasma pneumoniae and Chlamydophila pneumoniae. The method appears to be particularly useful in patients treated with antibiotics.
|
|
| 37. |
|
|
| 38. |
- Taha, Muhamed-Kheir, et al.
(författare)
-
Interlaboratory Comparison of PCR-Based Identification and Genogrouping of Neisseria meningitidis
- 2005
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 43:1, s. 144-149
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty clinical samples (18 cerebrospinal fluid samples and 2 articular fluid samples) were sent to 11 meningococcus reference centers located in 11 different countries. Ten of these laboratories are participating in the EU-MenNet program (a European Union-funded program) and are members of the European Monitoring Group on Meningococci. The remaining laboratory was located in Burkina Faso. Neisseria meningitidis was sought by detecting several meningococcus-specific genes (crgA, ctrA, 16S rRNA, and porA). The PCR-based nonculture method for the detection of N. meningitidis gave similar results between participants with a mean sensitivity and specificity of 89.7 and 92.7%, respectively. Most of the laboratories also performed genogrouping assays (siaD and mynB/sacC). The performance of genogrouping was more variable between laboratories, with a mean sensitivity of 72.7%. Genogroup B gave the best correlation between participants, as all laboratories routinely perform this PCR. The results for genogroups A and W135 were less similar between the eight participating laboratories that performed these PCRs.
|
|
| 39. |
|
|
| 40. |
- Thulin, Sara, et al.
(författare)
-
Total variation in the penA gene of Neisseria meningitidis : correlation between susceptibility to beta-lactam antibiotics and penA gene heterogeneity
- 2006
-
Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 50:10, s. 3317-3324
-
Tidskriftsartikel (refereegranskat)abstract
- In recent decades, the prevalence of Neisseria meningitidis isolates with reduced susceptibility to penicillins has increased. The intermediate resistance to penicillin (Pen(i)) for most strains is due mainly to mosaic structures in the penA gene, encoding penicillin-binding protein 2. In this study, susceptibility to beta-lactam antibiotics was determined for 60 Swedish clinical N. meningitidis isolates and 19 reference strains. The penA gene was sequenced and compared to 237 penA sequences from GenBank in order to explore the total identified variation of penA. The divergent mosaic alleles differed by 3% to 24% compared to those of the designated wild-type penA gene. By studying the final 1,143 to 1,149 bp of penA in a sequence alignment, 130 sequence variants were identified. In a 402-bp alignment of the most variable regions, 84 variants were recognized. Good correlation between elevated MICs and the presence of penA mosaic structures was found especially for penicillin G and ampicillin. The Pen(i) isolates comprised an MIC of >0.094 microg/ml for penicillin G and an MIC of >0.064 microg/ml for ampicillin. Ampicillin was the best antibiotic for precise categorization as Pen(s) or Pen(i). In comparison with the wild-type penA sequence, two specific Pen(i) sites were altered in all except two mosaic penA sequences, which were published in GenBank and no MICs of the corresponding isolates were described. In conclusion, monitoring the relationship between penA sequences and MICs to penicillins is crucial for developing fast and objective methods for susceptibility determination. By studying the penA gene, genotypical determination of susceptibility in culture-negative cases can also be accomplished.
|
|
| 41. |
- Unemo, Magnus, 1970-, et al.
(författare)
-
Comparison of serologic and genetic porB-based typing of Neisseria gonorrhoeae : consequences for future characterization
- 2003
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 41:9, s. 4141-4147
-
Tidskriftsartikel (refereegranskat)abstract
- Due to temporal changes in the epidemiology of gonorrhea, a precise characterization of Neisseria gonorrhoeae is essential. In the present study genetic heterogeneity in the porB genes of N. gonorrhoeae was examined, and serovar determination was compared to porB gene sequencing. Among 108 N. gonorrhoeae isolates, phylogenetic analysis of the entire porB alleles (924 to 993 bp) identified 87 unique sequences. By analyzing only the four to six most heterogeneous porB gene regions (174 to 363 bp), 86 out of these 87 genetic variants were identified. Consequently, analysis of shorter highly variable regions of the porB gene generates high-level discriminatory ability as well as fast, objective, reproducible, and portable data for epidemiological characterization of N. gonorrhoeae. Regarding putative antigenic epitopes of PorB for Genetic Systems monoclonal antibodies (MAbs), some of the previous findings were confirmed, but new findings were also observed. For several of the MAbs, however, the precise amino acid residues of PorB critical for single-MAb reactivity were difficult to identify. In addition, repeated serovar determination of 108 N. gonorrhoeae isolates revealed discrepancies for 34 isolates, mostly due to nonreproducible reactivity with single MAbs. Thus, the prospects of a genetic typing system with congruent translation of the serovar determination seem to be limited. In conclusion, analysis of short highly variable regions of the porB gene could form the basis for a fast molecular epidemiological tool for the examination of emergence and transmission of N. gonorrhoeae strains within the community.
|
|
| 42. |
- Unemo, Magnus, 1970-, et al.
(författare)
-
Molecular epidemiology of Neisseria gonorrhoeae : sequence analysis of the porB gene confirms presence of two circulating strains
- 2002
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 40:10, s. 3741-3749
-
Tidskriftsartikel (refereegranskat)abstract
- The phenotypic and genotypic characteristics of Neisseria gonorrhoeae strains fluctuate over time both locally and globally, and highly discriminative and precise characterization of the strains is essential. Conventional characterization of N. gonorrhoeae strains for epidemiological purposes is mostly based on phenotypic methods, which have some inherent limitations. In the present study sequence analysis of porB1b gene sequences was used for examination of the genetic relationships among N. gonorrhoeae strains. Substantial genetic heterogeneity was identified in the porB genes of serovar IB-2 isolates (8.1% of the nucleotide sites were polymorphic) and serovar IB-3 isolates (5.2% of the nucleotide sites were polymorphic) as well as between isolates of different serovars. The highest degree of diversity was identified in the gene segments encoding the surface-exposed loops of the mature PorB protein. Phylogenetic analysis of the porB1b gene sequences confirmed previous findings that have indicated the circulation of one N. gonorrhoeae strain each of serovar IB-2 and serovar IB-3 in the Swedish community. These strains caused the majority of the cases in two domestic core groups comprising homosexual men and young heterosexuals, respectively, and were also detected in other patients. The phylogenetic analyses of porB gene sequences in the present study showed congruence, but not complete identity, with previous results obtained by pulsed-field gel electrophoresis of the same isolates. In conclusion, porB gene sequencing can be used as a molecular epidemiological tool for examination of genetic relationships among emerging and circulating N. gonorrhoeae strains, as well as for confirmation or discrimination of clusters of gonorrhea cases.
|
|
| 43. |
- Unemo, Magnus, 1970-, et al.
(författare)
-
Molecular typing of Neisseria gonorrhoeae isolates by pyrosequencing of highly polymorphic segments of the porB gene
- 2004
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 42:7, s. 2926-2934
-
Tidskriftsartikel (refereegranskat)abstract
- For prevention and control of gonorrhea, an objective, highly discriminating, and reproducible molecular epidemiological characterization of Neisseria gonorrhoeae is essential. In the present study, in pursuance of providing such qualities, pyrosequencing technology, a fast real-time DNA sequence analysis, was applied to six short, highly polymorphic porB gene segments, with subsequent genetic variant (genovar) determination of the bacterial isolates. The sequencing templates were obtained by real-time PCR amplification, which also included fluorescence melting curve analysis of the entire porB gene in order to determine the genogroup (porB1a or porB1b allele) prior to pyrosequencing analysis. The PSQ 96 MA system used allowed rapid (in approximately 1.5 h) determination of 96 sequences of 20 to 65 correct nucleotides each. The results were reproducible and mostly in concordance with the results of conventional Sanger dideoxy sequencing, with the exception of shorter read lengths and some uncertainty in determining the correct number of identical nucleotides in homopolymeric segments. The number of sequence variants identified in each of the six highly polymorphic segments of the porB1a and porB1b alleles (encoding surface-exposed amino acid loops of the mature PorB protein) ranged from 5 to 11 and from 8 to 39, respectively. Among porB1a isolates (n = 22) and porB1b isolates (n = 65), 22 and 64 unique genovars, respectively, were identified. All isolates were typeable. The present results provide evidence of a high discriminatory ability, practically the same as that for sequencing of the entire porB gene. In conclusion, the fast and high-throughput pyrosequencing technology can be used for molecular epidemiological characterization of N. gonorrhoeae.
|
|
| 44. |
- Unemo, Magnus, 1970-, et al.
(författare)
-
Pulsed-field gel electrophoresis as an epidemiologic tool for Neisseria gonorrhoeae : Identification of clusters within serovars
- 2002
-
Ingår i: Sexually Transmitted Diseases. - : Ovid Technologies (Wolters Kluwer Health). - 0148-5717 .- 1537-4521. ; 29:1, s. 25-31
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The increasing incidence of gonorrhea in Sweden in 1998 was due to mostly domestic cases. Among these, two core groups were identified: homosexual men with serovar IB-2 and young heterosexuals with serovar IB-3.Goals: To explore the genetic homogeneity/heterogeneity within the predominant serovars, IB-2 and IB-3, of Neisseria gonorrhoeae in Sweden by pulsed-field gel electrophoresis (PFGE) and to compare these results to epidemiologic information, as well as examine the genetic diversity within and between the 25 other represented serovars of N gonorrhoeae.Study Design: By PFGE, 237 N gonorrhoeae isolates were examined, and the results were compared with epidemiologic data for the IB-2 and IB-3 isolates.Results: In 79% of the domestic IB-2 cases involving homosexuals and 66% of the domestic IB-3 cases involving young heterosexuals, the isolates were genetically indistinguishable by PFGE. A high genetic diversity was identified within and between the 27 included serovars.Conclusions: Examination by means of PFGE indicated that one N gonorrhoeae clone each of the serovars IB-2 and IB-3 created the majority of the two core groups of domestic cases.
|
|
| 45. |
|
|
| 46. |
|
|
