| 41. |
- Johnson, James R., et al.
(författare)
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Phylogenetic and pathotypic comparison of concurrent urine and rectal Escherichia coli isolates from men with febrile urinary tract infection.
- 2005
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Ingår i: Journal of Clinical Microbiology. - 0095-1137. ; 43:8, s. 3895-900
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Tidskriftsartikel (refereegranskat)abstract
- Among men with febrile urinary tract infection (FUTI), whether the host's fecal flora is the source for the urine strain ("fecal-urethral" hypothesis), and whether pathogenesis is driven by prevalence versus special pathogenicity, are unknown. Accordingly, pretherapy urine isolates from 65 men with FUTI were compared with concurrent rectal isolates from the same hosts according to serotype, genomic profile, phylogenetic group, and virulence genotype. The host's multiple rectal colonies included only the urine clone in 25% of subjects, the urine clone plus additional clones in 22%, and only nonurine clones in 54%. Compared with the 67 unique rectal clones, the 65 urine isolates were significantly enriched for phylogenetic group B2, virulence-associated serotypes, and specific virulence genes and contained more virulence genes (median, 10 versus 6: P < 0.001). In multivariable models, phylogenetic group B2, hlyD (hemolysin), cnf1 (cytotoxic necrotizing factor), iroN (siderophore receptor), ompT (outer membrane protease), and malX (pathogenicity island marker) most strongly predicted urine source. These findings challenge the fecal-urethral and prevalence hypotheses for FUTI pathogenesis and instead strongly support the possibility of alternate infection routes in some men and the special pathogenicity hypothesis. They also identify specific bacterial traits as potential targets for anti-FUTI interventions.
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| 42. |
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| 43. |
- Jönsson, Bodil, 1959, et al.
(författare)
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Molecular epidemiology of Mycobacterium abscessus, with focus on cystic fibrosis.
- 2007
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Ingår i: Journal of clinical microbiology. - 0095-1137. ; 45:5, s. 1497-504
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium abscessus has been isolated increasingly often from the respiratory tracts of cystic fibrosis (CF) patients. It is not known whether these organisms are transmitted from person to person or acquired from environmental sources. Here, colony morphology and pulsed-field gel electrophoresis (PFGE) pattern were examined for 71 isolates of M. abscessus derived from 14 CF patients, three non-CF patients with chronic respiratory M. abscessus infection or colonization, one patient with mastoiditis, and four patients with infected wounds, as well as for six isolates identified as environmental contaminants in various clinical specimens. Contaminants and wound isolates mainly exhibited smooth colony morphology, while a rough colony phenotype was significantly associated with chronic airway colonization (P=0.014). Rough strains may exhibit increased airway-colonizing capacity, the cause of which remains to be determined. Examination by PFGE of consecutive isolates from the same patient showed that they all represented a single strain, even in cases where both smooth and rough isolates were present. When PFGE patterns were compared, it was shown that 24 patients had unique strains, while four patients harbored strains indistinguishable by PFGE. Two of these were siblings with CF. The other two patients, one of whom had CF, had not had contact with each other or with the siblings. Our results show that most patients colonized by M. abscessus in the airways have unique strains, indicating that these strains derive from the environment and that patient-to-patient transmission rarely occurs.
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| 44. |
- Kasubi, Mabula Joseph, et al.
(författare)
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Prevalence of antibodies against herpes simplex virus types 1 and 2 in children and young people in an urban region in Tanzania.
- 2006
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Ingår i: Journal of clinical microbiology. - 0095-1137. ; 44:8, s. 2801-7
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) is transmitted by close contact, both sexual and nonsexual, and infections are acquired during childhood and adolescence. Herpes simplex virus type 2 (HSV-2), however, is thought to be transmitted mainly by sexual contact. Most HSV-2 infections are consequently expected to occur after the onset of sexual activity. Recent reports indicate an increasing prevalence of HSV-2 on the African continent, but most studies have been performed on adult cohorts. In the present study, we collected sera from Tanzanian children and young persons from 1 to 20 years old, with at least 100 individuals in each age group. Antibodies against HSV-1 and HSV-2 were detected by an in-house Western blot method which was shown to perform well in comparison with a commercial Western blot assay. Type-specific antibodies were also analyzed by two noncommercial enzyme-linked immunosorbent assay methods based upon the antigenicities of branched synthetic oligopeptides corresponding to epitopes in glycoprotein G of HSV-1 or HSV-2. The prevalence of HSV-1 antibodies increased gradually from 73% for the age group of 1 to 4 years to 92% for the age group of 17 to 20 years. The prevalence of HSV-2 antibodies was unexpectedly high, as 15% of the children were infected by the age of 8 years, with the incidence increasing gradually to 40% in the age group of 17 to 20 years. The reason for this unexpectedly high frequency is not clear but could suggest that nonsexual transmission of HSV-2 is more common than previously thought. There was no statistically significant association between seropositivities for HSV-2 and human immunodeficiency virus.
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| 45. |
- Kindberg, Elin, 1981-, et al.
(författare)
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Host genetic resistance to symptomatic norovirus (GGII.4) infections in Denmark
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:8, s. 2720-2
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Tidskriftsartikel (refereegranskat)abstract
- A total of 61 individuals involved in five norovirus outbreaks in Denmark were genotyped at nucleotides 428 and 571 of the FUT2 gene, determining secretor status, i.e., the presence of ABH antigens in secretions and on mucosa. A strong correlation (P = 0.003) was found between the secretor phenotype and symptomatic disease, extending previous knowledge and confirming that nonsense mutations in the FUT2 gene provide protection against symptomatic norovirus (GGII.4) infections. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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| 46. |
- Klint, Markus, et al.
(författare)
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High-resolution genotyping of Chlamydia trachomatis strains by multilocus sequence analysis
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:5, s. 1410-1414
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Tidskriftsartikel (refereegranskat)abstract
- Genotyping of Chlamydia trachomatis is limited by the low sequence variation in the genome, and no adequatemethod is available for analysis of the spread of chlamydial infections in the community. We have developeda multilocus sequence typing (MLST) system based on five target regions and compared it with analysis ofompA, the single gene most extensively used for genotyping. Sequence determination of 16 reference strains,comprising all major serotypes, serotypes A to L3, showed that the number of genetic variants in the fiveseparate target regions ranged from 8 to 16. The genetic variation in 47 clinical C. trachomatis isolates ofrepresentative serotypes (14 serotype D, 12 serotype E, 11 serotype G, and 10 serotype K strains) was analyzed;and the MLST system detected 32 variants, whereas 12 variants were detected by using ompA analysis.Specimens of the predominant serotype, serotype E, were differentiated into seven genotypes by MLST but intoonly two by ompA analysis. The MLST system was applied to C. trachomatis specimens from a population ofmen who have sex with men and was able to differentiate 10 specimens of one predominant ompA genotype Gvariant into four distinct MLST variants. To conclude, our MLST system can be used to discriminate C.trachomatis strains and can be applied to high-resolution molecular epidemiology.
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| 47. |
- Klint, Markus, et al.
(författare)
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Lymphogranuloma venereum prevalence in Sweden among men who have sex with men and characterization of Chlamydia trachomatis ompA genotypes
- 2006
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 44:11, s. 4066-4071
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Tidskriftsartikel (refereegranskat)abstract
- An outbreak of lymphogranuloma venereum (LGV) infections has recently been reported from The Netherlands and other European countries. The Swedish surveillance system has identified three LGV cases since 2004, all with clinically suspected infection in men who have sex with men (MSM). In order to assess the prevalence of LGV in a high-risk group of MSM and include clinically atypical cases, retrospective analysis of 197 Chlamydia trachomatis-infected men was performed. Sequencing of the ompA gene showed a different serotype distribution compared to recent Swedish studies in heterosexual populations. The most common types were G (45%), D (27%), and J (26%), whereas the normally predominant type E accounted for only 4% of the chlamydia cases. Furthermore, certain ompA genotype variants of the dominant serotypes were highly prevalent among MSM, and the reason for this is discussed. No additional case of LGV was detected by retrospective analysis of the high-risk MSM population. This indicates that, thus far, LGV in Sweden is only a result of sporadic import from infected MSM clusters abroad.
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| 48. |
- Kurt, Kevin, et al.
(författare)
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Multiplexed genotyping of methicillin-resistant Staphylococcus aureus isolates by use of padlock probes and tag microarrays
- 2009
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 47:3, s. 577-585
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Tidskriftsartikel (refereegranskat)abstract
- We developed and tested a ligase-based assay for simultaneous probing of core genome diversity and typing of methicillin resistance determinants in Staphylococcus aureus isolates. This assay uses oligonucleotide padlock probes whose two ends are joined through ligation when they hybridize to matching target DNA. Circularized probes are subsequently amplified by PCR with common primers and analyzed by using a microarray equipped with universal tag probes. Our set of padlock probes includes oligonucleotides targeting diagnostic regions in the mecA, ccrB, and ccrC genes of the SCCmec cassette in methicillin-resistant S. aureus (MRSA). These probes determine the presence and type of SCCmec cassettes (i.e., SCCmec types I to VI). Additional oligonucleotides interrogate a number of highly informative single nucleotide polymorphisms retrieved from a multilocus sequence typing (MLST) database. These latter probes enable the exploration of isolates' phylogenetic affiliation with clonal lineages of MRSA as revealed by MLST. The described assay enables multiplexed genotyping of MRSA based on a single-tube reaction. With a set of clinical isolates of MRSA and methicillin-susceptible S. aureus (n=66), 100% typeability and 100% accuracy were achieved. The assay described here provides valuable genotypic information that may usefully complement existing genotyping procedures. Moreover, the assay is easily extendable by incorporating additional padlock probes and will be valuable for the quick and cost-effective probing of large numbers of polymorphisms at different genomic locations, such as those ascertained through currently ongoing mutation discovery and genome resequencing projects.
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| 49. |
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| 50. |
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