| 31. |
- Bucardo, F, et al.
(författare)
-
Mutated G4P[8] rotavirus associated with a nationwide outbreak of gastroenteritis in Nicaragua in 2005
- 2007
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:3, s. 990-997
-
Tidskriftsartikel (refereegranskat)abstract
- During February and March 2005, one of the largest national recorded outbreaks of severe acute gastroenteritis occurred in Nicaragua, affecting ≥64,000 individuals and causing ≥56 deaths, predominantly in children under 5 years of age. Through a nationwide laboratory-based study, stool samples were collected and investigated for rotavirus. Of 108 stool samples examined, 72 (67%) were positive for rotavirus. While 69% (50/72) of the positive samples were found in children less than 2 years of age, 50% (6/12) of the adult samples were positive. A mutated G4P[8] strain was the most commonly recognized strain (85%), followed by mixed G strains (8%) and G9P[8] (7%) strains. Phylogenetic analysis of the VP7 gene revealed that the G4 strains belonged to the emerging lineage Ic and was distantly related to the ST3 and VA70 G4 strains. Secondary structure predictions of the VP7 G4 protein revealed an insert of an asparagine residue in position 76, which, combined with additional mutations, surprisingly modified two downstream β-sheets at amino acid positions 80 to 85 and 115 to 119. The 2005 G4P[8] strain compared to a G4P[8] strain from 2002 had a substitution of an asparagine residue for threonine (Asn→Thr) at position 96 within antigenic region A, thus eliminating a potential glycosylation site. The mutated G4 virus was introduced in Nicaragua after 2002 and probably emerged from Brazil, Argentina, or Uruguay. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
|
|
| 32. |
- Bucardo, Filemon, et al.
(författare)
-
Pediatric norovirus diarrhea in Nicaragua
- 2008
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 46:8, s. 2573-2580
-
Tidskriftsartikel (refereegranskat)abstract
- Information about norovirus (NoV) infections in Central America is limited. Through a passive community and hospital pediatric diarrhea surveillance program, a total of 542 stool samples were collected between March 2005 and February 2006 in León, Nicaragua. NoV was detected in 12% (65/542) of the children; of these, 11% (45/409) were in the community and 15% (20/133) were in the hospital, with most strains (88%) belonging to genogroup II. NoV infections were age and gender associated, with children of <2 years of age (P < 0.05) and girls (P < 0.05) being most affected. Breast-feeding did not reduce the number of NoV infections. An important proportion (57%) of NoV-infected children were coinfected with diarrheagenic Escherichia coli. A significant proportion (18/31) of NoV-positive children with dehydration required intravenous rehydration. Nucleotide sequence analysis (38/65) of the N-terminal and shell region in the capsid gene revealed that at least six genotypes (GI.4, GII.2, GII.4, GII.7, GII.17, and a potentially novel cluster termed "GII.18-Nica") circulated during the study period, with GII.4 virus being predominant (26/38). The majority (20/26) of those GII.4 strains shared high nucleotide homology (99%) with the globally emerging Hunter strain. The mean viral load was approximately 15-fold higher in children infected with GII.4 virus than in those infected with other G.II viruses, with the highest viral load observed for the group of children infected with GII.4 and requiring intravenous rehydration. This study, the first of its type from a Central American country, suggests that NoV is an important etiological agent of acute diarrhea among children of <2 years of age in Nicaragua.
|
|
| 33. |
|
|
| 34. |
- Bunikis, J, et al.
(författare)
-
Molecular polymorphism of the Lyme disease agent Borrelia garinii in northern Europe is influenced by a novel enzootic Borrelia focus in the North Atlantic
- 1996
-
Ingår i: Journal of Clinical Microbiology. - Washington, DC, United States : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 34:2, s. 364-368
-
Tidskriftsartikel (refereegranskat)abstract
- Lyme disease Borrelia species are distributed in temperate areas of North America and Eurasia. To elucidate the distribution of borreliae in subarctic regions, strains isolated from Ixodes ricinus and Ixodes uriae ticks found on islands in the northern Atlantic and Baltic Sea were molecularly characterized. All isolates were verified as Borrelia garinii by 16S rRNA gene analysis and immunoblotting with monoclonal antibodies specific for the outer surface proteins A and C. Three ribotypes (RTs) of B. garinii were delineated. I. ricinus complex-associated RT1 was phenotypically most heterogeneous. Two newly identified ribotypes were shared by different tick species and conformed to two established OspA serotypes. RT2 was restricted to the islands in the northern Baltic Sea, whereas RT3 was recovered also from ticks found in the North Atlantic. In conclusion, molecular polymorphism of the studied borrelia isolates suggests a complex enzootic potential of B. garinii in northern Europe and implies a novel, seabird tick I. uriae-associated enzootic focus of Lyme disease borreliae in the North Atlantic.
|
|
| 35. |
|
|
| 36. |
- Bölin, Ingrid, 1952, et al.
(författare)
-
Enterotoxigenic Escherichia coli with STh and STp genotypes is associated with diarrhea both in children in areas of endemicity and in travelers.
- 2006
-
Ingår i: Journal of clinical microbiology. - 0095-1137. ; 44:11, s. 3872-7
-
Tidskriftsartikel (refereegranskat)abstract
- Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea among children in developing countries and in travelers to areas of ETEC endemicity. ETEC strains isolated from humans may produce a heat-labile enterotoxin (LT) and two types of the heat-stable enterotoxin STa, called STh and STp, encoded by the estA gene. Two commonly used assay methods for the detection of STa, the infant mouse assay or different enzyme-linked immunosorbent assays, are unable to distinguish between the two subtypes of ST. Different genotypic methods, such as DNA probes or PCR assays, may, however, allow such discrimination. Using gene probes, it has recently been reported that ETEC strains producing STp as the only enterotoxin are not associated with diarrhea. In this study, we have used highly specific PCR methods, including newly designed primers for STh together with previously described STp primers, to compare the relative distribution of STh and STp in ETEC isolated from children with diarrhea in three different geographically distinct areas, i.e., Bangladesh, Egypt, and Guatemala, and from travelers to Mexico and Guatemala. It was found that ETEC strains producing STp were as commonly isolated from cases of diarrhea as strains producing STh both in Egypt and Guatemala, whereas STp strains were considerably less common in Bangladesh. No difference was found in the relative distribution of STh and STp in ETEC strains isolated from travelers with diarrhea and from asymptomatic carriers. Irrespective of ST genotype, the disease symptoms were also similar in both children and travelers.
|
|
| 37. |
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Christerson, Linus, et al.
(författare)
-
Chlamydia trachomatis Strains Show Specific Clustering for Men Who Have Sex with Men Compared to Heterosexual Populations in Sweden, the Netherlands, and the United States
- 2012
-
Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 50:11, s. 3548-3555
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution genotyping of Chlamydia trachomatis improves the characterization of strains infecting different patient groups and sexual networks. In this study, multilocus sequence typing (MLST) and ompA sequence determination were used for an analysis of C. trachomatis strains from 203 men who have sex with men (MSM) from Sweden, the Netherlands, and the United States. The results obtained were compared with data from 153 heterosexual women from Sweden and the Netherlands. The overlap in MLST/ompA profiles between MSM from Sweden and the Netherlands was 68%, while the overlap between heterosexual populations from these countries was only 18%. The distribution of genotypes in MSM from the United States was less similar to that in MSM from the European countries, with 45% and 46% overlaps for MSM in Sweden and the Netherlands, respectively. Minimum-spanning-tree analysis of MLST/ompA sequence types identified two large clusters that contained almost exclusively samples from MSM and comprised 74% of all MSM samples. Three other clusters were predominated by samples from women but also contained MSM specimens. Of 19 detected variants of the MLST target CT144, three variants were highly associated with MSM. Our study supports the hypotheses of both tissue tropism as well as epidemiological network structures as explanations for the linkage between specific genetic variants and sexual orientation.
|
|
