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Extended sequence typing of Campylobacter spp., United Kingdom.

Dingle KE, McCarthy ND, Cody AJ, Peto TE, Maiden MC - Emerging Infect. Dis. (2008)

Bottom Line: Supplementing Campylobacter spp. multilocus sequence typing with nucleotide sequence typing of 3 antigen genes increased the discriminatory index achieved from 0.975 to 0.992 among 620 clinical isolates from Oxfordshire, United Kingdom.This enhanced typing scheme enabled identification of clusters and retained data required for long-range epidemiologic comparisons of isolates.

View Article: PubMed Central - PubMed

Affiliation: John Radcliffe Hospital, Oxford, UK.

ABSTRACT
Supplementing Campylobacter spp. multilocus sequence typing with nucleotide sequence typing of 3 antigen genes increased the discriminatory index achieved from 0.975 to 0.992 among 620 clinical isolates from Oxfordshire, United Kingdom. This enhanced typing scheme enabled identification of clusters and retained data required for long-range epidemiologic comparisons of isolates.

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Clusters of related 10-locus types of Campylobacter spp. detected in Oxfordshire, United Kingdom, during a 1-year study. Five groups of isolates with identical genotypes show statistically significant clustering in time (p values are shown in the Table). Each group is indicated by 1 color. White bars indicate other isolates that share the same sequence type (ST) but that are differentiated by their different antigen type. Numbers of isolates of each genotype are shown on a weekly basis; week 1 corresponds to the start of the study on September 15, 2003.
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Figure 2: Clusters of related 10-locus types of Campylobacter spp. detected in Oxfordshire, United Kingdom, during a 1-year study. Five groups of isolates with identical genotypes show statistically significant clustering in time (p values are shown in the Table). Each group is indicated by 1 color. White bars indicate other isolates that share the same sequence type (ST) but that are differentiated by their different antigen type. Numbers of isolates of each genotype are shown on a weekly basis; week 1 corresponds to the start of the study on September 15, 2003.

Mentions: There were 68 groups of >2 isolates with identical 10-locus types, ranging in size from 2 to 34 isolates and accounting for 283 (48.5%) of the independent isolates. Of the remaining isolates, 290 (49.7%) had unique types, typing data were incomplete for the remaining 10 isolates (1.7%). A permutation test with 283 isolates belonging to a cluster showed highly significant temporal clustering of Campylobacter spp. isolates of identical genotype (p<0.0001). The extent of clustering was independent of group size (data not shown). Of 16 groups of >5 identical isolates, 5 exhibited significant temporal clustering (Table, Figure 2). Isolates belonging to the largest of these groups, comprising 34 isolates of ST-257, flaA 16, flaB 301, and porA 1, were submitted mainly in the last part of the study year with a peak of 5 isolates in week 39 (Figure 2). The second largest group, comprising 13 isolates, shared ST-51 and an identical porA type with a genotypic group comprising 7 isolates, but the 2 groups were distinct at both flaA and flaB loci. All members of these 2 groups were isolated from week 14 through week 40. Of the 12 isolates comprising the third largest group, all but 1 were isolated over a 17-week period (week 2 through week 18) at the beginning of the year (Figure 2). The smallest group of isolates to show evidence for temporal clustering comprised 5 identical isolates obtained during weeks 18–29. Some of the other genotypic groups were seen throughout the year, with no evidence for temporal clustering; for others, weak evidence of clustering was found (Table).


Extended sequence typing of Campylobacter spp., United Kingdom.

Dingle KE, McCarthy ND, Cody AJ, Peto TE, Maiden MC - Emerging Infect. Dis. (2008)

Clusters of related 10-locus types of Campylobacter spp. detected in Oxfordshire, United Kingdom, during a 1-year study. Five groups of isolates with identical genotypes show statistically significant clustering in time (p values are shown in the Table). Each group is indicated by 1 color. White bars indicate other isolates that share the same sequence type (ST) but that are differentiated by their different antigen type. Numbers of isolates of each genotype are shown on a weekly basis; week 1 corresponds to the start of the study on September 15, 2003.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2609887&req=5

Figure 2: Clusters of related 10-locus types of Campylobacter spp. detected in Oxfordshire, United Kingdom, during a 1-year study. Five groups of isolates with identical genotypes show statistically significant clustering in time (p values are shown in the Table). Each group is indicated by 1 color. White bars indicate other isolates that share the same sequence type (ST) but that are differentiated by their different antigen type. Numbers of isolates of each genotype are shown on a weekly basis; week 1 corresponds to the start of the study on September 15, 2003.
Mentions: There were 68 groups of >2 isolates with identical 10-locus types, ranging in size from 2 to 34 isolates and accounting for 283 (48.5%) of the independent isolates. Of the remaining isolates, 290 (49.7%) had unique types, typing data were incomplete for the remaining 10 isolates (1.7%). A permutation test with 283 isolates belonging to a cluster showed highly significant temporal clustering of Campylobacter spp. isolates of identical genotype (p<0.0001). The extent of clustering was independent of group size (data not shown). Of 16 groups of >5 identical isolates, 5 exhibited significant temporal clustering (Table, Figure 2). Isolates belonging to the largest of these groups, comprising 34 isolates of ST-257, flaA 16, flaB 301, and porA 1, were submitted mainly in the last part of the study year with a peak of 5 isolates in week 39 (Figure 2). The second largest group, comprising 13 isolates, shared ST-51 and an identical porA type with a genotypic group comprising 7 isolates, but the 2 groups were distinct at both flaA and flaB loci. All members of these 2 groups were isolated from week 14 through week 40. Of the 12 isolates comprising the third largest group, all but 1 were isolated over a 17-week period (week 2 through week 18) at the beginning of the year (Figure 2). The smallest group of isolates to show evidence for temporal clustering comprised 5 identical isolates obtained during weeks 18–29. Some of the other genotypic groups were seen throughout the year, with no evidence for temporal clustering; for others, weak evidence of clustering was found (Table).

Bottom Line: Supplementing Campylobacter spp. multilocus sequence typing with nucleotide sequence typing of 3 antigen genes increased the discriminatory index achieved from 0.975 to 0.992 among 620 clinical isolates from Oxfordshire, United Kingdom.This enhanced typing scheme enabled identification of clusters and retained data required for long-range epidemiologic comparisons of isolates.

View Article: PubMed Central - PubMed

Affiliation: John Radcliffe Hospital, Oxford, UK.

ABSTRACT
Supplementing Campylobacter spp. multilocus sequence typing with nucleotide sequence typing of 3 antigen genes increased the discriminatory index achieved from 0.975 to 0.992 among 620 clinical isolates from Oxfordshire, United Kingdom. This enhanced typing scheme enabled identification of clusters and retained data required for long-range epidemiologic comparisons of isolates.

Show MeSH