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Does typing of Chlamydia trachomatis using housekeeping multilocus sequence typing reveal different sexual networks among heterosexuals and men who have sex with men?

Versteeg B, Bruisten SM, van der Ende A, Pannekoek Y - BMC Infect. Dis. (2016)

Bottom Line: Using the adapted MLST-7 scheme, full MLST profiles were obtained for 187 of 188 tested specimens resulting in a high success rate of 99.5 %.Minimum spanning tree analyses was used to examine the clustering of MLST-7 data, which showed no reflection of separate transmission in MSM and heterosexual hosts.Moreover, typing using the hr-MLST-6 scheme identified genetically related clusters within each of clusters that were identified by using the MLST-7 scheme.

View Article: PubMed Central - PubMed

Affiliation: Public Health Laboratory, Cluster Infectious Diseases, Public Health Service Amsterdam, Amsterdam, The Netherlands.

ABSTRACT

Background: Chlamydia trachomatis infections remain the most common bacterial sexually transmitted infection worldwide. To gain more insight into the epidemiology and transmission of C. trachomatis, several schemes of multilocus sequence typing (MLST) have been developed. We investigated the clustering of C. trachomatis strains derived from men who have sex with men (MSM) and heterosexuals using the MLST scheme based on 7 housekeeping genes (MLST-7) adapted for clinical specimens and a high-resolution MLST scheme based on 6 polymorphic genes, including ompA (hr-MLST-6).

Methods: Specimens from 100 C. trachomatis infected men who have sex with men (MSM) and 100 heterosexual women were randomly selected from previous studies and sequenced. We adapted the MLST-7 scheme to a nested assay to be suitable for direct typing of clinical specimens. All selected specimens were typed using both the adapted MLST-7 scheme and the hr-MLST-6 scheme. Clustering of C. trachomatis strains derived from MSM and heterosexuals was assessed using minimum spanning tree analysis.

Results: Sufficient chlamydial DNA was present in 188 of the 200 (94 %) selected samples. Using the adapted MLST-7 scheme, full MLST profiles were obtained for 187 of 188 tested specimens resulting in a high success rate of 99.5 %. Of these 187 specimens, 91 (48.7 %) were from MSM and 96 (51.3 %) from heterosexuals. We detected 21 sequence types (STs) using the adapted MLST-7 and 79 STs using the hr-MLST-6 scheme. Minimum spanning tree analyses was used to examine the clustering of MLST-7 data, which showed no reflection of separate transmission in MSM and heterosexual hosts. Moreover, typing using the hr-MLST-6 scheme identified genetically related clusters within each of clusters that were identified by using the MLST-7 scheme.

Conclusion: No distinct transmission of C. trachomatis could be observed in MSM and heterosexuals using the adapted MLST-7 scheme in contrast to using the hr-MLST-6. In addition, we compared clustering of both MLST schemes and demonstrated that typing using the hr-MLST-6 scheme is able to identify genetically related clusters of C. trachomatis strains within each of the clusters that were identified by using the MLST-7 scheme.

No MeSH data available.


Related in: MedlinePlus

Minimum spanning tree showing the diversification by hr-MLST-6 of the clusters that were generated using the MLST-7 scheme. Each circle represents one ST. Size of the circles is proportional to the number of identical ST profiles. Bold lines connect types that differ for one single locus. Halos indicate the distinct clusters. Colours indicate the MLST-7 clusters from Fig. 1a: blue, cluster A (n = 75); orange, cluster B (n = 94); fuchsia, cluster C (n = 18)
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Fig2: Minimum spanning tree showing the diversification by hr-MLST-6 of the clusters that were generated using the MLST-7 scheme. Each circle represents one ST. Size of the circles is proportional to the number of identical ST profiles. Bold lines connect types that differ for one single locus. Halos indicate the distinct clusters. Colours indicate the MLST-7 clusters from Fig. 1a: blue, cluster A (n = 75); orange, cluster B (n = 94); fuchsia, cluster C (n = 18)

Mentions: Comparison of the two minimum spanning trees in Fig. 1 shows that the hr-MLST-6 scheme further diversified each of the clusters generated by using the adapted MLST-7 scheme. For example cluster A (11 STs; Fig. 1a) is subdivided into clusters I, II, and III, using the hr-MLST-6 scheme, and also the majority of the singletons and small clusters (Fig. 2) comprising 37 STs. Cluster B (9 STs; Fig. 1a) is further subdivided into clusters IV, V, VI, VII and some remaining singletons and small clusters (Fig. 2) comprising 39 STs. Cluster C (1 ST; Fig. 1a) is identical to cluster VIII (Figs. 1b and 2) but included 3 STs.Fig. 2


Does typing of Chlamydia trachomatis using housekeeping multilocus sequence typing reveal different sexual networks among heterosexuals and men who have sex with men?

Versteeg B, Bruisten SM, van der Ende A, Pannekoek Y - BMC Infect. Dis. (2016)

Minimum spanning tree showing the diversification by hr-MLST-6 of the clusters that were generated using the MLST-7 scheme. Each circle represents one ST. Size of the circles is proportional to the number of identical ST profiles. Bold lines connect types that differ for one single locus. Halos indicate the distinct clusters. Colours indicate the MLST-7 clusters from Fig. 1a: blue, cluster A (n = 75); orange, cluster B (n = 94); fuchsia, cluster C (n = 18)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4836166&req=5

Fig2: Minimum spanning tree showing the diversification by hr-MLST-6 of the clusters that were generated using the MLST-7 scheme. Each circle represents one ST. Size of the circles is proportional to the number of identical ST profiles. Bold lines connect types that differ for one single locus. Halos indicate the distinct clusters. Colours indicate the MLST-7 clusters from Fig. 1a: blue, cluster A (n = 75); orange, cluster B (n = 94); fuchsia, cluster C (n = 18)
Mentions: Comparison of the two minimum spanning trees in Fig. 1 shows that the hr-MLST-6 scheme further diversified each of the clusters generated by using the adapted MLST-7 scheme. For example cluster A (11 STs; Fig. 1a) is subdivided into clusters I, II, and III, using the hr-MLST-6 scheme, and also the majority of the singletons and small clusters (Fig. 2) comprising 37 STs. Cluster B (9 STs; Fig. 1a) is further subdivided into clusters IV, V, VI, VII and some remaining singletons and small clusters (Fig. 2) comprising 39 STs. Cluster C (1 ST; Fig. 1a) is identical to cluster VIII (Figs. 1b and 2) but included 3 STs.Fig. 2

Bottom Line: Using the adapted MLST-7 scheme, full MLST profiles were obtained for 187 of 188 tested specimens resulting in a high success rate of 99.5 %.Minimum spanning tree analyses was used to examine the clustering of MLST-7 data, which showed no reflection of separate transmission in MSM and heterosexual hosts.Moreover, typing using the hr-MLST-6 scheme identified genetically related clusters within each of clusters that were identified by using the MLST-7 scheme.

View Article: PubMed Central - PubMed

Affiliation: Public Health Laboratory, Cluster Infectious Diseases, Public Health Service Amsterdam, Amsterdam, The Netherlands.

ABSTRACT

Background: Chlamydia trachomatis infections remain the most common bacterial sexually transmitted infection worldwide. To gain more insight into the epidemiology and transmission of C. trachomatis, several schemes of multilocus sequence typing (MLST) have been developed. We investigated the clustering of C. trachomatis strains derived from men who have sex with men (MSM) and heterosexuals using the MLST scheme based on 7 housekeeping genes (MLST-7) adapted for clinical specimens and a high-resolution MLST scheme based on 6 polymorphic genes, including ompA (hr-MLST-6).

Methods: Specimens from 100 C. trachomatis infected men who have sex with men (MSM) and 100 heterosexual women were randomly selected from previous studies and sequenced. We adapted the MLST-7 scheme to a nested assay to be suitable for direct typing of clinical specimens. All selected specimens were typed using both the adapted MLST-7 scheme and the hr-MLST-6 scheme. Clustering of C. trachomatis strains derived from MSM and heterosexuals was assessed using minimum spanning tree analysis.

Results: Sufficient chlamydial DNA was present in 188 of the 200 (94 %) selected samples. Using the adapted MLST-7 scheme, full MLST profiles were obtained for 187 of 188 tested specimens resulting in a high success rate of 99.5 %. Of these 187 specimens, 91 (48.7 %) were from MSM and 96 (51.3 %) from heterosexuals. We detected 21 sequence types (STs) using the adapted MLST-7 and 79 STs using the hr-MLST-6 scheme. Minimum spanning tree analyses was used to examine the clustering of MLST-7 data, which showed no reflection of separate transmission in MSM and heterosexual hosts. Moreover, typing using the hr-MLST-6 scheme identified genetically related clusters within each of clusters that were identified by using the MLST-7 scheme.

Conclusion: No distinct transmission of C. trachomatis could be observed in MSM and heterosexuals using the adapted MLST-7 scheme in contrast to using the hr-MLST-6. In addition, we compared clustering of both MLST schemes and demonstrated that typing using the hr-MLST-6 scheme is able to identify genetically related clusters of C. trachomatis strains within each of the clusters that were identified by using the MLST-7 scheme.

No MeSH data available.


Related in: MedlinePlus