Multi-locus sequence analysis reveals a novel sequence type of Chlamydia trachomatis in Saratov Region, Russia.
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ABSTRACT:
SUBMITTER: Feodorova VA
PROVIDER: S-EPMC6658990 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:This is the first report to characterize the prevalence and genovar distribution of genital chlamydial infections among random heterosexual patients in the multi-ethnic Saratov Region, located in Southeast Russia. METHODS:Sixty-one clinical samples (cervical or urethral swabs) collected from a random cohort of 856 patients (7.1%) were C. trachomatis (CT) positive in commercial nucleic acid amplification tests (NAATs) and duplex TaqMan PCRs. RESULTS:Sequence analysis of the VDII region of the ompA gene revealed seven genovars of C. trachomatis in PCR-positive patients. The overall genovars were distributed as E (41.9%), G (21.6%), F (13.5%), K (9.5%), D (6.8%), J (4.1%), and H (2.7%). CT-positive samples were from males (n = 12, 19.7%), females (n = 42, 68.8%), and anonymous (n = 7, 11.5%) patients, with an age range of 19 to 45 years (average 26.4), including 12 different ethnic groups representative of this region. Most patients were infected with a single genovar (82%), while 18% were co-infected with either two or three genovars. The 1156 bp-fragment of the ompA gene was sequenced in 46 samples to determine single nucleotide polymorphisms (SNP) among isolates. SNP-based subtyping and phylogenetic reconstruction revealed the presence of 13 variants of the ompA gene, such as E (E1, E2, E6), G (G1, G2, G3, G5), F1, K, D (D1, Da2), J1, and H2. Differing genovar distribution was identified among urban (E>G>F) and rural (E>K) populations, and in Slavic (E>G>D) and non-Slavic (E>G>K) ethnic groups. Multilocus sequence typing (MLST) determined five sequences types (STs), such as ST4 (56%, 95% confidence interval, CI, 70.0 to 41.3), ST6 (10%, 95% CI 21.8 to 3.3), ST9 (22%, 95% CI 35.9 to 11.5), ST10 (2%, 95% CI 10.7 to 0.05) and ST38 (10%, 95% CI 21.8 to 3.3). Thus, the most common STs were ST4 and ST9. CONCLUSION:C. trachomatis is a significant cause of morbidity among random heterosexual patients with genital chlamydial infections in the Saratov Region. Further studies should extend this investigation by describing trends in a larger population, both inside and outside of the Saratov Region to clarify some aspects for the actual application of C. trachomatis genotype analysis for disease control.
| S-EPMC5895025 | biostudies-literature
Project description:BACKGROUND: The obligate intracellular growing bacterium Chlamydia trachomatis causes diseases like trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Several serovars and genotypes have been identified, but these could not be linked to clinical disease or outcome. The related Chlamydophila pneumoniae, of which no subtypes are recognized, causes respiratory infections worldwide. We developed a multi locus sequence typing (MLST) scheme to understand the population genetic structure and diversity of these species and to evaluate the association between genotype and disease. RESULTS: A collection of 26 strains of C. trachomatis of different serovars and clinical presentation and 18 strains of C. pneumoniae were included in the study. For comparison, sequences of C. abortus, C. psittaci, C. caviae, C. felis, C. pecorum (Chlamydophila), C. muridarum (Chlamydia) and of Candidatus protochlamydia and Simkania negevensis were also included. Sequences of fragments (400 - 500 base pairs) from seven housekeeping genes (enoA, fumC, gatA, gidA, hemN, hlfX, oppA) were analysed. Analysis of allelic profiles by eBurst revealed three non-overlapping clonal complexes among the C. trachomatis strains, while the C. pneumoniae strains formed a single group. An UPGMA tree produced from the allelic profiles resulted in three groups of sequence types. The LGV strains grouped in a single cluster, while the urogenital strains were distributed over two separated groups, one consisted solely of strains with frequent occurring serovars (E, D and F). The distribution of the different serovars over the three groups was not consistent, suggesting exchange of serovar encoding ompA sequences. In one instance, exchange of fumC sequences between strains of different groups was observed. Cluster analyses of concatenated sequences of the Chlamydophila and Chlamydia species together with those of Candidatus Protochlamydia amoebophila and Simkania negevensis resulted in a tree identical to that obtained with 23S RNA gene sequences. CONCLUSION: These data show that C. trachomatis and C. pneumoniae are highly uniform. The difference in genetic diversity between C. trachomatis and C. pneumoniae is in concordance with a later assimilation to the human host of the latter. Our data supports the taxonomy of the order of Chlamydiales.
| S-EPMC2268939 | biostudies-literature
Project description:Chlamydia comprises a group of obligate intracellular bacterial parasites responsible for a variety of diseases in humans and animals, including several zoonoses. Chlamydia trachomatis causes diseases such as trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Chlamydia pneumoniae is a common cause of community-acquired respiratory tract infections. Chlamydia psittaci, causing zoonotic pneumonia in humans, is usually hosted by birds, while Chlamydia abortus, causing abortion and fetal death in mammals, including humans, is mainly hosted by goats and sheep. We used multi-locus sequence typing to asses the population structure of Chlamydia. In total, 132 Chlamydia isolates were analyzed, including 60 C. trachomatis, 18 C. pneumoniae, 16 C. abortus, 34 C. psittaci and one of each of C. pecorum, C. caviae, C. muridarum and C. felis. Cluster analyses utilizing the Neighbour-Joining algorithm with the maximum composite likelihood model of concatenated sequences of 7 housekeeping fragments showed that C. psittaci 84/2334 isolated from a parrot grouped together with the C. abortus isolates from goats and sheep. Cluster analyses of the individual alleles showed that in all instances C. psittaci 84/2334 formed one group with C. abortus. Moving 84/2334 from the C. psittaci group to the C. abortus group resulted in a significant increase in the number of fixed differences and elimination of the number of shared mutations between C. psittaci and C. abortus. C. psittaci M56 from a muskrat branched separately from the main group of C. psittaci isolates. C. psittaci genotypes appeared to be associated with host species. The phylogenetic tree of C. psittaci did not follow that of its host bird species, suggesting host species jumps. In conclusion, we report for the first time an association between C. psittaci genotypes with host species.
| S-EPMC2996290 | biostudies-literature
Project description:The Uppsala University Chlamydia trachomatis multilocus sequence type (MLST) database (http://mlstdb.bmc.uu.se) is based on five target regions (non-housekeeping genes) and the ompA gene. Each target has various numbers of alleles-hctB, 89; CT058, 51; CT144, 30; CT172, 38; and pbpB, 35-derived from 13 studies. Our aims were to perform an overall analysis of all C. trachomatis MLST sequence types (STs) in the database, examine STs with global spread, and evaluate the phylogenetic capability by using the five targets. A total of 415 STs were recognized from 2,089 specimens. The addition of 49 ompA gene variants created 459 profiles. ST variation and their geographical distribution were characterized using eBURST and minimum spanning tree analyses. There were 609 samples from men having sex with men (MSM), with 4 predominating STs detected in this group, comprising 63% of MSM cases. Four other STs predominated among 1,383 heterosexual cases comprising, 31% of this group. The diversity index in ocular trachoma cases was significantly lower than in sexually transmitted chlamydia infections. Predominating STs were identified in 12 available C. trachomatis whole genomes which were compared to 22 C. trachomatis full genomes without predominating STs. No specific gene in the 12 genomes with predominating STs could be linked to successful spread of certain STs. Phylogenetic analysis showed that MLST targets provide a tree similar to trees based on whole-genome analysis. The presented MLST scheme identified C. trachomatis strains with global spread. It provides a tool for epidemiological investigations and is useful for phylogenetic analyses.
| S-EPMC4473235 | biostudies-literature
Project description:Chlamydia trachomatis is an obligate intracellular bacterial pathogen of humans that uses a type III secretion (T3S) system to manipulate host cells through the delivery of effector proteins into their cytosol and membranes. The function of T3S systems depends on small bacterial cytosolic chaperone-like proteins, which bind T3S substrates and ensure their appropriate secretion. To find novel T3S chaperone-substrate complexes of C. trachomatis we first searched its genome for genes encoding proteins with features of T3S chaperones. We then systematically tested for interactions between candidate chaperones and chlamydial T3S substrates by bacterial two-hybrid. This revealed interactions between Slc1 (a known T3S chaperone) or CT584 and several T3S substrates. Co-immunoprecipitation after protein expression in Yersinia enterocolitica and protein overlay binding assays indicated that Slc1 interacted with the N-terminal region of the known T3S substrates Tarp (a previously described substrate of Slc1), CT694, and CT695, and that CT584 interacted with a central region of CT082, which we identified as a C. trachomatis T3S substrate using Y. enterocolitica as a heterologous system. Further T3S assays in Yersinia indicated that Slc1 or CT584 increased the amount of secreted Tarp, CT694, and CT695, or CT082, respectively. Expression of CT584 increased the intra-bacterial stability of CT082, while Slc1 did not affect the stability of its substrates. Overall, this indicated that in C. trachomatis Slc1 is a chaperone of multiple T3S substrates and that CT584 is a chaperone of the newly identified T3S substrate CT082.
| S-EPMC3576375 | biostudies-literature
Project description:Chlamydia trachomatis is the most common cause of sexually transmitted infections in the UK, a statistic that is also reflected globally. There are three biovariants of C. trachomatis: trachoma (serotypes A-C) and two sexually transmitted pathovars; serotypes D-K and lymphogranuloma venereum (LGV). Trachoma isolates and the sexually transmitted serotypes D-K are noninvasive, whereas the LGV strains are invasive, causing a disseminating infection of the local draining lymph nodes. Genome sequences are available for single isolates from the trachoma (serotype A) and sexually transmitted (serotype D) biotypes. We sequenced two isolates from the remaining biotype, LGV, a long-term laboratory passaged strain and the recent "epidemic" LGV isolate-causing proctitis. Although the genome of the LGV strain shows no additional genes that could account for the differences in disease outcome, we found evidence of functional gene loss and identified regions of heightened sequence variation that have previously been shown to be important sites for interstrain recombination. We have used new sequencing technologies to show that the recent clinical LGV isolate causing proctitis is unlikely to be a newly emerged strain but is most probably an old strain with relatively new clinical manifestations.
| S-EPMC2134780 | biostudies-literature
Project description:UnlabelledThe Scc4 protein (CT663) of the pathogenic bacterium Chlamydia has been described as a type III secretion (T3S) chaperone as well as an inhibitor of RNA polymerase. To examine if these roles are connected, we first investigated physical interactions between Chlamydia trachomatis Scc4 and the T3S chaperone Scc1 and a T3S substrate, CopN. In a yeast 3-hybrid assay, Scc4, Scc1, and CopN were all required to detect an interaction, which suggests that these proteins form a trimolecular complex. We also detected interactions between any two of these three T3S proteins in a pulldown assay using only recombinant proteins. We next determined whether these interactions affected the function of Scc4 as an inhibitor of RNA transcription. Using Escherichia coli as a heterologous in vivo system, we demonstrated that expression of C. trachomatis Scc4 led to a drastic decrease in transcript levels for multiple genes. However, coexpression of Scc4 with Scc1, CopN, or both alleviated Scc4-mediated inhibition of transcription. Scc4 expression also severely impaired E. coli growth, but this growth defect was reversed by coexpression of Scc4 with Scc1, CopN, or both, suggesting that the inhibitory effect of Scc4 on transcription and growth can be antagonized by interactions between Scc4, Scc1, and CopN. These findings suggest that the dual functions of Scc4 may serve as a bridge to link T3S and the regulation of gene expression in Chlamydia.ImportanceThis study investigates a novel mechanism for regulating gene expression in the pathogenic bacterium Chlamydia. The Chlamydia type III secretion (T3S) chaperone Scc4 has been shown to inhibit transcription by RNA polymerase. This study describes physical interactions between Scc4 and the T3S proteins Scc1 and CopN. Furthermore, Chlamydia Scc1 and CopN antagonized the inhibitory effects of Scc4 on transcription and growth in a heterologous Escherichia coli system. These results provide evidence that transcription in Chlamydia can be regulated by the T3S system through interactions between T3S proteins.
| S-EPMC4573728 | biostudies-literature
Project description:BackgroundThe Chlamydia trachomatis incidence rate in Finnmark, the most northern and sparsely populated county in Norway, has been twice the national average. This population based cross-sectional study among Finnmark high school students had the following aims: i) to examine distribution of multilocus sequence types (STs) of C. trachomatis in a previously unmapped area, ii) to compare chlamydia genetic diversity in Finnmark with that of two urban regions, and iii) to compare discriminatory capacity of multilocus sequence typing (MLST) with conventional ompA sequencing in a large number of chlamydia specimens.MethodologyompA sequencing and a high-resolution MLST system based on PCR amplification and DNA sequencing of five highly variable genetic regions were used. Eighty chlamydia specimens from adolescents aged 15-20 years in Finnmark were collected in five high schools (n?=?60) and from routine clinical samples in the laboratory (n?=?20). These were compared to routine clinical samples from adolescents in Tromsø (n?=?80) and Trondheim (n?=?88), capitals of North and Central Norway, respectively.Principal findingsompA sequencing detected 11 genotypes in 248 specimens from all three areas. MLST displayed 50 STs providing a five-fold higher resolution. Two-thirds of all STs were novel. The common ompA E/Bour genotype comprised 46% and resolved into 24 different STs. MLST identified the Swedish new variant of C. trachomatis not discriminated by ompA sequencing. Simpson's discriminatory index (D) was 0.93 for MLST, while a corrected D(c) was 0.97. There were no statistically significant differences in ST genetic diversity between geographic areas. Finnmark had an atypical genovar distribution with G being predominant. This was mainly due to expansion of specific STs of which the novel ST161 was unique for Finnmark.Conclusions/significanceMLST revealed multiple new STs and a larger genetic diversity in comparison to ompA sequencing and proved to be a useful tool in molecular epidemiology of chlamydia infections.
| S-EPMC3314642 | biostudies-literature
Project description:We describe the cloning and sequence analysis of the region surrounding the gene for the alpha subunit of RNA polymerase from Chlamydia trachomatis. This region contains genes for proteins in the order SecY, S13, S11, alpha, and L17, which are equivalent to Escherichia coli and Bacillus subtilis r proteins. The incorporation of chlamydial alpha subunit protein into the E. coli RNA polymerase holoenzyme rather than its truncated variant lacking the amino terminus suggests the existence of structural conservation among alpha subunits from distantly related genera.
| S-EPMC176926 | biostudies-other
Project description:Chlamydia trachomatis is a strict human pathogen producing infections that cause medically important chronic inflammatory diseases, such as blinding trachoma and tubal factor infertility. Isolates exist as serotypes that fall into distinct biologic and pathological groups corresponding to differences in infection tissue tropism and invasion properties. Paradoxically, genome sequencing of several diverse strains has revealed a remarkable level of genomic synteny, suggesting that minor genetic differences determine the pathogen host- and tissue-specific infection characteristics. To better understand the genetic basis of chlamydial pathobiologic diversity, we performed comparative DNA-DNA microarray genomic hybridizations with all 15 C. trachomatis serovariants. We found there are few major genetic differences among the 15 serovars. An exception was the cytotoxin locus located in the plasticity zone, a region that exhibited significant polymorphisms among serovars. We therefore sequenced this region from all 15 serovars. The cytotoxin gene was interrupted by extensive mutations and deletions among the different serovars; however, three basic open reading frame motifs were discovered that correlated with noninvasive oculotropic, urogenitotropic, and invasive serovars. Of interest, only noninvasive genitotropic serovars possessed an intact N-terminal portion of the putative toxin gene. This region contains the UDP-glucose binding domain and the glycosyltransferase domain required for enzymatic activity of the clostridial toxin homologs, suggesting a role in urogenital infection or pathogenesis.
| S-EPMC529170 | biostudies-literature