(P13-LB) Buenos Aires Lymphogranuloma venereum outbreak reveals novel Chlamydia trachomatis sequence type and increased prevalence of uncommon strain, ST2, through high-resolution multilocus sequence typing

Tuesday, July 25, 2023

16:00 – 18:00 CST

Primary Presenter(s)

Marcelo Rodríguez Fermepin, PhD (he/him/his)

Full Professor
Universidad de Buenos Aires, Argentina. Instituto de Investigación en Fisiopatología y Bioquímica Clínica (INFIBIOC)
Buenos aires, Buenos Aires, Argentina

Co-Author(s)

Karina A. Büttner, MSc (she/her/hers)

Biochemistry
Universidad de Buenos Aires, Argentina. Instituto de Investigación en Fisiopatología y Bioquímica Clínica (INFIBIOC)
San Fernando, Buenos Aires, Argentina

Co-author(s)

ae

aNDREA cAROLINA eNTROCASSI

Universidad de Buenos Aires, Argentina. Instituto de Investigación en Fisiopatología y Bioquímica Clinica (INFIBIOC), Argentina
lg

lucia gallo vaulet

Universidad de Buenos Aires, Argentina. Instituto de Investigación en Fisiopatología y Bioquímica Clínica (INFIBIOC), Argentina
DL

Deysi López Aquino

División Cirugia, Hospital Fernandez, Buenos Aires, Argentina., Argentina
DC

Dolores Caffarena

Centro Privado de Cirugía y Coloproctología, Buenos Aires, Argentina., Argentina
LL

Luciana La Rosa

Centro Privado de Cirugía y Coloproctología, Buenos Aires, Argentina., Argentina
LS

Laura Svidler López

División Cirugia, Hospital Fernandez, Buenos Aires, Argentina., Argentina
Björn Herrmann

Uppsala University Hospital, Uppsala
Uppsala, Sweden

Background: Lymphogranuloma venereum (LGV) is a sexually transmitted disease caused by Chlamydia trachomatis serotypes L1 to L3. Since 2003, an increase in LGV cases were observed in Europe, with L2b as predominant genotype. In Buenos Aires, LGV has been detected since 2017, with a unique profile: 43% of LGV positive samples were L2b, 26% were L2, and 31% were L1 genotype, by analysis of the ompA gene. The study of genetic characteristics is essential to know the outbreak's genetic background and, in future studies, be able to relate these characteristics with different clinical presentations.

Methods: We recruited 239 samples from patients with symptoms compatible with proctitis, between 09/2017 and 08/2019. Anorectal swabs were tested for C. trachomatis by real-time PCR targeting the cryptic plasmid. Positive samples: 107/239 were genotyped by ompA PCR-RFLP and subsequent ompA sequencing (88 LGV, including 38 L2b (43%), 27 L1 (31%), and 23 L2 (26%). Twenty positive samples (10 L2b, 6 L1 and 4 L2) from this group, including those with ompA mutations, were selected for Multilocus sequence typing (MLST) according to Herrmann et al. (CT058, CT144, CT172, hctB, pbpB).

Results: Four samples corresponding to L2b genotype could not be analyzed due to deficiencies in the amplification of the target genes. The other samples corresponding to the L2b genotype, according to ompA, were determined as ST58 or ST143 in MLST, sequence types (ST) previously found in L2/L2b strains. Of the four L2 samples, two were ST58, one was ST141 (both previously corresponding to L2 genotypes) and one was a new ST (CT058 13; CT144 17; CT172 13; hctB 18; pbpB 28). Finally, the L1 samples, according to the ompA study, turned out to be ST2, a genotype poorly represented in the international database and that does not coincide with the STs previously associated with L1 ompA.

Conclusion: The analysis revealed one novel Chlamydia trachomatis ST and resulted in a MLST designation for L1 cases. The study using high-resolution genotyping provided increased possibilities for molecular epidemiology of LGV strains by using MLST. A high proportion LGV strains in Argentina differ genotypically from findings in Europe and North-America.