Spread of a new Chlamydia trachomatis variant from men who have sex with men to the heterosexual population after replacement and recombination in ompA and pmpH genes.
OBJECTIVE
Sexually transmitted infections are frequently related to outbreaks in high-risk populations due to the dense sexual networks. We wanted to determine the dissemination of a Chlamydia trachomatis variant characterized by the pmpH-recombinant gene between L and G genotypes, which was previously described in a high-risk population.


METHODS
A total of 449 samples were analysed in two periods ranging from 2009 to 2015 for detection of the pmpH-recombinant gene. For those samples yielding positive amplification, a sampling was selected for phylogenetic reconstructions based on sequencing of five chromosomal genes.


RESULTS
Globally this variant was found in 113 of the 449 samples (25%). During the first years (2009-13), this variant was found almost exclusively in rectal samples (30/112 samples) of men who have sex with men and in only one non-rectal sample (1/63). In 2014, this variant was also found in urethral and pharyngeal samples (1/24 and 1/7, respectively). However, in 2015, an epidemiological change was observed as the proportion of this variant had increased in rectal samples (20/51; 39%) and non-rectal samples, including cervical samples (51/142; 36.4%). The molecular characterization revealed the replacement of the ompA gene belonging to subtype G in samples recovered from 2009 to 2013 by the ompA gene belonging to subtype J after 2013.


CONCLUSIONS
Our data would support the evidence that subtype J could be a 'subtype bridge' between different sexual networks, as subtype J has been found in men who have sex with men and heterosexual populations in similar proportions. This work reveals the necessity of implementing molecular surveillance in extra-rectal samples to help us understand the gaps in transmission.
Servicio de Microbiología Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain; CIBER en Epidemiología y Salud Pública, Madrid, Spain.
M
M
Rodríguez-Domínguez
Servicio de Microbiología Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain; CIBER en Epidemiología y Salud Pública, Madrid, Spain.
J M
JM
González-Alba
Centro Sanitario Sandoval, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Clínico San Carlos, Madrid, Spain.
T
T
Puerta
Servicio de Microbiología Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain; Red Española de Investigación en Patología Infecciosa, Madrid, Spain.
L
L
Martínez-García
Centro Sanitario Sandoval, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Clínico San Carlos, Madrid, Spain; Laboratorio de Microbiología, Centro Sandoval, Madrid, Spain.
B
B
Menéndez
Servicio de Microbiología Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain; Red Española de Investigación en Patología Infecciosa, Madrid, Spain.
R
R
Cantón
Centro Sanitario Sandoval, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Clínico San Carlos, Madrid, Spain.
J
J
Del Romero
Servicio de Microbiología Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain; CIBER en Epidemiología y Salud Pública, Madrid, Spain; Unidad de Resistencia a Antibióticos y Virulencia Bacteriana, Madrid, Spain. Electronic address: juancarlos.galan@salud.madrid.org.
J C
JC
Galán
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002692:Chlamydia trachomatis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005838:Genotype; D020010:Heterosexuality; D018451:Homosexuality, Male; D006801:Humans; D008219:Lymphogranuloma Venereum / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D008297:Male; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D050505:Mutant Proteins / Q000235:genetics*; D011995:Recombination, Genetic
D001425:Bacterial Outer Membrane Proteins; D050505:Mutant Proteins; C410162:PmpH protein, Chlamydia trachomatis; C078167:OMPA outer membrane proteins
Chlamydia trachomatis; Molecular epidemiology; OmpA; Recombination; Spread