A 28-year-old woman presents to the gynaecology clinic with a 3-week history of mucopurulent cervical discharge and lower abdominal pain. She is sexually active with a new partner 6 weeks ago. Pelvic examination reveals cervical erythema and mucopurulent exudate. Gram stain of the cervical swab shows no intracellular gram-negative diplococci. Nucleic acid amplification test (NAAT) for Chlamydia trachomatis is positive. What is the most likely serovar involved in this presentation?