title: A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.
abstract: A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).
authors.affiliation: Molecular Diagnostic Laboratory, Atal-Medial Medical Diagnostic Center, Jan Tooropstraat 138, 1061 AD, Amsterdam, the Netherlands.
authors.forename: Ali
authors.initials: A
authors.lastname: Vahidnia
authors.affiliation: Department of Family Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: Pieter Jan
authors.initials: PJ
authors.lastname: van Empel
authors.affiliation: Molecular Diagnostic Laboratory, Atal-Medial Medical Diagnostic Center, Jan Tooropstraat 138, 1061 AD, Amsterdam, the Netherlands.
authors.forename: Sandra
authors.initials: S
authors.lastname: Costa
authors.affiliation: General practitioner office RTN OUD, Amsterdam, Netherlands.
authors.forename: Rob T N
authors.initials: RT
authors.lastname: Oud
authors.affiliation: Department of Clinical Pharmacy and Toxicology, Leiden University Medical Center, Leiden, Netherlands.
authors.forename: Tahar
authors.initials: T
authors.lastname: van der Straaten
authors.affiliation: Medical Microbiology Laboratory, Atal-Medial Medical Diagnostic Center, Jan Tooropstraat, Amsterdam, Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Bliekendaal
authors.affiliation: Medical Microbiology Laboratory, Atal-Medial Medical Diagnostic Center, Jan Tooropstraat, Amsterdam, Netherlands.
authors.forename: Joke
authors.initials: J
authors.lastname: Spaargaren
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002690:Chlamydia Infections; D003951:Diagnostic Errors; D005189:False Positive Reactions; D006069:Gonorrhea / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification*; D012007:Rectum / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; C090348:Opa protein, Neisseria
keywords: GP practice; Multiplex PCR; Mutation; Neisseria gonorrhea; Sexually transmitted infections