Naturally occurring Neisseria gonorrhoeae can have large deletions in housekeeping gene abcZ, making them untypable with multilocus sequence typing.

The abcZ gene is an essential housekeeping gene in all the Neisseria species. It is one of the seven genes used for multilocus sequence typing (MLST) this genus. It encodes the cytosolic component of an ATP-binding cassette (ABC) transporter complex of unknown function. We report here the finding of a strain of Neisseria gonorrhoeae with a 485 base pair deletion in the 5' region of the abcZ gene that truncates the protein product from 636 amino acids to 89 amino acids. A second open reading frame (ORF), encoding the latter 388 amino acids of the abcZ gene, was predicted downstream. The deletion will affect MLST profiling; interrogation of genomic sequences from PubMLST revealed that this isolate is not an anomaly. Deletions in abcZ were identified in 256 Neisseria genomes, roughly 0.6% of isolates. Furthermore, these deletions could leave the abcZ gene in a pseudogenized state. Our strain, isolated from a patient with symptoms of gonorrheal infection, nevertheless behaved normal in terms of growth and in vitro phenotypic properties.