There are three major Neisseria gonorrhoeae β-lactamase plasmid variants which are associated with specific lineages and carry distinct TEM alleles
Tabea Elsener, Keith A. Jolley, Eduard J. Sanders, Martin Maiden, Ana Cehovin, Christoph M. Tang
Abstract
Neisseria gonorrhoeae is a significant threat to global health with an estimated incidence of over 80 million cases each year and high levels of antimicrobial resistance. The gonococcal β-lactamase plasmid, p bla , carries the TEM β-lactamase, which requires only one or two amino acid changes to become an extended-spectrum β-lactamase (ESBL); this would render last resort treatments for gonorrhoea ineffective. Although p bla is not mobile, it can be transferred by the conjugative plasmid, pConj, found in N. gonorrhoeae . Seven variants of p bla have been described previously, but little is known about their frequency or distribution in the gonococcal population. We characterised sequences of p bla variants and devised a typing scheme, Ng_p bla ST that allows their identification from whole genome short-read sequences. We implemented Ng_p bla ST to assess the distribution of p bla variants in 15 532 gonococcal isolates. This demonstrated that only three p bla variants commonly circulate in gonococci, which together account for >99 % of sequences. The p bla variants carry different TEM alleles and are prevalent in distinct gonococcal lineages. Analysis of 2758 p bla -containing isolates revealed the co-occurrence of p bla with certain pConj types, indicating co-operativity between p bla and pConj variants in the spread of plasmid-mediated AMR in N. gonorrhoeae . Understanding the variation and distribution of p bla is essential for monitoring and predicting the spread of plasmid-mediated β-lactam resistance in N. gonorrhoeae .