Identification of Novel Neisseria gonorrhoeae Lineages Harboring Resistance Plasmids in Coastal Kenya

Abstract

BackgroundAfrica has the highest incidence of gonorrhea in the world. However, little is known about gonococcal populations in this continent or mechanisms of antimicrobial resistance (AMR).MethodsWhole-genome sequence data were analyzed from 103 Neisseria gonorrhoeae isolates from 73 patients, mainly men who have sex with men, from coastal Kenya. We annotated loci, defined the core genome, defined mechanisms of AMR, and performed phylogenetic analysis. For patients with multiple episodes of gonorrhea, we determined whether infections occurred with related strains.ResultsWe identified 3 clusters of isolates that are phylogenetically distinct from isolates found elsewhere. Plasmids were virtually ubiquitous: pTetM and pblaTEM were found in 97%, and 55% of isolates, respectively. This was associated with high doxycycline use for undiagnosed sexually transmitted infections. Twenty-three percent of multiple episodes of gonorrhea in the same individual were caused by a related strain, suggesting inadequate treatment or reinfection.ConclusionsThe prevalence of plasmid-mediated AMR in Kenyan gonococci contrasts with that in wealthy countries, where AMR is largely chromosomally mediated. Antimicrobials have a profound effect on the maintenance of lineages harboring plasmids. Doxycycline can select for tetracycline and penicillin resistance, through plasmid cooperation. Understanding the mechanisms of AMR in high-risk groups is required to inform treatment strategies.

Plasmid mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates from Kenya

“…African β-lactamase plasmid (pDJ5) which was first identified from Africa [ 16 , 64 ] was predominant. These findings are similar to observations of a previous study from Coastal Kenya [ 52 ]. The Asian type β-lactamase plasmid (pDJ4) initially described in Asia has been associated with epidemic outbreaks in Asian countries [ 12 ].…”

“…Of the 26 PPNG, 21 (80.8%) expressed TEM1 β-lactamase encoded by blaTEM-1 gene, while 5 (19.2%) isolates expressed a β-lactamase encoded by a recently described blaTEM allele (NEIS2357 allele 10) (Table 5 ) [ 52 ]. All these new TEM1 alleles were carried by African type TEM plasmids.…”

“…The Asian type β-lactamase plasmid (pDJ4) initially described in Asia has been associated with epidemic outbreaks in Asian countries [ 12 ]. Five of the PPNG harbored a unique blaTEM-239 allele which has only been reported in Kenya by a previous study [ 52 ]. In the study that unraveled blaTEM-239 , high level penicillin resistance was associated with the allele [ 52 ].…”

“…Five of the PPNG harbored a unique blaTEM-239 allele which has only been reported in Kenya by a previous study [ 52 ]. In the study that unraveled blaTEM-239 , high level penicillin resistance was associated with the allele [ 52 ]. However, from our findings, one isolate expressing TEM239 had an MIC suggesting intermediate susceptibility to penicillin while four were resistant.…”

Incident gonorrhoea and chlamydia among a prospective cohort of men who have sex with men in Kisumu, Kenya

“…These might also be infections from a new partner; we did not collect data that would allow us to differentiate whether they were with the same partner(s) over time. Alternatively, undertreatment or treatment failure may be a possible explanation for repeat infections of NG, although recent findings from a study including primarily MSM in coastal Kenya found that all isolates tested were susceptible to cefixime 22. Participants were asked to report on their own condom use and their partner’s.…”