Antimicrobial resistance and molecular characteristics of isolates in Ghana.

Introduction: Gonorrhoea is a disease associated with humans and caused by s ability to evolve and evade various treatment regimens can lead to untreatable gonorrhoea. In the absence of a viable vaccine and a national database on the antimicrobial resistance (AMR) and molecular characteristics of and with reliance on a syndromic management regime, continuous national antimicrobial resistance surveillance and molecular characterization of remain imperative. Only two gonococcal studies have described molecular characteristics linked to AMR in Ghana.

Methods: Secondary isolates (=4) were collected from two metropolises in Ghana: Tamale in the northern sector (=1) and Accra in the southern sector (=3). The isolates were confirmed and characterized using polymerase chain reaction (PCR) targeting the B and B genes, and the disc diffusion method was used to evaluate AMR. multi-antigen sequence typing (NG-MAST) and porin B (B) gene sequence analyses were employed to reveal the molecular epidemiology and evolutionary trajectory, respectively.

Results: All four isolates showed resistance to at least four of the tested antibiotics. One isolate showed resistance to all seven antibiotics, i.e. ceftriaxone, azithromycin, ciprofloxacin, tetracycline, erythromycin, togamycin and penicillin. NG-MAST typing revealed isolate S3 (MZ313864) as ST211. The locus of S2 (MZ313863) (transferrin-binding protein B; B) was identified as B1844, and its B locus, as B6412, with only 4 closely related variants but with 15 nucleotide differences. However, its sequence type does not exist. The B analysis identified isolate S3 (MZ313864) to be found globally, while S2 (MZ313863) is unique to this study.

Discussion: Despite the small number of isolates tested, this study recorded multidrug resistance and previously unknown gonococcal variants based on B gene. Additionally, the molecular typing schemes revealed a disparity between NG-MAST and the National Center for Biotechnology Information (NCBI) platforms. There is a need for continuous gonococcal AMR and molecular surveillance in Ghana to contribute to the global efforts to describe circulating strains and support proper application of the syndromic management regime to gonorrhoea.