Ramoplanin as a novel therapy for Neisseria gonorrhoeae infection: an in vitro and in vivo study in Galleria mellonella.

Neisseria gonorrhoeae is a bacterial pathogen that causes gonorrhoea, a sexually transmitted infection. Increasing antimicrobial resistance in N. gonorrhoeae is providing motivation to develop new treatment options. In this study, we investigated the effectiveness of the antibiotic ramoplanin as a treatment for N. gonorrhoeae infection. We tested the effectiveness of ramoplanin in vitro against 14 World Health Organization (WHO) reference strains of N. gonorrhoeae and found that it was active against all 14 strains tested. Furthermore, in a Galleria mellonella infection model of N. gonorrhoeae WHO P, we demonstrated that ramoplanin was active in vivo without any evidence of toxicity. This suggests that ramoplanin might be a new promising antibiotic treatment for gonorrhoea.

Gonorrhoea treatment combined with population-level general cephalosporin and quinolone consumption may select for Neisseria gonorrhoeae antimicrobial resistance at the levels of NG-MAST genogroup: An ecological study in Europe.

OBJECTIVES: The prevalence of Neisseria gonorrhoeae NG-MAST genogroup G1407, associated with decreased susceptibility to extended-spectrum cephalosporins and fluoroquinolone resistance, has declined in Europe and it switched from circulating predominantly in men who have sex with men (MSM) in 2009-2010 to heterosexuals in 2013. We hypothesise that changes to gonorrhoea treatment guidelines combined with differences in country-level consumption of cephalosporins and quinolones contributed to this shift. METHODS: Linear regression was used to evaluate the association between changes in prevalence of G1407 between 2009-2010 and 2013 and country-level consumption of quinolones and cephalosporins in 2011/12 in 20 European countries. RESULTS: Whilst the prevalence of G1407 declined between 2009-2010 and 2013 in the EU/EEA, its absolute prevalence increased by 10% or more in three countries. The national prevalence of G1407 in 2013 was positively associated with population-level general cephalosporin and quinolone consumption in the preceding 2 years. The association between the prevalence of G1407 and proportion of the national sample derived from MSM was non-significant in 2009-2010 and was negative in 2013. CONCLUSIONS: Our results are broadly compatible with the hypothesis that changes in gonorrhoea therapy to the more efficacious ceftriaxone (plus azithromycin) from 2010 to 2011 onwards resulted in a reduced prevalence of the resistance-associated G1407 overall but in MSM in particular. High population-level consumption of quinolones and cephalosporins in certain countries then contributed to the selection of G1407 predominantly in heterosexuals in these countries.

Does gonorrhoea screening intensity play a role in the early selection of antimicrobial resistance in men who have sex with men (MSM)? A comparative study of Belgium and the United Kingdom.

Background: It is unclear why antimicrobial resistance in Neisseriagonorrhoeae in the United Kingdom (UK) and the United States has tended to first appear in men who have sex with men (MSM). We hypothesize that increased exposure to antimicrobials from intensive STI screening programmes plays a role. Methods: We assess if there is a difference in the distribution of azithromycin, cefixime and ceftriaxone minimum inhibitory concentrations (MICs) between MSM and women in the United Kingdom (UK) where 70% of MSM report STI screening in the past year vs. Belgium where 9% report STI screening in the past year. Our hypothesis is that MICs of the MSM should be higher than those of the women in the UK but not Belgium. Data for the MICs were taken from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) in the UK in 2010/2011 and 2014 and a similar national surveillance programme in Belgium in 2013/2014 (the first most complete available data). We used the Mann-Whitney test to compare the MIC distributions between MSM and women within each country Results: In the UK the MICs for all three antimicrobials were significantly higher in MSM than women at both time points (P all <0.0005). In Belgium only the MIC distribution for azithromycin was higher in MSM (P<0.0005). Conclusion: The findings for cefixime and ceftriaxone, but not azithromycin are compatible with our hypothesis that screening-intensity could contribute to the emergence of AMR. Numerous other interpretations of our results are discussed.

Liver and renal safety of tenofovir disoproxil fumarate in combination with emtricitabine among African women in a pre-exposure prophylaxis trial.

BACKGROUND: Safety of tenofovir disoproxil fumarate/emtricitabine (TDF-FTC) has been studied more extensively among HIV-infected patients than among HIV-uninfected people. Using data from a pre-exposure trial - FEM-PrEP -, we determined the cumulative probabilities of grade 1+ ALT, AST and creatinine and grade 2+ phosphorus toxicities; ALT/AST toxicities by baseline hepatitis B status; and change in mean creatinine, phosphorus, ALT and AST levels controlling for TDF-FTC adherence. METHODS AND FINDINGS: FEM-PrEP was a randomized, blinded, placebo-controlled trial of daily TDF-FTC among women in Africa. Enrolled women were in general good health, HIV antibody negative, 18 to 35 years old, hepatitis B surface antigen negative, and had normal hepatic and renal function at baseline. AST, ALT, phosphorus and serum creatinine were measured regularly throughout the trial. TDF-FTC concentrations were measured to assess adherence to TDF-FTC. The cumulative probabilities of grade 1+ creatininemia and grade 2+ phosphatemia toxicities were not statistically different between TDF-FTC and placebo arms. The cumulative probabilities of grade 1+ ALT and AST toxicities were higher among participants in the TDF-FTC arm than in the placebo arm (p = 0.03 for both). The proportions of grade 1+ and grade 2+ ALT or AST toxicities were significantly higher in participants who were hepatitis B virus surface antibody (HBsAb) positive than in those who were HBsAb-negative. Women with good adherence had higher mean change from baseline to week 4 in their AST levels (2.90 (0.37, 5.42); p = 0.025) than women with less than good adherence. CONCLUSIONS: We did not observe a significant relationship between randomization to TDF-FTC and creatinine or phosphorus toxicities. Women randomized to TDF-FTC had higher rates of mild to moderate ALT/AST toxicities, especially women with prior hepatitis B virus exposure. We also observed a significant increase in AST from baseline to week 4 among women who had higher adherence to TDF-FTC during that interval. TRIAL REGISTER: #NCT00625404, February 19, 2008.