Molecular Epidemiology of β-Lactamase–Producing Neisseria gonorrhoeae Strains in Manaus, AM, Brazil

Genomic epidemiology of Neisseria gonorrhoeae elucidating the gonococcal antimicrobial resistance and lineages/sublineages across Brazil, 2015-16

OBJECTIVES

Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance is imperative internationally, but only eight (22.9%) countries in the WHO Region of the Americas reported complete AMR data to the WHO Global Gonococcal Antimicrobial Surveillance Program (WHO GASP) in 2016. Genomic studies are ideal for enhanced understanding of gonococcal populations, including the spread of AMR strains. To elucidate the circulating gonococcal lineages/sublineages, including their AMR determinants, and the baseline genomic diversity among gonococcal strains in Brazil, we conducted WGS on 548 isolates obtained in 2015-16 across all five macroregions in Brazil.

METHODS

A total of 548 gonococcal isolates cultured across Brazil in 2015-16 were genome sequenced. AMR was determined using agar dilution and/or Etest. Genome sequences of isolates from Argentina (n = 158) and the 2016 WHO reference strains (n = 14) were included in the analysis.

RESULTS

We found 302, 68 and 214 different NG-MAST, MLST and NG-STAR STs, respectively. The phylogenomic analysis identified one main antimicrobial-susceptible lineage and one AMR lineage, which was divided into two sublineages with different AMR profiles. Determination of NG-STAR networks of clonal complexes was shown as a new and valuable molecular epidemiological analysis. Several novel mosaic mtrD (and mtrR and mtrE) variants associated with azithromycin resistance were identified.

CONCLUSIONS

We describe the first genomic baseline data to support the Brazilian GASP. The high prevalence of resistance to ciprofloxacin, tetracycline and benzylpenicillin, and the high number of isolates with mosaic penA and azithromycin resistance mutations, should prompt continued and strengthened AMR surveillance, including WGS, of N. gonorrhoeae in Brazil.

First nationwide antimicrobial susceptibility surveillance for Neisseria gonorrhoeae in Brazil, 2015-16

Objectives

Gonorrhoea and antimicrobial resistance (AMR) in Neisseria gonorrhoeae are major public health concerns globally. Enhanced AMR surveillance for gonococci is essential worldwide; however, recent quality-assured gonococcal AMR surveillance in Latin America, including Brazil, has been limited. Our aims were to (i) establish the first nationwide gonococcal AMR surveillance, quality assured according to WHO standards, in Brazil, and (ii) describe the antimicrobial susceptibility of clinical gonococcal isolates collected from 2015 to 2016 in all five main regions (seven sentinel sites) of Brazil.

Methods

Gonococcal isolates from 550 men with urethral discharge were examined for susceptibility to ceftriaxone, cefixime, azithromycin, ciprofloxacin, benzylpenicillin and tetracycline using the agar dilution method, according to CLSI recommendations and quality assured according to WHO standards.

Results

The levels of resistance (intermediate susceptibility) to tetracycline, ciprofloxacin, benzylpenicillin and azithromycin were 61.6% (34.2%), 55.6% (0.5%), 37.1% (60.4%) and 6.9% (8.9%), respectively. All isolates were susceptible to ceftriaxone and cefixime using the US CLSI breakpoints. However, according to the European EUCAST cefixime breakpoints, 0.2% (n = 1) of isolates were cefixime resistant and 6.9% (n = 38) of isolates had a cefixime MIC bordering on resistance.

Conclusions

This study describes the first national surveillance of gonococcal AMR in Brazil, which was quality assured according to WHO standards. The high resistance to ciprofloxacin (which promptly informed a revision of the Brazilian sexually transmitted infection treatment guideline), emerging resistance to azithromycin and decreasing susceptibility to extended-spectrum cephalosporins necessitate continuous surveillance of gonococcal AMR and ideally treatment failures, and increased awareness when prescribing treatment in Brazil.

Temporal evolution of antimicrobial resistance among Neisseria gonorrhoeae clinical isolates in the most populated South American Metropolitan Region

A total of 124 Neisseria gonorrhoeae isolates recovered during a 12-year period (2003-2015) from outpatients assisted at Centro de Referência e Treinamento DST/AIDS-CRT of São Paulo city, Brazil, were analysed. The following resistance rates were observed: penicillin-59.6%, ciprofloxacin-15.3%, and azithromycin-6.7%. Although reduced susceptibility to these drugs was observed since 2003, no ceftriaxone-resistant isolates were detected. Ciprofloxacin- and azithromycin non-susceptible isolates were grouped in 11 clusters. Mutations were detected in GyrA and ParC of isolates 124 and 260, and a C₂₆₁₁T substitution on 23S rRNA alleles was also observed in isolate 260. Both isolates belonged to ST1901/ST6210 (MSLT/NG-MAST schemes).

Bacteriocins and other bioactive substances of probiotic lactobacilli as biological weapons against Neisseria gonorrhoeae

In the search of new antimicrobial agents against Neisseria gonorrhoeae, the bacteriocins-producing probiotic lactobacilli deserve special attention. The inhibitory effects of biosubstances such as organic acids, hydrogen peroxide and each bacteriocin-like inhibitory substance (BLIS) L23 and L60 on the growth of different gonococcal strains were investigated. Different non-treated and treated cell-free supernatants of two probiotic lactobacilli containing these metabolites were used. The aims of this work were (i) to evaluate the antimicrobial activity of the biosubstances produced by two probiotic lactobacilli, estimating the proportion in which each of them is responsible for the inhibitory effect, (ii) to define their minimum inhibitory concentrations (MICs) and, (iii) to determine the potential interactions between these biosubstances against N. gonorrhoeae. The main antimicrobial metabolites were the BLIS-es L23 and L60 in comparison with other biosubstances. Proportionally, their contributions to the inhibition on the gonococcal growth were 87.28% and 80.66%, respectively. The MIC values of bacteriocins were promising since these substances, when diluted, showed considerable inhibitory activity for all gonococci. In the interaction between bacteriocins, 100% of synergism was found on the gonococcal growth. In summary, this study indicates that both L23 and L60 could potentially serve to design new bioproducts against N. gonorrhoeae.