Susceptibility to ceftriaxone and occurrence of penicillinase plasmids in Neisseria gonorrhoeae strains isolated in Poland in 2012-2013

Genetic diversity of Neisseria gonorrhoeae multi-antigen sequence types in Russia and Europe

OBJECTIVES

The goal of this work was to assess the genetic diversity of Neisseria gonorrhoeae isolates in Russia and Europe and to compare the distribution of the N. gonorrhoeae multi-antigen sequencing types (NG-MAST) of Russian isolates with that of isolates from European countries.

METHODS

NG-MAST typing was performed for 804 N. gonorrhoeae isolates collected in Russia in 2013-2018. For isolates from European countries, data from the https://pathogen.watch/collection/eurogasp2013 database were used.

RESULTS

Among the isolates from Russia, 296 NG-MAST types were found. A maximum likelihood phylogenetic tree was constructed. Phylogenetic analysis revealed seven major genogroups uniting the most frequent Russian sequence types: G807, G1993, G9476, G14942, G1152, G9486, and G12531.

CONCLUSIONS

The NG-MAST type distribution in Russia differed from that in European countries. Most of the Russian isolates had sequence types that were not found in Europe. Only 33% of the Russian isolates belonged to genogroups established for European countries, and the widespread European genogroup G1407 was represented by only nine isolates. Analysis of the Russian isolates belonging to phylogenetically close European genogroups indicated similarities in drug resistance, although no epidemically dangerous drug-resistant clones were found among the Russian isolates.

Multiresistant Neisseria gonorrhoeae: a new threat in second decade of the XXI century

Neisseria gonorrhoeae is an etiologic agent of gonorrhoea, one of the most common sexually transmitted diseases caused by bacteria. For many years, infections caused by N. gonorrhoeae were considered to be relatively easy to treat; however, resistance has emerged successively to all therapeutic agents used in treatment of the disease, e.g., penicillin, ciprofloxacin or azithromycin. Currently, the global problem is the emergence and a threat of spread of N. gonorrhoeae strains resistant to extended-spectrum cephalosporins (ESC), such as injectable ceftriaxone and oral-used cefixime. Especially, dangerous are multi-resistant strains resistant simultaneously to ESC and azithromycin. Three strains with high-level resistance to azithromycin and resistant to ESC were first time isolated in 2018. Moreover, in 2018, the first ESBL was described in N. gonorrhoeae and that makes the threat of appearing the ESBL mechanism of resistance in N. gonorrhoeae more real, even though the strain was sensitive to ceftriaxone. Molecular typing revealed that variants resistant to ESC occurred also among strains belonging to epidemic clonal complex CC1 (genogroup G1407) distinguished in NG-MAST typing system. The G1407 genogroup, in particular the ST1407 sequence type, is currently dominant in most European countries. The presence of different mechanisms of drug resistance significantly affects clinical practice and force changes in treatment regimens and introduction of new drugs.

Resistance of Neisseria gonorrhoeae isolates to beta-lactam antibiotics (benzylpenicillin and ceftriaxone) in Russia, 2015-2017

The goal of this work was to study the phenotypic susceptibility and resistance determinants of N. gonorrhoeae isolates to beta-lactam antimicrobials (benzylpenicillin and ceftriaxone). A total of 522 clinical isolates collected in Russia in 2015–2017 were analysed for susceptibility using the agar dilution method. DNA loci involved in antimicrobial resistance were identified using DNA microarray analysis and sequencing. Resistance to benzylpenicillin remained high, with 7.7% of isolates resistant (MIC_pen > 1 mg/L) and 47.5% of isolates showing intermediate susceptibility (MIC_pen = 0.12–1 mg/L). The most frequent resistance determinant (72.4% isolates) was the Asp345 insertion in penA, both as a single mutation and in combination with other mutations, particularly with the substitution Leu421Pro in ponA (39.0%). Mutations affecting the influx and efflux of drugs were also found, including amino acid substitutions in PorB (26.8% isolates) and delA in the promoter region of mtrR (22.8%). The accumulation of mutations in chromosomal genes (penA, pon, porA, and mtrR) led to a stepwise increase in MIC_pen to values characteristic of intermediate resistance. The presence of bla_TEM plasmids was found in 25 isolates (4.8%), resulting in a strong increase in resistance to penicillin (MIC_pen > 16 mg/L) compared with the chromosomal mutations; 23 plasmids were of the African type with TEM-1 beta-lactamase, and two plasmids were of the Toronto/Rio type with TEM-135 beta-lactamase. Only three isolates were found with reduced susceptibility to ceftriaxone, with MIC_cef = 0.12–0.25 mg/L. Sequencing of penA did not reveal mutations associated with resistance to third-generation cephalosporins, and the gene structure was non-mosaic. The majority of isolates (21 of 25) carrying the bla_TEM plasmid also contained the conjugative plasmid with tetM (resistance to tetracyclines), consistent with previously reported data that the presence of the conjugative plasmid facilitates the transfer of other plasmids associated with antimicrobial resistance.

Antibiotic resistance and NG-MAST sequence types of Neisseria gonorrhoeae isolates in Poland compared to the world

Gonorrhoea is one of the most common sexually transmitted infections and in 2012, the World Health Organization estimated about 78 million of new global urogenital cases among adults per year. The main concern during the latest decade has been the emergence and spread of multidrug-resistant strains of Neisseria gonorrhoeae. Resistance has emerged internationally to the extended-spectrum cephalosporins, ceftriaxone and cefixime, which are the last remaining options for empiric first-line monotherapy of gonorrhoea. In Poland, the levels of resistance to ciprofloxacin, benzylpenicillin and tetracycline are high, and the prevalence of azithromycin resistance has increased. However, no resistance to ceftriaxone has been identified. The currently spread multidrug-resistant strains frequently represent epidemic clones. The present paper reviews and describes the antimicrobial resistance and N. gonorrhoeae multiantigen sequence typing (NG-MAST) sequence types of N. gonorrhoeae strains spreading in Poland compared to the world.