OBJECTIVES: Gonorrhoea remains a global public health problem and the treatment options are diminishing through the emergence of gonococci resistant to most antimicrobials. Previous in vitro studies have indicated a role for Neisseria gonorrhoeae pilQ alterations in conferring resistance to antimicrobials, including penicillin. In this study, we investigated whether pilQ polymorphisms were associated with decreased susceptibility to extended-spectrum cephalosporins (ESCs) in clinical gonococcal strains. METHODS: Full-length pilQ nucleotide and PilQ amino acid sequences from geographically and temporally diverse gonococcal clinical isolates (n = 63), including the 2008 WHO reference strains, representing a range of ceftriaxone and cefixime MICs (≤0.008-0.25 and <0.016-0.5 mg/L, respectively) and 38 N. gonorrhoeae multiantigen sequence types, were examined. Previously described alterations associated with decreased ESC susceptibility (mosaic penA, mtrR and penB alterations) were also examined. RESULTS: Fifteen different pilQ nucleotide sequence types and nine different PilQ amino acid sequence types were observed, with two PilQ types accounting for 53 (84%) of the isolates. Independent of other genetic resistance determinants (penA mosaic, mtrR promoter deletion and penB), only one pilQ alteration, a D526N substitution, provided a statistically significant association with ceftriaxone (P < 0.01) and cefixime (P < 0.05) MICs. However, the two isolates exhibiting D526N lacked all three previously described alterations associated with decreased ESC susceptibility, thereby providing an alternative basis for the low MICs (≤0.008 mg/L) observed for these strains. The previously described E666K (pilQ2) and F595L (pilQ1) mutations were absent in all 63 isolates. CONCLUSIONS: pilQ polymorphisms are unlikely contributors to decreased susceptibility to ESCs in clinical gonococcal strains.
OBJECTIVES: Gonorrhoea remains a global public health problem and the treatment options are diminishing through the emergence of gonococci resistant to most antimicrobials. Previous in vitro studies have indicated a role for Neisseria gonorrhoeae pilQ alterations in conferring resistance to antimicrobials, including penicillin. In this study, we investigated whether pilQ polymorphisms were associated with decreased susceptibility to extended-spectrum cephalosporins (ESCs) in clinical gonococcal strains. METHODS: Full-length pilQ nucleotide and PilQ amino acid sequences from geographically and temporally diverse gonococcal clinical isolates (n = 63), including the 2008 WHO reference strains, representing a range of ceftriaxone and cefixime MICs (≤0.008-0.25 and <0.016-0.5 mg/L, respectively) and 38 N. gonorrhoeae multiantigen sequence types, were examined. Previously described alterations associated with decreased ESC susceptibility (mosaic penA, mtrR and penB alterations) were also examined. RESULTS: Fifteen different pilQ nucleotide sequence types and nine different PilQ amino acid sequence types were observed, with two PilQ types accounting for 53 (84%) of the isolates. Independent of other genetic resistance determinants (penA mosaic, mtrR promoter deletion and penB), only one pilQ alteration, a D526N substitution, provided a statistically significant association with ceftriaxone (P < 0.01) and cefixime (P < 0.05) MICs. However, the two isolates exhibiting D526N lacked all three previously described alterations associated with decreased ESC susceptibility, thereby providing an alternative basis for the low MICs (≤0.008 mg/L) observed for these strains. The previously described E666K (pilQ2) and F595L (pilQ1) mutations were absent in all 63 isolates. CONCLUSIONS: pilQ polymorphisms are unlikely contributors to decreased susceptibility to ESCs in clinical gonococcal strains.
Authors: Walter Demczuk; Irene Martin; Pam Sawatzky; Vanessa Allen; Brigitte Lefebvre; Linda Hoang; Prenilla Naidu; Jessica Minion; Paul VanCaeseele; David Haldane; David W Eyre; Michael R Mulvey Journal: Antimicrob Agents Chemother Date: 2020-02-21 Impact factor: 5.191
Authors: A Jeanine Abrams; Robert D Kirkcaldy; Kevin Pettus; Jan L Fox; Grace Kubin; David L Trees Journal: Sex Transm Dis Date: 2017-08 Impact factor: 2.830
Authors: Raymond Heymans; Sylvia M Bruisten; Daniel Golparian; Magnus Unemo; Henry J C de Vries; Alje P van Dam Journal: Antimicrob Agents Chemother Date: 2012-01-03 Impact factor: 5.191
Authors: Supriya D Mehta; Ian Maclean; Jeckoniah O Ndinya-Achola; Stephen Moses; Irene Martin; Allan Ronald; Lawrence Agunda; Ruth Murugu; Robert C Bailey; Johan Melendez; Jonathan M Zenilman Journal: Antimicrob Agents Chemother Date: 2011-05-23 Impact factor: 5.191