title: Molecular analyses of TEM genes and their corresponding penicillinase-producing Neisseria gonorrhoeae isolates in Bangkok, Thailand.
abstract: Neisseria gonorrhoeae is a major public health problem globally, especially because the bacterium has developed resistance to most antimicrobials introduced for first-line treatment of gonorrhea. In the present study, 96 N. gonorrhoeae isolates with high-level resistance to penicillin from 121 clinical isolates in Thailand were examined to investigate changes related to their plasmid-mediated penicillin resistance and their molecular epidemiological relationships. A β-lactamase (TEM) gene variant, bla(TEM-135), that may be a precursor in the transitional stage of a traditional bla(TEM-1) gene into an extended-spectrum β-lactamase (ESBL), possibly causing high resistance to all extended-spectrum cephalosporins in N. gonorrhoeae, was identified. Clonal analysis using multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence typing (NG-MAST) revealed the existence of a sexual network among patients from Japan and Thailand. Molecular analysis of the bla(TEM-135) gene showed that the emergence of this allele might not be a rare genetic event and that the allele has evolved in different plasmid backgrounds, which results possibly indicate that it is selected due to antimicrobial pressure. The presence of the bla(TEM-135) allele in the penicillinase-producing N. gonorrhoeae population may call for monitoring for the possible emergence of ESBL-producing N. gonorrhoeae in the future. This study identified a bla(TEM) variant (bla(TEM-135)) that is a possible intermediate precursor for an ESBL, which warrants international awareness.
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Shu-Ichi
authors.initials: S
authors.lastname: Nakayama
authors.forename: Chanwit
authors.initials: C
authors.lastname: Tribuddharat
authors.forename: Sasiprapa
authors.initials: S
authors.lastname: Prombhul
authors.forename: Ken
authors.initials: K
authors.lastname: Shimuta
authors.forename: Somporn
authors.initials: S
authors.lastname: Srifuengfung
authors.forename: Magnus
authors.initials: M
authors.lastname: Unemo
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohnishi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D006069:Gonorrhea / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D038622:Internationality; D007564:Japan; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D010405:Penicillinase / Q000096:biosynthesis* / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction / Q000379:methods; D011634:Public Health; D013785:Thailand / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010405:Penicillinase; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1