P1-S1.40 Emerging molecular mutations of reduced susceptibility to third-generation Cephalosporins in<i>Neisseria gonorrhoeae</i>isolates from Saskatchewan, Canada
Notice bibliographique
Résumé
Background Third-generation cephalosporins (eg, ceftriaxone, Cro) are the antimicrobials of choice for the treatment of gonorrhoea. The molecular mechanisms causing reduced susceptibility to these antibiotics in Neisseria gonorrhoeae (Ng) isolates differ between isolates from different geographic regions. The objective of this research was to characterise mutations in penA, mtrR, porB and ponA associated with Cro reduced susceptibility (CroRed) in Ng isolates from Saskatchewan (SK), Canada. Methods A total of 320 of Ng isolates (2003 to 2008) from SK were tested for their antimicrobial susceptibility to Cro using the CLSI agar dilution method. 7% of the isolates (n=23) had Cro MICs of 0.03–0.06 mg/l and were defined as having CroRed phenotypes and 93% of the isolates (n=297) had MICs of <0.03 mg/l which were classified as susceptible (CroS). All CroRed isolates were analysed for mutations in penA (PBP2), mtrR (MtrR), porB (PorB) and ponA (PBP1). 123 (42%) CroS isolates were randomly selected as coselected Results In total, nine mutation patterns were observed in penA. Patterns I (31.7%), IX (29.2%) and XXII (26%) were most common in the 123 CroS isolates; while patterns IX (60.8%, p<0.05) and XXII (21.5%, p>0.05) were predominant in the 23 CroRed isolates. The mosaic penA pattern X was observed in only one isolate (Cro MIC=0.06 mg/l). Seven mutation patterns were noted in mtrR. Among the CroS isolates, 35.8% had a single mutation (G45D or A39T) in the DNA binding domain (DBD) and 17.8% of the isolates carried an A" nucleotide deletion (A−) in the mtr promoter coupled with a G45D mutation. Among the CroRed isolates, 65.2% carried G45D or A39T single mutations, significantly higher than that of CroS isolates (p<0.05). The mutation of A−/H105Y was observed in 21.7% of CroRed isolates as compared to 4% of CroS isolates (p<0.05). Five mutation patterns at residues G120 and A121 of PorB were observed in the CroRed isolates including double (47.8% vs 13% CroS isolates, p<0.05) or single (21.7% vs 26% CroS isolates, p>0.05) mutations. L421P in PBP1 was detected in 87% CroRed and 13% CroS isolates, respectively (p<0.05). Conclusions Mosaic penA pattern X was only observed in one CroRed isolate. The mutations associated with CroRed phenotypes include pattern IX of PBP2, mutations in DBD and a double mutation of A−/H105Y in mtrR, double mutations in PorB (positions G120 and A121) and L421P of PBP1.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».