Detection of CTX-M-15 ESBL in XDR Haemophilus parainfluenzae from a urethral swab.

OBJECTIVES: Haemophilus parainfluenzae is an opportunistic pathogen causing respiratory tract infection and sexually transmitted diseases. The emergence of multidrug resistance in this species is particularly worrisome, especially since the recent description of CTX-M-15 ESBL-producing isolates in Spain. The aim of this study was to characterize a CTX-M-15-producing H. parainfluenzae clinical isolate, HP01, obtained from a urethral swab. METHODS: MICs were determined with gradient strips for this isolate. Hydrolysis assays were performed with the ß LACTA test. Genomic DNA from HP01 was subjected to Illumina and Oxford Nanopore sequencing to investigate the genetic environment of blaCTX-M-15. Phylogenetic analysis was performed with available H. parainfluenzae genomes from the NCBI database, including CTX-M-15 producers. RESULTS: HP01, an XDR isolate, was resistant to penicillin, third-generation cephalosporins, fluoroquinolones, macrolides, cyclines and co-trimoxazole and susceptible only to carbapenems and rifampicin. HP01 carried blaTEM-1, blaCTX-M-15, tet(M), catS and mef(E)/mel and harboured amino acid substitutions in PBP3, PBP5, GyrA, ParC and FolA implicated in resistance. Genomic analysis revealed that blaCTX-M-15 was carried by a Tn3-like transposon inserted into a novel integrative and conjugative element (ICE), ICEHpaSLS, present on the chromosome and belonging to the ICEHin1056 family described in Haemophilus influenzae. The tet(M)-MEGA element was also detected on the chromosome. No plasmid was found. The phylogenetic analysis showed that four H. parainfluenzae producing CTX-M-15 clustered in the same clade. CONCLUSIONS: Here we report the description of an XDR H. parainfluenzae producing blaCTX-M-15 isolated from a urethral swab. The blaCTX-M-15 gene was inserted into an ICE structure similar to those recently described in CTX-M-15 producers in Spain. The emergence of XDR H. parainfluenzae producing blaCTX-M-15 is a matter of great concern. Careful surveillance is required to prevent its spread.

Early-Onset Infection Caused by Escherichia coli Sequence Type 1193 in Late Preterm and Full-Term Neonates.

Using whole-genome sequencing, we characterized Escherichia coli strains causing early-onset sepsis (EOS) in 32 neonatal cases from a 2019-2021 prospective multicenter study in France and compared them to E. coli strains collected from vaginal swab specimens from women in third-trimester gestation. We observed no major differences in phylogenetic groups or virulence profiles between the 2 collections. However, sequence type (ST) analysis showed the presence of 6/32 (19%) ST1193 strains causing EOS, the same frequency as in the highly virulent clonal group ST95. Three ST1193 strains caused meningitis, and 3 harbored extended-spectrum ß-lactamase. No ST1193 strains were isolated from vaginal swab specimens. Emerging ST1193 appears to be highly prevalent, virulent, and antimicrobial resistant in neonates. However, the physiopathology of EOS caused by ST1193 has not yet been elucidated. Clinicians should be aware of the possible presence of E. coli ST1193 in prenatal and neonatal contexts and provide appropriate monitoring and treatment.

Two cases of extensively drug-resistant (XDR) Neisseria gonorrhoeae infection combining ceftriaxone-resistance and high-level azithromycin resistance, France, November 2022 and May 2023.

We report two extensively drug-resistant (XDR) Neisseria gonorrhoeae (NG) isolates combining high-level resistance to azithromycin and resistance to ceftriaxone, obtained in France from two heterosexual patients, one of whom returned from Cambodia. Whole genome sequencing identified MLST ST16406, the mosaic penA-60.001 which caused ceftriaxone resistance in the internationally spreading FC428 clone, and the A2059G mutation in the 23S rRNA gene. The NG isolates F93 and F94 were related to XDR isolates detected in Austria and the United Kingdom in 2022.

In vitro activity of apramycin against 16S-RMTase-producing Gram-negative isolates.

OBJECTIVES: Apramycin is an aminoglycoside (AG) with a unique structure that is little affected by plasmid-mediated mechanisms of AG resistance, including most AG-modifying enzymes and 16S rRNA methyltransferases (16S-RMTases). We evaluate the activity of apramycin against a collection of 16S-RMTase-producing isolates, including Enterobacterales, non-fermenting bacteria, and carbapenemase producers. METHODS: In total, 164 non-duplicate 16S-RMTase-producing isolates, including 84 Enterobacterales, 53 Acinetobacter baumannii and 27 Pseudomonas aeruginosa isolates, were included in the study. Whole-genome sequencing (WGS) was performed on all isolates with Illumina technology. The minimum inhibitory concentration (MIC) of apramycin was determined by broth microdilution with customized Sensititre plates (Thermo Fisher Scientific, Dardilly, France). RESULTS: We found that 95% (156/164) of the 16S-RMTase-producing isolates were susceptible to apramycin, with a MIC50 of 4 mg/L and a MIC90 of 16 mg/L, respectively. Resistance rates were higher in P. aeruginosa (11%) than in A. baumannii (4%) or Enterobacterales (4%) (P < 0.0001 for each comparison). Eight isolates were resistant to apramycin, including one isolate with an MIC >64 mg/L due to the acquisition of the aac(3)-IV gene. The genetic environment of the aac(3)-IV gene was similar to that in the pAH01-4 plasmid of an Escherichia coli isolate from chicken in China. CONCLUSION: Resistance to apramycin remains rare in 16S-RMTase-producing isolates. Apramycin may, therefore, be an interesting alternative treatment for infections caused by 16S-RMTase and carbapenemase producers.