Antimicrobial Resistance Profiling and Genome Analysis of the penA-60.001 Neisseria gonorrhoeae Clinical Isolates in China in 2021.

BACKGROUND: Neisseria gonorrhoeae antimicrobial resistance (AMR) is an urgent public health threat. With dissemination of FC428-related clones, the efficacy of ceftriaxone has become controversial. METHODS: Agar dilution and whole genome sequencing were used to analyze AMR. RESULTS: High resistance to penicillin (75.2%), tetracycline (87.9%), ciprofloxacin (98.3%), ceftriaxone (8.9%), cefixime (14.3%), and azithromycin (8.6%) was observed among 463 isolates first collected in China in 2021. All penA-60.001 clones exhibited resistance to ceftriaxone or cefixime, and 1 of the 12 cases was resistant to azithromycin. ngMAST and ngSTAR of penA-60.001 isolates showed that single-nucleotide polymorphisms in the porB, tbpB, ponA, gyrA, and parC genes were the major causes of different sequence types. MLST-7365 (n = 5) and MLST-1903 (n = 3) were main genotypes, and the other 4 strains featured MLST-10314, MLST-13871, MLST-7827 and MLST-1600. Furthermore, resistance markers (eg, penA, blaTEM-1, blaTEM-135) and virus factors were detected. Most penA-60.001 strains were fully mixed with global FC428-related clones; 2021-A2 and F89 had the same origin; and 2021-A1 exhibited a unique evolutionary trajectory. CONCLUSIONS: Results provide the first demonstration of extremely severe AMR rates of N gonorrhoeae in China in 2021, particularly strains with ceftriaxone decreased susceptibility. The sustained transmission of penA-60.001 subclones might further threaten treatment effectiveness.

Molecular typing, and integron and associated gene cassette analyses in Acinetobacter baumannii strains isolated from clinical samples.

The present study aimed to investigate the association between drug resistance and class I, II and III integrons in Acinetobacter baumannii (ABA). Multilocus sequence typing (MLST) is a tool used to analyze the homology among house-keeping gene clusters in ABA and ABA prevalence and further provides a theoretical basis for hospitals to control ABA infections. A total of 96 clinical isolates of non-repeating ABA were harvested, including 74 carbapenem-resistant ABA (CRABA) and 22 non-CRABA strains, and used for bacterial identification and drug susceptibility analysis. Variable regions were sequenced and analyzed. Then, 7 pairs of housekeeping genes were amplified and sequenced via MLST and sequence alignment was performed against the Pub MLST database to determine sequence types (STs) strains and construct different genotypic evolutionary diagrams. The detection rate of CRABA class I integrons was 13.51% (10/74); no class II and III integrons were detected. However, class I, II and III integrons were not detected in non-CRABA strains. The variable regions of 9 of 10 class I integrons were amplified and 10 gene cassettes including aacC1, aac1, aadDA1, aadA1a, aacA4, dfrA17, aadA5, aadA1, aadA22 and aadA23 were associated with drug resistance. The 96 ABA strains were divided into 21 STs: 74 CRABA strains containing 9 STs, primarily ST208 and ST1145 and 22 non-CRABA strains containing 18 STs, primarily ST1145. Class I integrons are a critical factor underlying drug resistance in ABA. CRABA and non-CRABA strains differ significantly; the former primarily contained ST208 and ST1145, and the latter contained ST1145. Most STs were concentrated in intensive care units (ICUs) and the department of Neurology, with the patients from the ICUs being the most susceptible to bacterial infection. In the Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, ABA is potentially horizontally transmitted and MLST can be used for clinical ABA genotyping.