Emergence of aztreonam/avibactam and tigecycline-resistant Pseudomonas putida group Co-producing blaIMP-1, blaAFM-4 and blaOXA-1041 with a novel sequence type ST268 in Southwestern China

• Published in: Microbial pathogenesis Vol. 192; p. 106668
• Main Authors: Jian, Chunxia, Ye, Caihong, Guo, Tongtong, Hao, Jingchen, Ding, Yinhuan, Xiao, Xue, Xie, Wenchao, Zeng, Zhangrui, Liu, Jinbo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2024
• Subjects: AFM-4; Aztreonam-avibactam; Carbapenem-resistant Pseudomonas putida; OXA-1041; tmexCD-toprJ; tmexCD-toprJ; Aztreonam-avibactam; Carbapenem-resistant Pseudomonas putida; AFM-4; OXA-1041
• DOI: 10.1016/j.micpath.2024.106668
• ISSN: 0882-4010; 1096-1208

The emergence of carbapenem-resistant Pseudomonas putida (CRPP) has raised public awareness. This study investigated two strains from the Pseudomonas putida group that were resistant to carbapenem, tigecycline, and aztreonam-avibactam (ATM−AVI), with a focus on their microbial and genomic characteristics. We assessed the antibiotic resistance profile using broth dilution, disk diffusion, and E-test methods. Efflux pump phenotype testing and real-time quantitative PCR were employed to evaluate efflux pump activity in tigecycline resistance, while polymerase chain reaction was utilized to detect common carbapenem genes. Additionally, whole-genome sequencing was performed to analyze genomic characteristics. The transferability of blaIMP-1 and blaAFM-4 was assessed through a conjugation experiment. Furthermore, growth kinetics and biofilm formation were examined using growth curves and crystal violet staining. Both strains demonstrated resistance to carbapenem, tigecycline, and ATM-AVI. Notably, NMP can restore sensitivity to tigecycline. Subsequent analysis revealed that they co-produced blaIMP-1, blaAFM-4, tmexCD-toprJ, and blaOXA-1041, belonging to a novel sequence type ST268. Although they were closely related on the phylogenetic tree, they exhibited different levels of virulence. Genetic environment analysis indicated variations compared to prior studies, particularly regarding the blaIMP-1 and blaAFM-4 genes, which showed limited horizontal transferability. Moreover, it was observed that temperature exerted a specific influence on their biological factors. We initially identified two P. putida ST268 strains co-producing blaIMP-1, blaAFM-4, blaOXA-1041, and tmexCD-toprJ. The resistance to tigecycline and ATM-AVI can be attributed to the presence of multiple drug resistance determinants. These findings underscore the significance of P. putida as a reservoir for novel antibiotic resistance genes. Therefore, it is imperative to develop alternative antibiotic therapies and establish effective monitoring of bacterial resistance. •Two strains co-producing blaIMP-1, blaAFM-4, blaOXA-1041, and tmexCD-toprJ.•The genetic environment of these genes showed variations compared to earlier studies.•The efflux pump was involved in the resistance of two strains to tigecycline.•0.005 M EDTA can restore the sensitivity of two strains to aztreonam-avibactam.•This was the first discovery of blaAFM-4 and blaOXA-1041 in Pseudomonas putida.