Genomic Determinants of Pathogenicity and Antimicrobial Resistance of Nosocomial Acinetobacter baumannii Clinical Isolates of Hospitalized Patients (2019–2021) from a Sentinel Hospital in Hangzhou, China

Abstract

Purpose

Acinetobacter baumannii (A. baumannii or AB) is one of the most opportunistic, nosocomial pathogens threatening public healthcare across countries. A. baumannii has become a primary growing concern due to its exceptional ability to acquire antimicrobial resistance (AMR) to multiple antimicrobial agents which is increasingly reported and more prevalent every year. Therefore, there is an urgent need to evaluate the AMR knowledge of A. baumannii for effective clinical treatment of nosocomial infections. This study aimed to investigate the clinical distribution AMR phenotypes and genotypes, and genomic characteristics of A. baumannii isolates recovered from hospitalized patients of different clinical departments of a sentinel hospital to improve clinical practices.

Methods

A total of 123 clinical isolates were recovered from hospitalized patients of different clinical departments during 2019–2021 to analyze AMR patterns, and further subjected to whole-genome sequencing (WGS) investigations. Multi-locus sequence typing (MLST), as well as the presence of antimicrobial-resistant genes (ARGs), virulence factor genes (VFGs) and insertion sequences (ISs) were also investigated from WGS data.

Results

The results highlighted that A. baumannii clinical isolates had shown a high AMR rate, particularly from the intensive care unit (ICU), towards routinely used antimicrobials, ie, β-lactams and fluoroquinolones. ST2 was the most prevalent ST in the clinical isolates, it was strongly associated to the resistance of cephalosporins and carbapenems, with bla_OXA-23 and bla_OXA-66 being the most frequent determinants; moreover, high carrier rate of VFGs was also observed such as all strains containing the ompA, adeF, pgaC, lpsB, and bfmR genes.

Conclusion

Acinetobacter baumannii clinical isolates are mostly ST2 with high rates of drug resistance and carrier of virulence factors. Therefore, it requires measurements to control its transmission and infection.

Keywords:

• Acinetobacter baumannii
• antimicrobial resistance
• genetic determinants
• virulence factors
• whole-genome sequencing

Data Sharing Statement

The datasets generated for this study can be found in the NCBI Bioproject with the accession number PRJNA873189.

Ethics Approval and Informed Consent

This study was approved by the Ethics Committee of Hangzhou First People’ Hospital [Approval numbers 2019-020-01]. Waiving of informed consent was given due to the retrospective, non-interventional study design. All patient’s data were collected anonymously and ensured about the confidentiality of their information.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant number 81930111), the Natural Science Foundation of Zhejiang Province (grant number LZ22H190002), the Health & Medical Sci-Tech Project of Hangzhou Municipal Health Commission (Z2021005), the Science and Technology Project of Hangzhou Municipal (grant number 202204A001), and the Health & Medical Sci-Tech Project of Health Commission of Zhejiang Province (grant number 2020KY206, 2022PY016).

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; agreed to submit to the current journal; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.