Draft Genome Sequence of Multidrug-Resistant Acinetobacter baumannii smu isolated from a Bloodstream Infection in
Rekha Sharma1, Rohit Das2, Yezey Rikzing Bhutia3
1Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, 5 th Mile, Tadong, Gangtok, Sikkim 737102, India.
Abstract:
Septicemia remains a major cause of death in intensive care units and its treatment is increasingly challenged by multidrug-resistant pathogens. This study investigated bloodstream infections in 89 ICU patients at a tertiary hospital in Sikkim where the Neonatal ICU showed the highest burden. Acinetobacter baumannii was the predominant pathogen, including 13 MDR isolates. One highly resistant isolate, A. baumannii smu was selected for whole-genome sequencing. The smu strain had a genome size of 4.0 Mbp, assembled into three contigs with 182× coverage, an N50 of 3.98 Mb, and a GC content of 39.16%. Nineteen resistance genes were identified including β-lactamases (ADC-15B, OXA-98), aminoglycoside-modifying enzymes, and multiple efflux pumps. Virulence factors included acinetobactin-mediated iron uptake, biofilm-associated genes, OmpA, and phospholipases. The genome also harbored mobile genetic elements including insertion sequences and prophages. Pangenome analysis revealed 13 distinct genes associated with stress, tolerance, stability of plasmids, and possible resistance. This study provides a comprehensive genomic characterization of an MDR A. baumannii isolate from Sikkim, revealing its extensive resistance and virulence features, and providing baseline genomic data to support improved antibiotics use and infection control in the region.
Insights
Multidrug-resistant Acinetobacter baumannii infections are a critical threat in intensive care units (ICUs). Genomic analysis of a highly resistant strain from Sikkim reveals extensive resistance and virulence factors, aiding infection control strategies.
Area of Science:
- Microbiology
- Genomics
- Infectious Diseases
Background:
- Septicemia is a leading cause of death in intensive care units (ICUs).
- Multidrug-resistant (MDR) pathogens increasingly complicate septicemia treatment.
- The Neonatal ICU in Sikkim showed a high burden of bloodstream infections.
Purpose of the Study:
- To investigate bloodstream infections in ICU patients in Sikkim.
- To perform whole-genome sequencing of a highly resistant MDR Acinetobacter baumannii isolate.
- To characterize the genomic features, resistance, and virulence factors of the isolate.
Main Methods:
- Studied 89 ICU patients in a tertiary hospital in Sikkim.
- Identified Acinetobacter baumannii as the predominant pathogen.
- Conducted whole-genome sequencing on a selected MDR A. baumannii strain.
Main Results:
- Acinetobacter baumannii was the predominant pathogen, with 13 MDR isolates found.
- The sequenced smu strain (4.0 Mbp genome) possessed 19 resistance genes (e.g., β-lactamases, efflux pumps).
- Virulence factors included iron uptake systems, biofilm genes, OmpA, and phospholipases; mobile genetic elements were also identified.
Conclusions:
- Comprehensive genomic characterization of MDR A. baumannii from Sikkim.
- Identified extensive resistance and virulence mechanisms.
- Provides baseline genomic data for improved antibiotic use and infection control in the region.
