Rapid, simple multi-locus variable number tandem repeat analysis: a reliable tool for Klebsiella pneumoniae outbreak...

Area of Science:

• Microbiology
• Epidemiology
• Genetics

Background:

• Nosocomial infections caused by Klebsiella pneumoniae are a growing concern due to increasing multi-drug resistance.
• There is a critical need for rapid and efficient typing tools to monitor the spread of K. pneumoniae strains.

Purpose of the Study:

• To evaluate a rapid multiplex polymerase chain reaction (PCR) method utilizing multi-locus variable number tandem repeat analysis (MLVA) as a screening tool.
• To determine the relatedness of Klebsiella pneumoniae strains within a short timeframe (<5 hours).

Main Methods:

• Assessed the discriminatory power of MLVA on 72 diverse K. pneumoniae isolates, including community, virulent, and resistant strains.
• Compared MLVA results with whole-genome sequencing (WGS) and multi-locus sequence typing (MLST) for validation.
• Investigated suspected outbreak strains and a case of relapsed meningitis.

Main Results:

• MLVA demonstrated a discriminatory power comparable to MLST, yielding 54 unique profiles among 72 unrelated isolates (Hunter-Gaston index 0.989).
• MLVA generally correlated well with sequence types (STs), with minor exceptions noted.
• MLVA analysis suggested a common source for five out of seven neonatal sepsis isolates, excluding two with distinct profiles.

Conclusions:

• The MLVA approach is a valuable, rapid, and dependable tool for epidemiological investigations, requiring basic molecular biology equipment.
• MLVA effectively identifies sporadic isolates and aids in initial outbreak screening.
• Further analysis using highly discriminatory methods like WGS is recommended for strains sharing the same MLVA type.