Plasmid-mediated ROB-1 beta-lactamase in Pasteurella multocida from a human specimen

Area of Science:

• Microbiology
• Genetics
• Antimicrobial Resistance

Background:

• Pasteurella multocida is a significant pathogen in both humans and animals.
• Beta-lactam antibiotics are crucial for treating bacterial infections.
• Antibiotic resistance in bacteria poses a growing global health threat.

Purpose of the Study:

• To investigate the mechanism of beta-lactam resistance in a human isolate of Pasteurella multocida.
• To characterize the genetic element responsible for the observed resistance.

Main Methods:

• Phenotypic testing for beta-lactam antibiotic susceptibility.
• Enzyme assays to detect beta-lactamase production.
• Plasmid DNA isolation and characterization using restriction enzyme digestion (Sau3A).
• Gene hybridization using a probe specific for the blaROB-1 gene.

Main Results:

• The human Pasteurella multocida isolate exhibited resistance to beta-lactam antibiotics.
• ROB-1 beta-lactamase production was identified as the cause of resistance.
• The beta-lactamase gene (blaROB-1) was located on a 4.3-kb plasmid.
• The plasmid showed a close genetic relationship to a plasmid from a bovine Pasteurella strain based on restriction profiles and hybridization.

Conclusions:

• ROB-1 beta-lactamase confers beta-lactam resistance in this human Pasteurella multocida isolate.
• The genetic basis of resistance involves a plasmid similar to those found in animal strains, suggesting potential transmission.
• Understanding the epidemiology and genetic relatedness of resistance mechanisms is vital for controlling antimicrobial resistance.