Multiple antimicrobial resistance in plague: an emerging public health risk

Area of Science:

• Microbiology
• Genetics
• Public Health

Background:

• Antimicrobial resistance in Yersinia pestis, the plague bacterium, is uncommon but presents a significant biodefense and public health risk.
• The identification of the first multidrug-resistant (MDR) Y. pestis strain (IP275) in 1995 revealed a self-transmissible plasmid (pIP1202) conferring resistance to key anti-plague antimicrobials.

Purpose of the Study:

• To investigate the origin and dissemination of the MDR plasmid pIP1202 found in Yersinia pestis.
• To determine the prevalence of the pIP1202-like plasmid backbone in other bacterial pathogens, particularly those associated with agriculture and retail meat products.

Main Methods:

• Comparative DNA sequence analysis of Y. pestis plasmid pIP1202 against known IncA/C plasmids.
• Detection of the pIP1202-like plasmid backbone in MDR enterobacterial pathogens isolated from retail meat samples across the United States.

Main Results:

• The Y. pestis pIP1202 plasmid shares a highly similar IncA/C plasmid backbone with MDR plasmids from Salmonella enterica and Yersinia ruckeri, suggesting a common ancestor.
• The pIP1202-like plasmid backbone was identified in MDR enterobacteria from various retail meat products (beef, chicken, turkey, pork) across multiple US states between 2002 and 2005.

Conclusions:

• A common plasmid backbone is widely distributed among MDR zoonotic pathogens linked to agriculture.
• This reservoir of mobile antimicrobial resistance genes poses a significant public health concern due to its potential to spread to Y. pestis and other human and zoonotic pathogens.