A study on transferable R-plasmids among Shigella species at Lucknow

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Shigella infections remain a significant public health concern, particularly in developing countries.
• Understanding the prevalence of different Shigella serotypes and their antimicrobial susceptibility patterns is crucial for effective treatment and control.
• Limited data exists on the current serotype distribution and resistance profiles of Shigella strains in India.

Purpose of the Study:

• To determine the predominant Shigella serotypes circulating in India.
• To assess the antimicrobial susceptibility patterns of these Shigella strains.
• To investigate the role of R plasmids in the transfer of resistance.

Main Methods:

• A total of 500 Shigella strains were collected and characterized.
• Serotyping was performed to identify predominant serotypes.
• Antimicrobial susceptibility testing was conducted using standard methods.
• R plasmid extraction and transfer studies were performed using E. coli K-12 as a recipient.

Main Results:

• Shigella flexneri (48.4%) was the most prevalent serotype, followed by Shigella dysenteriae (30.6%).
• All tested strains were sensitive to nalidixic acid, gentamicin, kanamycin, neomycin, and furazolidine.
• Varying degrees of resistance were observed against streptomycin, chloramphenicol, tetracycline, and ampicillin.
• R plasmid transfer was successfully demonstrated in E. coli K-12.

Conclusions:

• Shigella flexneri is the dominant serotype in India, necessitating targeted surveillance and control measures.
• While some antibiotics remain effective, emerging resistance to commonly used drugs like ampicillin highlights the need for continuous monitoring.
• The presence and transfer of R plasmids contribute to the dissemination of antimicrobial resistance among Shigella strains.