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Updated: Jul 17, 2026
Screening Foodstuffs for Class 1 Integrons and Gene Cassettes
Published on: June 19, 2015
[Detection of class I integron and its relation to antimicrobial resistance of Shigella flexneri in children]
Hui Yu1, Xiao-hong Wang, Ying-zi Ye
1Department of Infectious Diseases, Laboratory of Bacteriology, Children's Hospital of Fudan University, Shanghai 200032, China.
Insights
Class I integron is prevalent in pediatric Shigella flexneri strains, detected in 90.2% of isolates. Integron carriage is significantly associated with increased antimicrobial resistance, particularly to ampicillin and chloramphenicol.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Context:
- Shigella flexneri is a significant cause of bacterial diarrhea in children.
- Integrons are genetic elements that contribute to antimicrobial resistance.
- Class I integrons are commonly found in clinical settings.
Purpose:
- To determine the prevalence of class I integrons in Shigella flexneri isolated from children.
- To investigate the association between class I integron carriage and antimicrobial resistance in Shigella flexneri.
Summary:
- Class I integron genes (intI1) were detected in 90.2% of 51 Shigella flexneri strains from children with diarrhea.
- The presence of class I integrons correlated with significantly higher resistance rates to ampicillin and chloramphenicol.
- Specific integron gene cassettes, including qacEDelta1-sul1 and ant(3'')-I, were identified in a substantial proportion of isolates.
Impact:
- This study highlights the high prevalence of class I integrons in pediatric Shigella flexneri, underscoring their role in the dissemination of antimicrobial resistance.
- Findings emphasize the need for monitoring integron-associated resistance in clinical Shigella flexneri isolates to guide effective treatment strategies.
Objective:
To investigate class I integron of Shigella flexneri, its prevalence in children, and its relation to bacterial resistance to antimicrobial agents.
Methods:
Totally 51 strains of Shigella flexneri were isolated from fecal samples of children suffering from bacterial diarrhea seen between June 2004 and November 2004 at Children's Hospital of Fudan University. Polymerase chain reaction (PCR) was employed to amplify various integron markers, including intI1, gene cassette region and 3' conserved region of class I intrgron; susceptibility of Shigella flexneri strains to 7 antimicrobial agents was determined by K-B (Kriby-Bauer) method.
Results:
Forty-six strains of Shigella flexneri had intI gene with a positive rate of 90.2% (46/51); 24 strains of Shigella flexneri were positive for qacEDelta1-sul1, the positive rate was 47.1% (24/51); proportion of the isolates positive for all the three regions of class I integron was 43.1% (22/51); 46 strains of intI positive Shigella flexneri were all positive for ant (3'')-I. Among 46 strains of intI positive isolates, proportions of the isolates positive and negative for qacEDelta1-sul1 were 47.8% (22/46) and 52.2% (24/46), respectively. In the class I integron positive Shigella flexneri, the resistance rates of ampicillin (chi(2) = 10.13, P < 0.01) and chloramphenicol (chi(2) = 19.97, P < 0.01) were significantly higher than those in the class I integron-negative group.
Conclusions:
Class I integron was detected in 90.2% of Shigella flexneri in children; carriage of class I integron is related to antimicrobial resistance of Shigella flexneri.
