Correlation of type 3 secretion system genes with antimicrobial resistance in Pseudomonas aeruginosa: A unique clinical signature.

Authors

Farkhanda Afaque, Aliya Hayat, Somia Gul, Ayaz Ahmed, Mahmooda Kazmi

Published in

Journal of Taibah University Medical Sciences. Volume 21. Issue 4. Pages 746-758. Epub Jul 09, 2026.

Abstract

Pseudomonas aeruginosa is a well-known opportunistic pathogen with intrinsic multidrug resistance, extensive drug resistance, and multiple virulence factors, making hospital-acquired infections therapy resistant. The type 3 secretion system (T3SS) and its four effector proteins, i.e., ExoS, ExoT, ExoU, and ExoY, have invasive and cytotoxic effects that lead to host cell death. The significant correlations of exo genes with the resistance attributes of P. aeruginosa in disease progression were evaluated in the current study.
In total, 102 random clinical strains of Pseudomonas were collected from local pathological settings in Karachi, Pakistan. The strains were conventionally characterized using Pseudomonas isolation agar. Biochemical identification was conducted by using QTS-24 strips to confirm P. aeruginosa, and molecular confirmation based on species-specific 16S rRNA genes. The strains were categorized based on antimicrobial sensitivity testing in accordance with CLSI guidelines. The virulence profiles of the selected multidrug-resistant (MDR) strains were obtained using the specific T3SS exo gene by PCR.
Among 102 strains, 44 strains were identified as P. aeruginosa. According to the drug resistance profiles for the P. aeruginosa strains, 80.6% (25/31) were MDR and 16.1% (6/31) were extremely drug resistant (XDR) based on multiple antibiotic resistance index (MARi) evaluations. The highest sensitivity was recorded for meropenem with 84%, followed by piperacillin with 66% and ertapenem with 64%. The maximum resistance was to colistin with 100% antimicrobial susceptibility testing (AST) where the resistance was characterized by a minimum inhibitory concentration value ≥ 4 μg/mL, and tigecycline and aztreonam with 82%. The most prevalent exo genes were exoS at 43%, followed by exoT at 30%, exoU at 13%, and exoY at 9%. Statistically significant correlations were found between exo genes and MARi resistotype groups, with a p-value <0.05 and Carmer's value of 1.00.
In this study, significant correlations were detected between drug resistance and T3SS exo genes, which are a severe threat to the healthcare sector, and systemic surveillance is necessary to ensure good health and well-being.

PMID:
42472007
Bibliographic data and abstract were imported from PubMed on 19 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.