Correlation of Pseudomonas aeruginosa genotype with antibiotic susceptibility and clinical features of induced central keratitis

Elizabeth P Shen; Yi-Ting Hsieh; Hsiao-Sang Chu; Shan-Chwen Chang; Fung-Rong Hu

doi:10.1167/iovs.14-15241

Correlation of Pseudomonas aeruginosa genotype with antibiotic susceptibility and clinical features of induced central keratitis

Invest Ophthalmol Vis Sci. 2014 Dec 23;56(1):365-71. doi: 10.1167/iovs.14-15241.

Authors

Elizabeth P Shen¹, Yi-Ting Hsieh², Hsiao-Sang Chu², Shan-Chwen Chang³, Fung-Rong Hu²

Affiliations

¹ Department of Ophthalmology, Taipei Tzuchi Hospital, The Buddhist Tzuchi Medical Foundation, Taipei, Taiwan Department of Ophthalmology, National Taiwan University Hospital, Medical College, National Taiwan University, Taipei, Taiwan.
² Department of Ophthalmology, National Taiwan University Hospital, Medical College, National Taiwan University, Taipei, Taiwan.
³ Department of Infectious Disease, Department of Internal Medicine, National Taiwan University Hospital, Medical College, National Taiwan University, Taipei, Taiwan.

PMID: 25537202
DOI: 10.1167/iovs.14-15241

Abstract

Purpose: To determine the association of type III secretion system (T3SS) genotype with antibiotic susceptibility, serotypes, and clinical manifestation of centrally located Pseudomonas aeruginosa keratitis.

Methods: Clinical characteristics of P. aeruginosa keratitis cases from 2001 to 2011 were analyzed. Each strain was serotyped and genotyped for T3SS exotoxin genes. Antibiotic sensitivity and minimum inhibitory concentrations were determined with agar dilution method. Prognostic factors affecting final visual outcomes and time to re-epithelialization were analyzed using linear and Cox regression models.

Results: Forty-four invasive and 28 cytotoxic strains were identified. Invasive strains occurred mostly in males (P = 0.03) with older age (P = 0.009) and ocular surgery or trauma history (P = 0.006), poor presenting (P = 0.04) and final (P < 0.0001) best spectacle-corrected visual acuity (BSCVA), and larger infiltration size (P = 0.03). Cytotoxic strains were associated with contact lens wear (P < 0.0001). Poor prognostic factors for final BCVA after adjusting for sex, age, and contact lens wear included invasive strains (P = 0.02), larger infiltration area (P = 0.02), deeper infiltrations (P = 0.02), and presence of hypopyon (P = 0.09). Factors affecting complete re-epithelialization time included invasive strains (P = 0.02), infiltration area (P = 0.01), depth (P = 0.02), and hypopyon (P = 0.03) after adjusting for age and sex. Serotypes 2, 6, and 11 were more commonly found among all isolates. A trend to increased fluroquinolone resistance is noted for invasive strains, although not reaching statistically significant difference.

Conclusions: Cytotoxic strains are associated with contact lens wear while invasive strains are related to poor prognosis and increased resistance to fluoroquinolones. Clinicians should be aware of the two different genotypes of P. aeruginosa affecting prognosis.

Keywords: P. aeruginosa; antibiotic sensitivity; clinical outcome; serotype; type III secretion system.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Anti-Bacterial Agents / therapeutic use*
Cornea / microbiology*
Cornea / pathology
DNA, Bacterial / genetics*
Eye Infections, Bacterial / drug therapy
Eye Infections, Bacterial / genetics*
Eye Infections, Bacterial / microbiology
Female
Follow-Up Studies
Genotype
Humans
Keratitis / drug therapy
Keratitis / genetics*
Keratitis / microbiology
Male
Middle Aged
Pseudomonas Infections / drug therapy
Pseudomonas Infections / genetics*
Pseudomonas Infections / microbiology
Pseudomonas aeruginosa / genetics*
Pseudomonas aeruginosa / isolation & purification
Retrospective Studies

Substances

Anti-Bacterial Agents
DNA, Bacterial