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Detection of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens-associated corneal ulcers.
Cornea. 2008 Apr; 27(3):320-6.C

Abstract

PURPOSE

In microbial keratitis associated with contact lens use, Pseudomonas is the most common etiologic agent. The purpose of this study was to report on the microbiological findings of 8 P. aeruginosa strains isolated from contact lens-associated corneal ulcers.

METHODS

Scrapings from contact lens-related corneal ulcers were inoculated for culture. Identification and antibiotic susceptibility testing were performed by using the Vitek system (bioMérieux). The Pseudomonas' ability to form biofilm; produce gelatinase, elastase, and alkaline protease; and adhere to and invade human corneal epithelial cells was studied. Polymerase chain reaction with enterobacterial repetitive intergenic consensus primers (ERIC-PCR) was used to establish clonal relationship between the different isolates.

RESULTS

All the strains showed multiple antibiotic resistance (resistance to 4 or more antibiotics), but all were susceptible to aminoglycosides and fluoroquinolones. Biofilm production was weak in 5 cases and absent in the remaining 3 cases. All isolates were able to produce alkaline protease and gelatinase but not elastase. Adherence to human corneal epithelial cells was poor (0-15 bacteria/cell) in 5 cases and medium (16-60 bacteria/cell) in 3 cases. Five isolates were found to be efficient invaders (>1000 CFU/mL). ERIC-PCR showed 8 different genetic patterns.

CONCLUSIONS

Because multiresistant Pseudomonas isolates are common, we recommend antibiotic susceptibility testing in all cases of Pseudomonas keratitis so that, if there is no response to initial empiric treatment, antibiotics can be modified according to susceptibility results. The ability to produce alkaline protease and gelatinase and invade the corneal epithelium may play a major role in the pathogenesis of contact lens-related P. aeruginosa keratitis. Also, ERIC-PCR seems to be an inexpensive, fast, reproducible, and discriminatory DNA typing tool for effective epidemiologic surveillance of P. aeruginosa isolates potentially transmissible between patients with ocular infections.

Authors+Show Affiliations

Institute of Ophthalmology, Section of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy. apinna@uniss.itNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

18362661

Citation

Pinna, Antonio, et al. "Detection of Virulence Factors in Pseudomonas Aeruginosa Strains Isolated From Contact Lens-associated Corneal Ulcers." Cornea, vol. 27, no. 3, 2008, pp. 320-6.
Pinna A, Usai D, Sechi LA, et al. Detection of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens-associated corneal ulcers. Cornea. 2008;27(3):320-6.
Pinna, A., Usai, D., Sechi, L. A., Molicotti, P., Zanetti, S., & Carta, A. (2008). Detection of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens-associated corneal ulcers. Cornea, 27(3), 320-6. https://doi.org/10.1097/ICO.0b013e31815c5a3f
Pinna A, et al. Detection of Virulence Factors in Pseudomonas Aeruginosa Strains Isolated From Contact Lens-associated Corneal Ulcers. Cornea. 2008;27(3):320-6. PubMed PMID: 18362661.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Detection of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens-associated corneal ulcers. AU - Pinna,Antonio, AU - Usai,Donatella, AU - Sechi,Leonardo A, AU - Molicotti,Paola, AU - Zanetti,Stefania, AU - Carta,Arturo, PY - 2008/3/26/pubmed PY - 2008/5/9/medline PY - 2008/3/26/entrez SP - 320 EP - 6 JF - Cornea JO - Cornea VL - 27 IS - 3 N2 - PURPOSE: In microbial keratitis associated with contact lens use, Pseudomonas is the most common etiologic agent. The purpose of this study was to report on the microbiological findings of 8 P. aeruginosa strains isolated from contact lens-associated corneal ulcers. METHODS: Scrapings from contact lens-related corneal ulcers were inoculated for culture. Identification and antibiotic susceptibility testing were performed by using the Vitek system (bioMérieux). The Pseudomonas' ability to form biofilm; produce gelatinase, elastase, and alkaline protease; and adhere to and invade human corneal epithelial cells was studied. Polymerase chain reaction with enterobacterial repetitive intergenic consensus primers (ERIC-PCR) was used to establish clonal relationship between the different isolates. RESULTS: All the strains showed multiple antibiotic resistance (resistance to 4 or more antibiotics), but all were susceptible to aminoglycosides and fluoroquinolones. Biofilm production was weak in 5 cases and absent in the remaining 3 cases. All isolates were able to produce alkaline protease and gelatinase but not elastase. Adherence to human corneal epithelial cells was poor (0-15 bacteria/cell) in 5 cases and medium (16-60 bacteria/cell) in 3 cases. Five isolates were found to be efficient invaders (>1000 CFU/mL). ERIC-PCR showed 8 different genetic patterns. CONCLUSIONS: Because multiresistant Pseudomonas isolates are common, we recommend antibiotic susceptibility testing in all cases of Pseudomonas keratitis so that, if there is no response to initial empiric treatment, antibiotics can be modified according to susceptibility results. The ability to produce alkaline protease and gelatinase and invade the corneal epithelium may play a major role in the pathogenesis of contact lens-related P. aeruginosa keratitis. Also, ERIC-PCR seems to be an inexpensive, fast, reproducible, and discriminatory DNA typing tool for effective epidemiologic surveillance of P. aeruginosa isolates potentially transmissible between patients with ocular infections. SN - 0277-3740 UR - https://www.unboundmedicine.com/medline/citation/18362661/Detection_of_virulence_factors_in_Pseudomonas_aeruginosa_strains_isolated_from_contact_lens_associated_corneal_ulcers_ DB - PRIME DP - Unbound Medicine ER -