Pseudomonas aeruginosa (Contact lens): Dose Response Models
Contents
General overview of Pseudomonas aeruginosa
Pseudomonas aeruginosa is a Gram-negative, aerobic rod belonging to the bacterial family Pseudomonadaceae. Like other members of the genus, Pseudomonas aeruginosa is a free-living bacterium, commonly found in soil and water. However, it occurs regularly on the surfaces of plants and occasionally on the surfaces of animals. Pseudomonas aeruginosa is an opportunistic pathogen, meaning that it exploits some break in the host defenses to initiate an infection. In fact, Pseudomonas aeruginosa is the epitome of an opportunistic pathogen of humans [1].
Pseudomonas aeruginosa generally invades the body or organs lacking natural defenses, and usually the infection are chronic rather than acute, evoking little systemic response. When introduced into the cornea, however, as in penetration by a foreign body or in contaminated medicines, it acts with extreme virulence, in many cases causing blindness and even necessitating enucleation [2]. It is the organism most frequently implicated in contact lens related keratitis [3].
Summary Data
Lawin-Brussel et al. (1993) studied the effect of Pseudomonas aeruginosa in experimental contact lens related microbial keratitis. Forty white New Zealand rabbits were used in the experiment. New and worn soft contact lenses soaked in 5 ml bacterial suspension of different concentration for an hour, then fitted into the eyes of the rabbit(one lense per rabbit). The clinical findings after seven days of contact lens wear and additional 48 hours of P. aeruginosa contaminated lens wear were recorded. The experimental dose unit was CFU/ml. However, Lawin-Brussel et al. (1993) had observed quantification of bacterial attachment on soft contact lens after an hour of soaking in different concentration of P. aeruginosa. Based on the figure, the bacterial attachment in a lens was calculated.
CFU/ml | CFU (per lens) |
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100 | 63.22 |
10000 | 2220.49 |
100000 | 13159.77 |
1000000 | 77991.7 |
10000000 | 86799.77 |
100000000 | 462219,6 |
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Optimization Output for experiment 299
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Optimization Output for experiment 300
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Optimization Output for pooled data (experiment 299 and 300)
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Summary
The animals with corneal ulceration and animals with severe stromal ulceration (with ring abscess and hypopyon) could be pooled. Hence a single pooled model could describe the distribution of both type of diseases due to contaminated contact lenses.
References
- ↑ Todar, K. (2012). Todar's Online Textbook of Bacteriology. Pseudomonas aeruginosa [1]
- ↑ Spencer, W. H. (1953). "PSEUDOMONAS AERUGINOSA INFECTIONS OF THE EYE." California Medicine 79(6): 438-443. Full text
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Lawin-Brüssel, C. A., M. F. Refojo, et al. (1993). "Effect of Pseudomonas aeruginosa Concentration in Experimental Contact Lens--Related Microbial Keratitis." Cornea 12(1): 10-18.PubMed Cite error: Invalid
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