Keratitis caused by Pseudomonas aeruginosa: treatment in the experiment (original) (raw)
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The pathogenesis of bacterial keratitis: studies with Pseudomonas aeruginosa
Clinical and Experimental Optometry, 2002
Bacterial infection of the cornea (Figure 1) is considered a relatively rare but serious medical condition requiring urgent medical attention because of the potential for reduced vision or even vision loss in the affected eye(s). Predisposing factors for infectious keratitis include the extended or overnight wear of soft contact lenses; 1,2 ocular surgical procedures, for example, LASIK; 3 ocular disease and ocular injury. 4 Bacteria isolated from patients with keratitis include a variety of gram-positive and gram-negative organisms such as Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and Serratia spp. Infecting bacteria are likely to be derived from environmental sources, patients' normal skin and nasopharyngeal flora, contact lens care solutions or lens cases, topical drug or irrigation solutions or ocular instruments. Continued incidence of infectious keratitis, 1,2,4 increasing antibiotic REVIEW The pathogenesis of bacterial keratitis: studies with Pseudomonas aeruginosa
Modeling of bacterial keratitis of Pseudomonas aeruginosa etiology in the experimental model
2021
Background: Pseudomonas aeruginosa keratitis demonstrates an aggressive course, high resistance to antimicrobial therapy, and it also leads to a significant reduction of visual acuity. The purpose of our study was to develop an experimental model of Pseudomonas aeruginosa keratitis and investigate clinical features of corneal lesions in rabbits. Material and methods: A total of 32 rabbits were divided randomly into three groups. The animals of the experimental group 1 (8 rabbits) underwent scarification of the cornea and instillation of archival strain suspension of P. aeruginosa into the conjunctival sac. In group 2 (12 rabbits), corneal de-epithelialization followed by instillation of microbial suspension was performed. In animals of group 3 (12 rabbits), after the de-epithelialization followed by instillation of one-day suspension of the pathogen, the cornea’s surface was covered with a sterile soft contact lens for 16–24 hours. In half of the animals (6 rabbits), the contact len...
Translational Vision Science & Technology
This study analyzed the susceptibilities of 17 contact lens (CL)-related keratitis isolates of Pseudomonas aeruginosa from Australia to antibiotics, multipurpose contact lens disinfecting solutions (MPDS), and disinfectants through minimum inhibitory (MIC) and minimum bactericidal concentrations. Methods: Antibiotics included ciprofloxacin, levofloxacin, gentamicin, tobramycin, piperacillin, imipenem, ceftazidime, and polymyxin B. The MPDS OPTI-FREE PureMoist, Complete RevitaLens OcuTec, Biotrue, and Renu Advanced Formula and the constituent disinfectants; alexidine dihydrochloride, polyquaternium-1, polyaminopropyl biguanide, and myristamidopropyl dimethylamine (Aldox) were analyzed. The combined susceptibility of disinfectants based on the MPDS formulation was assessed through fractional inhibitory concentration. Results: All isolates were susceptible to levofloxacin and gentamicin, 2/17 were resistant to ciprofloxacin; 1/17 was resistant to tobramycin, piperacillin, and polymyxin; and 3/17 were resistant to ceftazidime whereas 12/17 were resistant to imipenem. Of the four MPDSs, for Renu Advanced Formula 8/17 strains have an MIC ≤ 11.36 for OPTI-FREE PureMoist 14/17 strains have an MIC ≤ 11.36% for Complete RevitaLens 9/17 strains have an MIC ≤ 11.36, and for Biotrue 5/17 strains have MIC = 11.36. All strains were killed by 100% MPDS. At the concentrations used in the MPDSs, individual disinfectants were not active. From three tested isolates, no synergy was found in dual combinations of disinfectants. However, synergy was found for triple combination of disinfectants for three tested strains. Conclusions: Australian CL-related isolates of P aeruginosa were susceptible to most antibiotics. There was variability in susceptibility to different MPDS. Individual disinfectant excipients had limited activity. The combination of the disinfectants showed synergy, antagonism, and no interaction. Translational Relevance: This study will help to choose better preventive and treatment measures for microbial keratitis.
International journal of research publications, 2022
Background: Pseudomonas aeruginosa have a significant proportion of the causes of bacterial keratitis. Corneal ulcers infected with P. aeruginosa are more severe than other bacterial corneal ulcers. P. aeruginosa is often associated with keratitis that results from wearing contact lenses, which eventually leads to corneal ulcers. This study aims to determine the differences in the results of the antibiotic sensitivity test of P. aeruginosa from corneal scraping specimens of keratitis patients using contact lenses and non-contact lens users at RSUD dr. Soetomo. Methods: This study is an observational analytic study of secondary data from corneal scraping cultures of patients with keratitis infected with P. aeruginosa at Dr. Soetomo Hospital period January 2017-December 2020. Results: The total number of samples included in the inclusion criteria was 46 samples. Of the total sample, 8 (17.40%) were contact lens users and 38 (82.60%) were non-contact lenses. The male sex and female sex each as much as 50%. The distribution of sample age categories for 0-20 years was 21.74%, 21-40 years was 13.04%, 41-60 years was 41.30%, and >60 years was 23.91%. Based on samples from 8 contact lens patients, antibiotics were found to be 100% sensitive, namely
Antimicrobial Agents and Chemotherapy, 1993
This study was conducted to determine whether the age of the host influences the pathogenesis and therapeutic outcome of drug-treated Pseudomonas aeruginosa keratitis. Young (3- to 5-month-old) and old (1.5- to 3-year-old) rabbits were intrastromally infected with P. aeruginosa ATCC 27853. Sixteen hours later, rabbits in both age subpopulations were divided into three groups and treated topically as follows: group 1, phosphate-buffered saline; group 2, 0.3% ciprofloxacin; and group 3, 0.3% ciprofloxacin, 1.0% prednisolone, and 0.03% flurbiprofen. Drops were given every 15 min for 1 h and then every 30 min for 9 h. At 27 h postinfection, ocular pathology was graded with a slit lamp examination (SLE) scoring system. Aqueous humor was collected for ciprofloxacin quantitation, and corneas were harvested for bacterial enumeration and estimation of polymorphonuclear leukocytes. Young rabbits had more severe inflammation and pathology than old rabbits. At 27 h postinfection, SLE scores and...
Open Veterinary Journal, 2016
The purpose of this study was to evaluate the antibiotic susceptibility profile of Pseudomonas aeruginosa isolated from different animal species with septic ocular surface disease. Sixteen strains of P. aeruginosa were isolated from different species of animals (dog, cat, horse, penguin and brown bear) with ocular surface diseases such as conjunctivitis, keratocojnuctivits sicca and ulcerative keratitis. These isolates were tested against 11 different antimicrobials agents using the Kirby-Bauer disk-diffusion method. Minimum inhibitory concentrations (MICs) were determined using E-tests for two antibiotics (tobramycin and ciprofloxacin) commonly used in veterinary ophthalmology practice. Imipenem was the most effective antibiotic, with 100% of the strains being susceptible, followed by amikacin (87.5%), gentamicin, norfloxacin, gatifloxacin and polymyxin (both with 81.5%of susceptibility). MIC90 of ciprofloxacin was 2 µg/ml and the values found ranged from 0.094 µg/ml to 32 µg/ml. For tobramycin, MIC90 was 32 µg/ml and ranged from 0.25 µg/ml to 256 µg/ml. The most effective in vitro antibiotic tested against P. aeruginosa in this study was imipenem, followed by amikacin. The 3 mg/ml eye drops commercially available ciprofloxacin presentations were in vitro effective against all strains tested in this study if applied up to 4 hours after instillation. Whereas for tobramycin the 3 mg/ml eye drops commercial presentations were not in vitro effective against some strains isolated in this study. Thus for ocular infections with P. aeruginosa when using tobramycin the ideal recommendation would be to either use eye drops with higher concentrations or decrease the frequency intervals from four to a minimum of every two hours.
Phenotype of Pseudomonas aeruginosa Isolates Causing Corneal Infection Between 1997 and 2000
Cornea, 2003
Purpose. To investigate the relationship between functional phenotype of Pseudomonas aeruginosa and the associated human corneal infection. Methods. This was an experimental pilot study of patients presenting with corneal infections at the Jules Stein Eye Institute with presumed P. aeruginosa infection during the period from 12/30/97 to 9/1/00. Thirteen patients were admitted to the study based on positive identification of the causative pathogen as P. aeruginosa and patient consent. Data were collected (including bacterial cultures, lens wear schedule and care, gender and age, completed history questionnaire, clinical photographs). Statistical analysis of possible correlations was performed. Phenotypes of P. aeruginosa were determined, and clinical factors associated with infection were explored. Results. Both invasive and cytotoxic phenotypes of P. aeruginosa were isolated in equal proportion. Cytotoxic strains and invasive strains were found to be associated with patients younger than 50 years of age and older than 50 years of age, respectively. Conclusions. P. aeruginosa remains a significant pathogen in corneal infection, especially during contact lens wear. The age of the patient may influence the phenotype of P. aeruginosa causing infection. Since invasive and cytotoxic strains have different effects on corneal cells, treatment of the infection might require different approaches depending on this phenotype of the causative bacteria.
Infection and immunity
We have reported that some strains of Pseudomonas aeruginosa can enter corneal epithelial cells during experimental murine eye infection and when the cells are cultured in vitro. Following invasion, both the host cell and the intracellular bacteria can remain viable for up to 24 h. Others have reported that toxin-mediated damage of epithelial cells contributes to the pathogenesis of P. aeruginosa keratitis. To clarify the relationship between cell invasion and cytotoxicity, fourteen P. aeruginosa isolates were compared for their capacity to enter epithelial cells and for their ability to induce cytotoxicity. Bacterial invasion was quantified by gentamicin survival assays both in vivo and in vitro. Cytotoxicity was examined qualitatively by trypan blue exclusion assays and quantitatively by chromium release assays in vitro. A significant inverse correlation was found between the ability to induce cytotoxicity and epithelial cell invasion as measured by gentamicin survival assays. Both cytotoxic and noncytotoxic strains were identified among corneal and noncorneal isolates; all isolates that were not cytotoxic were capable of epithelial cell invasion. Efficient host cell invasion could not be demonstrated for cytotoxic strains; however, the gentamicin survival assay relies upon host cells retaining viability in order to yield useful results, and this may limit the effectiveness of this assay for testing epithelial cell invasion by cytotoxic strains. Since all of the corneal isolates that were tested were virulent in vivo, the results show that there are at least two different types of P. aeruginosa-induced disease, one caused by strains that are cytotoxic and the other involving bacteria that can enter epithelial cells and survive intracellularly without killing the host cell.
Journal of Medical Microbiology, 2008
Pseudomonas aeruginosa is one of the common pathogens associated with corneal infection, particularly in contact lens-related keratitis events. The pathogenesis of P. aeruginosa in keratitis is attributed to the production of virulence factors under certain environmental conditions. The aim of this study was to determine differences in the virulence factors of P. aeruginosa isolated from contact lens- and non-contact lens-related keratitis. Associations were assessed between type III secretion toxin-encoding genes, protease profiles, biofilm formation, serotypes and antibiotic-resistance patterns among 27 non-contact lens- and 28 contact lens-related P. aeruginosa keratitis isolates from Australia. Strains with a exoS +/exoU − genotype and a type I protease profile predominated in the non-contact lens-related keratitis isolates, whereas the exoS −/exoU + and a type II protease profile was associated with contact lens-related isolates (P<0.05). A strong biofilm formation phenotype...