Comparative histopathological study of the effect of three strains of pseudomonas aeruginosa on the rabbit's cornea

Three different strains of Pseudomonas aeruginosa were inoculated on scratched rabbit[s] cornea as an experimental model to study their histopathological effect. After one week light microscopic examination of the cornea affected by the haemolytic strain showed severe inflammatory reaction which led to occlusive vasculitis near descemet[s] membrane. Again the degenerated endothelial cells were interspersed, as well, with acute inflammatory cells. Some electron microscopic findings were common in corneas infected by the proteolytic strain as well as the lecithinase positive strain. They were in the form of widened intercellular spaces, disruption of cell membranes and degenerated forms of intracytoplasmic organelles. However, there was elastoid degeneration of the collagen in corneas affected by the proteolytic strain while collagen in corneas affected by lecithinase positive strain exhibited clear lyses. A striking finding was the distribution of tiny pigments all through the corneaI layers except the epithelial cells. Since this kind of corneal infection induced by three strains of Pseudomonas aeruginosa respond in three severe different mechanisms, it can be particularly dangerous to persons who have experienced industrial accidents, corneal abrasions induced by hard or soft contact lens or to immuno-compromised patients

Infantile dacryocystitis

Fifty infants aged from two months to one year were examined clinically and microbiologically; forty of them had inflammation of their lacrima sacs with positive lacrimal regurgitation test. The other ten infants had healthy eyes and were considered as normal controls. Swabs were taken from eyes of dacryocstitis, healthy eyes of dacryocystitis cases and eyes of normal control. Four swabs were taken from each eye. One for Gram stain, one for aerobic organisms, one for anaerobic organisms and the fourth one for fungal culture. Staphylococcus epidermidis was the most common organism isolated [52.5%], followed by streptococcus pneumoniae, 27.5% staphylococcus aureus, 12.5% streptococcus hemolyticus in 10%, etc. It is worthy to mention that some cases yielded more than one type of microorganism e.g. Staphylococcus epidermidis streptococcus pneumoniae and staphylococcus aures, etc,. Various of fungi were demonstracted in this work. They were either isolated alone [12.5%] or in combination with different types of bacteria [12.5%], Candia abicans and Aspergillus were the most common fungi siolated. Regarding the flora of the healthy eyes, there was no significant difference in bacterial flora of normal controls and healthy eyes of cases of dacryocysitis, According to micobiological findings and results of antibiogram, it is recommended to start treatment with erythromycin, keflex and nebcin till the results of culture and sensitivity are available