|Year : 1976 | Volume
| Issue : 4 | Page : 13-17
Invitro activity of Framycetin and Gentamicin against microbes producing ocular infection
VM Mahajan, SK Angra
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
V M Mahajan
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mahajan V M, Angra S K. Invitro activity of Framycetin and Gentamicin against microbes producing ocular infection. Indian J Ophthalmol 1976;24:13-7
|How to cite this URL:|
Mahajan V M, Angra S K. Invitro activity of Framycetin and Gentamicin against microbes producing ocular infection. Indian J Ophthalmol [serial online] 1976 [cited 2020 Aug 7];24:13-7. Available from: http://www.ijo.in/text.asp?1976/24/4/13/31275
Framycetin and gentamicin are the two antibiotics which have come into wide use recently in ophthalmic practice to combat the bacterial infections of the eye. The former is dispensed as framycetin sulphate (Soframycin) and the latter as gentamicin sulphate (Genticyn). Both are broad spectrum antibiotics as activity has been demonstrated against a wide variety of both Gram +ve and Gram -ve organisms.,,, Their topical application is useful in the treatment of superficial ocular infections. They are of special interest to the ophthalmologist since these can be administered subconjunctivally and intra-camerally to overcome intra-ocular infections.,,,,, It seems that with the advent of gentamicin and its ability for systemic use in contradiction to framycetin, it has gained a wider popularity. How far is it justified? A comparative sensitivity pattern and an analysis of the merits and demerits of these two drugs are the subject of this study.
| Material and Methods|| |
A total number of 300 strains of different organisms isolated in the laboratory from the clinical material obtained from the Centre's O.P.D. or the Hospital patients were studied. The material comprised coniuctival swabs, corneal scrapings, aqueous or vitreous aspirates, pus or enucleated eyeballs.
The sensitivity of these organisms was tested against Soframycin (100 ug/disc) and Genticyn(l0ug/disc) by the standardised disc agar diffusion methods. The nutrient agar medium was used for determining the susceptibility to the antibiotics and an inhibition zone diameter of 15mm or more was the criterion for the sensitivity of the organisms to both the antibiotics 6. The results were read after 24 hours incubation of the petriplates at 37°C.
| Results|| |
The details of 300 strains are given in [Table - 1]. Their disease-wise distribution is shown in [Table - 2]. Out of the strains tested, 266 were found to be sensitive to both the antibiotics. Only 34 strains were resistant to either of the two drugs. Seven isolates were resistant to both [Table - 3]. Out of the remaining 27, 18 were sensitive to Genticyn alone [Table - 4] and nine to Soframycin only [Table - 5].
| Dsicussion|| |
A total number of 300 strains of different organisms, most commonly encountered in ocular diseases, have been tested for their invitro sensitivity against Soframycin and Genticyn.
These antibiotics are of very wide use in ophthalmic practice. Only 34 strains were found to be resistant to both. A total number of 147 strains of Staphylococcus aureus were tested. All, except one, were sensitive to Genticyn and only two were resistant to Soframycin. The resistant strain to Genticyn was sensitive to Soframycin. Out of 43 strains of Staph. albus. seven were found resistant to Soframycin. All of them except one, were sensitive to Genticyn. The strain resistant to Genticyn was sensitive to Soframycin. It thus appears that Genticyn is better for Gram +ve cocci, 190 strains of which showed only two resistant strains, whereas ten were resistant to Soframycin. Out of 42 strains of Pseudomonas, 5 were resistant to Genticyn, three were sensitive to Soframycin. Out of the strains resistant to Soframycin, five were sensitive to Genticyn. Two strains (5%) were resistant to both the antibiotics. Thus, there seems hardly any difference between the two antibiotics to fight Pseudomonas infection. Out of the 19 strains of Mima, one strain was resistant to both and three were resistant to Genticyn. The strains resistant to Genticyn, were sensitive to Soframycin. Fifteen strains of Klebsiellae were tested, four were resistant to Soframycin and only one to Genticyn and one was resistant to both. All the strains of Esch. coli. (10) except one, were sensitive to both the antibiotics. All the 12 strains of Proteus were sensitive to both. Out of six strains of Moraxella, three were resistant to Genticyn and two to Soframycin. Out of the strains resistant to Genticyn, two were sensitive to Soframycin. Four out of five strains of Alkaligenes, were sensitive to both and one was resistant.
Ainslie and Henderson tested 250 strains of Staphylococci and all were found to be sensitive to Soframycin. In our series, 10 out of 190 strains were found insensitive, three of which were of Staph. aureus. Since it has been repeatedly shown experimentally as well as clinically that Staph. albus is also capable of producing ocular pathology in traumatised eyes,, its sensitivity was also tested. Seven strains were found to be resistant to Soframycin whereas one strain to Genticyn. It is thus concluded that Genticyn has an edge over Soframycin against Gram +ve cocci. Ainslie and Henderson tested 62 ocular strains of Pseudomonas and found most of them sensitive to Soframycin. Similar reports have been made by several other workers.,,. Our work also shows similar results; 2 out of 42 strains were resistant to both the drugs, whereas seven and five were resistant to Soframycin and Genticyn respectively. Thus a very dreadful organism producing ocular pathology and not amenable to ordinary antibiotics, has been found almost equally sensitive to both Soframycin as well as Genticyn. The strains resistant to Genticyn were sensitive to Soframycin and vice-versa. Since both these drugs can be injected subconjunctivally, and into the anterior chamber and the vitreous cavity, their importance in treating intraocular bacterial infections is considerable. May, Evicson and Peymen found a single intravitreal injection of gentamicin adequate to clear bacterial endophthalmitis, experimentally produced by Pseudomonas. It is conceivable, that Soframycin will also behave similarly. However, its use subconjunctivally in experimentally induced corneal infections due to Staphylococci and Pseudomonas has been highly commended and satisfactory results have been reported on corneal infections. Penicillin-resistant Acinetobactor was found to have better sensitivity to Soframycin than Genticyn in our series. Similarly penicillin-sensitive Moraxella also showed better results with Soframycin than Genticyn. However, it is amply clear that major antibiotics should not be used for a trivial infection because the patient may need a life-saving drug at a later date' and be unable to use it because of previous administration. As regards, other organisms, there were resistant strains of Klebsiellae to Soframycin than Genticyn. Esch. coli was equally sensitive to both.
While choosing a drug, it is axiomatic that whenever possible agents which are specifically effective against a known invader, should be selected. It is also equally important for the client that the disease gets cured with minimum expense and maximum rapidity. Soframycin and Genticyn have these merits and should not be over shadowed by each other though the latter has the advantage of being used systemically.
| Summary|| |
The invitro sensitivity of 300 strains of different organisms has been tested against Soframycin and Genticyn. Both the drugs were active against 266 strains (88.6%) and out of the remaining 34 (11.4%) were resistant to both, 8(3.0%) were resistant to Genticyn alone and 18 (6. 0%) resistant to Soframycin only. All strains of Staphylococcus aureus were sensitive to Genticyn while two were resistant to Soframycin. Staphylococcus albus was a problem organism for Soframycin, 7/44 strains of which were insensitive whereas only one strain was resistant to Genticyn. Out of 10 resistant strains of Pseudomonas, two were resistant to both and the remaining eight were resistant to one but sensitive to the other. Three strains each of Mima and Moraxella were resistant to Genticyn whereas only one and two strains respectively were insensitive to Soframycin. Thus, it appears that both these antibiotics are fairly effective against a variety of Gram+ve and Gram-ve organisms.
| Acknowledgements|| |
The authors are highly indebted to Prof. Lalit P. Agarwal for his keen interest and supervision of this work. We are also grateful to M/s. Roussel and Indian Schering Ltd., for the continuous supply of the sensitivity discs. The authors are also grateful to Shri Hardwari Lal for his technical assistance.
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