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Orbital Cellulitis Caused by Eikenella corrodens
398
AMERICAN JOURNAL OF OPHTHALMOLOGY
2. Rosenkopf, K. L.: Current concepts concerning the etiology and treatment of trigeminal neuralgia. J. Craniomandibul. Pract. 7:312, 1989. 3. Hakanson, S.: Trigeminal neuralgia treated by the injection of glycerol into the trigeminal cistern. Neurosurgery 9:638,1981.
Correspondence Correspondence concerning recent articles or other material published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8'/2 x H-inch bond paper with Ph-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before publication.
Orbital Cellulitis Caused by Eikenella corrodens EDITOR:
In the article, "Orbital cellulitis caused by
Eikenella corrodens," by R. Hernady, A. Zim-
merman, B. W. Katzen, and
J.
W. Karesh (Am.
J. Ophthalmol. 114:584, November 1992), the authors point out that infections secondary to
E. corrodens can lead to significant morbidity if
improperly recognized and treated. It was with surprise, then, that I found vancomycin listed as a potential therapeutic option for E. corrodens (a gram-negative rod). The authors state: "The organism is usually susceptible to penicillin, ampicillin, vancomycin, erythromycin, and chloramphenicol." The antibacterial spectrum of vancomycin is typically limited to aerobic and anaerobic gram-positive organisms.' Vancomycin has no noteworthy activity against most gram-negative bacteria except for occasional isolates of Neisseria gonorrhoeae Y A clinical report of successful treatment of meningitis secondary to Flavobacterium meningosepticum (a gramnegative rod) with vancomycin was not supported by subsequent in vitro susceptibility testing with vancomycin."
March, 1993
As a result of the known, limited, typical spectrum of activity of vancomycin, most clinicallaboratories would not routinely test gram-negative organisms (that is, Eikene/la species) for susceptibility to vancomycin. Published data on susceptibility for Eikenella species and vancomycin, then, are relatively difficult to locate. When searching for these data, however, it is important to note that an agar dilution method has been recommended as being most reliable for E. corrodens because of the organism's fastidious growth characteristics.4.5 Disk-agar susceptibility testing is thought to be less reliable for E. corrodens? In 1974, a report by Brooks and associates" (using agar dilution antimicrobial susceptibility testing) found that the minimal inhibitory concentration of vancomycin to inhibit 50% of E. corrodens growth was approximately 22 !J.g/ml. The minimal inhibitory concentration to inhibit 90% of E. corrodens growth was off the scale. This would indicate that E. corrodens is relatively resistant to standard achievable vancomycin serum concentrations. Effective antimicrobial therapy is usually selected with the intent of achieving peak levels two to four times the minimal inhibitory concentration at the site of infection. Since desirable ranges for therapeutic peak and trough serum vancomycin concentrations are only 20 to 40 ILg/ml and 5 to 10 ILg/mI,! respectively, E. corrodens would be considered resistant to vancomycin, on the basis of the data of Brooks and associates." Indeed, average serum vancomycin levels with typical dosing schedules can be as low as 8 !J.g/ml,2 Overall, then, a minimal inhibitory concentration of greater than 5 ILg/ml would generally indicate resistance to vancomycin." An additional report by Bottone, Kittick, and Schneierson," in 1973, concerning vancomycin susceptibility of the bacillus HB-l (subsequently considered synonymous with E. corrodens) employed the disk-agar method of testing, which as previously mentioned, is not considered reliable for E. corrodens. Disk-agar testing disclosed that all of the studied bacillus HB-l strains were susceptible to vancomycin at 5 ILg/ml. Given the usual spectrum of activity of vancomycin, Eikenella corrodens would be an interesting and important exception to the gram-positive rule-of-thumb should the data of Botonne, Kittick, and Schneierson" hold true in vivo.
Vol. 115, No.3
Correspondence
I certainly would be interested to review any updated susceptibility data from Dr. Hemady and associates concerning E. corrodens and vancomycin. Given the potential serious nature of improperly treated E. corrodens infections, accurate empiric antibiotic selection is imperative when the clinician is awaiting individual microbiologic susceptibility testing. Although vancomycin is not recommended as initial therapy by Dr. Hemady and associates for E. corrodens infections, accurate therapeutic recommendations concerning vancomycin are necessary to avoid a false sense of security for the clinician awaiting individual culture and sensitivity results.
vancomycin, an antibiotic typically used to treat infections caused by gram positive organisms. We wish to point out that the above quote originated from an early review of the literature by Dorff and colleagues.' and does not represent a recommendation by us, as Dr. Grimmett correctly indicates in his letter, to use vancomycin to treat infections caused by E. corrodens. Ampicillin, tetracycline, chloramphenicol, and penicillin appear to be more appropriate antimicrobials for such infections. We agree with Dr. Grimmett (as stated in our article on page 586) that agar dilution is the method of choice in susceptibility testing of E.
corrodens.
R. HEMADY, A. ZIMMERMAN, B. W. KATZEN, J. W. KARESH,
MICHAEL R. GRIMMETT, M.D.
Minneapolis, Minnesota
1. Wilhelm, M. P.: Vancomycin. Mayo Clin. Proc. 66:1165,1991. 2. Ingerman, M. J., and Santoro, J.: Vancomycin. A new old agent. Infect. Dis. Clin. North Am. 3:641, 1989. 3. Watanakunakorn, C.: Mode of action and invitro activity of vancomycin. J. Antimicrob. Chemother. 14:7, 1984. 4. Klein, B., Couch, J., and Thompson, J.: Ocular infections associated with Eikenella corrodens. Am. J. Ophthalmol. 109:127, 1990. 5. Stoloff, A. L., and Gillies, M. L.: Infections with Eikenella corrodens in a general hospital. A report of 33 cases. Rev. Infect. Dis. 8:50,1986. 6. Brooks, G. F., O'Donoghue, J. M., Rissing, J. P., Soapes, K., and Smith, J. W.: Eikenella corrodens, a recently recognized pathogen. Infections in medicalsurgical patients and in association with methylphenidate abuse. Medicine 53:325, 1974. 7. Bottone, E. J., Kittick, J., j-, Schneierson, S. S.: Isolation of bacillus HB-1 from human clinical sources. Am. J. Clin. Pathol. 59:560,1973.
EDITOR:
M.D. M.D. M.D. M.D.
Baltimore, Maryland
References
________ Reply
399
_
Dr. Grimmett expresses concern about our statement: "The organism is usually susceptible to penicillin, ampicillin, vancomycin, erythromycin, and chloramphenicol." Specifically, Dr. Grimmett questions the susceptibility of E. corrodens, a gram-negative bacillus, to
Reference 1. Dorff, J. G., Jackson, L. J., and Rytel, M. W.: Infections with Eikenella corrodens. A newly recognized human pathogen. Ann. Intern. Med. 80:305, 1974.
Argon Laser Gonioplasty in the Treatment of Angle-closure Glaucoma EDITOR:
In the article, "Argon laser gonioplasty in the treatment of angle-closure glaucoma," by H. W. Weiss, B. J. Shingleton, S. M. Goode, A. R. Bellows, and C. U. Richter (Am. J. Ophthaimol. 114:14, July 1992), the authors report on using argon laser gonioplasty to treat angie-closure glaucoma that was unrelieved by patent iridectomy. Unfortunately, they do not specify whether treatment with strong miotics had been tried before the gonioplasty. It has been our experience that this condition might respond well to miotic treatment. Occasionally the pressure remains within normal limits even after the drug has been discontinued.' It seems that strong miotics might have a permanent mechanical effect on the angle in this
AMERICAN JOURNAL OF OPHTHALMOLOGY
2. Rosenkopf, K. L.: Current concepts concerning the etiology and treatment of trigeminal neuralgia. J. Craniomandibul. Pract. 7:312, 1989. 3. Hakanson, S.: Trigeminal neuralgia treated by the injection of glycerol into the trigeminal cistern. Neurosurgery 9:638,1981.
Correspondence Correspondence concerning recent articles or other material published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8'/2 x H-inch bond paper with Ph-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before publication.
Orbital Cellulitis Caused by Eikenella corrodens EDITOR:
In the article, "Orbital cellulitis caused by
Eikenella corrodens," by R. Hernady, A. Zim-
merman, B. W. Katzen, and
J.
W. Karesh (Am.
J. Ophthalmol. 114:584, November 1992), the authors point out that infections secondary to
E. corrodens can lead to significant morbidity if
improperly recognized and treated. It was with surprise, then, that I found vancomycin listed as a potential therapeutic option for E. corrodens (a gram-negative rod). The authors state: "The organism is usually susceptible to penicillin, ampicillin, vancomycin, erythromycin, and chloramphenicol." The antibacterial spectrum of vancomycin is typically limited to aerobic and anaerobic gram-positive organisms.' Vancomycin has no noteworthy activity against most gram-negative bacteria except for occasional isolates of Neisseria gonorrhoeae Y A clinical report of successful treatment of meningitis secondary to Flavobacterium meningosepticum (a gramnegative rod) with vancomycin was not supported by subsequent in vitro susceptibility testing with vancomycin."
March, 1993
As a result of the known, limited, typical spectrum of activity of vancomycin, most clinicallaboratories would not routinely test gram-negative organisms (that is, Eikene/la species) for susceptibility to vancomycin. Published data on susceptibility for Eikenella species and vancomycin, then, are relatively difficult to locate. When searching for these data, however, it is important to note that an agar dilution method has been recommended as being most reliable for E. corrodens because of the organism's fastidious growth characteristics.4.5 Disk-agar susceptibility testing is thought to be less reliable for E. corrodens? In 1974, a report by Brooks and associates" (using agar dilution antimicrobial susceptibility testing) found that the minimal inhibitory concentration of vancomycin to inhibit 50% of E. corrodens growth was approximately 22 !J.g/ml. The minimal inhibitory concentration to inhibit 90% of E. corrodens growth was off the scale. This would indicate that E. corrodens is relatively resistant to standard achievable vancomycin serum concentrations. Effective antimicrobial therapy is usually selected with the intent of achieving peak levels two to four times the minimal inhibitory concentration at the site of infection. Since desirable ranges for therapeutic peak and trough serum vancomycin concentrations are only 20 to 40 ILg/ml and 5 to 10 ILg/mI,! respectively, E. corrodens would be considered resistant to vancomycin, on the basis of the data of Brooks and associates." Indeed, average serum vancomycin levels with typical dosing schedules can be as low as 8 !J.g/ml,2 Overall, then, a minimal inhibitory concentration of greater than 5 ILg/ml would generally indicate resistance to vancomycin." An additional report by Bottone, Kittick, and Schneierson," in 1973, concerning vancomycin susceptibility of the bacillus HB-l (subsequently considered synonymous with E. corrodens) employed the disk-agar method of testing, which as previously mentioned, is not considered reliable for E. corrodens. Disk-agar testing disclosed that all of the studied bacillus HB-l strains were susceptible to vancomycin at 5 ILg/ml. Given the usual spectrum of activity of vancomycin, Eikenella corrodens would be an interesting and important exception to the gram-positive rule-of-thumb should the data of Botonne, Kittick, and Schneierson" hold true in vivo.
Vol. 115, No.3
Correspondence
I certainly would be interested to review any updated susceptibility data from Dr. Hemady and associates concerning E. corrodens and vancomycin. Given the potential serious nature of improperly treated E. corrodens infections, accurate empiric antibiotic selection is imperative when the clinician is awaiting individual microbiologic susceptibility testing. Although vancomycin is not recommended as initial therapy by Dr. Hemady and associates for E. corrodens infections, accurate therapeutic recommendations concerning vancomycin are necessary to avoid a false sense of security for the clinician awaiting individual culture and sensitivity results.
vancomycin, an antibiotic typically used to treat infections caused by gram positive organisms. We wish to point out that the above quote originated from an early review of the literature by Dorff and colleagues.' and does not represent a recommendation by us, as Dr. Grimmett correctly indicates in his letter, to use vancomycin to treat infections caused by E. corrodens. Ampicillin, tetracycline, chloramphenicol, and penicillin appear to be more appropriate antimicrobials for such infections. We agree with Dr. Grimmett (as stated in our article on page 586) that agar dilution is the method of choice in susceptibility testing of E.
corrodens.
R. HEMADY, A. ZIMMERMAN, B. W. KATZEN, J. W. KARESH,
MICHAEL R. GRIMMETT, M.D.
Minneapolis, Minnesota
1. Wilhelm, M. P.: Vancomycin. Mayo Clin. Proc. 66:1165,1991. 2. Ingerman, M. J., and Santoro, J.: Vancomycin. A new old agent. Infect. Dis. Clin. North Am. 3:641, 1989. 3. Watanakunakorn, C.: Mode of action and invitro activity of vancomycin. J. Antimicrob. Chemother. 14:7, 1984. 4. Klein, B., Couch, J., and Thompson, J.: Ocular infections associated with Eikenella corrodens. Am. J. Ophthalmol. 109:127, 1990. 5. Stoloff, A. L., and Gillies, M. L.: Infections with Eikenella corrodens in a general hospital. A report of 33 cases. Rev. Infect. Dis. 8:50,1986. 6. Brooks, G. F., O'Donoghue, J. M., Rissing, J. P., Soapes, K., and Smith, J. W.: Eikenella corrodens, a recently recognized pathogen. Infections in medicalsurgical patients and in association with methylphenidate abuse. Medicine 53:325, 1974. 7. Bottone, E. J., Kittick, J., j-, Schneierson, S. S.: Isolation of bacillus HB-1 from human clinical sources. Am. J. Clin. Pathol. 59:560,1973.
EDITOR:
M.D. M.D. M.D. M.D.
Baltimore, Maryland
References
________ Reply
399
_
Dr. Grimmett expresses concern about our statement: "The organism is usually susceptible to penicillin, ampicillin, vancomycin, erythromycin, and chloramphenicol." Specifically, Dr. Grimmett questions the susceptibility of E. corrodens, a gram-negative bacillus, to
Reference 1. Dorff, J. G., Jackson, L. J., and Rytel, M. W.: Infections with Eikenella corrodens. A newly recognized human pathogen. Ann. Intern. Med. 80:305, 1974.
Argon Laser Gonioplasty in the Treatment of Angle-closure Glaucoma EDITOR:
In the article, "Argon laser gonioplasty in the treatment of angle-closure glaucoma," by H. W. Weiss, B. J. Shingleton, S. M. Goode, A. R. Bellows, and C. U. Richter (Am. J. Ophthaimol. 114:14, July 1992), the authors report on using argon laser gonioplasty to treat angie-closure glaucoma that was unrelieved by patent iridectomy. Unfortunately, they do not specify whether treatment with strong miotics had been tried before the gonioplasty. It has been our experience that this condition might respond well to miotic treatment. Occasionally the pressure remains within normal limits even after the drug has been discontinued.' It seems that strong miotics might have a permanent mechanical effect on the angle in this