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Ocular Aeromonas Hydrophila
OCULAR AEROMONAS HYDROPHlLA JOHN A. SMITH, M.D.
Vancouver, British Columbia, Canada
Aeromonas hydrophila is a gramnegative rod whose natural habitat is man's aquatic environment.' It rarely causes infection in humans. Its infrequent implication in human disease may be attributable in part to its misidentification." As described, such infections have been enteric, local, or septicemic." Patients with chronic liver disease, malignant disease, and suppression of immunity are particularlyv " prone to invasive disease, and local infection is usually the result of injury and contamination by soil or water.I-" Infections of the eye have been described on two previous occasions.t'-'? We describe four patients from whose eyes the organism was isolated in this hospital laboratory since 1970.
for four days. She was afebrile and her white blood cell count was 4,400/mm 3 • Her left eye showed a pure culture of A. hydrophila. She was treated with chloramphenicol 0.5% eyedrops given every two hours while awake and she recovered without incident. At the time of cataract extraction, which was deferred until six months later, there were no infectious complications and the preoperative eye swab showed no growth. Case 2-A 52-year-old man was seen in 1971 because of chest pain. At that time, the patient was noted to have severe, long-standing bilateral conjunctivitis. He wore hard contact lenses. He was afebrile and his white blood cell count was normal. Bacteriologic sampling of the conjunctiva showed A. hydrophila. There was no record of treatment or follow-up. Case 3-A 75-year-old man was operated on in 1971 for a cataract in the left eye. At the time of surgery, a swab was obtained for culture and this showed a pure growth of A. hydrophila. Chloramphenicol ophthalmic solution 0.5% was applied at the time of surgery and every four hours thereafter. He also was given 250 mg of tetracycline orally four times daily for two days. His maximum temperature was 37.4°C and white blood cell count was 4,OOO/mm3 . He was discharged from the hospital METHODS nine days later with no evidence of infection at any Bacterial identification was by stan- time. Six months later, he was admitted for needle dard methods. Aeromonas hudrophila excision of a cyclitic membrane complicating the cataract surgery. His conjunctival swab showed no is strongly hemolytic, oxidase-positive, bacteria and there was no evidence of infection. Case 4-A 7-year-old boy was admitted in 1977 motile, hydrogen sulfide negative, and indole-positive. It ferments glucose, su- because a safety pin had penetrated his right eye on the day before admission. A subconjunctival hemorcrose, maltose, and mannitol. It ferments rhage was noted, but there was no corneal laceralactose weakly. Antimicrobial suscepti- tion. A cellular response was evident in the anterior chamber and ultrasound examination of the orbit bility testing was by agar disk diffusion. showed debris in the anterior part of the vitreous cavity. The lens was cataractous with an organized CASE REPORTS white fibrous membrane behind it. Anterior vitrectomy and lensectomy were performed on the eye with Case I-An 87-year-old woman was admitted in no complications. At surgery, 5 ml of gentamicin 1972 for elective cataract extraction. She had a left ophthalmic solution (0.5%) was used to irrigate the ectropion dating from surgical excision of a squaeye and the patient was given 20 mg of gentamicin mous cell carcinoma of the left lower eyelid 14 years intramuscularly every eight hours for seven days, earlier. At the time of her admission, she had an and 250 mg of cloxacillin was given intravenously acute left-sided conjunctivitis that had been present every six hours for ten days. Gentamicin eyedrops and chloramphenicol eyedrops were instilled in the conjunctival sac every two hours while awake. His white blood cell count was 7,700/mm 3 and his From the Division of Microbiology, Vancouver maximum temperature during his two-week hospital General Hospital, and the Department of Pathology, stay was 37.8°C on one occasion. A conjunctival University of British Columbia, Vancouver, B.C., swab taken at surgery showed A. hudrophila and Canada. Hemophilus inf/uenzae. There was no clinical eviReprint requests to John A. Smith, M.D., Division dence of infection of the eye at any time during his of Microbiology, Vancouver General Hospital, 855 hospital stay or after discharge. W. 12 Ave., Vancouver, B.C., Canada, V5Z IM9. All the isolates of Aeromonas from these four AMERICAN JOURNAL OF OPHTHALMOLOGY 89:449--451, 1980 449
450
AMERICAN JOURNAL OF OPHTHALMOLOGY
cases were sensitive to tetracycline, chloramphenicol, and gentamicin. The H. infiuenzae isolated from Case 4 was not tested for antimicrobial susceptibility but all isolates at the time were considered sensitive to chloramphenicol. DISCUSSION
These four cases show the two possible roles of A. hudrophila in the eye. It may cause infection as exemplified by Cases 1 and 2, and it can cause asymptomatic colonization as shown by Cases 3 and 4. There are two previous reports of Aeromonas infections in the eye9,10 in which all three patients had suffered injury; one was struck by a seashell, one had a foreign body injury on an offshore oil rig, and one received an injury during a dynamite blast. Neither of the two patients with clinical infection described here gave a history of such injury. The patient described in Case 1 had a stenosed lacrimal duct and ectropion with chronic tearing, a condition conducive to the development of chronic conjunctivitis."! This patient seemed to have an acute four-day illness rather than a chronic infection. However, it is possible that the stenosed tear duct and ectropion were etiologic factors. There was no mention in the hospital record of Case 2 of the means of storage of the patient's contact lenses. Solutions used for this purpose may get contaminated with other water bacteria, and irritation of the cornea and conjunctiva by contact lenses together with contamination of storage solution may have been the c-ause of this patient's chronic conjunctivitis. It is not clear whether the presence of Aeromonas in the conjunctiva in Case 3 was caused by transient contamination or by chronic colonization. Certainly, Aeromonas is not frequently encountered in the eye swabs cultured in our laboratory, and this is in accord with the report by Feaster, Nisbet, and Barber.l'' Case 4 is more typical of the type of patients previously reported to have Aeromonas ophthalmic infection in that the
MARCH, 1980
patient suffered a penetrating injury.9,lO However, he did not develop clinical signs of infection. This may have been the result of vigorous antimicrobial therapy and effective surgery. According to Feaster, Nisbet, and Barber,"? the clinical features of Aeromonas infections in the eye are nonspecific. However, they state that the association of acute infection of the eye with a history of contamination by water or soil may be significant. The cases reported here indicate that lacrimal duct stenosis and the wearing of contact lenses may also be significant. The antimicrobial susceptibility patterns of the four isolates reported here, as well as the reports of others, indicate that chloramphenicol or aminoglycoside antimicrobials are the agents of choice in treatment. All strains are resistant to ampicillin. Cephalosporins, carbenicillin, and ticarcillin disodium are not as effective. 4,9,12,13 With increased awareness of this organism as a potential pathogen, and with appropriate bacteriologic identification procedures, including the routine use of the oxidase test in the identification of gram-negative rods, Aeromonas may be recognized more often in the future as an ophthalmic pathogen. SUMMARY
Aeromonas hudrophila was isolated from the eye swabs of four patients. Two were thought to have definite clinical infection; one had chronic conjunctivitis complicating the wearing of contact lenses, and the other had acute conjunctivitis associated with ectropion and lacrimal duct stenosis. Two patients had no clinical evidence of infection. Both of them had swabs taken at the time of surgery. One had a cataract extraction and the other had a lensectomy and vitrectomy for a penetrating injury. The outcome was satisfactory in the two patients in whom colonization occurred, and in the patient
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with acute conjunctivitis, all of whom received chloramphenicol with or without gentamicin. The fourth patient was not followed up. REFERENCES 1. Ewing, W. H., and Hugh, R.: Aeromonas. In Lennette, E. H., Spaulding, E. H., and Truant, J. P. (eds.): Manual of Clinical Microbiology. Washington, D.C., American Society for Microbiology, 1974, p.23O. 2. Trust, T. J., and Chipman, D. C.: Clinical involvement of Aeromonas hydrophila. Can. Med. Assoc. J. 120:942, 1979. 3. Shilkin, K. B., Annear, D. I., Hewett, L. H., and Laurence, B. H.: Infection due to Aeromonas hydrophila. Med. J. Aust. 1:351, 1968. 4. Bulger, H. J., and Sherris, J. C.: The clinical significance of Aeromonas hydrophila. Report of two cases. Arch. Intern. Med. 118:562, 1966. 5. Davis, W. A., Kane, J. G., and Garagusi, V. F.: Human Aeromonas infections. A review of the literature and a case report of endocarditis. Medicine 57:267, 1978.
451
6. Ketover, B. P., Young, L. S., and Armstrong, D.: Septicaemia due to Aeromonas hydrophila. Clinical and immunologic aspects. J. Infect. Dis. 127:284, 1973. 7. McCracken, A. W., and Barkley, H.: Isolation of Aeromonas species from clinical sources. J. Clin. Pathol. 25:970, 1972. 8. Hanson, P. G., Standridge, J., Jarrett, F., and Maki, D. G.: Fresh water wound infection .due to Aeromonas hydrophila. J.A.M.A. 238:1053, 1977. 9. Washington, J. A.: Aeromonas hydrophila in clinical bacteriologic specimens. Ann. Intern. Med. 76:611, 1972. 10. Feaster, F. T., Nisbet, H. M., and Barber, J. C.: Aeromonas hydrophila corneal ulcer. Am. J. OphthalmoI. 85:114, 1978. 11. Meek, E. 5., and Golden, B.: In Hoeprich, P. (ed.). Conjunctivitis and scleritis. Infectious Diseases. Hagerstown, Harper and How, 1977, p. 1172. 12. vonGraevenitz, A., and Mensch, A. H.: The genus Aeromonas in human bacteriology. New Engl. J. Med. 278:245, 1968. 13. Joseph, S. W., Daily, O. P., Hunt, W. S., Seidler, R. J., Allen, D. A., and Colwell, R. R.: Primary wound infection of a diver in polluted waters. J. Clin. Microbiol. 10:46, 1979.
Vancouver, British Columbia, Canada
Aeromonas hydrophila is a gramnegative rod whose natural habitat is man's aquatic environment.' It rarely causes infection in humans. Its infrequent implication in human disease may be attributable in part to its misidentification." As described, such infections have been enteric, local, or septicemic." Patients with chronic liver disease, malignant disease, and suppression of immunity are particularlyv " prone to invasive disease, and local infection is usually the result of injury and contamination by soil or water.I-" Infections of the eye have been described on two previous occasions.t'-'? We describe four patients from whose eyes the organism was isolated in this hospital laboratory since 1970.
for four days. She was afebrile and her white blood cell count was 4,400/mm 3 • Her left eye showed a pure culture of A. hydrophila. She was treated with chloramphenicol 0.5% eyedrops given every two hours while awake and she recovered without incident. At the time of cataract extraction, which was deferred until six months later, there were no infectious complications and the preoperative eye swab showed no growth. Case 2-A 52-year-old man was seen in 1971 because of chest pain. At that time, the patient was noted to have severe, long-standing bilateral conjunctivitis. He wore hard contact lenses. He was afebrile and his white blood cell count was normal. Bacteriologic sampling of the conjunctiva showed A. hydrophila. There was no record of treatment or follow-up. Case 3-A 75-year-old man was operated on in 1971 for a cataract in the left eye. At the time of surgery, a swab was obtained for culture and this showed a pure growth of A. hydrophila. Chloramphenicol ophthalmic solution 0.5% was applied at the time of surgery and every four hours thereafter. He also was given 250 mg of tetracycline orally four times daily for two days. His maximum temperature was 37.4°C and white blood cell count was 4,OOO/mm3 . He was discharged from the hospital METHODS nine days later with no evidence of infection at any Bacterial identification was by stan- time. Six months later, he was admitted for needle dard methods. Aeromonas hudrophila excision of a cyclitic membrane complicating the cataract surgery. His conjunctival swab showed no is strongly hemolytic, oxidase-positive, bacteria and there was no evidence of infection. Case 4-A 7-year-old boy was admitted in 1977 motile, hydrogen sulfide negative, and indole-positive. It ferments glucose, su- because a safety pin had penetrated his right eye on the day before admission. A subconjunctival hemorcrose, maltose, and mannitol. It ferments rhage was noted, but there was no corneal laceralactose weakly. Antimicrobial suscepti- tion. A cellular response was evident in the anterior chamber and ultrasound examination of the orbit bility testing was by agar disk diffusion. showed debris in the anterior part of the vitreous cavity. The lens was cataractous with an organized CASE REPORTS white fibrous membrane behind it. Anterior vitrectomy and lensectomy were performed on the eye with Case I-An 87-year-old woman was admitted in no complications. At surgery, 5 ml of gentamicin 1972 for elective cataract extraction. She had a left ophthalmic solution (0.5%) was used to irrigate the ectropion dating from surgical excision of a squaeye and the patient was given 20 mg of gentamicin mous cell carcinoma of the left lower eyelid 14 years intramuscularly every eight hours for seven days, earlier. At the time of her admission, she had an and 250 mg of cloxacillin was given intravenously acute left-sided conjunctivitis that had been present every six hours for ten days. Gentamicin eyedrops and chloramphenicol eyedrops were instilled in the conjunctival sac every two hours while awake. His white blood cell count was 7,700/mm 3 and his From the Division of Microbiology, Vancouver maximum temperature during his two-week hospital General Hospital, and the Department of Pathology, stay was 37.8°C on one occasion. A conjunctival University of British Columbia, Vancouver, B.C., swab taken at surgery showed A. hudrophila and Canada. Hemophilus inf/uenzae. There was no clinical eviReprint requests to John A. Smith, M.D., Division dence of infection of the eye at any time during his of Microbiology, Vancouver General Hospital, 855 hospital stay or after discharge. W. 12 Ave., Vancouver, B.C., Canada, V5Z IM9. All the isolates of Aeromonas from these four AMERICAN JOURNAL OF OPHTHALMOLOGY 89:449--451, 1980 449
450
AMERICAN JOURNAL OF OPHTHALMOLOGY
cases were sensitive to tetracycline, chloramphenicol, and gentamicin. The H. infiuenzae isolated from Case 4 was not tested for antimicrobial susceptibility but all isolates at the time were considered sensitive to chloramphenicol. DISCUSSION
These four cases show the two possible roles of A. hudrophila in the eye. It may cause infection as exemplified by Cases 1 and 2, and it can cause asymptomatic colonization as shown by Cases 3 and 4. There are two previous reports of Aeromonas infections in the eye9,10 in which all three patients had suffered injury; one was struck by a seashell, one had a foreign body injury on an offshore oil rig, and one received an injury during a dynamite blast. Neither of the two patients with clinical infection described here gave a history of such injury. The patient described in Case 1 had a stenosed lacrimal duct and ectropion with chronic tearing, a condition conducive to the development of chronic conjunctivitis."! This patient seemed to have an acute four-day illness rather than a chronic infection. However, it is possible that the stenosed tear duct and ectropion were etiologic factors. There was no mention in the hospital record of Case 2 of the means of storage of the patient's contact lenses. Solutions used for this purpose may get contaminated with other water bacteria, and irritation of the cornea and conjunctiva by contact lenses together with contamination of storage solution may have been the c-ause of this patient's chronic conjunctivitis. It is not clear whether the presence of Aeromonas in the conjunctiva in Case 3 was caused by transient contamination or by chronic colonization. Certainly, Aeromonas is not frequently encountered in the eye swabs cultured in our laboratory, and this is in accord with the report by Feaster, Nisbet, and Barber.l'' Case 4 is more typical of the type of patients previously reported to have Aeromonas ophthalmic infection in that the
MARCH, 1980
patient suffered a penetrating injury.9,lO However, he did not develop clinical signs of infection. This may have been the result of vigorous antimicrobial therapy and effective surgery. According to Feaster, Nisbet, and Barber,"? the clinical features of Aeromonas infections in the eye are nonspecific. However, they state that the association of acute infection of the eye with a history of contamination by water or soil may be significant. The cases reported here indicate that lacrimal duct stenosis and the wearing of contact lenses may also be significant. The antimicrobial susceptibility patterns of the four isolates reported here, as well as the reports of others, indicate that chloramphenicol or aminoglycoside antimicrobials are the agents of choice in treatment. All strains are resistant to ampicillin. Cephalosporins, carbenicillin, and ticarcillin disodium are not as effective. 4,9,12,13 With increased awareness of this organism as a potential pathogen, and with appropriate bacteriologic identification procedures, including the routine use of the oxidase test in the identification of gram-negative rods, Aeromonas may be recognized more often in the future as an ophthalmic pathogen. SUMMARY
Aeromonas hudrophila was isolated from the eye swabs of four patients. Two were thought to have definite clinical infection; one had chronic conjunctivitis complicating the wearing of contact lenses, and the other had acute conjunctivitis associated with ectropion and lacrimal duct stenosis. Two patients had no clinical evidence of infection. Both of them had swabs taken at the time of surgery. One had a cataract extraction and the other had a lensectomy and vitrectomy for a penetrating injury. The outcome was satisfactory in the two patients in whom colonization occurred, and in the patient
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AEROMONAS HYDROPHILA
with acute conjunctivitis, all of whom received chloramphenicol with or without gentamicin. The fourth patient was not followed up. REFERENCES 1. Ewing, W. H., and Hugh, R.: Aeromonas. In Lennette, E. H., Spaulding, E. H., and Truant, J. P. (eds.): Manual of Clinical Microbiology. Washington, D.C., American Society for Microbiology, 1974, p.23O. 2. Trust, T. J., and Chipman, D. C.: Clinical involvement of Aeromonas hydrophila. Can. Med. Assoc. J. 120:942, 1979. 3. Shilkin, K. B., Annear, D. I., Hewett, L. H., and Laurence, B. H.: Infection due to Aeromonas hydrophila. Med. J. Aust. 1:351, 1968. 4. Bulger, H. J., and Sherris, J. C.: The clinical significance of Aeromonas hydrophila. Report of two cases. Arch. Intern. Med. 118:562, 1966. 5. Davis, W. A., Kane, J. G., and Garagusi, V. F.: Human Aeromonas infections. A review of the literature and a case report of endocarditis. Medicine 57:267, 1978.
451
6. Ketover, B. P., Young, L. S., and Armstrong, D.: Septicaemia due to Aeromonas hydrophila. Clinical and immunologic aspects. J. Infect. Dis. 127:284, 1973. 7. McCracken, A. W., and Barkley, H.: Isolation of Aeromonas species from clinical sources. J. Clin. Pathol. 25:970, 1972. 8. Hanson, P. G., Standridge, J., Jarrett, F., and Maki, D. G.: Fresh water wound infection .due to Aeromonas hydrophila. J.A.M.A. 238:1053, 1977. 9. Washington, J. A.: Aeromonas hydrophila in clinical bacteriologic specimens. Ann. Intern. Med. 76:611, 1972. 10. Feaster, F. T., Nisbet, H. M., and Barber, J. C.: Aeromonas hydrophila corneal ulcer. Am. J. OphthalmoI. 85:114, 1978. 11. Meek, E. 5., and Golden, B.: In Hoeprich, P. (ed.). Conjunctivitis and scleritis. Infectious Diseases. Hagerstown, Harper and How, 1977, p. 1172. 12. vonGraevenitz, A., and Mensch, A. H.: The genus Aeromonas in human bacteriology. New Engl. J. Med. 278:245, 1968. 13. Joseph, S. W., Daily, O. P., Hunt, W. S., Seidler, R. J., Allen, D. A., and Colwell, R. R.: Primary wound infection of a diver in polluted waters. J. Clin. Microbiol. 10:46, 1979.