British Journal of Ophthalmology, 1979, 63, 449-454

Nocardia asteroides keratitis LAWRENCE W. HIRST,' G. KENNETH HARRISON,2 WILLIAM G. MERZ ,2 AND WALTER J. STARK' From the 'Wilmer Ophthalmological Institute of Johns Hopkins Hospital, Baltimore, Maryland,

and the 2Department of Laboratory Medicine, Johns Hopkins Hospital

Nocardia asteroides has been reported as the cause of keratitis in only 7 cases and of other ocular disease in another 12 cases. We report a case of N. asteroides keratitis that presented 3 weeks after rural trauma and progressed despite trials of appropriate antibiotics. Seven weeks after the original injury a successful conjunctival flap was placed over the cornea. The morphology and the sensitivity testing of N. asteroides with agar dilution methods are described. Further standardisation of susceptibility testing of N. asteroides to antibiotics appears necessary before reliable information can be obtained for clinical use. Moreover, our case did not show the relatively benign course of other reported cases of nocardia keratitis.

SUMMARY

Although fungal keratitis has been reported more often since the introduction of topical ocular steroid preparations (Haggerty and Zimmerman, 1958) there have been only 7 reports of Nocardia asteroides as the causative organism. A further 13 cases (3 bilateral) of ocular or periocular infection with this organism have also been reported. We report a case of a progressive N. asteroides corneal ulcer that was unresponsive to intensive oral and topical antibiotics. One year after a Gundersen conjunctival-flap operation the eye is quiet, and a potentially useful eye has been retained. Case report CLINICAL SUMMARY

A 17-year-old Caucasian boy sustained injury from foreign bodies in both corneas when dirt and debris from an exploding tractor tyre peppered his eyes. He had numerous foreign bodies removed from both eyes on the day of the accident and on the following day, and received topical sulphadiazine drops. His vision and comfort gradually improved over the ensuing 3 weeks, after which his left eye became painful and visual acuity progressively diminished. He was admitted to a local hospital and given sodium sulphacetamide eyedrops for 1 week without improvement. When seen at the Johns Hopkins Hospital about 1 month after the initial injury his right eye had 20/20 vision. There was a

Fig. 1 Nocardia asteroides ulcer on initial presentation at the Johns Hopkins Hospital, 4 weeks after trauma

half-thickness healed corneal laceration inferonasally, with a few foreign bodies trapped within the scar. His left eye was rather photophobic and had gross conjunctival chemosis and ciliary injection. There was a 5 x 5 mm one-third-thickness stromal ulcer inferonasally with irregular opaque edges (Fig. 1). Feathery projections from these edges extended for a further 1 to 2 mm at mid-stromal depth and there was a mid-stromal 'satellite' infiltrate 2 mm above the ulcer. The base of the ulcer was irregular and filled with mucus and corneal Address for reprints: Lawrence W. Hirst, MD, Wilmer debris. The pupil was mid-dilated, and there was Institute, Johns Hopkins Hospital, 600 North Wolfe Street, an intense fibrinous exudate in the anterior chamber. The lens, vitreous, and retina were normal. Vision Baltimore, Maryland 21205, USA 449

450

Lawrence W. Hirst, G. Kenneth Harrison, William G. Merz, and Walter J. Stark

was reduced to counting fingers at 3 ft (I m). Before the accident the patient had been in good health and had 20/20 vision, with surgery at the age of 3 for correction of strabismus. He had been on long-term tetracycline therapy for acne before this eye infection, but he ceased this medication on his first hospital admission after the infection. He gave a reliable history of penicillin allergy. Smears and cultures taken on his initial admission to the community hospital were reported a week later as positive for Nocardia asteroides and Alcaligenes species. At the Johns Hopkins Hospital, 28 days later, the corneal ulcer was again scraped for smears and cultures and the patient was begun on sulphadiazine orally, 2 g every 6 hours, 30% sulphacetamide drops every 2 hours, 3% atropine drops 3 times a day, achromycin drops every 2 hours, and gentamicin drops every 2 hours. Smears taken from corneal scrapings confirmed the presence of partially acid-fast Gram-positive organisms with branching hyphae, and after 2 days cultures confirmed the presence of N. asteroides. Other cytological examinations were normal except for neutrophilia. One week later the lesion and the surrounding infiltrate and anterior-chamber reaction had increased slightly. The ulcer was again scraped. No organisms were noted on smear, but cultures again grew N. asteroides. Six weeks after the initial injury, despite daily irrigation of the ulcer and continuation of the intensive antibiotics, an endothelial line of keratic precipitates developed around the ulcer. This line and the ulcer size and depth showed progression over the next 2 days. A hypopyon formed, and the endothelial line extended towards the limbus (Fig. 2). Topical antibiotics were discontinued and

Fig. 3 Nocardia asteroides ulcer, I year after successful treatment with conjunctival flap

subconjunctival gentamicin was begun, with continuation of the oral sulphadiazine. Over the next 5 days the ulcerated cornea thinned to less than one-quarter thickness, and the anteriorchamber reaction increased. A further scraping was performed, but no organisms were seen on smear. A conjunctival flap was placed over the entire cornea, and the eye soon became quiet. The oral sulphadiazine was continued for 2 months. One year later, the conjunctival flap had thinned and the anterior chamber, lens, and retina (posterior pole only) were visualised as normal. The intraocular pressure as measured by pneumotonometry was 15 mmHg. The nasal half of the cornea was thinned to halfthickness over an area of 5 x 4 mm (Fig. 3). The cornea in this area was opaque, but the eye was quiet, and the uncorrected vision was 20/200. Later a 7-mm penetrating keratoplasty was successfully performed, and no organisms were found on histological examination of the corneal specimen. MICROBIOLOGICAL EXAMINATION

Fig. 2 Progressive Nocardia asteroides ulcer, 6 weeks after trauma and 2 weeks after chemotherapy

Corneal scrapings submitted soon after the patient was admitted to the Johns Hopkins Hospital revealed an aerobic growth of a pure culture of small, white, raised, dry colonies. Gram staining showed Gram-positive branching pleomorphic rods. Acid-fast staining by the Ziehl-Neelsen technique with a 3 % HC1-ENH decolorisation for 10 seconds showed partially acid-fast organisms. Biochemical testing revealed no acid production from lactose and xylose, urea was decomposed but tyrosine and xanthine were not, and there was no casein hydrolysis. The organism was identified as Nocardia asteroides. Subsequent specimens from the corneal ulcer submitted 7 days later grew the same organisms

Nocardia asteroides keratitis in pure culture. Susceptibility testing of the organisms cultured at the Johns Hopkins Hospital was done by an agar dilution technique as follows. The inoculum was prepared by incubating the organism in Mueller Hinton broth for 24 hours at 35°C. After vigorous vortexing, the larger particles were allowed to settle, and the suspension was removed and standardised against a 0-5 MacFarland BaSO4 standard. This suspension was diluted 1:10 and 0-01 ml was applied to the surface of the antibioticcontaining Mueller Hinton agar by means of a replicating device. All plates were incubated at 35°C for 48 hours before being examined. Inhibition was defined as no growth, 3 or fewer colonies, or the presence of a slight haze. The minimal inhibitory concentration (MIC) results of the antibiotics tested were as follows: methicillin, greater than 16 jig/ml; penicillin, 16 ,ug/ml; erythromycin, greater than 2 jig/ml; clindamycin, 2 jig/ml; tetracycline, 16 [±g/ml; chloramphenicol, greater than 8 ,ug/ml; cephalothin, greater than 32 ,ug/ml; ampicillin, 2 ,ug/ml; gentamicin, greater than 1 ,ug/ml. Discussion

451 may be differentiated from mycobacteria because Nocardia is only partially acid-fast, it forms fragmenting mycelia and has true branching (Tsukamura, 1970). In addition, the 2 groups differ in the lipid composition of their cell walls (Davis et al., 1969; Lechevalier et al., 1971). Nocardia is commonly involved in pulmonary infections, but its role in ocular infections is limited, as is evident from a search of the available literature (Table 1) (Bruce and Locatcher-Khorazo, 1942; Benedict and Iverson, 1944; Smith, 1952; Schardt et al., 1956; Sigtenhorst and Gingrich, 1957; Henderson et al., 1960; Gingrich, 1962; Rees, 1962; Davidson and Foerster, 1967; Meyer et al., 1970; Burpee and Starke, 1971; Newmark et al., 1971; Panijayanond et al., 1972; Jampol et al., 1973; Rogers and Johnson, 1977; Sher et al., 1977). Most of the intraocular cases of nocardia infection can be traced to metastatic spread of proved primary infections elsewhere, (Davidson and Foerster, 1967; Meyer et al., 1970; Burpee and Starke, 1971; Panijayanond et al., 1972; Jampol et al., 1973; Rogers and Johnson, 1977; Sher et al., 1977) or following exogenous trauma such as cataract extraction (Meyer et al., 1970). Five of the 7 previously reported nocardia infections of the cornea were preceded by trauma; 4 of these occurred in a rural setting (Schardt et al., 1956; Sigtenhorst and

Nocardia are usually soil organisms, and, although they are worldwide in distribution, nocardial infections are rare, especially in the eye. The 2 Gingrich, 1957; Gingrich, 1962; Newmark et al., most usual modes of infection are inhalation of 1971), and 1 was from a fishing accident (Ralph organisms, leading to pulmonary nocardiosis; and et al., 1976). The trauma in all cases was considered contamination of skin wounds with soil, leading to trivial. The cases ran variable courses, but all chronic destructive mycetomas. Nocardia asteroides resolved with retention of the eye and with reasonis usually an opportunistic pathogen, and pulmonary ably good vision. The remaining 2 cases were or generalised nocardiasis has become increasingly associated with a keratoconjunctivitis of obscure prevalent in patients with severe systemic diseases origin (Bruce and Locatcher-Khorazo, 1942; Benewho are receiving corticosteroids or antineoplastic dict and Iverson, 1944). One of the cases responded drugs. In addition, nocardia may rarely cause infec- to therapy, but the other was deteriorating when tions in other sites. lost to follow-up. The Nocardia genus and the genus Actinomyces In only 3 of the 7 cases was the topical adminisare members of the family Actinomycetaceae. Both tration of corticosteroids (Sigtenhorst and Gingrich, genera grow as fragile branching filaments that 1957; Newmark et al., 1971; Ralph et al., 1976) a readily fragment into bacillary rod and twig-like possible predisposing factor, and in these cases the elements. Nocardia are aerobic and somewhat acid- drugs had been administered only briefly before fast, whereas Actinomyces are anaerobic and not the diagnosis of nocardial infection. These patients acid-fast. With their filamentous growth and retained excellent vision. Often, however, the isomycelia-like colonies, the actinomycetes have a lation of the causative organism may be delayed, striking resemblance to fungi. However, a number and steroids may have been given for several months. of basic biological properties establish them as Our case emphasises the rural trauma, the slow bacteria (Davis et al., 1969; Bach, 1975). Occasion- initial course of the disease, the characteristic ally confusion arises in differentiating Nocardia morphology of a 'fungal-type' ulcer, and the profrom rapidly growing mycobacteria. Similarity gressive nature of a nocardial infection when it is between the genus Mycobacterium and the genus unresponsive to treatment. In this case intensive Nocardia has also been reported with respect to sulphonamide therapy, topically and systemically, antigenic structure, cell-wall composition, and was given in conjunction with tetracycline and bacteriophage susceptibility. Nocardia, however, gentamicin. Daily toilet of the ulcer, and 3 of the

Lawrence W. Hirst, G. Kenneth Harrison, William G. Merz, and Walter J. Stark

452

Table 1 Review of literature on ocular nocardiosis (A) NOCARDIA KERATITIS Case report

Age

Sex

Bruce and Locatcher- 50 Khorazo (1942)

M

Benedict and Iverson (1944)

23

F

Schardt et al. (1956)

33

Predisposing

cause

Site of infection

Treatment

Outcome

Punctate kerato-

Potassium iodide (a, b)*

Quiet eye

Sulphanilamide (a)

4 years gradual deterioration

Positive smear and culture

Argyrol (a) Cautery oxytetra-

20/80 quiet

Positive culture

conjunctivitis ? Scarlet fever

Chronic kerato-

conjunctivitis

M

Stone trauma on farm

Corneal ulcer

Potassium iodide (a) Copper sulphate (a) Zinc sulphate (a) Metaphen (a) Penicillin (a)

Diagnostic criteria

cline (a) Atropine (a) Achromycin (a, b)

Sigtenhorst and Gingrich (1957)

?

Cotton branch injury

Corneal ulcer

Cotton plant scratch

Corneal ucler

Dirt injury

Corneal ulcer

Sulphacetamide (a) Atropine (a)

Excellent

Cortisone (a)

Gingrich (1962)

53

M

Sulphacetamide (a)

20/50

Positive culture

20/25

Positive culture

Penicillin (c)

Sulphadiazine (b) Newmark et al. (1971) 6

M

Oxytetracycline (a) Corticosteroid (a)

Chloramphenicol (a) Sulphacetamide (a) Tetracycline (a) Idoxuridine (a) Sulphadiazine (b) Ralph et al. (1976)

11

F

Fishline sinker abrasion

Corneal ulcer

Neomycin (a) Prednisone (a) Homatropine (a) Polymixin (a) Gentamicin (a) Erythromycin (a) Ampicillin (d) Sulphacetamide (a) Penicillin (a) Bacitracin (a)

Positive culture

*Route of administration: a, topical; b, systemic oral; c, systemic parenteral; d, periocular; e, intraocular

scrapings during the early course of the infection, always revealed only the presence of nocardia. The initial growth of alcaligenes was not observed on subsequent scrapings. Although it is not at all certain that long-term use of a broad-spectrum antibiotic contributed to a predisposing state, it is interesting to note that the patient was on continuous oral tetracycline therapy for acne at the time of his injury and subsequent infection, until he discontinued the tetracycline when he first entered the hospital. In-vitro testing revealed resistance of the nocardia to tetracycline. In the face of progressive corneal thinning and increased anterior-chamber reaction despite a 3week period of intensive chemotherapy, an operation for conjunctival flap was performed, and the oral sulphadiazine was continued for 2 months postoperatively. Therefore the dramatic response after surgery is more difficult to evaluate; it could have

been due to the prolonged chemotherapy, but the lack of favourable response to sulphadiazine preoperatively makes this unlikely. Sulphonamides, both systemic and topical, have remained the drugs of choice for ocular nocardia infections (Lerner and Baum, 1973; Ripon, 1974). Sulphadiazine and sulphamethoxazole still appear to be superior to newer antimicrobial agents for treatment of nocardiosis (Black and McNellis, 1971; Ripon, 1974). Cephaloridine and also a trimethoprim-sulphamethoxazole combination have both been used successfully in systemic nocardiosis (Baikie et al., 1970; Lerner and Baum, 1973; Maderazo and Quintiliani, 1974; Ripon, 1974). With the nocardia recovered in the present case, however, susceptibility testing against other antimicrobials was done by agar dilution, and the results were as reported above. There are many reports of antibiotic susceptibility

453

Nocardia asteroides keratitis Table 1-continued (B) OTHER OCULAR NOCARDIOSES Case report

Age

Sex

Predisposing

cause

Site of intection

Smith (1952)

Cutler's implant

Smith (1952)

Corn grain trauma Dacryocystitis

Henderson et al. (1960)

49

F

Cow's tail injury

Treatment

Outcome

Chronic orbital discharge

Nodular scleritis

Diagnostic criteria Nocardia isolated

Excision lump Normal eye atropine (a) Chloramphenicol (b) Staphylococcus toxoid (c) Typhoid vaccine (c)

Positive histology

Sulphadiazine (b) Sulphacetamide (a)

Penikett and Rees (1962)

80

Davidson and Foerster (1967)

46

M

? Pulmonary, primary

Endophthalmitis

Meyer et al. (1970)

76

F

Cataract extraction

Meyer et al. (1970)

67

M

Gunshot to chest, pneumonia

Meyer et al. (1970)

56

M

Burpee and Starke (1971)

20

M

F

Dacryocystitis

Clear

Positive culture

Corticosteroids (a, b)

Enucleated

Positive histology

Endophthalmitis

Corticosteroids (a, b) Amphotericin (e) Tetracycline (b)

Enucleated

Positive histology

Chorioretinitis

Penicillin (c) Sulphadiazine (b) Cycloserine (b)

Died

Positive histology

20/300

Positive histology

Enucleation

Positive blood and eye culture

Curetted; chlortetra-

cycline (d)

Chorioretinitis OD Iodides (a) Endophthalmitis OS Eviscerated Bomb injury; soft- Endophthalmitis OD Penicillin (c) tissue sepsis Limb surgery tetracycline (b)

Chloramphenicol cephalothin (c) Gentamicin sulphadiazine (b) Kanamycin (c) Panijayanond et al. (1972)

30

M

Renal transplanta- Endophthalmitis tion Immunosuppression Nephric abscess

Cycloserine (b) Sulphisoxazole (b)

20/20 OS

Enucleation

Positive culture Submandibular

gland, nephric abscess

Jampol et al. (1973)

40

M

Arm abscess

Episcleritis

Streptomycin (c)

Rogers and Johnson (1977)

38

77

M

F

Sulphisoxazole (b)

Positive culture, eye

Sulphadiazine (b) Ampicillin

Hypogammaglobu- Endophthalmitis OS Vitrectomy linaemia Pulmonary Chorioretinitis OD Ampicillin (e) nocardiosis Atropine (a) Dexamethasone (a) Neomycin (a) Minocycline (b) Erythromycin (c)

20/200

Malignant lymphoma Immunosuppres-

Died

Endophthalmitis Necropsy diagnosis

sion

of nocardia (Black and McNellis, 1971; Bach et al., 1973; Lerner and Baum, 1973). It is difficult to compare the results of our single strain of nocardia with those in the literature, since different strains vary in susceptibility. There are numerous problems

Positive culture, arm

Renal transplant Chorioretinitis Pulmonary abscess Sher et a. (1977 )

Died

Blood and

pulmonary Positive, vitreous histology

Positive necropsy

Histology

and variations inherent in the testing (Lerner and Baum, 1973; Bach, 1975). However, our method of susceptibility testing, which closely follows the method of Wallace et al. (1977), produced results similar to theirs.

454

Lawrence W. Hirst, G. Kenneth Harrison, William G. Merz, and Walter J. Stark

Because nocardia tends to grow in clumps it is difficult to prepare uniform and reproducible suspensions containing equivalent numbers of organisms. In addition,.in-vitro susceptibility is influenced by pH and type of agar used in the assay. Variation in these parameters may well explain conflicts in results of susceptibility testing reported in the past. Further, in-vitro susceptibility may not correlate well with clinical response (Black and McNellis, 1971; Bach et al., 1973; Lerner and Baum, 1973; Lennette et al., 1974). For example, cycloserine or even the sulphonamides may appear ineffective by in-vitro testing despite a good clinical response. After the present case 2 further isolates of Nocardia asteroides were obtained from 2 other patients with non-ocular nocardiosis. Antimicrobial susceptibility testing was performed as before. Marked differences from the present results were obtained with some of the antibiotics. We can conclude that susceptibility testing will continue to be difficult to evaluate until standardised methods of testing for this species are established. The favourable long-term result in this case appears to have been achieved by covering the cornea with a conjunctival flap, followed by penetrating keratoplasty 24 months later. References

Bach, M. C. (1975). The chemotherapy of infections due to Nocardia. International Journal of Clinical Pharmacology and Biopharmacy. 11, 283-285. Bach, M. C., Sabath, L. D., and Finaldn, M. (1973). Susceptibility of Nocardia asteroides to 45 antimicrobial agents in vitro. Antimicrobial Agents and Chemotherapy, 3, 1-8. Baikie, A. G., MacDonald, C. B., Mundy, G. R. (1970). Systemic nocardiosis treated with trimethoprim and sulphamethoxazole. Lancet, 2, 261. Benedict, W. L., and Iverson, H. A. (1944). Chronic keratoconjunctivitis associated with Nocardia. Archives of Ophthalmology, 32, 89-92. Black, W. A., and McNellis, D. A. (1971). Susceptibility of Nocardia species to modern antimicrobial agents. In Antimicrobial Agents and Chemotherapy-1970, Proceedings of the Tenth Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, Ill., 18-21 October 1970, pp. 346-349. Edited by Gladys L. Hobby. American Society for Microbiology: Bethesda, Md. Bruce, G. M., and Locatcher-Khorazo, D. (1942). Actinomyces: recovery of the streptothrix in a case of superficial punctate keratitis. Archives of Ophthalmology, 27, 294-298. Burpee, J. C., and Starke, W. R. (1971). Bilateral metastatic intraocular nocardiosis. Archives of Ophthalmology, 86, 666-669. Davidson, S., and Foerster, H. C. (1967). Intraocular nocardial abscess, endogenous. Transactions of the American Academy of Ophthalmology and Otolaryngology. 71, 847-850.

Davis, B. D., Dulbecco, R., Eisen, H. N., Ginsberg, H., and Wood, W. B., Jr., (1969). Microbiology, 1st edn., pp. 875-877. Harper & Row: New York. Gingrich, W. D. (1962). Keratomycosis. Journal of the American Medical Association, 179, 602-608. Haggerty, T. E., and Zimmerman, L. E. (1958). Mycotic keratitis. Southern Medical Journal, 51, 153-159. Henderson, J. W., Wellman, W. E., and Weed, L. A. (1960). Nocardiosis of the eye. Report of case. Proceedings of Staff Meetings of the Mayo Clinic, 35, 614-618. Jampol, L. M., Strauch, B. S., and Albert, D. M. (1973). Intraocular nocardiosis. American Journal of Ophthalmology, 76, 568-573. Lechevalier, M. P., Horan, A. C., and Lechevalier, H. (1971). Lipid composition in the classification of Nocardiae and Mycobacteria. Journal of Bacteriology, 105, 313-318. Lennette, E. H., Spaulding, E. H., and Truant, J. P. (1974). Manual of Clinical Microbiology, 2nd edn. American Society for Microbiology: Washington, DC. Lerner, P. I., and Baum, G. L. (1973). Antimicrobial susceptibility of Nocardia species. Antimicrobial Agents and Chemotherapy, 4, 85-93. Maderazo, E. G., and Quintiliani, R. (1974). Treatment of nocardial infection with trimethoprim and sulfamethoxazole. American Journal of Medicine, 57, 671-675. Meyer, S. L., Font, R. L., and Shaver, R. P. (1970). Intraocular nocardiosis: Report of three cases. Archives of Ophthalmology, 83, 536-541. Newmark, E., Polack, F. M., and Ellison, A. C. (1971). Report of a case of Nocardia asteroides keratitis. American Journal of Ophthalmology, 72, 813-815. Panijayanond, P., Olsson, C. A., Spivack, M. L., Schmitt, G. W., Idelson, B. A., Sachs, B. J., and Nasbeth, D. C. (1972). Intraocular nocardiosis in a renal transplant patient. Archives of Surgery, 104, 845-847. Penikett, E. J. K., and Rees, D. L. (1962). Nocardia asteroides infection. American Journal of Ophthalmology, 53, 10061008. Ralph, R. A., Lemp, M. A., Liss, G. (1976). Nocardia asteroides keratitis: A case report. British Journal of Ophthalmology, 60, 104-106. Ripon, J. W. (1974). Medical Mycology. Saunders: Phila-

delphia. Rogers, S. J., and Johnson, B. L. (1977). Endogenous Nocardia endophthalmitis: Report of a case in a patient treated for lymphocytic lymphoma. Annals of Ophthalmology, 9, 1123-1131. Schardt, W. M., Unsworth, A. C., and Hayes, C. V. (1956). Corneal ulcer due to Nocardia asteroides. American Journal of Ophthalmology, 42, 303-305. Sher, N. A., Hill, C. W., and Eifrig, D. E. (1977). Bilateral intraocular Nocardia asteroides infection. Archives of Ophthalmology, 95, 1415-1418. Sigtenhorst, M. L., and Gingrich, W. D. (1957). Bacteriologic studies of keratitis. Southern Medical Journal, 50, 346-350. Smith, C. H. (1952). Ocular actinomycosis. Proceedings of the Royal Society of Medicine, 46, 209-212. Tsukamura, M. (1970). Relationship between Mycobacterium and Nocardia. Japanese Journal of Microbiology, 14, 187-195. Wallace, R. J., Septimus, E. J., Musher, D. M., and Martin, R. R. (1977). Disk diffusion susceptibility testing of Nocardia species. Journal of Infectious Diseases, 135,

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