Vibrio parahaemolyticus, a gram-negative halophilic motile bacillus,1 is common to various marine environments,2'3 and has been widely reported as a source of epidemic gastroenteritis.4'5 Isolated cases of wound infections and septicemia have been reported,6'7 but to our knowledge no ocular infections have been noted. This is a report of endophthalmitis caused by V. parahaemolyticus and a discussion of the singular clinical presentation and cultural requirements of the organism.
A 9-year-old healthy white female was swimming in the Gulf of Mexico near Galveston, Texas in June 1 979. Fish parts and shellfish parts were noted in the water. She was struck by a wave and felt a sharp pain in her right eye but this abated rapidly. The next morning the vision was markedly decreased in the involved eye, the eyelids were swollen, the conjunctiva red, and the cornea appeared bright green to the parents. An ophthalmologist was consulted that day and a corneal puncture wound was noted at the 6 o'clock limbus. The anterior chamber was seen to be filled with a light green exudate, and endophthalmitis was diagnosed. Oral Keflex, 250 mg qid, and Maxitrol topically were started. After three days of such treatment, no clinical resolution was apparent and the patient was referred to The University of Texas Medical Branch at Galveston.
On the day of admission, four days postinjury, and three days after the start of Keflex, the vision in the right eye was HM with intact color discrimination. The corrected vision in the left eye was 20/20and the left eye was entirely normal in all respects for mild myopia. The right lids were edematous, the conjunctiva markedly red and chemotic, and the anterior chamber was filled with exudate. X-rays were negative for radio-opaque foreign bodies and the Bscan ultrasound was normal.
An anterior chamber paracentesis on the day of admission revealed possible gram + cocci and gram - rods; a few PMNs were present. Cultures from this material were eventually negative for bacteria and fungi. Methicillin, 100 mg, and Gentamicin, 20 mg, were injected sub-Tenon's, and IV Methicillin, 650 mg q 6 hours, and IV Gentamicin, 50 mg q 8 hours were started, along with topical Gentamicin and Atropine drops. Seven days later the vision was light perception only and a complete pupillary membrane had caused an iris bombe with a flat anterior chamber. The patient then underwent a pars plana lensectomy, removal of the pupillary membrane, sector iridectomy, and anterior vitrectomy with a Douvas rotoextractor. The cataractous lens had been almost entirely absorbed spontaneously, leaving only opaque juxtaposed anterior and posterior capsules. The anterior chamber deepened immediately and a greenish posterior light reflex was noted. SubTenon's antibiotics were again administered after vitreous aspirates were obtained for smears and cultures. No organisms were seen, but one culture yielded two colonies of an oxidase positive, gramnegative rod. The isolate had the characteristics shown in Table I and was identified as V. parahaemolyticus. It was found to be sensitive to ampicillin, chloramphenicol, sulfadiazine, and aminoglycoside antibiotics but relatively resistant to carbenicillin and cephalothin. The patient was maintained on IV methicillin and gentamicin, and oral prednisone, 60 mg qd was begun, but two days later the pupil was again occluded with inflammatory debris.
BIOCHEMICAL CHARACTERISTICS OF MARINE VIBRIO SPECIES
Two days later, 1 4 days after the injury, the patient underwent a final procedure, a pars plana posterior vitrectomy and pupillary membrane removal. The central vitreous was noted to have a peculiar clear bright green quality similar to mint jellly. Smears and cultures were negative. Intravitreal methicillin, 2 mg, and getamicin, 0.4 mg, were administered as well as additional sub-Tenon's doses of the same agents. IV methicillin and gentamicin were maintained and systemic steroids were continued in slowly decreasing doses. Six days later the vision was 20/1 00 with a +1 1 .00 sphere and intraocular inflammation was decreasing. IV antibiotics were stopped and oral ampicillin, 250 mg qid, was begun. The cornea was clear, the anterior chamber deep, and the pupil open. The injury scar was still visible at the 6 o'clock limbus (Fig. 1). Two months later the vision 20/60 best corrected, all antibiotics were stopped, and intraocular inflammation was decreasing.
V. parahaemolyticus is an ubiquitous marine organism first recognized as a cause of human disease by Fujino in a 1953 report of a 1950 epidemic of food poisoning in Japan. * Since that time V. parahaemolyticus has become recognized as the leading cause of epidemic gastroenteritis in Japan and has caused 16 major outbreaks of food poisoning in the United States. It has been isolated from sea water, shellfish, and marine sediments on all three coasts of the United States,2'1 and has caused isolated'''"' as well as epidemic cases4'5 of gastroenteritis. The usual human disease by V. parahaemolyticus is an acute gastroenteritis with diarrhea and abdominal pain the chief features. The disease begins 9 to 25 hours after ingesting raw or improperly cooked fish or shellfish and lasts two-three days, with a very low mortality. The organism has been isolated from fish and shellfish in Europe, Australia, and India, and indeed is believed to exist worldwide in estua ri ne environments. V. parahaemo/yticus has only occasionally been identified in tissue infections,6'7 and has never, to our knowledge, been previously recognized as the causative agent of ocular infections. One case of a "Vibrio" ocular infection has been reported, but the causative organism was an anaerobic bacterium, Butyrivibrio fibrisolvens. rather than a Vibrio species." The lack of reported V. parahaemolyticus ocular infections seems surprising given the ubiquitous nature of the organism and the popularity of marine sports. The usual cultural requirements of the organism and a lack of clinical suspicion of marine Vibrio infections may in part explain the absence of such reports.
Fig. I. The affected eye after lensectomy and vitrectomy. Site of the corneal perforating injury is visible at the 6 o'clock limbus.
Fig. 2. Gram stain of cu/ture material. Pleomorphic gram-negative rods.
V. parahaemolyticus is a marine bacterium that requires increased salt concentration for growth. However, V. parahaemolyticus can be cultured on agar media routinely used in a clinical laboratory, because these media contain sufficient salt to support growth of the organism. A selective, differential medium, such as thiosulfate-citrate-bile salts-sucrose agar (TCBS), may be useful for isolation of V. parahaemolyticus from specimens containing other bacteria.12 Colonies appear within 18-24 hours of incubation at which time they are 2-4 mm in diameter, rounded and smooth. Colonies on TCBS medium are bluish-green due to citrate utilization and they are distinguished from other organisms that may form yellow colonies due to fermentation of sucrose. Gram stained smears of V. parahaemolyticus from agar media (Fig. 2) reveal pleomorphic gramnegative rods with morphology ranging from typical small curved rods to large, swollen forms. The latter may be due to the osmotic effects of growth at low salt concentration.
V. parahaemolyticus is one of several pathogenic marine Vibrio species.1 This group of organisms is composed of curved gram-negative rods with polar flagella. These bacteria are oxidase positive and they ferment glucose and require salt from optimum growth. Three species are recognized - V. parahaemolyticus. V. alginolyticus, and an unnamed group referred to as lactose positive Vibrio. Tests that are useful in differentiating these three groups are Voges-Proskauer (VP), citrate, sucrose, ONPG, and salt requirements. V. alginolyticus is VP and sucrose positive but citrate negative, and it will grow in 10% NaCI (Table I). V. parahaemolyticus is VP and sucrose negative but citrate positive and it requires 3 to 8% NaCI for growth but will not grow in 10% NaCI. The lactose positive vibrio is nearly identical to V. parahaemolyticus except that it is ONPG positive. The organism isolated from the patient described here had the biochemical characteristics of V. parahaemolyticus. This organism has also been recovered from numerous seawater samples collected from Galveston island (unpublished observations).
V. parahaemolyticus isolates reported previously have shown variable susceptibility to antimicrobial agents. Most V. parahaemolyticus stains are resistant to penicillin, ampicillin, and carbenicillin and sensitive to cephalothin.' However, clinical isolates sensitive to ampicillin and resistant to carbenicillin and cephalothin have been reported,'1 and this was the pattern exhibited by the organism recovered from our patient. All isolates of V. parahaemolyticus have been reported to be susceptible to gentamicin that would appear to be the drug of choice for initial therapy. Susceptibility testing of clinical isolates is essential for the selection of appropriate a Iter nati ve antimicrobial therapy.
It is interesting to note that in experimental infections with V. parahaemolyticus in animals, green peritoneum is a hallmark autopsy findings.2 Our patient demonstrated a green anterior chamber exudate within 24 hours of injury, and the central vitreous was a peculiar clear green "mint jelly" color. Therefore, it would seem reasonable to suspect V. parahaemolyticus infection in any salt waterrelated ocular injury and especially when greenish discoloration of tissue or exudate is present.
A healthy child developed V. parahaemolyticus endophthalmitis after receiving a perforating corneal injury while swimming in the Gulf of Mexico. Peculiar greenish anterior chamber and vitreous exudates were a striking feature of the infection. A history of ocular injury in a salt water environment should alert the clinician to the possibility of infection due to a marine Vibrio, and appropriate means should be employed for the isolation and identification of such organisms.
1 . Hollis DG, Weaver RE, Baker GN, et al: Halophilic Vibrio species isolated from blood cultures. J Clin Microbiol 3:425, 1976.
2. Ward BQ: Isolations of organisms related to Vibrio parahemolyticus from American estuarne sediments. Appi Microbiol 16:543, 1968.
3. Krantz GE, Colwell RR, Lovelace E: Vibrio parahaemolyticus from the Blue Crab Callinectes sapidus in Chesapeake Bay. Science 164:1286, 1969.
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8. Fujino T, Okuno Y, Nakada D, et al: On the bactériologie examination of Shirasu-food poisoning. Med J Osaka Univ 4:299, 1953.
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10. Guthrie WW: Vibrio parahaemolyticus. JAMA 236:822, 1976.
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12. Lennette EH, Spaulding EH, Trauant JP: Manual of Clinical Microbiology, 2nd ed. Washington, American Society for Microbiology, 1 974, ? 920.
BIOCHEMICAL CHARACTERISTICS OF MARINE VIBRIO SPECIES