Scombroid

Several taxa of Enterobacteriaceae inclnding Morganella morganii, Proteus vulgaris, and Raoultella (Klebsiella) planticola are able to decarboxylate the amino acid histidine, which is abundant in the mnscle tissne of scombroid hsh (Yoshinaga and Frank 1982 Takahashi et al. 2003). The histamine produced has been associated with an incident of scombroid fish poisoning (Taylor et al. 1989). 

Taylor SL, JE Stratton, JA Nordlee (1989) Histamine poisoning (scombroid fish poisoning) an allergy-like intoxication. Clin Toxicol 27 225-240. 

Bjeldanes, L., Shultz, D.E. and Morris, M.M. (1978). On the aetiology of scombroid poisoning cadaverine potentiation of histamine toxicity in the guinea-pig, Food Cosmet. Toxicol., 16, 157. 

Lopez-Sabater, E., Rodriguez-Jerez, J.J., Hernandez-Herrero, M. and Mora-Ventura, M.T. (1996). Incidence of histamine-forming bacteria and histamine content in scombroid fish species from retail markets in the Barcelona area, Int. J. Food... 

Taylor, S., Guthertz, L.S., Leatherwood, M. and Lieber, E.R. (1979). Histamine production by Klebsiella pneumoniae and an incident of scombroid fish poisoning, Appl. Env. Microbiol., 37, 274. 

Scombroid poisoning is caused by ingestion of foods containing unusually high levels of histamine. 

Types of Fish. The fish most commonly implicated in these outbreaks are the so-called scombroid fish belonging to the families Scomberesocidae and Scombridae. These fish would include the many varieties of tuna, skipjack, bonito, albacore, mackerel, Spanish mackerel, bluefish, saury, butterfly kingfish, and seerfish. Tuna, skipjack, and mackerel are the most commonly involved scombroid fish. 

Several types of non-scombroid fish can also be incriminated in outbreaks of scombroid poisoning. Thus, scombroid poisoning is a... 

Among the non-scombroid fish, mahi-mahi is the most common fish implicated in histamine poisoning in the U.S. Other non-scombroid fish that have been involved in outbreaks of histamine poisoning are sardines, pilchards, anchovies, herring, black marlin, and kahawai. 

While the evidence implicating histamine as the causative agent of scombroid poisoning is compelling, Japanese investigators at one time isolated a histamine like substance called saurine that was possibly involved in scombroid poisoning (15). Saurine has since been identified as the phosphate salt of histamine (16). 

Given the compelling evidence that histamine is the causative agent in scombroid poisoning, orally administered histamine is remarkably non-toxic to humans (14.17.18). Weiss et al. (17) first demonstrated the lack of toxicity of orally administered histamine... 

This paradox between the lack of toxicity of pure histamine and the apparent toxicity of equivalent doses of histamine in spoiled fish could be explained by the existence of potentiators of histamine toxicity in spoiled fish. These potentiators would serve to lower the threshold dose of histamine necessary to elicit scombroid poisoning symptoms in humans. 

Several possible potentiators of histamine toxicity have been suggested by various in vivo and in vitro experiments, although none of these substances has been clearly implicated in scombroid poisoning. 

Further research will be necessary to demonstrate conclusively that inhibition of histamine metabolism is responsible for the potentiation of histamine toxicity that is apparently observed in scombroid poisoning. In vivo experiments will be necessary to show that hepatic histamine metabolism is also compromised by the ingestion of suspected potentiators. Also, the effectiveness of cadaverine and other possible potentiators must be demonstrated under conditions where the histamine level exceeds the potentiator concentration by a factor of approximately 10. This concentration ratio would parallel that found in spoiled tuna more closely than the levels used in the experiments of Lyons et al. (48). 

Histamine also acts on extravascular smooth muscles to cause contraction or relaxation. Most often, contraction is due to activation of Hj receptors and relaxation to activation of H2 receptors (32). In man, histamine causes contraction of bronchial and intestinal smooth muscles. Histamine-induced contraction of guinea pig ileum is a standard bioassay for histamine. Its effects on smooth muscle of the eye and genitourinary tract are important in some species but not in human ( ). In scombroid poisoning cases. 

Histamine also evokes a copious secretion of highly acidic gastric juice from the gastric glands at doses below those that influence blood pressure (32). This effect of histamine is mediated through 2 receptors on the parietal cells. The importance of this effect in scombroid poisoning is not knowi. Histamine also has some stimulant actions on salivary, pancreatic, intestinal, bronchial, and lacrimal secretions (32), but these effects are relatively unimportant. 

The threshold toxic dose for histamine in foods is not precisely known. Estimates are difficult to acquire from outbreaks of histamine poisoning because of the variability in histamine content in the fish (1,65). Simidu and Hibiki ( ) estimated the threshold toxic dose for histamine in fish to be approximately 60 mg/100 g, but their methods were not terribly precise. Based on experience acquired in the investigation of hundreds of scombroid poisoning incidents, the U.S. Food and Drug Administration recently established 50 mg/100 g as the hazard action level for histamine in tuna. They have not yet established regulatory limits for histamine in other fish or cheese. 

Amine build-up in fish muscle usually results from decarboxylation of amino acids in the muscle by enzymes of bacterial origin. This review will present information on the activity of bacterial decarboxylases and the formation of amines in fish. Mechanisms of decarboxylase action and production of bacterial decarboxylases in fish muscle are discussed. Emphasis is placed upon studies dealing with formation of histidine decarboxylase and histamine. Histamine, because of its involvement in Scombroid food poisoning, has been extensively studied with regard to its formation in fish and fishery products. 

Examples of amines that frequently occur in fish muscle include cadaverine from lysine, putrescine from ornithine and histamine from histidine. Histamine, because of its involvement in Scombroid food poisoning (histamine intoxication), has been extensively studied with respect to factors influencing its formation in many different fish species. Tuna and other fish from the families Scomberesocidae and Scombridae and a non-scombroid fish, mahi-mahi (dolphin fish) have been most... 

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