Inhibition of histamine accumulation by novel histaminedegradingspecies of Staphylococcus sp. isolated from goats and sheepmilk

Background and Aim : Histamine is an active amine compound that occurs in various fermentedfood that may causes adverse effects on the human health. Certain microorganisms are able todegrade histamine by an oxidative deamination reaction.Methods : Therefore, the present study aimed to quantify histamine forming and/or degradingactivity of the isolates derived from milk of goat and sheep herds, in Iran, by Capillary ZoneElectrophoresis (CZE) method; and we evaluated the molecular characteristics of staphylococcalisolates.Results : Among ۲۴۳ staphylococcal isolates, ۲۹ histamine-degrading bacteria were identified.One of these isolates, identified as Staph. epidermidis, No. ۶۰۵, exhibited the highest activitycompared to others, degrading available histamine to ۵۸.۳۳% within ۲۴ h. By PCR analysis, theisolate, No. ۶۰۵ that exhibited remarkable histamine-degrading activity lacked the genes encodingcoagulase and DNase, nor did it harbor any of the five classical enterotoxin genes.Conclusion : This is the first report that seven Staphylococcus species including, Staph.chromogenes, Staph. aureus, Staph. haemolyticus, Staph. epidermidis, Staph. pseudintermedius,Staph. agnetis and Staph. hyicus were able to degrade histamine, which were hitherto not knownto have this capacity. Therefore, Histamine-degrading activity is a definite criterion to introducefermenting organisms able to decrease histamine content in different food products.

کلیدواژه ها:

Staphylococcus ، histamine degradation ، milk ، capillary zone electrophoresis ، enterotoxin