intestinal carriage of numbers of this magnitude

Выражение встречается в следующем контексте:

In a study of bird droppings around Boston Harbor that compared fecal coliforms, enterococci, and F-specific coliphages, the cfu/g of coliforms found in bird droppings were as follows: goose, 10^1-10^5; pigeon, 10^5-10^9; and herring gull, 10^3-10^8. Further, up to 10^6 somatic coliphages, 10^8 enterococci, and 10^2 F-specific coliphages per gram of feces were found. The intestinal carriage of numbers of this magnitude by these healthy avians can lead to the unjustified rejection of water or seafood products from such environments.

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