22623
In this study , metabolic labeling of bacterial glycans with an azide - containing sugar allowed selective delivery of immune stimulants to azide - covered Hp .
 Chemical: azide; Chemical: azide
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: azide, azide 
Answer:
 Chemical: azide; Chemical: azide