I have a client whose doctor said she has strep from contaminated implements.
Based upon the history of your client, it seems to me that it would be more likely that the client developed an allergy to the acrylic material rather than an infection of the skin due to contaminated implements. It is possible, however, that if a person gets an allergic reaction on the skin and around the nails with a rash, then a secondary strep infection could develop because the skin is now open the not completely normal. However, this would not be due to contaminated implements. If you clean your instruments properly after every use and sterilize them, then it is not very likely that your client developed an infection from your implements in the first place. It should be added that simply cleaning the instruments is not adequate. They must be properly disinfected after each use.