It is common to speak of an entire species of bacteria as pathogenic when it is identified as the cause of a disease (cf. Koch's postulates). However, the modern view is that pathogenicity depends on the microbial ecosystem as a whole.
If someone files a motion before the date an answer to a complaint is due, the timeline to respond to the motion is: 10 days from the date of service of the motion, OR. the date the defendantâs answer is due (20 days from the date the complaint was served), whichever is later.
As you pointed out, your mother's response to the summons and complaint will be due within 20 days after she received service. Your mother will need to file an answer in response to the complaint. (The alternative would be to file a motion to dismiss.