Miscellaneous antibacterial agents

Metronidazole is not active against which of the following organism

A 30 years old sexually active female presents with vulvar irritation, redness and foul smelling vaginal discharge. Vaginal discharge wet mount shows highly motile pear shaped flagellated protozoa. Which of the following drugs is appropriate to be given to her and her partner?

A woman presents in OPD with complain of abdominal pain and blood stained foul smelling diarrhea alternating with constipation since one week. She gives a history of an out of city picnic with her friends 15 days ago. Stool examination shows entamoeba histolytica cysts. Which of the following drugs would be most suitable for this patient?

Fidaxomicin is a narrow-spectrum antibiotic. It inhibits bacterial RNA polymerase. It is approved for treatment of which of the following infections?