<Ul> <Li> Salmonella typhi </Li> <Li> Salmonella typhimurium </Li> </Ul> <Tr> <Td> Shigella </Td> <Td> <Ul> <Li> Shigella sonnei </Li> </Ul> </Td> <Td> Negative </Td> <Td> rods </Td> <Td> Facultative anaerobic </Td> <Td> extracellular </Td> </Tr> <Ul> <Li> Shigella sonnei </Li> </Ul> <Tr> <Td> Staphylococcus </Td> <Td> <Ul> <Li> Staphylococcus aureus </Li> <Li> Staphylococcus epidermidis </Li> <Li> Staphylococcus saprophyticus </Li> </Ul> </Td> <Td> Positive, darkly </Td> <Td> Round cocci </Td> <Td> Facultative anaerobic </Td> <Td> extracellular, facultative intracellular </Td> </Tr>

Determine whether each pathogen on the list below is an extracellular or an intracellular pathogen