Example of Shape Bacteria Examples Coccus (plural cocci) round or ballshaped bacterium Staphylococcus aureus, agent of skin infection Bacillus (bacilli) rod or cylindrical shaped bacterium Bacillus cereus, agent of food poisoning Escherichia coli, agent of traveler's diarrhea, food poisoningGram Negative bacilliInclude bacteria such as Ecoli, salmonella, and shigella Cocci have a spherical shape while bacilli have a rod shape There are 3 more types of bacteria which are less commonAnaerobic grampositive cocci are recovered from about % of specimens of intraabdominal infections, such as peritonitis and abscesses of the liver, spleen, and abdomen 24 Generally, these organisms are recovered with other organisms of intestinal origin, including Escherichia coli, the Bacteroides fragilis group, and Clostridium spp 3 Common Bacteria Shapes What is the difference between cocci and bacilli