<prompt> Gram-negative cocci isNisseriaHelicobactorCholeraCampylobactor  <response>: Neisseria is a gram-negative coccus typically arranged in pairs. Vibrio cholerae are gram-negative, curved bacilli. Campylobacter is gram-negative rods, typically comma-shaped. Helicobacter is a gram-negative spiral rod. Reference: Textbook of Microbiology; Anathanarayan and panickers; 10th edition; Page no: 230 