-Yersinia pestis is a nonmotile, non-spore forming, bipolar staining Gram-negative bacillus 

-Plague is a systemic zoonosis (infections in humans acquired by contact with animals) caused by Yersinia pestis, a gram-negative bacillus 

-It is a disease of rodents transmitted to humans by flea bites 

Symptoms & Signs 

Plague occurs in three common forms: 

Bubonic plague: sudden onset of fever, chills, prostration,headache, delirium,ulcer at the site of inoculation; regional lymphadenitis with suppuration of nodes (bubo) is the initial lesion

Pneumonic plague (Black Death): Cough, dyspnea, cyanosis, hemoptysis 

Septicemic plague: hemorrhage into skin and mucous membranes, shock

Diagnosis 

Aspirate from a bubo; culture of pus, sputum and blood; serologic testing 

Cultures show bipolar staining, Gram-negative coccobaccili (short rods with rounded ends with a ‘closed safety pin’ appearance) 

Treatment 

Doxycycline, ciprofloxacin,  levofloxacin, moxifloxacin, streptomycin, gentamicin, TMP-SMX