Bacteremia Bacterial Proteins Bacteriological Techniques Carbohydrate Metabolism Citrobacter Citrobacter freundii Classification Community-Acquired Infections Cross Infection Distributions Enterobacter infection Enterobacteriaceae Infections Enzymes Feces Hospitals, University Humans Identification Opportunistic Infections Retrospective Studies Sensitivity and Specificity Spain Species Specificity Surgical Wound Infection Urinary Tract Infections article bacteremia bacterial protein carbohydrate metabolism classification communicable disease