From the Research
Enterobacteriaceae should be classified into groups based on their biochemical properties, clinical significance, and antibiotic resistance patterns, with a focus on lactose fermentation, biochemical reactions, and resistance patterns such as ESBL and carbapenem-resistance, as this classification system helps clinicians identify bacteria quickly and select appropriate antimicrobial therapy 1. The primary classification of Enterobacteriaceae divides them into lactose fermenters and non-lactose fermenters, which is useful for initial identification in laboratory settings.
- Lactose fermenters include Escherichia, Klebsiella, and Enterobacter species, which produce acid from lactose and appear as pink or red colonies on MacConkey agar.
- Non-lactose fermenters include Salmonella, Shigella, and Proteus species, appearing as colorless colonies. Further grouping is based on biochemical reactions such as:
- Indole production
- Motility
- Urease activity
- Citrate utilization Clinically relevant groupings include:
- Opportunistic pathogens (E. coli, Klebsiella)
- Enteric pathogens (Salmonella, Shigella)
- Urinary tract pathogens (Proteus, Providencia) Some classifications focus on antibiotic resistance patterns, particularly:
- ESBL (Extended-Spectrum Beta-Lactamase) producers
- Carbapenem-resistant Enterobacteriaceae (CRE), which have significant treatment implications, as noted in studies on the emergence of carbapenemases, such as Klebsiella pneumoniae carbapenemases (KPCs) 2. This classification system helps clinicians identify bacteria quickly, predict their pathogenic potential, and select appropriate antimicrobial therapy based on typical susceptibility patterns of each group, with recent studies highlighting the importance of molecular methods and taxonomic revisions in the classification of Enterobacteriaceae 1.