Table 1.

Resistant strategies in K. pneumoniae

Resistant strategies in K. pneumoniae	Key findings	References
Enzymatic antibiotic inactivation and modification	β-Lactamase is an important resistance mechanism, which is divided into ESBLs, AmpC, and carbapenemases	[13,18]
Antibiotic targets alteration	K. pneumoniae causes drug resistance by mutating the target gene or methylating some bases	[19,20,21]
Porin loss and mutation	K. pneumoniae develops resistance by reducing the entry of antimicrobial agents into the bacteria by reducing the outer membrane pore protein	[25,26]
Increased efflux pump expression of the antibiotic	Efflux pumps reduce intracellular drug concentrations by releasing antimicrobial cells outside the cell, thereby reducing susceptibility to multiple antibiotics	[29]
Biofilm formation	Biofilms have osmotic barrier properties and are resistant to antimicrobial agents	[31,32,33]