Biochemical Test of Acinetobacter baumannii

Reviewed By: Prof Mariam Mirambo

Acinetobacter baumannii is a type of gram-negative bacteria that has emerged as a significant nosocomial (hospital-acquired) pathogen, particularly affecting individuals with compromised immune systems, such as those in intensive care units (ICUs). It is known for its ability to survive in harsh environments and its resistance to many commonly used antibiotics, making it a challenging pathogen to treat.

Acinetobacter baumannii is often associated with hospital-acquired infections, particularly in settings like ICUs, where patients may have compromised immune systems and may be on broad-spectrum antibiotics, which can promote the growth of resistant bacteria.

It often exhibits resistance to commonly used antibiotics such as penicillins, cephalosporins, fluoroquinolones, and carbapenems. This resistance can be due to a variety of mechanisms, including the production of enzymes that inactivate antibiotics, alterations in drug targets, and the presence of efflux pumps that remove antibiotics from the bacterial cell.

Basic CharacteristicsProperties (Acinetobacter baumannii)
Bile SolubilityNegative (-ve)
CatalasePositive (+ve)
CitratePositive (+ve)
CoagulaseNegative (-ve)
GasNegative (-ve)
Gelatin HydrolysisNegative (-ve)
Gram StainingNegative (-ve)
H2SNegative (-ve)
HemolysisNegative (-ve)
IndoleNegative (-ve)
MR (Methyl Red)Negative (-ve)
Nitrate ReductionNegative (-ve)
OF (Oxidative-Fermentative)Non- Fermentative (Oxidative)
OxidaseNegative (-ve)
PigmentNegative (-ve)
UreaseNegative (-ve)
VP (Voges Proskauer)Negative (-ve)
Fermentation of
DNaseNegative (-ve)
GalactosePositive (+ve)
GlucosePositive (+ve)
LactateVariable (+/-)
LactoseMostly Negative (-ve), Some Positive (+ve)
MalonatePositive (+ve)
MaltoseVariable (+/-)
MannitolNegative (-ve)
MannosePositive (+ve)
RhamnosePositive (+ve)
SucroseNegative (-ve)
XylosePositive (+ve)
Enzymatic Reactions
Arginine DehydrolasePositive (+ve)
AzelatePositive (+ve)
Beta LactamasePositive (+ve)
Esculin HydrolysisNegative (-ve)
HistamineNegative (-ve)
HistidinePositive (+ve)
LeucinePositive (+ve)
LysineVariable (+/-)
MalatePositive (+ve)
Phenylalanine DeaminasePositive (+ve)
Tyrosine HydrolysisPositive (+ve)