How do you identify Acinetobacter?
Accurate identification of genus Acinetobacter can be performed using preliminary tests, viz., Gram stain, catalase, oxidase, and motility, which can be easily performed in any clinical laboratory. In-house PCR standardized in our study is specific and sensitive for the identification of Acinetobacter species.
What are the identifying characteristics of Acinetobacter species?
Characteristics. Acinetobacters are short, plump rods, typically measuring 1.0–1.5 × 1.5–2.5 μm when in the logarithmic phase of growth, but they often become more coccoid in the stationary phase. They are Gram-negative but may appear Gram variable, as is typical of members of the Moraxellaceae generally.
Is Acinetobacter spp Gram positive or negative?
gram-negative
INTRODUCTION Acinetobacter is a gram-negative coccobacillus that has emerged from an organism of questionable pathogenicity to an infectious agent of importance to hospitals worldwide [1].
What is the Gram stain of Acinetobacter?
Acinetobacter baumannii are Gram-negative, strictly aerobic, catalase-positive, oxidase-negative bacteria which, in log phase, have the appearance of short, Gram-negative rods, but in stationary phase the organism has a coccoid appearance [1].
Is Acinetobacter gram-negative rods?
INTRODUCTION Acinetobacter is a gram-negative coccobacillus that has emerged from an organism of questionable pathogenicity to an infectious agent of importance to hospitals worldwide [1].
Does Acinetobacter grow on MacConkey Agar?
Most strains of Acinetobacter, except some of the A. lwoffii strain, grow well on MacConkey agar (without salt). Although officially classified as not lactose-fermenting, they are often partially lactose-fermenting when grown on MacConkey agar.
Which characteristic best differentiates Acinetobacter species from Moraxella species?
Moraxella spp. are oxidase positive and nonmotile, which distinguishes them from Acinetobacter spp. and most Pseudomonas spp. Moraxella spp.
Is Acinetobacter baumannii Gram stain?
Acinetobacter baumannii is a pleomorphic aerobic gram-negative bacillus (similar in appearance to Haemophilus influenzae on Gram stain) commonly isolated from the hospital environment and hospitalized patients. A baumannii is a water organism and preferentially colonizes aquatic environments.
What antibiotics treat Acinetobacter?
When infections are caused by antibiotic-susceptible Acinetobacter isolates, there may be several therapeutic options, including a broad-spectrum cephalosporin (ceftazidime or cefepime), a combination beta-lactam/beta-lactamase inhibitor (ie, one that includes sulbactam), or a carbapenem (eg, imipenem or meropenem).
Is Acinetobacter Gram-negative rods?
What Agar does Acinetobacter baumannii grow on?
baumannii. Sheep blood agar and MacConkey agar are conventionally used for detection of A. baumannii in clinical cultures; however, these methods are non-selective for A. baumannii.
What is the morphology of Acinetobacter baumannii?
A. baumannii is genomic species number 2 [2]. Variable morphology and staining of Acinetobacter species. The organism appears as gram-negative cocci and bacilli in the top figure A (Gram stain of sputum) but as gram-positive bacilli in the bottom figure B (Gram stain of blood).
What disease does Acinetobacter cause?
Acinetobacter baumannii can cause infections in the blood, urinary tract, and lungs (pneumonia), or in wounds in other parts of the body. It can also “colonize” or live in a patient without causing infections or symptoms, especially in respiratory secretions (sputum) or open wounds.
Does Acinetobacter grow on MacConkey agar?
Does Acinetobacter baumannii grow on MacConkey agar?
MacConkey agar may be reliable for isolating Acinetobacter species but it is non-selective for Acinetobacter and does not differentiate Acinetobacter from other non-lactose fermenting gram-negative bacteria.
How do you differentiate Moraxella and Neisseria?
They can be differentiated from Moraxella and Neisseria species by a catalase test. Most Kingella species are catalase negative; Moraxella and most Neisseria species (except Neisseria elongata) are catalase positive.
What shape is Acinetobacter?
Acinetobacter is notorious, however, for variable morphology, differential uptake of Gram stain, and relative lack of reactivity on biochemical assays (Figure). The organism is typically rod-shaped during rapid growth but forms coccobacilli during stationary phase.
What antibiotic treats Acinetobacter?
How do you identify Acinetobacter species?
Identification of Acinetobacter species is complicated by lack of standard identification techniques. Initially, identification was based on phenotypic characteristics such as growth temperature, colony morphology, growth medium, carbon sources, gelatin hydrolysis, glucose fermentation, among others.
How many species are there in the genus Acinetobacter?
The genus Acinetobacter comprises 38 validly named species. Identification of Acinetobacter species is complicated by lack of standard identification techniques.
What is Acinetobacter baumannii?
Acinetobacter species are a key source of infection in debilitated patients in the hospital, in particular the species Acinetobacter baumannii . Species of the genus Acinetobacter are strictly aerobic, nonfermentative, Gram-negative bacilli.
What is the Acinetobacter media?
Leeds Acinetobacter Medium is a novel antibiotic-containing selective medium that combines its selectivity with differential characteristics and has been used for the improved isolation of Acinetobacter species from both clinical and environmental sources ( Jawad et al., 1994 ).