**4. Antimicrobial resistance**

of healthcare workers are in frequent contact with these objects in patient surroundings. Hands become an important vectors of transmission in case of non-compliance with hand hygiene recommendations (Pittet et al., 2006). The ability of Acinetobacter to participate in biofilm formation promotes durability in surfaces and may contribute to continuation of environmen‐

Acinetobacter species posses the following virulence factors which enable transmission within health care settings: cell surface hydrophobicity, enzymes, toxic slime polysaccharides,

Acinetobacter spp. can cause infections in both hospital settings and in community. They are the second most commonly isolated non-fermenters in human specimens, after Pseudomonas aeruginosa. About 1-3% of health care-associated infections are caused by Acientobacter spp.

Acinetobacter poses little risk to healthy people. However, people who have weakened immune systems, chronic lung disease, or diabetes may be more susceptible to infections with Acinetobacter. Most infections caused by this multiresistant bacteria involve organ systems, which have a high fluid content (the respiratory tract, peritoneal fluid, and the urinary tract) and are associated with usage of indwelling devices. The distribution of the different types of hospital acquired infections is variable between hospitals and it depends on the hospital population and the type of performed procedures and interventions. Rates of mortality from Acinetobacter infections have a wide range from 5% in general wards to 54% in intensive care

One important feature of A. baumannii is its ability to cause outbreaks, which is in relation to antimicrobial resistance and resistance to desiccation (D'Agata et al., 2000; Villegas et Hart‐ stein, 2003). Acinetobacter spp. cause a wide range of health care-associated infections such as: ventilator-associated pneumonia, bloodstream infections, urinary tract infections, surgical site infections, meningitis, cholangitis, peritonitis, skin and wound infections, ventriculitis, and infective endocarditis. Suppuration is common feature in infections caused by Aciento‐ bacter (abscesses of the brain, lung and the thyroid; secondary infections of wounds or surgical

Acinetobacter can also cause infections in the community (Falagas et al., 2007). The predomi‐ nant community-acquired infections are: pneumonia, meningitis, cellulitis and bacteremia. High fatality rates in community were correlated to underlying conditions and risk factors,

Acinetobacter infections were also frequently reported during the natural disasters and wars (Iraq, Kuwait and Afghanistan wars). Pathogenic Acinetobacter infections were encountered in military personnel during the wars in Afghanistan and Iraq (O'Shea, 2012).Therefore it was

tal presence during outbreaks (Fournier et al., 2006).

86 Infection Control

verotoxins, siderophores and outer membrane proteins.

units (Kempf & Rolain, 2012).

trauma, and purulent lesions of the eye).

such as : alcoholism, diabetes and cancer.

named by media as Iraqibacter.

**3. Clinical importance — Infections and outbreaks**

The main challenge with A. baumannii is it's ability to acquire antimicrobial-resistance genes extremely rapidly, leading to multidrug resistance. Widespread use of antimicrobials within hospitals resulted to the emergence and increase of antimicrobial resistance among Acineto‐ bacter strains, in particular, the wide use of extended-spectrum cephalosporins and quinolones (Imperi et al, 2011).

Acinetobacter spp. are intrinsically less susceptible to antimicrobial agents than other repre‐ sentatives from the family Enterobacteriaceae. Various mechanisms played a role in the acquisition of a multiresistance phenotype amongst Gram-negative bacteria, including Acinetobacter strains such as: loss of porins, production of β-lactamases, increased expression of efflux pumps, presence of antibiotic-modifying enzymes, target site mutations, ribosomal mutations or modifications, metabolic bypass mechanisms and a mutation in the lipopolysac‐ charide (Poirel et al, 2011). The role of plasmids in the acquisition of antimicrobial resistance in A. baumannii is mostly related to their integron structures.

Acinetobacter spp have ability to acquire antimicrobial-resistance genes rapidly, leading to multidrug resistance. As a result, the clinical management of these infections has become a public health challenge in many countries. Nowadays, the most serious problem in the treatment of Acinetobacter infection is acquired multidrug-resistance, leaving only few antimicrobial agents as treatment options. This resistance is attributed to the presence of multiple resistant determinant among bacteria, which confers resistance to many groups of antimicrobial agents (Livermore, 2012). One of the main concerns about antimicrobial resist‐ ance in A.baumannii has been the resistance to the last line of antimicrobials through acquis‐ ition of carbapenem resistance - mainly through the acquisition of B and D class carbapenemases(Bou et al., 2012).
