Acinetobacter baummannii is aerobic, Gram negative and multidrug resistant bacterium (MDR) which is the main cause of the hospital acquired infection.Using nanoparticle as antimicrobial agents is a promising method to overcome the threat of MDR bacteria, this is not only because the natural effective properties of these particles against the bacterial cells, but it is also unlikely that microorganisms gain resistant against nanoparticles. In this study, silver nanoparticles (Ag-NPs) and synergistic effect of Ag-NPs with different antibiotics were tested against A. baummannii strain H72721 in Tryptic Soy Broth (TSB). Minimum inhibitory concentration (MIC) of each of the ampicillin, kanamycin, gentamycin and clindamycin on the bacterium was 11 mg/ml, 2 mg/ml, 0.5 mg/ ml, and 0.3 mg/ml respectively. In addition, MIC of the Ag-NPs alone towards the bacterial strain was found as (0.75 mg ml- 1). Interestingly, the inhibitory property of each of the tested antibiotics were greatly improved when they were used in combination with Ag-NPs compare to when they were used alone, and in case of each of the ampicillin and clindamycin the bacterial growth reduced 3 folds. Results from this study are strongly suggesting that Ag-NPs could be provide a successful approach to overcome the problem of MDR bacteria and could use as a superficial treatment for A. baummannii’s infections.

multidrug resistance, minimuminhibitory concentration, silver nanoparticles

Antibiotic resistance threats in the United States.

2013, Centers for Disease Control and Prevention.

Acinetobacter baumannii infections among patients at

military medical facilities treating injured U.S. service

members, 2002-2004. MMWR Morb Mortal Wkly

Rep, 2004. 53(45): p. 1063-6.

Davis, K.A., et al., Multidrug-Resistant Acinetobacter

Extremity Infections in Soldiers. Emerging Infectious

Diseases, 2005. 11(8): p. 1218-1224.

Howard, A., et al., Acinetobacter baumannii: an

emerging opportunistic pathogen. Virulence, 2012.

3(3): p. 243-50.

Turton, J.F., et al., Comparison of Acinetobacter

baumannii Isolates from the United Kingdom and the

United States That Were Associated with Repatriated

Casualties of the Iraq Conflict. Journal of Clinical

Microbiology, 2006. 44(7): p. 2630-2634.

Rice, L.B., Challenges in identifying new antimicrobial

agents effective for treating infections with Acinetobacter

baumannii and Pseudomonas aeruginosa. Clin

Infect Dis, 2006. 43 Suppl 2: p. S100-5.

Alsan, M. and M. Klompas, Acinetobacter baumannii:

An Emerging and Important Pathogen. Journal of

clinical outcomes management : JCOM, 2010. 17(8):

p. 363-369.

Urban, C., S. Segal-Maurer, and J.J. Rahal, Considerations

in Control and Treatment of Nosocomial

Infections Due to Multidrug-Resistant Acinetobacter

baumannii. Clinical Infectious Diseases, 2003. 36(10):

p. 1268-1274.

Harding, C.M., S.W. Hennon, and M.F. Feldman, Uncovering

the mechanisms of Acinetobacter baumannii

virulence. Nature Reviews Microbiology, 2018. 16(2):

p. 91.

WHO, Global priority list of antibiotic-resistant bacteria

to guide research, discovery, and development of

new antibiotics. Geneva: World Health Organization,

2017.

Pal, S., Y.K. Tak, and J.M. Song, Does the Antibacterial

Activity of Silver Nanoparticles Depend on the

Shape of the Nanoparticle? A Study of the Gram-Negative

Bacterium Escherichia coli. Applied and Environmental

Microbiology, 2007. 73(6): p. 1712-1720.

Stoimenov, P.K., et al., Metal Oxide Nanoparticles

as Bactericidal Agents. Langmuir, 2002. 18(17): p.

6679-6686.

Li, P., et al., Synergistic antibacterial effects of β-lactam

antibiotic combined with silver nanoparticles.

Nanotechnology, 2005. 16(9): p. 1912-1917.

Chudobova, D., et al., Effect of Ampicillin, Streptomycin,

Penicillin and Tetracycline on Metal Resistant and

Non-Resistant Staphylococcus aureus. International

Journal of Environmental Research and Public Health,

2014. 11(3): p. 3233-3255.

Kohanski, M.A., D.J. Dwyer, and J.J. Collins, How

antibiotics kill bacteria: from targets to networks.

Nature reviews. Microbiology, 2010. 8(6): p. 423-435.

Abdel Rahim, K.A. and A.M. Ali Mohamed, Bactericidal

and Antibiotic Synergistic Effect of Nanosilver

Against Methicillin-Resistant Staphylococcus aureus.

Jundishapur J Microbiol, 2015. 8(11): p. e25867.

Kim, S.-H., et al., Antibacterial activity of silver-

nanoparticles against Staphylococcus aureus and

Escherichia coli. Korean J. Microbiol. Biotechnol,

2011. 39(1): p. 77-85.

Gao, M., et al., Controlled synthesis of Ag nanoparticles

with different morphologies and their antibacterial

properties. Materials Science and Engineering: C,

2013. 33(1): p. 397-404.

McShan, D., et al., Synergistic antibacterial effect

of silver nanoparticles combined with ineffective

antibiotics on drug resistant Salmonella typhimurium

DT104. Journal of Environmental Science and Health,

Part C, 2015. 33(3): p. 369-384.

View All Artical