American Journal of Microbiological Research
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American Journal of Microbiological Research. 2014, 2(2), 60-62
DOI: 10.12691/ajmr-2-2-3
Open AccessArticle

Colistin, Polymyxin B and Tigecycline Suspectibility to Metallo Betalactamase Producing Acinetobacter Baumannii Isolated From Tertiary Health Care Hospital

Venkata sarada1, , Ratna Rao1, Ratna mani1 and K V Ramana2

1Department of microbiology, Apollo health city, Jubilee Hils, Hyderabad, Andhra Pradesh,India

2Department of microbiology, Prathima Institute of Medical Sciences, Karimnagar, Andhrapradesh, India

Pub. Date: March 19, 2014

Cite this paper:
Venkata sarada, Ratna Rao, Ratna mani and K V Ramana. Colistin, Polymyxin B and Tigecycline Suspectibility to Metallo Betalactamase Producing Acinetobacter Baumannii Isolated From Tertiary Health Care Hospital. American Journal of Microbiological Research. 2014; 2(2):60-62. doi: 10.12691/ajmr-2-2-3


Acinetobacter baumannii have emerged as important nosocomical pathogens especially in intensive care patients. Carbapenems are the choice of drug for their treatment but they started developing resistance to carbapenems predominatantly by producing Metallo beta-lactamases (MBL). Treatment of such carbapenem resistant Acinetobacter has led to reintroduction of polymyxins like colistin, polymyxin B and newer tetracycline group of drugs like tigecycline. As there were limited studies in on Minimum inhibitory concentrations (MIC) of MBL producing Acinetobacter to polymyxins and tigecyclines from india, the present study was undertaken. MBL detection was done by combined disc test with imipenem and EDTA. MIC of the drugs was determined by Agar dilution method. MIC50 and MIC90 of tigecycline were found to be 0.5 μg/ml and 1 μg/ml respectively. Suseptibility MIC ranges for tigecycline were found to be 0.5 to 2 μg/ml. Resistance rates for tigecycline were found to be 6%. MIC50 and MIC90 of colistin was found to be 2 μg/ml. Susceptibility MIC ranges for colistin were found to be 0.25 to 1 μg/ml. MIC50 and MIC90 of polymyxinB were found to be 1 μg/ml and 2 μg/ml respectively. Susceptibility MIC ranges for polymyxin B were found to be between 0.5 to 2ug/ml. The susceptibility rates with colistin and polymyxin B were found to be 99.2% and 100% respectively. Polymyxin B and colistin are very good drugs of choice for treatment of MBL producing Acinetobacter baumannii with 0.8% and 0% resistance rates. Though good sensitivity was noticed with tigecycline, we found 6% resistance rate.

Acinetobacter baumannii Metallo beta-lactamases(MBL) colistin polymyxin B Minimum inhibitory concentrations (MIC) tigecycline

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[1]  Maria C. B. Tognim, Ana C. Gales (july 2006) Dissemination of IMP-1 Metallo-b-Lactamase–Producing Acinetobacter Species in a Brazilian Teaching Hospital. Infect. Control Hosp. Epidemiol. 27: 742-747.
[2]  LisaA.Kroeger,Laurie B.Hovde (sept.2007) colistin Methanesulfonate against Multi drug resistant Acinetobacter baumanni in an In vitro Pharmacodynamic model. Antimicrob. Agents Chemother 51: 3431-3433.
[3]  Quale J, Bratu S, Landman (2003). Molecular epidemiology and mechanisms of carbapenem resistance in Acinetobacter baumannii endemic in New York City. Clin Infect Dis 37: 214-220.
[4]  Brand M, Wright Edward H(2008). Current Perspectives on Extended-Spectrum Beta-Lactamase–Producing Gram-Negative Bacilli. Journal of Pharmacy Practice 21: 338-345.
[5]  Alexandr Nemec & lenie dijshoorn (2010). Variations in colistin suspectibility among different species of the genus Acinetobacter. Antimicrob. Agents Chemother 65: 365-369.
[6]  M.Dizbay,A.Altuncekic (2008). Colistin and tigecycline susceptibility among multidrug-resistant Acinetobacter baumannii isolated from ventilator-associated pneumonia. Int J Antimicrob Agents 32: 29-32.
[7]  ME Evans, DJ Feola, RP Rapp(1999). Polymyxin B sulfate and colistin: old antibiotics for emerging multiresistant gram-negative bacteria. Ann Pharmacother 33: 960-967.
[8]  Matthew E, Falagas, Sofia K(2005) Colistin: The Revival of Polymyxins for the Management of Multidrug-Resistant Gram-Negative Bacterial Infections. Clin Infect Dis 40: 1333-41.
[9]  K. Gupta, S. Kaushal, S. C. Chopra (2006) Tigecycline a novel glyclycycline antibiotic.Indian J Pharmacol 38: 218-219.
[10]  Drosos E. Karageorgopoulos, Theodore Kelesidis (2008) Tigecycline for the treatment of multidrug-resistant (including carbapenem-resistant) Acinetobacter infections: a reviewof the scientific evidence. J Antimicrob Chemother 62: 45-55.
[11]  Thanaporn Hortiwakul, Pantip Chayakul, (2009). In Vitro Activity of Colistin, Fosfomycin, and Piperacillin/tazobactam Against Acinetobacter baumannii and Pseudomonas aeruginosa in Songklanagarind Hospital, Thailand. J Infect Dis Antimicrob Agents 26 : 91-96.
[12]  Marchiaro P, Mussi MA, Viale AM Villa(2005). Sensitive EDTA based Microbiological assays for detection of metallo β-lactamases in non fermentative Gram negative bacteria. J. Clin. Microbiol. 43:5648-5652.
[13]  Ramana KV, Mohanty SK, Wilson CG(2009). Staphylococcus aureus colonization of anterior nares of school going children. Indian J Pediatr 76:813-816.
[14]  Visanu Thamlikitkul, Surapee Tiengrim (2007).High tigecycline resistance in multidrug-resistant Acinetobacter baumannii J Antimicrob Chemother 60: 177-178.
[15]  María Eugenia Pacho, Manuel Enrique (2004).Activity of Tigecycline (GAR-936) against Acinetobacter baumannii Strains, Including Those Resistant to Imipenem. Antimicrob. Agents Chemother 48: 4479-4481.
[16]  Wayne, Pa (2000). Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. National Committee for Clinical LaboratoryStandards,.5th ed. Approved standard M7-A5.
[17]  Wayne, Pa. (2001). Performance standards for antimicrobial susceptibility testing. National Committee for Clinical Laboratory Standards. Eleventh informational supplement. M100-S11.
[18]  Thean Yen Tan and Lily Siew Yong Ng(2006), Comparison of three standardized disc susceptibility testing methods for colistin. J Antimicrob Chemother 58: 864-867.
[19]  Colistin, Rationale for the EUCAST clinical breakpoints(2010), version 1.0.
[20]  Drosos E. Karageorgopoulos, Theodore Kelesidis (2008). Tigecycline for the treatment of multidrug-resistant (including carbapenem-resistant) Acinetobacter infections: a review of the scientific evidence. J Antimicrob Chemother 62: 45-55.
[21]  A. C. Gales, R. N. Jones, H. S. Sader (2006) Global assessment of the antimicrobial activity of polymyxin B against 54 731 clinical isolates of Gram-negative bacilli: report from the SENTRY antimicrobial surveillance programme (2001-2004). Clin Microbiol Infect 12 : 315-321.
[22]  Ana c. gales, adriana o. reis and ronald n(2001). jones1Contemporary Assessment of Antimicrobial Susceptibility Testing Methods for Polymyxin B and Colistin: Review of Available Interpretative Criteria and Quality Control Guidelines. J clin microbiol 39: 183-190.
[23]  Alexandre Prehn Zavascki, Luciano Zubaran Goldani, Jian Li4 and Roger L. Nation4 (2007). Polymyxin B for the treatment of multidrug-resistant pathogens: a critical review. J Antimicrob Chemother 60: 1206-1215.