Reduced susceptibilityto Vancomycin in methicillin resistant Staphylococccusaureus: a time for action

Infections by Methicillin resistant Staphylococcusaureus (MRSA) is an often encountered therapeutic challenge. The problem is accentuated by the emergence of MRSA strains which are resistant to Vancomycin, the recommended agent for the treatment of MRSA infections. We therefore carried out this study to determine the MIC values of vancomycin for the MRSA isolated from different clinical specimens in Nepal Medical College. MICs were determined by agar dilution method. Out of the 82 MRSA isolates tested, 18 showed MIC of 2μg/ml and 29 isolates had MIC of 1μg/ml and 35 isolates had MIC of 0.5 μg/ml.Although none had a MIC in the intermediate or resistant zone, 18 (2.9%) had MIC in the upper limit of the sensitive zone which is a matter of concern and calls for prompt preventive actions.

[1]  Silvestre Joana,et al.  Is vancomycin MIC creep a worldwide phenomenon? Assessment of S. aureus vancomycin MIC in a tertiary university hospital , 2013, BMC Research Notes.

[2]  G. Sakoulas,et al.  Reduced vancomycin susceptibility among clinical Staphylococcus aureus isolates (‘the MIC Creep’): implications for therapy , 2012, F1000 medicine reports.

[3]  V. Murugaiyah,et al.  Emergence Of Vancomycin-Resistant Staphylococcus Aureus (VRSA) , 2011 .

[4]  C. Shivannavar,et al.  Vancomycin resistance among methicillin resistant Staphylococcus aureus isolates from intensive care units of tertiary care hospitals in Hyderabad , 2011, The Indian journal of medical research.

[5]  Safia Ahmed,et al.  Antimicrobial susceptibility pattern of Staphylococcus aureus on clinical isolates and efficacy of laboratory tests to diagnose MRSA: a multi-centre study. , 2011, Journal of Ayub Medical College, Abbottabad : JAMC.

[6]  H. K. Tiwari,et al.  High prevalence of multidrug-resistant MRSA in a tertiary care hospital of northern India , 2008, Infection and drug resistance.

[7]  K. Stellrecht,et al.  Relationship between Vancomycin MIC and Failure among Patients with Methicillin-Resistant Staphylococcus aureus Bacteremia Treated with Vancomycin , 2008, Antimicrobial Agents and Chemotherapy.

[8]  Á. Soriano,et al.  Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia. , 2008, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[9]  M. Jackson,et al.  2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Health Care Settings , 2007, American Journal of Infection Control.

[10]  G. Rahav,et al.  Prevalence and Characteristics of Heteroresistant Vancomycin-Intermediate Staphylococcus aureus Bacteremia in a Tertiary Care Center , 2007, Journal of Clinical Microbiology.

[11]  Guiqing Wang,et al.  Increased Vancomycin MICs for Staphylococcus aureus Clinical Isolates from a University Hospital during a 5-Year Period , 2006, Journal of Clinical Microbiology.

[12]  A. L. Darini,et al.  First Report of Vancomycin-Resistant Staphylococci Isolated from Healthy Carriers in Brazil , 2005, Journal of Clinical Microbiology.

[13]  K. Ko,et al.  Emergence in Asian Countries of Staphylococcus aureus with Reduced Susceptibility to Vancomycin , 2004, Antimicrobial Agents and Chemotherapy.

[14]  F. Tenover,et al.  Characterization of Staphylococci with Reduced Susceptibilities to Vancomycin and Other Glycopeptides , 1998, Journal of Clinical Microbiology.

[15]  Y. Fukuchi,et al.  Dissemination in Japanese hospitals of strains of Staphylococcus aureus heterogeneously resistant to vancomycin , 1997, The Lancet.

[16]  R. Wenzel,et al.  The epidemiology of intravenous vancomycin usage in a university hospital. A 10-year study. , 1993, JAMA.