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Introduction: Tigecycline is a potential therapeutic agent for multidrug resistant gram positive and gram negative organisms. The clinical efficacy of synergic combination of daptomycin with betalactam antibiotics have been described against various species of Enterococcus isolates. Aim: To detect the in-vitro activity of tigecycline and daptomycin against Enterococcus species and to compare their antimicrobial activity by Vitek 2 automated system. Materials and Methods: This was a cross-sectional study conducted at Department of Microbiology, Vinayaka Mission's Kirupananda Variyar (VMKV) Medical College and Hospitals, Salem, Tamil Nadu, India. Isolates of Enterococcus obtained over a period of two years from March 2016 - March 2018 from various clinical samples were identified by standard biochemical method and their antimicrobial susceptibility pattern was determined. Minimum Inhibitory Concentration (MIC) of tigecycline and daptomycin was determined by Vitek 2 automated system. Analysis of data was done by using frequency distribution and percentage. Results: Out of 211 Enterococcus isolates studied, 23 (10.90%) isolates showed decreased susceptibility to daptomycin with MIC of =8 µg/mL. All isolates showed 100% susceptibility to tigecycline. Conclusion: The present study showed potent antimicrobial activity of tigecycline against various species of Enterococcus. Decreased susceptibility to daptomycin has been observed among the study isolates. Further clinical investigations are required to know the potential benefits of these agents in therapy. [ABSTRACT FROM AUTHOR]

Background: Globally, methicillin resistant Staphylococcus aureus (MRSA) is one of the most common pathogens that causes hospital- and community-acquired infections. The use of molecular typing methods is essential for determining the origin of the isolates, their clonal relations, and also epidemiological investigations. Objective: The purpose of this study was to determine the prevalence of antibiotic-resistant MRSA investigate the accessory gene regulator (agr) and staphylococcal cassette chromosome mec (SCCmec) types and perform multilocus sequence typing (MLST). Furthermore, the minimum inhibitory concentration of MRSA isolates was determined for vancomycin and daptomycin. Materials and Methods: Two hundred and fi fty-nine MRSA isolates were collected from Tertiary Care Hospitals in Coimbatore. Disk diffusion method was employed to assess the sensitivity of MRSA isolates to selected antibiotics and genetic analysis was performed using SCCmec, agr, and MLST typing by multiplexpolymerase chain reaction strategy. Minimal inhibitory concentration (MIC) was determined using Ezy MIC (vancomycin) and Biomerieux (daptomycin) E-test strip. Results: Of 259 MRSA isolates, 209 (80.7%) were confirmed as methicillin resistant. Antibiotic susceptibility pattern revealed that all the MRSA isolates were 100% sensitive to linezolid, rifampicin, teicoplanin, and vancomycin. MIC results showed that of 209 MRSA isolates, 10 were found to be vancomycin intermediate S. aureus and 100% of the MRSA isolates were daptomycin-susceptible. The agr group I and SCCmec Type III were the major type among MRSA isolates. In addition to these MLST typing revealed the prevalence of sequence type (ST) 239 (SLV of ST8) among the MRSA isolates. Conclusion: This study confirms that ST239 (Brazilian clone) of MRSA is predominant in this region which is responsible for the hospital-acquired MRSA infections. Thus, the study also suggests that vancomycin and daptomycin can still be used as an alternative drug for treating severe MRSA infections. [ABSTRACT FROM AUTHOR]

Background & objectives: Growing incidence of methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant enteroccoci (VRE) is posing a therapeutic problem due to limited drug options. Therefore, the present study was undertaken to check susceptibility of MRSA and VRE isolates against new antimicrobials such as daptomycin and linezolid. Methods: A total of 586 Gram-positive isolates comprising 442 S. aureus and 144 enterococci isolated from hospitalized cases included in the study, were subjected to in vitro antimicrobial susceptibility testing by disc diffusion method. One hundred twenty four enterococci obtained from rectal swabs of neonates were also included. Minimum inhibitory concentration (MIC) was determined for daptomycin, linezolid, vancomycin and teicoplanin against 50 each isolates of MRSA and VRE by E strip. Results: Among the staphylococci, 326 (73.85%) isolates were MRSA. MIC for vancomycin and teicoplanin among MRSA was ≤3 μg/ml. MIC for daptomycin among MRSA was found to be in the range of 0.064-1.5 μg/ml. Percentage of VRE among clinical samples was 14.29 per cent while it was 47.06 per cent among enterococci from rectal swabs of neonates. MIC was >256 μg/ml for vancomycin among VRE and was associated with van A genotype. MIC range for daptomycin among VRE was 0.38-3 μg/ml. MIC for linezolid among MRSA and VRE was in the range of 0.25 to 1 and 0.38 -1.5 μg/ml, respectively. Interpretation & conclusions: The present study showed a rise in MIC to vancomycin for sizable number of MRSA and growing percentage of VRE at our centre. Daptomycin and linezolid showed 100 per cent activity against MRSA and VRE. [ABSTRACT FROM AUTHOR]

Abstract: The in vitro activity of daptomycin and selected comparator agents against Staphylococcus aureus and vancomycin-resistant Enterococcus faecium (VREF) isolates recovered from hospitalized patients with skin and soft tissue infection''s was evaluated by Clinical and Laboratory Standards Institute broth microdilution method. Daptomycin was the most active agent against both S. aureus (MIC90, 1 μg/mL; 100% susceptible) and VREF (MIC90, 4 μg/mL; 100% susceptible), making it an excellent therapeutic option. [Copyright &y& Elsevier]

Increased vancomycin minimum inhibitory concentration (MIC) levels in Staphylococcus aureus and their association with vancomycin treatment failure are well-known problems. Few studies have recognized progressive increases in glycopeptide MIC levels for S. aureus strains in recent years. This study determined glycopeptide and daptomycin susceptibility among methicillin resistant S. aureus (MRSA) strains. A total of 776 clinical isolates of MRSA recovered from 2009 to 2012 were studied for glycopeptide and daptomycin susceptibility using the E-test method. The vancomycin MIC geometric mean (GM) of the MRSA isolates was 0.923, 0.944, 1.134 and 1.294 mg/L in the years 2009, 2010, 2011 and 2012, respectively, and the trend significantly increased over the years (P < 0.0001). Similarly, the teicoplanin MIC GM was 1.47, 1.49, 1.8 and 2.04 mg/L in the years from 2009 to 2012, respectively (P < 0.0001). MIC shifts were not found for daptomycin (P > 0.232). A significant increase in the MIC for glycopeptides was observed among the clinical MRSA isolates at our center over a 4-year period. However, the daptomycin MIC did not increase in the observed MRSA isolates., (Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)