Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections

Authors

  • Ariana ALMAŞ
  • Mirela FLONTA Hospital for Clinical Infectious Diseases, 23 Iuliu Moldovan, 400348 Cluj-Napoca, Romania.
  • Mirela PETRAŞCU “Iuliu Haţieganu” University of Medicine and Pharmacy, Department of Microbiology, 13 Emil Isac, 400023 Cluj-Napoca, Romania.
  • Violeta NĂSTASE Hospital for Clinical Infectious Diseases, 23 Iuliu Moldovan, 400348 Cluj-Napoca, Romania.
  • Ioana COLOSI “Iuliu Haţieganu” University of Medicine and Pharmacy, Department of Microbiology, 13 Emil Isac, 400023 Cluj-Napoca, Romania.

Keywords:

Staphylococcus, bloodstream infection, methicillin resistance

Abstract

Objectives: The aim of this study was to evaluate the distribution of Staphylococcus species in bloodstream infections and to assess their susceptibility to methicillin. Material and Methods: Between January 1st 2008 - December 31st 2010, 7424 blood culture sets were submitted to the Laboratory Department of the Hospital for Clinical Infectious Diseases in Cluj-Napoca, Romania. The blood cultures were performed using BacT/Alert until January 2010 and BacT/Alert 3D automated system (bioMérieux) after that date. The blood culture bottles were incubated at 37°C in a continuously monitoring system for up to 7 days. The strain identifications were performed by conventional methods, ApiStaph galleries and  Vitek 2 Compact system. Susceptibility to methicillin was determined by disk diffusion method with cefoxitin disk and by using Vitek 2 Compact system. Results: From the total number of performed blood cultures, 568 were positive with Staphylococcus species. From 168 bacteriemic episodes 103 were with Staphylococcus aureus. Among 65 coagulase-negative staphylococci isolates, Staphylococcus epidermidis was the most frequently isolated species (34), followed by Staphylococcus hominis (15), Staphylococcus haemolyticus (8), Staphylococcus saprophyticus (3), Staphylococcus cohnii (1), Staphylococcus auricularis (1), and 3 strains that were not identified at species level. Methicillin resistance was encountered in 53.40% of Staphylococcus aureus strains and in 80% of coagulase-negative staphylococci. Conclusions: An important percentage of blood cultures were contaminated with Staphylococcus species. The main species identified in true bacteriemia cases were Staphylococcus aureus and Staphylococcus epidermidis. The percentage of methicillin-resistance, proved to be high not only for coagulase-negative staphylococci but also for Staphylococcus aureus.

Author Biography

Ariana ALMAŞ

medic primar medicina de laborator

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Published

15.06.2011

How to Cite

1.
ALMAŞ A, FLONTA M, PETRAŞCU M, NĂSTASE V, COLOSI I. Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections. Appl Med Inform [Internet]. 2011 Jun. 15 [cited 2024 May 29];28(2):22-30. Available from: https://ami.info.umfcluj.ro/index.php/AMI/article/view/154

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