Vitek gp

Polystyrene tubes (12 mm × 75 mm) (Sarstedt) were filled with 3 mL of 0.45% sterile saline (CareFusion). Homogenous suspensions of bacteria were prepared in the 3 mL 0.45% sterile saline. Suspensions were examined using the DensiCheck Plus (BioMérieux) device to ensure that the suspensions were within the turbidity range of 0.5–0.63 (McFarland standard) for both Gram‐positive and Gram‐negative bacteria. The appropriate Vitek cards (Vitek GP and Vitek GN) (BioMérieux), which contained 64 wells with miniaturized selective media and biochemical reagents, were used for bacterial identification. The Vitek system identified the bacteria by filling the Vitek wells with the standard turbidity bacteria suspension in 3 mL of 0.45% sterile saline. The colour codes from the miniaturized selective media as well as the results of the miniaturized biochemical tests were analysed by the Vitek 2 Compact system software (Version 08.01, BioMérieux) to identify the bacteria species.

The swabs were transported in Amies medium to the microbiology department of our hospital as soon as possible and no longer than 2–4 h from the collection. Specimens were inoculated on Columbia agar containing 5% sheep blood and on chocolate agar. The inoculated plated media were incubated at 35 °C for 48 h in 5% to 10% CO₂. Identification of microorganisms was performed by examining the morphology of the colonies, Gram stain, and other conventional methods such as sensitivity to optochin disk (5 mg) for S. pneumoniae, resistance to bacitracin disk (10 units), and V and X factor growth requirements for H. influenzae, positive oxidase test for Moraxella catarrhalis, positive catalase, and coagulase test for S. aureus and sensitivity to bacitracin disk (0.04 units) for S. pyogenes. Further identification of organisms was performed by Vitek GP (Biomerieux) for S. pneumoniae, S. pyogenes, and S. aureus and by Vitek NH (Biomerieux) for H. influenzae and M. catarrhalis. Susceptibility to antibiotics was tested by the standard disk diffusion method, according to CLSI guidelines.