Oxidase strips

Oxidase was determined with Oxidase strips (OXOID, Adelaide, Australia) by applying the bacterial colony with a plastic loop to the strip and observing the appearance of the color, with the purple color indicating the positive reaction.
After the initial division of the bacteria into gram-positive and gram-negative, they were identified with the VITEK 2.0 automatic system (bioMérieux, Craponne, France). Tests were performed in accordance with the instructions of the system manufacturer, using appropriate cards.
According to the instructions of the manufacturer, the bacterial suspension in 0.45% NaCl solution with a turbidity of 0.5 degrees McFarland (0.50–0.63°MF) was made.
Mold fungi were identified in the direct preparation based on morphological features, and yeast-like fungi were identified from the suspension with a turbidity of 2°MF (1.80–2.20°MF) using VITEK 2 YST cassettes (bioMérieux, Craponne, France).

Escherichia coli was isolated and identified according to Nolan et al. [1 ]. Briefly, all the collected samples were pre-enriched in buffered peptone water (Lab M, UK) and incubated aerobically at 37°C for 24 h. A loopful of the broth culture was inoculated onto MacConkey agar (Neogen, US) and eosin methylene blue agar (Lab M) plates, which were incubated at 37°C for 24 h. The isolated colonies were identified morphologically and biochemically (oxidase strips and triple sugar iron agar were from Oxoid, UK; urea, Simmons’ citrate agar, and peptone water were from Lab M; and Kovacs reagent was from HiMedia, India) [1 ]. In addition, antisera against somatic (O) antigens (Denka Seiken Co., Tokyo, Japan) were used for serotyping isolated E. coli following the manufacturer’s instructions.