Pathogens with positive gram stain consisted of 44.4%, which included Streptococcus spp (26, 7%) and Streptococcus pneumoniae (17, 7%); pathogens with negative gram stain consisted of 55.6%, which included Morraxella catarrhalis (18, 9%), Pseudomonas aeruginosa (11, 1%), Acinetobacter baumanii (8, 9%), Enterobacter agglomerans (8, 9%), Klebsiella pneumoniae (5, 6%), Escherichia coli (2, 2%).