RESUMO
Background: While recognizing the etiology of community-acquired pneumonia is necessary for formulating local antimicrobial guidelines, limited data is published about this etiology in Egyptian pediatric patients. The aim of this study is to elucidate the common bacterial pathogens causing CAP among immunocomptent infants and preschool children admitted to Zagazig university Pediatric hospital. Methods: 48 infant and preschool children admitted to pediatric hospital of Zagazig university and presented with signs of pneumonia according to WHO. Etiological agents were identified using conventional bacteriological identification methods and Ig M antibodies detection against common a typical bacteria and respiratory viruses. Results: Staph. Aureus 35.4% is the most common pathogen detected in sputum regardless the age group .In blood culture results negative results in most cases of pneumonia 62.5%. Staph. Aureus is the most common pathogen detected in blood culture in positive cases regardless the age group 18.7% , E Coli 6.25%, Klebsiella 2.08.In Serology results significant difference according to age in viral pneumonia occurrence and non significant difference in bacterial pneumonia based on serological findings with higher diagnosis of Legionella pneumophila 33.33% as a causative organism. Conclusion: This study provides preliminary data regarding the spectrum and frequency of microorganisms causing CAP in infants and preschool children