MICROBIOLOGICAL STUDY ON MICROORGANISMS CAUSING RESPIRATORY TRACT INFECTIONS IN UPPER EGYPT

Abstract

Respiratory tract infections are recognized widely as the leading cause of mortality among children in most developing countries (Grondahl eta/., 1999). Poverty, overcrowding, air pollution, malnutrition, and delayed and inappropriate case management are reasons for high case fatality rates from such infections (EI-Hadi, 2003).

In this study, 559 different strains were isolated fit>m 322 patients suffering from respiratory tract infections of different ages and sexes. Samples were taken from patients attending the clinics of El-Minia General, University and Chest hospitals. Of the total number of isolates Staph. aureus was the most prevalent organism in patients suffering from upper respiratory tract infections (76 strains, 20.94%) while both Staph. aureus and Strept. pneumoniae were the most prevalent organisms in patients suffering from lower respiratory tract infections (23 strains, 11.73%). The incidence of infection was the highest in patients of age group between 1-20 years (39.75%) and the lowest in patients of age group more than 60 years (13.35%). Staph. aureus was the most prevalent organism in age groups 1-20, 21-40 and 41-60 years (20.85%, 17.02% and 16.67% respectively) while in age group more than 60 years both Staph.

aureus and K. pneumoniae were the most prevalent organisms with equal

• incidences (12% each). Antibiotic susceptibility pattern was tested using different antimicrobial agents. Quinolones including levofloxacin,

gatifloxacin, ofloxacin and ciprofloxacin showed the highest activities (100%, 100%, 96.44% and 93.39% respectively). Amoxycillin and tetracycline showed the least activities (36.64% a:-:d 32.06% respectively). Strains of Staph. aureus resistant to amoxycillin were tested for P­

lactamase production. Out of the tested strains, 62.5% were P-lactamase producers.