ABSTRACT
Klebsiella pneumoniae. Klebsiella has been a frequently isolated nosocomial pathogen (69, 70), and, despite the availability of potent antimicrobial agents, invasive Klebsiella infections were associated with a high mortality rate, ranging between 24% and 50% in bacteremic patients (69,71). Numerous studies had been reported regarding the immunogenicity of capsular polysaccharide antigens of the Klebsiella group (KCP) (72, 73), but relatively little attention was given to the type 0 antigens. Klebsiella was shown to be the leading cause of epidemic extraintestinal infection in neonates, was second only to P. aeruginosa in case fatality rates, and was second only to E. coli as the cause of nosocomial infections (74, 75). Viruses Respiratory Syncytial Virus. Respiratory syncytial virus (RSV) was regarded worldwide as the most important pediatric pathogen of the lower respiratory tract. It caused annual epidemics between December and April in temperate zones of the northern hemisphere (76). Serological surveys worldwide had demonstrated that approximately half of the infants who lived through a single RSV epidemic were infected (77). RSV was the single most serious cause of respiratory disease in young children, the major cause of severe pneumonia and bronchiolitis, and the most common cause of acute lower respiratory tract diseases. Respiratory illness due to RSV was the most common cause for rehospitalization of preterm infants, both with and without bronchopulmonary dysplasia (78,79).
