[The relationship between different serological types of Pseudomonas aeruginosa strain in lower respiratory tract and its clinical significance].
OBJECTIVE: To explore the relationship between different serological types of pseudomonas aeruginose (PA) in sputum and its clinical significance. METHOD: PA was detected by Vitek-Ams GNI card and its sensitivity to 12 kinds of antibiotics was measured with GNS-GA, its different serological types were assayed with standard diagnostic serum of type 20. RESULT: 14 different serological types were isolated from 101 strains of PA in sputum (with the typed rate 84.2%). Among them, type 6, type 1, and type 3 were higher with 23.7%, 13.9% and 10.9% respectively. But another 15.8% of strains couldn't be differentiated, so called untyped PA group, among them 10 strains with mucoid-like colony (63% of this untyped group). Patients suffered with this group were older and were very seriously infected with higher mortality (13%). They often suffered from serious COPD and bronchiectasis. The sensitivities of all PA strains to antibiotics in vitro as follows: tobramycin 92.0%, ceftazidine 89.1%, ciprofloxacin 87.1%, ticarcillin 82.2%, and gentamycin 76.2%. Among 12 PA strains tested with imipenem sensitive test, only one strain of mucoid-like colony had been found resistant. CONCLUSION: Identification of serological type of PA can be used as an important method to make out if the infection comes from the same source, and for surveillance of hospital infection, and to show the main types of PA in some district. But the sensitivity of antibiotics in vitro is no definitive correlation with PA serological types. The disease infected with untyped PA strains have its clinically special characteristics and must be kept attention.