Variation Of Pathogenic Bacteria Isolated From Patients During Antibiotics Targeted Therapy In Intensive Care Unit

Objective To approach the changing spectrum of the pathogenic bacteriaduring seven days antibiotics targeted therapy in intensive careunit(ICU).Methods The relevant bacterial materials from 100 patients ofhospital-acquired pneumonia(HAP) identified pathogenic bacteria andadopted antibiotic according to susceptibility test in time wereinvestigated, and the relationships were analyzed the characteristicchanged of pathogenic bacteria with the age,the time of medication andthe length of stay.Results Among all the bacterial isolates(n=295) in ICU, the percentageof Gram-negative bacilli was 62．4%. The leading causative microorganismsisolated were Pseudomonas aeruginosa 22．4% ( 66/295 ),methicillinresistant staphylococcus aureus(MRSA) 20．7% (61/95) and Acinetobacterspp.10．5% (30/295) . Adopting one kind or above one kind of antibioticsaccording to the result of cultivanting bacteria, the ratio and type ofpathogenic bacteria were possible to chang already after three to sevendays using sensitive antibiotics. The Variation of the ratio of pathogenicbacteria were 56．8%,60．9%,59．1% (P<0．01) respectively in the third day,the fourth day and the fifth day, displaying sensitive pathogenic bacteriadiminished gradually. The type of pathogenic bacteria begins variation in the third day, all the more in the sixth day and the seventh day, were 66．0%,77．1% (P<0．01) each, displaying new non-sensitive pathogenic bacteriaappearanced. With increasing of the types of antibiotics used, The typevariation of pathogenic bacteria showed to increase gradually. Whentreating Gram-negative bacilli, new pathogenic bacteria, for instance,Candida albicans and MRSA appearanced usually. But When treating Gram-positive bacilli, Candida albicans,Pseudomonas aeruginosa andEnterobacter cloacae appearanced easily. There was relationship betweenthe variation of pathogenic bacteria and age,the length of stay of thepatients. The more older of age and the more longer the length of stay,the type variation of pathogenic bacteria was more predominant.Conclusion New non-sensitive pathogenic bacteria appearanced alreadyduring seven days antibiotics targeted therapy in intensive care unit. Andthe variation of pathogenic bacteria was related to the time and type ofusing antibiotic and the age and length of stay. The more longer of thetime and the more type of using antibiotic, the more older of age and themore longer the length of stay, the type variation of pathogenic bacteriawas more predominant. Monitoring the chang of pathogenic bacteria indynamic state, adjusting promptly an?rational application of antibioticsis very important to suppress the spectrum changing and antibioticresistance of the bacteria.