Olejnízková Katerina, Holá Veronika
Mikrobiologický ústav LF a FN u sv. Anny v Brne.
Epidemiol Mikrobiol Imunol. 2012 May;61(1-2):21-8.
Healthcare quality improvement brings about an increasing number of invasive diagnostic and therapeutic procedures and thus also an increasing number of high-risk patients prone to hospital infections. Pseudomonas aeruginosa is one of the most commonly isolated nosocomial species and the treatment of the infection is often long and problematic, with frequent recurrences. The pathogenesis of Pseudomonas infection is associated with a range of virulence factors. In the present study, 93 catheter isolates of Pseudomonas aeruginosa were screened for the biofilm formation, motility and secretion of selected extracellular products. A high rate of the strains tested were producers of hemolysins, LasB elastase, and pyoverdines (> 70%). The biofilm formation was detected in 80% of isolates and formation of aerated biofilm was present in 90% of isolates with a positive correlation found between the two types of biofilm formation (p = 0.00583; gamma = 0.551). All strains showed swarming motility, 95% of strains showed swimming motility, and 75% of strains showed twitching motility. Among the virulence factors studied, only pyocyanin and pyochelin were produced by a lower proportion of isolates (< 25%). A positive correlation was seen between the production of some extracellular molecules (pyochelin and pyocyanin, pyocyanin and LasB elastase, and LasB elastase and haemolysins), between biofilm formation and formation of aerated biofilm, and between formation of aerated biofilm and pigments (pyoverdine and pyocyanin) production. On the other hand, a negative correlation was found between biofilm production and LasB elastase production and between the production of biofilm under immersion and pigments (pyoverdine and pyocyanin) production. All correlations are significant at the level p = 0.05, with the correlation coefficient gamma > 0.50.
医疗质量的提高带来了越来越多的侵入性诊断和治疗程序，因此也出现了越来越多易发生医院感染的高危患者。铜绿假单胞菌是最常见的医院分离菌之一，该感染的治疗通常漫长且存在问题，还经常复发。铜绿假单胞菌感染的发病机制与一系列毒力因子有关。在本研究中，对93株铜绿假单胞菌导管分离株进行了生物膜形成、运动性及特定胞外产物分泌情况的筛选。所测试的菌株中，产生溶血素、LasB弹性蛋白酶和绿脓菌素的比例较高（>70%）。80%的分离株检测到生物膜形成，90%的分离株形成了充气生物膜，且两种生物膜形成类型之间存在正相关（p = 0.00583；γ = 0.551）。所有菌株均表现出群游运动性，95%的菌株表现出泳动运动性，75%的菌株表现出颤动运动性。在所研究的毒力因子中，只有绿脓杆菌素和绿脓菌素由较低比例的分离株产生（<25%）。在一些胞外分子（绿脓菌素和绿脓杆菌素、绿脓杆菌素和LasB弹性蛋白酶、LasB弹性蛋白酶和溶血素）的产生之间、生物膜形成与充气生物膜形成之间、充气生物膜形成与色素（绿脓菌素和绿脓杆菌素）产生之间均观察到正相关。另一方面，发现生物膜产生与LasB弹性蛋白酶产生之间以及浸没状态下生物膜产生与色素（绿脓菌素和绿脓杆菌素）产生之间呈负相关。所有相关性在p = 0.05水平上均具有显著性，相关系数γ>0.50。
