Interaction of Streptococcus pneumoniae and Moraxella catarrhalis:: Investigation of the indirect pathogenic role of β-lactamase-producing moraxellae by use of a continuous-culture biofilm system
Interaction of Streptococcus pneumoniae and Moraxella catarrhalis:: Investigation of the indirect pathogenic role of β-lactamase-producing moraxellae by use of a continuous-culture biofilm system
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DOI：
10.1128/aac.42.10.2521
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发表时间：
1998-10-01
影响因子：
4.9
通讯作者：
Struthers, JK
中科院分区：
文献类型：
--
作者：
Budhani, RK;Struthers, JK
大多数临床分离的卡他莫拉菌产生β-内酰胺酶，这种酶在间接致病性现象中的作用已得到广泛认可，在间接致病性现象中，肺炎链球菌等真正的病原体免受某些β-内酰胺抗生素的作用。通过使用简单的连续培养生物膜系统，已经表明肺炎球菌获得超过10（12）CFU/生物膜的高滴度；此外，使用的青霉素敏感肺炎球菌在这些生物膜中仍然对一系列β-内酰胺抗生素敏感（R，K，Budhani和J，K，Struthers，J，Antimicrob，Chemother，40：601-602，1997），该系统用于表征该分离株与β-内酰胺酶阴性或阳性莫拉氏菌一起生长时的抗生素敏感性，当在苄青霉素或阿莫西林存在的情况下，与产生β-内酰胺酶的莫拉氏菌一起生长，肺炎球菌在被认为具有耐药性的抗生素浓度范围内受到保护。使用阿莫西林克拉维酸时，两种微生物的滴度在莫拉氏菌变得敏感的抗生素浓度下下降。肉汤培养物的无细胞上清液、生物膜和生物膜流出物中的β-内酰胺酶活性水平揭示了这种活性的明显差异；生物膜中的水平显着低于肉汤培养物上清液中的水平，该系统似乎适合研究抗生素应激下的生物体以及研究细菌在这种条件下的相互作用。
The majority of clinical isolates of Moraxella catarrhalis produce beta-lactamase, The role of this enzyme in the phenomenon of indirect pathogenicity, in which a true pathogen such as Streptococcus pneumoniae is protected from the action of certain beta-lactam antibiotics, is well recognized, By using a simple continuous-culture biofilm system, it has been shown that the pneumococcus attains high titers in excess of 10(12) CFU/biofilm; furthermore, the penicillin-sensitive pneumococcus used remained susceptible to a range of beta-lactam antibiotics in these biofilms (R, K, Budhani and J, K, Struthers, J, Antimicrob, Chemother, 40:601-602, 1997), This system was used to characterize the antibiotic susceptibility of this isolate when grown with beta-lactamase-negative or -positive moraxellae, When grown with beta-lactamase-producing moraxellae in the presence of either benzylpenicillin or amoxicillin, the pneumococcus was protected in the range of the antibiotic concentrations to which it would be considered resistant. With amoxicillin-clavulanic acid the titers of the two organisms collapsed at the antibiotic concentration at which moraxellae became susceptible. The levels of beta-lactamase activity in cell-free supernatants of broth culture, in biofilm, and in biofilm effluent revealed distinct differences in this activity; levels in biofilm were significantly lower than those in broth culture supernatants, The system appears suitable for studying organisms under antibiotic stress and for investigating the interactions of bacteria under such conditions.