Abstract：
The ability of most opportunistic bacteria to form biofilms, coupled with antimicrobial resistance, hinder the efforts to control widespread infections, resulting in high risks of negative outcomes and economic costs. Endolysins are promising compounds that efficiently combat bacteria, including multidrug-resistant strains and biofilms, without a low probability of subsequent emergence of stable endolysin-resistant phenotypes. However, the details of antibiofilm effects of these enzymes are poorly understood. To elucidate the interactions of bacteriophage endolysins LysAm24, LysAp22, LysECD7, and LysSi3 with bacterial films formed by Gram-negative species, we estimated their composition and assessed the endolysins\' effects on the most abundant exopolymers in vitro. The obtained data suggests a pronounced efficiency of these lysins against biofilms with high (Klebsiella pneumoniae) and low (Acinetobacter baumannii) matrix contents, or dual-species biofilms, resulting in at least a twofold loss of the biomass. These peptidoglycan hydrolases interacted diversely with protective compounds of biofilms such as extracellular DNA and polyanionic carbohydrates, indicating a spectrum of biofilm-disrupting effects for bacteriolytic phage enzymes. Specifically, we detected disruption of acid exopolysaccharides by LysAp22, strong DNA-binding capacity of LysAm24, both of these interactions for LysECD7, and neither of them for LysSi3.
摘要：
大多数机会细菌形成生物膜的能力，再加上抗菌素耐药性，阻碍控制广泛感染的努力，导致负面结果和经济成本的高风险。内皮素是有效对抗细菌的有前途的化合物，包括多重耐药菌株和生物膜，没有随后出现稳定内溶素抗性表型的低概率。然而,这些酶的抗生物膜作用的细节知之甚少。为了阐明噬菌体内溶素LysAm24，LysAp22，LysECD7和LysSi3与革兰氏阴性物种形成的细菌膜的相互作用，我们估计了它们的组成，并评估了细胞内溶素对体外最丰富的外聚合物的影响。获得的数据表明，这些溶素对高（肺炎克雷伯菌）和低（鲍曼不动杆菌）基质含量的生物膜具有显着的效率，或者双物种生物膜，导致至少两倍的生物量损失。这些肽聚糖水解酶与生物膜的保护性化合物如细胞外DNA和聚阴离子碳水化合物不同地相互作用,表明了对细菌分解噬菌体酶的生物膜破坏作用。具体来说,我们检测到LysAp22对酸性胞外多糖的破坏，LysAm24的强DNA结合能力，这两种相互作用对于LysECD7，对于LysSi3都没有。
