Biofilms: The Stronghold of Legionella pneumophila

Abstract

Legionellosis is mostly caused by Legionella pneumophila and is defined as a severe respiratory illness with a case fatality rate ranging from 5% to 80%. L. pneumophila is ubiquitous in natural and anthropogenic water systems. L. pneumophila is transmitted by inhalation of contaminated aerosols produced by a variety of devices. While L. pneumophila replicates within environmental protozoa, colonization and persistence in its natural environment are also mediated by biofilm formation and colonization within multispecies microbial communities. There is now evidence that some legionellosis outbreaks are correlated with the presence of biofilms. Thus, preventing biofilm formation appears as one of the strategies to reduce water system contamination. However, we lack information about the chemical and biophysical conditions, as well as the molecular mechanisms that allow the production of biofilms by L. pneumophila. Here, we discuss the molecular basis of biofilm formation by L. pneumophila and the roles of other microbial species in L. pneumophila biofilm colonization. In addition, we discuss the protective roles of biofilms against current L. pneumophila sanitation strategies along with the initial data available on the regulation of L. pneumophila biofilm formation.

Lewofloksacyna i moksyfloksacyna w leczeniu zakażeń bakteryjnych

“…epithelial lining fluid -ELF) w stosunku do stę-żenia w surowicy wynosi 1,88, co potwierdza doskonałą penetrację do dróg oddechowych [25]. Podobnie wykazano, że lek aktywnie wnika do komórek fagocytujących i osią-ga w neutrofilach stężenie 8,8-9,8 wyższe niż w środowi-sku zewnątrzkomórkowym, co decyduje o jego skutecznym działaniu przeciwko patogenom wewnątrzkomórkowym, takim jak Chlamydophila pneumoniae czy Legionella pneumophila oraz w zwalczaniu biofilmu w zakażeniu wywoła-nym przez Pseudomonas aeruginosa [26][27][28][29][30].…”

Knowledge to Predict Pathogens: Legionella pneumophila Lifecycle Critical Review Part I Uptake into Host Cells

“…Reviews that discuss growth and survival of Legionella either depend on a laboratory-based models, differing significantly from the biofilm environment, or the article focuses on some particular pathway, proteins, or genetics that affect Legionella's lifecycle. However, they do not focus on all of these aspects in one article [46,68,[70][71][72][73][74][75].…”

“…The bacterium has an ideal pH of 6.0-8.0. L. pneumophila is tolerant of low-nutrient environments but does require iron to survive and thrive [45,46]. In harsh environments, the bacteria can enter a viable but non-culturable (VBNC), state in which it will not replicate, but can be resuscitated in more friendly conditions [47].…”

Creating a customized intracellular niche: subversion of host cell signaling byLegionellatype IV secretion system effectors

“…are ubiquitously found in the environment, where they occur as planktonic bacteria or reside in biofilm communities (Fliermans et al 1981;Abdel-Nour et al 2013). However, the most important step of their environmental life cycle and main driving force for their evolution seems to be their interaction with protozoa (Rowbotham 1980;Amaro et al 2015).…”