Obligate intracellular bacterial parasites of acanthamoebae related to Chlamydia spp

Amann, Rudolf; Springer, Nina; Schönhuber, Wilhelm; Ludwig, Wolfgang; Schmid, E.; Müller, Karl-Dieter; Michel, R.

doi:10.1128/aem.63.1.115-121.1997

Cited by 238 publications

(119 citation statements)

References 38 publications

(35 reference statements)

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“…The host spectrum was investigated to characterize other endosymbionts of FLA, indicating that transmission to other hosts could be performed with several endosymbionts (Horn et al, 2000;Michel et al, 2000;Collingro et al, 2005). However, other studies pointed out very restricted hosts spectrum for several endosymbiotic associations, sometimes limited to the genus or subgenus level (Gautom and Fritsche, 1995;Amann et al, 1997;Birtles et al, 2000;Horn et al, 2001).…”

Section: Pyriformis Likely Has a Narrow Host Spectrummentioning

confidence: 99%

Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free‐living amoeba

Delafont

Samba-Louaka

Bouchon

et al. 2015

Environ Microbiol Rep

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The TM6 phylum belongs to the so-called microbial dark matter that gathers uncultivated bacteria detected only via DNA sequencing. Recently, the genome sequence of a TM6 bacterium (TM6SC1) has led to suggest that this bacterium would adopt an endosymbiotic life. In the present paper, free-living amoebae bearing a TM6 strain were isolated from a water network. The amoebae were identified as Vermamoeba vermiformis and the presence of a TM6 strain was detected by polymerase chain reaction and microscopy. The partial sequence of its 16S rRNA gene showed this strain to be closely related to the sequenced TM6SC1 strain. These bacteria displayed a pyriform shape and were found within V. vermiformis. Therefore, these bacteria were named Vermiphilus pyriformis. Interactions studies showed that V. pyriformis was highly infectious and that its relation with V. vermiformis was specific and highly stable. Finally, it was found that V. pyriformis inhibited the encystment of V. vermiformis. Overall, this study describes for the first time an endosymbiotic relationship between a TM6 bacterium and a free-living amoeba in the environment. It suggests that other bacteria of the TM6 phylum might also be endosymbiotic bacteria and may be found in other free-living amoebae or other organisms.

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Section: Pyriformis Likely Has a Narrow Host Spectrummentioning

confidence: 99%

Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free‐living amoeba

Delafont

Samba-Louaka

Bouchon

et al. 2015

Environ Microbiol Rep

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“…First described in 1997, Parachlamydia acanthamoebae is an obligate intracellular bacterium naturally infecting free-living amoebae (Amann et al ., 1997). The human pathogenicity of this Chlamydia -like organism is supported by a growing body of evidence (reviewed in Greub and Raoult, 2002a).…”

Section: Introductionmentioning

confidence: 99%

Intracellular trafficking of Parachlamydia acanthamoebae

Greub

Mège

Gorvel

et al. 2005

Cellular Microbiology

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SummaryParachlamydia acanthamoebae is an obligate intracellular bacterium that naturally infects free-living amoebae. It is a potential agent of pneumonia that resists destruction by human macrophages. However, the strategy used by this Chlamydia -like organism in order to resist to macrophage destruction is unknown. We analysed the intracellular trafficking of P. acanthamoebae within monocyte-derived macrophages. Infected cells were immunolabelled for the bacteria and for various intracellular compartments by using specific antibodies. We analysed the bacteria colocalization with the different subcellular compartments by using epifluorescence and confocal microscopy. Bacterial replication took place 4-6 h post infection within acidic vacuoles. At that time, P. acanthamoebae colocalized with Lamp-1, a membrane marker of late endosomal and lysosomal compartments. A transient accumulation of EEA1 15 min post infection, and of rab7 and the mannose 6-phosphate receptor 30 min post infection confirmed that P. acanthamoebae traffic through the endocytic pathway. The acquisition of Lamp-1 was not different after infection with living and heat-inactivated bacteria. However, 24.5% and 79.5% of living and heat-inactivated P. acanthamoebae , respectively, colocalized with the vacuolar proton ATPase. Moreover, P. acanthamoebae did not colocalized with cathepsin D, a lysosomal hydrolase, suggesting that P. acanthamoebae interferes with maturation of its vacuole. Thus, P. acanthamoebae survives to destruction by human macrophages probably by controlling the vacuole biogenesis.

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“…Indeed, most amoebae feed on other bacteria, and amoebal co-culture are therefore less subject to contamination. This technique has enabled us to isolate various Chlamydia-related bacteria, such as Parachlamydia acanthamoebae [22], Estrella lausannensis [23,24] and Criblamydia sequanensis [25]. Culture with arthropod cell lines is a promising model to help identify arthropod-transmitted zoonotic agents.…”

Section: Development Of New Diagnostic Toolsmentioning

confidence: 99%

Emerging bacterial pathogens: the past and beyond

Vouga

Greub

2016

Clinical Microbiology and Infection

164

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Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases.

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Obligate intracellular bacterial parasites of acanthamoebae related to Chlamydia spp

Cited by 238 publications

References 38 publications

Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free‐living amoeba

Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free‐living amoeba

Intracellular trafficking of Parachlamydia acanthamoebae

Emerging bacterial pathogens: the past and beyond

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