<i>Francisella philomiragia</i> Biofilm Formation and Interaction With the Aquatic Protist <i>Acanthamoeba castellanii</i>

Verhoeven, Anne B.; Durham-Colleran, Meghan W.; Pierson, Tony; Boswell, William T.; Hoek, Monique L. van

doi:10.1086/bblv219n2p178

Cited by 45 publications

(52 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…strain in the presence of FLA was not observed (Figures 1-3), which is contrary to the previous studies reporting increases in Francisella CFU densities following co-culture with FLA [33][34][35][36]. Specifically, 3−4 log 10 CFU mL −1 increases of LVS and Fn were observed by days 6−15 in the presence of Ac30010, Ac30234, and Vv at 25−30°C incubation and MOI of 10 [33,35,36]. However, in all of those studies, the assay buffer used was ATCC 712 medium, or peptone yeast extract (PYG) broth, which is the nutrient rich growth medium for propagation of Ap, Ac30010, and Ac30234 cells.…”

Section: Discussioncontrasting

confidence: 97%

“…Despite the similarities in co-culture conditions evaluated and the rigorous testing of numerous Francisella and FLA strains in this study, amplification of each Francisella spp. strain in the presence of FLA was not observed (Figures 1-3), which is contrary to the previous studies reporting increases in Francisella CFU densities following co-culture with FLA [33][34][35][36]. Specifically, 3−4 log 10 CFU mL −1 increases of LVS and Fn were observed by days 6−15 in the presence of Ac30010, Ac30234, and Vv at 25−30°C incubation and MOI of 10 [33,35,36].…”

Section: Discussioncontrasting

confidence: 89%

See 1 more Smart Citation

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Buse

Schaefer

Rice

2016

Acta Microbiologica et Immunologica Hungarica

View full text Add to dashboard Cite

Transmission of Francisella tularensis, the etiologic agent of tularemia, has been associated with various water sources. Survival of many waterborne pathogens within free-living amoeba (FLA) is well documented; however, the role of amoebae in the environmental persistence of F. tularensis is unclear. In this study, axenic FLA cultures of Acanthamoeba castellanii, Acanthamoeba polyphaga, and Vermamoeba vermiformis were each inoculated with virulent strains of F. tularensis (Types A and B), the attenuated live vaccine strain, and Francisella novicida. Experimental parameters included low and high multiplicity of infection and incubation temperatures of 25 and 30°C for 0-10 days. Francisella spp. survival was enhanced by the presence of FLA; however, bacterial growth and protozoa infectivity were not observed. In contrast, coinfections of A. polyphaga and Legionella pneumophila, used as an amoeba pathogen control, resulted in bacterial proliferation, cytopathic effects, and amoebal lysis. Collectively, even though short-term incubation with FLA was beneficial, the long-term effects on Francisella survival are unknown, especially given the expenditure of available amoebal derived nutrients and the fastidious nature of Francisella spp. These factors have clear implications for the role of FLA in Francisella environmental persistence.

show abstract

Section: Discussioncontrasting

confidence: 97%

Section: Discussioncontrasting

confidence: 89%

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Buse

Schaefer

Rice

2016

Acta Microbiologica et Immunologica Hungarica

View full text Add to dashboard Cite

show abstract

“…Because APMV's fibrils are important for its adhesion to A. castellanii cells, which seems to occur through viral interactions with GlcNAc and mannose, we investigated if the giant virus could adhere to other organisms that display one or more of these glycans (as well as their polymers, chitin and peptidoglycan) on their structures. Considering that the entry of APMV into amoebae occurs via phagocytosis, the association of the virus with organisms present in aquatic macro-or microniches (bacteria, fungi, and aquatic arthropods) may increase the chances of an encounter between the virus and its natural host, because interactions between amoebae and bacterial biofilms, insects, and microcommunities containing fungal species have already been described (18)(19)(20). To test this hypothesis, viral particles were incubated with distinct representatives of the microbial world, such as fungi (which have mannose and chitin on their cell walls) and both Gram-positive and Gram-negative bacteria (which have peptidoglycans on their cell walls).…”

Section: Resultsmentioning

confidence: 99%

Mimivirus Fibrils Are Important for Viral Attachment to the Microbial World by a Diverse Glycoside Interaction Repertoire

Rodrigues

Silva

Dornas

et al. 2015

J Virol

View full text Add to dashboard Cite

Acanthamoeba polyphaga mimivirus (APMV) is a giant virus from the Mimiviridae family. It has many unusual features, such as a pseudoicosahedral capsid that presents a starfish shape in one of its vertices, through which the ϳ1.2-Mb double-stranded DNA is released. It also has a dense glycoprotein fibril layer covering the capsid that has not yet been functionally characterized. Here, we verified that although these structures are not essential for viral replication, they are truly necessary for viral adhesion to amoebae, its natural host. In the absence of fibrils, APMV had a significantly lower level of attachment to the Acanthamoeba castellanii surface. This adhesion is mediated by glycans, specifically, mannose and N-acetylglucosamine (a monomer of chitin and peptidoglycan), both of which are largely distributed in nature as structural components of several organisms. Indeed, APMV was able to attach to different organisms, such as Gram-positive bacteria, fungi, and arthropods, but not to Gram-negative bacteria. This prompted us to predict that (i) arthropods, mainly insects, might act as mimivirus dispersers and (ii) by attaching to other microorganisms, APMV could be ingested by amoebae, leading to the successful production of viral progeny. To date, this mechanism has never been described in the virosphere. IMPORTANCEAPMV is a giant virus that is both genetically and structurally complex. Its size is similar to that of small bacteria, and it replicates inside amoebae. The viral capsid is covered by a dense glycoprotein fibril layer, but its function has remained unknown, until now. We found that the fibrils are not essential for mimivirus replication but that they are truly necessary for viral adhesion to the cell surface. This interaction is mediated by glycans, mainly N-acetylglucosamine. We also verified that APMV is able to attach to bacteria, fungi, and arthropods. This indicates that insects might act as mimivirus dispersers and that adhesion to other microorganisms could facilitate viral ingestion by amoebae, a mechanism never before described in the virosphere.

show abstract

“…However, the patient in this report has no known history of water exposure. Research has demonstrated that F. philomiragia is capable of forming robust biofilms in association with aquatic amoebae and, in prolonged coincubation, is capable of infecting amoebae (13). Such association may permit both the persistence of the organism in the environment and its dissemination to hosts that come in contact with F. philomiragia-infected amoebae via waterway exposure.…”

mentioning

confidence: 99%

Francisella philomiragia Bacteremia in a Patient with Acute Respiratory Insufficiency and Acute-on-Chronic Kidney Disease

et al. 2015

View full text Add to dashboard Cite

e Francisella philomiragia is a very uncommon pathogen of humans. Diseases caused by it are protean and have been reported largely in near-drowning victims and those with chronic granulomatous disease. We present a case of F. philomiragia pneumonia with peripheral edema and bacteremia in a renal transplant patient and review the diverse reports of F. philomiragia infections. CASE REPORTA 63-year-old female from Indiana presented to an Indianapolis hospital with worsening shortness of breath, nonproductive cough, and increasing bilateral peripheral edema. The patient was afebrile, normotensive, and normocardic but was tachypnic (40 bpm) and denied having fevers, chills, or other symptoms of an infectious process while at home. Significant medical history obtained at the time of presentation included a renal transplant secondary to polycystic kidney disease 14 years prior for which she receives chronic immunosuppressive therapy (tacrolimus and prednisone). The patient did not report recent travel outside Indiana, exposure to wild animals or recreational water sources, or exposure to sick individuals. Because of the possibility of acute transplant rejection, the patient was admitted to the intensive care unit for extensive evaluation. A chest X-ray performed at the time of admission revealed bilateral perihilar and upper-lobe infiltrates consistent with bilateral bronchopneumonia, prompting the collection of a set of blood cultures from the left arm and of another set from the right arm and initiation of empirical broad-spectrum antimicrobial therapy with vancomycin and piperacillin-tazobactam. Aside from blood cultures, no other microbiology testing was performed. Laboratory studies conducted at the time of admission revealed leukocytosis (11,600 cells/l) with 93% neutrophils, anemia (3.32 million cells/l), kidney failure (elevated levels of urea nitrogen [48 mg/dl] and creatinine [3.70 mg/dl]), and hyperglycemia (127 mg of glucose/dl). Elevated levels of procalcitonin (1.86 ng/ml), hematuria (25 cells/l), and proteinuria (500 mg/ dl) were also noted. Because of the possibility of acute-on-chronic kidney disease, a renal biopsy was subsequently performed, and it revealed acute allograft rejection.Following approximately 24 h of incubation in a continuousmonitoring blood culture instrument (BD Bactec 9240; BD Diagnostic Systems, Sparks, MD), the aerobic bottles from both sets of blood cultures signaled positively. Gram stains of broth from both bottles revealed pleomorphic, Gram-negative coccobacilli (Fig. 1A). Subcultures of the blood culture broth grew medium-sized (ϳ5-mm diameter), glossy, convex colonies resembling a member of the Enterobacteriaceae on sheep blood and chocolate agars after 48 h of incubation at 35°C in 5% CO 2 . A Gram stain of the colonies revealed organisms with morphologies identical to those seen in the blood culture broth smear. The isolate tested positive for cytochrome oxidase and catalase. Together, these observations ruled out possible select agents, including Francisella tularensis a...

show abstract

Francisella philomiragia Biofilm Formation and Interaction With the Aquatic Protist Acanthamoeba castellanii

Cited by 45 publications

References 60 publications

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Mimivirus Fibrils Are Important for Viral Attachment to the Microbial World by a Diverse Glycoside Interaction Repertoire

Francisella philomiragia Bacteremia in a Patient with Acute Respiratory Insufficiency and Acute-on-Chronic Kidney Disease

Contact Info

Product

Resources

About