Purification and Characterization of an Extracellular Serine Proteinase from Acanthamoeba castellanii

Cho, Jung-Hwa; Na, Byoung-Kuk; Kim, Tong‐Soo; Song, Chang Yong

doi:10.1080/152165400300001534

Cited by 29 publications

(5 citation statements)

References 10 publications

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“…FLA are capable of secreting compounds that lyse and/or kill bacteria [ 40 – 42 ]. To explore the possibility that amoebae release factors capable of killing X .…”

Section: Resultsmentioning

confidence: 99%

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Interactions of free-living amoebae with rice bacterial pathogens Xanthomonas oryzae pathovars oryzae and oryzicola

et al. 2018

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BackgroundFree-living amoebae (FLA) are voracious feeders, consuming bacteria and other microbes during colonization of the phytobiome. FLA are also known to secrete bacteriocidal or bacteriostatic compounds into their growth environment.Methodology and principal findingsHere, we explore the impacts of co-cultivation of five FLA species, including Acanthamoeba castellanii, A. lenticulata, A. polyphaga, Dictyostelium discoideum and Vermamoeba vermiformis, on survival of two devastating bacterial pathogens of rice, Xanthomonas oryzae pathovars (pv.) oryzae and oryzicola. In co-cultivation assays, the five FLA species were either bacteriostatic or bactericidal to X. oryzae pv. oryzae and X. oryzae pv. oryzicola. Despite these effects, bacteria were rarely detected inside amoebal cells. Furthermore, amoebae did not disrupt X. oryzae biofilms. The bactericidal effects persisted when bacteria were added to a cell-free supernatant from amoebal cultures, suggesting some amoebae produce an extracellular bactericidal compound.Conclusions/SignificanceThis work establishes novel, basal dynamics between important plant pathogenic bacteria and diverse amoebae, and lays the framework for future mechanistic studies.

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“…FLA are capable of secreting compounds that lyse and/or kill bacteria [ 40 – 42 ]. To explore the possibility that amoebae release factors capable of killing X .…”

Section: Resultsmentioning

confidence: 99%

“…FLA species may also secrete different antimicrobial factors into their surroundings [ 40 , 42 , 43 ], and the fresh media supplements may have diluted any toxic factor produced by Acanthamoeba species, allowing X . oryzae to survive and multiply.…”

Section: Resultsmentioning

confidence: 99%

Interactions of free-living amoebae with rice bacterial pathogens Xanthomonas oryzae pathovars oryzae and oryzicola

et al. 2018

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“…They may be potential virulence factors of Acanthamoeba by acting both as anti-oxidants and anti-inflammatory agents. They may also provide additional targets for chemotherapy and immuno-diagnosis of Acanthamoeba infections [ 15 ]. A. castellanii iron superoxide dismutase may play essential roles in the survival of amoebae not only by protecting themselves from endogenous oxidative stress, but also by detoxifying oxidative killing of amoebae by host immune effector cells [ 50 ].…”

Section: Pathogenesis Of Acanthamoeba Keratitismentioning

confidence: 99%

An update onAcanthamoebakeratitis: diagnosis, pathogenesis and treatment

2015

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Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections.

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“…After corneal epithelial adhesion by protein-binding mechanisms, the infectious organisms destroy the epithelium and invade the Bowman membrane through different cytopathic effects such as cytolysis, phagocytosis, or inducing apoptosis [ 5 , 11 ]. Once within the corneal stroma, Acanthamoeba generate different proteases to induce the host collagenolytic effect [ 12 , 13 ], resulting in the characteristic ring infiltrate seen on slit lamp examination. Further, in vitro examinations have found a chemotactic affinity of Acanthamoeba to corneal nerves [ 14 ], which may explain the perineural infiltrates and the severe pain out of proportion to the clinical signs in infectious states.…”

Section: Introductionmentioning

confidence: 99%

Assessing PCR-Positive Acanthamoeba Keratitis—A Retrospective Chart Review

Blaser,

Bajka,

Grimm

et al. 2024

Microorganisms

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Ophthalmologists’ diagnostic and treatment competence in Acanthamoeba keratitis varies widely. This investigator-initiated, retrospective, single-center chart review examined the electronic patient files regarding PCR-positive Acanthamoeba keratitis. We included corneal and contact lens assessments. We further reviewed the patient’s medical history, corneal scraping results regarding viral or fungal co-infections, and the duration from symptom onset to final diagnosis. We identified 59 eyes of 52 patients from February 2010 to February 2023, with 31 of 52 (59.6%) being female patients. The median (IQR, range) patient age was 33 (25.3 to 45.5 [13 to 90]) years, and the mean (SD, range) time to diagnosis after symptom onset was 18 (10.5 to 35 [3 to 70]) days. Overall, 7 of 52 (7.7%) patients displayed a bilateral Acanthamoeba infection, and 48 (92.3%) used contact lenses at symptom onset. Regarding other microbiological co-infections, we found virologic PCR testing in 45 of 52 (86.5%) patients, with 3 (6.7%) positive corneal scrapings. Fungal cultures were performed in 49 of 52 (94.2%) patients, with 5 (10.2%) positive corneal scrapings. The medical treatment success rate was 45/46 (97.8%). This study raises awareness of patient education in contact lens handling and screens for further microbial co-infections in suspected Acanthamoeba cases.

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Purification and Characterization of an Extracellular Serine Proteinase from Acanthamoeba castellanii

Cited by 29 publications

References 10 publications

Interactions of free-living amoebae with rice bacterial pathogens Xanthomonas oryzae pathovars oryzae and oryzicola

Interactions of free-living amoebae with rice bacterial pathogens Xanthomonas oryzae pathovars oryzae and oryzicola

An update onAcanthamoebakeratitis: diagnosis, pathogenesis and treatment

Assessing PCR-Positive Acanthamoeba Keratitis—A Retrospective Chart Review

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