A Comparative Genomic Approach to Determine the Virulence Factors and Horizontal Gene Transfer Events of Clinical Acanthamoeba Isolates

Gu, Xiaobin; Lu, Xiuhai; Lin, Shudan; Shi, Xuliang; Shen, Yue; Lu, Qingsong; Yang, Yiying; Yang, Jing; Cai, Jiabei; Fu, Chunyan; Lou, Yongliang; Zheng, Meiqin

doi:10.1128/spectrum.00025-22

Cited by 16 publications

(18 citation statements)

References 65 publications

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“…While studied for decades, Acanthamoeba research has only recently expanded to utilize robust -omic methods to understand more about this amoeba’s dynamic lifecycle ( Bernard et al, 2022 ). Even now, limited genome annotation and no stable methods for impacting gene expression have significantly hampered Acanthamoeba research where the pathogenesis of other ocular microorganisms like Pseudomonas are well-described and the risk factors for infection clearly delineated ( Gu et al, 2022 ). Equally, the infrequent diagnosis of Acanthamoeba keratitis’ has prevented significant investment in treatment development and infection prevention, despite devastating outcomes for those affected ( Siddiqui and Khan, 2012 ; Szentmary et al, 2019 ).…”

Section: Discussionmentioning

confidence: 99%

Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection

et al. 2022

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IntroductionAcanthamoeba keratitis is often caused when Acanthamoeba contaminate contact lenses and infect the cornea. Acanthamoeba is pervasive in the environment as a motile, foraging trophozoite or biocide-resistant and persistent cyst. As contact lens contamination is a potential first step in infection, we studied Acanthamoeba’s behavior and interactions on different contact lens materials. We hypothesized that contact lenses may induce aggregation, which is a precursor to encystment, and that aggregated encystment would be more difficult to disinfect than motile trophozoites.MethodsSix clinically and/or scientifically relevant strains of Acanthamoeba (ATCC 30010, ATCC 30461, ATCC 50370, ATCC 50702, ATCC 50703, and ATCC PRA-115) were investigated on seven different common silicone hydrogel contact lenses, and a no-lens control, for aggregation and encystment for 72 h. Cell count and size were used to determine aggregation, and fluorescent staining was used to understand encystment. RNA seq was performed to describe the genome of Acanthamoeba which was individually motile or aggregated on different lens materials. Disinfection efficacy using three common multi-purpose solutions was calculated to describe the potential disinfection resistance of trophozoites, individual cysts, or spheroids.ResultsAcanthamoeba trophozoites of all strains examined demonstrated significantly more aggregation on specific contact lens materials than others, or the no-lens control. Fluorescent staining demonstrated encystment in as little as 4 hours on contact lens materials, which is substantially faster than previously reported in natural or laboratory settings. Gene expression profiles corroborated encystment, with significantly differentially expressed pathways involving actin arrangement and membrane complexes. High disinfection resistance of cysts and spheroids with multi-purpose solutions was observed.DiscussionAggregation/encystment is a protective mechanism which may enable Acanthamoeba to be more disinfection resistant than individual trophozoites. This study demonstrates that some contact lens materials promote Acanthamoeba aggregation and encystment, and Acanthamoeba spheroids obstruct multi-purpose solutions from disinfecting Acanthamoeba.

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Section: Discussionmentioning

confidence: 99%

Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection

et al. 2022

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“…It is generally believed that the adhesion of Acanthamoeba to the cornea is a crucial prerequisite for the subsequent inflammatory response and the degree of adhesion is directly proportional to the strength of the host’s inflammatory response ( Wang and Zhu, 2010 ). LBP participates in the initial phase where infiltration is limited to the corneal epithelium, particularly in the intercellular space ( Gu et al, 2022 ). Therefore, the selectivity of Acanthamoeba for the host cornea also determines the differences in the specificity of AK in different hosts.…”

Section: Acanthamoeba Related Diseasesmentioning

confidence: 99%

Biological characteristics and pathogenicity of Acanthamoeba

et al. 2023

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Acanthamoeba is an opportunistic protozoa, which exists widely in nature and is mainly distributed in soil and water. Acanthamoeba usually exists in two forms, trophozoites and cysts. The trophozoite stage is one of growth and reproduction while the cyst stage is characterized by cellular quiescence, commonly resulting in human infection, and the lack of effective monotherapy after initial infection leads to chronic disease. Acanthamoeba can infect several human body tissues such as the skin, cornea, conjunctiva, respiratory tract, and reproductive tract, especially when the tissue barriers are damaged. Furthermore, serious infections can cause Acanthamoeba keratitis, granulomatous amoebic encephalitis, skin, and lung infections. With an increasing number of Acanthamoeba infections in recent years, the pathogenicity of Acanthamoeba is becoming more relevant to mainstream clinical care. This review article will describe the etiological characteristics of Acanthamoeba infection in detail from the aspects of biological characteristic, classification, disease, and pathogenic mechanism in order to provide scientific basis for the diagnosis, treatment, and prevention of Acanthamoeba infection.

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“…The authors reported genes coding for metalloprotease, laminin-binding protein, and heat shock proteins (HSP) and identified several endosymbionts such as species of Chlamydiae , Mycobacterium , Legionella , Burkholderia , Rickettsia, and Pseudomonas , which were significantly different among the isolated, being Pseudomonas spp. the most common bacteria shared in all strains, so they discussed the possibility that this genus may be closely related to virulence and pathogenicity; however, more studies are needed to prove this hypothesis [ 167 ].…”

Section: Advances In Genomic Epidemiologymentioning

confidence: 99%

Distribution and Current State of Molecular Genetic Characterization in Pathogenic Free-Living Amoebae

et al. 2022

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Free-living amoebae (FLA) are protozoa widely distributed in the environment, found in a great diversity of terrestrial biomes. Some genera of FLA are linked to human infections. The genus Acanthamoeba is currently classified into 23 genotypes (T1-T23), and of these some (T1, T2, T4, T5, T10, T12, and T18) are known to be capable of causing granulomatous amoebic encephalitis (GAE) mainly in immunocompromised patients while other genotypes (T2, T3, T4, T5, T6, T10, T11, T12, and T15) cause Acanthamoeba keratitis mainly in otherwise healthy patients. Meanwhile, Naegleria fowleri is the causative agent of an acute infection called primary amoebic meningoencephalitis (PAM), while Balamuthia mandrillaris, like some Acanthamoeba genotypes, causes GAE, differing from the latter in the description of numerous cases in patients immunocompetent. Finally, other FLA related to the pathologies mentioned above have been reported; Sappinia sp. is responsible for one case of amoebic encephalitis; Vermamoeba vermiformis has been found in cases of ocular damage, and its extraordinary capacity as endocytobiont for microorganisms of public health importance such as Legionella pneumophila, Bacillus anthracis, and Pseudomonas aeruginosa, among others. This review addressed issues related to epidemiology, updating their geographic distribution and cases reported in recent years for pathogenic FLA.

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A Comparative Genomic Approach to Determine the Virulence Factors and Horizontal Gene Transfer Events of Clinical Acanthamoeba Isolates

Abstract: Acanthamoeba has the ability to cause serious blinding keratitis. Although the prevalence of this phenomenon has increased in recent years, our knowledge of the underlying opportunistic pathogenic mechanism maybe remains incomplete.

Cited by 16 publications

References 65 publications

Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection

Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection

Biological characteristics and pathogenicity of Acanthamoeba

Distribution and Current State of Molecular Genetic Characterization in Pathogenic Free-Living Amoebae

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