Disseminated Acanthamoeba infection in a child with symptomatic human immunodeficiency virus infection

Friedland, Leonard R.; Raphael, Steven; Deutsch, Ellen S.; Johal, J.; Martyn, Lois J.; Visvesvara, Govinda S.; Lischner, Harold W.

doi:10.1097/00006454-199205000-00012

Cited by 54 publications

(31 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Since then, an increasing number of cases of disseminated Acanthamoeba infections have been reported in individuals with AIDS (40,65,69,77,125,128,143,149,159,173,178,192,214,224,258,295,307,322,373,375,380,406,407,420,438,442,446,474) (see Table FIG (65,149,159,406,438,474). While cerebrospinal fluid (CSF) lymphocytosis is observed in non-AIDS Acanthamoeba-infected individuals, CSF may be devoid of cells in HIV-positive patients (149).…”

Section: Infections In Patients With Aidsmentioning

confidence: 99%

“…Cutaneous disease has also been documented for non-HIV-infected patients with amebic encephalitis, for patients undergoing immunosuppressive therapy for organ transplantation (421,449), or for individuals with immunological diseases (159,277,337,421,460). The cutaneous form of the disease is characterized by the presence of hard erythematous nodules or skin ulcers (40,77,143,157,179,258,295,322,380,438,446). Early manifestations of the cutaneous form of acanthamoebiasis include the presence of firm papulonodules that drain purulent material and then develop into nonhealing indurated ulcerations (295,380).…”

Section: Cutaneous Acanthamebiasismentioning

confidence: 99%

“…Acanthamoeba spp. also have been associated with cutaneous lesions and sinusitis in AIDS patients and other immunocompromised individuals (128,143,164,179,282,295,446). The first suggestion that Acanthamoeba could cause disease in humans came in 1958 during polio vaccine safety trials.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Acanthamoebaspp. as Agents of Disease in Humans

2003

View full text Add to dashboard Cite

Acanthamoeba spp. are free-living amebae that inhabit a variety of air, soil, and water environments. However, these amebae can also act as opportunistic as well as nonopportunistic pathogens. They are the causative agents of granulomatous amebic encephalitis and amebic keratitis and have been associated with cutaneous lesions and sinusitis. Immuno compromised individuals, including AIDS patients, are particularly susceptible to infections with Acanthamoeba. The immune defense mechanisms that operate against Acanthamoeba have not been well characterized, but it has been proposed that both innate and acquired immunity play a role. The ameba's life cycle includes an active feeding trophozoite stage and a dormant cyst stage. Trophozoites feed on bacteria, yeast, and algae. However, both trophozoites and cysts can retain viable bacteria and may serve as reservoirs for bacteria with human pathogenic potential. Diagnosis of infection includes direct microscopy of wet mounts of cerebrospinal fluid or stained smears of cerebrospinal fluid sediment, light or electron microscopy of tissues, in vitro cultivation of Acanthamoeba, and histological assessment of frozen or paraffin-embedded sections of brain or cutaneous lesion biopsy material. Immunocytochemistry, chemifluorescent dye staining, PCR, and analysis of DNA sequence variation also have been employed for laboratory diagnosis. Treatment of Acanthamoeba infections has met with mixed results. However, chlorhexidine gluconate, alone or in combination with propamidene isethionate, is effective in some patients. Furthermore, effective treatment is complicated since patients may present with underlying disease and Acanthamoeba infection may not be recognized. Since an increase in the number of cases of Acanthamoeba infections has occurred worldwide, these protozoa have become increasingly important as agents of human disease

show abstract

Section: Infections In Patients With Aidsmentioning

confidence: 99%

Section: Cutaneous Acanthamebiasismentioning

confidence: 99%

See 1 more Smart Citation

Acanthamoebaspp. as Agents of Disease in Humans

2003

View full text Add to dashboard Cite

show abstract

“…Acanthamoeba are the causative agents of life-threatening granulomatous amoebic encephalitis (GAE) in immunocompromised patients (Jones et al, 1975;Martinez, 1987;Di Gregorio et al, 1992;Friedland et al, 1992;Gonzalez et al, 1986;Gordon et al, 1992) and a common amoebic keratitis, a sight-threatening disease of the eye, which is mostly associated with contact-lens use (Chynn et al, 1995;Moore & McCulley, 1989;Wright et al, 1985;Mathers et al, 1996;Niederkorn et al, 1999;Marciano-Cabral & Cabral, 2003;Khan, 2003). In addition, Acanthamoeba have been associated with cutaneous lesions and sinusitis in immunocompromised patients (reviewed by Marciano-Cabral & Cabral, 2003).…”

Section: Introductionmentioning

confidence: 99%

Acanthamoeba induces cell-cycle arrest in host cells

Sissons

Alsam

Jayasekera

et al. 2004

Journal of Medical Microbiology

View full text Add to dashboard Cite

Acanthamoeba can cause fatal granulomatous amoebic encephalitis (GAE) and eye keratitis. However, the pathogenesis and pathophysiology of these emerging diseases remain unclear. In this study, the effects of Acanthamoeba on the host cell cycle using human brain microvascular endothelial cells (HBMEC) and human corneal epithelial cells (HCEC) were determined. Two isolates of Acanthamoeba belonging to the T1 genotype (GAE isolate) and T4 genotype (keratitis isolate) were used, which showed severe cytotoxicity on HBMEC and HCEC, respectively. No tissue specificity was observed in their ability to exhibit binding to the host cells. To determine the effects of Acanthamoeba on the host cell cycle, a cell-cycle-specific gene array was used. This screened for 96 genes specific for host cell-cycle regulation. It was observed that Acanthamoeba inhibited expression of genes encoding cyclins F and G1 and cyclin-dependent kinase 6, which are proteins important for cell-cycle progression. Moreover, upregulation was observed of the expression of genes such as GADD45A and p130 Rb, associated with cell-cycle arrest, indicating cell-cycle inhibition. Next, the effect of Acanthamoeba on retinoblastoma protein (pRb) phosphorylation was determined. pRb is a potent inhibitor of G 1 -to-S cell-cycle progression; however, its function is inhibited upon phosphorylation, allowing progression into S phase. Western blotting revealed that Acanthamoeba abolished pRb phosphorylation leading to cell-cycle arrest at the G 1 -to-S transition. Taken together, these studies demonstrated for the first time that Acanthamoeba inhibits the host cell cycle at the transcriptional level, as well as by modulating pRb phosphorylation using host cell-signalling mechanisms. A complete understanding of Acanthamoeba-host cell interactions may help in developing novel strategies to treat Acanthamoeba infections. INTRODUCTIONAcanthamoeba are the causative agents of life-threatening granulomatous amoebic encephalitis (GAE) in immunocompromised patients (Jones et al., 1975;Martinez, 1987;Di Gregorio et al., 1992;Friedland et al., 1992;Gonzalez et al., 1986;Gordon et al., 1992) and a common amoebic keratitis, a sight-threatening disease of the eye, which is mostly associated with contact-lens use (Chynn et al., 1995;Moore & McCulley, 1989;Wright et al., 1985; Mathers et al., 1996;Niederkorn et al., 1999;Marciano-Cabral & Cabral, 2003;Khan, 2003). In addition, Acanthamoeba have been associated with cutaneous lesions and sinusitis in immunocompromised patients (reviewed by Marciano-Cabral & Cabral, 2003). Over the past few decades, Acanthamoeba infections have remained significant and are on the rise. This is due to increasing populations of contact-lens wearers and immunocompromised patients, as well as improved awareness and detection of these emerging diseases. However, the precise mechanisms associated with the pathogenesis and pathophysiology of Acanthamoeba infection remain unclear. The clinical outcome of Acanthamoeba infection is dependent on the virulence of...

show abstract

“…Although the species of Acanthamoeba can cause fatal infections involving brain (Gonzalez et al 1986, Di Gregorio et al 1991, Friedland et al 1992, Gordon et al 1992, however, they are most frequently associated with eye keratitis (Auran et al 1987, John 1993, Badenoch et al 1994, Niederkorn et al 1999. Acanthamoeba keratitis is characterised by intense pain and a slowly worsening clinical course.…”

mentioning

confidence: 99%

Genotypic, phenotypic, biochemical, physiological and pathogenicity-based categorisation of Acanthamoeba strains

Khan

Tareen²

2003

FOLIA PARASIT

View full text Add to dashboard Cite

Abstract. The genus Acanthamoeba includes more than 20 morphological species, but classification is problematical. Recently, the discovery of substantial interstrain differences in ribosomal DNA (rDNA) sequences has prompted questions about the relatedness of strains of the same species. In this study, therefore, we have investigated relationships between two isolates of A. polyphaga, CCAP 1501/3c and ATCC 30871, using morphological, biochemical, physiological, molecular and cytotoxicity assays. We observed that A. polyphaga ATCC 30871 exhibited up to six arms in endocyst while A. polyphaga CCAP 1501/3c exhibited a maximum of 5 arms thus indicating their position in group 2 and 3, respectively. Acanthamoeba polyphaga ATCC 30871 exhibited growth at 37°C and growth on 1M mannitol plates while A. polyphaga CCAP 1501/3c did not. In addition, both isolates exhibited differences in isoenzyme banding patterns and rDNA restriction fragment polymorphisms. More importantly, A. polyphaga ATCC 30871 produced cytotoxicity on corneal epithelial cells while A. polyphaga CCAP 1501/3c had no effects, suggesting differences in pathogenicity. Thus, all the results provide evidence for significant differences between the strains and further provided the basis for reclassification of the isolates. Implications of these results in the clinical diagnosis of pathogenic Acanthamoeba are discussed.

show abstract

Disseminated Acanthamoeba infection in a child with symptomatic human immunodeficiency virus infection

Cited by 54 publications

References 0 publications

Acanthamoebaspp. as Agents of Disease in Humans

Acanthamoebaspp. as Agents of Disease in Humans

Acanthamoeba induces cell-cycle arrest in host cells

Genotypic, phenotypic, biochemical, physiological and pathogenicity-based categorisation of Acanthamoeba strains

Contact Info

Product

Resources

About