Chapter-06.02 Intestinal Amebae, Free-Living Ameba and Balantidium Coli

2018 ◽  
pp. 451-458
Author(s):  
Apurba Sastry ◽  
Sandhya K
2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S246-S246
Author(s):  
Kevin O’Laughlin ◽  
Jennifer R Cope ◽  
Zachary A Marsh

Abstract Background Acanthamoeba is a free-living ameba found worldwide in soil and water that can cause severe illness. Transmission is thought to be through the skin, eyes, or lungs; Acanthamoeba can cause disseminated infection (Acanthamoeba disease) in addition to the more widely recognized Acanthamoeba keratitis. Infections however are rare, and only case reports or small case series have been published. We review Acanthamoeba disease cases from the Centers for Disease Control and Prevention (CDC) free-living ameba registry to characterize the disease in the United States. Methods CDC maintains a free-living ameba (FLA) registry of laboratory-confirmed Acanthamoeba cases (excluding keratitis) sourced from published case reports, CDC case report forms, and CDC laboratory results. SAS© version 9.4 software was used to calculate descriptive statistics and frequencies. Results We identified 163 cases of Acanthamoeba disease between 1956 and 2018. Of cases with documented outcome, 85% were fatal (105/124). Most (88%) cases were in patients who were immunocompromised (136/155): 66 people living with HIV (of whom 49 were classified as having AIDS); 33 recipients of organ transplantation; 30 people diagnosed with malignancy. The most common manifestation of disease was encephalitis (49%). Other clinical presentations included cutaneous lesions (20%) and rhinosinusitis (6%); 40 cases involved multiple organ systems. Median patient age was 42 years (range 0–83 years). Males accounted for 71% (114/160) of cases. California (29) and Texas (14) had the most case reports; 30 other states reported cases. The source of exposure was unknown in most cases (75%); soil and water were documented in 14 and 17 cases, respectively. Conclusion Acanthamoeba disease in the United States is primarily characterized by encephalitis and cutaneous lesions that affect predominately immunocompromised individuals. Acanthamoeba as a cause of encephalitis in immunocompromised patients should be considered by clinicians, which may lead to earlier diagnosis and treatment. Disclosures All Authors: No reported disclosures


1990 ◽  
Vol 37 (4) ◽  
pp. 25s-33s ◽  
Author(s):  
GOVINDA S. VISVESVARA ◽  
JEANETTE K. STEHR-GREEN

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S22-S22 ◽  
Author(s):  
Jennifer Cope ◽  
Shantanu Roy ◽  
Ibne Ali

Abstract Background The genus Acanthamoeba are free-living amebae found worldwide in water, including tap water, and soil that can cause rare but severe infections of the eye, skin, and central nervous system. Acanthamoeba spp. generally cause disease in immunocompromised persons, including those with HIV, hematologic malignancies, and solid organ transplants. The route of transmission and incubation period are not well known in humans, but animal studies have shown that disease can be produced via the intranasal, intrathecal, and intravenous routes. We describe 5 cases of Acanthamoeba disease among immunocompromised patients who practiced nasal rinsing prior to becoming ill. Methods The Centers for Disease Control and Prevention (CDC) offers a clinical consultation service for free-living ameba infections and maintains a Free-living Ameba laboratory with confirmatory diagnostic testing capabilities. When an Acanthamoeba case is confirmed in the United States, details about the case are collected on a standardized case report form which includes questions about the case–patient’s water and soil exposure prior to becoming ill. Questions about nasal rinsing were added to the form in 2011. Results Five Acanthamoeba case patients in CDC’s free-living ameba database were reported to have performed nasal rinsing prior to becoming ill. The median age was 60 years (range 36–73 years) and 3 of 5 patients were female. Two were solid-organ transplant patients (heart and kidney), 2 had chronic lymphocytic leukemia, and 1 had HIV. Three patients presented only with encephalitis and died. The 2-organ transplant patients had a combination of rhinosinusitis, osteomyelitis, and skin lesions. One survived and the other died, the cause of which was unrelated to Acanthamoeba. All reported using tap water to perform nasal rinsing, most for sinus congestion using a neti pot or similar device and one for religious purposes. Conclusion Acanthamoeba is an inhabitant of water, including treated tap water. Immunocompromised patients, like those presented here, might be at risk for infections caused by Acanthamoeba transmitted via tap water used for nasal rinsing. Clinicians caring for immunocompromised patients should advise their patients not to use tap water for nasal or sinus rinsing. Disclosures All authors: No reported disclosures.


1980 ◽  
Vol 49 (1) ◽  
pp. 7-12 ◽  
Author(s):  
A. Julio Mart�nez ◽  
Cirilo Sotelo-Avila ◽  
Hilda Alcal� ◽  
Eddy Willaert

2005 ◽  
Vol 71 (5) ◽  
pp. 2244-2249 ◽  
Author(s):  
Winlet Sheba Shadrach ◽  
Kerstin Rydzewski ◽  
Ulrike Laube ◽  
Gudrun Holland ◽  
Muhsin Özel ◽  
...  

ABSTRACT Balamuthia mandrillaris is a free-living ameba and an opportunistic agent of granulomatous encephalitis in humans and other mammalian species. Other free-living amebas, such as Acanthamoeba and Hartmannella, can provide a niche for intracellular survival of bacteria, including the causative agent of Legionnaires' disease, Legionella pneumophila. Infection of amebas by L. pneumophila enhances the bacterial infectivity for mammalian cells and lung tissues. Likewise, the pathogenicity of amebas may be enhanced when they host bacteria. So far, the colonization of B. mandrillaris by bacteria has not been convincingly shown. In this study, we investigated whether this ameba could host L. pneumophila bacteria. Our experiments showed that L. pneumophila could initiate uptake by B. mandrillaris and could replicate within the ameba about 4 to 5 log cycles from 24 to 72 h after infection. On the other hand, a dotA mutant, known to be unable to propagate in Acanthamoeba castellanii, also did not replicate within B. mandrillaris. Approaching completion of the intracellular cycle, L. pneumophila wild-type bacteria were able to destroy their ameboid hosts. Observations by light microscopy paralleled our quantitative data and revealed the rounding, collapse, clumping, and complete destruction of the infected amebas. Electron microscopic studies unveiled the replication of the bacteria in a compartment surrounded by a structure resembling rough endoplasmic reticulum. The course of intracellular infection, the degree of bacterial multiplication, and the ultrastructural features of a L. pneumophila-infected B. mandrillaris ameba resembled those described for other amebas hosting Legionella bacteria. We hence speculate that B. mandrillaris might serve as a host for bacteria in its natural environment.


1982 ◽  
Vol 94 (1) ◽  
pp. 143-149 ◽  
Author(s):  
J M Heiple ◽  
D L Taylor

Changes in pH are measured in pinosomes and phagosomes of single specimens of the giant, free-living ameba, Chaos carolinensis. Measurements of pH are made microfluorometrically, as previously described (Heiple and Taylor. 1980. J. Cell Biol. 86:885-890.) by quantitation of fluorescence intensity ratios (Ex489nm,/Ex452nm, Em520-560nm from ingested fluorescein thiocarbamyl (FTC)-ovalbumin. After 1 h of pinocytosis (induced in acid solution), FTC-ovalbumin is found in predominantly small ( less than or equal to 5 micrometers in diameter), acidic (pH less than or equal to 5.0-6.2) vesicles of various shape and density. As the length of ingestion time increases (up to 24 h), the probe is also found in vesicles of increasing size (up to 100 micrometers in diameter), increasing pH (up to pH approximately 8.0), and decreasing density. Co-localization of fluorescein and rhodamine fluorescence, after a pulse-chase with fluorescein- and rhodamine-labeled ovalbumin, suggests vesicle growth, in part, by fusion. The pH in a single phagosome is followed after ingestion of ciliates in neutral solutions of FTC-ovalbumin. A dramatic acidification (delta pH greater than or equal to - 2.0) begins within 5 min of phagosome formation and appears to be complete in approximately 20 min. Phagosomal pH then slowly recovers to more neutral values over the next 2 h. pH changes observed in more mature populations of pinosomes within a single cell may reflect those occurring within a single phagosome. Phagosomal and pinosomal pH changes may be required for lysosomal fusion and may be involved in regulation of lysosomal enzyme activity.


Author(s):  
Jennifer R. Cope ◽  
Ibne Karim M. Ali ◽  
Ourania Georgacopoulos

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