<i>Acanthamoeba polyphaga</i> in Rheumatoid Arthritis: Possibility for a Chronic Infection

Jeansson, Stig; Kvien, Tore K

doi:10.1046/j.1365-3083.2001.00926.x

Cited by 11 publications

(7 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chappell et al (78) suggested that while serious ocular disease and CNS infections are rare, mucosal infections may contribute significantly to large numbers of undiagnosed sinus or pulmonary infections. The presence of a higher frequency of A. polyphaga-specific immunoglobulin M (IgM) and a lower frequency of IgG antibodies in serum from rheumatoid arthritis (RA) patients than from matched controls has been reported (204). The higher titers of A. polyphaga-specific IgM in RA patients than in matched controls were thought to be due to persistent or repeated antigenic stimulation by A. polyphaga.…”

Section: Role Of the Immune System In Acanthamoeba Infectionsmentioning

confidence: 99%

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: Role Of the Immune System In Acanthamoeba Infectionsmentioning

confidence: 99%

Acanthamoebaspp. as Agents of Disease in Humans

2003

View full text Add to dashboard Cite

show abstract

“…However, these amoebae can infect a variety of mammals, including humans, thereby producing severe and often fatal diseases. They act as opportunistic as well as nonopportunistic pathogens, are the causative agents of granulomatous amoebic encephalitis and amoebic keratitis, and have been associated with cutaneous lesions and sinusitis (18,20,(37)(38)(39). Both trophozoites and cysts have been shown to be resistant to chlorination used for disinfecting water systems (30,35,36).…”

mentioning

confidence: 99%

Acanthamoeba castellaniiPromotion of In Vitro Survival and Transmission of Coxsackie B3 Viruses

Mattana¹,

Serra

Mariotti³

et al. 2006

Eukaryot Cell

View full text Add to dashboard Cite

This work was undertaken to determine whether Acanthamoeba could play a role in the survival and transmission of coxsackieviruses and focused on in vitro interactions between Acanthamoeba castellanii and coxsackie B3 viruses (CVB-3). Residual virus titer evaluations and immunofluorescence experiments revealed a remarkable CVB-3 adsorption on amoeba surfaces and accumulation inside cells. The survival of viruses was independent of the dynamics of amoeba replication and encystment. In addition, our results indicated that virus-infected amoebas can release infectious viruses during interaction with human macrophages. On the basis of these data, Acanthamoeba appears to be a potential promoter of the survival of coxsackieviruses and their transmission to human hosts.Free-living amoebas of the genus Acanthamoeba are ubiquitous in nature (34); they have been isolated from air (19, 32, 33), soil (2, 3, 6, 29), and water environments, including chlorinated swimming pools (10), drinking water (17, 28), cooling towers (5), natural thermal water (31), hospital water networks (35), and marine water (4). Acanthamoeba is characterized by a feeding and replicating trophozoitic stage which under adverse conditions can develop to a dormant cyst stage (34). Cysts are highly resistant forms capable of withstanding disinfection, desiccation, and extremes of temperature. When favorable conditions occur, the cysts hatch and the trophozoites emerge to feed and replicate. Acanthamoeba species are not parasites, as they do not require the infection of a host organism to complete their life cycles (11, 37). However, these amoebae can infect a variety of mammals, including humans, thereby producing severe and often fatal diseases. They act as opportunistic as well as nonopportunistic pathogens, are the causative agents of granulomatous amoebic encephalitis and amoebic keratitis, and have been associated with cutaneous lesions and sinusitis (18,20,(37)(38)(39). Both trophozoites and cysts have been shown to be resistant to chlorination used for disinfecting water systems (30,35,36).In addition, Acanthamoeba amoebas play a role as reservoirs for Legionella pneumophila and other amoeba-resistant microorganisms that include bacteria, fungi, and viruses (15).Enteroviruses (polioviruses, coxsackieviruses, echoviruses, and newer enteroviruses) are naked small RNA viruses of the Picornaviridae family. They are important human pathogens often causing mild febrile illness, but clinical manifestations of enterovirus infections also include meningitis, encephalitis, paralysis, and myocarditis (16,27). Gastrointestinal involvement may also result. Transmission from person to person proceeds through the fecal-oral route. These viruses are widespread in marine water and also may be acquired by eating contaminated aquatic organisms (14). Although labile, they may persist in free-flowing estuarine or marine waters for several months and in some cases during the winter months (21). Although their life span in water may be prolonged by the influence of estu...

show abstract

“…These amoebas have been associated with amoebic keratitis, especially in contact lens wearers, and with chronic but fatal granulomatous amoebic meningoencephalitis (GAE) (27). They have also been identified as agents of cutaneous nodules and abscesses, arthritis, and rhinosinusitis (16,24,40,41). Most recently, Acanthamoeba has been recognized as an opportunistic pathogen of humans and other animals and is known to cause a spectrum of infections in immunocompromised individuals, including those with AIDS (4,6,8,20,37).…”

mentioning

confidence: 99%

In Vitro Evaluation of the Effectiveness of the Macrolide Rokitamycin and Chlorpromazine against Acanthamoeba castellanii

Mattana¹,

Biancu²,

Alberti³

et al. 2004

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The present study demonstrates the in vitro effectiveness of the macrolide rokitamycin and the phenothiazine compound chlorpromazine against Acanthamoeba castellanii. Growth curve evaluations revealed that both drugs inhibit trophozoite growth in dose-and time-dependent ways. The effects of both drugs when they were used at the MICs at which 100% of isolates are inhibited were amoebistatic, but at higher doses they were amoebicidal as well as cysticidal. Experiments showed that when rokitamycin was associated with chlorpromazine or amphotericin B, rokitamycin enhanced their activities. Furthermore, low doses of rokitamycin and chlorpromazine, alone or in combination, blocked the cytopathic effect of A. castellanii against WKD cells derived from the human cornea. These results may have important significance in the development of new anti-Acanthamoeba compounds.Acanthamoebas are small, ubiquitous, free-living amoebas which can exist in two forms: the motile trophozoite form and the double-walled cyst form (26,32). In the encysted state they are protected from unfavorable environmental conditions and are resistant to extremes of temperature, desiccation, and microbial agents (3,18,19,42). Human infections are generally site specific: corneal and neural tissues are the primary targets, although other tissues can be affected. These amoebas have been associated with amoebic keratitis, especially in contact lens wearers, and with chronic but fatal granulomatous amoebic meningoencephalitis (GAE) (27). They have also been identified as agents of cutaneous nodules and abscesses, arthritis, and rhinosinusitis (16,24,40,41). Most recently, Acanthamoeba has been recognized as an opportunistic pathogen of humans and other animals and is known to cause a spectrum of infections in immunocompromised individuals, including those with AIDS (4,6,8,20,37). Eradication of these protozoa from infection sites is difficult because under adverse conditions the amoeba encyst and medical therapy is often less effective against cysts than against trophozoites. There are numerous reports of drugs that have the potential for the treatment of Acanthamoeba keratitis. Infections with this organism are usually treated with a combination of cationic antiseptics (polyhexamethylene biguanide), which inhibit the membrane, and aromatic diamidines (propamidine isethionate), which inhibit DNA synthesis (23,25,28,31). More recently, chlorhexidine, alone or in combination with propamidine isethionate, has also been successfully applied (35). The therapeutic treatment for GAE or disseminated acanthamoebiasis is more problematic. Although two GAE cases were successfully treated by chemotherapy with ketoconazole or fluconazole and sulfadiazine after surgical excision of the lesions (29, 36), at present, no clinical trial of these treatments for Acanthamoeba systemic infections has yet been attempted. This is due to the low sensitivity of Acanthamoeba to many antiamoebic agents and, in the case of GAE, to the weak abilities of these agents to cross the blood...

show abstract

Acanthamoeba polyphaga in Rheumatoid Arthritis: Possibility for a Chronic Infection

Cited by 11 publications

References 23 publications

Acanthamoebaspp. as Agents of Disease in Humans

Acanthamoebaspp. as Agents of Disease in Humans

Acanthamoeba castellaniiPromotion of In Vitro Survival and Transmission of Coxsackie B3 Viruses

In Vitro Evaluation of the Effectiveness of the Macrolide Rokitamycin and Chlorpromazine against Acanthamoeba castellanii

Contact Info

Product

Resources

About