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Current Status of Acanthamoeba in Iran: A Narrative Review Article.

Niyyati M, Rezaeian M - Iran J Parasitol (2015 Apr-Jun)

Bottom Line: In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples.No restrictions were placed on study date, study design or language of publication.We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

ABSTRACT

Background: Free-living amoebae belonging to the genus Acanthamoeba have an environmental distribution. Amoebic keratitis due to these protozoan parasites continue to rise in Iran and worldwide. In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples. However, there is no thorough review about Acanthamoeba genotypes and their distribution in environmental sources such as water, dust and biofilm in Iran. Besides, according to increasing cases of Amoebic keratitis in the region awareness regarding the pathogenic potential of these sight-threatening amoebae is of utmost importance.

Methods: We conducted a thorough review based on the database sources such as MEDLINE, PubMed and Google scholar. No restrictions were placed on study date, study design or language of publication. We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples.

Results: According to our thorough review Acanthamoeba belonging to T4 genotype is the most prevalent type strain in environmental and clinical samples in several regions in Iran and worldwide, however, there are reports regarding Acanthamoeba belonging to other genotypes such as T2, T3, T5, T6 and T11 and the mentioned point could leads us to more researches with the goal of presenting the real genotype dominance of Acanthamoeba and related disease in the country.

Conclusion: Overall, the present review will focus on present status of genotypes of Acanthamoeba in Iran during recent years.

No MeSH data available.


Related in: MedlinePlus

Acanthamoeba spp. cysts isolated from Acanthamoeba keratitis (triangular shape cysts are shown) (Magnification: x10)
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Figure 3: Acanthamoeba spp. cysts isolated from Acanthamoeba keratitis (triangular shape cysts are shown) (Magnification: x10)

Mentions: The only reported disease related to Acanthamoeba in Iran is AK. Encephalitis due to Acanthamoeba has not been reported yet, mainly due to lack of knowledge regarding Acanthamoeba as an agent of central nervous system infections. So far, there are 150 cases of AK in Iran, although it seems that these numbers is lower than the true cases. The first cases of AK in Iran were reported in a soft contact lens wearer (15). In 2007, a ten year survey regarding AK was reported by Rezaeian et al. whom showed among 142 patients, 49 (34.5%) present with AK. The most common age was between 15–25 yr (75.5%). Interestingly, 44 patients (89.79%) were contact lens wearers for cosmetic purposes or visual corrections. Among them 41 patients (93.18%) wore soft contact lenses and three patients were hard contact lens wearers (25). Among 50 keratitis patient, 13 were positive for Acanthamoeba (26). Three species including A. griffin, A. palesinensis and A. castellanii were identified in their samples. Another study revealed Acanthamoeba as a causal agent in 15 (30%) of 50 keratitis samples. Among these clinical isolates, 13 (86.7%) belonged to female patients and 2 (13.3%) were male. All positive specimens belonged to soft contact lens wearers and only one belonged to a patient with a history of hard contact lens usage. Regarding genotype identification, 13 (86.7%) of these isolates belonged to T4 genotype. However, it is important to mention there was a mixed genotype belonging to Acanthamoebae T4 and T11 genotypes in one patient. Other genotypes identified in the clinical specimens were T11 (13.3%) and T3 (6.7%) (17). Another survey of the 90 asymptomatic contact lens wearers, 9 (10%) were positive for FLA outgrowth. Morphological analysis revealed that 3 isolates were belonged to Hartmannella genus according to small round cysts and 6 isolates were belonged to Acanthamoeba genus based on the star shape of endocysts. Sequencing revealed that Acanthamoeba belonged to T4, T3 and T5 genotype (27). Acanthamoeba isolated from contact lenses or corneal scarping is presented in Fig. 3–4.


Current Status of Acanthamoeba in Iran: A Narrative Review Article.

Niyyati M, Rezaeian M - Iran J Parasitol (2015 Apr-Jun)

Acanthamoeba spp. cysts isolated from Acanthamoeba keratitis (triangular shape cysts are shown) (Magnification: x10)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4522290&req=5

Figure 3: Acanthamoeba spp. cysts isolated from Acanthamoeba keratitis (triangular shape cysts are shown) (Magnification: x10)
Mentions: The only reported disease related to Acanthamoeba in Iran is AK. Encephalitis due to Acanthamoeba has not been reported yet, mainly due to lack of knowledge regarding Acanthamoeba as an agent of central nervous system infections. So far, there are 150 cases of AK in Iran, although it seems that these numbers is lower than the true cases. The first cases of AK in Iran were reported in a soft contact lens wearer (15). In 2007, a ten year survey regarding AK was reported by Rezaeian et al. whom showed among 142 patients, 49 (34.5%) present with AK. The most common age was between 15–25 yr (75.5%). Interestingly, 44 patients (89.79%) were contact lens wearers for cosmetic purposes or visual corrections. Among them 41 patients (93.18%) wore soft contact lenses and three patients were hard contact lens wearers (25). Among 50 keratitis patient, 13 were positive for Acanthamoeba (26). Three species including A. griffin, A. palesinensis and A. castellanii were identified in their samples. Another study revealed Acanthamoeba as a causal agent in 15 (30%) of 50 keratitis samples. Among these clinical isolates, 13 (86.7%) belonged to female patients and 2 (13.3%) were male. All positive specimens belonged to soft contact lens wearers and only one belonged to a patient with a history of hard contact lens usage. Regarding genotype identification, 13 (86.7%) of these isolates belonged to T4 genotype. However, it is important to mention there was a mixed genotype belonging to Acanthamoebae T4 and T11 genotypes in one patient. Other genotypes identified in the clinical specimens were T11 (13.3%) and T3 (6.7%) (17). Another survey of the 90 asymptomatic contact lens wearers, 9 (10%) were positive for FLA outgrowth. Morphological analysis revealed that 3 isolates were belonged to Hartmannella genus according to small round cysts and 6 isolates were belonged to Acanthamoeba genus based on the star shape of endocysts. Sequencing revealed that Acanthamoeba belonged to T4, T3 and T5 genotype (27). Acanthamoeba isolated from contact lenses or corneal scarping is presented in Fig. 3–4.

Bottom Line: In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples.No restrictions were placed on study date, study design or language of publication.We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

ABSTRACT

Background: Free-living amoebae belonging to the genus Acanthamoeba have an environmental distribution. Amoebic keratitis due to these protozoan parasites continue to rise in Iran and worldwide. In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples. However, there is no thorough review about Acanthamoeba genotypes and their distribution in environmental sources such as water, dust and biofilm in Iran. Besides, according to increasing cases of Amoebic keratitis in the region awareness regarding the pathogenic potential of these sight-threatening amoebae is of utmost importance.

Methods: We conducted a thorough review based on the database sources such as MEDLINE, PubMed and Google scholar. No restrictions were placed on study date, study design or language of publication. We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples.

Results: According to our thorough review Acanthamoeba belonging to T4 genotype is the most prevalent type strain in environmental and clinical samples in several regions in Iran and worldwide, however, there are reports regarding Acanthamoeba belonging to other genotypes such as T2, T3, T5, T6 and T11 and the mentioned point could leads us to more researches with the goal of presenting the real genotype dominance of Acanthamoeba and related disease in the country.

Conclusion: Overall, the present review will focus on present status of genotypes of Acanthamoeba in Iran during recent years.

No MeSH data available.


Related in: MedlinePlus