Pathogenic and free-living Acanthamoeba are widely distributed in the environment and have been reported to cause keratitis and universally fatal encephalitis. Primary cutaneous acanthamoebiasis caused by Acanthamoeba is exceedingly rare and presents as isolated necrotic cutaneous lesions without involvement of the cornea or central nervous system. Cutaneous acanthamoebiasis often occurs in immunocompromised patients and is likely overlooked or even misdiagnosed only by cutaneous biopsy tissue histopathological analysis. Here, we report a HIV-infected 63-year-old female with oral leukoplakia for 4 months and scattered large skin ulcers all over the body for 2 months. The cause of the cutaneous lesions was unclear through cutaneous specimens histopathological analysis, and subsequently Acanthamoeba were detected by metagenomic next-generation sequencing (mNGS), which may be the cause of cutaneous lesions. Based on the mNGS results, a pathologist subsequently reviewed the previous pathological slides and found trophozoites of Acanthamoeba so that the cause was identified, and the skin ulcers improved significantly after treatment with multi-drug combination therapy. Acanthamoeba is also a host of pathogenic microorganisms. The presence of endosymbionts enhances the pathogenicity of Acanthamoeba, and no other pathogens were reported in this case. mNGS is helpful for rapidly diagnosing the etiology of rare skin diseases and can indicate the presence or absence of commensal microorganisms.

Infections caused by free-living amoebae pose a significant public health threat owing to growing populations of immunocompromised hosts combined with diagnostic delays, treatment difficulties, and high case fatality rates. Nasopharyngeal infections caused by Acanthamoeba are rare and the optimal treatment is not well established. We report a case of Acanthamoeba rhinosinusitis in a patient with chronic lymphocytic leukemia who presented with headaches and chronic rhinosinusitis refractory to multiple courses of antibiotics. A diagnosis of Acanthamoeba rhinosinusitis was established through broad-range polymerase chain reaction testing on sinus tissue. The patient had a favorable response to treatment, which included surgical debridement, cessation of immunosuppressants, and a three-drug regimen consisting of miltefosine, fluconazole, and sulfadiazine.

Acanthamoeba spp. are rare etiological agents of meningoencephalitis with high mortality. We present three cases of Acanthamoeba meningoencephalitis in immunocompetent individuals from Eastern India. The first patient presented with fever and headache; the second with headache, visual disturbance, and squint; and the third presented in a drowsy state. The cases presented on March 3, 18, and 21, 2023 respectively. The first two patients had concomitant tubercular meningitis for which they received antitubercular therapy and steroid. Their cerebrospinal fluid showed slight lymphocytic pleocytosis and increased protein. The diagnosis was done by microscopy, culture, and polymerase chain reaction. They received a combination therapy comprising rifampicin, fluconazole, and trimethoprim-sulfamethoxazole. The first patient additionally received miltefosine. She responded well to therapy and survived, but the other two patients died despite intensive care. Detection of three cases within a period of 1 month from Eastern India is unusual. It is imperative to sensitize healthcare providers about Acanthamoeba meningoencephalitis to facilitate timely diagnosis and treatment of the disease.

Acanthamoeba keratitis is a potentially sight-threatening infection of the cornea that can lead to blindness. Over the past few decades, there has been a rise in the reported cases worldwide, which is in line with the increase of contact lens wearers. Here, we present three cases of Acanthamoeba keratitis with different outcomes.

A case of Acanthamoeba rhinorrhea in a 32 years female, who was recently recovered from COVID-19 infectionat a tertiary care institute in India. Though, there was no standard treatment protocol for management of amoebic-meningo encephalitis. The patient was managed successfully with combination therapy of amphotericin B and miltefosine. Agents having trophicidal and cysticidal activities are used for treatment of CNS Acanthamoeba infection. COVID 19 infection, steroid therapy anddiabetes mellitus which lead to low immunitywere found to be associated contributing factors.

BACKGROUND: The occurrence of granulomatous amoebic encephalitis (GAE) was investigated due to the exposure of a large number of immunocompromised patients to opportunistic Acanthamoeba infections, which in most cases are fatal.
METHODS: In this case-control study, 160 samples from the nasal mucosa of immunocompromised patients were collected between February 2019 to February 2020 in Isfahan, central Iran, using sterile cotton swabs; 150 ethnically matched controls were included. The pathogenic potential of the identified isolates was evaluated using temperature and osmotolerance assays. The identification of Acanthamoeba infection was confirmed by both morphological and phylomolecular tools.
RESULTS: Of 310 collected samples, 32 strains, including 25 (15.6%) and 7 (4.6%) isolates, were positive for the Acanthamoeba genus in the patient and control groups, respectively. The topology of the phylogenetic tree indicated that all the Acanthamoeba strains belonged to the T4 genotype. Only five of the isolates genotyped as T4 were positive for potential pathogenic assays. The heterogeneity analysis of 18S ribosomal RNA sequences of Acanthamoeba in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and hepatitis B and C patients revealed significant genetic diversity (haplotype diversity [Hd] 0.511) compared with that of healthy individuals (Hd 0.210).
CONCLUSIONS: The circulation of pathogenic isolates of Acanthamoeba, particularly in HIV/AIDS patients, along with their genetic traits, indicates that clinicians should be more aware of fatal cases of GAE, especially in suspected encephalitis, in Iran and worldwide.

The cases illustrate Acanthamoeba coinfection with Pseudomonas aeruginosa or microsporidia in the cornea.
This case series aimed to alert clinicians toward considering Acanthamoeba coinfection in the cornea when unusual presentation such as perineuritis or epitheliitis was observed in clinical images. Increased suspicion of Acanthamoeba coinfection may facilitate early diagnosis and prompt management, eventually leading to good vision outcomes.
An 11-year-old boy wearing orthokeratology lens for myopia control complained of pain in the right eye for 1 week. A paracentral corneal ulcer with perineuritis was observed. Culture from corneal tissue revealed P. aeruginosa , and an in vivo confocal microscopic examination showed highly reflective and oval-shaped structures indicating Acanthamoeba coinfection. Corneal lesions gradually improved under 0.02% polyhexamethylene biguanidine, 0.1% propamidine isethionate, and 0.3% ciprofloxacin. At 1 year, the final best-corrected visual acuity was 20/25 with residual paracentral corneal opacity. Another 20-year-old man complained of pain in the right eye for 2 weeks. Multiple raised corneal lesions associated with epitheliitis were found. Moreover, 1% acid-fast staining showed oval-shaped spores, and microsporidia infection was inferred. In addition, polymerase chain reaction results obtained after subjecting the patient to corneal debridement revealed positivity for Acanthamoeba . Polyhexamethylene biguanidine (0.02%) and 0.5% moxifloxacin were prescribed, and the lesions subsided. At a 2-year follow-up, the final best-corrected visual acuity was 20/25.
Perineuritis in orthokeratology lens wearers and epitheliitis without any predisposing factor are unusual presentations of Acanthamoeba coinfection in the cornea. These corneal findings should arouse the suspicion of coinfection and enable the clinicians to conduct the appropriate workup and initiate adequate treatment. This case series demonstrated that early diagnosis and prompt treatment can improve visual prognosis.

Various components in the cell are responsible for maintaining physiological levels of reactive oxygen species (ROS). Several different enzymes exist that can convert or degrade ROS; among them are the superoxide dismutases (SODs). If left unchecked, ROS can cause damage that leads to pathology, can contribute to aging, and may, ultimately, cause death. SODs are responsible for converting superoxide anions to hydrogen peroxide by dismutation. Here we review the role of different SODs on the development and pathogenicity of various eukaryotic microorganisms relevant to human health. These include the fungal aging model, Podospora anserina; various members of the genus Aspergillus that can potentially cause aspergillosis; the agents of diseases such as Chagas and sleeping disease, Trypanosoma cruzi and Trypanosoma brucei, respectively; and, finally, pathogenic amoebae, such as Acanthamoeba spp. In these organisms, SODs fulfill essential and often regulatory functions that come into play during processes such as the development, host infection, propagation, and control of gene expression. We explore the contribution of SODs and their related factors in these microorganisms, which have an established role in health and disease.

Acanthamoeba brain abscess is very rare and most often fatal. There remains no standardized regimen for its management. We report a case in northern Australia of an immunosuppressed 57-year-old man who presented with diarrhea and weight loss, and was diagnosed with multiple Acanthamoeba brain abscesses after neurological deterioration. This case is the first successful treatment with surgical excision followed by combination antimicrobial therapy including miltefosine. This case was treated initially as nocardiosis or melioidosis, emphasizing the importance of considering differentials such as Acanthamoeba during workup of atypical infection. We present a literature review of the 14 Acanthamoeba brain abscess cases reported in the English literature, of which five were successfully treated. Our review shows a predilection for multiple brain abscesses and an increased mortality rate compared with the general brain abscess population.

Acanthamoeba keratitis (AK), the vision-threatening disease caused by the amphizoic, potentially parasitic amoebae is growing threat for public health in Poland and worldwide. The report presents the case of 70-year-old man with severe keratitis admitted to an Ophthalmology Clinic. Before admission, the patient had been treated for 6 months with antibacterial and antifungal drugs in other units, without improvement in the eye condition. The use of in vivo confocal microscopy and in vitro cultivation allowed diagnosis to be verified and AK successfully treated. Awareness of the threat to public health caused by Acanthamoeba spp is still insufficient. If there is failure in response to first line therapy, AK should be taken into account,despite the lack of identified risk factors. In vitro monitoring of amoebic strain can be helpful for prognosis of the course of the corneal disease. Improvement in duration from first symptoms until proper diagnosis is decisive for better treatment efficacy.