Cases Of Primary Amoebic Meningoencephalitis Research Articles

Exploring therapeutic approaches against Naegleria fowleri infections through the COVID box

Naegleria fowleri, known as the brain-eating amoeba, is the pathogen that causes the primary amoebic meningoencephalitis (PAM), a severe neurodegenerative disease with a fatality rate exceeding 95%. Moreover, PAM cases commonly involved previous activities in warm freshwater bodies that allow amoebae-containing water through the nasal passages. Hence, awareness among healthcare professionals and the general public are the key to contribute to a higher and faster number of diagnoses worldwide. Current treatment options for PAM, such as amphotericin B and miltefosine, are limited by potential cytotoxic effects. In this context, the repurposing of existing compounds has emerged as a promising strategy. In this study, the evaluation of the COVID Box which contains 160 compounds demonstrated significant in vitro amoebicidal activity against two type strains of N. fowleri. From these compounds, terconazole, clemastine, ABT-239 and PD-144418 showed a higher selectivity against the parasite compared to the remaining products. In addition, programmed cell death assays were conducted with these four compounds, unveiling compatible metabolic events in treated amoebae. These compounds exhibited chromatin condensation and alterations in cell membrane permeability, indicating their potential to induce programmed cell death. Assessment of mitochondrial membrane potential disruption and a significant reduction in ATP production emphasized the impact of these compounds on the mitochondria, with the identification of increased ROS production underscoring their potential as effective treatment options. This study emphasizes the potential of the mentioned COVID Box compounds against N. fowleri, providing a path for enhanced PAM therapies.

Naegleria fowleri: An emerging issue of significant concern in Pakistan

There is thermophilic flagellate amoeba that is known as Naegleria fowleri and it is labelled as brain-eating amoeba. This is a causative agent for primary amoebic meningoencephalitis (PAM), a dangerous waterborne disease affecting humans and animals. Pakistan is ranked the 2nd most affected country, where most of the cases are reported from the biggest city of Pakistan i.e. Karachi. An immediate epidemiologic examination of the relevant environmental issues is required in order to determine the causes of this abrupt increase in PAM cases. Furthermore, many people in Pakistan do not have access to medical services, and those that do exist are inaccessible. Lack of potable water, sanitation, and knowledge exacerbates water-borne illness outbreaks. Authorities must detect widespread health issues and take action to alleviate suffering. Furthermore, there is an immediate need to educate individuals on the significance of using boiling water for nasal cleaning, particularly after swimming.

Pro-inflammatory cytokine responses to Naegleria fowleri infection.

Naegleria fowleri, or the "brain-eating amoeba," is responsible for a rare, but lethal, infection known as primary amoebic meningoencephalitis (PAM). Confirmed PAM cases have seen both a rise in numbers, as well as expansion of geographic range over the past several decades. There is no effective therapy for PAM and the clinical prognosis remains grim with a mortality rate over 95%. The role of the immune response in disease prevention and disease severity remains unclear. In this review, we explore potential roles of inflammatory immune responses to N. fowleri in disease pathogenesis with a primary focus on pro-inflammatory cytokines IL-1, IL-6, and TNFα. We also discuss modulating proinflammatory cytokines as an additional immune therapy in PAM treatment.

Imidazothiazole Derivatives Exhibited Potent Effects against Brain-Eating Amoebae

Naegleria fowleri (N. fowleri) is a free-living, unicellular, opportunistic protist responsible for the fatal central nervous system infection, primary amoebic meningoencephalitis (PAM). Given the increase in temperatures due to global warming and climate change, it is estimated that the cases of PAM are on the rise. However, there is a current lack of awareness and effective drugs, meaning there is an urgent need to develop new therapeutic drugs. In this study, the target compounds were synthesized and tested for their anti-amoebic properties against N. fowleri. Most compounds exhibited significant amoebicidal effects against N. fowleri; for example, 1h, 1j, and 1q reduced N. fowleri's viability to 15.14%, 17.45% and 28.78%, respectively. Furthermore, the majority of the compounds showed reductions in amoeba-mediated host death. Of interest are the compounds 1f, 1k, and 1v, as they were capable of reducing the amoeba-mediated host cell death to 52.3%, 51%, and 56.9% from 100%, respectively. Additionally, these compounds exhibit amoebicidal properties as well; they were found to decrease N. fowleri's viability to 26.41%, 27.39%, and 24.13% from 100%, respectively. Moreover, the MIC50 values for 1e, 1f, and 1h were determined to be 48.45 µM, 60.87 µM, and 50.96 µM, respectively. Additionally, the majority of compounds were found to exhibit limited cytotoxicity, except for 1l, 1o, 1p, 1m, 1c, 1b, 1zb, 1z, 1y, and 1x, which exhibited negligible toxicity. It is anticipated that these compounds may be developed further as effective treatments against these devastating infections due to brain-eating amoebae.

Case Report: Recognition of Devastating Primary Amoebic Meningoencephalitis (PAM) Caused by Naegleria fowleri: Another Case in South China Detected via Metagenomics Next-Generation Sequencing Combined With Microscopy and a Review

IntroductionPrimary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri is seldom reported in mainland China.MethodsOne case from South China was presented, and the clinical features of the PAM, especially the early CT features, were compared to those in the literatures from PubMed/Web of Science/China National Knowledge internet (CNKI).Case Presentation and ResultsA 47-year-old man with a high fever came to the fever clinic. Twelve hours later, the man lost consciousness and exhibited generalized tonic-clonic seizures and needed ventilator-controlled ventilation. Then, he was admitted to the neurology intensive care unit (NICU). The opening pressure of his cerebrospinal fluid (CSF) was over 500 mm H2O with highly increased leukocyte/protein levels and very low glucose levels. Three days after admission, high copy numbers of Naegleria fowleri amoebae were detected by metagenomics next-generation sequencing (mNGS) and cysts were visible with wet mount microscopy. Four days after admission, the patient experienced brain death. However, the relatives of the patient did not want to give up, and he received amphotericin B (AmB). During hospitalization, he suffered from severe damage to the liver and kidneys and electrolyte disorders that required continuous renal replacement therapy (CRRT).ReviewAll 20 included PAM patients suffered from fever. Seventeen of them had headache and neck stiffness. Ten of them showed generalized brain edema. To date, 7 cases of PAM have been reported in China. Only one patient survived. Most of the patients showed generalized brain edema. Only the surviving patient showed focal edema. He died three months later.ConclusionRapidly progressive meningoencephalitis in which the CSF results are similar to those suffered from a bacterial infection should be considered a possible case of PAM. It can be rapidly detected with microscopy in CSF wet mounts but needs further molecular investigation for confirmation, and mNGS should be a new method used for rapid and precise identification. Moreover, CRRT may prolong the survival time of PAM patients with multiple organ failure.

Central nervous system infections caused by pathogenic free-living amoebae: An Indian perspective.

Pathogenic free-living amoebae (FLA), namely Acanthamoeba sp., Naegleria fowleri and Balamuthia mandrillaris are distributed worldwide. These neurotropic amoebae can cause fatal central nervous system (CNS) infections in humans. This review deals with the demographic characteristics, symptoms, diagnosis, and treatment outcomes of patients with CNS infections caused by FLA documented in India. There have been 42, 25, and 4 case reports of Acanthamoeba granulomatous amoebic encephalitis (GAE), N. fowleri primary amoebic meningoencephalitis (PAM), and B. mandrillaris meningoencephalitis (BAE), respectively. Overall, 17% of Acanthamoeba GAE patients and one of the four BAE patients had some form of immunosuppression, and more than half of the N. fowleri PAM cases had history of exposure to freshwater. Acanthamoeba GAE, PAM, and BAE were most commonly seen in males. Fever, headache, vomiting, seizures, and altered sensorium appear to be common symptoms in these patients. Some patients showed multiple lesions with edema, exudates or hydrocephalus in their brain CT/MRI. The cerebrospinal fluid (CSF) of these patients showed elevated protein and WBC levels. Direct microscopy of CSF was positive for amoebic trophozoites in 69% of Acanthamoeba GAE and 96% of PAM patients. One-fourth of the Acanthamoeba GAE and all the BAE patients were diagnosed only by histopathology following autopsy/biopsy samples. Twenty-one Acanthamoeba GAE survivors were treated with cotrimoxazole, rifampicin, and ketoconazole/amphotericin B, and all eleven PAM survivors were treated with amphotericin B alongside other drugs. A thorough search for these organisms in CNS samples is necessary to develop optimum treatment strategies.

Aquatics: A Boon or Bane under the Shadow of Naegleria fowleri:A Meta-analysis and Systemic review

Water sports activities during hot summer seasons attract all age groups specially children and young adult. Same season acts favorably for multiplication of Naegleria fowleri in stagnant or slow moving water and exposure will lead to highly fatal Primary Amoebic Meningoencephalitis. Naegleria fowleri travels from nasopharyngeal mucosa to brain to cause highly fatal disease. In-spite of more than 300 cases reported worldwide the figure is still underreported or erroneously reported due to Clinical & Biochemical similarity with Acute Bacterial Meningitis. Radiological finding CT or MRI scan are also initially normal for initial 2 days and unable to differentiate between bacterial or parasitic meningoencephalitis. Diagnosis of low surviving disease depend mainly on Microscopy/Giemsa staining, which can be confirmed by amoebic culture, PCR and gene sequencing with the help of reference center (CDC). Treatment can be intravenous and/or intrathecal Amphotericin-B, Rifampicin and Fluconazole. Miltefosine shows some promising results but not found satisfactory. So, prevention is the only hope to fight with Naegleria fowleri infection, which needs to be looked at seriously by concerned authorities, especially in developing countries. A total of 29 articles selected for meta-analysis study from Pubmed & Google Scholar. Surprising water exposure history found in many article that included enjoyment in Water-Splashing Festival, bathing in pond & unchlorinated water, religious nasal cleaning practice with contaminated water, accidental fall in river with remain submerged for long time and many more, were results in fatal Primary Amoebic Meningoencephalitis. This review cover clinical management of the cases of Primary Amoebic Meningoencephalitis as well as more important it’s preventive aspect which include identification of source of Naegleria fowleri, restricted activity with public awareness about unknown dangers of fatal disease acquired during enjoyment, which was missed by some authors.

Evaluation of Indolocarbazoles from Streptomyces sanyensis as a Novel Source of Therapeutic Agents against the Brain-Eating Amoeba Naegleria fowleri.

Naegleria fowleri is an opportunistic pathogenic free-living amoeba which is able to rapidly colonize the central nervous system (CNS) and causes a lethal infection known as primary amoebic meningoencephalitis (PAM). Furthermore, more than 98% of the known cases of PAM are fatal and affect mainly children under 12 and young adults. Until now, no fully effective therapeutic agents against N. fowleri are available and hence the urgent need to find novel agents to treat PAM. At present, PAM therapy is based on the combination of amphotericin B, miltefosine, among others, with unwanted toxic effects. Recently, our team isolated various indolocarbazoles (ICZs) from the culture of a mangrove strain of Streptomyces sanyensis which showed activity against kinetoplastids and the Acanthamoeba genus. Hence, in this study, the activity of the previously isolated ICZs, staurosporine (STS), 7-oxostaurosporine (7OSTS), 4′-demethylamino-4′-oxostaurosporine, and streptocarbazole B, was evaluated against two type strains of N. fowleri. Furthermore, the performed activity assays revealed that STS was the most active ICZ presenting an inhibitory concentration 50 (IC50) of 0.08 ± 0.02 µM (SI 109.3). Moreover, STS induced programmed cell death (PCD) in the treated amoebae by triggering DNA condensation, mitochondrial disfunction, cell membrane disruption, and reactive oxygen species (ROS) generation. Therefore, STS could be a promising therapeutic agent against PAM.

Gold-Conjugated Curcumin as a Novel Therapeutic Agent against Brain-Eating Amoebae.

Balamuthia mandrillaris and Naegleria fowleri are free-living amoebae that cause infection of the central nervous system, granulomatous amoebic encephalitis (GAE) and primary amoebic meningoencephalitis (PAM), respectively. The fact that mortality rates for cases of GAE and PAM are more than 95% indicates the need for new therapeutic agents against those amoebae. Considering that curcumin exhibits a wide range of biological properties and has shown efficacy against Acanthamoeba castellanii, we evaluated the amoebicidal properties of curcumin against N. fowleri and B. mandrillaris. Curcumin showed significant amoebicidal activities with an AC50 of 172 and 74 μM against B. mandrillaris and N. fowleri, respectively. Moreover, these compounds were also conjugated with gold nanoparticles to further increase their amoebicidal activities. After conjugation with gold nanoparticles, amoebicidal activities of the drugs were increased by up to 56 and 37% against B. mandrillaris and N. fowleri, respectively. These findings are remarkable and suggest that clinically available curcumin and our gold-conjugated curcumin nanoparticles hold promise in the improved treatment of fatal infections caused by brain-eating amoebae and should serve as a model in the rationale development of therapeutic interventions against other infections.

Naegleria fowleri after 50 years: is it a neglected pathogen?

It has been 50 years since the first case of primary amoebic meningoencephalitis (PAM), an acute and rapidly fatal disease of the central nervous system (CNS), was reported in Australia. It is now known that the aetiological agent of PAM is Naegleria fowleri, an amoeba that is commonly known as 'the brain-eating amoeba'. N. fowleri infects humans of different ages who are in contact with water contaminated with this micro-organism. N. fowleri is distributed worldwide and is found growing in bodies of freshwater in tropical and subtropical environments. The number of PAM cases has recently increased, and the rate of recovery from PAM has been estimated at only 5 %. Amphotericin B has been used to treat patients with PAM. However, it is important to note that there is no specific treatment for PAM. Moreover, this amoeba is considered a neglected micro-organism. Researchers have exerted great effort to design effective drugs to treat PAM and to understand the pathogenesis of PAM over the past 50 years, such as its pathology, molecular and cellular biology, diagnosis and prevention, and its biological implications, including its pathogenic genotypes, its distribution and its ecology. Given the rapid progression of PAM and its high mortality rate, it is important that investigations continue and that researchers collaborate to gain better understanding of the pathogenesis of this disease and, consequently, to improve the diagnosis and treatment of this devastating infection of the CNS.

Comparison of the clinical presentations of Naegleria fowleri primary amoebic meningoencephalitis with pneumococcal meningitis: a case-control study.

Primary amoebic meningoencephalitis (PAM) is a rare but fatal infection caused by Naegleria fowleri. The infection is acquired by deep nasal irrigation with infected water. Patients present with signs and symptoms similar to pneumococcal meningitis, leading to delayed diagnosis and treatment and hence high mortality. We conducted a case-control study comparing culture proven cases of PAM with pneumococcal meningitis presenting to our center between April 2008 and September 2014. Only patients with blood and/or cerebrospinal fluid cultures positive for Streptococcus pneumoniae during the same time period were included for comparison. There were 19 cases of PAM and pneumococcal meningitis, each. When comparing PAM with pneumococcal meningitis, patients with PAM were more likely to be male (89.5 vs. 36.8%), younger (mean age: 30 vs. 59years), present with seizures (42.1 vs. 5.3%). Both groups of patients presented with similar vital signs and there were no remarkable differences on physical examinations, Glasgow Coma Scale scores, laboratory and radiological investigations and cerebrospinal fluid parameters. PAM was also more likely to present if the city's average maximum temperature was higher in the previous week (mean: 34.6 vs. 30°C). There was history of fresh water contact in only one patient. On multivariate analysis, PAM was more likely if patients presented when the city's average maximum temperature was high, being young males. PAM and pneumococcal meningitis remain virtually indistinguishable; however, these predictive features should be validated in a prospective study and may lead to a viable algorithm for early management of these patients.

Detection of the free living amoeba Naegleria fowleri by using conventional and real-time PCR based on a single copy DNA sequence

The amoeba-flagellate Naegleria fowleri is a causative agent of primary amoebic meningoencephalitis (PAM). This thermophilic species occurs worldwide and tends to proliferate in warm aquatic environment. The PAM cases remain rare but this infection is mostly fatal. Here, we describe a single copy region which has been cloned and sequenced, and was used for both conventional and real-time PCR. Targeting a single-copy DNA sequence allows to directly quantify the N. fowleri cells. The real-time PCR results give a detection limit of 1 copy per reaction with high reproducibility without the need of a Taqman probe. This procedure is of interest as compared to other procedures which are mostly based on the detection of multi-copy DNA associated with a Taqman probe.

Diagnosis, Clinical Course, and Treatment of Primary Amoebic Meningoencephalitis in the United States, 1937-2013

Primary amoebic meningoencephalitis (PAM) is a rapidly progressing waterborne illness that predominately affects children and is nearly always fatal. PAM is caused by Naegleria fowleri, a free-living amoeba found in bodies of warm freshwater worldwide. We reviewed exposure location, clinical signs and symptoms, diagnostic modalities, and treatment from confirmed cases of PAM diagnosed in the United States during 1937-2013. Patients were categorized into the early (ie, flu-like symptoms) or late (ie, central nervous system signs) group on the basis of presenting clinical characteristics. Here, we describe characteristics of the survivors and decedents. The median age of the patients was 12 years (83% aged ≤18 years); males (76%) were predominately affected (N = 142). Most infections occurred in southern-tier states; however, 4 recent infections were acquired in northern states: Minnesota (2), Kansas (1), and Indiana (1). Most (72%) of the patients presented with central nervous system involvement. Cerebrospinal fluid analysis resembled bacterial meningitis with high opening pressures, elevated white blood cell counts with predominantly neutrophils (median, 2400 cells/μL [range, 5-26 000 cells/μL]), low glucose levels (median, 23 mg/dL [range, 1-92 mg/dL]), and elevated protein levels (median, 365 mg/dL [range, 24-1210 mg/dL]). Amoebas found in the cerebrospinal fluid were diagnostic, but PAM was diagnosed for only 27% of the patients before death. Imaging results were abnormal in approximately three-fourths of the patients but were not diagnostic for amoebic infection. Three patients in the United States survived. To our knowledge, this is the first comprehensive clinical case series of PAM presented in the United States. PAM is a fatal illness with limited treatment success and is expanding into more northern regions. Clinicians who suspect that they have a patient with PAM should contact the US Centers for Disease Control and Prevention at 770-488-7100 (available 24 hours/day, 7 days/week) to discuss diagnostic testing and treatment options (see cdc.gov/naegleria).

Primary Meningoencephalitis in a New Born Due to Naegleria Spp. - Extremely Rare Case Presentation with Review of Literature

Primary Meningoencephalitis in a New Born Due to Naegleria Spp. - Extremely Rare Case Presentation with Review of Literature Primary amoebic meningoencephalitis (PAM) caused by free living amoebae Naegleria fowleri is a rare condition. We report a case of primary meningoencephalitis in a 5 day old, male child who presented with respiratory distress and multiple seizures. Patient presented with acute on chronic meningitis and CSF examination revealed xanthochromia with increased CSF protein. Wet mount of CSF showed motile amoebae suggestive of naegleria species. Baby was put on ventilatory support, anticonvulsants were started along with liposomal Amphotericin B to which the child responded. We also reviewed last 10 Indian cases of primary amoebic meningoencephalitis (PAM) in which only 4 patients were cured.

Distribution systems as reservoirs of Naegleria fowleri and other amoebae

Naegleria fowleri is the etiologic agent of primary amoebic meningoencephalitis (PAM), a rapidly fatal disease. Although PAM generally occurs after recreational exposure to contaminated water, two fatal cases of PAM were linked to a drinking water supply in Arizona. This study tested the ability of distribution system biofilms to be reservoirs for N. fowleri and other amoebae. When introduced to laboratory pipe loops, N. fowleri attached to biofilms and survived for five months. In two fullscale distribution systems, amoebic activity was detected in 67% of biofilm samples tested, regardless of chlorination. Amoebic activity occurred mostly in locations associated with stagnant water and high bacterial counts. Legionella was also found in 65% of biofilm samples. Although N. fowleri was never detected in field samples, the observed risk factors—high bacterial counts, amoebic activity, and the presence of Legionella in biofilms—suggest that N. fowleri could thrive in both systems if introduced.

Development of a rapid DNA extraction method and one-step nested PCR for the detection of Naegleria fowleri from the environment

Naegleria fowleri is a small free-living amoebo-flagellate found in natural and manmade thermal aquatic habitats worldwide. The organism is pathogenic to man causing fatal primary amoebic meningoencephalitis (PAM). Infection typically results from bathing in contaminated water and is usually fatal. It is, therefore, important to identify sites containing N. fowleri in the interests of preventive public health microbiology. Culture of environmental material is the conventional method for the isolation of N. fowleri but requires several days incubation and subsequent biochemical or molecular tests to confirm identification. Here, a nested one-step PCR test, in conjunction with a direct DNA extraction from water or sediment material, was developed for the rapid and reliable detection of N. fowleri from the environment. Here, the assay detected N, fowleri in 18/109 river water samples associated with a nuclear power plant in South West France and 0/10 from a similar site in the UK. Although culture of samples yielded numerous thermophilic free-living amoebae, none were N. fowleri or other thermophilic Naegleria spp. The availability of a rapid, reliable and sensitive one-step nested PCR method for the direct detection of N. fowleri from the environment may aid ecological studies and enable intervention to prevent PAM cases.

Primary Amoebic Meningoencephalitis in an Infant due toNaegleria fowleri

Primary amoebic meningoencephalitis (PAM) caused by free-living amebae Naegleria fowleri is a rare and fatal condition. A fatal case of primary amoebic meningoencephalitis was diagnosed in a 5-month-old infant who presented with the history of decrease breast feeding, fever, vomiting, and abnormal body movements. Trophozoites of Naegleria fowleri were detected in the direct microscopic examination of CSF and infant was put on amphotericin B and ceftazidime. Patient condition deteriorated, and he was discharged against medical advice and subsequently expired. We also reviewed previously reported 8 Indian cases of primary amoebic meningoencephalitis (PAM) and observed that for the last 5 years, none of the patients responded to amphotericin B. Has an era of amphotericin B-resistant Naegleria fowleri been emerged? Management strategy of PAM needs to be reviewed further.

Concentration of Naegleria fowleri in natural waters used for recreational purposes in Sonora, Mexico (November 2007–October 2008)

A survey was designed to know the concentration of Naegleria fowleri in recreational areas in Hornos, Sonora, during a year. Samples were taken monthly at La Isleta and Las Palmas and the total amoeba counts were obtained by the most probable number method (MPN). The identification of N. fowleri was made by PCR. The maximum concentration of total thermophilic amoebae was 9175 MPN/L for La Isleta and 3477 MPN/L for Las Palmas. Thermophilic Naegleria were present mainly during summer and fall. October’s concentrations were up to 201 MPN/L, at both places. The maximum concentrations of N. fowleri were 201 MPN/L and 18 MPN/L for La Isleta and Las Palmas respectively, and were isolated from August to October. The presence of N. fowleri in these particular natural bodies of water reinforces the need for adaptation of preventive measures to avoid cases of primary amoebic meningoencephalitis.

Primary amoebic meningoencephalitis: two new cases from Pakistan

Naegleria fowleri causes a fatal infection of the central nervous system. Only one case of N. fowleri meningoencephalitis has previously been reported from Pakistan. We describe two cases of primary amoebic meningoencephalitis. A 24-year-old man presented with a two-day history of high grade fever, headaches and vomiting. He was put on intrathecal amphotericin B, fluconazole and rifampicin when motile trophozoites were identified on a wet mount of cerebrospinal fluid. The patient did not improve and died on the sixth day of admission. The second case was a 30-year-old man who presented with a three-day history of high grade fever, vomiting and agitation. His clinical course was marked by a rapid deterioration. He received intrathecal amphotericin B, fluconazole and broad spectrum antibiotics when motile trophozoites on wet mount were observed. Again, the patient's condition did not improve and he died on the eighth day of admission.

Paravahlkampfia francinae n. sp. Masquerading as an Agent of Primary Amoebic Meningoencephalitis

Paravahlkampfia francinae n. sp., a new species of the free-living amoeba genus Paravahlkampfia, designated as CDC:V595, was isolated from the cerebrospinal fluid of a patient with headache, sore throat, and vomiting, typical symptoms of primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri. The isolate grew at 33 degrees C, 37 degrees C, 40 degrees C, and 42 degrees C and destroyed mammalian cell cultures. However, it did not kill young mice upon intranasal inoculation. P. francinae does not produce flagellates and does not grow on agar plates coated with Gram-negative bacteria such as Escherichia coli, the usual food source of Paravahlkampfia ustiana, the type species of the genus. The trophozoite at light microscopy exhibited eruptive locomotion and possessed a single vesicular nucleus. Ultrastructurally, the trophozoites had numerous mitochondria with discoidal cristae but did not have a Golgi apparatus. The trophozoites differentiated into cysts after consuming most of the monolayer. The cyst had an inner well-differentiated endocyst and an outer thin, wrinkled, and wavy ectocyst with no pores. During excystation trophozoites ruptured the cyst wall and emerged from the cysts. A unique feature seen in the cysts was the presence of bacterial endosymbionts, both in the endoplasm and within the cyst wall. Full-length sequencing analysis of the 18S and 5.8S RNA genes of P. francinae showed that they were distinct from those of other Paravahlkampfia species. The patient recovered within a few days indicating that some of the previously reported cases of PAM that survived may have been due to P. francinae.