Last data update: Oct 07, 2024. (Total: 47845 publications since 2009)
Records 1-24 (of 24 Records) |
Query Trace: Ali IKM[original query] |
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Acanthamoeba infection and nasal rinsing, United States, 1994-2022
Haston JC , Serra C , Imada E , Martin E , Ali IKM , Cope JR . Emerg Infect Dis 2024 30 (4) 783-785 We describe 10 patients with nonkeratitis Acanthamoeba infection who reported performing nasal rinsing before becoming ill. All were immunocompromised, 7 had chronic sinusitis, and many used tap water for nasal rinsing. Immunocompromised persons should be educated about safe nasal rinsing to prevent free-living ameba infections. |
Endophthalmitis, cutaneous nodules, and brain lesions in stem cell transplant recipient
Axell-House DB , Nagarajan P , Bhatti MM , Mehta RS , Roy S , Ali IKM , John TM . Clin Infect Dis 2023 77 (8) 1212-1215 A 46-year-old man with relapsed acute myeloid leukemia underwent his second matched related donor stem cell transplant (SCT), after fludarabine and melphalan conditioning followed by post-transplant cyclophosphamide. He engrafted on day +20. On day +27, he developed fever, sinusitis, left eyelid swelling, and right eye subconjunctival swelling (Figure 1A). He required an urgent right vitrectomy for endophthalmitis. Seven days later, he developed skin nodules on his upper and lower extremities which progressively enlarged and became more diffuse (Figure 1Band 1C). Laboratory tests showed leukopenia (white blood cell count 3.1 × 109/L), anemia (Hb 7.2 g/dL), and severe thrombocytopenia (25 × 109/L) with normal electrolytes, and normal renal and hepatic function. Blood, urine, and sputum cultures were no growth, and infectious serologies, nucleic acid, and antigen tests were negative, including for human immunodeficiency virus, syphilis, Toxoplasma, tuberculosis, cytomegalovirus, and Strongyloides. Nasal endoscopy did not demonstrate necrosis of sinus tissue, and sinus swab cultures did not grow any organisms of clinical significance. Wide excisional skin biopsies of skin lesions demonstrated a lymphohistiocytic infiltrate and panniculitis (Figure 2A) and circular structures (Figure 2B). Vitrectomy was performed for endophthalmitis, and vitreous fluid cultures had no growth. Positron emission tomography (PET) demonstrated diffuse subcutaneous foci most numerous of the lower extremities, and a left occipitotemporal focus (Figure 3A). Shortly thereafter, he developed acute encephalopathy, drowsiness, and rhythmic movements of his right arm concerning for seizures. Brain magnetic resonance imaging (MRI) demonstrated abnormalities of the left frontal gyrus, occipital lobe, parieto-occipital sulcus, and cerebellum, concerning for embolic strokes (Figure 3B). He continued to have fever and progression of skin lesions despite treatment with meropenem, vancomycin, minocycline, and amphotericin. What is the likely diagnosis? |
Naegleria genus pangenome reveals new structural and functional insights into the versatility of these free-living amoebae.
Dereeper A , Allouch N , Guerlais V , Garnier M , Ma L , De Jonckheere JF , Joseph SJ , Ali IKM , Talarmin A , Marcelino I . Front Microbiol 2022 13 1056418 INTRODUCTION: Free-living amoebae of the Naegleria genus belong to the major protist clade Heterolobosea and are ubiquitously distributed in soil and freshwater habitats. Of the 47 Naegleria species described, N. fowleri is the only one being pathogenic to humans, causing a rare but fulminant primary amoebic meningoencephalitis. Some Naegleria genome sequences are publicly available, but the genetic basis for Naegleria diversity and ability to thrive in diverse environments (including human brain) remains unclear. METHODS: Herein, we constructed a high-quality Naegleria genus pangenome to obtain a comprehensive catalog of genes encoded by these amoebae. For this, we first sequenced, assembled, and annotated six new Naegleria genomes. RESULTS AND DISCUSSION: Genome architecture analyses revealed that Naegleria may use genome plasticity features such as ploidy/aneuploidy to modulate their behavior in different environments. When comparing 14 near-to-complete genome sequences, our results estimated the theoretical Naegleria pangenome as a closed genome, with 13,943 genes, including 3,563 core and 10,380 accessory genes. The functional annotations revealed that a large fraction of Naegleria genes show significant sequence similarity with those already described in other kingdoms, namely Animalia and Plantae. Comparative analyses highlighted a remarkable genomic heterogeneity, even for closely related strains and demonstrate that Naegleria harbors extensive genome variability, reflected in different metabolic repertoires. If Naegleria core genome was enriched in conserved genes essential for metabolic, regulatory and survival processes, the accessory genome revealed the presence of genes involved in stress response, macromolecule modifications, cell signaling and immune response. Commonly reported N. fowleri virulence-associated genes were present in both core and accessory genomes, suggesting that N. fowleri's ability to infect human brain could be related to its unique species-specific genes (mostly of unknown function) and/or to differential gene expression. The construction of Naegleria first pangenome allowed us to move away from a single reference genome (that does not necessarily represent each species as a whole) and to identify essential and dispensable genes in Naegleria evolution, diversity and biology, paving the way for further genomic and post-genomic studies. |
Cutaneous acanthamoeba infection presenting with granulomatous vasculitis
Park M , Googe PB , Derebail VK , Saha MK , Matkovic E , Cope JR , Ali IKM , Ziemer C , Wu S . SKIN J Cutan Med 2023 7 (2) 700-704 Cutaneous acanthamoebiasis is a rare diagnosis that carries a mortality rate of over 70%.2 This disease predominantly affects immunocompromised individuals, though infections have been reported in immunocompetent individuals.2 We report a fatal case of cutaneous Acanthamoeba infection in a patient with granulomatous vasculitis on biopsy, initially thought to be antineutrophil cytoplasmic antibody (ANCA)-negative vasculitis. The patient primarily presented with ulcerating nasal lesions, which subsequently developed into widespread cutaneous lesions. Diagnosis was made months after presentation when amebae were identified during histopathological examination of biopsies obtained repeatedly after the patient failed to improve on standard therapies for ANCA-negative vasculitis. Treatment was unsuccessful, and the patient died due to complications of widespread Acanthamoeba infection. Cutaneous acanthamoebiasis should be considered in the differential diagnosis of granulomatous vasculitis that fails to improve on standard therapies. Early detection and treatment may improve outcomes and reduce mortality in this highly fatal infection. © 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. |
Case of primary amebic meningoencephalitis associated with surfing at an artificial surf venue: Environmental investigation
Miko S , Cope JR , Hlavsa MC , Ali IKM , Brown TW , Collins JP , Greeley RD , Kahler AM , Moore KO , Roundtree AV , Roy S , Sanders LL , Shah V , Stuteville HD , Mattioli MC . ACS ES T Water 2022 Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. In September 2018, a 29-year-old man died of PAM after traveling to Texas. We conducted an epidemiologic and environmental investigation to identify the water exposure associated with this PAM case. The patients most probable water exposure occurred while surfing in an artificial surf venue. The surf venue water was not filtered or recirculated; water disinfection and water quality testing were not documented. N. fowleri and thermophilic amebae were detected in recreational water and sediment samples throughout the facility. Codes and standards for treated recreational water venues open to the public could be developed to address these novel venues. Clinicians and public health officials should also consider novel recreational water venues as a potential exposure for this rare amebic infection. Not subject to U.S. Copyright. Published 2023 by American Chemical Society. |
The epidemiology and clinical features of non-keratitis acanthamoeba infections in the United States, 1956-2020
Haston JC , O'Laughlin K , Matteson K , Roy S , Qvarnstrom Y , Ali IKM , Cope JR . Open Forum Infect Dis 2023 10 (1) ofac682 BACKGROUND: Acanthamoeba is a free-living ameba that can cause severe disease affecting the central nervous system, skin, sinuses, and other organs, particularly in immunocompromised individuals. These rare but severe infections are often fatal, yet incompletely described. METHODS: Cases included were either reported to the Centers for Disease Control and Prevention (CDC) Free-Living Ameba program or published in scientific literature. Characteristics of all patients in the United States with laboratory-confirmed non-keratitis Acanthamoeba infections were described using descriptive statistics, and associations with survival were determined using χ(2) and Fisher exact tests. RESULTS: Of 173 patients identified, 71% were male and the median age was 44 years (range, 0-87 years). Of these, 26 (15%) survived. Most patients (88%) had at least 1 immunocompromising condition, most commonly human immunodeficiency virus (39%), cancer (28%), and solid organ or hematopoietic stem cell transplant (28%). Granulomatous amebic encephalitis (GAE) was the most common disease presentation (71%). Skin (46%), sinuses (29%), lungs (13%), and bone (6%) were also involved. Nearly half of patients (47%) had involvement of >1 organ system. Survival was less frequent among those with GAE (3%, P < .001) compared with cutaneous disease, rhinosinusitis, or multiorgan disease not including GAE. Of 7 who received the currently recommended treatment regimen, 5 (71%) survived. CONCLUSIONS: Non-keratitis Acanthamoeba infections occur primarily in immunocompromised individuals and are usually fatal. Survival may be associated with disease presentation and treatment. Providers who care for at-risk patients should be aware of the various disease manifestations to improve early recognition and treatment. |
Acanthamoeba castellanii encephalitis in a patient with AIDS: a case report and literature review
Damhorst GL , Watts A , Hernandez-Romieu A , Mel N , Palmore M , Ali IKM , Neill SG , Kalapila A , Cope JR . Lancet Infect Dis 2021 22 (2) e59-e65 Amoebic encephalitis is a rare cause of CNS infection for which mortality exceeds 90%. We present the case of a 27-year-old man with AIDS who presented to a hospital in Atlanta (Georgia, USA) with tonic-clonic seizures and headache. His clinical condition deteriorated over several days. Brain biopsy revealed lymphohistiocytic inflammation and necrosis with trophozoites and encysted forms of amoebae. Immunohistochemical and PCR testing confirmed Acanthamoeba castellanii encephalitis, typically described as granulomatous amoebic encephalitis (GAE). No proven therapy for GAE is available, although both surgical and multiagent antimicrobial treatment strategies are often used. Most recently, these include the antileishmanial agent miltefosine. Here we review all cases of GAE due to Acanthamoeba spp in people with HIV/AIDS identified in the literature and reported to the Centers for Disease Control and Prevention. We describe this case as a reminder to the clinician to consider protozoal infections, especially free-living amoeba, in the immunocompromised host with a CNS infection refractory to traditional antimicrobial therapy. |
Death From Primary Amebic Meningoencephalitis After Recreational Water Exposure During Recent Travel to India-Santa Clara County, California, 2020.
Harris GR , Karmarkar EN , Quenelle R , Chaille L , Madhok J , Tien V , Gupta J , Jain S , Liu M , Roy S , Narasimhan S , Kimura A , Cope JR , Ali IKM . Open Forum Infect Dis 2021 8 (8) ofab322 BACKGROUND: In February 2020, a man returned to the United States after an 11-day trip to India and died of primary amebic meningoencephalitis (PAM), caused by nasal exposure to the free-living ameba Naegleria fowleri found in warm water. We identified potential exposures, confirmed etiology, and described the molecular epidemiology of the infection. METHODS: We reviewed medical records to describe his clinical course and interviewed his family to determine water exposures. Genotyping was performed on the N. fowleri strain and compared with North American strains through repetitive nonpolymorphic nuclear loci analysis to identify differences. We reviewed N. fowleri strains in the National Center for Biotechnology Information database (GenBank) to determine genotypes present in India. RESULTS: The patient became acutely encephalopathic 3 days after returning; the only known nasal water exposure was at an indoor swimming pool in India 5 days earlier. Cerebrospinal fluid (CSF) testing demonstrated neutrophil-predominant pleocytosis and low glucose, but negative gram stain and culture. CSF microscopy revealed trophozoites; N. fowleri was detected by real-time polymerase chain reaction. Classical genotyping confirmed genotype I, common in the United States and among Indian strains in GenBank. The North American N. fowleri strains and the patient's strain varied at 5 nonpolymorphic loci. CONCLUSIONS: A man died from PAM after likely exposure at a vacation rental pool in India. We recommend including PAM in the differential diagnosis when CSF studies suggest bacterial meningitis but gram stain is negative. Genotyping can advance our understanding of N. fowleri molecular epidemiology and support future investigations. |
Comparative Genomic and Transcriptomic Analysis of Naegleria fowleri Clinical and Environmental Isolates.
Joseph SJ , Park S , Kelley A , Roy S , Cope JR , Ali IKM . mSphere 2021 6 (4) e0063721 Out of over 40 species of Naegleria, which are free-living thermophilic amebae found in freshwater and soil worldwide, only Naegleria fowleri infects humans, causing primary amebic meningoencephalitis (PAM), a typically fatal brain disease. To understand the population structure of Naegleria species and the genetic relationships between N. fowleri isolates and to detect pathogenic factors, we characterized 52 novel clinical and environmental N. fowleri genomes and a single Naegleria lovaniensis strain, along with transcriptomic data for a subset of 37 N. fowleri isolates. Whole-genome analysis of 56 isolates from three Naegleria species (N. fowleri, N. lovaniensis, and Naegleria gruberi) identified several genes unique to N. fowleri that have previously been linked to the pathogenicity of N. fowleri, while other unique genes could be associated with novel pathogenicity factors in this highly fatal pathogen. Population structure analysis estimated the presence of 10 populations within the three Naegleria species, of which 7 populations were within N. fowleri. The whole-nuclear-genome (WNG) phylogenetic analysis showed an overall geographical clustering of N. fowleri isolates, with few exceptions, and provided higher resolution in identifying potential clusters of isolates beyond that of the traditional locus typing. There were only 34 genes that showed significant differences in gene expression between the clinical and environmental isolates. Genomic data generated in this study can be used for developing rapid molecular assays and to conduct future population-based global genomic analysis and will also be a valuable addition to genomic reference databases, where shotgun metagenomics data from routine water samples could be searched for the presence of N. fowleri strains. IMPORTANCE N. fowleri, the only known Naegleria species to infect humans, causes fatal brain disease. PAM cases from 1965 to 2016 showed <20 cases per year globally. Out of approximately 150 cases in North America since 1962, only four PAM survivors are known, yielding a >97% case fatality rate, which is critically high. Although the pathogenesis of N. fowleri has been studied for the last 50 years, pathogenetic factors that lead to human infection and breaching the blood-brain barrier remain unknown. In addition, little is known regarding the genomic diversity both within N. fowleri isolates and among Naegleria species. In this study, we generated novel genome sequences and performed comparative genomic and transcriptomic analysis of a set of 52 N. fowleri draft genome sequences from clinical and environmental isolates derived from all over the world in the last 53 years, which will help shape future genome-wide studies and develop sensitive assays for routine surveillance. |
A case report of primary amebic meningoencephalitis in North Florida
Anjum SK , Mangrola K , Fitzpatrick G , Stockdale K , Matthias L , Ali IKM , Cope JR , O'Laughlin K , Collins S , Beal SG , Saccoccio FM . IDCases 2021 25 e01208 Primary amebic meningoencephalitis is a rare, usually fatal disease, caused by Naegleria fowleri. This case highlights the challenging clinicopathologic diagnosis in a 13-year-old boy who swam in freshwater in northern Florida where a previous case had exposure to a body of water on the same property in 2009. © 2021 |
Draft Chromosome Sequences of a Clinical Isolate of the Free-Living Ameba Naegleria fowleri.
Ali IKM , Kelley A , Joseph SJ , Park S , Roy S , Jackson J , Cope JR , Rowe LA , Burroughs M , Sheth M , Batra D , Loparev V . Microbiol Resour Announc 2021 10 (15) We present the chromosome sequences of a Naegleria fowleri isolate from a human primary amebic meningoencephalitis (PAM) case. The genome sequences were assembled from Illumina HiSeq and PacBio sequencing data and verified with the optical mapping data. This led to the identification of 37 contigs representing 37 chromosomes in N. fowleri. |
Geographic range of recreational water-associated primary amebic meningoencephalitis, United States, 1978-2018
Gharpure R , Gleason M , Salah Z , Blackstock AJ , Hess-Homeier D , Yoder JS , Ali IKM , Collier SA , Cope JR . Emerg Infect Dis 2021 27 (1) 271-274 Naegleria fowleri is a free-living ameba that causes primary amebic meningoencephalitis (PAM), a rare but usually fatal disease. We analyzed trends in recreational water exposures associated with PAM cases reported during 1978-2018 in the United States. Although PAM incidence remained stable, the geographic range of exposure locations expanded northward. |
A real-time PCR assay for simultaneous detection and differentiation of four common Entamoeba species that infect humans.
Ali IKM , Roy S . J Clin Microbiol 2020 59 (1) There are over forty species within the genus Entamoeba, eight of which infect humans. Of these, four species (Entamoeba histolytica, E. dispar, E. moshkovskii, and E. bangladeshi) are morphologically indistinguishable from each other, yet differentiation is important for appropriate treatment decisions. Here, we developed a hydrolysis probe-based tetraplex real-time PCR assay that can simultaneously detect and differentiate these four species in clinical samples. In this assay, multi-copy SSU rDNA sequences were used as targets. We determined that the tetraplex real-time PCR can detect amebic DNA corresponding to as few as 0.1 trophozoite-equivalent of any of these species. We also determined that this assay can detect E. histolytica DNA in the presence of 10-fold more DNA from another Entamoeba species in the mixed infection scenarios. With a panel of more than 100 well-characterized clinical samples diagnosed and confirmed using a previously published duplex real-time PCR (capable of detecting E. histolytica and E. dispar), our tetraplex real-time PCR assay demonstrated comparable sensitivity and specificity with that of the duplex real-time PCR assay. The advantage of our assay over the duplex assay is that it can specifically detect two additional Entamoeba species and can be used in conventional PCR format. This newly-developed assay will allow further characterization of the epidemiology and pathogenicity of the four morphologically-identical Entamoeba species especially in low resource settings. |
HMG-CoA Reductase Inhibitors as Drug Leads against Naegleria fowleri .
Hahn HJ , Abagyan R , Podust LM , Roy S , Ali IKM , Debnath A . ACS Chem Neurosci 2020 11 (19) 3089-3096 Primary amebic meningoencephalitis (PAM), caused by the free-living ameba Naegleria fowleri, has a fatality rate of over 97%. Treatment of PAM relies on amphotericin B in combination with other drugs, but few patients have survived with the existing drug treatment regimens. Therefore, development of effective drugs is a critical unmet need to avert deaths from PAM. Since ergosterol is one of the major sterols in the membrane of N. fowleri, disruption of isoprenoid and sterol biosynthesis by small-molecule inhibitors may be an effective intervention strategy against N. fowleri. The genome of N. fowleri contains a gene encoding HMG-CoA reductase (HMGR); the catalytic domains of human and N. fowleri HMGR share <60% sequence identity with only two amino acid substitutions in the active site of the enzyme. Considering the similarity of human and N. fowleri HMGR, we tested well-tolerated and widely used HMGR inhibitors, known as cholesterol-lowering statins, against N. fowleri. We identified blood-brain-barrier-permeable pitavastatin as a potent amebicidal agent against the U.S., Australian, and European strains of N. fowleri. Pitavastatin was equipotent to amphotericin B against the European strain of N. fowleri; it killed about 80% of trophozoites within 16 h of drug exposure. Pretreatment of trophozoites with mevalonate, the product of HMGR, rescued N. fowleri from inhibitory effects of statins, demonstrating that HMGR of N. fowleri is the target of statins. Because of the good safety profile and availability for both adult and pediatric uses, consideration should be given to repurposing the fast-acting pitavastatin for the treatment of PAM. |
Diagnostic evaluation of fatal Balamuthia mandrillaris meningoencephalitis in a captive Bornean orangutan (Pongo pygmaeus) with identification of potential environmental source and evidence of chronic exposure
Hawkins SJ , Struthers JD , Phair K , Ali IKM , Roy S , Mull B , West G . Primates 2020 62 (1) 51-61 A female Bornean orangutan (Pongo pygmaeus) aged 11 years and 6 months was examined by veterinarians after caretakers observed lethargy and facial grimacing. Within 72 h the primate had left-sided hemiparesis that worsened over the next week. An MRI revealed a focal right-sided cerebral mass suspected to be a neoplasm. Ten days after onset of clinical signs, the orangutan died. On postmortem exam, the medial right parietal lobe was replaced by a 7 × 4 × 3.5 cm focus of neuromalacia and hemorrhage that displaced the lateral ventricle and abutted the corpus callosum. Histopathology of the cerebral lesion revealed pyogranulomatous meningoencephalitis with intralesional amoeba trophozoites and rare cysts. Fresh parietal lobe was submitted to the Centers for Disease Control and Prevention lab for multiplex free-living amoebae real-time PCR and detected Balamuthia mandrillaris DNA at a high burden. Mitochondrial DNA was sequenced, and a 760-bp locus 19443F/20251R was compared to several human infections of B. mandrillaris and shown to be identical to the isolates from four human cases of encephalitis: 1998 in Australia, 1999 in California, 2000 in New York, and 2010 in Arizona. Indirect immunofluorescent antibody testing of stored serum samples indicated exposure to B. mandrillaris for at least 2 years prior to death. Within 1 week of the orangutan's death, water from the exhibit was analyzed and identified the presence of B. mandrillaris DNA, elucidating a possible source of exposure. B. mandrillaris, first reported in a mandrill in 1986, has since occurred in humans and animals and is now considered an important emerging pathogen. |
A rare cause of left-sided weakness in an elderly woman: amoebic encephalitis
Pan D , Bridges LR , du Parcq J , Mahadeva U , Roy S , Ali IKM , Cosgrove CA , Chiodini PL , Zhang L . Lancet 2020 396 (10244) e1 An 85-year-old Gujarati woman with a 1-day history of confusion, left-sided weakness, and slurred speech attended our hospital. She had a history of headaches, which had been extensively investigated for 2 years from 2013. She also had hypertension. She had no history of recent travel. | | On examination, she was afebrile. She had a dense left hemiparesis; cranial nerves, visual fields, and fundoscopy examinations were normal. She was also in atrial fibrillation. | | A CT scan of the patient's brain showed multiple cortical and subcortical, hypodense lesions; an MRI showed the lesions to be ring-enhancing, with surrounding vasogenic oedema (figure). A CT of the chest, abdomen, and pelvis found no abnormalities and a transthoracic echo was normal. |
Epidemiology and clinical characteristics of primary amebic meningoencephalitis caused by Naegleria fowleri: A global review
Gharpure R , Bliton J , Goodman A , Ali IKM , Yoder J , Cope JR . Clin Infect Dis 2020 73 (1) e19-e27 BACKGROUND: Primary amebic meningoencephalitis (PAM) is a rapidly progressive and often fatal condition caused by the free-living ameba Naegleria fowleri. To estimate the global occurrence, characterize the epidemiology, and describe the clinical features of PAM, we report a series of PAM cases published in the international literature and reported to CDC. METHODS: We performed a literature search of PAM case reports published through 2018. Additionally, we included cases reported through CDC's Free-Living Ameba surveillance or diagnosed via CDC's Free-Living and Intestinal Amebas Laboratory. Cases were classified as confirmed, probable, or suspect on the basis of confirmatory testing, presentation, exposure, and disease course. RESULTS: A total of 381 PAM cases were identified. From 1965 to 2016, the number of reported cases increased an average of 1.6% per year. Seven reported survivors were classified as confirmed.The most commonly reported exposure associated with PAM was swimming/diving, and the most common class of water source was lakes/ponds/reservoirs. Patients were predominantly male (75%), with a median age of 14 years. Confirmed and probable cases were similar in their survival, course of illness, and CSF findings. CONCLUSIONS: PAM is a rare but deadly disease with worldwide occurrence. Improved clinician awareness, resulting in earlier diagnosis and treatment, may contribute to increased survival among PAM patients. The probable case definition used in this study appears to capture cases of PAM, as evidenced by similarities in outcomes, clinical course, and CSF profile to confirmed cases. In the absence of confirmatory testing, clinicians could use this case definition to identify cases of PAM. |
Entamoeba histolytica infections in wild and semi-wild orangutans in Sumatra and Kalimantan
Stuart P , Yalcindag E , Ali IKM , Peckova R , Nurcahyo W , Morrogh-Bernard H , Foitova I . Am J Primatol 2020 82 (5) e23124 Key to the success of orangutan conservation management practices is the prevention of the introduction of infectious diseases to the remaining populations. Previous reports of Entamoeba spp. positive orangutans are of concern as Entamoeba spp. infection has been linked to morbidity and mortality in primates. It remains to be determined if the Entamoeba species infecting orangutans is the pathogenic Entamoeba histolytica. Orangutan fecal samples have been collected from orangutans from sites in Sumatra (Bukit Lawang, Ketambe, and Suaq, 241 samples from 64 individuals), and two sites in Kalimantan (Sebangau and Tuanan, 129 samples from 39 individuals). All samples were from wild orangutans except for a proportion from Sumatra which were from semi-wild (108 samples, 10 individuals). E. histolytica-specific nested PCR assays were carried out on the fecal samples. A total of 36 samples from 17 individuals tested positive for E. histolytica. When compared with published sequences using NCBI BLAST the E. histolytica positive samples showed a 98-99% concordance. The majority (76%, n = 36) of the positive isolates came from semi-wild orangutans in Bukit Lawang. This study supports the growing body of evidence that contact with humans is an important risk factor for infection of wild primates with E. histolytica. |
Identification of Entamoeba histolytica in patients with suspected amebiasis in Jordan using PCR-based assays
Al-Dalabeeh EA , Irshaid FI , Roy S , Ali IKM , Al-Shudifat AM . Pak J Biol Sci 2020 23 (2) 166-172 BACKGROUND AND OBJECTIVE: Identification of Entamoeba histolytica (E. histolytica) by microscopy alone can be problematic because E. dispar and E. moshkovskii are morphologically similar to E. histolytica. Therefore, this study aimed to assess the performance of microscopy in the detection of E. histolytica in stool specimens with the help of PCR-based assays and enzyme-linked immunosorbent assay (ELISA). MATERIALS AND METHODS: Between September, 2017 and September, 2018, 200 stool specimens were obtained from Jordanian patients with suspected amebiasis. All specimens were subjected to microscopic analysis. DNA was extracted from the microscopy-positive stool samples. A conventional PCR and a duplex real-time PCR were performed to detect E. histolytica and E. dispar. RESULTS: By microscopy, 35% (70/200) of specimens were tested positive for Entamoeba complex. All 70 microscopic-positive Entamoeba complex samples were negative for the presence of E. histolytica by the NOVITEC(R) E. histolytica ELISA assay. All 70 samples positive by microscopy were negative for the presence of E. histolytica and E. dispar by PCR-based assays. CONCLUSION: We suspect some of these microscopy-positive stool specimens might contain a potentially novel species of Entamoeba that could not be detected by ELISA or PCR-based assays specific for E. histolytica and E. dispar. Diagnosis of amebiasis remains challenging here in Jordan and hence highlighting the need for improved diagnostic method. |
A case of primary amebic meningoencephalitis caused by Naegleria fowleri in Bangladesh
Sazzad HMS , Luby SP , Sejvar J , Rahman M , Gurley ES , Hill V , Murphy JL , Roy S , Cope JR , Ali IKM . Parasitol Res 2019 119 (1) 339-344 We present the first recognized case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in a 15-year-old male from Bangladesh. He performed daily nasal rinsing with untreated ground water and bathed in untreated ground water or river water, which likely exposed him to N. fowleri. |
Granulomatous amoebic encephalitis caused by Acanthamoeba in a patient with AIDS: a challenging diagnosis
Lau HL , De Lima Corvino DF , Guerra FMJr , Malik AM , Lichtenberger PN , Gultekin SH , Ritter JM , Roy S , Ali IKM , Cope JR , Post MJD , Gonzales Zamora JA . Acta Clin Belg 2019 76 (2) 1-5 INTRODUCTION: Acanthamoeba spp. is a ubiquitous free-living amoeba that causes human infections affecting predominantly the cornea and central nervous system. The diagnosis and treatment of Acanthamoeba encephalitis is very challenging. CASE SUMMARY: A 53-year-old male with HIV/AIDS was admitted for altered mental status and fever. On initial examination, he had left hemianopia with left-sided weakness and numbness. MRI revealed an inflammatory and enhancing parenchymal mass associated with leptomeningeal enhancement in the occipitoparietal lobe containing multiple punctate hemorrhages. He was treated with empiric antibiotics for presumptive toxoplasmosis, brain abscess, fungal infection and tuberculosis with an unremarkable lymphoma work up. Initial brain biopsy studies were unremarkable except for non-specific granulomas and adjacent necrotic tissue. The patient passed away 2.5 months after initial presentation with no diagnosis. Post-mortem testing by the Centers for Disease Control and Prevention (CDC) confirmed the diagnosis of granulomatous amoebic encephalitis (GAE) by visualization with immunohistochemistry staining and PCR. Recovery is rare from GAE likely due to delay in diagnosis. CONCLUSIONS: This case illustrates the importance of including GAE into the differential diagnosis of brain mass. We advocate early molecular testing of tissue specimen by the CDC to achieve an appropriate diagnosis, and a multidisciplinary approach for the management of this condition. |
Non-granulomatous cerebellar infection by Acanthamoeba spp. in an immunocompetent host
Modica S , Miracco C , Cusi MG , Tordini G , Muzii VF , Iacoangeli F , Nocentini C , Ali IKM , Roy S , Cerase A , Zanelli G , De Luca A , Montagnani F . Infection 2018 46 (6) 885-889 Acanthamoeba spp. is a free-living amoeba, frequently involved in keratitis by contact lens in immunocompetent hosts. Anecdotal reports associate Acanthamoeba spp. as a cause of severe granulomatous encephalitis in immunocompromised and, less frequently, in immunocompetent subjects. Data regarding clinical and therapeutic management are scanty and no defined therapeutic guidelines are available. We describe an unusual case of non-granulomatous Acanthamoeba cerebellitis in an immunocompetent adult male, with abrupt onset of neurological impairment, subtle hemorrhagic infarction at magnetic resonance imaging, and initial suspicion of cerebellar neoplasm. Histopathological findings of excised cerebellar mass revealed the presence of necrosis and inflammation with structure resembling amoebic trophozoites, but without granulomas. Polymerase chain reaction from cerebellar tissue was positive for Acanthamoeba T4 genotype. Due to gastrointestinal intolerance to miltefosine, the patient was treated with long-term course of fluconazole and trimethoprim/sulphamethoxazole, obtaining complete clinical and neuroradiological resolution. |
Canine amoebic meningoencephalitis due to Balamuthia mandrillaris
Chien RCC , Telford CR , Roy S , Ali IKM , Shieh WJ , Confer AW . Vet Parasitol Reg Stud Reports 2018 13 156-159 A 1-year-old Siberian Husky dog with acute-onset of seizures, recumbency, paddling, and muscular fasciculations was autopsied. A locally extensive hemorrhagic and malacic focus was noted in the right cerebral frontal cortex, and severe necrotizing and hemorrhagic, neutrophilic meningoencephalitis was diagnosed microscopically. Amoebic trophozoites and cysts were identified within the affected cerebral parenchyma and confirmed by indirect immunofluorescence assay and real-time PCR as Balamuthia mandrillaris. B. mandrillaris is found in soil and water and the infection has been reported in both immunocompromised and immunocompetent humans and rarely in the dog. |
Acanthamoeba endophthalmitis during treatment for cutaneous disease in a renal transplant patient
Kutner A , Aldrich M , Patel S , Kang JJ , Amin B , Mann R , Ali IKM , Brasil Martines R , Cope JR , De Boccardo GO , Puius YA . Transpl Infect Dis 2018 20 (2) e12843 Acanthamoeba infections are difficult to diagnose and treat. We present a renal transplant patient who developed Acanthamoeba endophthalmitis on therapy with posaconazole and miltefosine for cutaneous acanthamobiasis. The patient was maintained on intracameral voriconazole injections, and oral azithromycin, fluconazole, and flucytosine. This case highlights novel presentations and treatments for acanthamoebic infection. This article is protected by copyright. All rights reserved. |
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