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The European Respiratory Journal Nov 2008Among the micro-organisms that may affect the respiratory apparatus are the protozoa. The diseases they may give rise to constitute a relatively uncommon group of... (Review)
Review
Among the micro-organisms that may affect the respiratory apparatus are the protozoa. The diseases they may give rise to constitute a relatively uncommon group of respiratory ailments with, in the majority of cases, an underlying clinical situation corresponding to states of suppressed immunity (AIDS, transplants, malign haemopathies, corticotherapy, etc.). Other factors, such as visits to endemic areas and immigration, also have to be taken into account. In view of the probable increase in the number of cases and the appearance of new emerging diseases, it is the intention of the present work to review the publications available, in different fields of medicine, that refer to the principal kinds of protozoa (Entamoeba, Acanthamoeba, Balamuthia, Leishmania, Trypanosoma, Trichomonas, Lophomonas, Cryptosporidium, Cyclospora, Toxoplasma, Plasmodium, Babesia, Encephalitozoon, Enterocytozoon and Balantidium) and, at the same time, detail and comment on the latest findings on this subject.
Topics: Animals; Antiprotozoal Agents; Cryptosporidium; Entamoeba histolytica; Eukaryota; Humans; Immune System; Leishmania; Pulmonary Medicine; Respiratory Tract Infections; Trypanosoma
PubMed: 18978136
DOI: 10.1183/09031936.00022008 -
Tropical Parasitology 2015Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis...
Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis and pathophysiology of B. mandrillaris encephalitis. B. mandrillaris has two stages in its life cycle, an active trophozoite stage during which it divides mitotically. However, under unfavorable conditions, the trophozoite transforms into a dormant cyst stage. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. Several lines of evidence suggest that B. mandrillaris encephalitis develops as a result of hematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption, and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of this devastating infection. Here, we present a brief overview of the current understanding of the morphology, biology, pathogenesis, and pathophysiology of B. mandrillaris encephalitis.
PubMed: 25709948
DOI: 10.4103/2229-5070.149888 -
Therapeutic Advances in Infectious... 2024Granulomatous amebic encephalitis, caused by the free-living amebae or species, is a rare and deadly infectious syndrome with a current mortality rate of >90%. Much... (Review)
Review
Granulomatous amebic encephalitis, caused by the free-living amebae or species, is a rare and deadly infectious syndrome with a current mortality rate of >90%. Much work remains to define the optimal treatment for these infections. Here, we provide a comprehensive overview of the supporting evidence behind antimicrobials currently recommended by the Centers for Disease Control and Prevention (CDC) with updated statistics on survival rates and medication usage from the CDC Free-Living Ameba Database. We also discuss promising treatments, especially the emerging therapeutic agent nitroxoline, and provide recommendations for the next steps in this area.
PubMed: 38312848
DOI: 10.1177/20499361241228340 -
Parasitology Research Jan 2017Pathogenic free-living amoebae (FLA), such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba species isolated from aquatic environments have been implicated...
Pathogenic free-living amoebae (FLA), such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba species isolated from aquatic environments have been implicated in central nervous system, eye and skin human infections. They also allow the survival, growth and transmission of bacteria such as Legionella, Mycobacteria and Vibrio species in water systems. The purpose of this study was to investigate the co-occurrence of potentially pathogenic FLA and their associated bacteria in hospital water networks in Johannesburg, South Africa. A total of 178 water (n = 95) and swab (n = 83) samples were collected from two hospital water distribution systems. FLA were isolated using the amoebal enrichment technique and identified using PCR and 18S rDNA sequencing. Amoebae potentially containing intra-amoebal bacteria were lysed and cultured on blood agar plates. Bacterial isolates were characterized using the VITEK®2 compact System. Free-living amoebae were isolated from 77 (43.3 %) of the samples. Using microscopy, PCR and 18S rRNA sequencing, Acanthamoeba spp. (T3 and T20 genotypes), Vermamoeba vermiformis and Naegleria gruberi specie were identified. The Acanthamoeba T3 and T20 genotypes have been implicated in eye and central nervous system infections. The most commonly detected bacterial species were Serratia marcescens, Stenotrophomonas maltophilia, Delftia acidovorans, Sphingomonas paucimobilis and Comamonas testosteroni. These nosocomial pathogenic bacteria are associated with systematic blood, respiratory tract, the urinary tract, surgical wounds and soft tissues infections. The detection of FLA and their associated opportunistic bacteria in the hospital water systems point out to a potential health risk to immune-compromised individuals.
Topics: Amoeba; Bacteria; Cross Infection; Fresh Water; Hospitals; Humans; South Africa
PubMed: 27730363
DOI: 10.1007/s00436-016-5271-3 -
Antibiotics (Basel, Switzerland) Apr 2020and are opportunistic protozoan pathogens capable of producing infection of the central nervous system with more than 95% mortality rate. Previously, we have...
and are opportunistic protozoan pathogens capable of producing infection of the central nervous system with more than 95% mortality rate. Previously, we have synthesized several compounds with antiamoebic properties; however, synthesis of compounds that are analogues of clinically used drugs is a highly desirable approach that can lead to effective drug development against these devastating infections. In this regard, compounds belonging to the azole class possess wide range of antimicrobial properties and used clinically. In this study, six novel benzimidazole, indazole, and tetrazole derivatives were synthesized and tested against brain-eating amoebae. These compounds were tested for their amoebicidal and static properties against and . Furthermore, the compounds were conjugated with silver nanoparticles and characterized. The synthetic heterocyclic compounds showed up to 72% and 65% amoebicidal activities against and respectively, while expressing up to 75% and 70% amoebistatic activities, respectively. Following conjugation with silver nanoparticles, amoebicidal activities of the drugs increased by up to 46 and 36% versus and Minimal effects were observed when the compounds were evaluated against human cells using cytotoxicity assays. In summary, azole compounds exhibited potent activity against and Moreover, conjugation of the azole compounds with silver nanoparticles further augmented the capabilities of the compounds against amoebae.
PubMed: 32316387
DOI: 10.3390/antibiotics9040188 -
The Journal of International Medical... May 2022is a free-living heterotrophic amoeba found in soil that causes a rare and usually fatal granulomatous amebic encephalitis. We report an immunocompetent patient...
is a free-living heterotrophic amoeba found in soil that causes a rare and usually fatal granulomatous amebic encephalitis. We report an immunocompetent patient infected with encephalitis diagnosed by next-generation sequencing (NGS). Clinical manifestations included sudden headache and epilepsy with disturbance of consciousness. The opening pressure of cerebrospinal fluid (CSF) was 220 mmHO, with mildly elevated white blood cell numbers and elevated protein levels. Cranial magnetic resonance imaging revealed abnormal signals in the right frontal lobe, left parietal lobe, and left occipital lobe. CSF NGS detected . Albendazole and metronidazole combined with fluconazole were administered to the patient immediately, but his condition deteriorated and he eventually died. Encephalitis caused by is rare and has a high mortality rate. Clinical manifestations are complex and diverse, but early diagnosis is very important for successful treatment. This can be aided by the metagenomic NGS of CSF.
Topics: Amebiasis; Balamuthia mandrillaris; Encephalitis; High-Throughput Nucleotide Sequencing; Humans; Magnetic Resonance Imaging; Male
PubMed: 35505464
DOI: 10.1177/03000605221093217 -
Revista Do Instituto de Medicina... Jun 2017Rotavirus and pathogenic free-living amoebae are causative agents of important health problems, especially for developing countries like Pakistan where the population...
Rotavirus and pathogenic free-living amoebae are causative agents of important health problems, especially for developing countries like Pakistan where the population has limited access to clean water supplies. Here, we evaluated the prevalence of rotavirus and free-living amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri) in drinking water supplies of Karachi, Pakistan. Six water filtration plants that supply drinking water to the population of Karachi were investigated. Additionally, drinking water samples from households were analyzed for the presence of rotavirus and free-living amoebae. Rotavirus was present in 35% of the water samples collected from water filtration plants; however, domestic tap water samples had a prevalence of only 5%. Out of 20 water samples from filtration plants, 13 (65%) were positive for Acanthamoeba spp., and one (5%) was positive for B. mandrillaris. Out of 20 drinking water samples collected from different areas of Karachi, 35% were positive for Acanthamoeba spp. Rotavirus was detected in 5% of the drinking water samples tested. Overall, these findings showed for the first time the presence of rotavirus, in addition to pathogenic free-living amoebae in drinking water supplies of Karachi that could be an important public health risk for the affected population.
Topics: Acanthamoeba; Balamuthia mandrillaris; Humans; Naegleria; Pakistan; Rotavirus; Water; Water Microbiology; Water Supply
PubMed: 28591260
DOI: 10.1590/S1678-9946201759032 -
Journal of Clinical Microbiology Oct 2021
Retraction for Pietrucha-Dilanchian et al., "Balamuthia mandrillaris and Amebic Encephalitis with Neurotoxoplasmosis Coinfection in a Patient with Advanced HIV Infection".
PubMed: 34664998
DOI: 10.1128/JCM.01838-21 -
Infection and Drug Resistance 2023Central nervous system infection by is a rare and severe condition, which has a fatality rate of approximately 95% and often evades timely diagnosis due to its rarity...
Central nervous system infection by is a rare and severe condition, which has a fatality rate of approximately 95% and often evades timely diagnosis due to its rarity and non-specific clinical manifestations. Here, we report a case of encephalomyelomeningitis caused by in a male who presented with transient coma, nausea, and vomiting when working in a garbage dump. Initial magnetic resonance imaging (MRI) of the brain showed normal signals. Despite receiving steroids as well as antibacterial and antiviral treatment, he developed urinary and fecal dysfunction, inability to walk, and deterioration of consciousness. Both brain and spinal cord MRI revealed abnormal findings, and next-generation sequencing of the cerebrospinal fluid showed the presence of . A combination of fluconazole and albendazole was administered; however, the patient deteriorated gradually and died 30 days after the onset. We suggest the unbiased metagenomic sequencing of the affected tissues/CSF in patients with CNS infections that are difficult to diagnose or treat, and multiple tests at different stages of the disease may be required.
PubMed: 36756612
DOI: 10.2147/IDR.S400692 -
Parasitology Research Aug 2022Free-living amoebae (FLA) are protozoa which have been reported in different countries worldwide from diverse sources (water, soil, dust, air), contributing to the...
Free-living amoebae (FLA) are protozoa which have been reported in different countries worldwide from diverse sources (water, soil, dust, air), contributing to the environmental microbiological contamination. Most of the FLA species present a life cycle with two different phases: an active vegetative and physiologically form named trophozoite, and an extremely resistant phase called cyst. Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, Sapinia pedata, Vahlkampfia spp., Paravahlkampfia spp. and Vermamoeba vermiformis have been reported not only as causal agents of several opportunistic diseases including fatal encephalitis or epithelial disorders, but also as capable to favour the intracellular survival of common pathogenic bacteria, which could avoid the typical water disinfection systems, non-effective against FLAs cysts. Even though Santiago Island possesses high levels of humidity compared to the rest of the archipelago of Cape Verde, the water resources are scarce. Therefore, it is important to carry out proper microbiological quality controls, which currently do not contemplate the FLA presence in most of the countries. In the present work, we have reported the presence of Acanthamoeba spp. (69.2%); Vannella spp. (15.4%); Vermamoeba vermiformis (7.7%) and the recently discovered Stenamoeba dejonckheerei (7.7%) in different water sources of Santiago Island.
Topics: Acanthamoeba; Amoeba; Cabo Verde; Lobosea; Water
PubMed: 35660958
DOI: 10.1007/s00436-022-07563-y