Comparison of bacterial diversity and distribution on the gills of Atlantic salmon (Salmo salar L.): an evaluation of sampling techniques.

AIMS: Assess bacterial diversity and richness in mucus samples from the gills of Atlantic salmon in comparison to preserved or fixed gill filament tissues. Ascertain whether bacterial diversity and richness are homogeneous upon different arches of the gill basket. METHODS AND RESULTS: Bacterial communities contained within gill mucus were profiled using 16S rRNA gene sequencing. No significant difference in taxa richness, alpha (P > 0·05) or beta diversity indices (P > 0·05) were found between the bacterial communities of RNAlater preserved gill tissues and swab-bound mucus. A trend of lower richness and diversity indices were observed in bacterial communities from posterior hemibranchs. CONCLUSIONS: Non-lethal swab sampling of gill mucus provides a robust representation of bacterial communities externally upon the gills. Bacterial communities from the fourth arch appeared to be the least representative overall. SIGNIFICANCE AND IMPACT OF THE STUDY: The external mucosal barriers of teleost fish (e.g. gill surface) play a vital role as a primary defence line against infection. While research effort on the role of microbial communities on health and immunity of aquaculture species continues, the collection and sampling processes to obtain these data require evaluation so methodologies are consistently applied across future studies that aim to evaluate the composition of branchial microbiomes.

Contrasting microbiota profiles observed in children carrying either Blastocystis spp. or the commensal amoebas Entamoeba coli or Endolimax nana.

Recent studies have shown how intestinal parasites can modulate gut microbiota. This observation is not surprising since the human intestinal lumen, like any other niche, is a battlefield of microbial competition, and Eukaryotes can affect bacterial populations. Intestinal pathogenic protist has been associated with reshaping the microbial community structure; however, the interactions between the colonic bacterial communities and parasites like Blastocystis spp., Entamoeba coli, and Endolimax nana have been poorly studied. In this work, we studied the distal intestinal bacterial microbiota of 49 children attending 7 public daycare centers in Medellin, Colombia, and compared the bacterial microbiota structure in the presence or absence of the protists Blastocystis spp., E. coli, and E. nana. Parasite colonization was associated with an increase in bacterial richness. Moreover, Blastocystis spp. presented a positive relationship with Prevotella, since this bacterium was selectively enriched in children carrying it. Remarkably, the E. coli colonized children showed a microbial profile that was closer to uninfected controls, although some bacterial taxa displayed to be enriched. This is the case for Akkermansia, which showed to be favored in E. coli colonized individuals, while notably reduced in the Blastocystis spp. parasitized group.

Acanthamoeba spp. y Naegleria spp. aisladas del Río Pamplonita, zona metropolitana de Cúcuta, Colombia / Acanthamoeba spp. and Naegleria spp. isolated from Pamplonita river, metropolitan area of Cucuta, Colombia

Introducción: Acanthamoeba y Naegleria son géneros de amebas de vida libre resistentes a cambios extremos de temperatura y pH, aislados de diversos ambientes (suelo, aire y agua). Debido a la cantidad de habitantes que se benefician de las aguas del Río Pamplonita, al desconocimiento de su presencia en la región y al aumento de enfermedades relacionadas con el consumo de agua, se considera necesario realizar estudios sobre la distribución de estos microorganismos. Objetivo: Identificar Acanthamoeba spp. y Naegleria spp. en aguas del curso principal del río Pamplonita de la zona metropolitana de Cúcuta, Colombia. Métodos: La búsqueda de las amebas de interés se realizó mediante examen directo y cultivo a 28, 37 y 42 °C en agar no nutritivo a partir de 21 muestras de agua de siete sectores del río Pamplonita. Adicionalmente, se midió pH y temperatura in situ y se determinó la carga de coliformes. Resultados: Se encontró que 76,2 por ciento de las muestras fueron positivas para alguna de las amebas. La Acanthamoeba fue la que se aisló con mayor frecuencia. El 28,6 por ciento de los cultivos incubados a 42 °C fueron positivos principalmente para Naegleria spp., lo que indica que estos aislados termotolerantes podrían tener potencial patógeno. Conclusiones: Acanthamoeba spp. y Naegleria spp. son frecuentes en aguas del Río Pamplonita en áreas de importante intervención humana. El hallazgo de amebas termotolerantes alerta sobre el riesgo de salud para la población que se encuentra expuesta a esta fuente hídrica(AU)

Introduction: Acanthamoeba and Naegleria are genus of free-living amoeba (AVL) resistant to extreme changes in temperature and pH, isolated from different environments (soil, air and water). Due to the number of inhabitants that benefit from the waters of Pamplonita River, the lack of knowledge about its presence in the region and the increase of diseases related to water consumption, it is necessary to carry out studies on its distribution. Objective: To identify Acanthamoeba spp and Naegleria spp in the water of the main course of Pamplonita River, in the metropolitan area of Cúcuta, Colombia. Methods: The search for the amoebas of interest was performed by direct examination and culture at 28, 37 and 42 °C on non-nutritive agar from 21 water samples from seven sectors of Pamplonita River. Additionally, pH and temperature were measured in situ and the coliforms´ load was also determined. Results: It was found that 76.2 percent of the samples were positive for some of the amoebas, with Acanthamoeba being the most frequently isolated. 28.6 percent of the cultures incubated at 42 °C were positive mainly for Naegleria spp, indicating that these thermotolerant isolates could have pathogen potential. Conclusions: Acanthamoeba spp and Naegleria spp are frequent in waters of Pamplonita River which are areas of important human intervention. The finding of thermotolerant amoebas warns about the health risk for the population that is exposed to this water source(AU)

'Candidatus Cochliophilus cryoturris' (Coxiellaceae), a symbiont of the testate amoeba Cochliopodium minus.

Free-living amoebae are well known for their role in controlling microbial community composition through grazing, but some groups, namely Acanthamoeba species, also frequently serve as hosts for bacterial symbionts. Here we report the first identification of a bacterial symbiont in the testate amoeba Cochliopodium. The amoeba was isolated from a cooling tower water sample and identified as C. minus. Fluorescence in situ hybridization and transmission electron microscopy revealed intracellular symbionts located in vacuoles. 16S rRNA-based phylogenetic analysis identified the endosymbiont as member of a monophyletic group within the family Coxiellaceae (Gammaprotebacteria; Legionellales), only moderately related to known amoeba symbionts. We propose to tentatively classify these bacteria as 'Candidatus Cochliophilus cryoturris'. Our findings add both, a novel group of amoeba and a novel group of symbionts, to the growing list of bacteria-amoeba relationships.

Complete genome sequence and bioinformatics analyses of Bacillus thuringiensis strain BM-BT15426.

OBJECTIVES: This study aimed to investigate the genetic characteristics of Bacillus thuringiensis strain BM-BT15426. METHODS: B. thuringiensis strain was identified by sequencing the PCR product (amplifying 16S rRNA gene) using ABI Prism 377 DNA Sequencer. The genome was sequenced using PacBio RS II sequencers and assembled de novo using HGAP. Also, further genome annotation was performed. RESULTS: The genome of B. thuringiensis strain BM-BT15426 has a length of 5,246,329 bp and contains 5409 predicted genes with an average G + C content of 35.40%. Three genes were involved in the "Infectious diseases: Amoebiasis" pathway. A total of 21 virulence factors and 9 antibiotic resistant genes were identified. CONCLUSIONS: The major pathogenic factors of B. thuringiensis strain BM-BT15426 were identified through complete genome sequencing and bioinformatics analyses which contributes to further study on pathogenic mechanism and phenotype of B. thuringiensis.

Experimental demonstration of the possible role of Acanthamoeba polyphaga in the infection and disease progression in Buruli Ulcer (BU) using ICR mice.

The transmission of Buruli ulcer (BU), caused by Mycobacterium ulcerans (MU), remains puzzling although a number of hypothesis including through bites of infected aquatic insects have been proposed. We report the results of experiments using ICR mice that give credence to our hypothesis that Acanthamoeba species may play a role in BU transmission. We cocultured MU N2 and MU 1615 which expresses red fluorescent protein (RFP) and Acanthamoeba polyphaga (AP), and confirmed infected AP by Ziehl-Neelsen (ZN) staining. We tested for viability of MU inside AP and observed strong RFP signals inside both trophozoites and cysts after 3 and 42 days of coculturing respectively. ICR mice were topically treated, either on shaved intact or shaved pinpricked rumps, with one of the following; MU N2 only (2.25 x 106 colony forming units [CFU] / ml), MU N2:AP coculture (2.96 x 104 CFU: 1.6 x 106 cells/ml), AP only (1.6 x 106 cells/ml), PYG medium and sterile distilled water. Both MU N2 only and MU N2:AP elicited reddening on day (D) 31; edema on D 45 and D 44 respectively, and ulcers on D 49 at pinpricked sites only. To ascertain infectivity and pathogenicity of MU N2 only and MU N2:AP, and compare their virulence, the standard mouse footpad inoculation method was used. MU N2:AP elicited reddening in footpads by D 3 compared to D 14 with MU N2 only of the same dose of MU N2 (2.96 x 104 CFU). ZN-stained MU were observed in both thin sectioned and homogenized lesions, and aspirates from infected sites. Viable MU N2 were recovered from cultures of the homogenates and aspirates. This study demonstrates in ICR mice MU transmission via passive infection, and shows that punctures in the skin are prerequisite for infection, and that coculturing of MU with AP enhances pathogenesis.

Azole Antifungal Agents To Treat the Human Pathogens Acanthamoeba castellanii and Acanthamoeba polyphaga through Inhibition of Sterol 14α-Demethylase (CYP51).

In this study, we investigate the amebicidal activities of the pharmaceutical triazole CYP51 inhibitors fluconazole, itraconazole, and voriconazole against Acanthamoeba castellanii and Acanthamoeba polyphaga and assess their potential as therapeutic agents against Acanthamoeba infections in humans. Amebicidal activities of the triazoles were assessed by in vitro minimum inhibition concentration (MIC) determinations using trophozoites of A. castellanii and A. polyphaga. In addition, triazole effectiveness was assessed by ligand binding studies and inhibition of CYP51 activity of purified A. castellanii CYP51 (AcCYP51) that was heterologously expressed in Escherichia coli. Itraconazole and voriconazole bound tightly to AcCYP51 (dissociation constant [Kd] of 10 and 13 nM), whereas fluconazole bound weakly (Kd of 2,137 nM). Both itraconazole and voriconazole were confirmed to be strong inhibitors of AcCYP51 activity (50% inhibitory concentrations [IC50] of 0.23 and 0.39 µM), whereas inhibition by fluconazole was weak (IC50, 30 µM). However, itraconazole was 8- to 16-fold less effective (MIC, 16 mg/liter) at inhibiting A. polyphaga and A. castellanii cell proliferation than voriconazole (MIC, 1 to 2 mg/liter), while fluconazole did not inhibit Acanthamoeba cell division (MIC, >64 mg/liter) in vitro. Voriconazole was an effective inhibitor of trophozoite proliferation for A. castellanii and A. polyphaga; therefore, it should be evaluated in trials versus itraconazole for controlling Acanthamoeba infections.

Bis-benzimidazole hits against Naegleria fowleri discovered with new high-throughput screens.

Naegleria fowleri is a pathogenic free-living amoeba (FLA) that causes an acute fatal disease known as primary amoebic meningoencephalitis (PAM). The major problem for infections with any pathogenic FLA is a lack of effective therapeutics, since PAM has a case mortality rate approaching 99%. Clearly, new drugs that are potent and have rapid onset of action are needed to enhance the treatment regimens for PAM. Diamidines have demonstrated potency against multiple pathogens, including FLA, and are known to cross the blood-brain barrier to cure other protozoan diseases of the central nervous system. Therefore, amidino derivatives serve as an important chemotype for discovery of new drugs. In this study, we validated two new in vitro assays suitable for medium- or high-throughput drug discovery and used these for N. fowleri. We next screened over 150 amidino derivatives of multiple structural classes and identified two hit series with nM potency that are suitable for further lead optimization as new drugs for this neglected disease. These include both mono- and diamidino derivatives, with the most potent compound (DB173) having a 50% inhibitory concentration (IC50) of 177 nM. Similarly, we identified 10 additional analogues with IC50s of <1 µM, with many of these having reasonable selectivity indices. The most potent hits were >500 times more potent than pentamidine. In summary, the mono- and diamidino derivatives offer potential for lead optimization to develop new drugs to treat central nervous system infections with N. fowleri.

Prompt diagnosis and extraordinary survival from Naegleria fowleri meningitis: a rare case report.

Primary amoebic meningoencephalitis is a rare fatal meningitis caused by free living amoeba Naegleria fowleri, found in freshwater ponds and lakes. It infects children and young adults with exposure due to swimming or diving. We report a case of N. fowleri meningitis in a 6-year-old boy who presented with signs and symptoms of acute bacterial meningitis. No history of travelling or swimming was present. However, the boy frequently played with water stored from a "kuhl" (diversion channels of water). Wet mount of cerebrospinal fluid (CSF) revealed amoeboid and actively motile flagellate forms of trophozoites. CSF culture done on 1.5% non-nutrient agar plates with a lawn culture of Escherichia coli kept at 37°C for 15 days did not reveal any growth. The test of flagellation on passing CSF in distilled water was however positive in 3 h. Water of the "kuhl" from the stored tank also showed actively motile trophozoites similar to the forms obtained from the CSF. Based on our reports, the boy was immediately treated with amphotericin B, rifampicin and fluconazole for 21 days. Repeat CSF examination after 14 days did not reveal any trophozoites in wet mount and patient was discharged after 3 weeks of successful treatment.

War on terror cells: killing the host that harbours 'superbugs' is an infection control strategy in our fight against infectious diseases.

It is proposed that targeting the environmental host that harbour 'superbugs' is an effective strategy in our fight against infectious diseases.

Iodamoeba butschlii in an anal pap test confirmed by iodine stain.

We report the finding of Iodamoeba butschlii amebic cysts on a liquid-based anal Pap smear from an HIV-positive male. Iodine staining of the smear confirmed the diagnosis. It is important to distinguish I. butschlii from pathogenic ameobae and other organisms seen on anal Pap smears.

Survey of Naegleria fowleri in geothermal recreational waters of Guadeloupe (French West Indies).

In 2008 a fatal case of primary amoebic meningoencephalitis, due to the amoeboflagellate Naegleria fowleri, occurred in Guadeloupe, French West Indies, after a child swam in a bath fed with geothermal water. In order to improve the knowledge on free-living amoebae in this tropical part of France, we investigated on a monthly basis, the presence of Naegleria spp. in the recreational baths, and stream waters which feed them. A total of 73 water samples, 48 sediments and 54 swabs samples were collected from 6 sampling points between June 2011 and July 2012. The water samples were filtered and the filters transferred to non-nutrient agar plates seeded with a heat-killed suspension of Escherichia coli while sediment and swab samples were placed directly on these plates. The plates were incubated at 44°C for the selective isolation of thermophilic Naegleria. To identify the Naegleria isolates the internal transcribed spacers, including the 5.8S rDNA, were amplified by polymerase chain reaction and the sequence of the PCR products was determined. Thermophilic amoebae were present at nearly all collection sites. The pathogenic N. fowleri was the most frequently encountered thermophilic species followed by N. lovaniensis. The concentration of N. fowleri was rather low in most water samples, ranging from 0 to 22 per liter. Sequencing revealed that all N. fowleri isolates belonged to a common Euro-American genotype, the same as detected in the human case in Guadeloupe. These investigations need to be continued in order to counsel the health authorities about prevention measures, because these recreational thermal baths are used daily by local people and tourists.

Primary amebic meningoencephalitis: a case report and literature review.

Primary amebic meningoencephalitis (PAM) is a rare but nearly always fatal disease caused by infection with Naegleria fowleri, a thermophilic, free-living ameba found in freshwater environments. Cases of N. fowleri infection have been reported from many of the southern-tier states in the United States, with Florida and Texas disproportionately represented among them. Primary amebic meningoencephalitis presents clinically in a fashion that may be indistinguishable from bacterial and viral meningitis. Unfortunately, because the disease is so rare, PAM is often excluded from the differential diagnosis of children with meningitis resulting in delayed diagnostic and therapeutic efforts.Pediatric acute care practitioners in emergency departments, general pediatric wards, and critical care units, especially those practicing in the southern United States, should be familiar with the risk factors for acquisition of PAM, its clinical presentation, and the fact that common empiric treatment of bacterial meningitis will not treat N. fowleri. Herein, we present the case of an adolescent who died of PAM and review the (a) epidemiology, (b) pathophysiology, (c) available diagnostic modalities, (d) treatment options, and (e) outcomes of patients treated for N. fowleri infection of the central nervous system.

Nuevos métodos para el diagnóstico microbiológico de la amebiasis y de otros protozoarios intestinales / New methods for the microbiological diagnosis of amebiasis and other intestinal protozoa

La Organización Mundial de la Salud (OMS) ubica a las enfermedades diarreicas en segundo lugar como causa de morbi-mortalidad de niños en países en vías de desarrollo, siendo las infecciones por protozoarios intestinales proporcionalmente una causa trascendente en dichas regiones. La mayoría de estos parásitos se transmiten por vía fecal-oral o por contacto interpersonal y exhiben ciclosde vida que, en general se desarrollan en dos estadios: el trofozoíto que coloniza el intestino y el quiste que es excretado con las heces y cuya rígida pared protectora, le confiere resistencia en el ambiente, permitiendo de este modo la propagación de la enfermedad. Entamoeba histolytica es uno de los agentes infecciosos de mayor distribución mundial, y es aproximadamente la causa de 100.000 muertes por año, siendo responsable de uno de los problemas de salud más serios en países en vías de desarrollo. Se reconocen al menos ocho amebas que podrían colonizar el intestino del hombre: E. histolytica, E. dispar, E. moshkovskii, E. coli, E. hartmanni, E. polecki, Iodamoeba butschlii y Endolimax nana. Aunque sólo E. histolytica es considerada como el agente etiológico de la Amebiosis. Su presentación clínica va desde la colonización asintomática, la disentería amebiana, hasta la propagación extraintestinal, originando abscesos en diversos órganos y tejidos. Por este motivo, la correcta identificación de E. histolytica en heces y tejidos y diferenciándola de otras amebas comensales y de otros protozoarios representa un desafío en la práctica médica, a que de ello dependerá el tratamiento y el pronóstico de laenfermedad.(AU)

Abstract: The World Health Organization (WHO) includes diarrhea a the second leading cause of morbidity and mortality of children in developing countries. Among these causes, infections by intestinal protozoan parasites represent an important percentage in any place of the world. Most of these parasites are transmitted by the fecal-oral route or by inter personal contact and exhibit simple life cycles, consisting in the disease-causing, proliferating trophozoites and the dormant, resistant cyst responsible for the transmission of the infection among susceptible hosts. Entamoeba histolytica is one of the most frequent of those parasites, causing about 100.000 deaths per year in developing countries, being one of the major health problems in areas where basic sanitation practices are inefficient. At least eight species of Entamoeba have been reported to infect the human large intestine: E. histolytica, E. dispar, E. moshkovskii, E. coli, E. hartmanni, E. polecki, odamoeba butschlii and Endolimax nana, although E. histolytica is the only one considered to cause pathology in humans. Clinical manifestation of this infection varies from asymptomatic infection to dysentery and extraintestinal invasion, producing abscesses in many tissues. Therefore, the correct identification of E. histolytica in stool and tissue samples and its differential diagnostic is an important challenge in parasitology because treatment and prognosis depend of the valid identification of this parasite.The health issue of protozoan intestinal infections, both in developed and developing parts of the world, is of such importance that it is clearly necessary the development of novel, better, cheap, and faster diagnostic methods. The incorporation of new approaches and technology to the efficient and sensitive detection of these infections is significantly relevant.(AU)

Nuevos métodos para el diagnóstico microbiológico de la amebiasis y de otros protozoarios intestinales / New methods for the microbiological diagnosis of amebiasis and other intestinal protozoa

La Organización Mundial de la Salud (OMS) ubica a las enfermedades diarreicas en segundo lugar como causa de morbi-mortalidad de niños en países en vías de desarrollo, siendo las infecciones por protozoarios intestinales proporcionalmente una causa trascendente en dichas regiones. La mayoría de estos parásitos se transmiten por vía fecal-oral o por contacto interpersonal y exhiben ciclosde vida que, en general se desarrollan en dos estadios: el trofozoíto que coloniza el intestino y el quiste que es excretado con las heces y cuya rígida pared protectora, le confiere resistencia en el ambiente, permitiendo de este modo la propagación de la enfermedad. Entamoeba histolytica es uno de los agentes infecciosos de mayor distribución mundial, y es aproximadamente la causa de 100.000 muertes por año, siendo responsable de uno de los problemas de salud más serios en países en vías de desarrollo. Se reconocen al menos ocho amebas que podrían colonizar el intestino del hombre: E. histolytica, E. dispar, E. moshkovskii, E. coli, E. hartmanni, E. polecki, Iodamoeba butschlii y Endolimax nana. Aunque sólo E. histolytica es considerada como el agente etiológico de la Amebiosis. Su presentación clínica va desde la colonización asintomática, la disentería amebiana, hasta la propagación extraintestinal, originando abscesos en diversos órganos y tejidos. Por este motivo, la correcta identificación de E. histolytica en heces y tejidos y diferenciándola de otras amebas comensales y de otros protozoarios representa un desafío en la práctica médica, a que de ello dependerá el tratamiento y el pronóstico de laenfermedad.

Abstract: The World Health Organization (WHO) includes diarrhea a the second leading cause of morbidity and mortality of children in developing countries. Among these causes, infections by intestinal protozoan parasites represent an important percentage in any place of the world. Most of these parasites are transmitted by the fecal-oral route or by inter personal contact and exhibit simple life cycles, consisting in the disease-causing, proliferating trophozoites and the dormant, resistant cyst responsible for the transmission of the infection among susceptible hosts. Entamoeba histolytica is one of the most frequent of those parasites, causing about 100.000 deaths per year in developing countries, being one of the major health problems in areas where basic sanitation practices are inefficient. At least eight species of Entamoeba have been reported to infect the human large intestine: E. histolytica, E. dispar, E. moshkovskii, E. coli, E. hartmanni, E. polecki, odamoeba butschlii and Endolimax nana, although E. histolytica is the only one considered to cause pathology in humans. Clinical manifestation of this infection varies from asymptomatic infection to dysentery and extraintestinal invasion, producing abscesses in many tissues. Therefore, the correct identification of E. histolytica in stool and tissue samples and its differential diagnostic is an important challenge in parasitology because treatment and prognosis depend of the valid identification of this parasite.The health issue of protozoan intestinal infections, both in developed and developing parts of the world, is of such importance that it is clearly necessary the development of novel, better, cheap, and faster diagnostic methods. The incorporation of new approaches and technology to the efficient and sensitive detection of these infections is significantly relevant.

Role of voriconazole in combined acanthamoeba and fungal corneal ulcer.

We report a case of a 21 year old male who presented with smear-proven fungal corneal ulcer in left eye, refractory to treatment with topical natamycin. Corneal smears and culture were taken along with anterior chamber tap for microbiological investigations and intracameral 1% voriconazole was injected followed by institution of oral as well as topical voriconazole drops. Corneal and aqueous smear as well as culture confirmed the presence of acanthamoeba. The keratitis responded favourably to voriconazole therapy which was instituted along with topical trophicidal drugs and anterior chamber became quiet by 7th day. The patient was slowly tapered from voriconazole and was off the drug by 6 months. At one year follow up, he continues to remain asymptomatic. The possibility exists that the fungal organisms had either partially or completely responded to natamycin eye drops and voriconazole therapy further inhibited their growth along with being highly efficacious in suppressing acanthamoeba trophozoites. Voriconazole may be specifically instrumental in corneal ulcers with coinfection of acanthamoeba and fungal organisms and preventing recrudescence of both. Normal saline wet mount and 10% KOH mount of paracentesis sample for suspicious cases of refractory corneal ulcers to specifically look for trophozoites in order to institute timely treatment are recommended.

In the case of transmission of Mycobacterium ulcerans in buruli ulcer disease Acanthamoeba species stand accused.

Buruli ulcer disease caused by Mycobacterium ulcerans results in extensive destruction of skin and soft tissue and long-term functional disabilities that ultimately require surgery and rehabilitation. The disease is associated with aquatic and swampy environments with the mycobacterium occurring in biofilms, soil, aquatic insects, fish and wildlife however, the mode of transmission to humans remains an enigma. Current transmission ideas including bites from predatory water bugs and mosquitoes, do not explain satisfactorily the spasmodic disease distribution in human populations. Here we argue that Acanthamoeba species are the natural hosts of M. ulcerans and are mainly responsible for disease transmission because; (i) Acanthamoebae are known natural hosts of several microbial pathogens including M. marinum, M. avium and Legionella pneumophila, (ii) culture of slow-to-grow microbial pathogens hosted in nature by Acanthamoeba spp is enhanced when the media is seeded with the protozoa, (iii) acanthamoebae and M. ulcerans share similar bio-ecological and epidemiological settings, (iv) documented evidence that prior growth of L. pneumophila and M. avium in acanthamoebae influences entry mechanisms, intracellular growth and virulence in human monocytes, (v) Acanthamoeba spp also infect humans and cause diseases via routes of openings including broken skin and sites of trauma similar to M. ulcerans and (vi) M. ulcerans is rather a fastidious intracellular organism as recent analysis of the genome indicate. We argue further that temperature plays a significant role in transmission determining the fate of either the intracellular microbe or the host cells. Also, Acanthamoeba-pathogen association has a long evolutionary history because the same set of bacterial genes and gene products e.g. in L. pneumophila are required for survival in both mammalian and protozoan host cells. We suggest that the involvement of Acanthamoeba in the transmission of M. ulcerans to humans better explains the disease's epidemiology.

Epizootic fatal amebiasis in an outdoor group of Old World monkeys.

BACKGROUND: Entamoeba (E.) histolytica is an obligate parasite of humans and non-human primates. METHODS: This report describes the pathomorphological, immunohistological, and microbiological findings of fatal E. histolytica infection in two mantled guerezas (Colobus guereza) and one Hanuman langur (Semnopithecus entellus) from an epizootic outbreak of amebiasis in an open-range recreation park. RESULTS: Pathomorphological examination revealed multifocal necrotizing and granulomatous hepatitis with intralesional protozoan trophozoites in all three cases. In addition, necrotizing and ulcerative gastritis was detected in both mantled guerezas. Furthermore, oligofocal acute pulmonary embolization was detected in one of these cases. No extra-hepatic lesions were observed in the Hanuman langur. Immunohistological examination confirmed the etiologic diagnosis of E. histolytica-induced lesions. CONCLUSIONS: Although E. histolytica is a rarely diagnosed pathogen in Western European countries, veterinarians and animal keepers involved in handling and care taking of non-human primates should be aware of the potential threat caused by this zoonotic parasite.

Absceso hepático amebiano autóctono en España: ¿una enfermedad emergente? Descripción de 2 nuevos casos clínicos y de una técnica diagnóstica basada en la reacción en cadena de la polimerasa / Autochthonous amebic liver abscess in Spain: An emerging disease? Case report and description of a PCR-based diagnostic test

Introducción: En España se está detectando un aumento de la amebiasis en personas sin antecedentes de viajes o que no proceden de zonas endémicas.Material y métodos: En este trabajo se presentan 2 nuevos casos de absceso hepático amebiano (AHA) autóctono y se revisan otros 21 casos de AHA descritos con anterioridad en España en pacientes que nunca habían salido de la Península Ibérica. Además, se describe una técnica molecular de reacción en cadena de la polimerasa para el diagnóstico de Entamoeba histolytica.Resultados: Veinte casos (87%) se dieron en varones. La edad de los enfermos varió entre 26 y 77 años. Dos de las 3 mujeres con amebiasis extraintestinal tenían el virus de la inmunodeficiencia humana. En 17 individuos no se encontraron datos de exposición a los que se les pudiera atribuir el contagio de la infección. En los 6 restantes se registraron antecedentes de contacto directo con enfermos de amebiasis o con personas o alimentos sospechosos procedentes de zonas endémicas.Discusión: La infección por E. histolytica se está convirtiendo en una infección emergente en el medio. La amebiasis debería considerarse en el diagnóstico diferencial de entidades clínicas compatibles, incluso en ausencia de antecedentes epidemiológicos de viajes o inmigración. Las nuevas técnicas diagnósticas moleculares pueden ayudar a caracterizar esta infección y deben considerarse métodos de referencia junto con las pruebas serológicas (AU)

Introduction: In Spain an increase in cases of amebiasis has been detected in patients with no history of traveling to, or immigration from, endemic areas.Material and Methods: This study describes two new cases of amebic hepatic abscess due to native protozoa and reviews 21 more cases of amebic hepatic abscess reported in Spanish patients who had never left the Iberian Peninsula. In addition, a new PCR-based technique for diagnosing Entamoeba histolytica is described.Results: Twenty cases (87%) occurred in men. The age range of the affected patients was 26 to 77 years. Two of the 3 women with extraintestinal amebiasis were HIV-positive. There was no history of exposure to the parasite in 17 cases. In the remaining 6 cases, direct contact with patients affected with amebiasis or with individuals or foods from endemic areas was recorded.Conclusion: Entamoeba histolytica infection is becoming an emerging disease in our country. Amebiasis should be included in the differential diagnosis of consistent clinical entities even when there is no background of traveling or immigration. New molecular diagnostic tools can help to characterize this infection and should be considered reference techniques in combination with serological methods (AU)