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Parasite (Paris, France) 2024Wild rodents are key carriers of various human pathogens, including Blastocystis spp. Our study aimed to assess the prevalence and genetic characteristics of...
Molecular investigation of Blastocystis sp. infections in wild rodents from the Inner Mongolian Autonomous Region and Liaoning province, China: High prevalence and dominance of ST4.
Wild rodents are key carriers of various human pathogens, including Blastocystis spp. Our study aimed to assess the prevalence and genetic characteristics of Blastocystis among wild rodents in the Inner Mongolian Autonomous Region and Liaoning Province of China. From November 2023 to February 2024, 486 rodents were captured in these regions. Fresh feces were collected from the intestines of each rodent for the isolation of DNA and PCR amplification of the vertebrate cytochrome b (cytb) gene to identify rodent species. Subsequently, PCR analysis and sequencing of the partial small subunit of the ribosomal RNA (rRNA) gene were utilized to detect Blastocystis in all fecal samples. Of the total samples, 27.4% (133/486) were found to be Blastocystis positive. The results revealed the presence of four species of rodents infected with Blastocystis, 32.3% (63/195) in Rattus norvegicus, 15.1% (16/106) in Mus musculus, 20.2% (18/89) in Apodemus agrarius, and 37.5% (36/96) in Cricetulus barabensis. Sequence analysis confirmed the existence of five Blastocystis subtypes: ST1 (n = 4), ST2 (n = 2), the ST4 (n = 125, the dominant subtype), ST10 (n = 1), and a novel ST (n = 1). The identified zoonotic subtypes (ST1, ST2, ST4, and ST10) highlight the possible role played by wild rodents in the transmission of Blastocystis to humans, thereby elevating the chances of human infection. Meanwhile, the discovery of novel sequences also provides new insights into the genetic diversity of this parasite.
Topics: China; Rodentia; Blastocystis; Blastocystis Infections; Rodent Diseases; Cytochromes b; Feces; RNA, Ribosomal, 18S; Prevalence; Genotype; Genetic Variation; Phylogeny
PubMed: 38912917
DOI: 10.1051/parasite/2024031 -
PLoS Neglected Tropical Diseases Jun 2024Febrile illnesses that persist despite initial treatment are common clinical challenges in (sub)tropical low-resource settings. Our aim is to review infectious...
BACKGROUND
Febrile illnesses that persist despite initial treatment are common clinical challenges in (sub)tropical low-resource settings. Our aim is to review infectious etiologies of "prolonged fevers" (persistent febrile illnesses, PFI) and to quantify relative contributions of selected neglected target diseases with limited diagnostic options, often overlooked, causing inadequate antibiotic prescriptions, or requiring prolonged and potentially toxic treatments.
METHODS
We performed a systematic review of articles addressing the infectious etiologies of PFI in adults and children in sub-/tropical low- and middle-income countries (LMICs) using the PRISMA guidelines. A list of target diseases, including neglected parasites and zoonotic bacteria (e.g., Leishmania and Brucella), were identified by infectious diseases and tropical medicine specialists and prioritized in the search. Malaria and tuberculosis (TB) were not included as target diseases due to well-established epidemiology and diagnostic options. Four co-investigators independently extracted data from the identified articles while assessing for risk of bias.
RESULTS
196 articles from 52 countries were included, 117 from Africa (33 countries), 71 from Asia (16 countries), and 8 from Central and -South America (3 countries). Target diseases were reported as the cause of PFI in almost half of the articles, most frequently rickettsioses (including scrub typhus), relapsing fever borreliosis (RF-borreliosis), brucellosis, enteric fever, leptospirosis, Q fever and leishmaniasis. Among those, RF-borreliosis was by far the most frequently reported disease in Africa, particularly in Eastern Africa. Rickettsioses (including scrub typhus) were often described in both Africa and Asia. Leishmaniasis, toxoplasmosis and amoebiasis were the most frequent parasitic etiologies. Non-target diseases and non-tropical organisms (Streptococcus pneumoniae, Escherichia coli, and non-typhoidal Salmonella spp) were documented in a fifth of articles.
CONCLUSIONS
Clinicians faced with PFI in sub-/tropical LMICs should consider a wide differential diagnosis including enteric fever and zoonotic bacterial diseases (e.g., rickettsiosis, RF-borreliosis and brucellosis), or parasite infections (e.g., leishmaniasis) depending on geography and syndromes. In the absence of adequate diagnostic capacity, a trial of antibiotics targeting relevant intra-cellular bacteria, such as doxycycline or azithromycin, may be considered.
PubMed: 38905305
DOI: 10.1371/journal.pntd.0011978 -
PloS One 2024The development and application of functional feed ingredients represents a great opportunity to advance fish growth and health, boost the immune system, and induce...
The development and application of functional feed ingredients represents a great opportunity to advance fish growth and health, boost the immune system, and induce physiological benefits beyond those provided by traditional feeds. In the present study, we looked at the feasibility of in vitro methods for screening the qualities of functional feed ingredients using the fish cell line RTgill-W1, which has never been used in fish nutrition, and the culture of Paramoeba perurans. Five functional feed ingredients (arginine, β-glucan, vitamin C, and two phytogenic feed additives) were selected to investigate their effects on cell viability and reactive oxygen species production. Three of the selected ingredients (arginine and two phytogenic feed additives) were additionally tested to assess their potential amoebicidal activity. As these functional ingredients are the core of a commercially available feed (Protec Gill, Skretting AS), their beneficial effects were further assessed in a field trial in fish affected by complex gill disease. Here, the analyzed parameters included the evaluation of macroscopic and histopathological gill conditions, pathogen detections, and analyses of plasma parameters. RTgill-W1 cell line assays were a good tool for screening functional ingredients and provided information about the optimal ingredient concentration ranges, which can be helpful for adjusting the concentrations in future feed diets. Through the culture of P. perurans, the tested ingredients showed a clear amoebicidal activity, suggesting that their inclusions in dietary supplements could be a viable way to prevent microbial infections. A three-week period of feeding Protec Gill slowed the disease progression, by reducing the pathogen load and significantly improving gill tissue conditions, as revealed by histological evaluation. The use of diets containing selected functional ingredients may be a feasible strategy for preventing or mitigating the increasingly common gill diseases, particularly in cases of complex gill disease, as documented in this study.
Topics: Animals; Salmo salar; Animal Feed; Fish Diseases; Gills; Cell Line; beta-Glucans; Arginine; Ascorbic Acid; Reactive Oxygen Species; Dietary Supplements; Amebiasis; Cell Survival
PubMed: 38900829
DOI: 10.1371/journal.pone.0304112 -
Microbiology Spectrum Jun 2024Diarrheal diseases with infectious etiology remain a major cause of death globally, particularly in low-income countries. is a pathogenic protozoan parasite that is the...
Diarrheal diseases with infectious etiology remain a major cause of death globally, particularly in low-income countries. is a pathogenic protozoan parasite that is the causative agent of amebiasis. Amebiasis has a wide presentation in clinical severity with many factors, including the bacterial microbiota, contributing to this variation. The innate immune response also plays a critical role in regulating the severity of infection, with neutrophils reported to have a protective role. Despite this, the precise mechanism of how neutrophils mediate amebic killing is poorly understood. Thus, modern platforms that allow for inquiry of granulocyte-ameba interactions will increase our understanding of this disease. Herein, we describe an assay for neutrophil killing of by utilizing high-dimensional spectral flow cytometry. Neutrophils were isolated from wild-type 5-week-old C57BL/6 mice and co-cultured with at various multiplicity of infections (MOIs). After co-culture, neutrophils and were stained for spectral flow cytometry. Cell populations were identified using surface markers and fluorescence minus one (FMO) controls. We have previously shown that animals colonized with a component of the human microbiota, , were protected from . This protection was associated with elevated neutrophil count. Here, we explored amebic killing capacity and observed that neutrophils from animals with possessed heightened amebic killing compared with controls. Thus, this study establishes a novel platform that can provide an in-depth analysis of granulocyte-parasite interactions in various contexts, including during alteration of the intestinal microbiota.IMPORTANCEThe tools for studying host immune cell interactions are limited. Factors, such as parasite heterogeneity, infectivity, and difficulties with culture systems and animal models, make interrogation of these interactions challenging. Thus, researchers can benefit from next-generation models that allow for the analysis of both host and parasite cells. Here, we demonstrate the use of a novel platform that allows for the determination of parasite-host cell interactions and customizable high-dimensional phenotyping of both populations. Indeed, spectral flow cytometry can approach >40 markers on a single panel and can be paired with custom-developed parasite antibodies that can be conjugated to fluorochromes via commercially available kits. This platform affords researchers the capability to test highly precise hypotheses regarding host-parasite interactions.
PubMed: 38888326
DOI: 10.1128/spectrum.00472-24 -
Scientific Reports Jun 2024Natural products play a significant role in providing the current demand as antiparasitic agents, which offer an attractive approach for the discovery of novel drugs....
Natural products play a significant role in providing the current demand as antiparasitic agents, which offer an attractive approach for the discovery of novel drugs. The present study aimed to evaluate in vitro the potential impact of seaweed Padina pavonica (P. pavonica) extract in combating Acanthamoeba castellanii (A. castellanii). The phytochemical constituents of the extract were characterized by Gas chromatography-mass spectrometry. Six concentrations of the algal extract were used to evaluate its antiprotozoal activity at various incubation periods. Our results showed that the extract has significant inhibition against trophozoites and cysts viability, with complete inhibition at the high concentrations. The IC of P. pavonica extract was 4.56 and 4.89 µg/mL for trophozoites and cysts, respectively, at 24 h. Morphological alterations of A. castellanii trophozoites/cysts treated with the extract were assessed using inverted and scanning electron microscopes and showed severe damage features upon treatment with the extract at different concentrations. Molecular Docking of extracted compounds against Acanthamoeba cytochrome P450 monooxygenase (AcCYP51) was performed using Autodock vina1.5.6. A pharmacokinetic study using SwissADME was also conducted to investigate the potentiality of the identified bioactive compounds from Padina extract to be orally active drug candidates. In conclusion, this study highlights the in vitro amoebicidal activity of P. pavonica extract against A. castellanii adults and cysts and suggests potential AcCYP51 inhibition.
Topics: Acanthamoeba castellanii; Molecular Docking Simulation; Acanthamoeba Keratitis; Plant Extracts; Antiprotozoal Agents; Trophozoites; Animals; Humans
PubMed: 38871751
DOI: 10.1038/s41598-024-63691-8 -
Cureus May 2024() infections typically present with fever and gastrointestinal symptoms. This case report on enteritis documents atypical clinical, radiological, and endoscopic...
() infections typically present with fever and gastrointestinal symptoms. This case report on enteritis documents atypical clinical, radiological, and endoscopic findings raising diagnostic challenges. A 31-year-old male in the Kingdom of Saudi Arabia (KSA) presented with severe abdominal pain, vomiting, bloody diarrhea, and no fever. Initial diagnosis included amebiasis and other gastroenteritis infections. Despite treatment with ciprofloxacin and metronidazole, the patient's condition did not improve, and he kept having intractable abdominal pain and vomiting. Subsequent investigations, including abdominal ultrasound and esophagogastroduodenoscopy, revealed extensive and rapidly progressive intestinal inflammation with wall thickening and ascites. Stool culture eventually identified a multidrug-resistant strain of , sensitive only to ceftriaxone. Treatment with ceftriaxone and continuous infusion of proton pump inhibitor (PPI) led to significant improvement. The absence of fever in the context of bloody diarrhea, and the rapid development of ascites not improving with first-line treatment of gastroenteritis, led to the search for other diagnoses such as inflammatory bowel syndromes or tuberculosis. The presentation of diffuse intestinal wall thickening with intractable vomiting, bloody diarrhea, and progressively increasing ascites is not frequently encountered with . The case also underscores the growing concern of antibiotic-resistant strains. The patient's response to targeted antibiotic therapy emphasizes the importance of accurate microbial identification and susceptibility testing in managing infectious diseases. This case report illustrates an atypical presentation of enteritis with progressively increasing ascites and increased intestinal wall thickening. The uncommon complicated clinical picture led to challenges in diagnosis and management. It emphasizes the need for high clinical suspicion and comprehensive diagnostic approaches in atypical cases of common infections, especially in the context of increasing antibiotic resistance.
PubMed: 38868285
DOI: 10.7759/cureus.60217 -
Frontiers in Cellular and Infection... 2024Pathogenic and free-living are widely distributed in the environment and have been reported to cause keratitis and universally fatal encephalitis. Primary cutaneous...
Pathogenic and free-living are widely distributed in the environment and have been reported to cause keratitis and universally fatal encephalitis. Primary cutaneous acanthamoebiasis caused by is exceedingly rare and presents as isolated necrotic cutaneous lesions without involvement of the cornea or central nervous system. Cutaneous acanthamoebiasis often occurs in immunocompromised patients and is likely overlooked or even misdiagnosed only by cutaneous biopsy tissue histopathological analysis. Here, we report a HIV-infected 63-year-old female with oral leukoplakia for 4 months and scattered large skin ulcers all over the body for 2 months. The cause of the cutaneous lesions was unclear through cutaneous specimens histopathological analysis, and subsequently were detected by metagenomic next-generation sequencing (mNGS), which may be the cause of cutaneous lesions. Based on the mNGS results, a pathologist subsequently reviewed the previous pathological slides and found trophozoites of so that the cause was identified, and the skin ulcers improved significantly after treatment with multi-drug combination therapy. is also a host of pathogenic microorganisms. The presence of endosymbionts enhances the pathogenicity of , and no other pathogens were reported in this case. mNGS is helpful for rapidly diagnosing the etiology of rare skin diseases and can indicate the presence or absence of commensal microorganisms.
Topics: Humans; Female; High-Throughput Nucleotide Sequencing; Amebiasis; Metagenomics; Middle Aged; Acanthamoeba; HIV Infections; Skin; Treatment Outcome
PubMed: 38863830
DOI: 10.3389/fcimb.2024.1356095 -
Infection & Chemotherapy May 2024Enterocolitis and gastroenteritis remain major health problems, particularly in children living in developing countries. Intestinal protozoa, such as , and are...
BACKGROUND
Enterocolitis and gastroenteritis remain major health problems, particularly in children living in developing countries. Intestinal protozoa, such as , and are frequently associated with these conditions. Amebic colitis can cause serious complications, including fulminant necrotizing colitis, toxic megacolon, extraintestinal amebiasis, and stunting in children. The diagnosis of amoebiasis is challenging, relying on microscopic examination, which cannot distinguish from the nonpathogenic and Therefore, this study aimed to identify intestinal parasites, particularly , their prevalence, and the clinical characteristics of patients admitted for enterocolitis and gastroenteritis at a tertiary-referral hospital.
MATERIAL AND METHODS
A cross-sectional, retrospective study was conducted at a national, tertiary-referral government hospital, in Jakarta. Of the 111 retrieved medical records from hospitalized patients with enterocolitis and gastroenteritis, 54 (48.6%) fecal samples were still available in the laboratory storage and referred to the parasitology laboratory. All fecal samples underwent the following tests: 1) direct stool examination, after staining with 1% Lugol's solution, and using the water-ether concentration method; 2) modified acid-fast staining for coccidian parasites; 3) Jones' culture medium to detect ; 4) copro-antigen assay to detect and and 5) a polymerase chain reaction (PCR) assay to identify . Clinical and demographic data were obtained from the medical records.
RESULTS
Largely, patients (44.1%) were from the cohort of young children ≤5 years old, followed by adults aged 19-60 years old (24.3%). Both cohorts exhibited polyparasitism. Intestinal parasites were detected in 17 out of the 54 samples (31.4%). These included 6 (11.1%), 2 (3.7%),5 (9.2%), 3 (5.5%), 2 (3.7%), and 1 (1.8%) samples that were positive for , , , , and respectively. PCR analysis revealed that 10 samples were positive for infection, eight of which originated from pediatric patients.
CONCLUSION
At a national tertiary-referral hospital in Indonesia, infection was most prevalent among pediatric patients with enterocolitis. and were the two main species identified by PCR. Therefore, PCR assays and fecal occult-blood tests are recommended in cases of enterocolitis and gastroenteritis.
PubMed: 38859717
DOI: 10.3947/ic.2023.0099 -
Veterinary Parasitology Jul 2024Blastocystis inhabits the digestive tracts of a diverse range of hosts. Transmission patterns, including host specificity, and the clinical and public health...
Blastocystis inhabits the digestive tracts of a diverse range of hosts. Transmission patterns, including host specificity, and the clinical and public health significance of Blastocystis in humans remain poorly understood. This study aimed to investigate the distribution and genetic diversity of Blastocystis in herbivorous and carnivorous reptiles in Eastern Thailand. A total of 501 faecal samples were collected from 363 iguanas, 79 bearded dragons, 50 tortoises, and nine snakes in an animal breeding farm in Chonburi Province, Eastern Thailand. Detection and differentiation of Blastocystis was based on amplification, sequencing, and phylogenetic analysis of specific small subunit (SSU) ribosomal RNA genes from faecal DNA extracted from the samples. Altogether 101/501 samples (20 %) were polymerase chain reaction (PCR) and sequencing-positive for Blastocystis, 90 (89 %) of which were from iguanas; the remaining positive samples were from African spurred tortoise (n=6), Bearded dragon (n=3), Leopard tortoise (n=1), and Red-footed tortoise (n=1). Phylogenetic analysis revealed that most of the Blastocystis sequences from iguanas were largely similar, and they were distinct from those of the tortoises. Subtype 17 was found in the three bearded dragons and likely reflected Blastocystis from prey animals. This is the largest survey of Blastocystis in reptiles to date. Remarkable differences in Blastocystis colonization rates and genetic diversity were observed between iguanas and other reptile orders, and what was considered Blastocystis colonization was only observed in herbivorous reptiles.
Topics: Animals; Blastocystis; Thailand; Genetic Variation; Blastocystis Infections; Host Specificity; Phylogeny; Feces; Reptiles; Turtles; Lizards; Snakes
PubMed: 38838380
DOI: 10.1016/j.vetpar.2024.110218 -
Parasites & Vectors May 2024Proteases produced by Acanthamoeba spp. play an important role in their virulence and may be the key to understanding Acanthamoeba pathogenesis; thus, increasing...
Characterization of novel extracellular proteases produced by Acanthamoeba castellanii after contact with human corneal epithelial cells and their relevance to pathogenesis.
BACKGROUND
Proteases produced by Acanthamoeba spp. play an important role in their virulence and may be the key to understanding Acanthamoeba pathogenesis; thus, increasing attention has been directed towards these proteins. The present study aimed to investigate the lytic factors produced by Acanthamoeba castellanii during the first hours of in vitro co-culture with human corneal epithelial cells (HCECs).
METHODS
We used one old and one recent Acanthamoeba isolate, both from patients with severe keratitis, and subsets of these strains with enhanced pathogenic potential induced by sequential passaging over HCEC monolayers. The proteolytic profiles of all strains and substrains were examined using 1D in-gel zymography.
RESULTS
We observed the activity of additional proteases (ranging from 33 to 50 kDa) during the early interaction phase between amoebae and HCECs, which were only expressed for a short time. Based on their susceptibilities to protease inhibitors, these proteases were characterized as serine proteases. Protease activities showed a sharp decline after 4 h of co-incubation. Interestingly, the expression of Acanthamoeba mannose-binding protein did not differ between amoebae in monoculture and those in co-culture. Moreover, we observed the activation of matrix metalloproteinases in HCECs after contact with Acanthamoeba.
CONCLUSIONS
This study revealed the involvement of two novel serine proteases in Acanthamoeba pathogenesis and suggests a pivotal role of serine proteases during Acanthamoeba-host cell interaction, contributing to cell adhesion and lysis.
Topics: Humans; Acanthamoeba castellanii; Epithelial Cells; Coculture Techniques; Epithelium, Corneal; Peptide Hydrolases; Acanthamoeba Keratitis; Serine Proteases; Protozoan Proteins; Virulence
PubMed: 38812022
DOI: 10.1186/s13071-024-06304-7