CRISPR/Cas system, an adaptive immune system with clustered regularly interspaced short palindromic repeats, may interfere with exogenous nucleic acids and protect prokaryotes from external damages, is an effective gene editing and nucleic acid detection tools. The CRISPR/Cas system has been widely applied in virology and bacteriology; however, there is relatively less knowledge about the application of the CRISPR/Cas system in parasitic diseases. The review summarizes the mechanisms of action of the CRISPR/Cas system and provides a comprehensive overview of their application in gene editing and nucleic acid detection of parasitic diseases, so as to provide insights into future studies on parasitic diseases.
［摘要］ 成簇规律间隔短回文重复序列 (clustered regularly interspaced short palindromic repeats, CRISPR) 及其相关蛋白 (CRISPR-associated protein, Cas) 系统 (CRISPR/Cas系统) 为具有规律簇状短回文重复序列结构的适应性免疫系统, 能干 扰外源性核酸, 保护原核生物免受外部侵害, 是一种有效的基因编辑及核酸检测工具。CRISPR/Cas系统在病毒和细菌 领域应用广泛, 但在寄生虫病领域研究相对较少。本文分类探讨了CRISPR/Cas系统的作用机制, 全面综述了其在寄生 虫基因编辑与核酸检测中的应用, 旨在为未来寄生虫病相关研究提供参考。.

The introduced salmonid ectoparasite Gyrodactylus salaris has been detected on Atlantic salmon in 53 Norwegian rivers and in 39 Norwegian fish farms. In affected rivers, the mortality of Atlantic salmon juveniles is very high, estimated to a mean of 86%. G. salaris has been considered one of the biggest threats to wild Norwegian Atlantic salmon stocks. With various measures, the authorities have reduced the potential for further spread of the parasite to new rivers and fish farms, and G. salaris has been eradicated from 43 rivers and all fish farms. Furthermore, the eradication process is almost completed in five affected rivers located at the Norwegian west coast, while preparations for the eradication in the remaining five rivers in the southeastern part of Norway have begun. The goal of Norwegian management is to eradicate the introduced pathogenic G. salaris strains from all occurrences in Norway. In fish farms, the parasite has been removed by mandatory slaughter of infected fish. In rivers, G. salaris has mostly been removed by killing all the fish hosts with rotenone. The indigenous genetic Atlantic salmon stocks are re-established after eradication of the parasite. New methods are developed using chemicals that kill the parasite without killing fish in the rivers. Norwegian authorities have so far used more than NOK 1.5 billion on research, monitoring and combating G. salaris. However, the benefits are considered many times greater than the spending. Without control measures, G. salaris would likely have spread to new Atlantic salmon rivers where the same catastrophic outcome had to be expected. The Norwegian authorities seem to meet the goal in their long-term work to halt the spread of G. salaris and to eradicate the parasite in affected rivers.

One of the most dangerous parasite infections, cysticercosis, is found practically everywhere in the world. Cysticercus cellulosae is the larval stage of the swine tapeworm Taenia solium, which causes cysticercosis. Orbital or ocular cysticercosis (OOC) is an avoidable cause of blindness. There are two types of ocular cysticercosis: intraocular (in the anterior chamber, subretinal space, or vitreous) and extraocular (in the orbital tissues or subconjunctival space). Here, we report a rare case of extraocular muscle cysticercosis that presented as a solitary, well-defined lobulated mass near the medial canthus in the right eye and was well managed medically with antihelminthic drugs and corticosteroid therapy. The key to diagnosing myocysticercosis is orbital imaging. Although brain and ocular involvement in cysticercosis is common, extraocular muscle cysticercosis is extremely uncommon and mainly affects young people and children. Orbital pseudotumor, idiopathic myositis, and hydatid cysts are a few differential diagnoses for ocular cysticercosis. It is critical to recognize and treat such illnesses as early as feasible to avoid serious consequences. Public health measures are essential to eradicate this disease in the area.

Lung cancer with brain metastasis has a high morbidity and mortality worldwide. Neurocysticercosis is a parasitic infection commonly found in regions with poor sanitation. We present a case with the coexistence of lung cancer and neurocysticercosis. A 57-year-old Caucasian female, with a history of secondhand smoke exposure, presented with a cough. Further evaluation revealed a lesion in the right upper lobe of the lung on a CT scan, a frontal lobe lesion on brain MRI, and hypermetabolic lymph nodes on a PET scan. Biopsies confirmed invasive moderately differentiated adenocarcinoma, indicating stage 4 lung cancer with a solitary brain metastasis. The patient underwent stereotactic radiosurgery for the brain lesion and subsequently received chemoradiation therapy. Upon completion of therapy, the patient showed improvement in both lung and brain lesions. Durvalumab maintenance therapy was initiated. However, a follow-up MRI of the brain revealed a new lesion in the right lateral ventricle. Stereotactic radiosurgery was performed to target this lesion. Five months later, a repeat MRI showed growth of the brain lesion. Given the atypical image finding, a biopsy of the right lateral ventricle lesion was performed, revealing an unexpected diagnosis of calcified parenchymal neurocysticercosis. The patient was referred to an infectious disease specialist who started the patient on dexamethasone without antiparasitic treatment. The co-occurrence of metastatic lung cancer to the brain and neurocysticercosis presents significant diagnostic and therapeutic complexities. Despite stereotactic radiosurgery, the patient\'s neurologic symptoms failed to improve, and subsequent radiographic assessments yielded inconclusive results. Consequently, a brain biopsy was performed, deviating from the usual practice in cancer management, revealing the unexpected presence of neurocysticercosis. This unforeseen diagnosis underscores the critical significance of contemplating alternative etiologies in patients exhibiting atypical clinical manifestations, particularly in regions devoid of prevalent parasitic infections. This case highlights the challenges in identifying and managing complex cases involving lung cancer and neurocysticercosis, where treatment decisions must balance the need for oncologic control and the management of parasitic infection.

This is the first report of parasitic granulomatous dermatitis caused by Pelodera spp. in a buffalo. The affected buffalo was about seven years old, was a female of the Murrah breed and belonged to a property located on Marajó Island in the State of Pará. During the clinical examination, the animal was in a standing position and presented several multifocal nodular and placoid masses throughout the body, mostly on the forelimbs, hindlimbs, abdomen, mammary glands, perineum, vulva and tail. These masses were also observed on the nasal mucosa, head, neck, back and chest. On macroscopic examination, the skin had several multifocal-to-coalescent sessile nodular and placoid lesions. Histopathology of the skin showed a marked reduction in the number of hair follicles. In the superficial dermis, there was significant multifocal-to-coalescent inflammatory infiltration, consisting of macrophages, epithelioid macrophages, lymphocytes, plasma cells and multinucleated giant cells. In the remaining hair follicles, there were numerous cross and longitudinal sections of small rhabditoid nematodes characterized by a thin cuticle, platymyarian musculature, an intestinal tract, a rhabditiform esophagus and lateral alae (morphologically compatible with Pelodera spp.). The diagnosis of parasitic dermatitis was confirmed by histopathological skin lesions associated with the presence of intralesional rhabditiform larvae morphologically compatible with Pelodera spp.

BACKGROUND: Angiostrongyliasis is a highly dangerous infectious disease. Angiostrongylus cantonensis larvae migrate to the mouse brain and cause symptoms, such as brain swelling and bleeding. Noncoding RNAs (ncRNAs) are novel targets for the control of parasitic infections. However, the role of these molecules in A. cantonensis infection has not been fully clarified.
METHODS: In total, 32 BALB/c mice were randomly divided into four groups, and the infection groups were inoculated with 40 A. cantonensis larvae by gavage. Hematoxylin and eosin (H&E) staining and RNA library construction were performed on brain tissues from infected mice. Differential expression of long noncoding RNAs (lncRNAs) and mRNAs in brain tissues was identified by high-throughput sequencing. The pathways and functions of the differentially expressed lncRNAs were determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. The functions of the differentially expressed lncRNAs were further characterized by lncRNA‒microRNA (miRNA) target interactions. The potential host lncRNAs involved in larval infection of the brain were validated by quantitative real-time polymerase chain reaction (qRT‒PCR).
RESULTS: The pathological results showed that the degree of brain tissue damage increased with the duration of infection. The transcriptome results showed that 859 lncRNAs and 1895 mRNAs were differentially expressed compared with those in the control group, and several lncRNAs were highly expressed in the middle-late stages of mouse infection. GO and KEGG pathway analyses revealed that the differentially expressed target genes were enriched mainly in immune system processes and inflammatory response, among others, and several potential regulatory networks were constructed.
CONCLUSIONS: This study revealed the expression profiles of lncRNAs in the brains of mice after infection with A. cantonensis. The lncRNAs H19, F630028O10Rik, Lockd, AI662270, AU020206, and Mexis were shown to play important roles in the infection of mice with A. cantonensis infection.

BACKGROUND: Parasitic diseases pose challenges in impoverished urban settlements with limited access to clean water, proper hygiene, and sanitation (WASH). This study assesses WASH practices and risk perceptions of parasitic infections among households in the Bataan Shipyard and Engineering Corporation (BASECO) Compound in Manila, an urban poor community in the Philippines.
METHODS: A cross-sectional study design was employed to collect data through a self-administered questionnaire. Descriptive statistical analysis was performed to assess the sociodemographic profile, household WASH practices, and respondents\' risk perception of parasitic infections. Linear regression analysis was utilized to examine the relationship between these variables.
RESULTS: A survey was conducted with 363 households, of which 237 (65.3%) used distilled and purified water from the water refilling stations in the community for drinking. Meanwhile, 120 households (33.10%) consumed tap water. Boiling water was a commonly used method (n=146; 56.60%) for treating drinking water. Most households had flush toilets with septic tanks (n=244; 67.20%), water sources for handwashing (n=307; 84.57%) and soap for handwashing (n=356; 98.10%). On average, they washed their hands 6-10 times daily (n=159; 43.80%). Most households were aware that drinking untreated water (n=318; 87.6%), improper food washing (n=309; 85.1%), using contaminated water sources (n=301; 82.9%), and consuming raw or undercooked meat (n=298; 82.1%) could lead to parasitic infections. 316 respondents (87.1%) identified diarrhea as the most common symptom of parasitic infection. Relationships were found between access to drinking water and the number of household members (B=0.191; p-value=0.001), personal hygiene and the respondents\' knowledge of parasitic infections (B=0.112; p-value=0.047), and the overall WASH score with household income (B=0.105; p-value=0.045).
CONCLUSIONS: The WASH conditions in BASECO, Manila need improvement. Factors associated with their WASH practices include risk perception of parasitic diseases, socioeconomic disparity, and household overcrowding. These factors play a crucial role in identifying areas for improvement and promoting health policies for urban poor communities in the Philippines.

According to the World Health Organization, Chagas disease (CD) is the most prevalent poverty-promoting neglected tropical disease. Alarmingly, climate change is accelerating the geographical spreading of CD causative parasite, Trypanosoma cruzi, which additionally increases infection rates. Still, CD treatment remains challenging due to a lack of safe and efficient drugs. In this work, we analyze the viability of T. cruzi Akt-like kinase (TcAkt) as drug target against CD including primary structural and functional information about a parasitic Akt protein. Nuclear Magnetic Resonance derived information in combination with Molecular Dynamics simulations offer detailed insights into structural properties of the pleckstrin homology (PH) domain of TcAkt and its binding to phosphatidylinositol phosphate ligands (PIP). Experimental data combined with Alpha Fold proposes a model for the mechanism of action of TcAkt involving a PIP-induced disruption of the intramolecular interface between the kinase and the PH domain resulting in an open conformation enabling TcAkt kinase activity. Further docking experiments reveal that TcAkt is recognized by human inhibitors PIT-1 and capivasertib, and TcAkt inhibition by UBMC-4 and UBMC-6 is achieved via binding to TcAkt kinase domain. Our in-depth structural analysis of TcAkt reveals potential sites for drug development against CD, located at activity essential regions.

OBJECTIVE: Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally.
METHODS: Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR.
RESULTS: We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission.
CONCLUSIONS: We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

BACKGROUND: Possible resistance to recommended treatments for scabies has emerged recently. In response to anecdotal reports of a recent increase in treatment failure with permethrin, the British Association for Sexual Health and HIV (BASHH) released a statement alerting members to this.
OBJECTIVE: To examine attendances and the treatment pathways for scabies cases seen at local sexual health clinics.
METHODS: A case note review of scabies attendances between January 2017 and December 2023 was conducted. Data collected included patient demographics, clinical information, and scabies treatment histories. Statistical analysis was performed.
RESULTS: 143 patients attended with scabies. The number of scabies cases did not appear to increase significantly from 2017 to 2023 (p = .09). There was significant increase in median number of treatments per case per year over time (p = .013). The number of individuals needing second-line treatments increased significantly over time (p-trend < 0.001).
CONCLUSIONS: Individuals with scabies are requiring more treatments to clear infection. Use of ivermectin has risen in the last year suggesting that second-line treatment is increasingly needed for eradication. Whilst treatment failure may be due to non-compliance with treatment and decontamination efforts for both index and contacts, the more recent change in findings could be attributed to a fall in permethrin efficacy.