Rapid diagnosis of alveolar echinococcosis from lung puncture sample using metagenomic next-generation sequencing: a case report.

INTRODUCTION: Alveolar echinococcosis (AE), caused by the larval forms of Echinococcus multilocularis, is a zoonotic disease affecting the liver, lungs, lymph nodes, kidneys, brain, bones, thyroid, and other organs. Diagnosing AE in a non-endemic area is usually challenging. With the rapid development and increasing application of sequencing techniques in recent years, metagenomic next-generation sequencing (mNGS) has become a powerful tool for diagnosing rare infectious diseases. CASE PRESENTATION: A 45-year-old woman was admitted to the hospital for the presence of pulmonary shadows for more than 3 months. The lung computed tomography (CT) at a local hospital revealed scattered solid and quasi-circular nodules in the left upper lobe, left lower lobe, right middle lobe, and right lower lobe. The largest nodule was located in the dorsal part of the right lung, measuring 2.0 × 1.7 × 1.5 cm. Moreover, abdominal CT revealed one space-occupying lesion each in the left and right lobes. The pathological analysis of the lung biopsy specimen revealed infiltration of lymphocytes, plasma cells, and eosinophils in the alveolar wall and interstitial area. No pathogenic bacteria were observed in the sputum smear and culture tests. There were no parasite eggs in the stool. The mNGS of the lung puncture tissue revealed 6156 sequence reads matching E. multilocularis; thus, the condition was diagnosed as AE. Albendazole 400 mg was administered twice daily, and the patient was stable during follow-up. CONCLUSION: This case emphasizes the role of mNGS in diagnosing AE. As a novel, sensitive, and accurate diagnostic method, mNGS could be an attractive approach for facilitating early diagnosis and prompt treatment of infectious diseases, especially when the infection was caused by rare pathogens.

Evaluating the Toxocara cati extract as a therapeutic agent for allergic airway inflammation.

BACKGROUND: The hygiene hypothesis suggests that early life exposure to helminth infections can reduce hypersensitivity in the immune system. OBJECTIVE: The present study aims to evaluate the effects of Toxocara cati (T. cati) somatic products on allergic airway inflammation. METHODS: Between 2018 and 2020, T. cati adult worms were collected from stray cats in Mashhad, Iran (31 out of 186 cats), and their somatic extract was collected. Thirty BALB/c mice were equally divided into three groups, including the OVA group (sensitized and challenged with ovalbumin), the somatic administered group (received somatic extract along with ovalbumin sensitization), and the PBS group (sensitized and challenged with phosphate buffer saline). Bronchoalveolar lavage (BAL) fluid was collected to assess the number of cells, and lung homogenates were prepared for cytokine analysis. Histopathological analysis of the lungs was performed, and inflammatory cells and mucus were detected. Cytokine levels (IL-4, IL-5, IL-10) were measured using enzyme-linked immunosorbent assay (ELISA), and ovalbumin-specific immunoglobulin E (IgE) levels were determined using a capture ELISA. RESULTS: The somatic group significantly decreased regarding the lung pathological changes, including peribronchiolitis, perivasculitis, and eosinophil influx, compared to the group treated with ovalbumin alone. These changes were accompanied by a decrease in proinflammatory cytokines IL-4 and IL-5 and an increase in the anti-inflammatory cytokine IL-10, indicating a shift toward a more balanced immune response. The number of inflammatory cells in the BAL fluid was also significantly reduced in the somatic group, indicating a decrease in inflammation. CONCLUSION: These preclinical findings suggest that in experimental models, T. cati somatic extract exhibits promising potential as a therapeutic agent for mitigating allergic airway inflammation. Its observed effects on immune response modulation and reduction of inflammatory cell infiltration warrant further investigation in clinical studies to assess its efficacy and safety in human patients.

Organ-specific Toxocara canis larvae migration and host immune response in experimentally infected mice.

We investigated organ specific Toxocara canis larval migration in mice infected with T. canis larvae. We observed the worm burden and systemic immune responses. Three groups of BALB/c mice (n=5 each) were orally administered 1,000 T. canis 2nd stage larvae to induce larva migrans. Mice were sacrificed at 1, 3, and 5 weeks post-infection. Liver, lung, brain, and eye tissues were collected. Tissue from 2 mice per group was digested for larval count, while the remaining 3 mice underwent histological analysis. Blood hematology and serology were evaluated and compared to that in a control uninfected group (n=5) to assess the immune response. Cytokine levels in bronchoalveolar lavage (BAL) fluid were also analyzed. We found that, 1 week post-infection, the mean parasite load in the liver (72±7.1), brain (31±4.2), lungs (20±5.7), and eyes (2±0) peaked and stayed constant until the 3 weeks. By 5-week post-infection, the worm burden in the liver and lungs significantly decreased to 10±4.2 and 9±5.7, respectively, while they remained relatively stable in the brain and eyes (18±4.2 and 1±0, respectively). Interestingly, ocular larvae resided in all retinal layers, without notable inflammation in outer retina. Mice infected with T. canis exhibited elevated levels of neutrophils, monocytes, eosinophils, and immunoglobulin E. At 5 weeks post-infection, interleukin (IL)-5 and IL-13 levels were elevated in BAL fluid. Whereas IL-4, IL-10, IL-17, and interferon-γ levels in BAL fluid were similar to that in controls. Our findings demonstrate that a small portion of T. canis larvae migrate to the eyes and brain within the first week of infection. Minimal tissue inflammation was observed, probably due to increase of anti-inflammatory cytokines. This study contributes to our understanding of the histological and immunological responses to T. canis infection in mice, which may have implications to further understand human toxocariasis.

Succinate coenzyme A ligase ß-like protein from Trichinella spiralis is a potential therapeutic molecule for allergic asthma.

BACKGROUND: For decades, studies have demonstrated the anti-inflammatory potential of proteins secreted by helminths in allergies and asthma. Previous studies have demonstrated the immunomodulatory capabilities of Succinate Coenzyme A ligase beta-like protein (SUCLA-ß) derived from Trichinella spiralis, a crucial excretory product of this parasite. OBJECTIVE: To explore the therapeutic potential of SUCLA-ß in alleviating and controlling ovalbumin (OVA)-induced allergic asthma, as well as its influence on host immune modulation. METHODS: In this research, we utilized the rTs-SUCLA-ß protein derived from T. spiralis to investigate its potential in mitigating airway inflammation in a murine model of asthma induced by OVA sensitization/stimulation, both pre- and post-challenge. The treatment's efficacy was assessed by quantifying the extent of inflammation in the lungs. RESULTS: Treatment with rTs-SUCLA-ß demonstrated efficacy in ameliorating OVA-induced airway inflammation, as evidenced by a reduction in eosinophil infiltration, levels of OVA-specific Immunoglobulin E, interferon-γ, interleukin (IL)-9, and IL-17A, along with an elevation in IL-10. The equilibrium between Th17 and Treg cells plays a pivotal role in modulating the abundance of inflammatory cells within the organism, thereby ameliorating inflammation and alleviating symptoms associated with allergic asthma. CONCLUSIONS AND CLINICAL RELEVANCE: Our data revealed that T. spiralis-derived Ts-SUCLA-ß protein may inhibit the allergic airway inflammation by regulating host immune responses.

A novel mechanism of resveratrol alleviates Toxoplasma gondii infection-induced pulmonary inflammation via inhibiting inflammasome activation.

BACKGROUND: Infection by Toxoplasma gondii can lead to severe pneumonia, with current treatments being highly inadequate. The NLRP3 inflammasome is one member of the NOD-like receptor family with a pyrin domain, which is crucial in the innate immune defense against T. gondii. Research has shown that resveratrol (RSV) prevents lung damage caused by this infection by inhibiting the T. gondii-derived heat shock protein 70/TLR4/NF-κB pathway, thus reducing the macrophage-driven inflammatory response. However, it should be mentioned that the participation of NLRP3 inflammasome in the immune response to the lung injuries caused by T. gondii infections is not entirely clear. PURPOSE: This study aims to clarify how RSV ameliorates lung damage triggered by Toxoplasma gondii infection, with a particular focus on the pathway involving TLR4, NF-κB, and the NLRP3 inflammasome. METHODS: Both in vitro and in vivo models of infection were developed by employing the RH strain of T. gondii in BALB/c mice and RAW 264.7 macrophage cell lines. The action mechanism of RSV was explored using techniques such as molecular docking, surface plasmon resonance, ELISA, Western blot, co-immunoprecipitation, and immunofluorescence staining. RESULTS: Findings indicate that the suppression of TLR4 or NF-κB impacts the levels of proteins associated with the NLRP3 inflammasome pathway. Additionally, a significant affinity for binding between RSV and NLRP3 was observed. Treatment with RSV led to a marked reduction in the activation and formation of the NLRP3 inflammasome within lung tissues and RAW 264.7 cells, alongside a decrease in IL-1ß concentrations in the bronchoalveolar lavage fluid. These outcomes align with those seen when using the NLRP3 inhibitor CY-09. Moreover, the application of CY-09 prior to RSV negated the latter's anti-inflammatory properties. CONCLUSION: Considering insights from previous research alongside the outcomes of the current investigation, it appears that the TLR4/NF-κB/NLRP3 signaling pathway emerges as a promising target for immunomodulation to alleviate lung injury from T. gondii infection. The evidence gathered in this study lays the groundwork for the continued exploration and potential future clinical deployment of RSV as a therapeutic agent with anti-Toxoplasma properties and the capability to modulate the inflammatory response.

Emerging human pulmonary dirofilariasis in Hungary: a single center experience.

BACKGROUND: Human pulmonary dirofilariasis (HPD) is rare in Hungary, and it stems from Dirofilaria immitis, mainly transmitted through mosquito bites, with dogs as primary hosts. Despite its prevalence in veterinary settings, human cases are infrequent. Historically, Mediterranean countries report most HPD cases, but sporadic cases occur in temperate European regions. Radiologically, HPD often manifests in a non-specific manner, resembling pulmonary neoplasms, leading to unnecessary surgery and patient distress. METHODS: This study presents a notable case series from Hungary, encompassing a 12-year period, documenting 5 instances of HPD with the aim to provide baseline estimate of occurrence for future comparison. RESULTS: Among the patients studied, all were of middle age (median: 52 years, range: 37-69) and exhibited tumor-like lesions, primarily localized to the right lung, necessitating lobectomy or wedge resection. Histological examination consistently revealed a necrotizing granulomatous response characterized by remnants of helminths, without the presence of ovules. Furthermore, rigorous diagnostic procedures excluded other potential infectious agents through specialized staining techniques. Polymerase chain reaction analysis definitively confirmed the diagnosis of HPD in each case. CONCLUSIONS: This case series highlights HPD as a seldom zoonosis, with a probable escalation in its occurrence within temperate regions. Therefore, clinicians should maintain a heightened awareness of HPD in the differential diagnosis of pulmonary coin lesions. Early recognition and diagnosis are paramount for appropriate management and prevention of potential complications associated with this increasingly recognized infectious entity.

Th2-biased immune responses to body migrating Ascaris larvae in primary infection are associated with pathology but not protection.

Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae are responsible for the unequal distribution of worms in natural host populations and thus investigated a susceptible versus a resistant mouse strain. In mice, the roundworm larvae develop until the lung stage and thus early anti-Ascaris immune responses against the migrating larvae in the liver and lung can be deciphered. Our data show that susceptible C57BL/6 mice respond to Ascaris larval migration significantly stronger compared to resistant CBA mice and the anti-parasite reactivity is associated with pathology. Increased eosinophil recruitment was detected in the liver and lungs, but also in the spleen and peritoneal cavity of susceptible mice on day 8 post infection compared to resistant mice. In serum, eosinophil peroxidase levels were significantly higher only in the susceptible mice, indicating functional activity of the recruited eosinophils. This effect was associated with an increased IL-5/IL-13 production by innate lymphoid cells and CD4+ T cells and a pronounced type 2 macrophage polarization in the lungs of susceptible mice. Furthermore, a comparison of wildtype BALB/c and eosinophil-deficient dblGATA-1 BALB/c mice showed that eosinophils were not essential for the early control of migrating Ascaris larvae. In conclusion, in primary infection, a strong local and systemic type 2 immune response during hepato-tracheal helminth larval migration is associated with pathology rather than protection.

Proteomic change in the upper lobe of the left lung of Beagle dogs at the lung migration stage of Toxocara canis infection.

BACKGROUND: Toxocara canis is considered one of the most neglected parasitic zoonoses and threatens the health of millions of people worldwide with a predilection for pediatric and adolescent populations in impoverished communities. Exploring the invasion and developmental mechanisms associated with T. canis infection in its definitive canine hosts will help to better control zoonotic toxocariasis. METHODS: Proteomic changes in samples from the upper lobe of the left lung of Beagle puppies were systematically analyzed by quantitative proteomic technology of data-independent acquisition (DIA) at 96 h post-infection (hpi) with T. canis. Proteins with P-values < 0.05 and fold change > 1.5 or < 0.67 were considered proteins with differential abundance (PDAs). RESULTS: A total of 28 downregulated PDAs and 407 upregulated PDAs were identified at 96 hpi, including RhoC, TM4SFs and LPCAT1, which could be associated with the maintenance and repair of lung homeostasis. GO annotation and KEGG pathway enrichment analyses of all identified proteins and PDAs revealed that many lung proteins have correlation to signal transduction, lipid metabolism and immune system. CONCLUSIONS: The present study revealed lung proteomic alterations in Beagle dogs at the lung migration stage of T. canis infection and identified many PDAs of Beagle dog lung, which may play important roles in the pathogenesis of toxocariasis, warranting further experimental validation.

Ascaris suum infection in juvenile pigs elicits a local Th2 response in a setting of ongoing Th1 expansion.

Ascaris spp. undergo extensive migration within the body before establishing patent infections in the small intestinal tract of humans and pigs. However, whether larval migration is critical for inducing efficient type 2 responses remains poorly understood. Therefore, we investigated systemic versus local adaptive immune responses along the hepato-tracheal migration of Ascaris suum during primary, single infections in conventionally raised pigs. Neither the initial invasion of gut tissue nor migration through the liver resulted in discernable Th2 cell responses. In contrast, lung-stage larvae elicited a Th2-biased pulmonary response, which declined after the larvae had left the lungs. In the small intestine, we observed an accumulation of Th2 cells upon the arrival of fourth-stage larvae (L4) to the small intestinal lumen. In parallel, we noticed robust and increasing Th1 responses in circulation, migration-affected organs, and draining lymph nodes. Phenotypic analysis of CD4+ T cells specifically recognizing A. suum antigens in the circulation and lung tissue of infected pigs confirmed that the majority of Ascaris-specific T cells produced IL-4 (Th2) and, to a much lesser extent, IL-4/IFN-g (Th2/1 hybrids) or IFN-g alone (Th1). These data demonstrate that lung-stage but not the early liver-stage larvae lead to a locally restricted Th2 response. Significant Th2 cell accumulation in the small intestine occurs only when L4 complete the body migration. In addition, Th2 immunity seems to be hampered by the concurrent, nonspecific Th1 bias in growing pigs. Together, the late onset of Th2 immunity at the site of infection and the Th1-biased systemic immunity likely enable the establishment of intestinal infections by sufficiently large L4 stages and pre-adult worms, some of which resist expulsion mechanisms.

A single subcutaneous dose of eprinomectin (Eprecis®) is effective against common gastrointestinal nematodes and lungworms in experimentally infected lactating goats.

BACKGROUND: The health and productivity of dairy goats continue to be impacted by gastrointestinal nematodes (GIN) and lungworms (LW). Eprinomectin (EPN) is frequently selected for treatment because it is generally effective and does not require a milk withdrawal period. However, some factors, such as lactation, can have an impact on EPN pharmacokinetics and potentially its efficacy. To evaluate whether this can alter the efficacy of Eprecis® 2%, an eprinomectin injectable solution, a study was performed in lactating goats using the dose currently registered in cattle, sheep and goats (0.2 mg/kg). METHODS: This study was a blinded, randomized, controlled trial performed according to the VICH guidelines. Eighteen (18) worm-free lactating goats were included and experimentally challenged on day 28 with a mixed culture of infective gastrointestinal and lung nematode larvae (Haemonchus contortus, Trichostrongylus colubriformis, Teladorsagia circumcincta, Dictyocaulus filaria). At D-1, fecal samples were collected to confirm patent infection in all animals. On D0, the goats were randomly allocated into two groups of nine goats; group 1 was treated with Eprecis® 2% at 0.2 mg/kg BW by subcutaneous injection, while group 2 remained untreated. Fecal samples for egg counts were collected from all animals on days 3, 5, 7, 9, 11 and 14. On D14, all goats were killed, and the abomasum, small intestine and lungs were removed, processed and subsampled to record the number and species of worms. RESULTS: The treatment was well tolerated. After treatment, the arithmetic mean FEC decreased in the treated group and remained < 5 EPG until the end of the study, while the arithmetic mean FEC in the control group remained > 849.0 EPG. At D14, goats in the treated group had very limited or zero total worm counts, whereas all animals from the control group had a high worm burden. The measured efficacy was 100.0% against H. contortus and T. colubriformis, 99.9% against T. circumcincta and 98.0% against D. filaria. CONCLUSIONS: Eprinomectin (Eprecis®, 20 mg/ml), administered at the label dose (0.2 mg/kg), is highly effective against gastrointestinal nematodes and lungworms in lactating goats.

The role of cattle in the transmission of cystic echinococcosis in a highly endemic area of the Peruvian Andes.

Cystic echinococcosis (CE) causes significant losses in Andean livestock production and affects Andean food security. However, more studies are needed to understand the epidemiology of the disease. In addition, the potential contribution of Andean cattle to the transmission of Echinococcus granulosus sensu lato needs to be known. This study aimed to determine the CE-prevalence and its association with risk factors, such as age and sex of the animals, the parasite load (number of cysts/organ) of condemned organs, and the viability and fertility of Echinococcus cysts from cattle in the Andes. The prevalence was examined in 348 cattle from an authorized slaughterhouse of Huancayo at 3300 m altitude. Cyst burden was determined by extracting all cysts from the total of the CE-infected organs. Cyst fertility and protoscolices viability were analysed from 90 randomly selected CE-infected organs. The CE prevalence was 35.6% (124/348; 95% CI: 30.6%-40.6%). There was no significant effect of age and sex on CE prevalence. CE was significantly more prevalent (p < 0.05) in lungs than livers, 34.8% (121/348; 95% CI: 29.8%-39.8%) vs 8.9% (31/348; 95% CI: 5.9%-11.9%). Most (75%) infected organs had one to five cysts. The mean cyst burden was significantly (p = 0.018) higher in the lungs than livers, 6.4 ± 4.9 vs 3.7 ± 2.9. Cyst fertility was 1.6% (10/608; 95% CI: 0.6%-2.6%). Despite the high CE prevalence, infected organs from Andean cattle play a minor role in CE transmission to dogs in the central Peruvian Andes.

Interstitial macrophage phenotypes in Schistosoma-induced pulmonary hypertension.

Background: Schistosomiasis is a common cause of pulmonary hypertension (PH) worldwide. Type 2 inflammation contributes to the development of Schistosoma-induced PH. Specifically, interstitial macrophages (IMs) derived from monocytes play a pivotal role by producing thrombospondin-1 (TSP-1), which in turn activates TGF-ß, thereby driving the pathology of PH. Resident and recruited IM subpopulations have recently been identified. We hypothesized that in Schistosoma-PH, one IM subpopulation expresses monocyte recruitment factors, whereas recruited monocytes become a separate IM subpopulation that expresses TSP-1. Methods: Mice were intraperitoneally sensitized and then intravenously challenged with S. mansoni eggs. Flow cytometry on lungs and blood was performed on wildtype and reporter mice to identify IM subpopulations and protein expression. Single-cell RNA sequencing (scRNAseq) was performed on flow-sorted IMs from unexposed and at day 1, 3 and 7 following Schistosoma exposure to complement flow cytometry based IM characterization and identify gene expression. Results: Flow cytometry and scRNAseq both identified 3 IM subpopulations, characterized by CCR2, MHCII, and FOLR2 expression. Following Schistosoma exposure, the CCR2+ IM subpopulation expanded, suggestive of circulating monocyte recruitment. Schistosoma exposure caused increased monocyte-recruitment ligand CCL2 expression in the resident FOLR2+ IM subpopulation. In contrast, the vascular pathology-driving protein TSP-1 was greatest in the CCR2+ IM subpopulation. Conclusion: Schistosoma-induced PH involves crosstalk between IM subpopulations, with increased expression of monocyte recruitment ligands by resident FOLR2+ IMs, and the recruitment of CCR2+ IMs which express TSP-1 that activates TGF-ß and causes PH.

Differential protective impact of peptide vaccine formulae targeting the lung- and liver-stage of challenge Schistosoma mansoni infection in mice.

The study aimed to elicit protective immune responses against murine schistosomiasis mansoni at the parasite lung- and liver stage. Two peptides showing amino acid sequence similarity to gut cysteine peptidases, which induce strong memory immune effectors in the liver, were combined with a peptide based on S. mansoni thioredoxin peroxidase (TPX), a prominent lung-stage schistosomula excretory-secretory product, and alum as adjuvant. Only one of the 2 cysteine peptidases-based peptides in a multiple antigenic peptide construct (MAP-3 and MAP-4) appeared to adjuvant protective immune responses induced by the TPX peptide in a MAP form. Production of TPX MAP-specific IgG1 serum antibodies, and increase in lung interleukin-1 (IL-1), uric acid, and reactive oxygen species (ROS) content were associated with significant (P < 0.05) 50 % reduction in recovery of lung-stage larvae. Increase in lung triglycerides and cholesterol levels appeared to provide the surviving worms with nutrients necessary for a stout double lipid bilayer barrier at the parasite-host interface. Surviving worms-released products elicited memory responses to the MAP-3 immunogen, including production of specific IgG1 antibodies and increase in liver IL-33 and ROS. Reduction in challenge worm burden recorded 45 days post infection did not exceed 48 % associated with no differences in parasite egg counts in the host liver and small intestine compared to unimmunized adjuvant control mice. Alum adjuvant assisted the second peptide, MAP-4, in production of IgG1, IgG2a, IgG2b and IgA specific antibodies and increase in liver ROS, but with no protective potential, raising doubt about the necessity of adjuvant addition. Accordingly, different vaccine formulas containing TPX MAP and 1, 2 or 3 cysteine peptidases-derived peptides with or without alum were used to immunize parallel groups of mice. Compared to unimmunized control mice, significant (P < 0.05 to < 0.005) 22 to 54 % reduction in worm burden was recorded in the different groups associated with insignificant changes in parasite egg output. The results together indicated that a schistosomiasis vaccine able to entirely prevent disease and halt its transmission still remains elusive.

Untargeted metabolomics to discriminate liver and lung hydatid cysts: Importance of metabolites involved in the immune response.

The Echinococcus granulosus sensu lato species complex is responsible for the neglected zoonotic disease known as cystic echinococcosis (CE). Humans and livestock are infected via fecal-oral transmission. CE remains prevalent in Western China, Central Asia, South America, Eastern Africa, and the Mediterranean. Approximately one million individuals worldwide are affected, influencing veterinary and public health, as well as social and economic matters. The infection causes slow-growing cysts, predominantly in the liver and lungs, but can also develop in other organs. The exact progression of these cysts is uncertain. This study aimed to understand the survival mechanisms of liver and lung CE cysts from cattle by determining their metabolite profiles through metabolomics and multivariate statistical analyses. Non-targeted metabolomic approaches were conducted using quadrupole-time-of-flight liquid chromatography/mass spectrometry (LC-QTOF-MS) to distinguish between liver and lung CE cysts. Data processing to extract the peaks on complex chromatograms was performed using XCMS. PCA and OPLS-DA plots obtained through multiple statistical analyses showed interactions of metabolites within and between groups. Metabolites such as glutathione, prostaglandin, folic acid, and cortisol that cause different immunological reactions have been identified both in liver and lung hydatid cysts, but in different ratios. Considering the differences in the metabolomic profiles of the liver and lung cysts determined in the present study will contribute research to enlighten the nature of the cyst and develop specific therapeutic strategies.

"Cell blocking" the parasitic imposter: In a rare case of isolated pulmonary cysticercosis.

Isolated pulmonary cysticercosis is a rare manifestation of human cysticercosis which mainly affects central nervous system, skeletal muscles, eyes and subcutaneous tissues. Pulmonary involvement is usually a part of disseminated disease and mainly presents as bilateral pulmonary nodules. We report a rare case of isolated pulmonary cysticercosis presenting as lung cyst with pleural effusion. The diagnosis was made on pleural fluid cytology and cell block preparation. Herein we wish to recapitulate the importance of cell block as a diagnostic aid for parasitic infections, where morphological features and architectural patterns are as clearly discernable as in histopathology.

The Impact of Pulmonary Hydatid Cyst Rupture on COVID-19 Symptom Severity.

BACKGROUND: Co-infection with other microorganisms such as parasites in patients with COVID-19 can affect the clinical outcome and require prompt diagnosis and appropriate therapy. CASE PRESENTATION: We present a case of an adult male with chest pain, dyspnea, cough, diplopia, and anorexia who was confirmed to have acute COVID-19 pneumonia. 2 weeks prior to admission, a hydatid lung cyst was identified on examination, but the patient refused surgery. Thoracoabdominal computed tomography (CT) revealed a rupture of the lung hydatid cyst and co-infection with COVID-19. The patient has prescribed a treatment protocol for COVID-19 and albendazole. Despite measures taken to manage severe inflammation and decreasing blood oxygen levels, the patient required admission to the intensive care unit (ICU) and intubation. After approximately 3 weeks of hospitalization, the patient was successfully extubated and discharged uneventfully from the hospital. Oral albendazole was prescribed for follow-up treatment. CONCLUSION: Our case highlights the importance of considering hydatid cysts in the differential diagnosis of patients with COVID-19, especially those living in endemic areas.

Granulomatous pneumonia in a cow infected with Toxoplasma gondii.

We report a confirmed case of Toxoplasma gondii infection in the lungs of a cow exhibiting respiratory symptoms. At slaughter, white nodules were discovered in lung tissue, accompanied by enlarged hilar lymph nodes. Histological examination revealed the disappearance of alveolar structures in nodular areas, replaced by granulomas containing inflammatory cells. Immunohistochemical staining with anti-T. gondii antibody and nucleotide sequencing of 18S rDNA confirmed T. gondii infection. However, the link between T. gondii and observed symptoms remains unclear. Various factors, including host genetics, underlying diseases, infection route, and exposure level, may contribute to these uncommon symptoms. Although T. gondii infections in cattle are traditionally considered asymptomatic, our study suggests the possible existence of clinical symptoms associated with Toxoplasma infection. Beef cattle are generally not assumed to be a relevant source of human T. gondii infection; however, sporadic transmission by infected edible beef to humans cannot be completely excluded and deserves further studies.

Host gastric corpus microenvironment facilitates Ascaris suum larval hatching and infection in a murine model.

Ascariasis (roundworm) is the most common parasitic helminth infection globally and can lead to significant morbidity in children including chronic lung disease. Children become infected with Ascaris spp. via oral ingestion of eggs. It has long been assumed that Ascaris egg hatching and larval translocation across the gastrointestinal mucosa to initiate infection occurs in the small intestine. Here, we show that A. suum larvae hatched in the host stomach in a murine model. Larvae utilize acidic mammalian chitinase (AMCase; acid chitinase; Chia) from chief cells and acid pumped by parietal cells to emerge from eggs on the surface of gastric epithelium. Furthermore, antagonizing AMCase and gastric acid in the stomach decreases parasitic burden in the liver and lungs and attenuates lung disease. Given Ascaris eggs are chitin-coated, the gastric corpus would logically be the most likely organ for egg hatching, though this is the first study directly evincing the essential role of the host gastric corpus microenvironment. These findings point towards potential novel mechanisms for therapeutic targets to prevent ascariasis and identify a new biomedical significance of AMCase in mammals.

Blockage of mechanosensitive Piezo1 channel alleviates the severity of experimental malaria-associated acute lung injury.

BACKGROUND: Malaria-associated acute lung injury (MA-ALI) is a well-recognized clinical complication of severe, complicated malaria that is partly driven by sequestrations of infected red blood cells (iRBCs) on lung postcapillary induced impaired blood flow. In earlier studies the mechanosensitive Piezo1 channel emerged as a regulator of mechanical stimuli, but the function and underlying mechanism of Piezo1 impacting MA-ALI severity via sensing the impaired pulmonary blood flow are still not fully elucidated. Thus, the present study aimed to explore the role of Piezo1 in the severity of murine MA-ALI. METHODS: Here, we utilized a widely accepted murine model of MA-ALI using C57BL/6 mice with Plasmodium berghei ANKA infection and then added a Piezo1 inhibitor (GsMTx4) to the model. The iRBC-stimulated Raw264.7 macrophages in vitro were also targeted with GsMTx4 to further explore the potential mechanism. RESULTS: Our data showed an elevation in the expression of Piezo1 and number of Piezo1+-CD68+ macrophages in lung tissues of the experimental MA-ALI mice. Compared to the infected control mice, the blockage of Piezo1 with GsMTx4 dramatically improved the survival rate but decreased body weight loss, peripheral blood parasitemia/lung parasite burden, experimental cerebral malaria incidence, total protein concentrations in bronchoalveolar lavage fluid, lung wet/dry weight ratio, vascular leakage, pathological damage, apoptosis and number of CD68+ and CD86+ macrophages in lung tissues. This was accompanied by a dramatic increase in the number of CD206+ macrophages (M2-like subtype), upregulation of anti-inflammatory cytokines (e.g. IL-4 and IL-10) and downregulation of pro-inflammatory cytokines (e.g. TNF-α and IL-1ß). In addition, GsMTx4 treatment remarkably decreased pulmonary intracellular iron accumulation, protein level of 4-HNE (an activator of ferroptosis) and the number of CD68+-Piezo1+ and CD68+-4-HNE+ macrophages but significantly increased protein levels of GPX4 (an inhibitor of ferroptosis) in experimental MA-ALI mice. Similarly, in vitro study showed that the administration of GsMTx4 led to a remarkable elevation in the mRNA levels of CD206, IL-4, IL-10 and GPX-4 but to a substantial decline in CD86, TNF-α, IL-1ß and 4-HNE in the iRBC-stimulated Raw264.7 cells. CONCLUSIONS: Our findings indicated that blockage of Piezo1 with GsMTx4 alleviated the severity of experimental MA-ALI in mice partly by triggering pulmonary macrophage M2 polarization and subsequent anti-inflammatory responses but inhibited apoptosis and ferroptosis in lung tissue. Our data suggested that targeting Piezo1 in macrophages could be a promising therapeutic strategy for treating MA-ALI.

Safety of Three-Dimensional Conformal Radiotherapy on the Sheep with Pulmonary Cystic Echinococcosis: A Preliminary Study.

PURPOSE: Radiotherapy showed the potential to effectively kill the cysts of pulmonary cystic echinococcosis (CE). However, little is known about its safety. This study was designed to investigate the safety of three-dimensional conformal radiotherapy (3D-CRT) on the normal lung tissue adjacent to the cyst and blood of sheep naturally infected with pulmonary CE. METHODS: Twenty pulmonary CE sheep were randomly divided into control group (n = 5) and radiation groups with a dose of 30 Gray (Gy) (n = 5), 45 Gy (n = 5), and 60 Gy (n = 5), respectively. Animals in control group received no radiation. Heat shock protein 70 (Hsp70), tumor growth factor-ß (TGF-ß), matrix metalloproteinase-2 (MMP-2) and MMP-9 in the lung tissues adjacent to the cysts, which were considered to be closely related to the pathogenesis of CE, were evaluated after 3D-CRT. A routine blood test was conducted. RESULTS: The results showed that there were multiple cysts of various sizes with protoscoleces in the lung tissues of sheep, and necrotic cysts were found after 3D-CRT. 3D-CRT significantly increased the mRNA level of Hsp70, enhanced the protein level of TGF-ß and slightly increased the expression of MMP-2 and MMP-9 in lung tissues adjacent to the cysts. 3D-CRT did not significantly alter the amount of WBC, HB and PLT in sheep blood. CONCLUSIONS: The results suggested that 3D-CRT may suppress the inflammation and induce less damage of the normal lung tissues and blood. We preliminarily showed that 3D-CRT under a safe dose may be used to treat pulmonary CE.