Lack of evidence of IgE allergic sensitisation from working with lactic acid bacteria in the dairy foods industry

This research communication aimed to evaluate the level of immunoglobulin E from lactic acid bacteria (LAB) that are used in dairy industries. Previous studies have demonstrated that workers report symptoms of irritation and are frequently IgG-sensitised to LAB. Workers (n = 44) from a probiotic production unity and the control lab were seen by a medical practitioner and responded to an occupational questionnaire. Specific IgE by the DELFIA® technique against 6 strains of LAB were measured on 44 exposed workers and 31 controls sera. Levels of specific IgE were low and no difference was observed between the two groups. This lack of IgE response could be explained by a healthy worker effect, an efficient implementation of personal protective equipment or by an absence of allergic mechanisms to account for the self-reported irritative symptoms. Despite the high concentrations of LAB, preventive measures are effective enough to guarantee no allergic effect and to prevent other adverse health effects. The implementation of preventive measures to avoid or reduce exposure to dust of LAB, and more generally to milk powder, is recommended in all dairy industry

Innate and adaptive immune responses following PD-L1 blockade in treating chronic murine alveolar echinococcosis.

BACKGROUND Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) immune checkpoint blockade is efficacious in certain cancer therapies. OBJECTIVES The present study aimed to provide a picture about the development of innate and adaptive immune responses upon PD-L1 blockade in treating chronic murine AE. METHODS Immune treatment started at 6 weeks post E. multilocularis-infection, and was maintained for 8 weeks with twice per week anti-PD-L1 administration (intraperitoneal). The study included an outgroup-control with mice perorally medicated with albendazole five days/week, and another one with both treatments combined. Assessment of treatment efficacy was based on determining parasite weight, innate and adaptive immune cell profiles, histopathology, and liver tissue cytokine levels. RESULTS/CONCLUSIONS Findings showed that the parasite load was significantly reduced in response to PD-L1 blockade, and this blockade a) contributed to T cell activity by increasing CD4+ /CD8+ effector T cells, and decreasing Tregs; b) had the capacity to re-store DCs and Kupffer cells/Macrophages; c) suppressed NKT and NK cells; and thus d) lead to an improved control of E. multilocularis infection in mice. This study suggests that the PD-L1 pathway plays an important role by regulating adaptive and innate immune cells against E. multilocularis infection, with significant modulation of tissue inflammation

Echinococcus vogeli Infection in a Hunter, French Guiana

Echinococcus vogeli infection in a hunter from the rain forest of French Guiana was confirmed by imaging and mitochondrial DNA sequence analysis. Serologic examination showed typical patterns for both alveolar and cystic echinococcosis. Polycystic echinococcis caused by E. vogeli may be an emerging parasitic disease in Central and South America

Genetic diversity of Echinococcus multilocularis specimens isolated from Belgian patients with alveolar echinococcosis using EmsB microsatellites analysis.

The genetic diversity of Echinococcus multilocularis (E. multilocularis) specimens isolated from patients with alveolar echinococcosis (AE), is a major field of investigation to correlate with sources of infection, clinical manifestations and prognosis of the disease. Molecular markers able to distinguish samples are commonly used worldwide, including the EmsB microsatellite. Here, we report the use of the EmsB microsatellite polymorphism data mining for the retrospective typing of Belgian specimens of E. multilocularis infecting humans. A total of 18 samples from 16 AE patients treated between 2006 and 2021 were analyzed through the EmsB polymorphism. Classification of specimens was performed through a dendrogram construction in order to compare the similarity among Belgian samples, some human referenced specimens on the EWET database (EmsB Website for the Echinococcus Typing) and previously published EmsB profiles from red foxes circulating in/near Belgium. According to a comparison with human European specimens previously genotyped in profiles, the 18 Belgian ones were classified into three EmsB profiles. Four specimens could not be assigned to an already known profile but some are near to EWET referenced samples. This study also highlights that some specimens share the same EmsB profile with profiles characterized in red foxes from north Belgium, the Netherlands, Luxembourg and French department near to the Belgian border. Furthermore, Belgian specimens present a genetic diversity and include one profile that don't share similarities with the ones referenced in the EWET database. However, at this geographical scale, there is no clear correlation between EmsB profiles and geographical location. Further studies including additional clinical samples and isolates from foxes and rodents of south Belgium are necessary to better understand the spatial and temporal circumstances of human infections but also a potential correlation between EmsB profiles and parasite virulence

Molecular typing of Belgian Echinococcus multilocularis specimens from alveolar echinococcosis human lesions using EmsB microsatellites analysis

peer reviewedBackground. The genetic diversity of Echinococcus multilocularis (Em) is a major field of investigations to correlate with sources of infection or variable clinical manifestations of the alveolar echinococcosis (AE). Molecular markers able to distinguish strains are already used such as EmsB microsatellites. This marker is present in about 40 copies in the Em genome. Here, we report the use of EmsB microsatellite polymorphism for the typing of Belgian specimens isolated from patients with AE between 2019 and 2020. Material and methods. Total genomic DNA was isolated from liver, pleural fluid and bile samples using a DNA extraction kit for tissue (Qiagen). The PCR was performed according to Knapp et al, 2020. The EmsB A primer was 5’-labeled with FAM-fluorochrome. Fragment size analysis was performed on an ABI3500 automatic sequencer (ThermoFisher). The fluorescence signal was detected by colorimetric reading. Correspondences were established to assess the size of the amplified fragments using Gene mapper (ThermoFisher). “R studio” was used to generate a distance matrix, calculate the Euclidian distance and obtain a UPGMA method dendrogram in order to assess the similarity among samples. The profiles obtained were compared with those included in the EWET data collection. Results Seven specimens have been successfully analyzed. According to a comparison with European samples previously characterized (Knapp et al., 2020), 3 Belgian specimens shared the same P5 genomic profile while one strain had a P8 profile. These P5 and P8 strains were included into European profiles with strains from France, Switzerland and Germany. The three other isolates could not be classified into existing profiles but were placed between P6 and P7 profiles. Five strains originated from patients living in Wallonia, the Southern part of Belgium (Namur, Hainaut and Luxembourg) while the two others originated from neighboring provinces (Walloon Brabant and Bruxelles). Conclusions The EmsB microsatellites analysis allowed to genotypically characterize Em clinical specimens isolated in Belgium for the first time. This study highlights that some samples share the same genotypic profile but that heterogenetic diversity exist in Belgium. Some profiles are unique and differ from other European profiles. Further studies including more clinical samples are ongoing

Exposure to field vs. storage wheat dust: different consequences on respiratory symptoms and immune response among grain workers.

The aim of this study was to understand the differential acute effects of two distinct wheat-related dusts, such as field or stored wheat dust handling, on workers' health and how those effects evolved at 6 month intervals. Exposure, work-related symptoms, changes in lung function, and blood samples of 81 workers handling wheat and 61 controls were collected during the high exposure season and 6 months after. Specific IgG, IgE, and precipitins against 12 fungi isolated from wheat dust were titrated by enzyme-linked immunosorbent assay, dissociation-enhanced lanthanide fluorescence immunoassay, and electrosyneresis. The level of fungi was determined in the workers' environment. Levels of exhaled fraction of nitrogen monoxide (F <sub>E</sub> NO) and total IgE were obtained. Exposure response associations were investigated by mixed logistic and linear regression models. The recent exposure to field wheat dust was associated with a higher prevalence for five of six self-reported airway symptoms and with a lower F <sub>E</sub> NO than those in the control population. Exposure to stored wheat dust was only associated with cough. No acute impact of exposure on respiratory function was observed. Exposure to field wheat dust led to workers' sensitization against the three field fungi Aureobasidum, Cryptococcus, and Phoma, although exposure to storage wheat dust was associated with tolerance. The level of Ig remained stable 6 months after exposure. The clinical picture of workers exposed to field or storage wheat dust differed. The systematic characterization of the aerosol microbial profile may help to understand the reasons for those differences

Alveolar echinococcosis in solid organ transplant recipients: a case series from two national cohorts

Alveolar echinococcosis (AE) is a severe parasitic infection caused by the ingestion of Echinococcus multilocularis eggs. While higher incidence and faster evolution have been reported in immunosuppressed patients, no studies have been performed specifically on AE in transplant patients. We searched for all de novo AE cases diagnosed between January 2008 and August 2018 in solid organ transplant (SOT) recipients included in the Swiss Transplant Cohort Study and the FrancEchino Registry. Eight cases were identified (kidney = 5, lung = 2, heart = 1, liver = 0), half of which were asymptomatic at diagnosis. AE diagnosis was difficult due to the low sensitivity (60%) of the standard screening serology (Em2+) and the frequently atypical radiological presentations. Conversely, Echinococcus Western blot retained good diagnostic performances and was positive in all eight cases. Five patients underwent surgery, but complete resection could only be achieved in one case. Moreover, two patients died of peri-operative complications. Albendazole was initiated in seven patients and was well tolerated. Overall, AE regressed in one, stabilized in three, and progressed in one case, and had an overall mortality of 37.5% (3/8 patients). Our data suggest that AE has a higher mortality and a faster clinical course in SOT recipients; they also suggest that the parasitic disease might be due to the reactivation of latent microscopic liver lesions through immune suppression. Western blot serology should be preferred in this population. Finally, surgery should be considered with caution, because of its low success rate and high mortality, and conservative treatment with albendazole is well tolerated

PLoS One

OBJECTIVE: Different phenotypes of wheezing have been described to date but not in early life. We aim to describe wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort. METHODS: We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy). RESULTS: Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa = 2.19) or 2 siblings (ORa = 2.23) compared to none, nocturnal cough (OR = 5.2), respiratory distress (OR = 4.1) and excess bronchial secretions (OR = 3.47) at two months, reflux in the child at 2 months (OR = 1.55), maternal history of asthma (OR = 1.46) and maternal smoking during pregnancy (OR = 1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR = 1.13) and paternal history of asthma (OR = 1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa = 1.9) compared to none, nocturnal cough at 2 months (OR = 1.76) and excess bronchial secretions at 2 months (OR = 1.65) were significantly associated with persistent compared to intermittent wheezing. CONCLUSION: Respiratory symptoms (cough, respiratory distress, and excessive bronchial secretion) were significantly associated with a high risk of persistent wheezing at one year. Smoking exposure during pregnancy was also a risk factor for persistent and incident wheezing