Predicting the immunomodulatory activity of probiotic lactic acid bacteria using supervised machine learning in a Cornu aspersum snail model.

In the process of screening for probiotic strains, there are no clearly established bacterial phenotypic markers which could be used for the prediction of their in vivo mechanism of action. In this work, we demonstrate for the first time that Machine Learning (ML) methods can be used for accurately predicting the in vivo immunomodulatory activity of probiotic strains based on their cell surface phenotypic features using a snail host-microbe interaction model. A broad range of snail gut presumptive probiotics, including 240 new lactic acid bacterial strains (Lactobacillus, Leuconostoc, Lactococcus, and Enterococcus), were isolated and characterized based on their capacity to withstand snails' gastrointestinal defense barriers, such as the pedal mucus, gastric mucus, gastric juices, and acidic pH, in association with their cell surface hydrophobicity, autoaggregation, and biofilm formation ability. The implemented ML pipeline predicted with high accuracy (88 %) strains with a strong capacity to enhance chemotaxis and phagocytic activity of snails' hemolymph cells, while also revealed bacterial autoaggregation and cell surface hydrophobicity as the most important parameters that significantly affect host immune responses. The results show that ML approaches may be useful to derive a predictive understanding of host-probiotic interactions, while also highlighted the use of snails as an efficient animal model for screening presumptive probiotic strains in the light of their interaction with cellular innate immune responses.

Interventional Study of Nonpharmaceutical Measures to Prevent COVID-19 Aboard Cruise Ships.

Cruise ships carrying COVID-19-vaccinated populations applied near-identical nonpharmaceutical measures during July-November 2021; passenger masking was not applied on 2 ships. Infection risk for masked passengers was 14.58 times lower than for unmasked passengers and 19.61 times lower than in the community. Unmasked passengers' risk was slightly lower than community risk.

Randomized, placebo-controlled, double-blinded study of prophylactic cranberries use in women with recurrent uncomplicated cystitis.

BACKGROUND: Τhe adherence of p-fimbriated Escherichia coli (E. coli) to urothelial cells leading to recurrent urinary tract infections (rUTIs) may be prevented by proanthocyanidins (PACs) contained in American cranberries. PURPOSE: The purpose of this clinical trial was to assess the clinical utility of prophylactic use of high-dose PACs daily in women with a history of rUTIs. MATERIALS AND METHODS: 172 adult women with a history of rUTIs, defined as ≥ 2 within a 6-month period or ≥ 3 within a 12-month period were enrolled and randomized in two groups to receive either Cysticlean™ 240 mg or placebo for a 12-month period. Urine samples, vaginal and rectal swabs were collected at initial and quarterly study visits. The primary study endpoints were the number of urinary tract infections (UTIs) and changes in Quality of Life (QoL), assessed by the 36-Item Short Form Survey (SF-36) questionnaire. RESULTS: 160 adult women of median age 40 years old (range 19-82) were finally analyzed in this randomized, placebo-controlled, double-blinded clinical trial. In response to intervention, the number of UTIs was significantly lower (Incidence rate ratio IRR 0.49, p < 0.001) and QoL was slightly improved. The numbers of E. coli isolates detected in vaginal (IRR 0.71, p value < 0.001) and in rectal swabs (IRR 0.87, p value < 0.001) were also significantly decreased. No adverse events were reported. CONCLUSION: The daily use of Cysticlean™ 240 mg was associated with a reduction of UTIs and a prolongation of UTI-free survival compared to placebo treatment, supporting its use as prophylaxis in this patient population. TRIAL REGISTRATION: Clinicaltrials.gov, identifier NCT03032003.

Does tourism affect the long term course of COVID-19 pandemic in a country of destination? Evidence from a popular Greek island in 2020 where control measures were implemented.

Greece opened its points of entry on July 1, 2020, with specific guidelines for travellers arriving by sea, air or land. The aim of this article is to examine the effect of tourism on the long term course of the Coronavirus Disease 2019 (COVID-19) pandemic during the pre-vaccination era (June to December 2020) on the popular Greek island of Crete. To achieve this, a cross-sectional serosurvey, repeated at monthly intervals, was conducted to compare the seroprevalence in Crete with seroprevalence in the mainland of Greece. Crete welcomed nearly 2,000,000 travellers during the 2020 summer season. Left-over serum samples were collected and obtained from public and private laboratories located in Greece, including the island of Crete. These samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies. A total of 55,938 samples were collected, 3,785 of which originated from Crete. In Crete, the seroprevalence ranged between 0% (June 2020) and 2.58% (December 2020), while the corresponding seroprevalence in Greece was 0.19% and 10.75%, respectively. We identified 4.16 times lower seropositivity in Crete (2.58%) in comparison with the mainland of Greece (10.75%) during December 2020. Moreover, the monthly infection fatality rate (IFR) in Crete was calculated at 0.09%, compared with 0.21% in mainland Greece for December 2020. The island of Crete presented more than four times lower seroprevalence than the mainland of Greece, despite being a highly attractive tourist destination. This evidence supports the idea that tourism may not have affected the long term course of the COVID-19 pandemic in Greece. However, due to contradicting results from previous studies, further investigation is needed.

Dynamics of Anti-SARS-CoV-2 IgA and IgG Responses and Their Protective Effect against Fatal Disease after Booster COVID-19 Vaccination.

During the post-coronavirus disease (COVID-19) era, a primary question is whether booster vaccination is effective against severe COVID-19 and should be recommended, particularly to individuals at high risk for severe disease (i.e., the elderly or those with additional severe comorbidities). From December 2020 to February 2023, a cohort study was conducted to estimate IgG and IgA immunogenicity and the dynamics of booster mono- and bivalent COVID-19 mRNA vaccines in 260 individuals (male/female: 114/146, median age: 68 years, interquartile range (IQR) = 31) who initially received either mRNA (218) or adenovirus-vector-based vaccines (42). Participants were followed until the 90th day after the third booster dose. Our cohort study indicated a beneficial effect of booster vaccination on the magnitude of IgG and IgA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. We found that second and third booster doses were more protective than one against fatal disease (p = 0.031, OR 0.08). In conclusion, booster COVID-19 vaccination should be strongly recommended, especially to individuals at high risk for severe/fatal disease.