Effect of COVID-19 isolation measures on physical activity of children and their parents, and role of the family environment: a cross-sectional study.

Background: The rigorous isolation measures due to the COVID-19 pandemic seriously impacted children's lifestyles. A descriptive cross-sectional study was carried out to collect and analyze information about physical activity habits of children and their parents during the social distancing period resulting from the COVID-19 pandemic. Methods: An online questionnaire was administered to 363 families (507 children aged 5-13) recruited by convenience sampling, asking for physical activity type and frequency before, during, and after the lockdown period (9th March - May 3rd 2020), education, outdoor spaces, and children's weight gain perception. Results: Results show a remarkable decrease in children's physical activity during lockdown (88.9 vs 39.8% active children) associated with older age and low availability of outdoor spaces (p<0.001). Parents' physical activity was related to educational level, and a slight but significant correlation between parents' education and children's physical activity was found, especially with father's university degree (p<0.05). Active mothers significantly influenced children's physical activity during the lockdown, especially if not engaged in smart working. The return to an active lifestyle by children did not reach previous levels (75.9% active children) and was directly related to parent's physical activity. Finally, the risk of weight gain was lower in active children during the lockdown (OR = 0.46; p<0.001). Conclusions: This work highlights the importance of physical activity during a pandemic event to prevent the risk of gaining weight, and underlines the relevance of the entire family system as a source of promotion of healthy behaviors in children.

A multiplex magnetic capture hybridization and multiplex Real-Time PCR protocol for pathogen detection in seafood.

Seafood could become a source of bacterial pathogens by exposure to contaminated water or through processing practices, thus representing a public health hazard. Conventional culture-based analytical methods take several days to be completed, while the molecular rapid identification of bacterial pathogens is crucial for effective disease control. The developed application consist of a multiplex magnetic capture hybridisation (mMCH) assay for the simultaneous isolation of Salmonella spp. and Listeria monocytogenes DNA from seafood, using paramagnetic amino-modified nanoparticles with capture oligonucleotides, and a triplex Real-Time PCR with an Internal Amplification Control (IAC), in accordance with ISO 22174. The detection probability was 100% with 10 genome equivalents of each target species co-amplified in the same reaction. The complete molecular procedure was tested on raw and smoked salmon fillets artificially contaminated with known amounts of one or both target bacteria (1-10(3)cfu/g), directly or after culture enrichment, and compared for equivalence with the standard methods. Results revealed a complete agreement between the two approaches, with a sensitivity of 1 cfu/g, in enriched samples, and higher sensitivity (10(2)-10(3)cfu/g) of the molecular method in samples examined before culture enrichment. The proposed procedure was also able to identify a natural contamination by L. monocytogenes in smoked salmon with a considerable shortening of time.

Development of a multiplex PCR assay for Photobacterium damselae subsp. piscicida identification in fish samples.

A multiplex polymerase chain reaction protocol for the detection of Photobacterium damselae and subspecies piscicida and damselae discrimination, with internal amplification control, was developed. Assay specificity was assessed by testing 19 target and 25 non-target pure cultures. The detection limit was 500 fg, corresponding to 100 genome equivalents. The optimized protocol was also prevalidated with spleen, kidney and blood samples from infected and uninfected sea bass, without any culture step, and it can be proposed as a valid alternative to culture standard methods for the rapid and specific diagnosis of photobacteriosis in fish.

A combination of diagnostic tools for rapid screening of ovine listeriosis.

A combined serological and PCR method for the detection of Listeria monocytogenes infection in symptomatic and asymptomatic ovine flocks was evaluated. Seventy-eight milk samples and 157 serum samples were analysed using a L. monocytogenes PCR detection kit and an anti-listeriolysin O IgG immunoassay kit. The combined use of these commercial kits allowed a rapid and effective detection of L. monocytogenes infection in both the early stage, before seroconversion, and in a later phase, even after antibiotic therapy.

Development of a magnetic capture hybridization-PCR assay for Listeria monocytogenes direct detection in milk samples.

AIMS: A rapid and sensitive method for Listeria monocytogenes direct detection from milk was developed. It is based on a magnetic capture hybridization procedure for selective DNA purification, followed by PCR identification. A comparison with two similar commercial systems from Dynal (Dynabeads) was carried out. METHODS AND RESULTS: The technique used previously developed nanoparticles modified with a 21-mer oligonucleotide. This sequence, sharing homology with all the L. monocytogenes strains, was selected on hlyA gene and located outside the desired specific PCR site to avoid cross-contaminations. Capture probe properties, in term of spacer length and purification, were determined to obtain the highest hybridization efficiency. Its specificity was tested in hybridization experiments with nontarget bacterial species. Any inhibitory effect of the nanoparticles on PCR was also examined. The amplification performed with the purified DNA could reliably identify a 10 CFU ml(-1) contamination rate. CONCLUSIONS: The optimized purification method showed a high specificity and sensitivity, with a detection level one log more sensitive than PCR carried out with nucleic acids obtained using commercial nanoparticles. SIGNIFICANCE AND IMPACT OF THE STUDY: The method, avoiding pre-enrichment, provides a rapid alternative to conventional microbiological detection methods. Furthermore, it is suitable for automation and can be proposed for the screening of a large number of samples.

Antifungal activity of Brassica oleracea var. botrytis fresh aqueous juice.

The antifungal activity of fresh, aqueous Brassica oleracea var. botrytis juice against Candida albicans and other pathogenic fungi was investigated. The juice was found to be effective both in inhibiting the growth of blastoconidia and reducing the appearance of C. albicans germ tubes. Furthermore, the juice inhibited the growth of some pathogenic, filamentous fungi.

Evaluation of the environmental impact of microbial aerosols generated by wastewater treatment plants utilizing different aeration systems.

Using three sampler devices (SAS, Andersen Six-Stages and All Glass Impinger), the environmental impact of bacterial and fungal aerosols generated by municipal wastewater treatment plants operating with different methods of sludge oxygenation were evaluated. The highest microbial concentrations were recovered above the tanks (2247 cfu m-3) and in downwind positions (1425 cfu m-3), where a linear correlation (P < 0.05) was found between the quantity of sewage treated and the entities of microbial aerosol dispersion. Moreover, an exponential increase (P < 0.05) in the bacteria recovered from the air occurred at increasing times of treatment. However, after long-term plant operation, high bacterial and fungal concentrations were found in almost all of the sites around the plant. Coliforms, enterococci, Escherichia coli and staphylococci were almost always recovered in downwind positions. Considerable fractions (20-40%) of sampled bacteria were able to penetrate the final stages of the Andersen apparatus and thus, are likely to be able to penetrate the lungs. The plant operating with a fine bubble diffused air system instead was found to generate rather low concentrations of bacteria and fungi; moreover, staphylococci and indicator micro-organisms were almost absent. Finally, salmonellae, Shigella, Pseudomonas aeruginosa and Aeromonas spp. were not detected in either of the plants. The results indicate a remarkable dispersion of airborne bacteria and fungi from tanks in which oxygen is supplied via a mechanical agitation of sludge, and suggest the need to convert them to diffused aeration systems which pose a lesser hazard for human health.

Increased microbicidal activity of human monoblastoid cells upon long-term exposure to dideoxycytidine.

2',3'-Dideoxycytidine (ddC) is a nucleoside analogue currently used in AIDS therapy. We had previously found that long term exposure of U937 human monoblastoid cells to ddC induces the selection of drug-resistant cells (U937-R). In the present work we investigated some important biochemical properties and functional activities of these resistant cells. The results obtained show that U937-R maintained the properties of cell aggregation, adhesion and differentiation. Basal respiration, protein kinase C activity, superoxide anion release and intracellular free calcium were all increased in the drug-resistant line. Phagocytosis of fungi (Candida albicans) and bacteria (Staphylococcus aureus and Salmonella anatum) were similar in U937 and U937-R cells. Killing of C. albicans was significantly higher in drug-resistant cells (29.07 +/- 2.23% of killing vs 19.07 +/- 2.01 in the control; p < 0.001). Similarly, the bacterial killing was enhanced in U937-R cells (34.07 +/- 8.06% vs 22.60 +/- 4.41% in the control; p < 0.05). Thus, the results presented in this paper provide evidence of an increased microbicidal activity of human monocytic cells upon long term exposure to ddC, most likely due to an increased oxidative metabolism.