Based on the fact that mycotoxins and the food-borne bacteria coexist in the natural environment and pose a significant health hazard to humans and animals, it is important to investigate the immunosuppressive mechanism of ZEA (zearalenone), DON (deoxynivalenol), and their combination in bacterial infections. In this study, we established a mouse model of mycotoxin low-dose exposure combined with Listeria monocytogenes infection and investigated the effects of ZEA, DON and their combination on Th1-mediated anti-intracellular bacterial infection based on CD4⁺ T cell activation and differentiation using both in vitro and in vivo analyses. The present study showed that both ZEA and DON aggravated Listeria monocytogenes infection in mice and affected the activation of CD4⁺ T cells and Th1 differentiation, including the effects on costimulatory molecules CD28 and CD152 and on cross-linking of IL-12 and IL-12R, by inhibiting T cell receptor (TCR) signaling. When compared with ZEA, DON was found to have a greater impact on many related indicators. Surprisingly, the combined effects of ZEA and DON did not appear to enhance toxicity compared to treatment with the individual mycotoxins. Our findings more clearly revealed that exposure to low-dose ZEA and DON caused immunosuppression in the body by mechanisms including inhibition of CD4⁺ T cells activation and reduction of Th1 cell differentiation, thus exacerbating infection of animals by Listeria monocytogenes.

The distribution of Staphylococcus aureus and Listeria monocytogenes in the sea water and marine organisms of Peter the Great and Nha Trang bays, the phenotypic properties and antibiotic sensitivity of the isolates were studied. S. aureus was recorded from 9.3% samples in the Sea of Japan and from 20.4% samples in the South China Sea, L. monocytogenes respectively from 5.9 % and 5.8 % samples. S. aureus and L. monocytogenes found in the tropics differed in their phenotypic properties from those found in the temperate zone. Antibiotic resistance was detected in 81.8% and 71.8% of S. aureus strains and in 19% and 71.4% of L. monocytogenes strains respectively from Peter the Great Bay and from Vietnam. The results show that multiresistant strains of S. aureus and L. monocytogenes are widespread throughout Peter the Great and Nha Trang bays and present a hazard to the health of humans and marine animals.

This study aimed to evaluate possible synergistic interactions on antimicrobial and antioxidant efficacy of clove and cinnamon oil components in combination and characterization of compounds responsible for synergistic interactions using TLC bioautography followed by checkerboard titration, isobologram analysis, and spectrometric characterization. Among the combinations tested, cinnamaldehyde from cinnamon oil and eugenol from clove oil in combination showed a synergistic antimicrobial interaction against foodborne microbes Listeria monocytogenes (fractional inhibitory concentration index (FICI): 0.31), Salmonella typhimurium (FICI: 0.41), and Aspergillus niger (FICI: 0.48), and synergistic antioxidant efficacy (combination index: 0.78) in in vitro model. Cinnamaldehyde/eugenol blend did not show any cytotoxic effect (IC₅₀ > 1000 μg/ml) in human normal keratinocyte cell line. The results provide evidence that the cinnamaldehyde/eugenol blend may help in designing a more potent novel natural antimicrobial and antioxidant agent in food and pharmaceutical industries.

Listeria monocytogenes (L. monocytogenes) is frequently detected in ruminants, especially dairy cattle, and associated with the sporadic and epidemic outbreak of listeriosis in farms. In this epidemiological study, the prevalence, virulence, antibiotic resistance profiles, and genetic diversity of L. monocytogenes in three Egyptian dairy cattle farms were investigated. The risk factors associated with the fecal shedding of L. monocytogenes were analyzed. The L. monocytogenes strains from the three farms were categorized into distinct genotypes based on sampling site and sample type through enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). A total of 1896 samples were collected from animals, environments, and milking equipment in the three farms. Results revealed that 137 (7.23%) of these samples were L. monocytogenes positive. The prevalence of L. monocytogenes in the animal samples was high (32.1%), and the main environmental source of prevalent genotypes in the three farms was silage. For all sample types, L. monocytogenes was more prevalent in farm I than in farms II and III. Risk factor analysis showed seasonal variation in production hygiene. For all sample types, L. monocytogenes was significantly more prevalent in winter than in spring and summer. The level of L. monocytogenes fecal shedding was high likely because of increasing age, number of parities, and milk yield in dairy cattle. Two virulence genes, namely, hlyA & prfA, were also detected in 93 strains, whereas only one of these genes was found in 44 residual strains. Conversely, iap was completely absent in all strains. The strains exhibited phenotypic resistance to most of the tested antibiotics, but none of them was resistant to netilmicin or vancomycin. According to sample type, the strains from the animal samples were extremely resistant to amoxicillin (95.2%, 80/84) and cloxacillin (92.9%, 78/84). By comparison, the strains from the environmental samples were highly resistant to cefotaxime (86.95%, 20/23). Furthermore, 25 multi-antibiotic resistance (MAR) patterns were observed in L. monocytogenes strains. All strains had a MAR index of 0.22–0.78 and harbored antibiotic resistance genes, including extended-spectrum β-lactamase (blaCTX-M [92.7%] and blaDHA-1 [66.4%]), quinolones (qnrS [91.2%], qnrA [58.4%], parC [58.4%], and qnrB [51%]), macrolides (erm[B] [76.6%], erm(C) [1.5%], and msr(A) [27%]), trimethoprim (dfrD [65.7%]), and tetracyclines (tet(M) [41.6%], tet(S) [8%], and int-Tn [26.3%]). ERIC-PCR confirmed that the strains were genetically diverse and heterogeneous. A total of 137 isolated L. monocytogenes strains were classified into 22 distinct ERIC-PCR groups (A–V). Among them, ERIC E (10.2%) was the most prevalent group. These results indicated that environment and milking equipment served as reservoirs and potential transmission ways of virulent and multidrug-resistant L. monocytogenes to dairy animals, consequently posing threats to public health. Silage is the main environmental source of prevalent genotypes on all three farms. Therefore, hygienic measures at the farm level should be developed and implemented to reduce L. monocytogenes transmission inside dairy cattle farms.

The aim of this study was to evaluate the agricultural reuse of the digestate products (DPs) obtained from mesophilic anaerobic co-digestion of different organic wastes (sludge, cattle slurries and organic fraction of municipal solid wastes). At this scope, the content of faecal indicators and pathogens as well as the heavy metal concentration of DPs was monitored. The fertilizing performance of the DPs was also investigated. Co-digestion trials were performed using laboratory-scale (LRs) and pilot-scale reactors (PRs). The microbiological analysis of DPs showed the common presence of Salmonella and an inadequate reduction of indicator organisms during the digestion process, both in the LRs and the PRs. Moreover, the presence of pathogens (e.g. Listeria monocytogenes) in some DP samples highlighted the importance of the microbiological quality evaluation of the DPs to study the possible health risks for consumer. In several samples of DPs, the Cu, Ni and Zn contents exceeded the maximum admissible concentration for fertilizer, as specified by Italian law, suggesting possible environmental contamination if the DPs are used for agricultural purposes. Considering the fertilizing performance, significant differences of growth parameters were observed only for the DPs that were produced by LRs. In conclusion, this work can be considered as a preliminary study to evaluate the possible agricultural reuse of the digestate obtained from different organic wastes.

A combined use of silver nanoparticles (AgNPs) with different types of disinfectants as antimicrobial might be useful in mitigating the problem of development of bacterial resistance with a strong enhancement of the biocidal effect of disinfectants. To evaluate the biocidal activity of silver nanoparticles and its loaded forms, five commercial disinfectants (quaternary ammonium compounds (benzalkonium chloride (BC) and TH⁴⁺), Virkon®S, sodium hypochlorite, and hydrogen peroxide (H₂O₂)) were used against Listeria monocytogenes (L. monocytogenes) isolates at different concentrations and exposure times to reveal intra-species variability and the percentage of resistance to antimicrobial agents used. Therefore, a total of 260 specimens from animal and human stool as well as environmental samples from dairy cattle farms were cultured for isolation of L. monocytogenes. Thereafter, bacterial isolates were identified using PCR. Silver nanoparticle was synthesized using chemical reduction. Both silver nanoparticles and its loaded forms were characterized by transmission electron microscopy (TEM). The sensitivity test of 60 strains of L. monocytogenes bacteria to AgNPs and its loaded forms was evaluated using broth macrodilution method. Virkon®S/AgNPs 2.0% exhibited the highest bactericidal effect (100%) against L. monocytogenes strains followed by H₂O₂/AgNPs 5.0% and TH⁴⁺/AgNPs 1.0% (90% each). Furthermore, the percentage of resistance of L. monocytogenes was 0.0% to both H₂O₂/AgNPs 5.0% and Virkon®S/AgNPs 2.0%. In conclusion, monitoring the main source of contamination with Listeria monocytogenes in dairy cattle farms is an essential factor to achieve an efficient control. Moreover, the use of the disinfectants, Virkon®S 2.0%, H₂O₂ 5.0%, and TH⁴⁺1.0%, loaded on silver nanoparticles composite had the strong bactericidal effect against L. monocytogenes.

The selection of suitable natural raw materials in the cosmetic research and development is a key point, in order not only to obtain the expected results but also to avoid undesirable side effects. In this study, spirulina platensis, pomegranate (Punica granatum) peel, and moringa leaves alone were evaluated for anti-oxidant and antimicrobial properties. The chemical composition (moisture, dry matter, protein, lipid, and ash) and total polyphenols, flavonoids, and carotenoids content were evaluated in the three extracts. Total antioxidant capacity and ferric reducing activity power of extracts were also studied. Using agar diffusion method, the anti-Micrococcus luteus, Staphylococcus aureus, E. coli, Listeria monocytogenes, Salmonella typhimurium, and Enterococus faecalis activities were measured. Interestingly, after combinations, pomegranate peel/spirulina (A), and moringa/spirulina (B): 25%/75% and 50%/50%, we have found that pomegranate peel can be incorporated into cosmetic formulations as an excellent preservative due to its exceptionally amount of phenolic compounds, powerful antioxidant activity, and its antibacterial activity against pathogenic strains.

We used a green sol–gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger). An antimicrobial susceptibility testing of CAS was measured. Results of disc diffusion method pointed out that the diameters of the zone using well diffusion were wider than disc diffusion methods, and the findings also showed that the MIC of the CAS disinfectant against E. coli, S. enterica, and P. aeruginosa was 100 mg/L within 20 min of contact time. Meanwhile, the MIC of the CAS disinfectant was 100 mg/L within 40 min of contact time for the other strains. The efficacy of antimicrobial action (100%) reached within 20 to 40 min against all tested microbes. Herein, the antimicrobial susceptibility testing of CAS disinfectant showed no toxicity for human and bacterial cells. It can be concluded that nanoporous CAS is a promising, economically, and worthy weapon for water disinfection.

New approaches are required for prevention and control of biofilm-producing bacteria and consequently mitigating the health problems of bovine clinical mastitis. This work designed to determine prevalence rates of biofilm-producing bacteria that causing bovine clinical mastitis and evaluate the anti-biofilm effectiveness of novel nanocomposite of zinc–aluminum layered double hydroxide intercalated with gallic acid (GA) as chelating agent (Zn-Al LDH/GA) on the prevention and control of environmental pathogenic bacteria; Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus), and Coagulase-negative staphylococci (CNS), besides Listeria monocytogenes (L. monocytogenes) and assess the ability to use as an antimicrobial agent, and/or sanitizer for milking equipment. All samples (n = 230) involved clinical mastitis cow’s milk (n = 50) beside environmental samples (n = 180) were collected then examined for isolation and identification of bacterial pathogens. Zn-Al LDH/GA nanocomposite was synthesized using co-precipitation method, then characterized by Fourier-transform infrared spectroscopy (FT-IR); X-ray diffraction (XRD); field emission scanning electron microscopy (FESEM); high-resolution transmission electron microscopy (HRTEM); thermogravimetric analysis (TGA); differential thermal analysis (DTA); zeta potential; DLS analysis; and Brunauer, Emmett, and Teller (BET) surface area. The anti-biofilm activity of nanocomposite against mastitis-causing bacteria was detected using the broth micro-dilution and disc-diffusion assay. Results, the minimum concentration of Zn-Al LDH/GA that inhibited the growth of gram-positive and negative bacteria, were 312–625 and 5000 μg/mL, respectively. The LD₅₀ of Zn-Al LDH/GA was determined in mice at 1983.3 mg/kg b.wt. As a conclusion, Zn-Al LDH/GA nanocomposite proved its efficiency as an antimicrobial agent and/or sanitizer used for cleaning of milking equipment, due to it could inhibit the growth and multiplication of potentially pathogenic bacteria that causing clinical mastitis and its formation of biofilm on the milking equipment. Zn-Al LDH/GA was found to use under varying pH conditions compared with other commercial sanitizer used besides the formation of nanocomposite increases the material stability.

Wastewater stabilization ponds (WSPs) are commonly used to treat municipal wastewater in Arctic Canada. The biological treatment in the WSPs is strongly influenced by climatic conditions. Currently, there is limited information about the removal of fecal and pathogenic bacteria during the short cool summer treatment season. With relevance to public health, the objectives of this paper were to determine if treatment in arctic WSPs resulted in the disinfection (i.e., removal of fecal indicator bacteria, Escherichia coli) and removal of selected human bacterial pathogens from the treated effluent. The treatment performance, with focus on microbial removal, was assessed for the one-cell WSP in Pond Inlet (Nunavut [NU]) and two-cell WSP in Clyde River (NU) over three consecutive (2012–2014) summer treatment seasons (late June-early September). The WSPs provided a primary disinfection treatment of the wastewater with a 2–3 Log removal of generic indicator E. coli. The bacterial pathogens Salmonella spp., pathogenic E. coli, and Listeria monocytogenes, but not Campylobacter spp. and Helicobacter pylori, were detected in the untreated and treated wastewater, indicating that human pathogens were not reliably removed. Seasonal and annual variations in temperature significantly (p < 0.05) affected the disinfection efficiency. Improved disinfection and pathogen removal was observed for the two-cell system in Clyde River as compared to the one-cell system in Pond Inlet. A quantitative microbial risk assessment should be performed to determine if the release of low levels of human pathogens into the arctic environment poses a human health risk.