scholarly journals Oral Immunization of Recombinant Lactococcus lactis and Enterococcus faecalis Expressing Dendritic Cell Targeting Peptide and Hexon Protein of Fowl Adenovirus 4 Induces Protective Immunity Against Homologous Infection

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhipeng Jia ◽  
Chunli Ma ◽  
Xuelian Yang ◽  
Xinghui Pan ◽  
Guangxing Li ◽  
...  

Hepatitis-hydropericardium syndrome (HPS) causes severe economic losses in the global poultry industry. The present study aims to explore oral immunization of recombinant Lactococcus lactis and Enterococcus faecalis expressing Hexon protein of fowl adenovirus 4 (FAdV-4). The bacteria L. lactis NZ9000 and E. faecalis MDXEF-1 were, respectively, modified as host strain to deliver truncated Hexon protein (ΔHexon) or ΔHexon protein fusing with dendritic cell (DC) targeting peptide (DC-ΔHexon) on the surface of bacteria. The expression of target protein in L. lactis NZ9000 and E. faecalis MDXEF-1 were detected by western blot. To evaluate the immune responses and protective efficacies provided by the live recombinant bacteria, chickens were immunized with the constructed ΔHexon-expressing bacteria three times at 2-week intervals, then experimentally challenged with hypervirulent FAdV-4/GX01. The results showed that oral immunizations with the four ΔHexon-expressing bacteria (NZ9000/ΔHexon-CWA, NZ9000/DC-ΔHexon-CWA, MDXEF-1/ΔHexon-CWA, and MDXEF-1/DC-ΔHexon-CWA), especially the two bacteria carrying DC-targeting peptide, stimulated higher levels of ΔHexon-specific sera IgG and secretory IgA (sIgA) in jejunal lavage fluid, higher proliferation of peripheral blood lymphocytes (PBLs) and higher levels of Th1/Th2-type cytokines, along with significantly decreased virus loads in liver and more offered protective efficacies against FAdV infection compared with PBS and empty vector control groups (p < 0.01). For chickens in the group MDXEF-1/DC-ΔHexon-CWA, the levels of aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in sera, and the virus loads in livers were significantly decreased vs. the other three ΔHexon-expressing bacteria (p < 0.01). The pathological changes in the hearts, livers, spleens and kidneys of chickens in MDXEF-1/DC-ΔHexon-CWA group were relatively slight compared to infection control group and other three ΔHexon-expressing bacteria groups. The rate of protection in MDXEF-1/DC-ΔHexon-CWA group was 90%. The present work demonstrated that cell surface-displayed target protein and immune enhancers in L. lactis and E. faecalis might be a promising approach to enhance immunity and immune efficacy against pathogen FAdV-4 infection.

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 262 ◽  
Author(s):  
Gang Li ◽  
Guanliu Yu ◽  
Yujuan Niu ◽  
Yumei Cai ◽  
Sidang Liu

Serotype 4 fowl adenovirus (FAdV-4) is the main pathogen for hydropericardium syndrome (HPS) in chickens. It has caused major economic losses in the global poultry industry. Currently, FAdV-4′s transmission routes in chickens remain unclear. Here we investigate the airborne transmission routes of FAdV-4 in chickens. A total of 45 ten-day-old chickens were equally divided into three groups (infected group/isolator A, airborne group/isolator B, and control group/isolator C). Of note, isolators A and B were connected by a leak-free pipe. The results showed that the virus could form a viral aerosol, detected in isolators two days post infection (dpi). The viral aerosol reached a peak at 4 dpi in the infected group. Healthy chickens in the airborne group were infected by the virus at 8 dpi. The chickens of the airborne group demonstrated subclinical symptoms capable of shedding the virus for some time. This finding suggests that FAdV-4 can be efficiently transmitted among chickens by aerosol transmission. These findings have significant implications for developing strategies to control this infectious disease epidemic.


Viruses ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 106 ◽  
Author(s):  
Xingyu Hou ◽  
Xinpeng Jiang ◽  
Yanping Jiang ◽  
Lijie Tang ◽  
Yigang Xu ◽  
...  

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 741
Author(s):  
Zheng Wang ◽  
Ge Yang ◽  
Biao Ren ◽  
Yuan Gao ◽  
Xian Peng ◽  
...  

The infection of Enterococcus faecalis and its interacting microorganisms in the root canal could cause persistent apical periodontitis (AP). Antibacterial root canal sealer has favorable prospects to inhibit biofilms. The purpose of this study was to investigated the antibacterial effect of root canal sealer containing dimethylaminododecyl methacrylate (DMADDM) on persistent AP in beagle dogs for the first time. Persistent AP was established by a two-step infection with Enterococcus faecalis and multi-bacteria (Enterococcus faecalis, Lactobacillus acidophilus, Actinomycesnaeslundii, Streptococcus gordonii). Root canal sealer containing DMADDM (0%, 1.25%, 2.5%) was used to complete root canal filling. The volume of lesions and inflammatory grade in the apical area were evaluated by cone beam computer tomography (CBCT) and hematoxylin-eosin staining. Both Enterococcus-faecalis- and multi-bacteria-induced persistent AP caused severe apical destruction, and there were no significant differences in pathogenicity between them. DMADDM-modified sealer significantly reduced the volume of periapical lesion and inflammatory grade compared with the control group, among them, the therapeutic effect of the 2.5% group was better than the 1.25% group. In addition, E.faecalis-induced reinfection was more sensitive to the 2.5% group than multi-bacteria reinfection. This study shows that root canal sealer containing DMADDM had a remarkable therapeutic effect on persistent AP, especially on E. faecalis-induced reinfection.


2016 ◽  
Vol 37 (4) ◽  
pp. 1919
Author(s):  
Átilla Holanda de Albuquerque ◽  
Régis Siqueira de Castro Teixeira ◽  
Débora Nishi Machado ◽  
Elisângela De Souza Lopes ◽  
Ruben Horn Vasconcelos ◽  
...  

Several cases of animal and human salmonellosis caused by the Salmonella serotype Typhimurium have been reported. In animals, subclinical infection favors pathogen dissemination through feces. In this context, the domestic pigeon (Columba livia) with an asymptomatic condition may play an important role in the transmission of salmonellosis, through the elimination of contaminated feces in commercial aviaries or in poultry feed facilities, causing economic losses to the poultry industry and presenting a risk to public health. This study aimed to evaluate the mortality, clinical signs and the presence of Salmonella Typhimurium in the feces and organs of chicks previously inoculated with bacteria isolated from a pigeon. One-day-old chicks were distributed in two experimental groups (G1 and G2) of 32 birds each, and a control group of six birds. Two inocula of 0.4 and 0.7 mL with 105 and 106 colony forming units were used in G1 and G2 birds, respectively. At 1, 4, 7 and 14 days post-inoculation (dpi) fecal samples were pooled from each cage and individual cloacal swabs were collected. At 14 dpi, all chicks were euthanized and samples were collected from the liver, spleen, lung, cecum and intestine for microbiological analysis. Mortality was only observed among G2 birds (6.25%). Most birds presented clinical signs of diarrhea at 4 dpi and no symptom as observed at 14 dpi. The results from cloacal swabs demonstrated bacterial elimination in 68.8% and 53.1% of G2 and G1 birds, respectively at 1 dpi. Additionally, fecal samples had elevated bacterial shedding in all four periods of observation , with a higher excretion at 4 dpi (62.5%) for both groups. Among G2 birds, 74.2% were positive for the pathogen in the intestine; G1 birds presented the lowest rate of lung infection (29%), and both groups had more than 50% positivity for liver and caeca. The results revealed that infected chicks with a Salmonella Typhimurium strains isolated from pigeons may host the pathogen in several organs, and simultaneously present diarrheic disorders with significant levels of bacterial excretion in feces.


PLoS ONE ◽  
2017 ◽  
Vol 12 (11) ◽  
pp. e0187718 ◽  
Author(s):  
Pui-Fong Jee ◽  
Vunjia Tiong ◽  
Meng-Hooi Shu ◽  
Jing-Jing Khoo ◽  
Won Fen Wong ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 259-259
Author(s):  
Yuhui Zheng ◽  
Shengli Li

Abstract Bovine mastitis is one of the major diseases which directly affects the milk production performance and it causes huge economic losses in the dairy industry. Bacterial infection is the main risk factor of bovine mastitis and the antibiotic therapy is the primary choice to control the disease. However, persistence use of antibiotic increases the incidence of bacterial resistance and traces of antibiotic residues in animal products. Lactobacillus casei Zhang is one of the probiotics with multiple biological functions, which has certain bacteriostatic effect on pathogenic microorganism. The purpose of this study was to explore the effect of Lactobacillus casei Zhang (L. casei Zhang) on the prevention of E. coli-induced milk-blood barrier damage. Bovine mammary epithelial cells (BMECs) were used to establish a milk-blood model and Control group (PBS), E. coli group, and L. casei Zhang pretreatment plus E. coli group were set up respectively. The results showed that: L. casei Zhang could significantly reduce the increase of LDH release caused by E. coli treatment (P< 0.05). And it can also significantly reduce the decrease of transmembrane resistance of monolayer cells caused by E. coli treatment (P< 0.05). In addition, L. casei Zhang could significantly reduce the expression of tight junction proteins ZO-1, Claudin-1, Claudin-4 and Occludin (P < 0.05). In conclusion, L. casei Zhang could effectively improve the damage of the blood-milk barrier caused by E. coli and could protect BMECs during bacterial infection.


2018 ◽  
Vol 29 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Larissa Tais Soligo ◽  
Ediléia Lodi ◽  
Ana Paula Farina ◽  
Matheus Albino Souza ◽  
Cristina de Mattos Pimenta Vidal ◽  
...  

Abstract The aim of this study was to compare the efficacy of grape seed extract (GSE), calcium hypochlorite [Ca(ClO)2], and sodium hypochlorite (NaOCl) irrigant solutions with rotary or reciprocating instrumentation for disinfection of root canals inoculated with Enterococcus faecalis. The mesiobuccal root canals of mandibular molars were prepared and inoculated with Enterococcus faecalis for 21 days. The roots were then randomly divided into the following eight experimental groups (n=11) according to the instrumentation technique and disinfection protocol: ProTaper Next or Reciproc R25 with sodium chloride (control group), 6% NaOCl, 6% Ca(ClO)2, or 50% GSE used for irrigation during instrumentation. The antimicrobial activity was determined on the basis of a reduction in colony-forming units (CFUs) counted on bacterial samples collected before and after root canal instrumentation and expressed as a percentage of reduction. Data were evaluated by two-way ANOVA followed by Tukey HSD post-hoc tests (p<0.05). No significant differences were observed in bacterial reduction between the ProTaper Next and Reciproc R25 systems (p>0.05), regardless of the irrigant solution used. Furthermore, all active solutions (6% NaOCl, 50% GSE, and 6% Ca(ClO)2) showed similar potential to reduce bacterial counts (p>0.05) and were significantly more effective than sodium chloride (control) (p<0.05). The results suggest that the GSE and Ca(ClO)2 have potential clinical application as irrigant solutions in endodontic therapy since they present bactericidal efficacy against Enterococcus faecalis.


2020 ◽  
Vol 10 (12) ◽  
pp. 4290 ◽  
Author(s):  
Nasim Chiniforush ◽  
Maryam Pourhajibagher ◽  
Steven Parker ◽  
Stefano Benedicenti ◽  
Abbas Bahador ◽  
...  

The purpose of this study was to evaluate the in vitro effect of the chlorophyllin–phycocyanin mixture (Photoactive+) as a photosensitizer (PS) during antimicrobial photodynamic therapy (aPDT) on the count of Enterococcus faecalis (E. faecalis) using different light sources. The antimicrobial effect of aPDT with chlorophyllin–phycocyanin mixture using different light sources including diode laser (λ = 660 nm), diode laser (λ = 635 nm), LED (λ = 450 ± 30 nm) alone or in combination was assessed using microbial cell viability assay against E. faecalis. In addition, the cell cytotoxicity of Photoactive+ was assessed on human gingival fibroblast (HuGu) cells by MTT assay; E. faecalis growth when treated by both red wavelengths (635 nm, 660 nm) and combination of LED (420–480 nm) and red wavelengths (635 nm, 660 nm), significantly reduced compared to the control group (p < 0.05). There was no significant reduction in the number of viable cells exposed to Photoactive+ compared to the control group (p < 0.05). This study shows that the application of chlorophyllin–phycocyanin mixture and irradiation with emission of red light achieved a better result for bacterial count reduction, compared to a control. This component can be applied safely due to very negligible cytotoxicity.


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