Co-Infection of Escherichia coli, Enterococcus faecalis and Chlamydia psittaci Contributes to Salpingitis of Laying Layers and Breeder Ducks

The pharmaceutical effect of Korean wild ginseng residue extract on the performance, microbiota quality, cytokine expression, and the ginseng saponin content of laying hen

In this study, a total of 312 Hyline brown laying hen of 1.92 ± 0.12 kg acquired at 24-wk old were employed to evaluate the pharmaceutical effect of Korean wild ginseng residue extract administered via drinking water on the performance, microbiota quality, cytokine expression, and the ginsenoside saponin (GS) content of laying hen for 12 wk. In the experiments, basic feed (CON) was compared with basic feed + 0.05% wild ginseng in drinking water (WGD1), basic feed + 0.1% wild ginseng in drinking water (WGD2), and basic feed + 0.5% wild ginseng in drinking water (WGD3). At the end of study, hen-day egg production (HDEP), average egg weight (AEW), and egg mass (EM) were linearly higher (p < 0.05) in WGD3 at wk 30 to 33, 34 to 37 wk, and the cumulative wk compared with CON. Feed conversion ratio (FCR) was linearly lower in WGD3 at 34 to 37 wk, and the cumulative wk compared with CON. Relative expression of tumor necrosis factor alpha (TNF-α) was linearly lower (p < 0.05) in the WGD3 at wk 30 to 33, and 34 to 37 wk compared with CON. The GS in egg yolk was linearly higher (p < 0.05) in laying hens supplemented the WGD3 treatment at wk 34 to 37, while the fecal microflora quantity of Lactobacillus was linearly higher (p < 0.05) in WGD3 at wk 30 to 33, till 34 to 37 wk, and Escherichia coli (E. coli) was linearly lower (p < 0.05) in the WGD2 and WGD3 from 2637 wk compared with CON. We concluded the result in HDEP, AEW, EM, and FCR were due to the increase in GS content, tentatively leading to an improvement in the TNF-α, and fecal microflora quality such as Lactobacillus and E. coli in the WGD3. We therefore recommend the use of WGD3 at application level 0.5% in drinking water for optimum laying performance from 30 to 37 wk.

Gut microbiota and serum metabolome reveal the mechanism by which TCM polysaccharides alleviate salpingitis in laying hens challenged by bacteria

This paper aimed to evaluate the effect of 3 kinds of TCM polysaccharides instead of antibiotics in preventing salpingitis in laying hens. After feeding the laying hens with Lotus leaf polysaccharide, Poria polysaccharide, and Epimedium polysaccharide, mixed bacteria (E. coli and Staphylococcus aureus) were used to infect the oviduct to establish an inflammation model. Changes in antioxidant, serum immunity, anti-inflammatory, gut microbiota, and serum metabolites were evaluated. The results showed that the 3 TCM polysaccharides could increase the expression of antioxidant markers SOD, GSH, and CAT, and reduce the accumulation of MDA in the liver; the contents of IgA and IgM in serum were increased. Decreased the mRNA expression of TLR4, NFκB, TNF-α, IFN-γ, IL1β, IL6, and IL8, and increased the mRNA expression of anti-inflammatory factor IL5 in oviduct tissue. 16sRNA high-throughput sequencing revealed that the 3 TCM polysaccharides improved the intestinal flora disturbance caused by bacterial infection, increased the abundance of beneficial bacteria such as Bacteroides and Actinobacillus, and decreased the abundance of harmful bacteria such as Romboutsia, Turicibacter, and Streptococcus. Metabolomics showed that the 3 TCM polysaccharides could increase the content of metabolites such as 3-hydroxybutyric acid and isobutyl-L-carnitine, and these results could alleviate the further development of salpingitis. In conclusion, the present study has found that using TCM polysaccharides instead of antibiotics was a feasible way to prevent bacterial salpingitis in laying hens, which might make preventing this disease no longer an issue for breeding laying hens.

Multi-omics analysis reveals the molecular regulatory network underlying the prevention of Lactiplantibacillus plantarum against LPS-induced salpingitis in laying hens

BACKGROUND

Salpingitis is one of the common diseases in laying hen production, which greatly decreases the economic outcome of laying hen farming. Lactiplantibacillus plantarum was effective in preventing local or systemic inflammation, however rare studies were reported on its prevention against salpingitis. This study aimed to investigate the preventive molecular regulatory network of microencapsulated Lactiplantibacillus plantarum (MLP) against salpingitis through multi-omics analysis, including microbiome, transcriptome and metabolome analyses.

RESULTS

The results revealed that supplementation of MLP in diet significantly alleviated the inflammation and atrophy of uterus caused by lipopolysaccharide (LPS) in hens (P < 0.05). The concentrations of plasma IL-2 and IL-10 in hens of MLP-LPS group were higher than those in hens of LPS-stimulation group (CN-LPS group) (P < 0.05). The expression levels of TLR2, MYD88, NF-κB, COX2, and TNF-α were significantly decreased in the hens fed diet supplemented with MLP and suffered with LPS stimulation (MLP-LPS group) compared with those in the hens of CN-LPS group (P < 0.05). Differentially expressed genes (DEGs) induced by  MLP were involved in inflammation, reproduction, and calcium ion transport. At the genus level, the MLP supplementation significantly increased  the abundance of Phascolarctobacterium, whereas decreased the abundance of Candidatus_Saccharimonas in LPS challenged hens (P < 0.05). The metabolites altered by dietary supplementation with MLP were mainly involved in galactose, uronic acid, histidine, pyruvate and primary bile acid metabolism. Dietary supplementation with MLP inversely regulates LPS-induced differential metabolites such as LysoPA (24:0/0:0) (P < 0.05).

CONCLUSIONS

In summary, dietary supplementation with microencapsulated Lactiplantibacillus plantarum prevented salpingitis by modulating the abundances of Candidatus_Saccharimonas, Phascolarctobacterium, Ruminococcus_torques_group and Eubacterium_hallii_group while downregulating the levels of plasma metabolites, p-tolyl sulfate, o-cresol and N-acetylhistamine and upregulating S-lactoylglutathione, simultaneously increasing the expressions of CPNE4, CNTN3 and ACAN genes in the uterus, and ultimately inhibiting oviducal inflammation.

Physcion, a novel anthraquinone derivative against Chlamydia psittaci infection

Physcion, a natural anthraquinone derivative, has been reported to exert remarkable antibacterial activities against Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa. However, it is not fully illustrated as anti-Chlamydia substance. In the present study, minimum inhibitory concentration(MIC)values for physcion against Chlamydia psittaci(C.psittaci) 6BC, C.psittaci SBL and C.psittaci HJ were 128 μg/mL,256 μg/mL and 128 μg/mL while minimum bactericidal concentration (MBC) values were 256 μg/mL,512 μg/mL and 256 μg/mL,respectively. Moreover, Chlamydial adhesion to Hela 229 cells was blocked in a dose-dependent manner and RB-to-EB differentiation was inhibited by physcion from 28 to 48 hpi.Post treatment,upregulation of LC3-II was in a dose-dependent manner, indicating physcion activated autophagy and bacterial clearance.To validate clinical efficacy,49 SPF chickens aged 21days were divided into 5 groups and infected intra-laryngeally with 0.2 mL of 1 × 10⁷ IFU/mL C.psittaci 6 BCE.Three days later, birds received orally with serial doses of physcion (4 mg/kg to 9 mg/kg), or 3 mg/kg of doxycycline for 6 days.Chickens with difficulty in breathing were alleviated significantly with increasing concentrations of physicon.Postmortem,lesions of air sacs were reduced significantly in a dose-dependent manner.More importantly,birds with 9 mg/kg of physcion could alleviate lesions of air sacs and lungs, and reduce bacterial loads in spleens, which was comparable to doxycycline treatment. Based on above evidences, physcion is a promising cost-effective natural drug by blocking Chlamydial adhesions to host cells, RB-to-EB differentiation and activating bacterial autophagy and it will be a good alternative to doxycycline combating virulent C.psittaci infection, contributing to eradication of Chlamydial transmission from animals to human beings.

Effects of salpingitis simulation on the morphology and expression of inflammatory-related genes of oviduct in laying hens

This study was conducted to simulate salpingitis of laying hens by observing the morphology and expression of inflammatory genes in the oviduct. A total of one hundred twenty 81-wk-old Roman Pink laying hens in good physical condition without the oviduct disease with an average egg production rate of 76% were fed a basal diet for 2 wks and then randomly allocated into 4 groups (6 replicates/group, 5 birds/replicate). The experimental treatments were as follows: 1) Control group (treated with PBS); 2) Organic chemical reagent (OCR) group; 3) Lipopolysaccharide (LPS) group; 4) LPS + OCR group. First, the chickens were kept upside down to make ectropion and exposure of the apertura uterinae; then prepared reagents were poured into the uterine part of the fallopian tube by using the chicken vas deferens (1 mL/layer); finally, the chickens were kept in the inverted position for 5 to 10 min. The fallopian tube samples (the magnum, isthmus, and uterus) were collected after 48 h of treatment. Compared with the control, treatment with LPS+OCR decreased (P < 0.05) the secondary villus length and primary villus area in magnum and villus length in isthmus (P < 0.05). An increase (P < 0.05) of the intervillous space of uterus was observed in LPS + OCR group compared with the control. The expressions of interleukin-6 mRNA of magnum and interferon-γ (IFN-γ) of isthmus in the LPS and LPS+OCR treatments were higher (P < 0.05) than that in control. Compared with the control, treatment with LPS+OCR increased (P < 0.05) the expressions of IFN-γ mRNA of magnum and IFN-γ, tumor necrosis factor-α and inducible nitric oxide synthase mRNA of uterus in laying hens. In conclusion, the results of morphological damage of fallopian tube tissue and increased expression of inflammatory factors in LPS + OCR treatment group suggested that LPS+OCR treatment can provide data basis to establish salpingitis model in laying hens for studying the pathogenesis of it.

Research Note: Disturbance of intracellular calcium signal in salpingitis simulation of laying hens

This study investigated whether there is disturbance of calcium signal in the simulated salpingitis of laying hens. A total of 90 Roman Pink layers (81 wk; 1.916 ± 0.17 kg) were divided into 3 groups (Control treated with PBS, 1.85 mg lipopolysaccharide (LPS)/layer as LPS group, 1.85 mg LPS/layer as LPS+organic chemical reagent (OCR) group) with 6 replicates of 5 layers. Compared with the Control, the mRNA expression of calcium/calmodulin dependent protein kinase IV (CaMK IV), sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA), and plasma membrane calcium-transporting ATPase (PMCA) were not only decreased (P < 0.05) in magnum of laying hens from LPS and LPS+OCR groups, but also in isthmus and uterus of hens from LPS+OCR group. Moreover, the mRNA expression of calcium sensing receptor (CaSR) and Orai1 in uterus from LPS+OCR group were higher (P < 0.05) than that from Control. The relative fluorescence intensity of Ca²⁺ in uterus from LPS and LPS+OCR groups were significantly higher than that from Control (P < 0.05). In conclusion, it existed that the linkage of simulated salpingitis treated with LPS+OCR and altered intracellular calcium signals in layers, which provided a new insight for alleviating salpingitis and uterine dysfunction of laying hens.

A Novel Intranasal Vaccine With PmpGs + MOMP Induces Robust Protections Both in Respiratory Tract and Genital System Post Chlamydia psittaci Infection

Chlamydia psittaci (C. psittaci) is a crucial zoonotic pathogen that causes severe respiratory and reproductive system disease in humans and animals. In our pioneer study, polymorphic membrane protein G (PmpG) mediated attachment to host cells as the adhesions and induced immunity against C. psittaci infection. We hypothesize that multiple PmpG antigens adjuvanted with Vibrio cholerae ghost (VCG) and chitosan gel might trigger full protection via the intranasal route (i.n). In the present study, 40 SPF chickens were randomly divided into four groups, including the PmpGs + MOMP group (i.n), major outer membrane protein (MOMP) group (i.n), PmpGs (Pmp17G + Pmp20G + Pmp21G) group (i.n), and control groups (VCG + chitosan gel) (i.n). Post twice immunizations, the PmpGs + MOMP group yielded highly level-specific IgG, IgA antibodies, and lymphocyte proliferation. As for cytokines, IFN-γ expression was upregulated significantly, while IL-10 concentration was downregulated in the PmpGs + MOMP group compared with other groups. Post challenge, exudate inflammations in air sacs, bacterial loads in lungs, and bacterial shedding in throat swabs were reduced significantly in the PmpGs + MOMP group. In the second experiment, 100 breeder ducks were divided into the PmpGs + MOMP group (i.n), the commercial MOMP group (via intramuscular injection, i.m), the inactivated EBs group (i.n), and the control group (i.n), 25 ducks per group. Post challenge, the reduced egg production recovered soon in the inactivated EBs group and the PmpGs + MOMP group. Moreover, the aforementioned two groups induced higher robust IgG antibodies, lymphocyte proliferation, and IFN-γ secretions than the commercial MOMP vaccine did. Postmortem, lower bacterial loads of spleens were determined in the PmpGs + MOMP group and the inactivated EBs group. However, bacterial clearance of follicular membranes and shedding from the vaginal tract were not significant differences among the three tested groups. Furthermore, the PmpGs + MOMP group induced lower inflammations in the follicles and oviducts. Based on the above evidence, the combination of PmpGs and MOMP adjuvanted with chitosan gel and VCG via intranasal route could induce full protection both in the respiratory system and genital tract post C. psittaci infection. More importantly, the combination antigens are superior to the inactivated EBs antigen due to no contamination to the environment and less genital inflammation. The combination of PmpGs + MOMP adjuvanted with VCG and chitosan gel might be a promising novel vaccine by blocking C. psittaci infection from animals to human beings.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial-resistant Enterococcus faecalis in poultry

Enterococcus faecalis (E. faecalis) was identified among the most relevant antimicrobial-resistant (AMR) bacteria in the EU for poultry in a previous scientific opinion. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9 and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with uncertain outcome. According to the assessment here performed, it is uncertain whether AMR E. faecalis can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (33-66% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that the bacterium does not meet the criteria in Sections 1, 2 and 4 (Categories A, B and D; 0-5%, 5-10% and 1-10% probability of meeting the criteria, respectively) and the AHAW Panel is uncertain whether it meets the criteria in Sections 3 and 5 (Categories C and E, 33-66% and 33-66% probability of meeting the criteria, respectively). The animal species to be listed for AMR E. faecalis according to Article 8 criteria are mostly birds of the orders Galliformes and Anseriformes, but also mammals and reptiles can serve as reservoirs.

Molecular characterization of antimicrobial resistance and virulence factors of Enterococcus faecalis from ducks at slaughterhouses

This study investigated the prevalence of antimicrobial resistant Enterococcus faecalis (E. faecalis) from ducks at slaughterhouses, analyzed antimicrobial resistance genes and virulence-associated genes of the isolates. Multilocus sequence typing (MLST) was performed to characterize their molecular characteristics. A total of 227 E. faecalis isolates (67.8%) were obtained from cecum (n = 114), cloaca (n = 50), skin (n = 59), and rinsed water (n = 4). These E. faecalis exhibited high level of resistance against tetracycline (95.6%), doxycycline (94.3%), linezolid (75.8%), erythromycin (72.2%), followed by norfloxacin (56.8%), vancomycin (38.3%), penicillin (36.1%), teicoplanin (30.8%). Lower level of resistance was found to high-level streptomycin (19.8%), imipenem (15.9%) and high-level gentamicin (5.7%). The vast majority of isolates (90.3%) were multidrug resistant (MDR). Moreover, the commonly observed resistance genes were optrA (90.7%) and ermB (90.3%), followed by aph(3’)-Ⅲ (86.8%), tetM (84.6%), acc(6’)-aph(2) (77.5%), blaZ (76.7%) and aac(6’)-Ie-aph(2”)-Ia (75.8%). The less frequently observed genes were vanC (19.8%), blaTEM (4.8%), vanM (2.6%), and vanA (0.4%). None of the strains carried aph(2”)-Ic and vanB genes. Furthermore, a high prevalence of ten virulence determinants was identified, and efaA (99.1%) was predominant, followed by eep (97.4%), srtA (96.9%), asa1 (95.6%), fsrB (92.1%), sprE (89.9%), aggA (63.9%), gelE (56.4%), esp (33.9%), and cylL (15.4%). Eleven isolates (4.9%) co-carried all of the tested virulence-associated genes. MLST analysis demonstrated that, E. faecalis isolates consisted of 12 known STs and 5 new STs, among which 6 of the identified STs were associated with nosocomial infection. Our data indicated that retail ducks serve as an important source of MDR E. faecalis with high pathogenicity potential, and suggested that transmission to humans could not be excluded.