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This study investigated whether adding Herba Houttuyniae to feed can improve intestinal function and prevent diseases for koi carp (Cyprinus carpio) infected with Aeromonas veronii. There was a total of 168 koi carp with an average body length of (9.43 ± 0.99) cm and an average body weight of (26.00 ± 11.40) g. The K group was the control group fed with basal feed, while the C group was fed with feed with a H. houttuyniae content of six per thousand. After 14 days of feeding, the fish were fasted for a day and then intraperitoneally injected with A. veronii for artificial infection, injection dose is 0.2 mL, and the concentration is 1 × 107 CFU/mL. Samples were collected from the two groups on days 0, 1, 2, and 4. The fold height, intestinal villus width, and muscle layer thickness in the gut of the koi carp were measured. In addition, on day 4, the activities of trypsin, α-amylase, and lipase in the gut were determined, and the intestinal flora of the carp in both groups was tested. The results showed that on the second and fourth days of sampling, the fold height and muscle layer thickness in the C group were significantly higher than those in the K group (P < 0.05). The villus width in the C group was slightly higher than that in the K group, but the difference was not significant (P > 0.05). Microscopic observation revealed that the intestinal structure of the carp in the C4 (day 4 in C group) group was more intact than that in the K4 (day 4 in K group) group. Moreover, the activities of trypsin, α-amylase, and lipase in the foregut and midgut in the C4 group were higher than those in the K4 group (P < 0.05). The activities of trypsin and α-amylase in the hindgut in the C4 group were higher than those in the K4 group (P < 0.05). Furthermore, beneficial bacteria, especially those in the genus Cetobacterium, were more abundant in the intestinal tract of the carp in the C4 group compared to the K group. In addition, comparisons and tests of IL-4 and IL-10 in the intestines of the fish in both groups demonstrated that the H. houttuyniae added to feed enhanced the immune function of the fish intestines after bacterial attack. In conclusion, for koi carp infected with A.veronii, adding H. houttuyniae to their feed not only improves the activity of digestive enzymes and the morphological structure of the intestine but also optimizes the beneficial intestinal microbiota, thereby protecting the intestinal tract. [ABSTRACT FROM AUTHOR]

At present, radiotherapy (RT) still acquires limited success in clinical due to the lessened DNA damage under hypoxia and acquired immune tolerance owing to the amplified programmed death ligand‐1 (PD‐L1) expression. Incredibly, intracellular PD‐L1 expression depression is proven to better sensitize RT by inhibiting DNA damage repair. However, the disability of the clinically used antibodies in disrupting the extracellular PD‐L1function still limits the effectiveness of radio‐immunotherapy. Therefore, better PD‐L1 regulation strategies are still urgently needed to better sensitize radio‐immunotherapy. Hence, for this purpose, TPP‐LND is synthesized by linking mitochondrial‐targeted triphenylphosphine cations (TPP+) to the antineoplastic agent lonidamine (LND), which significantly reduces the dose needed for LND to induce effective oxidative phosphorylation inhibition (2 vs 300 µM). Then, TPP‐LND is wrapped with liposomes to form TPP‐LND@Lip nanoparticles. By doing this, TPP‐LND@Lip nanoparticles can sensitize RT by reversing the hypoxic microenvironment of tumors to generate more DNA damage and reducing the expression of PD‐L1 via enhancing the adenosine 5′‐monophosphate‐activated protein kinase activation. As expected, these well‐designed economical TPP‐LND@Lip nanoparticles are more effective than conventional anti‐PD‐L1 antibodies to some extent. [ABSTRACT FROM AUTHOR]

Providencia rettgeri infection has occurred occasionally in aquaculture, but is rare in turtles. Here, a pathogenic P. rettgeri strain G0519 was isolated from a diseased slider turtle (Trachemys scripta) in China, and qPCR assay was established for the RTX toxin (rtxD) gene. Histopathological examination showed that many inflammatory cells were infiltrated into heart, liver and intestine, as well as the necrosis of liver, kidney and spleen. The genome consisted of one circular chromosome (4.493 Mb) and one plasmid (18.8 kb), and predicted to contain 4170 and 19 protein-coding genes, respectively. Multiple pathogenic and virulence factors (e.g., fimbria, adhesion, invasion, toxin, hemolysin, chemotaxis, secretion system), multidrug-resistant genes (e.g., ampC, per-1, oxa-1, sul1, tetR) and a novel genomic resistance island PRI519 were identified. Comparative genome analysis revealed the closest relationship was with P. rettgeri, and with P. heimbachae closer than with other Providencia spp. To our knowledge, this was first report on genomic characterization of multidrug-resistant pathogenic P. rettgeri in cultured turtles. [ABSTRACT FROM AUTHOR]