Maternal Phlorizin Intake Protects Offspring from Maternal Obesity-Induced Metabolic Disorders in Mice via Targeting Gut Microbiota to Activate the SCFA-GPR43 Pathway.

Maternal obesity increases the risk of obesity and metabolic disorders (MDs) in offspring, which can be mediated by the gut microbiota. Phlorizin (PHZ) can improve gut dysbiosis and positively affect host health; however, its transgenerational metabolic benefits remain largely unclear. This study aimed to investigate the potential of maternal PHZ intake in attenuating the adverse impacts of a maternal high-fat diet on obesity-related MDs in dams and offspring. The results showed that maternal PHZ reduced HFD-induced body weight gain and fat accumulation and improved glucose intolerance and abnormal lipid profiles in both dams and offspring. PHZ improved gut dysbiosis by promoting expansion of SCFA-producing bacteria, Akkermansia and Blautia, while inhibiting LPS-producing and pro-inflammatory bacteria, resulting in significantly increased fecal SCFAs, especially butyric acid, and reduced serum lipopolysaccharide levels and intestinal inflammation. PHZ also promoted intestinal GLP-1/2 secretion and intestinal development and enhanced gut barrier function by activating G protein-coupled receptor 43 (GPR43) in the offspring. Antibiotic-treated mice receiving FMT from PHZ-regulated offspring could attenuate MDs induced by receiving FMT from HFD offspring through the gut microbiota to activate the GPR43 pathway. It can be regarded as a promising functional food ingredient for preventing intergenerational transmission of MDs and breaking the obesity cycle.

Florfenicol Enhances Colonization of a Salmonella enterica Serovar Enteritidis floR Mutant with Major Alterations to the Intestinal Microbiota and Metabolome in Neonatal Chickens.

Florfenicol is an important antibiotic commonly used in poultry production to prevent and treat Salmonella infection. However, oral administration of florfenicol may alter the animals' natural microbiota and metabolome, thereby reducing intestinal colonization resistance and increasing susceptibility to Salmonella infection. In this study, we determined the effect of florfenicol (30 mg/kg of body weight) on gut colonization of neonatal chickens challenged with Salmonella enterica subsp. enterica serovar Enteritidis. We then analyzed the microbial community structure and metabolic profiles of cecal contents using microbial 16S amplicon sequencing and liquid chromatography-mass spectrometry (LC-MS) untargeted metabolomics, respectively. We also screened the marker metabolites using a multi-omics technique and assessed the effect of these markers on intestinal colonization by S. Enteritidis. Florfenicol administration significantly increased the loads of S. Enteritidis in cecal contents, spleen, and liver and prolonged the residence of S. Enteritidis. Moreover, florfenicol significantly affected cecal colony structures, with reduced abundances of Lactobacillus and Bacteroidetes and increased levels of Clostridia, Clostridium, and Dorea. The metabolome was greatly influenced by florfenicol administration, and perturbation in metabolic pathways related to linoleic acid metabolism (linoleic acid, conjugated linoleic acid [CLA], 12,13-EpOME, and 12,13-diHOME) was most prominently detected. We screened CLA and 12,13-diHOME as marker metabolites, which were highly associated with Lactobacillus, Clostridium, and Dorea. Supplementation with CLA maintained intestinal integrity, reduced intestinal inflammation, and accelerated Salmonella clearance from the gut and remission of enteropathy, whereas treatment with 12,13-diHOME promoted intestinal inflammation and disrupted intestinal barrier function to sustain Salmonella infection. Thus, these results highlight that florfenicol alters the intestinal microbiota and metabolism of neonatal chickens and promotes Salmonella infection mainly by affecting linoleic acid metabolism. IMPORTANCE Florfenicol is a broad-spectrum fluorine derivative of chloramphenicol frequently used in poultry to prevent/treat Salmonella. However, oral administration of florfenicol may lead to alterations in the microbiota and metabolome in the chicken intestine, thereby reducing colonization resistance to Salmonella infection, and the possible mechanisms linking antibiotics and Salmonella colonization in poultry have not yet been fully elucidated. In the current study, we show that increased colonization by S. Enteritidis in chickens administered florfenicol is associated with large shifts in the gut microbiota and metabolic profiles. The most influential linoleic acid metabolism is highly associated with the abundances of Lactobacillus, Clostridium, and Dorea in the intestine. The screened target metabolites in linoleic acid metabolism affect S. Enteritidis colonization, intestinal inflammation, and intestinal barrier function. Our findings provide a better understanding of the susceptibility of animal species to Salmonella after antibiotic intervention, which may help to elucidate infection mechanisms that are important for both animal and human health.

Enrofloxacin Shifts Intestinal Microbiota and Metabolic Profiling and Hinders Recovery from Salmonella enterica subsp. enterica Serovar Typhimurium Infection in Neonatal Chickens.

Enrofloxacin is an important antibiotic used for prevention and treatment of Salmonella infection in poultry in many countries. However, oral administration of enrofloxacin may lead to the alterations in the microbiota and metabolome in the chicken intestine, thereby reducing colonization resistance to the Salmonella infection. To study the effect of enrofloxacin on Salmonella in the chicken cecum, we used different concentrations of enrofloxacin to feed 1-day-old chickens, followed by oral challenge with Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium). We then explored the distribution pattern of S. Typhimurium in cecum contents in vivo and analyzed the microbial community structure of cecum contents using microbial 16S amplicon sequencing. Untargeted metabolomics was used to explore the gut metabolome on day 14. Faecalibacterium and Anaerostipes, which are closely related to the chicken intestinal metabolome, were screened using a multi-omics technique. The abundance of S. Typhimurium was significantly higher in the enrofloxacin-treated group than in the untreated group, and S. Typhimurium persisted longer. Moreover, the cecal colony structures of the three groups exhibited different characteristics, with Lactobacillus reaching its highest abundance on day 21. Notably, S. Typhimurium infection is known to affect the fecal metabolome of chickens differently. Thus, our results suggested that enrofloxacin and Salmonella infections completely altered the intestinal microbiota and metabolism of chickens.IMPORTANCE In this study, we examined the effects of S. Typhimurium infection and enrofloxacin treatment on the microbiota and metabolite synthesis in chicken cecum, in order to identify target metabolites that may promote S. Typhimurium colonization and aggravate inflammation and to evaluate the important microbiota that may be associated with these metabolites. Our findings may facilitate the use of antibiotics to prevent S. Typhimurium infection.

Simultaneous and visual detection of infectious bronchitis virus and Newcastle disease virus by multiple LAMP and lateral flow dipstick.

Infectious bronchitis virus (IBV) and Newcastle disease virus (NDV) are both important viruses seriously affecting poultry industry worldwide. In this study, reverse-transcription LAMP (RT-LAMP) was combined with lateral flow dipstick (LFD) forming a novel detection tool which could simultaneously detect IBV and NDV visually. Primers targeted the 5'-untranslated region (5'-UTR) of IBV genome and the conserved region of NDV large polymerase gene (LP). The specificity and sensitivity of this multiple reverse transcription-LAMP-LFD (mRT-LAMP-LFD) assay were compared with those of conventional RT-PCR, nested RT-PCR (nRT-PCR), quantification RT-PCR (qRT-PCR), and RT-LAMP monitored by electrophoresis. No non-specific amplifications were observed when the assays were tested with unrelated viruses. According to the sensitivity study, when detecting IBV or NDV alone, the lowest detection limits of mRT-LAMP-LFD were 100.8 IBV RNA copies/reaction and 100.7 NDV RNA copies/reaction. Furthermore, when detecting IBV and NDV simultaneously, the lowest detection limit was the same as that of the single detection assays. In the clinical sample study, mRT-LAMP-LFD performed the best among these assays. When tested with IBV or NDV single infected samples, the mean detection rates were 98.65% and 97.25%, respectively. In the IBV and NDV co-infected sample study, the mean detection rates of IBV and NDV were both 95%. This study showed that mRT-LAMP-LFD was a promising qualitative detection tool suitable for field single or multiple IBV and NDV detection.

A loop-mediated isothermal amplification coupling with a lateral flow dipstick for rapid and specific detection of fowl adenovirus serotype-4.

Fowl adenovirus serotype-4 (FAdV-4) has been recognized as a predominant threat to the broilers aged from three to five weeks. Hydropericardium syndrome (HPS) is one of its major clinical diseases by FAdV-4 resulting in heavy economic losses. In this study, a loop-mediated isothermal amplification coupling with a lateral flow dipstick (LAMP-LFD) was developed for rapid and specific detection of fowl adenovirus serotype-4. The optimized LAMP-LFD can be completed in 60 min at 65 °C. The minimum detection limits of PCR, real-time PCR, nested PCR and LAMP-LFD are 1 × 104 copies/µl, 1 × 102 copies/µl, 10 copies/µl and 10 copies/µl respectively. Moreover, the specificity of the LAMP-LFD assay is satisfactory and does not produce cross reactions with other species. In field samples, 150 samples were assayed by PCR and LAMP-LFD. They agreed on the diagnosis "positive" in 13% of clinical samples, and they agreed on the diagnosis "negative" in 85% of clinical samples. Their probability of agreement is p0 = 147/150 = 13% + 85% = 98%. LAMP-LFD can potentially be modified and applied as a diagnostic tool for FAdV-4 infection especially in resource-limited areas, such as small breeding farms and basic veterinary labs to offer an affordable diagnostic.

Construction and Immunogenicity of Novel Chimeric Virus-Like Particles Bearing Antigens of Infectious Bronchitis Virus and Newcastle Disease Virus.

Infectious bronchitis virus (IBV) and Newcastle disease virus (NDV) are two poultry pathogens seriously affecting the poultry industry. Here, IBV S1 and the ectodomain of NDV F proteins were separately linked with the trans-membrane and carboxy-terminal domain of IBV S protein (STMCT), composing rS and rF; thus, a novel chimeric infectious bronchitis-Newcastle disease (IB-ND) virus-like particles (VLPs) vaccine containing the rS, rF, and IBV M protein was constructed. Under the transmission electron microscope (TEM), VLPs possessing similar morphology to natural IBV were observed. To evaluate the immunogenicity of chimeric IB-ND VLPs, specific pathogen-free (SPF) chickens were immunized with three increasing doses (50, 75, and 100 µg protein of VLPs). Results of ELISAs detecting IBV and NDV specific antibodies and IL-4 and IFN-γ T cell cytokines indicated that vaccination with chimeric IB-ND VLPs could efficiently induce humoral and cellular immune responses. In the challenge study, chimeric IB-ND VLPs (100 µg protein) provided 100% protection against IBV or NDV virulent challenge from death, and viral RNA levels in tissues and swabs were greatly reduced. Collectively, chimeric IB-ND VLPs are highly immunogenic and could provide complete protection from an IBV or NDV virulent challenge. Chimeric IB-ND VLPs are an appealing vaccine candidate and a promising vaccine platform bearing multivalent antigens.

An IncX1 plasmid isolated from Salmonella enterica subsp. enterica serovar Pullorum carrying blaTEM-1B, sul2, arsenic resistant operons.

We have identified an IncX1 plasmid named pQJDSal1 from Salmonella enterica subsp. enterica serovar Pullorum (S. Pullorum). The plasmid is 67,685 bp in size and has 72 putative genes. pQJDSal1 harbors a conserved IncX1-type backbone with predicted regions for conjugation, replication and partitioning, as well as a toxin/antitoxin plasmid addiction system. Two regions (A and B) that have not been previously reported in IncX1 plasmids are inserted into the backbone. Region A (10.7 kb), inserted between parA and taxD, consists of a new Tn6168-like transposon containing an arsenic resistant operon arsB2CHR and sulfonamide resistance gene sul2. Region B contains another arsenic resistant operon arsADHR, resistance gene blaTEM-1B and three transposable elements. Conjugation experiments showed that pQJDSal1 could transfer from S. Pullorum to Escherichia coli (E. coli) J53. Statistical analysis of 70 sequenced IncX1 plasmids revealed that IncX1 plasmids harbored various antibiotic resistance genes. The results highlight the importance of IncX1 plasmids in disseminating antibiotic resistance genes.

Distribution of Salmonella Enteritidis in internal organs and variation of cecum microbiota in chicken after oral challenge.

The aim study was to explore the distribution of Salmonella Enteritidis (S. enteritidis) in internal organs and variation of cecum microbiota in newly hatched chicken after oral challenge during a 21-day period. The quantities of S. enteritidis DNA in different internal organs (heart, liver, spleen, stomach, pancreas, small intestine, blood and cecum contents) were determined by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). The result showed that all of the above-mentioned samples were positive at 12 h post inoculation (PI) after oral challenge. The highest copy numbers of S. enteritidis in all tissue were heart and liver, with about 2 × 102 to 6 × 106 copies of DNA target sequences/0.5 g. The copy number of S. enteritidis in the stomach was only lower than the heart and liver. The blood at 8 d PI, the pancreas at 10 d PI, the heart at 14 d PI and the stomach at 17 d PI didn't have a positive result. However, the liver, spleen, cecum contents and small intestine were all positive during the 21-day period. The cecum contents at 0 d PI, 4 d PI and 10 d PI from the control group and experiment group were collected for bacterial 16 S rRNA sequencing targeting the V3-V4 hypervariable region. The result showed that at the 0 d PI, the main cecum microbiota ingredient of the two-day old chicken was Enterobacteriaceae (Proteobacteria) and the other microbiology species were fewer. At the 10 d PI, the microbiota ingredient of cecum became abundant and stable mainly including the families Ruminococcaceae (Firmicutes), Enterobacteriaceae (Proteobacteria), Lachnospiraceae (Firmicutes) and clostridiacaea (Firmicutes) both of the two group, suggesting Salmonella infection with 2-day old chicken might not significantly change cecum microbiota community. The study indicated the major organs, which carried numerous S. enteritidis, providing a significantly guideline for salmonella detection in poultry and revealed the main microbiota ingredient of chicken cecum.