-
Microbiome Dec 2022After millions of years of coevolution, symbiotic microbiota has become an integral part of the host and plays an important role in host immunity, metabolism, and...
Significant alterations of intestinal symbiotic microbiota induced by intraperitoneal vaccination mediate changes in intestinal metabolism of NEW Genetically Improved Farmed Tilapia (NEW GIFT, Oreochromis niloticus).
BACKGROUND
After millions of years of coevolution, symbiotic microbiota has become an integral part of the host and plays an important role in host immunity, metabolism, and health. Vaccination, as an effective means of preventing infectious diseases, has been playing a vital role in the prevention and control of human and animal diseases for decades. However, so far, minimal is known about the effect of vaccination on fish symbiotic microbiota, especially mucosal microbiota, and its correlation with intestinal metabolism remains unclear.
METHODS
Here we reported the effect of an inactivated bivalent Aeromonas hydrophila/Aeromonas veronii vaccine on the symbiotic microbiota and its correlation with the intestinal metabolism of farmed adult Nile tilapia (Oreochromis niloticus) by 16S rRNA gene high-throughput sequencing and gas chromatography-mass spectrometry metabolomics.
RESULTS
Results showed that vaccination significantly changed the structure, composition, and predictive function of intestinal mucosal microbiota but did not significantly affect the symbiotic microbiota of other sites including gill mucosae, stomach contents, and stomach mucosae. Moreover, vaccination significantly reduced the relative abundance values of potential opportunistic pathogens such as Aeromonas, Escherichia-Shigella, and Acinetobacter in intestinal mucosae. Combined with the enhancement of immune function after vaccination, inactivated bivalent Aeromonas vaccination had a protective effect against the intestinal pathogen infection of tilapia. In addition, the metabolite differential analysis showed that vaccination significantly increased the concentrations of carbohydrate-related metabolites such as lactic acid, succinic acid, and gluconic acid but significantly decreased the concentrations of multiple lipid-related metabolites in tilapia intestines. Vaccination affected the intestinal metabolism of tilapia, which was further verified by the predictive function of intestinal microbiota. Furthermore, the correlation analyses showed that most of the intestinal differential microorganisms were significantly correlated with intestinal differential metabolites after vaccination, confirming that the effect of vaccination on intestinal metabolism was closely related to the intestinal microbiota.
CONCLUSIONS
In conclusion, this paper revealed the microbial and metabolic responses induced by inactivated vaccination, suggesting that intestinal microbiota might mediate the effect of vaccination on the intestinal metabolism of tilapia. It expanded the novel understanding of vaccine protective mechanisms from microbial and metabolic perspectives, providing important implications for the potential influence of vaccination on human intestinal microbiota and metabolism. Video Abstract.
Topics: Animals; Humans; Cichlids; Gastrointestinal Microbiome; Tilapia; RNA, Ribosomal, 16S; Probiotics; Animal Feed
PubMed: 36510260
DOI: 10.1186/s40168-022-01409-6 -
Frontiers in Cellular and Infection... 2022The influence of dietary probiotic on the growth performance, digestive enzyme activity, immune parameters and disease resistance of yellow catfish () was evaluated....
The influence of dietary probiotic on the growth performance, digestive enzyme activity, immune parameters and disease resistance of yellow catfish () was evaluated. Commercial diet (C) or diet containing 10 cfu/g (T) was fed for 4 weeks, and final weight (FW), specific growth rate (SGR) and feed conversion ratio (FCR) were improved (0.05) in the T group. Dietary increased protease and amylase activities in the digestive tract after 2 and 4 weeks, respectively. Respiratory burst (RB), plasma lysozyme (LZM) activity, total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity were also elevated (0.05). Immune-related genes signal transducer and activator of transcription 1 (STATA-1), immunoglobulin M (IgM) and C-type lectin (CTL) were upregulated (0.05), but interleukin-1 β (IL-1β) was not (0.05). Intestinal microbiota analysis showed that the community structure was significantly different between the two groups; the relative abundance of was increased but was decreased in T. Moreover, challenge tests showed that the resistance of fish fed against and was significantly enhanced (0.05). In conclusion, dietary supplementation of can effectively improve the growth performance, digestive enzyme activity, immune responses, intestinal microbiota composition and disease resistance of yellow catfish.
Topics: Animals; Catfishes; Bacillus amyloliquefaciens; Gastrointestinal Microbiome; Disease Resistance; Diet; Gastrointestinal Agents
PubMed: 36452300
DOI: 10.3389/fcimb.2022.1047351 -
Frontiers in Microbiology 2022Meat inspection is important to ensure food safety and protect public health. Visual inspection of slaughtered carcasses for pathological changes should be supported by...
Meat inspection is important to ensure food safety and protect public health. Visual inspection of slaughtered carcasses for pathological changes should be supported by bacteriological analysis to determine whether the entire carcass or parts of it should be condemned. The aim of this study was to determine the bacterial species present in different sample types from condemned broiler carcasses. Furthermore, we investigated the genetic characteristics, zoonotic potential, and relatedness of , the predominant bacterial species isolated from the carcasses. A total of 400 broiler carcasses condemned because of cellulitis (100), scratches (100), hepatitis (100), and healthy control carcasses (100) were selected. Samples of meat, pathological lesion, and bone marrow of each carcass were obtained for microbial analysis. From the analyzed samples, 469 bacterial isolates were recovered with . accounting for 45.8%, followed by spp. (27.9%), in particular . . The highest rate of bacterial isolation was observed in carcasses condemned with cellulitis, whereas carcasses with hepatitis had the lowest rate of bacterial isolation. Forty-four . isolates originating from different sample types were selected for whole genome sequencing. A clonal relationship was shown between . from different sample types of the same carcass condemned with cellulitis and scratches. A major clade of . was found in carcasses condemned with cellulitis with isolates containing (A), (A), and genes that confer resistance to macrolides, tetracycline, and ampicillin, respectively. . in this clade all belonged to ST117 and clustered with . isolates previously collected from dead chickens and carcasses condemned due to cellulitis in Denmark, Finland, and the United Kingdom. Bacterial evaluation results of carcasses condemned with cellulitis, scratches (moderate to severe skin lesion), and acute hepatitis confirmed the need for total condemnation of carcasses with these pathological findings. A similar evaluation should be done for carcasses affected with chronic hepatitis, and minor scratches lesions.
PubMed: 36439808
DOI: 10.3389/fmicb.2022.1020586 -
Aquaculture International : Journal of... 2023This study aimed to develop and evaluate live and inactivated vaccines to pathogenicity in Nile tilapia. Therefore, five well-identified isolates, including A (HY1), A...
This study aimed to develop and evaluate live and inactivated vaccines to pathogenicity in Nile tilapia. Therefore, five well-identified isolates, including A (HY1), A (HY2), A (HY3), A (HY4), and A (HY6) isolated from diseased Nile tilapia (), were used for vaccine preparation. Virulence genes detected by a polymerase chain reaction (PCR) and lethal dose determination were conducted. Nile tilapia, each with a body weight of 25 ± 0.5 g were divided into six experimental groups (each of 20): T1 group (control), fish were injected with saline as a negative control, T2 group (formalin-killed vaccine) for the A (HY2) strain, T3 group ( formalized killed vaccine) for the A (HY4), T4 group (autoclaved vaccine) for the A (HY2), T5 group (autoclaved vaccine) for A (HY4), and T6 (live vaccine) for A (HY1), triplicate. At the end of the immunization period, all groups were challenged by , A (HY2). Blood samples were drawn 21 days post-immunization and 3 days after the challenge test for antibody titer assay. The results showed that the pathogenicity of strains A (HY2) and A (HY4) was the strongest, as the lethality rates (LR) were 100% and 90%, respectively, whereas the pathogenicity was moderate for strains A (HY3) and A (HY6) (LR 60% for each). A (AY1) was the weakest strain as no dead fish was found for this strain. The presence of , and genes as the main cause of the pathogenesis. The best protective efficacy was obtained from the live vaccine, A (HY1) with a protective rate of about 94.12% (relative percentage of survival, RPS), compared to autoclaved killed vaccines and formalin-killed vaccines. Based on immunoglobulin estimation (IgM) and RPS%, our data concluded that A (HY1) live vaccine had the best vaccine prophylactic effect against the highly pathogenic strain A(HY2).
PubMed: 36439703
DOI: 10.1007/s10499-022-01023-1 -
Fish and Shellfish Immunology Reports Dec 2022is a highly infectious pathogen, which causes high mortality rate in frog farming. Therefore, it is urgent to develop a rapid and sensitive detection method. In this...
is a highly infectious pathogen, which causes high mortality rate in frog farming. Therefore, it is urgent to develop a rapid and sensitive detection method. In this study, two rapid and specific methods including recombinase polymerase amplification combined with lateral flow dipstick (RPA-LFD) and fluorescent probe-based recombinase polymerase amplification (exo RPA) were established to effectively detect , which can accomplish the examination at 38 °C within 30 min. The limiting sensitivity of RPA-LFD and exo RPA (10 copies/μL) was ten-fold higher than that in generic PCR assay. The specificities of the two methods were verified by detecting multiple DNA samples (, CyHV-2 and ), and the result showed that the single band was displayed in DNA only. By tissue bacterial load and qRT-PCR assays, brain is the most sensitive tissue. Random 24 black spotted frog brain samples from farms were tested by generic PCR, basic RPA, RPA-LFD and exo RPA assays, and the results showed that RPA-LFD and exo RPA methods were able to detect accurately and rapidly. In summary, the methods of RPA-LFD and exo RPA were able to detect conveniently, rapidly, accurately and sensitively. This study provides prospective methods to detect infection in frog culture.
PubMed: 36419595
DOI: 10.1016/j.fsirep.2022.100059 -
IDCases 2022Aeromonads are a well-known cause of gastrointestinal illness in humans; however, extra-intestinal infections due to spp. have been increasingly reported. Severe...
cellulitis, bacteremia, and sepsis in a patient with liver cirrhosis and end-stage renal disease following a minor abrasion with exposure to pond water: A case report and literature review.
Aeromonads are a well-known cause of gastrointestinal illness in humans; however, extra-intestinal infections due to spp. have been increasingly reported. Severe infection and septic shock due to spp. is rare, though the risk is greater for immunocompromised individuals. Patients with liver cirrhosis have been noted to be at especially high risk for severe infection due to spp. Several cases of septicemia due to have been reported in the literature. We report a rare case of septicemia in a patient with known liver cirrhosis and end-stage renal disease following a minor abrasion with exposure to pond water. The patient's history fostered clinical suspicion of infection and tailored early diagnosis and treatment.
PubMed: 36388852
DOI: 10.1016/j.idcr.2022.e01631 -
Frontiers in Microbiology 2022The aquatic environment is an important medium for the accumulation and dissemination of antibiotic-resistant bacteria as it is often closely related to human...
The aquatic environment is an important medium for the accumulation and dissemination of antibiotic-resistant bacteria as it is often closely related to human activities. Previous studies paid little attention to the prevalence and mechanism of polymyxin-resistant bacteria in the aquatic environment. As a Gram-negative opportunistic pathogen widely distributed in aquatic ecosystems, the antibiotic-resistant profile of spp. deserves much attention. In this study, we identified 61 spp. isolates from water samples in the section of the Yangtze River. The total polymyxin B (PMB) resistance rate of these strains was 49.18% (30/61), showing a high level of polymyxin resistance in spp. The MIC and MIC for PMB exhibited a significant discrepancy among different species ( < 0.001). The MIC and MIC for PMB in the were 128 mg/L and above 128 mg/L while in and , the MIC and MIC value were both 2 mg/L. Only two . strains (MIC = 2 mg/L) and one . strain (MIC = 0.5 mg/L) were identified as carrying mobilized polymyxin resistant gene ., and .. All genes were located in the chromosome. This is the first report that the downstream region of -3.42 was the truncated -like gene separated by the insertion sequences of IS (1,674 bp) and IS (1,084 bp). Analysis of epidemiology of -positive genomes from GenBank database showed that the genus and the aquatic environment might be the potential container and reservoir of . By the whole-genome sequencing and qRT-PCR, we inferred that the sequence differences in the AAA domain of MlaF protein and its expression level among these three species might be involved in the development of polymyxin resistance. Our study provided evidences of the possible mechanism for the variety of polymyxin susceptibility in different species of the genus and a theoretical basis for the surveillance of the aquatic environment.
PubMed: 36386612
DOI: 10.3389/fmicb.2022.1030564 -
Pathogens (Basel, Switzerland) Oct 2022is associated with substantial economic losses in the fish industry and with food-borne illness in humans. This study aimed to determine the prevalence, antibiogram...
is associated with substantial economic losses in the fish industry and with food-borne illness in humans. This study aimed to determine the prevalence, antibiogram profiles, sequence analysis, virulence and antimicrobial resistance genes, and pathogenicity of recovered from . A total of 80 fish were randomly gathered from various private farms in Suez Province, Egypt. Subsequently, samples were subjected to clinical, post-mortem, and bacteriological examinations. The retrieved isolates were tested for sequence analysis, antibiogram profile, pathogenicity, and PCR detection of virulence and resistance genes. The prevalence of in the examined was 22.5 % (18/80). The phylogenetic analyses revealed that the tested strains shared high genetic similarity with other strains from India, UK, and China. Using PCR it was revealed that the retrieved isolates harbored the A, , , AII, , , and virulence genes with prevalence of 100%, 82.9%, 61.7%, 55.3%, 44.7%, 36.17%, and 29.8%, respectively. Our findings revealed that 29.8% (14/47) of the retrieved strains were XDR to nine antimicrobial classes and carried , , A, A1, and 1 resistance genes. Likewise, 19.1% (9/47) of the obtained strains were MDR to eight classes and possessed , , A, A1, and 1 genes. The pathogenicity testing indicated that the mortality rates positively correlated with the prevalence of virulence-determinant genes. To our knowledge, this is the first report to reveal the occurrence of XDR and MDR in , an emergence that represents a risk to public health. Emerging XDR and MDR in frequently harbored A, , , AII, and virulence genes, and , 1, A, , , and A1 resistance genes.
PubMed: 36365013
DOI: 10.3390/pathogens11111262 -
Microorganisms Nov 2022is as an important opportunist pathogen of many aquatic animals, which is wildly distributed in various aquatic environments. In this study, a dominant bacterium GJL1...
is as an important opportunist pathogen of many aquatic animals, which is wildly distributed in various aquatic environments. In this study, a dominant bacterium GJL1 isolated from diseased was identified as according to the morphological, physiological, and biochemical characteristics, as well as molecular identification. Detection of the virulence genes showed the isolate GJL1 carried outer membrane protein A (), flagellin (, , ), aerolysin (), cytolytic enterotoxin (), DNases (), and hemolysin (), and the isolate GJL1 also produced caseinase, lipase, gelatinase, and hemolysin. The virulence of strain GJL1 was confirmed by experimental infection; the median lethal dosage (LD) of the GJL1 for largemouth bass was 3.6 × 10 CFU/mL, and histopathological analysis revealed that the isolate could cause obvious inflammatory responses in Additionally, the immune-related gene expression in was evaluated, and the results showed that , , , , and were significantly upregulated after infection. Our results indicated that was an etiological agent causing the mass mortality of , which contributes to understanding the immune response of against infection.
PubMed: 36363790
DOI: 10.3390/microorganisms10112198 -
Children (Basel, Switzerland) Nov 2022species are emerging human enteric pathogens. However, there is no systematic analysis of infection in the pediatric population in Latvia. The aim of the study was to...
PURPOSE
species are emerging human enteric pathogens. However, there is no systematic analysis of infection in the pediatric population in Latvia. The aim of the study was to describe potential sources, prevalence of infection, associated virulence factors and antimicrobial resistance of spp. isolated from fecal samples.
METHODS
Stool samples (n = 1360) were obtained from the Children's Clinical University Hospital between 2020 and 2021. The target population was pediatric patients, 0 to 18 years of age, with a preliminary diagnosis of gastroenteritis. Identification was performed by Maldi-TOF, antimicrobial resistance by Vitek2 and 9 virulence factors by polymerase chain reaction (PCR).
RESULTS
spp. were isolated in 50 stool samples; positive findings made up 3.6% of all study cases and included four species: , , , and . In 42% of the samples, appeared alongside the other significant pathogens: , , , norovirus, adenovirus, and rotavirus. The study population positive for spp. infection contained 28 male (56%) and 22 female (44%) patients; median age was 4.56 years. The most common symptoms were: diarrhea, blood in stool, vomiting, abdominal pain, and fever. Aside from expected natural resistance, no significant antibacterial resistance was detected. The presence of multiple virulence genes was noticed in all isolates. No statistically significant correlation was found between the virulence patterns, bacterial species, and the intensity of clinical symptoms.
DISCUSSION
According to the clinical data and the results of this study spp. has an important role in pediatric practice and requires appropriate attention and monitoring.
PubMed: 36360412
DOI: 10.3390/children9111684