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Frontiers in Immunology 2021Bacterial infection presents severe challenge to tilapia farming, which is largely influenced by water temperature. However, how water temperature determines tilapias'...
Bacterial infection presents severe challenge to tilapia farming, which is largely influenced by water temperature. However, how water temperature determines tilapias' survival to infection is not well understood. Here, we address this issue from the perspective of metabolic state. Tilapias were more susceptible to infection at 33°C than at 18°C, which is associated with differential metabolism of the fish. Compared to the metabolome of tilapia at 18°C, the metabolome at 33°C was characterized with increased an tricarboxylic acid cycle and a reduced level of -inositol which represent the most impactful pathway and crucial biomarker, respectively. These alterations were accompanied with the elevated transcriptional level of 10 innate immune genes with infection time, where , , , and exhibited a higher expression at 33°C than at 18°C and was attenuated by exogenous -inositol in both groups. Interestingly, exogenous -inositol inactivated the elevated TCA cycle inhibiting the enzymatic activity of succinate dehydrogenase and malate dehydrogenase. Thus, tilapias showed a higher survival ability at 33°C. Our study reveals a previously unknown relationship among water temperature, metabolic state, and innate immunity and establishes a novel approach to eliminate bacterial pathogens in tilapia at higher water temperature.
Topics: Animals; Biomarkers; Disease Resistance; Energy Metabolism; Fish Diseases; Host-Pathogen Interactions; Immunity, Innate; Inositol; Metabolome; Metabolomics; Temperature; Tilapia; Water
PubMed: 34566956
DOI: 10.3389/fimmu.2021.682724 -
Water Research Sep 2019The wide application of chlorine disinfectant for drinking water treatment has led to the appearance of chlorine-resistant bacteria, which pose a severe threat to public...
The wide application of chlorine disinfectant for drinking water treatment has led to the appearance of chlorine-resistant bacteria, which pose a severe threat to public health. This study was performed to explore the physiological-biochemical characteristics and environmental influence (pH, temperature, and turbidity) of seven strains of chlorine-resistant bacteria isolated from drinking water. Ozone disinfection was used to investigate the inactivation effect of bacteria and spores. The DNA concentration and cell surface structure variations of typical chlorine-resistant spores (Bacillus cereus spores) were also analysed by real-time qPCR, flow cytometry, and scanning electron microscopy to determine their inactivation mechanisms. The ozone resistance of bacteria (Aeromonas jandaei < Vogesella perlucida < Pelomonas < Bacillus cereus < Aeromonas sobria) was lower than that of spores (Bacillus alvei < Lysinibacillus fusiformis < Bacillus cereus) at an ozone concentration of 1.5 mg/L. More than 99.9% of Bacillus cereus spores were inactivated by increasing ozone concentration and treatment duration. Moreover, the DNA content of Bacillus cereus spores decreased sharply, but approximately 1/4 of the target genes remained. The spore structure exhibited shrinkage and folding after ozone treatment. Both cell structures and gene fragments were damaged by ozone disinfection. These results showed that ozone disinfection is a promising method for inactivating chlorine-resistant bacteria and spores in drinking water.
Topics: Chlorine; Disinfectants; Disinfection; Drinking Water; Ozone; Spores, Bacterial; Water Purification
PubMed: 31158616
DOI: 10.1016/j.watres.2019.05.014 -
Environmental Research Apr 2023The global decline in amphibian populations is a major environmental issue. Chytridiomycosis, Ranaviruses and the red-leg syndrome have been identified in unusual...
The global decline in amphibian populations is a major environmental issue. Chytridiomycosis, Ranaviruses and the red-leg syndrome have been identified in unusual mortality events. However, these infections do not account for all causes of declining amphibian populations. Moreover, several cases of amphibian mortality are difficult to solve without resorting to an interdisciplinary approach. Two cases of unusual mortality in Rana temporaria occurred at two high-mountain ponds (northwest Italy) in April and May 2021. Water and frog samples were analysed to understand the possible causes responsible for the unusual mortalities. Results of the main physicochemical (pH, conductivity, dissolved oxygen, chemical and biochemical oxygen demand) and nutrient (ammonia/ammonium, nitrite, nitrate, total phosphorus) parameters revealed a good condition of the water quality, with the absence of the main cyanotoxins (microcystins/nodularins). However, unseasonably high spring water temperatures were recorded in both ponds (12.73 °C and 14.21 °C for Frog Pond and Selleries Pond, respectively). Frogs (n = 50; snout-vent length: 7.0-9.8 cm; body mass: 85-123 g) collected from Frog Pond mainly presented bumps on the ventral cavity and dermal ulceration associated with the isolation of Carnobacterium maltaromaticum. On the other hand, frogs (n = 5; snout-vent length: 8.0-9.1 cm; body mass: 87-92 g) from Selleries Pond presented petechiae and dermal ulcerations on the rear limbs associated with the isolation of Aeromonas salmonicida and A. sobria. In both mortality events, the interdisciplinary approach revealed an association between frog mortalities and the isolation of bacteria. Isolated bacteria are considered opportunistic pathogens, and the high values of the water temperature has certainly led a stress on the frogs, favouring the spread of bacteria and the death of the frogs. Further studies are needed to assess the pathophysiological effects of the opportunistic bacteria here isolated, clarifying the interactions between emerging pathogens and climate change.
Topics: Animals; Rana temporaria; Ponds; Climate Change; Amphibians; Ranavirus
PubMed: 36736753
DOI: 10.1016/j.envres.2023.115411 -
Food Safety (Tokyo, Japan) Jun 2021Colistin (CST) is considered the last resort for the treatment of infectious diseases due to multidrug-resistant bacteria. Since the r-1 gene has been reported in...
Colistin (CST) is considered the last resort for the treatment of infectious diseases due to multidrug-resistant bacteria. Since the r-1 gene has been reported in isolated from food, animals, and humans in China, the prevalence of CST-resistant bacteria has been of great concern. Here, we investigated the prevalence of CST resistance and plasmid-mediated colistin-resistance genes () in gram-negative bacteria isolated among retail meats in Japan. CST-resistant bacteria were isolated from 310 domestic retail meats (103 chicken meat, 103 pork, and 104 beef) purchased between May 2017 and July 2018 from retail shops in Japan using CST-containing media and antimicrobial susceptibility testing. The gene was investigated in isolates with a CST minimum inhibitory concentration of ≥1 μg/mL. Excluding the intrinsically CST-resistant isolates, CST-resistant bacteria were isolated from 39 of the total chicken meats (37.9%), 19 of the pork samples (18.4%), and 18 of the beef samples (17.3%). A total of 459 isolates were identified, out of which 99 were CST-resistant. CST resistance (resistance breakpoints: , >4 μg/mL; others, >2 μg/mL) was found in spp. (48/206, 23.3%), spp. (5/112, 4.5%), (23/39, 59%), spp. (4/26, 15.4%), spp. (2/23, 8.7%), spp. (2/16, 12.5%), spp. (7/14, 50%), spp. (1/8, 12.5%), spp. (5/7, 71.4%), spp. (1/4, 25%), and spp. (1/2, 50%). The gene was detected in 16 isolates: -1 in 14 isolates of from 10 chicken samples (9.7%), and -3 in two isolates of from pork and chicken samples (each 1.0%). The findings of this study highlight the necessity of surveillance of CST resistance and resistance genes in bacteria that contaminate retail meats.
PubMed: 34249589
DOI: 10.14252/foodsafetyfscj.D-21-00002 -
Fish Physiology and Biochemistry Feb 2022Mercury (Hg) is a global pollutant that affects the health of humans and ecosystems. Selenium (Se) is an essential trace element for many organisms including humans....
Mercury (Hg) is a global pollutant that affects the health of humans and ecosystems. Selenium (Se) is an essential trace element for many organisms including humans. Bacillus subtilis is one of the main probiotics used in aquaculture, and has a certain adsorption effect on heavy metals. The interaction between Hg and Se was rigorously studied, especially due to the observation of the protective effect of Se on Hg toxicity. The objective of this study was to research the effects of Hg, Se, and B. subtilis on inflammation and intestinal microbes in common carp. The common carp was exposed to Hg (0.03 mg/L), and 10 cfu/g Se-rich B. subtilis was added to the feed. After 30 days of feeding, samples were taken to evaluate the growth performance, serological response, inflammatory response, and intestinal microbial changes. In this study, when fish were exposed to Hg, the growth performance of the Se-rich B. subtilis plus 0.03 mg/L Hg fish group was lower than that of the control group and higher than 0.03 mg/L Hg; The levels of serum immunoglobulin M (IgM) and lysozyme (LZM) decreased, but after supplementation with Se-rich B. subtilis, the levels of LZM and IgM increased; Hg treatment significantly upregulated the mRNA expression of interleukin-1β (IL-1β), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and nuclear factor-kB (NF-κB P65), but downregulated the mRNA expression of interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and NF-kappa-B inhibitor alpha (IkBα). However, compared with the Hg group, the Se-rich B. subtilis plus Hg group can significantly increase the mRNA expression levels of IL-1β, IL-8, TNF-α, and NF-κB P65, but reduce the regulation of IL-10, TGF-β, and IkBα expression. Through the analysis of the microbiological, we found that the Hg group was mainly composed of Aeromonas sobria and Aeromonas hydrophila. However, in the Se-rich B. subtilis treatment group, we found that Aeromonas sobria was significantly less than the Hg group. Se-rich B. subtilis improves Hg-induced intestinal microbial changes, alleviates the abundance of Aeromonas, and alleviates the inflammation of the fish. The results of this study show that Se-rich B. subtilis dietary supplements can effectively protect common carp against Hg toxicity.
Topics: Aeromonas; Animal Feed; Animals; Bacillus subtilis; Carps; Dietary Supplements; Ecosystem; Gastrointestinal Microbiome; Immunity, Innate; Immunoglobulin M; Inflammation; Interleukin-10; Interleukin-8; Mercury; NF-kappa B; Probiotics; RNA, Messenger; Selenium; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha
PubMed: 35064384
DOI: 10.1007/s10695-022-01046-8 -
Frontiers in Veterinary Science 2022The pharmacokinetics and tissue distribution of enrofloxacin were determined in Yellow River carp () reared at 20°C after single oral administration of enrofloxacin at...
The pharmacokinetics and tissue distribution of enrofloxacin were determined in Yellow River carp () reared at 20°C after single oral administration of enrofloxacin at 10 mg·kg body weight (BW). Plasma, bile, and different tissue samples, including liver, kidney, gill, gut, and skin-muscle, were collected at predetermined times points. An HPLC method was developed to simultaneously determine the concentrations of enrofloxacin and its metabolite, ciprofloxacin. However, ciprofloxacin was only detectable in some liver samples with trace levels. Then the average enrofloxacin concentrations vs. time data were subjected to a non-compartmental analysis using WinNonLin 5.2 software. Multiple peaking profiles were observed in all enrofloxacin concentration-time curves. The peak concentration (C) values were observed as 0.79, 1.01, 2.09, 2.85, 4.34, 10.78, and 13.07 μg·ml (or g) in plasma, skin-muscle, gill, kidney, liver, bile, and gut, respectively, and the corresponding time to reach peak concentration (T) was 8, 8, 1, 8, 1, 72, and 4 h, respectively. The values of elimination half-life (T ) of enrofloxacin in different tissues was in the following order: gill (291.13 h) > liver (222.29 h) > kidney (157.22 h) > plasma (129.44 h) > gut (91.47 h) > skin-muscle (87.77 h) > bile (86.22 h). The present results showed that enrofloxacin had a wide distribution in different tissues, however slow absorption and elimination in Yellow River carp. Additionally, enrofloxacin exhibited large distribution in bile, indicating that bile excretion might be the primary elimination route of enrofloxacin in Yellow River carp. A withdrawal period was calculated as 379.2 °C-day for single oral dosing of enrofloxacin at 10 mg/kg BW. Based on the calculated PK/PD indices of AUC/MIC or C/MIC, the current enrofloxacin dosing regimen might have a positive therapeutic effect on the infection of , or . However, the depletion study following multiple oral doses should be carried out in Yellow River carp reared at lower temperatures, and the withdrawal period should also be further calculated.
PubMed: 35187147
DOI: 10.3389/fvets.2022.822032 -
Fish & Shellfish Immunology Sep 2022Several studies have looked into the use of basil, Ocimum basilicum (L.) in aquaculture as a dietary additive; however, more research is needed to see the possibility of...
Chitosan-Ocimum basilicum nanocomposite as a dietary additive in Oreochromis niloticus: Effects on immune-antioxidant response, head kidney gene expression, intestinal architecture, and growth.
Several studies have looked into the use of basil, Ocimum basilicum (L.) in aquaculture as a dietary additive; however, more research is needed to see the possibility of it's including in nanocarriers in aquafeeds. An experiment was undertaken to highlight the efficacy chitosan-Ocimum basilicum nanocomposite (COBN), for the first time, on Nile tilapia (Oreochromis niloticus) growth, stress and antioxidant status, immune-related parameters, and gene expression. For 60 days, fish (average weight: 23.55 ± 0.08 g) were fed diets provided with different concentrations of COBN (g/kg): 0 g [COBN0], 1 g [COBN1], 2 g [COBN2], and 3 g [COBN3], where COBN0 was kept as control diet. Following the trial, the fish were challenged with pathogenic bacteria (Aeromonas sobria) and yeast (Candida albicans) infection. In comparison to the control (COBN0), a notable increase in growth parameters (weight gain, feed intake, and specific growth rate) and intestinal morphometric indices (average intestinal goblet cells count, villous width, and length) in all COBN groups was observed, where COBN2 and COBN3 groups had the highest values. The COBN diets significantly (p < 0.05) declined levels of serum triglycerides, glucose, cholesterol, and hepatic malondialdehyde. Moreover, the higher levels of serum biochemical biomarkers (growth hormone, total protein, globulin, and albumin), immunological parameters (phagocytic activity%, nitric oxide, and lysozyme), and hepatic antioxidant parameters (superoxide dismutase, total antioxidant capacity, and glutathione peroxidase) were obvious in the COBN2 and COBN3 groups followed by COBN1. The immune-antioxidant genes (TNF-α, IL-10, IL-1β, TGF-β, GPx, and SOD) were found to be considerably up-regulated in all COBN groups (COBN2 and COBN3 followed by COBN1). Fifteen days post-challenge with A. sobria and C. albicans, the highest survival rate was recorded in the COBN2 group (83.33 and 91.67%) followed by the COBN3 group (75 and 83.33%), respectively. The findings showed that a dietary intervention with COBN can promote growth, intestinal architecture, immunity, and antioxidant markers as well as protect O. niloticus against A. sobria and C. albicans infection. As a result, the COBN at a dose of 2 g/kg could be used as a food additive for the sustainable aquaculture industry.
Topics: Albumins; Animal Feed; Animals; Antioxidants; Chitosan; Cichlids; Diet; Dietary Supplements; Fish Diseases; Food Additives; Gene Expression; Glucose; Glutathione Peroxidase; Gram-Negative Bacterial Infections; Growth Hormone; Head Kidney; Interleukin-10; Malondialdehyde; Muramidase; Nanocomposites; Nitric Oxide; Ocimum basilicum; Superoxide Dismutase; Transforming Growth Factor beta; Triglycerides; Tumor Necrosis Factor-alpha
PubMed: 35985625
DOI: 10.1016/j.fsi.2022.08.020 -
Current Microbiology Aug 2020Antimicrobial and heavy-metal resistance of 29 Aeromonas spp. (Aeromonas hydrophila n = 9, Aeromonas enteropelogenes n = 14, Aeromonas veronii n = 3,...
Antimicrobial and heavy-metal resistance of 29 Aeromonas spp. (Aeromonas hydrophila n = 9, Aeromonas enteropelogenes n = 14, Aeromonas veronii n = 3, Aeromonas salmonicida n = 2, and Aeromonas sobria n = 1) isolated from Pacific abalone marketed in Korea were analyzed. All isolates were found to be resistant against ampicillin. High level of resistant to cephalothin (86%), rifampicin (73%), imipenem (42%), and oxytetracycline (35%) were also detected. Thirteen (45%) of the isolates showed multiple antimicrobial resistance (MAR) index ≥ 0.2. The PCR assays implied the presence of qnrS, qnrB, qnrA, tetB, tetA, aac (3')- IIa, aac(6')-Ib, aphAI-IAB, bla, bla, and intI1 genes among 76%, 28%, 14%, 17%, 3%, 3%, 41%, 10%, 41%, 28%, and 66% of the isolates, respectively. Class 1 integron gene cassette profiles aadA1(3%) and aadA2 (3%) were also identified. Lead (Pb) resistance was the highest (69%) among 5 heavy metals tested, whereas 38%, 27%, and 20% of the isolates were resistant to Cadmium (Cd), Chromium (Cr), and Copper (Cu), respectively. Heavy-metal resistance genes, CopA, CzcA, and merA were positive in 83%, 75%, and 41% of the isolates, respectively. In conclusion, observed genotypic and phenotypic resistance profiles of Aeromonas spp. against antimicrobials and heavy metals reveal the ability of serving as a source of antimicrobials and heavy-metal-resistant traits.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Gastropoda; Metals, Heavy; Microbial Sensitivity Tests; Republic of Korea; Seafood
PubMed: 32300925
DOI: 10.1007/s00284-020-01982-9 -
Anais Da Academia Brasileira de Ciencias 2021In this study, it was determinated the essential oil of cultivated apple mint, Mentha suaveolens Ehrh. composition and in vitro antibacterial activity of against 11 fish...
In this study, it was determinated the essential oil of cultivated apple mint, Mentha suaveolens Ehrh. composition and in vitro antibacterial activity of against 11 fish pathogen bacteria including Gram-positive (Staphylococcus warneri, Staphylococcus sp., Lactococcus garvieae, Vagococus salmoninarum) and Gram-negative (Aeromonas hydrophila, Aeromonas sobria Aeromonas cavieae, Vibrio anguillarum, Pseudomonas aeroginosa, Yersinia ruckeri, Edwardsiella tarda) by using agar diffusion assay. The main component of M. suaveolence oil was obtained as piperitenone oxide. The essential oil exhibited strong inhibitory activity such as inhibition zone sizes: 30-50mm at 250-1000 µL mL-1 concentrations against V. anguillarum; 16-20mm at 31.25-125 µL mL-1 concentrations against P. aeroginosa; 15-18mm at 500-1000 µL mL-1 concentrations against A. sobria. However, it was found to be moderately effective against E. tarda (8-15 mm), Y. ruckeri (9-12mm), S. warneri (9-10mm), V. salmoninarum (9mm) and Staphylococcus sp. (8-9mm). The essential oil showed weak inhibitory activity against A. cavieae (5-8), A. hydrophila (6-7mm), L. garvieae (5-7mm). Thus, effect of essential oil of M. suaveolens on immune response and disease resistance against Vibrio anguillarum, A. sobria and P. aeroginosa should be investigated in vivo in cultured fish species in future studies.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Fish Diseases; Lactococcus; Mentha; Oils, Volatile; Staphylococcus; Vibrio
PubMed: 34468488
DOI: 10.1590/0001-3765202120190478 -
Archives of Razi Institute Dec 2021The current study aimed to isolate and identify the bacteria associated with burn wounds and investigate the antimicrobial susceptibility pattern against a group of most...
The current study aimed to isolate and identify the bacteria associated with burn wounds and investigate the antimicrobial susceptibility pattern against a group of most commonly prescribed antibiotics. In total, 105 burn wound swabs were collected from burn patients admitted to the burn unit of Al-Sadr Teaching Hospital in Misan City, Iraq. The swabs had been cultured on different media; the colonies were diagnosed based on the phenotypic and culture characteristics. The bacteria were identified through cultural characters and Gram staining diagnosed by VITEK 2 Compact Automated Systems. In total, there were nine distinct bacterial isolations, of which, was the most common pathogen [20%] followed by [17.14%], .[16.19%], [13.33%], [10.47%], [7.6%], [6.6%], and at last, and , which had the same percentage [4.7%]. Most isolates showed high resistance to Tobramycin, Trimethoprim, Cephalothin, and Imipenem while isolates mostly had high susceptibility to Amikacin, Cefotaxime, and Ciprofloxacin. Wound burn infection still represents a serious problem for burn patients with many bacteria developing different degrees of resistance to most known antibiotics.
Topics: Anti-Bacterial Agents; Bacteria; Iraq; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Humans
PubMed: 35546990
DOI: 10.22092/ari.2021.356367.1833