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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 -
Journal of Animal Physiology and Animal... Mar 2024The dietary effects of the green microalga Tetraselmis suecica (TS) on the growth, digestive enzymes, immune and antioxidant responses, genes expression, and disease...
Dietary effects of microalga Tetraselmis suecica on growth, antioxidant-immune activity, inflammation cytokines, and resistance of Nile tilapia fingerlings to Aeromonas sobria infection.
The dietary effects of the green microalga Tetraselmis suecica (TS) on the growth, digestive enzymes, immune and antioxidant responses, genes expression, and disease resistance of Nile tilapia (Oreochromis niloticus) fingerlings were investigated. This microalga was mixed with the diet' ingredients at doses of 0.0 (the control), 5, 10, 15, and 20 g/kg diet and then fed to fish daily for 84 days. After the feeding trial, fish were experimentally challenged with Aeromonas sobria, infection and fish mortalities were recorded for another 10 days. Dietary TS significantly (p < 0.05) enhanced growth, digestive enzymes activities, and blood proteins, particularly at the level of 15 g/kg diet. Feeding the fish on 15 TS/kg feed exhibited highest mRNA expressions of GH and IGF-1 genes as well as SOD, CAT, and GPx genes compared to other TS groups. Moreover, highest levels of hepatic antioxidant and immune indices were found in the treatment of 15 g TS/kg feed. Significant downregulation of IL-1β and IL-8 genes expression and significant upregulation of IL-10 gene expression were observed in TS-fed fish, principally in fish groups fed on 15-20 g TS/kg feed. Conversely, hepatic malondialdehyde levels, blood glucose, and the activities of transaminases (ALT and AST) were significantly (p < 0.05) decreased in fish fed with 15-20 g TS/kg diet. Serum bactericidal activity against A. sobria was significantly higher in TS-fed fish groups, and its highest levels were found in treatments of 15-20 g/kg diet. Of interest, the survival rates of fish groups fed diets with 10-20 g TS/kg feed were higher after the challenge with A. sobria infection than the control group. Accordingly, we can conclude that supplementing fish diets with a 15 g TS/kg diet enhanced the growth, antioxidant and immune activities, and resistance of Nile tilapia fingerlings to possible A. sobria infection.
Topics: Animals; Antioxidants; Dietary Supplements; Microalgae; Cytokines; Cichlids; Diet; Inflammation; Animal Feed; Fish Diseases; Gram-Negative Bacterial Infections; Aeromonas
PubMed: 38054788
DOI: 10.1111/jpn.13911 -
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 -
APMIS : Acta Pathologica,... Aug 2019Two quite different disc contents are used for antimicrobial susceptibility testing of two fluoroquinolone drugs, flumequine and enrofloxacin, in the disc diffusion...
Two quite different disc contents are used for antimicrobial susceptibility testing of two fluoroquinolone drugs, flumequine and enrofloxacin, in the disc diffusion test, 30 and 5 µg, respectively. Using the SRA method, single-strain regression analysis, we studied the impact of disc content when testing two relevant bacterial species, Aeromonas sobria and Vibrio anguillarum. There were no major differences between the antimicrobial regression lines for the two species. Wild-type strains produced acceptable zones of inhibition over a wide range of disc contents. The flumequine 30 µg disc should be lowered in its drug content. No rational reasons for choosing so different disc contents for the two antimicrobials were apparent. At present, the choice of disc content for new antimicrobials are outside the realm of clinical microbiologists. It is recommended that reference authorities, such as EUCAST, CLSI and USCAST, are consulted for the choice of disc contents in the future.
Topics: Aeromonas; Anti-Bacterial Agents; Enrofloxacin; Fluoroquinolones; Microbial Sensitivity Tests; Regression Analysis; Vibrio
PubMed: 31231825
DOI: 10.1111/apm.12972 -
Animals : An Open Access Journal From... Apr 2021African catfish () were subjected to a 30-day feeding trial to determine the appropriateness of using plant protein (PP) (soybean and sunflower meal) as a fishmeal (FM)...
African catfish () were subjected to a 30-day feeding trial to determine the appropriateness of using plant protein (PP) (soybean and sunflower meal) as a fishmeal (FM) replacement in the diet and its effects on immune status, antioxidant activity, pituitary adenylate cyclase-activating polypeptide () gene expression, and disease resistance. A total of 150 (51.01 ± 0.34 g) were randomly distributed among five groups in triplicate. Five experimental diets were formulated to replace 0 (control), 33.5, 50, 66.5, and 100% FM with soybean and sunflower meal to form the experimental diets (R0, R33.5, R50, R66.5, and R100, respectively). After 30 days, the diet containing PP for FM had no significant impact on total, and differential leukocyte counts determined at the end of the feeding period. The total globulin concentration showed significantly greater differences in the following order R0 > R33.5 > R50 > R66.5 > R100. The R0 group had the highest concentration of serum γ-globulin, while R100 had the lowest concentration. The antioxidant status complements 3 (C3), lysozyme activity (LYZ), and antiprotease activity were not significantly different between R0, R33.5, and R50 groups, while they were significantly lower in R100. The serum nitric oxide activity (NO) exhibited significantly greater differences in the following order R0 > R33.5 > R50 > R66.5 > R100. was significantly higher in the R33.5 group. The highest cumulative mortality caused by was recorded in the R100 group (60%) and the lowest in the R0 group (30%). In conclusion, the results indicate that the immunological responses and antioxidant status of were not affected when they consumed a diet with FM replaced by up to 50% with PP (SBM and SFM) with methionine and lysine supplementation, but total globulin, NO, and cumulative mortality were impaired with a diet containing a 100% FM replacement.
PubMed: 33922697
DOI: 10.3390/ani11051223