-
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 -
Probiotics and Antimicrobial Proteins Dec 2023The study focuses on the isolation, characterization, and expression analysis of a lectin from the hepatopancreas of Macrobrachium rosenbergii. The protein was isolated...
Characterization of a Lipopolysaccharide- and Beta-1,3-Glucan Binding Protein (LGBP) from the Hepatopancreas of Freshwater Prawn, Macrobrachium rosenbergii, Possessing Lectin-Like Activity.
The study focuses on the isolation, characterization, and expression analysis of a lectin from the hepatopancreas of Macrobrachium rosenbergii. The protein was isolated by affinity chromatography on a melibiose-agarose column. The molecular weight of the native protein was found to be ~120 kDa which consists of a single polypeptide of ~39.5 kDa. On mass spectrometric analysis, the protein was identified as lipopolysaccharide- and beta-1,3-glucan binding protein (LGBP). LGBP showed hemagglutination with rabbit RBC like a lectin and its carbohydrate-binding specificity was determined by the hemagglutination inhibition test. The protein also showed antibacterial activity against two Gram-negative bacteria Vibrio harveyi and Aeromonas sobria, and one Gram positive bacteria Bacillus cereus in the disc diffusion test. Rabbit antiserum was raised against the purified LGBP and used to develop a sandwich ELISA system for quantitation of the protein in hepatopancreas and serum samples of M. rosenbergii. The expression of the LGBP transcripts in muscle, hepatopancreas, and gill tissues from M. rosenbergii juveniles at 72 h post-challenge of V. harveyi was not modulated as noticed in qPCR analysis. However, significant increases in the concentrations of LGBP protein in hepatopancreas (5.23 ± 0.45 against 3.43 ± 0.43 mg/g tissue in control) and serum (1.08 ± 0.14 against 0.61 ± 0.08 µg/ml in control) were observed in the challenged group of prawns in ELISA suggesting its putative role against bacterial infections. The study for the first time characterized the native LGBP of M. rosenbergii showing a multifunctional role in immunity.
Topics: Animals; Rabbits; Palaemonidae; Lipopolysaccharides; Hepatopancreas; Lectins
PubMed: 36593373
DOI: 10.1007/s12602-022-10021-x -
South Asian Journal of Cancer Jul 2022Bikram Das Aeromonas is a water-dwelling Gram-negative bacillus primarily associated with gastrointestinal tract diseases. Aeromonas sobria causing gastroenteritis...
Bikram Das Aeromonas is a water-dwelling Gram-negative bacillus primarily associated with gastrointestinal tract diseases. Aeromonas sobria causing gastroenteritis has been reported in India. In immunocompromised host, Aeromonas sobria can also present with severe necrotizing skin and soft tissue infection with a high mortality rate. We report a case of Aeromonas sobria sepsis with skin and soft tissue infection in the background of immunosuppression. Fifty-year-old male who underwent an unrelated donor peripheral stem cell transplant for relapsed pre-B acute lymphoblastic leukemia in complete clinical remission on graft versus host disease prophylaxis, post-white blood cell engraftment presented with acute onset lethargy, lower limb pain without fever, or any skin changes initially. He rapidly worsened clinically over few days and developed sepsis, multiorgan dysfunction with the appearance of erythema and blister over the lower limb, and Fournier's gangrene of scrotum. He was found to have Aeromonas sobria bacteremia with isolated resistance to carbapenems while sensitive to all other classes of antibiotics. Despite appropriate antibiotic therapy and supportive measures, he succumbed to death for this invasive bacterial disease. Aeromonas should be considered a cause of sepsis in immunosuppressed hosts, especially those with hematological malignancy presenting with necrotizing skin and soft tissue infection. Considering the virulence of this pathogen, despite the very susceptible antibiogram, such patients must be managed aggressively. Early recognition of the disease with a combination of medical and surgical management might help to improve the outcome.
PubMed: 36588616
DOI: 10.1055/s-0042-1743164 -
BMC Veterinary Research Dec 2022Bacterial pathogens are a great threat to fish production. Gram-negative bacteria are among the major bacterial fish pathogens and are zoonotic with the potential to...
Isolation and identification of major bacteria from three Ethiopian rift valley lakes live and processed fish, and water samples: implications in sanitary system of fish products.
Bacterial pathogens are a great threat to fish production. Gram-negative bacteria are among the major bacterial fish pathogens and are zoonotic with the potential to infect humans. This cross-sectional study was conducted to isolate and identify major gram-negative bacteria from live and processed fish, and water samples from Lakes Hawassa, Langanoo and Ziway. A total of 674 different types of samples: 630 tissue samples (210 samples for each intestine, Kkidney and liver collected from 210 live fish (Oreochromis niloticus, Cyprinus carpio and Clarias gariepinus), 20 processed fish samples from lake Ziway fish processing center and 24 lake water samples were included in the study from each lake. The mean values of pH, temperature, dissolved oxygen and nitrate in all water samples were within the normal range at which most freshwater fish species become non-stressed. Of a total of 674 samples included in the study, bacteria were isolated from 154(22.8%) samples with significant difference (P < 0.05) observed in some isolates with respect to sample origin. Of these 154 isolates, 103(66.8%) isolates were gram-negative bacteria consisting of 15 species based on morphology and a range of biochemical tests. From live fish samples, Escherichia coli was the dominant species with 15 isolates followed by Edwardsiella tarda (12), Salmonella Paratyphi (10), Salmonella Typhi (9), Shigella dysenteriae (7), Shigella flexneri (7), Klebsiella pneumonia (7), Enterobacter aerogenes (6), Enterobacter cloacae (5), Pseudomonas aeruginosa (5), Vibrio parahemolyticus (5), Aeromonas sobria (4), Citrobacter freundii (4), Citrobacter koseri (4) and Plesiomonas shigelloides (3). The detection of the common fecal coliforms (E. coli, K. pneumoniae and E. aerogenes) and Salmonella spp. in processed fish indicates the potential danger of passage of pathogenic bacteria and/or their poisons to humans via infected and/or contaminated fish products. Human infection by pathogenic fish bacteria and food poisoning is possible through contamination of fish product in fish production chain due to inadequate handling, poor hygiene and contact with contaminated water. Therefore, producers, consumers and all other stakeholders need to be cautious during handling, processing and consumption of fish harvested from the study lakes.
Topics: Animals; Bacteria; Carps; Cross-Sectional Studies; Escherichia coli; Fish Products; Gram-Negative Bacteria; Lakes; Water; Ethiopia
PubMed: 36517783
DOI: 10.1186/s12917-022-03508-w -
Molecules (Basel, Switzerland) Dec 2022Crawfish can be easily spoiled due to their rich nutrition and high water content, which is difficult to preserve. In this study, the dominant spoilage organisms in...
Crawfish can be easily spoiled due to their rich nutrition and high water content, which is difficult to preserve. In this study, the dominant spoilage organisms in crawfish which were stored at 4 °C in vacuum packaging were identified by high-throughput sequencing technology; after sequencing the full-length 16S rRNA gene, the changes in the bacterial community structure, diversity and quality (texture, flavor, etc.) were analyzed. Our results reflected that the specific spoilage organisms (SSOs) of crawfish were , Shewanella putrefaciens, Trichococcus pasteurii and , since their abundances significantly increased after being stored for 12 days at 4 °C under vacuum conditions. At the same time, the abundance and diversity of the microbial community decreased with storage time, which was related to the rapid growth of the dominant spoilage organisms and the inhibition of other kinds of microorganisms at the end of the spoilage stage. Function prediction results showed that the gene which contributed to metabolism influenced the spoilage process. Moreover, the decline in texture of crawfish was negatively correlated to the richness of SSOs; this may be because SSOs can produce alkaline proteases to degrade the myofibrillar protein. On the contrary, the unpleasant flavor of crawfish, resulting from volatile flavor compounds such as S-containing compounds and APEOs, etc., is negatively correlated to the richness of SSOs, due to the metabolism of SSOs by secondary metabolites such as terpenoids, polyketides and lips, which can lead to decarboxylation, deamination and enzymatic oxidation. These results are very important to achieve the purpose of targeted inhibition of crawfish spoilage at 4 °C in vacuum packaging.
Topics: Animals; RNA, Ribosomal, 16S; Food Packaging; Food Microbiology; Vacuum; Microbiota; Astacoidea; Food Preservation
PubMed: 36500719
DOI: 10.3390/molecules27238618 -
Scientific Reports Dec 2022The uncontrolled discharge of industrial wastes causes the accumulation of high heavy metal concentrations in soil and water, leading to many health issues. In the...
The uncontrolled discharge of industrial wastes causes the accumulation of high heavy metal concentrations in soil and water, leading to many health issues. In the present study, a Gram-negative Aeromonas sobria was isolated from heavily contaminated soil in the Tanjaro area, southwest of Sulaymaniyah city in the Kurdistan Region of Iraq; then, we assessed its ability to uptake heavy metals. A. sobria was molecularly identified based on the partial amplification of 16S rRNA using novel primers. The sequence was aligned with 33 strains to analyze phylogenetic relationships by maximum likelihood. Based on maximum tolerance concentration (MTC), A. sobria could withstand Zn, Cu, and Ni at concentrations of 5, 6, and 8 mM, respectively. ICP-OES data confirmed that A. sobria reduced 54.89% (0.549 mM) of the Cu, 62.33% (0.623 mM) of the Ni, and 36.41% (0.364 mM) of the Zn after 72 h in the culture medium. Transmission electron microscopy (TEM) showed that A. sobria accumulated both Cu and Ni, whereas biosorption was suggested for the Zn. These findings suggest that metal-resistant A. sobria could be a promising candidate for heavy metal bioremediation in polluted areas. However, more broadly, research is required to assess the feasibility of exploiting A. sobria in situ.
Topics: RNA, Ribosomal, 16S; Phylogeny; Iraq; Metals, Heavy
PubMed: 36481784
DOI: 10.1038/s41598-022-25781-3 -
Journal of the American Chemical Society Nov 2022Efficient, site-specific, and bio-orthogonal conjugation of chemical functionalities to proteins is of great utility in fundamental research as well as industrial...
Efficient, site-specific, and bio-orthogonal conjugation of chemical functionalities to proteins is of great utility in fundamental research as well as industrial processes (e.g., the production of antibody-drug conjugates and immobilization of enzymes for biocatalysis). A popular approach involves reacting a free N-terminal cysteine with a variety of electrophilic reagents. However, current methods for generating proteins with N-terminal cysteines have significant limitations. Herein we report a novel, efficient, and convenient method for producing recombinant proteins with free N-terminal cysteines by genetically fusing a Met-Pro-Cys sequence to the N-terminus of a protein of interest and subjecting the recombinant protein to the sequential action of methionine and proline aminopeptidases. The resulting protein was site-specifically labeled at the N-terminus with fluorescein and a cyclic cell-penetrating peptide through native chemical ligation and a 2-cyanobenzothiazole moiety, respectively. In addition, the optimal recognition sequence of proline aminopeptidase was determined by screening a combinatorial peptide library and incorporated into the N-terminus of a protein of interest for most efficient N-terminal processing.
Topics: Cysteine; Aminopeptidases; Recombinant Proteins; Fluorescein; Peptide Library
PubMed: 36378906
DOI: 10.1021/jacs.2c10194 -
Animals : An Open Access Journal From... Nov 2022Plant-derived bioactive compounds with promising nutritional and therapeutic attributes (phytogenics) are among the top priorities in the aquaculture sector. Therefore,...
Plant-derived bioactive compounds with promising nutritional and therapeutic attributes (phytogenics) are among the top priorities in the aquaculture sector. Therefore, the impact of thymol (Thy) and/or thymoquinone (ThQ) on the growth, immune response antioxidant capacity, and () resistance of Nile tilapia was investigated. Four fish groups were fed a control diet and three basal diets supplemented with 200 mg/kg diet of Thy or ThQ and a blend of both Thy and ThQ at a level of 200 mg/kg diet each. At the end of the feeding trial (12 weeks), the tilapias were challenged intraperitoneally with virulent (2.5 × 10 CFU/mL) harboring aerolysin () and hemolysin () genes. The results revealed that tilapias fed diets fortified with a combination of Thy and ThQ displayed significantly enhanced growth rate and feed conversion ratio. Notably, the expression of the genes encoding digestive enzymes (pepsinogen, chymotrypsinogen, α-amylase and lipase) and muscle and intestinal antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase) was significantly upregulated in Thy/ThQ-fed fish. An excessive inflammatory response was subsided more prominently in the group administrated Thy/ThQ as supported by the downregulation of , and genes and in contrast, the upregulation of the anti-inflammatory gene. Remarkably, dietary inclusion of Thy/ThQ augmented the expression of autophagy-related genes, whilst it downregulated that of gene improving the autophagy process. Furthermore, Thy/ThQ protective effect against was evidenced via downregulating the expression of its and virulence genes with higher fish survival rates. Overall, the current study encouraged the inclusion of Thy/ThQ in fish diets to boost their growth rates, promote digestive and antioxidant genes expression, improve their immune responses and provide defense against infections with great economic benefits.
PubMed: 36359158
DOI: 10.3390/ani12213034 -
International Journal of Molecular... Oct 2022species are opportunistic bacteria causing a vast spectrum of human diseases, including skin and soft tissue infections, meningitis, endocarditis, peritonitis,...
species are opportunistic bacteria causing a vast spectrum of human diseases, including skin and soft tissue infections, meningitis, endocarditis, peritonitis, gastroenteritis, and finally hemorrhagic septicemia. The aim of our research was to indicate the molecular alterations in proteins and lipids profiles resulting from and subsp. infection in trout kidney tissue samples. We successfully applied FT-IR (Fourier transform infrared) spectroscopy and MALDI-MSI (matrix-assisted laser desorption/ionization mass spectrometry imaging) to monitor changes in the structure and compositions of lipids, secondary conformation of proteins, and provide useful information concerning disease progression. Our findings indicate that the following spectral bands' absorbance ratios (spectral biomarkers) can be used to discriminate healthy tissue from pathologically altered tissue, for example, lipids (CH/CH), amide I/amide II, amide I/CH and amide I/CH. Spectral data obtained from 10 single measurements of each specimen indicate numerous abnormalities concerning proteins, lipids, and phospholipids induced by infection, suggesting significant disruption of the cell membranes. Moreover, the increase in the content of lysolipids such as lysophosphosphatidylcholine was observed. The results of this study suggest the application of both methods MALDI-MSI and FT-IR as accurate methods for profiling biomolecules and identifying biochemical changes in kidney tissue during the progression of infection.
Topics: Animals; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Lipidomics; Proteomics; Trout; Spectroscopy, Fourier Transform Infrared; Aeromonas; Phospholipids; Proteins; Biomarkers; Kidney; Amides
PubMed: 36293421
DOI: 10.3390/ijms232012551 -
The Brazilian Journal of Infectious... 2022
Topics: Aeromonas; Aneurysm, Infected; Aortitis; Bacteremia; Humans; Soft Tissue Infections
PubMed: 36037846
DOI: 10.1016/j.bjid.2022.102699