Contemporary threats of bacterial infections in freshwater fish

AbstractChanges occurring in freshwater ecosystems seem to be fundamental in the development of all microorganisms, including those pathogenic to fish. This has been especially evident in recent years during which dynamic variations in bacterial fish pathology have been observed. Gram-negative bacteria commonly known to be pathogenic to fish, likeAeromonasspp.,Flavobacteriumspp.,Pseudomonasspp., andShewanella putrefaciensare replaced by other species, which until now have not been known to be virulent or even conditionally pathogenic to fish. Nowadays, among these other speciesAcinetobacterspp.,Plesiomonas shigelloides,Sphingomonas paucimobilis, andStenotrophomonas maltophiliaare the most frequently isolated from fish exhibiting clinical signs of disease. Two Gram-positive bacteria have become pathogens of particular importance in fish pathology in Poland:Lactococcus garviaeandStreptococcus iniae. In addition, infections caused by the Gram-positive bacteriumKocuria rhizophilahave appeared in recent years. This bacterium has not been known until now to be pathogenic to fish. Therefore, this infection could be called an emergent disease.

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Inhibition of Aspergillus flavus and Selected Gram-positive Bacteria by Chelation of Essential Metal Cations by Polyphosphates

Journal of Food Protection ◽

10.4315/0362-028x-54.5.360 ◽

1991 ◽

Vol 54 (5) ◽

pp. 360-365 ◽

Cited By ~ 31

Author(s):

S.J. KNABEL ◽

H.W. WALKER ◽

P.A. HARTMAN

Keyword(s):

Aspergillus Flavus ◽

Binding Sites ◽

Iron Supplementation ◽

Cation Binding ◽

Gram Negative Bacteria ◽

Positive Bacterium ◽

Gram Positive ◽

Tetrasodium Pyrophosphate ◽

Gram Positive Bacteria ◽

And Staphylococcus Aureus

A simple well-plate technique was utilized to determine the effect of various metals on the growth of microorganisms in media containing different polyphosphates. Aspergillus flavus and four gram-positive bacteria were completely inhibited by media containing 1% of various alkaline polyphosphates, whereas four gram-negative bacteria were not. Significant differences were observed between the type of polyphosphate added, the type of metal added, and the species of gram-positive bacterium inhibited. The addition of Mg2+ stimulated growth of A. flavus and Bacillus cereus in the presence of tetrasodium pyrophosphate, whereas Mn2+ permitted growth of A. flavus and Staphylococcus aureus in the presence of sodium hexametaphosphate. Iron supplementation allowed the growth of S. aureus and Listeria monocytogenes on media containing 1 % tetrasodium pyrophosphate. A method for determining the amount of calcium and magnesium in water was modified to detect free Mg2+ by replacing EDTA with phosphate. The addition of free Mg2+, but not Mg2+ chelated by tetrasodium pyrophosphate, permitted the growth of B. cereus on a medium containing tetrasodium pyrophosphate. It is speculated that polyphosphates specifically inhibited A. flavus and gram-positive bacteria by removing essential metals from cation-binding sites located within their cell walls.

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Aptamer Affinity-Bead Mediated Capture and Displacement of Gram-Negative Bacteria Using Acoustophoresis

Micromachines ◽

10.3390/mi10110770 ◽

2019 ◽

Vol 10 (11) ◽

pp. 770

Author(s):

SangWook Lee ◽

Byung Woo Kim ◽

Hye-Su Shin ◽

Anna Go ◽

Min-Ho Lee ◽

...

Keyword(s):

Binding Affinity ◽

High Purity ◽

Bacterial Infections ◽

High Volume ◽

Flow Mode ◽

Separation Performance ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Here, we report a simple and effective method for capturing and displacement of gram-negative bacteria using aptamer-modified microbeads and acoustophoresis. As acoustophoresis allows for simultaneous washing and size-dependent separation in continuous flow mode, we efficiently obtained gram-negative bacteria that showed high affinity without any additional washing steps. The proposed device has a simple and efficient channel design, utilizing a long, square-shaped microchannel that shows excellent separation performance in terms of the purity, recovery, and concentration factor. Microbeads (10 µm) coated with the GN6 aptamer can specifically bind gram-negative bacteria. After incubation of bacteria culture sample with aptamer affinity bead, gram-negative bacteria-bound microbeads, and other unbound/contaminants can be separated by size with high purity and recovery. The device demonstrated excellent separation performance, with high recovery (up to 98%), high purity (up to 99%), and a high-volume rate (500 µL/min). The acoustophoretic separation performances were conducted using 5 Gram-negative bacteria and 5 Gram-positive bacteria. Thanks to GN6 aptamer’s binding affinity, aptamer affinity bead also showed binding affinity to multiple strains of gram-negative bacteria, but not to gram-positive bacteria. GN6 coated bead can capture Gram-negative bacteria but not Gram-positive bacteria. This study may present a different perspective in the field of early diagnosis in bacterial infectious diseases. In addition to detecting living bacteria or bacteria-derived biomarkers, this protocol can be extended to monitoring the contamination of water resources and may aid quick responses to bioterrorism and pathogenic bacterial infections.

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Phytochemical, antibacterial and antioxidant screening of Artemisia santolinifolia various parts

Bioscience Journal ◽

10.14393/bj-v37n0a2021-54206 ◽

2021 ◽

Vol 37 ◽

pp. e37061

Author(s):

Tabinda Nowsheen ◽

Ali Hazrat ◽

Sayed Wadood Ali Shah ◽

Shabana Bibi ◽

Afshan Begum ◽

...

Keyword(s):

Inhibitory Concentration ◽

Methanolic Extract ◽

Antibacterial Activities ◽

Significant Inhibition ◽

Antioxidant Potential ◽

Gram Negative Bacteria ◽

Positive Bacterium ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Methanolic Extracts

The current study was carried out to explore the phytochemical, antioxidant potential and antibacterial activities of the crude methanolic extract of A. santolinifolia Turcz. Ex Besser. The antioxidant activity was carried out by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay, while methanolic extract displayed the highest scavenging activity (DPPH) was 61.31µg/ml on Artemisia santolinifolia root and the lowest (51.05µg/ml) was record for their leaves. Similarly, in (ABTS) the highest activity (89.16µg/ml) was recorded for roots of A. santolinifolia followed by leaves (68.14µg/ml). In low inhibitory concentration assay, the crude methanolic extracts showed significant inhibition against all tested microbes on different concentrations like 25 µg/ml, 50 µg/ml, and 100 µg/ml. The leaves extract of A. santolinifolia AsL showed MIC of 12.5µg/ml for B. subtilis, a gram-positive bacterium, 50µg/ml for gram positive bacteria S. aureus and 37.5 µg/ml for gram negative bacteria P. aeruginosa that is almost equal to the response of standard ciprofloxacin. Our current study revealed that Artemisia santolinifolia root (AsR) exhibited a significant antioxidant potential while AsL showed good antibacterial effect which is suggested to be used for treatment and management of different infectious diseases.

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Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

International Astronomical Union Colloquium ◽

10.1017/s0252921100015025 ◽

1997 ◽

Vol 161 ◽

pp. 491-504 ◽

Cited By ~ 3

Author(s):

Frances Westall

Keyword(s):

Cell Wall ◽

Life Forms ◽

Cation Binding ◽

Positive Bacterium ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Transmission Electron ◽

Hydrothermal Sediments ◽

Identification Of Bacteria ◽

The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

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Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123830 ◽

1992 ◽

Vol 50 (1) ◽

pp. 686-687

Author(s):

Jacob S. Hanker ◽

Paul R. Gross ◽

Beverly L. Giammara

Keyword(s):

Chronic Arthritis ◽

Blood Cultures ◽

Gram Negative Bacteria ◽

Infectious Arthritis ◽

Bacterial Arthritis ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.3.25 ◽

2019 ◽

Vol 10 (03) ◽

Author(s):

Elaf Ayad Kadhem ◽

Miaad Hamzah Zghair ◽

Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽

Hussam H. Tizkam ◽

Shoeb Alahmad

Keyword(s):

Antibacterial Activity ◽

Magnesium Oxide ◽

Diffusion Method ◽

Oxide Nanoparticles ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Magnesium Oxide Nanoparticles ◽

Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

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BAKTERI PADA KARANG SCLERACTINIA DI KAWASAN PERAIRAN BUNAKEN, MOROTAI DAN RAJA AMPAT

JURNAL PESISIR DAN LAUT TROPIS ◽

10.35800/jplt.8.1.2020.28110 ◽

2020 ◽

Vol 8 (1) ◽

pp. 122

Author(s):

Eghbert Eghbert Elvan Eghbert Elvan Ampou ◽

Iis Iis Triyulianti ◽

Nuryani Widagti ◽

Suciadi Catur Nugroho ◽

Yuli Pancawati

Keyword(s):

Scleractinian Coral ◽

Gram Negative Bacteria ◽

Hard Coral ◽

Field Sampling ◽

Bacterial Isolation ◽

Gram Positive ◽

Coral Mucus ◽

Gram Negative ◽

Gram Positive Bacteria

Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of gram-positive and gram-negative bacteria. The method used for field sampling is time swim, which is by diving at a depth of 5-10 meters for ± 30 minutes and randomly taking samples of coral mucus using siring or by taking directly on corals (reef branching). Mucus samples were analyzed by bacterial isolation in the laboratory. The result shows that there were differences between gram-positive and gram-negative bacteria in the three research sites and that gram-positive bacteria were higher or dominant. Further research that can identify the bacteria species and explain its relationship to the ecosystem is highly recommended.Keywords: Bacteria, Scleractinian coral, gram-positive and -negative, Bunaken, Morotai, Raja Ampat AbstrakPenelitian tentang karang keras (Scleractinian coral) yang terkontaminasi bakteri masih belum banyak dilakukan, terutama di perairan Indonesia. Penelitian ini mengambil sampel mucus karang pada tahun 2010 di 3 (tiga) lokasi berbeda, yakni Bunaken (Mei); Morotai (September) dan Raja Ampat (November), yang difokuskan pada analisis bakteri gram postif dan gram negatif. Metode yang digunakan untuk pengambilan sampel di lapangan adalah time swim, yaitu dengan penyelaman pada kedalaman 5-10 meter selama ±30 menit dan mengambil sampel mucus karang secara acak menggunakan siring atau dengan mengambil langsung pada karang (fraksi cabang). Sampel mucus dianalisis dengan cara isolasi bakteri di laboratorium. Hasil analisis menunjukkan bahwa ada perbedaan antara bakteri gram positif dan gram negative di tiga lokasi survei dan bakteri gram positif lebih tinggi atau dominan. Penelitian lebih lanjut yang dapat menentukan jenis bakteri serta menjelaskan hubungannya dengan ekosistem sangat disarankan untuk dilakukan.Kata Kunci : Bakteri, Scleractinian coral, gram positif dan negatif, Bunaken, Morotai, Raja Ampat

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N-Doped Carbon Quantum Dots as Fluorescent Bioimaging Agents

Crystals ◽

10.3390/cryst11070789 ◽

2021 ◽

Vol 11 (7) ◽

pp. 789

Author(s):

Shih-Fu Ou ◽

Ya-Yun Zheng ◽

Sin-Jen Lee ◽

Shyi-Tien Chen ◽

Chien-Hui Wu ◽

...

Keyword(s):

Quantum Dots ◽

Carbon Nanomaterials ◽

Graphene Quantum Dots ◽

Carbon Quantum Dots ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Fluorescence Characteristics ◽

And Staphylococcus Aureus

Graphene quantum dots, carbon nanomaterials with excellent fluorescence characteristics, are advantageous for use in biological systems owing to their small size, non-toxicity, and biocompatibility. We used the hydrothermal method to prepare functional N-doped carbon quantum dots (N-CQDs) from 1,3,6-trinitropyrene and analyzed their ability to fluorescently stain various bacteria. Our results showed that N-CQDs stain the cell septa and membrane of the Gram-negative bacteria Escherichia coli, Salmonellaenteritidis, and Vibrio parahaemolyticus and the Gram-positive bacteria Bacillus subtilis, Listeria monocytogenes, and Staphylococcus aureus. The optimal concentration of N-CQDs was approximately 500 ppm for Gram-negative bacteria and 1000 ppm for Gram-positive bacteria, and the exposure times varied with bacteria. N-Doped carbon quantum dots have better light stability and higher photobleaching resistance than the commercially available FM4-64. When excited at two different wavelengths, N-CQDs can emit light of both red and green wavelengths, making them ideal for bioimaging. They can also specifically stain Gram-positive and Gram-negative bacterial cell membranes. We developed an inexpensive, relatively easy, and bio-friendly method to synthesize an N-CQD composite. Additionally, they can serve as a universal bacterial membrane-staining dye, with better photobleaching resistance than commercial dyes.

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Gram-positive bacteria cell wall-derived lipoteichoic acid induces inflammatory alveolar bone loss through prostaglandin E production in osteoblasts

Scientific Reports ◽

10.1038/s41598-021-92744-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tsukasa Tominari ◽

Ayumi Sanada ◽

Ryota Ichimaru ◽

Chiho Matsumoto ◽

Michiko Hirata ◽

...

Keyword(s):

Cell Wall ◽

Bone Loss ◽

Alveolar Bone ◽

Osteoclast Differentiation ◽

Lipoteichoic Acid ◽

Alveolar Bone Loss ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

AbstractPeriodontitis is an inflammatory disease associated with severe alveolar bone loss and is dominantly induced by lipopolysaccharide from Gram-negative bacteria; however, the role of Gram-positive bacteria in periodontal bone resorption remains unclear. In this study, we examined the effects of lipoteichoic acid (LTA), a major cell-wall factor of Gram-positive bacteria, on the progression of inflammatory alveolar bone loss in a model of periodontitis. In coculture of mouse primary osteoblasts and bone marrow cells, LTA induced osteoclast differentiation in a dose-dependent manner. LTA enhanced the production of PGE2 accompanying the upregulation of the mRNA expression of mPGES-1, COX-2 and RANKL in osteoblasts. The addition of indomethacin effectively blocked the LTA-induced osteoclast differentiation by suppressing the production of PGE2. Using ex vivo organ cultures of mouse alveolar bone, we found that LTA induced alveolar bone resorption and that this was suppressed by indomethacin. In an experimental model of periodontitis, LTA was locally injected into the mouse lower gingiva, and we clearly detected alveolar bone destruction using 3D-μCT. We herein demonstrate a new concept indicating that Gram-positive bacteria in addition to Gram-negative bacteria are associated with the progression of periodontal bone loss.

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Pyelonephritis in Pediatric Uropathic Patients: Differences from Community-Acquired Ones and Therapeutic Protocol Considerations. A 10-Year Single-Center Retrospective Study

Children ◽

10.3390/children8060436 ◽

2021 ◽

Vol 8 (6) ◽

pp. 436

Author(s):

Giovanni Parente ◽

Tommaso Gargano ◽

Stefania Pavia ◽

Chiara Cordola ◽

Marzia Vastano ◽

...

Keyword(s):

Escherichia Coli ◽

Retrospective Study ◽

Success Rate ◽

Pediatric Population ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Significant Difference ◽

Klebsiella Spp

Pyelonephritis (PN) represents an important cause of morbidity in the pediatric population, especially in uropathic patients. The aim of the study is to demonstrate differences between PNs of uropathic patients and PNs acquired in community in terms of uropathogens involved and antibiotic sensitivity; moreover, to identify a proper empiric therapeutic strategy. A retrospective study was conducted on antibiograms on urine cultures from PNs in vesicoureteral reflux (VUR) patients admitted to pediatric surgery department and from PNs in not VUR patients admitted to Pediatric Emergency Unit between 2010 and 2020. We recorded 58 PNs in 33 patients affected by VUR and 112 PNs in the not VUR group. The mean age of not VUR patients at the PN episode was 1.3 ± 2.6 years (range: 20 days of life–3 years), and almost all the urine cultures, 111 (99.1%), isolated Gram-negative bacteria and rarely, 1 (0.9%), Gram-positive bacteria. The Gram-negative uropathogens isolated were Escherichia coli (97%), Proteus mirabilis (2%), and Klebsiella spp. (1%). The only Gram-positive bacteria isolated was an Enterococcus faecalis. As regards the antibiograms, 96% of not VUR PNs responded to beta-lactams, 99% to aminoglycosides, and 80% to sulfonamides. For the VUR group, mean age was 3.0 years ± 3.0 years (range: 9 days of life–11 years) and mean number of episodes per patient was 2.0 ± 1.0 (range: 1–5); 83% of PNs were by Gram-negatives bacteria vs. 17% by Gram-positive: the most important Gram-negative bacteria were Pseudomonas aeruginosa (44%), Escherichia coli (27%), and Klebsiella spp. (12%), while Enterococcus spp. determined 90% of Gram-positive UTIs. Regimen ampicillin/ceftazidime (success rate: 72.0%) was compared to ampicillin/amikacin (success rate of 83.0%): no statistically significant difference was found (p = 0.09). The pathogens of PNs in uropathic patients are different from those of community-acquired PNs, and clinicians should be aware of their peculiar antibiotic susceptibility. An empiric therapy based on the association ampicillin + ceftazidime is therefore suggested.

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