scholarly journals Air-nanobubbles ineffective to reduce pathogenic bacteria in fresh and brackish waters

2021 ◽  
Author(s):  
Jose A. Domingos ◽  
Qianjun Huang ◽  
Hong Liu ◽  
Ha Thanh Dong ◽  
Nareerat Khongcharoen ◽  
...  

ABSTRACTNanobubble (NB) technology has been hailed as a novel way to disinfect water. Previous studies suggested that when NBs collapse, they create shock waves that result in OH- free radicals, which can damage cells, including bacteria. In this study, we investigated, through a series of 11 experiments, the potential use of air nanobubbles (128 ± 44 nm, mean ± SD) to reduce the concentration of various pathogenic bacteria including Aeromonas hydrophila, A. veronii, Vibrio parahaemolyticus, and Streptococcus agalactiae under controlled, tank-based laboratory conditions. Despite the high number of nanobubbles continuously added to a relatively small volume of water in experimental tanks (50-100 L), we did not observe a consistent or significant decrease in bacteria that would control disease outbreaks. Although most of the experiments were conducted in fresh water on A. hydrophila, results were consistent across fresh and brackish water experiments, Gram-negative and Gram-positive bacteria, and a range of nanobubble concentrations. This study suggests air nanobubbles on their own are inadequate to significantly reduce high levels of pathogenic bacteria in water. We propose to explore other gases for improving the disinfection properties of this technology.SIGNIFICANCE STATEMENTAir nanobubbles did not sufficiently reduce the level of bacteria in laboratory experiments.

2010 ◽  
Vol 9 (2) ◽  
pp. 127
Author(s):  
. Sunarto ◽  
. Sukenda ◽  
. Widanarni

The ability of probiotic bacteria to control disease infection has been used in aquaculture. This experiment was conducted to isolate and characterize probiotic bacteria; the competition test its ability probiotic bacteria against pathogenic bacteria; and to improve survival rate of Leptobarbus hoeveni. The bacteria were isolated from Leptobarbus hoeveni and its culture environment, and then tested to know its ability to inhibit bacterial fish pathogen in-vitro. Furthermore, the selected probiotic bacteria were tested in vivo to evaluate their ability to inhibit pathogen of Leptobarbus hoeveni.  The result showed that probiotic bacteria inhibit the growth of Streptococcus iniae, Flexibacter columnaris, Mycobacterium fortuitum and Aeromonas hydrophila in vitro.  Isolate DD3 was the best of candidate probiotic because of the ability to inhibit pathogen, especially A. hydrophila, the most virulent bacteria in Leptobarbus hoeveni.<br /><br />Key Words  : probiotic bacteria, Leptobarbus hoeveni, pathogenic bacteria<br /><br />Abstrak<br /><br />Kemampuan bakteri probiotik untuk mengendalikan penyakit infeksi telah digunakan dalam akuakultur. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri probiotik, menguji kemampuan bakteri probiotik terhadap bakteri patogen, sehingga dapat meningkatkan tingkat kelangsungan hidup ikan jelawat. Bakteri diisolasi dari usus ikan jelawat dan lingkungan budaya, kemudian diuji kemampuannya menghambat bakteri patogen secara in-vitro. Selanjutnya bakteri probiotik yang dipilih diuji secara in vivo untuk mengevaluasi kemampuannya dalam menghambat patogen di dalam tubuh ikan jelawat. Dari hasil penelitian diperoleh bakteri probiotik yang diisolasi dari usus dan lingkungan budaya ikan jelawat menunjukkan penghambatan pertumbuhan terhadap Streptococcus iniae, Flexibacter columnaris, Mycobacterium fortuitum dan Aeromonas hydrophila secara in vitro. Isolat DD3 merupakan kandidat probiotik terbaik, karena mempunyai kemampuan untuk menghambat bakteri patogen,  khususnya bakteri  A. hydrophila adalah bakteri yang paling viluren bagi ikan jelawat.<br />    <br />Kata Kunci:   bakteri probiotik, ikan jalawat dan baktri patogen<br />


2021 ◽  
Vol 322 ◽  
pp. 02004
Author(s):  
Desy Sugiani ◽  
Nunak Nafiqoh ◽  
Hessy Novita ◽  
Tuti Sumiati ◽  
Septyan Andriyanto ◽  
...  

Alternative prevention should be developed to control disease outbreaks in Tilapia culture caused by co-infections of Aeromonas hydrophila and Streptococcus agalactiae. Applications of vaccines with low cost and simple methods are highly recommended. This study was conducted to find out the safety and the efficacy of immersion vaccine in Tilapia used bivalent vaccines with formalin inactivated of S. agalactiae and A. hydrophila. Tilapia (Oreochromis niloticus) were divided into two groups, vaccinated and not vaccinated, with single and double doses immersion. The results showed that single and double doses of immersion vaccine were safe for fish (SR 100%) and effectively increased the antibody titer values compared to non-vaccinated fish. The immersion vaccine method can be recommended as an alternative to controlled fish diseases, especially for both Motile Aeromonads Septicaemia and Streptococcosis caused by A. hydrophila and S. agalactiae infections, respectively.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olivia Nathalia ◽  
Diana Elizabeth Waturangi

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.


2021 ◽  
pp. 088391152110142
Author(s):  
Velu Gomathy ◽  
Venkatesan Manigandan ◽  
Narasimman Vignesh ◽  
Aavula Thabitha ◽  
Ramachandran Saravanan

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.


2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.


2011 ◽  
Vol 4 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Jeffrey Blazar ◽  
Marc Allard ◽  
E. Kurt Lienau

AbstractFood safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published <abs>Food safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published literature. We highlight at least eleven different species of insects, including the lesser mealworm, Alphitobius diaperinus (Panzer); secondary screwworm, Cochliomyia macellaria (Fabricius); synanthropic flies [flesh fly, Sarcophaga carnaria (L.); house fly, Musca domestica (L.); fruit fly, Drosophila melanogaster (Meigen); and stable fly, Stomoxys calcitrans (L.)], American cockroach, Periplaneta americana (L.); German cockroach, Blatella germanica (L.); Oriental cockroach, Blatta orientalis (L.); Pacific beetle cockroach, Diploptera punctata (Eschscholtz); and Speckled feeder cockroach, Nauphoeta cinerea (Olivier), which act as vectors for Salmonella spp. or Escherichia coli and illustrate how these insects are successful vectors of foodborne disease outbreaks. We propose that insects be considered as one of the latest issues in food safety initiatives. Not only are some insects extremely important contributors to diseases, but now we suggest that more research into insects as potential carriers of E. coli and Salmonella spp., and therefore as contributing to foodborne disease outbreaks, is granted.


Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.


1999 ◽  
Vol 43 (7) ◽  
pp. 1693-1699 ◽  
Author(s):  
Jamese J. Hilliard ◽  
Raul M. Goldschmidt ◽  
Lisa Licata ◽  
Ellen Z. Baum ◽  
Karen Bush

ABSTRACT Many pathogenic bacteria utilize two-component systems consisting of a histidine protein kinase (HPK) and a response regulator (RR) for signal transduction. During the search for novel inhibitors, several chemical series, including benzoxazines, benzimidazoles, bis-phenols, cyclohexenes, trityls, and salicylanilides, were identified that inhibited the purified HPK-RR pairs KinA-Spo0F and NRII-NRI, with 50% inhibitory concentrations (IC50s) ranging from 1.9 to >500 μM and MICs ranging from 0.5 to >16 μg/ml for gram-positive bacteria. However, additional observations suggested that mechanisms other than HPK inhibition might contribute to antibacterial activity. In the present work, representative compounds from the six different series of inhibitors were analyzed for their effects on membrane integrity and macromolecular synthesis. At 4× MIC, 17 of 24 compounds compromised the integrity of the bacterial cell membrane within 10 min, as measured by uptake of propidium iodide. In this set, compounds with lower IC50s tended to cause greater membrane disruption. Eleven of 12 compounds inhibited cellular incorporation of radiolabeled thymidine and uridine >97% in 5 min and amino acids >80% in 15 min. The HPK inhibitor that allowed >25% precursor incorporation had no measurable MIC (>16 μg/ml). Fifteen of 24 compounds also caused hemolysis of equine erythrocytes. Thus, the antibacterial HPK inhibitors caused a rapid decrease in cellular incorporation of RNA, DNA, and protein precursors, possibly as a result of the concomitant disruption of the cytoplasmic membrane. Bacterial killing by these HPK inhibitors may therefore be due to multiple mechanisms, independent of HPK inhibition.


Author(s):  
Alfabetian Harjuno Condro Haditomo ◽  
Angela Mariana Lusiastuti ◽  
Widanarni Widanarni

ABSTRAK   Pengendalian penyakit bakterial yang umum dilakukan dengan pemakaian antibiotik atau  bahan kimia sudah tidak diperbolehkan lagi karena menimbulkan patogen yang resisten  terhadap bahan kimia tersebut, terlebih jika penggunaan tidak sesuai dengan anjuran yang diberikan. Dampak negatif terhadap kesehatan konsumen berupa residu antibiotik juga menjadi pertimbangan yang harus diperhatikan. Manipulasi terhadap populasi mikroba yang berada di perairan guna pencegahan sebelum terjadinya serangan bakteri yang bersifat mematikan perlu dilakukan sebagaimana konsep probiotik sebagai biokontrol. Tujuan penelitian ini adalah menguji kandidat probiotik dalam menekan atau menghambat bakteri patogen Aeromonas hydrophila. Penelitian ini dilaksananakan dalam dua tahap. Tahap pertama adalah tahap pengujian bakteri kandidat probiotik secara in vitro menggunakan metode zona hambat dan kultur bersama pada media agar.  Tahap kedua adalah uji tentang bakteri kandidat probiotik dengan patogen pada media budidaya. Hasil terbaik penelitian tahap pertama pada  uji kultur bersama antara kandidat probiotik B. firmus dengan A. hydrophila pada skala in vitro adalah dengan penambahan probiotik  B. firmus sebanyak 108 cfu/ml. Sedangkan pada penelitian tahap kedua didapatkan hasil berturut-turut perlakuan D dengan tingkat kelangsungan hidup (SR) mencapai 90%, perlakuan C dengan SR 75%, perlakuan A dengan SR 50% dan perlakuan K dengan SR 50%.   Kata kunci: Bacillus firmus, probiotik, Aeromonas hydrophila, media budidaya   ABSTRACT  Controlling bacterial disease with the use of antibiotics or chemicals is no longer allowed as it results in pathogens that are resistant to the chemicals, especially when not in accordance with the recommendations provided. The negative impactsof the antibiotics residues on the consumers’ health  also need to be considered. Manipulation of microbial populations present in the waters as preventation before the lethal attack of bacteria needs to be done which is in accordance with the concept of probiotics as biocontrol.The purpose of this study was to test the probiotic candidates in suppressing or inhibiting pathogenic bacteria Aeromonas hydrophila. This study was conducted in two stages. The first stage was to test a candidate probiotic bacteria in vitro using culture methods and inhibition zone on the media together. The second stage wasto test candidate probiotic bacteria to pathogens on the cultivation media. The best results in the first phase of the research is shared culture test between probiotic candidate B. FIRMUS with A. hydrophila on vitro scale is the addition of the probiotic B. FIRMUS 108 cfu / ml. While in the second phase of the research results obtained successively: treatment D with a survival rate (SR) reaches 90%, treatment C with SR 75%, treatment A with SR 50% and treatment K with SR 50%. Keywords: Bacillus FIRMUS, probiotics, Aeromonas hydrophila, media cultivation


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