An investigation of sudden death in farmed infantSiamesecrocodiles during winter and spring in Hainan, China

2017 ◽  
Author(s):  
Jiping Zheng ◽  
Jifeng Zeng ◽  
Guiying Guo ◽  
Jiahao Jiang ◽  
Nuo Yang ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Abdominal Cavity ◽  
Edwardsiella Tarda ◽  
Internal Organs ◽  
Antimicrobial Drugs ◽  
Highly Sensitive ◽  
One Year ◽  
Enterobacter Asburiae ◽  
Proteus Penneri

Sudden deaths without any specific clinical sign occurred among one year old young ones on Siamese crocodile (Crocodylus siamensis) farms in Hainan province, China, during winter and spring in 2012 - 2013. The autopsy showed that the internal organs seemed normal except full of clear ascites in abdominal cavity. There were total six bacterial species isolated, Edwardsiella tarda, Proteus penneri, Proteus vulgaris, Enterobacter asburiae, Citrobacter freundii and Micrococcus luteus from either the heart bloods or the spleens and livers. The virulence of isolated strains was tested by intraperitoneal inoculation in female Chinese edible frogs (Rana rugulosa or Hoplobatrachus rugulosus). The six-day mortality revealed that E. tarda was the most pathogenic, whereas P. penneri and E. asburiae exhibited no infection at all, and the rest demonstrated similar inconspicuous toxicity. All these findings suggest that E. tarda would be the principal suspect causing death of Siamese crocodile. The sensitivities of the E. tarda isolates were tested against 20 kinds of antimicrobial drugs. The results showed that ceftazidime, norfloxacin and amikacin were highly sensitive to the isolates of E.tarda.

scholarly journals Phylogenetic Relationship of Bacterial Species Involved in Bioremediation of Hydrocarbon Polluted Soils

2019 ◽  
pp. 1-13
Author(s):  
R. B. Agbor ◽  
S. P. Antai
Keyword(s):  
Crude Oil ◽  
Phylogenetic Relationship ◽  
Bacterial Species ◽  
Soil Samples ◽  
Bacterial Counts ◽  
Top Soil ◽  
Significant Difference ◽  
Enterobacter Asburiae ◽  
Proteus Penneri ◽  
Relationship Of

The bio-stimulation of hydrocarbon degrading microbial population in soil using agricultural wastes was carried out. Top soil (0-25 cm depth) from three points were bulked to form composite soil samples, 6 kg each of the composite soil sample was weighed and transferred into 150 plastic buckets with drainage holes at the base. The soil in each plastic bucket was spiked with 300 ml crude oil and amended with different concentrations of agro-wastes and allowed for duration of 30, 60 and 90 days.  The soil samples were then collected and analysed for both total heterotrophic bacterial counts and crude-oil utilizing bacterial counts. Data collected were subjected to a three-way analysis of variance and significant means were separated using Least Significant Difference Test at 5% probability level. The result showed that the application of the amendments increased the bacterial counts in the soil at different treatment levels. However, a higher proliferation rate was observed with bacteria counts exposed to higher waste concentrations compared to their counterparts exposed to lower waste concentrations. The phylogenetic relationship of the hydrocarbon degrading bacterial species shows that the identified bacteria were in two clusters: cluster 1 consist of Bacillus cereus, Bacillus thuringiensis, Bacillus altitudinis, Pseudomonas aeruginosa, Proteus mirabilis and Proteus penneri, while cluster 2 consist of Serratia marcescens, Providencia rettgeri and Enterobacter asburiae. The bacterial species obtained shows a greater relationship, this imply that the similarity of the bacterial species could be the reason for their high proficiency in degrading the hydrocarbons in the soil.

scholarly journals Utilization of induction furnace steel slag based iron oxide nanocomposites for antibacterial studies

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
J. Baalamurugan ◽  
V. Ganesh Kumar ◽  
T. Stalin Dhas ◽  
S. Taran ◽  
S. Nalini ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Iron Oxide ◽  
Building Materials ◽  
Induction Furnace ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Steel Slag ◽  
If Steel ◽  
Growth Inhibitory ◽  
Microplate Reader

AbstractMetals and metal oxide-based nanocomposites play a significant role over the control of microbes. In this study, antibacterial activity of iron oxide (Fe2O3) nanocomposites based on induction furnace (IF) steel slag has been carried out. IF steel slag is an industrial by-product generated from secondary steel manufacturing process and has various metal oxides which includes Al2O3 (7.89%), MnO (5.06), CaO (1.49%) and specifically Fe2O3 (14.30%) in higher content along with metalloid SiO2 (66.42). Antibacterial activity of iron oxide nanocomposites has been revealed on bacterial species such as Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus. Micrococcus luteus has undergone maximum zone of inhibition (ZOI) of 12 mm for 10 mg/mL concentration of steel slag iron oxide nanocomposite. Growth inhibitory kinetics of bacterial species has been studied using ELISA microplate reader at 660 nm by varying the concentration of steel slag iron oxide nanocomposites. The results illustrate that IF steel slag is a potential material and can be utilized in building materials to increase the resistance against biodeterioration. Graphic abstract

scholarly journals Evaluation of Commercial Disinfectants against Staphylococcus lentus and Micrococcus spp. of Poultry Origin

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Otun Saha ◽  
Nadira Naznin Rakhi ◽  
Arif Istiaq ◽  
Israt Islam ◽  
Munawar Sultana ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Bacterial Species ◽  
16S Rrna Gene Sequencing ◽  
Average Diameter ◽  
Diffusion Method ◽  
Dilution Method ◽  
Rrna Gene ◽  
Poultry Farms ◽  
Rrna Gene Sequencing ◽  
Selection Of

Introduction. Effective sanitation strategies for poultry farms require an appropriate selection of the disinfectant based on the contaminants present and their sensitivity to the disinfectants. Aim. The current study investigated the prevalence of streptococci/micrococci in poultry farms of Bangladesh and the efficacy of commercial disinfectants (Savlon, Lysol, Quatovet, Virkon S, and Virocid) along with alcohol against these pathogens to adopt appropriate strategies. Materials and Methods. Conventional approaches and the 16S rRNA gene sequencing were performed to confirm the isolates at the species level along with microtiter biofilm assay to determine their biofilm-forming ability. Efficacy of the disinfectants was tested against those isolates using agar well diffusion and minimum inhibitory concentration (MIC) test by broth dilution method using different dilutions of the disinfectants. Results. Staphylococcus lentus (n = 32), Micrococcus luteus (n = 7), and Micrococcus aloeverae (n = 4) were confirmed among 102 presumptively screened streptococci/micrococci isolates from 43 samples. No single disinfectant showed equally high efficacy against all three bacterial species in agar well diffusion test, although Virocid showed the lowest MIC against all three of them. Lysol was least effective among the commercial disinfectants by both MIC and diffusion method, although each commercial disinfectant was more effective than alcohol. Considering both the average diameter of the inhibition zones and the MIC values, efficacy can be interpreted as Virocid > Quatovet > Savlon > Virkon S > Lysol. Although the efficacy decreased with decreasing concentration, the disinfectants retained a satisfactory level of efficacy at 50% concentration. Among test pathogens, M. aloeverae was the most sensitive to the disinfectants and the weakest biofilm producers, whereas 4/14 S. lentus and 1/5 M. luteus were strong biofilm producers, which may cause more reduction in the efficacy in environmental conditions. Conclusion. As no ideal disinfectant was found in the study, the efficacy of the disinfectants should be routinely evaluated and validated to ensure the sanitation standards in the poultry sector.

Air and hygiene quality in crowded housing environments – a case study of subdivided units in Hong Kong

2016 ◽  
Vol 26 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Ka Man Lai ◽  
Ka Man Lee ◽  
William Yu
Keyword(s):  
Hong Kong ◽  
Urban Poor ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Environmental Parameters ◽  
Bacterial Counts ◽  
Building Conditions ◽  
Skin Bacteria ◽  
Allergen Analysis ◽  
Staphylococcus Spp

The purpose of this study is to explore the environmental quality and hygiene in crowded living environments, subdivided units in Hong Kong. Subdivided units are an emerging form of housing environment for the urban poor. It is hypothesised that subdivided unit residents have a higher risk of exposure to poor hygiene conditions but no measurement has ever been taken to test this hypothesis. Twenty questionnaires and environmental assessments were conducted. Dominant bacterial species were identified as Micrococcus luteus and Staphylococcus spp., and the microbial counts were correlated with building, occupants and environmental parameters. Driven by the high bacterial counts and poor hygiene observation, eight subdivided units were selected for endotoxin, glucan and allergen analysis in bed and floor dust. Total airborne bacterial counts and endotoxin and glucan in dust were found at very high levels in some subdivided units, while unexpectedly, the allergen and mould levels were low. In crowded environments the skin bacteria may mislead the environmental and atmospheric bacterial contamination. Outdoor microbial pollution and deteriorated building conditions can be the main source of indoor contamination. ‘Good’ or ‘Excellent’ class of bacterial counts satisfying the Indoor Air Quality Objective does not guarantee a low endotoxin and glucan level.

scholarly journals An in-depth investigation of 11 pulsars discovered by FAST

2020 ◽  
Vol 495 (3) ◽  
pp. 3515-3530 ◽  
Author(s):  
A D Cameron ◽  
D Li ◽  
G Hobbs ◽  
L Zhang ◽  
C C Miao ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Radio Astronomy ◽  
Lessons Learned ◽  
Polarization Angle ◽  
Next Generation ◽  
Highly Sensitive ◽  
Linearly Polarized ◽  
Drift Scan ◽  
One Year ◽  
The Way

ABSTRACT We present timing solutions and analyses of 11 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These pulsars were discovered using an ultrawide bandwidth receiver in drift-scan observations made during the commissioning phase of FAST, and were then confirmed and timed using the 64-m Parkes Radio Telescope. Each pulsar has been observed over a span of at least one year. Highlighted discoveries include PSR J0344−0901, which displays mode-changing behaviour and may belong to the class of so-called swooshing pulsars (alongside PSRs B0919+06 and B1859+07); PSR J0803−0942, whose emission is almost completely linearly polarized; and PSRs J1900−0134 and J1945+1211, whose well-defined polarization angle curves place stringent constraints on their emission geometry. We further discuss the detectability of these pulsars by earlier surveys, and highlight lessons learned from our work in carrying out confirmation and monitoring observations of pulsars discovered by a highly sensitive telescope, many of which may be applicable to next-generation pulsar surveys. This paper marks one of the first major releases of FAST-discovered pulsars, and paves the way for future discoveries anticipated from the Commensal Radio Astronomy FAST Survey.

scholarly journals Sarconesin II, a New Antimicrobial Peptide Isolated from Sarconesiopsis magellanica Excretions and Secretions

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2077 ◽  
Author(s):  
Andrea Díaz-Roa ◽  
Abraham Espinoza-Culupú ◽  
Orlando Torres-García ◽  
Monamaris M. Borges ◽  
Ivan N. Avino ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Multidrug Resistant ◽  
Peptide Sequence ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Conserved Domain ◽  
Health Institutions

Antibiotic resistance is at dangerous levels and increasing worldwide. The search for new antimicrobial drugs to counteract this problem is a priority for health institutions and organizations, both globally and in individual countries. Sarconesiopsis magellanica blowfly larval excretions and secretions (ES) are an important source for isolating antimicrobial peptides (AMPs). This study aims to identify and characterize a new S. magellanica AMP. RP-HPLC was used to fractionate ES, using C18 columns, and their antimicrobial activity was evaluated. The peptide sequence of the fraction collected at 43.7 min was determined by mass spectrometry (MS). Fluorescence and electronic microscopy were used to evaluate the mechanism of action. Toxicity was tested on HeLa cells and human erythrocytes; physicochemical properties were evaluated. The molecule in the ES was characterized as sarconesin II and it showed activity against Gram-negative (Escherichia coli MG1655, Pseudomonas aeruginosa ATCC 27853, P. aeruginosa PA14) and Gram-positive (Staphylococcus aureus ATCC 29213, Micrococcus luteus A270) bacteria. The lowest minimum inhibitory concentration obtained was 1.9 μM for M. luteus A270; the AMP had no toxicity in any cells tested here and its action in bacterial membrane and DNA was confirmed. Sarconesin II was documented as a conserved domain of the ATP synthase protein belonging to the Fli-1 superfamily. The data reported here indicated that peptides could be alternative therapeutic candidates for use in infections against Gram-negative and Gram-positive bacteria and eventually as a new resource of compounds for combating multidrug-resistant bacteria.

scholarly journals Evolution of subpatent parasitaemia in Trypanosoma cruzi chronically infected mice with the help of a cyclophosphamide amplification transfer assay

1991 ◽  
Vol 33 (6) ◽  
pp. 509-514 ◽  
Author(s):  
José M. Alvarez ◽  
Ayumi Oshima ◽  
Veronica Mozer ◽  
Liliane Guimarães ◽  
Hércules Menezes
Keyword(s):  
Trypanosoma Cruzi ◽  
Acute Phase ◽  
Chronic Phase ◽  
Detection Tool ◽  
Highly Sensitive ◽  
Parasite Detection ◽  
Cyclophosphamide Treatment ◽  
One Year ◽  
Cruzi Infection

We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transferred with one Y strain parasite and in 20% of animals transferred with one CL strain parasite). Using acute phase bloodforms, the assay proved to be more sensitive than conventional subinoculation when dealing with the CL, but not the Y strain of the parasite. With the help of this parasite detection tool, we have studied during a one year period, the evolution of subpatent parasitaemias in a group of mice which survived through chemotherapy from lethal acute phase of T. cruzi infection. Cyclophosphamide transfer assay revealed occult parasitaemias in 100% of the chronic animals, nevertheless, continuous and discontinuous patterns of positivity were observed.

scholarly journals COMPARATIVE ANALYSIS OF METAL NANOPARTICLES SYNTHESIZED FROM HIBISCUS ROSA SINESIS AND THEIR ANTIBACTERIAL ACTIVITY ESTIMATION AGAINST NINE PATHOGENIC BACTERIA

2017 ◽  
Vol 10 (5) ◽  
pp. 323
Author(s):  
Shruti Tyagi
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Au Nanoparticles ◽  
Size Range ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Cost Effective ◽  
Antibacterial Activities ◽  
Agar Disc ◽  
Vis Spectroscopy

Objective: This study demonstates  a simple, cost effective protocol  for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities  of AgNPs  and AuNPs were evaluated against  9 pathogenic bacterial species  Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs  were obtained in 13.01 to 28.14 nm size range, while AuNPs were in  6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates  that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities  of AgNPs,  the zone of inhibition significantly increased with the  increases of concentrations of AgNPs in all pathogenic bacterial species  except  in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity  was displayed  only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial  agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold  nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.  

scholarly journals Biosorption and Characterization of Metal Tolerant Bacteria Isolated from Palar River Basin Vellore

2013 ◽  
Vol 6 (1) ◽  
pp. 125-131 ◽  
Author(s):  
S. Silambarasan ◽  
J. Abraham
Keyword(s):  
Heavy Metals ◽  
Antibiotic Resistance ◽  
River Basin ◽  
Metal Tolerance ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Heavy Metal Tolerance ◽  
Enterobacter Aerogenes ◽  
Alcaligenes Faecalis ◽  
Antibiotics Resistance

Metal pollution is a growing problem and microbes have adapted to tolerate the presence of metals and even use them. The investigation was carried out to screen for bisorption property of metals by bacteria and check for correlation between tolerance to heavy metals and antibiotic resistance. Soil samples were collected from Palar River basin site of Vellore and five distinct bacteria were isolated. Antibiotic resistance (bacitracin, chloramphenicol, streptomycin, rifampicin, penicillin and ampicillin) was checked and tolerance to heavy metals was screened (Cd, Pb, Cu and Zn). It was found that most of the bacterial isolates had multiple antibiotic resistances which might be due to the stress caused by heavy metals released into the Palar river basin, Vellore. The multiple antibiotics resistance of this bacterial species was found to be associated with tolerance to metals. Biosorption studies revealed that Alcaligenes faecalis could tolerate 59% Cd, 61% Pb, 40% Cu, 39% Zn and Staphylococcus aureus removed 60% Cd, 63% Pb, 42% Cu, 41% Zn and Streptococcus lactis absorbed 61% Cd, 57% Pb, 37% Cu, 38% Zn and Micrococcus luteus reduced 56% Cd, 61% Pb, 39% Cu, 41% Zn and Enterobacter aerogenes removed 60% Cd, 55% Pb, 62% Cu, 67% Zn. Keywords: Antibiotic resistant; Heavy metal tolerance; Biosorption; Metal polluted soils. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i1.14678 J. Sci. Res. 6 (1), 125-131 (2014)      

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