scholarly journals Valley Fever on the Rise—Searching for Microbial Antagonists to the Fungal Pathogen Coccidioides immitis

2019 ◽  
Vol 7 (2) ◽  
pp. 31 ◽  
Author(s):  
Antje Lauer ◽  
Joe Baal ◽  
Susan Mendes ◽  
Kayla Casimiro ◽  
Alyce Passaglia ◽  
...  
Keyword(s):  
Health Hazard ◽  
Bacterial Species ◽  
Bacterial Isolates ◽  
Coccidioides Immitis ◽  
Valley Fever ◽  
Streptomyces Spp ◽  
Pure Cultures ◽  
Arid Desert ◽  
Selection Of

The incidence of coccidioidomycosis, also known as Valley Fever, is increasing in the Southwestern United States and Mexico. Despite considerable efforts, a vaccine to protect humans from this disease is not forthcoming. The aim of this project was to isolate and phylogenetically compare bacterial species that could serve as biocontrol candidates to suppress the growth of Coccidioides immitis, the causative agent of coccidioidomycosis, in eroded soils or in areas close to human settlements that are being developed. Soil erosion in Coccidioides endemic areas is leading to substantial emissions of fugitive dust that can contain arthroconidia of the pathogen and thus it is becoming a health hazard. Natural microbial antagonists to C. immitis, that are adapted to arid desert soils could be used for biocontrol attempts to suppress the growth of the pathogen in situ to reduce the risk for humans and animals of contracting coccidioidomycosis. Bacteria were isolated from soil samples obtained near Bakersfield, California. Subsequently, pairwise challenge assays with bacterial pure cultures were initially performed against Uncinocarpus reesii, a non-pathogenic relative of C. immitis on media plates. Bacterial isolates that exhibited strongly antifungal properties were then re-challenged against C. immitis. Strongly anti-C. immitis bacterial isolates related to Bacillus subtilis and Streptomyces spp. were isolated, and their antifungal spectrum was investigated using a selection of environmental fungi.

scholarly journals Screening and isolation of arsenic tolerant Rhizobacteria from arsenic contaminated areas of Bangladesh

2019 ◽  
Vol 30 ◽  
pp. 17-25
Author(s):  
AM Taher ◽  
QF Quadir ◽  
MZ Hossen ◽  
T Nazneen ◽  
A Rahman
Keyword(s):  
Plant Species ◽  
Agar Medium ◽  
Plant Roots ◽  
Bacterial Isolates ◽  
Biochemical Traits ◽  
Nutrient Agar Medium ◽  
Pure Cultures ◽  
Maximum Tolerance ◽  
Solubilizing Capacity ◽  
Selection Of

An experiment was carried out to collect and isolate arsenic (As) tolerant rhizobacteria from As contaminated areas of Faridpur district. A total of 32 root samples of 17 plant species were collected from six locations of Bhanga and Nagarkanda upazila. From the plant roots, 16 rhizobacterial isolates were separated and their pure cultures were prepared. The collected rhizobacterial isolates were then characterized for morphological and biochemical traits. Among the bacterial isolates four were gram negative and 12 were gram positive. About 12 bacterial isolates had catalase producing capacity and the remaining three were negative to catalase test. Four bacterial isolates gave the positive HCN test. These bacterial isolates were grown on Pikovskays media to determine their phosphorus (P) solubilizing capacity. Four bacterial isolates had P solubilizing capacity and their Phosphorus Solubilizing Index (PSI) ranged between 3.00 and 4.66. However, isolate FB4 gave the highest P solubilization (4.66 PSI). For the evaluation of As tolerance, nutrient agar medium was prepared with different concentrations of As ranging from 30 to 600 ppm and the bacterial isolates were allowed to grow on the As contaminated medium for 36 hours. Isolate FB9 and FB4 showed maximum tolerance against As upto 600 ppm. Hence, these two isolates, both collected from Bhanga upazila and from wild brinjal species (Solanum capsicoides). Further research is needed to assess their effect on As dynamics at the rhizosphere, selection of suitable plant species for bacterial association and their potentials for field applications. Progressive Agriculture, Vol. 30, Suppl. 1: 17-25, 2019

DIVERSITY OF CULTURABLE BACTERIAL MICROBIOTA OF THE Eisenia foetida DIGESTIVE TRACT

2018 ◽  
Vol 41 (3) ◽  
pp. 255-264 ◽  
Author(s):  
J. Abraham Pérez-Pérez ◽  
David Espinosa-Victoria ◽  
Hilda V. Silva-Rojas ◽  
Lucía López-Reyes
Keyword(s):  
Bacterial Diversity ◽  
Digestive Tract ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
Rrna Gene ◽  
Eisenia Foetida ◽  
Bacterial Isolates ◽  
Bacterial Microbiota ◽  
Decomposition Of Organic Matter ◽  
Earthworm Gut

Bacteria are an unavoidable component of the natural earthworm diet; thus, bacterial diversity in the earthworm gut is directly linked to decomposition of organic matter and development of the surrounding plants. The aim of this research was to isolate and to identify biochemically and molecularly the culturable bacterial microbiota of the digestive tract of Eisenia foetida. Earthworms were sourced from Instituto de Reconversión Productiva y Bioenergética (IRBIO) and Colegio de Postgraduados (COLPOS), México. Bacterial isolation was carried out on plates of Brain Heart Infusion (BHI) culture medium. Fifty six and 44 bacterial isolates were obtained from IRBIO and COLPOS, respectively. The population was composed of 44 Gram-negative and 56 Gram-positive isolates. Over 50 % of the bacterial isolates were rod-shaped cells. The 16S rRNA gene was sequenced and nine genera were identified in worms from IRBIO (Bacillus, Paenibacillus, Solibacillus, Staphylococcus, Arthrobacter, Pantoea, Stenotrophomonas, Acinetobacter and Aeromonas) and six in worms from COLPOS (Bacillus, Paenibacillus, Stenotrophomonas, Staphylococcus, Acinetobacter and Aeromonas). Bacillus was the predominant genus, with eight and six species in the oligochaetes from IRBIO and COLPOS, respectively. The most represented bacteria in the worms from both sites were Bacillus sp. and B. subtilis. The predominance of Bacillus was probably due to spore formation, a reproductive strategy that ensures survival and dispersion in the soil and oligochaetes digestive tract. The gut of E. foetida not only harbored bacterial species of agronomic importance but also species potentially pathogenic for humans (Staphylococcus warneri, Pantoea agglomerans and Stentrophomonas sp.). The larger bacterial diversity in worms from IRBIO could be due to their feeding on cattle manure, which is a rich source of bacteria.

scholarly journals Potential impact of biocide adaptation on selection of antibiotic resistance in bacterial isolates

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Engy Elekhnawy ◽  
Fatma Sonbol ◽  
Ahmed Abdelaziz ◽  
Tarek Elbanna
Keyword(s):  
Antibiotic Resistance ◽  
Cross Resistance ◽  
Main Body ◽  
Bacterial Isolates ◽  
New Agents ◽  
Biocidal Products ◽  
Potential Impact ◽  
Emergence Of Resistance ◽  
Vital Factor ◽  
Selection Of

Abstract Background Antibiotic resistance in pathogenic bacterial isolates has increased worldwide leading to treatment failures. Main body Many concerns are being raised about the usage of biocidal products (including disinfectants, antiseptics, and preservatives) as a vital factor that contributes to the risk of development of antimicrobial resistance which has many environmental and economic impacts. Conclusion Consequently, it is important to recognize the different types of currently used biocides, their mechanisms of action, and their potential impact to develop cross-resistance and co-resistance to various antibiotics. The use of biocides in medical or industrial purposes should be monitored and regulated. In addition, new agents with biocidal activity should be investigated from new sources like phytochemicals in order to decrease the emergence of resistance among bacterial isolates.

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.

Antimicrobial resistance in zoonotic bacteria: lessons learned from host-specific pathogens

2008 ◽  
Vol 9 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Trudy M. Wassenaar ◽  
Peter Silley
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Species ◽  
Lessons Learned ◽  
Animal Host ◽  
Relative Contribution ◽  
Single Animal ◽  
Resistance Patterns ◽  
Animal Hosts ◽  
Zoonotic Bacteria ◽  
Selection Of

AbstractThe relative contribution of veterinary and human clinical treatments to the selection of antimicrobial resistance in zoonotic pathogens remains controversial. In this review, we consider bacterial pathogens that differ in host specificity and address their resistance profiles: pathogens that only occur in the human host, pathogens that are specific to particular food-producing animals and pathogens that occur in both host types. Compared with those pathogens restricted to a single animal host, pathogens found in both human and animal hosts appear to have higher incidences of resistance. However, the most urgent and severe resistance problems occur with pathogens exclusively infecting humans. Differences exist in the available genetic repertoire of a bacterial species and these are reflected in the observed resistance patterns; it is important to note that different bacterial species do not automatically result in similarly resistant populations when they undergo comparable selection in different host species. Thus, within a bacterial species, prevalence of resistance can differ between populations isolated from different hosts. For some species, fluctuations in dominant subpopulations, for instance particular serotypes, can be the most important factor determining resistance. The frequently expressed opinion that veterinary use of antimicrobials is at the heart of many resistance problems may be an oversimplification of the complex forces at play.

Suitability of Natural Geomedia for Radwaste Storage

1982 ◽  
Vol 15 ◽  
Author(s):  
W. S. Fyfe
Keyword(s):  
Rock Properties ◽  
Fracture Flow ◽  
Time Prediction ◽  
Sedimentary Sequences ◽  
Rock Types ◽  
Direct Observations ◽  
Long Time ◽  
Mining Disturbance ◽  
Selection Of

ABSTRACTSelection of the best rock types for radwaste disposal will depend on their having minimal permeability, maximal flow dispersion, minimal chance of forming new wide aperture fractures, maximal ion retention, and minimal thermal and mining disturbance. While no rock is perfect, thinly bedded complex sedimentary sequences may have good properties, either as repository rocks, or as cover to a repository.Long time prediction of such favorable properties of a rock at a given site may be best modelled from studies of in situ rock properties. Fracture flow, dispersion history, and geological stability can be derived from direct observations of rocks themselves, and can provide the parameters needed for convincing demonstration of repository security for appropriate times.

scholarly journals Rapid Detection, Identification, and Enumeration ofEscherichia coli Cells in Municipal Water by Chemiluminescent In Situ Hybridization

2001 ◽  
Vol 67 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Henrik Stender ◽  
Adam J. Broomer ◽  
Kenneth Oliveira ◽  
Heather Perry-O'Keefe ◽  
Jens J. Hyldig-Nielsen ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
16S Rrna ◽  
Sensitivity And Specificity ◽  
Bacterial Species ◽  
Rdna Sequence ◽  
Sequence Information ◽  
Sequence Alignments ◽  
E Coli ◽  
Municipal Water

ABSTRACT A new chemiluminescent in situ hybridization (CISH) method provides simultaneous detection, identification, and enumeration of culturableEscherichia coli cells in 100 ml of municipal water within one working day. Following filtration and 5 h of growth on tryptic soy agar at 35°C, individual microcolonies of E. coliwere detected directly on a 47-mm-diameter membrane filter using soybean peroxidase-labeled peptide nucleic acid (PNA) probes targeting a species-specific sequence in E. coli 16S rRNA. Within each microcolony, hybridized, peroxidase-labeled PNA probe and chemiluminescent substrate generated light which was subsequently captured on film. Thus, each spot of light represented one microcolony of E. coli. Following probe selection based on 16S ribosomal DNA (rDNA) sequence alignments and sample matrix interference, the sensitivity and specificity of the probe Eco16S07C were determined by dot hybridization to RNA of eight bacterial species. Only the rRNA of E. coli and Pseudomonas aeruginosa were detected by Eco16S07C with the latter mismatch hybridization being eliminated by a PNA blocker probe targetingP. aeruginosa 16S rRNA. The sensitivity and specificity for the detection of E. coli by PNA CISH were then determined using 8 E. coli strains and 17 other bacterial species, including closely related species. No bacterial strains other thanE. coli and Shigella spp. were detected, which is in accordance with 16S rDNA sequence information. Furthermore, the enumeration of microcolonies of E. coli represented by spots of light correlated 92 to 95% with visible colonies following overnight incubation. PNA CISH employs traditional membrane filtration and culturing techniques while providing the added sensitivity and specificity of PNA probes in order to yield faster and more definitive results.

scholarly journals In situ identification of Gram-negative bacteria in human lungs using a topical fluorescent peptide targeting lipid A

2018 ◽  
Vol 10 (464) ◽  
pp. eaal0033 ◽  
Author(s):  
Ahsan R. Akram ◽  
Sunay V. Chankeshwara ◽  
Emma Scholefield ◽  
Tashfeen Aslam ◽  
Neil McDonald ◽  
...  
Keyword(s):  
Lipid A ◽  
Respiratory Infections ◽  
Bacterial Species ◽  
Water Soluble ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Human Lungs ◽  
Fluorescent Peptide ◽  
Bacterial Lipid

Respiratory infections in mechanically ventilated patients caused by Gram-negative bacteria are a major cause of morbidity. Rapid and unequivocal determination of the presence, localization, and abundance of bacteria is critical for positive resolution of the infections and could be used for patient stratification and for monitoring treatment efficacy. Here, we developed an in situ approach to visualize Gram-negative bacterial species and cellular infiltrates in distal human lungs in real time. We used optical endomicroscopy to visualize a water-soluble optical imaging probe based on the antimicrobial peptide polymyxin conjugated to an environmentally sensitive fluorophore. The probe was chemically stable and nontoxic and, after in-human intrapulmonary microdosing, enabled the specific detection of Gram-negative bacteria in distal human airways and alveoli within minutes. The results suggest that pulmonary molecular imaging using a topically administered fluorescent probe targeting bacterial lipid A is safe and practical, enabling rapid in situ identification of Gram-negative bacteria in humans.

scholarly journals Strategic selection of an optimal sorbent mixture for in-situ remediation of heavy metal contaminated sediments: Framework and case study

2012 ◽  
Vol 105 ◽  
pp. 1-11 ◽  
Author(s):  
Y.W. Chiang ◽  
R.M. Santos ◽  
K. Ghyselbrecht ◽  
V. Cappuyns ◽  
J.A. Martens ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Contaminated Sediments ◽  
In Situ Remediation ◽  
Selection Of

scholarly journals Prilog poznavanju djelovanja Mateja Andrijina Moronzona*

Ars Adriatica ◽  
2016 ◽  
pp. 103
Author(s):  
Barbara Španjol-Pandelo
Keyword(s):  
Comparative Analysis ◽  
Virgin Mary ◽  
Main Role ◽  
Huge Number ◽  
General Acceptance ◽  
Parish Church ◽  
Archival Documents ◽  
First Time ◽  
Selection Of

Matteo Moronzon, a member of the Venetian family of woodcarvers, was mentioned for the first time in 1407 according to the present known archival documents. Probably after being trained in his father's workshop in Venice, he moved to Zadar with his family – his wife Francisca and sons Pietro and Francesco. In 1418 he undertook the commission of furnishing carved choir stalls for the cathedral of St. Anastasia in Zadar. Various archival documents testify that Matteo lived and worked in Zadar for many years. Therefore it can be assumed that he probably founded his own workshop in Zadar where his son Francesco was trained too. Apart from the attempt to reconstruct Matteo's life and career, the aim of this paper is to interpret one important woodcarving work of art preserved in situ: choir stalls in the former cathedral of Rab, today the arch parish church of the Assumption of the Blessed Virgin Mary in Rab. Without doubt Matteo was the master carver in the production of the choir stalls in Zadar. Since he lived in Zadar it was not unusual that he had the main role in carving the stalls. In Zadar the selection of motives is more balanced and there are no significant differences in the modelling of decorative elements. However, the question whether Matteo carved absolutely everything or he had assistants arises. Considering the amount of work that had to be done it must be assumed that he had assistants who participated in work and helped him to shape the stalls. However, in literature Matteo was considered the only and undisputed author of the choir stalls in Zadar, mostly because of the preserved document. The analysis of the choir stalls in Rab by Ivo Petricioli as well as their evident formal and stylistic similarities with the stalls from the cathedral in Zadar have led to the general acceptance of the hypothesis that they were carved at the workshop of Matteo Moronzon. However, a comprehensive comparative analysis that could confirm that hypothesis was still missing. The analysis of the details and the whole led to the overall conclusion that there were a huge number of similarities between the choir stalls in Rab and Zadar. Therefore it was concluded that Matteo was the principal designer of the choir stalls in Rab who also carved the best parts in Rab, while others, less successful parts, were made by his apprentices and assistants who at the time lived on the island of Rab. In this respect, if Matteo was accepted as the author of the choir stalls of the cathedral in Zadar he must also be accepted as the author of the choir stalls from the excathedral in Rab.

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