Interactions between micro-organisms on skin

Author(s):  
W. C. Noble

SynopsisThe mechanisms of interaction are discussed in general terms; this is followed by a review of interaction which may occur in tinea paedis.The production of penicillin-like and other antibiotics by dermatophyte fungi in lesions of athletes foot may result in the selection of an antibiotic-resistant bacterial flora which, perhaps by production of antibiotic or other secondary metabolites, can reduce the viability of the fungi. The effect on the host is to bring about a change from a fungal skin lesion which is dry and scaly to a bacterial lesion which is macerated and malodorous.

Author(s):  
Ana Rita Almeida ◽  
Marta Tacão ◽  
Joana Soares ◽  
Inês Domingues ◽  
Isabel Henriques

The emergence of antibiotic-resistant pathogens due to worldwide antibiotic use is raising concern in several settings, including aquaculture. In this work, the selection of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) was evaluated after exposure of zebrafish to oxytetracycline (OTC) for two months, followed by a recovery period. The selection of ARB in water and fish was determined using selective media. The abundance of tetA genes was estimated through qPCR. Higher prevalence of ARB was measured in all samples exposed to the antibiotic when compared to control samples, although statistical significance was only achieved five days after exposure. Isolates recovered from samples exposed to the antibiotic were affiliated with Pseudomonas and Stenotrophomonas. Various antibiotic susceptibility profiles were detected and 37% of the isolates displayed multidrug resistance (MDR). The selection of the tetA gene was confirmed by qPCR at the highest OTC concentration tested. Two MDR isolates, tested using zebrafish embryos, caused significant mortality, indicating a potential impact on fish health and survival. Overall, our work highlights the potential impact of antibiotic contamination in the selection of potential pathogenic ARB and ARGS.


2021 ◽  
Author(s):  
Muhammad Jahangeer ◽  
Areej Riasat ◽  
Zahed Mahmood ◽  
Muhammad Numan ◽  
Naveed Munir ◽  
...  

Chemotherapeutic agents produce from numerous sources such as animals, plants and micro-organisms are derived from the natural products. Although the existing therapeutic pipeline lacks fungal-derived metabolites, but hundreds of secondary metabolites derived from fungi are known to be possible chemotherapies. Over the past three decades, several secondary metabolites such as flavonoids, alkaloids, phenolic and polyketides have been developed by Saccharomyces cerevisiae species with exciting activities that considered valued for the growth of new chemotherapeutic agents. Many secondary metabolites are protective compounds which prevent abiotic and biotic stresses, i.e. predation, infection, drought and ultraviolet. Though not taking part in a living cell’s central metabolism, secondary metabolites play an important role in the function of an organism. Nevertheless, due to slow biomass build-up and inadequate synthesis by the natural host the yield of secondary metabolites is low by direct isolation. A detailed comprehension of biosynthetic pathways for development of secondary metabolites are necessary for S. cerevisiae biotransformation. These metabolites have higher inhibitory effect, specificity among cancer and normal cells, and the mechanism of non-apoptotic cell killing. This study shows the significance of bioactive compounds produced by S. cerevisiae species with their possible activity and value in chemotherapeutic drugs pipeline. The isolation and alteration of these natural secondary metabolites would promote the development of chemotherapeutic drugs.


2021 ◽  
Vol 2021 ◽  
pp. 1-30
Author(s):  
Najwan Jubair ◽  
Mogana Rajagopal ◽  
Sasikala Chinnappan ◽  
Norhayati Binti Abdullah ◽  
Ayesha Fatima

Microbial resistance has progressed rapidly and is becoming the leading cause of death globally. The spread of antibiotic-resistant microorganisms has been a significant threat to the successful therapy against microbial infections. Scientists have become more concerned about the possibility of a return to the pre-antibiotic era. Thus, searching for alternatives to fight microorganisms has become a necessity. Some bacteria are naturally resistant to antibiotics, while others acquire resistance mainly by the misuse of antibiotics and the emergence of new resistant variants through mutation. Since ancient times, plants represent the leading source of drugs and alternative medicine for fighting against diseases. Plants are rich sources of valuable secondary metabolites, such as alkaloids, quinones, tannins, terpenoids, flavonoids, and polyphenols. Many studies focus on plant secondary metabolites as a potential source for antibiotic discovery. They have the required structural properties and can act by different mechanisms. This review analyses the antibiotic resistance strategies produced by multidrug-resistant bacteria and explores the phytochemicals from different classes with documented antimicrobial action against resistant bacteria, either alone or in combination with traditional antibiotics.


Author(s):  
María Napal Fraile ◽  
Ana María Mendióroz Lacambra ◽  
Alicia Peñalva Vélez

Educating for Sustainability involves promoting sustainable competences in students. Not in vain, wider societal changes that ensure a balance between economic growth, respect for the environment and social justice must start with individual actions, implying knowledge, capacity and willingness to act. However, and although there is wide consensus that education should promote the development of competences for life, putting this theoretical tenet into may entail more problems. Competence is most often expressed in general terms without a specific definition of the intervening elements (knowledge, skills, values, attitudes), which may collide with the necessity of teachers – as learning planners - concrete entities on which to base their process of design. So that, in this work we propose a series of indicators that serve to characterize the four dimensions of scientific competence – contents of science, contents about science, value of science and utility of science-. Although they are primarily intended to be used to filter multimedia resources in an educational platform, this proposal of indicators can be extrapolated to the management and selection of a variety of resources and activities, and for sharing the objectives and evidences for the acquisition of competencies.


1986 ◽  
Vol 237 (3) ◽  
pp. 899-906 ◽  
Author(s):  
B M Dunn ◽  
M Jimenez ◽  
B F Parten ◽  
M J Valler ◽  
C E Rolph ◽  
...  

The hydrolysis of the chromogenic peptide Pro-Thr-Glu-Phe-Phe(4-NO2)-Arg-Leu at the Phe-Phe(4-NO2) bond by nine aspartic proteinases of animal origin and seven enzymes from micro-organisms is described [Phe(4-NO2) is p-nitro-L-phenylalanine]. A further series of six peptides was synthesized in which the residue in the P3 position was systematically varied from hydrophobic to hydrophilic. The Phe-Phe(4-NO2) bond was established as the only peptide bond cleaved, and kinetic constants were obtained for the hydrolysis of these peptide substrates by a representative selection of aspartic proteinases of animal and microbial origin. The value of these water-soluble substrates for structure-function investigations is discussed.


1998 ◽  
Vol 1998 ◽  
pp. 28-28
Author(s):  
J. Hills ◽  
J.V. Nolan ◽  
G.N. Hinch ◽  
J.J. Lynch

Recent studies have shown that when offered a choice of feeds with different concentrations of a particular nutrient (crude protein), sheep can select a diet that meets their current requirements (Kyriazakis and Oldham 1993). To further examine this diet selection behaviour a choice of foods differing in the concentration of S was offered to sheep that were either in a sulphur (S) adequate or a S depleted state. Study of S selection was considered to be the next logical step after protein because of its role in the synthesis of proteins by the rumen micro-organisms.


2020 ◽  
Vol 22 (5) ◽  
pp. 1110-1124 ◽  
Author(s):  
Colin J. Cunningham ◽  
Maria S. Kuyukina ◽  
Irena B. Ivshina ◽  
Alexandr I. Konev ◽  
Tatyana A. Peshkur ◽  
...  

The problems associated with potential risks of antibiotic resistance spreading during bioremediation of oil-contaminated soil are discussed. Careful selection of bacterial strains and pretreatment of organic wastes used as fertilizers are suggested.


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