Probiotics are known to have a long history of safe use and can be formulated into many different types of products, including foods, drugs, and dietary supplements. Several probiotic microorganisms ...like genus Lactococcus, Lactobacillus, Streptococcus, Enterococcus, Bifidobacterium, Pediococcus and Propionibacteria spp. are these days used in fermented dairy products and drug formulations. Due to their human consumption, safety of these organisms is of primary importance as their resistance towards antibiotics can be one of the possible threat. The gravity of this issue is further compounded by the possibility of bacteria to transfer resistance determinants horizontally to pathogens and commensal gut microbiota. Antibiotic resistance in these beneficial microbes, either intrinsic or due to any mutation does not manifest a safety concern in itself. Some probiotic strains with intrinsic antibiotic resistance per se could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, have often been detected in the typical probiotic genera, and hence constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue. Plasmid-associated antibiotic resistance, which occasionally occurs, is a matter of concern as it can be detrimental to use of probiotics owing the possibility of the resistance spreading to harmful microorganisms inhabiting the same niche. Further, the presence of transferable antibiotic resistance genes even to a less innocuous member of the gut microbial community poses a safety hazard and needs to be taken into account. Probiotic safety is beleaguered with the scarcity of well designed and targeted studies and needs to be dealt in right perspective. This review aims to deliberate on the presence of antibiotic resistance in commercially used probiotic organisms and their potential transfer to pathogens and other commensal microbiota present in the gut.
•Antibiotic resistance is a burning issue worldwide.•Probiotics can act as a mode of resistance transfer to pathogens.•Complete review of antibiotic resistance reported in commercial probiotics
Two novel macrocyclic complexes of Cr (III) and Fe (III) were synthesized by template methodology leading to the formation of a complex of type MLXX
2
.yH
2
O where L is a macrocyclic ligand obtained ...from Hydrazinecarbothioamide and 2-Sulfanylidene-1,3-diazinane-4,6-dione and
X
= NO
3
−
y
= 2 for Cr(III) and 3 for Fe(III) complexes. The newly prepared complexes were spectroscopically and physicochemically analysed by various techniques like IR, ESI–MS, EPR, CHN, UV–visible, PXRD, magnetic moment, TGA and molar conductance measurements. Antioxidant studies were performed for both metal complexes. In addition to these, compounds were successfully also screened for their biological efficacies against a few pathogenic strains of bacteria and fungi.
CaTiO 3 :xEr 3+ (0.1≤x≤7 mole%) phosphor materials were meticulously prepared through the solution combustion method. Comprehensive analyses employing Powder X-ray Diffraction (PXRD), Field Emission ...Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR) were conducted to investigate the phase, morphology, and vibrational characteristics of the synthesized phosphors. A detailed luminescence study was undertaken using photoluminescence spectroscopy, revealing distinctive 4f-4f transitions associated with Er 3+ in both excitation and emission spectra. The application of Dexter's theory provided insights into the quenching mechanism inherent in CaTiO 3 :Er 3+ phosphors. Photometric studies were carried out to evaluate the suitability of the synthesized material for solid-state lighting applications. Furthermore, to assess the thermal stability of the phosphor material, the activation energy was computed. The fluorescence intensity ratio of thermally coupled energy levels of Er 3+ ion was utilized to assess the temperature-sensing capabilities of the synthesized material. This material may be suitable for solid-state lighting and optical thermometry applications.
The aim of our study was to assess the antibiotic resistance among commercially available probiotic Lactobacilli. A total of 30 isolates were characterized after isolation from 19 commercial ...products, including Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus plantarum and Lactobacillus fermentum. All the isolates were further subjected to antibiotic susceptibility test using disc diffusion method against a total of 45 antibiotics. Most of the isolates were found to exhibit multiple resistance against some of the most commonly used antibiotics. The isolates showed high level of resistance toward nalidixic acid, vancomycin, kanamycin, teicoplanin, co‐trimoxazole, amikacin, streptomycin, norfloxacin, cefepime and nitrofurantoin. Besides, isolates displayed a low level of resistance toward tobramycin, gentamicin, ampicillin, cefaclor, methicillin, penicillin, tetracycline, levofloxacin, azithromycin, chloramphenicol, amoxyclav, sulbactam, oxacillin, ofloxacin, ciprofloxacin, cloxacillin and novobiocin. All the isolates were found to be susceptible against cefatrixone, ceftazidime, cefadroxil, cefotaxime, cephalothin, cefoperazone and netillin, whereas none of the strains showed resistant to clindamycin, erythromycin, linezolid, quinupristin/dalfopristin and doxycycline. The present study showed that antibiotic resistance is prevalent in different species of probiotic strains, which may pose a food safety concern. Hence, antibiotic sensitivity should be considered as an important part of safety assessment for the evaluation of probiotics.
Practical Applications
Antibiotic resistance has become a major public health concern and is drawing the interest of health and research professionals all around the world. Commercial probiotics are generally considered as safe for humans but due to their very high consumption there is a need to put sufficient safeguards to protect the consumers from any adverse effects. The safety of these probiotic strains is becoming prerequisite with antibiotic resistance as an emerging issue and their potential to transfer antibiotic resistance genes to pathogenic/commensal bacteria cannot be neglected. The anticipated problem is that probiotic strains and starter cultures might contain naturally occurring antibiotic resistance genes which if present on mobile genetic elements can be transferred to commensal and pathogenic organisms in the gut. The European Food Safety Authority recommends that bacterial strains harboring transferable antibiotic resistance genes should not be used in animal feeds, fermented and probiotic foods for human use.
Probiotic lactobacilli are generally recognized as safe (GRAS) and are being used in several food and pharma formulations. However, growing concern of antibiotic resistance in bacterial strains of ...food origin and its possible transmission via functional foods is increasingly being emphasized.
This study screened potential probiotic lactic acid bacteria (LAB) strains for their phenotypic and genotypic antibiotic resistance profiles.
Susceptibility to different antibiotics was assayed by the Kirby Bauer standard disc diffusion protocol. Both conventional and SYBR-RTq-PCR were used for detection of resistance coding genes.
A variable susceptibility pattern was documented against different antibiotic classes. LAB strains irrespective of origin displayed marked phenotypic resistance against cephalosporins, aminoglycosides, quinolones, glycopeptides; and methicillin among beta-lactams with few exceptions. In contrast, high sensitivity was recorded against macrolides, sulphonamides and carbapenems sub-group of beta-lactams with some variations. parC, associated with ciprofloxacin resistance was detected in 76.5% of the strains. Other prevalent resistant determinants observed were aac(6?)Ii (42.1%), ermB, ermC (29.4%), and tetM (20.5%). Six (?17.6%) of the isolates were free from genetic resistance determinants screened in this study.
Study revealed presence of antibiotic resistance determinants among lactobacilli from both fermented foods and human sources.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The study examines the impact of the Microfinance Institutions’ (MFIs) size on their client targeting. Using MFI clients’ household data, the study considers household income, wealth, human ...development, caste, settlement type, and purposes of loans as different client targeting dimensions. The analysis is based on a sample survey of over 301 women clients who had received loans exclusively from 12 big and 13 small MFIs.The results indicate that the MFI size has an adverse effect on social performance. As the MFIs grow in size, they tend to target and serve the wealthier and non-agriculturally employed clients residing in urban areas. The women’s passive role in borrowing emerges as yet another concern. The instances of poverty penalty among the poor clients as reflected through higher interest rates for small-sized loans are yet another concern. The target towards poverty eradication may turn out to be a far cry under the large-sized MFIs.
: Since introduction of functional foods, commercialization of the traditionally used probiotics has ushered in more followers into the new fraternity of sophisticated, health‐conscious consumers. ...In 1995, this was followed by the first introduction of prebiotics. Prebiotics are defined as “a non‐digestible feed supplement, beneficially affecting the host by selectively stimulating growth and/or activity in one or a limited number of bacteria in the colon.” The number of new product introductions with prebiotics has steeply increased over the last few years. Paradoxically, probiotics have limited applications as these cannot be used in wide range of food products because of their viability issue. Fortunately, prebiotics do not suffer from any such constraint and can be used in a wide range of food products. Probiotics do not have a long shelf life in their active form. In most cases, refrigeration is required to maintain the shelf life. While probiotics are predominantly used in fermented dairy products, the use of prebiotics has expanded into other food categories. Prebiotics have successfully been incorporated in a wide variety of human food products such as baked goods, sweeteners, yoghurts, nutrition bars, and meal replacement shakes. For instance, the introduction of galacto‐oligosaccharides (GOS) into baby foods has been very successful. GOS, which are identical to the human milk oligosaccharides, has emerged with strong clinical support for both digestive and immune health. Various aspects related to GOS such as types and functions of functional food constituents with special reference to GOS, their role as prebiotics, and enhanced industrial production through microbial intervention are dealt in this review.
Abstract The melt quenching procedure has been followed to synthesize transparent Tb 3+ singly activated and Tb 3+ /Eu 3+ co-activated TeO 2 –WO 3 –K 2 O–ZnO–Bi 2 O 3 (TWKZBi) glasses. The structural ...characteristics of the prepared TWKZBi glass samples were examined through x-ray diffraction. The existence of functional units corresponding to the different vibrations has been examined via Raman spectroscopy. The photoluminescent characteristics and energy transfer (ET) analysis in the Tb 3+ /Eu 3+ co-activated TWKZBi glasses were investigated in depth. Several emission peaks have been observed in Tb 3+ doped TWKZBi glasses under n-UV and blue excitations and the maximum luminescent intensity has been detected for 2.0 mol% of Tb 3+ doped TWKZBi glass sample. The emission spectra of co-doped Tb 3+ and Eu 3+ ions in the TWKZBi glasses have been studied, and the maximum ET efficiency is found to be 32.82% under n-UV excitation. The ET from sensitizer (Tb 3+ ) to activator (Eu 3+ ) ions happen through dipole–dipole interaction, as confirmed by Dexter’s and Reisfeld’s approximation. The colour-tunable emission in the prepared glass samples can be achieved via varying the content of activator ions. The decay profiles for the 5 D 4 level of Tb 3+ ions diminish with varying the concentration of Eu 3+ ions, confirming the ET from Tb 3+ to Eu 3+ ions. Furthermore, temperature-dependent photoluminescence studies show that the Tb 3+ /Eu 3+ co-doped TWKZBi glasses have good thermal stability. All the aforementioned results reveal the suitability of the Tb 3+ /Eu 3+ co-activated TWKZBi glass samples for photonic applications.
PDF
