scholarly journals Low Endotoxin Recovery—Masking of Naturally Occuring Endotoxin

2019 ◽  
Vol 20 (4) ◽  
pp. 838 ◽  
Author(s):  
Johannes Reich ◽  
Felix Weyer ◽  
Hiroshi Tamura ◽  
Isao Nagaoka ◽  
Hubert Motschmann

Endotoxins are cell wall components of Gram-negative bacteria. A release of endotoxins into the human blood stream results in an inflammation reaction that can lead to life-threatening conditions like sepsis. Therefore, control for endotoxin contamination of intravenously administered drugs is crucial. Drugs are usually tested for putative endotoxin contamination with Limulus-based tests. However, validity of the compendial test procedures is questioned in the case of low endotoxin recovery (LER). To assure validity, regulatory authorities request hold-time studies of endotoxin in addition to pharmacopoeial requirements. Within these studies, endotoxin is added (spiked) to an undiluted product. The spiked product is held for a certain period of time and subsequently diluted for endotoxin determination. Due to the known heterogeneity of endotoxin the question has been raised as to which source represents the most adequate endotoxin spike. In the present study, endotoxin hold-time studies were analyzed by using different sources of endotoxin. Highly purified endotoxin, crude endotoxin extracts (Naturally Occurring Endotoxin) from different bacterial species and varied growth conditions as well as endogenous endotoxin contaminations were investigated. The results clearly demonstrate that endotoxin masking—an effect of LER—is dependent on the endotoxin source used. Various parameters such as bacterial strain and growth conditions lead to different masking susceptibilities. Due to these effects it is impossible to predict the susceptibility of bacterial endotoxin contamination to LER. In order to determine whether a sample is prone to LER, an endotoxin spike that is susceptible to LER is required.

2007 ◽  
Vol 73 (21) ◽  
pp. 6864-6869 ◽  
Author(s):  
Diana Axelsson-Olsson ◽  
Patrik Ellstr�m ◽  
Jonas Waldenstr�m ◽  
Paul D. Haemig ◽  
Lars Brudin ◽  
...  

ABSTRACT In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 104 CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1257
Author(s):  
Rita Carmona ◽  
Sandra Díaz del Moral ◽  
Silvia Barrena ◽  
Ramón Muñoz-Chápuli

Different sources have been claimed for the embryonic origin of the coronary endothelium. Recently, the potential of circulating cells as progenitors of the cardiac endothelium has also been suggested. In a previous study we have shown that circulating progenitors are recruited by the embryonic endocardium and incorporated into the coronary vessels. These progenitors derive from a mesodermal lineage characterized by the expression of Gata4 under control of the enhancer G2. Herein, we aim to trace this specific lineage throughout postnatal stages. We have found that more than 50% of the adult cardiac endothelium derives from the G2-GATA4 lineage. This percentage increases from embryos to adults probably due to differential proliferation and postnatal recruitment of circulating endothelial progenitors. In fact, injection of fetal liver or placental cells in the blood stream of neonates leads to incorporation of G2-GATA4 lineage cells to the coronary endothelium. On the other hand, labeling of the hematopoietic lineage by the stage E7.5 also resulted in positive coronary endothelial cells from both, embryos and adults. Our results suggest that early hematopoietic progenitors recruited by the embryonic ventricular endocardium can become the predominant source of definitive endothelium during the vascularization of the heart.


2019 ◽  
Vol 116 (20) ◽  
pp. 10072-10080 ◽  
Author(s):  
Bradley E. Poulsen ◽  
Rui Yang ◽  
Anne E. Clatworthy ◽  
Tiantian White ◽  
Sarah J. Osmulski ◽  
...  

Genomics offered the promise of transforming antibiotic discovery by revealing many new essential genes as good targets, but the results fell short of the promise. While numerous factors contributed to the disappointing yield, one factor was that essential genes for a bacterial species were often defined based on a single or limited number of strains grown under a single or limited number of in vitro laboratory conditions. In fact, the essentiality of a gene can depend on both the genetic background and growth condition. We thus developed a strategy for more rigorously defining the core essential genome of a bacterial species by studying many pathogen strains and growth conditions. We assessed how many strains must be examined to converge on a set of core essential genes for a species. We used transposon insertion sequencing (Tn-Seq) to define essential genes in nine strains ofPseudomonas aeruginosaon five different media and developed a statistical model,FiTnEss, to classify genes as essential versus nonessential across all strain–medium combinations. We defined a set of 321 core essential genes, representing 6.6% of the genome. We determined that analysis of four strains was typically sufficient inP. aeruginosato converge on a set of core essential genes likely to be essential across the species across a wide range of conditions relevant to in vivo infection, and thus to represent attractive targets for novel drug discovery.


With ever rising emission of pollutant gases from different sources like factories, auto mobiles and power, it is a subject of emerging concerns that some strong measures are required to monitor and control these pollutant. Breathing of these gases may cause serious harmful effects to anyone. In these gases, Carbon Monoxide (CO) is often called "Silent Killer" as being colour-less, odour-less and poisonous, it is undetectable by humans. When inhaled it, it deprives blood stream of oxygen and suffocates its victim. In this paper we are proposing a simple system to monitor Carbon Monoxide (CO). Carbon Monoxide (CO) detectors are used to detect CO. This paper also discusses analysis of amount of these CO based a data set from Kaggle and prediction of possible amount of CO in air using regression. The prediction accuracy which is measured as RMSE is 0.17766.


Author(s):  
C.P. Jamsheera ◽  
B.V. Pradeep

Bacterial cellulose (BC) is a natural polymer secreted as a protective cell covering of certain bacterial species. In contrary to plant cellulose, BC possesses some unique features like high moisture-holding capacity, high durability, high liquid absorbing capabilities, biostability, and biodegradability, makes BC an excellent raw material in wide-ranging areas like biomedical, food, agriculture, paper, textile industries and electronics. The main objective of this review is to discuss various aspects of BC production (different sources for bacterial strain isolation, culture media and, its alternatives also major culture techniques). In addition, various applications of BC are also reviewed.


2005 ◽  
Vol 26 (3) ◽  
pp. 114
Author(s):  
Derek W S Harty

Infective endocarditis (IE) is a life threatening, endovascular infection occurring when bacteria enter the blood stream and adhere to heart valves. Mortality rates remain in the range of 11-27%. The most common infecting micro-organisms are now the staphylococci (44%) although streptococci (31%) and particularly the oral streptococci (21%) are still major causative agents. Many different oral streptococci have been isolated from IE cases, the most common being Streptococcus sanguinis, Streptococcus oralis, Streptococcus gordonii, Streptococcus mitis, Streptococcus anginosus group and mutans streptococci.


2021 ◽  
Vol 9 (10) ◽  
pp. 2158
Author(s):  
Marina Georgalaki ◽  
Georgia Zoumpopoulou ◽  
Rania Anastasiou ◽  
Maria Kazou ◽  
Effie Tsakalidou

One of the main lactic acid bacterial species found in the kefir grain ecosystem worldwide is Lactobacillus kefiranofaciens, exhibiting strong auto-aggregation capacity and, therefore, being involved in the mechanism of grain formation. Its occurrence and dominance in kefir grains of various types of milk and geographical origins have been verified by culture-dependent and independent approaches using multiple growth media and regions of the 16S rRNA gene, respectively, highlighting the importance of their combination for its taxonomic identification. L. kefiranofaciens comprises two subspecies, namely kefiranofaciens and kefirgranum, but only the first one is responsible for the production of kefiran, the water-soluble polysaccharide, which is a basic component of the kefir grain and famous for its technological as well as health-promoting properties. L. kefiranofaciens, although very demanding concerning its growth conditions, can be involved in mechanisms affecting intestinal health, immunomodulation, control of blood lipid levels, hypertension, antimicrobial action, and protection against diabetes and tumors. These valuable bio-functional properties place it among the most exquisite candidates for probiotic use as a starter culture in the production of health-beneficial dairy foods, such as the kefir beverage.


2019 ◽  
Author(s):  
Yu-Xiang Chen ◽  
Zhi-yu Xu ◽  
Xueliang Ge ◽  
Suparna Sanyal ◽  
Zhi John Lu ◽  
...  

AbstractAlternative ribosome subunit proteins are prevalent in the genomes of diverse bacterial species but their functional significance is controversial. Attempts to study microbial ribosomal heterogeneity have mostly relied on comparing wild-type strains with mutants in which subunits have been deleted, but this approach does not allow direct comparison of alternate ribosome isoforms isolated from identical cellular contexts. Here, by simultaneously purifying canonical and alternative RpsR ribosomes from Mycobacterium smegmatis, we show that alternative ribosomes have distinct translational features compared with their canonical counterparts. Both alternative and canonical ribosomes actively take part in gene translation, although they translate a subset of genes with differential efficiency as measured by ribosome profiling. We also show that alternative ribosomes have a relative defect in initiation complex formation. Our work convincingly confirms the distinct and non-redundant contribution of alternative bacterial ribosomes for adaptation to hostile environments.Significance StatementMany organisms, including most bacteria code for multiple paralogues of some ribosomal protein subunits. The relative contribution of these alternative subunits to ribosome function and gene translation is unknown and controversial. Furthermore, many studies on alternative ribosomes have been confounded by isolation of alternative and canonical ribosomes from different strains and/ or different growth conditions, potentially confounding results. Here, we show unequivocally that one form of alternative ribosome from Mycobacterium smegmatis actively engages in gene translation, but its translational profile from an identical cellular context is subtly different from canonical ribosomes. Given the prevalence of alternative ribosomal genes in diverse organisms, our study suggests that alternative ribosomes may represent a further layer of regulation of gene translation.


Author(s):  
Herbert Azairwe ◽  
Mudingoto Eddie ◽  
Rashid Humayoon ◽  
Dimpal Khambhati

Electrolyte bottle monitoring has become difficult due to tight schedules most especially during these pandemic times that have left health workers with little or no time. Improper monitoring of electrolyte bottles can result into serious life-threatening risks. We intend to design a reusable electrolyte level sensor using Ultrasonic sensor and Arduino Nano. The project will have a transmitter circuit that will use Rf communication to send the data to receiver circuit for processing. The transmitter circuit has an ultrasonic sensor that will be used to measure the distance of electrolyte level in bottle. The data is then sent wirelessly to the receiver circuit where percentage of the electrolyte level is shown on LCD module. If it shows 100% electrolyte consumed, then an alarm is sent off alerting the health worker in charge. It is also our aim to develop an electrolyte level detector that is reusable, efficient and most importantly affordable for health care industries. Building such a monitoring system, will reduce patient hazards and also improve health care service delivery in terms of accuracy. Health care workers will not need to constantly or manually assess the level of electrolyte left in the bottle most especially during night shifts. Air particles or bubbles can enter the patient’s blood stream if electrolyte bottle gets empty and still attached to patient. If these particles enter, it can result into immediate death. With further developments, it can be upgraded to send message to a doctor/nurse’s phone, along with the patient’s room number and other specifications.


1929 ◽  
Vol 49 (4) ◽  
pp. 559-573 ◽  
Author(s):  
René Dubos

The growth of many pathogenic organisms in plain meat infusion broth is possible only when a large inoculum is used. This requirement is much less strict when the broth cultures are incubated (a) under anaerobic conditions, (b) in fresh media very recently boiled or autoclaved, (c) in fresh media reduced by means of hydrogen, or to which small amounts of cysteine or of blood have been added. It is suggested that these findings can be accounted for by assuming that the bacterial species under consideration can multiply only in media the oxidation potential of which is below a critical value. The favorable growth conditions obtained by the procedures enumerated above may be attributed to the establishment of a proper reduction potential in the medium; the same result is obtained by using a large inoculum, owing to the reducing properties of bacterial cells.


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