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The Invisible Army
Published in Norman Begg, The Remarkable Story of Vaccines, 2023
Bacteria are single-celled, living organisms. They are tiny. Measuring between one and ten micrometres (millionths of a metre) across, they are only visible under a microscope. In comparison, human hair is between 17 and 180 micrometres thick. Bacteria can replicate themselves every twenty minutes, and have adapted to live in almost any environment. They have been found thriving in radioactive waste, boiling hot acid springs and deep in the earth’s crust. One gram of soil from your garden contains 40 million bacteria. The total weight of all the bacteria on planet earth exceeds the weight of all the animals (including humans). Our bodies are teeming with bacteria. We have 37 trillion of them, the same as the total number of cells in our body. If you were to lay all the bacteria in your body, side by side, they would stretch around the circumference of the earth. Your gut alone contains up to a thousand different species of bacteria. Most of these are harmless passengers and some are actually very helpful. We couldn’t live without the bacteria that inhabit our gut, helping us digest our food. The bacteria that inhabit our gut are collectively called our microbiome. A poorly functioning gut microbiome makes us prone to obesity, inflammatory bowel disease, and autoimmune diseases of the bowel. A bacterium that attacks its host is thankfully a rare event. Tuberculosis, whooping cough, diphtheria and tetanus are all examples of infections caused by bacteria that have decided to turn nasty.
Infectious Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Susanna J. Dunachie, Hanif Esmail, Ruth Corrigan, Maria Dudareva
Bacteria are identified or speciated by using a series of physical characteristics (see Figure 3.8). Some of these are listed below. Gram reaction to staining with crystal violet: Gram-positive bacteria stain purple due to their thick layer of peptidoglycan in the cell wall retaining the dye, while Gram-negative bacteria stain red, because their thinner peptidoglycan wall does not retain the crystal violet dye during the decolouring process. Gram-positive and Gram-negative bacteria respond differently to antibiotics.Cell shape: Bacteria can be cocci, bacilli or spirals.Atmospheric preference: Organisms are aerobic, requiring oxygen, or anaerobic, requiring an atmosphere with very little or no oxygen. Organisms that grow in either atmosphere are known as facultative anaerobes.Requirement for special media or intracellular growth.
Bacterial, Mycobacterial, and Spirochetal (Nonvenereal) Infections
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Laboratory studies: Diagnosis is usually based on the clinical presentation, and bacterial cultures are useful to identify the organism and antibiotic sensitivities; however, cultures are not always necessary. In recurrent or severe skin infections, such as carbuncles, investigations to rule out an underlying contributory factor, such as diabetes mellitus, is necessary.
Development over time in point-of-care test use in Danish daytime and out-of-hours general practice: a register-based study
Published in Scandinavian Journal of Primary Health Care, 2023
Niels Kjær, Malene Plejdrup Hansen, Henrik Schou Pedersen, Morten Bondo Christensen, Linda Huibers
Infections are a common cause of serious illness worldwide [1,2]. A substantial part of contacts with general practice concerns symptoms related to infections, in particular outside office hours [3–5]. In case of a bacterial infection, antibiotic treatment can be indicated. Antibiotic prescribing patterns vary significantly [6–9], and excessive use contributes to the increasing problems with antimicrobial resistance [10]. The last decades, several point-of-care tests (POCTs), such as C-reactive protein (CRP) and Rapid streptococcal detection test (RADT), have been introduced to perform on site testing in case of suspected infections. CRP and RADT POCTs aim to support general practitioners (GPs) to identify patients who will benefit from antibiotic treatment [11,12], thereby reducing diagnostic uncertainty and contributing to prudent use of antibiotics [9,11,13–15]. A recent study found that patient age, sociodemographic factors, and comorbidity influence the decision to perform a CRP test in Danish general practice [16].
Patterns of Nutritional Supplement Use in Children with Tourette Syndrome
Published in Journal of Dietary Supplements, 2023
Bobbie L. Smith, Amanda K. Ludlow
The nutritional supplements found to be taken most by the children with TS diagnosis were magnesium, multivitamin, probiotics and omega-3 fatty acids. These findings are similar to those found in children with ASD (28). Research regarding the effectiveness, efficacy and safety of using these supplements requires further investigation. For example, there are no studies to date assessing the effectiveness of probiotics, multivitamins or magnesium in children with TS. Probiotics are bacteria that help to maintain positive gut health and can also regulate inflammation and immune function. Studies have indicated that TS has been associated with imbalances in the gut microbiota (29). While, children commonly take multivitamins, often to maintain health and prevent deficiencies (14), the effectiveness of these supplements has yet to be investigated addressing symptoms of TS. However, preliminary studies on comorbid disorders, such as ASD, show improvement in core symptomology (30, 31). In the current study multivitamins and probiotics were mainly taken to improve children’s overall health; however, no notable changes were observed for multivitamin consumption. For probiotics, there was some improvement in behavior and social interaction observed by caregivers.
A simple AI-enabled method for quantifying bacterial adhesion on dental materials
Published in Biomaterial Investigations in Dentistry, 2022
Hao Ding, Yunzhen Yang, Xin Li, Gary Shun-Pan Cheung, Jukka Pekka Matinlinna, Michael Burrow, James Kit-Hon Tsoi
Research on bacterial growth has been studied for decades. Conceptually, this is a simple process because most bacterial growth follows binary fission. Typically, bacterial growth on material in vitro follow a growth curve that includes four phases: (1) the (initial) lag phase: bacteria is maturing and metabolically active before the start of exponential growth; (2) the exponential (or log) phase: bacteria is growing at a constant rate; (3) the stationary phase: the growth rate of the bacteria is equal to the death rate due to limited nutrients; (4) and the death phase: a decrease in live bacteria due to lack of nutrients [6]. However, unlike controlled laboratory conditions, intraoral conditions such as environment, nutrients, temperature, and moisture levels are dynamic and diversified. Thus, the bacterial growth phases may coexist and overlap within the same biofilm. As such, the bacterial or biofilm growth and activity may be described more realistically as adhesion, growth, maturation and dispersion. This superimposition of phases makes it challenging when investigating the behavior of bacterial growth on materials surfaces. In fact, studying initial bacterial adhesion on the tooth or dental material surfaces [7–9] is of vital importance, because this can better understand the various types of bacterial adherence on different surfaces for anti-bacterial strategies of dental materials. Thus, the mechanisms of bacteria-material interaction and how bacteria react on different surfaces can be explored.