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Vibrio harveyi is a marine bacteria that emits light only at high population density. The bacterial bioluminescence is controlled by a system called quorum sensing. In this system, signaling molecules are secreted, and when they bind to cell surface receptors, they turn on many genes, including those that produce bioluminescence.

This integrative case study is based on real events that the author experienced with her ten-year-old daughter. Although the names have been changed, all of the events (symptoms, diagnoses and treatments, types of healthcare professionals) are recorded exactly as they occurred. Both asthma and pneumonia are common in the United States (and globally). Many of the drugs described in the case study are frequently prescribed for a wide variety of ailments. The four "episodes" that constitute the case cover 1) a study of asthma triggers, incidence and treatment; 2) side effects and possible medication errors associated with steroids; 3) causes, diagnosis, treatment and prevention of community-acquired bacterial pneumonia; and 4) the mechanism of action of two different antibiotics. The "epilogue" explores a few larger themes related to healthcare and public health (e.g., continuity of care, drug resistance, asthma prevention programs). The case study could be used in an undergraduate, upper-level, infectious disease, microbiology, public health or physiology course or in a graduate-level health professions program.

calorimetry carbon transfer: snails/elodea investigating bacterial growth mutations in fruit flys Gel Electrophoresis bacterial transformation comparing hominoid skulls testing antibacterial agents plant transpiration exploring plant responses insects and crime scene analysis interpreting bird response blood typing

Microbes 2,500 meters below the seafloor in Japan are most closely related to bacterial groups that thrive in forest soils on land, suggesting that they might be descendants of ones that survived when their terrestrial habitat was flooded 20 million years ago

 Students must consider the role of rumen bacteria and how genetic modification may alter the potential of these bacteria. The case engages students in learning basic principles of bacterial genetics and biotechnology as they consider how microbes and microbial processes impact the environment. The case could also be used in an introductory genetics or biotechnology course.

An exciting new test might help us save antibiotics. Needing only a drop of blood, researchers at Duke have developed a rapid assay that can tell viral infections-which generally can't be treated-from bacterial ones that may benefit from antibiotics. While I don't usually write about drugs or products in development, this test piqued my interest and left me excited about its potential to help contain antibiotic overuse.

This case is an account of the events that led Drs. Robin Warren and Barry Marshall to the bacterial theory of ulcers. The two physicians refused to accept the standard explanations for what they had observed and instead developed an alternative hypothesis, saving countless patients from unnecessary pain and suffering. Along the way they transformed the way the medical community viewed peptic ulcer disease. The case shows the importance of curiosity, serendipity, and tenacity in scientific inquiry; how science is built upon the work of others; how assumptions can cloud people's views, leaving them closed to new ideas; and how scientific "truth" can and does change when faced with new data and new interpretations. It is appropriate for use in any course at the high school or undergraduate level that teaches students about the scientific method and/or the sociology, nature, and history of science.

Course notes with informative table on bacterial evolution and notes about endosymbiosis.

Dubilier is hardly alone in her plight. A heaping teaspoon of soil or a shot of ocean water may contain as many as one million bacterial species. Many of them are potential gold mines of chemicals and metabolites with medicinal, engineering, and energy applications. But when researchers have tried to culture these microbes in the lab, only a minority of cells form colonies. Clearly, nutrients, a carbon source, and time are usually not enough to coax bacteria isolated from the wild to grow in a laboratory setting. So what's the missing ingredient?

Such descriptions of GMOs raises fears about whether gene transfer between species is outside of how evolution operates and therefore unnatural. Research, however, has repeatedly shown the opposite to be true. In May 2015, researchers showed that practically every known species of cassava (sweet potato) contained genes from Agrobacterium, a bacterial species whose genes we have also harnessed to create other GM crops. The genes were inserted over 8,000 years ago and may have helped the tuber evolve into its current, edible form. This phenomenon of genetic transfer during evolution between species, also known as 'horizontal gene transfer' is not restricted to plants.

Discover natural selection as a mechanism of evolution with the Amoeba Sisters. This video also uncovers the relationship of natural selection and antibiotic resistance in bacteria.

Discover natural selection as a mechanism of evolution with the Amoeba Sisters. This video also uncovers the relationship of natural selection and antibiotic resistance in bacteria.

This interrupted case study introduces the topic of bacterial sporulation and cannibalism in Bacillus subtilis. The storyline follows Susan and her lab mates who are presenting research at a lab meeting when Susan falls asleep and dreams they are stranded on a deserted island. She makes connections between their fight for survival in the dream and the survival mechanisms of the bacteria they study in the lab. The benefits of sporulation under conditions of sustained stress are fairly obvious, but Susan's dream is used to examine the idea that sporulation may not always be beneficial and that bacteria would not want to commit to entering such a state in response to temporary stresses. Through the analysis of actual data from the scientific literature, students uncover a mechanism by which B. subtilis delays its commitment to sporulation by killing members of its own species to release nutrients (i.e., cannibalism). Originally developed for a general undergraduate microbiology course when discussing the structure and growth of prokaryotic cells, the case could also be used in an introductory biology course that emphasizes bacteria and data literacy.

In order to be useful in treating human infections, antibiotics must selectively target bacteria for eradication and not the cells of its human host. Indeed, modern antibiotics act either on processes that are unique to bacteria--such as the synthesis of cell walls or folic acid--or on bacterium-specific targets within processes that are common to both bacterium and human cells, including protein or DNA replication. Following are some examples.

Researchers at the University of Pennsylvania performed "stress tests" on pregnant mice using a predator's odor, restraint, or unfamiliar noises. After the mice gave birth, the scientists analyzed the bacterial communities in their vaginas and in their pups' colons. The researchers found that stress during pregnancy altered the expression levels of several proteins involved in vaginal immunity and the frequency of Lactobacillus bacteria, which, expectedly, correlated to lower frequencies of Lactobacillus within their pups' gut microbiomes. Male pups of stressed mothers also displayed an increase in anaerobic bacteria like Clostridium and Bacteroidesin.

Neutrophils are our body's first line of defense against bacterial infections. After leaving nearby blood vessels, these cells recognize chemicals produced by bacteria in a cut or scratch and migrate "toward the smell". The above neutrophils were placed in a gradient of fMLP (n formyl methionine- leucine- phenylalanine), a peptide chain produced by some bacteria. The cells charge out like a "posse" after the bad guys.

list of infectious viral and bacterial disease, Rhode Island Dept of Health

The mouse is the leading organism for disease research. A rich resource of genetic variation occurs naturally in inbred and special strains owing to spontaneous mutations. However, one can also obtain desired gene mutations by using the following processes: targeted mutations that eliminate function in the whole organism or in a specific tissue; forward genetic screens using chemicals or transposons; or the introduction of exogenous transgenes as DNAs, bacterial artificial chromosomes (BACs) or reporter constructs. The mouse is the only mammal that provides such a rich resource of genetic diversity coupled with the potential for extensive genome manipulation, and is therefore a powerful application for modeling human disease.

This case study presents the story of Phil, an undergraduate majoring in biology, whose Russian cousin Dimitri has contracted tuberculosis (TB) from inmates at the prison where he works.  Phil learns that his cousin's failure to complete his antibiotic regimen likely contributed to the evolution of antibiotic-resistant TB in his body.  Phil consults with his friend Stacy, and together they try to understand Dimitri's condition by applying what they are learning in their genetics lab experiment about the role of random mutation in bacterial evolution (including the development of antibiotic resistance) through Luria- Delbrück fluctuation analysis. The same analysis includes calculation of the mutation rate, which Phil realizes is sufficient to cause MRSA and other antibiotic-resistant infections. This case study was originally developed for concurrent use in freshman/sophomore-level genetics, elementary statistics, and precalculus. However, it is also very appropriate for courses in introductory biology, evolutionary biology, and biostatistics. The teaching notes discuss various ways to run the case depending on the mathematics and biology background of students.

Men shed more bacteria into their surroundings than women do, studies have shown. Now scientists have found that men and women have different effects on the variety of bacteria inside a home, too. The variation comes down to skin biology and "perhaps to body size and hygiene practices," note researchers who sequenced the genes in dust that had settled on the tops of doors in 1,200 homes across the U.S. Dogs apparently alter indoor bacteria more extensively than humans or cats. The bacterial signatures of each of these living beings are unique enough that by simply testing dust in a home, investigators can accurately predict if more women or men live there and if dogs or cats do as well.