E. coli in the context of "Facultative anaerobe"

A urinary tract infection (UTI) is an infection that affects a part of the urinary tract. Lower urinary tract infections may involve the bladder (cystitis) or urethra (urethritis) while upper urinary tract infections affect the kidney (pyelonephritis). Symptoms from a lower urinary tract infection include suprapubic pain, painful urination, frequency and urgency of urination despite having an empty bladder. Symptoms of a kidney infection, on the other hand, are more systemic and include fever or flank pain usually in addition to the symptoms of a lower UTI. Rarely, the urine may appear bloody. Symptoms may be vague or non-specific at the extremities of age (i.e. in patients who are very young or old).

The most common cause of infection is E. coli, though other bacteria or fungi may sometimes be the cause. Risk factors include female anatomy, sexual intercourse, diabetes, obesity, catheterisation, and family history. Although sexual intercourse is a risk factor, UTIs are not classified as sexually transmitted infections (STIs). Pyelonephritis usually occurs due to an ascending bladder infection but may also result from a blood-borne bacterial infection. Diagnosis in young healthy women can be based on symptoms alone. In those with vague symptoms, diagnosis can be difficult because bacteria may be present without there being an infection. In complicated cases or if treatment fails, a urine culture may be useful.

Illicium verum (star anise or badian, Chinese star anise, star anise seed, star aniseed and star of anise) is a medium-sized evergreen tree native to South China and northeast Vietnam. Its star-shaped pericarps harvested just before ripening are a spice that closely resembles anise in flavor. Its primary production country is China, followed by Vietnam and other Southeast Asian countries. Star anise oil is highly fragrant, used in cooking, perfumery, soaps, toothpastes, mouthwashes, and skin creams. Until 2012, when they switched to using genetically modified E. coli, Roche Pharmaceuticals used up to 90% of the world's annual star anise crop to produce oseltamivir (Tamiflu) via shikimic acid.

The lactose operon (lac operon) is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria. Although glucose is the preferred carbon source for most enteric bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available through the activity of β-galactosidase. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes for this reason. This lactose metabolism system was used by François Jacob and Jacques Monod to determine how a biological cell knows which enzyme to synthesize. Their work on the lac operon won them the Nobel Prize in Physiology in 1965.

Most bacterial cells including E. coli lack introns in their genome. They also lack a nuclear membrane. Hence the gene regulation by lac operon occurs at the transcriptional level, by controlling transcription of DNA.

In obstetrics, lochia is the vaginal discharge after giving birth, containing blood, mucus, and uterine tissue. Lochia discharge typically continues for four to eight weeks after childbirth, a time known as the postpartum period or puerperium. A 2016 review ties this "lochial period" to worldwide customs of postpartum confinement, a time for the new mother and baby to bond.

Lochia is sterile for the first two days, but not so by the third or fourth day, as the uterus begins to be colonized by vaginal commensals such as non-hemolytic streptococci and E. coli. The Cleveland Clinic recommends that pads be used instead of tampons to absorb the fluid as materials should not be inserted in the vagina soon after childbirth.

Hemolytic–uremic syndrome (HUS) is a syndrome characterized by low red blood cells, acute kidney injury (previously called acute renal failure), and low platelets. Initial symptoms typically include bloody diarrhea, fever, vomiting, and weakness. Kidney problems and low platelets then occur as the diarrhea progresses. Children are more commonly affected, but most children recover without permanent damage to their health, although some children may have serious and sometimes life-threatening complications. Adults, especially the elderly, may show a more complicated presentation. Complications may include neurological problems and heart failure.

Most cases occur after infectious diarrhea due to a specific type of E. coli called O157:H7. Other causes include S. pneumoniae, Shigella, Salmonella, and certain medications. The underlying mechanism typically involves the production of Shiga toxin by the bacteria. Atypical hemolytic uremic syndrome (aHUS) is often due to a genetic mutation and presents differently. However, both can lead to widespread inflammation and multiple blood clots in small blood vessels, a condition known as thrombotic microangiopathy.

Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speciation event (orthologs), or a duplication event (paralogs), or else a horizontal (or lateral) gene transfer event (xenologs).

Homology among DNA, RNA, or proteins is typically inferred from their nucleotide or amino acid sequence similarity. Significant similarity is strong evidence that two sequences are related by evolutionary changes from a common ancestral sequence. Alignments of multiple sequences are used to indicate which regions of each sequence are homologous.