**4. Urinary tract infection in diabetics**

bacteria. Therefore, bacteria can multiply and make foundation for infection also. High glucose concentration in the urine can allow urinary colonization by microorganisms. Moreover, multiple mechanisms were involved in UTI patients with diabetes. Diabetic female, diabetic overweight, and diabetic obese patients are having the highest risk of UTI. In general diabetic population, other risk factors associated with urinary tract infection were found to be diabetic nephropathy, diabetes with hypertension, and insulin therapy. Emphysematous pyelonephritis, emphysematous cystitis, renal and perinephric abscesses, urosepsis, and bacteremia are the complications of diabetes-associated UTI. Longer hospitalization, recurrence of UTI, relapse and re-infection, bacteremia, azotemia, and septic shock are the outcomes of

46 Microbiology of Urinary Tract Infections - Microbial Agents and Predisposing Factors

Diabetes is a persistent disease. This disease is characterized by increase of blood glucose level. The reasons of increase of blood glucose level may be either insufficient production of insulin, a hormone that regulates the blood glucose level, or the insulin produced cannot be used properly. Frequent urination, increased thirst, and increased hunger are the common symptoms of diabetes. Uncontrolled blood sugar level can cause many complications. These complications include cardiovascular disease, stroke, chronic kidney disease, foot ulcers, damage to the eyes, diabetic ketoacidosis, etc. Diabetes mellitus can be described as group of metabolic disorders causing increase in blood sugar level due to defect in insulin secretion, insulin action, or both [2]. The digestive system breaks carbohydrates, sugars, and starches found in many foods into glucose, which is a type of sugar that enters the bloodstream [3]. By the action of the hormone insulin, cells throughout the body absorb glucose and use it for energy. Diabetes develops when the body does not produce enough insulin or is unable to use insulin effectively or both. Insulin is produced in the pancreas. Clusters of cells found in the pancreas are called islets. Pancreas having islets, which contain beta cells, produces insulin

• Type 1 diabetes also called as insulin-dependent diabetes mellitus (type I diabetes occurs

• Type 2 diabetes also called as noninsulin-dependent diabetes mellitus (type II diabetes

• Gestational diabetes mellitus (GDM) (diabetes detected in the second or third trimester of

• Specific types of diabetes due to other reasons, for example, monogenic diabetes syndromes (such as maturity-onset diabetes of the young [MODY] and neonatal diabetes),

due to β-cell destruction, usually leading to absolute insulin deficiency).

occurs due to a progressive loss of insulin secretion).

pregnancy that is not clearly overt diabetes).

diabetes-associated UTI [1].

and releases it into the blood.

**3. Types of diabetes**

**2. Diabetes**

Infections are frequent causes of morbidity and mortality in diabetic patients. Evidence suggesting that urinary tract infection (UTI) is the most common bacterial infections among diabetic patients. High glucose concentration in the urine can provide a rich source of nutrients for bacteria [5, 6]. Therefore, bacteria can multiply and make foundation for infection; also, high glucose concentration in the urine can allow urinary colonization by microorganisms. Moreover, some of the immunological defects like impaired neutrophil function, reduced T cell-mediated immune response, low levels of prostaglandin E, thromboxane B2, and leukotriene B4 may contribute to the increased risk for infection. Other conditions such as bladder dysfunction (incomplete bladder emptying) caused by autonomic neuropathy also may contribute to the increased risk for infection [7, 8]. UTI in diabetes can lead to severe complications including bacteremia, renal abscess, and renal papillary necrosis. In some cases, diabetes modifies the genitourinary system and may cause damage to the organ, which leads to pyelonephritis. This type of UTI occurs 15 times more frequently in diabetic patients. Therefore, early diagnosis and correct treatment are very important for diabetes patients with UTI [9, 10]. Molecular reasons for an increased frequency of UTI in diabetic patients include depression in the function of polymorphonuclear leucocytes especially during acidosis, dysfunction of chemotaxis, and phagocytosis [10]. High blood glucose levels may cause nerve damage, affecting the ability of the bladder to sense the presence of urine and thus allowing urine to stay for a long time in the bladder and increasing probability of infection [11].

Various types of UTI in patients with diabetes include

