Infectious Diseases, Microbiology & Beneficial Microbes

Bacterial Infections and Diseases

Bacterial infections occur when harmful bacteria invade the body, leading to various health issues. Bacteria are microscopic, single-celled organisms that can inhabit diverse environments and can be both beneficial and harmful. Pathogenic bacteria can cause illness by producing toxins, attacking cells, and triggering immune responses.

• Gram-positive bacteria: These have a thick cell wall. Notable examples include Staphylococcus aureus, which causes skin infections and pneumonia, and Streptococcus pyogenes, responsible for strep throat and skin infections.
• Gram-negative bacteria: These have a thinner cell wall. Examples include Escherichia coli, which causes UTIs and gastrointestinal infections, and Salmonella, known for causing food poisoning.
• Anaerobic bacteria: These bacteria can survive without oxygen and are often found in deep wounds and the gastrointestinal tract. Examples include Clostridium difficile, which causes severe diarrhea, and Bacteroides fragilis, leading to intra-abdominal infections.

Common bacterial diseases:

• Tuberculosis (TB): Caused by Mycobacterium tuberculosis, TB primarily affects the lungs but can also impact other body parts. Symptoms include coughing, chest pain, fever, fatigue, and weight loss.
• Urinary tract infection (UTI): Often caused by Escherichia coli, UTIs can also be caused by other bacteria. Symptoms include frequent urination, pain during urination, cloudy or bloody urine, and pelvic pain.
• Salmonellosis: Caused by various strains of Salmonella, salmonellosis is typically contracted from contaminated food or water, with symptoms including diarrhea, fever, abdominal cramps, nausea, and vomiting.