Bacterial Pathogens Part 3 E Coli O157 H7 Strain of E Coli due to the ingestion of undercooked beef or fruits and vegetables contaminated with fecal material Leads to acute bloody diarrhea Bacteria found in intestinal tract of cattle Can lead to kidney disease and failure especially in children Bacteria is long lasting and persists Food and waterbourne transmission Typhoid Fever Invasive disease of the small intestine Caused by one species only Salmonella Typhi Not common in the US anymore Common in crowded city slums and military Carriers develop the disease and harbor the bacteria then shed the microbes Fecal oral transmission into fecal matter Disease is harder to control with carriers because the disease can be transmitted through direct contact Disease can be fatal if not treated Treatment Antibiotics o Most people usually recover when treated with many antibiotics Non Typhoid Salmonella Less invasive intestinal infection Ingest bacteria then grows in intestines Bacteria doesn t get into the bloodstream but it is still severe Causes prolonged diarrhea and cramps Can develop disease from several major groups of bacterial species Each group has hundreds of serotypes o Serotype Kind of variation Common species S enteritidis there are several dozen variations in one species Fecal oral transmission Mainly zoonotic diseases and some human diseases Direct and indirect human to human contact Animal feces contaminate food o Chicken eggs contaminated with feces o Cattle can harbor E Coli Direct contact with animal feces ex pet reptiles The Plague Black Death Yersinia pestis Transmitted through animal reservoirs and vectors Spread rapidly person to person or by fleas and small rodents o Infected flea regurgitates fluids of bacteria into a persons bite wound Zoonotic disease Still present in rodent populations in the southwestern US Forms o Bubonic Bacteria replicates in lymph nodes in groin or upper thigh area Inflammation and swelling occur called bubos o Septicemic o Pneumonic Spirochetes Tightly coiled spiral shaped bacteria with endoflagella Genus Borrelia Lyme Disease Common in Ohio and eastern US Zoonotic disease Deer tick is the vector preferred host is the deer but can feed on other animals Deer and mice are the reservoir Disease more common due to o More humans living near woodlands o Increasing deer populations Humans commonly infected when tick is in the nymph stage about 1 mm Tick latches on to skin and causes a bullseye shaped rash at bite location for about 70 of people 30 do not develop rash Symptoms o Early signs fever headache malaise feel poorly prodromal o Later signs Polyarthritis Arthritis and pain in many joints Cardiac Dysrhythmias irregular heartbeat Neurologic facial palsy Paralysis of the face o History of hiking o Rash o Serologic testing blood test check to see if there are specific antibodies to the barillia bacteria Diagnosis Treatment o Tetracycline o Amoxicillin Prevention o Insect repellant o Proper clothing Genus Treponema Gram cell wall Fastidious Requires vitamins or growth factors to persist Spiral morphology with endoflagellum Treponema pallidum Sexually transmitted Cause of syphilis Congenital can be spread from mother to child through child birth Non sexually transmitted types found in the tropics chancres only on arms and legs not genitals 100 000 cases reported in the US Stages of Syphillis o Primary Initial infection Open lesions on genitals painless hard chancres o Secondary Spirochetes spread all over the body in a rash Fever and headache Spirochetes get into bloodstream and spread Disease best to be treated in the primary or secondary stage before severe damage o Latency o Tertiary Latent up to 20 years with no symptoms Neurosyphilis Damage to the brain causing confusion and convulsions Damage to the heart and aorta Destroys patches of damaged tissues called gummas More serious than chancres and damage is irreversible Diagnosis Treatment o Serologic testing blood samples o Darkfield microscopy on lesions scrape chancre sores o Penicillin o Pre antibiotic era treatments mercurial arsenicals Genus Legionella Causes Legionnaires Disease Bacteria lives as commensal in large protozoa amoeba Gram obligate aerobes Commonly occurs when water has been infected with bacteria and people Fastidious Found in aquatics inhale the water vapor Legionnaires Disease o Respiratory infection due to aerosol transmission o Bacterial survives in pulmonary macrophages Once in the lungs bacteria looks for cells to get into pulmonary macrophages then engulf bacteria o Can cause fatal pneumonia Diagnosis o Special staining and DNA probes o Hard to detect o More difficult to treat than typical cases Treatment o Erythromycin o Rifampin Campylobacter and Helicobacter Both rod shaped bacteria Cause digestive tract infections in humans Campylobacter o Intestinal infections from eating bad chicken o Diarrhea and cramping Helicobacter o Infection in the stomach o Secretes chemicals that neutralizes stomach acid then erodes lining of o If not treated bleeding ulcers can occur which are much more serious the stomach cells and painful
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