Classification of Salmonella Enterica PDF

Classification of Salmonella enterica Typhoidal Salmonella (causing typhoidal fever): S. enterica subsp. enterica serovar Typhi (Salmonella Typhi) S. enterica subsp. enterica serovar Paratyphi (Salmonella Paratyphi) Non-typhoidal Salmonella (do not cause typhoidal fever; cause milder d...

Classification of Salmonella enterica Typhoidal Salmonella (causing typhoidal fever): S. enterica subsp. enterica serovar Typhi (Salmonella Typhi) S. enterica subsp. enterica serovar Paratyphi (Salmonella Paratyphi) Non-typhoidal Salmonella (do not cause typhoidal fever; cause milder disease symptoms): S. enterica subsp. enterica serovar Enteritidis (Salmonella Enteritidis) S. enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) Diseases caused by Salmonella: salmonellosis  Typhoid fever Salmonella Typhi produces a febrile illness called typhoid fever. Symptoms are poor appetite, headaches, generalized aches and pains, fever, and lethargy (drowsy and dull). Bacteria can systematically spread and replicate in liver, spleen, and bone marrow. A milder form of this disease, referred to as paratyphoid fever, is produced by Salmonella Paratyphi. They are strict human pathogens (no other reservoirs); these infections are passed person to person; asymptomatic long- term colonization occurs commonly, and carrier can still transfer the bacteria (approximately 3%-5% of patients become carriers of the bacteria after the acute illness). Individuals can develop typhoid fever after ingesting food or water contaminated during handling by a human carrier.  “Typhoid Mary” Mary Mallon (September 23, 1869 – November 11, 1938), better known as Typhoid Mary, was the first Quarantined in isolation for three person in the United States decades until her death. identified as an asymptomatic This is before modern antibiotics are carrier of the pathogen associated discovered. with typhoid fever. She has been a cook in a few families and was presumed to have infected 51 people, three of whom died. Typhoid Mary was the first asymptomatic typhoid carrier to be identified by medical science, and there was no policy providing Wikipedia guidelines for handling the situation.  16.5 Deltaproteobacteria and Epsilonproteobacteria Deltaproteobacteria (Figure 16.16) key genera: Bdellovibrio, Helicobacter pylori Myxococcus, Desulfovibrio, Geobacter, Syntrophobacter eight orders characterized bacterial predators (Myxococcales and Bdellovibrionales) metal and sulfur reducers (Desulfuromonadales, Desulfovibrionales, Desulfobacterales, Desulfarculales, Syntrophobacterales)  Epsilonproteobacteria key genera: Campylobacter, Helicobacter Campylobacter and Helicobacter gram-negative, oxidase- and catalase-positive, motile spirilla most pathogenic to humans and animals microaerophilic Campylobacter cause acute gastroenteritis resulting in bloody diarrhea. Helicobacter pylori causes chronic and acute gastritis and peptic ulcers.  Helicobacter Curved, gram-negative rods; catalase- and oxidase-positive and do not ferment. Helicobacters have a bacillary or spiral shape in young cultures (0.5 to1.0 µm wide by 2 to 4µm long) and, like campylobacters, can assume coccoid forms in older cultures. Highly motile and produce urease: help them to live in low pH. Domain: Bacteria Scanning electron micrograph of Help bacteria to Helicobacter pylori increase the pH Phylum: Proteobacteria Class: Epsilonproteobacteria Order: Campylobacterales Family: Helicobacteraceae Genus: Helicobacter Species: H. pylori  Helicobacter diseases Colonization with H. pylori leads to histologic evidence of gastritis (that is, infiltration of neutrophils and mononuclear cells into the gastric mucosa). The acute phase of gastritis is characterized by a feeling of fullness, nausea, vomiting, and hypochlorhydria (decreased acid production in the stomach). Approximately 10% to 15% of patients with chronic gastritis will progress to develop peptic ulcers. The infection can also be asymptomatic; Helicobacter pylori colonizes the stomach in about 50% of all humans and more common in developing countries. Epidemiologic studies have shown that individuals infected with H. pylori have an increased risk of gastric adenocarcinoma (gastric cancer). 2005 Nobel prize winning discovery http://www.nobelprize.org/ Laboratory diagnosis of helicobacter Diagnosis: – Helicobacters are relatively difficult to isolate in culture so can not be identified by biochemical testing. – Histologic examination of gastric biopsy specimens with hematoxylin-eosin, Gram stain and the Warthin- Starry silver stain (the most sensitive; also used for spirochetes; silver ions bind protein molecules). – Presence of urease activity in biopsy specimens. – A number of polyclonal and monoclonal immunoassays for H. pylori antigens. – PCR.  Urease test for diagnosis of Helicobacter pylori infection https://www.sciencedirect.com/science/article/pii/S209012321830016X II. Firmicutes, Tenericutes, and Actinobacteria 16.6 Firmicutes: Lactobacillales 16.7 Firmicutes: Nonsporulating Bacillales and Clostridiales 16.8 Firmicutes: Sporulating Bacillales and Clostridiales 16.9 Tenericutes: The Mycoplasmas 16.10 Actinobacteria: Coryneform and Propionic Acid Bacteria 16.11 Actinobacteria: Mycobacterium 16.12 Filamentous Actinobacteria: Streptomyces and Relatives  Mycobacterium leprae Mycoplasma pneumoniae Streptococcus pyogenes Lactobacillus Listeria monocytogenes Staphylococcus aureus Enterococcus Figure 16.17 16.7 Firmicutes: Nonsporulating Bacillales and Clostridiales Key genera: Listeria, Staphylococcus, Sarcina Listeria in order Bacillales found widely in soils, opportunistic pathogen that causes foodborne illness gram-positive, catalase-positive rod-shaped, facultatively aerobic chemoorganotrophs often grow well at low temperatures (i.e., refrigerated foods)  Listeria monocytogenes Gram-positive coccobacilli, often arranged in pairs, motile, weak β-hemolysis. Growth slowly. Ability to grow at 4° C, in a wide pH range, and in the presence of salt can lead to high concentrations of the bacteria in contaminated foods. Domain: Bacteria L. monocytogenes Kingdom: Eubacteria Phylum: Firmicutes Class: Bacilli Order: Bacillales Family: Listeriaceae Genus: Listeria Species: L. monocytogenes  Listerine is a brand of antiseptic mouthwash product and named after “Joseph Lister”. The active ingredients are four essential oils: menthol, thymol, methyl salicylate, and eucalyptol with 21.6%-26.9% ethanol. Joseph Lister, was a British surgeon and a pioneer of antiseptic surgery. Lister tested anti-infection results of spraying instruments, the surgical incisions, and dressings with a solution of carbolic acid (phenol). He also instructed surgeons under his responsibility to wear clean gloves and wash their hands before and after operations with 5% phenol solutions. His work led to a reduction in post-operative infections and made surgery safer for patients, distinguishing himself as the "father of modern surgery". Listeria monocytogenes L. monocytogenes Sir Joseph Lister 45 Wikipedia