Some members of the Enterobacteriaceae
Enterobacteriaceae
The family Enterobacteriaceae is a very large family of Gram-negative bacteria that has been studied and characterized for almost a hundred years. It was first proposed by Rahn in 1936 and now included over 50 genera and over 200 species. Its classification above the level of famil…
What does Enterobacteriaceae mean?
Enterobacteriaceae. Enterobacteriaceae is a large family of gram negative, non-spore forming rods, which are facultative anaerobes and capable of fermenting sugars to various end products. From: Food Chemistry, 2015.
Is Enterobacter the same as Enterobacteriaceae?
Is Enterobacter the same as Enterobacteriaceae? Enterobacter, (genus Enterobacter), any of a group of rod-shaped bacteria of the family Enterobacteriaceae. Enterobacter are gram-negative bacteria that are classified as facultative anaerobes, which means that they are able to thrive in both aerobic and anaerobic environments.
What is the cause and treatment for Enterobacter cloacae?
This bacterium can cause multiple pathologies such as:
- Infections in the urinary and gastrointestinal tract.
- Thrombocytopenia (reduction of platelets in the bloodstream).
- Respiratory system infections: Infections of this type include asymptomatic colonization, tracheobronchitis, pneumonia, lung abscess, and empyema.
- Soft Tissue and Skin Infections: Conditions caused by E. ...
What is the abbreviation for Enterobacteriaceae?
What is the abbreviation for Enterobacteriaceae counts? What does EBC stand for? EBC abbreviation stands for Enterobacteriaceae counts.
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Why are the Enterobacteriaceae of medical significance?
Enterobacter species are responsible for causing many nosocomial infections, and less commonly community-acquired infections, including urinary tract infections (UTI), respiratory infections, soft tissue infections, osteomyelitis, and endocarditis, among many others.
What is special about Enterobacteriaceae?
Enterobacter, (genus Enterobacter), any of a group of rod-shaped bacteria of the family Enterobacteriaceae. Enterobacter are gram-negative bacteria that are classified as facultative anaerobes, which means that they are able to thrive in both aerobic and anaerobic environments.
What bacteria under the family Enterobacteriaceae are of medical importance What are the diseases caused by these organisms?
Enterobacteriaceae includes, along with many harmless symbionts, many of the more familiar pathogens, such as Salmonella, Escherichia coli, Klebsiella, and Shigella. Other disease-causing bacteria in this family include Enterobacter and Citrobacter.
Who are the members of Enterobacteriaceae?
The Enterobacteriaceae are a large family of bacteria, including many of the more familiar pathogens, such as Salmonella, Shigella and Escherichia coli. Members of the Enterobacteriaceae are bacilli (rod-shaped), facultative anaerobes, fermenting sugars to produce lactic acid and various other end products.
Why are enteric bacteria important?
Enteric bacteria are typically harmless and help maintain a healthy intestinal environment. However, certain strains of enteric bacteria may be pathogenic, causing illness in humans. Once bacteria enter the body, the immune system of some individuals can fight off the infection.
Can motility be used to help identify many medically important pathogenic bacteria such as the Enterobacteriaceae?
Motility has long been recognized as an important taxonomic tool and biological characteristic of microorganisms. The presence of flagella occurs primarily in bacilli but there are a few flagellated cocci, thus motility is a very important means of identification in the family Enterobacteriaceae.
Are Enterobacteriaceae beneficial?
While a decrease in Enterobacteriaceae may be beneficial in reducing the native reservoir of UTI-causing bacteria, decreasing Enterobacteriaceae may otherwise be relevant. For example, high fecal Enterobacteriaceae levels are reported in patients with inflammatory bowel diseases [19].
What is the most significant and most commonly observed infection causing agent in health care?
Pseudomonas aeruginosa. Pseudomonas infection is caused by strains of bacteria found widely in the environment; the most common type causing infections in humans is called Pseudomonas aeruginosa. Serious Pseudomonas infections usually occur in people in the hospital and/or with weakened immune systems.
What are the most common microorganisms found in health care associated infections?
Most Common Healthcare-Associated Infections: 25 Bacteria, Viruses Causing HAIsAcinetobacter baumannii. ... Bacteroides fragilis. ... Burkholderia cepacia. ... Clostridium difficile. ... Clostridium sordellii. ... Carbapenem-resistant Enterobacteriaceae. ... Enterococcus faecalis. ... Escherichia coli.More items...•
What general characteristics do members of the family Enterobacteriaceae have in common?
Members of the family Enterobacteriaceae have the following characteristics: They are gram-negative rods, either motile with peritrichous flagella or nonmotile; grow on peptone or meat extract media without the addition of sodium chloride or other supplements; grow well on MacConkey agar; grow aerobically and ...
Which of the following is useful in the identification of Enterobacteriaceae as a coliform?
IMViC is useful for identifying enterobacteriaceae, because each separate substrate is able to identify a different type of enterobacteriaceae, also use serological tests and phage tests.
Which is member of the Enterobacteriaceae cause food spoilage?
Some members of the Enterobacteriaceae family also cause food spoilage such as Erwinia spp. and Pectobacterium spp. In the food industry, Enterobacteriaceae are commonly used as indicator organisms that can indicate poor hygiene practices or failure of a manufacturing process.
What is the role of Enterobacteriaceae in the human body?
The Enterobacteriaceae includes organisms with a wide range of disease-causing potential, encompassing beneficial commensal microbiota, opportunistic pathogens that can inflict considerable morbidity and mortality on compromised hosts, and principal pathogens capable of initiating illness in individuals in perfect health.
What are the organisms in Enterobacteriaceae?
Enterobacteriaceae is a large, heterogeneous group of Gram-negative rods that includes bacteria that naturally inhabit the mammalian gut but also can occur and multiply in other environments – for example, species of Escherichia, Citrobacter, Enterobacter, Proteus, Hafnia, Klebsiella, Providencia, and Serratia, and also some of the most important enteric pathogens, such as Salmonella spp., Shigella spp., Yersinia enterocolitica, and pathogenic E. coli. All members of the Enterobacteriaceae family ferment glucose with acid production and reduce nitrates. Certain physiological groups of organisms may be recognized within Enterobacteriaceae. Psychrotrophic members of this family are not uncommon, although the Enterobacteriaceae are regarded widely as being mesophilic. The psychrotrophic strains of Enterobacter, Hafnia, and Serratia may grow in temperatures as low as 0 °C.
What temperature does Enterobacteriaceae grow?
The psychrotrophic strains of Enterobacter, Hafnia, and Serratia may grow in temperatures as low as 0 °C. Enterobacteriaceae is a useful indicator of hygiene and postprocessing contamination of heat-processed foods. This family has been used as indicators of food quality and also for food safety.
What is the most common cause of pneumonia in the elderly?
Enterobacteriaceae may cause community-acquired pneumonia in the elderly and are implicated in ventilator-associated pneumonia.63 In particular, K. pneumoniae and E. cloacae are among the most frequent bacteria responsible for ventilator-associated pneumonia, after Staphylococcus aureus and Pseudomonas aeruginosa.
How many species are there in Enterobacteriaceae?
There are over 30 genera and 120 species of Enterbacteriaceae but more than 95% of clinically significant strains fall into 10 genera and less than 25 species.
Which family of organisms ferment glucose?
All members of the Enterobacteriaceae family ferment glucose with acid production and reduce nitrates. Certain physiological groups of organisms may be recognized within Enterobacteriaceae. Psychrotrophic members of this family are not uncommon, although the Enterobacteriaceae are regarded widely as being mesophilic.
Is Escherichia coli a Gram negative bacteria?
Enterobacteriaceae. Enterobacteriaceae are Gram-negative bacteria of a large family that includes Escherichia coli, Klebsiella, Salmonella, Shigella and Yersinia pestis. From: Saliva Protection and Transmissible Diseases, 2017. Download as PDF.
Why are enterobacteria important?
Some enterobacteria are important pathogens, e.g. Salmonella, or Shigella e.g. because they produce endotoxins. Endotoxins reside in the cell wall and are released when the cell dies and the cell wall disintegrates. Some members of the Enterobacteriaceae produce endotoxins that, when released into the bloodstream following cell lysis, ...
What is the order of Enterobacteriaceae?
Enterobacteriaceae was originally the sole family under the order 'Enterobacteriales'. The family contained a large array of biochemically distinct species with different ecological niches, which made biochemical descriptions difficult. The original classification of species to this family and order was largely based on 16S rRNA genome sequence analyses, which is known to have low discriminatory power and the results of which changes depends on the algorithm and organism information used. Despite this, the analyses still exhibited polyphyletic branching, indicating the presence of distinct subgroups within the family.
What genes are used in carbapenem resistant Enterobacteriaceae?
Various carbapenemases genes (blaOXA-48, blaKPC and blaNDM-1, blaVIM and blaIMP) have been identified in carb apenem resistant Enterobacteriaceae including Escherichia coli and Klebsiella pneumoniae.
What are the other bacteria that cause disease?
Other disease-causing bacteria in this family include Enterobacter and Citrobacter. Members of the Enterobacteriaceae can be trivially referred to as enterobacteria or "enteric bacteria", as several members live in the intestines of animals.
What is the name of the bacteria that makes up the majority of the isolates?
In a clinical setting, three species make up 80 to 95% of all isolates identified. These are Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis . However, Proteus mirabilis is now considered a part of the Morganellaceae, a sister clade within the Enterobacterales .
What is the size of a rod-shaped bacillus?
Members of the Enterobacteriaceae are bacilli (rod-shaped), and are typically 1–5 μm in length. They typically appear as medium to large-sized grey colonies on blood agar, although some can express pigments.
How many genera are there in the bacterium?
It was first proposed by Rahn in 1936, and now includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but one classification places it in the order Enterobacterales of the class Gammaproteobacteria in the phylum Proteobacteria.
What is the family of Enterobacteriaceae?
Enterobacteriaceae are a large family of Gram-negative bacteria that includes a number of pathogens such as Klebsiella, Enterobacter, Citrobacter, Salmonella, Escherichia coli, Shigella, Proteus, Serratia and other species.
Which group of antibiotics are resistant to Enterobacteriaceae?
Enterobacteriaceae, like all bacteria, can develop resistance to antibiotics, including the carbapenem group of antibiotics, which are sometimes referred to as the last line of antibiotic treatment against resistant organisms.
How have enterobacteriaceae impacted the world?
Some members of the Enterobacteriaceae have had a large impact on infectious diseases, clinical microbiology and public health. They are involved in diarrhoeal diseases and recognised as one of the major bacterial food-borne pathogens. New scientific and ecological advances have revealed an expansion of the area of Enterobacteriaceae, including emerging pathogenic strains. The ILSI Europe expert group therefore reviewed the potential impacts of these microorganisms on food safety and microbiological risk assessment. The report focuses on advances in taxonomy, virulence characteristics, survival and persistence of Coliforms and Enterobacteriaceae. There are currently 48 genera and 219 species recognised within the Enterobacteriaceae and these numbers are likely to increase in the future. Consequently, there have been many changes in bacterial taxonomy resulting in the introduction of new genera and species and the reclassification of some existing bacteria belonging to the Enterobacteriaceae. Methods for the detection and enumeration of Enterobacteriaceae have changed little since they were first introduced and many still rely on the growth of the bacterium in selective media along with the use of carbohydrate (e.g. glucose) as an energy source. In contrast, several rapid methods are now available for detection of specific pathogenic members of the Enterobacteriaceae found in foods including Salmonella and E. coli O157. The initial Enterobacteriaceae contamination level in the raw materials is predominantly governed by Good Agricultural Practices (GAP) during primary production and subsequently during slaughter of livestock at the abattoir. Further along the food supply chain, contamination by Enterobacteriaceae, including pathogens, must be prevented or controlled by the application of one or more of the acknowledged quality assurance systems including Hazard Analysis and Critical Control Point (HACCP) systems and Good Manufacturing Practices (GMP).
What is the energy source used in the detection of Enterobacteriaceae?
Methods for the detection and enumeration of Enterobacteriaceae have changed little since they were first introduced and many still rely on the growth of the bacterium in selective media along with the use of carbohydrate ( e.g. glucose) as an energy source.
How many species are there in the Enterobacteriaceae?
There are currently 48 genera and 219 species recognised within the Enterobacteriaceae and these numbers are likely to increase in the future. Consequently, there have been many changes in bacterial taxonomy resulting in the introduction of new genera and species and the reclassification of some existing bacteria belonging to the Enterobacteriaceae.
Overview
Model organisms and medical relevance
Escherichia coli is one of the most important model organisms, and its genetics and biochemistry have been closely studied.
Some enterobacteria are important pathogens, e.g. Salmonella, or Shigella e.g. because they produce endotoxins. Endotoxins reside in the cell wall and are released when the cell dies and the cell wall disintegrates. Some members of the Enterobacteriaceae produce endotoxins that, whe…
Morphology
Members of the Enterobacteriaceae are bacilli (rod-shaped), and are typically 1–5 μm in length. They typically appear as medium to large-sized grey colonies on blood agar, although some can express pigments.
Most have many flagella used to move about, but a few genera are nonmotile. Most members of Enterobacteriaceae have peritrichous, type I fimbriae involved in the adhesion of the bacterial cell…
Metabolism
Like other Pseudomonadota, Enterobactericeae have Gram-negative stains, and they are facultative anaerobes, fermenting sugars to produce lactic acid and various other end products. Most also reduce nitrate to nitrite, although exceptions exist. Unlike most similar bacteria, Enterobacteriaceae generally lack cytochrome c oxidase, there are exceptions.
Catalase reactions vary among Enterobacteriaceae.
Ecology
Many members of this family are normal members of the gut microbiota in humans and other animals, while others are found in water or soil, or are parasites on a variety of different animals and plants.
Historical systematics and taxonomy
Enterobacteriaceae was originally the sole family under the order 'Enterobacteriales'. The family contained a large array of biochemically distinct species with different ecological niches, which made biochemical descriptions difficult. The original classification of species to this family and order was largely based on 16S rRNA genome sequence analyses, which is known to have low discriminatory power and the results of which changes depends on the algorithm and organism …
Molecular signatures
Analyses of genome sequences from Enterobacteriaceae species identified 21 conserved signature indels (CSIs) that are uniquely present in this family in the proteins NADH:ubiquinone oxidoreductase (subunit M), twitching motility protein PilT, 2,3-dihydroxybenzoate-AMP ligase, ATP/GTP-binding protein, multifunctional fatty acid oxidation complex (subunit alpha), S-formylglutathione hydrolase, aspartate-semialdehyde dehydrogenase, epimerase, membrane prot…
Genera
The following genera have been validly published, thus they have "Standing in Nomenclature". The year the genus was proposed is listed in parentheses after the genus name.
• Biostraticola (2008)
• Buttiauxella (1982)
• Cedecea (1981)