Taxonomy
Family: Alcaligenaceae, is a new member of the alcaligenaceae family

Gyiorum (meaning “from the limbs”) was selected as the name of the species because the majority of strains were isolated from human leg wounds.

Clinical significance
Kerstersia gyiorum is an extremely rare pathogen of human infection.
It can cause chronic infection in patients mostly with underlying conditions. They are isolated from wounds, respiratory tract, urine specimens and most frequently from chronic supperative otitis media.
It can easily be misdiagnosed if proper diagnostic methods are not used.

Increased use of MALDI-TOF MS in the clinical setting may increase reporting of this atypical isolate.

Taxonomy
Family: Moraxellaceae
Formily: Moraxella
P. phenylpyruvicus

Natural habitat
They can be isolated from soil, seawater, seabirds especially penguins, fish, poultry,irradiated foods and from human clinical isolates.
It may occasionally be an opportunistic human pathogens.

Clinical significance
Can cause humans infections such asendocarditis, peritonitis, and fungating lesions of the foot, but those infections caused by this bacterium are rare.

BE AWARE that Brucella sp can be MISIDENTIFIED as P. phenylpurivicus or H. influenzae

Taxonomy
Family: Flavobacteriaceae

Natural habitat
In the environment, does not belong to the normal flora of the human being.

Clinical significance
Is mainly found in from wounds caused by animal (mostly dogs) bites.
Meningitis or septicemia has occured in patients either bitten by a dog or with continuous contact with cats.

Is an intracellular bacteria, which includes mycobacteria, Listeria, Legionella, Brucella, Coxiella and Rickettsia

F. tularensis is a potential BIOTERRORIST agent

F.tularensis subsp tularensis (type A) is one of the most infectious pathogen known in human medicine.
The infective dose in humans is extremely low: 25 bacteria in an aerosol.

Taxonomy
Family: Francisellaceae
F. tularensis subsp tularensis (type A) → virulent
F. tularensis subsp holartica (type B) → less virulent
F. tularensis subsp mediasiatica → moderate virulence
F. tularensis subsp novicida → low virulence

F. philomiraghia

Tularemia is a bacterial zoonotic disease of the northern hemisphere.
F.tularensis is highly virulent for humans and a range of animals such as rodents, hares and rabbits. It is transmitted to humans by arthropod bites, contact with infected animals, ingestion of contaminated water or food and inhalation infected aerosols.

There is no human to human transmission.

Clinical significance
F. tularensis subsp tularensis, can cause serious cinical manifestation and significant mortality if untreated. High fever is accompanied by progressive weakness, malaise, anorexia and loss of weight. Respiratory symptoms, including a dry cough, a sore throat and substernal pain may occur whether or not the disease is acquired by inhalation. Gastrointestinal symptoms such as nausea, vomiting and diarrhoea.

Taxonomy
Family: Pseudomonadaceae

P. monteillii belongs to the Fluorescent Group

Natural habitat
Isolated from soil, plants, water surfaces, rarely from clinical samples,
and isolated from human clinical samples like placenta, stool, bile, biological fluid, bronchial aspirate, urine and pleura fluid.

Clinical significance
Unknown, possible opportunistic pathogen.

Taxonomy
Family: Methylobacteriaceae

Natural habitat
They are isolated mostly from vegetation, but may also occasionally be found in the hospital enviroment.
Tap water has been implicated as a possible agent of transmission in hospital environment.

Methylobacterium species are a cause of health care-associated infections, including infections in immunocompromised hosts.
The ability of Methylobacterium to form biofilms and to develop resistance to high temperatures, drying, and desinfecting agents may explain the colonization of Methylobacterium in the hospital environment in e.g. endoscopes.
Due to its slow growth, it can be easily missed during microbiological surveillance of endoscope reprocessing.

They are able to utilize methanol as a sole source of carbon and energy, although this characteristic may be lost on subculture.

Clinical significance
They have been reported to cause septicemia, continous ambulatory peritoneal dialysis related peritonitis, skin ulcers, synovitis, and other infections often in immunocompromised patients, as well as pseudoinfections.

Taxonomy
Family: Methylobacteriaceae

Natural habitat
They are isolated mostly from vegetation, but may also occasionally be found in the hospital enviroment.
Tap water has been implicated as a possible agent of transmission in hospital environment.

Methylobacterium species are a cause of health care-associated infections, including infections in immunocompromised hosts.
The ability of Methylobacterium to form biofilms and to develop resistance to high temperatures, drying, and desinfecting agents may explain the colonization of Methylobacterium in the hospital environment in e.g. endoscopes.
Due to its slow growth, it can be easily missed during microbiological surveillance of endoscope reprocessing.

They are able to utilize methanol as a sole source of carbon and energy, although this characteristic may be lost on subculture.

Clinical significance
They have been reported to cause septicemia, continous ambulatory peritoneal dialysis related peritonitis, skin ulcers, synovitis, and other infections often in immunocompromised patients, as well as pseudoinfections.

Taxonomy
Family: Pseudomonadaceae
Formerly: Chryseomonas

Natural habitat
Is an oppertunistic pathogen, found ubiquitously in damp enviroments.

Clinical significance
P. luteola is a rare cause of infections in humans.
There have been case reports of a variety of different infections, including bacteremia, cellulitis, osteomyelitis, peritonitis, endocarditis, and postsurgical meningitis.

Also infections in patients with underlying diseases or in association with foreign body.

Is an intracellular bacteria, which includes mycobacteria, Listeria, Legionella, Brucella, Coxiella and Rickettsia

Taxonomy
Family: Francisellaceae

Natural habitat
They are widely distributed in the natural environment (salty water) and is of low virulence, although it may cause disease in immunocompromised individuals.

Clinical significance
Francisella philomiragia, is of low virulence and occasionallycauses disease in immunocompromised individuals.
They may cause pneumoniae or fever with or without organ manifestation, such as meningitis or peritonitis

Human infections caused by F. philomiragia are rare and considered opportunistic infections, infecting primarily patients with underlying immunocompromissing conditions.

Taxonomy
Family: Weeksellaceae
Genus: Empedobacter falsenii
Formely: Wautersiella

Natural habitats
In the environment, does not belong to the normal flora of the human being.

Clinical significance
This organism has been isolated from clinical specimens, including blood, respiratory samples, wounds, pleural fluid,and the urinary tract, though it is an extremely rare cause of nosocomial infection, it may be significant resistant to many antibiotics, including carbapenems.

Altough infection with W. falsenii remains rare, this bacterium should not be underestimated mainly because of its natural resistance to many available antimicrobials.

Taxonomy
Family: Legionellaceae

Natural habitats
Almost all of the Legionella spp have been isolated from aqueous environmental sources.

It is assumed that the natural reservoir of all the Legionellaceae is our aqueous environment and that humans are an accidental host of the bacterium.

Environmental L. pneumophila is a facultative intracellular parasite of several different free-living amoebae, such as Acanthamoeba and Naegleria, existing in microbial consortia in biofilms and free-flowing water.

Many different Legionella spp exist in nature within free-living amoebae, and as a result, these otherwise fastidious bacteria can multiply within the amoebae and be protected from biocides.

Clinical significance
L. pneumophila serogroup 1 causes 95-98% of community-acquired Legionnaires Disease.

Infection is acquired by aerosol inhalation of contaminated water (e.g. cooling towers or aerosol generating devices), although micro aspiration may also be a mechanism of acquiring the disease.

L. pneumophila causing more than 90% of cases of Legionnaires Disease.

Legionnaires Disease,
is a type of bacterial pneumonia, caused by L. pneumophila and other Legionella spp.

The pneumonia ranges in severity from mild to fatal, with an average fatality rate of 12%.
Major risk factors for the disease include immunosuppression of the cellular immune system, cigarette smoking, use of well water, chronic heart or lung disease, and chronic renal failure.

Several Burkholderia species have been isolated from human clinical samples, but only Burkholderia cepacia complex, B. gladiola, B. mallei, B. pseudomallei are generally recognized as human pathogens.

Taxonomy
Family: Burkholderiaceae

Natural habitat
They are found in soil and surface water primarily in tropical and subtropical areas.
They have been isolated in the rice-growing regions of northeast Thailand, western Cambodia, Laos, and southern and central Vietnam. Also in northern Australia, Madagascar and Mauritius.

They can survive deep in the ground and to be rinsed during the rainy season to the surface.

Transmission
There is no person to person transmission

B. pseudomallei is acquired from the environment by inoculation through cut or abraded skin, inhalation, or ingestion.

Clinical significance
B. pseudomallei is the causative agent of the human and animal disease melioidosis.

Melioidosis
is an especially important potential travel related illness for those with CF, and persistent colonization of airways with B. pseudomallei can occur in CF despite prolonged therapy.

Infection with this organism should be considered in the differential diagnosis of any individual with a fever of unknown origin or a tuberculosis-like illness who has a history of travel to a region where B. pseudomallei infection is endemic.

Several Burkholderia species have been isolated from human clinical samples, but only Burkolderia cepacia complex, B. gladioli , B. mallei and B. pseudomallei are generally recognized as human pathogens.

Taxonomy
Family: Burkholderiaceae

Burkholderia cepacia complex includes genomospecies
B. ambifaria, B. anthina, B. arboris, B. cepacia, B. cenocepacia, B. diffusa, B. dolosa, B. latens, B. metallica, B. multivorans, B. phenazinium, B. pyrrocinia, B. seminalis, B. stabilis, B. vietnamiensis

Natural habitat
They are found in water and soil and can survive for prolonged periods in moist environments.
These bacteria can act as a powerful pesticide, capable of eliminating many soil-borne plant pathogens.

Transmission
B. cepacia complex is highly transmissible between cystic fibrosis patients and can be transferred from one CF patient to another in hospitals, health clinics, and social environments.

They are a significant risk factor for morbidity and mortality in CF.

Clinical significance
B. cepacia complex has long been recognized as an occasional opportunistic human pathogen, capable of causing a variety of infections, including bacteremia, urinary tract infection, peritonitis, and pneumonia in persons with underlying illness.

Like cystic fibrosis (CF), they are particularly susceptible to infection.

Cystic fibrosis
is a genetic, life-threatening disorder that primarily affects the digestive system and the lungs.

It is a most common potentially lethal autosomal recessive disease.

Strains of B. cepacia complex are frequently associated with aggressive pneumonia that is accompanied by rapidly fatal bacteremia.(cepacia syndrome)

Several Burkholderia species have been isolated from human clinical samples, but only Burkoldeia cepacia complex, B. gladioli , B. mallei and B. pseudomallei are generally recognized as human pathogens.

Taxonomy
Family: Burkholderiaceae

Burkholderia cepacia complex includes genomospecies
B. ambifaria, B. anthina, B. arboris, B. cepacia, B. cenocepacia, B. diffusa, B. dolosa, B. latens, B. metallica, B. multivorans, B. phenazinium, B. pyrrocinia, B. seminalis, B. stabilis, B. vietnamiensis

Natural habitat
They are found in water and soil and can survive for prolonged periods in moist environments.
These bacteria can act as a powerful pesticide, capable of eliminating many soil-borne plant pathogens.

Transmission
B. cepacia complex is highly transmissible between cystic fibrosis patients and can be transferred from one CF patient to another in hospitals, health clinics, and social environments.

They are a significant risk factor for morbidity and mortality in CF.

Clinical significance
B. cepacia complex has long been recognized as an occasional opportunistic human pathogen, capable of causing a variety of infections, including bacteremia, urinary tract infection, peritonitis, and pneumonia in persons with underlying illness.

Like cystic fibrosis (CF), they are particularly susceptible to infection.

Cystic fibrosis
is a genetic, life-threatening disorder that primarily affects the digestive system and the lungs.
It is a most common potentially lethal autosomal recessive disease.

Strains of B. cepacia complex are frequently associated with aggressive pneumonia that is accompanied by rapidly fatal bacteremia. (cepacia syndrome)

Several Burkholderia species have been isolated from human clinical samples, but only Burkoldeia cepacia complex, B. gladioli , B. mallei and B. pseudomallei are generally recognized as human pathogens.

Taxonomy
Family: Burkholderiaceae

Burkholderia cepacia complex includes genomospecies
B. ambifaria, B. anthina, B. arboris, B. cepacia, B. cenocepacia, B. diffusa, B. dolosa, B. latens, B. metallica, B. multivorans, B. phenazinium, B. pyrrocinia, B. seminalis, B. stabilis, B. vietnamiensis

Natural habitat
They are found in water and soil and can survive for prolonged periods in moist environments.
These bacteria can act as a powerful pesticide, capable of eliminating many soil-borne plant pathogens.

Transmission
B. cepacia complex is highly transmissible between cystic fibrosis patients, CF, and can be transferred from one CF patient to another in hospitals, health clinics, and social environments.

They are a significant risk factor for morbidity and mortality in CF.

Clinical significance
B. cepacia complex has long been recognized as an occasional opportunistic human pathogen, capable of causing a variety of infections, including bacteremia, urinary tract infection, peritonitis, and pneumonia in persons with underlying illness.

Like cystic fibrosis (CF), they are particularly susceptible to infection.

Cystic fibrosis
is a genetic, life-threatening disorder that primarily affects the digestive system and the lungs.

It is a most common potentially lethal autosomal recessive disease.

Strains of B. cepacia complex are frequently associated with aggressive pneumonia that is accompanied by rapidly fatal bacteremia.(cepacia syndrome)

Taxonomy
Family: Moraxellaceae

Natural habitat
They are common inhabitants of the upper respiratory tract

Clinical significance
Usually nonpathogenic and rarely infects humans

They have been reported as rare causative pathogen of infections in humans.

Brucella cultures should be handled using BSL-3 practices, with culture manipulations being done in a biological safety cabinet.

General information
Brucella from Sir David Bruce (1855-1931), microbiologist in Australia and England.

Brucellosis continues to be one of the most common laboratory-acquired infections.

Practices associated with transmission in the laboratory include unprotecting handling of specimens, sniffing of plates, mouth pipetting and exposure of the eyes, nose, or mouth to infectious aerosols.

Taxonomy
Family: Brucellaceae

Natural habitats
Brucella are facultative intracellular parasites, taking as their natural habitat a variety of animal species.

Human pathogen in order of decreasing virulence

B. melitensis - Malta fever sheep, goats, alpacas and camel
B. suis - Brucellosis pigs, swine, reindeer and caribou
B. abortus - Bang's disease cattle, camels, buffalo, yaks and horses
B. canis - Brucellosis dogs

Malditof knows only B. melitensis

Clinical significance

Transmission from human to human is very rare

Brucellosis
Although the disease can begin acutely, the beginning is usually insidious and is characterized by slight fever without local symptoms.
The fever is irregular and is accompanied with complaints of headache, malaise, fatigue, sweating and joint problems.

They can live intracellular and invade a variety of tissues.

Incubation period of 1 week to 2-3 months.

Sometimes it proceeds acutely with wavy fever (febris undulans).
They spread into the bloodstream and localize in the liver, spleen, bone and other tissues and form granulomas there.
Are therefore difficult to reach for the immune system and antibiotics.

Complications include bacterial endocarditis, nephritis, meningoencephalitis and orchitis.

The fatality rate is <1% and is mainly associated with the occurrence of bacterial endocarditis.

In non-zoonotic areas the infection proceeds possibly exacerbated by doctor's delay, probably due to a slower running diagnostics because the disease is low in the differential diagnosis.

Serology
Usually the diagnosis is established by serological testing.
Practical nature of the reasons are: it can take up to 4 weeks before a culture is positive and in practice, the patient is often already used antibiotics, so the culture is useless.

Taxonomy
Family: Alcaligenaceae

Natural habitat
B. parapertussis, once thought to be strictly a human pathogen, is also found in sheep.

The bacterium is spread by airborne droplets, its incubation period is 7-14 days.

Clinical significance
B. parapertussis causes a pertussis syndrome similar to but usually less severe than that caused by B. pertussis

While B. parapertussis may be quite prominent in isolated outbreaks, overall is account for 2-20% of Bordetella isolates.

Symptomatic
B. parapertussis infections is more commonly present as a nonspecific cough illness or bronchitis.

Mixed infections
by B. pertussis and B. parapertussis have been reported, and this should be considered when examining primary cultures from clinical specimens.

Pertussis (or whooping cough) ⇒ see B. pertussis

Taxonomy
Family: Alcaligenaceae

Natural habitats
B. pertussis is thought to be a strictly human pathogen
The bacterium is spread by airborne droplets, its incubation period is 7-14 days.

Clinical significance
B. pertussis cause pertussis, or whooping cough.

Pertussis (or whooping cough)
is an infection of the respiratory system characterized by a “whooping” sound when the person breathes in.

B. pertussis continues to circulate in population where high vaccination coverage of infants and children is achieved, because the protection induced after natural infection and vaccination decreases after several years.

Pertussis is most dangerous in infants, and most hospitalizations and death occur in this age group.
The signs and symptoms are similar to a common cold; running nose, sneezing, mild cough, and low-grade fever.
The patient becomes more contagious during the catarral stage of infection, normally two weeks after the coughing begins.

It may become airborne when the persons cough, sneezes, or laughs.

The cough is a crowing inspiratory sound characteristic of pertussis. After a spell, the patient might make a “whooping” sound when breathing in, or may vomit.

Adults have milder symptoms, such as prolonged coughing without the “whoop”.
Infants less than six month also may not have the typical whoop.

A coughing spell may last a minute or more, producing cyanosis, apnoea, and seizures.

When not in a coughing fit, the patient does not experience trouble breathing.

General Information
This organism is known to spontaneously develop L forms (bacteria without cell walls) which may allow its persistence in some sites

Taxonomy
Family: Leptotrichiaceae

Natural habitats
In the upper respiratory tract of rats (mice, gerbils, squirrels, ferrets, weasels and other rodents)

Clinical significance
They are pathogenic for humans and are transmitted by 2 routes
1. rat bite or contact with rat feces or saliva
►Rat-bite fever
2. ingestion of contaminated food
► Haverhill fever

The patient develop acute onset of chills, fever, headache, vomiting and often severe joint pains.

Complication can occur, including endocarditis, brain abscess, prostatitis and pancreatitis

Taxonomy
Family: Pseudomonadaceae
Genus: formerly Flavimonas

Natural habitat
Isolated from soil, water, plants and clinical specimens.
Does not belong to the human flora.

Clinical significance
Has only rarely been associated with human infections.

Infections is frequently linked to implanted or indwelling materials or to invasive procedures.

Taxonomy
Family: Pseudomonadaceae
Genus: Stutzerimonas stutzeri
Formely: Pseudomonas stutzeri

Natural habitat
Occurs everywhere in soil and water. Is also found in humus, manure, straw, sewage, stagnant water, utensils in hospitals and eye makeup

Clinical significance
Infections are rare and mostly in patients with underlying disease and who have been exposed to contaminated medical instruments and solutions.

Taxonomy
Family: Pseudomonadaceae

Natural habitat
Isolated from soil, plants, water surfaces, rarely from clinical samples.

Clinical significance
Opportunistic pathogen.

General information
Its name come from the production of the soluble fluorescent pigment pyoverdin

Taxonomy
Family: Pseudomonadaceae

Natural habitat
Isolated from soil, plants, water surfaces, rarely from clinical samples.

Clinical significance
They are common course of food contamination.

In food, P. fluorescens is a common contaminant, especially since it actively enjoys lower temperatures like those found in fridges.

Dairy products are especially vulnerable to P. fluorescens contamination.

Taxonomy
Family: Pseudomonadaceae

Natural habitat
Widely distributed in nature. Isolated from soil, water, plants and clinical human specimens.
It is also found in most man-made environments throughout the world.
Because they survive in a moist environment, they can cause problems in a hospital.

Pseudomonas found in all types of aqueous solutions, including disinfectants, soap, eye drops, dialysis fluid, sink etc

Clinical significance
Is the most important pathogen of the genus Pseudomonas.
They cause a broad spectrum of infections, ranging from superficial skin lesions to sepsis.
Infections occur mainly in patients with burns, cystic fibrosis, acute leukemia, organ transplants, otitis externa ("swimmer 's ear") and intravenous drug users.
They also cause urinary tract-, lower respiratory- and eye infections.

Taxonomy
Family: Weeksellaceae

Natural habitat
In the environment, does not belong to the normal flora of the human being.

Clinical significance
Is mainly found in urine and vagina.

Taxonomy
Family: Xantomonadaceae
Formerly: Pseudomonas maltophilia, Xanthomonas maltophilia

Malditof also has S. acidaminiphila, S. nitireducens, S. rhizophilia these are apathogenic

Natural habitat
In the environment, especially water and in the water from hospitals.

Does not belong to the normal flora of the human being.

Clinical significance
It is an important pathogen of nosocomial (hospital-acquired infections) which is associated with a substantial morbidity and mortality, especially in weakened or immune compromised patients on a respirator.
They are increasingly isolated.

They have been isolated in, bacteriemia, pneumonia, UTI, eye infections, endocarditis, meningitis, peritonitis, cholangitis and soft tissue infections.

S. maltophilia is also becoming more common in CF patients.

Taxonomy
Family: Sphingomonadaceae
- S. parapaucimobilis

Malditof
All others are apathogenic

Natural habitat
In the environment, especially water and in the water from hospitals.

Does not belong to the normal flora of the human being.

Clinical significance
Virulence factor is unknown.

Transmission probably due to exposure to contaminated instruments or solutions.

Catheter-related sepsis, liquor, wound and urinary tract infections occur.

Of this genus are S. paucimobilis and S. parapaucimobilis clinically important

General information
Sphingobacterium species are capable of behaving as an opportunistic pathogen and producing severe infection in compromised patients.

Taxonomy
Family: Sphingobacteriaceae
Formerly: Flavobacterium

Natural habitat
In the environment, in food products, in an aqueous environment of a hospital, such as; the sink, incubators, water from the tap, hemodialysis systems and all kinds of aqueous solutions.

Does not belong to the normal flora of the human being.

Clinical significance
They are rarely involved in human infections.

Two species S. multivorum and S. spiritivorum have occasionally been associated with bacteremia, peritonitis and chronic respiratory infections in patients with severe underlying conditions.

General information
Sphingobacterium species are capable of behaving as an opportunistic pathogen and producing severe infection in compromised patients.

Taxonomy
Family: Sphingobacteriaceae
Formerly: Flavobacterium

Natural habitat
In the environment, in food products, in an aqueous environment of a hospital, such as; the sink, incubators, water from the tap, hemodialysis systems and all kinds of aqueous solutions.

Does not belong to the normal flora of the human being.

Clinical significance
They are rarely involved in human infections. Two species S.multivorum and S. spiritivorum have occasionally been associated with bacteremia, peritonitis and chronic respiratory infections in patients with severe underlying conditions.

Taxonomy
Family: Comamonadaceae
Formerly: Comamonas, Pseudomonas

Natural habitat
Environment, soil, water and hospital environment, does not belong to the human flora.

Clinical significance
Clinical significance is unknown. Is rarely found in patients.

Transmission probably due to exposure to contaminated instruments or solutions.

Taxonomy
Family: Burkholderiaceae
Formerly: Ralstonia

Natural habitat
They are found worldwide in the environment, water, soil, on plants, fruits and vegetables.
Because they survive in a moist environment, they can also cause problems in a hospital.

Clinical significance
Is rarely found as a cause of infection.
Are isolated from CF patients.
Still, the pathogenic role in this uncertain.

General information
In the past, its effects have often been attributed wrongly to Shewanella putrefaciens.
There has been a rising number of disease cases attributed to S. algae in the last decade, thanks to correct classification

Taxonomy
Family: Shewanellaceae / Formerly: Pseudomonas

Natural habitat
In the environment and in food products, does not belong to the normal flora of the human being.
- S. algae occurs in the vicinity of salt water
- S. putrefaciens isolated from fish, chicken, meat, fresh and saltwater.

Clinical significance
Clinical significance unknown.
Shewanella algae is of interest because of its potential to be a serious human pathogen.
It is known to cause peritonitis and obstructive pneumonia, ear infections, bacteraemia, rare occurrences of skin and soft tissue infections, bone and joint infections, and many others.

S. algae is most commonly isolated in humans

> 80% (Note errors) and is considered to be more virulent than S. putrefaciens

Taxonomy
Family: Shewanellaceae
Formerly: Pseudomonas Malitof apathogenic: S. baltica, S. fidelis, S. frigidimarina, S. profunda

Natural habitat:
In the environment and in food products, does not belong to the normal flora of the human being.
- S. algae occurs in the vicinity of salt water
- S. putrefaciens isolated from fish, chicken, meat, fresh and saltwater.

Clinical significans
Clinical significance unknown.
Is often found in mixed cultures. In cellulitis, otitis media, skin and soft tissue infections, peritonitis, respiratory- and urinary tract infections S. algae is most commonly isolated in humans
> 80% (Note errors) and is considered to be more virulent than S. putrefaciens

Taxonomy
Family: Acetobacteracea

Natural habitat
Unknown, it is rarely found in humans.

Clinical significance
Clinical significance unknown.

Most isolates from blood, wounds or urinary tract are found in immune compromised individuals.

Taxonomy
Family: Rhizobiaceae
Formely: Rhizobium
Genus: Agrobacter

Natural habitat
Environment, soil, water and plants.
They are no part of the flora of man.

Clinical significance
Transmission probably due to exposure to contaminated instruments or solutions.

Has a low virulence, except in people with lowered immunity.

Taxonomy
Family: Burkholderiaceae
Formerly Burkholderia

Natural habitat
They are found in moist environments such as soils, on plants, fruits and vegetables.
Because they survive in a moist environment, they can cause problems in a hospital.

Be isolated from CF patients.

Clinical significance
They are rarely found as a cause of infection.
The bacteria has seriously affected humans with poor health.
Several hospitals have reported outbreaks, in particular, patients with cystic fibrosis and Crohn’s Disease have been shown to be infected R. pickettii

They can cause pneumonia, meningitis, endocarditis, osteomyelitis, bacteremia and nosocomial infections.

Taxonomy
Family: Rhodobacteracea
Formerly classified as a eugenic oxidizer group 2 (EO-2)

Natural habitat
In the environment, does not belong to the normal flora of the human being.

Clinical significance
Isolated from various wounds and blood

Taxonomy
Family: Alcaligenaceae

Formerly Moraxella urethralis

Natural habitat
Unknown, can colonize the distal (bottom section) of the urethra

O. urethralis is commensal in the urogenitaliën

Clinical significance
Transmission through manipulation of catheters.

These microorganisms are usually isolated from the urinary tract and also known as cause of urosepsis.

Ochrobactrum species are closely related to Brucella species

Taxonomy
Family: Brucellaceae
Genus: Brucella anthropi
Formely: Ochrobactrum anthropi

Natural habitat
Commonly found in soil and water or in hospital environment,

Clinical significance
Cases of pathogenic O. anthropi are rare.

Infections usually take place through the use of contaminated equipment, or in the hospital wounds obtained by the application of catheters and the like.

This is probably due to the ability to attach itself to plastic. The severity of the infection which then occurs is dependent on the host. It can be a bacterieëmie, sepsis, to cause septic shock.

Taxonomy
Family: Flavobacteriaceae
previously known as Flavobacterium odoratum

Natural habitat
Commonly found in soil and water.
Water in the hospital environment is frequently suspected of carrying this organism.

Clinical significance
They are rare clinical isolates and are often not considered pathogenic.

Taxonomy
Family: Moraxellaceae

Natural habitat
Is a commensal organism of the upper respiratory tract

Clinical significance
Usually nonpathogenic.

May be involved in chronic bronchitis and upper respiratory disease and it has been found in individuals with endophtalmitis and occasionally in blood in systemic disease.

Taxonomy
Family: Moraxellaceae

Natural habitat
The natural habitat is not certain

Clinical significance
Pathogenicity uncertain

Patients with cystic fibrosis (CF) may be colonized with unusual gram-negative bacilli whose identification is difficult and clinical impact unclear.

Taxonomy
Family: Rhodospirillaceae

Relationship
I.limosus belongs to the α-proteobacteria (class), and is therefore not closely related to B.cepacia complex or P. aeruginosa

Natural habitat
The natural reservoir is yet to be discovered, but its relationship with other non-fermentative rods suggests ecological resources

Clinical significance
I. limosus is able to stay for several months in the respiratory tract of CF-patients

Just as with the P. aeruginosa is an abundant production of mucus from I. limosus favorable for a persistent chronic infection.

However, the pathogenic role of I. limosus is unclear.

Taxonomy
Family: Flavobacteriaceae
Formerly known as Flavobacterium and Chryseobacterium meningosepticum

Natural habitat
They are ubiquitous in the environment, in food products, and in an aqueous environment of the hospital, such as the sink, incubators, tapwater, or hemodialysis systems.

They are not a member of the normal human flora.

Clinical significance
The species are also a rare cause of nosocomial infections including bacteremia, pneumonia, endocarditis and meningitis, especially in immunocompromised patients.

Several studiessuggest that E. anophelis, and not E. meningoseptica, is the predominant human pathogen of this genus, but the identification of this species is difficult.

Taxonomy
Family: Flavobacteriaceae
Formerly Flavobacterium indologenes,

Apathogen: C.ginsenosidimutans, C.hagamense, C.joostei, C.oranimense, C.scophthalmum

Natural habitat
They are ubiquitous in the environment, in food products, in an aqueous environment of a hospital, such as; the sink, incubators, water from the tap, hemodialysis systems and all kind of aqueous solutions.

They are not a member of the normal human flora.

Clinical significance
Transmission through contaminated equipment or solutions.
Origin is not always known.
Almost never a clinical significance.

Described as a cause of bacteremia in immunocompromised patients or hospital infection through contaminated instruments
and has been identified as the cause of neonatal meningitis.

No transmission from human to human

B. vesicularis and B. diminuta, formely classified as members of group IV of the genus Pseudomonas, are the most frequently isolated Brevundimonas species in human infections

Taxonomy
Family: Caulobacteriaceae

B. vesicularis and B. diminuta are the only human pathogens.
Not pathogenic: B. aurantiaca, B. intermedia, B. nasdae, B. subvibrioides

Natural habitat
They are ubiquitous in the environment.
Because they survive in a moist environment, they can cause problems in a hospital.

Clinical significance
They are rarely isolated from clinical samples.

Very few cases of bacteremia have been reported, with pneumonia, infective endocarditis and spontaneous bacteria peritonitis being the most common foci of infection.

Both B. vesicularis and B. diminuta have been described as opportunistic pathogens in immunocompromised hosts

Taxonomy
Family: Alcaligenaceae

Natural habitats
Human are not natural carriers of B. bronchoseptica, which typically infects the respiratory tracts of smaller mammals (cat, dogs, rabbits etc)

Man is infected through contaminated aerosols animals, such as kennel cough.

B. bronchoseptica can persist in the environment for extended periods.

Clinical significance
They can cause infectious bronchitis, but rarely infect humans

Taxonomy
Family: Alcaligenaceae,
also former Alcaligenes odorans

Natural habitats
It is commonly found in the enviroment, soil and water.

They are also present in a hospital environment, where it is wet, such as; respirators and dialysis systems and can sometimes colonize the skin.

Clinical significance
Alcaligenes faecalis is usually a non-pathogenic bacteria that harbors in the human intestinal tract.

They are commonly found in mixed cultures, especially in diabetic ulcers of the legs and feet .

Transmission of A.faecalis probably due to exposure to contaminated instruments or solutions.

Taxonomy
Family: Alcaligenaceae
Genus: Achromobacter
Formely: Alcaligenes xylosoxidans

Natural habitat
They exist in water environment and can cause health care-associated infections and bacteremia in immunocompromised patients with indwelling catheters.

Clinical significance
It is a relatively frequent agent of infection in immunocompromised patients, causing both local and systemic infections in nosocomial settings.

They can cause infections, especially for patients with cystic fibrosis (CF).
They do not seem to have a significant impact on lung function.

They are capable of causing a wide range of infections, such as bacteremia, meningitis, pneumonia, and peritonitis.

It had also been involved in nosocomial infections attributed to contaminated disinfectans, dialysis fluids, saline solution, and water.

The name Acinetobacter (from the Greek akineto, "nonmotile") reflects the fact that these bacteria do not have flagella and consequently, lack swimming motility.

A. baumannii is part of the ACB complex (A. calcoaceticus and A. baumannii).

Taxonomy
Family: Moraxellaceae

Natural habitat
Acinetobacter species are widely distributed in nature and have been found in soil, sewage, water and in the hospital environment.
They are able to survive on moist and dry surfaces, and also be present in foodstuff and on the healthy human skin.

Clinical significance
A. baumannii ventilator-associated pneumonia and bloodstream infections have been documented to be associated with a high degree of mortality and morbidity.

Particular manifestations of A. baumannii are its implication in infections in soldiers that have been severly wounded in war and in victims of natural disasters.

Although severe infections with A. baumannii have been documented, Infections like, respiratory, urinary tract, wound infections, abscesses and meningitis in debilitated humans,
colonization is much more frequent than infection, and differentiation between these conditions can be difficult.

Still, although they are uncommon, community-acquired pneumonia with A. baumannii occur.

The ability of this microorganism to acquire antimicrobial multiresistance and his high capacity for survival on most environmental surfaces has led to an increase concern regarding hospital acquired infections.

A possible mechanism contributing to survival of A. baumannii is its ability to form a biofilm-like structure at the air/liquid interface, known as a pellicle.