Streptobacillus moniliformis | |
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Scientific classification | |
Domain: | Bacteria |
Phylum: | Fusobacteriota |
Class: | Fusobacteriia |
Order: | Fusobacteriales |
Family: | Leptotrichiaceae |
Genus: | Streptobacillus |
Species: | S. moniliformis |
Binomial name | |
Streptobacillus moniliformis | |
Streptobacillus moniliformis is a non-motile, Gram-negative rod-shaped bacterium that is a member of the family Leptotrichiaceae. [2] The genome of S. moniliformis is one of two completed sequences of the order Fusobacteriales. [3]
Its genus name comes from the Ancient Greek word στρεπτός : streptós for "curved" or "twisted", and the Latin word bacillus meaning "small rod." The specific name moniliformis means "necklace like". [4] S. moniliformis is microaerophilic, requiring less oxygen than is present in the atmosphere for its growth. [5]
S. moniliformis was first isolated from a rat-bitten man in 1914 by German microbiologist H. Schottmüller, who described it as Streptothrix muris ratti. [6] In the United States during the year 1916, S. moniliformis was determined to be the causative source of rat-bite fever. [7]
Some isolates of S. moniliformis have been collected from the upper respiratory tract of domestic and wild rats. [8] Two known variants of S. moniliformis have been identified. The bacillary type is pathogenic. [5] In contrast, the spontaneously occurring L-form, which lacks a cell wall and whose colonies grow in a "fried egg" formation, is non-pathogenic. [5]
The bacterium S. moniliformis is a gram-negative pleomorphic rod occurring frequently in chains and tangled filaments with bulbous or Monilia-like swellings. The organism presents phenotypically as being facultatively anaerobic, non-motile, weakly ferments glucose and maltose, is catalase and oxidase-negative, does not reduce nitrate, and exhibits no growth on MacConkey agar. Morphologically, colonies of S. moniliformis are 1–2 mm in size, smooth, convex, non-hemolytic (varied presentation with an α-hemolysis is not uncommon) and gray in color. When cultured in broth, a typical "puff-ball" appearance is seen. [9]
Streptobacillus moniliformis was previously classified under the family Fusobacteriaceae. [10] It was later regrouped with three other genera: Sebaldella , Sneathia , and Leptotrichia . [2] [3] [11] These four genera were classified under the family Leptotrichiaceae following comparative analyses of the 16S ribosomal RNA gene sequences [12] and 16S-23S rDNA internal transcribed spacer sequences among members of the phylum Fusobacteria. [11] Identification of conserved signature indels unique to Fusobacteria and its primary clades as well as phylogenetic analysis of members of Fusobacteria based on concatenated sequences of 17 conserved proteins further support the distinction between the two families. [11]
S. moniliformis was formerly classified as the only member of the genus Streptobacillus. [2] However, Streptobacillus strains HKU33T and HKU34 were isolated in Hong Kong in September 2014. [2] Streptobacillus HKU33T was found in pus isolated from the abscess of a 38-year-old patient with quinsy and HKU34 from the elbow joint fluid of a 64-year-old patient with septic arthritis. [2] Following analysis of the 16S rRNA gene sequences found in members of Leptotrichiaceae and partial sequences of the recA, groEl, and gyrB genes present in both isolates, the two strains were taxonomically grouped under the novel species Streptobacillus hongkongensis sp. nov. [2]
The U.S. Department of Energy's Joint Genome Institute (DOE JGI) sequenced the complete genome of S. moniliformis DSM 12112. [3] It is made up of one circular chromosome of 1,673,280 base pairs as determined from a combination of Sanger and 454 sequencing. [3] The mol% of guanine and cytosine in the DNA is 26.3% with 1,511 protein coding genes out of the 1,566 genes predicted. [3] These low G+C values were previously only seen in members of the order Mycoplasmatales, which includes the genus Mycoplasma , indicating a relationship between Mycoplasma and S. moniliformis. [3] [13] However, 16S rRNA gene analysis showed this relation to be incorrect. [12] S. moniliformis also has a single circular plasmid pSMON01 that is 10,702 base pairs long with 1,511 protein coding genes. [3]
The fastidious nature of Streptobacillus moniliformis makes it difficult to culture, with current published recommendations stating it requires media supplemented with 20% serum, ascitic fluid, or whole blood in order to grow. Numerous published reports also state that the organism is inhibited by the polyanionic detergent sodium polyanethole sulfonate (SPS-trade name; Liquoid; Hoffman-La Roche, Inc., Nutley, N.J.), the main anticoagulant in modern commercially available blood culture bottles, used in automated continuous blood culture instruments. [9]
Optimizing the best chances for organism recovery should include the aseptic collection of blood or sterile body fluids into commercial blood culture bottles (documenting the amount of blood drawn from the patient, if applicable) during the acute phase of infection, and collected in duplicate with optimal volumes of inoculation for the isolation and growth of S. moniliformis being 10 ml for adolescent to adult patients. In a pediatric population, 4–5 ml should be extrapolated. Bottles should be incubated minimally for 7 days to ensure the best chance for organism recovery when working with low levels of bacteremia. If not yet detected by day 7, they should be blind sub-cultured to rule out a false-negative blood culture result. Automated continuous blood culturing instrumentation growth and fluorescent detection data should be checked manually during the course of incubation in order to rule out missed false-negative samples. [9]
Once a bottle shows signs of organism growth and detection, a Gram stain should be performed followed by inoculation of blood onto rabbit or sheep blood agar and brain heart infusion broth and incubated aerobically at 35 °C, 35–37 °C, or 5% CO2 enriched (microaerophilic) environment for a minimum of 3–4 days. [9]
While the organism has been reported to be inhibited by specific blood culture additives, specifically SPS in the clinical lab, current research has proposed methods to overcome this limitation with "100% culture, growth success rates". According to Szewc et al., their research into the "reported" fastidious nature of S. moniliformis, and its inhibition by the anticoagulant SPS showed, that when using a specific volume of blood for inoculum, it resulted in 100% recovery and successful growth of this organism and appeared to overcome the inhibitions and limitations that historically have been observed when using SPS for blood culturing and recovering S. moniliformis in a clinical setting. [9]
In the U.S., rat bite fever is primarily caused by transmission of S. moniliformis from the bite of a rat. [14] However, approximately 30% of patients diagnosed with rat bite fever do not recall being scratched or bitten by an infected animal. [8] [15] Transmission of the bacterium is also known to occur via consumption of infected water, close contact with, or handling of rats. [14] [16] Haverhill fever, named after the 1926 outbreak of the disease in Haverhill, Massachusetts, is a form of rat bite fever that can result from ingesting food contaminated with S. moniliformis. [5] In 1986 at a boarding school in the United Kingdom, another outbreak of Haverhill fever was reported. Some 304 people were reported to have been afflicted. [17] Infection was suspected to have resulted from the consumption of either unpasteurized milk or water contaminated with rat feces. [18] Infected individuals described symptoms including a sudden development of vomiting, severe headache, and cold sweats with a high fever. [18] Parker and Hudson first isolated the cause of this outbreak, which they named Haverhilia multiformis. [15] This organism was later matched to S. moniliformis after further research. [19]
Symptoms of rate bite fever include the abrupt onset of fever ranging from 38 °C to 41 °C. [5] Approximately 75% of infected individuals develop a rash in addition to hemorrhaging vesicles. [14] Both the rash and vesicles are usually located on the hands and feet, although the rash has been known to spread to other parts of the body. [10]
The microaerophilic nature of S. moniliformis makes identification difficult. [5] PCR testing is being utilized more for its identification. [19] However, there is still a 13% mortality rate for untreated cases. [16] Immunocompromised individuals, such as HIV-positive individuals, are more at risk of death from this disease. [20] Lab personnel and pet store workers, who work closely with animals on a daily basis, also have an increased risk of infection. [5]
Although S. moniliformis is believed to be part of the commensal bacteria of the respiratory tract of rats, [13] rats have occasionally shown signs of the disease. [5] Antibiotics used to treat infection may cause the formation of the L-form, which persists in the body, although this form is not pathogenic. [5]
Yersinia pestis is a gram-negative, non-motile, coccobacillus bacterium without spores that is related to both Yersinia enterocolitica and Yersinia pseudotuberculosis, the pathogen from which Y. pestis evolved and responsible for the Far East scarlet-like fever. It causes the disease plague, which caused the Plague of Justinian and the Black Death, the deadliest pandemic in recorded history. Plague takes three main forms: pneumonic, septicemic, and bubonic. It is a facultative anaerobic organism that can infect humans primarily via the Oriental rat flea, but also through airborne droplets for its pneumonic form. Yersinia pestis is a parasite of its host, the rat flea, which is also a parasite of rats, hence Y. pestis is a hyperparasite.
Campylobacter jejuni is a species of pathogenic bacteria that is commonly associated with poultry, and is also often found in animal feces. This species of microbe is one of the most common causes of food poisoning in Europe and in the US, with the vast majority of cases occurring as isolated events rather than mass outbreaks. Active surveillance through the Foodborne Diseases Active Surveillance Network (FoodNet) indicates that about 20 cases are diagnosed each year for each 100,000 people in the US, while many more cases are undiagnosed or unreported; the CDC estimates a total of 1.5 million infections every year. The European Food Safety Authority reported 246,571 cases in 2018, and estimated approximately nine million cases of human campylobacteriosis per year in the European Union. In Africa, Asia, and the Middle East, data indicates that C. jejuni infections are endemic.
Streptobacillus is a genus of fastidious microaerophilic Gram-negative bacteria, which grow in culture as rods in chains.
Rat-bite fever (RBF) is an acute, febrile human illness caused by bacteria transmitted by rodents, in most cases, which is passed from rodent to human by the rodent's urine or mucous secretions. Alternative names for rat-bite fever include streptobacillary fever, streptobacillosis, spirillary fever, bogger, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and caused by two specific types of bacteria:
Sodoku is a bacterial zoonotic disease. It is caused by the Gram-negative rod Spirillum minus. It is a form of rat-bite fever (RBF).
Seoul orthohantavirus (SEOV) is a member of the genus Orthohantavirus of rodent-borne viruses, and is one of the four hantaviruses that are known to cause Hantavirus hemorrhagic fever with renal syndrome (HFRS). It is an Old World hantavirus; a negative sense, single-stranded, tri-segmented RNA virus.
Pseudomonas stutzeri is a Gram-negative soil bacterium that is motile, has a single polar flagellum, and is classified as bacillus, or rod-shaped. While this bacterium was first isolated from human spinal fluid, it has since been found in many different environments due to its various characteristics and metabolic capabilities. P. stutzeri is an opportunistic pathogen in clinical settings, although infections are rare. Based on 16S rRNA analysis, this bacterium has been placed in the P. stutzeri group, to which it lends its name.
Enterobacter cloacae is a clinically significant Gram-negative, facultatively-anaerobic, rod-shaped bacterium.
Bartonella quintana, originally known as Rochalimaea quintana, and "Rickettsia quintana", is a bacterium transmitted by the human body louse that causes trench fever. This bacterial species caused outbreaks of trench fever affecting 1 million soldiers in Europe during World War I.
Orientia tsutsugamushi is a mite-borne bacterium belonging to the family Rickettsiaceae and is responsible for a disease called scrub typhus in humans. It is a natural and an obligate intracellular parasite of mites belonging to the family Trombiculidae. With a genome of only 2.0–2.7 Mb, it has the most repeated DNA sequences among bacterial genomes sequenced so far. The disease, scrub typhus, occurs when infected mite larvae accidentally bite humans. This infection can prove fatal if prompt doxycycline therapy is not started.
Haverhill fever is a systemic illness caused by the bacterium Streptobacillus moniliformis, an organism common in rats and mice. If untreated, the illness can have a mortality rate of up to 13%. Among the two types of rat-bite fever, Haverhill fever caused by Streptobacillus moniliformis is most common in North America. The other type of infection caused by Spirillum minus is more common in Asia and is also known as Sodoku.
Spirillum minus is an organism associated with rat-bite fever that has never been fully identified and was assigned to the genus Spirillum in 1887 based on morphology, although it is not a validly published name. As Spirillum species generally obligately microaerophiles and are not found in mammals, this organism may be misclassified. Sequencing data should help to resolve this question.
Ehrlichia ewingii is a species of Rickettsiales bacteria. It has recently been associated with human infection, and can be detected via PCR serological testing. The name Ehrlichia ewingii was proposed in 1992.
Streptococcus zooepidemicus is a Lancefield group C streptococcus that was first isolated in 1934 by P. R. Edwards, and named Animal pyogens A. It is a mucosal commensal and opportunistic pathogen that infects several animals and humans, but most commonly isolated from the uterus of mares. It is a subspecies of Streptococcus equi, a contagious upper respiratory tract infection of horses, and shares greater than 98% DNA homology, as well as many of the same virulence factors.
Staphylococcus is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. Staphylococcus species are facultative anaerobic organisms.
Campylobacter showae is a Gram-negative, chemoheterotrophic, microaerophilic, motile bacteria belonging to the Campylobacter Genus. The type strain of this species, SU A4, was first isolated from plaque samples taken from the gingival crevices of the human oral cavity but has since also been found in colonic tissues and stool. Since its discovery, C. showae has been implicated in various medical conditions including Crohn's disease, periodontitis, inflammatory bowel disease, and ulcerative colitis due to its pathogenic nature.
Brevinema andersonii, named for John F. Anderson, who first described the organism. This organism is a Gram-negative, microaerophilic, helical shaped, chemoorganotrophic organism from the genus Brevinema. Brevinema andersonii is host associated, strains have been isolated from blood and other tissues of short-tailed shrews and white-footed mice and are infectious for laboratory mice and Syrian hamsters.B. andersonii is readily identified by restriction enzyme analysis, and SDS-PAGE, or fatty acid composition data. Another identifier for B. andersonii is the sheathed periplasmic flagella in the 1-2-1 configuration. While cells are visible by dark-field or phase-contrast microscopy, they cannot be seen when bright-field microscopy is used.
Leptotrichia goodfellowii is a Gram-negative, non-spore-forming and non-motile anaerobic bacterium from the genus of Leptotrichia which has been isolated from human blood of an endocarditis patient. It is associated with infections in the oral cavity and respiratory tract. While primarily associated with opportunistic infections in immunocompromised individuals, its exact pathogenic mechanisms and clinical significance warrant further investigation.
Christensenella hongkongensis is a species of clinically relevant gram-positive coccobacilli, first isolated from patients in Hong Kong and Canada in 2006. Although the species remains relatively rare, it has a high mortality rate of up to 50%. Christensenella is thought to be broadly distributed globally, as it has been isolated from patient blood cultures around the world including Hong Kong, South Korea, New Zealand, Canada, Sweden, France and Italy. Fewer than 15 cases of C. hongkongensis have been observed worldwide.
Actinomyces massiliensis is an anaerobic, mesophilic, Gram-positive bacterium originally isolated from a human blood sample and belonging to the genus Actinomyces.