1. Background
     Discovery    Phylogeny    Ecology  

2. Characteristics

3. Metabolism

4. Genomics

5. Fort Bragg, North Carolina Outbreak

6. Isolation of Main Pathogenic Strains
     Bonito Strain    Cascata Strain    Hook Strain  

7. Pathogenesis
     Entry    Attachment    Virulence Factors    Symptoms    Treatment  

8. References

9. External links

Leptospira noguchii is a gram-negative, pathogenic organism.^[1] L noguchii is famous for causing the febrile illness in Fort Bragg, NC during World War II.^[2][3] There was 40 cases of this fever documented during each summer from 1942 to 1944; however, there were 0 deaths recorded from this outbreak.^[3] Unlike other strains of Leptospira that cause leptospirosis, L. noguchii is characterized by showing a pretibial rash on the victim.^[2]{{TOC left}}

Background

Discovery

Phylogeny

Originally, there were only two species classifications of Leptospira.^[5] They were categorized as Leptospira interrogans, the pathogenic species, and Leptospira biflexa, the nonpathogenic species.^[5] However, in 1989, it was discovered that there were 21 different species of Leptospira.^[5] Within these 21 species, Leptospira noguchii was recognized. However, conjugation is very common among the genetic materials making them hard to distinguish individual species.^[5]

Ecology

Characteristics

Metabolism

Genomics

Fort Bragg, North Carolina Outbreak

In the summer of 1942, Fort Bragg, NC endured an outbreak of a sickness which presented with malaise, general aches and pains, headaches, and post-orbital pains.^[12] 40 patients came in with these similar symptoms.^[12] Upon obtaining information about their recent actions, locations, and barracks, most patients said that they recently swam in lakes close to the Fort Bragg military complex.^[12] In about 95% of the patients presented with Splenomegaly in the early stages, and then on the fourth day a pretibial rash presented in most of the patients.^[12] While the patients were recovering, the doctors taking care of the soldier were stumped by the pathogen after the differential diagnosis.^[12] The doctors requested the Surgeon General was petitioned by the U.S. army to send others to help research the unidentified pathogen.^[12]

Dr. Norman H. Topping, Maj. Cornelius B. Phillips, and Dr. John R. Paul all were sent to investigate the pathogen.^[12] They concluded that the pathogen was water-borne and not transferred by any kind of insect.^[12] In 1944, Capt. Hugh Tatlock finally completed a transfer of the pathogen to a mammal, causing them to figure out that the pathogen is only transferrable between mammals.^[12] In 1945, Capt. Tatlock finally thought he classified the pathogen as a virus.^[12] Later, in 1951, when the necessary technology became available to perform agglutination tests and cross-reference agglutination tests, they found that it was a species of the genus Leptospira.^[12] At the time, the pathogen was thought to be called Leptospira Autumnalis, but upon further study of the whole-genome, it was later reclassified as a serovar of Leptospira noguchii.^[1][12] This Leptospirosis became known as “Fort Bragg Fever.”^[13]

Isolation of Main Pathogenic Strains

Bonito Strain

The Bonito strain of L. noguchii was isolated from a 34-year-old man in Brazil that was suffering from Leptospirosis.^[13] The man is suspected to have contracted this disease through interaction with rats, dogs, and other farm animals.^[13] The man was taken to the Hospital Santa Casa de Misericórdia, Pelotas, and his lab results showed an elevated bilirubin level.^[13] This strain was able to be isolated from a blood culture at the hospital.^[13]

Cascata Strain

This strain was initially obtained form a 16-year-old boy in Brazil via a blood culture.^[13] This patient also reported being around rats and dogs; however, he was not hospitalized for his illness.^[13]

Hook Strain

This strain was isolated from a dog found in Brazil that appeared to be suffering form anorexia.^[13] The dog died form this strain of L. noguchii, and the symptoms present were slightly different than when humans were infected.^[13] The dog presented with disorientation, diarrhea, vomiting, anorexia, and lethargy.^[13] The Hook strain was isolated from the kidney tissue, as this is where L. noguchii typically resides in its host.^[13]

Pathogenesis

Entry

As it enters through the mucosal membranes or abrasions on the skin, its travels in your bloodstream to your kidney's renal tubing, where it stays an enters the incubation period.^[1] A unique adaptation of Leptospira noguchii is that it can complete translational movement in thick liquids, giving it the ability to penetrate deep tissue.^[1]

Attachment

Virulence Factors

Pathogenic Leptospira spp. has features of both a gram-positive and gram-negative pathogen.^[63] Features of the gram-negative pathogen is the presences of lipopolysaccharides (LPS), but the closeness of the cytoplasmic membrane to the cell wall shows more of a gram-positive feature.^[63] Also, the virulence factors on the flagella of pathogenic leptospires have thought to be involved in the overall infection.^[63] Leptospira noguchii specifically creates a median lethal dose (LD₅₀) of three to 100 leptospires.^[63] L. noguchii also uses the Lsa24 protein to avoid the immune system of the host and antibacterials by binding to factor H.^[1] While the most important virulence factor has not yet been identified, some of the other proteins that are considered to be contributors to the main virulence are hemolysins, more specifically phospholipase C, sphingomylinase-like proteins, and pore-forming proteins.^[1]

Symptoms

The disease typically begins with fever, and will then lead to other symptoms.^[69]

The symptoms in humans include: High fever (102 °F-104 °F), headache, chills, muscle aches, vomiting, jaundice, conjunctivitis, abdominal pain, diarrhea, and a pretibial rash.^[14] Some complications are Weil's syndrome which is a multi-system organ complication causing jaundice, meningitis, pulmonary hemorrhage, hepatic and renal dysfunction, and cardiovascular collapse.^[15]

Treatment

References

External links

• Type strain of Leptospira noguchii at BacDive - the Bacterial Diversity Metadatabase

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