Leptospira noguchii

Leptospira noguchii was originally cultured in 1907, but was thought to be Spirochaeta interrogans due to the question mark shape of the cell.^[2] However, upon further research on the 16s rRNA Yasuda et al. was able to classify this organism as Leptospira noguchii.^[2]

Originally, there were only two species classifications of Leptospira.^[7] They were categorized as Leptospira interrogans, the pathogenic species, and Leptospira biflexa, the nonpathogenic species.^[7] However, in 1989, it was discovered that there were 21 different species of Leptospira.^[7] Within these 21 species, Leptospira noguchii was recognized. However, conjugation is very common among the genetic materials making them hard to distinguish individual species.^[7]

Leptospira noguchii can grow in stagnant water, and is known to grow optimally between 28 °C - 30 °C at a pH between 7.2 and 7.6.^[8] L. noguchii is also known to have a parasitic relationship and grow in host's kidneys. It can be isolated from urine, blood, and cerebrospinal fluid.^[1]

Leptospira noguchii are spirochete-shaped, gram-negative bacterium that typically range from 0.1 μm by 6 μm to 0.1 μm to 20 μm.^[9][10] Leptospira noguchii also lacks glycolipids in their peptidoglycan and contain diaminopimelic acid.^[10] L. noguchii is a motile organism due to having amphitrichous flagella on opposing ends of each other.^[11] Leptospira organisms can be cultured in Ellinghausen-McCullough-Johnson-Harris medium at 30 °C.^[12] Due to Leptospira’s morphology, researchers typically use dark-field microscopy as opposed to Light-field microscopy because the amphitrichous flagella produce quick movements along the microscope that are hard to see on a light-field microscope.^[11]

Leptospira noguchii is a chemoorganotrophic organism.^[1] The metabolism of L. noguchii is unusual due to the fact that the main source of energy and carbon comes from beta-oxidation of long-chained fatty acids.^[11] An interesting fact about Leptospira noguchii is that it the ability to process glucose; however, this is not its preferred way to obtain energy, though it has the necessary enzymes to perform this process.^[11] This organism is also able to use the respiratory electron transport chain due to being an aerobic organism that can also survive in microaerophilic environments.^[11] The characteristic of being aerobic allows this organism to perform oxidative phosphorylation in order to produce ATP for energy.^[11]

Leptospira noguchii has a low GC content of 35.63% while the genome size is 4.76 Mbp.^[13] The sequencing of the genome was accomplished using BASys, which is bacterial annotation system.^[13] There are a total of 4,535 coding sequences within L. noguchii's genome that have been identified.^[13]

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.^[14] 40 patients came in with these similar symptoms.^[14] 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.^[14] 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.^[14] While the patients were recovering, the doctors taking care of the soldier were stumped by the pathogen after the differential diagnosis.^[14] At the request of the doctors, the Surgeon General was petitioned by the U.S. army to send others to help research the unidentified pathogen.^[14]

Dr. Norman H. Topping, Maj. Cornelius B. Phillips, and Dr. John R. Paul all were sent to investigate the pathogen.^[14] They concluded that the pathogen was water-borne and not transferred by any kind of insect.^[14] 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 transferable between mammals.^[14] In 1945, Capt. Tatlock finally thought he classified the pathogen as a virus.^[14] 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.^[14] 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][14] This Leptospirosis became known as “Fort Bragg Fever.”^[4]

The Bonito strain of L. noguchii was isolated from a 34-year-old man in Brazil that was suffering from Leptospirosis.^[4] The man is suspected to have contracted this disease through interaction with rats, dogs, and other farm animals.^[4] The man was taken to the Hospital Santa Casa de Misericórdia, Pelotas, and his lab results showed an elevated bilirubin level.^[4] This strain was able to be isolated from a blood culture at the hospital.^[4]

This strain was initially obtained form a 16-year-old boy in Brazil via a blood culture.^[4] This patient also reported being around rats and dogs; however, he was not hospitalized for his illness.^[4]

This strain was isolated from a dog found in Brazil that appeared to be suffering from anorexia.^[4] The dog died form this strain of L. noguchii, and the symptoms present were slightly different than when humans were infected.^[4] The dog presented with disorientation, diarrhea, vomiting, anorexia, and lethargy.^[4] The Hook strain was isolated from the kidney tissue, as this is where L. noguchii typically resides in its host.^[4]