What do Lyme disease and syphilis have in common?

[tara]

What do What do Lyme disease and syphilis have in common?

http://www.ncbi.nlm.nih.gov/books/bv...brk.chapter.14

Diseases spread by ticks are not recent phenomena to the New World. However, one tick-borne disease, known in Europe since the beginning of the century, has only recently emerged in the United States and is now the most common tick-borne disease on this side of the Atlantic.

In the mid-1970s, a number of residents of the small town of Lyme in Connecticut were afflicted with an unusual arthritis-like condition. Most new cases were observed in the summer and early fall of each year, and the incidence was soon linked to recent tick bites in a high percentage of patients.

The organism that causes Lyme disease is a bacterium, Borrelia burgdorferi, which was cultured from the midgut of Ixodes ticks in the mid-1980s. It is shaped like a wave or helix and belongs to a whole class of bacteria that can be identified by this distinctive shape, the spirochetes, which include some other nasty human pathogens that can cause syphilis, tick-borne relapsing fever, dysentery, and leptospirosis.

We now have the full sequence of the B. burgdorferi genome. It has a total of 853 genes on one linear chromosome and an additional 430 genes on 11 plasmids. The chromosomal genes are required for cell growth, although there are no genes present that are involved in the synthesis of amino acids, fatty acids, enzyme cofactors, or nucleotides. The genes on the plasmids may be involved in infectivity and virulence. One of the chromosomal genes codes for "outer surface protein A" (OspA), which has been the focus of a search for a vaccine against Lyme disease. Recent clinical trials using a recombinant form of OspA as a vaccine look extremely promising.

But what of the relatives of B. burgdorferi? Perhaps one of the most infamous of these is Treponema pallidum, the bacterium that causes syphilis. in contrast to Lyme disease, syphilis is not a modern affliction; it was first recognized in the 15th century in Europe. It is similar to B. burgdorferi in that it is a spirochete with a relatively small genome and requires a host to survive; however, at the genomic level, the two organisms are not very closely related to each other at all.
Of the 1041 protein-coding regions in Treponema pallidum, 476 are shared with B. burgdorferi, but nearly half of these are common to other bacteria too, and most have a predicted biological function. Of the genes with unknown function, there are about 50 that are conserved only in the spirochetes and are not found in any other bacteria. Some of these are likely to represent genes that code for spirochete-specific traits, such as their helical shape and perhaps elements of their pathogenicity.

The comparison of whole genomes may help pinpoint genes that make an organism a successful pathogen or suited to living in a particular environment. Furthermore, the identification of related genes in different species gives a new twist to the classification of different organsims, deepening our understanding of their relationship to each other across the whole evolutionary spectrum.
syphilis have in common?

http://www.ncbi.nlm.nih.gov/books/bv...brk.chapter.14

Diseases spread by ticks are not recent phenomena to the New World. However, one tick-borne disease, known in Europe since the beginning of the century, has only recently emerged in the United States and is now the most common tick-borne disease on this side of the Atlantic.
In the mid-1970s, a number of residents of the small town of Lyme in Connecticut were afflicted with an unusual arthritis-like condition. Most new cases were observed in the summer and early fall of each year, and the incidence was soon linked to recent tick bites in a high percentage of patients.
The organism that causes Lyme disease is a bacterium, Borrelia burgdorferi, which was cultured from the midgut of Ixodes ticks in the mid-1980s. It is shaped like a wave or helix and belongs to a whole class of bacteria that can be identified by this distinctive shape, the spirochetes, which include some other nasty human pathogens that can cause syphilis, tick-borne relapsing fever, dysentery, and leptospirosis.

We now have the full sequence of the B. burgdorferi genome. It has a total of 853 genes on one linear chromosome and an additional 430 genes on 11 plasmids. The chromosomal genes are required for cell growth, although there are no genes present that are involved in the synthesis of amino acids, fatty acids, enzyme cofactors, or nucleotides. The genes on the plasmids may be involved in infectivity and virulence. One of the chromosomal genes codes for "outer surface protein A" (OspA), which has been the focus of a search for a vaccine against Lyme disease. Recent clinical trials using a recombinant form of OspA as a vaccine look extremely promising.

But what of the relatives of B. burgdorferi? Perhaps one of the most infamous of these is Treponema pallidum, the bacterium that causes syphilis. in contrast to Lyme disease, syphilis is not a modern affliction; it was first recognized in the 15th century in Europe. It is similar to B. burgdorferi in that it is a spirochete with a relatively small genome and requires a host to survive; however, at the genomic level, the two organisms are not very closely related to each other at all.

Of the 1041 protein-coding regions in Treponema pallidum, 476 are shared with B. burgdorferi, but nearly half of these are common to other bacteria too, and most have a predicted biological function. Of the genes with unknown function, there are about 50 that are conserved only in the spirochetes and are not found in any other bacteria. Some of these are likely to represent genes that code for spirochete-specific traits, such as their helical shape and perhaps elements of their pathogenicity.

The comparison of whole genomes may help pinpoint genes that make an organism a successful pathogen or suited to living in a particular environment. Furthermore, the identification of related genes in different species gives a new twist to the classification of different organsims, deepening our understanding of their relationship to each other across the whole evolutionary spectrum.

[tara]

Lyme Disease and Syphilis-- http://www.angelfire.com/biz/romarkaraoke/lymeart.html

Several authors have noted similarities between Lyme disease and syphilis (3, 59, 103). Both are caused by a spirochete; syphilis by T. pallidum and Lyme disease by B. burgdorferi. Both start with skin inoculation and a localized skin reaction, followed by a desseminated multisystemic infection. Both may progress in stages. Both can cause meningitis, encephalitis, cognitive deficits, cranial neuropathy, and vasculitis.

Both diseases can, in rare cases, lead to the Tullio phenomenon (40), characterized by nausea and nystagmus in response to sound stimulation. (This syndrome was previously considered pathognomonic for syphilis.)

Antibiotic treatment of both diseases may lead to an initial worsening of symptoms, including neuropsychiatric ones (33, 104). The mechanism of injury in both infections is thought to be primarily indirect: one of immunopathogenesis, not a direct effect of the spirochete itself. 



Both T. pallidum and B. burgdorferi can rapidly invade the CNS, within the first few weeks after infection. Both spirochetes can remain latent for long periods of time before the onset of disease. Both spirochetes can pass through or between endothelial cells (105, 106), thereby enabling dissemination and extensive tissue involvement.

Both may persist in the host to cause a chronic infection. 

Unlike T. pallidum , which is generally transmitted from host to host, the Lyme spirochete is carried by a vector. Furthermore, radiculopathy and peripheral neuropathy are features of Lyme disease that syphilis does not share. 

Neurosyphilis is known to be associated with memory problems, depression, mania, psychosis, and personality changes, such as irritability, emotional lability, and apathy (107).

Recent evidence suggests that Lyme borreliosis, the "new great imitator" (59), may be associated with a similarly wide spectrum of psychiatric disorders. What Hollos and Ferenczi (10 wrote about syphilis in 1925 bears analogy to the present state of knowledge about Lyme disease: 

The psychical symptomatology of paresis is by no means only an intellectual deterioration. On the contrary, it contains almost all the mental symptoms that occur in other psychoses, very frequently the most characteristic symptoms of mania, of melancholia, of paranoia, and of dementia praecox. In many cases the diagnosis for a long time oscillates between a "functional psychosis" and paresis, and only the beginning of pupillary stiffness, a facial palsy, or the finding of a "positive Wasserman," is the determining factor.

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Syphilis is a great mimic. Always keep this condition in mind when encountering patients with cranial neuropathies, optic neuropathies, anterior uveitis, chorioretinitis, retinal vascular occlusion, and chronic anterior segment inflammation.

Manifestations of syphilis can be complicated by concurrent HIV infection. Always consider HIV infection in patients with syphilis. Further, concurrent infections with gonorrhea and chlamydia frequently occur, and should also be investigated.

Nearly 45 percent of males manifesting bilateral tonic pupils will test positive for syphilis.
Lyme disease, another spirochetal disease, is also a great mimic and behaves very similar to syphilis.

In fact, Lyme disease can cause false-positive readings on both specific and non-specific tests for syphilis. Always consider Lyme disease as a possibility when testing for syphilis, particularly in cases where a history of sexual contact is absent. In these cases, particularly in endemic areas, try to elicit a history of tick bite.

Stromal interstitial keratitis is a manifestation of primarily congenital syphilis, but may exist in acquired syphilis. When encountering stromal interstitial keratitis, consider testing for syphilis if the cause does not seem to be congenital. Interstitial keratitis is treated with high doses of potent topical steroids, as this is inflammatory in nature and not actual stromal infection.