Lyme spirochetes, primarily Borrelia burgdorferi, are extremely small, spiral-shaped bacteria. They are typically about 0.2 to 0.3 micrometers (μm) in diameter and usually 20 to 30 micrometers long[9], with some reaching up to 50 micrometers in length. For reference, the average human hair is about 70 micrometers in diameter. So 25 micrometers would be approximately: One-third the thickness of a typical human hair. This size makes them difficult to observe without the aid of a microscope. The size of Borrelia Colonies is generally larger than individual spirochetes. The aggregates, referred to as biofilm-like structures, can consist of multiple spirochetes and can reach sizes of up to 100 micrometers (µm) in diameter, depending on the growth conditions and the number of spirochetes in the aggregation.
Visibility of Lyme Spirochetes
To see Lyme spirochetes, a microscope is necessary. They are often visualized using dark-field microscopy or special staining techniques that enhance their visibility against the background. Under a microscope, they appear as corkscrew-shaped organisms, which is characteristic of spirochetes[18][20].
Visualizing Lyme with Optical Coherence Tomography OCT
Lyme Bacteria Visualized During Opthamology
Ultrahigh-resolution OCT systems have been developed that significantly enhance imaging capabilities. For instance, the use of titanium-sapphire (Ti:Al₂O₃) lasers allows for axial resolutions of 2-3 micrometers, which is substantially better than traditional systems that typically achieve resolutions of 10-15 micrometers. This improvement enables the detailed visualization of retinal structures and could facilitate better monitoring of diseases, including those caused by pathogens like Borrelia.
High-resolution optical coherence tomography (OCT) scans typically have a resolution that is potentially sufficient to visualize spirochetes, such as Borrelia burgdorferi, which are approximately 10-30 micrometers in diameter. The axial and lateral resolutions of OCT systems can range from around 4.2 µm to 13 µm, depending on the specific technology used[3]. While spirochetes are slender and can be challenging to detect using standard microscopy due to their small size and morphology, specialized imaging techniques like intravital microscopy have been developed to visualize them in situ[1][2].
In summary, while standard OCT can not visualize Lyme bacteria, a high resolution OCT can provide high-resolution imaging and may be capable of visualizing spirochetes due to their size and the capabilities of the imaging technology. Newer Ultra High Res OCT would be even more likely to visualize Lyme bacteria if it happened to appear in this part of the eye. More specialized methods are typically required, however, for direct observation of these organisms.
Are You Sure I Couldn’t See One with the Naked Eye?
It would be extremely challenging, if not impossible, for the average person to see an object 30 micrometers long and only a few micrometers thick with the naked eye, even if it was moving. Here’s why:
1. The smallest objects visible to the naked human eye are generally around 40-50 micrometers in size[6]. An object 30 micrometers long falls below this threshold.
2. The human eye’s angular resolution is about 1 arcminute, which corresponds to about 0.3 mm (300 micrometers) at a distance of 1 meter[18]. This is significantly larger than the object in question.
3. Under normal lighting conditions and at a typical reading distance of about 400 mm, the smallest object resolution for the naked eye is approximately 0.116 mm (116 micrometers)[18]. This is still much larger than a 30-micrometer object.
4. Even at closer inspection distances of 200-250 mm, which are used in laboratory settings, the smallest size recognizable to the naked eye is about 58-72 micrometers[18]. The object described is still smaller than this limit.
5. While movement might help draw attention to an object, it doesn’t fundamentally change the eye’s ability to resolve such small details.
That being said, there are a few caveats:
– If the object were highly reflective or emitting light, it might be possible to detect its presence, even if the shape couldn’t be resolved[21].
– Individuals with exceptionally good eyesight might perform slightly better than these averages.
– The thickness of a few micrometers would make this object essentially invisible in terms of width.
While it’s theoretically possible to detect the presence of very small, moving objects under ideal conditions, resolving the shape or details of something 30 micrometers long and only a few micrometers thick would be beyond the capabilities of the unaided human eye.
How About In a Test Tube of Liquid?
What about in a glass test tube in great lighting if it was floating in liquid, slightly magnified by the curature of the glass? In a glass test tube filled with liquid and under good lighting conditions, it is possible to see an object that is 30 micrometers long and a few micrometers thick, especially if the object is floating and the glass’s curvature slightly magnifies it.
Factors Influencing Visibility
1. Refractive Index Matching: If the liquid in the test tube has a refractive index similar to that of the glass, the object may appear less visible or even “disappear.” For example, when a Pyrex test tube is submerged in vegetable oil, both materials have nearly the same refractive index, which minimizes reflection and refraction at their boundary, making the glass appear invisible[1][3][4].
2. Lighting Conditions: Adequate lighting enhances visibility. If the test tube is well-lit, it may help in detecting the object, even if it is small. The presence of light can allow for better contrast against the background, aiding in visibility.
3. Curvature of the Glass: The curvature of the glass can act as a lens, potentially magnifying the object slightly. This effect could make it easier to see the object, depending on the curvature and the observer’s distance from the tube[1][2].
4. Movement: If the object is moving, this can draw attention to it, making it easier to notice despite its small size. The motion may create a visual cue that helps the observer focus on the object.
While the average human eye typically struggles to resolve objects smaller than 40-50 micrometers under normal circumstances, the combination of a suitable liquid, good lighting, and the magnifying effect of curved glass could allow for the detection of a 30-micrometer-long object in a test tube, particularly if it is moving. However, the narrow width–0.2 to 0.3 micrometers (μm) in diameter–would probably still make this difficult and perhaps impossible.
Context of Visibility
While the spirochetes themselves are tiny, the ticks that transmit Lyme disease, particularly the nymphal stage of the blacklegged tick (or deer tick), are also very small—about the size of a poppy seed (approximately 1 to 2 mm). This makes them difficult to spot on the skin, and many people do not notice when they are bitten. You may read that “proper tick removal is crucial, as the ticks need to be attached for over 24 hours to transmit the bacteria.” Except that’s partly a lie, one of many that swirl around this disease causing great misery.
The Myth:
The part about ticks needing to be attached for over 24 hours to transmit bacteria is not entirely accurate. There is no little timer inside the tick that waits for 24 hours to release the bacteria. While it’s true that the risk of disease transmission increases with longer attachment times, it’s not a hard and fast rule. Here’s why:
- Different pathogens have different transmission times.
- If a tick has previously fed and then reattached to a new host, it may be able to transmit pathogens more quickly.
- Some tick-borne pathogens, like Powassan virus, can be transmitted in as little as 15 minutes of attachment.
- Rocky Mountain spotted fever – In some experimental settings, transmission occurred in as little as 2 hours[26].
- Anaplasmosis and babesiosis can potentially be transmitted within the first 24 hours of tick attachment.
- Borrelia burgdorferi (the bacteria causing Lyme disease) typically takes 36-48 hours for transmission, but this is not a hard and fast rule. It could happen much faster.
- Research shows that blacklegged ticks in animal models can transmit the Lyme disease spirochete, Borrelia burgdorferi, in less than 16 hours, and a minimum time has never been established[25].
The CDC and other health organizations emphasize removing ticks as soon as they are discovered, regardless of how long they may have been attached. This is because while the risk does increase with time, there’s no guaranteed “safe” period of attachment.
While longer attachment times do increase risk, it’s a myth that ticks need to be attached for over 24 hours to transmit disease. Prompt removal is always the best practice.
Read More
[1] https://journals.plos.org/plospathogens/article?id=10.1371%2Fjournal.ppat.1000090
[2] https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.628045/full
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9599122/
[4] https://lymediagnostics.com/2021/01/11/what-is-wrong-with-microscopy-in-borreliosis/
[5] https://lymediagnostics.com/detection-of-spirochetes-based-on-morphology/
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4994469/
[7] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/spirochaetaceae
[8] https://journals.asm.org/doi/10.1128/mbio.01598-23
[9] https://www.cdc.gov/lyme/media/pdfs/Lyme-Disease-What-you-need-to-know.pdf
[10] https://www.pennmedicine.org/for-patients-and-visitors/patient-information/conditions-treated-a-to-z/lyme-disease
[11] https://www.msdmanuals.com/home/infections/bacterial-infections-spirochetes/lyme-disease
[12] https://www.cdc.gov/lyme/causes/index.html
[13] https://dph.illinois.gov/topics-services/diseases-and-conditions/tickborne-illnesses/lyme-disease.html
[14] https://www.mass.gov/info-details/lyme-disease
[15] https://ufhealth.org/conditions-and-treatments/lyme-disease
[16] https://news.northeastern.edu/2022/07/12/lyme-disease-tick/
[17] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/borrelia-burgdorfer
[18] https://en.wikipedia.org/wiki/Naked_eye
[19] http://www.icq.eps.harvard.edu/MagScale.html
[20] https://www.reddit.com/r/askscience/comments/kdk8u/what_is_the_smallest_object_you_can_physically/
[21] https://www.sciencefocus.com/the-human-body/how-small-can-the-naked-eye-see
[22] https://www.wonderopolis.org/wonder/what-is-the-smallest-thing-you-can-see/
[23] https://www.bench.com/setting-the-benchmark/how-big-is-a-micron
[24] https://homework.study.com/explanation/human-vision-can-distinguish-objects-down-to-about-a-4th-of-a-millimeter-250-micrometers-given-this-which-of-the-following-are-generally-visible-to-the-human-eye-a-proteins-b-bacterial-cell.html
[25] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4278789/
[26] https://www.consumerreports.org/health/outdoor-safety/how-quickly-can-an-attached-tick-make-you-sick-a6286230428/