This work was partially supported by the Natural Science and Engineering Research Council of Canada and the Canadian Lyme disease Foundation (AB and VL), the Swedish Research Council (SB, M-LF and IN), TA&#268;R GAMA 2 project - &#34;Support of application potential verification 2.0 at the Biology Centre CAS&#34; (TP01010022) (MG and NR), and by a grant from Ministry of Health of the Czech Republic NV19-05-00191 (MG and NR). We thank S. Vranjes (2021, Rudenko lab) for the image in Figure 4 and J. Thomas-Ebbett (2021, Lloyd lab) for the images in Figure 5. We thank all researchers who have contributed to the field and apologize to those whose work we were not able to cite due to space limitations.

No conflicts of interest were declared.

The laboratory culture of bacteria is the springboard for research. The profound advantage conferred by the ability to culture is exemplified by the struggle, over more than a century culminating only recently in success, to culture Treponema pallidum, the spirochete that is the etiological agent of syphilis44. Borrelia spirochetes are also challenging to culture, but culture is possible23,24,...

Borrelia is a genus of spirochete bacteria that encompasses three major clades: the Lyme borreliosis (LB) group, the relapsing fever (RF) group, and a less well-characterized group seemingly restricted to reptiles. Borrelia taxonomy is in flux with the advent of molecular methodologies that allow genome and proteome comparisons, as is true of most other taxonomic groups1,2,3,4,5,6,7. The LB group (also called the Lyme disease group) has traditionally been termed Borrelia burgdorferi sensu lato after its best-characterized member Borrelia burgdorferi sensu stricto.&#160;This paper uses the currently most widely used terminology: the LB, the RF, and the reptile-associated group, and describes the culture protocols for the LB and the RF groups.
As would be expected for a member of the family Spirochaetaceae, Borrelia can adopt the distinctively long and thin spiral shape, typically 20-30 &#181;m long and 0.2-0.3 &#181;m wide. However, Borrelia cells are highly pleomorphic and can adopt many other shapes in both culture and in vivo1,8 as a result of their complex cellular and genetic structure. In its spirochetal form, the planar sine wave morphology results from its axial endoflagella rotating in the periplasmic space between the inner and outer membranes. This structure enables the cells to be highly motile, with the outer membrane containing proteins that enable the cell to interact with host tissues9,10. The expression of the outer membrane proteins is tightly regulated and affect not only host tissue invasion but also interaction with the host immune system11. This complex gene expression allows the Borrelia cells to shuttle between the very different environments of vertebrate hosts and invertebrate vectors. The genome of Borrelia is unusual among prokaryotes, consisting of a linear rather than a circular chromosome. In addition to the linear chromosome, Borrelia species contain 7-21 plasmids, some linear and some circular. The plasmids harbor the majority of genes required for host adaptation and virulence, and the circular plasmids derived from prophages are thought to be responsible for the majority of horizontal gene flow between spirochetal cells12,13. Consistent with a role in host adaptation, some, possibly many or all, members of the Lyme borreliosis group lose plasmids in culture14. The best studied &#34;lab adapted&#34; strain of B. burgdorferi, B31, has only seven of the nine plasmids found in wild isolates of this species15. Similarly, B. garinii loses plasmids in culture16. Some studies have shown that RF species and B. miyamotoi retain plasmids when cultured14,17, but recent work demonstrates altered plasmids and infectivity with long-term in vitro cultivation18.
Culture-based methods remain the gold standard for the laboratory detection of bacterial infections, for both research and clinical work14,17. The culture of pathogens from bodily fluids or tissues directly detects replicating pathogens and provides source material for research14,17. This protocol demonstrates the methodology and recipes required to successfully culture the spirochetes of the LB group as well as RF Borrelia and B. miyamotoi. The basic medium for growing Borrelia spirochetes is the Barbour-Stoenner-Kelly medium (BSK-II or the commercially available BSK-H), with or without antibiotics to reduce the growth of contaminating prokaryotes. This medium was adapted from a medium originally used to support RF Borrelia19, further modified by Stoenner20 and then by Barbour21. Many modifications have since been developed, each having effects on bacterial physiology that can affect growth, infectivity, and pathogenicity22. This medium reliably supports the growth of spirochetes in established cultures and has been used to isolate spirochetes from tick, mammal, and clinical samples23. The more recently developed variation, modified Kelly-Pettenkofer (MKP) medium, can provide better isolation success, morphology, and motility when isolating new Borrelia isolates from environmental samples, when the number of spirochetes present in the sample available to seed the culture is low23,24. In all cases, the success of cultivation is critically dependent on the freshly prepared medium and the use of appropriate ingredients; not all commercial ingredients produce high-quality medium. Inoculated cultures can be conveniently incubated without shaking in a conventional 32-34 &#176;C incubator in the presence of a small amount of residual ambient oxygen. Borrelia spirochetes are anaerobes but are exposed in nature to fluctuations in oxygen and carbon dioxide concentrations and respond with changes in gene expression26,27,28,29. Thus, gene expression, growth, and other metabolic studies should control for oxygen and carbon dioxide levels with the use of an oxygen-controlled incubator or anaerobic chamber. In culture, cultures are checked weekly, or more often, for the presence of spirochetes with either darkfield microscopy or phase contrast microscopy. Culture smears can be stained with either silver stains, immunohistochemistry, or through the use of fluorescently tagged strains29,30. PCR followed by DNA sequencing is a sensitive and specific method to detect and genetically identify or confirm the Borrelia species30,31,32,33.
Many minor variations on BSK-II exist, and some are commercially available. The protocol described here in section 1 has been adapted from Barbour (1984)21. Liquid MKP medium is a more recently developed medium and is described in section 2. It is prepared according to a previously reported protocol33,34, which, similarly to BSK medium, consists of two steps: preparation of basic medium and preparation of complete medium. Borrelia culture medium can be prepared with or without antibiotics, as described in section 3; the antibiotics act to reduce contaminating bacteria introduced when inoculating with clinical or environmental samples, as described in section 4; if inoculating with pure Borrelia sp. culture, antibiotics may not be needed. Making long-term Borrelia stocks is often important, and a protocol for doing so is described in section 5. Section 6 describes using these media to isolate pure Borrelia sensu lato clones from clinical or environmental samples. There are a number of approaches possible36; below is one found to be effective. The plating medium used in this protocol is a modification of BSK-II plating medium37&#160;and MKP medium34 (with rabbit serum increased to 10%38).

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1.7 mL tubes</td>
			<td>VWR</td>
			<td>87003-294</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>0.2&#160;&#181;m Sterile syringe filter&#160;</td>
			<td>VWR</td>
			<td>28145-501</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>10 &#181;L barrier pipette tip</td>
			<td>Neptune</td>
			<td>BT10XLS3</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>10 mL Serological pipettes&#160;</td>
			<td>Celltreat</td>
			<td>229011B</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>1000 &#181;L barrier pipette tip</td>
			<td>Neptune</td>
			<td>BT1000.96</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>15 mL tube</td>
			<td>Celltreat</td>
			<td>188261</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>20 &#181;L barrier pipette tip</td>
			<td>Neptune</td>
			<td>BT20</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>20 mL Sterile syringe&#160;</td>
			<td>BD</td>
			<td>309661</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>200 &#181;L barrier pipette tip</td>
			<td>Neptune</td>
			<td>BT200</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>25 mL Screw Cap Culture Tubes</td>
			<td>Fisher Scientific</td>
			<td>14-933C</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>25 mL Serological pipettes</td>
			<td>Celltreat</td>
			<td>229025B</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>3 mL Sterile syringe</td>
			<td>BD</td>
			<td>309657</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>35% BSA&#160;</td>
			<td>Sigma</td>
			<td>A-7409</td>
			<td>Source is important - see note</td>
		</tr>
		<tr>
			<td>5 mL Serological pipettes&#160;</td>
			<td>Celltreat</td>
			<td>229006B</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>50 mL tube</td>
			<td>Celltreat</td>
			<td>229421</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>6.5 ml MKP glass tubes&#160;</td>
			<td>Schott</td>
			<td>Schott Nr. 26 135 115</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Amikacine</td>
			<td>Sigma</td>
			<td>PHR1654</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Amphotericin B</td>
			<td>Sigma</td>
			<td>A9528-100MG</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Bactrim/rimethoprim/sulfamethoxazole</td>
			<td>Sigma</td>
			<td>PHR1126-1G</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>BBL Brucella broth&#160;</td>
			<td>BD</td>
			<td>211088</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Biosafety Cabinet</td>
			<td>Labconco</td>
			<td>302419100</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Blood collection tubes (yellow top - ACD)</td>
			<td>Fisher Scientific</td>
			<td>BD&#160;Vacutainer Glass Blood Collection Tubes with Acid Citrate Dextrose (ACD)</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>BSK-H Medium [w 6% Rabbit serum]&#160;</td>
			<td>Darlynn biologicals</td>
			<td>BB83-500</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>centrifuge&#160;</td>
			<td>Eppendorf</td>
			<td>model 5430</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Citric acid TrisodiumSaltDihydrate</td>
			<td>Sigma</td>
			<td>C-8532 100 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>CMRL</td>
			<td>Gibco BRL</td>
			<td>21540 500 mL</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>CMRL-1066</td>
			<td>Gibco</td>
			<td>21-510-018</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Cryogenic Tubes (Nalgene)</td>
			<td>Fisher Scientific</td>
			<td>5000-0020</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Deep Petri with stacking ring 100 mm &#215; 25 mm</td>
			<td>Sigma</td>
			<td>P7741</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Digital Incubator</td>
			<td>VWR</td>
			<td>model 1545</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>ThermoFisher</td>
			<td>D12345</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Filters for filter sterilization</td>
			<td>Millipore 0.22&#956;m GPExpressPLUS Membrane</td>
			<td>SCGPU05RE</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Gelatin</td>
			<td>Difco BD</td>
			<td>214340 500 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Glass Culture Tubes</td>
			<td>Fisher Scientific</td>
			<td>99449-20</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sigma</td>
			<td>G-7021 1 kg</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma</td>
			<td>G5516</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Hemafuge (Hematocrit &#38; Immuno hematology centrifuge )</td>
			<td>Labwissen</td>
			<td>Model 3220</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Sigma&#160;</td>
			<td>H-3784 100 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>N-acetylglucoseamine</td>
			<td>Sigma&#160;</td>
			<td>A-3286 25 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Neopeptone</td>
			<td>Difco&#160; BD</td>
			<td>211681 500 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Neubauer Hematocytometer</td>
			<td>Sigma&#160;</td>
			<td>Z359629</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Phase contrast microscope&#160;</td>
			<td>Leitz</td>
			<td></td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Phosphomycin</td>
			<td>Sigma</td>
			<td>P5396-1G</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Phosphomycine</td>
			<td>Sigma</td>
			<td>P5396</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Pipetboy</td>
			<td>Integra</td>
			<td></td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Precision Standard Balance</td>
			<td>OHAUS</td>
			<td>model TS200S</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Pyruvic acid (Na salt)</td>
			<td>Sigma</td>
			<td>P-8574 25 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Rabbit Serum&#160;</td>
			<td>Gibco</td>
			<td>16-120-032</td>
			<td>Source is important&#160;</td>
		</tr>
		<tr>
			<td>Rabbit Serum&#160;</td>
			<td>Sigma</td>
			<td>R-4505&#160; 100 mL</td>
			<td>Source is important&#160;</td>
		</tr>
		<tr>
			<td>Rifampicin</td>
			<td>Sigma</td>
			<td>R3501-1G</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sigma</td>
			<td>S-5761&#160;&#160;&#160;&#160; 500 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Sufametaxazole&#160;</td>
			<td>Sigma</td>
			<td>PHR1126</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>TC Yeastolate</td>
			<td>Difco&#160; BD</td>
			<td>255752 100 g</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Transfer Pipettes</td>
			<td>VWR</td>
			<td>470225-044</td>
			<td>Standard item - any supplier will do</td>
		</tr>
		<tr>
			<td>Trimethoprim</td>
			<td>Sigma</td>
			<td>PHR1056</td>
			<td>Standard item - any supplier will do</td>
		</tr>
	</tbody>
</table>

cultivation methods of spirochetes from borrelia burgdorferi sensu lato complex and relapsing fever borrelia

The Borrelia consists of three groups of species, those of the Lyme borreliosis (LB) group, also known as B. burgdorferi sensu lato (s.l.) and recently reclassified into Borreliella, the relapsing fever (RF) group Borrelia, and a third reptile-associated group of spirochetes. Culture-based methods remain the gold standard for the laboratory detection of bacterial infections for both research and clinical work, as the culture of pathogens from bodily fluids or tissues directly detects replicating pathogens and provides source material for research. Borrelia and&#160;Borreliella spirochetes&#160;are fastidious and slow growing, and thus are not commonly cultured for clinical purposes; however, culture is necessary for research. This protocol demonstrates the methodology and recipes required to successfully culture LB and RF spirochetes, including all recognized species from B. burgdorferi s.l. complex including&#160;B. afzelii, B. americana, B. andersonii, B. bavariensis, B. bissettii/bissettiae, B. burgdorferi sensu stricto&#160;(s.s.), B. californiensis, B. carolinensis, B. chilensis, B. finlandensis, B. garinii, B. japonica, B. kurtenbachii, B. lanei, B. lusitaniae, B. maritima, B. mayonii, B. spielmanii, B. tanukii, B. turdi, B. sinica, B. valaisiana, B. yangtzensis, and RFspirochetes, B. anserina, B. coriaceae, B. crocidurae, B. duttonii, B. hermsii, B. hispanica, B. persica, B. recurrentis, and B. miyamotoi. The basic medium for growing LB and RF spirochetes is the Barbour-Stoenner-Kelly (BSK-II or BSK-H) medium, which reliably supports the growth of spirochetes in established cultures. To be able to grow newly isolated Borrelia isolates from tick- or host-derived samples where the initial spirochete number is low in the inoculum, modified Kelly-Pettenkofer (MKP) medium is preferred. This medium also supports the growth of B. miyamotoi. The success of the cultivation of RF spirochetes also depends critically on the quality of ingredients.

Borrelia culture media BSK and MKP, and variants, are rich culture media with ingredients that need to be prepared and sterilized sequentially. When correctly prepared, BSK medium should be red-orange and clear (Figure 1). Turbidity and precipitation that persist after warming indicate problematic ingredients, medium production, or contamination; such medium is best discarded. If gelatin is added to BSK and with MKP, the medium will be gelatinous when refrigerated; upon warming, it ...

Watch this Scientific Journal Video about Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia at JoVE.com

Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia

In vitro culture is a direct detection method for the presence of living bacteria. This protocol describes methods for the culture of diverse Borrelia spirochetes,&#160;including those of the Borrelia burgdorferi sensu lato complex, relapsing fever Borrelia species, and Borrelia miyamotoi. These species are fastidious and slow growing but can be cultured.

Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia

The Borrelia consists of three groups of species, those of the Lyme borreliosis (LB) group, also known as B. burgdorferi sensu lato (s.l.) and recently ...

cultivation-methods-spirochetes-from-borrelia-burgdorferi-sensu-lato

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Immunology and Infection

4.5K Views.  Mt. Allison University. In vitro culture is a direct detection method for the presence of living bacteria. This protocol describes methods for the culture of diverse Borrelia spirochetes, including those of the Borrelia burgdorferi sensu lato complex, relapsing fever Borrelia species, and Borrelia miyamotoi. These species are fastidious and slow growing but can be cultured.

Video: Cultivation Methods of Spirochetes from Borrelia burgdorferi Sensu Lato Complex and Relapsing Fever Borrelia

A Protocol for Collecting and Staining Hemocytes from the Yellow Fever Mosquito Aedes aegypti

Mosquitoes are vectors for a number of disease-causing pathogens such as the yellow fever virus, malaria parasites and filarial worms. Laboratories are investigating anti-pathogen components of the innate immune system in disease vector species in the hopes of generating transgenic mosquitoes that are refractory to such pathogens1, 2. The innate immune system of mosquitoes consists of several lines of defense 3. Pathogens that manage to escape the barrier imposed by the epithelium-lined mosquito midgut 4 enter the hemolymph and encounter circulating hemocytes, important cellular components that encapsulate and engulf pathogens 5, 6. Researchers have not found evidence for hematopoietic tissues in mosquitoes and current evidence suggests that the number of hemocytes is fixed at adult emergence and numbers may actually decline as the mosquito ages 7. The ability to properly collect and identify hemocytes from medically important insects is an essential step for studies in cellular immunity. However, the small size of mosquitoes and the limited volume of hemolymph pose a challenge to collecting immune cells. 
Two established methods for collecting mosquito hemocytes include expulsion of hemolymph from a cut proboscis 8, and volume displacement (perfusion), in which saline is injected into the membranous necklike region between the head and thorax (i.e., cervix) and the perfused hemolymph is collected from a torn opening in a distal region of the abdomen 9, 10. These techniques, however, are limited by low recovery of hemocytes and possible contamination by fat body cells, respectively 11. More recently a method referred to as high injection/recovery improved recovery of immunocytes by use of anticoagulant buffers while reducing levels of contaminating scales and internal tissues 11. While that method allows for an improved method of collecting and maintaining hemocytes for primary culture, it entails a number of injection and collecting steps that are not necessary if the downstream goal is to collect, fix and stain hemocytes for diagnostics. Here, we demonstrate our method of collecting mosquito hemolymph that combines the simplicity of perfusion, using anticoagulant buffers in place of saline solution, with the accuracy of high injection techniques to isolate clean preparations of hemocytes in Aedes mosquitoes.

A Protocol for Collecting and Staining Hemocytes from the Yellow Fever Mosquito Aedes aegypti

A simplified yet accurate method to collect and stain mosquito hemocytes is described. Our method combines the simplicity of perfusion with the accuracy of high injection techniques to isolate clean preparations of hemocytes in Aedes mosquitoes. This method facilitates studies requiring knowledge of the types of hemocytes and their abundance.

 Mosquitoes are vectors for a number  of disease-causing pathogens such as the yellow fever virus, malaria parasites  and filarial worms. Laboratories are ...

Cercarial Transformation and in vitro Cultivation of Schistosoma mansoni Schistosomules

Schistosome parasites are the causative agents of schistosomiasis, a chronically debilitating disease that affects over 200 million people globally and ranks second to malaria among parasitic diseases in terms of public health and socio-economic impact (1-4). Schistosome parasites are trematode worms with a complex life cycle interchanging between a parasitic life in molluscan and mammalian hosts with intervening free-swimming stages. Briefly, free-swimming cercariae infect a mammalian host by penetrating the skin with the aid of secreted proteases, during which time the cercariae lose their tails, transforming into schistosomules. The schistosomules must now evade the host immune system, develop a gut for digestion of red blood cells, and migrate though the lungs and portal circulation en route to their final destination in the hepatic portal system and eventually the mesenteric veins (for S. mansoni) where male and female worms pair and mate, producing hundreds of eggs daily. Some of the eggs are excreted from the body into fresh water, where the eggs hatch into free-swimming miracidia (5-10). The miracidia infect specific snail species and transform into mother and daughter sporocysts, which in turn, produce infective cercariae, completing the life cycle. Unfortunately, the entire schistosome life cycle cannot be cultured in vitro, but infective cercariae can be transformed into schistosomules, and the schistosomules can be cultured for weeks for the analysis of schistosome development in vitro or microarray analysis. In this protocol, we provide a visual description of cercarial transformation and in vitro culturing of schistosomules. We shed infectious cercariae from the snail host Biomphalaria glabrata and manually transform them into schistosomules by detaching their tails using an emulsifying double-ended needle. The in vitro cercarial transformation and schistosomules culture techniques described avoid the use of a mammalian host, which simplifies visualization of schistosomes and facilitates the collection of the parasite for experimental analysis. in vitro transformation and culturing techniques of schistosomes have been done for years (11, 12), but no visual protocols have been developed that are available to the entire community.

Cercarial Transformation and in vitro Cultivation of Schistosoma mansoni Schistosomules

We describe an in vitro method for culturing schistosomula of the flatworm parasite Schistosoma mansoni, via the harvesting and transformation of infective cercariae from the fresh water snail intermediate host Biomphalaria glabrata.

Schistosome parasites are the causative agents of schistosomiasis, a chronically debilitating disease that affects over 200 million people globally and ...

Real-time Live Imaging of T-cell Signaling Complex Formation

Protection against infectious diseases is mediated by the immune system 1,2. T lymphocytes are the master coordinators of the immune system, regulating the activation and responses of multiple immune cells 3,4. T-cell activation is dependent on the recognition of specific antigens displayed by antigen presenting cells (APCs). The T-cell antigen receptor (TCR) is specific to each T-cell clone and determines antigen specificity 5. The binding of the TCR to the antigen induces the phosphorylation of components of the TCR complex. In order to promote T-cell activation, this signal must be transduced from the membrane to the cytoplasm and the nucleus, initiating various crucial responses such as recruitment of signaling proteins to the TCR;APC site (the immune synapse), their molecular activation, cytoskeletal rearrangement, elevation of intracellular calcium concentration, and changes in gene expression 6,7. The correct initiation and termination of activating signals is crucial for appropriate T-cell responses. The activity of signaling proteins is dependent on the formation and termination of protein-protein interactions, post translational modifications such as protein phosphorylation, formation of protein complexes, protein ubiquitylation and the recruitment of proteins to various cellular sites 8. Understanding the inner workings of the T-cell activation process is crucial for both immunological research and clinical applications.
Various assays have been developed in order to investigate protein-protein interactions; however, biochemical assays, such as the widely used co-immunoprecipitation method, do not allow protein location to be discerned, thus precluding the observation of valuable insights into the dynamics of cellular mechanisms. Additionally, these bulk assays usually combine proteins from many different cells that might be at different stages of the investigated cellular process. This can have a detrimental effect on temporal resolution. The use of real-time imaging of live cells allows both the spatial tracking of proteins and the ability to temporally distinguish between signaling events, thus shedding light on the dynamics of the process 9,10. We present a method of real-time imaging of signaling-complex formation during T-cell activation. Primary T-cells or T-cell lines, such as Jurkat, are transfected with plasmids encoding for proteins of interest fused to monomeric fluorescent proteins, preventing non-physiological oligomerization 11. Live T cells are dropped over a coverslip pre-coated with T-cell activating antibody 8,9, which binds to the CD3/TCR complex, inducing T-cell activation while overcoming the need for specific activating antigens. Activated cells are constantly imaged with the use of confocal microscopy. Imaging data are analyzed to yield quantitative results, such as the colocalization coefficient of the signaling proteins.

We describe a live-cell imaging method that provides insight into protein dynamics during the T-cell activation process. We demonstrate the combined usage of the T-cell spreading assay, confocal microscopy and imaging analysis to yield quantitative results to follow signaling complex formation throughout T-cell activation.

Protection against infectious diseases is mediated by the immune system 1,2. T lymphocytes are the master coordinators of the immune system, regulating ...

Establishment and Optimization of a High Throughput Setup to Study Staphylococcus epidermidis and Mycobacterium marinum Infection as a Model for Drug Discovery

Zebrafish are becoming a valuable tool in the preclinical phase of drug discovery screenings as a whole animal model with high throughput screening possibilities. They can be used to bridge the gap between cell based assays at earlier stages and in vivo validation in mammalian models, reducing, in this way, the number of compounds passing through to testing on the much more expensive rodent models. In this light, in the present manuscript is described a new high throughput pipeline using zebrafish as in vivo model system for the study of Staphylococcus epidermidis and Mycobacterium marinum infection. This setup allows the generation and analysis of large number of synchronous embryos homogenously infected. Moreover the flexibility of the pipeline allows the user to easily implement other platforms to improve the resolution of the analysis when needed. The combination of the zebrafish together with innovative high throughput technologies opens the field of drug testing and discovery to new possibilities not only because of the strength of using a whole animal model but also because of the large number of transgenic lines available that can be used to decipher the mode of action of new compounds.

Establishment and Optimization of a High Throughput Setup to Study Staphylococcus epidermidis and Mycobacterium marinum Infection as a Model for Drug Discovery

This video article describes the high throughput pipeline that has been successfully established to infect and analyze large numbers of zebrafish embryos providing a new powerful tool for compound testing and drug discovery using a whole animal vertebrate organism.

Zebrafish are becoming a valuable tool in the preclinical phase of drug discovery screenings as a whole animal model with high throughput screening ...

Cultivation of Heligmosomoides Polygyrus: An Immunomodulatory Nematode Parasite and its Secreted Products

Heligmosomoides polygyrus (formerly known as Nematospiroides dubius, and also referred to by some as H. bakeri) is a gastrointestinal helminth that employs multiple immunomodulatory mechanisms to establish chronic infection in mice and closely resembles prevalent human helminth infections. H. polygyrus has been studied extensively in the field of helminth-derived immune regulation and has been found to potently suppress experimental models of allergy and autoimmunity (both with active infection and isolated secreted products). The protocol described in this paper outlines management of the H. polygyrus life cycle for consistent production of L3 larvae, recovery of adult parasites, and collection of their excretory-secretory products (HES).

Cultivation of Heligmosomoides Polygyrus: An Immunomodulatory Nematode Parasite and its Secreted Products

Heligmosomoides polygyrus is a murine nematode with powerful immunomodulatory capabilities that closely resemble those of highly-prevalent human helminth infection. Here we describe a protocol for the long-term maintenance of the H. polygyrus lifecycle.

Heligmosomoides polygyrus (formerly known as Nematospiroides dubius, and also referred to by some as H. bakeri) is a gastrointestinal helminth that ...

Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens

A key aspect of the immune response to bacterial colonization of the host is phagocytosis. An opsonophagocytic killing assay (OPKA) is an experimental procedure in which phagocytic cells are co-cultured with bacterial units. The immune cells will phagocytose and kill the bacterial cultures in a complement-dependent manner. The efficiency of the immune-mediated cell killing is dependent on a number of factors and can be used to determine how different bacterial cultures compare with regard to resistance to cell death. In this way, the efficacy of potential immune-based therapeutics can be assessed against specific bacterial strains and/or serotypes. In this protocol, we describe a simplified OPKA that utilizes basic culture conditions and cell counting to determine bacterial cell viability after co-culture with treatment conditions and HL-60 immune cells. This method has been successfully utilized with a number of different pneumococcal serotypes, capsular and acapsular strains, and other bacterial species. The advantages of this OPKA protocol are its simplicity, versatility (as this assay is not limited to antibody treatments as opsonins), and minimization of time and reagents to assess basic experimental groups.

This opsonophagocytic killing assay is used to compare the ability of phagocytic immune cells to respond to and kill bacteria based on different treatments and/or conditions. Classically, this assay serves as the gold&#160;standard for assessing effector functions of antibodies raised against a bacterium as opsonin.

A key aspect of the immune response to bacterial colonization of the host is phagocytosis. An opsonophagocytic killing assay (OPKA) is an experimental ...

In Vitro ELISA Test to Evaluate Rabies Vaccine Potency

The growing global concern for the animal welfare is encouraging manufacturers and the National Control Laboratories (OMCLs) to follow the 3Rs strategy for the Replacement, Reduction, and Refinement of the laboratory animal testing. The development of in vitro approaches is recommended at the WHO and European levels as alternatives to the NIH test for evaluating the rabies vaccine potency. At the surface of the rabies virus (RABV) particle, trimers of glycoprotein constitute the major immunogen to induce Viral Neutralizing Antibodies (VNAbs). An ELISA test, where Neutralizing Monoclonal Antibodies (mAb-D1) recognize the trimeric form of the glycoprotein, has been developed to determine the contents of the native folded trimeric glycoprotein along with the production of the vaccine batches. This in vitro potency test demonstrated a good concordance with the NIH test and has been found suitable in collaborative trials by RABV vaccine manufacturers and OMCLs. Avoidance of animal use is an achievable objective in the near future.
The method presented is based on an indirect ELISA sandwich immunocapture using the mAb-D1 which recognizes the antigenic sites III (aa 330 to 338) of the trimeric RABV glycoprotein, i.e., the immunogenic RABV antigen. mAb-D1 is used for both coating and detection of glycoprotein trimers present in the vaccine batch. Since the epitope is recognized because of its conformational properties, the potentially denatured glycoprotein (less immunogenic) cannot be captured and detected by the mAb-D1. The vaccine to be tested is incubated in a plate sensitized with the mAb-D1. Bound trimeric RABV glycoproteins are identified by adding the mAb-D1 again, labeled with peroxidase and then revealed in the presence of substrate and chromogen. Comparison of the absorbance measured for the tested vaccine and the reference vaccine allows for the determination of the immunogenic glycoprotein content.

Here we describe an indirect ELISA sandwich immunocapture to determine the immunogenic glycoprotein contents in rabies vaccines. This test uses a neutralizing Monoclonal Antibody (mAb-D1) recognizing glycoprotein trimers. It is an alternative to the in vivo NIH test to follow the consistency of vaccine potency during production.

The growing global concern for the animal welfare is encouraging manufacturers and the National Control Laboratories (OMCLs) to follow the 3Rs strategy ...

Essential Components of Borreliella (Borrelia) burgdorferi In Vitro Transcription Assays

Borreliella burgdorferi is a bacterial pathogen with limited metabolic and genomic repertoires. B. burgdorferi transits extracellularly between vertebrates and ticks and dramatically remodels its transcriptional profile to survive in disparate environments during infection. A focus of B. burgdorferi studies is to clearly understand how the bacteria responds to its environment through transcriptional changes. In vitro transcription assays allow for the basic mechanisms of transcriptional regulation to be biochemically dissected. Here, we present a detailed protocol describing B. burgdorferi RNA polymerase purification and storage, sigma factor purification, DNA template generation, and in vitro transcription assays. The protocol describes the use of RNA polymerase purified from B. burgdorferi 5A4 RpoC-His (5A4-RpoC). 5A4-RpoC is a previously published strain harboring a 10XHis-tag on the rpoC gene encoding the largest subunit of the RNA polymerase. In vitro transcription assays consist of the RNA polymerase purified from strain 5A4-RpoC, a recombinant version of the housekeeping sigma factor RpoD, and a PCR-generated double-stranded DNA template. While the protein purification techniques and approaches to assembling in vitro transcription assays are conceptually well understood and relatively common, handling considerations for RNA polymerases often differ from organism to organism. The protocol presented here is designed for enzymatic studies on the B. burgdorferi RNA polymerase. The method can be adapted to test the role of transcription factors, promoters, and post-translational modifications on the activity of the RNA polymerase.

Essential Components of Borreliella Borrelia burgdorferi In Vitro Transcription Assays

In vitro transcription assays can decipher the mechanisms of transcriptional regulation in Borreliella burgdorferi. This protocol describes the steps to purify B. burgdorferi RNA polymerase and perform in vitro transcription reactions. Experimental approaches using in vitro transcription assays require reliable purification and storage of active RNA polymerase.

Borreliella burgdorferi is a bacterial pathogen with limited metabolic and genomic repertoires. B. burgdorferi transits extracellularly between ...

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Introducing foreign DNA into the spirochete Borrelia burgdorferi has been almost exclusively accomplished by transformation using electroporation. This process has notably lower efficiencies in the Lyme disease spirochete relative to other, better-characterized Gram-negative bacteria. The rate of success of transformation is highly dependent upon having concentrated amounts of high-quality DNA from specific backgrounds and is subject to significant strain-to-strain variability. Alternative means for introducing foreign DNA (i.e., shuttle vectors, fluorescent reporters, and antibiotic-resistance markers) into B. burgdorferi could be an important addition to the armamentarium of useful tools for the genetic manipulation of the Lyme disease spirochete. Bacteriophage have been well-recognized as natural mechanisms for the movement of DNA among bacteria in a process called transduction. In this study, a method has been developed for using the ubiquitous borrelial phage &#966;BB-1 to transduce DNA between B. burgdorferi cells of both the same and different genetic backgrounds. The transduced DNA includes both borrelial DNA and heterologous DNA in the form of small shuttle vectors. This demonstration suggests a potential use of phage-mediated transduction as a complement to electroporation for the genetic manipulation of the Lyme disease spirochete. This report describes methods for the induction and purification of phage &#966;BB-1 from B. burgdorferi, the use of this phage in transduction assays, and the selection and screening of potential transductants.

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

The ability of bacteriophage to move DNA between bacterial cells makes them effective tools for the genetic manipulation of their bacterial hosts. Presented here is a methodology for inducing, recovering, and using &#966;BB-1, a bacteriophage of Borrelia burgdorferi, to transduce heterologous DNA between different strains of the Lyme disease spirochete.

Introducing foreign DNA into the spirochete Borrelia burgdorferi has been almost exclusively accomplished by transformation using electroporation. This ...

Multiplex Immunoassay for Borrelia-Specific IgG and IgM in Serum

Simultaneous Detection of Different Antibody Classes in a Multiplexed Serological Test

To monitor the progression of infectious diseases, it is useful to assess immunoreactivity against various antigenic determinants, and measure different antibody isotypes because they appear at different stages of the host immune response. With Lyme borreliosis, the pathogenic agent can be one of the multiple members of the Borrelia species. Therefore, correct sample classification requires evaluating the immunoreactivity against different antigens of different Borrelia species. Additionally, anti-pathogen IgG and IgM responses can have different elicitation time courses during disease progression. Here we demonstrate the development of a two-reporter multiplex immunoassay that has utility in identifying Borrelia-specific immune response in human serum samples by simultaneously evaluating both IgG and IgM immunoreactivity against different bacterial antigens in the same reaction well. This dual-reporter approach retains the analytical performance of single-reporter methods while conserving time and resources and reducing sample size requirements. This assay allows essentially double the serological information to be generated from a blood sample in half the time.

Author Spotlight: Expanding the Scope of Multiplex Immunoassays for Lyme Borreliosis Diagnostics and Pathogen Research 

A three-channel dual-reporter fluorescence flow analysis system was used to develop a bead-based multiplex immunoassay that simultaneously evaluates serum samples for IgG and IgM elicited against multiple antigens of different Borrelia species that cause Lyme borreliosis in Europe and North America.

To monitor the progression of infectious diseases, it is useful to assess immunoreactivity against various antigenic determinants, and measure different ...