Infection Rate Of Mice Research Articles

Cloning ospA of Borrelia Burgderferi for Plant Expression

Abstract Borrelia burgdorferi (Lyme disease) is a vector-borne disease that is both very common in the Mid-Atlantic region and which causes long term negative health effects. It is primarily spread to humans by deer ticks, and because one of the main ways that it is passed between ticks is by previously infected mouse blood, our goal is to design an oral vaccine which decreases infection rates in mice. Our goal is to do this by inserting outer surface protein A (ospA) of B. burgdorferi into a plant vector: pCambia 1201. Agrobacterium tumefaciens was used as a means of introducing the vector (bearing B. burgdorferi ospA) into Arabidopsis thaliana. The pCambia vector was introduced into A. tumefaciens competent cells after being purified from E. coli colonies which had undergone a similar transformation process, as E. coli is more suitable for cloning. The successfully electroporated A. tumefaciens was then plated and colonies were picked and grown as liquid cultures. Those liquid cultures transformed with both the ospA bearing pCambia and a control pCambia were used for floral dip of Arabidopsis thaliana (both ospA bearing and pCambia only control plants). These dipped plants’ seeds have been tested for successful transformation, and one plant has been found to contain the sequence for ospA. Continued floral dips will be undertaken to increase the number of positive plants, and to develop a proper control for testing efficacy as a vaccine. Any additional seeds of positive plants will be planted and crossed to ensure use of only plants which express pCambia in later testing, and to ensure that the process has been successful. Supported by Frostburg State University Department of Biology and FSU Foundation

Effect of equal concentration of Helicobacter pylori suspension on gastric mucosa in mice by different gavage methods

To investigate the effects of equal concentration of Helicobacter pylori suspension on gastric mucosal infection in mice by different gavage methods. Methods: Six-week-old male C57BL/6 mice were infected by a suspension of Brucella broth containing the same amount of NCTC11637 Helicobacter pylori suspension by A, B, C, and D methods. For method A, the mice were intragastrically administered with Helicobacter pylori suspension (0.2 mL per mouse), once two day for 5 times; for method B, the mice were intragastrically administered with Helicobacter pylori (0.2 mL per mouse) once a day for 5 times; for method C, the mice were perfused with 0.4 mL per mouse of Helicobacter pylori suspension on the first day, then once a day and 0.2 mL per mouse for 3 times; for method D, the mice were administrated with 0.4 mL per mouse Helicobacter pylori suspension on the first day, 0.2 mL per mouse every other day for 3 times. For method E, the mice received equal amounts of normal saline. The mice were killed at 2, 4, and 6 weeks after gavage. The gastric mucosa was detected by rapid urease test for Helicobacter pylori infection, and gastric mucosa was taken for HE staining to observe the degree of infection. Results: After 2 weeks of gavage, the infection rates of the mice in A, B, C, and D group were 33.3%, 50.0%, 66.7%, and 33.3%, respectively. The degree of inflammation infection was as following order: C group>B group>D group>A group>E group. The infection rates of mice after 4 weeks of gavage in the A, B, C, and D groups were 50.0%, 83.3%, 83.3%, and 66.7%, respectively. The degree of inflammation infection was as following order: C group>B group>D group>A group>E group. After 6 weeks of gavage, the infection rate in A, B, C, and D groups was 100%, while the degree of inflammation infection was as following order: C group>D group>B group>A group>E group. Conclusion: At the acute stage of Helicobacter pylori infection, different gavage methods show different infection rates in mice, and the degree of inflammation is different. At the chronic stage, different gavage methods display the same infection rate in mice with different degree. The gavage method that 0.4 mL Helicobacter pylori suspension on the first day, then once a day and 0.2 mL for 3 times is most conducive to Helicobacter pylori colonization in the gastric mucosa of mice. This method can induce the the most seriou inflammatory infection and is beneficial to the successful establishment of the Helicobacter pylori infection model.

Schistosoma Mansoni Cercarial Host Location and Infection under Simulated Natural Conditions in Egypt

This study was performed in water ditches under simulated natural conditions in Egypt to elucidate the effect of various environmental factors on Schistosoma mansoni cercarial host location and infection of the definitive host (using albino mice). Evaluation of these factors was dependent on both infection rate of exposed mice as well as the schistosome worm load under the same experimental conditions. The seasonal water temperature proved to be a very important factor and this was proven by the infection rate of mice and the worm load recovered were lower in January and April (16 degrees C and 22 degrees C midday water temperature) and much higher in July and October (29 degrees C and 25 degrees C). The daytime factor is similarly important as temperature illustrated by the schistosome infection of mice groups exposed at 8-10 am was much higher than in groups exposed between 1 pm and 3pm (p < 0.001). The greatest infection rate of mice and worm load were obtained when the shedding snails were close to the exposed group of mice. Both criteria increased with the increase of cercarial density in the water. The length of exposure period is also an extremely important factor for schistosome infection, being highest 87.5% (p < 0.001) in3 hours exposure period. Infection rate was found to be 88.2% and 55.6% of shedding snails were located at water surface and midway to the bottom, respectively, and no infection occurred when located at the bottom. The schistosome infection of mice decreased in presence of increasing density of the floating plant Eichhornia crassipes in the ditch water, but low condensation of the submersed plant Ceratophyllum demersum appeared to have stimulating effect.

Borrelia burgdorferi infection in white-footed mice (Peromyscus leucopus) in hemlock (Tsuga canadensis) habitat in western Pennsylvania.

White-footed mice (Peromyscus leucopus) were captured and their tissues sampled from 27 sites in seven counties of western Pennsylvania in 1990 for isolation and identification of Borrelia burgdorferi. Two hundred sixty mice were captured from which there were 27 isolations. Significantly more mice were captured and significantly more isolations made from hemlock (Tsuga canadensis) habitat than from deciduous species forest. Hemlock habitat is sparse and focal but evidently increases winter survival of mice, and thus possibly results in increased infection rates in mice.

Spatial and Temporal Dispersion of Immature Ixodes dammini on Peromyscus leucopus in Northwestern Illinois

Infestation by immature Ixodes dammini and infection by Borrelia burgdorferi of the white-footed mouse Peromyscus leucopus were studied in Castle Rock State Park in northwestern Illinois during June-October 1990. Prevalence and intensity of infestation of larvae on mice were highest in August with a smaller peak in early June. The distribution of larvae on mice was highly aggregated during each of the sampling periods. Aggregation appears to be the result of a series of nonrandom successful attachments by single larvae, rather than of simultaneous attachment by clumps of larvae. Infection rate of mice by B. burgdorferi averaged 21.4% with a peak of 28.6% in August. A comparison of the numbers of attached immature ticks collected from mice and of questing ticks collected through dragging indicated that the larvae-to-nymph ratio was higher on mice than on drags. Given the low total numbers of nymphs collected from mice, this suggests a potential role for other hosts of I. dammini nymphs in northwestern Illinois.