Development of quantitative PCRs for Ehrlichia canis, a Canine Tick-borne bcteria in Thailand

Name: Peeravit Sumpavong

LCSH: Kasetsart University -- Theses. M.S. (Animal Health Technology) 2020

Classification :.LCCS: QR201.E45

LCSH: Kasetsart University. Department of Veterinary Technology -- Theses

LCSH: Ehrlichiosis

LCSH: Ehrlichia

LCSH: Tick-borne diseases in animals -- Thailand

LCSH: Dogs -- Diseases

LCSH: Dogs -- Infections

Abstract: With diverse local genotypes of Ehrlichia canis, the systematic evaluation of a suitable gene is required for TaqMan real-time PCR (rtPCR). The rtPCR of the dsb and gltA genes were analyzed using 10-fold dilutions of the recombinant plasmids and 60 samples (30 blood samples and 30 tick samples) from unknown dogs with relevant clinical signs. The conventional PCR (cPCR) positive results of dsb were 11 samples from dog bloods and 1 sample from tick and the positive results of gltA were 12 samples from dog bloods and 1 tick sample. The positive samples were cloned into pGEM-T Easy vector and preparation of serial dilution. The rtPCRs of both loci were performed in all dilutions. The dsb and gltA genes showed a high degree of linearity (R2 ≥ 0.975 and 0.993, respectively). The overall precision of gltA was higher (lower mean percentage of relative standard deviation; % RSD) but not significantly so. The rtPCR and cPCR detection limits were 10-7 and 10-6 , respectively, for both loci. The rtPCR positive results of dsb were 22 samples from dog bloods and 5 samples from tick samples and the positive results of gltA were 15 samples from dog bloods and 3 samples from tick samples. There were no significant differences among the blood samples using rtPCR of the dsb (22/8; 73.3%) and gltA (15/15; 50%) loci (p-value=0.06). The rtPCR results of the dsb gene (22/8) were significantly different from the cPCR results (11/19) (p-value=0.004). Surprisingly, the rtPCR results (15/15) of the gltA gene were not significantly different from the cPCR (12/18) (pvalue=0.43). The mean Ct value based on the dsb rtPCR (22 positive cases, mean Ct value 30.2) was higher than the gltA rtPCR results (15 positive cases, mean Ct value 27.4) from dog bloods. The mean Ct value based on the dsb rtPCR was 35.995 from 5 positive ticks and the mean Ct value based on the the gltA rtPCR was 35.95 from 3 positive ticks. We found positive blood samples with Ct values above 30 based on dsb rtPCR in all seven discordant blood samples compared with the gltA rtPCR. The Ct values of both loci in tick samples were higher than the mean Ct values in dog blood samples. The dsb gene seemed to be the more sensitive method in naturally infected dogs. This study suggested that TaqMan realtime PCR of the dsb gene should be selected for E. canis research in this region.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Sarawan Kaewmongkol

Role: Thesis Advisor

Name: Gunn Kaewmongkol

Role: Thesis CO-Advisor

Modified: 2025-07-17

Issued: 2025-07-17

วิทยานิพนธ์/Thesis

application/pdf

URL: https://www.lib.ku.ac.th/KUthesis/2564/peeravit-sum-all.pdf

CallNumber: QR201.E45 .P44

eng

Spatial: Thailand

DegreeName: Master of Science

Level: Master's Degree

Descipline: Animal Health Technology

Grantor: Kasetsart University

©copyrights Kasetsart University

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	peeravit-sum-all.pdf	1.71 MB	1	2025-10-27 11:36:14

ใช้เวลา

0.023601 วินาที