Seroprevalence, isolation, molecular detection and genetic diversity of Toxoplasma gondii from small ruminants in Egypt

Abstract

Toxoplasmosis is an infectious zoonotic disease caused by protozoan Toxoplasma gondii. Detection of T. gondii infection with touchy and particular strategies is a key advance to control and prevent toxoplasmosis. Genotyping can explain the virulence, epidemiology and setting up new methodologies for diagnosis and control in human and animals. The point of this study was to assess the seroprevalence of T. gondii in sheep and goat in Egypt and to comprehend the genetic variety of T. gondii isolates circling in Egypt. Blood samples were gathered from 113 ewes and 95 she-goats from three Egyptian governorates (Cairo, Giza and Al-Sharkia). Also blood and tissue samples were gathered from 193 sheep and 51 goats from Cairo and Giza abattoirs. All samples were assayed serologically utilizing ELISA and OnSite Toxo IgG/IgM Rapid test cassettes (OTRT) tests and the tissue samples of the seropositive animals were digested and microscopically examined then bio-assayed in mice as viability test. All the T. gondii isolates undergo molecular identification using PCR and genotyped utilizing nPCR/RFLP analysis of SAG2 gene. The total seropositivity of live sheep and goat was 47.15 and 39.2% utilizing ELISA and OTRT respectively. Concerning abattoirs, seropositivity, positive microscopic examination, mice viability from sheep samples were 47.1%, 37.3% and 44.1% respectively while that of goats were 45.5%, 33.3% and 48.6% respectively. Eighteen T. gondii isolates were affirmed utilizing PCR. Genotyping confirmed 10 isolates (55.5%) as type II, 6 (33.3%) as type III and 2 (11.1%) as atypical genotypes. Type II and III are the genotypes mostly circling among small ruminants in Egypt and this is most significance for the public health in Egypt.

Keywords: Egypt; Genotyping; Goat; SAG2 gene; Sheep; Toxoplasma gondii.

Fig. 1

Detection of T. gondii isolates DNA by PCR. M, 100 bp ladder; Lane 1, Positive control; Lanes 2–6, selected positive local T. gondii DNA (193 bp)

Fig. 2

Nested PCR amplification of 5′ end of SAG2 gene resolved in 2% agarose gel electrophoresis shows amplification products of samples (lanes 2–8) at 242 bp, lane 1 = the positive control (RH strain), (M) marker = 100 bp DNA ladder

Fig. 3

Nested PCR amplification of 3′ end of SAG2 gene resolved in 2% agarose gel electrophoresis shows amplification products of samples (lanes 2–11) at 222 bp, lane 1 = the positive control (RH strain), (M) marker = 100 bp DNA ladder

Fig. 4

SAG2 nested PCR analysis. (A) Sau3AI restriction analysis of the 5′ amplification products from type I (RH), II (Me 49), and III (VEG) strains. (B) HhaI restriction analysis of the 3′ amplification products from type I, II, and III strains

Fig. 5

The restriction pattern of 5′ SAG2 amplified products by Sau3AI enzyme showing digested PCR products for samples in lanes 3–8, lane 1 = negative control, lane 2 = RH positive control, 242 bp (undigested), (M) marker = 100 bp DNA ladder

Fig. 6

The restriction pattern of 3′ SAG2 amplified products by HhAI enzyme showing digested PCR products for samples in lanes 2–11, lane 1 = RH positive control, 222 bp (undigested), lane 12 = negative control, (M) marker = 100 bp DNA ladder