Experimental infection of post-weaned pigs with F18-encoding enterotoxigenic and enterotoxigenic/shigatoxigenic Escherichia coli strain isolated from the diarrheic feces in Korea.

Background: In the porcine industry, Escherichia coli (E. coli) infections have been causing post-weaning diarrhea (PWD) and edema disease (ED) for many years. It is classified into pathotypes and serotypes in animals according to virulence factors. Serotyping is performed for O, K, H, and F antigens, essential for discriminating pathogenicity and epidemiology. Furthermore, E. coli strains that produce F18 fimbriae are major sources of ED and PWD associated with Shiga-toxin producing E. coli (STEC) expressing F18ab and enterotoxigenic E. coli (ETEC) expressing F18ac, respectively. Aim: To investigate the pathogenicity potential and infection characteristics of experimental infection and confirm the pathological features of the Korean STEC/ETEC strains F18ab and F18ac in piglets. Methods: Three-week-old pigs were randomized into three experimental groups: infected G1 (F18ab), infected G2 (F18ac), and G3 (control). General health status was monitored daily, and pathological changes were evaluated. Results: Diarrhea occurred in all infected piglets. Pathological changes were only observed in the small intestine and regional lymph nodes. In G1, mucosal necrosis, inflammatory cell infiltration with hemorrhagic lesions, and apoptotic cell death in the tunica media of arterioles in the small intestine were observed. In contrast, the mucosa and epithelium appeared almost intact, with no abnormal vessel lesions in G2. Conclusion: Both strains, isolated from pigs in Korea, could be infected and did not spread from the alimentary tract to other organs. The pathological features were quite different among the F18 subtypes. The F18ab strain was more virulent than F18ac, and the virulence characteristics of the F18ac strain were more similar to ETEC than STEC.

Prevalence, genetic characteristics, and antimicrobial resistance of Clostridioides difficile isolates from horses in Korea.

OBJECTIVES: Clostridioides difficile is an etiological agent of enteric diseases in humans and animals. Animals are considered a potential reservoir due to the genetic and antimicrobial resistance similarities between human and animal C. difficile isolates. In this study, we evaluated the genetic characteristics and antimicrobial resistance profiles of C. difficile isolated from 942 fecal samples collected from horses in South Korea during 2019-2020. METHODS: The C. difficile isolates were tested for toxin genes including tcdA (A), tcdB (B), and cdtAB (CDT) and deletions of the tcdC gene by PCR. In addition, ribotyping, multilocus sequence typing, and antimicrobial susceptibility tests were performed. RESULTS: Twenty-three (2.4%) C. difficile isolates were associated with diarrhea in foals under 1 year old during the spring-summer period. Of these, 82.6% were toxigenic strains, determined to be A+B+CDT+ (52.1%) or A+B+CDT‒ (30.4%). All isolates were susceptible to metronidazole and vancomycin, and resistant to cefotaxime and gentamicin, and 76.2% were multidrug resistant (MDR). RT078/ST11/Clade 5 was the most common genotype (47.8%), which was also found in animals and humans worldwide. All RT078/ST11/Clade 5 strains were toxigenic and had deletions of the tcdC gene. About half of these strains were resistant to moxifloxacin, and 63.6% were MDR. CONCLUSIONS: C. difficile isolates in this study consisted mostly of toxigenic and MDR strains, and their genetic properties were highly similar to human C. difficile isolates. These results suggest high possibilities of zoonotic transmission and can provide knowledge for establishing strategies for the treatment and prevention of C. difficile infection.

Relationship between virulence factors and antimicrobial resistance genes of pathogenic Escherichia coli from diarrheic weaned piglets.

A total of 690 pathogenic Escherichia (E.) coli isolates from weaned piglets were examined for antimicrobial resistance phenotypes, resistance genes, and virulence gene profiles. Also, 29 enterotoxigenic E. coli (ETEC) and 35 Shiga-toxin producing E. coli (STEC) isolates were analyzed using multi-locus sequence typing (MLST). Comparisons of the associations between antimicrobial resistance phenotypes, resistance genes, and virulence genes were performed separately by assessing odds ratio (OR). Although majorities of associations were not confirmed however, we found that associations between specific virulence factors-antimicrobial resistance. F18 encoding isolates showed association with resistance to cefazolin (OR = 3.08) and cefoxitin (OR = 3.65), and also with antimicrobial resistance gene mcr-3 (OR = 4.58). There was a high correlation between F4-STb (OR = 13.56), F4-LT (OR = 8.77), F4-EAST-I (OR = 4.97), and F18-Stx2e (OR = 3.83). Most of ETEC (21 of 29, 72.4%) isolates were assigned to ST100, and 20 of 35 STEC isolates (57.1%) were ST1. There were 5 clusters, and each cluster showed specific antimicrobial resistance patterns. Cluster I showed resistance to gentamicin, streptomycin, neomycin, nalidixic acid, ciprofloxacin, norfloxacin, trimethoprim / sulfamethoxazole, and tetracyclines whereas, cluster V showed resistance to ampicillin, amoxicillin / clavulanic acid, cephalothin, cefoxitin, cefazolin, norfloxacin, and colistin. Although there is need to do more experiments to clarify why certain virulence factors showed relationship with antimicrobial resistance, it is clear that there is a significant association between specific virulence genes and antimicrobial resistance in E. coli from weaned piglets with enteric colibacillosis in Korea.

Distribution of Gastrointestinal Parasitic Infection in Domestic Pigs in the Republic of Korea: Nationwide Survey from 2020-2021.

This study aimed to examine the distribution of gastrointestinal parasitic infections in domestic pigs in the Republic of Korea. From May 2020 to October 2021, 364 pig fecal samples were collected from 75 farms in 7 Provinces and microscopically examined. A total of 170 (46.7%) pigs were infected with at least one of the following parasites: Balantioides coli, strongyles, Ascaris suum, Trichuris suis, and coccidia. By parasite species, B. coli, strongyles, A. suum, T. suis, and coccidia oocysts or eggs were detected in 144 (39.6%), 24 (6.6%), 14 (3.8%), 4 (1.1%), and 1 (0.3%) samples, respectively. One hundred fifty-four, 15, and 1 cases showed single, double, and triple infections, respectively. Of the swine fecal samples from 75 farms, 69 specimens (92.0%) were infected with 1 or more parasites. All surveyed farms across the country exhibited a positive rate of over 30%, among which the highest positive rate was 65.0% in Chungcheongnam-do, and Jeollabuk-do was followed by 61.9%. Winter showed a statistically lower prevalence than other seasons. This study showed that gastrointestinal parasites are prevalent in pigs in Korea, although the diversity of parasites is low.

Identification of Zoonotic Balantioides coli in Pigs by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Its Distribution in Korea.

Balantioides coli is a zoonotic protozoan parasite whose main reservoir is pigs. Recent studies have shown that B. coli variant A but not B has zoonotic potential. While B. coli infection has been reported in different animals and countries, the prevalence of the zoonotic variant is limited due to a lack of molecular information. Therefore, this study investigated the prevalence of B. coli in domestic pigs in Korea and assessed its zoonotic potential. A total of 188 pig fecal samples were collected from slaughterhouses in Korea. B. coli was identified by microscopy and molecular methods. B. coli was identified in 79 (42.9%) and 174 (94.6%) samples by microscopy and polymerase chain reaction (PCR), respectively. This study also developed a PCR-restriction fragment length polymorphism (PCR-RFLP) method to differentiate B. coli variant A from B without sequence analysis. Using this method, 62 (33.7%) and 160 (87.0%) samples were positive for variants A and B, respectively, and 48 (26.1%) samples were co-infected with both variants. Sequence and phylogenetic analyses showed a high genetic diversity of B. coli in pigs in Korea. To our knowledge, this is the first study to develop a method to differentiate B. coli variants A and B without sequence analysis and to assess the molecular epidemiology of B. coli in pigs. Continuous monitoring of zoonotic B. coli in pigs should be performed as pigs are the main source of human balantidiasis.

Phage Display Screening of Bovine Antibodies to Foot-and-Mouth Disease Virus and Their Application in a Competitive ELISA for Serodiagnosis.

For serodiagnosis of foot-and-mouth disease virus (FMDV), monoclonal antibody (MAb)-based competitive ELISA (cELISA) is commonly used since it allows simple and reproducible detection of antibody response to FMDV. However, the use of mouse-origin MAb as a detection reagent is questionable, as antibody responses to FMDV in mice may differ in epitope structure and preference from those in natural hosts such as cattle and pigs. To take advantage of natural host-derived antibodies, a phage-displayed scFv library was constructed from FMDV-immune cattle and subjected to two separate pannings against inactivated FMDV type O and A. Subsequent ELISA screening revealed high-affinity scFv antibodies specific to a serotype (O or A) as well as those with pan-serotype specificity. When BvO17, an scFv antibody specific to FMDV type O, was tested as a detection reagent in cELISA, it successfully detected FMDV type O antibodies for both serum samples from vaccinated cattle and virus-challenged pigs with even higher sensitivity than a mouse MAb-based commercial FMDV type O antibody detection kit. These results demonstrate the feasibility of using natural host-derived antibodies such as bovine scFv instead of mouse MAb in cELISA for serological detection of antibody response to FMDV in the susceptible animals.

O-Serogroups and Pathovirotypes of Escherichia coli Isolated from Post-Weaning Piglets Showing Diarrhoea and/or Oedema in South Korea.

This study aimed to determine the prevalence of several pathovirotypes and evaluate the association of haemolysis with the virotypes of pathogenic E. coli isolated from post-weaning piglets in South Korea from 2015 to 2019. We isolated 890 E. coli and tested for O-serogroups, virulence genes, haemolysis, and multilocus sequence typing. The predominant virotypes were STb:EAST1:AIDA-I, F18b:Stx2e:AIDA-I, F18:STa:STb:Stx2e, and eae:Paa in enterotoxigenic E. coli (ETEC), Shiga toxin-producing E. coli (STEC), ETEC/STEC, and enteropathogenic E. coli (EPEC), respectively. Regarding serogroups, O139, O149, O141, and O121 were mostly detected in F18:Stx2e:AIDA-I, F4:LT:STb:EAST1, F18:STa:STb, and F18:Stx2e:EAST1, respectively. There was a significant change in the frequency of the O141:F18ac:STa:STb (an increase from 1.6% to 10.1%) and O139:F18ab:Stx2e:AIDA-I (a decrease from 13.0% to 5.3%) virotypes in ETEC and STEC, respectively, from 2015 to 2019. The O141:F18ac:STa:STb virotype was mostly detected in the central area and was spreading to the southern area. The odds ratios between haemolysis and virotypes were 11.0, 6.25, and 8.57 in F18:STa:STb, F18:Stx2e:AIDA-I, and F4:LT:STb:EAST1, respectively. Our findings provide insights regarding the recent prevalence of pathogenic E. coli in South Korea and could be used for the development of vaccines for E. coli responsible for PWD and ED in post-weaning piglets.

Virulence genes and antimicrobial resistance of pathogenic Escherichia coli isolated from diarrheic weaned piglets in Korea.

For efficient prevention and treatment of enteric colibacillosis, understanding about latest virulence factors and antimicrobial resistance of Escherichia coli is essentially needed. The aim of this study was to survey antimicrobial resistance and determine the prevalence of fimbriae and enterotoxin genes among 118 pathogenic E. coli isolates obtained from Korean pigs with diarrhea between 2016 and 2017. The genes for the toxins and adhesins were amplified by polymerase chain reaction (PCR). The susceptibility of the E. coli isolates to antimicrobials were tested using the standard Kirby-Bauer disk diffusion method. The most prevalent fimbrial antigen was F18 (40.7%), followed by F4 (16.9%), and the most prevalent combinations of toxin genes were Stx2e (21.2%), STb:EAST-1 (19.5%), and STa:STb (16.9%), respectively. Among the pathotypes, enterotoxigenic E. coli (ETEC) was the most predominant (67.8%), followed by Shiga-toxin producing E. coli (STEC, 23.7%). We confirmed high resistance rates to chloramphenicol (88.1%), tetracycline (86.4%), streptomycin (86.4%), and ampicillin (86.4%). And the majorities of isolates (90.7%) showed multi-drug resistance which means having resistance to 3 or more subclasses of antimicrobials. Results of this study can be a source of valuable data for investigating the epidemiology of and control measures for enteric colibacillosis in Korean piggeries.

Virulence and antimicrobial resistance profiles of Escherichia coli encoding mcr gene from diarrhoeic weaned piglets in Korea during 2007-2016.

OBJECTIVE: This study aimed to analyse the presence of mcr genes and virulence genes in Escherichia coli (E. coli) isolates from diarrhoeic piglets between 2007-2016 in Korea. METHODS: A total of 364 E. coli isolates were obtained from diarrhoeic weaned piglets between 2007-2016. Minimum inhibitory concentrationss were determined according to the Clinical and Laboratory Standards Institute (CLSI). DNA samples were tested for the presence of mcr-1, mcr-2 and mcr-3 genes. Furthermore, multiplex PCR was used to detect toxin, fimbrial and non-fimbrial adhesin genes. RESULTS: It was found that 2.5% (nine of 364) of the isolates carried the mcr genes. Four isolates carried the mcr-1 gene and eight isolates had the mcr-3 gene. Three isolates carried both mcr-1 and mcr-3 genes; the mcr-2 gene was not found. All isolates carrying mcr genes were multidrug-resistant. F18 (77.8%, seven of nine) and Stx2e (44.4%, four of nine) were frequently detected in E. coli carrying the mcr gene. CONCLUSIONS: In conclusion, it would appear that the most prevalent mcr gene of E. coli from diarrhoeic weaned piglets in Korea was mcr-3. It is believed that this is the first report of two plasmid-mediated colistin resistance genes - mcr-1 and mcr-3 - coexisting in the same isolates (0258, 0491, 0516) from piglets with diarrhoea in Korea. Those mcr-positive isolates showed multidrug resistance and the majority of those encoded Stx2e and F18. This indicates the risk of inefficient treatment for oedema disease in weaned piglets.

Development of Monoclonal Antibody Specific to Foot-and-Mouth Disease Virus Type A for Serodiagnosis.

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease affecting cloven-hoofed livestock worldwide. FMD virus (FMDV) type A is one of the most common causes of FMD outbreaks among the seven FMDV serotypes, and its serological diagnosis is therefore important to confirm FMDV type A infection and to determine FMD vaccine efficacy. Here, we generated monoclonal antibodies (mAbs) specific to FMDV type A via hybridoma systems using an inactivated FMDV type A (A22/Iraq/1964) and found 4 monoclones (#29, #106, #108, and #109) with high binding reactivity to FMDV type A among 594 primary clones. In particular, the #106 mAb had a higher binding reactivity to the inactivated FMDV type A than the other mAbs and a commercial mAb. Moreover, the #106 mAb showed no cross-reactivity to inactivated FMDV type South African territories 1, 2, and 3, and low reactivity to inactivated FMDV type O (O1 Manisa). Importantly, the solid-phase competitive ELISA (SPCE) using horseradish peroxidase (HRP)-conjugated #106 mAb detected FMDV type A-specific Abs in sera from FMD type A-vaccinated cattle more effectively than a commercial SPCE. These results suggest that the newly developed FMDV type A-specific mAb might be useful for diagnostic approaches for detecting Abs against FMDV type A.

Prevalence of O-serogroups, virulence genes, and F18 antigenic variants in Escherichia coli isolated from weaned piglets with diarrhea in Korea during 2008-2016.

To diagnose colibacillosis, detection of O-serogroups and virulence genes has been recommended worldwide. The prevalence of virulence factors can fluctuate over time. The objectives of this study were to determine the prevalence of O-serogroups, virulence genes, and F18 subtypes among pathogenic Escherichia coli isolated from weaned piglets with diarrhea in Korea. Between 2008 and 2016, 362 E. coli were isolated from weaned piglets with diarrhea. Hemolysis was determined in blood agar, and O-serogroups were identified using the slide agglutination technique. The genes for the toxins and fimbriae were amplified by polymerase chain reaction (PCR). Real-time PCR was conducted to discriminate between F18 subtypes. Although the most prevalent serogroup was O149 (11.3%) in the last 9 years, O139 (19.1%) became the most prevalent in recent years (2015-2016). The most predominant pathotype was enterotoxigenic E. coli (61.3%). The frequencies of Shiga-like toxin-producing E. coli (STEC) (23.4%), O139 (19.1%), Stx2e (35.1%), and F18ab (48.7%) increased over the most recent years. Although enterotoxigenic E. coli was the most predominant pathotype, the frequencies of O139, Stx2e, STEC, and F18ab have increased in recent years. These results demonstrate that there have been temporal changes in the predominant O-serogroups and virulence genes over the last decade in Korea. These findings can be practicable for use in epidemiology and control measures for enteric colibacillosis in Korean piggeries.

Prevalence of antibodies against severe fever with thrombocytopenia syndrome virus in shelter dogs in the Republic of Korea.

The purpose of this study was to investigate the seroprevalence of antibodies against severe fever with thrombocytopenia syndrome virus (SFTSV) in shelter dogs in the Republic of Korea (ROK) using an indirect immunofluorescence assay and virus neutralization test. Sera were collected from 426 dogs in 12 animal shelters throughout the ROK from March 2016 to November 2016. Overall, 59 of 426 (13.9%) samples were seropositive for antibodies against SFTSV. A significant difference was observed in accordance with the sampling region (p<0.001), but not according to the sex (p=0.279) or breed (p=0.729) of the dogs. The seroprevalence of SFTSV showed an inversely proportional trend to the latitude of the sampling regions: the highest rate was observed in the southern region followed by the Jeju-do region. This is the first report on the nationwide prevalence of antibodies against SFTSV in companion dogs in animal shelters throughout the ROK.

Molecular detection and phylogenetic analysis of severe fever with thrombocytopenia syndrome virus in shelter dogs and cats in the Republic of Korea.

Severe fever with thrombocytopenia syndrome is a tick-borne infectious disease. The present study investigated the prevalence of severe fever with thrombocytopenia syndrome virus (SFTSV) in shelter dogs and cats in the Republic of Korea (ROK). Blood samples were collected from 426 dogs and 215 cats in animal shelters throughout the ROK in 2016. Of the tested samples, one (0.2%) dog and one (0.5%) cat were positive for SFTSV. Phylogenetic analysis of the sequences obtained in the present study showed that the viruses belonged to the J3 clade, which is considered the dominant clade in the ROK. This study reports the first molecular detection of SFTSV in shelter dogs and cats in the ROK.

Capsular serotypes, virulence-associated genes and antimicrobial susceptibility of Streptococcus suis isolates from pigs in Korea.

Streptococcus suis is an important pig pathogen with potential for human transmission. The serotype distributions and phenotypic characteristics vary over time and among regions; however, little is known about the characteristics of S. suis isolates in Korea. In this study, 240 S. suis isolates collected from pigs in Korea in 2009-2010 were serotyped by coagglutination tests, subsequently screened for three virulence-associated genes (mrp, epf and sly) and tested for antimicrobial susceptibility. As for 80 isolates, the serotypes of which were relevant to human infections, clonal complexes (CCs) were further identified by PCR. Serotype 3 was the most prevalent (15.8%), followed by serotype 2 (15.0%), with geographical variation for each serotype. Overall, 55.4% of the isolates carried mrp, whereas only 3.8% carried epf. CC25 was the most prevalent (41.3%) and was related to serotypes 2 and 9. The isolates showed higher susceptibility to ampicillin (93.4%) and ceftiofur (90.8%) than to the other antimicrobial agents tested. The highest resistance rate was observed to tetracycline (98.0%), followed by erythromycin (88.8%). In addition, the resistance to certain antimicrobials was significantly associated, in part, with virulence-associated genes or serotypes. Therefore, continuous characterization of S. suis is essential for the benefit of veterinary and human medicine.

Low Prevalence of Clostridium difficile in Slaughter Pigs in Korea.

Clostridium difficile is an important cause of enteric disease in humans and animals. The prevalence of C. difficile infection is increasing, and the bacterium is frequently found in meat products, suggesting the possibility of animal-to-human transmission. Therefore, food animals must be assessed for their role as reservoirs of C. difficile. In this study, C. difficile was isolated from 2 (0.3%) of 659 slaughtered pigs in Korea. Both isolates were characterized as ribotype 078 and were multidrug resistant. The low occurrence suggests only a limited risk of C. difficile transmission from porcine food products; however, C. difficile ribotype 078 is an important pathogen in both pigs and humans, and further studies are necessary to investigate the occurrence of C. difficile in retail meats and other food animals.

Serology and clinical relevance of Corynebacterium pseudotuberculosis in native Korean goats (Capra hircus coreanae).

This study was conducted to assess the seroprevalence and clinical relevance of Corynebacterium pseudotuberculosis, which is the causative agent of caseous lymphadenitis (CLA), in native Korean goats (Capra hircus coreanae). A total of 466 native Korean goats from 40 herds (11 to 12 samples per herd) were randomly selected throughout the nation and evaluated by direct palpation, bacterial isolation, ELISA, and PCR. In serological examinations, 267 (57.3 %) of the goats tested were positive against C. pseudotuberculosis. When seroprevalence was analyzed according to age, region, and season, statistically significant differences were observed in relation to all three parameters (P < 0.05). For clinical examination, the superficial lymph nodes of all goats were palpated to diagnose CLA. Pus samples taken from superficial abscesses were used for bacterial isolation. Among the 466 goats tested, 34 (7.3 %) were presumptively diagnosed with CLA, and C. pseudotuberculosis was isolated from 24 goats (70.6 % of goats with CLA lesions) whose infections were confirmed by PCR. Considering the high seroprevalence and bacterial isolation rate from most of the superficial CLA lesions, it is suspected that many internal CLA lesions exist in this goat population. These results suggest that C. pseudotuberculosis infection is widespread in native Korean goats, and appropriate control programs need to be established.

Antimicrobial resistance, virulence genes and PFGE-profiling of Escherichia coli isolates from South Korean cattle farms.

To estimate the prevalence of Escherichia coli with potential pathogenicity in cattle farm in South Korea, a total of 290 E. coli isolates were isolated from cattle farms over a period of 2 years in South Korea. These were examined for phenotypic and genotypic characteristics including antimicrobial susceptibility, serotype, and gene profiles of virulence and antimicrobial resistance. The most dominant virulence gene was f17 (26.2%), followed by stx2 (15.9%), ehxA (11.0%), stx1 (8.3%), eae (5.2%), and sta (4.1%). Some shiga-toxin producing E. coli isolates possessed eae (15.9%). All isolates except for one showed resistance to one or more antimicrobials, with 152 isolates exhibiting multidrug-resistance. The most prevalent resistance phenotype detected was streptomycin (63.1%), followed by tetracycline (54.5%), neomycin (40.3%), cephalothin (32.8%), amoxicillin (30.0%), ampicillin (29.7%), and sulphamethoxazole/trimethoprim (16.6%). The associated resistance determinants detected were strA-strB (39.0%), tet(E) (80.0%), tet(A) (27.6%), aac(3)-IV (33.1%), aphA1 (21.4%), bla TEM (23.8%), and sul2 (22.1%). When investigated by O serotyping and PFGE molecular subtyping, the high degree of diversity was exhibited in E. coli isolates. These results suggest that E. coli isolates from South Korean cattle farms are significantly diverse in terms of virulence and antimicrobial resistance. In conclusion, the gastroinstestinal flora of cattle could be a significant reservoir of diverse virulence and antimicrobial resistance determinants, which is potentially hazardous to public health.

Molecular and serologic detection of Coxiella burnetii in native Korean goats (Capra hircus coreanae).

The occurrence of Q fever in native Korean goats (Capra hircus coreanae) was investigated for the first time in the country using ELISA and PCR. A total of 597 blood samples were collected from goats belonging to five different provinces of Korea. To detect Coxiella burnetii, sera were separated from the whole blood and analysed by ELISA; DNA was extracted directly from the whole blood and analysed by PCR. Overall, 114 (19.1%, 95% C.I.=16.1-22.4) and 57 goats (9.5%, 95% C.I.=7.5-12.2) tested positive for C. burnetii in the ELISA- and PCR-based screening, respectively, while 18 goats (3.0%, 95% C.I.=1.9-4.7) tested positive in both the assays. There was a significant difference between the number of ELISA- and PCR-positive goats (P<0.05). The seroprevalence of Q fever was significantly higher among the adult goats (≥1y, 22.0%) than among the young goats (<1y, 13.8%) (P<0.05). While the results of the serologic analysis showed no seasonal variation, data from the PCR-based assay indicated that there were a higher number of positive cases during the cold seasons. Because Q fever infection has high rates of prevalence in native Korean goats, further studies on humans at a high risk of contracting this disease should be conducted. The PCR-based assay used in this study is a useful method for the direct detection of C. burnetii in blood samples from small ruminants.

Detection and determination of Toxoplasma gondii seroprevalence in native Korean goats (Capra hircus coreanae).

Toxoplasma gondii is an important zoonotic protozoan pathogen that causes serious illness in immunocompromised humans and infection in animals worldwide. The current study was conducted for detection of T. gondii infection and determination of the seroprevalence of the pathogen in native Korean goats (Capra hircus coreanae). Analysis of a total of 610 sera samples collected from 60 herds between 2009 and 2011 were performed using a commercial enzyme-linked immunosorbent assay (ELISA) kit for detection of anti-T. gondii IgG antibodies. Among the animals tested, 5.1% (31/610) showed seropositivity for anti-T. gondii antibodies, and 38.3% (23/60) of the herds were seropositive. The prevalence rates between young (<1 year) and adult (≥1 and ≤3 years) goats were 7.0% and 4.1%, respectively, without statistical significance (p>0.05). Likewise, the prevalence rates observed during cold season (October-March) and warm season (April-September) were 2.9% and 5.5%, respectively, without statistical significance. Seroprevalence rates observed in the northern, central, and southern regions were 7.9%, 3.8%, and 4.2%, respectively. In conclusion, we report for the first time on the seroprevalence of anti-T. gondii antibodies in native Korean goats (Capra hircus coreanae). The results of this study also indicate that there is a nationwide distribution of T. gondii infection among goats. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of T. gondii infection within goats is recommended.