Haemagglutination-inhibiting (HI) antibodies against strains of influenza A virus in horse and pig sera in Nigeria

Sera from horses and pigs obtained from Lagos and Ibadan respectively were examined for haemagglutination-inhibiting (HI) antibodies to two strains each of H3N2 and H1N1 subtypes of influenza A virus. More horse sera had HI antibodies to the H3N2 than the H1N1 strains while pig sera reacted almost equally with strains of both subtypes. All the horse sera had HI antibodies to the two strains of H3N2 subtype (A/Mississippi/1/85 and A/Leningrad/360/86), while 87% and 14% of the horses examined were positive to A/Taiwan/1/86 and A/Chile/1/83. On the other hand HI antibody prevalence to the two subtypes in pigs are as follows, for H3N2 A/Mississippi/1/85 (86%), A/Victoria/3/75 (94%); for H1N1 A/Chile/1/83 (87%) and A/Taiwan 1/86 (79%). Analysis of the data by the Chi-square test showed significant difference between the prevalence of HI antibodies to the influenza A virus strains in horse sera examined while there was no significant difference between HI antibody prevalence to the four strains in pigs. The study shows that horses and pigs circulate influenza A virus in Nigeria and may serve as origin of human epidemics.     

Genetic relationship among several pig populations in East Asia analysed by blood groups and serum protein polymorphisms

The gene frequencies were calculated to investigate genetic variation apparent in blood group and serum protein systems in Asian native pigs. The results revealed that gene frequencies were generally similar in the nine pig populations, except in some systems. Differences of gene frequencies were recognized in HpY and Cpc detected on Taoyuan pigs of Taiwan and Ohmini pigs of Japan, respectively. TfC and AmC alleles were found in eight pig populations except Ohmini pigs. The overall genetic distances were calculated by gene frequencies of 13 loci and it was observed that Taoyuan pigs are closer to Ohmini pigs than to Short-ear pigs of Taiwan and other East Asian native pigs. However, the genetic distances between Asian native pigs and European or American breeds were larger than those among East Asian native pig populations.     

Genetic relationship among several pig populations in East Asia analysed by blood groups and serum protein polymorphisrns

The gene frequencies were calculated to investigate genetic variation apparent in blood group and serum protein systems in Asian native pigs. The results revealed that gene frequencies were generally similar in the nine pig populations, except in some systems. Differences of gene frequencies were recognized in Hp^Y and Cp^c detected on Taoyuan pigs of Taiwan and Ohmini pigs of Japan, respectively. Tf^C and Am^C alleles were found in eight pig populations except Ohmini pigs.
The overall genetic distances were calculated by gene frequencies of 13 loci and it was observed that Taoyuan pigs are closer to Ohmini pigs than to Short-ear pigs of Taiwan and other East Asian native pigs. However, the genetic distances between Asian native pigs and European or American breeds were larger than those among East Asian native pig populations.     

The pig as an intermediate host for Taiwan Taenia infection

Eggs (1000-100,000/animal) of Taiwan Taenia were inoculated per os into 14 Small-Ear-Miniature (SEM), 19 Landrace-Small-Ear-Miniature (L-SEM), and 5 Duroc-Yorkshire-Landrace (DYL) pigs. These animals were sacrificed 7-107 days after infection. Thirty-four pigs were found to be infected with Taiwan Taenia cysticerci and the infection rates of SEM, L-SEM, and DYL were 86%, 89% and 100% respectively. The cysticerci recovery rates of SEM, L-SEM and DYL pigs were 27.2%, 1.7% and 0.27% respectively. Cysticerci were recovered only from the livers and none were found in muscles, viscera or other parts of the carcasses. More cysticerci were located in the liver parenchyma (71%) than on the liver surface (29%). Taiwan Taenia cysticerci were smaller than those of classical T. saginata or T. solium. Moreover, Taiwan Taenia cysticerci had 2 rows of rudimentary hooklets on the scolex. The results of this study indicate that young pigs are good intermediate hosts for Taiwan Taenia and that the SEM pig is a satisfactory host for experimental studies with this tapeworm. These results were similar to other studies with different geographic strains of the T. saginata-like tapeworm in the Far East. These strains appear to be the same and possibly a new species.     

Experimental infection of Indonesia Taenia (Samosir strain) in domestic animals

Three 58-day old Small-Ear-Miniature (SEM) pigs, six 36-day old Landrace-Small-Ear-Miniature (L-SEM) pigs, and two 5-day old Holstein calves were each fed 3000 or 30,000 Indonesia Taenia (Samosir strain) eggs and sacrificed 27-195 days after inoculation. A total of 4922 cysticerci were recovered only from the livers of the three SEM pigs (1977 cysticerci) and six L-SEM pigs (2945 cysticerci). The infection rate in pigs was 100%. Cysticerci recovery rates of SEM and L-SEM pigs were 22.0% and 1.6%, respectively. Calves were not susceptible to Indonesia Taenia. More cysticerci were found in the liver parenchyma (L-SEM, 66.4%; SEM, 76.2%) than on the liver surface (L-SEM, 33.6%; SEM, 23.8%) of the infected animals. Most (99.86%) of the cysticerci recovered from the livers of L-SEM pigs were degenerated or calcified but 77.9% of those in the livers of SEM pigs were mature and only 22.1% were degenerated or calcified. Measurements of length, width, diameters of protoscolex, rostellum, and sucker and hooklet pattern indicated that Indonesia Taenia is very similar to Taiwan Taenia and very different from Taenia saginata and Taenia solium. The present findings indicate that Indonesia Taenia and Taiwan Taenia may be the same new species.     

National seroprevalence of Toxoplasma gondii in pigs

Serum samples from 11,842 commercial pigs killed in 1983-1984 throughout the United States were tested for anti-Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Anti-T. gondii antibodies were found in 23.9% of pigs. At dilutions of 1:25, 1:50, and 1:500, 13.5%, 6.9%, and 3.5% were serologically positive, respectively. The prevalence of anti-T. gondii antibodies was higher in breeder pigs (42%) than in market pigs (23%). These results indicate that anti-T. gondii antibodies are widespread in the national swine herd.     

An Association of Genotypes and Antimicrobial Resistance Patterns among Salmonella Isolates from Pigs and Humans in Taiwan

We collected 110 Salmonella enterica isolates from sick pigs and determined their serotypes, genotypes using pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility to 12 antimicrobials and compared the data with a collection of 18,280 isolates obtained from humans. The pig isolates fell into 12 common serovars for human salmonellosis in Taiwan; S. Typhimurium, S. Choleraesuis, S. Derby, S. Livingstone, and S. Schwarzengrund were the 5 most common serovars and accounted for a total of 84% of the collection. Of the 110 isolates, 106 (96%) were multidrug resistant (MDR) and 48 (44%) had PFGE patterns found in human isolates. S. Typhimurium, S. Choleraesuis, and S. Schwarzengrund were among the most highly resistant serovars. The majority of the 3 serovars were resistant to 8–11 of the tested antimicrobials. The isolates from pigs and humans sharing a common PFGE pattern displayed identical or very similar resistance patterns and Salmonella strains that caused severe infection in pigs were also capable of causing infections in humans. The results indicate that pigs are one of the major reservoirs to human salmonellosis in Taiwan. Almost all of the pig isolates were MDR, which highlights the necessity of strictly regulating the use of antimicrobials in the agriculture sector in Taiwan.     

Seroprevalence of Toxoplasma gondii and Neospora caninum in slaughtered pigs in the Czech Republic

In the Czech Republic, sera from 551 clinically healthy adult slaughtered pigs (females, 6-8 months old) were collected during the first half of June in 2010. Sera were tested for Toxoplasma gondii-specific IgG antibodies by an enzyme-linked immunosorbent assay; samples with more than 50% S/P were considered as positive. The same samples were also analysed for Neospora caninum antibodies using a commercial competitive-inhibition enzyme-linked immunosorbent assay; samples with more than 30% inhibition were considered as positive. Antibodies against T. gondii were found in 198 pigs (36%) in all districts with prevalences ranging from 18% to 75%. Antibodies against N. caninum were found in 16 pigs (3%); positive animals were found in 4 districts with prevalences ranging from 1% to 20%. Indication of mixed infections (concurrent presence of both N. caninum and T. gondii antibodies) was found in 8 (1·5%) pigs. The results of our study indicate that pigs in the Czech Republic have a relatively high seroprevalence for T. gondii, while they have only a low seroprevalence for N. caninum. Therefore, natural infection with T. gondii seems to be very common in Czech pigs. It is the first evidence of N. caninum antibodies in pigs in the Czech Republic. These results complete data about N. caninum infection in pigs in Europe.     

Immunoluminescent detection of antibodies to testicular antigens in experimental autoimmune orchitis]

Antibodies interacting with spermatid structures in the testis sections and with acrosome and caudal regions of spermatozoa in the smears of sperm were determined in the sera of guinea pigs and mice with experimental autoimmune orchitis by the indirect immunofluorescent method. The antibodies were found in mice from the 14th to the 30th day and in guinea pigs from the 14th to the 60th day after immunization. Circulation time and the level of the fluorescent antibodies were significantly decreased in immunized female guinea pigs and mice. Fluorescent antibodies did not show cytotoxic effect and belonged to the IgG fraction. The fluorescent antibodies of guinea pigs did not react with the mouse testicular antigens in cross reaction. The analogous results were seen in the cross reaction of the mouse antibodies with the guinea pig antigens.     

Serological evidence of leptospiral infection in pig populations in different districts in Japan

Serum samples were collected from 938 pigs of 24 farms in Hokkaido, Kagoshima, and Okinawa prefectures in Japan in 2001-2005. Enzyme-linked immunosorbent assay (ELISA) was used for the detection of antibodies to LipL32 antigen which is common to Leptospira interrogans. Samples positive in ELISA were then investigated by microscopic agglutination test for the identification of causal leptospires. Antibodies specific to leptospires of serovars Copenhageni, Bratislava, Australis and Javanica were detected in serum samples of pigs from each of the three districts. In addition, antibodies to leptospires of serovars Autumnalis and Tarassovi were predominantly detected in those from Kagoshima. The present study, thus, revealed that leptospires belonging to different serovars prevail in the pig population in Japan. In addition, it is the first detection of antibodies to leptospires belonging to serovars Javanica and Tarassovi in pigs in Japan.     

Toxocara infection in pigs. The use of indirect fluorescent antibody tests and an in vitro larval precipitate test for detecting specific antibodies.

An in vitro larval precipitate test using second-stage Toxocara canis larvae and an indirect fluorescent antibody (IFA) test employing cuticles of T. canis larvae as antigen were evaluated using antisera produced in pigs experimentally infected with T. canis, T. cati, Ascaris suum, Toxascaris leonina and Parascaris equorum. The former test was both specific and sensitive and is suggested as a reliable and simple method of detecting Toxocara antibodies in pigs. The latter test was considered unsuitable because of cross-reactions that occurred when sera from pigs infected with other ascarids were tested. An IFA test for Ascaris antibodies, employing cuticles of A. suum larvae as antigen, is described. The degree of specificity of this test suggests that it may be of value in the detection of antibodies to Ascaris in pigs under natural conditions.     

Anti-Toxoplasma gondii antibodies in cattle and pigs in a highly endemic area for human toxoplasmosis in Brazil

Sera from 77 cattle and 61 pigs from herds of Campos dos Goytacazes and neighborhood, north of Rio de Janeiro state, Brazil, were analyzed for the presence of antibodies anti-Toxoplasma gondii via ELISA. The seropositivity was confirmed at 49.4% (38 of 77) for cattle and at 11.5% (7 of 61) for pigs. Pigs bred under free-ranging systems presented with 20.6% (7 of 34) seropositivity and no pigs bred under indoor systems were positive (n = 27). The seropositivity verified for cattle and pigs confirmed the extensive distribution of the parasite in this region. In the face of these data, we discuss the potential risk for human infection by consumption of raw or undercooked meat in this geographic region of Brazil. This is the first report of seropositivity for anti-T. gondii antibodies in cattle in the north of Rio de Janeiro State, Brazil.     

Prevalence of Toxoplasma gondii in slaughtered pigs in the state of Pernambuco, Brazil

The object of this study was to investigate Toxoplasma gondii antibodies and parasite DNA in pigs in the state of Pernambuco, Brazil. Blood samples were collected from 305 slaughtered pigs in 11 municipalities, and their sera were tested for T. gondii antibodies using the indirect fluorescent antibody test (IFAT, cutoff 1:64); 38 (12.5%) samples were positive. Attempts were made to detect T. gondii DNA in the heart tissue of seropositive pigs using the B 1 gene and PCR; 21 (55.2%) of the 38 hearts were positive. This is the first detection of T. gondii DNA in tissues of serologically positive swine in the State of Pernambuco, Brazil.     

Experimental infection of Philippine Taenia in domestic animals.

In the present study, six 34-44-day-old Small-Ear-Miniature pigs and one 14-day-old Holstein calf were each fed 10,000 Philippine Taenia eggs and sacrificed 27-43 days after inoculation. The infection rate was 100% for both pigs and calf with cysticerci recovery rates of 11 and 6%, respectively. A total of 6431 cysticerci were recovered only from the livers of the six pigs and 597 only from the liver of the calf; more occurred in the parenchyma (pigs 75%, calf 83%) than on the surface (pigs 25%, calf 17%). Mature cysticerci were found in four of the six pigs. A total of 317 cysticerci recovered from the pig livers were mature and the rest were either immature (926), degenerate or calcified (5188). All 597 cysticerci recovered from the liver of the calf were degenerate or calcified. Measurements of length, width, diameter of protoscolex, rostellum, and sucker and hooklet pattern indicated that Philippine Taenia is very similar to Taenia from Taiwan, Korea, Indonesia and Thailand and very different from classical T. saginata and T. solium.     

White spots of the liver in pigs experimentally infected with Ascaris suum

To make clear the relationship between Ascaris suum infection and the appearance of white spot lesions on the surface of the liver in pigs, three groups of pigs were inoculated orally with embryonated A. suum eggs and observed clinicopathologically. Group A of three pigs were inoculated 21 times with 100 eggs each of the nematode, group B of three pigs 4 times with 50,000 eggs each for 10 weeks, and group C of two pigs 2 times with 50,000 eggs each at a one-week interval. All the pigs were sacrificed at the same time 1 week after the final inoculation. Such signs of the nematode infection as dyspnea, coughing and fever appeared in all the pigs of groups B and C seven days after inoculation to continue for several days. In addition, peripheral blood eosinophilia was recorded in these animals 7 or 14 days after inoculation. At autopsy, mesh-worked white spots, some compact and others lymphonodular, were observed on the surface of the liver in all the pigs of the three groups. Main white spots were mesh-worked and lymphonodular in the pigs of group A. They were severe and compact in group B. Therefore, they were rough to the touch. In group C mesh-worked white spots fused with one another and covered the surface of the liver. These white spot lesions observed were morphologically very similar to those found in the field conditions. Complement-fixating antibodies reacting to adult A. suum antigen were detected only in sera from the pigs of group B. Moreover, antibodies involved in the intradermal reaction of immediate type were found in the pigs of groups A and B.     

Prevalence of antibody to Toxoplasma gondii and Trichinella spp. in feral pigs (Sus scrofa) of eastern North Carolina

Feral pigs (Sus scrofa) survive in many climates, reproduce year-round, and are dietary generalists. In the United States, the size and range of the feral pig population has expanded, resulting in greater interaction with humans and domestic swine and increased potential for disease transmission. We conducted a serosurvey in feral pigs from eastern North Carolina to determine exposure to the zoonotic parasites, Toxoplasma gondii and Trichinella spp. Between September 2007 and March 2009, blood serum was collected from 83 feral pigs harvested at Howell Woods Environmental Learning Center, Four Oaks, North Carolina, USA. We used a modified agglutination test to test for T. gondii antibodies and an enzyme-linked immunosorbent assay to test for Trichinella spp. antibodies. The prevalences of antibodies to T. gondii and Trichinella spp. were 27.7% and 13.3%, respectively and 4% (n=3) had antibodies to both agents. We detected an increased risk of T. gondii antibodies with age, whereas the risk of exposure to T. gondii across years and between sexes was similar. In eastern North Carolina, feral pigs have been exposed to T. gondii and Trichinella spp. and may pose a health risk to domestic swine and humans.     

The experimental infection of pigs with different numbers of Taenia solium eggs: immune response and efficiency of establishment

Three of 4 pigs inoculated with 10 eggs of Taenia solium became infected. In those pigs infected with larger numbers of eggs, all became infected. Specific antibodies against the metacestodes were found in serum at day 30 postinoculation (PI) in animals that received 1,000 or more eggs and at day 60 in those that received 10 or 100 eggs. The concentration and diversity of antibodies increased up to the day of death in pigs that received 10,000 or 100,000 eggs. All pigs infected with 1,000 or more eggs developed antibodies, but only 40% and 75% of pigs that received 10 and 100 eggs, respectively, developed antibodies. Metacestodes were found in the muscles of 23 of the 27 infected animals. In 35.7% of the pigs that received 1,000 or more eggs, metacestodes were also found in the brain. Most of the metacestodes found in pigs infected with 10 or 100 eggs were caseous, whereas in pigs infected with 1,000 or more eggs the majority of metacestodes were vesicular. This study shows that the severity of T. solium infection and the possible regulation of the immune system-evasion mechanisms depend on the number of metacestodes that succeed in establishing themselves and remain vesicular.     

Pestivirus Infections in Norway. Serological Investigations in Cattle,Sheep and Pigs

Serum samples from 1133 dairy cows (187 herds), 3712 ewes (103 flocks) and 1317 adult pigs (877 herds), were tested for neutralizing antibodies against the NADL strain of bovine virus diarrhoea virus. The prevalence rate of seropositive animals was 18.5% in cattle, 4.5% in sheep and 2.2% in pigs, such seroreactors being found in 28 % of the cattle herds and 18 % of the sheep flocks. In all three species the rate showed considerable herd and geographical variation. In cattle the seroreactor rate was similar in herds with normal reproduction and in 62 herds with problems of repeat breeding. Of 31 pig sera containing antibodies against the NADL strain, 27 were also positive in a neutralization test for antibodies against swine fever virus (Baker strain). However, all sera showed a higher titre of antibodies against the bovine strain than against the swine fever virus. It was concluded that the immune response of the pigs had been induced by ruminant pestivirus, and not by swine fever virus.     

Seroprevalence of Toxoplasma gondii infection in domestic pigs in Durango State, Mexico

Little is known concerning the prevalence of Toxoplasma gondii infection in pigs in Mexico. Accordingly, antibodies to T. gondii were determined in 1,074 domestic pigs in Durango, Mexico using the modified agglutination test. Two groups (A, B) of pigs were sampled: Group A pigs (n = 555) were raised in 3 geographical regions in Durango State and Group B pigs (n = 519) were from Sonora State but slaughtered in Durango City. Overall, antibodies to T. gondii were found in 136 (12.7%) of 1,074 pigs with titers of 1∶25 in 29, 1∶50 in 23, 1∶100 in 18, 1∶200 in 22, 1∶400 in 12, 1∶800 in 8, 1∶1,600 in 2, and 1∶3,200 or higher in 22. Of the pigs raised in Durango State, seroprevalence varied with age, management, and the geographic region; pigs raised in backyards in the mountainous region had a significantly higher seroprevalence (32.1%) than those raised in the valley (13.0%) and the semi-desert regions (14.0%). In Group A pigs from Durango, seroprevalence of T. gondii infection was significantly higher in pigs older than 8 mo (19.5%) than in younger pigs (10.9%). In the whole pig population (Groups A and B together), seroprevalence was higher in pigs raised in Durango (16.0%) than in those raised in Sonora (9.1%) and higher in mixed-breed pigs (15.7%) than in pure-bred pigs (10.3%). This is the first, in-depth study on the seroprevalence of T. gondii infection of pigs in Mexico and the first report on pigs from Durango State, Mexico. Results indicate that infected pork is likely an important source of T. gondii infection for humans in Durango State.     

Antibodies to Epstein-Barr Virus in a Burkitt''s Lymphoma Cell Line in Taiwan Monkeys (Macaca cyclopis)

The prevalence of Taiwan monkeys with antibodies to Epstein-Barr virus, as detected by the indirect immunofluorescence technique, was lower than that of healthy persons in Taiwan.