Enzyme-linked immunosorbent assay for the detection of canine Leptospira antibodies using recombinant OmpL1 protein

OmpL1 is a 31-kDa outer membrane protein characterized in 1993 and known to be expressed only in pathogenic Leptospira spp. Recombinant OmpL1 (GST-rOmpL1) was expressed for use as an ELISA antigen for the detection of anti-Leptospira antibodies. In immunoblot analysis, the protein reacted with sera of dogs infected with three different serotypes of Leptospira interrogans, while did not react with sera of dogs both uninfected negative controls and infected with Borrelia burgdorferi, which is closely related to Leptospira spp. Moreover, in ELISA using GST-rOmpL1, the optical density (O.D.) values from the positive controls were very high (1.125 +/- 0.549). In contrast, the O.D. values from clinically healthy dogs and dogs with diseases other than leptospirosis were very low (0.109 +/- 0.046 and 0.089 +/- 0.046, respectively). These data suggest that the detection of anti-Leptospira antibodies by ELISA using the GST-rOmpL1 protein can be applied for diagnosis of canine leptospirosis.     

A serosurvey for antibodies to Leptospira in dogs in the lower North Island of New Zealand

AIMS: To investigate the prevalence of antibodies to endemic and exotic Leptospira serovars in samples from a serum bank, collected from dogs in the lower North Island of New Zealand. METHODS: Sera (n=466), which had been collected from apparently healthy dogs, were screened using the microscopic agglutination test (MAT) for antibodies to serovars L. borgpeterseni serovar hardjo, L. interrogans serovars pomona, copenhageni and canicola, and L. kirschneri serovar grippotyphosa. RESULTS: Antibody to Leptospiral antigen was found in 14.2% of dogs tested. The highest level of reactivity was with serovar copenhageni, to which 9.5% (41/433) of sera were positive. Antibodies to serovars grippotyphosa and canicola were not detected in this population of dogs. CONCLUSIONS: Leptospira infection is relatively common in dogs in the lower North Island . CLINICAL RELEVANCE: Vaccination of dogs against leptospirosis should be considered using vaccine containing antigen to serovars hardjo, pomona and copenhageni. The presence of moderate levels of copenhageni antibody in dogs in the lower North Island raises the possibility that this serovar has become established in rodent populations in this region.     

Prevalence of serum antibodies against six Leptospira serovars in healthy dogs

OBJECTIVE: To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan. DESIGN: Cross-sectional study. ANIMALS: 1,241 healthy dogs at least 4 months of age. PROCEDURES: Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status. RESULTS: 309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers. CONCLUSIONS AND CLINICAL RELEVANCE: Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.     

Occurrence of anti-<Emphasis Type="Italic">Leptospira</Emphasis> spp. antibodies in <Emphasis Type="Italic">Rhipidomys</Emphasis> spp. from a forest fragment of the Brazilian Cerrado

Leptospirosis is a zoonotic disease of world importance, and its transmission depends on the interaction between humans and animals. Given the necessity to investigate potential hosts of Leptospira spp., this study verified the prevalence of different serovars in the species of Rhipidomys spp., a widespread sigmodont rodent in Brazil. The studied population originates from a semi-evergreen forest located in the county of Uberlândia, in the state of Minas Gerais. The microscopic agglutination test (MAT) was performed with 14 serovars. Thirteen out of the 43 wild rodents captured showed a positive agglutination reaction, with a greater prevalence of the serovars Pyrogenes, Copenhageni, and Canicola. This study found a prevalence of 30.3% anti-Leptospira spp. antibodies; all positive animals were reactive to more than one serovar.     

Leptospirosis in dogs in Slovakia]

Out of 571 serologically investigated dogs from Bratislava and all regions of Slovakia and Moravia, 26.1% presented antibodies reacting with leptospiral antigens. The lowing seropositivity in dogs from Bratislava was found in lap dogs--11.1%, the highest one in farm dogs--35.3% (Tab. I). The seropositivity of police dogs from different regions of Slovakia and Moravia varied from 24.0% to 47.6% (Tab. II). The age of dogs progressing, their seropositivity rose from 3.1% in animals younger than one year to 33.3% in those aged seven years and in older ones (Tab. III). The predominant serovars causing infections of dogs were L. grippotyphosa (58.9% of infections) and serovars of both Sejroe (21.0%) and Icterohaemorrhagiae groups (15.3%). The serovars bratislava/jalna, pomond/mozdok and tarassovi were only rarely involved in these infections, canicola and arborea only exceptionally (Tab. IV). At present, in the Czechoslovak conditions the dogs do not play a significant role as reservoirs of human leptospirosis, and the predominant serovars may only cause irregular and short-time lasting leptospiruria. This is why the reasonableness of actual vaccination of dogs, possibly with the exception of the vaccination against Weil's disease, is doubtful. Dog is a good indicator of the distribution of different leptospiral serovars in its environment. It seems reasonable to practice occasionally serological investigations of these animals in order to detect possible changes in infecting leptospiral serovars. Consequently, adequate epizootological measures could be taken (e. g. modification of the composition of a leptospiral vaccine for dogs).     

Seroprevalence of leptospirosis in Korean municipal zoo animals

From 2002 to 2005, we collected 118 serum samples from 34 species belonging to 13 families of zoo animals in Korea and determined the prevalence of antibodies for 18 serovars of Leptospira spp. using the microscopic agglutination test (MAT). Twenty-nine (25%) of the serum samples tested were positive for one or more of the serovars. There were no significant differences in relation to genders: 23% and 26% of positives occurring in male and female animals, respectively (P>0.05). However, the seroprevalence for the Leptospira spp. was significantly higher (P<0.05) in herbivores (45%) than in either carnivores (17%) or omnivores (17%). Among the 5 serovars detected in this study, the most common was sejroe (n=27; 87% of all positive reactions). All positive reactions showed low titers (< or = 1:200) and the positives were most frequently detected in 1:25 (58%) and 1:50 (23%) serum dilutions. The highest antibody titer (1:200) was observed for the serovars sejroe (n=1) and bratislava (n=1). We conclude that the exposure of zoo animals to Leptospira spp. is relatively common in Korea and produces low MAT titers, with sejroe being the most commonly encountered serovar.     

Seroprevalence of Leptospira spp. in clinically healthy horses in Switzerland

A retrospective, cross-sectional study was conducted to determine the leptospiral seroprevalence in clinically healthy horses in Switzerland. A representative sample of 615 horse sera was examined by microscopic agglutination test for the presence of antibodies against 15 Leptospira?spp. serovars. In total, 58.5?% (n?=?360) of the horses were positive for one or more of the antigens analysed, with 20.3?% of them showing titres >=?400. The most prevalent serovar was Pyrogenes (22.6?%), followed by serovars Canicola (22.1?%) and Australis (19.2?%). Older horses, mares, ponies and animals spending increased time on pasture exhibited significantly higher prevalence rates (p?相似文献   

Serological evidence of Leptospira sp. in humans from Fernando de Noronha Island,Brazil

The prevalence of leptospirosis in humans is highly variable, being influenced by climatic factors, the presence of reservoirs, occupational exposure, recreational activity, and socioeconomic conditions. The objective of this study was to estimate the prevalence of Leptospira sp. and identify the predominant human serovars on the island of Fernando de Noronha, Brazil, based on a microscopic agglutination test. The prevalence of anti-Leptospira antibodies was 1.17% (4/341; I.C. 0.46%–2.98%), with the predominance of serovars Icterohaemorrhagiae, Javanica, Mini and Louisiana. This is the first study on the occurrence of antibodies against Leptospira sp. in humans in Fernando de Noronha and highlights the need to implement control and prevention strategies in this island environment.     

Leptospira antibody detection in dog serum in the years 1985 to 1988

In 1985-1988, 993 serum samples of dogs from Southern Bavaria and 408 samples from Northern Bavaria and from several Lands of the Federal Republic of Germany were tested for antibodies against the serovars canicola, icterohaemorrhagiae, grippotyphosa, bratislava, pomona, saxkoebing, sejroe and hardjo by using the microscopic agglutination test (MAT). 683 seras (48.75%) out of altogether 1401 samples showed a reaction against one up to seven serovars. The mostly low canicola- and icterohaemorrhagiae titers, having been proved in over 30% of the samples, can be put down to the fact, that usually the dogs had been vaccinated. Most frequently titers were found with the serovars grippotyphosa and bratislava--in Southern Bavaria 28.3%, in Northern Bavaria and other Lands of the Federal Republic of Germany 18.6%. The prevalence of titers against serovar saxkoebing, with or without a reaction against other serovars out of homologous and heterologous serogroups, reach up to 3.2% in sendings coming from Southern Bavaria and in other sendings up to 6.1%.     

Leptospira spp. in horses in southern Brazil: Seroprevalence,infection risk factors,and influence on reproduction

Leptospirosis in horses is often associated with reproductive disorders. In the southern states of Brazil, horses are used for various jobs and cultural practices; nevertheless, serological surveillance for Leptospira is rare. Therefore, the objective of this study was to determine the seroprevalence of Leptospira spp. in horses in southern Brazil, as well as to identify the risk factors for infection and its impacts on reproduction. We performed microscopic agglutination tests for 12 serovars that corresponding 9 serogroup (Sejroe, Icterohaemorrhagiae, Australis, Pyrogenes, Pomona, Canicola, Grippotyphosa, Tarassovi and Ballum) in 595 samples from 60 herds. A brief history was obtained to analyze risk factors for reproductive disorders. A total of 45.9% of the tested horses were seropositive, of which the most frequent serogroups were Icterohaemorrhagiae (Icterohaemorrhagiae and Copenhageni serovars) and Ballum (Ballum serovar). Simple infections were found in 45.4% of seropositive animals, while mixed infections occurred in 54.6% of horses. There was a correlation between seropositivity and age and sex, that is, seropositivity was more frequent in animals over 6 years old and in females. There was no correlation between seropositivity and reproductive disorders. We conclude that there is a high seroprevalence of Leptospira spp. in southern Brazil with predominance of Icterohaemorrhagiae serogroup, mainly in older animals. Location, breeds, contact with dogs or other domestic animals are not risk factors, whereas gender is a risk factor. Reproductive disorders are not due to leptospirosis in the study region.     

A cross-sectional study of Leishmania spp. infection in clinically healthy dogs with polymerase chain reaction and serology in Greece

The prevalence of gastrointestinal parasites in stray dogs, and dogs with owners was investigated by fecal examinations from 271 dogs employing sedimentation, simple flotation and centrifugation-flotation methods. The centrifugation-flotation method, when compared to simple flotation or sedimentation methods was generally more accurate in the diagnosis of all intestinal parasites, but statistical differences were detected only in relation to Giardia spp. and Cystoisospora spp. (synonym Isospora spp.). The following parasites, with their respective prevalence, were diagnosed in the fecal samples: Ancylostoma spp. (23.6%); Toxocara canis (5.5%); Trichuris vulpis (4.8%); Spirocerca lupi (1.9%); Dipylidium caninum (0.7%); Giardia spp. (12.2%); Hammondia heydorni (2.6%); Cystoisospora spp. (8.5%); and Sarcocystis spp. (2.2%). The prevalence of most parasites was similar for dogs of mixed-breed and for dogs of a defined-breed, except for Cystoisospora spp. and T. canis which showed a significantly higher prevalence in mixed-breed dogs. The prevalence of Ancylostoma spp. (17.1%) was significantly lower in stray dogs than in those with an owner (31.9%) and the prevalence of Giardia spp. and Cystoisospora spp. was higher in stray dogs (P < 0.05). No effect of season on the occurrence of the different parasite genera could be observed, except for Ancylostoma spp., for which an increase in the percentage of dogs shedding eggs was observed at the beginning of Summer with a peak occurrence during April and May (Autumn). The prevalence of Ancylostoma spp., T. canis, T. vulpis, Giardia spp. and Cystoisospora spp. was higher in adult males than in adult females, but significant differences between the two groups occurred only with Giardia spp. Young animals were found to more frequently shed Nematode eggs in feces than adult animals.     

Serological findings in cases of acute leptospirosis in the dog

Fourteen dogs which had died from acute leptospirosis, three dogs which survived an acute attack of leptospirosis and seven healthy dogs living in close contact with the animals which died were examined for the presence of lepto-spiral antibodies by the microscopic agglutination test. Twelve dogs had titres of 1:3200 or greater. The predominant titre was directed against serovar bratislava in seven cases, serovar grippothyphosa in two cases and both these serovars in two cases. In one case the predominant titre was directed against serovars bratislava, grippothyphosa, copenhageni (serogroup icterohaemorrhagiae) and pomona. The present study and other recent reports suggest that the epidemiology of canine leptospirosis is changing with the emergence of serovars differing from those typically infecting dogs, namely canicola and icterohaemorrhagiae.     

A parasitological, molecular and serological survey of Hepatozoon canis infection in dogs around the Aegean coast of Turkey

Canine hepatozoonosis is caused by the tick-borne protozoon Hepatozoon spp. The prevalence of the infection in the Aegean coast of Turkey was investigated by examination of blood smear parasitology and polymerase chain reaction (PCR) using blood samples from 349 dogs collected from Central Aydin, Kusadasi, Selcuk, Central Manisa, Bodrum and Marmaris within the Aegean coast of Turkey. The indirect fluorescent antibody test (IFAT) for the detection of Hepatozoon canis antibodies was also used to detect the exposure rate to H. canis. PCR amplifying a 666bp fragment of 18S rRNA gene of Hepatozoon spp. was used in the epidemiological survey. The prevalence of Hepatozoon spp. infection was 10.6% by blood smear parasitology and 25.8% by PCR. IFAT revealed that 36.8% of serum samples were positive for antibodies reactive with Hepatozoon spp. The PCR products of 18S rRNA gene of Hepatozoon spp. isolated from six infected dogs, one isolate originating from each of the six different locations, were sequenced. The results of sequence analysis indicate that they are closely related to Indian and Japanese isolates of H. canis. This is the first epidemiological study on the prevalence of H. canis infection in the dog, in Turkey.     

Biochemical analysis by SDS-PAGE and western blotting of the antigenic relationship between Leptospira and equine ocular tissues.

The antigenic relationship between Leptospira interrogans, equine cornea and lens was previously noted in our studies. Serum antibodies from horses inoculated with serovars wolffi, pomona, icterohaemorrhagiae, and tarassovi, were able to bind to five antigenic fractions from both cornea and lens, as demonstrated by immunoblotting. These antigens seem to be made up of protein and carbohydrates. After treatment with periodate for cleavage of glycoside ring structures, those fractions kept their condition of target for anti-Leptospira antibodies. Nevertheless, all fractions lost that condition after being subjected to peptide hydrolysis.     

Necrotic enteritis in collared (Pecari tajacu) and white-lipped (Tayassu pecari) peccaries

An outbreak of necrotic enteritis caused by Clostridium perfringens type C was diagnosed in captive collared (Pecari tajacu) and white-lipped (Tayassu pecari) peccaries housed in the Laboratory of Applied Ethology of Universidade Estadual de Santa Cruz located in Ilhéus, State of Bahia, Brazil. Four collared peccaries and three white-lipped peccaries, all juveniles (25-105 days old), were affected. For all affected animals, lethargy and inappetance were followed by sudden death within 24 hours. Histopathology of intestinal wall, culture of C. perfringens type C, and the identification of beta-toxin from intestinal content confirmed the diagnosis.     

Prevalence and antimicrobial susceptibility of Salmonella infections in free-range pigs

The prevalence of Salmonella spp. infection was determined in 67 free-range pig herds in southern Spain. Microbiological assessment was performed on ileocolic lymph nodes collected at slaughter according to ISO 6579:2002 procedures. Overall, 33% of herds were infected and the prevalence of infection was 5.3%. Salmonella spp. serovars most frequently isolated were Anatum and Typhimurium, although uncommon serovars such as Hessarek and Mikawasima were also detected. Isolates were tested against 16 antimicrobial agents and exhibited resistance to streptomycin (46%), tetracycline (30%), sulphonamides (25%) and ampicillin (23%) by the break-point method. Multi-drug resistance, defined as resistance to ≥ 4 antimicrobials, was 36%.     

Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraíba, Northeast region of Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.     

Circulation of Toxocara spp. in suburban and rural ecosystems in the Slovak Republic

Toxocara spp., the common roundworms of domestic and wild animals, are the causative agents of larval toxocarosis in humans. The migration of Toxocara larvae in men causes clinical syndrome, called larva migrans visceralis or larva migrans ocularis. The objective of the present work was to investigate the prevalence of toxocarosis in dogs, red foxes (Vulpes vulpes), and small mammals in the Slovak Republic. T. canis infection was diagnosed in 16.6% out of 145 dogs examined. Young animals showed significantly higher positivity (50.0%) than adults (12.4%). Coprological investigation of 310 red foxes showed 8.1% prevalence of T. canis, with higher occurrence in animals from rural conditions (8.6%) than from suburban environment (5.6%). Out of 710 small mammals examined, anti-Toxocara antibodies were detected in 7.7% of the animals. The most frequently seropositive species was Apodemus agrarius (15.9%). Seropositivity of small mammals from suburban localities was higher (10%) compared with rural areas (5.8%), with adult animals exhibiting higher seropositivity (8.0%) than subadults (6.8%). Our results have confirmed the importance of dogs, red foxes and small mammals in circulation of this serious helminthozoonosis in suburban and rural ecosystems.     

Serologic and blood culture survey of Trypanosoma cruzi infection in four canine populations of southern Louisiana

Blood culture and serologic testing were used to study the prevalence of Trypanosoma cruzi infection in a group of 85 dogs from southern Louisiana rural environment. These dogs were known to have been in contact with wild mammalian hosts of the hemoflagellate. Results were compared with blood culture and serologic test results in 103 dogs from a rural environment and with limited known wild mammalian T cruzi host contact. Serologic test results for the 188 dogs from the rural environment were compared with results for 176 dogs from an urban animal shelter and for 100 household pet dogs from an urban southern Louisiana environment. Blood culture was not performed on urban dogs. Culture results were negative in all dogs from rural environments. Serologic evidence of infection was obtained for 4 of the 85 (4.7%) dogs of rural environment with known host contact. Of 176 dogs from the animal shelter, 4 (2.3%) had high antibody titer to T cruzi, and 11 others had low titer (less than 2 adjusted ELISA units [aEU]). Two and 4 dogs of the housed urban and rural groups, respectively, had antibody titer to T cruzi that was less than 2 aEU. Results indicate that prevalence for exposure to T cruzi antigen is higher in dogs with high potential contact with the vector and wild mammalian hosts of T cruzi, whether they are from rural or urban environment. Furthermore, results indicate that similar studies on high-risk human populations may be indicated.     

Seroepidemiology of leptospirosis, toxoplasmosis, and leishmaniosis among dogs in Ankara, Turkey

Seroprevalence of five different Leptospira interrogans serovars, Toxoplasma gondii and Leishmania infantum in stray dogs in Ankara was investigated. A total of 116 dog sera collected from apparently healthy stray dogs were tested for L. interrogans serovars by microscopic agglutination test (MAT), for T. gondii antibodies by Sabin-Feldman dye test (SFDT), and for L. infantum antibodies by indirect fluorescence antibody test (IFAT). Of the 116 dogs, 51 (43.96%) were seropositive for leptospirosis, 72 (62.06%) for T. gondii and 3 (2.58%) for L. infantum. No statistically significant difference was observed between male and female dogs in the seroprevalences of toxoplasmosis and leptospirosis (P>0.05), but statistically significant difference was observed among different age groups in the seroprevalences of toxoplasmosis and leptospirosis (P<0.05). Although the seroprevalence of L. infantum was low, asymptomatic animals should be considered as a reservoir for the spread of the disease.