Detection of antibodies against Brucella abortus, Leptospira spp., and Apicomplexa protozoa in water buffaloes in the Northeast of Argentina

A systematic review and meta-analysis of bovine brucellosis seroprevalence in Latin America and the Caribbean

Introduction

Bovine brucellosis is a significant public health problem in countries with economic and zoonotic implications. Although relevant, there are no previous systematic reviews about bovine brucellosis in Latin America.

Methods

We performed a systematic literature review in five data-bases to assess the seroprevalence of Brucella in cattle. A meta-analysis with a random-effects model was performed to calculate the pooled prevalence and 95% confidence intervals (95%CI). In addition, measures of heterogeneity (Cochran's Q statistic and I2 test) were reported.

Results

The literature search yielded 3,403 articles, of which 65 studies were fully valid for analysis. The pooled seroprevalence for Brucella in bovine (n ​= ​46,883,177) was 4.0% (95%CI: 3.0%-5.0%; p ​< ​0.001), and Venezuela was the country with the highest prevalence (16.0%). By regions, the highest seroprevalence is in Central America and the Caribbean islands (8.0%,95%CI: 3.0%-15.0%; p ​< ​0.001, I2 ​= ​99.85).

Conclusions

Some countries reported still relevant seroprevalences of bovine brucellosis, especially at the Central America and Caribbean islands. Multiple factors may influence the survival and spread of pathogens in the environment; farms located in regions bordering forest areas, in areas of difficult access to the veterinary service; extensive beef herds raised at pastures with different age and productive groups inter-mingled, and minimal concerns regarding hygiene practices and disease prevention measures. Bovine brucellosis has not been eliminated and needs to be considered with new tools for prevention and control, especially being a zoonosis.

Neosporosis in Argentina: Past, present and future perspectives

Neosporosis, caused by the protozoan Neospora caninum, was first diagnosed in Argentinean cattle in the 90's. With a national bovine stock of approximately 53 million head, the cattle industry is socially and economically relevant. Severe economic losses have been estimated at US$ 33 and 12 million annually in dairy and beef cattle, respectively. Approximately 9% of bovine abortions in the Buenos Aires province are caused by N. caninum. In 2001, the first isolation of N. caninum oocysts from feces of a naturally infected dog was performed in Argentina and named as NC-6 Argentina. Further strains were isolated from cattle (NC-Argentina LP1, NC-Argentina LP2) and axis deer (Axis axis, NC-Axis). Epidemiological studies revealed a high distribution of Neospora-infections not only in dairy but also in beef cattle, with seroprevalence rates of 16.6-88.8% and 0-73%, respectively. Several experimental infection studies in cattle have been carried out, as well as attempts to develop effective vaccines to avoid Neospora-abortions and transmission. However, no vaccine has proven successful for its use in daily practice. Reduction of seroprevalence, vertical transmission and Neospora-related abortions have been achieved in dairy farms by the use of selective breeding strategies and embryo transfer. Neospora-infections have been also detected in goats, sheep, deer, water buffaloes (Bubalus bubalis) and gray foxes (Lycalopex griseus). Moreover, Neospora-related reproductive losses were reported in small ruminants and deer species and could be more frequent than previously thought. Even though diagnostic methods have been improved during the last decades, control of neosporosis is still not optimal. The development of new strategies including new antiprotozoal drugs and vaccines is highly needed. This paper reviews the information from the previous 28 years of research of N. caninum in Argentina, including seroprevalence and epidemiological studies, available diagnostic techniques, experimental reproduction, immunization strategies, isolations and control measures in domestic and non-domestic animals from Argentina.

Leptospirosis genital incidental en machos Bubalus bubalis del estado Portuguesa, Venezuela

La leptospirosis constituye una importante causa de infertilidad en bóvidos. En Bubalus bubalis, Leptospira spp. infecta el tejido renal, así como los órganos sexuales, por lo que puede excretarse, tanto en orina como en semen. Solo un número limitado de estudios en todo el mundo han investigado la seroprevalencia de la enfermedad en machos bovinos y los riesgos reproductivos relacionados con la eliminación del patógeno en el semen. Se reportan aquí los resultados de la evaluación serológica, microbiológica, seminal e histopatológica de machos bufalinos adultos del municipio Esteller, estado Portuguesa, Venezuela, infectados naturalmente con Leptospira spp. Se evaluaron 17 búfalos mestizos Murrah de 40 meses de edad, previo al beneficio, con 500 kilos de peso promedio, no vacunados, a los cuales se les tomaron muestra de suero sanguíneo, orina, semen y se midió circunferencia escrotal junto a otros parámetros reproductivos. Exclusivamente 15 animales mostraron títulos entre 50 y 200 en la MAT, exclusivamente para L. hebdomadis. Los 2 animales negativos a MAT resultaron positivos en cultivo bacteriológico de orina o semen a Leptospira spp. De 6 animales beneficiados, MAT y bacteriológicamente positivos a leptospira en semen y orina, se extrajeron riñones, testículos y epidídimos para examen histopatológico. De epidídimos y riñónes se aislaron Leptospira spp., no así de testículos. Sin embargo, el diagnóstico histopatológico en testículo y epidídimo indicó degeneración de células seminíferas compatible con infección bacteriana. El riñón presentó nefritis intersticial crónica. Hubo disminución en el promedio de la circunferencia escrotal, baja intención de monta, baja concentración espermática, ausencia de ondas, pocos espermatozoides móviles, baja motilidad espermática y más de 30 % de mortalidad espermática de las muestras de semen evaluadas, indicando baja calidad del eyaculado. Las anomalías seminales mayores y menores superaron las escalas recomendadas para la especie. Se reportan aquí resultados exclusivos de búfalos machos infectados individualmente con L. hebdomadis, excretada por orina y semen, responsable de afectar el tracto reproductivo de manera incidental, ocasionando daños espermáticos, del epidídimo y daño renal, en una explotación mixta arrocera, con presencia de roedores, potenciales transmisores de la leptospirosis.

Seroprevalence of Neospora caninum and risk factors associated with infection in water buffaloes (Bubalus bubalis) from Maranhão State, Brazil

The aim of this work was to determine the seroprevalence of Neospora caninum in buffaloes (Bubalus bubalis) from Maranhão State, Brazil, and identify risk factors associated with infection. In total, 338 buffaloes of different ages and both sexes from four farms were randomly selected. Information about the study region, animals and management was collected using an epidemiological questionnaire. Sera were subjected to an indirect fluorescent antibody test (IFAT) to detect anti-N caninum antibodies, while N. caninum DNA was detected using the polymerase chain reaction (PCR) assays. The overall seroprevalence of N. caninum in buffaloes was 27.5% (93/338), while DNA was detected in 3.0% (3/101) samples. The proportion of positive animals detected by IFAT and PCR simultaneously was 2.6% (2/77). The risk factors for N. caninum infection were contact with fomites (p = 0.022), management conditions (p = 0.005), calving interval of 20 months (p = 0.010) and deworming management (application 3 times a year in adults and calves, p = 0.020; change of anthelmintic group, p = 0.040). By multivariate analysis, management conditions was a risk factor for N. caninum infection with odds ratio of 2.2 (95% CI 1.0-4.6). This is the first report of the prevalence and risk factors for neosporosis in B. bubalis of Maranhão State, Brazil. Thus, N. caninum is widely distributed in buffalo herds in Maranhão, with management conditions being a risk factor for infection. Further studies should be conducted to elucidate the importance of buffaloes in the epidemiology of neosporosis in Maranhão State.

The global seroprevalence of Toxoplasma gondii infection in bovines: a systematic review and meta-analysis

Bovines, especially cattle, are considered as one of the main sources of Toxoplasma gondii infection for humans. A more comprehensive understanding of the occurrence of T. gondii is needed to provide a global perspective on the prevalence of T. gondii in bovines. Here, we present the results of the first systematic review and meta-analysis on the global T. gondii seroprevalence in bovines. Six databases (PubMed, ScienceDirect, Web of Science, Scopus, ProQuest and Google Scholar) were comprehensively searched for relevant studies published between 1 January 1967 and 30 May 2019. Among 7691 publications searched, 178 studies (from 50 countries) with 193 datasets were included in the meta-analysis. The global pooled and weighted seroprevalence of T. gondii among bovines was 17.91% [95% confidence interval (CI): 15.32–20.6]. Weighted prevalence based on the host was as follows: cattle 16.94% (95% CI: 14.25–19.81), buffalo 22.26% (95% CI: 16.8–29), yak 23% (95% CI: 14–33) and bison 8.1% (95% CI: 3.9–13.7). Continued monitoring on the status of T. gondii seroprevalence in bovines is essential. Study on the prevalence of T. gondii in the products of bovines such as milk, meat, etc., which are considered as the source of transmission of infection to humans, is recommended.

Seroprevalence of Brucellosis in Buffalo Worldwide and Associated Risk Factors: A Systematic Review and Meta-Analysis

Background: Brucellosis is an important zoonotic disease caused by Brucella spp. Brucellosis is widely distributed in more than 160 or 170 countries around the world, where it poses a huge threat to animal husbandry and human health. About 150 million head of water buffalo, distributed across more than 40 countries worldwide, are kept for the purposes of service, milk, and meat. High incidence of Brucella spp. in buffalo has negatively affected dairy products and meat products.

Results: We searched all research related to seroprevalence of brucellosis in water buffalo anywhere in the world in PubMed, Science Direct, SpringerLink, China National Knowledge Infrastructure, Wanfang Database, and VIP Chinese Journal Databases. A total of 26 articles published from 1985 to 2020 met the final selection criteria. The overall seroprevalence of buffalo brucellosis worldwide was 9.7%. The seroprevalence before 2010 (20.8%) (95% CI: 5.6–42.2) was much higher than the seroprevalence rate from 2010 to 2020 (4.2%) (95% CI: 1.8–7.5). Subgroup analysis by feeding mode found that the point estimate of seroprevalence in stock buffalo (11.5%) (95% CI: 3.6–23.0) was higher than that in captive buffalo (10.6%) (95% CI: 4.9–18.1). Subgroup analysis by farming mode found that the seroprevalence was higher in captive-bred buffalo (10.7%) (95% CI: 6.6–15.7) than in intensively farmed buffalo (8.5) (95% CI: 0.9–22.2). The seroprevalence in buffalo living in dry lands (6.4%) (95% CI: 2.0–12.9) is greater than that in buffalo living in wetlands (5.1%) (95% CI: 1.8–10.4) (P < 0.05). The seroprevalence in female buffalo (10.1%) (95% CI: 3.4–19.7) was higher than that in male buffalo (4.4%) (95% CI: 2.0–7.4). The seroprevalence in lactating buffalo was higher than that in buffalo of other ages (26.9%) (95% CI: 1.8–66.5). Subgroup analysis by detection method found that the seroprevalence detected by the complement fixation test (27.3%) (95% CI: 0.7–70.8) was much higher than that detected by other methods.

Conclusion: The results of this meta-analysis showed that buffalo brucellosis infection is very common in buffalo herds around the world. Although the seroprevalence of brucellosis in buffalo and humans is relatively low, serious effects upon animal husbandry and public health make it necessary to take effective control and preventive measures to control the spread of this disease.

Isolation of an atypical Leptospira strain assigned to the Sejroe serogroup from a water buffalo in Brazil

The isolation of leptospires from buffaloes worldwide is still limited to a few strains. Thus, the aim of this study was to describe the first Leptospira isolate from buffalo urine, assigned to the Sejroe serogroup, which does not belong to the Wolffi subgroup, traditionally isolated in Brazil. A total of 244 urine samples of water buffaloes (Bubalus bubalis) raised in the Brazilian Amazon were subjected to bacteriological culturing and polymerase chain reaction (PCR) for the detection of leptospires. The obtained isolate was characterized by serogrouping using polyclonal antibodies, partial DNA sequencing, Hardjo-Bovis-specific PCR, multiple-locus variable-number tandem repeat analysis (MLVA/VNTR) and experimental infection in hamsters. PCR was performed on the urine samples; 11/244 were positive (4.5 %) for Leptospira, and only one isolate was recovered (0.4 %). Regarding characterization, the isolate was assigned to the Sejroe serogroup with high titers (12,800) for the Saxkoebing and Sejroe serovar antisera. The isolate was negative for Hardjo-Bovis-specific PCR, and the species Leptospira borgpetersenii was identified by DNA sequencing. The MLVA results showed that the VNTR profile of the isolate was 1-2-5, compatible with that of serovars Sejroe/Istrica. In the experimental infection in hamsters, the animals did not develop clinical signs, and no macroscopic lesions were observed on the organs at necropsy; however, the strain was detected in the kidneys, uterus, and testicles of the animals. The isolate described herein highlights infection by Sejroe strains that may be overlooked in buffaloes and that may be different from those normally isolated and used in serological studies.

Leptospira interrogans serogroup Pomona strains isolated from river buffaloes

At present, little is known regarding the prevalence of buffalo leptospirosis worldwide, especially with respect to which Leptospira strains may infect this animal species. Furthermore, most investigations into this disease in buffaloes have only been performed with serological studies. In Brazil, particularly in the Amazon, buffalo production is growing and is just as important as cattle production, although few studies have been performed on buffalo compared to cattle. Thus, the aim of this study was to isolate and characterise Leptospira strains from river buffaloes raised in the Brazilian Amazon region. We collected 109 kidney samples from slaughtered buffaloes raised in the Amazon Delta region of Brazil. The samples were analysed by bacteriological culture for the isolation of leptospires, and the obtained isolates were serologically and molecularly characterised by microscopic agglutination test (MAT), DNA sequencing and multiple locus variable-number tandem repeat analysis (MLVA). Five isolates were obtained, and in serogrouping analyses, these isolates were only reactive for the Pomona serogroup, with an observed titre of 25,600. The DNA sequencing results revealed that all the isolates belonged to the species Leptospira interrogans, and the MLVA results showed that the VNTR loci 4, 7 and 10 profile of all the isolates was 4-1-10. In this study, we observed that Pomona serogroup strains circulate in buffaloes in the Amazon, showing that in Brazil, buffaloes can be affected by Leptospira strains other than the Sejroe group, which are adapted to cattle.

First report of pathogenic Leptospira spp. in Tadarida brasiliensis bats (family Molossidae) and Eptesicus furinalis (family Vespertilionidae) of Argentina. New host species in this country?

Leptospirosis is an endemic disease caused by Leptospira spp., a bacterium that affects animals and humans. In recent years, the number of reports of leptospirosis in wild animals has increased, which highlights the need to study the infectious agents in these animals. In this study, a duplex PCR for the detection of leptospiral DNA was performed on 50 kidney samples from bats, and a MAT (Microscopic Agglutination Test) for serological detection of anti-leptospiral antibodies was applied to 47 serum samples from bats from different regions of Buenos Aires Province, Argentina. DNA was extracted using Chelex-100 and duplex PCR was performed by targeting the detection of genes secY and flaB, of pathogenic Leptospira spp. Of the 50 kidney samples, 3 were positive for Eumops sp. and Tadarida brasiliensis by duplex PCR. Of the 47 serum samples, 12 were positive for different serovars: Leptospira interrogans serovars Icterohaemorrhagiae, Cynopteri and Bataviae, and Leptospira borgpetersenii serovar Ballum. This is the first report of the detection of pathogenic leptospires by serology in bats belonging to the T. brasiliensis and Eptesicus furinalis species in Argentina. In addition, this is the first report of the detection of pathogenic leptospiral DNA by PCR in T. brasiliensis species. The detection of Leptospira spp. in these wild animals shows that they may play an important role as wildlife reservoirs of leptospires.

A Review of Toxoplasmosis and Neosporosis in Water Buffalo (Bubalus bubalis)

Toxoplasmosis and neosporosis are diseases with worldwide distribution that are associated with reproductive problems in livestock and responsible for economic losses. This review presents an overview of the current knowledge relative to these diseases in water buffalo (Bubalus bubalis). In general, buffalo are considered resistant to clinical toxoplasmosis because there are studies only reporting serological evidence of natural infection in these animals. Studies have described age, poor hygienic status of the farm, and presence of cats as risk factors for the development of Toxoplasma gondii infection in buffalo. It must be highlighted that buffalo meat, which does not receive adequate freezing treatment, could be a potential source for toxoplasmic human infection as well as the importance of raw buffalo milk in the transmission of toxoplasmosis to human beings. Neospora caninum is considered one of the major causes of abortion and responsible for huge economic losses in cattle. Vertical transmission is the main route to infect calves, and is responsible for maintaining the parasite within a herd. In buffalo, vertical transmission is also described; moreover, although there are indications that N. caninum may be associated with abortion in dairy buffalo, the reproductive importance of neosporosis is apparently lower in buffalo relative to cattle. Most studies have identified a higher time of exposition to N. caninum oocysts relative to age. The household system was also described as a risk factor for infection, possibly due to persistent contact between the home-raised buffalo and canids. The fetal immune competence of buffalo is similar to bovine, and buffalo fetus are highly susceptible to infection during the first trimester of pregnancy, indicating that N. caninum may be an abortigenic agent in buffaloes. Alternatively, it is interesting to note there is evidence that the inflammatory response in pregnant buffalo infected with N. caninum is mild enough to avoid abortion in most cases. It is proposed that the possible transmission of toxoplasmosis through unprocessed milk and buffalo meat may occur, which is important in terms of public health. Additionally, there is strong evidence to suggest that N. caninum may be associated with abortion in buffalo.

Prevalence of Leptospira serogroups in buffaloes from the Brazilian Amazon

Although Brazil has one of the largest buffalo populations in the Americas, buffalo leptospirosis is still poorly explored when compared to that in bovines; thus, the aim of this research was to carry out a large serological study for leptospirosis in this species in the Brazilian Amazon. For this, we collected 1,405 serum samples from buffaloes raised in the Amazon delta region, which is considered a major area of buffalo production in Brazil. The test used was a microscopic agglutination test (MAT) adopting 34 Leptospira antigens, some of which have never been tested for buffaloes in Brazil, including autochthonous strains; in total, 20 serogroups were evaluated. From the total of 1,405 serum samples, 894 (63.6%) reacted in the MAT to at least one of the 20 serogroups, and 511 (36.4%) did not react. The serogroups Sejroe, Autumnalis and Pomona were the most prevalent, with titres ranging from 100 to 12,800, and the autochthonous strains used were not significant in relation to the reference serovars. Leptospirosis in buffaloes seems to have a serological profile similar to leptospirosis in cattle, mainly due to the prevalence of the Sejroe serogroup; however, the results of this study suggested that in the Brazilian Amazon, Leptospira strains that are serologically distinct from the autochthonous strains isolated in the southeastern region of Brazil may be circulating in these animals. Other serovars could also be inserted into the panel of antigens used in MAT for serological studies on buffaloes.

Prevalence and associated factors with Neospora caninum infection in female water buffaloes (Bubalus bubalis) from Pernambuco, Brazil

Neosporosis is one of the major parasitic diseases that causes reproductive problems, making it a limitation for optimal efficiency in livestock. The aim of the present study was to conduct a seroepidemiological survey for bubaline neosporosis and to analyse associated factors associated with N. caninum infection in female water buffaloes in the State of Pernambuco, northeast Brazil. The prevalence of N. caninum infection in the bubaline herds examined was 35.4% (122/345; 95% CI: 30.4%-40.7%), at least 1 Neospora-positive animal was found in each farm. Associated factors for N. caninum infection identified in this study were exclusive pasture feeding (OR: 5.91, p <0.001) and purchase of animals of free fair and from reputable sellers (OR: 1.85; p =0.045). In this survey, we document the occurrence of neosporosis in female water buffaloes. Associated factors should be controlled in order to reduce the risk of N. caninum infection in these herds.

Exposure to Neospora spp. and Besnoitia spp. in wildlife from Israel

Neosporosis and besnoitiosis, caused by cyst-forming protozoa Neospora caninum and Besnoitia besnoiti, respectively, are parasitic infestations of livestock in Israel. These parasites cause significant economic losses in cattle due to reproductive and productive disorders. Both parasites have been detected in several wild ruminant species throughout other regions of the world, while the existence of a sylvatic life cycle in Israel remains uncertain. Thus, a wide panel of 871 sera from two wild carnivores and nine wild ruminant species were tested. All sera were first analysed by MAT for an initial screening and positive samples were confirmed a posteriori by Western blot. Additionally, a complementary IFAT was used for the detection of antibodies against N. caninum. Neospora antibodies were present in six out of the 11 species investigated, whereas Besnoitia antibodies were undetected. Golden jackal, red fox, addax, Arabian oryx, Persian fallow deer, mouflon, mountain gazelle, Nubian ibex, scimitar horned oryx and water buffalo were seropositive against N. caninum infection by IFAT and/or MAT. Moreover, the presence of Neospora spp.-specific antibodies was confirmed by Western blot in golden jackal (6/189; 3.2%), red fox (1/75; 1.3%), Persian fallow deer (13/232; 5.6%), mouflon (1/15; 16.7%), Nubian ibex (22/55; 40%) and water buffalo (12/18; 66.7%). Addax (1/49) and water buffalo (1/18) were MAT-seropositive against B. besnoiti but were seronegative by Western blot. Hence, Neospora sylvatic cycle is present in Israel and may cross over to a domestic life cycle. In contrast, wildlife species investigated are unlikely to present a risk of transmitting Besnoitia to livestock in Israel.

Brucellosis in water buffaloes

ABSTRACT: The domestication of water buffaloes (Bubalus bubalis) originated in India and China and spread throughout the world and represents an important source of food of high biological value. Given the importance and relevance of brucellosis for buffalo production, this article reviews the history, etiopathogenesis, epidemiology, clinical signs, anatomopathological findings, diagnosis and control of the disease, focusing on data from studies on water buffaloes performed in different countries and the Brazilian Amazon biome.

Molecular epidemiology of pathogenic Leptospira spp. among large ruminants in the Philippines

The extent of Leptospira infection in large ruminants resulting to economic problems in livestock industry in a leptospirosis-endemic country like the Philippines has not been extensively explored. Therefore, we determined the prevalence and carrier status of leptospirosis in large ruminants using molecular techniques and assessed the risk factors of acquiring leptospirosis in these animals. Water buffalo and cattle urine samples (n=831) collected from 21 farms during 2013-2015 were subjected to flaB-nested PCR to detect pathogenic Leptospira spp. Leptospiral flaB was detected in both species with a detection rate of 16.1%. Leptospiral DNA was detected only in samples from animals managed in communal farms. Sequence analysis of Leptospira flaB in large ruminants revealed the formation of three major clusters with L. borgpetersenii or L. kirschneri. One farm contained Leptospira flaB sequences from all clusters identified in this study, suggesting this farm was the main source of leptospires for other farms. This study suggested that these large ruminants are infected with various pathogenic Leptospira species causing possible major economic loss in the livestock industry as well as potential Leptospira reservoirs that can transmit infection to humans and other animals in the Philippines.

Antibodies against Neospora caninum, Sarcocystis spp. and Toxoplasma gondii detected in buffaloes from Rio Grande do Sul, Brazil

ABSTRACT: The presence of antibodies against Neospora caninum, Sarcocystis spp. and Toxoplasma gondii was evaluated in buffaloes (Bubalus bubalis) from Rio Grande do Sul state (RS), southern Brazil. Serum samples (n=220) were analyzed for antibodies by indirect fluorescent antibody test (IFAT). Antibody presence was considered when the titers were equal or higher than 100 for these protozoa. A total of 60.5% (133/220) buffalo serum samples were positive for at least one of the protozoa evaluated in this study. Antibodies for N. caninum, Sarcocystis spp. and T. gondii were found in 36.4% (80/220), 25.5% (56/220) and 16.8% (37/220) of the buffaloes respectively, indicating a higher frequency of N. caninum infection (p=0.0133). The IFAT is a suitable method to diagnose N. caninum, Sarcocystis spp. and T. gondii infection in buffaloes for detecting IgG antibodies. This study demonstrates the presence of these three protozoa in buffalo herds in RS, Brazil, which may be source of infection to other animals. The high frequency of animals positive for N. caninum is important and could be related to reproductive problems. Additionally, the presence of Sarcocystis spp. and T. gondii in buffaloes can be a possible public health issue.

A review of Neospora caninum in water buffalo (Bubalus bubalis)

A number of countries in the world have reported infections with Neospora caninum in water buffalo (Bubalus bubalis), from Africa to Asia, Europe and South America and recently Australia. In general, clinical manifestations (such as abortion) seem rare, which has raised the prospect that buffalo may be inherently resistant to clinical effects of N. caninum infection. Worldwide, the seroprevalence of N. caninum infection (as a measure of exposure determined by the detection of antibody) in buffalo is high, at approximately 48%. This reported seroprevalence is three or four times higher than that reported from the world's cattle populations, which have collective seroprevalence rates of 16.1% for dairy cattle and 11.5% for beef cattle. However, there is a lack of standardisation in seroprevalence studies and some studies may well under-estimate the true level of infection. Epidemiologic evidence supports post-natal transmission, and in utero transmission has also been demonstrated. The causes for water buffalo to have markedly higher seroprevalence but apparently lower neosporosis abortion rates than cattle warrant further investigation.

Abortion and foetal lesions induced by Neospora caninum in experimentally infected water buffalos (Bubalus bubalis)

The water buffalo (Bubalus bubalis) is an important species in several countries for its milk and meat production, as well as for transport and other agricultural activities. It is, in general, considered more resistant than cattle to different parasitic diseases, also less demanding for forage quality. It has been postulated that buffalo may be resistant to abortion caused by neosporosis, because of high serological prevalences found in buffalo herds from different localities, with no description of Neospora caninum-related abortion. Recent studies have demonstrated the potential impact of neosporosis in pregnant water buffalo cows. In this work, three pregnant buffalo cows were experimentally infected with Nc-1 strain of N. caninum, and abortion was detected 35 days post-infection. Molecular and histopathological results found in post-mortem tissues are described and discussed, confirming the susceptibility of water buffalos to abortion caused by N. caninum.

Seroprevalence of Toxoplasma gondii infection in water buffaloes (Bubalus bubalis) in Veracruz State, Mexico and its association with climatic factors

Background

Infection with Toxoplasma gondii in water buffaloes (Bubalus bubalis) is of epidemiological importance because of the risk for transmission to humans. We sought to determine the seroprevalence of T. gondii infection in 339 water buffaloes in Veracruz State, Mexico using the modified agglutination test (MAT, cut off 1:25). Seroprevalence association with general characteristics of buffaloes and their environment was also investigated.

Results

Antibodies to T. gondii were found in 165 (48.7%) of the 339 buffaloes with MAT titers of 1:25 in 104, 1:50 in 52, and 1:100 in 9. Bivariate analysis showed that seroprevalence of T. gondii infection was similar in buffaloes regardless of their general characteristics i.e., age, sex, and breed. In contrast, the seroprevalence in buffaloes varied significantly with environmental characteristics including altitude, mean annual temperature, and mean annual rainfall of the municipalities studied. Multivariate analysis showed that T. gondii seropositivity in buffaloes was associated with a mean annual rainfall between 1266–1650 mm (OR = 1.84; 95% CI: 1.15-2.94; P = 0.01).

Conclusions

Results indicate that environmental characteristics may influence the seroprevalence of T. gondii infection in buffaloes. This is the first report on the seroprevalence of T. gondii infection in buffaloes in Mexico. Further research is needed to assess the risk for infection in humans associated with the ingestion of raw or undercooked meat from buffaloes infected with T. gondii.