Species Of Warm-blooded Animals Research Articles

Prevalence of Toxoplasma gondii Antibodies and Risk Factors in Two Sympatric Invasive Carnivores (Procyon lotor and Nyctereutes procyonoides) from Zgorzelec County, Poland.

The intracellular protozoan Toxoplasma gondii is distributed worldwide and infects many species of warm-blooded animals. Most mammals, including humans, can serve as intermediate hosts. This pathogen, with its zoonotic potential, causes toxoplasmosis, a condition that can range from subclinical to fatal in humans. It is therefore important to assess the occurrence of the pathogen, even if only indirectly through the detection of antibodies. Epidemiological data on the seroprevalence in wild animals, including invasive species, are rare in Poland. Therefore, we tested 197 wild raccoons (Procyon lotor) and 89 raccoon dogs (Nyctereutes procyonoides) from Zgorzelec County, southwestern Poland, for the presence of antibodies. Samples were collected between January 2019 and December 2020 and analysed using a commercial indirect modified agglutination test (MAT, cut-off 1:25). The statistical analysis revealed significant differences in seroprevalence between the two predatory species. Of the 197 surveyed raccoons, 96 (48.73%; 95% confidence interval (CI): 41.73-55.73%) tested positive, while 25 of the 89 raccoon dogs (28.09%; 95% CI: 18.70-37.48%) were positive. Regarding risk factors, body weight and sex influenced the presence of T. gondii antibodies in both the species, with a higher likelihood of seropositivity among heavier animals and females, respectively. For raccoon dogs, juveniles were more likely to be seropositive than adults at a given weight. Our results suggest that T. gondii infection is widespread in the regional raccoon and raccoon dog populations, indicating a high level of parasite circulation in the environment.

Prevalence and Haplotypes of Toxoplasma gondii in Native Village Chickens and Pigs in Peninsular Malaysia.

Toxoplasma gondii is an important zoonotic foodborne parasite capable of infecting almost all warm-blooded animal species worldwide. Toxoplasmosis is usually acquired via ingestion of undercooked infected animal tissues resulting in life-threatening consequences for unborn foetus and immunocompromised individuals. A cross-sectional study was carried out to determine the prevalence of T. gondii infection, its associated risk factors in farms, and haplotypes isolated from the native village chicken and pig populations in Peninsular Malaysia. The seroprevalence of T. gondii in village chickens at the animal level was low at 7.6% (95% CI: 4.60-11.60), while at the farm level, it was 52.0% (95% CI: 31.30-72.20). For pigs, the animal-level seroprevalence of T. gondii was 3.0% (95% CI: 1.60-5.10), while the farm-level, it was 31.6% (95% CI: 12.60-56.60). The PCR-based DNA detection on meat samples from chickens (n = 250) and pork (n = 121) detected 14.0% (95% CI: 9.95-18.9) and 5.8% (95% CI: 2.4-11.6) positive, respectively. Six unique T. gondii haplotypes were isolated from the tissue samples. Multivariable logistic regression analysis showed that feeding the chickens farm-produced feeds and allowing wild animals access to pig farms were significant determinants for farm-level seropositivity. Providing hygienic and good quality feeds to chickens and increasing biosecurity in pig farms through prevention of access by wildlife may reduce the risk of transmission of T. gondii infection in the local chickens and pig farms.

Flea parasitism in wild mammals in the metropolitan region of Sorocaba, São Paulo, Brazil.

Fleas are eurixenous ectoparasites that can parasitize different species of warm-blooded animals, including humans, with the possibility of causing irritation and blood spoliation. They are vectors responsible for the transmission of numerous pathogens and have a wide geographical distribution, more frequently in warm regions. Domestic animals (dogs and cats) are preferred hosts, but parasitism can also occur in wild hosts, with a greater variety of parasitic species and strong interaction between these siphonapters and their hosts. During the period from January 2021 to June 2023, flea specimens were collected from wild animals coming from the metropolitan region of Sorocaba, São Paulo. Some of these animals were animals from the zoo's own stock, which were diagnosed with parasitism during routine examinations and others were rescued from the natural environment and sent to the zoo. The flea specimens collected were packed in alcohol 700 GL and sent for microscopic diagnosis. Four groups were diagnosed at the specific level: Ctenocephalides felis, Rhopalopsyllus lutzi, R. lugrubis and Tunga penetrans, and two groups as unidentified species, belonging to the genera Rhopalopsyllus and Polygenis. The parasitized animals were all mammals, belonging to eleven different species, distributed in the Orders Carnivora, Didelphimorphia, Rodentia and Cingulata. Studies on the parasitofauna of wild animals contribute to a greater knowledge about the distribution of parasitic agents and their relationships with the host species.

Investigation of Toxoplasma gondii Seropositivity in Pregnant Women in Kastamonu Province, Turkey

Toxoplasma gondii (T. gondii) is a protozoan parasite that infects most warm-blooded animal species and causes toxoplasmosis. Especially infections that occur during pregnancy can lead to serious clinical symptoms. This study retrospectively revealed the T. gondii seroprevalence of pregnant women in Kastamonu province, Turkey. Anti-T. gondii IgM and IgG positivity of 1.294 pregnant women between the ages of 15-44 years who applied to the Obstetrics and Gynecology Outpatients of Kastamonu Training and Research Hospital from January 2018 to January 2022 were investigated retrospectively. The IgG avidity test was performed for both anti-T. gondii IgM and IgG positivity. Anti-T. gondii IgM and IgG seropositivity were determined as 1.1% (n=14) and 20.3% (n=263), respectively. Anti-T. gondii IgM and IgG positivity were detected together in 11 pregnant women. IgG avidity test results of only six pregnant women could be reached, two pregnant had high IgG avidity, and four pregnant had low IgG avidity. Anti-T. gondii IgG positivity rate increased with increasing age (p=0.039). The number of seronegative pregnant women was considered high in Kastamonu. It is significant for expectant mothers to know about prevention methods in order not to acquire toxoplasmosis.

Rhamnose-Positive Strains of Plague Agent: Virulence and Epidemiological Significance

The aim of the review is to show the groundlessness of the unconditional assessment of rhamnose-positive strains of plague pathogen as avirulent for most species of carriers and humans and having no epidemiological significance. The main carriers of rhamnose-positive strains are several species of voles and the Mongolian pika. The vast majority of experts are of the opinion that rhamnose-positive (“vole`s” and “pika`s”) strains of Yersinia pestis are avirulent or weakly virulent for many species of warm-blooded animals and humans, and therefore have no epidemiological significance. However, in a series of experiments on infecting marmots, ground squirrels, and large gerbils with rhamnose-positive strains, some of the experimental animals fell ill acutely and died from the plague. In nature, rhamnose-positive strains have been isolated from carcasses of relatively resistant red marmots. When evaluating the epidemiological significance of rhamnose-positive strains, such an important criterion as the presence or absence of effective factors and pathways of pathogen transmission in foci of the vole and pika types is omitted. Voles and pikas are not eaten; therefore, the contact route of infecting humans in these foci is impossible. The second way of transmission of the pathogen to humans – vector-borne – is difficult due to the lack of migration of vole fleas from burrows to the surface and their low efficiency as vectors. Nevertheless, cases of human infection with rhamnose-positive strains of the plague agent in the Caucasus and Mongolia give grounds to assert that at least some rhamnose-positive strains have a sufficiently high virulence and are capable of causing infectious process in humans as well. Therefore, epidemiological surveillance in the foci of plague of the vole and pika types cannot be totally abandoned. It can be conducted according to an abbreviated scheme.

НІМФИ КЛІЩІВ ВИДУ IXODES RICINUS, ЇХ ЖИВЛЕННЯ НА ТВАРИНАХ І ЛЮДИНІ ТА ЕПІДЕМІОЛОГІЧНА РОЛЬ

Studies show that rodents are only one link in the food chain of the forest mite. J. Anderson [2] points out that in Europe this species attracts more than 300 species of warm-blooded animals and humans. The populational ecology and distribution of certain rodent species are related to the epidemiological situation among humans, mainly in the case of transmission of certain tick-borne pathogens, such as Borrelia burgdorferi sensu lato or tick-borne encephalitis virus (CE). Randolph S. E. [15] and Krebs C. J. [6] point to certain patterns in the biology of Ixodes mites and rodents. In particular, it has been noticed that in the spring the life cycle of mites is dominated by adults that feed on macro-mammals.
 During 2017–2019, larvae, nymphs and adult mites of the Ixodes ricinus were collected from humans and animals and studied in a specialized laboratory of I. Horbachevsky Ternopil National Medical University. During 2017–2021, more than 1,900 specimens of mites were identified and studied. In this article, special attention is paid to the nymphs of this species. This is due to the fact that nymphs feed not only on animals, as in most other Ixodes mites, but also actively attack humans. The analysis of the ratio of nymphs and adults attacking people in the spring-summer and autumn periods of 2017–2019 has been carried out and the peculiarities of their epidemiological condition during the highest activity of ticks have been studied.
 Certain patterns have been established, in particular, the frequency of their attacks on humans compared to adults correlates from 1.16 to 3.55 and is highest in April-May and then in September. The frequency of attacks of different stages of mites is obviously due to the life cycle of this type of mite and the ability to provide itself with food. It is possible that the high number of nymphs in April-May due to the inability to complete its life cycle in autumn, due to the lack of a host-host and the need to overwinter at the larval or nymph stage. Those individuals that manage to complete their life cycle in the fall, overwinter in the adult stage and in the spring they are already active in this life form. The lack of a host can be explained by the factor of a small number of murine rodents, due to which a large number of larvae and nymphs cannot continue their development.
 Analysis of the epidemiological situation showed that in May, the infection with pathogens in nymphs ranges from 33 % to 48 % and in females - from 50 % to 65 %. In June, this indicator decreases significantly, and in September it rises again to 35–56 % in nymphs and 25–38 % in females.

Physicochemical parameters, organoleptic property, and Escherichia coli load of fresh turkey organs

Escherichia coli is a common microorganism of the digestive microflora of many warm-blooded animal species, including humans. The presence of E. coli in food is an indicator of faecal contamination and ultimately, possible contamination by pathogenic digestive microflora. The aim of the present work was to study the physicochemical parameters, organoleptic property, and E. coli load in turkey organs (thigh, upper thigh, breast, throat, liver, wing, and skin). A total of 224 samples were purchased from several markets, and subjected to different experiments. Results showed that the best overall scores for organoleptic property were recorded for breast (8.64 ± 0.43) and upper thigh (7.12 ± 0.72). The physicochemical parameter results varied across the studied organs. E. coli was isolated up to 100, 93.75, 90.62, 87.50, 62.5, 56.25, and 40.62% in the skin, wing, throat, liver, thigh, breast, and upper thigh samples, respectively. The highest E. coli loads were recorded in the skin, throat, and wing at 3.89, 3.52, and 3.27 log10 CFU/g, respectively. The present work highlighted the physicochemical parameters, organoleptic property, and E. coli load of turkey organs purchased from several districts of Kenitra city, and discussed a number of practices to improve turkey meat quality and protect consumer health from coliform contamination.

Prevalence of Toxoplasma Gondii in Retail Fresh Meat Products from Free-range Chickens in Spain.

IntroductionToxoplasma gondii is one of the most prevalent zoonotic protozoan parasites worldwide and affects the vast majority of warm-blooded animal species, including humans. Postnatal infection in humans occurs through the ingestion of sporulated T. gondii oocysts or via the oral intake of parasite tissue cysts during the consumption of raw or undercooked meat. In this regard, given their high exposure to oocysts, chickens (Gallus domesticus) raised on the ground constitute a potential source of T. gondii.Material and MethodsFor the first time in Spain, a survey was undertaken in commercial retail free-range poultry. A total of 50 thighs from different animals were analysed. The samples were homogenised and an acid pepsin digestion procedure was applied prior to molecular analysis. Toxoplasma gondii DNA was isolated from meat by qPCR. Two sets of primers were used for DNA amplification targeting the specific sequence of a 529 bp repeat element and another set of primers was utilised for the surface antigen protein-1 gene.ResultsDNA extracted from 5 out of 50 tissue samples was positive for both genes by qPCR amplification.ConclusionThe 10% prevalence of Toxoplasma infection found in commercial free-range chickens raises public health issues.

Low prevalence of viable Toxoplasma gondii in swine from slaughter houses in the central of China.

Toxoplasma gondii is widely distributed and can infect many species of warm-blooded animals, including swine. This study aimed to evaluate the prevalence of T. gondii in swines from the central of China. A total of 2798 samples, including 305 hearts, 2086 diaphragms, and 407 sera were collected from different swine in Henan Province, China. The modified agglutination test was used to detect antibodies against T. gondii in sera from jugular vein blood and heart blood (cut-off: 1:25), diaphragm juice (cut-off: 1:10). T. gondii DNA was screened from the digestive fluids of all diaphragm tissue samples and seropositive hearts, and attempt to isolate viable T. gondii strain by bioassay in mice. A total of 9.94% (278/2798) swine tested positive for T. gondii antibodies. Region, but not gender, was associated with T. gondi seropositivity in swine. T. gondii nucleic acid was not found in the tissue digestive fluids (2090 swines). Three groups of mice showed T. gondii antibodies after having been bioassayed with diaphragm samples (n=81, which came from 2090 swine). No viable T. gondii strain was isolated from muscle of swine. This is the first large-scale survey T. gondi infection in swine from the central of China. Overall, the prevalence of viable T. gondii in swine was low. Nevertheless, T. gondii infection is present in swine from the central of China. Consumers may acquire T. gondii infection from ingestion of raw or undercooked pork.

Molecular Study of Toxoplasma gondii Isolates Originating from Humans and Organic Pigs in Belgium

Toxoplasma gondii is a worldwide prevalent, zoonotic parasite of major importance for public health, which can infect any warm-blooded animal species, including humans. Humans can get infected by consumption of meat from a chronically infected animal, by ingestion of sporulated oocysts (resulting from the sexual replication in felids), via contaminated water, soil, or vegetables, and by vertical transmission via the placenta. Infection through meat consumption is estimated to be one of the main sources of human toxoplasmosis cases in developed countries, and more specifically pork is considered to be responsible for 41% of foodborne human toxoplasmosis cases in the United States. To better assess the role of pork as a source of T. gondii infection in humans in Belgium, parasites were isolated from pigs to compare with human clinical isolates in a molecular epidemiological study. A positive result was obtained by magnetic capture-quantitative polymerase chain reaction for T. gondii in 14 out of the 92 hearts sampled during 2016 and 2017 from pigs raised in organic farms. From 9 of these 14 samples, parasites were isolated by mouse bioassay, demonstrating the presence of viable T. gondii in animals intended for human consumption. When genotyped and compared with 15 human isolates obtained during 2015 and 2016, a highly related structured population was demonstrated. Overall, these findings demonstrate the presence of infectious T. gondii in pigs intended for human consumption. Therefore, a potential transmission of T. gondii strains from pigs to humans could occur. However, both species could also be infected via a common source of infection such as oocysts. Furthermore, Belgium does not have an official surveillance program for T. gondii in human cases or food-producing animals; as a consequence, the detection of the infection source of a patient is very rare. Overall, this study reinforces the identification of pork as a potential risk for the consumers.

Systemic Toxoplasmosis in Kittens

Background: Toxoplasmosis is a worldwide disease that affects virtually all species of warm-blooded animals. The felids, domestic and wild, are considered the definitive hosts of the protozoan. In Brazil, Toxoplasma gondii infection has been diagnosed in horses, goats, primates, dogs and cats. In the backlands of Paraíba, the disease has been sporadically reported affecting dogs with canine distemper and swine, but cases of systemic toxoplasmosis in cats have not yet been described. The aim of the present study was to describe the main epidemiological, clinical and anatomopathological aspects of two cases of systemic toxoplasmosis in kittens.Cases: Two kittens were affected with three (cat 1) and six (cat 2) months old, females, and crossbreed. The kittens had not been vaccinated or dewormed, and were raised with other cats in a peridomiciliary regime in a rural area in the backlands of Paraíba. Cat 1 was thin, apathetic, dehydrated, tachypneic and with pale mucous membranes. Cat 2, showed inappetence, apathy, jaundice, fever, dehydration, dyspnea and abdominal breathing pattern. At necropsy, non-collapsed, shiny, reddish lungs with multifocal whitish areas, punctuated or nodular, measuring from 0.1 to 0.3 cm in diameter, were found on the pleural surface and parenchyma. The livers were pale, with lobular pattern accentuation, and reddish depressed multifocal areas randomly distributed on the capsular surface. Histologically, multifocal to coalescent areas of necrosis, moderate (cat 1) or marked (cat 2), associated with intralesional bradyzoites and tachyzoites and variable lymphoplasmacytic infiltrate were observed. In cat 2, numerous bradyzoites were visualized in the gray matter of the left cerebral hemisphere (temporal and parietal lobes), sometimes associated with a moderate lymphoplasmacytic inflammatory infiltrate. In the perivascular spaces of the cerebral cortex, discrete inflammatory lymphoplasmacytic infiltrate (perivascular cuffs) were observed. Immunohistochemistry for T. gondii revealed strong immunolabelling of the parasitic organisms.Discussion: The diagnosis of systemic toxoplasmosis was established based on anatomopathological findings and histomorphological characteristics of the agent, being confirmed by immunohistochemistry. The systemic disease occurs most often in young animals, especially immunocompromised or immunologically immature neonates. In these kittens, it was not possible to determine the presence of an intercurrent immunosuppressive condition; however, both animals were kept in the peridomiciliary regime and were in contact with other cats, which may have acted as a source of infection. Besides, both kittens were raised in rural environments, condition that associated with the usual predatory behavior of this species may have favored the ingestion of infected intermediate hosts. The clinical signs of the disease vary considerably depending on the location and severity of the lesions. Infection in cats usually is asymptomatic or promotes self-limiting diarrhea as a result of protozoal enteroepithelial replication; but in some cases the protozoan can spread to other tissues, determining the occurrence of necrotic processes, dysfunction and clinical manifestations. Systemic toxoplasmosis occurs sporadically in kittens in the backlands of Paraíba, with pulmonary and hepatic clinical manifestations. The histopathological findings are characterized by tissue necrosis and lymphoplasmacytic inflammation associated with intralesional protozoa. The diagnosis can be established based on the histomorphologic characteristics of the agent and confirmed by immunohistochemistry.

Evaluation of Protective Immune Response Induced by a DNA Vaccine Encoding GRA8 against Acute Toxoplasmosis in a Murine Model.

Toxoplasma gondii is an apicomplexan zoonotic protozoan parasite that infects most species of warm-blooded animals, including humans. The heavy incidence and severe or lethal damage caused by T. gondii infection clearly indicate a need for the development of an effective vaccine. T. gondii GRA8 is a member of the dense granules protein family and is used as a marker of acute infection. In the present study, we evaluated the protective immunity induced by DNA vaccination based on a recombinant eukaryotic plasmid, pDsRed2-GRA8, against acute toxoplasmosis in mice. BALB/c mice were intramuscularly immunized with the pDsRed2-GRA8 plasmid and then challenged by infection with the highly virulent GFP-RH strain of T. gondii. The specific immune responses and protective efficacy against T. gondii of this vaccine were analyzed by measuring cytokine and serum antibody titers, splenocyte proliferation assays, and the survival times of mice after challenge. Our results showed that mice immunized with pDsRed2-GRA8 demonstrated specific humoral and cellular responses, induced higher IgG antibody titers with predominant IgG2a production; increased levels of IL-10, IL-12 (p70), IFN-γ, TNF-α, and splenocyte proliferation; and prolonged survival times compared to those of control mice. The present study showed that DNA immunization with pDsRed2-GRA8 induced humoral and cellular immune responses, and all immunized mice showed greater Th1-type immune responses and longer survival times than those of control mice. These results indicated that T. gondii GRA8 DNA immunization induces a partial protective effect against acute toxoplasmosis.

Population sensitivities of animals to chronic ionizing radiation-model predictions from mice to elephant

Model predictions of population response to chronic ionizing radiation (endpoint ‘morbidity’) were made for 11 species of warm-blooded animals, differing in body mass and lifespan – from mice to elephant. Predictions were made also for 3 bird species (duck, pigeon, and house sparrow). Calculations were based on analytical solutions of the mathematical model, simulating a population response to low-LET ionizing radiation in an ecosystem with a limiting resource (Sazykina, Kryshev, 2016). Model parameters for different species were taken from biological and radioecological databases; allometric relationships were employed for estimating some parameter values. As a threshold of decreased health status in exposed populations (‘health threshold’), a 10% reduction in self-repairing capacity of organisms was suggested, associated with a decline in ability to sustain environmental stresses. Results of the modeling demonstrate a general increase of population vulnerability to ionizing radiation in animal species of larger size and longevity. Populations of small widespread species (mice, house sparrow; body mass 20–50 g), which are characterized by intensive metabolism and short lifespan, have calculated ‘health thresholds’ at dose rates about 6.5–7.5 mGy day−1. Widespread animals with body mass 200–500 g (rat, common pigeon) – demonstrate ‘health threshold’ values at 4–5 mGy day−1. For populations of animals with body mass 2–5 kg (rabbit, fox, raccoon), the indicators of 10% health decrease are in the range 2–3.4 mGy day−1. For animals with body mass 40–100 kg (wolf, sheep, wild boar), thresholds are within 0.5–0.8 mGy day−1; for herbivorous animals with body mass 200–300 kg (deer, horse) – 0.5–0.6 mGy day−1. The lowest health threshold was estimated for elephant (body mass around 5000 kg) - 0.1 mGy day−1. According to the model results, the differences in population sensitivities of warm-blooded animal species to ionizing radiation are generally depended on the metabolic rate and longevity of organisms, also on individual radiosensitivity of biological tissues. The results of ‘health threshold’ calculations are formulated as a graded scale of wildlife sensitivities to chronic radiation stress, ranging from potentially vulnerable to more resistant species. Further studies are needed to expand the scale of population sensitivities to radiation, including other groups of wildlife - cold-blooded species, invertebrates, and plants.

Role of an estradiol regulatory factor-hydroxysteroid dehydrogenase (HSD) in Toxoplasma gondii infection and pathogenicity

Toxoplasma gondii is an apicomplexan parasite that infects most species of warm-blooded animals, including humans, and causes abortions and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, while the hormones progesterone and estradiol simultaneously increase. Thus, it has been suggested that these hormones could affect parasite reproduction. This study was mainly focused on an estradiol regulatory factor-Hydroxysteroid dehydrogenase (HSD) gene in T. gondii.Our data showed that estradiol promoted Pru (Type II) and VEG (Type III) infection and thus significantly contributed to the pathogenicity of T. gondii in mice. Subsequently, we found that this phenomenon may relate to the interplay of T. gondii and estradiol. We reported that estradiol can enter T. gondii tachyzoites. Bioinformatics analysis showed that T. gondii may have a residual estradiol metabolism-related gene HSD. To verify the gene function, HEK293T cells were transiently transfected with Tg-HSD and gene expression was induced. Then, HPLC (high-performance liquid chromatography) analysis showed that Tg-HSD can efficiently transform estrone into estradiol. Moreover, Tg-HSD −overexpressing parasites showed significantly enhanced pathogenicity and upregulation of estradiol levels in mice. In conclusion, estradiol can promote T. gondii infection in vitro and in vivo, and this may be related to its Tg- HSD gene.

Antibody Detection, Isolation, Genotyping, and Virulence of Toxoplasma gondii in Captive Felids from China.

The felids are the only definitive hosts of Toxoplasma gondii, which could excrete oocysts into the environment and provide an infection source for toxoplasmosis in various warm-blooded animal species, particularly the captive felids that live close to human communities. The infection rate of the captive felids is a perfect standard in detecting the presence of Toxoplasma gondii oocysts in the environment. In this study, sera or tissue samples from zoo (1 young tiger, 2 adult tigers, 6 young lions), farm (10 masked palm civets), and pet hospital (28 cats) from Henan Province (China) were collected. The sera (n = 47) were tested for immunoglobulin G (IgG) antibodies against T. gondii by using modified agglutination test (MAT), whereas the hearts tissue (n = 40) were bioassayed in mice to isolate T. gondii strains. The genotype was distinguished by using PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, GRA6, BTUB, L358, c22-8, PK1, c29-2, and Apico). The detection rate for the T. gondii antibody in captive felids was 21.3% (10/47). One viable T. gondii strain (TgCatCHn4) was obtained from a cat heart tissue, and its genotype was ToxoDB#9. The oocysts of ToxoDB#9 were collected from a T. gondii-free cat. The virulence of TgCatCHn4 was low and no cysts were detected in the brain of mice at 60 days post-inoculation. The finding of the present study suggested a widespread exposure of T. gondii for felids in Henan Province of central China, particularly those from the zoological gardens and homes. ToxoDB#9 was the predominant strain in China. Preventive measures against T. gondii oocyst contamination of various components of the environment should thus be implemented, including providing pre-frozen meat, well-cooked cat food, cleaned fruits and vegetables, monitoring birds and rodents, inactive T. gondii oocysts in felids feces, and proper hygiene.

A comparison between serological and molecular tests in diagnosis of Toxoplasma gondii infection among stray cats in Ahvaz, southwestern Iran

Toxoplasma gondii infects all species of warm-blooded animals, including humans, and domestic cats and other felidae are its definitive hosts. The aim of the present survey was to compare serological and molecular tests in accurate diagnosis of T. gondii infection among stray cats in Ahvaz, Iran. A total of 100 cats were examined for the detection of serum antibodies against T. gondii (chronic phase) by enzyme-linked immunosorbent assay (ELISA) and modified agglutination test (MAT) and for the presence of antigen in the blood (active phase) by polymerase chain reaction (PCR). The studied cats were divided into seven age groups. According to the obtained results from ELISA, MAT, and PCR, the prevalence rates of T. gondii infection were 30%, 39%, and 8%, respectively. Kappa test showed that there was a good agreement between ELISA and MAT results (0.80), but it was obtained 0.24 for MAT and PCR and 0.34 for ELISA and PCR, indicating a fair agreement between them. The seroprevalence of this parasite was 53.33% and 48.71% in male cats and 46.66% and 51.28% in females based on ELISA and MAT, respectively. Gender did not significantly affect the prevalence of this infection (P>0.05), but there was a significant difference between age groups, with the highest rate belonging to cats aged less than three years (P<0.05). It can be concluded that the serologic tests such as ELISA and MAT have a good agreement in diagnosis of toxoplasmosis. Our findings showed that a considerable percentage of the cats were infected with chronic form of toxoplasmosis.

Immuno-Efficacy of a T. gondii Secreted Protein with an Altered Thrombospondin Repeat (TgSPATR) As a Novel DNA Vaccine Candidate against Acute Toxoplasmosis in BALB/c Mice.

Toxoplasma gondii (T.gondii) is distributed worldwide and infects most species of warm-blooded animals, including humans. Toxoplasmosis has serious consequences, especially in people with an impaired or immature immune system. Thus, an effective vaccine is urgently required. Secretory microneme proteins are essential for the adhesion and invasion of T. gondii. The gene encoding the microneme protein, T. gondii secreted protein with an altered thrombospondin repeat (TgSPATR), we constructed a recombinant eukaryotic plasmid, pVAX1-TgSPATR, as a DNA vaccine, injected it intramuscularly into BALB/c mice and evaluated the induced immune response. Lymphocyte proliferation assays, cytokine (IFN-γ, IL-2, IL-4, IL-10), and antibody determinations showed that mice immunized with pVAX1-TgSPATR produced humoral and mixed Th1/Th2 type cellular immune responses. The survival times of mice immunized with pVAX1-TgSPATR were also significantly prolonged (15.7 ± 1.42 days) compared with control groups, which died within 7 days of challenge (p < 0.05). The current study indicated that pVAX1-TgSPATR induce a T. gondii specific immune response and might be a promising vaccine candidate against toxoplasmosis. To the best of our knowledge, this is the first report to evaluate the immunoprotective value of TgSPATR against T. gondii.

The Change of a Medically Important Genus: Worldwide Occurrence of Genetically Diverse Novel Brucella Species in Exotic Frogs.

The genus Brucella comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for Brucella. In this study, however, we show that novel Brucella species are distributed among exotic frogs worldwide. Comparative recA gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical Brucella species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like B. inopinata, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical Brucella species revealed additional genetic material, absent from classical Brucella species but present in Ochrobactrum, the closest genetic neighbor of Brucella, and in other soil associated genera of the Alphaproteobacteria. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical Brucella species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic Brucella with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer.

Evaluation of Protective Immune Responses Induced by Recombinant TrxLp and ENO2 Proteins against Toxoplasma gondii Infection in BALB/c Mice.

Toxoplasma gondii is an obligate intracellular parasitic protozoan that can infect almost all species of warm-blooded animals. As any chemical-based drugs could not act against the tissue cyst stage of T. gondii, vaccination may be one of the ideal control strategies. In the present study, two new vaccine candidates, named TgENO2 and TgTrxLp, were purified from Escherichia coli with pET-30a(+) expression system and then were injected into BALB/c mice to evaluate the protective efficacy against acute and chronic toxoplasmosis. The results showed that both the recombinant proteins, either alone or in combination, could elicit strong humoral and cellular immune responses with a higher level of IgG antibodies, IFN-γ, IL-2, CD4+, and CD8+ T cells as compared to those in mice from control groups. After acute challenge with tachyzoites of the GJS strain, mice immunized with rTgTrxLp (8 ± 2.77 d), rTgENO2 (7.4 ± 1.81 d), and rTgTrxLp + rTgENO2 (8.38 ± 4.57 d) proteins showed significantly longer survival time than those that received Freund's adjuvant (6.78 ± 2.08 d) and PBS (6.38 ± 4.65 d) (χ 2 = 9.687, df = 4, P = 0.046). The protective immunity of rTgTrxLp, rTgENO2, and rTgTrxLp + rTgENO2 proteins against chronic T. gondii infection showed 69.77%, 58.14%, and 20.93% brain cyst reduction as compared to mice that received PBS. The present study suggested that both TgENO2 and TgTrxLp were potential candidates for the development of multicomponent vaccines against toxoplasmosis.

Current progress toward vaccines against Toxoplasma gondii

Toxoplasma gondii is an intracellular protozoan parasite that can infect many warm-blooded animal species and humans. Despite substantial knowledge of the biology, epidemiol- ogy, and host-pathogen interactions of T. gondii, there are still very few effective control strategies to prevent oocyst shedding in cats, tissue cysts in livestock for consumption, and infection and disease in humans. This article reviews current progress and targets for vaccination against T. gondii.