Experimental Toxocara cati infection in gerbils and rats

Mongolian gerbils and Wistar rats were inoculated orally with 240 and 2,500 Toxocara cati embryonated eggs, respectively, to evaluate the larval recovery in different tissues and organs, such as the liver, lungs, heart, kidney, and skeletal muscles after 5, 30, 49, 70, and 92 days post-infection (PI). Larval recovery rates were 1.7-30.0% in Mongolian gerbils on days 5-92 PI and 0.2-3.8% in rats on the same days. These results indicate that Mongolian gerbils and Wistar rats are suitable experimental paratenic hosts for the study of neurological toxocariasis as well as visceral toxocariasis.     

Toxocara cati: an underestimated zoonotic agent

The role of Toxocara cati as a zoonosis is reviewed. It is suggested that, despite case histories of human infection in the literature, historical factors have led to T. cati being under-recognized as a zoonosis, particularly when compared with the prominence given to Toxocara canis in dogs. Differentiation of the two infections remains challenging even today. It is recommended that further work be conducted to facilitate differentiation so that the importance of T. cati as a zoonosis can be clearly defined.     

Longevity of Toxocara cati Larvae and Pathology in Tissues of Experimentally Infected Chickens

This study was conducted to determine the distribution patterns and duration of stay of Toxocara cati larvae in organs of chickens and to investigate chronic phase and potential zoonotic risk of toxocariasis in chickens. Chickens were orally infected with 1,000 embryonated T. cati eggs and necropsied 240 days post-infection. Organs of the chickens were examined at gross and microscopic levels; tissues were digested to recover larvae. Peribronchiolitis with infiltration of lymphocytes, and hyperplasia of bronchiolar associated lymphatic tissues (BALT) and goblet cells, were evident in the lungs of infected chickens. There were mild hemorrhages and infiltration of lymphocytes and a few eosinophils in the meninges. Larvae were recovered from 30% of the exposed chickens. Larvae recovery indicated that T. cati larvae stay alive for at least 240 days in the chicken brain. Therefore, chickens may potentially act as a paratenic host in nature and transfer T. cati larvae to other hosts.     

Loop-mediated isothermal amplification assay for detection and discrimination of Toxocara canis and Toxocara cati eggs directly from sand samples

We developed a novel and simple method, using loop-mediated isothermal amplification (LAMP), for the detection and discrimination of Toxocara canis and Toxocara cati eggs. The new method employs 4 steps: (1) concentration of Toxocara eggs in a small amount of sand; (2) dissolution of the proteinaceous membrane of eggs and simultaneously separation of them from the sand using NaClO treatment; (3) extraction of DNA using NaOH treatment; and (4) detection of T. canis / T. cati DNA using a LAMP assay. All these steps are fast, easy to perform, and do not require expensive equipment or reagents. The novel method was tested both experimentally and in a field study. In the laboratory, we could reliably detect as few as 3 T. canis eggs in artificially contaminated sand, if the experiment was repeated twice. In the field trial, we were able to detect T. cati DNA from 4 natural sandpits having moderate to heavy contamination, although not in a single lightly contaminated sandpit. All of the examined sandpits were found to be contaminated with eggs of T. cati, but none appeared to contain T. canis. Our new method could extract DNA from T. canis and T. cati eggs directly from sand samples as well as detect and distinguish these 2 species in a few easy steps, with markedly reduced time and expense.     

A survey study on gastrointestinal parasites of stray cats in northern region of Nile delta, Egypt

A survey study on gastrointestinal parasites in 113 faecal samples from stray cats collected randomly from Kafrelsheikh province, northern region of Nile delta of Egypt; was conducted in the period between January and May 2010. The overall prevalence was 91%. The results of this study reported seven helminth species: Toxocara cati (9%), Ancylostoma tubaeforme (4%), Toxascaris leonina (5%), Dipylidium caninum (5%), Capillaria spp. (3%), Taenia taeniformis (22%) and Heterophyes heterophyes (3%), four protozoal species: Toxoplasma gondii (9%), Sarcocyst spp. (1%), Isospora spp. (2%) and Giardia spp. (2%) and two arthropod species; Linguatula serrata (2%) and mites eggs (13%). The overall prevalence of intestinal parasites may continue to rise due to lack of functional veterinary clinics for cat care in Egypt. Therefore, there is a need to plan adequate control programs to diagnose, treat and control gastrointestinal parasites of companion as well as stray cats in the region.     

Observations on Toxocara pteropodis infections in mice

Infection in mice with Toxocara pteropodis was investigated. In mice fed infective eggs, third-stage larvae hatched out and penetrated the mucosa, predominantly that of the lower intestine. They travelled via the portal vein to the liver, where they remained at least 14 months. They grew in length from 430 +/- 15 micron, at three days post infection (p.i.), to 600 +/- 50 micron, at six to nine weeks p.i., after which time growth ceased. Blood eosinophilia appeared at 28 days p.i., and eosinophil levels continued to rise gradually beyond this time. In female mice the larvae did not migrate from the liver in response to pregnancy or lactation. When infective eggs were inoculated subcutaneously or intra-peritoneally, larvae hatched out and ultimately appeared in the liver in larger numbers than seen with oral infections.     

Survey of Campylobacter jejuni in stray cats in southern Italy

Aim: To evaluate the presence of thermotolerant Campylobacter spp. in stray cats in southern Italy. Methods and Results: One hundred and thirteen animals were trapped in two different environments (urban area, harbour area) of the city of Naples. From each cat, rectal swabs were collected. The samples were processed in order to detect thermotolerant Campylobacter spp. by culture methods. The positive samples were then confirmed by multiplex polymerase chain reaction. Campylobacter jejuni was isolated from 19/113 (16·8%) stray cats, whereas Campylobacter coli was not isolated. The cat data (age, environment and sex) were analysed by two statistical analyses using the C. jejuni status (positive/negative) as a dependent variable. As regards statistical regression model results, age and environment were risk factors for C. jejuni positivity. In particular, cats older than 1 year had a significantly higher risk of being positive for C. jejuni than cats aged up to 1 year (OR = 10·440; P = 0·000). Moreover, cats living in the harbour area had a significantly higher risk to be a carrier of C. jejuni than cats living in urban area (OR = 17·911; P = 0·008). Conclusion: The findings of the present survey confirm stray cats as potential carriers of C. jejuni. Significance and Impact of the Study: This is the first study on the prevalence of C. jejuni in stray cats in Europe.     

Prevalence of Toxoplasma gondii in stray cats of Gyeonggi-do, Korea

Toxoplasma gondii is an obligate intracellular zoonotic protozoan with a worldwide distribution. It infects humans as well as a broad spectrum of vertebrate hosts. Cats and wild felidae play crucial roles in the epidemiology of toxoplasmosis. This study was performed to survey the prevalence of T. gondii infection among stray cats in the Gyeonggi-do, Republic of Korea. A total of 174 stray cat blood samples were collected from Gwacheon-si (n=20), Bucheon-si (82), and Yangju-si (72). Positive sera for T. gondii were identified in 14 samples (8.1%) exclusively via the latex agglutination test, 28 (16.1%) via ELISA, and 23 (13.2%) via PCR analysis. The overall infection rate of female stray cats (29.2%) presented as higher than that of male cats (24.0%). This study suggests that T. gondii is widespread in the stray cat population of Gyeonggi-do, Korea. It is urgently needed to control urban stray cat population and to reduce the risk of zoonotic transmission of toxoplasmosis to other animal hosts and humans.     

Utilizing a polymerase chain reaction method for the detection of Toxocara canis and T. cati eggs in soil

A polymerase chain reaction (PCR) technique has been used for the differentiation of T. canis and T. cati eggs isolated from soil and previously identified from microscopical observations. The method, using specific primers for the identification of the two Toxocara species, was assessed in both the field and laboratory. Successful results were obtained when only a single or large numbers of eggs were recovered from 40 g soil samples. The method is sensitive, allows analysis of material independent of the stage of egg development and can be adapted for the recovery of other species of parasites from soil.     

Seroprevalence of Toxocara canis antibodies in humans in northern Jordan.

Sera of 699 individuals, aged between 5-24 years, from the Irbid area, Jordan, were tested for Toxocara canis antibodies using an ELISA-IgG test. Crude prevalence was 10.9% (76 of 699) but age-adjusted prevalence was 14.3%. The highest prevalence was observed in females aged 5-9 years, 23.3% (7 of 30), and males of 15-19 years of age, 19.5% (16 of 82). The lowest prevalence was observed in females aged 20-25 years, 5.2% (8 of 155). Significant differences (P < 0.05) between the prevalences of the toxocaral antibodies in males and females were observed in the age groups 5-9, 15-19 and 20-24 years. The trend of prevalence in relation to age was different according to sex.     

Oocyst-induced Toxoplasma gondii infections in cats

To investigate the oocyst-induced cycle with a 21+ day prepatent period, 32 cats were fed 5 x 10(5) to 2 x 10(7) sporulated oocysts of Toxoplasma gondii and necropsied between 4 hr and 41 days thereafter. The presence of the earliest stages in 7 cats was tested in mice. The tissues of 25 cats were studied histologically; 17 were bioassayed by feeding them to cats to determine, by the length of the prepatent period, whether bradyzoites were present. Based on previous studies, a short (3-10 days) prepatent period indicated that bradyzoites were present in an oral inoculum and a long (greater than 21 days) prepatent period indicated the presence of tachyzoites only. Tissues from 14 cats were also bioassayed in mice for the presence of bradyzoites, using their resistance to pepsin as indicator. Six were studied by both methods. Based on these criteria, tachyzoites predominated in extraintestinal organs during the first 14 days after infection. They were found as early as 4 hr in mesenteric lymph nodes where their number reached 10(4) after 6 and 9 days; they were present after 1 day in all levels of the small intestine and after 6 days in the liver, lung, and blood. Bradyzoites were first detected 10 days after oocyst feeding; they predominated by the third week of infection and were present up to 41 days. Enteroepithelial stages were found histologically only in 2 cats, 24 and 41 days after inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pathological and haematological responses of cats experimentally infected with Toxocara canis larvae

Responses of eight adult cats to one or two infections with larvae of Toxocara canis were studied up to 39 days post infection (DPI). Clinically, all cats remained normal throughout the study. The major necropsy finding was multifocal, white to grey nodules mainly within the liver, lungs and kidneys; live larvae were found in liver nodules. Histologically, the nodules were eosinophilic granulomas. Granulomas containing a larval section were observed mainly within the liver. All infected cats had variably severe, eosinophilic arteritis and bronchiolitis and medial hypertrophy and hyperplasia of the pulmonary arteries. No inflammatory eye lesions were detected. Circulating eosinophil levels increased in all infected cats; peak values of 15,790 and 10,050 eosinophils microliters-1 were observed at 25 or 32 DPI in cats receiving a single or double infection, respectively. Bone marrow of all infected cats exhibited marked eosinophilic hyperplasia which did not correlate with the level of circulating eosinophilia. Thus, infection of cats by the larvae of T. canis causes disseminated eosinophilic and granulomatous disease with marked pulmonary artery and airway lesions.     

Ocular larva migrans caused by Toxocara cati in Mongolian gerbils and a comparison of ophthalmologic findings with those produced by T. canis

To elucidate the pathogenic potential of Toxocara cari, we observed the ophthalmologic changes of the fundi in Mongolian gerbils, Meriones unguiculatus, after oral inoculation of 17 embryonated eggs/g body weight. Ophthalmic conditions in 8 T. cati-infected gerbils were monitored using an ophthalmoscope from day 0 to day 156 and were compared with those of 57 T. canis-infected gerbils. The results showed that T. cati larvae migrated into the eye of the gerbil and then elicited ophthalmic changes, including retinal (25%) and vitreous (50%) hemorrhaging, vasculitis (37.5%), and exudative lesions (25%). Lesions were less prevalent, however, in T. cati-infected than in T. canis-infected gerbils. Unlike in T. canis-infected gerbils, the hemorrhagic lesions did not reappear in T. cati-infected gerbils after they were absorbed. These findings suggested that T. cati larvae are a potentially hazardous pathogen for ocular toxocariasis and that Mongolian gerbils infected with T. cati may be a useful model for the study of human ocular toxocariasis caused by T. cati. This is the first study to report that T. cati larvae can induce ophthalmic lesions in the retina of gerbils.     

Patterns of parasitic infections in faecal samples from stray cat populations in Qatar

The parasite fauna of stray cat populations, comprising mainly helminth parasites, is described for the first time from the arid environment of the Qatar peninsula. During the winter and summer months of 2005, 824 faecal samples were examined from six sites in Qatar. Up to seven species of parasites were identified, six of which were nematodes - Strongyloides stercoralis as the most prevalent (18.4%), followed by Aelurostrongylus abstrusus (7.5%), Toxocara cati (6.1%), Ancylostoma tubaeforme (5.9%) and Physaloptera sp. (4.8%) and Toxascaris leonina (0.7%) - and one sporozoan species, Isospora felis (0.5%). Unidentified cestode eggs were also recovered from 10.7% of samples examined. The parasite species were found to be highly overdispersed in faecal samples from all sites, whereas the prevalence and intensity of infections were influenced by site and season. Infection levels tended to be higher during the winter season, especially in the case of A. abstrusus and A. tubaeforme, when conditions of temperature and humidity were more favourable for the development of egg and/or larval stages of parasites compared with the extremely hot and dry summer months. The results are discussed in relation to the distribution of the cat population in the vicinity of Doha and its outskirts and the potential threat of parasite transmission to human communities in Qatar.     

Spacing pattern in a social group of stray cats: effects on male reproductive success

Reproductive consequences of male spacing patterns have received relatively little attention in nonterritorial mammals, in particular in group-living species, where most studies have focused on the relation between social rank and reproductive success. We investigated the effects of spacing pattern on male reproductive success within a social, nonterritorial, promiscuous population of stray cats, Felis catus. Male home ranges overlapped home ranges of many females, consistent with a promiscuous mating system. Furthermore, males with the largest home ranges included the most female home ranges; they successfully reproduced with these females and had the highest reproductive success. Home range size predicted male reproductive success even when controlling for the effect of social rank. However, males also reproduced with females whose home range did not overlap their home range, suggesting that males can make quick excursions outside their home range to find new mating opportunities. We conclude that, in group-living situations, a male's ability to maintain a large home range may be one of the principal causes of variation in mating success in the stray cat.