Further evidences on a new diagnostic approach for monitoring human Leishmania (L.) infantum chagasi infection in Amazonian Brazil

This was a prospective study carried out during a period over 2 years (May/2006–September/2008) with a cohort of 1,099 individuals of both genders, aged 1 year old and older, from an endemic area of American visceral leishmaniasis (AVL) in Pará state, Brazil. The object was to analyze the prevalence and incidence of human Leishmania (L.) infantum chagasi infection as well as the dynamics evolution of its clinical-immunological profiles prior identified: (1) asymptomatic infection (AI); (2) symptomatic infection (SI = AVL); (3) sub-clinical oligosymptomatic infection (SOI); (4) sub-clinical resistant infection (SRI) and; (5) indeterminate initial infection (III). The infection diagnosis was performed by using both the indirect fluorescent antibody test and leishmanin skin test with amastigotes and promastigotes antigens of L. (L.) i. chagasi, respectively. A total of 187 cases of infection were recorded in the prevalence (17%), 117 in the final incidence (6.9%), and 304 in the accumulated prevalence (26.7%), which provided the following distribution into the clinical-immunological profiles: AI, 51.6%; III, 22.4%; SRI, 20.1%; SOI, 4.3%; and SI (=AVL), 1.6%. The major finding regarding the dynamics evolution of infection was concerned to III profile, from which the cases of infection evolved to either the resistant profiles, SRI (21 cases, 30.8%) and AI (30 cases, 44.1%), or the susceptible SI (=AVL; 1 case, 1.5%); the latter 16 cases remained as III till the end of the study. These results provided the conclusion that this diagnostic approach may be useful for monitoring human L. (L.) i. chagasi infection in endemic area and preventing the high morbidity of severe AVL cases.     

Seroepidemiology of Toxoplasma gondii, Neospora caninum, and Leishmania spp. infections and risk factors for cats from Brazil

The seroprevalence of infection by Toxoplasma gondii, Neospora caninum, and Leishmania spp. was detected through an indirect immunofluorescence in 70 cats from the Andradina Municipality, S?o Paulo State, Brazil. Anti-T. gondii antibodies (titer >64) were detected in 15.7% (11/70) of animals, whereas positivity for N. caninum (titer 16) was not observed in any animal. Of the cats from urban and rural areas, 10.4% (5/48) and 27.2% (6/22) were positive for T. gondii, respectively. Breed, age, food, and contact with animals of other species were significant for considering the positivity for T. gondii (P ≤ 0.0001). Cats having access to streets (17.1%, 11/64), cats cohabiting with rats (19.6%, 10/51), and cats feeding on homemade food and raw milk (27.2%, 6/22) were positive for T. gondii. In addition, 4.2% (3/70) of the cats were positive for Leishmania spp. by ELISA technique and negative by IFAT without coinfection with T. gondii and Leishmania spp. There was no serological positivity against feline immunodeficiency virus or feline leukemia virus. In conclusion, T. gondii infection in part of the feline population from Andradina is not linked to immunosuppressions or coinfections but probably to postnatal infection in association with the type of diet and presence of rats.     

Lectin-binding properties of different Leishmania species

Carbohydrate cell-surface residues on stationary promastigotes of 19 isolates of Leishmania were studied with a panel of 27 highly purified lectins, which were specific for N-acetyl-D-glucosamine, D-mannose, L-fucose, D-galactose, N-acetyl-D-galactosamine, and sialic acid. The specificity of the cell-surface carbohydrates was analyzed by agglutination and radioiodinated lectin-binding assays. L. (L.) amazonensis and L. (L.) donovani were agglutinated by 12 and 10 of the 27 lectins used, respectively. Artocarpus integrifolia lectin (Jacalin) was incapable of agglutinating the tested species of the donovani complex, and this result was confirmed by radioiodinated Jacalin-binding assays. Jacalin had an average of 3.8 × 10⁶ receptors/L. (L) amazonensis promastigote and bound with an association constant of 5 × 10⁶ M ⁻¹. Received: 14 September 1998 / Accepted: 27 January 1999     

Evidence of Increased Risk for Leishmania infantum Infection Among HIV-Seronegative Intravenous Drug Users from Southern Spain

 To assess the prevalence of markers of Leishmania infection, 93 intravenous drug users and 77 non-users of intravenous drugs underwent a Leishmania skin test and a serum Leishmania antibody search. All participants were human immunodeficiency virus seronegative. The Leishmania skin test was positive in 24 intravenous drug users and in 10 non-users of intravenous drugs (P=0.038). Leishmania seropositivity was detected in 3 of 11 active intravenous drug users and in 3 of 82 former drug injectors (P=0.02). Positivity in the Leishmania skin test was associated with intravenous drug use (adjusted odds ratio, 2.33; 95% confidence interval, 1.03–5.24). The prevalence of Leishmania infection markers among intravenous drug users is higher than that among controls. This suggests that this parasite spreads through the sharing of needles.     

<Emphasis Type="Italic">Blastocystis hominis</Emphasis> infection in long-term care facilities in Taiwan: prevalence and associated clinical factors

Blastocystis hominis is probably the most common protozoan found in the human gut worldwide. In Taiwan, the prevalence of B. hominis infection is yet to be determined but is expected to be relatively higher among foreign workers. No data is available on the prevalence of B. hominis infection in long-term care facilities in Taiwan. This study included 713 subjects (552 residents and 161 care workers) from ten long-term care facilities in Taiwan who completed stool microscopic examinations with Merthiolate-iodine-formalin stain technique. The prevalence rate of blastocystosis was the highest among foreign and domestic care workers followed by residents (12.2%, 4.6%, and 2.7%, respectively). Older age (p = 0.04) and lower educational level (p = 0.008) were significantly associated with blastocystosis among care workers. Among residents, B. hominis infection was negatively associated with prolonged use of antibiotics within 3 months prior to examination (p = 0.05) and positively associated with tracheostomy in-place (p = 0.028). In conclusion, B. hominis infection was the most prevalent intestinal parasitic infection among both care workers and residents of long-term care facilities in Taiwan. Use of antibiotics was negatively associated with B. hominis infection among residents. Additionally, appropriate preventive measures should be implemented to older care workers with lesser educational attainment in order to reduce the risk of blastocystosis infection.     

In vitro and in vivo antileishmanial efficacy of nitazoxanide against Leishmania donovani

Control of Leishmania infection relies primarily on chemotherapy, and the current drug available for treating leishmaniasis is limited. Nitazoxanide (NTZ) is a broad spectrum antiparasitic agent with activity against protozoa, nematodes, cestodes, and trematodes. In the present study, the in vitro antileishmanial efficacy of NTZ was evaluated by incubation of Leishmania donovani promastigotes with NTZ, indicating that NTZ can affect the ultrastructure of parasite promastigote and efficiently inhibit the parasite growth. Moreover, 200 μg/ml NTZ inhibited >90% of promastigotes growth, showing similar activity of the reference drug amphotericin B (P > 0.05). Therapeutic efficacy of NTZ against L. donovani-infected BALB/c mice demonstrated that oral NTZ produced a significant reduction of parasite burden in spleen and liver from L. donovani-infected mice, compared with the untreated mice (P < 0.05). These results indicated NTZ may be a novel therapeutic drug for leishmaniasis.     

Infection level of the Asian tapeworm (<Emphasis Type="Italic">Bothriocephalus acheilognathi</Emphasis>) in the cyprinid fish, <Emphasis Type="Italic">Schizothorax niger</Emphasis>, from Anchar Lake,relative to season,sex, length and condition factor

Various studies have shown that the Asian fish tapeworm, Bothriocephalus acheilognathi causes great economic loss in hatcheries, fish farms as well as in lakes. In order to understand the seasonal variation of infection in a nutrient-enriched lake, parasitological investigation was carried out in the indigenous cyprinid fish, Schizothorax niger Heckel 1838 from September, 2008 to August, 2009. Overall, this study revealed definite seasonality of infection (p < 0.05), with greater infection in summer (prevalence = 39.5%) and lesser in winter (prevalence = 8.1%). The prevalence among different seasons revealed significant differences (p < 0.05). Sex was not an important factor influencing the prevalence of the Asian tapeworm. A strong positive correlation (Pearson’s correlation, r = 0.7; p = 0.02) between total length of S. niger and number of Asian fish tapeworms was observed. Similarly, a strong positive correlation existed between weight of fish and number of tapeworms (Pearson’s correlation, r = 0.7; p = 0.005). Prevalence and mean abundance were positively and significantly correlated with water temperature (r = 0.8, p < 0.01 and r = 0.8, p < 0.01, respectively). Thus seasonal dynamics, total length and weight of the host significantly influenced the tapeworm infection. The above findings will be useful in devising the appropriate control strategies for the Asian tapeworm in wild fish in Kashmir valley as well as in similar climatic zones of other parts of the world. Also, information from this study will be used to assess the spread and extent of B. acheilognathi which is a potential threat to the indigenous fish fauna of Anchar Lake.     

In vitro and in vivo activity of <Emphasis Type="Italic">Aloe vera</Emphasis> leaf exudate in experimental visceral leishmaniasis

The leishmanicidal activity of Aloe vera leaf exudate (AVL) has been demonstrated in promastigotes and axenic amastigotes, but its effectiveness in animal models has not been evaluated. The presence of alkaloids, triterpenes, cyanidines, proanthocyanidines, tannins, and saponins in AVL was identified. Its effectiveness in four Leishmania donovani strains was studied both in promastigotes (IC₅₀ ranged from 70–115 μg/ml) and amastigotes (IC₅₀ ranged from 3.1–11.4 μg/ml). In amastigotes, the killing by AVL was facilitated through its induction of nitric oxide in leishmania-infected macrophages. The safety index was good as AVL up to 300 μg/ml remained non-toxic to monocytes and macrophages. In a L. donovani BALB/c mouse model, oral or subcutaneous administration of AVL (15 mg/kg body weight × 5 days) reduced parasitemia by >90% in the liver, spleen, and bone marrow without impairment of hepatic and renal functions. Collectively, we conclude that AVL shows promising antileishmanial activity and may provide a new lead agent in the treatment of Leishmaniasis. Chitra Mandal and Mitali Chatterjee should be considered as joint senior authors.     

Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae–S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim–sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim–sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community.     

Immunization against leishmaniasis by PLGA nanospheres encapsulated with autoclaved Leishmania major (ALM) and CpG-ODN

Various adjuvants and delivery systems have been evaluated for increasing the protective immune responses against leishmaniasis and mostly have been shown not to be effective enough. In this study, poly(d,l-lactide-co-glycolide) (PLGA) nanospheres as an antigen delivery system and CpG-ODN as an immunoadjuvant have been used for the first time to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter of ALM + CpG-ODN-loaded nanospheres was 300 ± 128 nm. BALB/c mice were immunized three times in 3-week intervals using ALM plus CpG-ODN-loaded nanospheres [(ALM + CpG-ODN)_PLGA], ALM encapsulated PLGA nanospheres [(ALM)_PLGA], (ALM)_PLGA + CpG, ALM + CpG, ALM alone, or phosphate buffer solution (PBS). The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, was observed in mice immunized with (ALM + CpG-ODN)_PLGA. The (ALM)_PLGA, (ALM)_PLGA + CpG, and ALM + CpG were also showed a significantly (P < 0.05) smaller footpad swelling compared to the groups received either PBS or ALM alone. The mice immunized with (ALM + CpG-ODN)_PLGA, (ALM)_PLGA + CpG, and ALM + CpG showed the highest IgG2a/IgG1 ratio, interferon-γ production, and lowest interleukin-4 production compared to the other groups. It is concluded that when both PLGA nanospheres and CpG-ODN adjuvants were used simultaneously, it induce stronger immune response and enhance protection rate against Leishmania infection.     

Age-influenced population kinetics and immunological responses of <Emphasis Type="Italic">Leishmania donovani</Emphasis> in hamsters

Susceptibility of animals to infections depends upon various factors including sex and age of the host, which plays a pivotal role. In this communication, we have investigated the “intake” of Leishmania donovani infection in young (3–4 weeks old) and adult (15–16 weeks old) golden hamsters. The splenic parasite load in young hamsters on day 15 post infection (p.i.) was 54 ± 4 amastigotes/100 macrophage nuclei and increased to 106.3 ± 3.5 on day 30 p.i. However, adult group showed 2.2-(P < 0.001) and 1.75-fold (P < 0.001) lesser parasite burden on these days, respectively. But as the disease progresses further, differences in parasite burden become less significant, as revealed by comparable levels of parasite loads at 2 months p.i. Spleen weight measurements correspond to the above observations. In the young group, the levels of antileishmanial antibody rise two and 4.5 times on days 15 and 30 p.i., respectively, as compared to only 1.3 and 2.3 times increase in their respective adult counterparts. However, after 2 months of infection both groups recorded analogous (12-fold) rise in antibody levels. Both mitogenic and antigenic responses in adult hamsters were less suppressed compared to young hamsters on days 15 and 30 p.i. However, both groups exhibited highly suppressed cell-mediated immune (CMI) responses after 2 months of infection. These findings implicate that age of the host may influence the susceptibility and resistance to Leishmania infection.     

In vitro sensitivity of Blastocystis hominis to garlic, ginger, white cumin, and black pepper used in diet

To determine the growth pattern and in vitro susceptibility of Blastocystis hominis to metronidazole (MTZ), garlic, ginger, white cumin, and black pepper. Stool specimens were collected from 16 irritable bowel syndrome (IBS) and 10 controls between July–November 2010. Stool microscopy and culture for B. hominis was performed. Drug susceptibility assays was done using 0.01 and 0.1 mg/ml of MTZ, garlic, ginger, white cumin, and black pepper. Effect was assessed on B. hominis culture after 48 h. Stool DNA was extracted using stool DNA extraction kit (Qiagen) and polymerase chain reaction (PCR) done using subtype-specific sequence-tagged-site primers. B. hominis genotype 3 and coinfection of 1 and 3 tended to grow well in culture compared to isolated type 1 infection. Exposed to MTZ at a concentration of 0.01 mg/ml, 38% (6/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) of B. hominis from control (p = 0.001). When they were exposed to MTZ at 0.1 mg/ml, 56% (9/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.01). Forty-four percent (7/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) B. hominis from control when exposed to garlic at a concentration of 0.01 mg/ml (p = 0.003) and following exposure to garlic at 0.1 mg/ml, 38% (6/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.001). B. hominis isolates from IBS had a cell count of 6,625 at a MTZ concentration of 0.01 mg/ml that reduced to 1,250 as MTZ concentration was increased to 0.1 mg/ml (p = 0.08). B. hominis from IBS with a mean cell count of 3 × 10⁵ at baseline decreased to 1 × 10⁴ when exposed to garlic at 0.01 mg/ml (p < 0.001) and to 1 × 10³ (p < 0.001) when garlic was 0.1 mg/ml. B. hominis from IBS cell count decreased to 1 × 10⁵ when exposed to white cumin at 0.01 mg/ml (p = 0.01) and to 1 × 10⁵ (p < 0.001) when white cumin was 0.1 mg/ml. Exposed to black pepper at 0.1 mg/ml, cell count of B. hominis from IBS decreased to 1 × 10⁵ (p = 0.01). B. hominis from IBS decreased to 1.3 × 10⁵ exposed to ginger at 0.01 mg/ml (p = 0.001). B. hominis isolates were mostly genotypes 3, type 1 and 3 coinfection, and non-typeable B. hominis isolates. B. hominis isolates from IBS mostly genotype 1 demonstrated an increased sensitivity to garlic at 0.01 mg/ml with a B. hominis cell count of 3,714 compared to 6,142 when exposed to 0.01 mg/ml of MTZ. However, this sensitivity did not increase as garlic concentration was increased to 0.1 mg/ml, for B. hominis cell count was 6,000 compared to 1,428 as MTZ was increased to 0.1 mg/ml.     

Prevalence of toxin genes in consecutive clinical isolates of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> and clinical impact

Even if Panton–Valentine leukocidin (PVL), toxic shock syndrome toxin-1 (TSST-1), staphylococcal enterotoxins (SEB and SEC), and exfoliative toxins (ETA and ETB) may be associated with severe infections, the clinical significance of their presence in clinical isolates of Staphylococcus aureus remains poorly documented. In this study, we evaluated the prevalence of toxin genes and the relationship between their presence and the severity of infection. We screened for the presence of these six toxin genes among 186 consecutive S. aureus clinical isolates (resistant or not to methicillin) during a two-month period. We compared the toxin gene profile between strains recovered from patients presenting uncomplicated infections (n = 151) and from patients suffering from severe infections (n = 35). At least one toxin gene was detected in 55 (29.6%) isolates as follows: pvl (n = 1), tst + sec (n = 5), seb (n = 19), seb + sec (n = 1), sec (n = 28), and eta (n = 1). The proportion of toxin-producing strains among patients with uncomplicated infections (27.8%) and patients with severe infections (37.1%) was not statistically different (p = 0.3044), even if the severity of infection tended to be associated with the presence of sec (p = 0.0655). Although the prevalence of toxin genes was relatively high herein, no statistically significant association between the severity of infection and the presence of toxin genes was observed.     

A prevalence screen of MRSA nasal colonisation amongst UK doctors in a non-clinical environment

Screening for methicillin-resistant Staphylococcus aureus (MRSA) carriage in healthcare workers (HCWs) is both contentious and confounded by a lack of knowledge of background prevalence rates. This study examines prevalence of nasal MRSA carriage amongst a spectrum of medical professionals in a non-clinical environment. Medical conference attendees volunteered for screening for nasal MRSA carriage, and anonymised demographic data and attitudes towards screening were recorded. Two hundred sixty volunteers participated. One hundred seventy-three participants (67%) were from the British Medical Association′s Annual Representatives Meeting, and 87 participants (33%) were attending the Association of Surgeons in Training conference. Six (2%) participants were positive for MRSA nasal carriage (BMA = 1%, ASIT = 5%; p = 0.099). Participants from a surgical specialty (4.8%) were more likely to be MRSA positive (p = 0.039). All positive samples came from male participants (p = 0.182). However, there was no significant association with gender, seniority or country of employment and MRSA status. Routine screening for MRSA was supported by 63% of participants in HCWs; 36% had previously undergone such screening. MRSA nasal carriage rates within this cross-sectional study are lower than studies reporting carriage rates in HCWs within the clinical environment. Further research is required to examine the relationship between MRSA nasal colonisation status of a HCW and subsequent MRSA infection in patients.     

Partial anaerobiosis induces infectivity of Leishmania infantum promastigotes

Leishmania infantum stationary-phase promastigotes could acquire infectivity via preincubation in a partially anaerobic medium (95% air/5% CO₂) for 16 h before the infection, whereas promastigotes were efficiently destroyed when no CO₂ was present. Incubation of L. infantum promastigotes with additional glucose (20 and 50 mM) greatly increased infection parameters in the absence of CO₂; this is consistent with a “reverse Pasteur effect.” Results showed that culture at 33 °C permitted survival and amastigote multiplication (a nearly 10-fold increase in amastigotes as compared with those observed in 37 °C cultures). This finding was obtained with the two strains of L. infantum tested (Doba and PB75). Received: 28 November 1998 / Accepted: 17 December 1998     

Pulmonary <Emphasis Type="Italic">Mycobacterium simiae</Emphasis> infection: comparison with pulmonary tuberculosis

To identify the clinical and radiological features distinguishing Mycobacterium simiae respiratory infection from pulmonary tuberculosis, the demographics, underlying conditions, and clinical and radiological findings of 121 consecutive patients with pulmonary tuberculosis and 102 with M. simiae respiratory infection were compared retrospectively. In the M. simiae group, the patients were older (mean age 69 ± 16 years vs. 47 ± 21 years, p = 0.0001), with a female predominance (62% vs. 45%, p = 0.008). Only 4% were of Ethiopian origin compared to 25% of the tuberculosis group (p = 0.0001). M. simiae infection was associated with significantly higher rates of smoking history, underlying chronic obstructive pulmonary disease, zero human immunodeficiency virus (HIV) infection compared to 10% in the tuberculosis group (p = 0.001), blunted symptoms, and noncavitary infiltrates in the lower/middle lobes on chest X-ray. HIV-negative patients with M. simiae respiratory infection are distinguishable from patients with pulmonary tuberculosis by several demographic, clinical, and radiological features. These findings have important diagnostic and therapeutic implications.     

Association between multiple sclerosis and Candida species: evidence from a case-control study

Candida infection among multiple sclerosis (MS) patients has not been studied in depth. We determined whether there is an association between serological evidence of Candida infection and MS. Blood specimens were obtained from 80 MS patients and 240 matched controls. Immunofluorescence analysis and ELISA were used to detect Candida species antibodies and slot-blot to detect antigens. Using immunofluorescence analysis, moderate to high concentrations of serum antibodies to Candida famata were present in 30 (37.5%) MS patients vs. 30 (12.5%) controls (p < 0.001). Results for Candida albicans were 47.5% (38/80) in MS patients vs. 21.3% (51/240) in controls (p < 0.001), for Candida parapsilosis 37% (28/80) vs. 17.1% (41/240) (p < 0.001) and for Candida glabrata 46.3% (37/80) vs. 17.5% (42/240) (p < 0.001), respectively. After adjusting for age and gender, the odds ratios (95% confidence intervals) for MS, according to the presence of Candida antigens were: 2.8 (0.3–23.1, p = 0.337) for Candida famata; 1.5 (0.7–3.4, p = 0.290) for Candida albicans; 7.3 (3.2–16.6, p < 0.001) for Candida parapsilosis; and 3.0 (1.5–6.1, p = 0.002) for Candida glabrata. The results were similar after excluding ten patients on immunosuppressants. The results of this single study suggest that Candida species infection may be associated with increased odds of MS.     

Field validation of a competitive ELISA for detection of <Emphasis Type="Italic">Theileria annulata</Emphasis> infection

In previous studies, Theileria annulata surface protein (TaSP) was identified as an immunodominant antigen and successfully used to develop a recombinant-protein-based indirect enzyme-linked immunosorbent assay (ELISA) for the detection of circulating antibodies in serum of T. annulata-infected animals. To increase the specificity, a competitive ELISA (cELISA) was developed using recombinant TaSP antigen and a monoclonal antibody (1C7) specifically binding to TaSP. Since the cELISA accurately differentiated T. annulata-infected from uninfected animals, a study was performed to analyse the suitability of the cELISA in the field. For this, 230 sera with unknown status from different governorates in the north of Iraq were analysed using both the indirect and competitive ELISA and were compared. There was a significant (p < 0.5 × 10⁻¹⁹) correlation (r = 0.556) between the tests, whereby the cELISA detected more sera as negative (44/230) compared to the indirect ELISA (21/270). Accordingly, less sera were determined to be positive in the competitive (186/230) than in the indirect ELISA (209/230). Sensitivity and specificity of the cELISA taking the indirect ELISA as a reference were 84.2% and 52.4%, respectively. Accordingly, the calculated prevalence of T. annulata infection was 90.9%, and the positive predictive value was determined to be 94.6%. Taken together, the cELISA proved its suitability for field application and was found qualified for use in serological surveys to monitor the prevalence of T. annulata infection and to identify carrier animals.     

Detection of dog filariasis in Marajo Island,Brazil by classical and molecular methods

Canine filariasis in domestic and wild dogs, foxes, and wolves is caused by several species of filarids. Although these filarial species inhabit different loci in the vertebrate definitive hosts, they generally release microfilariae into the bloodstream. Data about filarial infection in dogs in Brazil, especially on the Marajo Island, is scarce. For this reason, we conducted an analysis of 188 domestic dogs within two Marajo Island municipalities. The overall prevalence of microfilaremic was 32.45%; taken by blood smear and modified Knott’s method. No significant difference of positivity between male and female was observed (X ² Yates’s correction = 0.341; p = 0.559). Significant age–infection ratios were detected (X ² = 32.943; p < 0.0001). A high occult infection was detected (53.84%). PCR of rDNA and phylogenetic tree indicated that the microfilariae and adult worms found in domestic dogs from Marajo Island were Dirofilaria immitis.     

Diagnosis of Sarcocystis cruzi, Neospora caninum, and Toxoplasma gondii infections in cattle

The aim of the study was to diagnose Sarcocystis sp. infections in cattle and to detect coinfections by Toxoplasma gondii and/or Neospora caninum. Blood, diaphragm, esophagus, and myocardium from 90 beef cattle from Argentina were collected. Histopathological, immunohistochemical, polymerase chain reaction assays, and direct microscopical examination were carried out. Sarcocysts from myocardium were measured and counted. Indirect fluorescent antibody test (IFAT) for the three protozoans was performed. Sarcocystis cruzi sarcocysts were found in 100% of myocardium samples. Sarcocysts per gram ranged from 8 to 380 with higher values found in adult cattle (p < 0.001). T. gondii and N. caninum were not detected by immunohistochemistry. T. gondii DNA was found in myocardium of 2/20 seropositive animals, while N. caninum DNA was not found. Antibodies against S. cruzi were detected in all samples, those against N. caninum in 73% and against T. gondii in 91% of the samples (IFAT titer ≥25). It is concluded that serology by IFAT is a suitable method to diagnose these protozoan infections due to its specific IgG detection; therefore, IFAT may be a useful tool to evaluate the impact of each protozoan infection in coinfected animals. Financial support for this study was provided by SeCyT through BID 1728 PICT No. 10858/8.