Seroprevalence estimation and management factors associated with high herd seropositivity for <Emphasis Type="Italic">Anaplasma marginale</Emphasis> in commercial dairy farms of Puerto Rico

A cross-sectional study was conducted to determine individual cow seroprevalence of Anaplasma marginale in adult lactating dairy cattle of Puerto Rico (PR) and to assess the associations of farm management factors on herd seroprevalence. Antibody activity against A. marginale was determined using the MSP-5 competitive enzyme-linked immunosorbent assay. Serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 3 to 100% with an overall individual cow seroprevalence for A. marginale of 27.4%. Factors associated with high herd seropositivity were pasture grazing as the main feed source (OR = 6.5, 95% CI = 1.2–34), observed monkeys on the premises (OR = 13, 95% CI = 1.2–138), use of 11% permethrin (OR = 17, 95% CI = 2.2–129), farmers who attended an acaricide certification program (OR = 0.18, 95% CI = 0.04–0.74), and lack of a fly control program (OR = 5.6, 95% CI = 1.3–24).     

<Emphasis Type="Italic">Theileria</Emphasis> (<Emphasis Type="Italic">Babesia</Emphasis>) <Emphasis Type="Italic">equi</Emphasis> and <Emphasis Type="Italic">Babesia caballi</Emphasis> Infections in Horses in Galicia,Spain

The control of equine piroplasmosis is becoming increasingly important to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Theileria equi and Babesia caballi) in Galicia, north-west Spain, and to compare haematological and serum biochemistry parameters between non-parasitaemic horses and horses parasitaemic with T. equi and B. caballi. Sixty serum samples (control group) were taken from healthy horses pastured on two farms, and examined for evidence of equine T. equi and B. caballi infection by indirect fluorescent antibody test (IFAT). Of the 60 samples, 24 (40%) and 17 (28.3%) samples were positive for T. equi and B. caballi, respectively. Twelve (20%) samples were positive for both parasites. Haematology and serum biochemistry were compared between controls and a series of 36 horses clinically affected by T. equi (25) or B. caballi (11). Compared with the healthy group, there was a 43% and 37% decrease in the haematocrit for T. equi and B. caballi infection, respectively. Parasitaemic horses presented an intense anaemia and serum biochemistry signs of liver damage. The anaemia was more severe in T. equi-infected than in B. caballi-infected horses. Our results suggest that equine piroplasmosis is widespread in the region and is a cause for concern.     

A new PCR-RFLP method for detection of <Emphasis Type="Italic">Anaplasma marginale</Emphasis> based on 16S rRNA

Species of the genus Anaplasma (Rickettsiales: Anaplasmataceae) are obligate intracellular tick borne pathogens. Three species of Anaplasma that infect cattle and sheep (A. marginale, A. centrale and A. ovis) are well recognized. Of these erythrocytic Anaplasma, A. marginale can cause diseases in the livestock with high economical losses. Species-specific PCR based on 16S rRNA gene is commonly used for detection of Anaplasma species but can not differentiate A. marginale, A. centrale and A. ovis because of sequence similarity. In this study DNA extraction was performed on 50 blood samples with presence of Anaplasma spp. in marginal point of erythrocytes in their blood smears. The extracted DNA from blood cells was analyzed by PCR and PCR-RFLP using primers derived from 16S rRNA gene and restriction endonuclease Bst1107 I. The restriction endonuclease Bst1107I only recognizes the sequence (GTATAC) in corresponding PCR product of A. marginale and cut it. The nucleotide sequence of the A. marginale 16S rRNA gene was determined and compared with the sequences of A. marginale in GenBank. The 16S rRNA of A. marginale in Iran was completely similar to the related sequence deposited in GenBank at accession number of M60313. In the present study we propose a new PCR-restriction fragment length polymorphism analysis (RFLP) method based on 16S rRNA gene for specific detection of A. marginale.     

Seroprevalence Estimation and Risk Factors for <Emphasis Type="Italic">A. marginale</Emphasis> on Smallholder Dairy Farms in Tanzania

A cross-sectional serological survey of A. marginale was conducted on 200 randomly selected smallholder farms in each of the Tanga and Iringa Regions of Tanzania between January and April 1999. Sera, from dairy cattle of all ages, sexes and breeds were tested for antibodies against A. marginale using an indirect enzyme-linked immunosorbent assay. Antibodies to A. marginale were present in cattle throughout the study areas and the overall prevalence was 20% for Tanga and 37% for Iringa. The forces of infection based on the age seroprevalence profile were estimated at 8 for Tanga and 15 for Iringa per 100 cattle years-risk, respectively. In both regions, seroprevalence increased with age (β = 0.01 and 0.017 per year of age, p < 0.005, in Tanga and Iringa, respectively). Older animals in Iringa were significantly and negatively associated with decreased seropositivity (β = −0.002, p = 0.0029). Further results of logistic regression models reveal that geographic location of animals in Tanga was associated with seropositivity (odds ratio (OR) = 2.94, p = 0.005, for Tanga Rural and OR = 2.38, p = 0.066, for Muheza). Animals acquired as a gift in Iringa had higher odds for seropositivity than brought-in cattle (OR = 2.44, p = 0.005). Our study has identified and quantified some key risk factors that can guide planners devising disease control strategies.     

Investigation of seroprevalence of <Emphasis Type="Italic">Theileria equi</Emphasis> and <Emphasis Type="Italic">Babesia caballi</Emphasis> in horses in Nigde province,Turkey

The prevalence of equine piroplasmosis caused by Theileria equi and Babesia caballi in Nigde, in central Anatolia, Turkey has remained unknown. Serum samples were obtained from a total of 125 horses and were tested for antibodies to T. equi and B. caballi using the Indirect Fluorescence Antibody Test (IFAT). Twenty-three (18.4%) horses were seropositive for equine piroplasmosis. Anti-T. equi was observed in 16 horses (12.8%) while anti-B. caballi was detected in 12 horses (9.6%). In addition, 5 serum samples were positive for both parasites. The prevalence rates of antibodies to T. equi and B. caballi for female and male horses were statistically indifferent (p = 0.19 and 0.90). The difference between the seropositivity rates to T. equi among age groups was statistically insignificant (p = 0.44) while the difference to B. caballi among age groups is statistically significant (p = 0.01). Seropositivity rates ranged from 2.9% to 25.7% for T. equi and 2.9% to 14.3% for B. caballi from the selected districts in Nigde. A statistically significant difference on seropositivity rates for the study sites was observed for only T.equi (p = 0.03). This study indicates that T. equi is higher than B. caballi in Nigde. This study was supported by the Scientific Research Projects Unit of Nigde University (FEB 2007/08).     

Pathological,serological, and virological findings in sheep infected simultaneously with <Emphasis Type="Italic">Bluetongue</Emphasis>, <Emphasis Type="Italic">Peste-des-petits-ruminants</Emphasis>, and <Emphasis Type="Italic">Sheeppox viruses</Emphasis>

In this study, pathological, serological and virological examinations were performed on 15 sheep from a flock of 250 sheep and lambs that suffer from simultaneous naturally occurring BTV, PPRV and SPV outbreaks. SPV was diagnosed macroscopically and histopathologically, BTV was diagnosed by ELISA, and PPRV was diagnosed pathologically and by ELISA. Clinically fever, diarrhea, depression, polypnea, conjunctivitis, lacrimation, rhinitis, erosive stomatitis, edema of eyelids, photophobia, cutaneous eruption with erythematous areas especially noticeable in wool-free parts of the body and axilla lesions evolving into papules were observed. At necropsy, the most effected organs were lungs and gut. Subepicardial hemorrhages were also commonly seen. While typical pox lesions were observed in some lambs, usually fibrinous pleuropneumonia was more prominent lung lesion. SPV and PPRV lesions were seen at the histopathological examination of the lesioned tissues, BT lesions were mild than SPV and PPRV microscopically. Serum and leukocyte samples of 15 animals were examined for PPRV and BTV by ELISA; 5 samples were positive for PPRV and 6 BTV, 4 were positive for both PPRV and BTV simultaneously. One hundred animals died, most were lambs. Mortality rates were 100% in lambs and 80% in the herd.     

Prevalence of thin-walled <Emphasis Type="Italic">Sarcocystis cruzi</Emphasis> and thick-walled <Emphasis Type="Italic">Sarcocystis hirsuta</Emphasis> or <Emphasis Type="Italic">Sarcocystis hominis</Emphasis> from cattle in Iran

Bovine sarcocystosis is caused by Sarcocystis cruzi and is known to cause considerable morbidity and mortality in cattle. This species is distributed worldwide in cattle and is the most prevalent of the Sarcocystis species infecting cattle. There is high infection rate of sarcocyst in cattle in Iran, but to our knowledge, there is no study about identification of Sarcocystis species. This work aimed to survey prevalence of S. cruzi cyst in slaughtered cattle of Isfahan, Iran. In this study, esophageal and diaphragmatic muscles of 100 cattle were collected from Fesaran abattoir of Isfahan and examined for the presence of Sarcocystis spp. cysts macroscopically and microscopically. No macroscopic sarcocysts were found in any of the samples. In light microscopy, 89 out of 100 cattle (89%) had thin-walled cysts of S. cruzi, while 21 out of them (21%) had thick-walled sarcocysts. In addition to light microscopy, ultrastructural features of the thin-walled cyst confirmed the presence of S. cruzi.     

Seroprevalence and risk factors for bovine brucellosis in domestic yaks (<Emphasis Type="Italic">Bos grunniens</Emphasis>) in Tibet,China

A cross-sectional study was conducted in three counties (Damxung, Maizhokunggar and Yadong) in Tibet in April and May 2015. A total of 1,523 yaks owned by 181 herders were randomly selected and blood sampled. Sera were tested using the rose bengal test (RBT) and a competitive immune-enzymatic assay (C-ELISA) and the test results interpreted in parallel. The individual yak prevalence was 2.8% (95% CI 2.0–3.7) with a herd prevalence of 18.2% (95% CI 12.9–24.6). At the individual level, two predictor variables, age and production system, were significantly associated with seropositivity by a binary logistic regression analysis. The odds of Brucella infection were significantly higher in older Yaks (3–5 years old, OR = 4.51; 95% CI 1.53–19.29; ≥6 years old, OR = 3.89; 95% CI 1.23–17.21) compared to those of younger yaks (≤2 years old). The odds of seropositivity for yaks managed under an agro-pastoral production system were 2.9 (95% CI 1.48–5.86) times higher compared to those managed under a pastoral production system. At the herd level, an association between the infection with Brucella and a history of abortions in the herd was observed (OR = 4.98, 95% CI 1.48–16.62). Surprisingly, vaccination was not associated with a lower level of infection (p = 0.49 and p = 0.99 for individual and herd level data, respectively). The results of the survey indicate that bovine brucellosis is endemic among the yak population in the plateau region of China, and the risk factors identified in the study should be considered in the epidemiology of the disease and when developing control programs for the disease.     

Biological control of <Emphasis Type="Italic">Ascaris suum</Emphasis> eggs by <Emphasis Type="Italic">Pochonia chlamydosporia</Emphasis> fungus

Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26°C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs.     

Prevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> and <Emphasis Type="Italic">Neospora caninum</Emphasis> infections in sheep from Federal District,central region of Brazil

Serum samples from 1028 sheep were collected from 32 herds within Federal District, in the central region of Brazil. The samples were examined by indirect fluorescent antibody test (IFAT) using sera diluted 1:64 and 1:50 as cut-off values for the detection of antibodies against Toxoplasma gondii and Neospora caninum, respectively. The observed prevalence for T. gondii infection was 38.22% (26.81%<CI 0.95<49.62%), and the titers ranged from 64 to 65536. The observed prevalence for N. caninum infection was 8.81% (7.08%<CI 0.95<10.53%). The titers ranged from 50 to 51200. The reactant sera to both pathogens corresponded to 4.67% of the samples. The risk factors were not determined because of the absence of negative herds for T. gondii and the high proportion of positive herds for N. caninum (87.50%). The prevalence for T. gondii infection was significantly higher among males than in females. The present work is the first report on seroprevalence of T. gondii and N. caninum in sheep from Federal District and shows that infection by both parasites is widespread in the ovine population from this region.     

Immunoprotection of recombinant <Emphasis Type="Italic">Eg</Emphasis>.P29 against <Emphasis Type="Italic">Echinococcus granulosus</Emphasis> in sheep

Objective

This study aims to investigate the immunoprotection of recombinant Eg.P29 (rEg.P29) vaccine and analyze the underlying mechanism in sheep.

Methods

Three groups of male sheep were immunized subcutaneously with rEg.P29 and PBS, Freund’s complete adjuvant as controls, respectively. After prime-boost vaccination, the sheep were challenged with encapsulated Echinococcus granulosus eggs. The percentage of protection in sheep was determined 36 weeks after the infection. Humoral immune response was analyzed for specific IgG, IgG1, IgG2, IgM and IgE levels. Moreover, cytokines including interferon (IFN)-γ, interleukin (IL)-2, IL-4,and IL-10 were also evaluated.

Results

Immunization with rEg.P29 induced protective immune responses up to 94.5 %, compared with immunoadjuvant group. The levels of specific IgG, IgG1, IgG2, and IgE as well as IFN-γ, IL-2, and IL-4 significantly increased after two immunizations (P < 0.05); however, the levels of IgM and IL-10 did not show difference.

Conclusion

rEg.P29 showed Immunoprotection and induced Th1 and Th2 immune responses; hence, rEg.P29 is a potential vaccine for E. granulosus infection.

     

Annual Variations in <Emphasis Type="Italic">Leptospira</Emphasis> Seroprevalence among Sows in Southern Vietnam

A serological survey was conducted among sows in the Mekong delta in southern Vietnam in 1999 to investigate variations in leptospiral Seroprevalence over a one-year period. In this region, leptospirosis is endemic and a high leptospiral Seroprevalence has been shown in the pig population. In this study, the serology of six Leptospira serovars was analysed by the microscopic agglutination test for 429 sows at five large-scale state farms sampled during the dry period, the rainy period and the early dry period. The serovars included were L. interrogans serovar (sv) autumnalis strain Akiyama A, L. interrogans sv bratislava strain Jez, L. interrogans sv icterohaemorrhagiae strain Kantorowicz, L. interrogans sv pomona strain Pomona, L. borgpetersenii sv tarassovi strain Perepelitsin, and L. kirschneri sv grippotyphosa strain Duyster. Variations in Seroprevalence over the year were found for sv bratislava and sv icterohaemorrhagiae: the Seroprevalence was higher during the dry period compared with the rainy period (p = 0.07 and p = 0.005, respectively) and the early dry period (p = 0.00006 and p = 0.0006, respectively). It is concluded that in regions where water is constantly abundant and where animals are exposed to the outdoor environment all year round there are highly significant variations in leptospiral Seroprevalence over the year.     

Experimental infection of <Emphasis Type="Italic">Peste des Petit Ruminant</Emphasis> virus and <Emphasis Type="Italic">Mannheimia haemolytica</Emphasis> A2 in goats: immunolocalisation of <Emphasis Type="Italic">Mannheimia haemolytica</Emphasis> antigens

Nigerian strain of Peste des Petit Ruminant (PPR) virus and Mannheimia haemolytica (MH) biotype A serotype 2, was used successfully to reproduce a concurrent disease in West African Dwarf goats. The development of the various pathological features were studied at regular intervals following infection. The acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together with a moderate bronchial and bronchiolar epithelial necrosis. This progressed to a milder acute broncho interstitial pneumonia with giant cells. At this stage, the mucosal immunity were well developed especially the aggregate form of NALT and more of nodular forms of BALT. The organisms were demonstrated with strong immunostaining in the necrotic center, necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte in the alveoli and respiratory airways. The bacterial antigens were observed as a strong immunostaining in the blood vessels of the nasal septum, sinusoid in the liver and interstium of the kidney, cytoplasm of alveolar macrophages, pneumocytes, bronchial and bronchiolar epithelium, in the monocytes in the blood vessels. These findings confirmed the enhancement of MH tropism especially in the respiratory tract, liver and kidney. It also showed that West african dwarf goats are highly susceptible to the intratracheal combined infection of PPR virus and MH. The fact that the infection induces strong mucosal responses, this phenomenon can be explored in Africa with the use of combined PPR virus and MH intranasal vaccines to curtail the menace of pneumonia associated with the combined infection on field.     

Control of <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in sheep using basidiocarps of <Emphasis Type="Italic">Agaricus blazei</Emphasis> Murril

Objective

This study evaluated the effects in vitro and in vivo of Agaricus blazei against Haemonchus contortus in sheep.

Methods

The in vitro efficacy of aqueous extract on egg hatching inhibition (EHI) was investigated and after 72 h incubation with varying concentrations the effects on, blastomeres, embryonated eggs, and first stage larvae (L1) were evaluated. Larval development inhibition (LDI) for dry powder and the aqueous extract were evaluated in fecal cultures of sheep infected with H. contortus. In vivo efficacy was determined by reduction in fecal egg count (FEC). Lambs were treated with powder A. blazei (11.4 g/kg pc) or trichlorfon, or were untreated and the possible toxicity of this fungus was monitored by plasmatic enzyme analysis.

Results

Concentrations equal to and higher than 3.62 mg/mL and of aqueous extract were 100% effective in the EHI test. In the LDI test, LC90 was estimated for 5.66 and 106.0 mg/g fecal culture for aqueous extract and powder, respectively. The mean FEC in lambs 14 days post-treatment with A. blazei powder was significantly lower than observed for the negative control, and the serum levels of aspartate transaminase and alanine transaminase were normal.

Conclusion

The fungi supplementation promotes, respectively, high and moderate anthelmintic efficacy with in vitro and in vivo tests, respectively, suggesting it as an alternative or complementary treatment for haemonchosis in sheep.

     

Risk factors for <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subspecies <Emphasis Type="Italic">paratuberculosis</Emphasis> in Fars province (Southern Iran) dairy herds

A cross-sectional study was conducted from March to August 2006 in dairy herds in Fars province, southern Iran to determine the herd-level risk factors for infection with Mycobacterium avium subspecies paratuberculosis (MAP). Statistical analysis using multivariable logistic regression showed that contamination of udders of periparturient cows with manure (OR = 6.4, P = 0.02) and history of having suspected cases of Johne's disease in the herd (OR = 6.7, P = 0.04) were significantly associated with the herd infection status. No relationship between breed, herd size and other management practices with the infection status of the herd were found in this study. Implementing high sanitary measures in the farm, particularly with respect to manure handling and cleaning could be considered as one of the important aspects in controlling disease in the region as well as in the future educational effort.     

The analysis of <Emphasis Type="Italic">groEL</Emphasis> gene in <Emphasis Type="Italic">Salmonella enterica</Emphasis> subspecies <Emphasis Type="Italic">enterica</Emphasis> serovar Typhimurium isolated from avians by PCR-Restriction Fragment Length Polymorphism method

Salmonella enterica subspecies enterica serovar Typhimurium causes food-borne outbreaks and systemic diseases in humans and animals. groEL gene (also known as mopA gene in S. Typhimurium), possessing conserved sequence, plays an important role in invasion of bacteria. The purpose of present study was to identify the polymorphism of groEL gene among different avians in different regions by PCR-RFLP method. Fifty two S. Typhimurium isolates (Broiler (n = 13), Layer (n = 12), Duck (n = 5), Goose (n = 5), Sparrow (n = 8), Canary (n = 3), Pigeon (n = 5) and Casco parrot (n = 1). were identified using serotyping as well as multiplex-PCR. Then, amplification of groEL gene performed and amplified products subjected to restriction digestion with BsuRI enzyme. Three RFLP profiles, A, B and C, generated DNA fragments between approximately 100–1,000 bp in size, were observed. The RFLP profile A was observed in 35 (67.3%), profile B in 14 (26.9%) and profile C in 3 (5.77%) of isolates. S. Typhimurium isolates recovered from 13 broilers (two of which profile A, 9 profile B and 2 profile C) and from 8 sparrows (two of which profile A, 5 profile B and 1 profile C) showed all three profiles, but 12 layers and other avians (including Canary (n = 3), Goose (n = 5), Duck (n = 5), Pigeon (n = 5) and Casco parrot (n = 1)) showed profile A. None of these profiles was allotted for a special region. The result of present study showed that S. Typhimurium undergoes genetic mutations in groEL gene under unpleasant milieu in different regions and in different avians. Thus, genetic diversity, despite conserved nature of groEL gene in S. Typhimurium, may exist but it depends on the condition where bacteria have settled. To our knowledge, three RFLP profiles of groEL gene generated by BsuRI restriction enzyme were not reported previously.