Comparison of selected biochemical parameters between naturally infected and non-infected goats with Anaplasma ovis

There are few extensive studies about biochemical profiles of caprine anaplasmosis caused by Anaplasma ovis. For detection of A. ovis and its effect on serum biochemical parameters in goats of north and northeast Iran, blood samples were collected from 84 goats of different ages and of both sexes from ten suspected herds to anaplasmosis. Forty-seven out of 84 samples were positive (infected), and 37 samples were negative (uninfected) for A. ovis by PCR method. Biochemical analysis of infected goats indicated a significant (P?<?0.05) elevation of serum aspartate aminotransferase, γ-glutamyl transferase, urea, creatinine, total bilirubin, and direct bilirubin, in addition to a nonsignificant (P?>?0.05) increase of total protein, albumin, and triglyceride, when compared to the uninfected goats. The cholesterol concentration in the infected goats was lower than that in the uninfected goats, but this difference was not statistically significant (P?>?0.05). The result of this study indicated that A. ovis infection in goats could be associated with marked alterations in serum biochemical parameters which could be helpful in the diagnosis of caprine anaplasmosis.     

Identification of hard ticks collected from sheep naturally infected with Anaplasma ovis in Isfahan province, central Iran

Attached ticks and blood samples were collected from 150 sheep in Isfahan province, central part of Iran. Blood samples were analyzed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Of the 150 sheep examined, 50 (33.33%) were found positive for Anaplasma ovis by PCR-RFLP. Of 50 sheep naturally infected with A. ovis, 553 ixodid ticks were collected. The ticks were identified (three species belonging to two genera) as follows: Rhipicephalus sanguineus (53.9%), Hyalomma marginatum marginatum (27.5%), and Hyalomma anatolicum anatolicum (18.6%). All A. ovis-infected sheep were infested with R. sanguineus. This suggests that R. sanguineus may be one of the main vectors of sheep anaplasmosis in the central part of Iran.     

Status of lipid peroxidation and antioxidant enzymes in goats naturally infected with Babesia ovis

This study aimed to assess lipid peroxidation and antioxidant enzymes in goats naturally infected with Babesia ovis. Red blood cell count (RBC), hemoglobin (Hb) concentration, packed cell volume (PCV), malondialdehyde (MDA) concentration, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities and total antioxidant capacity (TAC) were determined in 15 goats naturally infected with B. ovis as well as same number of healthy goats. The parasitological diagnosis was confirmed using polymerase chain reaction (PCR) analysis by amplifying a partial 18S rRNA gene sequence of B. ovis. Percentage of parasitemia varied from 0.01 to 1%. The activities of erythrocyte GSH-Px, SOD, CAT and TAC were significantly lower (p<0.05) in the infected goats than in healthy ones. MDA concentration in erythrocytes of infected goats was significantly higher in infected goats than in healthy ones (p?0.05). Severity of parasitemia showed a positive correlation with the MDA and negative correlation with PCV, SOD, CAT, GSH-Px and TAC. Also, MDA was negatively correlated with PCV, SOD, CAT, GSH-Px and TAC. The results of this study suggested that oxidative damage to RBCs may contribute to the pathogenesis of anemia in caprine babesiosis.     

Cloned DNA probes identify Anaplasma ovis in goats and reveal a high prevalence of infection.

Anaplasma organisms are observed in erythrocytes from goats with anemia and weight loss in Kenya. Three anaplasmas have been isolated in nature, Anaplasma ovis, Anaplasma marginale, and Anaplasma centrale. The two recognized species, A. ovis and A. marginale, are known to infect goats. Since only A. ovis causes clinical disease in goats, the Anaplasma species in goats in Kenya were identified. To detect A. ovis, a 9.6-kilobase-pair section of genomic DNA was cloned into pBR322 (pAO12A) and was used in conjunction with an A. marginale DNA probe previously derived from a gene coding for a 105,000-molecular-weight surface protein (Am105L) of A. marginale. In Southern blots, pAO12A DNA hybridized to several at least partially homologous sequences that were present in A. ovis and A. marginale genomic DNAs. The pAO12A DNA did not hybridize to Babesia bovis genomic or goat leukocyte DNA. The Anaplasma species that infected goats was identified as A. ovis by (i) DNA hybridization with pAO12A, (ii) hybridization of the A. marginale DNA probe to A. centrale and A. marginale genomic DNAs and lack of hybridization to A. ovis genomic DNA from an isolate obtained in Idaho and Anaplasma DNA from infected goats in Kenya, (iii) the intraerythrocytic location of Anaplasma organisms in infected goat blood, and (iv) the host specificity of the Anaplasma organisms for goats but not for cattle. Also, by using the two Anaplasma DNA probes, the prevalence of A. ovis in goats from seven locations in Kenya was found to range from 22 to 87%. The pAO12A DNA probe detected a 0.0035% A. ovis parasitemia in infected blood, an improved sensitivity which is suitable for use in surveillance and epidemiological studies.     

Disease syndromes in sheep and goats naturally infected with Trypanosoma congolense

The course of naturally acquired Trypanosoma congolense infections was observed in two breeds of sheep and two of goats grazed in an endemic area of Kenya over a period of eight months. Three syndromes of the disease are described on the basis of the duration of detectable parasitaemia and each syndrome is described in terms of clinical observations. The first two syndromes, the acute and sub-acute, are sub-divided on the basis of the outcome of the disease, either fatal or self-cure, but the third syndrome, the chronic, invariably ended fatally.     

Detection of Anaplasma ovis infection in goats by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay.

A competitive inhibition enzyme-linked immunosorbent assay (ELISA) based on a major surface protein 5 (MSP5) B-cell epitope conserved among Anaplasma species was used to detect goats infected with Anaplasma ovis. We examined strains of A. ovis isolated from goats in Kenya and demonstrated that MSP5 and the target B-cell epitope, bound by monoclonal antibody ANAF16C1, were conserved. Sera from 149 goats in four regions of Kenya and from 302 goats in six U.S. states were tested for the presence of epitope-specific antibodies with the MSP5 competitive inhibition ELISA. Evidence that the assay can be used to detect A. ovis-infected goats includes the following: (i) 53 goats raised in confinement with arthropod control were all seronegative; (ii) six goats experimentally infected with A. ovis seroconverted at the same time that they developed detectable rickettsemia; (iii) seroconverted goats remained seropositive, consistent with the persistence of A. ovis in goats and the presence of anti-MSP5 antibody in cattle persistently infected with Anaplasma marginale; and (iv) 119 of 127 known A. ovis-infected goats in Kenya were seropositive. A. ovis infection, as determined serologically and by demonstration of infected erythrocytes, in goats from the four regions in Kenya was highly prevalent. In contrast, despite the presence of A. ovis and competent arthropod vectors in the United States, the prevalence of infection appeared to be very low. The high prevalence in Kenya and the occurrence of anemia in persistently infected goats may be impediments to current efforts to increase milk yields on small farms.     

Microscopical and immunological features of tuberculoid granulomata and cavitary pulmonary tuberculosis in naturally infected goats

Caprine tuberculosis is caused by bacteria of the Mycobacterium tuberculosis complex (Mycobacterium bovis and Mycobacterium caprae). Although typical tuberculoid granulomata are usually observed in the lungs and lymph nodes of infected goats, the presence of cavitary lesions with exuberant mycobacterial growth is also a common feature in this species. The aim of this study was to characterize the immunological mechanisms that lead to liquefaction and cavity formation by comparing granulomata and cavitary lesions. Samples from animals positive by skin testing were collected for microscopical and immunohistochemical examination. Samples were also collected for analysis of cytokine gene expression in the lesions by real time polymerase chain reaction. There were marked differences between granulomata and cavitary lesions. In cavitary lesions there was a substantial population of neutrophils and a significant decrease in the number of CD4(+) T cells, with concomitant increases in other T-cell populations (CD8(+) and cells expressing the γδ form of the T-cell receptor). The enzyme iNOS was strongly expressed by macrophages in the cavitary lesions. There was no difference in the balance of pro- and anti-inflammatory cytokine gene expression in the lesions. These findings suggest that cavitary lesions are reactivation sites, where conditions are optimal for Mycobacterium proliferation and that immunological mechanisms may underlie the severe destruction of lung tissue that characterizes the cavitary pathology.     

Recurrent bacteraemia in sheep infected persistently with Anaplasma phagocytophilum

Following experimental or natural infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever (TBF), sheep may be infected persistently for several months or years. In the present study, quantitative real-time polymerase chain reaction was used to investigate the duration and magnitude of primary bacteraemia and to establish whether the organism is present continuously in the peripheral blood after the period of primary bacteraemia and the cessation of clinical signs. Persistent infection was characterized by a clearly defined period of primary bacteraemia followed by recurrent cycles of bacteraemia, usually lasting a few days and of lower magnitude, interspersed by negative periods of variable duration in which bacterial DNA could not be detected. During a 150-day period of consecutive sampling of four sheep, A. phagocytophilum was detected on 64.25 ± 4.9 occasions, which means that on average bacterial DNA was detected in 42.8 ± 3.3 percent of all samples, with the positive days falling into 15-20 distinct cycles. Primary bacteraemia lasted for 15.5 ± 2.33 days, but secondary and subsequent cycles of bacteraemia were short-lived, with 61% of the cycles lasting only 1-2 days and 39% lasting for 3 or more days. Secondary and subsequent cycles of bacteraemia were not accompanied by febrile responses or other clinical features of TBF. For three animals, bacterial DNA was detected at 311, 318 and 358 days post infection, indicating the long-term persistence of A. phagocytophilum within peripheral blood.     

Atypical PrPsc distribution in goats naturally affected with scrapie

The brain and spinal cord of 48 goats from two Greek herds in which scrapie had been reported were examined. All animals were symptomless at the time of euthanasia. Notably, no lesions were observed either at the level of the obex or at other regions of the brain and spinal cord. Immunohistochemical examination revealed PrPsc labelling of the linear and fine punctuate types, mainly in the cerebral cortices, of 36 goats. Twenty-seven of them were negative by ELISA (designed to detect proteinase-resistant PrP) at the level of the obex but positive in a pooled brain sample, and the majority carried PrP genotypes associated with scrapie susceptibility. Surprisingly, in 16 of the 27 animals, PrPsc deposits were detected only in the rostral parts of the brain. In addition, nine animals which were ELISA-positive at the level of the obex exhibited positive immunoreactivity, but not in the dorsal vagal nucleus. The findings indicate that this unusual scrapie type may have been underdiagnosed previously and may be of importance in scrapie surveillance programmes.     

Livestock trypanosomosis in Uganda: parasite heterogeneity and anaemia status of naturally infected cattle, goats and pigs

The prevalence and pathogenic effects of trypanosomosis were determined in cattle, goats and pigs reared in Kasese, Jinja and Rakai districts, Uganda; presence of trypanosomes was detected by buffy coat technique (BCT). The overall prevalence of trypanosomosis in cattle was 7.6 % (144/1,891), 0.7 % in goats (4/573) and 2.3 % in pigs (9/386). Internal transcribed spacer 1 (ITS1) of ribosomal DNA polymerase chain reaction was utilised to identify trypanosomes to species level and revealed infections in 108 of the 144 trypanosome-positive cattle while all infected goats and pigs gave amplicons. Trypanosoma vivax was the most prevalent trypanosome species in cattle in single and mixed infections compared to infections involving Trypanosoma congolense and Trypanosoma brucei; in pigs, eight were mixed infections with one single T. vivax infection. No predominant trypanosome species was detected in goats. Anaemia, the main trypanosomosis pathological feature, was investigated by determining packed cell volume (PCV). Mean PCV values by t test in infected individuals were significantly lower than non-infected individuals (P?<?0.05) for all animal species. However, the proportion of anaemic animals was not significantly different in infected and non-infected individuals. In addition, the percent of infected animals by Fisher’s exact test depended on district of origin and species but not sex. These findings show that trypanosomosis is a major cause of anaemia in livestock in endemic areas. Cattle were the major animal species affected by trypanosomosis; similar genotypes of trypanosomes were detected in the three animal species. BCT was more effective than ITS1 rDNA detecting trypanosomes in naturally infected cattle.     

Ultrastructure and pathology of <Emphasis Type="Italic">Besnoitia caprae</Emphasis> in the naturally infected goats of Kerman,East of Iran

A disease with clinical manifestations of thickening and alopecia of the skin over the lower limbs, around the eyes, face, and nose, thickening and shrinkage of the scrotum, and presence of white granular cysts in the sclero-conjunctiva in goats in Kerman Province, were reported to the Pathology Department of Shiraz Veterinary School. Primary histopathological studies demonstrated an outbreak of caprine besnoitiosis in this region. To study the histopathological and ultrastructural features of the disease, samples were collected from various organs of the suspected slaughtered goats for further investigations. In histopathological studies, dermis and subcutaneous fascia covering lower portion of the limbs, skin over frontal sinus, ear tips, scrotum, eye lids as well as the eye's sclera, epididymal and testicular parenchyma, and their tunics were severely infected with Besnoitia cysts. Tongue, pharynx, prepuce and penis, deeper striated muscles, subcutaneous bone matrices, abomasum, esophagus, subcutaneous tendons, and periosteal surfaces of the limb bones showed lower rates of infection. Except the vagina and vestibule, no cyst was observed in other female urogenital organs, the central nervous system, intestines, heart, liver, spleen, and different lymph nodes. The host reaction to the cysts was variable, ranging from the absence of inflammatory cells around intact normal cysts up to infiltration of macrophages, lymphocytes, plasma cells, eosinophils, fibroblasts, and connective tissues around the degenerated cysts. Ultrastructural studies showed this coccidian parasite belonged to eukaryotic protozoa, and the cystic form had the typical feature of the Besnoitia spp. of the apicomplexa. This study showed that the organism demonstrated ultrastructurally minor differences with other Besnoitia species infecting other animal species.     

Comparison of immunoglobulin G subclass profiles induced by measles virus in vaccinated and naturally infected individuals

A total of 258 human sera positive for measles antibodies were divided into four different groups: group 1 contained 54 sera from children after natural measles infection (immunoglobulin M [IgM] positive, early infection phase), group 2 contained 28 sera from children after measles vaccination (IgM positive, early infection phase), group 3 contained 100 sera from healthy adults (natural long-lasting immunity), and group 4 contained 76 sera from healthy children (postvaccinal long-lasting immunity). In the early phase of infection, the percent distributions of measles virus-specific IgG isotypes were similar between natural and postvaccinal immune responses. IgG1 and IgG4 were the dominant isotypes, with mean levels of detection of 100% (natural infection) and 100% (postvaccinal) for IgG1 and 96% (natural infection) and 92% (postvaccinal) for IgG4. In comparison, the IgG4 geometric mean titer (GMT) in the early phase of natural infection was significantly higher than the IgG4 GMT detected in the postvaccinal immune response (80 versus 13; 95% confidence interval). In the memory phase, IgG2 and IgG3 responses decreased significantly in both natural infection and postvaccinal groups, while IgG1 levels were maintained. In contrast, the IgG4 postvaccinal immune response decreased strongly in the memory phase, whereas IgG4 natural long-lasting immunity remained unchanged (9 versus 86%; P < 0.05). The results obtained suggest that IgG4 isotype could be used in the early phase of infection as a quantitative marker and in long-lasting immunity as a qualitative marker to differentiate between natural and postvaccinal immune responses.     

Persistence of Anaplasma ovis Infection and Conservation of the msp-2 and msp-3 Multigene Families within the Genus Anaplasma

Goats which have recovered from acute Anaplasma ovis infection remain seropositive, although infected erythrocytes cannot be detected by microscopic examination. Persistence of A. ovis 17 to 21 months following experimental infection was demonstrated by PCR detection of the msp-5 gene. Quantitative analysis of persistent rickettsemia over time showed that all levels were below the limit of microscopic detection and ranged from a low of 10² organisms/ml to peaks of 10⁶ organisms/ml. Two patterns of persistent rickettsemia were observed: the first was characterized by cyclic fluctuations at 6- to 9-week intervals, similar to the pattern described for A. marginale-infected cattle, while in the second pattern, repetitive cycles did not occur and the rickettsemia levels were relatively constant. The msp-2 and msp-3 multigene families, which provide the genetic capacity for outer membrane protein antigenic variation during persistent A. marginale rickettsemia, were identified in the A. ovis genome by Southern blot analysis, and expression of an MSP-2 homologue was confirmed by using immunoblots.     

Serologic profiles for Sarcocystis sp. and Neospora caninum and productive performance in naturally infected beef calves

Sarcocystis sp. and Neospora caninum infections affect cattle worldwide causing important economic losses. The objective of the present study was to trace serologic profiles for Sarcocystis sp. and N. caninum in naturally infected beef calves and analyze their relationship with transmission routes and productive performance. Samples were collected in two cow-calf operations located in Buenos Aires province, Argentina. In farm 1, 43 calves were bled and weighed three times. In farm 2, 69 calves were bled and weighed six times. Sarcocystis sp. and N. caninum immunofluorescence antibody test (IFAT) titers were averaged for each sampling point in order to trace serologic profiles for each infection. Categories were created to evaluate differences in daily weight gain. For S. cruzi antigen, animals were separated in a low-titer (≤200) and high-titer group (>200); for N. caninum, animals were grouped as infected and uninfected. Sarcocystis sp. antibody titer as well as the number of infected animals increased gradually over time in both farms. In farm 2 the low-titer group had significantly higher daily weight gain than the high-titer group. For N. caninum 44% (farm 1) and 65% (farm 2) of calves were considered infected, and the serological profile was horizontal or decreasing over time. However, seroprevalence increased in both farms and vertical and horizontal transmission frequency were estimated between 18.5%–29% and 22–25.5%, respectively. No differences were detected in daily weight gain between N. caninum groups from both farms. This is the first report of serological profiles for Sarcocystis sp. and N. caninum by IFAT in naturally infected beef calves and their relationship to different transmission routes and productive performance.     

Antigastric autoantibodies in ferrets naturally infected with Helicobacter mustelae

Infection with Helicobacter pylori has been associated with induction of autoantibodies that cross-react with the gastric mucosa. There have been discordant reports as to whether or not these autoantibodies arise due to molecular mimicry between H. pylori and host cell antigens on parietal cells. In this study, we investigated whether molecular mimicry by H. mustelae causes autoantibodies in infected ferrets. Serum from H. mustelae-infected ferrets reacted with parietal cells in the ferret gastric mucosa but not with duodenal or colonic mucosa. These sera did not react with the blood group A epitope on erythrocytes or H. mustelae lipopolysaccharide, and absorption with H. mustelae whole cells or red blood cells did not remove autoantibodies. In conclusion, ferrets naturally infected with H. mustelae generate antibodies that react with parietal cells, but these autoantibodies are not due to molecular mimicry.     

Unidirectional suppression of Anaplasma phagocytophilum genotypes in infected lambs

Five-month-old lambs were simultaneously infected with different doses of two 16S rRNA genetic variants of Anaplasma phagocytophilum and thereafter followed for clinical observation and blood sampling. The result of the study indicates a unidirectional suppression of genotypes in infected lambs, at least during a certain period of an A. phagocytophilum infection.