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1.
Twenty-six calves, born from 25 Anaplasma-infected, intact and splenectomized cows, from a herd kept under strict tick-free laboratory conditions, were monitored for the presence of Anaplasma antibodies, using the rapid card agglutination test. Serum was collected at birth, weekly for 12 weeks, and then monthly for approximately 6 months. Specific antibodies passively acquired could be detected in calf sera for an average period of 8 weeks after birth. Calves that remained positive for longer than 12 weeks were suspected of having contracted in utero infections. Infection of the calves was confirmed by splenectomy. It was concluded that 4 calves in Group I contracted in utero infections. Two of the dams were chronically infected, whilst the other 2 underwent acute primary reactions during the 1st and 2nd trimesters of gestation, respectively. Subsequently all calves born from infected cows in this tick-free herd were serologically screened before being splenectomized at an average age of 8 months. Out of 50 cows, 8 in utero infected calves were identified serologically and this finding was confirmed through splenectomy or subinoculation of blood. Both Anaplasma centrale and Anaplasma marginale were carried transplacentally. Splenectomized and intact cows, chronically infected or undergoing primary reactions during the 1st, 2nd or 3rd trimester of gestation, produced infected calves. A 15,6% incidence of in utero transmitted infections were observed amongst 77 calves under these conditions. None of the 13 splenectomized cows, undergoing primary A. centrale infections during gestation, aborted. Clinical signs of disease were not observed in any of the 12 in utero infected calves prior to splenectomy. The implications of these findings are discussed. 相似文献
2.
The incidence of blood parasites in trade cattle was surveyed with emphasis on tick-borne parasites, using blood smears and immunofluorescent antibody (IFA) techniques. With the blood smear method, about 9 and 8.9% of cattle examined were found positive for Babesia bigemina and Anaplasma marginale, respectively. Percentage infections with other parasites were 3.33, 1.92, 0.75, 0.75 and 0.58, respectively, for Babesia bovis, Trypanosoma brucei, Anaplasma centrale, Eperythrozoon and Theileria species as well as Trypanosoma congolense. The incidence of A. marginale infection was at its peak during the rainy season while B. bigemina was most prevalent during the dry season. There were mixed infections of Anaplasma and Babesia (1.42%); Babesia and trypanosomes (1.00%); Babesia and Eperythrozoon (0.75%) and Babesia and Theileria (0.75%). Using the indirect fluorescent antibody test, 93, 55 and 68% of cattle sera examined were found to be positive for B. bigemina, B. bovis and A. marginale, respectively. Forty-nine percent of the positive sera of B. bigemina had highest titres. The importance of using serological means for determining the endemic levels of tick-borne diseases in cattle in Nigeria is discussed. 相似文献
3.
Nicola Decaro Grazia Carelli Eleonora Lorusso Maria Stella Lucente Grazia Greco Alessio Lorusso Arianna Radogna Luigi Ceci Canio Buonavoglia 《Journal of veterinary diagnostic investigation》2008,20(5):606-611
Anaplasma marginale and Anaplasma centrale are rickettsial pathogens responsible for acute disease and mild infections, respectively, in cattle herds. A duplex real-time polymerase chain reaction (PCR) assay with probes labeled with different fluorophores was developed for simultaneous detection and quantification of A. marginale and A. centrale DNA in bovine blood samples. The assay was able to detect as few as 10(1) and 10(2) DNA copies for A. marginale and A. centrale, respectively, with optimal specificity and reproducibility. Analysis by real-time and nested PCR carried out on 54 samples previously tested by reverse line blot hybridization showed that the established duplex real-time PCR assay can detect and quantify the 2 Anaplasma spp., even if present simultaneously in the same blood samples. Such an assay could be used in pathogenesis studies on bovine acute anaplasmosis. 相似文献
4.
N. I. Paull R. J. Parker A. J. Wilson R. S. F. Campbell† 《Australian veterinary journal》1980,56(6):267-271
Natural infection of calves with Anaplasma marginale was studied in two endemic areas of tropical north Queensland. Infection, assessed by a micro-complement fixation test, occurred throughout the year but was most frequent just after the summer wet season. Infection was clinically inapparent. Calves vaccinated with A. centrale did not show improved growth rate when compared with non-vaccinated calves. The complement fixation test was shown to be most effective in the detection of recent infections. 相似文献
5.
Cross-bred Bos taurus calves, aged between 6 and 8 months, were inoculated with the Onderstepoort Anaplasma centrale live blood vaccine. One group of 15 calves were inoculated once only, while a 2nd group of 15 were revaccinated 6 months later. All the animals were challenged with approximately 1 X 10(10) Anaplasma marginale parasites of a known virulent strain 8 months after the first vaccination. The results of blood smear examination and the card agglutination test indicated that only 20 out of 30 animals vaccinated contracted A. centrale infections after the first attempt, and 3 out of 5 after the second. The vaccine conferred only partial immunity to challenge with a virulent A. marginale strain. 相似文献
6.
Molecular conservation of MSP4 and MSP5 in Anaplasma marginale and A. centrale vaccine strain 总被引：1，自引：0，他引：1
Anaplasma centrale msp4 and msp5 genes were cloned and sequenced, and the recombinant proteins were expressed. The identity between Anaplasma marginale and A. centrale MSP4 was 83% in the nucleotide sequences and 91.7% in the encoded protein sequences. A. centrale msp5 nucleotide sequences shared 86.8% identity with A. marginale msp5, and there was 92.9% homology between A. centrale and A. marginale encoded amino acids of the MSP5 protein. Southern blots hybridized with probes derived from the msp4 and msp5 central regions indicate that msp4 and msp5 of A. centrale are encoded by single copy genes. Recombinant MSP4 and MSP5 fusion proteins reacted with anti-A. marginale monoclonal antibodies ANAR76A1 and ANAF16C, respectively, demonstrating the conservation of conformation-sensitive B-cell epitopes between A. centrale and A. marginale. These data demonstrate the structural and antigenic conservation of MSP4 and MSP5 in A. centrale and A. marginale. This conservation is consistent with the cross-protective immunity between A. marginale and A. centrale and supports the development of improved vaccines based upon common outer membrane proteins. 相似文献
7.
Tick-borne diseases of cattle in Paraguay. II. Immunisation against anaplasmosis and babesiosis 总被引：1，自引：0，他引：1
A total of 102 susceptible adult Holstein Friesian cattle imported into an area of Paraguay where anaplasmosis and babesiosis are endemic were immunised by infection with Anaplasma centrale and attenuated forms of Babesia bigemina and Babesia bovis obtained from Uruguay. The results indicated that the attenuated forms of both Babesia species protected cattle against heterologous field challenge whereas A. centrale did not invariably confer sufficient protection against a field challenge of A. marginale. 相似文献
8.
Tick transmission of Anaplasma centrale 总被引：1，自引：0，他引：1
Anaplasma centrale was isolated from a field collection of Rhipicephalus simus. Transstadial transmission of A. centrale with adult ticks was demonstrated, but the infection was not carried transovarially. Ticks from this collection were subsequently reared as a non-infected, laboratory strain. It was proved that the Onderstepoort live blood vaccine strain of A. centrale, isolated by Theiler in 1911, is still tick transmissible after more than 75 years of needle passage through cattle in the laboratory. Attempts to demonstrate transstadial transmission of the vaccine strain with Boophilus decoloratus and Boophilus microplus failed. 相似文献
9.
ABSTRACT: Chlamydiaceae are Gram-negative obligate intracellular bacteria. They are responsible for a broad range of diseases in animals and humans. In pigs, Chlamydia suis, Chlamydia abortus, Chlamydia pecorum and Chlamydia psittaci have been isolated. Chlamydiaceae infections in pigs are associated with different pathologies such as conjunctivitis, pneumonia, pericarditis, polyarthritis, polyserositis, pseudo-membranous or necrotizing enteritis, periparturient dysgalactiae syndrome, vaginal discharge, return to oestrus, abortion, mummification, delivery of weak piglets, increased perinatal and neonatal mortality and inferior semen quality, orchitis, epididymitis and urethritis in boars. However, Chlamydiaceae are still considered as non-important pathogens because reports of porcine chlamydiosis are rare. Furthermore, Chlamydiaceae infections are often unnoticed because tests for Chlamydiaceae are not routinely performed in all veterinary diagnostic laboratories and Chlamydiaceae are often found in association with other pathogens, which are sometimes more easily to detect. However, recent studies have demonstrated that Chlamydiaceae infections in breeding sows, boars and piglets occur more often than thought and are economically important. This paper presents an overview on: the taxonomy of Chlamydiaceae occurring in pigs, diagnostic considerations, epidemiology and pathology of infections with Chlamydiaceae in pigs, public health significance and finally on prevention and treatment of Chlamydiaceae infections in pigs. 相似文献
10.
Shkap V Leibovitz B Krigel Y Molad T Fish L Mazuz M Fleiderovitz L Savitsky I 《Veterinary microbiology》2008,130(3-4):277-284
Bovine anaplasmosis, caused by Anaplasma marginale, the intraerythrocytic rickettsia, is controlled by vaccination with live Anaplasma marginale ss centrale (A. centrale), a subspecies of relatively low pathogenicity. We have experimentally demonstrated that an animal primarily infected with A. marginale, or with the related vaccine subspecies A. centrale can be infected with the heterologous subspecies, and carries both bacteria. The co-infection was detected in experimentally cross-infected calves for up to 3 months after the last inoculation with the heterologous subspecies. The occurrence of characteristic cyclic rickettsemia of A. centrale and A. marginale was observed by examination of Giemsa-stained blood smears, or by the presence of specific rickettsial DNA confirmed in PCR assays based on specific msp1a and msp4 for A. marginale, and on specifically designed msp3 and msp4 primers for A. centrale. Sequence analysis of msp4-specific fragments for each subspecies revealed the presence of dual infection in both calves on days 30 and 60 after cross-inoculation with the heterologous Anaplasma subspecies. The experimental cross-infection of calves clearly demonstrated that the concept of "infection exclusion" does not apply to Anaplasma infection in cattle; as there was no infection exclusion of A. marginale in A. centrale-infected cattle, and vice versa. The present results confirmed our previous findings that cattle grazing in an anaplasmosis-endemic field were subject to concomitant infection with both the vaccine A. centrale and the field A. marginale strains. 相似文献
11.
Management of anaerobic infections 总被引：1，自引：0，他引：1
S W Dow 《Veterinary Clinics of North America: Small Animal Practice》1988,18(6):1167-1182
Successful management of anaerobic infection first requires an accurate diagnosis. Cytologic examination of wound exudates and inspection for characteristic clinical clues greatly facilitates an accurate initial diagnosis of anaerobic infection. Knowledge of antimicrobial activity against specific anaerobic pathogens is essential, since antibiotic susceptibility information is not routinely available. Whenever possible, antimicrobial and surgical therapy should be combined in managing anaerobic infections. Chloramphenicol, clindamycin, and metronidazole provide the most consistently reliable activity against pathogenic anaerobes, including Bacteroides. Penicillins are also generally effective, except for treatment of infections caused by penicillinase-producing strains of Bacteroides. Cephalosporins are not considered drugs of choice for anaerobic infections, although cefoxitin may in some instances be useful as monotherapy of mixed infections containing obligate anaerobes and coliform bacteria. Aminoglycosides and sulfonamides are ineffective and should be avoided for treatment of anaerobic infection. 相似文献
12.
Anaplasmosis can be diagnosed either by immunological techniques or by direct microscopic examination of blood smears. Both methods are time-consuming and labour intensive. The use of DNA probes in an hybridization assay may simplify the diagnosis of anaplasmosis in cattle and sheep. A genomic DNA library of Anaplasma centrale was constructed in an expression vector and screened to detect clones containing A. centrale DNA. Four probes which hybridized to A. centrale and Anaplasma marginale DNA were isolated. One of these (AC-1) hybridized only to A. centrale DNA, whereas AC-2, AC-3 and AC-4 could detect DNA from both A. centrale and A. marginale. Probes AC-1 and AC-2 could detect 127 ng and 8 ng DNA respectively, while AC-3 and AC-4 detected 64 ng A. centrale DNA. 相似文献
13.
Identification of immunodominant polypeptides common between Anaplasma centrale and Anaplasma marginale 总被引：2，自引：0，他引：2
V Shkap E Pipano T C McGuire G H Palmer 《Veterinary immunology and immunopathology》1991,29(1-2):31-40
High titered antibody from rabbits immunized with Anaplasma centrale or from cattle recovered from A. centrale infection bound predominantly to several 33-36 kDa polypeptides present in both A. centrale and the Israel-NT isolate of Anaplasma marginale. High titered bovine antibody against the Israel-NT isolate of A. marginale also reacted predominantly with A. centrale polypeptides in this size range. The immunodominance of the 33-36 kDa polypeptides and their cross-reactivity indicate that these shared epitopes may be primarily responsible for the cross-protective immunity between A. centrale and A. marginale. 相似文献
14.
Adult infections of Ostertagia circumcincta were successfully established in gerbils, although worm growth was retarded compared with infections in sheep. Chronic administration of beta-methasone to the host enhanced development of the parasite reproductive system but did not increase infection rate or prevent worm rejection. Infection rates achieved with single infections were not increased by using daily or weekly trickle infection regimes with or without prior exsheathment of larvae. Examination of stomachs from infected gerbils demonstrated pathological changes in the pyloric region which was the predilection site for O. circumcincta. This is in contrast to infections in sheep in which the fundic region of the abomasum is the preferred site. 相似文献
15.
Sting R Kopp J Mandl J Seeh C Seemann G Kimmig P Schmitt K Mentrup T 《Berliner und Münchener tier?rztliche Wochenschrift》2002,115(9-10):360-365
Investigations of 1167 dairy cows out of 105 herds with fertility disorders on secretion of Coxiella burnetii (C. burnetii) by the genitals as well as serological studies of these animals using ELISA demonstrated that C. burnetii infections are significantly associated with abortions but not with repeated inseminations without success or vaginal excretions. The demonstration of an increased risk of infections for persons caring for those dairy herds could be shown by a total of 253 serological studies. A comparison of these studies of farmers caring for dairy herds suffering from abortions a seroprevalence of > or = 20% showed that these persons revealed significantly more frequent antibodies against C. burnetii than farmers of the group compared with. Further studies showed that in herds suffering from abortions a seroprevalence of > or = 20% means an additional risk of infections of farmers. Vice versa abortions of the cows in herds with a seroprevalence of > or = 20% imply an additional infectious risk. 相似文献
16.
J Stiles 《Veterinary Clinics of North America: Small Animal Practice》2000,30(5):1135-1149
Dogs that live in tick-infested areas are at risk for contracting rickettsial infections. Clinical signs associated with ehrlichiosis or Rocky Mountain spotted fever may be dramatic or mild. Clinicians must consider the possibility of rickettsial diseases to request laboratory tests that will permit a proper diagnosis. Specific antimicrobial therapy usually brings about clinical improvement, although some dogs may not be cleared of rickettsial organisms, even with prolonged treatment. A small percentage of dogs die of rickettsial infections, either in the acute stage or owing to chronic bone marrow suppression and generalized debilitation. Ocular lesions are an important clinical sign in canine rickettsial infections and may aid the clinician in making a diagnosis and monitoring response to therapy. 相似文献
17.
H.J. Smith 《Veterinary parasitology》1978,4(3):265-273
Three of six ponies, 9 and 10 years of age, were each given in excess of 300 000 infective Trichonema larvae experimentally. Although all six ponies had both natural and experimental infections previously, they were virtually parasite-free during the 18-month period immediately preceding experimental reinfection.Appreciable resistance to Trichonema infections was indicated in these mature ponies by a longer prepatency and significantly smaller worm egg outputs than that which occurred when these animals were given comparable infections at a much younger age. Patent infections only developed in two of the three ponies beginning between 17 and 18 weeks post-reinfection with peak egg counts between 200 and 400 eggs per gram (epg) in one and 100 to 150 epg in the other. Within 10 days of reinfection, an abrupt rise in mean circulating eosinophils and an appreciable mean weight loss, which persisted for 2 years, occured in the reinfected but not the control ponies.The findings, particularly of unthriftiness characterized by persistent loss of weight in the reinfected but not the control ponies, demonstrated the pathogenesis of inhibited Trichonema larvae. 相似文献
18.
An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Anaplasma centrale and Anaplasma marginale 总被引：1，自引：0，他引：1
An enzyme-linked immunoassay (ELISA) was applied to detect antibodies to A. centrale and A. marginale using homologous and heterologous antigens. The assay was compared with the indirect fluorescent antibody (IFA) test, and although a similar degree of sensitivity was obtained, the ELISA test had several advantages. Partially purified Anaplasma initial bodies used for antigen preparations contained negligible amounts of residual erythrocytic material, and did not interfere with the specificity of the ELISA. The antigenic similarity between A. marginale and A. centrale was further substantiated by cross-reactivity obtained with heterologous antigens in both ELISA and IFA tests, and antibodies produced during natural infection with A. marginale were indistinguishable in both tests from those produced following vaccination with A. centrale. 相似文献
19.
Meléndez RD Toro Benítez M Niccita G Moreno J Puzzar S Morales J 《Veterinary microbiology》2003,94(4):335-339
The main objective of this work was to evaluate the safety of an Anaplasma centrale vaccine in pregnant pure bred Jersey cows selected from a herd located at Miranda State, Venezuela. Ten cows of 3-5 months of gestation were chosen and previous vaccination all cows were tested for Anaplasma antibodies by the indirect immunofluorescence assay (IFA), so only seronegative cows were included in the group, and for blood parameters, rectal temperature, and pregnancy. Selected cows were vaccinated intramuscularly with 1ml of an A. centrale live vaccine which had 10(8) A. centrale per ml. Over the next 2 months cows were checked weekly for hematological parameters and Anaplasma antibodies, and then for the next 2 months these evaluations were performed monthly. Among the values monitored were: A. centrale parasitemia, hematocrit, hemoglobin, and white blood cells (WBCs) (neutrophil, lymphocyte and eosinophil counts). Levels of Anaplasma antibodies were measured by IFA. Anaplasma were observed for the first time in blood films of two vaccinated cows at 14 days post-vaccination (PV), 6 out of 10 cows were A. centrale positive at 30 days PV, and all cows were A. centrale positive at 42 days PV. A. centrale often showed low parasitemia, 1-3%. Anaplasma antibodies were detected at day 14 PV in all vaccinated cows with a mean group titre of 360 (range: 80-1280). All vaccinated cows showed few changes in their hematologic parameters or in rectal temperature, and all gave birth to healthy calves. In conclusion, adult pregnant cows were safely vaccinated with this live A. centrale vaccine, which may help to develop a cross-protective immunity against field strains of A. marginale. 相似文献
20.
Experimentally induced infections in turkeys with Cryptosporidium baileyi isolated from chickens 总被引：1，自引：0，他引：1
Oocysts of Cryptosporidium baileyi isolated from chickens were inoculated by different routes into 3 groups of turkey poults. Intratracheal inoculation of oocysts produced clinical signs of respiratory tract disease, deaths, and gross lesions of airsacculitis. Parasites developed in the microvillous border of the nasopharynx, larynx, trachea, bronchi, and air sacs. Oral and intracloacal inoculations of oocysts caused no deaths or clinical signs of disease, but did produce patent infections. Respiratory tract infections limited to the nasopharynx, larynx, and trachea occurred in 3 orally inoculated poults. Respiratory tract infections were not observed in intracloacally inoculated poults. The mode of inoculation did not influence the distribution of C baileyi in the digestive tract. The cloaca was parasitized in 100% of the birds with intestinal infections, and the bursa of Fabricius was parasitized in 72.7%. 相似文献