Survey on blood-sucking lice (Phthiraptera: Anoplura) of ruminants and pigs with molecular detection of Anaplasma and Rickettsia spp.

Lice may serve as biological or mechanical vectors for various infectious agents. To investigate louse infestation of ruminants and pigs, and pathogens potentially transmitted by them, anopluran lice (n=1182) were collected in Hungary, and evaluated for the presence of anaplasma, rickettsia and haemotropic mycoplasma DNA. On cattle the following species were found: Linognathus vituli (57%), Haematopinus eurysternus (38%) and Solenopotes capillatus (5%). L. vituli had a lower mean individual count/host when compared to H. eurysternus. On calves only L. vituli was observed, with a higher louse burden than on full-grown cattle. H. eurysternus and S. capillatus were more likely to occur simultaneously with another species on the same host, than L. vituli. Goats infested with Linognathus stenopsis had the overall highest prevalence (68%), while pigs harbouring Haematopinus suis showed the lowest (<1%). Anaplasma DNA was detected in 50% of pools analysed. In L. vituli Anaplasma ovis (or a closely related novel Anaplasma marginale genotype) was identified. Anaplasma-positivity of H. suis suggests that pigs may extend the reservoir and/or host spectrum of relevant species. Anaplasma-infected L. stenopsis pools show for the first time that caprine anaplasmosis is endemic in Hungary. Rickettsia spp. were demonstrated from Linognathus spp. and H. eurysternus. No haemotropic mycoplasmas were detected in any samples. In conclusion, this is the first molecularly confirmed report of bovine and ovine Anaplasma spp. in L. vituli, L. stenopsis and H. suis. The present results suggest that phthirapterosis of domestic animals deserves more attention, and lice should be evaluated among the broad range of potential vectors of arthropod-borne pathogens.

Babesia divergens becoming extinct in cattle of Northeast Hungary: new data on the past and present situation.

Previously unpublished data from 1958 to 1967 attest the occurrence of Babesia divergens in cattle in several endemic foci of Northeast Hungary. During that period the number of clinical cases showed fluctuation with intervals of 4-5 years and monophasic seasonality (peaking in June). In order to assess the current status of bovine babesiosis in that region, blood samples were collected from 654 cattle on 44 farms of 36 settlements in or near the endemic area during 2005, and serum levels of IgG antibodies to B. divergens were measured by indirect fluorescent antibody test (IFAT). Only 2 samples (0.3%) showed positivity. In one village clinical babesiosis was observed over the past few years. Animals brought into the endemic area during the spring developed haemoglobinuria in the summer of the same year, but those introduced during the summer or autumn showed clinical signs only after two years. Sampled animals born and raised locally had neither haemoglobinuria nor seroconversion. Reduction in the number of cases during the past decades may have been influenced by the availability of hosts (i.e. decrease of cattle breeding) and the activity of vectors associated with climate-related changes (e.g. increase of annual sunlight hours in the endemic area). This is the first report on the prevalence of antibodies to B. divergens in cattle in Hungary.

Seroprevalence of neosporosis in beef and dairy cattle breeds in Northeast Hungary.

In order to assess the seroprevalence of bovine neosporosis with indirect fluorescent antibody test (IFAT), blood samples were collected randomly from 1063 beef and dairy cattle belonging to 12 different breeds in Northeast Hungary. Antibodies to Neospora caninum were detected in 27 (2.5%) of the animals, kept on 19 of the 42 settlements included in this survey. Since samples were collected on 50 farms, herd prevalence amounted to 38%. The percentage of cattle with seroconversion increased with age, suggesting a postnatal source of infection. The highest rate of positivity was detected in Aberdeen Angus (3.3%) and Holstein-Friesian cows (3.2%), and the lowest in Limousine (0.9%), but no breed predisposition was statistically substantiated. Neosporosis was more prevalent in dairy (3.4%) than in beef (1.9%) cattle, although the difference was not significant. Only three out of the seropositive cows, all of them Holstein-Friesians, had a history of abortion.

Serotypes of Pasteurella haemolytica and Pasteurella trehalosi isolated from farm animals in Hungary.

The biochemical and serological characteristics of 486 P. haemolytica and 31 P. trehalosi strains (517 in total) isolated from different lesions of cattle, sheep, goats, pigs and poultry were examined. A total of 476 P. haemolytica strains (97.9%) showed the characteristics typical of the former biotype A of P. haemolytica, while 10 isolates (2.1%), all from poultry, could not be biotyped. A total of 481 strains (93.0%) could be assigned to one of the 17 serotypes of P. haemolytica-P. trehalosi and 36 strains (7.0%) could not. The majority (83.6%) of the cattle isolates were serotypes A1 and A2. Among strains isolated from sheep all serotypes of P. haemolytica could be identified with the exception of A14, but serotypes A1, A2, A6, A8 and A5 were the most frequent. The overwhelming majority (94%) of the caprine isolates were A2, other serotypes occurred only sporadically. The pig isolates, which could be isolated only very rarely, represented different serotypes, while none of the 10 strains isolated from poultry could be biotyped or serotyped.

Detection of antibodies to Neospora caninum in bovine postabortion blood samples from Hungary.

In order to obtain data on the occurrence of the protozoan parasite Neospora caninum as a potential factor in the aetiology of reproduction problems in cattle, 97 postabortion sera were examined by ISCOM ELISA and IFAT for the presence of antibodies in N. caninum. The results showed 10% and 9% seropositivity by the ELISA and IFAT, respectively. In 2 of the 10 seropositive cases no other fetopathogenic agents (such as Chlamydia sp., Leptospira spp. or bovine viral diarrhoea virus) were detected. These data confirm the presence of N. caninum in cattle in Hungary.

Abortion of a sow caused by Pasteurella aerogenes.

Three strains of the Pasteurella aerogenes complex were isolated as sole pathogens from aborted fetuses of a sow aborted at the 12th week of gestation on a farm of 600 sows. Gross pathology showed no characteristic lesions. The isolates were biochemically identical and resembled P. pneumotropica on the basis of their strong indole and urease positivity but they produced gas, were ornithine decarboxylase negative and fermented mannitol but not trehalose. Only a few differences were apparent in biochemical characteristics between the isolated strains and P. aerogenes. They differed from the type strain of P. aerogenes in ornithine decarboxylase activity, indole production and lactose and mannitol fermentation; however, such strains do occur within this heterogeneous species. At the time of abortion the antibody titre of the aborted sow was 1 in 16 when examined with live bacterial suspension and 1 in 128 if boiled antigen was used. Similar strains could not be isolated from the vaginas of aborted sows or pregnant and newly farrowed sows in the same group. The bacteriological, serological and histological findings support the opinion of other workers on the occasional pathogenic nature of P. aerogenes.

Trials with an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of subclinical genital infections in rams caused by Histophilus ovis and Actinobacillus seminis.

The performance of an enzyme-linked immunosorbent assay (ELISA) was evaluated in the serological diagnosis of subclinical genital infection in 6 naturally infected ram flocks and 2 experimentally infected ram hoggets. The test employs lipopolysaccharide (LPS) antigen prepared by autoclaving from Actinobacillus seminis and Histophilus ovis. A total of 193 sheep (118 unmated virgin rams and 75 mature breeding rams) were examined clinically, serologically (by ELISA) and bacteriologically (semen bacteriology) at the same time. Serum samples from all animals were also tested by an ELISA employing LPS antigen prepared from Brucella ovis in the same way. Shedding of A. seminis and H. ovis did not show close correlation with serological positivity (Table 1), as only 9 (15.0%) out of the 60 A. seminis shedders were ELISA seropositive at the same time. As regards H. ovis only 10 (19.2%) out of the 52 H. ovis shedders were ELISA seropositive at the same time. The results indicate that, when used alone, the ELISA employing LPS antigen is unsuitable for diagnosing subclinical genital infection caused by H. ovis and A. seminis in rams. The authors discussed shortly the employing fields of this ELISA test in the diagnostic work.

Serogroups of Campylobacter fetus and Campylobacter jejuni isolated in cases of ovine abortion.

Of 38 aborted ovine fetuses from 23 sheep flocks 29 C. fetus subsp. fetus and 22 C. jejuni were isolated and examined biochemically and serologically for heat-stable antigens. Serologic examinations were carried out by passive haemagglutination test. In case of C. fetus subsp. fetus strains alkaline antigen extraction was used. Antisera to two serogroups of C. fetus and to Penner serotype reference strains 1 to 60 were produced in rabbits. Abortion was caused in 18 (78.3%) flocks by C. fetus subsp. fetus and in 5 (21.7%) flocks by C. jejuni. Six C. fetus subsp. fetus strains grew well at both 43 and 25 degrees C. With one exception all C. fetus subsp. fetus were resistant, whereas all 29 C. fetus subsp. venerealis strains were sensitive to 30 micrograms/ml cefoxitin and cefamandole. These two cephalosporins can be used to differentiate the two subspecies of C. fetus. Passive haemagglutination test using alkaline antigen extraction is a proper method for the examination of heat-stable antigens of both C. fetus subspecies. Out of 24 C. fetus subsp. fetus strains 13 belonged to serogroup A(01), and 11 to serogroup B(02). C. jejuni strains examined belonged to Penner serogroup 1 (6 strains), to serogroup 5 (4 strains) and to serogroup 8 (4 strains).

Characterization of Actinobacillus strains isolated from aborted swine fetuses.

Eleven Actinobacillus strains were isolated in pure culture from 12- to 13-week-old aborted swine fetuses. Apart from minor biochemical differences, they resembled strains isolated from sow vaginas by Ross et al. (1972) in the U. S. A. Some of the strains agglutinated sheep, cattle and horse but not pig, dog and chicken erythrocytes. Haemagglutination was mannose resistant and could be inhibited by specific hyperimmune serum. Heating above 70 degrees C diminished or abolished haemagglutination of the cultures. Electron microscopy showed no fimbriae on the surface of the bacteria.

Biochemical and serological properties of Actinobacillus pleuropneumoniae biotype 2 strains isolated from swine.

The biochemical and serological properties of 21 strains of Actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. For serologic typing, the indirect haemagglutination (IHA) and the double gel-diffusion tests were used. On the basis of their soluble surface antigens, our A. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. Serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. All strains contained two surface antigen components. In the strains belonging to serotype 1, one of the antigens was identical with the serotype-specific antigen of Pasteurella haemolytica T4. Both antigens of serotype 2 strains proved to be type-specific. Four strains received from Switzerland, including the holotype strain of A. pleuropneumoniae biotype 2, and three strains isolated from swine in the G.D.R. belonged to serotype 2. Both the double gel diffusion and the IHA tests detected a 2-way cross-reaction between biotype 1, serotype 2 and biotype 2, serotype 2 strains of A. pleuropneumoniae, which could be eliminated using cross-absorbed sera.

Characterization of Pasteurella haemolytica strains isolated from goats in Hungary.

Thirty-five Pasteurella haemolytica strains were isolated in Hungary from goat carcasses sent for postmortem examination from two farms with large goat flocks. All strains belonged to biotype A and with the exception of one strain of serotype A8 they belonged to serotype A2. No untypable strains were found by the indirect haemagglutination test.

Testicular lesions in rams infected by maedi/visna virus.

Pathological lesions were observed in the testicles of 5 out of 7 rams found to be infected by maedi virus serologically and by histopathological examination of the lungs. The interstitium of the testicles was infiltrated with lymphocytes, histiocytes and plasma cells. The infiltration was mainly perivascular and of varying severity, and was accompanied by fibrosis. The seminiferous tubules neighbouring the severely affected parts were atrophied and, as a result, in circumscribed areas of the testicles disturbances of spermatogenesis were observed. The epididymides were devoid of pathological changes. Studies are in progress to determine whether the testicular lesions are actually caused by maedi/visna virus. Transmission of the virus with infected rams' semen is possible.

Comparison of Listeria serotypes and phage types isolated from sheep, other animals and humans.

A total of 814 different faecal, nasal, vaginal and milk samples of 50 healthy cotted sheep was investigated for Listeria during an epidemic-free summer season. Forty ewes and 5 tegs excreted Listeria strains; 18.1% of all samples were positive. A total of 151 Listeria monocytogenes strains belonging to serotypes 1/2, 4, 5, 6 and unknown were identified and phage typed. On the basis of the serotype and phage type of the excreted strains the animals could be divided into 7 groups. Characters of strains isolated from the cotted sheep were compared with those cultivated from 68 dead animals received from 44 distinct settlements. Also properties of 10 Listeria strains originating from 8 ill patients infected in the same region from where the carcasses of the animals were sent to the laboratory were studied. Two human Listeria strains were identical in serotype and phage type with some animal strains.