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1.
Salmonellosis due to Salmonella enterica serovar Abortusovis (S. Abortusovis) is mainly characterized by abortion in sheep. Little is known about the immune response, which develops in the host as a result of infection. We evaluated the immune response of pregnant ewes vaccinated and successively exposed to full virulent S. Abortusovis. We found that vaccine constituted by inactivated S. Abortusovis induced both humoral and cellular-mediated immune response and that it provided protection against a challenge infection due to a fully virulent S. Abortusovis. Furthermore, we found an association between the lack of capability to produce IFN-gamma and abortion. This evidence suggests that protection against abortion can be associated to an IFN-gamma mediated mechanism. Our findings represent an interesting insight to better understand the interplay between host and S. Abortusovis and the effector mechanisms underpinning immune-based protection.  相似文献   

2.
In spring 2005, the outbreak of contagious abortion caused by Salmonella Abortusovis in 6 sheep flocks in Switzerland led to considerable economic losses. The Swiss small ruminant health service (BGK) evaluated this case. The aim was to identify the source of the epidemic in order to avoid further spread of infection and to evaluate the possibility of using vaccination. Moreover, a strategy for prevention of future outbreaks was developed. This article aims to increase disease awareness of food animal practitioners for Salmonella Abortusovis abortion in sheep.  相似文献   

3.
Genotyping of Salmonella strains is an important tool to discriminate among isolates and to improve epidemiological studies when an outbreak occurs. No phagetyping scheme is available for Salmonella enterica subsp. enterica serovar Abortusovis (SAO) and molecular methods previously used were not standardized and were time consuming. Among the DNA-based methods of genotyping, pulsed field gel electrophoresis (PFGE) is currently in use to subtype Salmonella isolates. In this study we evaluated the feasibility of genotyping of SAO by XbaI and BlnI restrictions. Separation of restricted fragments was performed by PFGE. To test the possibility to apply this methodology to epidemiological investigation, a collection of 38 SAO strains isolated in different regions of Italy were analyzed. Eighteen and 29 different PFGE profiles were defined for XbaI and BlnI digestions, respectively. The method demonstrated an adequate typing ability and an excellent discriminatory power. Results from this study show that PFGE may represent a powerful tool to discriminate within the SAO serovar, and provide useful information in support of traditional epidemiological investigations. In particular, this method could be used to identify the origin of infection during outbreaks within a single flock or in different herds.  相似文献   

4.
AIMS: To genotype Campylobacter fetus subsp. fetus isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the year 2000 breeding season. To compare the types found nationally with those found in the Hawke's Bay region in 1999, and strains held in the New Zealand Reference Culture Collection, Medical Section (NZRM) from a study published in 1987. METHODS: Campylobacter fetus subsp. fetus isolates cultured by veterinary diagnostic laboratories in the year 2000 breeding season, from sheep abortions from throughout New Zealand, were typed using pulsed-field gel electrophoresis (PFGE). In addition, seven freeze-dried C. fetus subsp. fetus isolates (strain numbers 2939-2945) from the NZRM, representing restriction types a-g found amongst sheep abortion isolates in a study published in 1987, were typed using PFGE. RESULTS: In total, 293 C. fetus subsp. fetus isolates from 200 farms were obtained from veterinary diagnostic laboratories. Twenty-two distinct PFGE profiles were identified amongst the isolates. PFGE type B1 was predominant in each region of New Zealand and was identified from 66% of farms overall. Of the C. fetus subsp. fetus restriction types a-g lodged with the NZRM, 3/7 had PFGE profiles indistinguishable from profiles found in the current study. The other four restriction types had PFGE profiles that were unique but similar to those found in the current study. CONCLUSIONS: PFGE type B1 was predominant amongst the C. fetus subsp. fetus isolates cultured from sheep abortions in each region of New Zealand in the year 2000, as was found in Hawke's Bay in 1999. The similarity between PFGE profiles of C. fetus subsp. fetus sheep abortion isolates from 1987 and 2000, and the relative prevalence of the PFGE groups, suggests that there has been no major genotypic shift in the population of C. fetus subsp. fetus implicated in sheep abortion in New Zealand during this time.  相似文献   

5.
Campylobacter species are a significant cause of sheep abortion in most sheep-raising countries. In New Zealand, Campylobacter fetus subsp. fetus is the leading cause of diagnosed sheep abortion and the species C. jejuni and C. coli have also been implicated. To date, strain typing information of C. jejuni sheep abortion isolates is limited. The objective of the present study was to genotype C. jejuni isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the 2000 breeding season, using pulsed-field gel electrophoresis (PFGE). In this study, C. jejuni isolates were cultured from approximately 10% of farms from which Campylobacter species were isolated from sheep abortions in the year 2000. This equated to 25 C. jejuni isolates from 21 farms. These isolates were obtained from the veterinary diagnostic laboratories and strain typed using the molecular typing technique PFGE. Ten distinct PFGE types were identified amongst the isolates. No particular PFGE type was found most frequently amongst these C. jejuni sheep abortion isolates. However, indistinguishable or similar C. jejuni PFGE types were identified from different aborted foetuses from the same flock, consistent with the role of C. jejuni as an infectious cause of abortion in sheep. These strain types were similar or indistinguishable from C. jejuni sheep abortion isolates obtained in 1999 in a smaller study (Mannering, S.A., Marchant, R.M., Middelberg, A., Perkins, N.R., West, D.M., Fenwick, S.G., 2003. Pulsed-field gel electrophoresis typing of C. fetus subsp. fetus from sheep abortions in the Hawke's Bay region of New Zealand. NZ Vet. J. 51, 33-37).  相似文献   

6.
Resistance to 16 antimicrobial agents was monitored in 109,125 Salmonella cultures isolated from animals, their environment and feedstuffs between 1988 and 1999. The sensitivity of the 6512 isolates of Salmonella enterica enterica serotype Dublin to all the antimicrobial agents tested varied from 98.2 per cent in 1997 to 99.7 per cent in 1990 and 1996. In contrast, among 28,053 isolates of Salmonella enterica enterica serotype Typhimurium, there was a marked decrease in their sensitivity to all the antimicrobial agents tested, from 57.4 per cent in 1992 to 7.6 per cent in 1995, owing to the widespread occurrence in farm animals of S Typhimurium isolates of the definitive type DT104, resistant to ampicillin, sulphonamides, streptomycin, chloramphenicol and tetracyclines, although the percentage of sensitive isolates increased to 18.4 per cent in 1999, when the incidence of DT104 had decreased. Some isolates of DT104 also showed an increase in resistance to potentiated sulphonamides (2.4 per cent in 1989 to 19.2 per cent in 1999) and nalidixic acid (0 per cent in 1992, 3.8 per cent in 1995 to a peak of 16.9 per cent in 1998). In 1996, 5.1 per cent of 1086 isolates of S Typhimurium from cattle and 35.9 per cent of 192 isolates of S Typhimurium from poultry showed resistance to nalidixic acid. Of the other 74,528 Salmonella isolates, the percentage of strains sensitive to all the antimicrobials tested decreased slightly from 88.2 per cent in 1988 to 70.6 per cent in 1996 and then increased slightly to 73.7 per cent in 1999. The commonest of these other Salmonella serotypes was Salmonella Enteritidis (20,982), which remained predominantly susceptible (ranging from 81.4 to 97.4 per cent) during the study period. Few isolates were resistant to commonly used veterinary antimicrobials, for example, furazolidone, the use of which was banned in 1990, and the aminoglycoside, apramycin.  相似文献   

7.
In this study, a dot-enzyme-linked immunosorbent assay (Dot-ELISA) was evaluated in comparison with a complement fixation test (CFT) for the detection of Campylobacter antibodies in sheep sera. Acid glycine extracts (AGE) of both Campylobacter fetus ssp. fetus and Campylobacter jejuni strains that had been isolated from the gall-bladder of slaughtered sheep was used as antigen in both tests. A total of 153 sheep sera from aborted (74) and slaughtered (79) sheep were examined by both Dot-ELISA and CFT. Twenty-two sera showed anti-complementary activity were not suitable for CFT. Of the 22 sera showing anti-complementary activity, two sera were found to be positive in Dot-ELISA. Eighty-eight (67.2%) of the remaining 131 sera were negative by both Dot-ELISA and CFT using AGE of both Campylobacter strains whereas 43 sera (32.8%) gave different reaction patterns in Dot-ELISA and CFT with the extracts of both Campylobacter strains. Twelve sera were positive by both tests using AGE of C. fetus ssp. fetus but CFT failed to detect antibodies in nine of these sera when AGE of C. jejuni was used. Twelve sera were positive by both tests only when AGE of C. fetus ssp. fetus was used. Eleven sera were positive only by CFT. Seven of these reacted only with the AGE of C. fetus ssp. fetus and four sera were positive by using AGE of both Campylobacter strains. The remaining eight sera were found to be positive only by dot-immunobinding assay either with the AGE of both Campylobacter strains or with the AGE of one of the Campylobacter strains. It is concluded that Dot-ELISA using AGE from C. fetus ssp. fetus could be employed for the detection of Campylobacter antibodies in sheep sera and the additional use of AGE from C. jejuni as antigen appeared not to be profitable for this purpose.  相似文献   

8.
An immunohistochemistry (IHC) procedure for the detection of Campylobacter fetus antigens using an avidin-biotin complex technique was performed on formalin fixed bovine and ovine fetal tissues from 26 natural cases of Campylobacter spp. abortion (four ovine and 22 bovine). The species of Campylobacter isolated included C. fetus ssp. venerealis from 13 bovine fetuses, C. fetus ssp. fetus from two ovine and one bovine fetus, Campylobacter jejuni from seven bovine fetuses, Campylobacter lari from two ovine fetuses and an unspeciated Campylobacter species in one bovine fetus. Histologic lesions identified in the aborted fetuses included placentitis, serositis, pneumonia, gastroenteritis, hepatitis and encephalitis. Campylobacter fetus antigens were identified by IHC in 13 of 13 bovine fetuses from which C. fetus ssp. venerealis was isolated and in two of two ovine fetuses from which C. fetus ssp. fetus was isolated. The IHC stains were negative in tissues from seven bovine fetuses from which C. jejuni was isolated, one bovine fetus infected with C. fetus ssp. fetus, one bovine fetus infected with the unspeciated Campylobacter and two ovine fetuses infected with C. lari. In positive cases, the IHC stain most frequently identified bacteria in the lung and gastrointestinal tract. The C. fetus IHC procedure performed on formalin fixed tissues is a practical tool for the diagnosis of natural cases of ovine and bovine abortion caused by C. fetus.  相似文献   

9.
10.
为探究缅甸蟒肺炎病因,本研究对海南文昌缅甸蟒养殖场的4条发病缅甸蟒进行了肺和心血组织的病原菌分离纯化、菌落及染色形态观察、生化、和16S rRNA分子鉴定,最后对各分离菌株进行了体外药敏实验。结果显示,全部分离株菌落及细胞形态特征一致,均为革兰氏阴性杆菌;糖醇发酵等生理生化特性与肠道沙门氏菌一致;根据16S rRNA基因的同源性比对,发现分离菌株与肠道沙门氏菌Salmonella enterica subsp.houtenae DSM 9221菌株同源性达到99%,可确定分离株全部为肠道沙门氏菌。通过23种抗菌药物的药物敏感性显示,所分离菌株对氟罗沙星等12种抗生素完全敏感。本研究结果表明海南文昌缅甸蟒肺炎病因为沙门氏菌感染,体外药敏实验可为该病的抗生素治疗提供使用参考。  相似文献   

11.
The relationship of 50 Campylobacter strains isolated from aborted ovine foetuses, and the faeces of sheep, cattle and chickens were determined by numerical analysis of electrophoretic (SDS-PAGE) protein profiles. Comparison of protein patterns by numerical methods revealed differences between C. fetus ssp. fetus, C. jejuni, and C. coli strains as well as heterogeneity among isolates from different outbreaks. Isolates from each farm produced a distinct cluster and flocks from different locations were found to be infected with relatively different strains. In most cases, protein patterns of ovine foetal isolates were very similar to those of ovine faecal isolates. Ovine isolates of C. fetus ssp. fetus, C. jejuni and C. coli gave similar protein patterns to the corresponding Campylobacter species isolated from cattle or chicken, on the same farm. Thus, it was concluded that certain protein types of ovine Campylobacter strains were more likely associated with local areas, and Campylobacter strains causing ovine abortions are distributed in the environment more widely than assumed to date.  相似文献   

12.
OBJECTIVE: To investigate Salmonella enterica infections at a Greyhound breeding facility. DESIGN: Cross-sectional study. ANIMAL AND SAMPLE POPULATIONS: 138 adult and juvenile dogs and S. enterica isolates recovered from the dogs and their environment. PROCEDURES: The investigation was conducted at the request of a Greyhound breeder. Observations regarding the environment and population of dogs were recorded. Fecal, food, and environmental specimens were collected and submitted for Salmonella culture. Isolates were serotyped and tested for susceptibility to 16 antimicrobials. Isolates underwent genetic analyses by use of pulsed-field gel electrophoresis and ribotyping. RESULTS: S. enterica was recovered from 88 of 133 (66%) samples of all types and from 57 of 61 (93%) fecal samples. Eighty-three (94.3%) of the isolates were serotype Newport, 77 (87.5%) of which had identical resistance phenotypes. Genetic evaluations suggested that several strains of S. enterica existed at the facility, but there was a high degree of relatedness among many of the Newport isolates. Multiple strains of Salmonella enterica serotype Newport were recovered from raw meat fed on 1 day. CONCLUSIONS AND CLINICAL RELEVANCE: S. enterica infections and environmental contamination were common at this facility. A portion of the Salmonella strains detected on the premises was likely introduced via raw meat that was the primary dietary constituent. Some strains appeared to be widely disseminated in the population. Feeding meat that had not been cooked properly, particularly meat classified as unfit for human consumption, likely contributed to the infections in these dogs.  相似文献   

13.
AIMS: To investigate the cause of an outbreak of ovine abortion in 1996 in a flock of 300 two-tooth (rising 2-year-old) ewes vaccinated against Campylobacter fetus fetus infection and to subsequently characterise the strain of C. fetus fetus isolated from aborted foetuses. METHODS: Standard bacteriological methods were used to identify C. fetus fetus isolates which were then antigenically typed and subjected to pulsed-field gel electrophoresis (PFGE) and compared to the vaccine strain. RESULTS: C. fetus fetus was identified as the causal agent of the abortions despite the ewes having been vaccinated before ram introduction and at the time of ram removal. Four isolates cultured from aborted material were indistinguishable when compared using antigenic typing and PFGE, but all differed from the vaccine strain. CONCLUSIONS: Within the limitations of the available typing systems, it is proposed that PFGE may be a useful tool to establish the distribution and strain variation of C. fetus fetus. CLINICAL RELEVANCE: This field case indicates the need for further study of non-vaccine C. fetus fetus strains which cause abortion in vaccinated ewes, and of the importance of these strains to the New Zealand sheep industry.  相似文献   

14.
By investigating the prevalence and resistance characteristics of Gram-negative bacteria from organic and conventional kept laying hens against 31 (Campylobacter: 29) different antibiotics using the microdilution method, we determined to what extent different keeping systems influence bacterial resistance patterns. For this purpose, samples from 10 organic and 10 conventional flocks in Bavaria (Germany) were investigated four times between January 2004 and April 2005. Altogether, 799 cloacal swabs and 800 eggs (contents and shells) were examined. The bacterial investigation performed with standardized cultural methods showed prevalence for all bacteria groups in about the same order of magnitude in the two different keeping systems: Salmonella spp. 3.5% (organic ([org])) versus 1.8% (conventional ([con])); Campylobacter spp. 34.8%(org) versus 29.0%(con) and E. coli 64.4%(org) versus 69.0%(con). Coliforms (Citrobacter, Enterobacter, Pantoea) were only isolated in single cases. In eggs, generally less bacteria were detected, predominantly Escherichia; Salmonella and Campylobacter were only scarcely isolated. Salmonella enterica ssp. enterica serovar Typhimurium (n=10) were resistant to up to nine, S. of the serogroup B (n=4) up to six antibiotics. All tested Salmonella (n=23) proved to be resistant to spectinomycin. Escherichia coli (n=257(org) and 276(con)) from organic layers showed significant lower resistance rates and higher rates of susceptible isolates to nine agents, namely amoxicillin/clavulanic acid, ampicillin, cefaclor, cefoxitin, cefuroxime, doxycycline, mezlocillin, neomycin and piperacillin. In contrast, only two antibiotics turned out to be more effective in conventional isolates (gentamicin and tobramycin). In the case of Campylobacter jejuni (n=118(org) and 99(con)), statistically significantly better rates were observed for isolates from organic flocks concerning imipenem and amoxicillin/clavulanic acid, whereas fosfomycin was more potent in strains from conventional flocks. Results of this study indicate that both resistance rates and mean minimum inhibitory concentrations of bacteria isolated from organic keeping systems have lower values than those from conventional ones, particularly recognizable for E. coli. Thus, organic livestock farming with its restrictions and additional requirements contributes to further effectiveness of antibiotics.  相似文献   

15.
The objective of this work was to determine whether persistence of certain Salmonella isolates in fish feed factories involved enhanced resistance to disinfectants or air-drying. Salmonella isolates known to be persistent in fish feed factories and Salmonella isolates from other origins were tested for their sensitivity to nine disinfectants by using a suspension test. More than 5log(10)reduction in viable count for all isolates was only achieved by two of the disinfectants at 80% of the lowest recommended user concentration. However, Salmonella isolates from fish feed factories were not more resistant to disinfectants compared to Salmonella from other origins. For four of the disinfectants, presence of fish feed had a more adverse effect on disinfection efficacy compared to the protein bovine serum albumin (BSA). In general, the Salmonella isolates were more resistant to disinfection than Escherichia coli DSM 682, a strain recommended in testing of disinfectants. The Salmonella isolates were also tested for their ability to survive air-drying at stainless steel surfaces, but there were no differences in survival of isolates from fish feed factories compared to isolates of other origin. In conclusion the Salmonella isolates from fish feed factories were not particularly resistant to disinfection or air-drying at surfaces. The data show that disinfectants to be used against Salmonella should be thoroughly tested and selected, since not all disinfectants appear to be effective against Salmonella.  相似文献   

16.
Salmonella enterica serovar subsp. enterica Livingstone and serovar Cerro isolates from a commercial egg-producing farm, which had previously been untypeable by pulsed-field gel electrophoresis (PFGE) because of DNA degradation during the PFGE process, successfully gave banding patterns using electrophoresis buffer supplemented with 50 microM thiourea. By PFGE in the presence of thiourea, DNA degradation-sensitive S. enterica serovar Cerro isolates from the commercial egg-producing farm were found to be genetically unrelated to S. enterica serovar Cerro isolates that gave the patterns in the absence of thiourea. Forty-five of 50 (90%) S. enterica serovar Livingstone isolates from the farm showed arbitrarily designated XbaI-digested patterns X1 and X2 that were distinguished by one-band difference and had an identical BlnI-digested pattern. In one of the two layer houses in the farm, the numbers of isolates having the pattern X2 increased from 57% in 1997 to 89% in 1998, whereas virtually all the isolates obtained from the other house in the same period showed the profile X1. This suggests that strains having the pattern X2 might have an advantage to preferentially colonize in the former house.  相似文献   

17.
The prevalence of faecal carriage of salmonella in 5393 pigs reared on 218 pig farms located in 31 of 47 prefectures in Japan over the period July 2003 to June 2005 was investigated. We isolated 172 strains belonging to 20 serovars and one untypable Salmonella enterica from 169 pig faecal samples (3.1%) collected from 48 farms (22.0%). The most prevalent type of S. enterica was untypable O4,12:d:- which lacks phase 2 flagellar antigen, representing 29.1% (50/172) of all isolates. Of 26 S. enterica serovar Typhimurium isolates, 16 strains appeared to be definitive phage type 104 (DT104) by polymerase chain reaction.  相似文献   

18.
Salmonella virulence plasmids (SVPs) are large and closely related low-copy plasmids harbored by certain serovars of Salmonella enterica subspecies enterica. These serovars not only comprise those of veterinary significance like Abortusequi, Abortusovis, Choleraesuis, Dublin and Gallinarum/Pullorum, but also Typhimurium and Enteritidis which currently are the most prevalent serotypes in humans and food animals. Experiments with several animal species gave evidence that SVPs increase Salmonella strains' capabilities to replicate in extraintestinal organs of infected hosts thus leading to death of those hosts more frequently and rapidly. The common feature of all SVPs is the "Salmonella plasmid virulence" locus (spv-locus), a highly conserved 7.8 kbp region that is most responsible for the SVP-encoded virulence phenotype of Salmonella. Although functional characterisation of spv gene products has made some progress the molecular mechanism of spv-mediated virulence has not been fully elucidated yet. Some SVPs carry additional gene loci causatively related to Salmonella virulence like the pef-operon of Typhimurium and Enteritidis strains which encodes an adhesive type of fimbria, or genes traT, rsk and rck which are involved in serum resistance. The frequent occurrence of SVPs in host-adapted serovars suggests that SVP-encoded factors represented selective advantages to some Salmonella variants in their effort to colonize certain new niches during Salmonella evolution. This study provides an overview over current knowledge about the virulence plasmids of Salmonella enterica.  相似文献   

19.
Blood samples were taken from 50 pigs in each of 59 farrow-to-finish production herds and from 40 pigs in each of four of five registered multiplying herds. Samples of feed and faeces were also collected from 17 of the production herds and from the four multiplying herds. The sera were tested for antibodies to Salmonella enterica by the Danish mix-ELISA, and the organisms were isolated, serotyped and sensitivity tested by standard techniques. The average within-herd seroprevalence was 3.4 per cent and at least one pig tested seropositive in 21 of the 59 herds. In the multiplying herds, only a single seroreactor was detected. Salmonellae were isolated from only five of 95 feed samples, from two of the 17 herds sampled, Salmonella tennessee in four of five samples from one herd and an untypable strain in one of five samples from another. Four infected faecal samples were detected in four herds; they harboured Salmonella typhimurium, Salmonella bredeney or Salmonella london. No salmonellae were isolated from the samples of feed and faeces taken from the multiplying herds. The S london and S typhimurium had a low sensitivity to streptomycin, kanamycin and neomycin, and the S typhimurium also had low sensitivity to amoxycillin, ticarcillin, piperacillin, amoxycillin + clavulanic acid, cefalotin and cefoperazone. The other isolates were sensitive to all the antimicrobial agents tested.  相似文献   

20.
AIM: To type Campylobacter isolates from sheep abortions from the Hawke's Bay region of New Zealand. METHODS: Campylobacter isolates were collected from aborted sheep fetuses from commercial farms in the Hawke's Bay region. Information on the Campylobacter vaccination status of flocks in the study was collected. Isolates were identified to species level using standard phenotypic tests, then typed using pulsed-field gel electrophoresis (PFGE). RESULTS: Eighty-one C. fetus subsp. fetus isolates were cultured from aborted sheep fetuses from 25 farms and four C. jejuni isolates were cultured from fetuses from three farms. The C. fetus subsp. fetus isolates were classified into six PFGE groups. A single pulsed-field type predominated amongst isolates from 19 of the 25 farms. The C. jejuni isolates comprised two types. CONCLUSIONS: A range of C. fetus subsp. fetus PFGE types was identified, and one type, B1, was found most frequently. Campylobacter fetus subsp. fetus was only isolated from samples from sheep that had not been vaccinated with C. fetus subsp. fetus vaccine that season.  相似文献   

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