鸡空肠弯曲菌对SPF雏鸡致病性研究

用鸡空肠弯曲菌（Ｃａｍｐｙｔｏｂａｃｅｃｒｉｅｊｕｎ：）对１日龄ＳＰＦ（Ｓｐｃｉｉｃ－ｐａｔｈｏｇｅｎｆｒｃｅ）雏鸡进行感染实验。随机将６０只１日龄ＳＰＦ雏鸡分为４组，那和对照组，每组１５只。分别用含菌７．５Ｘ１０８ＣＦＵ／ｍｌ、７．５ｘ１０４ＣＦＵ／ｍｌ，７．５×１０２ＣＦＵ／ｍｌ布氏肉汤菌液经口时ｔ、Ｊ、Ｉ组接种。接种后分别于２、４、６，８、１０日踏踏机取３只／组、经剖构观察病理变化；从心血、肝、胆汁、脾、肠内容物分离病原菌，测量肠道内物空肠弯曲菌菌数。得出以下结论；经口接种３．７５ｘ１０２ＣＦＵ空场弯曲菌即可造成１日龄ＳＰＦ雏鸡感染发病；感染鸡的主要病理变化为肝脏表面有点状，条索状或片状出血，同时伴有形状不规则大小不等的黄白色坏死灶，盲肠膨大充满气泡，十二指肠、空肠、直肠粘膜有散在的小出血点，首选检苗材料为胆汁、其次是脾、肝等器宫。     

Polyclonal activation of B cells occurs in lymphoid organs from porcine reproductive and respiratory syndrome virus (PRRSV)-infected pigs

Porcine reproductive and respiratory syndrome virus (PRRSV) induces a persistent viral infection associated with an inefficient humoral immune response. A study of lymphoid B cells and specific humoral immune response was performed in blood and several lymphoid organs collected from PRRSV experimentally-infected pigs. Groups of specific pathogen-free (SPF) pigs were infected with the LHVA-93-3 isolate of PRRSV, and blood, tonsils, spleen and mediastinal lymph nodes (MLN) were collected at various times postinfection (p.i.) (3-60 days). Lymphoid cells were isolated, immunolabeled for cytofluorometric determination of B cell percentages, used for counting specific anti-PRRSV antibody secreting B cells by an ELISPOT assay, or cultured for metabolic activity. The presence of anti-PRRSV antibodies in the serum of infected pigs was determined using a commercial ELISA assay. Virus detection was performed in all tissues, including lungs, by virus isolation and RT-PCR. The results show that percentages of B cells increased in tonsils as soon as 3 days until 17 days p.i. in PRRSV-infected pigs while they increased in spleen at 3 days p.i. only, due to an increase of larger Ig(high)-producing B cells. Metabolic activity of lymphoid cells from blood and spleen increased at 3 days p.i. only while lymphoid cells from tonsils and MLN transiently decreased at that time and increased thereafter up to 60 days p.i. Anti-PRRSV antibody-secreting B cells occurred in tonsils after 10 days p.i. and strongly increased up to 60 days p.i. However, specific anti-PRRSV-secreting B cells were detected in blood and spleen after 17 days p.i and in MLN only after 45 days p.i. Specific antibodies were detectable in serum at 10 days p.i., reached the maximum level at 45 days and remained high up to 60 days p.i. Infectious virus was detected in lungs and MLN as soon as 3 days p.i., and remained detectable up to 45 days p.i. in tonsils of one pig while viral RNA was detected in most organs up to 60 days p.i. In vitro experiments revealed that inactivated virus induced a stimulation of lymphoid cells isolated from PRRSV-infected pigs while it was cytotoxic for lymphoid cells from control pigs. Taken together, these results indicate that viral infection induced simultaneously a polyclonal activation of B cells, mainly in tonsils, and an exaggerated and prolonged specific humoral immune response due to persistent viral infection in lymphoid organs.     

The effects of intestinal Escherichia coli 263, intravenous infusion of Escherichia coli 263 culture filtrate and iron dextran supplementation on iron metabolism in the young pig

An experiment using 32 pigs in a 2(3) factorial arrangement of treatments was used to determine the effects on the (1) level of iron dextran supplementation, (2) iv infusion of an Escherichia coli 263 culture filtrate and (3) presence of E. coli 263 in a ligated intestinal segment, on the ability of the young pig to limit systemic Fe availability. Iron dextran was administered im 3 d postpartum. Culture filtrate was infused iv, E. coli were injected into ligated intestines and blood sampling was started at 14 d postpartum. Blood was taken every 2 h for 22 h, after which pigs were euthanized and livers, spleens and kidneys were removed. Pigs receiving 400 mg of iron dextran (HiFe) exhibited greater serum Fe (SFe) and lower total Fe-binding capacity (TIBC) than pigs injected with 100 mg Fe (LoFe). The effects of the E. coli culture filtrate infusion appeared to be associated with endotoxin-induced circulatory shock. The presence of E. coli in the intestine increased TIBC in LoFe pigs, but not in HiFe pigs. The increase in TIBC coincided with the time of maximal fluid secretion into the intestine. Intestinal E. coli also caused an increase in liver Fe content, particularly in HiFe pigs. These data suggest that intestinal E. coli can cause a shift of Fe from the plasma to the reticuloendothelial system, and pigs receiving high supplemental dosages of Fe are less able to limit the availability of Fe to microorganisms.     

Relationship between blood iron parameters and trichinellosis in swine

Reduced levels of total iron binding capacity and unsaturated iron binding capacity were observed in the blood of trichinous and iron-injected trichinous pigs. No change was observed in their serum iron and saturation concentration levels. Also, reduced iron concentration levels were observed in the livers of trichinous pigs, while increased iron concentration levels were observed in the spleens of trichinous pigs and the livers and spleens of iron-injected pigs. No difference was found with regard to weight gains, number of larvae per gram of tissues, or histologic characteristics of 'nurse cells'.     

Serologic survey for Bordetella bronchiseptica in Nebraska specific-pathogen-free pigs

The frequency of Bordetella bronchiseptica infection in Nebraska specific-pathogen-free (SPF) pigs was determined by serologic and bacteriologic cultural analysis. Serum samples from non-SPF herds were tested for comparison. A total of 1,282 of 1,397 (92%) of the SPF pigs tested had antibody to B bronchiseptica; 37 of 220 (17%) were culture-positive, and 67 of 4125 (1.6%) were considered suspicious for atrophic rhinitis during slaughter inspection. A higher percentage of the non-SPF pigs had titers to B bronchiseptica (642 of 659 pigs or 97% of the pigs tested). There was no relationship between the B bronchiseptica antibody titer, the isolation of B bronchiseptica, or the frequency of gross lesions of atrophic rhinitis from pigs within the herd. The serum agglutination test may be a more reliable procedure for determining the herd prevalence of B bronchiseptica than isolation of the organism by cultural methods.     

Transmission of pathogenic respiratory bacteria to specific pathogen free pigs at slaughter

The purpose of this study was to evaluate the transmission of pathogenic respiratory bacteria to thirteen 5-month-old specific pathogen free (SPF) pigs, during the slaughtering process in a commercial slaughterhouse. Before transportation, the SPF pigs and the lorry were checked to confirm the absence of pathogenic respiratory bacteria.

Nine SPF pigs (group 1) were in contact in a conventional slaughterhouse with finishing pigs, during 4 h before slaughtering. Four SPF pigs (group 2) were slaughtered immediately at arrival in the slaughterhouse.

Five bacterial pathogens (Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Pasteurella multocida, Haemophilus parasuis and Streptococcus suis) were detected by PCR, after slaughtering, from nasal cavities, tonsils and trachea in the two groups of pigs. Lung samples were PCR negative. Three and four bacterial species were isolated from the pigs of group 2 and group 1, respectively. Cultures were negative from the lungs.

All the bacterial species present in the SPF pigs were detected by PCR. P. multocida was isolated, from three samples of scalding water before the onset of slaughtering.

Our results suggest that the SPF pigs became contaminated mainly by the slaughterhouse environment and the scalding water. Histological examinations revealed that during scalding, contaminated water could reach the trachea and the lungs of pigs. Checks conducted at slaughter for respiratory disorders have to be carried on, but nasal cavities and tonsils are not appropriate for bacteriological investigations. Moreover, bacteriological results obtained from the lungs of slaughtered pigs have to be used with carefulness.     

Influence of On‐farm pig Salmonella status on Salmonella Shedding at Slaughter

The risk of Salmonella shedding among pigs at slaughter with regard to their previous on‐farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated‐measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non‐shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5–15.5) and 20.9 (3.7–118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN.     

Enterotoxigenic Escherichia coli in the jejunum of piglets with neonatal diarrhea

Thirty-two Escherichia coli colonies were taken from the primary step of cultivation of the jejunal contents of each of 10 dead piglets which had suffered from diarrhea. The organisms of each colony were examined for the presence of adhesion fimbria (F4 (K88) and F5 (K99)), production of heat-stable and heat-labile enterotoxin and of colicins.The presence of heat-labile enterotoxin in the intestinal content of the necropsied pigs was also tested, and results correlated with enterotoxin production of the isolated E. coli strains. In all but 3 pigs, 50–80 % of the E. coli strains were found to produce one or both of the enterotoxins and to possess the F4 of the F5 antigen. All bacteria producing both heat-labile and heat-stable enterotoxin proved to belong toi O group 149 and to possess the F4 antigen. Strains from 1 pig belonged to O group 64 and possessed the F5 antigen; these bacteria produced heat-stable enterotoxin only. Most of the enterotoxin-producing E. coli also produced colicins.After each subcultivation, the strains produced less heat-labile enterotoxin, some becoming negative when assayed.     

Levamisole mucosal adjuvant activity for a live attenuated Escherichia coli oral vaccine in weaned pigs

The present study tested the hypothesis that levamisole exerts its immunopotentiating activity in weaned pigs vaccinated against colibacillosis by priming the lymphocytes and macrophages in the mesenteric lymph node (MLN). Ten weaned piglets were used and allocated into two equal groups. The experimental group was intramuscularly primed with levamisole at an immunostimulatory dose of 2.5 mg/kg given daily, in three consecutive days, and controls received saline according to the same schedule. Both groups were orally vaccinated with the vaccinal Escherichia coli strain on day 0 and challenged with the virulent E. coli strain 7 days later. All pigs were killed on postchallenge day 6. Upon virulent challenge the health status of the two groups was evaluated by clinical observations, and expression of CD25, SWC7 and SWC9 activation antigens by MLN and spleen T and B cells and macrophages, respectively, was tested using flow cytometry. Priming by levamisole significantly contributed to the effectiveness of a live attenuated oral vaccine against porcine postweaning colibacillosis, as evidenced by a good health status of primed vaccinated vs. un-primed vaccinated pigs. The CD3+, CD25+ and SWC9+ MLN but not spleen T cells and macrophages increased in experimental vs. control pigs, implying that levamisole exerts its potentiating activity in the MLN by augmenting both recruitment and activation of cells that participate in cell-mediated immunity.     

猪细环病毒的检测及与多种病原混合感染的调查分析

为了解细环病毒(Torque teno virus,TTV)在广西猪群中的感染情况,本研究运用Nest-PCR方法,对2009—2011年采自广西140个规模猪场的156份血液、流产胎儿及肺脏、脾脏、肾脏、肝脏、淋巴结等组织样品进行检测,并对阳性样品的非编码区(UTR)进行克隆测序及遗传进化分析;同时对部分样品进行猪圆环病毒2型(PCV2)、猪繁殖与呼吸综合征病毒(PRRSV)、典型猪瘟病毒(CSFV)、伪狂犬病病毒(PRV)检测及细菌的分离鉴定。结果发现,广西猪群中TTV总感染率达到93.6%,TTV2的感染率(76.9%)不仅明显高于TTV1(16.7%),且毒株间遗传变异较大。TTV多与PCV2和PRRSV混合感染,且以与PRRSV混合感染率更高(64.29%)。猪群中存在2重、3重,甚至4重TTV与其他病毒的混合感染。临床上TTV与细菌的混合感染(或细菌继发感染)以链球菌和副猪嗜血杆菌多见。本研究证实在广西猪群中存在TTV感染,且存在普遍的TTV与PRRSV、PCV2和CSFV混合感染。     

Field outbreaks of colibacillosis of turkeys associated with hemorrhagic enteritis virus

In a study of field material and a survey conducted by the authors, typical signs of colibacillosis of 6-to-12-week-old poults included sudden onset, listlessness, rales, and high mortality. Signs persisted for about 2 weeks and were often followed by a low incidence of lameness caused by Escherichia coli. Gross lesions included enlarged and congested spleens and livers, and dilated discolored black or purple duodenal loops. Microscopic lesions included splenic and hepatic congestion. In some birds (freshly killed and fixed immediately), the epithelium at the tips of the duodenal villi was sloughing, but in other birds the villi were intact and normal in appearance. Splenic enlargement, the presence of intranuclear splenic inclusions similar to those found in hemorrhagic enteritis (HE), and the isolation of HE virus from some of the field spleens all indicated that inapparent HE infection often occurs at approximately the same time as this type of colibacillosis. It is therefore believed that HE infection often exacerbates colibacillosis of older poults.     

Campylobacter jejuni in poultry giblets

A total of 200 poultry giblets, 50 each of chickens, ducks, squab and turkeys, were examined for the presence of Campylobacter jejuni. In chicken giblets, C. jejuni was isolated from gizzards, hearts, livers and spleens with incidences of 28%, 10%, 40% and 16% respectively while 24%, 6%, 36% and 10% of duck gizzards, hearts, livers and spleens were positive for the organism, respectively. C. jejuni was detected in 6% of squab gizzards, in 10% of squab livers but failed to be detected in squab hearts & spleens. In turkey giblets, 16% of gizzards, 4% of hearts, 30% of livers and 8% of spleens were positive for the organism. C. jejuni was more frequently isolated from liver samples than gizzard, spleen and heart samples, each constituting of 29%, 18.5%, 8.5% and 5%, respectively. High incidence of C. jejuni was recorded among chicken giblets (23.5%), followed by duck giblets (19%), then turkey giblets (14.5%) and finally squab giblets (4%).     

Effects of an experimental infection with Actinobacillus pleuropneumoniae on the interferon-alpha and interleukin-6 producing capacity of porcine peripheral blood mononuclear cells stimulated with bacteria, virus or plasmid DNA

The effect of a bacterial infection on interferon-alpha (IFN-alpha) and interleukin-6 (IL-6) production by porcine cells was studied in specific pathogen-free (SPF) pigs, infected intranasally with Actinobacillus pleuropneumoniae serotype 2. Three experimental groups of five pigs were used: infected non-treated pigs, infected pigs that were treated with enrofloxacin at disease onset, and non-infected, non-treated control pigs. Blood samples were collected from all pigs on the day of infection and on days 1, 4, 7, 13 and 17 post-infection. Sera were analysed for presence of antibodies to A. pleuropneumoniae and for the cytokines IL-6 and IFN-alpha. Ability to produce these cytokines was tested in vitro using whole blood cultures stimulated with inactivated virus (Aujeszky's disease virus infected porcine kidney cells (ADV/PK-15)), inactivated bacteria (A. pleuropneumoniae) or bacterial plasmid (pcDNA3). All cytokine inducers were used neat or pre-incubated with the transfectious agent lipofectin. IL-6 appeared in the serum of all infected non-treated animals but no IFN-alpha was found in the serum of any of the experimental pigs. Accordingly, the bacteria induced a substantial IL-6 but hardly any IFN-alpha production when tested in vitro. However, following incubation with lipofectin, the inactivated bacteria as well as pcDNA3 became efficient inducers of IFN-alpha in whole blood cultures. The increased IFN-alpha production, previously recorded in vitro during the acute phase of infection with A. pleuropneumoniae, was confirmed using lipofected plasmid DNA and it was indicated that leukocytes obtained from infected but apparently cured animals also exhibited an increased production of IFN-alpha. Thus, even mild/sub-clinical bacterial infections may affect cytokine production in pigs.     

Bacterial microflora of normal and telangiectatic livers in cattle.

OBJECTIVE: To identify potential bacterial pathogens in normal and telangiectatic livers of mature cattle at slaughter and to identify consumer risk associated with hepatic telangiectasia. SAMPLE POPULATION: 50 normal livers and 50 severely telangiectatic livers. PROCEDURE: Normal and telangiectatic livers were collected at slaughter for aerobic and anaerobic bacterial culture. Isolates were identified, and patterns of isolation were analyzed. Histologic examination of all livers was performed. RESULTS: Human pathogens isolated from normal and telangiectatic livers included Escherichia coli O157:H7 and group-D streptococci. Most livers in both groups contained bacteria in low numbers; however, more normal livers yielded negative culture results. More group-D streptococci were isolated from the right lobes of telangiectatic livers than from the left lobes, and more gram-negative anaerobic bacteria were isolated from left lobes of telangiectatic livers than from right lobes. All telangiectatic lesions were free of fibrosis, active necrotizing processes, and inflammation. CONCLUSIONS AND CLINICAL RELEVANCE: The USDA regulation condemning telangiectatic livers is justified insofar as these livers contain more bacteria than normal livers do; however, normal livers contain similar species of microflora. Development of telangiectasia could not be linked to an infectious process. The finding of E coli O157:H7 in bovine livers suggests that information regarding bacterial content of other offal and muscle may identify sources of this and other potential foodborne pathogens and assist in establishing critical control points for the meat industry.     

Expression of Toll-like receptors, interleukin 8, macrophage migration inhibitory factor, and osteopontin in tissues from pigs challenged with Salmonella enterica serovar Typhimurium or serovar Choleraesuis

Two serovars of Salmonella enterica, namely serovar Typhimurium (ST) and serovar Choleraesuis (SC) account for the vast majority of clinical cases of swine salmonellosis worldwide. These serovars are thought to be transmitted among pigs in production settings mainly through fecal-oral routes. Yet, few studies have evaluated effects of these serovars on expression of innate immune targets when presented to pigs via repeated oral dosing in an attempt to model transmission in production settings. Thus, a primary objective of the current experiments was to evaluate expression of Toll-like receptors (TLR) and selected chemoattractive mediators (interleukin 8, IL8; macrophage migration inhibitory factor, MIF; osteopontin, OPN) in tissues from pigs exposed to ST or SC that had been transformed with kanamycin resistance and green (STG) or red (SCR) fluorescent protein to facilitate isolation from pen fecal samples. In vitro studies confirmed that STG and SCR largely (though not completely) retained their ability to upregulate IL8 and CC chemokine ligand 20 (CCL20) in cultured swine jejunal epithelial cells. Transformed bacteria were then fed to pigs in an in vivo study to determine tissue specific effects on mRNA relative expression. Pigs were fed cookie dough inoculated with bacteria on days 0, 3, 7, and 10 with 10(8)CFU STG (n=8) or SCR (n=8), while control (CTL) pigs (n=8) received dough without bacteria. Animals were sacrificed 14 days from the initial bacterial challenge and samples of tonsil, jejunum, ileum, colon, mesenteric lymph node (MLN), spleen, and liver were removed for subsequent RNA isolation. Expression of mRNA in tissues was determined using real-time quantitative PCR and expressed relative to 18S rRNA. Within CTL pigs, when expressed relative to the content in liver, mRNA for all targets demonstrated substantial tissue effects (P<0.001 for all TLR; MIF, and OPN; P<0.05 for IL8). Feeding STG and SCR resulted in significant (P相似文献   

Immune response to haemophilus parahaemolyticus (HP) infection in the pig I. In vitro tests to detect sensitized cells in the blood of infected and vaccinated animals

The in vitro immune response of pigs in herds infected or non-infected with H. parahaemolyticus (HP) was investigated by lymphocyte stimulation and leucocyte migration inhibition tests. The stimulation of pig lymphocytes with HP bacteria has been measured by ³H-thymidine incorporation. The response of the cells seems to be specific, lymphocytes from chronically HP-infected animals showed positive reactions with high frequency, while on the contrary, cells from SPF (specific pathogen free) animals reacted only occasionally to the HP antigens. However, in the leucocyte migration inhibition test the reactions were less specific; the widely occurring H. parasuis bacteria seem to possess antigen(s) which causes cross reactions with HP in this test.Vaccination with HP bacteria induced sensitive lymphocytes in the blood of SPF pigs and an increase of the in vitro lymphocyte reactions in already positive animals.     

Relationship between Salmonella infection,shedding and serology in fattening pigs in low–moderate prevalence areas

Salmonella is a major foodborne pathogen causing important zoonosis worldwide. Pigs asymptomatically infected in mesenteric lymph nodes (MLN) can be intermittent shedders of the pathogen through faeces, being considered a major source of human infections. European baseline studies of fattening pig salmonellosis are based on Salmonella detection in MLN. This work studies the relationship between Salmonella infection in MLN and intestinal content (IC) shedding at slaughter and the relationship between the presence of the pathogen and the serologic status at farm level. Mean Salmonella prevalence in the selected pigs (vertically integrated production system of Navarra, Spain) was 7.2% in MLN, 8.4% in IC and 9.6% in serum samples. In this low–moderate prevalence context, poor concordance was found between MLN infection and shedding at slaughter and between bacteriology and serology. In fact, most of shedders were found uninfected in MLN (83%) or carrying different Salmonella strains in MLN and in IC (90%). The most prevalent Salmonellae were Typhimurium resistant to ACSSuT ± Nx or ASSuT antibiotic families, more frequently found invading the MLN (70%) than in IC (33.9%). Multivariable analysis revealed that risk factors associated with the presence of Salmonella in MLN or in IC were different, mainly related either to good hygiene practices or to water and feed control, respectively. Overall, in this prevalence context, detection of Salmonella in MLN is an unreliable predictor of faecal shedding at abattoir, indicating that subclinical infections in fattening pigs MLN could have limited relevance in the IC shedding.     

新疆某猪场不同生长期的猪源大肠杆菌对抗生素耐药性调查

为了调查新疆某规模化养猪场不同生长期的猪源大肠杆菌对临床常用抗生素的耐药情况,从该猪场分别采集育肥猪、妊娠猪、保育猪和哺乳猪的粪样。试验采用微量肉汤稀释法,对从粪样中分离出的大肠杆菌进行最小抑菌浓度测定。结果显示,育肥猪、妊娠猪、保育猪和哺乳猪源大肠杆菌分离率分别为85.2%、83.0%、81.0%和83.0%。不同生长期的猪源大肠杆菌均对氨苄西林和阿莫西林/克拉维酸2种抗生素高度耐药,对头孢噻呋都较为敏感。哺乳猪和保育猪源大肠杆菌耐药情况严重,对多种抗生素高度耐药,以5耐为主;妊娠猪源大肠杆菌轻度耐药,以0耐为主;育肥猪源大肠杆菌以3耐为主。不同生长期的猪源大肠杆菌对临床常用抗菌药物的耐药程度不同。     

半乳甘露寡糖对猪门静脉血流速率、氨基酸和葡萄糖的净吸收量及耗氧量的影响

通过对10头15kg体重试验猪实施门静脉血管插管等外科手术,并结合回肠肠系膜静脉灌注对氨基马尿酸(PAH)技术,探讨半乳甘露寡糖对生长猪门静脉血浆流率(PVPF)和血液流率(PVBF)、氨基酸和葡萄糖的净吸收量及耗氧量的影响。10头杜长大阉公猪随机分为2个处理,每个处理5头,单笼饲养于可调节不锈钢代谢笼内,经过14d适应期后,在门静脉、肠系膜静脉、颈动脉安装插管,开始15d正式试验。对照组饲喂玉米-豆粕型基础饲粮,试验组饲喂基础饲粮 0.20%半乳甘露寡糖。结果表明,经过15d饲喂期后,与对照组相比,饲粮添加半乳甘露寡糖可显著降低试猪食后8h内门静脉的平均血浆流率和血液流率,显著提高食后8h内门静脉对氨基酸和葡萄糖的净吸收量,显著降低食后8h内门静脉的耗氧量,也就是说半乳甘露寡糖可通过减少生长猪小肠黏膜对氨基酸和葡萄糖的氧化而增加肠外组织对其吸收。     

Experimental studies in pigs on Trichinella detection in different diagnostic matrices

A total of 72 specific pathogen-free (SPF) and Iberian pigs (three animals per group) were inoculated with 200, 1000 or 20,000 muscle larvae of T. spiralis, T. nativa, T. britovi and T. pseudospiralis. For each animal, the muscle larva burden was evaluated in nine muscle samples by digestion. The anti-Trichinella IgG kinetics in blood samples, taken twice prior and at days 5, 10, 15, 20, 25, 30, 40, 50 and 60 post-inoculation, and in muscle juice, obtained at necropsy, was evaluated by an ELISA using an excretory/secretory antigen. The mean larval recovery rate in SPF/Iberian pigs corresponded with the level of inoculum dose, and tongue, diaphragm and masseter were identified as predilection muscles. In SPF and Iberian pigs receiving 20,000 larvae of T. spiralis, an earlier seroconversion was detected from day 25 post-inoculation. At a 10-fold dilution, the muscle juice showed a good test agreement with blood serum.