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Raghavendra G Amachawadi Wesley A Tom Michael P Hays Samodha C Fernando Philip R Hardwidge T G Nagaraja 《Journal of animal science》2021,99(4)
Liver abscesses in feedlot cattle are polymicrobial infections. Culture-based studies have identified Fusobacterium necrophorum as the primary causative agent, but a number of other bacterial species are frequently isolated. The incidence of liver abscesses is highly variable and is affected by a number of factors, including cattle type. Holstein steers raised for beef production have a higher incidence than crossbred feedlot cattle. Tylosin is the commonly used antimicrobial feed additive to reduce the incidence of liver abscesses. The objective of this study was to utilize 16S ribosomal RNA amplicon sequence analyses to analyze the bacterial community composition of purulent material of liver abscesses of crossbred cattle (n = 24) and Holstein steers (n = 24), each fed finishing diet with or without tylosin. DNA was extracted and the V3 and V4 regions of the 16S rRNA gene were amplified, sequenced, and analyzed. The minimum, mean, and maximum sequence reads per sample were 996, 177,070, and 877,770, respectively, across all the liver abscess samples. Sequence analyses identified 5 phyla, 14 families, 98 genera, and 102 amplicon sequence variants (ASV) in the 4 treatment groups. The dominant phyla identified were Fusobacteria (52% of total reads) and Proteobacteria (33%). Of the top 25 genera identified, 17 genera were Gram negative and 8 were Gram positive. The top 3 genera, which accounted for 75% of the total reads, in the order of abundance, were Fusobacterium, Pseudomonas, and Bacteroides. The relative abundance, expressed as percent of total reads, of phyla, family, and genera did not differ (P > 0.05) between the 4 treatment groups. Generic richness and evenness, determined by Shannon–Weiner and Simpson’s diversity indices, respectively, did not differ between the groups. The UniFrac distance matrices data revealed no clustering of the ASV indicating variance between the samples within each treatment group. Co-occurrence network analysis at the genus level indicated a strong association of Fusobacterium with 15 other genera, and not all of them have been previously isolated from liver abscesses. In conclusion, the culture-independent method identified the bacterial composition of liver abscesses as predominantly Gram negative and Fusobacterium as the dominant genus, followed by Pseudomonas. The bacterial community composition did not differ between crossbred and Holstein steers fed finishing diets with or without tylosin. 相似文献
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J. H. M. Van Zyl 《African Zoology》2013,48(1):55-71
We examined phylogenetic relationships of the Pachydactylus rugosus complex using DNA sequence data from segments of the mitochondrial genes cytochrome b and 16S ribosomal RNA. These molecular data support the contention that members of the rugosus complex, as defined by McLachlan (1979), form a monophyletic group. Further, high levels of sequence divergence observed between currently recognized subspecies (19.1–26.8 % for cytb), even across short geographic distances, support elevation of each member to full specific rank. The pattern of relationship within the P. rugosus complex species is P. rugosus (P. barnardi, P. formosus). Sequence data provide no evidence to support a close relationship between these taxa and P. capensis, to which previous workers had assigned both P. formosus and P. barnardi. 相似文献
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根据GenBank中乳酸杆菌16 S～23 S rRNA基因间沉默区序列设计引物,进一步鏊定猪源乳酸杆菌分离株HZ521;并通过体外试验,以嗜酸乳酸杆菌ATCC 4356为参考菌株,探讨HZ521株的益生素作用.部分16 S～23 S rRNA基因序列同源性分析结果表明,该分离株属于瑞士乳酸杆菌.HZ521株具有较强的产酸能力,能耐受强酸,对Hela细胞的黏附率为87.2%,显著高于ATCC 4356株(P<0.01).表明瑞士乳酸杆菌HZ521株具有益生素特性,可作为肠道益生素的候选菌株. 相似文献
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利用分子生物学技术对高原鼠兔感染皮蝇蛆16SrRNA基因进行了研究,扩增出长度为551 bp的序列,克隆测序,将其序列与GenBank中的皮蝇科、胃蝇科的序列进行了聚类分析,并构建分子进化树.结果显示,感染高原鼠兔的皮蝇蛆与皮蝇科的皮蝇蛆遗传距离更近,在一个大的进化树分支上,基因片段同源性84.6％～88.4％之间,与胃蝇科的红尾胃蝇基因片段同源性60.1％ ～64.4％之间.几株感染高原鼠兔的皮蝇蛆之间的基因片段同源性94.4％～99.6％之间. 相似文献
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《The Journal of Applied Poultry Research》2006,15(1):145-153
Necrotic enteritis is a complex disease condition of broiler chickens, commercial layer pullets, and turkeys and requires the presence of a toxigenic strain of Clostridium perfringens, alteration of bird diets, and damage to the intestinal epithelium. All of these alone, but especially in combination, result in significant alterations of the intestinal microflora. The intestinal microflora is part of a complex ecosystem that is involved in augmenting intestinal development, immune surveillance, and competitive exclusion against pathogenic organisms. However, when the microflora fails to protect the mucosa from pathogens, antimicrobials are used to reduce the numbers of pathogenic organisms or to prevent their colonization of the intestine. We were interested in studying the effects of monensin on the bacterial community within the ileum of chickens because ionophore antimicrobials are commonly used to prevent Eimeria infections in broilers. We used two 16S ribosomal DNA community analysis protocols, terminal restriction fragment length polymorphism analysis combined with 16S rDNA clone libraries. These methods showed that monensin caused significant alterations in the microbial community structure of the ileum. Whereas the ileal bacterial community of control birds primarily consisted of lactobacilli, monensin-treated birds had communities rich in clostridia. None of the birds exhibited signs of intestinal disease or mucosal lesions, which suggested that the clostridia were avirulent. Although the therapeutic benefits of monensin may largely result from its anticoccidial effects, its ability to foster a competitively exclusive bacterial community may contribute to the intestinal health of birds, thus preventing the development of necrotic enteritis. 相似文献
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研究为分离获得荷斯坦奶牛瘤胃内容物中的细菌,建立系统进化树,获取有益菌种。采用培养组学技术和16S rDNA分子鉴定方法相结合,对3头健康荷斯坦奶牛瘤胃内容物中细菌进行分离培养。共分离得到105株细菌,包括肠球菌属(Enterococcus)共15株14.29%,芽孢杆菌属(bacillus)共11株10.48%,不动杆菌属(Acinetobacter)共14株13.33%,葡萄球菌属(Staphylococcus)共22株20.95%,梭菌属(Clostridium)共1株0.95%,狭义梭菌属(Clostridium sensu stricto)共2株1.90%,短杆菌科(Brevibacteriaceae)共2株1.90%,链球菌属(Streptococcus)共11株10.48%,气球菌属(Aerococcus)共4株3.81%,柠檬酸杆菌属(Citrobacter)共14株13.33%,杆菌属(Brachybacterium)共1株0.95%,克雷伯氏菌属(Klebsiella)共1株0.95%,普罗维登斯菌属(Providencia)共3株2.86%,沙雷氏菌属(Serratia)共4株3.81%。结果中所占比例最高的菌属是葡萄球菌属;系统进化树分析和GenBank中的同源性比对结果发现,从细菌门、纲、目、科、属、种分析,分支明确;26个菌种同源性都在95.01%~100%之间。分离纯化出11株芽孢杆菌属(Bacillus)细菌具有潜在益生菌活性。可作为饲料添加剂饲喂荷斯坦奶牛。 相似文献
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Amy L. MacNeill James C. Steeil Olivier Dossin Patricia S. Hoien‐Dalen Carol W. Maddox 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2010,39(3):381-385
Abstract: A 4‐year‐old female spayed Bichon Frise dog that had been receiving cyclosporine A per os 3 times per week for 2 months to control allergic dermatitis developed lethargy, anorexia, fever, and multiple firm subcutaneous masses. Pyogranulomatous inflammation with branching nonseptate filamentous organisms approximately 2 μm in diameter, presumptively fungal organisms, was diagnosed by cytologic evaluation of fine‐needle aspirates from several masses. A partially acid‐fast actinomycete was cultured from 2 of the masses. The organism was identified as Nocardia abscessus (formerly Nocardia asteroides type 1) based on 16S ribosomal DNA sequencing of samples extracted from cultures and unstained cytologic smears. Immunosuppression caused by long‐term administration of cyclosporine A likely predisposed the dog to disseminated infection. To our knowledge, this is the first report of N. abscessus infection in a dog. This case demonstrates that N. abscessus may be mistaken for a fungal organism based on its cytologic appearance and underscores the importance of using molecular techniques for the diagnosis of suspected fungal diseases. 相似文献
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This experiment was aimed to study the effect of fructooligosaccharides on the structure and diversity of rumen bacterial community in dairy cows by 16S rDNA sequencing technology.Four lactating dairy cows with similar lactation stages and the same parity were randomly divided into two groups using two-phase cross design method.The cows in control group were fed with basal diet and that in test group were fed with the basal diet with 60 g/(d·head) fructooligosaccharides.The experiment was designed through 2×2 cross-over test with 21 d in each stage (14 d for pre-experiment and 7 d for test) and 14 d transitional period of cross test.The rumen fluid samples were collected at 0 (before feeding),2,4,6,9 and 12 h after feeding by cattle catheter.Each phase was collected continuously for 3 days,and the structure and diversity of rumen bacterial community were measured by 16S rDNA sequencing technology.The results of Alpha diversity indexes (Simpson,Shannon),richness indexes (Chao,Ace) and Beta diversity profile showed that the addition of fruitooligosaccharide decreased the bacterial diversity in the rumen of dairy cows.And the results of 16S rDNA sequencing showed that according to the analysis at phylum level,Bacteroidetes,Firmicutes and Proteobacteria accounted for more than 95% of the total bacterial population in cow rumen of two groups.The addition of fructooligosaccharides significantly decreased the abundance of Bacteria_NA (P < 0.05),and the abundance of Synergistetes showed an increasing trend (P=0.075).According to the analysis at genus level,fructooligosaccharides significantly increased the abundance of the Pseudomonas (P < 0.05),extremely significantly increased the abundance of Bacteroides (P < 0.01),while the abundance of Dehalobacterium significantly decreased (P < 0.05).Compared with the control group,the abundance of Ruminococcus,Butyrivibrio,Succiniclasticum and Lachnospiraceae_NA in test group was increased by 80.0%,7.5%,127.9% and 20.0%,respectively,but these differences were not significant (P > 0.05).Under the test conditions,the addition of fructooligosaccharides had a certain effect on the diversity and structure of rumen bacterial flora in dairy cows,which significantly increased the abundance of Pseudomonas which unfermented sugar,extremely significantly increased the abundance of Bacteroides which used carbohydrates as a source of fermentation,had an accelerating effect on the abundance of rumen fiber degrading bacteria. 相似文献
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Peter F. Lord Allan Carb William H. Halliwell James C. Prueter 《Veterinary radiology & ultrasound》1982,23(2):46-49
A 13-year-old male Setter-Springer crossbred dog was presented with signs of acute peritonitis three days after blunt abdominal trauma. In abdominal radiographs, a bubbly accumulation of gas in the central and cranioventral parts of the liver silhouette and mild peritoneal effusion were seen. At laparatomy, firm, necrotic, nodular hepatic masses containing gas were found to be ruptured. The histologic diagnoses were hepatic adenoma with hepatic necrosis and nodular hepatic hyperplasia. The pathogenesis of hepatic abscessation and the radiographic differential diagnosis of extraluminal abdominal gas are discussed. 相似文献
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Haruki Watanabe Makoto Kondo Tomomi Ban‐Tokuda Hiroki Matsui 《Animal Science Journal》2016,87(9):1188-1192
The purpose of this study was to investigate the diversity and fluctuation in the ciliate protozoan population in the rumen of cattle. DNA was extracted from the rumen of three ruminally cannulated, crossbred cattle and a polymerase chain reaction (PCR)‐derived clone library was constructed, using a specific primer set targeting 18S ribosomal RNA genes of ciliate protozoa. DNA fragments of seven selected clones were validated for standard DNA of the protozoa‐specific real‐time PCR assay. Furthermore, population fluctuation of ciliate protozoa and methanogens in the cattle rumen was determined by real‐time PCR. A total of 60 clones were sequenced, phylogenetically analyzed, and classified into 24 operational taxonomic units (OTUs) based on a 99% similarity criterion. More than 80% sequences were phylogenetically placed in the genus Entodinium. The rest of the sequences were placed in the genus Diploplastron (5%), Dasytricha (8.3%) and Isotricha (3.3%). The results suggest that Entodinium was the dominant group in the rumen of cattle used in this study. The ciliate protozoan population showed no significant change in numbers during the monitoring period and reached a peak at 3 h after feeding. Changes in the protozoa population were lower than those of the methanogens. 相似文献
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E. E. Turowski Z. Shen R. M. Ducore N. M. A. Parry A. Kirega F. E. Dewhirst J. G. Fox 《Zoonoses and public health》2014,61(8):571-580
Routine necropsies of 27 asymptomatic juvenile chinchillas revealed a high prevalence of gastric ulcers with microscopic lymphoplasmacytic gastroenteritis and typhlocolitis. Polymerase chain reaction (PCR) analysis using Campylobacter genus‐specific partial 16S rRNA primers revealed the presence of Campylobacter spp. DNA in the faeces of 12 of 27 animals (44.4%). Species‐specific partial 16S rRNA PCR and sequencing confirmed that these animals were colonized with Campylobacter lanienae, a gram‐negative, microaerophilic bacterium that was first identified on routine faecal screening of slaughterhouse employees and subsequently isolated from faeces of livestock. Campylobacter lanienae was isolated from the faeces of six PCR‐positive animals and identified with species‐specific PCR and full 16S rRNA sequencing. Phylogenetic analysis showed that these isolates clustered with C. lanienae strain NCTC 13004. PCR analysis of DNA extracted from gastrointestinal tissues revealed the presence of C. lanienae DNA in the caecum and colon of these chinchillas. Gastrointestinal lesions were scored and compared between C. lanienae‐positive and C. lanienae‐negative animals. There was no correlation between colonization status and lesion severity in the stomach, liver, duodenum, or colon. Possible routes of C. lanienae infection in chinchillas could include waterborne transmission and faecal–oral transmission from wild mice and rats or livestock. Based on these findings, the authors conclude that C. lanienae colonizes the lower bowel of chinchillas in the absence of clinical disease. This is the first report of C. lanienae in any rodent species. Campylobacter lanienae isolates from different mammalian species demonstrate heterogeneity by 16S rRNA sequence comparison. Analysis using rpoB suggests that isolates and clones currently identified as C. lanienae may represent multiple species or subspecies. 相似文献
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Valéria Café Mar?al Anna Oevermann Tim Bley Patrizia Pfister Julien Miclard 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(1):113-115
A 4-month-old female Holstein Friesian calf was referred to the Veterinary Teaching Hospital, University of Berne, Switzerland for evaluation of ataxia, weakness, apathy and stunted growth. Clinical examination revealed generalized ataxia, propioceptive deficits, decreased menace response and sensibility. Postmortem examination did not reveal macroscopic changes of major organs. Histologically, the brain and the spinal cord lesions were characterized by polymicrocavitation, preferentially affecting the white matter fibers at the junction of grey and white matter and by the presence of Alzheimer type II cells. The liver revealed lesions consistent with a congenital portosystemic shunt, characterized by increased numbers of arteriolar profiles and hypoplasia to absence of portal veins. The pathological investigations along with the animal history and clinical signs indicated a hepatic encephalomyelopathy due to a congenital portosystemic shunt. 相似文献
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The number and loci of nucleolar organizer regions (NOR) on chromosomes in Sika deer (Cervus nippon centralis) were determined by fluorescence in situ hybridization with a human 28S ribosomal RNA (rRNA) gene as a probe. Sika deer that live in Nikko National Park and its neighboring areas (Asio and Seta) in Japan were used. All of the analyzed metaphases had three or four NOR at the end of the first and second longest telocentric autosomes. Nucleolar organizer region association, which is associated specifically on parts of NOR between chromosomes, was also observed clearly. A Sika deer 28S rRNA gene was produced by a polymerase chain reaction method. The nucleotide sequence of a Sika deer 28S rRNA gene determined by an automatic sequencer was 97 bp, and showed homogeneity of 88% for the human sequence. 相似文献
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根据NCBI中已报道的嗜麦芽窄食单胞菌16S rDNA基因序列设计引物,对两株来源于猪“高热病”病料中的疑似嗜麦芽窄食单胞菌PSM-5、PSM-6进行PCR扩增。将扩增产物克隆至pMD18-T载体上,并转化到DH5α中。抽取质粒模板,进行PCR和双酶切鉴定并测序,从分子水平上予以鉴定。两株菌的16S rDNA基因扩增片段的核苷酸序列（GenBank登录号为GQ267816和GQ267817）与已经报道的嗜麦芽窄食单胞菌分离株的16S rDNA序列的相似性均在96.78%以上,最高达99.93%。本试验对通过16S rDNA鉴定嗜麦芽窄食单胞菌提供一定参考,同时对猪“高热病”的诊断治疗奠定细菌学方面的基础,对其发病机制的探讨提供依据。 相似文献
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Philip D. Koblik DVM William J. Hornof DVM MS Eugene M. Breznock DVM PhD 《Veterinary radiology & ultrasound》1983,24(5):226-231
Quantitative hepatic scintigraphy is a noninvasive test for measurement of relative arterial and portal blood flow to the liver. This technique has been used to evaluate human patients with known or suspected liver tumors or diffuse hepatocellular disease. A computer program to assess the hepatic perfusion index (HPI) in the normal dog is described. Factors affecting study quality and accuracy include injection technique, cardiac function, patient position, respiration, gross patient motion, and user intervention during data processing. HPI for a group of 12 normal dogs was 0.9±0.4 (X±SD). Quantitative scintigraphy could be used to evaluate dogs with primary or secondary liver tumors, portacaval shunts, or chronic liver disease 相似文献
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采用梅花鹿源坏死梭杆菌HNFnf分离株以不同浓度菌量于家兔耳缘静脉注射,尝试建立家兔感染坏死梭杆菌肝脓肿模型。通过观察家兔临床症状、剖检病变和病理组织学观察,建立了坏死梭杆菌分离株家兔感染模型。攻毒家兔7 d内全部死亡,死亡前家兔表现为采食减少、喜卧、后肢无力、消瘦等。尸体进行病理剖检可见明显病理变化,肺脏表面大量出血,且伴有结节样病变;肝脏质地较软,出现均匀的灰黄脓肿;脾脏严重肿大,呈暗紫色;肾脏多处出血斑;严重的肠道胀气,膀胱积尿。病理组织学观察可见肾脏近曲小管与远曲小管之间有少量的粉红色纤维素渗出;肝脏中形成明显的染色深蓝的脓肿结构,其周围有大量细胞核深染的炎性细胞浸润,肝脏肝小叶固有结构消失,肝细胞脂肪变性;肺泡和支气管内有大量红染的纤维素渗出。采取耳缘静脉攻毒方式,该细菌对家兔的最低致死量为1.2×1014 CFU。 相似文献