一起藏绵羊溶血性曼氏杆菌和多杀性巴氏杆菌混合感染的实验室诊断

为查明2021年四川省甘孜州某藏绵羊养殖场呼吸道疾病的发病病因,本研究采用PCR方法对送检的5份深部鼻腔棉拭子进行了“山羊副流感病毒3型、牛病毒性腹泻-黏膜病病毒、牛冠状病毒、多杀性巴氏杆菌、溶血性曼氏杆菌、绵羊肺炎支原体、丝状支原体簇成员”等常见呼吸道病原的检测。结果显示：多杀性巴氏杆菌和溶血性曼氏杆菌为阳性,其他病原为阴性;通过细菌分离培养成功获得5株溶血性曼氏杆菌和5株多杀性巴氏杆菌;分型结果显示5株溶血性曼氏杆菌为A2型,5株多杀性巴氏杆菌为D型。结合临床症状,确诊该场藏绵羊的呼吸道疾病是由A2型溶血性曼氏杆菌和D型多杀性巴氏杆菌混合感染所致。     

一起牛感染支原体与多杀性巴氏杆菌的诊断与治疗

2022年5月甘肃省某肉牛养殖场的部分犊牛,先后出现以咳嗽、呼吸急促、流鼻涕等为主的呼吸道症状,并陆续出现牛只死亡的情况,现场调查及临床检查后初步怀疑为细菌性病原感染。为进一步确诊病原并对症治疗,现场采集症状明显牛只的鼻拭子,同时对病死牛只进行解剖观察,无菌采集肺组织进行实验室病原检测。使用TaqMan探针荧光定量PCR进行3种(牛支原体、牛多杀性巴氏杆菌及牛溶血性曼氏杆菌)牛呼吸道疾病病原核酸检测。结果显示,病死牛只肺脏病变较为明显,肺尖实质化严重,上端有脂肪样颗粒状病灶;鼻拭子及肺组织呈牛支原体和多杀性巴氏杆菌核酸阳性。结果表明,该牛场本次发病是由于感染了牛支原体和牛多杀性巴氏杆菌引起的。通过采取隔离治疗、紧急免疫、严格消杀等综合性防控措施后,该牛场病情逐步好转并恢复正常生产。     

一种由5种细菌抗原和2种免疫原组成的新型多价牛细菌性呼吸道疾病疫苗安全性和效价检测

牛细菌性呼吸道疾病是造成犊牛高死亡率和巨大经济损失的最严重问题之一。由于没有多价疫苗,牛细菌性呼吸道疾病疫苗接种程序很复杂。本研究研发了新型多价牛细菌性呼吸道疾病疫苗,并进行了安全性和效价检验。新型多价牛细菌性呼吸道疾病疫苗由5种细菌抗原和2种免疫原组成,其中细菌抗原包括A型溶血性曼氏杆菌菌素、多杀性巴氏杆菌菌素、睡眠嗜血杆菌菌素、牛支原体菌素、化脓性隐秘杆菌菌素;免疫原包括A型溶血性曼氏杆菌白细胞类毒素、多杀性巴氏杆菌外膜蛋白。与没有接种疫苗的猪相比,接种5种细菌抗原的几内亚猪的ELISA抗体滴度升高。在本研究中,新型多价牛细菌性呼吸道疾病疫苗对犊牛和妊娠牛是安全的。用溶血性曼氏杆菌和多杀性巴氏杆菌对犊牛攻毒,和没有接种疫苗的犊牛相比,接种疫苗的犊牛平均日增重和抗体滴度明显增加（P〈0.05）,呼吸道症状极显著减轻（P〈0.01）,治疗频率极显著减少（P〈0.01）。有趣的是,溶血性曼氏杆菌白细胞类毒素和牛支原体抗体滴度与呼吸道症状减轻有密切相关性。接种新型多价牛细菌性呼吸道疾病疫苗将会是防制牛细菌性呼吸道疾病的一种经济有效的措施。     

一种由5种细菌抗原和2种免疫原组成的新型多价牛细菌性呼吸道疾病疫苗安全性和效价检测

牛细菌性呼吸道疾病是造成犊牛高死亡率和巨大经济损失的最严重问题之一。由于没有多价疫苗,牛细菌性呼吸道疾病疫苗接种程序很复杂。本研究研发了新型多价牛细菌性呼吸道疾病疫苗,并进行了安全性和效价检验。新型多价牛细菌性呼吸道疾病疫苗由5种细菌抗原和2种免疫原组成,其中细菌抗原包括A型溶血性曼氏杆菌菌素、多杀性巴氏杆菌菌素、睡眠嗜血杆菌菌素、牛支原体菌素、化脓性隐秘杆菌菌素;免疫原包括A型溶血性曼氏杆菌白细胞类毒素、多杀性巴氏杆菌外膜蛋白。与没有接种疫苗的猪相比,接种5种细菌抗原的几内亚猪的ELISA抗体滴度升高。在本研究中,新型多价牛细菌性呼吸道疾病疫苗对犊牛和妊娠牛是安全的。用溶血性曼氏杆菌和多杀性巴氏杆菌对犊牛攻毒,和没有接种疫苗的犊牛相比,接种疫苗的犊牛平均日增重和抗体滴度明显增加(P<0.05),呼吸道症状极显著减轻(P<0.01),治疗频率极显著减少(P<0.01)。有趣的是,溶血性曼氏杆菌白细胞类毒素和牛支原体抗体滴度与呼吸道症状减轻有密切相关性。接种新型多价牛细菌性呼吸道疾病疫苗将会是防制牛细菌性呼吸道疾病的一种经济有效的措施。     

一起肉牛副流感病毒3型、巴氏杆菌、牛支原体混合感染的诊治

牛呼吸道综合征往往是多种病原体混合感染引起,致病机制复杂。云南省昆明市某肉牛养殖场部分犊牛出现了以咳嗽、气短、流鼻涕、腹泻等呼吸道症状为主要表现的呼吸道疾病,随后多头相继死亡,剖检主要病变为气管、胃黏膜、小肠出血,肺脏肝变,肝脏出血肿大,心脏出血,心包黏连等;经采病料用常见呼吸道疾病病原（牛病毒性腹泻病毒,牛冠状病毒,牛副流感病毒3型,牛呼吸道合胞体病毒,牛疱疹病毒1型,多杀性巴氏杆菌,溶血性曼氏杆菌,牛支原体）8联PCR检测试剂盒检测,结果为副流感病毒3型、多杀性巴氏杆菌、牛支原体混合感染。经用加米霉素、10%替米考星和20%氟苯尼考等大环内酯类药物治疗,结合加强饲养管理,多数病牛恢复了健康。     

猪呼吸系统的几种重要传染病

猪呼吸系统疾病给养猪业造成巨大经济损失。良好的管理,适当的疫苗,及时治疗能减少这种损失,更重要的是兽医防疫人员要注意更新对疾病的认识,改进疾病诊断技术。 1 病原、症状及流行病学 1.1 猪支原体肺炎 又称猪地方流行性肺炎,原发病原为猪肺炎支原体。多杀性巴氏杆菌常与之并发。猪肺炎支原体首先损害粘膜防御系统,结果导致多杀性巴氏杆菌在呼吸道增殖。     

犊牛支原体肺炎的诊断和防治措施

牛支原体是危害我国养牛业的重要致病性支原体,目前已证实该病呈世界性分布,病原除导致牛肺炎、乳腺炎外,还导致关节炎、角膜结膜炎、耳炎、生殖道炎症、流产与不孕等多种病症。据报道,欧美国家约四分之一至三分之一的牛呼吸道疾病综合征是由牛支原体引起的。同时,牛支原体与其它病原的混合感染和协同致病性是牛支原体肺炎重要的致病机制之一。据报道,混合感染的常见病原菌主要包括:多杀性巴氏杆菌、化脓隐秘杆菌、     

多杀性巴氏杆菌和溶血性曼氏杆菌混合感染引起山羊肺炎的诊断

青海省湟中区某山羊场发生呼吸道疾病,为确定引起本次呼吸道疾病的病原,笔者对病死羊进行剖检,并进行病原分离、鉴定。同时,采用PCR方法,对多杀性巴氏杆菌、溶血性曼氏杆菌、绵羊肺炎支原体和丝状支原体等呼吸道相关病原进行分子检测。结果发现,患羊临床表现以咳嗽、呼吸困难、精神萎靡和鼻内有粘性分泌物为特征的肺炎,细菌分离获得多杀性巴氏杆菌和溶血性曼氏杆菌,未分离获得其他细菌性病原和支原体。PCR检测发现多杀性巴氏杆菌和溶血性曼氏杆菌阳性。根据临床症状、剖检变化和实验室检测,最后确诊为由多杀性巴氏杆菌和溶血性曼氏杆菌共同感染山羊引起的肺炎。     

肉牛牛支原体肺炎感染的细菌学研究

[目的]牛支原体肺炎是严重危害国内外肉牛养殖业的一种重要疾病,病原混合感染将加剧病情,增加临床治疗难度。本研究通过阐明我国牛支原体肺炎混合感染情况,为探讨更加有效的防控手段提供参考依据。[方法]近4年来采用门诊和出诊的方式,收集了全国范围内35个临床初诊为牛支原体肺炎的牛场病牛样本,进行牛支原体及混合感染细菌的分离和分型鉴定。[结果]确定了这类疾病的细菌学感染特征,表现为牛支原体感染占绝对优势,混合感染模式主要以牛支原体合并多杀性巴氏杆菌A型感染、牛支原体合并和化脓隐秘杆菌感染为主。[结论]经实验室检测证实临床初诊病例绝大部分为牛支原体肺炎,但混合感染很普遍。     

犊牛支原体肺炎继发牛A型多杀性巴氏杆菌感染的诊治

某奶牛场犊牛相继发生肺炎和关节炎,为确诊该牛场犊牛群发病的原因并提出防控方案,本试验剖检新生犊牛并采集病料,分别开展牛支原体及其他病原菌的分离培养、PCR鉴定及药敏分析;进行牛病毒性腹泻病毒、牛口蹄疫病毒和牛传染性鼻气管炎病毒PCR检测;制作犊牛肺脏组织病理切片并进行观察和评估。从犊牛肺脏组织分离到牛支原体和牛A型多杀性巴氏杆菌;牛病毒性腹泻病毒、牛口蹄疫病毒和牛传染性鼻气管炎病毒检测均为阴性;肺脏组织病理切片可见肺泡结构破坏、出血及大量炎性细胞浸润;药敏试验结果显示,牛支原体和牛A型多杀性巴氏杆菌分别对泰乐菌素和头孢唑啉敏感,但对青霉素、庆大霉素、林可霉素和氨苄西林均呈现耐药。该犊牛群确诊为牛支原体肺炎继发牛A型多杀性巴氏杆菌感染,采用泰乐菌素联合头孢唑啉肌肉注射,配合对症治疗和规范管理,有效控制了该场犊牛疾病。     

On the aetiopathogenesis of Mycoplasma pneumonia in calf

A pure culture of Mycoplasma (M.) bovis was isolated from calves with respiratory disease, exhibiting the picture of lymphohistiocytic proliferative pneumonia with presence of eosinophil plasmatic cells. A mixed infection of M. bovis and Pasteurella (P.) multocida was demonstrated in calves with exudative pneumonia. Both M. bovis and Haemophilus (H.) somnus were recovered from calves with necrotic pneumonia. All 3 organisms--M. bovis, P. multocida, and H. somnus--were present in cases of exudative-necrotic pneumonia. It was also shown that M. bovis played a primary role in the aetiopathogenesis of respiratory diseases caused by mixed infections.     

Prevalence of respiratory pathogens in diseased, non-vaccinated, routinely medicated veal calves

The prevalence of respiratory pathogens in diseased veal calves was determined in 24 respiratory disease outbreaks in 15 herds in Belgium. Bacteria were cultured from nasopharyngeal swabs and seroconversion against viruses and Mycoplasma bovis was determined on paired sera. At the individual calf level, Mycoplasma species, Mannheimia haemolytica and Pasteurella multocida, were isolated from 70.5 per cent, 21.5 per cent and 26.0 per cent of swabs, respectively. At the herd level, the presence of M bovis could be confirmed in 84.6 per cent of the herds examined. Seroconversion against bovine viral diarrhoea virus (BVDV) was present in 71.4 per cent of herds, parainfluenzavirus type 3 in 53.3 per cent, bovine respiratory syncytial virus in 40.0 per cent, bovine adenovirus type 3 in 46.7 per cent, bovine coronavirus in 30.0 per cent, and bovine herpesvirus type 1 in 26.7 per cent. At postmortem examination, Mycoplasma species could be cultured from 61.9 per cent of pneumonic lungs (n=21). Sixty per cent of calves tested were positive for BVDV (n=20), and 20.0 per cent were positive for bovine respiratory syncytial virus (n=16).     

Safety and efficacy testing of a novel multivalent bovine bacterial respiratory vaccine composed of five bacterins and two immunogens

Bovine bacterial respiratory diseases have been one of the most serious problems due to their high mortality and economic loss in calves. The vaccinations of bovine bacterial respiratory vaccines have been complex because of no multivalent vaccine. In this study, novel multivalent bovine bacterial respiratory vaccine (BRV) was developed and tested for its safety and efficacy. BRV was composed of two immunogens and five bacterins. These were leukotoxoid and bacterin of Mannheimia haemolytica type A, outer membrane protein and bacterin of Pasteurella multocida type A, and bacterins of Haemophilus somnus, Mycoplasma bovis, and Arcanobacterium pyogenes. ELISA antibody titers to five bacterial antigens in vaccinated guinea pigs increased, compared with those in unvaccinated ones. BRV was safe for calves and pregnant cattle in this study. In calves challenged with M. haemolytica and P. multocida, the average daily weight gain and antibody titers of vaccinated calves increased, and respiratory symptoms (P<0.05) and treatment frequency (P<0.01) of vaccinated calves significantly decreased, compared with those of unvaccinated calves. Interestingly, the antibody titers of M. haemolytica leukotoxoid and Mycoplasma bovis were closely related with the reduction of respiratory symptoms. BRV would be an ecomonical measure for the protection against bovine bacterial respiratory diseases.     

The microbial flora of the respiratory tract in feedlot calves: associations between nasopharyngeal and bronchoalveolar lavage cultures.

The upper and lower respiratory tracts of 59 feedlot calves with clinical signs of naturally occurring respiratory disease (cases) and 60 comparison (control) animals were cultured before treatment, using nasopharyngeal swabs (NPS) and bronchoalveolar lavage (BAL). The most prevalent organisms were Pasteurella multocida and Mycoplasma bovis. Isolations of P. multocida from NPS and BAL fluid were found to be significantly associated with morbidity (p less than or equal to 0.05), but the frequency with which other organisms were isolated from the nasopharynx and lungs was similar in cases and controls. There was evidence of moderate agreement between NPS and BAL isolates at the individual calf level using the kappa statistic, (range of kappa values = 0.47-0.61) but the variability of the kappa statistics was large. Therefore, in an individual calf NPS cultures did not accurately predict BAL cultures. The NPS and BAL culture results were quite similar at the group level, however.     

Isolation of Mycoplasmas from nasal swabs of calves affected with respiratory diseases and antimicrobial susceptibility of their isolates

Nasal swabs of 293 calves were examined for Mycoplasma. The samples were collected from calves affected with respiratory diseases on 71 farms in various parts of Japan between 1996 and 1997. Mycoplasma bovirhinis was isolated from 47 of 293 calves (16.0%). Mycoplasma alkalescens, M. bovis, M. arginini, M. bovigenitalium and Acholeplasma spp. were isolated from 19 (6.5%), seven (2.4%), four (1.4%), four (1.4%) and 18 (6.1%) calves, respectively. Pasteurella multocida and P. haemolytica were isolated from 60% of Mycoplasma-positive calves. However, other bacteria were not isolated from calves. To evaluate the antimicrobial susceptibility of their isolates, 68 M. bovirhinis, 21 M. alkalescens and 10 M. bovis strains were examined for 12 antimicrobial agents. All isolates showed higher susceptibility to tiamulin than to the other drugs used in the study. However, erythromycin had no effect on any of the Mycoplasma strains studied. The field isolates were less susceptible than the type strains to some drugs, such as spiramycin, oxytetracycline and tylosin.     

Clinical study of the disease of calves associated with Mycoplasma bovis infection

Clinical, bacteriological and serological examination of 35 calves from the age of 5 to 26 days was performed in a Holstein-Friesian dairy herd endemically infected with Mycoplasma bovis. M. bovis was isolated from 48.6% of nasal swabs taken from the calves at the age of 5 days, and from 91.4% of the same calves at the age of 26 days, indicating the gradual spread of infection. The isolation rate of Pasteurella multocida did not change much, and varied from 28.6 to 25.7%. No P. haemolytica could be detected. In addition to M. bovis and P. multocida, the herd was also infected with different viruses (including bovine viral diarrhoea virus, infectious bovine rhinotracheitis virus, bovine adenoviruses, parainfluenza-3 virus, and bovine respiratory syncytial virus) as a large proportion of the sera of newborn calves contained colostral antibodies against these viruses. In most of the newborn calves severe clinical signs (fever, depression, inappetence, hyperventilation, dyspnoea, nasal discharge and coughing) due to M. bovis infection developed. The clinical signs appeared already on the fifth day of life, and their incidence was the highest at the age of 10 to 15 days. Three calves (8.6%) died as a result of severe serofibrinous pneumonia. The surviving calves showed very poor weight gain (ranging from 1.5 to 3.5 kg) during the first two weeks of life.     

Etiology of respiratory disease in non-vaccinated, non-medicated calves in rearing herds

The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. Tracheobronchial lavage (TBL) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncytial virus (RSV), parainfluenza virus 3 (PIV3), bovine corona virus (BCV) and bovine adenovirus (BAV). Pasteurella multocida was the most common bacterial pathogen. It was isolated from 34% of the TBL samples in 28 herds and was associated with clinical respiratory disease (p < 0.05) when other pathogenic bacteria or mycoplasma were present in the sample. Mannheimia spp. and Histophilus somni were rarely found. Mycoplasma bovis was not detected at all. Ureaplasma diversum was associated with clinical respiratory disease (p < 0.05). TBL samples from healthy or suspect calves were more often negative in bacterial culture than samples from diseased calves (p < 0.05). No viral infections were detected in six herds, while 16-21 herds had RSV, BCV, BAV or PIV3. In the herds that had calves seroconverted to BCV, respiratory shedding of BCV was more frequently observed than faecal shedding. This study showed that the microbial combinations behind BRD were diverse between herds. M. bovis, an emerging pathogen in many countries, was not detected.     

Viral and bacterial pathogens in bovine respiratory disease in Finland

Pathogens causing bovine respiratory tract disease in Finland were investigated. Eighteen cattle herds with bovine respiratory disease were included. Five diseased calves from each farm were chosen for closer examination and tracheobronchial lavage. Blood samples were taken from the calves at the time of the investigation and from 86 calves 3-4 weeks later. In addition, 6-10 blood samples from animals of different ages were collected from each herd, resulting in 169 samples. Serum samples were tested for antibodies to bovine parainfluenza virus-3 (PIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine adenovirus-3 (BAV-3) and bovine adenovirus-7 (BAV-7). About one third of the samples were also tested for antibodies to bovine virus diarrhoea virus (BVDV) with negative results. Bacteria were cultured from lavage fluid and in vitro susceptibility to selected antimicrobials was tested. According to serological findings, PIV-3, BAV-7, BAV-3, BCV and BRSV are common pathogens in Finnish cattle with respiratory problems. A titre rise especially for BAV-7 and BAV-3, the dual growth of Mycoplasma dispar and Pasteurella multocida, were typical findings in diseased calves. Pasteurella sp. strains showed no resistance to tested antimicrobials. Mycoplasma bovis and Mannheimia haemolytica were not found.     

Diseases and pathogens associated with mortality in Ontario beef feedlots.

This study determined the prevalence of diseases and pathogens associated with mortality or severe morbidity in 72 Ontario beef feedlots in calves that died or were euthanized within 60 days after arrival. Routine pathologic and microbiologic investigations, as well as immunohistochemical staining for detection of bovine viral diarrhea virus (BVDV) antigen, were performed on 99 calves that died or were euthanized within 60 days after arrival. Major disease conditions identified included fibrinosuppurative bronchopneumonia (49%), caseonecrotic bronchopneumonia or arthritis (or both) caused by Mycoplasma bovis (36%), viral respiratory disease (19%), BVDV-related diseases (21%), Histophilus somni myocarditis (8%), ruminal bloat (2%), and miscellaneous diseases (8%). Viral infections identified were BVDV (35%), bovine respiratory syncytial virus (9%), bovine herpesvirus-1 (6%), parainfluenza-3 virus (3%), and bovine coronavirus (2%). Bacteria isolated from the lungs included M. bovis (82%), Mycoplasma arginini (72%), Ureaplasma diversum (25%), Mannheimia haemolytica (27%), Pasteurella multocida (19%), H. somni (14%), and Arcanobacterium pyogenes (19%). Pneumonia was the most frequent cause of mortality of beef calves during the first 2 months after arrival in feedlots, representing 69% of total deaths. The prevalence of caseonecrotic bronchopneumonia caused by M. bovis was similar to that of fibrinosuppurative bronchopneumonia, and together, these diseases were the most common causes of pneumonia and death. M. bovis pneumonia and polyarthritis has emerged as an important cause of mortality in Ontario beef feedlots.     

Pneumonia in calves: characterization of the bacterial spectrum and the resistance patterns to antimicrobial drugs

The population under study included young calves with pneumonia (group A, n = 13) and their controls (group B, n = 9), as well as older calves from which the lungs with (group C, n = 90) or without (group D, n = 10) lesions were collected after slaughter. Arcanobacterium pyogenes was the organism most commonly isolated from calves in group A (46%), followed by Haemophilus somnus (23%), Mannheimia haemolytica (15%), Streptococcus suis and Pasteurella multocida (7.7% each). Only S. suis (22%) and P. multocida (11%) were found in group B. P. multocida was isolated from 32% group C calves, H. somnus from 11%, A. pyogenes from 7.8%, M. haemolytica from 2.2% and S. suis from 1.1%. No specific pathogens were isolated in group D. Prevalence of Mycoplasma bovis infection was 69% in group A and 37% in group C. Ninety-eight strains were tested for resistAnce to antibiotics. Resistance to penicillin and ampicillin was present only in M. haemolytica (46%). High percentages of resistant strains were observed for streptomycin (48-100%), tetracycline (15-43%), sulfonamides alone (14-100%) or in combination with trimethoprim (0-100%). Therapeutic approaches to bacterial calf pneumonia in the area under study should be modified according to the isolated bacterial population, the observed antimicrobial resistances and the growing importance of Mycoplasma bovis.