Gastrointestinal nematode infections of goats in a sub-tropical and humid zone of India

Twelve hundred and twenty-eight goats (Capra hircus L.) from a sub-tropical and humid zone of India were examined for gastrointestinal nematodes. The species encountered in the region were: Haemonchus contortus, Bunostomum trigonocephalum, Oesophagostomum columbianum, Trichuris globulosa, O. aspersum, and T. ovis. The overall infection rate was 86.8%. Among various species found, H. contortus emerged as the most prevalent, although B. trigonocephalum and O. columbianum were also significantly in evidence. The seasonal fluctuation in infection was assessed by monitoring the faecal egg count of 1638 goats slaughtered during the 1-year period. The maximum values for the prevalence and overall mean eggs g-1 of faeces (EPG) were observed after the heavy rainfall season and remained at a relatively high level from July to December. H. contortus and O. columbianum appear to be of major importance as parasites in the goats of this climatic zone; the role of climatic factors in their prevalence is discussed.     

Prevalence of Sarcocystis in domestic pigs in India.

Muscle samples from 890 slaughtered pigs were examined for the presence of sarcocysts. A high prevalence rate of 67.98% was observed. Two types of microsarcocysts were recorded. The sarcocyst wall of one type had redial striations and the other possessed hair-like villar protrusions. The species were identified as Sarcocystis miescheriana and Sarcocystis suihominis; there was a slightly higher incidence of the latter species (47.11%) than of the former (43.14%). S. suihominis has been identified for the first time from pigs in India.     

西藏林芝地区藏猪消化道寄生虫流行情况调查

为掌握西藏林芝地区藏猪消化道寄生虫病流行情况,采用寄生虫学完全剖检法、粪便虫卵检查法,对2014年12月—2015年1月在西藏林芝地区112头屠宰藏猪、73份粪便进行寄生虫病流行情况调查。结果显示:共检测出寄生虫11种,隶属于5门、6纲、9目、10科、10属,其中线虫5种,绦虫蚴2种,原虫2种,吸虫1种,棘头虫1种。优势虫种和感染率为细颈囊尾蚴(42.9%)、野猪后圆线虫(38.4%)、棘球蚴(33.0%)、蛔虫(30.4%)、肝片吸虫(26.8%)、食道口线虫(18.8%)、毛首线虫(15.2%)、球虫(15.1%)、结肠小袋纤毛虫(6.8%)、蛭形巨吻棘头虫(5.6%)、六翼泡首线虫(2.7%)。结果表明:林芝地区藏猪胃肠道寄生虫感染普遍,感染率较高。     

兰州地区羊寄生虫感染情况调查及防治策略

通过对兰州地区羊寄生虫调查研究发现,羊线虫感染以食道口线虫、捻转血矛线虫、细颈线虫、毛圆线虫为主,平均感染率分别为78.1%、50%、46.3%、46%,其中食道口线虫高达78.1%,已呈流行态势;羊仰口线虫感染率低于以上几种线虫,在榆中和皋兰两县没有发现,其危害较低;夏伯特线虫、类圆线虫感染率比较低,只在个别地区发现,不会对本地羊群构成威胁。没有发现吸虫及绦虫感染;羊球虫感染率比较高,达50.4%;棘球蚴感染率非常低;弓形虫感染率约为3%左右,低于全国5%的平均感染率,没有发现羊泰勒虫感染;硬蜱及虱子普遍存在,90%以上的羊感染虱子;没有发现螨虫感染情况。由此可知,目前兰州地区羊寄生虫的种类虽然不多,主要以消化道线虫感染为主,但是感染强度比较大,而且与以前调查相比较有上升的趋势,这对于养羊业非常不利。     

Histopathological classification of systemic Mycobacterium avium complex infections in slaughtered domestic pigs

The aim of this study was to classify the histopathological features of pigs infected with Mycobacterium avium complex (MAC). We used slaughtered pig organs systemically infected with MAC. The results showed granulomatous lesions which were observed predominantly in the digestive organs and regional lymph nodes rather than respiratory organs. The histological picture showed a wide range of granulomatous stages from exudative to fibrotic reactions to the MAC infection. Eosinophils and giant cells were characteristically observed in the exudative reactions. The histopathological type in primary focus tended to be maintained in the respective organs. Most strains with the same genotype showed pathogenicity for guinea pigs irrespective of the type of granuloma. Although these findings suggest that different stages of a granulomatous lesion originating from the same causative agent might influence histological patterns, other possibilities such as the hereditary background of the host, or the effects of viral infections should be considered.     

Spirometra sp. in a domestic cat in India

Adult Spirometra sp. were found in an experimental cat. This is the first report from northern India. It is suggested that this infection may have resulted from the feeding of raw fish offal.     

Isolation and characterization of a Sagiyama virus from domestic pigs.

In 2002, a strain of Sagiyama virus (SAGV) designated ML/Taiwan/02 was isolated from farmed pigs in Taiwan. The nsP1 and E1 gene sequences of the ML/Taiwan/02 strain shared 98.6 and 96.7% homology, respectively, with corresponding genes of a Japanese strain of SAGV. Nucleotide and amino acid sequence comparison revealed this strain of SAGV to be most closely related to Getah virus, as opposed to its current classification as a subtype of Ross River virus. To investigate the seroprevalence of SAGV infection in Taiwan, a total of 586 pig sera collected from 11 of 17 Taiwanese districts were tested for serum neutralizing antibodies (SNA) against SAGV. Results indicated that 51% of the samples had SNA titer > or = 4, and 40% had SNA titer > or = 48, indicative of repeated exposure to SAGV in the field. To study the pathogenicity of the ML/Taiwan/02 strain, this strain was experimentally inoculated into 4-week-old specific-pathogen-free pigs that were seronegative for SAGV. Viremia was detected during postinoculation days (PID) 2-4, when the SNA titer was < or = 16. By PID 7, viremia was no longer detectable, coinciding with the increase of SNA titer to > or = 48. Clinical illnesses or remarkable lesions were not observed. To the authors' knowledge, this is the first reported isolation of a strain of SAGV from pigs in the field. The virus is experimentally nonpathogenic to pigs but is moderately widespread, most likely via repeated exposure to virus-carrying mosquitoes.     

北京地区奶牛寄生虫感染情况的调查

为了了解北京地区奶牛胃肠道寄生虫感染情况,采集北京地区成年牛和犊牛的粪样,用饱和盐水漂浮法、水洗沉淀法对粪样进行了定性检查,用麦克马斯特计数法对线虫卵和球虫卵囊进行了定量检查。结果发现,北京地区成年奶牛和犊牛粪样中检出的主要是线虫卵和球虫卵囊,未检出吸虫卵。成年奶牛粪样中线虫卵的阳性率为14.64%,平均EPG值范围为190~853,并在5~9月份出现一个比较明显的高峰期;球虫卵囊阳性率为49.15%,平均OPG值范围为125~346,高峰出现在5~11月份。犊牛粪样中线虫卵的阳性率为24.56%,平均EPG值范围为305~1 053,并在5~11月份出现一个比较明显的高峰期;粪样中球虫卵囊阳性率为65.02%,平均OPG值范围为2 540~7 648,并在7月份出现一个高峰。根据调查结果,对北京地区奶牛寄生虫病防治提出了建议。     

Functional and phylogenetic analyses of a melanocortin-4 receptor mutation in domestic pigs

The melanocortin-4 receptor (MC4R), a G protein-coupled seven-transmembrane receptor, which is expressed in the brain, plays an important role in the control of mammalian energy homeostasis. A missense mutation (Asp298Asn) was identified in the porcine MC4R gene, which is associated with growth and food intake traits. The Asn298 mutation occurs within a highly conserved motif, NPLIY, of all members of G protein-coupled receptors; whereas, Asp298 is conserved in all five melanocortin receptor subtypes. Functional analysis of the porcine MC4R variant was performed with an in vitro gene expression system in 293 cells. Ligand binding (NDP-alphaMSH) did not differ between Asp298 and Asn298 MC4R proteins. However, the Asn298 MC4R variant was unable to stimulate cAMP production in response to NDP-alphaMSH stimulation; whereas, the Asp298 variant could stimulate cAMP accumulation. These results demonstrate that the Asp298 is required for normal MC4R signaling to the adenylyl cyclase. Sequencing of the MC4R gene of seven diverse genera within the Suiformes that include Hippopotamidae (hippos), Tayassuidae (peccaries) and Suidae (pigs), revealed 62 nucleotide variations in MC4R. Phylogenetic relationships of MC4R variations are consistent with those previously described from morphological and physiological data among the subfamilies of the Suiformes. These findings revealed that a single missense mutation (Asp298Asn) of aspartic acid (Asp) to asparagine (Asn) in MC4R gene decreased cAMP content and MC4R signaling, but with no difference in the ligand binding was associated with growth and feed intake traits in domestic pigs.     

Campylobacter jejuni infections in gnotobiotic pigs

At 3 days of age, 12 gnotobiotic pigs were inoculated orally with broth cultures of Campylobacter jejuni. One pig was euthanatized and evaluated each day for 12 days. In the cecum and colon, there was diffuse edema, neutrophilic infiltration, and sloughing of epithelial cells from the mucosa on postinoculation days (PID) 2 through 5. Dysplastic colonic crypt epithelial cells were observed in the submucosa of the colon on PID 5 through 12. Curved, rod-shaped bacteria were detected on the surface of ileal, cecal, and colic absorptive and glandular epithelial cells. Bacteria also were found around small submucosal vessels on PID 3 and 4 and were associated with numerous perivascular neutrophils. The gnotobiotic pig appears to provide a simple, well-controlled in vivo model for the study of the pathogenesis of C jejuni infections in human beings, pigs, and other mammals.     

Clostridial enteric infections in pigs.

Clostridium perfringens types A and C and Clostridium difficile are the principal enteric clostridial pathogens of swine. History, clinical signs of disease, and gross and microscopic findings form the basis for a presumptive diagnosis of C. perfringens type-C enteritis. Confirmation is based on isolation of large numbers of type-C C. perfringens and/or detection of beta toxin in intestinal contents. Diagnosis of C. perfringens type-A infection, however, remains controversial, mostly because the condition has not been well defined and because type-A organisms and their most important major (alpha) toxin can be found in intestinal contents of healthy and diseased pigs. Isolation of large numbers of C. perfringens type A from intestinal contents, in the absence of other enteric pathogens, is the most reliable criterion on which to base a diagnosis. Recently, beta2 (CPB2) toxin-producing C. perfringens type A has been linked to disease in piglets and other animals. However, implication of CPB2 in pathogenesis of porcine infections is based principally on isolation of C. perfringens carrying cpb2, the gene encoding CPB2, and the specific role of CPB2 in enteric disease of pigs remains to be fully defined. Clostridium difficile can also be a normal inhabitant of the intestine of healthy pigs, and diagnosis of enteric infection with this microorganism is based on detection of its toxins in feces or intestinal contents.     

猪肺炎支原体的防治措施

猪肺支原体是猪地方性肺炎的主要病原体,其普遍存在于世界各地,会给养猪业造成巨大的经济损失.此病原体感染猪后通常黏附于猪呼吸道纤毛上皮,并会造成纤毛上皮的损伤.猪感染后主要表现为慢性咳嗽症状、容易发生其他呼吸道感染和生产性能下降.该病的控制可通过多种措施实现.首先应该完善管理措施.改善畜舍饲养环境,这包括实行全出/全进的饲养方式、减少会破坏群体免疫水平的因素、维持最佳的饲养密度、防止其他呼吸道疾病的感染,以及提供最佳的畜舍及环境条件.其次,当猪群处于呼吸道疾病感染的威胁之下时,战略性使用能够有效地预防猪肺炎支原体和最好还能预防大多数继发感染细菌的药物对预防本病非常有效.最后,商用疫苗已被广泛地用来控制猪肺炎支原体感染,接种疲苗的优点在于其能够减少临床症状、减轻肺脏损伤、减少药物的使用和提高猪群的生产性能.但是,疫苗仅能提供部分保护作用,并且不能防止病原体在猪体内的定殖.因此,应根据猪群的种类、猪场的生产系统和管理体制、感染的类型及猪农的喜好选择不同的免疫策略(免疫时机、母猪免疫、免疫接种再结合抗菌素治疗).新疫苗正在紧锣密鼓的研究之中.如气雾苗、通过饲料接种的疫苗以及亚单位苗和DNA疫苗.按年龄进行隔离饲养和药物治疗在猪群水平上根除猪肺炎支原体感染是可能的,但该病复发的威胁将永久存在.     

Control of Mycoplasma hyopneumoniae infections in pigs

Mycoplasma hyopneumoniae, the primary pathogen of enzootic pneumonia, occurs worldwide and causes major economic losses to the pig industry. The organism adheres to and damages the ciliated epithelium of the respiratory tract. Affected pigs show chronic coughing, are more susceptible to other respiratory infections and have a reduced performance. Control of the disease can be accomplished in a number of ways. First, management practices and housing conditions in the herd should be optimized. These include all-in/all-out production, limiting factors that may destabilize herd immunity, maintaining optimal stocking densities, prevention of other respiratory diseases, and optimal housing and climatic conditions. Strategic medication with antimicrobials active against M. hyopneumoniae and, preferably, also against major secondary bacteria may be useful during periods when the pigs are at risk for respiratory disease. Finally, commercial bacterins are widely used to control M. hyopneumoniae infections. The main effects of vaccination include less clinical symptoms, lung lesions and medication use, and improved performance. However, bacterins provide only partial protection and do not prevent colonization of the organism. Different vaccination strategies (timing of vaccination, vaccination of sows, vaccination combined with antimicrobial medication) can be used, depending on the type of herd, the production system and management practices, the infection pattern and the preferences of the pig producer. Research on new vaccines is actively occurring, including aerosol and feed-based vaccines as well as subunit and DNA vaccines. Eradication of the infection at herd level based on age-segregation and medication is possible, but there is a permanent risk for re-infections.     

Pathogenesis and management of wound infections in domestic animals

Abstract The pathogenesis of wound infections is largely dependent on adherence mechanisms and toxins. Studies of Staphylococcus intermedins indicate that pyoderma isolates can bind to extracellular matrix proteins exposed in wounds but interpretation of adherence studies is complicated as some organisms possess multiple mechanisms. Studies of blocking and promotion of adherence by antibiotics also show variability. Epidermolytic toxins are recognized in S. aureus and S. hyicus but not in S. intermedins, although a synergohymenotropic toxin has been described and canine syndromes occur where epidermal splitting and S. intermedins infection co-exist. Staphylococcal enterotoxins and toxic shock toxin-1 are recognized as superantigens which cause cytokine release non-specifically, promoting inflammation in wounds. Treatment of infected skin depends largely on antibiotics but drug resistance will limit this; a move towards vaccines and re-examination of the value of antisepsis is occurring. Use of dressings which reduce microbial growth must also be a factor in wound management. Resumen La patogenesis de las infecciones de heridas depende en gran medida de los mecanismos de adherencia y de las toxinas. Algunos estudios en Staphylococcus intermedius indican que los aislamientos a partir de áreas de pioderma pueden adherirse a proteinas de la matriz extracelular expuesta en las heridas aunque la interpretación de estudios de adherencia es complicado ya que algunos organismos poseen múltiples mecanismos. Los estudios con antibióticos sobre su capacidad de bloqueo y promoción de la adherencia también muestran variabilidad. Se reconocen toxinas epidermolíticas en S. aureus y S. hyicus pero no en S. intermedius, aunque se ha descrito una toxina sinergohimenotrópica y se producen sindromes caninos en áreas de coexistencia de rotura epidérmica y S. intermedius. Las enterotoxinas estafilocócicas y la Toxina-1 de Shock Tóxico son reconocidas como superantígenos que causan liberación inespecífica de citoquinas, promoviendo la inflamación a nivel de las heridas. El tratamiento de la piel infectada depende en gran medida de los antibióticos, aunque esto se encuentra limitado por las resistencias; se está tendiendo a las vacunaciones y a una re-evaluación del valor de la antisepsia. El uso de vendas que reduzcan el crecimiento bacteriano deberia también ser un factor en el manejo de heridas. [Noble, W.C., Lloyd, D.H. Pathogenesis and management of wound infections in domestic animals (Patogenesis y manejo de heridas infectadas en animales domesticos). Veterinary Dermatology 1997; 8 : 243–248] Zusammenfassung Die Pathogenese von Wundinfektionen hängt hauptsächlich von Haftungsmechanismen und Toxinen ab. Studien von Staphylokokkus intermedius weisen nach, dass Isolate von Pyodermien sich an in Wunden exponierte extrazelluläre Matrixproteine binden; die Interpretation dieser Haftungsstudien wird durch multiple Mechanismen einiger Organismen kompliziert. Studien, diese Haftung durch Antibiotika zu blockieren oder zu fördern, zeigen variable Ergebnisse. Epidermolytische Toxine sind für S. aureus und S. hyicus, aber nicht für S. intermedius beschrieben, obwohl von einem synergohymenotropischen Toxin berichtet wird und beim Hund Syndrome auftreten, in denen epidermale Spaltung und S. intermedius Infektion koexistieren. Enterotoxine und Toxischer Schock Toxin 1 von Staphylokokkus werden als Superantigene anerkannt, die nicht spezifische Zytokinfreisetzung verursachen und so die Entzündung in Wunden fördern. Die Behandlung infizierter Haut erfolgt weitgehend durch Antibiotika, aber Resistenzbildung wird deren Verwendung einschränken; im Moment geht die Tendenz mehr in Richtung Impfungen und die Neubewertung von Antisepsis. Die Verwendung von Verbandsmaterialien, die das Wachstum von Mikroorganismen einschränken, muss in der Wundversorgung berücksichtigt werden. [Noble, W.C., Lloyd, D.H. Pathogenesis and management of wound infections in domestic animals (Pathogenese und Versorgung von Wundinfektionen bei Haustieren). Veterinary Dermatology 1997; 8 : 243–248] Résumé La pathogénie des plaies infectées dépend largement de mécanismes d'adhérence et de toxines. L'étude de Staphylococcus intermedius montre que des germes de pyodermite peuvent adhérer aux protéines des matrices extracellulaires mises à nu par des blessures mais l'interprétation des études d'adhérence est compliquée par le fait que certains germes possèdent de multiples mécanismes. Des études d'inhibition ou d'activation d'adhérence par des antibiotiques démontrent également une variabilité. On connait l'existence de toxines épidermolytiques chez S. aureus et S. hyicus mais pas chez S. intermedius, bien qu'une toxine synergohymenotropique ait été décrite, et que des syndrômes où clivage épidermique et infection àStaphylococcus intermedius coexistent aient été décrit chez le chien. II est admis que des entérotoxines staphylococciques et la toxine 1 du choc toxique agissent comme des superantigènes qui provoquent une libération non spécifique de cytokines, provoquant l'inflammation des plaies. Le traitement des plaies infectées dépend largement des antibiotiques mais est limité par le phénomène d'antibiorésistance; actuellement, une tendance à reconsidérer la valeur des vaccins et de l'antisepsie se dessine. L'utilisation de pansements qui réduisent la prolifération bactérienne peut également être un facteur du traitement des plaies. [Noble, W.C., Lloyd, D.H. Pathogenesis and management of wound infections in domestic animals (Pathogénie et traitement des plaies infectées chez les animaux domestiques). Veterinary Dermatology 1997; 8 : 243–248]