吸血蓖子硬蜱成虫唾腺莱姆病螺旋体重度感染的发现

为了解莱姆病螺旋体在蜱体内的发育生物学，采用直接免疫荧光试验、银染色法组织学及电子显微镜观察螺旋体，结果显示，感染莱姆病螺旋体的饥饿蓖子硬蜱雌虫未吸血与吸血0．5和1天唾腺中无螺旋体。在吸血开始后2天出现唾腺的轻度感染，3天出现唾腺的中度感染，4天和5天出现重度感染。这些结果表明，莱姆病螺旋体媒介蜱唾腺的感染程度随吸血时间的延长而迅速增高，并可在缓慢吸血期的中后期形成重度感染。莱姆病螺旋体在吸血期媒介唾腺内的大量存在，特别是重度感染的发现，为该病原螺旋体由蟀向脊椎动物宿主传播的唾液分泌途径假设提供了有力证据。本研究对莱姆病螺旋体在吸血蟀唾腺内分裂增殖的可能性进行了讨论。     

Pseudomonas putida infection in rainbow trout

A disease outbreak occurred during the Spring of 2006 among rainbow trout, Oncorhynchus mykiss, kept in growout tanks. During the outbreak 35% of the rainbow trout died. Typical clinical signs were ulceration on the dorsal surface of the fish. Based on biochemical characteristics and sequence of 16S rRNA, the causative bacteria isolated from diseased fish were identified as Pseudomonas putida. Histologically, skin ulcer initially was characterized by sloughed off epithelia and epithelial necrosis. In the advanced form of the disease, almost all layers of the skin down to the epidermis were lost. Outside of Japan, this study reports the first P. putida infection in fish.     

Serogroup distribution,diversity of exotoxin gene profiles,and phylogenetic grouping of CTX-M-1- producing uropathogenic Escherichia coli

The emergence of CTX-M-1 producing Uropathogenic Escherichia coli (UPEC) has become a serious challenge. In addition to antimicrobial resistance, a number of virulence factors have been shown. Therefore, this study was designed to determine the prevalence of O- serogroups, phylogenetic groups, exotoxin genes, and antimicrobial resistance properties of CTX-M-1- producing UPEC. A total of 248 UPEC isolates were collected. The antibiotic resistance was performed, and PCR was used to detect the bla_CTX-M1, exotoxins, serogroups and phylogroups of UPEC. Of 248 isolates, 95 (38.3%) harbored bla_CTX-M-1. Of them, serogroups O1 and O25 were predominant, accounting for 20% and 13.7%, respectively. The hlyA was the dominant exotoxin gene (32.6%), followed by sat (28.4%), vat (22.1%), cnf (13.7%), picU (8.4%), and cdt (2.1%). The hlyA gene was significantly associated with pyelonephritis (P = 0.003). Moreover, almost half of the isolates (45.4%) belonged to phylogenetic group B2. Most of exotoxin genes were present in significantly higher proportions in group B2 isolates except cdt gene (P < 0.05). All of the isolates were susceptible to imipenem, nitrofurantoin, and fosfomycin. The CTX-M-1-producing UPEC strains causing nosocomial infections are more likely to harbor certain exotoxin genes, raising the possibility that this increase in virulence genes may result in an increased risk of complicated UTI.     

种衣剂对蔬菜种子萌发、带菌率及幼苗生长的影响

以5种蔬菜种子为材料,用不同的种衣剂处理,研究种衣剂对种子萌发、带菌率及幼苗生长的影响。结果表明,Apronmaxx和适乐时种衣剂可作为里绿花椰菜、京椒1号辣椒和中农7号黄瓜种子的包衣处理剂,不仅可显著降低种子带菌率,而且对种子活力影响不大;但对夏玉白萝卜和秋绿60大白菜种子萌发和幼苗生长有一定的抑制作用。锐胜、福.甲枯种衣剂对5种蔬菜的种子萌发和幼苗生长有一定的促进作用,但抑菌作用不大;华农D1种衣剂明显降低种子活力,故锐胜、福.甲枯和华农D1种衣剂均不适宜作为供试材料的包衣处理剂。     

新疆猪、牛、羊弓形虫病的血清学调查

目的为摸清新疆地区家畜弓形虫感染情况。方法作者对新疆乌鲁木齐周边地区的猪、牛和阿勒泰地区的牛、羊随机抽样,采用间接血凝试验(IHA)进行了血清学调查。结果乌鲁木齐周边地区的猪的感染率为66.39%(243/336),牛为31.94%(23/72);阿勒泰地区牛为31.8%(28/88),羊为33.33%(12/36);结论弓形虫在这三种动物中均有相当高的感染率,应引起人们的足够重视,加强防范。     

Sero-survey on Aino, Akabane, Chuzan, bovine ephemeral fever and Japanese encephalitis virus of cattle and swine in Korea

Vector-borne arboviruses produce mild to severe symptoms in domestic animals. Bovine ephemeral fever (BEF), Akabane, Aino, and Chuzan virus have been primarily attributed to reproductive disorders or febrile diseases in cattle, and Japanese encephalitis virus (JEV) is mainly associated with reproductive failures in swine. We investigated antibody titers from domestic swine against four bovine arboviruses (BEF, Akabane, Aino, and Chuzan virus) and from cattle against JEV in Korea. While the positive rates for Akabane and BEF were 37.4% and 15.7%, the positive incidence of Chuzan and Aino were relatively low, with positive rates of 3.04% and 0.4%, respectively, based on a virus neutralization assay. Antibody titers against more than one virus were also frequently detected in domestic swine. The incidence of JEV was 51.3% among domestic cattle. In addition, one positive case was detected in the thoracic fluids from 35 aborted calves, based on the hemagglutination inhibition test. Our results indicate that swine are susceptible hosts of bovine arboviruses without showing clinical symptoms in a natural environment. Moreover, we confirmed that JEV could be associated with reproductive failure in pregnant cattle, as were other vector-borne bovine arboviruses assessed in this study.     

Possibility of vancomycin-resistant enterococci transmission from human to broilers, and possibility of using the vancomycin-resistant gram-positive cocci as a model in a screening study of vancomycin-resistant enterococci infection in the broiler chick

In this study, vancomycin‐resistant enterococci (VRE) from humans and vancomycin‐resistant gram‐positive cocci (VRPC) from pigs were examined for their ability to transmit in the chick intestine (Experiment 1). A model study on the spread speed of VRPC was also estimated from chick to chick under semi‐production conditions with different administration routes (not inoculated, oral administration to a chick, sprayed on the floor) (Experiment 2). Furthermore, the disappearance of VRPC from their litter with composting processes was examined (Experiment 3). Each of six chicks was inoculated with VRPC or VRE at 1 day old in Experiment 1. All the chicks had VRPC or VRE in their glandular stomach at 22 days of age. In Experiment 2, 6 floor pens covered with sawdust were prepared and 20 chicks were allotted to each pen. The chicks were inoculated with VRPC at 1 day of age. The VRPC were detected in each group in cloacal swabs at 2 days of age (detection rate; 20–80%). And they were also detected in the not‐inoculated group. The VRPC detection rate gradually decreased, and detection was rare (0–10%) in the packing chicks (50 days old). VRPC were detected in the litter of each pen in Experiment 2. A composting process was effectively used to eliminate VRPC by the 6th week (Experiment 3).     

Absence of vertical transmission of Helicobacter pylori in an experimental murine model

Helicobacter pylori (H. pylori) infection is acquired mainly in early childhood but the precise transmission routes are unclear. This study examined the maternal H. pylori infection status in order to determine the potential of perinatal transmission. These issues were investigated using an experimental murine model, the Mongolian gerbil, which has been reported to be the most suitable laboratory animal model for studying H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into two groups. The stomachs of the mother and litters were isolated and assessed for the transmission of H. pylori at the prenatal period (2 weeks after pregnancy) and at the parturition day. The bacterial culture, polymerase chain reaction (PCR) and rapid urease test were used to examine the presence of the transmitted H. pylori. There was no H. pylori observed in any of the fetuses during pregnancy and in the litters at parturition. This suggests that vertical infection during the prenatal period or delivery procedure is unlikely to be route of mother-to-child transmission of a H. pylori infection.     

无锡地区鹅球虫种类的调查

采用饱和盐水漂浮法对无锡地区鹅感染球虫的种类及感染率等情况进行了初步调查。结果，从无锡地区17个不同鹅群的粪样中共获得8种球虫，其中艾美属球虫有6种，分别是有害艾美球虫、棕黄艾美球虫、赫氏艾美球虫、鹅艾美球虫、法氏艾美球虫、条纹艾美球虫；等孢属球虫1种，即鹅等孢球虫；泰泽属球虫1种，即稍小泰泽球虫。     

奶牛产后子宫感染与子宫免疫

非特异性子宫感染会降低奶牛的生产性能和奶牛场的潜在效益。发生子宫感染时常并发感染化脓性放线杆菌或混合感染其他细菌。当从产后21 d的奶牛子宫液中分离到化脓性放线杆菌时,说明奶牛发生了严重的子宫内膜炎,并且将导致产后第一个发情期不孕。然而引起子宫感染的确切原因尚不清楚,但可以肯定与多种因素有关。发生难产、胎衣不下、怀有双胎或死胎以及患有各种代谢紊乱疾病的奶牛比其他奶牛更容易发生子宫感染。分娩前后异常的免疫功能更容易导致发生严重的子宫感染。子宫感染一般不会引起奶牛死亡,但是发生子宫感染的奶牛其生产性能会受到很大影响。另外,子宫发生感染还会降低产奶量,并且对子宫感染的一些治疗措施还会对牛奶产生污染。因为感染的非特异性,所以子宫感染很难预防;注意加强卫生设施以及围产期的卫生,特别是在助产过程中的卫生,才可能是最好的预防方法。异常免疫功能导致奶牛发生子宫感染的现象,说明通过对免疫功能的调节来预防和治疗围产期奶牛子宫感染是有潜力的。