Failure to establish infection with Tetratrichomonas sp. in the reproductive tracts of heifers and bulls

Experimental infection of the reproductive tracts of heifers and bulls with Tetratrichomonas sp. isolated from preputial smegma of virgin bulls was attempted. Nine heifers and four bulls were challenged by inoculation of 7 x 10(6) Tetratrichomonas sp. into the vaginal lumen and preputial cavity, respectively. Vaginal mucus and preputial smegma samples were collected and cultured for Tetratrichomonas sp. Heifers were slaughtered in groups of three at 2, 9 and 21 days after inoculation. Two heifers and two bulls infected with Tritrichomonas foetus and two uninfected heifers were used as controls for the model infection. Tetratrichomonas sp. were only isolated in vaginal mucus of 7/9 inoculated heifers at 6h post-inoculation, and genital secretions taken at slaughter time from vagina, uterus and oviduct were cultural negative. Bulls challenged with Tetratrichomonas sp. remained cultural negative. Since Tetratrichomonas sp. survived only a few hours in the female genitalia and did not survive in the male genitalia after experimental challenge, Tetratrichomonas sp. did not colonize the genital tract. These were likely trichomonads from the digestive tract. Collection of clean samples without fecal contamination from the reproductive tract is proposed as a measure to avoid Tetratrichomonas sp. transitory genital infection.     

Escherichia coli associated endotoxemia in dogs with parvovirus infection

Escherichia coli bacteremia and endotoxemia were observed in 3 adult mongrel dogs which had been prediagnosed as canine parvoviral disease. The endotoxin level was 46.5 pg/ml in the plasma of clinical cases, while 2.3 pg/ml in healthy controls. The microflora of the feces was confused in the clinical cases. The percentage of E. coli was major in the feces. Serologically similar strains were isolated from the blood. These strains did not produce enterotoxins such as heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT). Histopathologically, the lesions in the small intestine consisted of epithelial degeneration and necrosis. Viral inclusion bodies were frequently observed in the epithelial cells. Disseminated intravascular coagulation was observed in various tissues including the liver and small intestinal submucosa. After experimental infection with CPV, all dogs showed various clinical signs. CPV was positive in the feces. Endotoxin level in the plasma gradually increased and high level continued for long period from 10 to 30 days. Mean maximum level of endotoxin in the experimental dogs was 73.6 pg/ml. These results indicate that intestinal flora plays a important role in the pathogenesis of CPV infection and that endotoxin is one of the factors which predispose to severe disease after the infection.     

北京顺义区肉鸭大肠杆菌及鸭疫里默氏菌感染情况的调查

为了调查北京顺义肉鸭大肠杆菌及鸭疫里默氏菌感染情况,对该区约50个小型肉鸭养殖农户,采集具有典型心包炎、肝周炎和气囊炎特征的病(死)鸭肝脏、心脏、脾脏等组织,经细菌分离纯化、革兰染色、瑞氏染色及16S r DNA序列分析从而鉴定菌株。共分离得到大肠杆菌33株,鸭疫里默氏菌9株。这42株细菌的药敏试验表明,鸭疫里默氏菌对大多数抗菌药物敏感,而大肠杆菌则表现出较强的耐药性。     

Intestinal changes associated with rotavirus and enterotoxigenic Escherichia coli infection in calves

Newborn calves inoculated with rotavirus, enterotoxigenic Escherichia coli (ETEC) serotype 020:K' x 106':K99:HNM, either alone or in combination, became depressed, anorectic, diarrhoeic and dehydrated. ETEC did not adhere to the intestine although there was extensive proliferation in the lumen. Only slight mucosal changes were induced by ETEC and the activity of membrane bound lactase remained normal. More severe mucosal damage and a decrease in lactase activity were found in newborn calves inoculated with either rotavirus or rotavirus and ETEC in combination. The most severe clinical illness was found in calves inoculated with both rotavirus and ETEC. Calves inoculated at 1 week of age with either rotavirus or ETEC remained clinically normal. Rotavirus infection produced slight mucosal changes and a reduction of lactase activity. In contrast, colostrum-fed or suckling calves up to 2 weeks old inoculated with both rotavirus and ETEC became clinically affected, showed severe mucosal damage and decreased lactase activity. There was no bacterial adhesion to the intestinal mucosa as observed by immunofluorescent labelling and light microscopy.     

Pharmacokinetics of cyclosporine in woodchucks and Pekin ducks

The purpose of this study was to evaluate the pharmacokinetics of cyclosporine (Cy) in woodchucks ( Marmota monax ) and Pekin ducks. These data are needed to design rational dosing regimens. Pharmacokinetic parameters were calculated from blood concentration-time data obtained following intravenous (i.v.) administration of 10 mg/kg body weight to woodchucks and Pekin ducks. Whole blood samples were collected in EDTA and assayed using a commercially available radioimmunoassay kit that employs a monoclonal antibody specific for Cy. The blood concentration-time profile best Dtted an open, two-compartmental model in Pekin ducks. Compartmental analysis of data in woodchucks did not adequately describe the data. When non-compartmental pharmacokinetic analysis of the data was performed, the resulting mean (± SD) pharmacokinetic parameters in woodchucks and Pekin ducks, respectively, were as follows: volume of distribution at steady-state, 2.9 (± 0.8) and 2.7 (± 0.2) L/kg; systemic clearance, 10.2 (± 2.8) and 28.6 (± 6.1) mL/kg/min; mean residence time, 4.8 (± 1.1) and 1.6 (± 0.3). These data suggest that Pekin ducks clear Cy at a faster rate than do woodchucks and that a greater dose of Cy should be administered to Pekin ducks in order to achieve adequate immunosuppression.     

Partial abortion associated with genital Escherichia coli infection in a bitch

A five-and-a-half weeks pregnant Airedale terrier with a genital haemorrhage was presented. It had a history of oestrous irregularities. It was found to be anaemic and Escherichia coli was isolated from vaginal swabs. Oestradiol and progesterone levels were normal. Two fetuses were aborted on day 41 of gestation. Antibiotic treatment was given. The haemorrhage ceased but on day 61 an abnormal vaginal discharge was seen. A caesarean operation was performed from which resulted three dead and two live fetuses, which died within two days. E coli was isolated from the uterine content, although the bitch was still receiving antibiotics; it was also still anaemic. It is probable that the haemorrhage was caused by an endotoxin produced by the E coli. The anaemia in the bitch did not improve the chances of fetal survival.     

A sequential histologic and immunohistochemical study of duck hepatitis B virus infection in Pekin ducks

Twenty-nine Pekin ducks were inoculated with duck hepatitis B virus (DHBV), DHBV-free serum, or saline at 1 day of age. Congenitally DHBV-infected ducks were also studied. Ducks were killed periodically during a 92-week study and examined histologically and immunohistochemically to assess liver and extrahepatic inflammation and to detect and characterize DHBV core antigen tissue distribution. DHBV infection produced an asymptomatic but persistent DHBV viremia in all ducks associated with a mild to moderate transient hepatic inflammation apparent at 3 to 6 weeks post-inoculation and waning afterwards. DHBV core antigen was detected in hepatocyte cytoplasm at 1 week post-inoculation, and by 3 weeks post-inoculation scattered pancreatic acinar and islet cells also contained viral antigen. Small numbers of mononuclear cells in the splenic white pulp also contained viral antigen. Viral antigen persisted in all of these tissues throughout the duration of the experiment. No inflammation or tissue injury was detected in any of the extrahepatic tissues during the course of DHBV infection. One DHBV-injected duck developed a hepatocellular carcinoma at 88 weeks of age. Isolated patches of neoplastic hepatocytes contained cytoplasmic DHBV core antigen. The results of this study indicate that DHBV, like mammalian hepadnavirus, is capable of producing a persistent infection of the liver and several extrahepatic tissues and suggest that persistent infection may be associated with the development of hepatocellular carcinoma.     

北京某鸭场鸭疫里默氏菌与大肠杆菌混合感染的诊治

自2012年7月30日起,北京市延庆县某鸭场开始出现大批鸭子发病及死亡。从发病鸭的内脏组织进行细菌分离,经过分离培养、革兰染色和瑞氏染色及16S rDNA序列分析,结合临床表现及剖检变化,确诊为鸭疫里默氏菌与大肠杆菌的混合感染。根据药敏试验结果选用抗菌药物进行治疗,该场的病情很快得到了控制。     

火鸡大肠杆菌组织滴虫和球虫的混合感染

某养殖场 1 995年 8月引进 1～ 2月龄尼古拉斯商品火鸡 840只 ,混群饲养于简易猪舍。引进时 ,发现火鸡群健康不佳 ,被毛较粗乱 ,即连续 5天以氟哌酸饮水和强力清毒灵全群喷雾消毒。因条件有限 ,火鸡群白天放养于荒草地 ,晚上赶进废旧猪舍过夜。棚舍低矮潮湿 ,地域狭小 ,使得饲养密度过大 ,达到 1 0只 /m2 。9月1日至 6日持续高温 ,昼间最高气温均在 36℃以上 ,9月 6日后气温虽略有下降 ,但也在 32℃以上。1　发病情况　自 9月 1日陆续出现病死火鸡 ,开始每天 1～ 2只 ,4天后上升到 6～ 7只 ,至 1 5日共死亡 81只 ,最多 1天达到 8只 ,损失惨…     

Ultrastructural alterations in the kidneys of Pekin ducks fed methylmercury.

Ultrastructural alterations in the kidneys of Pekin ducks were studied after subchronic exposure to methylmercury chloride. Twenty-four male and twenty-four female Pekin ducks, 12 weeks of age were fed 0.0 (control), 0.5, 5.0 and 15.0 parts per million of MeHgCl, mixed in a mash diet for 12 weeks. Birds were observed for clinical signs daily. Kidneys were fixed in situ by perfusion with 4% glutaraldehyde in 0.05 M phosphate buffer and routinely processed for electron microscopy. Only minor morphological changes were observed in the renal corpuscle of ducks in the 0.5 ppm group. The component cells of the renal corpuscle in the 5.0 and 15.0 ppm groups showed several ultrastructural alterations, including an increase in number and size of lysosomes and vacuoles in podocytes and mild vacuolation in mesangial cells. The juxtaglomerular cells of afferent arterioles had crystallized granules. No significant changes were observed in glomerular basement membrane thickness and width of podocyte pedicels. The proximal tubules of the 5.0 and 15.0 ppm groups showed some microvillar loss and an increase in the number and size of lipid droplets, vacuoles and lysosomal bodies. The distal tubular changes in the 5.0 and 15 ppm groups included electron lucency and vacuolation of cytoplasm as well as occasional mitochondrial swelling. The collecting ducts of 5.0 ppm and 15.0 ppm groups showed varying degrees of degenerative changes in both mucus secretory as well as absorptive cells. These results suggest that subchronic exposure of Pekin ducks to methylmercury chloride causes subtle ultrastructural changes in renal corpuscle and marked ultrastructural changes in proximal tubules and collecting ducts.     

The effects of Escherichia coli and its endotoxin on amyloidogenesis in ducks.

To compare the effects of two inocula on the induction of amyloidosis in normal and thymectomized ducks, 180 normal and 50 thymectomized ducks were injected intravenously weekly for up to 16 weeks with either crude endotoxin or crude whole cell extract of a virulent strain of Escherichia coli (O78), and another 60 ducks were injected with normal saline as study control. During the first 5 weekly injections, the initial doses of inducing agents were the smallest and then adjusted upward to the maximum study doses (1 or 2 mg/bird of crude endotoxin and 15-18 x 10(8) bacteria/bird of crude whole cell extract), which were then maintained over the course of the study. The incidence of amyloid deposition were: 50.00% (25/50) for thymectomized ducks that received 1 mg/bird/week of crude endotoxin, 61.67% (37/60) for intact ducks that received 15 x 10(8)-18 x 10(8) bacteria (crude whole cell extract)/bird/week, 53.33% (32/60) for intact ducks received 2 mg/bird/week of crude endotoxin, and 63.33% (38/60) for intact ducks received 1 mg/bird/week of crude endotoxin. The results suggest that crude whole cell extract and crude endotoxin induced amyloidosis in ducks at similar rates and that, in ducks, thymectomy has no appreciable effect on the occurrence of amyloidosis.     

Enhancement of enteropathogenic Escherichia coli pathogenicity in young turkeys by concurrent turkey coronavirus infection

In a previous study, turkey coronavirus (TCV) and enteropathogenic Escherichia coli (EPEC) were shown to synergistically interact in young turkeys coinfected with these agents. In that study, inapparent or mild disease was observed in turkeys inoculated with only TCV or EPEC, whereas severe growth depression and high mortality were observed in dually inoculated turkeys. The purpose of the present study was to further evaluate the pathogenesis of combined TCV/EPEC infection in young turkeys and determine the role of these agents in the observed synergistic interaction. Experiments were conducted to determine 1) effect of EPEC dose, with and without concurrent TCV infection, and 2) effect of TCV exposure, before and after EPEC exposure, on development of clinical disease. Additionally, the effect of combined infection on TCV and EPEC shedding was determined. No clinical sign of disease and no attaching and effacing (AE) lesions characteristic of EPEC were observed in turkeys inoculated with only EPEC isolate R98/5, even when turkeys were inoculated with 10(10) colony forming units (CFU) EPEC (high dose exposure). Only mild growth depression was observed in turkeys inoculated with only TCV; however, turkeys inoculated with both TCV and 10(4) CFU EPEC (low dose exposure) developed severe disease characterized by high mortality, marked growth depression, and AE lesions. Inoculation of turkeys with TCV 7 days prior to EPEC inoculation produced more severe disease (numerically greater mortality, significantly lower survival probability [P < 0.05], increased frequency of AE lesions) than that observed in turkeys inoculated with EPEC prior to TCV or simultaneously inoculated with these agents. Coinfection of turkeys with TCV and EPEC resulted in significantly increased (P < 0.05) shedding of EPEC, but not TCV, in intestinal contents of turkeys. These findings indicate that TCV infection predisposes young turkeys to secondary EPEC infection and potentiates the expression of EPEC pathogenicity in young turkeys.     

鸭疫里默氏菌病和大肠杆菌病多重PCR诊断方法的建立

参考GenBank中鸭疫里默氏菌和大肠杆菌的外膜蛋白A(OmpA)基因序列,应用PrimerPremier5.0软件在二者高度保守区设计了2对引物,建立了适合鸭疫里默氏菌和大肠杆菌的快速检测的多重PCR检测方法。以该方法对已分离并保存的鸭疫里默氏菌和大肠杆菌进行PCR扩增,分别扩增出与试验设计相符的670、408bp的特异性DNA片段。将扩增所得的DNA片段进行克隆测序,测序结果表明分别为鸭疫里默氏菌和大肠杆菌OmpA基因序列。该方法对鸭疫里默氏菌和大肠杆菌的检测下限分别为4×104CFU/mL和3×104CFU/mL。表明所建立的PCR方法具有特异、快速和敏感的特点,可用于诊断鸭疫里默氏菌、大肠杆菌以及两者的混合感染。     

Acute fibrinopurulent blepharitis and conjunctivitis associated with Staphylococcus hyicus, Escherichia coli, and Streptococcus sp. in chickens and turkeys

Multiple outbreaks of acute severe fibrinopurulent lesions of the eyelids occurred in chickens and turkeys. Lesions began as tiny foci of epidermal necrosis and ulceration and spread to involve the entire eyelid. Scabs overlying the epidermis contained large gram-positive cocci; lesser numbers of small cocci and gram-negative bacilli were in more superficial areas. Staphylococcus hyicus was isolated from birds in all stages of the disease. Escherichia coli and Streptococcus sp. were isolated only during severe stages; no anaerobic bacterial pathogens were isolated. Vasculitis and perivascular lymphocytic infiltrates in deep layers of the dermis suggested that a staphylococcal toxin may have been involved. The disease was not reproduced by scarifying S. hyicus onto the eyelids or by intravenous inoculation of retrovirus-infected chickens.     

Phenotypic characterization of ipaH+ Escherichia coli strains associated with yolk sac infection

Seventy-six Escherichia coli serotypes possessing the ipaH gene typical of enteroinvasive E. coli (EIEC) strains were characterized. Biochemical identification of our strains shows positive reactions for lactose fermentation (100% of strains), lysine decarboxylase (98.7% of strains) and motility (67.1% of strains), properties that do not correspond with those described to the EIEC group. The serotypes agree with an initial classification. In this, some common O antigens identified among ipaH+ strains were O2 (n=20), OR (n=11) and non-determined O? (n=10). The O2:NM serotype was the most common. Sixty-six percent (n=50) of the ipaH+ E. coli strains were colicin producers, of them, 26 (34%) produced Col V and other colicins, 13 (17%) produced colicins other than Col V, and 11 (14.5%) produced Col V only. Trimethoprim/Sulfa (72%), ampicillin (64.5%), enrofloxacin (55.3%), and ciprofloxacin (47.4%) were the major antimicrobial resistance frequencies observed. Twenty-five different multiresistance patterns were observed, where sixty-six strains (86.8%) were included. A MIC test showed that most of the strains were sensitive to low gentamicin and kanamycin concentrations, whereas most of the strains were resistant to tetracycline. An invasiveness assay showed that the predominant alterations caused to HEp-2 cells were changes in shape and staining, and in most of the specimens, a partial monolayer detachment was also seen. Fifteen strains invaded more than 30% of the monolayer cells, causing the formation of intercellular bridges or filipoidal-like protrusions. The results suggest the existence of specific clone complexes derived from EIEC strains adapted to the avian host. To our knowledge, this is the first study that demonstrates the presence of extraintestinal invasive E. coli (ExIEC) strains.     

Escherichia coli infection in lambs

Abstract

Extract

Published records of Escherichia coli infection in lambs have appeared with increasing frequency in recent years. Reports have come from Australia (Roberts, 1957 Roberts, D. S. 1957. Anst. vet. J., 33: 43–43.  [Google Scholar], 1958 Roberts, D. S. 1958. Anst. vet. J., 34: 152–152.  [Google Scholar]; Charles, 1957 Charles, G. 1957. Anst. vet. J., 33: 329–329.  [Google Scholar]) and from Britain (Terlecki and Shaw, 1959 Terlecki, S. and Shaw, W. G. 1959. Vet. Rec., 71: 181–181.  [Google Scholar]; Rees, 1958 Rees, T. A. 1958. J. comp. Path., 68: 399–399.  [Google Scholar]; Hughes, 1962 Hughes, L. E. 1962. Vet. Rec., 74: 350–350.  [Google Scholar]). In the Australian outbreaks, the age of affected lambs ranged from three to eight weeks, while in the British outbreaks lambs became affected within one day of birth. In both countries the illness lasted from one to three days. Characteristically, the infection localized in the central nervous system leading to purulent meningo-encephahtis, and in the joints causing fibrino-purulent arthritis.     

Escherichia coli bacteremia associated with hypertrophic osteodystrophy in a dog.

Escherichia coli bacteremia was detected in a dog that had hypertrophic osteodystrophy. The dog improved after treatment with cephalothin sodium, iv fluid therapy, and cage rest. The cause of hypertrophic dystrophy has not been determined, although an infectious cause has been suggested. Dogs that are suspected of having hypertrophic osteodystrophy should be monitored closely for evidence of septicemia, and the administration of prophylactic antibiotics may be advisable.     

Molecular investigation of Escherichia coli strains associated with apparently persistent urinary tract infection in dogs

Persistent Escherichia coli urinary tract infection (UTI) in dogs is a frustrating clinical problem. Affected dogs often appear to fail to respond to therapy or to reacquire infection shortly after therapy is completed. Urovirulence factors (UVFs) of the infecting E. coli, antibiotic resistance, and tissue colonization may be contributory but have not been evaluated in dogs with persistent E. coli UTI. In this study, the strain types of E. coli in dogs with persistent UTI were evaluated with pulsed-field gel electrophoresis (PFGE) to determine whether persistence was due to acquisition of new isolates or failure to eradicate existing isolates. UVFs in these isolates, assessed by polymerase chain reaction, and antibiograms were correlated with treatment outcome in these dogs. Results documented a mixed pattern: 9 dogs remained chronically infected with 1 or 2 strains, each with distinct reproducible UVFs, but 1 dog was infected with numerous unrelated E. coli strains over time. Two dogs had a mixed pattern, consisting of 1 or more episodes of persistent E. coli infection attributable to a single strain in addition to episodes caused by unrelated strains. Many isolates had no detectable UVFs, highlighting the likely importance of impaired colonization resistance in the affected dogs. Antibiotic resistance was common, often in response to previous treatments, especially with trimethoprim-sulfamethoxazole. Antibiotic resistance patterns differed significantly within PFGE strain types, suggesting lateral acquisition of resistance plasmids or integrons. These results can be used to help guide testing for and management of persistent E. coli UTI in dogs.     

Competitive exclusion treatment reduces the mortality and fecal shedding associated with enterotoxigenic Escherichia coli infection in nursery-raised neonatal pigs.

We have previously reported that the administration of a competitive exclusion culture (PCF-1), derived from the cecal microflora of a young, healthy pig and maintained in a continuous flow fermentation system to neonatal pigs resulted in a decrease in the incidence of fecal shedding and cecal colonization by Salmonella choleraesuis in pigs at weaning. In the present experiment, we describe the effects of the administration of a derivative of the PCF-1 culture, RPCF, against an enterotoxigenic E. coli infection in neonatal pigs raised off-sow. The administration of RPCF at 12 and 24 hours after birth resulted in significant (P < 0.05) reductions in mortality, incidence of fecal shedding, and in gut colonization by E. coli when compared to control values. The RPCF reduced mortality from 17.5%, observed in untreated pigs, to 4.4% in RPCF-treated pigs. Fecal shedding of E. coli was reduced significantly (P < 0.05) in RPCF-treated pigs between Days 1 and 3 post-challenge. These results indicate that the RPCF culture is effective against one of the most important causes of neonatal scours (E. coli infections) in piglets.     

Virulence factors of Escherichia coli associated with colisepticemia in chickens and turkeys.

Four hundred twenty turkey and 80 chicken Escherichia coli isolates from colisepticemic birds were examined for the following properties: heat-labile toxin (LT), heat-stable enterotoxin, verotoxin, colicinogenicity, hemolysin, and hydroxamate/aerobactin production. Twenty-four (5.7%) of the 420 turkey isolates and six (7.5%) of the 80 chicken isolates produced an LT that was cytotoxic for both Vero and Y-1 cells. In contrast, 48 (11.4%) of the turkey isolates and 18 (22.5%) of the chicken isolates produced a distinct LT that was cytotoxic only for Vero cells. In addition, 64 (80.0%) of the chicken isolates and 309 (74.0%) of the turkey isolates produced aerobactin. Colicinogenicity occurred in 51 (64.0%) of the chicken isolates, with 41 (51.0%) producing colicin V. By contrast, 254 (61.0%) of the turkey isolates produced a colicin, of which 176 (42.0%) produced colicin V. None of the chicken and turkey isolates produced hemolysin or heat-stable enterotoxin.