Epizootiologic background of dissimilar distribution of human cases of Lyme borreliosis and tick-borne encephalitis in a joint endemic area

Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are co-endemic in some parts of Europe, however, their distribution differs despite a common tick vector and comparable animal hosts. A serosurvey of game and small mammals was made in a highly endemic area and compared with historical data in human cases; the epidemiologic risk and the population density of game were modelled using a geographic information system. While LB-risk corresponded with an overall population density of game (red deer, roe deer, mouflon, wild boar) regardless of mouse abundance, TBE-risk suggested a dependence on the abundance of mice on the one hand, and game, particularly roe deer, on the other. While the prevalence of TBE-antibodies generally grew with the game’s age, it was virtually constant at about 65% in LB irrespective of species. It implies a cumulation of scarce TBE-infection histories during the game’s lifetime, and thus a limited size of TBE-foci relative to the living space of these animals, as well as omnipresent LB-foci, in which the animals became continuously re-infected. More ecological prerequisites seem necessary to keep TBE circulating in nature which may be responsible for its confined distribution.     

Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks

EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m²: 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2–7 EID50. Depending on the strain, the basic reproduction number (R₀) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R₀ estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R₀. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV.     

Factors influencing the cell adhesion and invasion capacity of Mycoplasma gallisepticum

Background

The cell invasiveness of Mycoplasma gallisepticum, the causative agent of respiratory disease in chickens and infectious sinusitis in turkeys, may be a substantial factor in the well-known chronicity of these diseases and in the systemic spread of infection. To date, not much is known about the host factors and mechanisms involved in promotion or obstruction of M. gallisepticum adherence and/or cell invasion.In the current study, the influence of extracellular matrix (ECM) proteins such as fibronectin, collagen type IV and heparin, as well as plasminogen/plasmin, on the adhesion and cell invasion levels of M. gallisepticum to chicken erythrocytes and HeLa cells was investigated in vitro. Two strains, R_high and R_low, which differ in their adhesion and invasion capacity, were analyzed by applying a modified gentamicin invasion assay. Binding of selected ECM molecules to M. gallisepticum was proven by Western blot analysis.

Results

Collagen type IV, fibronectin, and plasminogen exerted positive effects on adhesion and cell invasion of M. gallisepticum, with varying degrees, depending on the strain used. Especially strain R_high, with its highly reduced cell adhesion and invasion capabilities seemed to profit from the addition of plasminogen. Western and dot blot analyses showed that R_high as well as R_low are able to adsorb horse fibronectin and plasminogen present in the growth medium. Depletion of HeLa cell membranes from cholesterol resulted in increased adhesion, but decreased cell invasion.

Conclusion

ECM molecules seem to play a supportive role in the adhesion/cell invasion process of M. gallisepticum. Cholesterol depletion known to affect lipid rafts on the host cell surface had contrary effects on cell adherence and cell invasion of M. gallisepticum.     

Retrospective Study on Seroprevalence of Borrelia burgdorferi Antibodies in Horses in Minnesota

To determine the seroprevalence of Borrelia burgdorferi antibodies in horses in Minnesota, the database of the Veterinary Diagnostic Laboratory, University of Minnesota, was searched over a 10-year period (May 2001 to May 2010). A total of 1,260 equine serum samples submitted by 112 veterinary clinics were tested using an indirect fluorescent antibody test. Samples with titers of ≥1:320 were considered positive. The average rate of seroprevalence was 58.7%, indicating high exposure of horses to B burgdorferi in Minnesota. Our results indicate that borreliosis should be considered as a differential in cases of horses with undiagnosed musculoskeletal or neurologic disease.     

Serological Confirmation of Borrelia burgdorferi Infection in Dogs in the Czech Republic

From the epidemiological point of view, dogs are very important since they are considered a suitable indicator of the spread of human borreliosis. Serum samples obtained from healthy, asymptomatic military dogs from 12 different areas in the Czech Republic were examined for IgG antibodies to Borrelia burgdorferi sensu lato (s.l.). The total of 399 serum samples were tested by a whole-cell ELISA. Specific antibodies to Borrelia burgdorferi s.l. were detected in 26 cases (6.5%). In different localities, the seroprevalence varied from 0.0% to 28.6%. Two local isolated strains Br-75 (Borrelia afzelii) and Br-97 (Borrelia garinii) were used as antigens. A total of 22 (5.5%) were positive for antibodies to Borrelia afzelii and 19 (4.8%) were positive for antibodies to Borrelia garinii. Fifteen cases were positive for both antibodies. A significantly higher seroprevalence was found in younger dogs (1–3 years) than in older ones (p < 0.05). An analysis of seroprevalence by months of sampling showed no significant difference (p > 0.05).     

Prevalence of tick-borne encephalitis virus in ticks from southern Korea

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.     

Herbage intake by cattle on tarchonanthus veld in the Northern Cape as affected by stocking rate and grazing system 1

Abstract

In a trial with young Bonsmara cattle, four different stocking rates (10, 7, 6 and 4 ha/large stock unit) were applied in both a rotational and continuous grazing system. Feed intake was estimated during spring, summer, autumn and winter for four consecutive years starting in 1977.

Irrespective of the grazing system, feed intake declined with an increase in stocking rate. On average the highest intake was recorded in January and reached the lowest levels in October and July.

Livemass gain was found to be closely related to feed intake.     

Long-term Pulmonary Responses to Quadweekly Intermittent Intratracheal Spray Instillations of Magnetite (Fe3O4) Nanoparticles for 52 Weeks in Fischer 344 Rats

Information about potential risks of iron nanomaterials is still limited, while a wide variety of applications are expected. We recently reported acute phase responses of male and female Fischer 344 rats after a single intratracheal spray instillation of Fe₃O₄ nanoparticles (magnetite), clearly showing dose-dependent pulmonary inflammatory changes (Tada et al., J Toxicol Pathol 25, 233–239, 2012). The present study assessed long-term responses of male and female Fischer 344 rats to multiple administrations of magnetite. Ten-week-old male and female Fischer 344 rats (n=20/group) were exposed to a total of 13 quadweekly intermittent intratracheal spray instillations of magnetite during the experimental period of 52 weeks, at doses of 0, 0.2 (low), 1.0 (medium) and 5.0 (high-dose) mg/kg body weight per administration. Absolute and relative lung weights of the high-dose group were significantly higher than those of the control group. Macroscopically, slight enlargement and scattered black patches were recognized in the lungs and the lung-associated lymph nodes of the high-dose group. Histopathologically, infiltration of macrophages phagocytosing magnetite (all dose groups) and of chronic inflammatory cells (medium- and high-dose males and high-dose females), alveolar bronchiolization and granuloma (high-dose group) were observed. In addition, alveolar hyperplasias were observed in some rats of the high-dose group, and cytoplasmic overexpression of β-catenin protein was immunohistochemically found in such lesions. The present results clearly show that instilled magnetite causes chronic inflammatory responses in the lung. These responses occur in a dose-dependent manner without apparent differences among sexes     

Acute Phase Pulmonary Responses to a Single Intratracheal Spray Instillation of Magnetite (Fe3O4) Nanoparticles in Fischer 344 Rats

Iron nanomaterials are of considerable interest for application to nanotechnology-related fields including environmental catalysis, biomedical imaging, drug delivery and hyperthermia, because of their superparamagnetic characteristics and high catalytic abilities. However, information about potential risks of iron nanomaterials is limited. The present study assessed pulmonary responses to a single intratracheal spray instillation of triiron tetraoxide nanoparticles (magnetite) in rats. Ten-week-old male and female Fischer 344 rats (n=5/group) were exposed to a single intratracheal spray instillation of 0 (vehicle), 5.0, 15.0 or 45.0 mg/kg body weight (BW) of magnetite. After 14 days, the rats were sacrificed, and biological consequences were investigated. The lung weights of the 15.0 and 45.0 mg/kg BW male and female groups were significantly higher than those of the control groups. The lungs of treated rats showed enlargement and black patches originating from the color of magnetite. The typical histopathological changes in the lungs of the treated rats included infiltration of macrophages phagocytosing magnetite, inflammatory cell infiltration, granuloma formation and an increase of goblet cells in the bronchial epithelium. The results clearly show that instilled magnetite causes foreign body inflammatory and granulating lesions in the lung. These pulmonary responses occur in a dose-dependent manner in association with the increase in lung weight.     

The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs

Background

Tumors of the skin and subcutaneous tissue are the largest group of canine neoplasms. Total excision is still the most effective method for treatment of these skin tumors. For its universal properties the carbon dioxide (CO₂) laser appears to be an excellent surgical instrument in veterinary surgery. Laser techniques are alternatives to traditional methods for the surgical management of tumors. The aim of this study was to compare various types of laser techniques in skin oncologic surgery: excision, ablation and mixed technique and to suggest which technique of CO₂ laser procedure is the most useful in particular case of tumors in dogs.

Findings

The study was performed on 38 privately-owned dogs with total number of 40 skin tumors of different type removed by various CO₂ laser operation techniques from 2010–2013. The treatment effect was based on the surgical wound evaluation, the relative time of healing and possible local recurrence of the tumor after 3 months post surgery. Local recurrence was observed in two cases. The study showed that in 30 cases time needed for complete resection of lesions was less than 10 minutes. Time of healing was longer than 12 days in 6 cases (42.8%) with tumor excision and in 14 cases (87.5%) where excision with ablation technique was performed.

Conclusions

The advantages of the CO₂ laser surgery were better hemostasis, precision of working, non-contact dissection, less instruments at the site of operation and minimum traumatization of the surrounding tissues.     

Occurrence of mycotoxins in feed ingredients and complete feeds obtained from the Beijing region of China

Background

The current study was carried out to provide a reference for the control of mycotoxin contamination in feed ingredients and complete feeds for swine.

Methods

A total of 55 feed ingredients, including 14 corn, 13 wheat bran, 11 soybean meal and 17 dried distillers grains with solubles (DDGS) as well as 76 complete swine feeds including 7 creep feeds, 14 starter feeds, 14 grower feeds, 18 grower-finisher feeds, 10 gestating sow feeds, and 13 lactating sow feeds were randomly collected from 15 swine farms located in the Beijing region of China from July to August 2011. Immunoaffinity clean-up, using High-Performance Liquid Chromatography (HPLC) in combination with UV or Fluorescence Detection, was used for quantitative analysis of aflatoxin B₁ (AFB₁), deoxynivalenol (DON), zearalenone (ZEA) and ochratoxin A (OTA) in the ingredients and complete feeds.

Results

DON and ZEA were the most prevalent mycotoxins found. DON was detected at percentages of 93, 92, 54, 100 and 97% with a mean level of 1.01, 0.44, 0.05, 1.36 and 0.65 ppm in the samples of corn, wheat bran, soybean meal, DDGS and complete feeds, respectively. The detected percentages of ZEA were 100, 100, 54, 100 and 100 with mean levels of 109.1, 14.9, 9.2, 882.7 and 58.9 ppb in the same samples. In the wheat bran and soybean meal samples, the content of all four mycotoxins were below the maximum limits set by Chinese regulations while the percentage of samples that exceeded regulatory limits were 7, 57 and 7% for corn, and 7, 14 and 3% for the complete feeds for AFB₁, DON and OTA respectively. DDGS showed the most serious mycotoxin contamination and the percentage of samples that exceeded regulatory limits were 6, 88 and 41%, for AFB₁, DON and ZEA, respectively.

Conclusions

This paper is the first to present data on the natural occurrence of AFB₁, DON, ZEA and OTA in ingredients and complete feeds obtained from swine farms in China’s Beijing region. The data shows that feed ingredients and complete swine feeds obtained from these farms are most often contaminated with DON followed by contamination with AFB₁ and ZEA.     

生产用培养基对猪丹毒杆菌G4T10株安全及免疫原性试验的比较研究

为明确生产用培养基对猪丹毒杆菌G4T10株安全性及免疫原性影响,采用2种不同批次的肉肝胃膜消化汤（20120123批和130226批）及马丁琼脂（20120904批和130129批）进行猪丹毒杆菌G4T10株培养和选菌,然后进行安全及免疫原性试验。结果共筛选出4种不同优势菌落,其中一株的菌落（20120123批肉肝胃膜消化汤＋20120904批马丁琼脂）形态最好,具有良好的安全性及免疫原性（小鼠全试验9／10存活,其免疫后攻毒达9／9保护）;而有一株菌落（20120123批肉肝胃膜消化汤十130129批马丁琼脂）形态最差,其安全性及免疫原性试验结果差（小鼠安全试验仅6／10存活,其免疫后攻毒仅达2／5保护）。试验表明,不同批次生产用培养基对猪丹毒活疫苗（G4T10株）质量影响大。     

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.     

Abattoir-based study on the epidemiology of caprine tuberculosis in Ethiopia using conventional and molecular tools

Background

Despite the important role of goats for meat and milk production in Ethiopia, little information is available on the epidemiology of caprine tuberculosis (TB). Caprine TB is important as milk is usually consumed raw particularly by Ethiopian pastoralists. The objectives of the present study were to estimate the prevalence of TB in goats at an abattoir, to evaluate associated risk factors and to characterize the causative mycobacteria.

Methods

A cross-sectional study was conducted on 1990 randomly selected male goats that were slaughtered at Luna Export Abattoir of central Ethiopia. Postmortem examination, mycobacterial culturing and molecular typing techniques like genus typing, deletion typing and spoligotyping were used.

Result

The overall prevalence of caprine TB-like lesions was 3.5%. The lesion prevalence increased significantly with increasing age. Mycobacteria were found by culture and seen as acid fast bacilli in 12% of the goats with TB-like lesions. Characterization of the eight isolates using multiplex polymerase chain reaction (PCR) indicated that five of them belonged to the genus Mycobacterium. Four of the latter were confirmed to be members of the M. tuberculosis complex. Further characterization of the three M. tuberculosis isolates by spoligotyping identified them as type SIT53 and two new spoligotypes.

Conclusion

The isolation of M. tuberculosis from goats in this study indicates a potential risk of transmission of M. tuberculosis between humans and goats.     

Immunohistochemical Expressions of Main PGE(2) Biosynthesis-related Enzymes and PGE(2) Receptor in Rat Nephrogenesis

Endogenous prostaglandin (PG) E(2) plays important roles in renal homeostasis. Immunoexpressions of PGE(2) biosynthesis-related enzymes, cyclooxygenase (COX)-2 and microsomal PGE(2) synthetase (mPGES)-1 and EP4 (a PGE(2) receptor), were investigated in renal development. Kidney tissues were obtained from fetuses on gestation days 18 and 21 and neonates on days 1 to 18. In fetuses and early neonates, the expressions of COX-2, mPGES-1 and EP4 were observed in developing renal tubules, indicating that COX-2 and its product, PGE(2), play important roles in blastemal cell-derived renal tubular development via EP4. Cyclin D1 expression was seen in both the nucleus and cytoplasm of the developing tubules. These findings differed from the decreased COX-2 expression and exclusive nuclear expression of cyclin D1 seen in abnormal epithelial regeneration of injured renal tubules in cisplatin-treated rats in our previous articles. Collectively, PGE(2), induced by COX-2, regulates renal tubular epithelial formation via EP4.     

Some Reproductive and Clinical Aspects of Endotoxins in Cows with Special Emphasis on The Role of Prostaglandins

Endotoxin from Salmonella typhimurium was administered intravenously to 3 cows. It produced an immediate increase in blood prostaglandin metabolite levels causing either luteolysis or a temporary drop in progesterone concentrations depending on the degree of prostaglandin synthesis. The clinical effects on heart rate, respiratory rate, ruminai contraction rate, body temperature and other general signs were studied. The cows showed a transient increase in heart and respiratory rate and a decrease in ruminai activity. The temperature responded by a small initial decrease and a secondary increase. Other symptoms included muscular weakness and shivering, excessive salivation and diarrhoea. Plasma Ca levels showed a direct decrease and then slowly increased to initial levels in the course of several days. The role of endotoxins in Gram-negative infections and their mode of action on the body are discussed with special emphasis on the role of prostaglandins on reproductive function.     

The Effect of Induced Standing Reflex,Cervical Stimulation and Insemination on Intraluminal Pressure Variations in the Isthmus of the Oviduct in Unrestrained Gilts

Four gilts were each equipped with 2 ultra-miniature pressure sensors, placed at 2 different points along the same isthmus of the oviduct, on the morning of the first day of standing oestrus (Day 1). Intraluminal pressure recordings were started the same afternoon. After an initial recording period, intraluminal pressure was recorded while the gilts showed standing oestrus and during cervical stimulation followed by insemination with either 100 ml saline or 100 ml boar semen. Monitoring of the pressure variations in the isthmus was continued for up to 6.5 h after the last insemination. Blood samples for monitoring oestradiol-17B, progesterone and 15-ketodihydroprostaglandin F_2α were collected before and after each manipulation of the gilt and every 30 min during the rest of the test period. None of the above manipulations had any consistent effect on the intraluminal pressure in the porcine isthmus, although, a clear 15-ketodihydroprostaglandin F_2α peak could be seen after insemination with boar semen.     

Evaluation of total oxidant and antioxidant status in dogs under different CO2 pneumoperitoneum conditions

Background

The induction of the pneumoperitoneum increases intraabdominal pressure (IAP), causing splanchnic ischemia, whereas its deflation normalizes IAP and splanchnic blood flow. We investigated the oxidant-antioxidant status of dogs who underwent low pressure (7 mm Hg), standard pressure (12 mm Hg), and high pressure (15 mm Hg) pneumoperitoneum.

Results

Twenty-four beagle dogs (12 males and 12 females), 4–6 years old, weighing 8–11 kg were used. The animals were assigned to one of four groups (n = 6 dogs). Group 1 served as a control; these animals received only anaesthesia for 90 min. In groups 2, 3 and 4, intra-abdominal pressure was increased to 7, 12 and 15 mmHg, respectively, and maintained for 60 min. Total oxidant status (TOS) and total antioxidant status (TAS) were determined in venous blood samples. The percentage ratio of TOS to TAS provided an oxidative stress index (OSI).No significant difference in TOS levels was found among the groups. A significant decrease in TAS levels and an increase in OSI levels were observed at 90 min and 24 h of pneumoperitoneum deflation within group 4. No differences were found among the groups.

Conclusions

A high pressure pneumoperitoneum induced significant changes in TAS and OSI. In addition, TOS and TAS levels are useful markers for evaluating changes in the oxidative status caused by a pneumoperitoneum during laparoscopy. Furthermore, a low-pressure pneumoperitoneum could attenuate oxidative stress induced by CO₂ insufflation in dogs.     

Relationship of Cell Proliferating Marker Expressions with PGE(2) Receptors in Regenerating Rat Renal Tubules after Cisplatin Injection

Cisplatin, an anticancer drug, is well known to have nephrotoxicity as an adverse effect. We investigated the expressions of cell cycle markers and prostaglandin E(2) (PGE(2)) receptors (EP) in the affected renal tubules in rats injected with a single dose (6 mg/kg body weight) of cisplatin. On days 1-3 after dosing, the affected renal epithelial cells were almost desquamated, showing necrosis. On day 5 onwards, the renal tubules were rimmed by flattened or cuboidal epithelial cells with basophilic cytoplasm; BrdU-immunopositive cells began to significantly increase, indicating regeneration. Simultaneously, TUNEL-positive apoptotic cells were also seen. On days 1-5, cyclin D1-immunopositive cells were decreased with an increased expression in p21 mRNA, indicating G(1) arrest in the cell cycle. The affected renal epithelial cells began to react to EP4 receptor, but not to EP2 receptor. Some EP4 receptor-reacting epithelial cells gave a positive reaction to BrdU or cyclin D1. Collectively, the affected renal tubules underwent various alterations such as necrosis, apoptosis, regeneration and G(1) arrest; the aspects might be influenced by endogenous PGE(2) through EP4 receptor.