Concepts and Direction of Induced Systemic Resistance in Plants and its Application

Resistance to plant disease is often specific and metabolites and receptors contributing to this specificity may have specific structures. However, simple, structurally-unrelated compounds induce systemic resistance in unrelated plants to diverse pathogens including fungi, bacteria and viruses. Both resistance and induced systemic resistance (ISR) are associated with the rapid accumulation of the same structurally unrelated putative defense compounds that have diverse functions. It has been suggested that cultivar (race)-specific resistance is initiated by the specific interaction of a pathogen product (or pathogen induced product) and a plant receptor. However, restricted infection by pathogens can result in ISR and many different compounds can cause ISR. It is thus evident that there are both specific and non-specific routes to the master switch for ISR and there may be more than one master switch. Are reactive oxygen species and free radicals regulating the master switch(es) via both routes? It is also evident there are many switches, other than the master switch. Adding to the complexity of resistance and ISR are the observations that different compounds and pathways may mediate different biochemical resistances. Activation of one of the pathways may antagonize or enhance the activation or effectiveness of another. The review will address these complexities and questions and propose directions of research which require high priority. Factors which encourage and suppress the application of ISR in agriculture will also be addressed.     

Alien species of aphids (Hemiptera: Aphididae) found in Serbia,new to the Balkan Peninsula

New alien species of aphids (Illinoia liriodendri (Monell), Wahlgreniella nervata (Gillete), Takecallis arundicolens (Clarke) and Tinocallis takachihoensis Higuchi) have been found for the first time in Serbia. These records are new for the Balkan Peninsula. Data of Ericaphis scammelli (Mason), species recently mentioned in Serbia, are also presented in the text. The species have been found during the last five years at four sites (Belgrade, Zemun, Mladenovac and Bojnik) on five cultivated plants. Ericaphis scammelli is a pest of blueberry and a vector of Blueberry scorch virus. The other four develop colonies on decorative plants: I. liriodendri has been found on Liriodendron tulipifera, W. nervata on Rosa sp., T. arundicolens on Pseudosasa japonica and T. takachihoensis on Ulmus x hollandica. The origin of three of the species (E. scammelli, I. liriodendri and W. nervata) is North America and two (T. arundicolens and T. takachihoensis) have come from East Asia. Their morphology, biology and the damage they inflict are discussed here, as well as their potential economic and environmental threat. Only parthenogenetic viviparous females of all 5 species have been collected. Their biology has not been studied enough in Europe and needs further examination. Original drawings of all species are presented.     

Toxoplasma gondii infection in slaughter pigs in Serbia: seroprevalence and demonstration of parasites in blood

ABSTRACT: A seroepizootiological study of Toxoplasma gondii infection involving a total of 488 slaughter pigs (468 market-weight pigs and 20 sows) in the Belgrade area, also included examination of the presence of T. gondii in the blood. Blood sampled at the slaughter line was examined for specific antibodies by modified direct agglutination, and blood clots of those seropositive at titres of 1:50-1:12800 were bioassayed in mice. The overall seroprevalence was 9.2%, significantly higher (p = 0.0063) in sows (30.0%) than in market-weight pigs (8.3%). Amongst the 22 bioassays performed, a total of 16 (72.7%) were positive, by observation of T. gondii cysts (12), seropositivity (7, including 3 in which cysts were not detected), and/or detection of T. gondii DNA by real-time PCR (12, including one otherwise negative). The positive bioassays originated from the blood of 12 market-weight pigs and 4 sows. Despite a general increase in the rate of demonstration of T. gondii with the increase in the specific antibody level, the association was not significant (p = 0.101). The risk of infection was 41-fold increased in sows vs market-weight pigs, and 15-fold in pigs from smallholders' finishing type farms vs those from large farrow-to-finish farms. The presence of viable T. gondii in a proportion of the samples indicates that some of the pigs had an active parasitaemia at the time of slaughter, which, along with the seroprevalence established, points to a potential source of human infection in Serbia. This is the first report on parasitaemia in naturally infected swine.     

Effects of feeding buffering mineral mixture on subacute rumen acidosis and some production traits in dairy cows

This trial was designed in order to evaluate the incidence of subacute rumen acidosis (SARA) during early lactation and to investigate the possibilities for its prevention by use of a buffering mineral mixture. On the beginning of the trial it was found that the pH value of rumen fluid in 4 animals was lower than normal (pH < 6.0) and that 20% of animals have had SARA. The control and the experimental group of cows were fed the same meal with exception of concentrated feed which in the experimental group contained the mineral mix with buffering activity in amount of 1%. Continuous addition of buffering mineral mixture in the amount of 1% in concentrated feed for early lactation cows successfully prevents SARA formation and leads to increased milk production, as well as increased milk fat and protein content.     

Fructose 1,6-biphosphate aldolase in the sera of Simmental young bulls Connection with the fattening capacity, muscle quantity and protein content

SUMMARY: The activity of enzyme aldolase (ALD) was determined in the sera of Simmental young bulls, with the purpose to see whether there exists a relationship between the enzyme activity and fattening capacity and whether the ALD could be an indicator of the muscle quantity and protein content. Early ALD activity was correlated with slaughter weight and ADG in the last fattening month. The regression analysis suggests that young bulls with higher serum ALD acitivity at the start of the experiment had more total muscles and less bone in the analysed rib part. On the basis of ALD activity in the first fattening month it was possible to estimate protein and fat content in the MLD. ZUSAMMENFASSUNG: Fructose-1,6-biphosphat Aldolase beim Serum Simmentaler Jungbullen. Beziehung zwischen Mastf?higkeit, Muskelmenge und Proteingehalt Aldolase (ALD) Enzymt?tigkeit im Serum von Simmentaler Jungbullen wurden in Hinblick auf eine Beziehung mit Mastf?higkeit, Muskelmenge und Proteingehalt untersucht. Es zeigt sich eine Korrelation zwischen früher ALD Aktivit?t und Schlachtgewicht und Tageszuwachs im Endmastmonat. Regressionsanalyse ergab, da? Jungbullen mit h?herer ALD Aktivit?t bei Mastbeginn mehr Muskelanteil im m. longissimus dorsi und weniger Knochen besitzen. ALD Aktivit?t im ersten Mastmonat erlaubt Sch?tzung des Protein- und Fettgehalts im m. long, dorsi. RESUMEN: Fructosa 1,6-bifosfato aldolasa en el suero de los terneros simentales. Relatión con sus capacidades de ser cebados, su cantidad de músculos y el contenido de proteínas Con el fin de establecer la relación entre la actividad de enzimas y las capacidades durante el proceso de la ceba, asf como para precisar si el ALD puede servir como indicador de la cantidad de músculos y el contenido de proteinas, intentaba determinarse la actividad de los enzimas de aldolasa (ALD) en el suero de los terneros simentales. A base de la actividad indicial del ALD, es posible estimar el peso final de matadero y la crecencia diaria media durante el último mes de la ceba. Tras una análisis regresiva se ha probado que los terneros con una actividad mayor del ALD en el suero a principios del proceso de su ceba tienen más músculos en total en la parte de costillas y m. longissimus dorsi mientras que tienen menos huesos. A base de la actividad del ALD durante el primer mes de la ceba es posible estimar el contenido de proteinas y grasa en m. long, dorsi. RéSUMé: Fructose 1.6-biphosphate aldolase dans le sérum des taurillons de Simmental. Le rapport entre l'aptitude à l'angraissement, la proportion des muscles et la teneur en protéines On a déterminé l'activité de l'enzyme aldolase (ALD) dans le sérum des taurillons de Simmental afin de vérifier s'il existait un rapport entre l'activité des enzymes et l'aptitude à l'engraissement et si l'ALD pouvait être indicatrice de la proportion de muscles et de la teneur en protéines. A la base de l'activité initiale de l'ALD, il est possible d'évaluer le poids de la carcasse et le gain quotidien moyen au cours du dernier mois d'engrais. Par analyse régressive, il a été établi que les taurillons à l'activité supérieure de l'ALD dans le sérum avaient au début de l'engrais plus de muscles au total dans la région costale et le m. longissimus dorsi et moins d'os. A la base de l'activité de l'ALD au cours du premier mois d'engrais il est possible d'évaluer la teneur en protéines et en graisse dans le muscle longissimus dorsi.     

N. femoralis, N. obturatorius and N. ischiadicus: deviation in creation in the dogs

Two hundred and twelve dog cadavers belonging to different breeds were examined, to investigate the formation of the femoral, obturator and the sciatic nerve. Besides the commonly described formation patterns of the mentioned nerves, some variations were also found. These variations were not gender-related, but on the other hand we discovered a certain correlation between the variations appearing in the formation of the femoral, obturator and the sciatic nerve. In 74.05% of cases, the femoral nerve was formed from ventral branches of the 4th, 5th and 6th lumbar nerve, and 16.98% of the dogs had the nerve formed from ventral branches of the 3rd, 4th and 5th lumbar nerve. Many dogs (i.e. 2.30%) had the femoral nerve formed from the ventral branches of the 5th, 6th and 7th, the 3rd, 4th, 5th and 6th or the 4th, 5th, 6th and 7th lumbar nerve, respectively. In 1.88% of dogs in particular, the femoral nerve was formed from ventral rami of the 4th and 5th lumbar nerve. In 66.98% of the examined dogs, the obturator nerve was formed from the ventral branches of the 4th, 5th and 6th lumbar nerve, followed by 16.59% of the dogs with the obturator nerve formed from the ventral rami of the 4th and 5th lumbar nerve and 9.43% of dogs in which the nerve was formed from the ventral branches of the 5th and 6th lumbar nerve. In 4.71% of dogs, the obturator nerve was formed from the ventral rami of the 4th, 5th, 6th and 7th lumbar nerve, while only 2.30% of the examined dogs had the same nerve formed from the ventral branches of the 5th, 6th and 7th lumbar nerve. The sciatic nerve was formed from ventral branches of the 6th and 7th lumbar nerve and the 1st sacral nerve in 86.79% of the dogs. In 5.18% of cases, the same nerve was formed from a junction of the ventral branches of the 7th lumbar and the 1st and 2nd sacral nerve, and, in the same percentage of cases, it was formed from a junction of ventral branches of the 6th and 7th lumbar nerve and the 1st and 2nd sacral nerve. In 2.83% of the dogs, it was formed from a junction of the ventral branches of the 6th and 7th lumbar and the 1st sacral nerve. The correlation of variations established in the formation of the femoral, obturator and the sciatic nerve was not statistically significant.     

Microbiological identification and analysis of swine tonsils collected from carcasses at slaughter

The primary objective of this 7-month study was to determine the prevalence of porcine pathogens of the tonsil of the soft palate of swine at slaughter. Additional objectives were to determine if sampling the carcasses of normal or abnormal hogs provided different microbiological profiles and if the slaughter plant provides a feasible sampling frame and environment for detecting and monitoring important pathogens in tonsils that have health implications for both swine and humans. A total of 395 samples were collected from 264 farms. Of these, 180 tonsils were collected from normal carcasses and 215 tonsils were collected from carcasses that were diverted to the hold rail. Laboratory testing included bacteriological culture and identification as well as real time-polymerase chain reaction (PCR) testing for porcine reproductive and respiratory syndrome virus (PPRSV) and immunohistochemistry (IHC) for porcine circovirus-2 (PCV-2). The most commonly isolated bacteria included: Streptococcus suis (53.7%), Arcanobacterium pyogenes (29.9%), Pasteurella multocida (27.3%), and Streptococcus porcinus (19.5%). Virus screening revealed evidence of PRRSV and PCV-2 in 22.0% and 11.9% of the samples, respectively. Salmonella Typhimurium and Yersinia enterocolitica were isolated in 0.5% and 1.8% of the samples, respectively. Tonsils collected from the hold rail were more likely to be positive for Staphylococcus hyicus [odds ratio (OR) = 7.51, confidence interval (CI) = 2.89 to 19.54], Streptococcus porcinus (OR = 9.93, CI = 4.27 to 23.10), and Streptococcus suis (OR = 2.16, CI = 1.45 to 3.24). Tonsils collected from abnormal carcasses were less likely to be positive for Staphylococcus aureus (OR = 0.05, CI = 0.005 to 0.482).     

Antimutagenic effects of extracts from sage (Salvia officinalis) in mammalian system in vivo

Naturally occurring antimutagenic factors, especially those of plant origin, have recently become a subject of intensive research. Antimutagenic properties of terpenoid fractions of sage (Salvia officinalis) were tested in mammalian system in vivo through examining the ability of sage to decrease the frequency of aberrant cells induced by a potent mutagen. First, groups of mice were treated with three concentrations of sage alone and it was established that the frequency of aberrant cells after treatment with a concentration of 25 microL/kg was not significantly different from the negative control (olive oil), while that found after treatment with the 50 microL/kg concentration differed significantly (chi2(1) = 4.05, p < 0.05). Sage used at a concentration of 100 microL/kg was cytotoxic. Mitomycin C (MMC), known as a potent mutagen, was used for induction of chromosome aberrations. Post-treatment with sage suppressed the effects of MMC significantly. Both concentrations (25 microL/kg and 50 microL/kg) produced a significant decrease in the frequency of aberrations relative to MMC (chi2(1) = 5.42, p < 0.02, chi2(1) = 14.93, p < 0.001, respectively). The percent of aberrations decreased with increasing concentrations of sage. Only nontoxic concentrations of sage without mutagenic effects can be recommended for use as inhibitors of mutagenesis or carcinogenesis.     

Comparison of antibody values in sera of pigs vaccinated with a subunit or an attenuated vaccine against classical swine fever

Ten pigs, aged 85 days, were vaccinated with a subunit vaccine containing 32 g of classical swine fever virus glycoprotein E2 (gp E2) (group 1), and a further 10 pigs were vaccinated with a C strain vaccine (10^4±0.15 TCID₅₀/ml), produced by amplification in minipig kidney (MPK) cell culture (group 2). Nine non-vaccinated pigs served as a control group (group 3). Serum samples were collected before (day 0) and at 4, 10, 21 and 28 days after vaccination and were analysed by two commercially available enzyme immunoassays and by a neutralizing peroxidase-linked assay (NPLA). At the same times, peripheral blood was taken for determining the total leukocyte count and the body temperature was taken daily. Antibodies were not detected in serum samples collected before vaccination (day 0), and no side-effects that could be connected with vaccination were observed during the trial. Ten days after vaccination 6/10 pigs vaccinated with the subunit vaccine were seropositive. On days 21 and 28, the ratios of serologically positive to vaccinated pigs were 9/10 and 10/10, respectively. Four of the ten pigs that were vaccinated with the C strain vaccine were positive on day 21 and 9/10 on day 28. However, the results of the NPLA showed that only 4/10 pigs had an antibody titre >1:32 at the end of the trial in both the vaccinated groups, even though the subunit vaccine initiated an earlier and higher level of neutralizing antibodies than the vaccine produced from the C strain. Challenge was performed 28 days after vaccination on four randomly selected pigs from both vaccinated groups. The pigs survived the challenge without showing any clinical signs of classical swine fever (CSF), while two nonvaccinated control pigs died on the 10th and 12th days after infection.