Genotype profiles of Actinobacillus pleuropneumoniae isolated from pigs in Vojvodina, Serbia

Background: Actinobacillus pleuropneumoniae (A. pleuropneumoniae) is one of the most important bacterial respiratory pathogens. It is the only etiological agent of porcine pleuropneumonia (PPP) or it appears as a secondary bacterial infection in the swine respiratory disease complex (PRDC). In Serbia, apart from the identification of serotype 2, no tests have been performed to establish the presence of other A. pleuropneumoniae serotypes in the pig population. The aim of this study was to perform genotyping of A. pleuropneumoniae isolates originating from pig farms in Serbia by apx genes and using multiplex polymerase chain reaction (mPCR). Materials, Methods & Results: Isolates of A. pleuropneumoniae examined in this study were obtained from lungs with macroscopically visible alterations characteristic of a A. pleuropneumoniae. A total of 46 isolates were examined. They were extracted from the lung tissue samples of pig carcasses from 9 farms across different parts of Serbia. Genotyping of isolates was performed in the previously described manner. Briefly, 5 pairs of oligonucleotide primers were used for amplification of 4 different apx genes which encode synthesis of exotoxins (ApxI , ApxII , ApxIII i ApxIV) characteristic for all A. pleuropneumoniae serotypes and biovars. Amplification of appropriate genome parts was performed with a reaction chain polymerase (PCR) in multiplex (m) format using appropriate diagnostic kits to extract DNA from bacteria and perform mPCR reaction. The results of genotyping of 46 isolates of A. pleuropneumoniae indicate the existence of a large number of different serotypes of A. pleuropneumoniae on the studied farms or that different serotypes of this microorganism circulate in the pig population in Serbia. In addition to the detection of dominant serotype 2, which was established on 7 farms, of which in 4 farms it was the only detected serotype, in the examined pig population the presence of serotypes 3, 5, 6, 7 and 9 was also found. Furthermore, the presence of 2 different serotypes of A. Pleuropneumoniae was also detected on 3 farms; on the first farm serotypes 2 and 3, on the second farm serotypes 2 and 6, and on the third farm serotypes 2 and 7. Discussion: Although the research was done with a relatively small number of isolates of A. pleuropneumoniae, comparing the obtained results with the results on the presence and prevalence of appropriate serotypes from other countries, we concluded that there is significant diversity of this pathogen in the pig population in farms of Serbia. Detection of different serotypes of A. pleuropneumoniae in the pig population and the presence of several different serotypes on 1 farm was established for the very first time in Serbia. All isolates from our study can be characterized as highly virulent, considering that the clinical symptoms, pathological findings and the results of bacteriological examination indicated A. pleuropneumoniae to be the cause of animal death. Like in the neighbouring countries, the strongly pathogenic serotype 9 and the less pathogenic serotype 2 are the most frequently identified causative agents of porcine pleuropneumonia in the Autonomous Province of Vojvodina, Republic of Serbia. The necessity to establish the presence of all A. pleuropneumoniae serotypes in the pig population, and in particular to determine the presence of different serotypes on individual farms, is crucial for several reasons: making a definitive e diagnosis; development of prophylactic strategies for medicines; implementation of immunoprophylactic vaccination.

Effects of ketoprofen administration on relation between acute phase proteins and metabolic parameters in cows during early lactation

Background: Acute phase proteins (APPs) are clinically useful parameters for measuring the occurrence and severity ofinflammatory responses in cattle. As large group of proteins, APPs are mainly secreted by hepatocytes whose concentrationincrease or decrease as response to tissue injury, inflammation or infection. The transition from late pregnancy to earlylactation is associated with a compromised immune status coupled with increased acute phase response. Non-steroidalanti-inflammatory drugs (NSAIDs) are used in treatment of inflammatory conditions. The main objective of the presentstudy was to analyze the effects of a preventive administration of the NSAID (ketoprofen) in post-calving dairy cows onconcentration of APPs (haptoglobin and fibrinogen) and their relationship with indicators of liver function.Materials, Methods & Results: The treatment group (n = 15) was given an intramuscular injection of ketoprofen in theconcentration of 3 mg/kg during three consecutive days after calving. The control group (n = 15) was not treated withketoprofen. Blood samples were taken from coccygeal vein, on the first day of treatment and in the first and second weekpostpartum and they were analyzed for metabolic parameters (albumin and aspartat aminotransferaze) and APPs such ashaptoglobin and fibrinogen. Compared with control, ketoprofen administration decrease the levels of haptoglobin and fibrinogen and AST activity. Increase in albumin concentration was recorded in experimental group of cows compared withcontrol. Negative correlations (P < 0.01) were found between the haptoglobin concentration and albumin concentrationand aspartate aminotransferaze activity. Discussion: As inflammatory indicator in dairy cows, it is recorded that serum concentrations of haptoglobin is increasedduring mastitis. Beside haptoglobin, fibrinogen represents one of the APPs whose serum concentration increases during response in the acute phase. During the first and second week...

Effects of ketoprofen administration on relation between acute phase proteins and metabolic parameters in cows during early lactation

Background: Acute phase proteins (APPs) are clinically useful parameters for measuring the occurrence and severity ofinflammatory responses in cattle. As large group of proteins, APPs are mainly secreted by hepatocytes whose concentrationincrease or decrease as response to tissue injury, inflammation or infection. The transition from late pregnancy to earlylactation is associated with a compromised immune status coupled with increased acute phase response. Non-steroidalanti-inflammatory drugs (NSAIDs) are used in treatment of inflammatory conditions. The main objective of the presentstudy was to analyze the effects of a preventive administration of the NSAID (ketoprofen) in post-calving dairy cows onconcentration of APPs (haptoglobin and fibrinogen) and their relationship with indicators of liver function.Materials, Methods & Results: The treatment group (n = 15) was given an intramuscular injection of ketoprofen in theconcentration of 3 mg/kg during three consecutive days after calving. The control group (n = 15) was not treated withketoprofen. Blood samples were taken from coccygeal vein, on the first day of treatment and in the first and second weekpostpartum and they were analyzed for metabolic parameters (albumin and aspartat aminotransferaze) and APPs such ashaptoglobin and fibrinogen. Compared with control, ketoprofen administration decrease the levels of haptoglobin and fibrinogen and AST activity. Increase in albumin concentration was recorded in experimental group of cows compared withcontrol. Negative correlations (P < 0.01) were found between the haptoglobin concentration and albumin concentrationand aspartate aminotransferaze activity. Discussion: As inflammatory indicator in dairy cows, it is recorded that serum concentrations of haptoglobin is increasedduring mastitis. Beside haptoglobin, fibrinogen represents one of the APPs whose serum concentration increases during response in the acute phase. During the first and second week...(AU)

Effects of iron administration method on anemia prevention and production performance of piglets

Background: Anemia caused by iron deficiency can lead to increased susceptibility to infection, lower production performance and higher mortality rates. Modern piglets grow rapidly, as within a few days of birth they double their body weight, thereby increasing blood volume. This increasing amount of blood naturally increases the requirement for hemoglobin (Hb) production, each molecule of which contains iron. This study examined the impact of different an iron application method on hematological values of iron (Fe), hemoglobin (Hb), hematocrit (Hct) and production performance of piglets in the suckling and nurturing stages. Materials, Methods & Results: The study was performed on two farrow-to-finish farms (I and II) of capacities of 2500 and 900 sows, respectively. Piglets were divided into four experimental groups: the IM group was given iron intramuscularly on the third day of life; the SC group was given iron subcutaneously on the third day of life; the PO group was given iron perorally on the third day of life; and the control group C was not given any iron. On the third day of life and at weaning (day 28) piglets body weights were measured and their blood was taken for analysis, while at the end of the nurturing stage (day 70), only body weights were measured. The influence of the farm was tested, as well as the impact of the day of blood sample collection and the [...](AU)

Effects of iron administration method on anemia prevention and production performance of piglets

Background: Anemia caused by iron deficiency can lead to increased susceptibility to infection, lower production performance and higher mortality rates. Modern piglets grow rapidly, as within a few days of birth they double their body weight, thereby increasing blood volume. This increasing amount of blood naturally increases the requirement for hemoglobin (Hb) production, each molecule of which contains iron. This study examined the impact of different an iron application method on hematological values of iron (Fe), hemoglobin (Hb), hematocrit (Hct) and production performance of piglets in the suckling and nurturing stages. Materials, Methods & Results: The study was performed on two farrow-to-finish farms (I and II) of capacities of 2500 and 900 sows, respectively. Piglets were divided into four experimental groups: the IM group was given iron intramuscularly on the third day of life; the SC group was given iron subcutaneously on the third day of life; the PO group was given iron perorally on the third day of life; and the control group C was not given any iron. On the third day of life and at weaning (day 28) piglets body weights were measured and their blood was taken for analysis, while at the end of the nurturing stage (day 70), only body weights were measured. The influence of the farm was tested, as well as the impact of the day of blood sample collection and the [...]

Findings of antibodies to Mycoplasma suis on swine farms in Serbia

Background: Hemoplasmas are eperythrocytic procaryotes, including Mycoplasma species which were recently transferred from the genera Eperythrozoon and Haemobartonella, based on their similarity of the 16S rRNA sequences, and newly identified hemotropic mycoplasmas. Eperythrozoonosis of pigs is caused by the haemotrophic bacterium M. suis, and the disease has a worldwide distribution. The disease manifests as a severe and often fatal acute febrile icteroanemia, mainly in piglets, pregnant sows before parturition and fattening pigs exposed to stress. The aim of this study was to determine the seroprevalence of IgG to M. suis in swine populations in Serbia, using a Western Blot test with the recombinant protein MSG1. Materials, Methods & Results: Four farms were chosen to represent the main swine-producing geographic regions of Serbia, including South Backa District (farms 1 and 2), North Backa District (farm 3) and Branicevo District (farm 4). A total of forty-six clinically healthy pigs, age 8-20 weeks, were included in the study. Blood samples from pigs randomly selected from the four farms were collected by jugular vein puncture into serum vacutainer tubes with clot activator. After clotting at room temperature for 1 h, blood samples were centrifuged at 1500 g, for 15 min at room temperature. Sera were carefully harvested and stored at -20°C until assayed. The sera samples were tested by the Western Blot test with recombinant protein MSG1 (p40). Production of recombinant protein MSG1 (p40), dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting were performed as previously described by Hoelzle. Specific IgG antibodies to MSG1 of M. suis were identified in 20 of the 46 samples tested, giving a total seroprevalence of 43.47%. The M. suis-specific antibody response was detected in pigs from all tested farms, within farm seroprevalences of 54.54% on farm 1; 27.27% on farm 2; 36.36% on farm 3 and 53.84% on farm 4. Discussion: Reports on the prevalence of swine infected with Mycoplasma suis in other countries are rare, but have been communicated for USA, Brazil, Japan, Portugal, China and Germany. Previously published values of the prevalence of the pigs infected with haemoplasmas in Serbia, determined through a microscopic examination of the peripheral blood smear according to Giemsa was 39% and with Acridine orange was 47%. These prevalences are similar to the overall prevalence found in this study (43.47%). In this present study, the prevalence of M. suis in the farm pigs studied in Serbia (43.47%) was higher than the serological evidence of the infection reported in pigs in the USA, Brazil and Japan, but lower than the prevalence in sows in Portugal and China. In this present study, the prevalence of M. suis on the studied pig farms in Serbia (43.47%) was more similar to results obtained in Germany, where M. suis infections were detected in 79 out of 196 pig farms (40.3%) by employing a quantitative real-time LightCycler PCR. Also, M. suis was detected in 36 out of 359 wild German boars (10.03%) with similar methodology. Our seroprevalence of anti-M. suis IgG in farmed pigs is probably higher than that in wild boar because of the conditions of intensive breeding on pig farms, but perhaps this may also be partly due to the different geographic locality, and/or to different analytical methods. This overall determined seroprevalence of 43.47% from a small sample within a relatively small area suggests a signifi cantly higher presence of infection on pig farms in Serbia, and hence, significantly more economic losses in pig production than could be expected based on the worldwide reports of M. suis prevalence.