Serological evidence of hepatitis E virus infection in pigs from Northern Bulgaria

The purpose of the present study was to investigate pigs in Northern Bulgaria for serological evidence of hepatitis E virus (HEV). Sera from 225 individuals from three industrial farms were tested for anti‑HEV IgG antibodies. The overall HEV seroprevalence was 36% (81/225); weaners 6.8% (5/74); fattening pigs 38.7% (29/75) and in sows 61.8% (47/76). Compared to weaners, HEV positivity was higher in fattening pigs and sows: OR = 8.70 (95% CI: 3.14‑24.12) and OR = 22.37 (95% CI: 8.07‑61.96), respectively. These data confirm that HEV is endemic in pigs throughout Bulgaria, and can be a Public Health problem due to the transmission of HЕV to humans through the consumption of pork meat and pork products.

Seroprevalence of Hepatitis E Virus Infection Among Wild Boars in Western Bulgaria

Scientific evidence indicates that hepatitis E virus (HEV) infection is a zoonotic disease. Domestic pigs and wild boars are the main animal reservoir for HEV worldwide. The aim of this study was to analyze the seroprevalence of HEV infection among wild boars in western Bulgaria. Serum samples from 240 wild boars from two regions of the country (northwestern and southwestern) were tested for anti-HEV Immunoglobulin G (IgG) antibodies. The overall HEV seroprevalence was 40.8% (98/240); northwestern region 40.0% (48/120); southwestern region 41.7% (50/120). HEV seropositivity in the southwestern region was higher than in the northwestern region: odds ratio = 1.071 (95% confidence interval: 0.640-1.793). This research provided the first seroprevalence study to HEV in wild boars from western Bulgaria.

High Seroprevalence of Hepatitis E Virus Infection Among East Balkan Swine (Sus scrofa) in Bulgaria: Preliminary Results

The East Balkan swine (Sus scrofa) is the only aboriginal pig breed in Bulgaria, and it is indigenous to the eastern part of the country. The aim of the present study was to investigate East Balkan swine (EBS) in Bulgaria for serological evidence of hepatitis E virus (HEV). Sera from 171 swine from two parts of the country (northeastern and southeastern) were tested for anti-HEV IgG antibodies. The overall HEV seroprevalence was 82.5% (141/171), and for weaners it was 77.2% (44/57), for fattening pigs 79.0% (45/57), and for adults 91.2% (52/57). HEV positivity was higher in fattening pigs and adults compared to weaners: OR = 1.108 (95% CI: 0.456–2.692) and OR = 3.073 (95% CI: 1.016–9.294), respectively. This study provides the first evidence of exposure to HEV in EBS from Bulgaria.

Molecular profiling and antimicrobial susceptibility of Escherichia coli O157:H7 isolated in Bulgaria

The purpose of this study was to detect the presence of shiga-toxin producing Escherichia coli (STEC) in faeces of healthy dairy cattle and to determine the sensitivity of isolates to several anti­microbial drugs. A total of 1,104 anal swab samples originating from 28 cattle farms were examined. After the primary identification, 30 strains were found to belong to serogroup О157. By means of conventional multiplex PCR, isolates were screened for presence of resistance genes stx1, stx2 and eaeА. Twenty-nine strains possesses amplicons with a size corresponding to genes stx2 and eaeA, one had amplicons also for the stx1 gene and one lacked amplicons of all three genes. Twenty-eight strains demonstrated amplicons equivalent to gene H7. The results from phenotype analysis of resistance showed preserved sensitivity to ceftriaxone, ceftazidime, cefotaxime, cephalothin, streptomycin, gentamicin, tetracycline, enrofloxacin and combinations sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Sensitivity to ampicillin was relatively preserved, although at a lower extent.

Seroprevalence of Hepatitis E Virus Infection in Pigs from Southern Bulgaria

Hepatitis E virus (HEV) has been isolated from humans and several animals' species. During the last years, the knowledge of HEV infection dramatically changed and enriched. The aim of this study was to estimate the seroprevalence of HEV in industrial pigs in different districts of Southern Bulgaria. Three hundred sixty swine serum samples were tested for anti-HEV IgG antibodies. The samples were collected from four industrial farms from three districts of Southern Bulgaria. HEV-specific antibodies in porcine serum were detected by enzyme-linked immunosorbent assay (PrioCHECK HEV Ab porcine). The overall HEV seroprevalence was 60.3%. The seropositivity varied widely depending on age groups and investigated farms. The overall prevalence in weaners was 25%, in fattening pigs 75.8%, and in group of sows was found the highest HEV positivity of 80%. The occurrence of HEV positivity in sows and fattening pigs presented odds ratio (OR) = 17.200 (95% confidence interval [CI]: 8.8-33.7) and OR = 11.342 (95% CI: 6.1-21.0), respectively, compared to weaners. The study indicated that HEV is widespread in industrial farms in Bulgaria and presented high seroprevalence in pigs. The results found that HEV seropositivity showed age dependency. The National Health Authorities should raise awareness of HEV and its zoonotic potential.

Microbiological and antibacterial resistance profile in canine otitis externa – a comparative analysis

The aim of the present study was to compare the prevalence of microbial agents involved in canine otitis externa and their sensitivity to antibacterial drugs in two periods: 2007–2011 and 2013–2017. For 2013–2017, coagulase-positive staphylococci were the dominating bacterial species (186 isolates), followed by Pseudomonas aeruginosa (82 strains). The rate of isolated yeasts (mainly Malassezia pachydermatis) was substantially high (152 isolates). Compared to the earlier period (2007–2011) a tendency to more frequent occurrence of co-infections was noted – 61.7% and more than 80% of co-infections involved yeasts. Antibacterial resistance patterns showed a clear trend to increased resistance of coagulase-positive staphylococci and β-haemolytic streptococci to amoxicillin/clavulanic acid (42% and 50% respectively) and gentamicin (29%, 40%). Increased resistance of P. aeruginosa was established to gentamicin (16%) and amikacin (18%). The prevalence of pseudomonads resistant to enrofloxacin was lower (27%).

Serological Evidence of Borrelia burgdorferi, Anaplasma phagocytophilum and Ehrlichia Spp. Infections in Horses from Southeastern Bulgaria

Lyme Borreliosis and granulocytic anaplasmosis are less extensively studied in horses than in dogs and humans. Equine ehrlichiosis is not known in Europe and is in the initial stage of investigation in South, Central, and North America. The aim of this study was to determine the seroprevalence of these infections in Bulgaria. A total of 155 horses were investigated from five regions in Southeastern Bulgaria. Horses were tested for Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia spp. antibodies by a commercial rapid ELISA test. B. burgdorferi and A. phagocytophilum antibodies were found in all five regions (Burgas, Sliven, Stara Zagora, Haskovo, and Kardzhali) at frequencies of 36/155 (23.2%; 95% CI: 16.8-30.7%; ranging by region from 6.4% to 50%) and 31/155 (20%; 95% CI: 14-27.2%; ranging by region from 10% to 30.8%), respectively. Antibodies against Ehrlichia spp. were found in horses from three regions (Burgas, Stara Zagora, and Haskovo) at a rate of 6/155 (3.9%; 95% CI: 1.4-8.2%; ranging by region from 5.7% to 6.4%). The combination of B. burgdorferi/A. phagocytophilum (11/155; 7.1%; 95% CI: 3.6-12.3%) was the most common coexposure observed, followed by B. burgdorferi/Ehrlichia spp. (2/155; 1.3%; 95% CI: 0.2-4.6%) and A. phagocytophilum/Ehrlichia spp. (1/155; 0.6%; 95% CI: 0-3.5%). The study shows that horses in Bulgaria are exposed or coexposed to three tick-transmitted zoonotic bacterial species. Furthermore, it reports Ehrlichia spp. seroreactivity in equines in Europe.

Influence of exhaustive aerobic exercise on some cytokines and serum iron parameters in canine experimental model

The aim of the experiment was to study the effect of exhaustive exercise on some cytokines and iron status parameters. We used 12 male, mongrel dogs divided into two groups – animals from experimental group were submitted to exercise at moderate intensity with exhaustion as the end-point; animals from control group did no exercise. Serum levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), hepcidin prohormone, serum iron (SI), total iron binding capacity (TIBC) and transferrin saturation (TS) were measured before exercise (BE), right after exercise (0 hour) and on 2, 4, 24, 48 and 72 hours after exercise. SI, TIBC and TS were measured also on day 7 and 14 after exercise. Serum levels of TNF-α increased after the exhaustive exercise. Serum levels of IL-6 demonstrated an increase at 0 hour, but increase was not statistically significant compared to BE level. Serum levels of hepcidin prohormone marked a slight increase 48 hours after the exercise, but change was insignificant. Levels of SI decreased on hour 72 (P<0.01) and on day 7 (P<0.01) and 14 (P<0.05) after the exercise, as compared to BE level. Similar were changes in TS. TIBC decreased on 4, 24 and 72 hours (P<0.05) after exercise, but only compared to control group. In conclusion, exhaustive exercise causes inflammatory response and a significant decrease in SI levels.

Comparative Clinical and Haematological Investigations in Lactating Cows with Subclinical and Clinical Ketosis

Ketosis of lactating cows is among the most common metabolic diseases in modern dairy farms. The economic importance of the disease is caused by the reduced milk yield and body weight loss, poor feed conversion, lower conception rates, culling and increased mortality of affected animals. In the present study, a total of 47 high-yielding dairy cows up to 45 days in milk (DIM) are included. All animals were submitted to physical examination wich included checking the rectal body temperature, heart rate, respiratory and rumen contraction rates, and inspection of visible mucous coats. The body condition was scored, and blood β-hydroxybutyrate (BHBA) concentrations were assayed. The cows were divided into 3 groups: first group (control) (n=24) with blood β-hydroxybutyrate level <1.2 mmol/l, second group (n=15) with blood β-hydroxybutyrate between 1.2-2.6 mmol/l (subclinical ketosis) and third group (n=8) with blood β-hydroxybutyrate >2.6 mmol/l (clinical ketosis). Whole blood samples were obtained and analyzed for Red Blood Cell (RBC, 1012/l), Hemoglobin (HGB, g/l), Hematocrit (HCT, %), Mean Corpuscular Volume (MCV, fl), Mean Corpuscular Hemoglobin (MCH, pg), Mean Corpuscular Hemoglobin Concentration (MCHC, g/l), White Blood Cell (WBC, 109/l), Lymphocytes (LYM, 109/l), Monocytes (MON, 109/l), Granulocytes (GRA, 109/l), Red Blood Distribution Width (RDW, %), Red Blood Cell Distribution Width Absolute (RDWa, fl), Platelets (PLT, 109/l) and Mean Platelet Volume (MPV, fl). In this study, deviations in the clinical parameters in the control group and in those with subclinical ketosis were not identified. The cows from the third group (clinical ketosis) exhibited hypotonia, anorexia and body weight loss vs. control group. Hematological analysis showed leukocytosis and lymphocytosis in cows with subclinical ketosis vs. control group. In cows with clinical ketosis WBC counts decreased (leukopenia), while hemoglobin content and hematocrit values are higher vs. control group. Blood BHBA values are higher in both groups of ketotic cows vs. the control group. The other analyzed parameters (RBC, MCH, MCHC, MCV, RDW, RDWa, MON, GRA, PLT and MPV) were close to control values.