Хетерозисни прояви по технологични параметри в F1 хибриди лук за сушене

The suitability of newly developed F1 onion (Allium cepa L.) hybrids for drying was evaluated in 3-year experiment by the expression of the heterosis effect toward the time for reaching to the minimal equilibrium moisture content during the drying process. Lines, varieties and F1 onion hybrids of three types (hot, semi-hot and sweet) with yellow envelope flakes and different morphological characteristics were used. The drying time for the investigated variants ranged between 70 and 180 minutes. The bulbs of hybrid Liaskovski sterile x Jubilei 50 (LA x J50) F1 were dried most rapidly. The hypothetical heterosis varied from -17.65% to 46.67%. Heterosis manifestations concerning drying time of onion bulbs were expressed but they have not economic importance. Therefore the heterosis breeding is not the way for increasing the suitability of onion for drying. Systematic investigations on the initial plant material before including in the hybridization in order to search parental components with optimal values of the drying parameters have to be on the focus.В тригодишен експеримент е оценена пригодността за сушене на новосъздадени F1 хибриди лук (Allium cepa L.) чрез изследване на хетерозисния ефект по отношение на времето за достигане до минималното равновесно съдържание на влага по време на процеса на изсушаване. Използвани са три типа линии, сортове и F1 хибриди лук (люти, полулюти и сладки) с жълти обвивни люспи и различна морфологична характеристика. Времето на сушене за изследваните варианти варира между 70 и 180 минути. Луковиците на хибрида Лясковски стерилен х Юбией 50 (LA x J50) F1 се изсушават най-бързо. Хипотетичният хетерозис варира от -17.65% до 46.67%. Установени са прояви на хетерозис, отнасящи се до времето на сушене на луковиците, но без икономическо значение.Това показва, че хетерозисната селекция при лука не е пътят, по който може да се увеличи пригодността му засушене. На фокус трябва да бъдат систематични изследвания на растителния материал преди включването му в хибридизация с цел търсене на родителски компоненти с оптимални стойности на параметрите на сушене

Serological and Molecular Detection of Coxiella Burnetii in Clinical Samples from Veterinarians and Cattle Farm Workers from Gabrovo Region, Bulgaria

Coxiella burnetii, which causes Q fever, is a highly infectious agent that is widespread around the world.  During the last decades, the number of cases reported in Bulgaria varied from year to year. The present study aimed to determine the frequency of C. burnetii infection using ELISA and conventional PCR among freelance veterinarians and cattle farm workers in Gabrovo province, Bulgaria. In the period April 2020 to June, 2021 a total of 154 blood samples of target group was tested in the National Reference Laboratory of Cell cultures, rickettsia and oncogenic viruses (NRL CCROV) at NCIPD - Sofia. Diagnosis of C. burnetii was performed by indirect enzyme-linked immunosorbent assay ELISA (anti-Coxiella burnetii ph. II IgG/IgM) and by end-point PCR technique (to detect the sodB gene region of C. burnetii). By indirect ELISA assay of the tested 154 clinical samples, anti-C. burnetii positive ph. II IgM antibodies were registered in 37% of samples. A relatively high percentage are affected in the active age between 50-60 years old. Anti-C. burnetii positive ph. II IgG antibodies were proven at 50% of tested samples. A positive PCR signal for C. burnetii DNA was obtained at 37/154 (20% of samples) and follows the above reported trend of acute infection of active age patients. Around 10% of tested samples were positive for three C. burnetii laboratory markers. We conclude that Q fever is endemic in Bulgaria. More research is necessary in different Bulgarian regions to set the human risk groups, to diagnose acute and chronic Q fever and to determine the economic impact of Q fever in the cattle industry. In the NRL CCROV was developed diagnostic scheme including complex methods to improve early laboratory diagnosis of C. burnetii, allowing taking proper treatment of suspected with Q fever patients

Mini Review: Q Fever (Coxiellosis): Epidemiology, Pathogenesis and Current Laboratory Diagnosis

Q fever is zooantroponozis with global distribution caused by the strictly intracellular bacterium Coxiella burnetii. Causative agent of Q fever is an obligate intracellular parasite, classified in the genus Coxiella, family Coxiellaceae, class Gammaproteobacteria. The importance of the disease was assessed both in terms of human health and the serious economic damage they cause on livestock. Clinical manifestation of Q fever in humans is characterized by a wide variety - from asymptomatic infection to a chronic disease that can be fatal. Several basic methods have been developed to detection of C. burnetii. PCR and C. burnetii genomic sequences in whole blood are a sensitive and safe method of detection, with >90% sensitivity. A four-fold or greater rise of (CF) antibody (phase 2) between the paired sera is also diagnostic approach. Sensitivity of a four-fold rise in titre has been estimated as 73% ÷78% and specificity has been estimated as 90%, respectively. EIA is method with highly sensitive and specific. EIA detect IgM and then IgG antibodies which develop to phase II antigens in 10 to 14 days from symptom onset. IFA tests are of particular value for confirmation of acute infection and for diagnosis of chronic infection with high sensitivity. The technique detected IgG, IgM and IgA immunoglobulin classes. Suitable specimens for C. burnetii detection are blood samples. Although scientific interest in Q fever has always existed, a number of facts concerning the unforeseen nature of the epidemic, various clinical manifestations both in humans and in animals, the opportunities for chronic and other features of infection remain unclear. For this reason, timely and highly sensitive laboratory diagnosis is crucial for the outcome of the disease and subsequent treatment and monitoring

HEALTHCARE WORKERS IN BULGARIA - ARE THEY PROTECTED FROM VACCINE-PREVENTABLE INFECTIONS?

Background: Healthcare workers (HCWs) are at increased risk of exposure to many viral infections, including vaccine preventable diseases (VPDs) such as measles, mumps and rubella (MMR) as compared to non-HCWs. Immunity of HCWs against these viruses is mandatory in a healthcare setting due to possible exposure from patients or colleagues. Aim: To provide an assessment of anti-measles, mumps and rubella IgG seropositivity among Bulgarian HCWs employed in hospitals and regional health inspectorates (RHI), as an indicator of protective immunity against MMR in this risk group.  Materials and Methods: In the current study, 181 HCWs from Infectious Units in regional hospitals in the country, and HCWs from the RHI, involved in the monitoring and surveillance of MMR cases in Bulgaria were screened. Serum specimens from all participants were tested by a commercial indirect enzyme-linked immunosorbent assay (Anti-Measles, Anti-Mumps, Anti-Rubella IgG EIA-Euroimmun®, Germany) for presence of IgG antibodies against measles, mumps and rubella, as an indicator of protective immunity.  Results: The study included 181 HCWs, 25 male and 156 female, aged 22 to 66 years. The average protective seroprevalence for measles, mumps and rubella was 82.9%, 76.2% and 92.3% percent, respectively. The highest share of negative results were obtained for mumps-specific IgG – 23.2% (42/181), followed by measles 16.6% (60/181) and rubella-specific IgG 7.7% (19/181). Regarding the age distribution, the highest number of HCWs non-immune to measles and mumps was found among the 31- 40-year olds, and against mumps – among the 41-50-year-olds. Conclusion: HCWs are at greater risk of contracting infections than the general population because of contact with sick patients or infectious material. Infected healthcare workers can spread nosocomial diseases to vulnerable patients with more severe illness, leading to complications and even death. Therefore, the vaccination status of HCWs must be strictly monitored

EVALUATION OF INTERACTIONS OF SARS-COV-2 STRUCTURAL PROTEINS WITH SPECIFIC ANTIBODIES BY SPR ASSAY

Background: The World Health Organization admitted that the vaccination against Covid 19 limited the deaths, but not the spread of the disease. This requires a method allowing a specific, rapid and accurate diagnosis of the disease. We report a SPR assay that meets the requirements and can be applied no only for SARS Cov-2 diagnosis but as a tool for early diagnosis of otherinfections. Methods: Surface plasmon resonance (SPR) method was used to identify the binding of S/N protein to monoclonal antibodies. N-protein monoclonal antibody (NP mAb), S-protein monoclonal antibody (SP mAb), and receptor bind domain (RBD) antibody were used as recognition molecules. Ligands were deposited by the matrix-assisted laser evaporation (MAPLE) method, which guarantees maximum interaction specificity. Results: We registered S/N protein binding to the corresponding mAbs and S protein to RBD antibody with high sensitivity: the interactions were observed at protein concentration about 130 femtomoles (fM). A very good specificity was observed: the measured S protein binding activity to NP mAb was below the limit of detection (LOD). The same was noticed for N protein binding to SP mAb. Conclusions: The presented SPR assay possesses high sensitivity and selectivity and provides quantitative analysis. This makes it applicable for following the evolution of acute SARS-CoV-2 infection, especially at the early stages of viral replication which can be clinically useful

Dried Blood Spots as a Clinical Samples for Laboratory Diagnosis and Surveillance of Vaccine-Preventable Diseases in Bulgaria

In recent years the dried blood spots (DBS) had new and innovative applications in medicine, neonatology, virology and microbiology. This study aimed to evaluation of the frequency of detection of viral IgM/IgG markers in dried blood spots and introducing an easy-to-implement protocol for serum extraction in measles, mumps and rubella surveillance. The total 204 clinical samples (102 serum samples and 102 dried blood spots) collected from 102 patients were included. All specimens were tested for presence of specific viral markers (IgM and IgG antibodies) by a commercial indirect enzyme-linked immunosorbent assay (ELISA). Of all tested patients, three (3/102, 2.94%, 95% CI: 0 ÷ 6.22) were confirmed for acute measles infection and two (2/102, 1.96%, 95% CI: 0 ÷ 4.65) for mumps. Double positive ELISA-IgM results were found in their serum samples and DBS. No acute rubella infection and rubella IgM marker were detected in both clinical samples. By immunoassay analysis of all 102 patients, measles, mumps and rubella IgG were found in 83/102 (81%, 95% CI: 73.40 ÷ 88.60), 76/102 (75%, 95% CI: 66.60 ÷ 83.40) and 79/102 (77%, 95% CI: 68.83 ÷ 85.17) serum samples.  Comparative results were obtained in the adequately obtained DBS. Viral IgG seroprevalence in DBS were obtained in 79/102 (77%, 95% CI: 68.83 ÷ 85.17) for measles, 69/102 (68%, 95% CI: 58.67 ÷ 77.33) for mumps and 73/102 (72%, 95% CI: 63 ÷ 81) for rubella, respectively. Double negative results for each screened viral markers were proven in six tested patients.The study shown higher extinction value (Ratio and NovaTec units) in DBS compared to serum samples of same persons were calculated. Our studies show over 90% coincidence in combined ELISA assay of viral markers against measles, mumps, and rubella in serum samples and DBS. DBS clinical approach is non-aggressive and more acceptable to the public (including young children, pregnant women, etc.). It has a variety of new and innovative applications in medicine and in particular in the laboratory diagnosis of acute and past (presence of protective immunity) measles, mumps and rubella infection in the phase of elimination

A Review on Dried Blood Spots (DBS) as Alternative, Archival Material for Detection of Viral Agents (Measles, Mumps, Rubella, Hepatitis B Virus)

In recent years there appears a variety of new and innovative applications of the dried blood spots. The areas of their range of application are medicine, neonatology, virology, microbiology, toxicology and pharmacokinetics, metabolic exchange, therapeutic drug monitoring, toxicology, and control of environmental pollution. The advantages of DBS technology can be combined into four main groups: (1) compared to conventional venipuncture, requires less blood volume, which is especially important in pediatrics and neonatology; (2) the procedure for blood collection is easy, inexpensive and noninvasive; (3) the risk of bacterial contamination or hemolysis is minimal; and (4) DBS can be maintained for a long time with almost no impact on the quality of the analysis. In recent years is increasing the application of DBS as method for seroepidemiological survey with focus viral infections: measles, mumps, rubella and hepatitis B virus. The DBS technique is optimized as an alternative approach (non-invasive, inexpensive, not requiring trained staff and cold chain for transport and storage) of venipuncture collection of clinical material in virology.This method facilitates the scientific researches about the concentration of virus specific antibodies in peripheral blood taken from a finger or heel; determining the percentage susceptibility / protection of the studied group of patients againt vaccine-preventable infectious - measles, mumps, rubella and hepatitis B; social benefits - non-invasive technique for testing of small children and infants and applications in regions in the countries with not well developed logistics infrastructure

Infectious Agents and Miscarriage in Bulgaria

A number of infection agents have been linked to miscarriage and to other adverse outcomes of pregnancy, such as stillbirth and preterm delivery. The purpose of present study was to determine the implication and prevalence of viral agents (parvovirus B19, rubella, CMV and adenoviruses) and Chlamydia trachomatis in the etiology of miscarriage during the first and second trimester of pregnancy. A total of 62 serum samples from women with miscarriage (n=32) and control group of healthy women (n=30) for period January 2015 – June 2016 were tested by ELISA (detected of specific IgM/IgG antibodies) and PCR (detected of specific genomic region) assays. The possible role of B19V, Ch. trachomatis and adenoviruses for miscarriages were detected in 6/32 (18.75%) by ELISA and in 7/32 (21,87%) by PCR methods. The seroprevalence of protective IgG antibodies in the highest level was proven against rubella 25/32 (78,12%) and the lowest – against adenoviruses (1/32, 6,25%). All tested healthy women in the control group had a negative result for acute infection for the five tested infectious agents. The detailed study aimed at enriching the diagnostic palette of these infectious pathogens is necessary for understanding the exact mechanisms behind infection-induced miscarriages and could lead to effective treatment and thus prevention

Mini Review: Chemical Characterization and Evaluation of Antiviral and Antibacterial Activity of Extracts from Graptopetalum paraguayense E. Walther (Crassulaceae)

Graptopetalum paraguayense E. Walther (GP) is a traditional Chinese herbal medicine belonging to the Crassulaceae family As herbal medicine, GP possesses several biological/pharmacological perspectives. It was found that GP aqueous extracts exhibit anti-inflammatory and hepatoprotective, antioxidant, anti-hypertensive and antihyperglycemic, immunomodulatory, antineoplastic, antiviral and antibacterial activities. The GP contains in the high range levels phenolic compounds and anthocyanins. Despite the intense study of the plant, little data exist regarding its chemical composition. It was found that the GP aqueous extract has no cytotoxic effect on RD and Lep cells. The extract effectively inhibited herpes simplex virus (HSV) replication in dose-dependent manner moderate activity as well as Gram-positive bacterial strains

Immunity to mumps virus in children population in Bulgaria

AbstractMumps is an acute, contagious, viral vaccine-preventable disease caused by mumps virus (MuV). The measles, mumps, rubella (MMR) vaccine that is used in many countries is considered highly effective with decreased MuV incidence, but suboptimal MuV long-term immunity. This study assessed the MuV seropositivity and antibody titre among vaccinated children in Bulgaria to provide evidence for a better understanding of MuV circulation and immunity in Bulgaria. The samples from 734 immunized children (369 females and 365 males) aged 1 to 16, divided into four age groups (≥1, 2–6, 7–11, and 12–16) were tested. Qualitative and quantitative indirect enzyme-linked immunosorbent assay (Anti-Mumps IgG ELISA, Euroimmun, Germany) was performed to determine the mumps IgG antibody levels in sera. Among all participants, protective MuV immunity was identified in 93%. MuV IgG antibody positivity ranged between 87% in the age group between 1 and 2 years and 96% in the age group 12–16 years, but no statistically significant difference was found among age groups. At the same time, there was a statistically significant difference (p = 0.01) between seropositivity in male and female participants, with male participants having an overall seropositivity of 90% and female 95%. Among the antibody-positive samples, the quantitative measurements of median anti-MuV IgG concentrations showed that titres decreased with increasing age. A slightly waning immunity following vaccination was observed, but positivity remained high among vaccinated children over the years. Similar studies show that maintaining high immunity is crucial to prevent mumps outbreaks