Latent Carriers Research Articles

Research on safety strategies for nucleic acid testing in sudden epidemic conditions based on a SEIARD dynamic model

Infectious diseases have caused enormous disasters in human society, and asymptomatic carriers are an important challenge in our epidemic prevention and control process. Nucleic acid testing has played an important role in rapid testing for asymptomatic individuals. How to carry out nucleic acid testing in a scientific manner is a practical problem encountered in normal production and life. Based on the real COVID-19 epidemic data from Shanghai, we established a susceptible-exposed-infected-asymptomatic-recovered-death (SEIARD) dynamic model. The least squares method was used to fit the data and estimate the unknown parameters β and E(0) in the model, and MATLAB software was employed to simulate the development of the epidemic. The data fitting results indicated that the SEIARD model can better describe the early development patterns of the epidemic (R2 = 0.98; MAPE = 2.54%). We calculated the basic reproduction number of the Shanghai epidemic as R0 = 2.86. As the frequency of nucleic acid testing increased, the basic reproduction number R0 continued to decrease. When there is one latent carrier and one asymptomatic carrier in the nucleic acid testing team, the number of queues is directly proportional to the number of infected individuals, the nucleic acid testing team increases by 50 people, and the number of new asymptomatic cases increases by approximately 4 people. If both susceptible individuals (S) and asymptomatic patients (A) are not wearing masks, the infection rate reaches approximately 7%; after wearing masks, the final infection rate is less than 1% at 1.5 m between two people. The queue spacing is inversely proportional to the number of infected individuals. With a distance of d = 1 m, a nucleic acid testing team of 100 people added 8% of the infected individuals; when d = 1.5 m, fewer than 2% of the newly infected individuals. The results confirmed that controlling the queue size for nucleic acid testing, strictly wearing masks, and maintaining a queue spacing of more than 1.5 m are safe and effective nucleic acid testing strategies. Our findings are also applicable to the prevention of other newly emerging infectious diseases.

Endoparasites of rabbits and hares.

Nematode, cestode, protozoan, microsporidian, and pentastomid parasites affect domesticated and wild rabbits, hares, and jackrabbits of the genera Brachylagus, Lepus, Oryctolagus, Pentalagus, and Sylvilagus. Some endoparasite infections are of limited or no significance, whereas others have potentially profound consequences. Accurate identification of endoparasites of rabbits, hares, and jackrabbits is an important facet of the work of veterinary pathologists engaged in lagomorph pathology. Here I review endoparasites from the pathologist's perspective, focusing on pathogenesis, lesions, and implications of infection. Stomach nematodes Graphidium strigosum and Obeliscoides cuniculi are infrequently pathogenic but may cause gastritis and gastric mucosal thickening. Nematodes Passalurus ambiguus, Protostrongylus spp., Trichostrongylus spp., and Trichuris spp. are rarely associated with disease. Adult Capillaria hepatica (syn. Calodium hepaticum) nematodes and non-embryonated eggs cause granulomatous hepatitis in wild Oryctolagus cuniculus and Lepus europaeus, resulting in multifocal, off-white, hepatic lesions, which may be misdiagnosed as hepatic eimeriosis. When the rabbit is an intermediate host for carnivore cestodes, the space-occupying effects of Cysticercus pisiformis and Coenurus serialis may have pathologic consequences. Eimeria stiedai is a major cause of white-spotted liver in O. cuniculus, particularly in juveniles. Enteric coccidiosis is a noteworthy cause of unthriftiness in young animals, and frequently manifests as diarrhea with grossly appreciable multifocal off-white intestinal lesions. O. cuniculus is the natural host for the zoonotic microsporidian Encephalitozoon cuniculi. Infection may be acute and focused mainly on the kidneys, or it may follow a chronic disease course, frequently with neurologic lesions. A latent carrier status may also develop.

Effect of dry period immunization of Salmonella Dublin latent carriers with a commercial live culture vaccine on intrauterine transmission based on the presence of precolostral antibodies in offspring

Salmonella Dublin latent carrier cows represent a high risk for infection of newborn calves via intrauterine transmission and shedding of bacteria in feces and colostrum at calving. Vaccination of these latent carrier dams during late gestation boosts immunity against S. Dublin. This could reduce the activation of the dormant bacteria during the periparturient immune dysfunction period, thereby reducing the risk of early-life infection in the offspring. Thus, the objective of this study was to evaluate the extent to which vaccinating S. Dublin latent carrier cows at dry-off with a commercial live culture vaccine reduces bacterial shedding at calving and intrauterine infection to calves. To identify latent carriers, we screened 1,084 cows in 4 Michigan commercial dairy farms with a history of S. Dublin. Cows were defined as latent carriers when they showed 3 consecutive positive milk antibody ELISA tests conducted every 2 mo. Subsequently, 148 latent carriers were randomly allocated to the vaccine or control group. Vaccine cows received a commercial live culture vaccine subcutaneously (SC) at dry-off and a booster 2 weeks later. Control cows received saline SC at the same times. At calving, we collected fecal and colostrum samples from the dam and a pre-colostral serum sample from the calf. Bacterial shedding was evaluated in feces and colostrum both qualitatively and quantitatively through bacterial culture and qPCR, respectively. Intrauterine transmission was defined when a calf was positive for serum antibody ELISA at birth. Vaccination decreased the likelihood of calves being born S. Dublin seropositive (Relative Risk [95%CI]) = 0.19 [0.04 - 0.84]). However, no S. Dublin positive isolates were identified through either bacteriological culture or qPCR in feces or colostrum. Vaccination of S. Dublin latent-carrier cows at dry-off reduced intrauterine transmission to calves. Further research is warranted into the potential of vaccination to decrease vertical transmission of S. Dublin in dairy farms. Additionally, the absence of S. Dublin positive fecal and colostrum samples warrants further evaluation of the detection methods for identifying latent carriers or S. Dublin isolation, as well as the role of latent carriers in infecting newborn calves in the maternity area at birth.

Lingering Effects of Early Institutional Rearing and Cytomegalovirus Infection on the Natural Killer Cell Repertoire of Adopted Adolescents.

Adversity during infancy can affect neurobehavioral development and perturb the maturation of physiological systems. Dysregulated immune and inflammatory responses contribute to many of the later effects on health. Whether normalization can occur following a transition to more nurturing, benevolent conditions is unclear. To assess the potential for recovery, blood samples were obtained from 45 adolescents adopted by supportive families after impoverished infancies in institutional settings (post-institutionalized, PI). Their immune profiles were compared to 39 age-matched controls raised by their biological parents (non-adopted, NA). Leukocytes were immunophenotyped, and this analysis focuses on natural killer (NK) cell populations in circulation. Cytomegalovirus (CMV) seropositivity was evaluated to determine if early infection contributed to the impact of an atypical rearing. Associations with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), two cytokines released by activated NK cells, were examined. Compared to the NA controls, PI adolescents had a lower percent of CD56bright NK cells in circulation, higher TNF-α levels, and were more likely to be infected with CMV. PI adolescents who were latent carriers of CMV expressed NKG2C and CD57 surface markers on more NK cells, including CD56dim lineages. The NK cell repertoire revealed lingering immune effects of early rearing while still maintaining an overall integrity and resilience.

Assessment of BoAHV-1 Seronegative Latent Carrier by the Administration of Two Infectious Bovine Rhinotracheitis Live Marker Vaccines in Calves.

Seronegative latent carriers (SNLCs) are animals that carry the virus without detectable antibodies and pose a risk for disease transmission and diagnostic challenges, suggesting the importance of consideration of marker vaccines in managing them. Therefore, in this study, we evaluated two modified live infectious bovine rhinotracheitis (IBR) marker vaccines (single and double deletions) for their ability to generate SNLC calves. These vaccines were administered to four groups (n = 3 in each group) of three-month-old calves in the presence or absence of passive immunity. Three hundred days after the first vaccination and after confirming the IBR seronegativity of all animals, dexamethasone was administered intravenously for five consecutive days. Only animals immunized with the modified live IBR marker vaccine (single deletion) in the absence of passive immunity exhibited a more enduring immune response than those vaccinated in the presence of passive immunity. Moreover, the administration of a modified live IBR marker vaccine (double deletion) to calves with passive immunity generated SNLC. These findings underscore the potential of live IBR marker vaccine (double-deletions) to aid serological diagnostic tools and develop vaccination protocols in achieving the desired immune response, particularly in the context of latent carrier status, offering valuable insights into optimizing vaccination strategies for effective IBR control.

Phenotypic features of genetically modified DMD-XKOXWT pigs

IntroductionDuchenne muscular dystrophy (DMD) is a hereditary neuromuscular disorder caused by mutation in the dystrophin gene (DMD) on the X chromosome. Female DMD carriers occasionally exhibit symptoms such as muscle weakness and heart failure. Here, we investigated the characteristics and representativeness of female DMD carrier (DMD-XKOXWT) pigs as a suitable disease model. MethodsIn vitro fertilization using sperm from a DMD-XKOY↔XWTXWT chimeric boar yielded DMD-XKOXWT females, which were used to generate F2 and F3 progeny, including DMD-XKOXWT females. F1–F3 piglets were genotyped and subjected to biochemical analysis for blood creatine kinase (CK), aspartate aminotransferase, and lactate dehydrogenase. Skeletal muscle and myocardial tissue were analyzed for the expression of dystrophin and utrophin, as well as for lymphocyte and macrophage infiltration. ResultsDMD-XKOXWT pigs exhibited various characteristics common to human DMD carrier patients, namely, asymptomatic hyperCKemia, dystrophin expression patterns in the skeletal and cardiac muscles, histopathological features of skeletal muscle degeneration, myocardial lesions in adulthood, and sporadic death. Pathological abnormalities observed in the skeletal muscles in DMD-XKOXWT pigs point to a frequent incidence of pathological abnormalities in the musculoskeletal tissues of latent DMD carriers. Our findings suggest a higher risk of myocardial abnormalities in DMD carrier women than previously believed. ConclusionsWe demonstrated that DMD-XKOXWT pigs could serve as a suitable large animal model for understanding the pathogenic mechanism in DMD carriers and developing therapies for female DMD carriers.

Clinically significant and colonizing <em>Enterobacteria</em> isolates with extended spectrum beta-lactamase production and their significance in horse breeding

This review article is devoted to the problem of the emergence and spread of antibiotic-resistant enterobacteria producing beta-lactamase in horse breeding. Foal colibacillosis is an acute infectious disease of young animals, manifested by diarrhea, signs of severe intoxication and dehydration of the body, caused by pathogenic Escherichia coli. Foals get sick in the first 3-7 days after birth. Infection occurs alimentary, less often – aerogenic and intrauterine transmission. The source of infection are sick and recovered animals. The duration of the disease is 2-3 days with a mortality rate of up to 90%, which leads to multiple economic losses. Multiresistant Escherichia coli can accumulate in the intestines of healthy animals and be excreted with fecal matter into the environment, which leads to the spread of pathogenic microflora among livestock. In this case, the animals are latent or hidden carriers that do not show clinical signs of the disease. Clinically significant isolates are causative agents of infectious and inflammatory diseases. These microorganisms represent a potential hazard for the development of an infectious process, they exhibit virulent properties that lead to damage to the tissues of the host organism, which significantly limits the possibility of their eradication. Along with clinically significant isolates, there are colonizing isolates that do not cause infection at a specific site. It should be noted that under certain conditions, the colonizing isolate can cause an infectious process. Irrational use of antimicrobials is a key reason for the development of tolerance. Also, the untimely detection of enzyme inactivation of antibiotics by laboratory methods and the spread of resistance genes play an important role. Currently, disks and media with antibacterial drugs are widely used to detect multidrug resistance of microorganisms. Along with these methods, PCR diagnostics and sequencing are used to accurately determine antibiotic resistance genes. Due to the importance and relevance of this topic, many scientists are conducting research to detect and study the multiresistance of enterobacteria such as E. coli, and their spread among animals.

PRODUCTION TRIALS OF A VACCINE MADE FROM THE ATTENUATED <i>ESCHERICHIA COLI</i> AС-16 STRAIN

Swollen piglet disease is a significant intestinal infection caused by Escherichia coli, which poses a danger to animals and birds that act as reservoirs for the pathogen. The source of the pathogen in piglets is believed to be sick and over-infected animals or latent bacterial carriers, which form the continuous epizootic chain. Therefore, live vaccines are considered promising for avoiding of swollen piglet disease. This article aims to present the production trials of an attenuated vaccine from the E. coli AC-16 strain, which is currently being developed as a potential solution for preventing escherichiosis. The live attenuated vaccine demonstrated stable residual virulence and activity control when tested on laboratory animals (white mice). In total, 1364 piglets and 262 cows were vaccinated from 2020 to 2022. Piglets from the vaccinated swine were born viable and did not fall ill with escherichiosis. During this period, no cases of illness or death of calves from escherichiosis were reported.

Metabolic biological markers for diagnosing and monitoring the course of tuberculosis

The international biomedical community has been currently facing a need to find a simple and most accessible type of analysis that helps to diagnose tuberculosis (TB) with the maximum reliability even before the onset of clinical manifestations. Tuberculosis results in more deaths than any other pathogen, second only to pneumonia caused by the SARS-CoV-2 virus, but the majority of infected people remain asymptomatic. In addition, it is important to develop methods to distinguish various forms of tuberculosis infection course at early stages and to reliably stratify patients into appropriate groups (persons with a rapidly progressing infection, chronic course, latent infection carriers). Immunometabolism investigates a relationship between bioenergetic pathways and specific functions of immune cells that has recently become increasingly important in scientific research. The host anti-mycobacteria immune response in tuberculosis is regulated by a number of metabolic networks that can interact both cooperatively and antagonistically, influencing an outcome of the disease. The balance between inflammatory and immune reactions limits the spread of mycobacteria in vivo and protects from developing tuberculosis. Cytokines are essential for host defense, but if uncontrolled, some mediators may contribute to developing disease and pathology. Differences in plasma levels of metabolites between individuals with advanced infection, LTBI and healthy individuals can be detected long before the onset of the major related clinical signs. Changes in amino acid and cortisol level may be detected as early as 12 months before the onset of the disease and become more prominent at verifying clinical diagnosis. Assessing serum level of certain amino acids and their ratios may be used as additional diagnostic markers of active pulmonary TB. Metabolites, including serum fatty acids, amino acids and lipids may contribute to detecting active TB. Metabolic profiles indicate about increased indolamine 2.3-dioxygenase 1 (IDO1) activity, decreased phospholipase activity, increased adenosine metabolite level, and fibrous lesions in active vs. latent infection. TB treatment can be adjusted based on individual patient metabolism and biomarker profiles. Thus, exploring immunometabolism in tuberculosis is necessary for development of new therapeutic strategies.

IDENTIFICATION OF FERTILITY HAPLOTYPES IN THE BELARUSIAN POPULATION OF HOLSTEIN CATTLE

Long-term artificial selection of highly productive breeding animals, latent carriers of genetic diseases, has led to the accumulation of recessive mutations in the cattle population. Since 2007, the Laboratory of Animal Genetics has been researching the fertility haplotypes of Holstein cattle (HHC, HHB, and HHD), and since 2016, the Laboratory has started additional research by other haplotypes (HH0, HH1, HH3, HH4, HH5, HCD) that affect reproductive traits and are associated with embryonic and early postembryonic death of calves. Earlier developed methods allowed us to identify mutations in the FANCI, APAF1, SMC2, GART, TFB1M, SLC35A3, ITGB2, APOB, and UMPS genes associated with these haplotypes. Monitoring cattle populations in Belarus (n = 4101 heads) made it possible to reveal the frequency of occurrence of the hidden carriers of mutant alleles of the HH0 haplotype amounting to 3.42%, HH1 — 2.82%, HH3 — 3.75%, HH4 — 0.59%, HCD — 2.35%, HH5 — 2.2%, HHC — 2.56%, HHB — 0.65%, and HHD — 0%. We believe that further DNA diagnostics of foreign and domestic breeding will allow diminishing the spread of genetic defects that degrade the reproductive qualities of cattle.

First Evidence for Colonizing of Acanthamoeba T4 Genotype in Urinary Tracts of Patients with Recurrent Urinary Tract Infections.

Limited evidence about the presence of Acanthamoeba spp. in urine specimens collected from urinary catheters of the patients in the intensive care units persuaded our study. No evidence has been found about colonizing of Acanthamoeba spp., in urinary tracts of patients with recurrent urinary tract infections (UTIs) yet. In this study, 50 urine samples were collected from patients presenting with recurrent UTI. The type of bacteria causing UTI was determined by using bacteriological tests. To cultivate Acanthamoeba spp., in a sterile condition, 10mL of urine was centrifuged and the sediment was cultivated on non-nutrient agar. Genotypes were determined by sequencing the DF3 region of the 18S rRNA gene. The bacteriological test findings on the urine samples of the UTI patients (n = 30) demonstrated that those were found to be positive for Escherichia coli (n = 17), Staphylococcus aureus (n = 6), Pseudomonas aeruginosa (n = 4) and Klebsiella spp. (n = 3) respectively. Moreover, a total of 50 urine samples was examined; 6 (6/50; 12%) and 11 (11/50; 22%) were positive by using culture and the PCR test for Acanthamoeba spp., respectively. Sequencing analysis showed all isolates were T4 genotype. Our data showed that the high relative prevalence of Acanthamoeba T4 genotype spp., in the urine of recurrent UTI patients. As well as, providing the first evidence for colonizing of the Acanthamoeba in the urinary tracts of patients with recurrent UTIs. These findings, warrant further investigation among those patients to fully appraise the role of Acanthamoeba spp., as possible latent carriers for resistant bacteria and biofilm formation in the future.

Оцінка ефективності препарату «Феліферон»® в комплексній терапії інфекційного ринотрахеїту котів

Relevance of the topic. Infectious feline rhinotracheitis, like herpesvirus infection is an acute disease characterized by damage to the eyes and respiratory system. Cats of all breeds are ill regardless of age. Kittens can become infected from mothers carrying the virus. In small populations of healthy animals the prevalence of the virus is less than 1 %, while in large populations it can reach 20 %. In shelters, the risk of contamination and infection is higher - up to 50 %. Almost all animals with primary infection become latent carriers throughout their lives. The incidence can reach 55%, the mortality rate is 5 – 25 %. The causative agent - a DNA-containing virus has a tropism for the epithelial cells of the mucous membranes of the nasal cavity, tonsils, trachea, conjunctiva. Diagnostic methods for detecting latent carriage have not yet been developed, since the virus remains in the form of genomic DNA in the nucleus of latently infected neurons without replication. Laboratory diagnosis of feline rhinotracheitis is currently most often performed by isolating the pathogen or by PCR using swabs from the oral cavity and conjunctiva. The PCR method allows detecting the virus and is the laboratory “gold standard” of diagnostics. Antibodies to the pathogen can be detected using a neutralization test or ELISA in serum, conjunctival mucus and cerebrospinal fluid. Direct methods for diagnosing herpesvirus infection in chronic or latent course have not been developed. For the treatment of viral diseases of small pets, immunomodulators are widely used, which stimulate the immune system. Some drugs tend to induce the production of its own interferon in the body. However, their use often does not give a therapeutic effect due to the peculiarities of the pathogenesis of the disease and the replication of the pathogen. To date, preparations based on the species-specificity of feline interferon have not been available on the domestic market, and attempts to use human interferon for the treatment of viral infections in cats have not yielded the expected result with prolonged and repeated courses due to the formation of neutralizing antibodies in the animal's body.

Indicators and risk factors of infectious laryngotracheitis in layer hen flocks in Algeria.

Background and Aim:Since 2017, there have been epidemics with respiratory disorders in the laying hen farms in Algeria, as signs and lesions, respiratory difficulties, and hemorrhagic tracheitis, which closely like laryngotracheitis. This study aimed to analyze the epidemiological, serological, and clinical indicators, as well as the risk factors, of infectious laryngotracheitis (ILT) in layer hen flocks in Algeria.Materials and Methods:A total of 1728 layer hens were sampled randomly from 48 poultry houses. Blood samples were collected from each hen at the wing vein area, and an indirect enzyme-linked immunosorbent assay was done using an IDvet® kit.Results:The flocks showed 56.25% seroprevalence. Clinical signs and gross lesions of ILT suspect cases included respiratory signs characterized by hemorrhagic tracheitis and sinusitis; conjunctivitis; egg drop; and a low mortality rate varying from 5% to 20%. Statistical analyses showed the effect of risk factors on the seropositivity for ILT in 48 layer flocks. When the vaccination was not applied, flocks were significantly more seropositive by 54% (odds ratio OR=1.54, p=0.01) compared to vaccinated flocks. Furthermore, flocks with poor hygiene were more seropositive by 68% (OR=1.68, p=0.002) compared to those with good hygiene. Finally, flocks with decreased egg production between 10% and 30% were significantly more seropositive by 42% (OR=1.42, p=0.04) than those with egg production >30%.Conclusion:The serological survey revealed anti-ILT virus antibodies, signifying the circulation of this virus in layer hen farms in Algeria. Correct vaccination protocol, strict biosecurity measures, rapid diagnosis, and detection of latent carriers are necessary to control and eradicate the disease from layer farms.

Tams 1 based PCR assay for detection of theileriosis in indigenous calves from semi-arid regions of India

Lower parasitemia often skips the conventional microscopic and serological techniques from detecting latent, cryptic and/or chronic carrier states of bovine tropical theileriosis (BTT). Hence the molecular detection of the parasitic DNA remains a highly authenticated tool. Oligonucleotide primers (TBR F/R) were custom designed and used for PCR amplification of T. annulata. The sensitivity and specificity of PCR was compared with blood microscopy based on kappa value predictions. A total of 8 samples were found positive by blood smear examination whereas PCR detected 12 infections. Blood smear examination was kept as a gold standard for detecting actual number of confirmed positive cases, for being 100% sensitive along with 93.65% specific, respectively, in detecting calf theileriosis. The described PCR-based assay provides a valuable tool to study the epidemiology of BTT in calves and some vital data regarding epidemiology of theileriosis in calves from semi-arid parts of India has been generated. Such a record for screening of calves for theileriosis is missing from Indian context.

Pharmacokinetic and Efficacy Study of Acyclovir Against Cyprinid Herpesvirus 3 in Cyprinus carpio.

Cyprinid Herpesvirus 3 (CyHV-3), more commonly known as Koi Herpesvirus (KHV), is a re-emergent virus causing acute systemic infection with high mortality rates in koi fish (Cyprinus carpio). Survivors from outbreaks can become latent carriers, with viral reactivation under stressful conditions and permissible temperatures. No vaccines or treatments are currently available in the United States. Acyclovir has been shown effective in vitro against KHV. This study aimed to evaluate the cytotoxicity of acyclovir and cidofovir to koi fin (KF1) cells, the efficacy of a single antiviral intracoelomic dose in a koi fingerling cohabitation challenge, and the pharmacokinetics of the effective antiviral. Initially, a lactate dehydrogenase release-based assay revealed no significant acyclovir or cidofovir cytotoxicity to KF1 cells for 24 h at up to 1,500 μM. In laboratory-controlled challenges, KHV associated mortalities occurred 2 weeks post-infection. At this point, fish were treated with an antiviral (10 mg/kg acyclovir or 5 mg/kg cidofovir) or sterile phosphate-buffered solution. Morbidity and mortality were monitored for 30 days. A significant cumulative mortality reduction (p ≤ 0.05), and a 3-day mortality delay were detected in the acyclovir-treated group. Similar viral loads were detected in gills recovered from mortalities throughout the challenge and surviving fish at the end of the challenge regardless of treatment. For pharmacokinetic analysis, blood was collected at various timepoints after acyclovir administration. Liquid chromatography tandem mass spectrometry plasma analysis indicated a 141 μM peak plasma concentration at 0.75 h, a 14 h half-life, and a 0.05/h elimination rate constant. Histopathology of target tissues detected no evidence of acyclovir toxicity. Results suggest that a single 10 mg/kg dose of acyclovir administered intracoelomically to koi fingerlings is safe and reduces cumulative mortality during a KHV mortality event. However, multiple doses are probably required for effective treatment of pet fish.

Deploying Machine and Deep Learning Models for Efficient Data-Augmented Detection of COVID-19 Infections.

This generation faces existential threats because of the global assault of the novel Corona virus 2019 (i.e., COVID-19). With more than thirteen million infected and nearly 600000 fatalities in 188 countries/regions, COVID-19 is the worst calamity since the World War II. These misfortunes are traced to various reasons, including late detection of latent or asymptomatic carriers, migration, and inadequate isolation of infected people. This makes detection, containment, and mitigation global priorities to contain exposure via quarantine, lockdowns, work/stay at home, and social distancing that are focused on “flattening the curve”. While medical and healthcare givers are at the frontline in the battle against COVID-19, it is a crusade for all of humanity. Meanwhile, machine and deep learning models have been revolutionary across numerous domains and applications whose potency have been exploited to birth numerous state-of-the-art technologies utilised in disease detection, diagnoses, and treatment. Despite these potentials, machine and, particularly, deep learning models are data sensitive, because their effectiveness depends on availability and reliability of data. The unavailability of such data hinders efforts of engineers and computer scientists to fully contribute to the ongoing assault against COVID-19. Faced with a calamity on one side and absence of reliable data on the other, this study presents two data-augmentation models to enhance learnability of the Convolutional Neural Network (CNN) and the Convolutional Long Short-Term Memory (ConvLSTM)-based deep learning models (DADLMs) and, by doing so, boost the accuracy of COVID-19 detection. Experimental results reveal improvement in terms of accuracy of detection, logarithmic loss, and testing time relative to DLMs devoid of such data augmentation. Furthermore, average increases of 4% to 11% in COVID-19 detection accuracy are reported in favour of the proposed data-augmented deep learning models relative to the machine learning techniques. Therefore, the proposed algorithm is effective in performing a rapid and consistent Corona virus diagnosis that is primarily aimed at assisting clinicians in making accurate identification of the virus.

Polymerase chain reaction for detection of some highly dangerous viral fish disease agents

Today viral fish diseases cause major losses in the world aquaculture. Pathogen spread often occurs during the transportation of fish from infected farms to the disease-free ones. Therefore, the import of fish stocking material to Russia from countries with a different epidemic situation requires risk-based monitoring and forecasting. Diagnostics is of primary importance in the complex of measures to prevent the spread of viral infections in fish. To date, laboratory diagnostics of viral fish diseases is based on pathogen isolation and its identification using serological methods which require a lot of time and are performed only in large research institutes with specialized laboratories. Molecular diagnostic methods are more sensitive and high-performance. The article presents the results of using reverse transcription polymerase chain reaction to detect a number of highly dangerous viral diseases of fish (Salmonidae). As a result of this work, primers were selected and the temperature and time conditions of the reaction were optimized for the identification of infectious hematopoietic necrosis, viral hemorrhagic septicemia and infectious salmon anemia. The results obtained during the research allowed us to establish that this diagnostic method is highly specific with analytical sensitivity to infectious salmon anemia virus of 2.5 lg TCD50/сm3, to infectious hematopoietic necrosis – 2.9 lg TCD50/сm3 and to viral hemorrhagic septicemia – 4.2 lg TCD50/ сm3. The described method was used to identify reference and field strains available at the FGBI ARRIAH Reference Laboratory for Aquaculture Diseases and isolated in different years in fish farms in the territory of the Russian Federation. The research data correlated with the results obtained from virus neutralization in cell culture and ELISA performed using commercial kits. The proposed method of RT-PCR allows to detect pathogens both in fish with pronounced clinical signs and in latent virus carriers.

Abstract P5-08-10: Surveillance for BRCA1/2 mutation carriers - Is "early detection" really early enough?

Abstract Background: Annual MRI screening is associated with a significant reduction in the incidence of advanced-stage breast cancer (BC) in BRCA1/2 mutation carriers. The purpose of our study was to assess stage at diagnosis and therapeutic approaches in BRCA1/2 carriers and compare these parameters in women who developed BC while adhering to the recommended surveillance scheme ("known carriers"), with BC cases who became aware of their BRCA carreirship after BC diagnosis ("latent carriers"). Methods: Retrospective data were collected on BRCA1/2 mutation carriers treated for BC at the Sheba medical center, both at the oncology institute and the high-risk clinic. The main variables evaluated were tumor characteristics, stage at diagnosis, and treatment decisions. Results: Overall, 529 BRCA1/2 carriers were identified. At the time of data summary, relevant clinical information was available for 297 patients. Median follow-up time was 77.4 months (range, 2.5-519). The group of known carriers included 95 women (median age at diagnosis 41.9 [range 27.8-80.3 years]), 70 (74%) were BRCA1 carriers, 23 (24%) BRCA2 carriers, and 2 (2.1%) carried mutations in both genes. The median age at diagnosis of 202 latent carriers was 43.7 (range 23.8-75 years), p=0.8284. Of latent carriers 117 (58%) were BRCA1 mutation carriers and 85 (42%) harbored a BRCA2 mutation. In the group of known carriers, 19% were diagnosed with carcinoma in situ (DCIS) vs. 5% in the group of latent carriers (p=00012). Stage T1N0 disease was diagnosed in 54/95 (56.8%) of known carriers vs. 59/202 (29.2%) of latent carriers (p<0.00001). Node-positive disease was diagnosed in 11/95 (11.6%) of known carriers vs. 98/202 (48.5%) of latent carriers (p<0.00001). Metastatic disease was diagnosed at presentation in none of the known carriers vs. 4/202 (2%) of latent carriers (p=0.16758). Overall, in the group of known carriers (including all stages) 46/95 (48.4%) received neoadjuvant (n=12) or adjuvant (n=34) chemotherapy (71.7% of them for triple-negative disease), and 41/95 (43.2%) received radiotherapy. In the group of latent carriers, 162/202 (80.2%) received neoadjuvant (n=74) or adjuvant (n=88) chemotherapy (p<0.00001), 59.3% of them for triple-negative disease, and 173/202 (85.6%) underwent radiotherapy. Contralateral risk-reducing mastectomy (CRRM) was performed by 59/95 (62%) of the known carriers, 73% of them at the time of primary tumor resection and the rest – at a later stage. Among latent carriers, 82/202 (40.6%) underwent CRRM, 44% at the time of primary tumor resection (p=0.00054). Conclusions: As expected, diagnosis of early stage disease (DCIS or T1N0) was significantly higher in the group of known BRCA1/2 carriers - disease that was diagnosed in the course of tight surveillance. Yet, despite this early stage diagnosis, chemotherapy and radiotherapy treatments were employed in a substantial proportion of these cases. Healthy BRCA1/2 mutation carriers should be informed about these chemotherapy and radiotherapy rates while discussing risk-reducing surgical options. There is an urgent need for a more accurate ability to predict individual mutation carrier cancer risk, as well as tools for selection of patients with stage I triple-negative disease who will do well without chemotherapy. Citation Format: Rinat Bernstein Molho, Bella Kaufman, Merav A Ben David, Miri Sklair-Levy, Yael Laitman, Eitan Friedman. Surveillance for BRCA1/2 mutation carriers - Is "early detection" really early enough? [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-08-10.

Virom/SARS-CoV2 interakcija - upražnjeno mesto za prirodne komponente

One of the most striking marks of infection caused by the SARS-CoV-2 is the distinguishing heterogeneity of the clinical presentations in a population that varies from asymptomatic to severe forms. Pandemic proportion brings into the foreground the number of people with severe forms of the disease, putting aside the fact that a large portion of the population is an asymptomatic, making them silent carriers of the virus. Additional confusion is made by inconsistent data about the presence of the virus in the nasopharyngeal region and the manifestation of the disease symptoms. Different tissue distribution of virus in the body starting from guts, liver, muscles, kidney etc. without any signs of tissue destruction, opens up the possibility that individuals with negative results of PCR test in the nasopharyngeal swab may also be latent carriers of the infection. Overall clinical presentation of the disease is influenced by the initial protection gained through the accumulated "experience" collected from previous encountering of corona family and noncorona viruses, resulting in overlapping of the humoral and cellular immunity. Apart from this, unjustifiably neglected but very significant form of host defense against infection is disease tolerance based on cohabitation with pathogen. It is important to note that consequences of the disease tolerance in terms of pathological and epidemiological aspects are quite different then classical antiviral immune response. This work will elaborate the impact of virome on the course of infection at all stages taking into account both immune resistance, as an ability of the host immune system to eliminate pathogen, and disease tolerance, as a form of host defense with neutral to positive impact to pathogen load. Also, in accordance with the above mentioned, the potential of naturally occurring compounds to profile the course of infection and to support currently available protocols for COVID-19 treatment was discussed.

110 Absence of transmission of Mycoplasma bovis via naturally contaminated semen during invitro fertilization

Mycoplasma bovis (Mbo) has been isolated from genital tracts of bulls, and it can survive in processed semen. Experimental studies have shown that Mbo inoculation into the uterus or insemination with Mbo-infected semen can cause bursitis, salpingitis, abortion, and infertility. The control of Mbo is very difficult because of latent carrier animals, increasing resistance to antibiotics, and unavailability of effective vaccines. The aim of this study was to follow the passage of Mbo infection from naturally contaminated semen to transferable embryos during bovine invitro embryo production (IVP). (Unless otherwise stated, all chemicals used were purchased from Sigma-Aldrich.) Two batches of slaughterhouse-derived oocytes were matured in tissue culture medium 199 (TCM-199) with glutamax-I (Gibco™; Invitrogen Corporation) supplemented with 0.25mM sodium pyruvate, 100IUmL−1 penicillin, 100µgmL−1 streptomycin, 2ngmL−1 FSH (Puregon, Organon), 1µgmL−1 β-oestradiol (E-2257), and 10% heat-inactivated fetal bovine serum (FBS; Gibco™) for 24h at 38.5°C in maximal humidity in 5% CO2 in air. Matured oocytes were fertilized for 20h in IVF-TL medium supplemented with 10µgmL−1 of heparin and 2mM of PHE at 38.5°C in maximal humidity in 5% CO2 in air, using spermatozoa per mL as a final concentration. The batches of oocytes were divided between uninfected IVP bull (N=205) and naturally Mbo-infected AI bull (N=690). Zygotes were cultured in G1/G2 media (Vitrolife) supplemented with bovine serum albumin, fatty acid free (4mgmL−1), at 38.5°C in maximal humidity in 5% O2, 5% CO2, and 90% N2. Blastocysts were collected for Mbo cultures on Days 7 and 8 (IVF=Day 0). Samples of washed semen, fertilization medium, cumulus cells, culture medium, all wash media, and transferable embryos (with and without zona pellucidae) were collected for Mbo cultures. Half of the embryos were treated with trypsin according to IETS standards after the collections. The Mbo cultures were performed in accordance with procedures previously described by Bölske (1988 Zentralbl. Bakteriol. Mikrobiol. Hyg. A 69, 331-340), followed by detection with real-time PCR. Infection with Mbo does not seem to have negative effects on fertilization (cleavage rates: 77.1% and 89.0% for IVP and Mbo AI bulls, respectively) or embryo development rates (blastocyst rate: 26.3% and 32.5% for IVP and Mbo AI bulls, respectively). Following Mbo cultures, only washed semen was found to be Mbo positive via real-time PCR. We conclude that M. bovis is not likely transmitted in bovine IVP when using naturally infected semen. We acknowledge Tiina Kortelainen for technical assistance and the Ministry of Agriculture and Forestry for funding.