Carrier Testing Research Articles

Evaluation of chlorine dioxide in liquid state and in gaseous state as virucidal agent against avian influenza virus and infectious bronchitis virus.

The antiviral activity of chlorine dioxide (ClO2) in liquid (ClO2 gas dissolved liquid) and gaseous state against avian influenza virus (AIV) and infectious bronchitis virus (IBV) was evaluated. To evaluate the effect of ClO2 in liquid state, suspension tests (10 ppm) and carrier tests in dropping / wiping techniques (100 ppm) were performed. In the suspension test, virus titers were reduced below the detection limit within 15 sec after treatment, in spite of the presence of an accompanying organic matter. In the carrier test by dropping technique, AIV and IBV were reduced to below the detection limit in 1 and 3 min, respectively. Following wiping technique, no virus was detected in the wiping sheets after 30 sec of reaction. Both viruses adhering to the carriers were also reduced by 3 logs, thereby indicating that they were effectively inactivated. In addition, the effect of ClO2 gas against IBV in aerosols was evaluated. After the exposure of sprayed IBV to ClO2 gas for a few seconds, 94.2% reduction of the virus titer was observed, as compared to the pre-treatment control. Altogether, hence, ClO2 has an evident potential to be an effective disinfectant for the prevention and control of AIV and IBV infections on poultry farms.

Comparison of the virucidal efficacy of essential oils (cinnamon, clove, and thyme) against hepatitis A virus in suspension and on food-contact surfaces

Essential oils (EOs) have been used for centuries as flavor enhancers in foods, and owing to their antimicrobial properties, they have potential as natural food preservatives. However, their effect on food-borne viruses is unknown. Therefore, in this study, the virucidal effects of three EOs (cinnamon, clove, and thyme) on the infectivity of the hepatitis A virus (HAV) were investigated. Different concentrations of each EO (0.05, 0.1, 0.5, and 1%) were mixed with viral suspensions in accordance with ASTM E1052–11:2011 and incubated for 1 h at room temperature. The EOs exhibited a concentration-dependent effect in the suspension tests, and HAV titers decreased by approximately 1.60 log PFU/mL when treated with EOs at the highest concentration of 1%. The antiviral effect of EOs treated at 1% for 1 h was also evidenced in surface disinfection tests according to the OECD:2013, as approximately 2 log PFU/mL reduction on hard food-contact surfaces (stainless steel and polypropylene) and approximately 2 and 1.4 log PFU/mL reduction on low-density polyethylene and kraft (soft food-contact surfaces), respectively. Moreover, RT-qPCR results revealed that HAV genome copies were negligibly reduced until treated with a high concentration (1%) in suspension and carrier tests. Overall, our findings highlighted the potential of cinnamon, clove, and thyme EOs as natural disinfectants capable of limiting HAV (cross-) contamination conveyed by food-contact surfaces. These findings advance our knowledge of EOs as antimicrobials and their potential in the food sector as alternative natural components to reduce viral contamination and improve food safety.

The completion of indicated paternal prenatal genetic and carrier testing at a public hospital in Los Angeles, California

PurposePregnant individuals are routinely advised to undergo genetic carrier screening, followed by carrier screening in the reproductive partner if the patient’s screen is positive. The objective of our study was to identify completion rates of and barriers to partner carrier screening or genetic testing. MethodsWe conducted a retrospective cohort study examining the completion of indicated partner genetic screening or testing at the Los Angeles General Medical Center Genetics clinic from January 1, 2017, to October 31, 2022. We examined factors linked to completing partner genetic screening or testing, including sociodemographic factors for patients and their partners, testing indications, and pregnancy characteristics via bivariate analyses (eg, t test, χ2, and Fisher’s exact tests). ResultsIn this primarily low-income, publicly insured, Spanish-speaking population, we identified 98 pregnancies for which partner genetic screening or testing was indicated. Only 26.5% (n = 26) completed testing, which did not vary by indication, parental age, parental race, parity, or primary language. Completion of partner genetic screening or testing was significantly linked to earlier gestational age at referral for genetic counseling (19.1 versus 21.5 weeks, P = .006). In 4 cases, being unable to obtain partner test results led to invasive diagnostic testing of the pregnant patient. ConclusionLess than one-third of pregnancies received indicated partner genetic screening or testing. Early referral to genetic counseling may improve partner testing completion rates, which could avoid invasive and unnecessary diagnostic testing in the pregnant patient.

A Case Report of the First Filipino Infant Diagnosed with Cystic Fibrosis through the Philippine Newborn Screening Program

Cystic Fibrosis (CF) is a rare condition among Asians and has not been reported in the Philippines as of this time.The inclusion of this disease in the Philippines’ Expanded Newborn Screening Program (ENBS) has provided thisFilipino family the opportunity of early detection and appropriate management of this condition that could ensure the survival of the proband and his other surviving siblings.Here we present a case of a 24-month-old male who had a positive Expanded Newborn Screening (ENBS) test forcystic fibrosis and eventually underwent further tests to confirm a homozygous deletion of exons 1 - 2 of the CFTR gene. He subsequently had recurrent pneumonia but is being managed by a team consisting of a pulmonologist, gastroenterologist, and a metabolic dietitian. The proband had an older sibling whose Newborn Screening (NBS) test was normal and who eventually expired from recurrent bouts of pneumonia. This sibling was never managed as a case of cystic fibrosis. Implications on the diagnosis and management of CF in the local setting is also discussed.The importance of an appropriate CF panel customized to the local population should be reiterated and carrier testing should be encouraged to help with proper family counseling for future pregnancies for the family involved.

Decontamination of Tomato Brown Rugose Fruit Virus-Contaminated Shoe Soles under Practical Conditions

Due to its global spread, easy mechanical transmissibility inside greenhouses, and detrimental effects on marketability, Tomato brown rugose fruit virus (ToBRFV) is considered to be one of the biggest threats to tomato production. Regarding such crop epidemics, it is essential to identify all conceivable transmission routes and to interrupt them with effective decontamination strategies. We analyzed the potential efficacy of reliable shoe sole cleaning in combination with a disinfection measure. For this purpose, first, a suspension test was undertaken that involved applying different disinfectants to an infected plant homogenate. This was followed by a simulated carrier test. Finally, shoe-sole decontamination was tested under practical conditions. The extent of decontamination was determined by bioassays of the infectivity of the initial load remaining after treatment. Thereby, necrotic local lesions on the susceptible indicator plant Nicotiana tabacum cv. Xanthi NN were counted. Recommendations for practical applications, based on suspension or simulated carrier tests, are limited in their applicability, since very short contact times between ToBRFV and disinfectants reduce efficacy. Under practical conditions, the approved disinfectant MENNO Florades was able to achieve complete inactivation of the virus in the disinfection mat following mechanical depletion from the shoe soles.

Exome Sequencing Revealed a Novel Splice Site Variant in the CRB2 Gene Underlying Nephrotic Syndrome.

Background and Objectives: Nephrotic syndrome (NS) is a kidney disease where the patient has a classic triad of signs and symptoms including hypercholesterolemia, hypoalbuminemia, proteinuria (>3.5 g/24 h), and peripheral edema. In case of NS, the damaged nephrons (structural and functional unit of the kidney) filter unwanted blood contents to make urine. Thus, the urine contains unwanted proteins (proteinuria) and blood cells (hematuria), while the bloodstream lacks enough protein albumin (hypoalbuminemia). Nephrotic syndrome is divided into two types, primary NS, and secondary NS. Primary NS, also known as primary glomerulonephrosis, is the result of a glomerular disease that is limited to the kidney, while secondary NS is a condition that affects the kidney and other parts of the body. The main causes of primary NS are minimal change disease, membranous glomerulonephritis, and focal segmental glomerulosclerosis. In the present study we recruited a family segregating primary NS with the aim to identify the underlying genetic etiology. Such type of study is important in children because it allows counseling of other family members who may be at risk of developing NS, predicts risk of recurrent disease phenotypes after kidney transplant, and predicts response to immunosuppressive therapy. Materials and Methods: All affected individuals were clinically evaluated. Clinical examination, results of laboratory tests, and biopsy investigations led us to the diagnosis. The next-generation sequencing technique (whole-exome sequencing) followed by Sanger sequencing identified a novel homozygous splice site variant (NM_173689.7: c.941-3C>T) in the CRB2 gene. The variant was present in a homozygous state in the affected individuals, while in a heterozygous state in phenotypically normal parents. Results: The study expanded the spectrum of the mutations in the gene CRB2 responsible for causing NS. Conclusions: In addition, the study will also help in genetic counseling, carrier testing, and prenatal and/or postnatal early diagnosis of the disease in the affected family.

Identification of Biallelic dystrophin gene variants during maternal carrier testing for Becker muscular dystrophy and review of the DMD exon 49-51 deletion phenotype.

Dystrophinopathies are X-linked recessive conditions caused by pathogenic variants in the dystrophin (DMD) gene. In a family that included two boys with Becker muscular dystrophy (BMD) due to a DMD deletion of exons 45-47, maternal carrier testing unexpectedly identified biallelic DMD deletions of exons 45-47 and 49-51. The patient's mild phenotype in the setting of biallelic DMD variants prompted further investigation of the exon 49-51 deletion in particular, via literature review and retrospective chart review of patients who have been evaluated in our institution's comprehensive neuromuscular center and/or diagnosed in our clinical genetic testing laboratory. To our knowledge, this is only the fifth case of confirmed biallelic DMD variants in a female. In males, the DMD exon 49-51 deletion appears to result in a mild BMD phenotype with low or normal creatine kinase levels. This deletion comprised 19% (4/21) of dystrophinopathies diagnosed by chromosomal microarray (CMA) in males during the past ten years in our clinical laboratory. Most individuals identified by chart review were diagnosed through CMA, despite the fact that microarray was genome-wide and not DMD-specific. This case raised important genetic counseling issues. The DMD exon 49-51 deletion appears to cause a variable but generally mild BMD phenotype. Its relatively frequent detection by CMA suggests it may be underdiagnosed.

Couple screening for recessively inherited disorders.

Couple screening aims to identify couples with an increased risk of having a child affected with an autosomal recessive or X-linked disorder, in order to facilitate informed reproductive decision making. Both expectant parents should be screened as a single entity, instead of individual testing. Carrier testing was typically performed for a few relatively common recessive disorders associated with significant morbidity, reduced life expectancy and often because of a considerably higher carrier frequency in a specific population for certain diseases. However, new genetic testing technologies enable the expansion of screening to multiple conditions, genes and sequence variants. There are multiple reproductive options for screening couples at risk, particularly when genetic traits are detected in the preconception period.

Psychosocial Issues Related to Newborn Screening: A Systematic Review and Synthesis.

Genomic advances have contributed to a proliferation of newborn screening (NBS) programs. Psychosocial consequences of NBS have been identified as risks to these public health initiatives. Following PRISMA guidelines, this systematic review synthesizes findings from 92 evidence-based, peer-reviewed research reports published from 2000 through 2020 regarding psychosocial issues associated with NBS. Results describe parents’ knowledge of and attitudes towards NBS, reactions to and understanding of positive NBS results, experiences of communication with health providers, decisions about carrier testing, and future pregnancies. Findings also explain the impact of positive NBS results on parent–child relationships, child development, informing children about carrier status, family burden, quality of life, and disparities. In conclusion, psychosocial consequences of receiving unexpected neonatal screening results and unsolicited genetic information remain significant risks to expansion of NBS. Findings suggest that risks may be mitigated by improved parent NBS education, effective communication, individualized genetic counseling, and anticipatory developmental guidance. Clinicians need to take extra measures to ensure equitable service delivery to marginalized subpopulations. Future investigations should be more inclusive of culturally and socioeconomically diverse families and conducted in low-resource countries. Providing these countries with adequate resources to develop NBS programs is an essential step towards achieving international health equity.

A novel homozygous variant in the GLI1 underlies postaxial polydactyly in a large consanguineous family with intra familial variable phenotypes

Polydactyly is a human inherited disorder caused by to anomalies in the genes involved in autopod development. The disorder segregates in both autosomal recessive and autosomal dominant form. Up till now, eleven genes causing non-syndromic polydactyly, have been identified. This includes ZNF141, GLI3, ZRS in LMBR1, MIPOL1, PITX1, IQCE, GLI1, FMA92A1, KIAA0825, STKLD1, and DACH1. In the present study, we have investigated a large consanguineous family of Pakistani origin segregating polydactyly in autosomal recessive pattern. Clinical examination of affected individuals revealed a non-syndromic form of the disorder. Genetic study based on homozygosity mapping and Sanger sequencing using DNA of the normal and affected individuals found a novel homozygous missense sequence variant [NM_005269.3: c.1133C > T, p.(Ser378Leu)] in the GLI1 located on human chromosome 12q13.3. In silico analysis of the identified variant showed a significant change in the secondary structure of the mutant protein that affects its function. Findings of the present study expand the mutation spectrum of the GLI1. In addition, the study will help in prevention of the disorder through carrier testing and bringing awareness among families affected with polydactyly.

Evaluation of the efficacy of ethanol, peracetic acid, and quaternary ammonium compounds against murine norovirus using carrier and suspension tests

Virucidal suspension testing is commonly used as an authorized test for disinfectants. However, this method could not precisely evaluate the effect of disinfectants on food-contact surfaces. To solve this problem, a carrier testing method needs to be established in the food-processing industries by following a standard guideline. Therefore, we employed two murine norovirus strains (MNV-1 and MNV-S99) to evaluate the antiviral efficacy of three disinfectants, i.e., ethanol, peracetic acid (PAA), and quaternary ammonium compounds (QACs) after three contact times (1, 5 and 10 min) as per the OECD guidelines regarding the carrier test. Following this, we compared the results of carrier testing results with those of suspension testing. The standard level of antiviral efficacy for disinfectants was determined by ≥ 3 log10 (99.9%) and ≥4 log10 (99.99%) reduction of viral titers in carrier and suspensions tests, respectively. In the carrier test, ethanol and PAA were effective against both MNVs and showed the standard level of performance at selected concentrations and contact times; the exception being the highest concentration of ethanol (90% for all contact times) and lowest concentration of PAA (80 ppm for 1 min). QACs were not effective against both MNVs at all selected concentrations and contact times. In the case of suspension test, ethanol and PAA exhibited the best antiviral efficacy and showed the standard level of performance at all contact times and concentrations; while, all concentrations of QACs were not enough to reduce the MNV-1 titers for achieving the standard level of performance during experimental conditions. This study showed that ethanol and PAA could inactivate MNVs under surface and suspension conditions. Therefore, these results could provide valuable information for establishing standard antiviral efficacy tests and approaches to control viral transmission via surfaces.

Suitability of Methods to Determine Resistance to Biocidal Active Substances and Disinfectants—A Systematic Review

Biocide resistance is an increasing concern. However, it is currently unknown if an elevated MIC value for an isolate correlates with a lower log10 reduction in suspension tests or carrier tests. The aim of this review was therefore to evaluate if isolates with a suspected tolerance to a biocidal active substance reveal an elevated MIC value and an impaired efficacy in suspension tests and carrier tests. A Medline search was done on 6 July 2022 using the following terms: “resistance biocidal MIC suspension” (16 hits), “resistance biocidal MIC carrier” (22 hits), “resistance biocidal suspension carrier” (41 hits), “tolerance biocidal MIC suspension” (1 hit), “tolerance biocidal MIC carrier” (4 hits) and “tolerance biocidal suspension carrier” (3 hits). Studies were included when a tolerance or resistance to the biocidal active substance or disinfectant was suspected and at least two of the three endpoints were evaluated in parallel in comparison to the control isolates. In three out of five studies, the elevated MIC values did not correlate with an impaired bactericidal efficacy against the biocide-tolerant isolates. In three out of five studies, an impaired activity in the suspension tests was described that correlated with an impaired efficacy in the carrier tests (peracetic acid-tolerant K. pneumoniae and glutaraldehyde-tolerant M. chelonae; the two other studies did not allow a comparison. Overall, the results from the suspension tests and tests under practical conditions allowed to determine a clinically relevant resistance.

Design of Test Equipment for Hydrostatic Transducers and Hydraulic Fluids

The article refers to the proposed test equipment used to monitor the service life of hydrostatic transducers and fluids under constant or dynamic operating pressure loading. The proposed laboratory test equipment enables simultaneous testing of hydrostatic transducers and energy carriers in two hydraulic circuits and is designed to measure the flow characteristics and technical life of hydrostatic transducers with different energy carriers. The benefit of the proposed device is the possibility of simultaneous testing of the transducers as well as the performance of verification measurements of individual circuits, which was preceded by the development of a theoretical design. This includes the calculations necessary to determine the power of the drive, the cooling power as well as the definition of other parameters and elements of the hydraulic system. The design of the device was based on technical characteristics, load characteristics obtained by own measurements, and characteristics of individual hydraulic and electrohydraulic elements. On the basis of the prepared laboratory test equipment, it is possible to significantly shorten the time of operational tests and perform repeated tests under the same operational load with different types of energy carriers. The hydraulic circuit (primary or secondary) can be loaded through a proportional electrohydraulic pressure valve, which is able to simulate the load with the operational pressure curve obtained by measurement, as well as the cyclic stress, the frequency, amplitude, and rate of increase of which can be defined according to the selected methodology. A verification measurement of the flow characteristics of the used transducers was also carried out, which confirmed the correct function and design of the test laboratory equipment. The achieved results can be used in mechanical engineering for the accelerated life test of hydrostatic transducers, which are often used in mobile energy devices working in environmentally sensitive areas. The proposed laboratory test equipment will be used for testing ecological energy carriers, increasing the efficiency of energy conversion in agricultural facilities using biomass.

Preimplantation genetic testing for BRCA gene mutation carriers: A cost effectiveness analysis (340)

Objectives: To investigate the cost-effectiveness of preimplantation genetic testing for selection and transfer of BRCA negative embryo in BRCA mutation carriers compared to natural conception. Methods: The cost-effectiveness of two strategies, conception through IVF/PGT-M and BRCA negative embryo transfer versus natural conception with a 50% chance of BRCA positive newborn for BRCA mutation carriers, was compared using a Markovian process decision analysis model. Costs of the two strategies were compared using quality-adjusted life years (QALYs’). All costs were discounted by 3%. Incremental cost-effectiveness ratio (ICER) compared to the willingness to pay threshold was used for cost-effectiveness analysis. A probabilistic sensitivity analysis (Monte Carlo simulation) was conducted with all variables, using 100 trials, each included 10,000 couples, to evaluate model uncertainties. Results: IVF/ PGT-M is cost-effective with an ICER of 150,219 new Israeli Shekels, per QALY gained (equivalent to 44,480 USD), at a 3% discount rate. Discount rate and uptake of risk reduction salpingo- oophorectomy (RRSO) are the most influential parameters that affect the ICER. Increasing uptake of RRSO would make the ICER highly cost-effective. Conclusions: IVF/ PGT-M and BRCA negative embryo transfer compared to natural conception among BRCA positive parents is costeffective and may be offered for selected couples with high BRCA mutation-related morbidity or mortality. Our results could impact decisions regarding conception among BRCA positive couples and health care providers. Objectives: To investigate the cost-effectiveness of preimplantation genetic testing for selection and transfer of BRCA negative embryo in BRCA mutation carriers compared to natural conception. Methods: The cost-effectiveness of two strategies, conception through IVF/PGT-M and BRCA negative embryo transfer versus natural conception with a 50% chance of BRCA positive newborn for BRCA mutation carriers, was compared using a Markovian process decision analysis model. Costs of the two strategies were compared using quality-adjusted life years (QALYs’). All costs were discounted by 3%. Incremental cost-effectiveness ratio (ICER) compared to the willingness to pay threshold was used for cost-effectiveness analysis. A probabilistic sensitivity analysis (Monte Carlo simulation) was conducted with all variables, using 100 trials, each included 10,000 couples, to evaluate model uncertainties. Results: IVF/ PGT-M is cost-effective with an ICER of 150,219 new Israeli Shekels, per QALY gained (equivalent to 44,480 USD), at a 3% discount rate. Discount rate and uptake of risk reduction salpingo- oophorectomy (RRSO) are the most influential parameters that affect the ICER. Increasing uptake of RRSO would make the ICER highly cost-effective. Conclusions: IVF/ PGT-M and BRCA negative embryo transfer compared to natural conception among BRCA positive parents is costeffective and may be offered for selected couples with high BRCA mutation-related morbidity or mortality. Our results could impact decisions regarding conception among BRCA positive couples and health care providers.

Detection of Structural Variants by NGS: Revealing Missing Alleles in Lysosomal Storage Diseases

Lysosomal storage diseases (LSDs) are a heterogeneous group of rare multisystem metabolic disorders occurring mostly in infancy and childhood, characterized by a gradual accumulation of non-degraded substrates inside the cells. Although biochemical enzymatic assays are considered the gold standard for diagnosis of symptomatic patients, genotyping is a requirement for inclusion in enzyme replacement programs and is a prerequisite for carrier tests in relatives and DNA-based prenatal diagnosis. The emerging next-generation sequencing (NGS) technologies are now offering a powerful diagnostic tool for genotyping LSDs patients by providing faster, cheaper, and higher-resolution testing options, and are allowing to unravel, in a single integrated workflow SNVs, small insertions and deletions (indels), as well as major structural variations (SVs) responsible for the pathology. Here, we summarize the current knowledge about the most recurrent and private SVs involving LSDs-related genes, review advantages and drawbacks related to the use of the NGS in the SVs detection, and discuss the challenges to bring this type of analysis in clinical diagnostics.

Inactivation methods for human coronavirus 229E on various food-contact surfaces and foods.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of the COVID-19 outbreaks, is transmitted by respiratory droplets and has become a life-threatening viral pandemic worldwide. The aim of this study was to evaluate the effects of different chemical (chlorine dioxide [ClO2] and peroxyacetic acid [PAA]) and physical (ultraviolet [UV]-C irradiation) inactivation methods on various food-contact surfaces (stainless steel [SS] and polypropylene [PP]) and foods (lettuce, chicken breast, and salmon) contaminated with human coronavirus 229E (HCoV-229E). Treatments with the maximum concentration of ClO2 (500 ppm) and PAA (200 ppm) for 5 min achieved >99.9% inactivation on SS and PP. At 200 ppm ClO2 for 1 min on lettuce, chicken breast, and salmon, the HCoV-229E titers were 1.19, 3.54, and 3.97 log10 TCID50/mL, respectively. Exposure (5 min) to 80 ppm PAA achieved 1.68 log10 reduction on lettuce, and 2.03 and 1.43 log10 reductions on chicken breast and salmon, respectively, treated with 1500 ppm PAA. In the carrier tests, HCoV-229E titers on food-contact surfaces were significantly decreased (p < 0.05) with increased doses of UV-C (0–60 mJ/cm2) and not detected at the maximum UV-C dose (Detection limit: 1.0 log10 TCID50/coupon). The UV-C dose of 900 mJ/cm2 proved more effective on chicken breast (>2 log10 reduction) than on lettuce and salmon (>1 log10 reduction). However, there were no quality changes (p > 0.05) in food samples after inactivation treatments except the maximum PAA concentration (5 min) and the UV-C dose (1800 mJ/cm2).

A Review of Commonly Used Methodologies for Assessing the Antibacterial Activity of Honey and Honey Products.

Honey, a naturally sweet and viscous substance is mainly produced by honeybees (Apis mellifera) from flower nectar. Honey exerts a plethora of biological and pharmacological activities, namely, antioxidant, antimicrobial and anti-inflammatory activity, because of the presence of an extensive variety of bioactive compounds. The antibacterial activity is one of the most reported biological properties, with many studies demonstrating that honey is active against clinically important pathogens. As a result, beside honey’s widespread utilization as a common food and flavouring agent, honey is an attractive natural antimicrobial agent. However, the use of neat honey for therapeutic purposes poses some problems, for instance, its stickiness may hamper its appeal to consumers and health care professionals, and the maintenance of an adequate therapeutic concentration over a sufficient timeframe may be challenging due to honey liquidity and leakage. It has motivated researchers to integrate honey into diverse formulations, for example, hydrogels, dressings, ointments, pastes and lozenges. The antibacterial activity of these formulations should be scientifically determined to underscore claims of effectiveness. Some researchers have made efforts to adapt the disc carrier and suspension test to assess the antimicrobial activity of topical products (e.g., silver-based wound dressings). However, there is currently no established and validated method for determining the in vitro antimicrobial potential of natural product-based formulations, including those containing honey as the active principle. Against the backdrop of a brief discussion of the parameters that contribute to its antibacterial activity, this review provides an outline of the methods currently used for investigating the antibacterial activity of neat honey and discusses their limitations for application to honey-based formulations.

Evaluation of Virucidal Quantitative Carrier Test towards Bovine Viruses for Surface Disinfectants While Simulating Practical Usage on Livestock Farms.

Livestock farming is affected by the occurrence of infectious diseases, but outbreaks can be prevented by effective cleaning and disinfection along with proper farm management. In the present study, bovine coronavirus (BCoV) and bovine rotavirus A (RVA) were inactivated using food additive-grade calcium hydroxide (FdCa(OH)2) solution, quaternary ammonium compound (QAC) and their mixture through suspension tests as the primary screening, and afterward via carrier tests using dropping or dipping techniques as the secondary screenings. Viruses in the aqueous phase can be easily inactivated in the suspension tests, but once attached to the materials, they can become resistant to disinfectants, and require longer times to be inactivated. This highlights the importance of thorough cleaning with detergent before disinfection, and keeping elevated contact durations of proper disinfectants to reduce viral contamination and decrease infectious diseases incidence in farms. It was also reaffirmed that the suspension and carrier tests are necessary to evaluate disinfectants and thus determine their actual use. Particularly, the mixture of QAC and FdCa(OH)2 was found to exhibit synergistic and broad-spectrum effects compared to their use alone, and is now recommended for use on livestock farms.

P-548 IMPORTANCE OF EXPANDED CARRIER SCREENING AMONG OOCYTE DONORS - questions and concerns

Abstract Study question To examine the utility of a range of expanded screening panels for oocyte donors. Summary answer Expanded carrier screening with NGS data identified that 86% of gamete donors were carriers of at least one condition while 302 genes were tested. What is known already The level of genetic testing for oocyte donors is not regulated in most countries. The use of expanded carrier screening is recommended more widely. If the egg donor is a carrier, there is a 50% chance that the offspring will also be carriers. Expanded carrier screening is performed to determine the potential effects of positive carrier status, which guarantees safety for future pregnancy. From practical experience, more genes are tested for a donor, more potential mutations are detected. Study design, size, duration A cohort of 92 potential oocyte donor applicants aged 18-30 years old, who were qualified for oocyte donation after full screening, tested negative on an initial cystic fibrosis carrier test for 11 most common CFTR mutations (PCR panel), was further screened with expanded commercial carrier testing panel (302 genes) using next-generation sequencing (NGS) data. Participants/materials, setting, methods A cohort of 92 potential oocyte donor applicants aged 18-30 years old, who tested negative on an initial cystic fibrosis carrier test for 11 most common CFTR mutations (PCR panel), was further screened with expanded commercial carrier testing panel (302 genes) using next-generation sequencing (NGS) data. Main results and the role of chance Genotyping results for all donors were analyzed; 38% (35/92) of donors were identified as carriers for one condition, 34% (31/92)- for two conditions, 7% (6/92)- for three conditions and 7% (6/92)- for four conditions, including cystic fibrosis. Among the most prevalent conditions in our study were: Hemochromatosis: Type 1: HFE Related- 22%, Cystic Fibrosis: CFTR-related conditions 11%, Biotinidase deficiency– 7,6%, 21-Hydroxilase-Deficient Congenital Nonclassical Adrenal Hyperplasia- 6,5%, Krabbe disease – 6,5%, Usher syndrome: USH2A-related conditions – 6,5%, Nonsyndromic deafness: GJB2- related conditions- 5,4% and Smith-Lemli-Opitz syndrome (5,4%). Limitations, reasons for caution Each donor was consented for genetic testing Wider implications of the findings This study shows a need to provide the explicit requirement for oocyte donor genetic testing and guidelines to satisfy quality and safety and not reduce the number of donors carries of mutations, but to implement a practice of genetic matching. Trial registration number not applicable

O-146 Extended carrier testing of inherited disorders for reproductive risk assessment in preconception care

Abstract Study question What are the clinical implications of extended carrier screening including genetic risk factors linked to infertility and pregnancy? Summary answer The preconception care is simplified by combining the carrier screening for autosomal recessive and X-linked disorders with examination of other risk factors in one test. What is known already Preconception care includes screening for autosomal recessive and X-linked disorders, usually based on family history or ethnicity. Current molecular genetic methods allow simultaneous detection of mutations in a large number of genes and thus developing a unified test for all couples. Study design, size, duration Retrospective analysis of results from 19944 individuals (9972 couples) examined between March 2017 and July 2021. Participants/materials, setting, methods Massively parallel sequencing panel CarrierTest screens for mutations in 80 genes associated with severe inherited diseases along with common risk factors for infertility, pregnancy loss and IVF-related treatment complications. Main results and the role of chance The risk of disorders with autosomal recessive inheritance was found in 1.59 % of couples and risk of X- linked disorders in 1.56 % of couples. Risk of pregnancy complications due to inherited thrombophilia (Factor 5 Leiden mutation and Factor 2 Prothrombin mutation) in the woman was detected in 10.4 % couples and due to the M2 haplotype of ANXA5 gene in 3.53 % couples. Increased sensitivity for FSH due to the FSHR gene Ser680Asn variant in homozygous state was found in 30.7 % of women and microdeletions of chromosome Y associated with male infertility were detected in 0.72 % of men. Limitations, reasons for caution The findings in most genes for autosomal recessive genes are likely to represent the real population frequency of carriers, but in other categories the data are influenced by selection of patients and couples for testing due the reproductive problems or family history. Wider implications of the findings Implementation of CarrierTest allowed us to considerably extend the breadth of tested severe diseases and risk factors and thus to offer the examined couples the opportunity of primary prevention of the consequences of their carrier status. Trial registration number Not applicable