PCR-based Screening Research Articles

Phenotypic Assessment of Clinical Escherichia coli Isolates as an Indicator for Uropathogenic Potential.

For women in the United States, urinary tract infections (UTIs) are the most frequent diagnosis in emergency departments, comprising 21.3% of total visits. Uropathogenic Escherichia coli (UPEC) causes ~80% of uncomplicated UTIs. To combat this public health issue, it is vital to characterize UPEC strains as well as to differentiate them from commensal strains to reduce the overuse of antibiotics. It has been challenging to determine a consistent genetic signature that clearly distinguishes UPEC from other E. coli strains. Therefore, we examined whether phenotypic data could be predictive of uropathogenic potential. We screened 13 clinical strains of UPEC, isolated from cases of uncomplicated UTI in young otherwise healthy women, in a series of microbiological phenotypic assays using UPEC prototype strain CFT073 and nonpathogenic E. coli strain MG1655 K-12 as controls. Phenotypes included adherence, iron acquisition, biofilm formation, human serum resistance, motility, and stress resistance. By use of a well-established experimental mouse model of UTI, these data were able to predict the severity of the bacterial burden in both the urine and bladders. Multiple linear regression using three different phenotypic assays, i.e., growth in minimal medium, siderophore production, and type 1 fimbrial expression, was predictive of bladder colonization (adjusted R2 = 0.6411). Growth in ex vivo human urine, hemagglutination of red blood cells, and motility modeled urine colonization (adjusted R2 = 0.4821). These results showcase the utility of phenotypic characterization to predict the severity of infection that these strains may cause. We predict that these methods will also be applicable to other complex, genetically redundant, pathogens. IMPORTANCE Urinary tract infections are the second leading infectious disease worldwide, occurring in over half of the female population during their lifetime. Most infections are caused by uropathogenic Escherichia coli (UPEC) strains. These strains can establish a reservoir in the gut, in which they do not cause disease but, upon introduction to the urinary tract, can infect the host and elicit pathogenesis. Clinically, it would be beneficial to screen patient E. coli strains to understand their pathogenic potential, which may lead to the administration of prophylactic antibiotic treatment for those with increased risk. Others have proposed the use of PCR-based genetic screening methods to detect UPEC strains and differentiate them from other E. coli pathotypes; however, this method has not yielded a consistent uropathogenic genetic signature. Here, we used phenotypic characteristics such as growth rate, siderophore production, and expression of fimbriae to better predict uropathogenic potential.

PCR-Based Screening of Spinal Muscular Atrophy for Newborn Infants in Hyogo Prefecture, Japan.

Spinal muscular atrophy (SMA) is a common devastating neuromuscular disorder, usually involving homozygous deletion of the SMN1 gene. Newly developed drugs can improve the motor functions of infants with SMA when treated in the early stage. To ensure early diagnosis, newborn screening for SMA (SMA-NBS) via PCR-based genetic testing with dried blood spots (DBSs) has been spreading throughout Japan. In Hyogo Prefecture, we performed a pilot study of SMA-NBS to assess newborn infants who underwent routine newborn metabolic screening between February 2021 and August 2022. Hyogo Prefecture has ~40,000 live births per year and the estimated incidence of SMA is 1 in 20,000-25,000 based on genetic testing of symptomatic patients with SMA. Here, we screened 8336 newborns and 12 screen-positive cases were detected by real-time PCR assay. Multiplex ligation-dependent probe amplification assay excluded ten false positives and identified two patients. These false positives might be related to the use of heparinized and/or diluted blood in the DBS sample. Both patients carried two copies of SMN2, one was asymptomatic and the other was symptomatic at the time of diagnosis. SMA-NBS enables us to prevent delayed diagnosis of SMA, even if it does not always allow treatment in the pre-symptomatic stage.

Cross-sectional comparison of superficial swab and fine-needle aspiration: Improving the diagnostic workup of horses with sarcoids

Although bovine papillomavirus (BPV)-induced equine sarcoids are often identified solely by clinical examination, confirmation of the clinical diagnosis is essential for correct treatment selection. Only few approaches are presently available for this purpose. PCR-based screening for BPV in superficial swabs is widely-used to support clinical suspicion. While this method effectively detects sarcoid involvement in ulcerated lesions, sensitivity is lower in tumors with intact epithelium. This cross-sectional study compared the diagnostic characteristics of superficial swabs and fine-needle aspirates (FNA) with the aim to validate FNA as an alternative sampling method to detect BPV in suspect lesions. Among 63 lesions confirmed as sarcoids from 58 horses, compared to swabs FNA detected a greater proportion of BPV positives in general (swab, 70 %,;95 % confidence intervals [CI], 58.5 %−81.2 %; FNA, 98 %, 95 % CI, 95.3 %−100 %; P = 0.0001) and among a non-ulcerated subgroup (swab, 63 %, 95 % CI, 50.4 %−76.6 %; FNA, 98 %, 95 % CI, 91.4 %−100 %; P = 0.0001). Furthermore, the sensitivity, as well as the negative predictive value and accuracy of FNA for matched samples from 58 horses were superior to surface swabbing for the group of all horses and the subgroup that included only lesions with an intact epidermis (n = 48), with differences ranging from 23 % (95 % CI, 11.4 %−34.6 %) to 52 % (95 % CI, 25.9 %−78.1 %). Other advantages of FNA identified were a higher chance of adequate sampling and a reduced risk of unwanted detection of superficial contamination or latent BPV in keratinocytes. The ability to consistently detect BPV in all clinical lesion types indicates that FNA shows promise as a valid diagnostic tool to improve the consistency and quality of the diagnostic workup of equine sarcoids.

Nested Real-Time PCR Assessment of Vertical Transmission of Sandalwood Spike Phytoplasma ('Ca. Phytoplasma asteris').

Simple SummaryThe Sandalwood Spike disease (SSD) related to ‘Ca. Phytoplasma asteris’ has almost wiped out the sandalwood population from the forests of southern India. It is known that sap-sucking insect vectors transmit phytoplasmas; however, their transmission through seeds needs thorough investigation. We found that 38.66% and 23.23% of one-month and four-month-old seedlings, respectively, tested positive for SSD phytoplasma screened using modified real-time qPCR assays in insect-free environments. Considering the current efforts to reestablish the healthy sandalwood population and its commercial importance, these findings are worrisome. The role of some other microbes in the high mortality rates of sandalwood seedlings remains unknown and requires further investigation.The Sandalwood Spike disease (SSD)-related to ‘Ca. Phytoplasma asteris’ has threatened the existence of sandalwood in India. The epidemiology of SSD is still poorly understood despite the efforts to understand the involvement of insect vectors in SSD transmission and alternate plant hosts over the last two decades. Apart from the transmission of SSD phytoplasma through insect vectors, the information on vertical transmission is entirely unknown. Over 200 seeds from SSD-affected trees and over 500 seedlings generated using commercially purchased seeds were screened for the presence of SSD phytoplasma to understand the vertical transmission in an insect-free environment. The end-point nested PCR and real-time nested PCR-based screening revealed an alarming rate of 38.66% and 23.23% phytoplasma positivity in one-month and four-month-old seedlings, respectively. These results were further validated by visualizing the phytoplasma bodies in sandalwood tissues using scanning electron microscopy. The presence of phytoplasma DNA in the seeds and seedlings is a concern for the commercial distribution of sandalwood seedlings in the current setup. This also poses a fear of spreading the disease to newer areas and negatively affecting the economy. The seedling mortality was also suspected to be associated with isolated bacterial and fungal isolates such as Erwinia, Curtobacterium, Pseudomonas, Rhodococcus, Aspergillus, Fusarium, and Neofusicoccum isolated using a culture-dependent approach. These findings strongly recommend the accreditation of commercial production of sandalwood seedlings curtailing SSD phytoplasma’s menace. Additionally, a new nested end-point and qRT PCR assays developed in this study proved valuable for the rapid screening of phytoplasma in many plant samples to detect phytoplasmas.

Two Distinct Genomic Lineages of Sinaivirus Detected in Guyanese Africanized Honey Bees.

ABSTRACTOver the past decade or so, PCR-based screening programs have reported that Africanized honey bees (AHB) are also hosts to viruses commonly found in European honey bees. Very little is known about the genomic variants found in AHB. Here, we present two distinct lineages of sinaiviruses in AHB.

CRISPR Del/Rei: a simple, flexible, and efficient pipeline for scarless genome editing

Scarless genome editing of induced pluripotent stem cells (iPSCs) is crucial for the precise modeling of genetic disease. Here we present CRISPR Del/Rei, a two-step deletion-reinsertion strategy with high editing efficiency and simple PCR-based screening that generates isogenic clones in ~ 2 months. We apply our strategy to edit iPSCs at 3 loci with only rare off target editing.

Identification of sex-specific markers and ZW-chromosome DNA clones from the genomic BAC library of the Chinese mitten crab Eriocheir sinensis

A ZW-ZZ sex determination system was previously proposed based on sex linkage analysis in the Chinese mitten crab, Eriocheir sinensis. In this study, we successfully identified a sex-specific marker from sex-linked markers in the genetic map and verified in different wild populations of E. sinensis. To further identify ZW chromosome DNA, we constructed a highly redundant genomic bacterial artificial chromosome (BAC) library for the Chinese mitten crab. The library was generated from high-molecular weight genomic DNA isolated from hemocytes and muscle in a female crab, which was comprising of 153,984 clones arrayed in 401,384-well microtiter plates. The average inserts size is 72 kb, representing 8.7-fold haploid genome coverage. By using sex specific markers, PCR-based screening was performed to identify ZW-derived BAC clones. Three W and Z-derived BAC clones were isolated, respectively. One of W-derived (P282E18) BAC clones was sequenced and assembled into a 43 kb contig without any gap. The W-derived BAC inserts can be mapped to an assembled contig of E. sinensis genome with 95% similarity in the aligned region, demonstrating that the BAC library is a valuable resource for discriminating Z and W chromosome contigs in the assembled haploid genome. The sex-specific marker provides a powerful tool not only for distinguishing the gender of larval or early juvenile E. sinensis without sexual dimorphism and sex-reversed individuals in monosex crab breeding, but also for identification of ZW-derived BAC clones used in the assembly of Z and W chromosomes in E. sinensis.

The characterization of multiple novel paramyxoviruses highlights the diverse nature of the subfamily Orthoparamyxovirinae.

The subfamily Orthoparamyxovirinae is a group of single-stranded, negative-sense RNA viruses that contains many human, animal, and zoonotic pathogens. While there are currently only forty-two recognized species in this subfamily, recent research has revealed that much of its diversity remains to be characterized. Using a newly developed nested PCR-based screening assay, we report here the discovery of fifteen orthoparamyxoviruses in rodents and shrews from Belgium and Guinea, thirteen of which are believed to represent new species. Using a combination of nanopore and sanger sequencing, complete genomes could be determined for almost all these viruses, enabling a detailed evaluation of their genome characteristics. While most viruses are thought to belong to the rapidly expanding genus Jeilongvirus, we also identify novel members of the genera Narmovirus, Henipavirus, and Morbillivirus. Together with other recently discovered orthoparamyxoviruses, both henipaviruses and the morbillivirus discovered here appear to form distinct rodent-/shrew-borne clades within their respective genera, clustering separately from all currently classified viruses. In the case of the henipaviruses, a comparison of the different members of this clade revealed the presence of a secondary conserved open reading frame, encoding for a transmembrane protein, within the F gene, the biological relevance of which remains to be established. While the characteristics of the viruses described here shed further light on the complex evolutionary origin of paramyxoviruses, they also illustrate that the diversity of this group of viruses in terms of genome organization appears to be much larger than previously assumed.

Target capture sequencing reveals a monoclonal outbreak of respiratory syncytial virus B infections among adult hematologic patients

BackgroundRespiratory syncytial virus (RSV) causes community-acquired respiratory tract infections during winter. However, outbreaks in hospitals also occur repeatedly. In particular, patients with hematologic malignancies are at an increased risk for a severe and potentially fatal course of RSV infection. Here we present the investigation of an RSV outbreak in a hematology ward for adults following the ORION statement.MethodsAn epidemiologic and molecular outbreak analysis was performed. We developed and employed a minimal oligonucleotide probe set in target capture probe sequencing that allows cost-effective RSV-A or -B capturing to reconstruct RSV genomes from clinical samples.ResultsFour adult patients were involved in the outbreak caused by RSV-B in March 2019. The enforcement of the pre-existing infection control measures by effective training of hospital staff contributed to a successful containment. PCR-based RSV screening on the ward enabled early detection of new cases and rapid isolation measures. The molecular analysis demonstrated that the outbreak sequences were highly related and distinct to other RSV-B strains circulating at the same time.ConclusionsA multimodal infection control concept is essential for the timely detection and control of RSV outbreaks in patients with hematological disease. Among other measures, preventive screening for respiratory viruses is recommended. Furthermore, the integration of conventional and molecular epidemiology, such as whole-genome sequencing and variant calling, significantly contributes to the understanding of transmission pathways. Based on this, appropriate conclusions can be drawn for targeted prevention measures that have prepared us for the COVID-19 pandemic beyond the RSV approach described here.

Implementation of genetic screening test to reduce the incidence of dapsone hypersensitivity syndrome among patients with leprosy in Papua, Indonesia: a study protocol

IntroductionThe mainstay of leprosy treatment is multidrug treatment (MDT), which contains rifampicin, dapsone and clofazimine. The occurrence of dapsone hypersensitivity syndrome (DHS), a sudden, potentially fatal and traumatic adverse reaction...

Culicoides segnis and Culicoides pictipennis Biting Midges (Diptera, Ceratopogonidae), New Reported Vectors of Haemoproteus Parasites.

As bloodsuckers of birds, Culicoides biting midges (Diptera, Ceratopogonidae) play an important role in the transmission of avian haemosporidian (Haemoproteus) parasites, which are prevalent in many bird populations and cause disease, pathology, or even mortality in their hosts. Information about the role of the various Culicoides species in the transmission of Haemoproteus parasites remains insufficient. This presents an obstacle for the better understanding of the epizootiology of haemoproteosis. The aim of this study was to determine new Culicoides species involved in the transmission of Haemoproteus parasites in the wild. Biting midges were collected using UV traps on the Curonian Spit, Lithuania. Only parous Culicoides females were investigated: they were identified and were diagnosed for the presence of Haemoproteus parasites using both microscopy and PCR-based methods. We collected and dissected 420 parous Culicoides females. PCR-based screening showed that 28 parous Culicoides biting midges were infected with avian Haemoproteus parasites. Haemoproteid DNA was detected in Culicoides kibunensis, Culicoides pictipennis, Culicoides festivipennis, Culicoides segnis, Culicoides pallidicornis, and Culicoides obsoletus biting midges. The DNA of Haemoproteus palloris, genetic lineage hWW1, was found for the first time in C. pallidicornis. Haemoproteus sporozoites were detected in the salivary glands of two Culicoides segnis biting midges. According to the PCR results, one female contained Haemoproteus tartakovskyi (genetic lineage hHAWF1) DNA and another Haemoproteus majoris (genetic lineage hCCF5) DNA. The sporozoites of Haemoproteus parasites were also detected in the salivary glands of four C. pictipennis biting midges using microscopy, and this finding was confirmed by PCR as Haemoproteus parabelopolskyi DNA (genetic lineage hSYAT02) was detected in three out of the four biting midges. The obtained results supplement existing information about Culicoides biting midges as natural vectors of Haemoproteus spp. and add two new Culicoides species to the vector list, showing the low specificity of these parasites for the invertebrate hosts.

Targeted (PCR-based) screening of antibiotic resistance genes' prevalence in the gut microbiota of tribal people of Nabarangpur, Odisha, India.

Antibiotic resistance is a major public health concern worldwide. The gut microbiota harbours multiple antibiotic resistant genes (ARGs) that contribute to the existing and future microbial population in a community or ecosystem. This study aimed to investigate the prevalence of 35 antibiotic resistance genes (ARGs) in the gut microbiota of the tribal people of Nabarangpur, Odisha, India. A total of 83 faecal samples were collected from three different tribes (Bhatra, Gond, and Paraja). Total faecal DNA was extracted, and the simplex polymerase chain reaction was performed to detect selected ARGs. Further analysis was done to estimate the incidence of these ARGs across these tribes based on alcohol consumption habits. We identified a higher prevalence of tetracycline resistance genes (tetW, tetQ and tetM) in the gut microbiota among three populations. Furthermore, a significant (P = 0·024) difference in ARG prevalence against vancomycin in individuals with and without alcohol consumption habits was noticed. The overall distribution of ARGs among the three major tribes of this location was found to be very similar. Together, irrespective of the tribes, the people of this location have gut microbiota harbouring different kinds of ARGs and tetracycline-resistant genes are the most commonly found ARGs.

SARS-CoV-2 infection among educational staff in Berlin, Germany, June to December 2020.

BackgroundSARS-CoV-2 infections in preschool and school settings potentially bear occupational risks to educational staff.AimWe aimed to assess the prevalence of SARS-CoV-2 infection in teachers and preschool educators and at identifying factors associated with infection.MethodsWe analysed cross-sectional data derived from 17,448 voluntary, PCR-based screening tests of asymptomatic educational staff in Berlin, Germany, between June and December 2020 using descriptive statistics and a logistic regression model.ResultsParticipants were largely female (73.0%), and median age was 41 years (range: 18-78). Overall, SARS-CoV-2 infection proportion was 1.2% (95% CI: 1.0–1.4). Proportion of positive tests in educational staff largely followed community incidence until the start of the second pandemic wave, when an unsteady plateau was reached. Then, the proportion of positive tests in a (concurrent) population survey was 0.9% (95% CI: 0.6–1.4), 1.2% (95% CI: 0.8–1.8) in teachers and 2.6% (95% CI: 1.6–4.0) in preschool educators. Compared with teachers, increased odds of infection were conferred by being a preschool educator (adjusted odds ratio (aOR): 1.6; 95% CI: 1.3–2.0) and by contact with a SARS-CoV-2 infected individual outside of work (aOR: 3.0; 95% CI: 1.5–5.5). In a step-wise backward selection, the best set of associated factors with SARS-CoV-2 infection involved age, occupation, and calendar week.ConclusionsThese results indicate that preschool educators bear increased odds of SARS-CoV-2 infection compared with teachers. At the same time, the private environment appeared to be a relevant source of SARS-CoV-2 infection for educational staff in 2020.

PCR-based screening of MNS glycophorin variants in patients suspected of having anti-Mia

Background:MNS glycophorin variants such as glycoprotein (GP.) Mur, GP.Hop, GP.Bun, GP.HF, GP.Hut, and GP.Vw are known to carry multiple antigens, including Mia (MNS7). In East and Southeast Asians, an antibody to Mia is not only commonly found, but also clinically significant. Purpose and Methods: In this study, deoxyribonucleic acid (DNA) samples from 47 patients suspected of having anti-Mia by serological screening were genotyped for GP.Mur, GP.Hop, GP.Bun, GP.HF, GP.Hut, and GP.Vw variants using polymerase chain reaction (PCR) assay. Results: All patients were found to be negative for the presence of Mia-positive glycophorin variants. Conclusions: The presence of anti-Mia cannot be excluded in patients studied, as genotyping shows that Mia-positive MNS glycophorin variants are not present. Bangladesh Journal of Medical Science Vol. 21 No. 02 April’22 Page : 432-437

Gene Editing in Green Alga Chlamydomonas reinhardtii via CRISPR-Cas9 Ribonucleoproteins.

With the establishment of the CRISPR-Cas9 molecular tool as a DNA editing system in 2012, the handling of gene editing experiments was strongly facilitated pushing reverse genetics approaches forward in many organisms. These new gene editing technologies also drastically increased the possibilities for design-driven synthetic biology. Here, we describe a protocol for gene editing in the green algae Chlamydomonas reinhardtii using preassembled CRISPR-Cas9 ribonucleoproteins.The three sections of the protocol guide through a complete gene editing experiment, starting with the experimental design and the choice of suitable CRISPR target sites and how to perform a Cas9 in vitro test digestion. The second part covers the transformation of algal cells with Cas9 RNPs using electroporation. In the last part, the PCR-based screening for mutants and isolation of clones is explained.

Efficacy of FFP3 respirators for prevention of SARS-CoV-2 infection in healthcare workers.

Respiratory protective equipment recommended in the UK for healthcare workers (HCWs) caring for patients with COVID-19 comprises a fluid-resistant surgical mask (FRSM), except in the context of aerosol generating procedures (AGPs). We previously demonstrated frequent pauci- and asymptomatic severe acute respiratory syndrome coronavirus 2 infection HCWs during the first wave of the COVID-19 pandemic in the UK, using a comprehensive PCR-based HCW screening programme (Rivett et al., 2020; Jones et al., 2020). Here, we use observational data and mathematical modelling to analyse infection rates amongst HCWs working on 'red' (coronavirus disease 2019, COVID-19) and 'green' (non-COVID-19) wards during the second wave of the pandemic, before and after the substitution of filtering face piece 3 (FFP3) respirators for FRSMs. Whilst using FRSMs, HCWs working on red wards faced an approximately 31-fold (and at least fivefold) increased risk of direct, ward-based infection. Conversely, after changing to FFP3 respirators, this risk was significantly reduced (52-100% protection). FFP3 respirators may therefore provide more effective protection than FRSMs for HCWs caring for patients with COVID-19, whether or not AGPs are undertaken. Wellcome Trust, Medical Research Council, Addenbrooke's Charitable Trust, NIHR Cambridge Biomedical Research Centre, NHS Blood and Transfusion, UKRI.

CBIO-15. LOSS OF WILLIAMS SYNDROME TRANSCRIPTION FACTOR (WSTF) LEADS TO IMPROVED TEMOZOLOMIDE SENSITIVITY IN HUMAN GLIOBLASTOMA CELLS IRRESPECTIVE OF MGMT EXPRESSION

Abstract BACKGROUND The prognosis for glioblastoma multiforme (GBM) patients is poor with a median survival of approximately 15 months. The DNA repair protein O 6-methylguanine-DNA methyltransferase (MGMT) counteracts the effects of temozolomide (TMZ) chemotherapy and is thus associated with poor outcome in GBM patients. Williams Syndrome Transcription Factor (WSTF) has been suggested to regulate the DNA damage response pathway (DDR) in both an indirect (through chromatin remodeling) and direct manner (by phosphorylating H2AX at Tyr142). However, whether WSTF has any role in the development of resistance against chemotherapy through its functions in the DDR in GBMs, is so far unknown. In this study, we investigated whether a loss of WSTF sensitizes different MGMT-proficient and -deficient GBM cell lines to TMZ treatment. METHODS We generated WSTF knockout clones from both MGMT-proficient (LN18, T98G) and -deficient GBM cell lines (U-251) using CRISPR/Cas9 gene-editing technology with lentiviral vectors. The PCR-based screening results combined with the T7 endonuclease mismatch assay for bi-allelic monoclonal knockouts were verified via sequencing and immunoblotting to identify candidate knockout clones. Colony formation assays were performed to determine the survival ability in response to TMZ treatment. Statistical analysis was performed using two-way ANOVA. RESULTS WSTF knockout clones showed a significant decrease in colony formation after TMZ-treatment compared to the corresponding control groups (non-target single guide RNA) (LN18: Clone 59 vs control: p= 0.0456, T98G: All three studied clones vs control: p< 0.0001, U-251: Clone 7/35.1/70.2 vs control: p< 0.0001/p= 0.0107/p= 0.0119). CONCLUSION WSTF is an important factor in both MGMT de- and proficient GBM cell lines for response against TMZ chemotherapy. The loss of WSTF leads to a significantly increased TMZ sensitivity in clinically relevant concentrations for all the studied cell lines. Ongoing studies are investigating the underlying mechanisms and potential alterations in the DDR pathway caused by WSTF loss.

Optimizing and evaluating PCR-based pooled screening during COVID-19 pandemics

Population screening played a substantial role in safely reopening the economy and avoiding new outbreaks of COVID-19. PCR-based pooled screening makes it possible to test the population with limited resources by pooling multiple individual samples. Our study compared different population-wide screening methods as transmission-mitigating interventions, including pooled PCR, individual PCR, and antigen screening. Incorporating testing-isolation process and individual-level viral load trajectories into an epidemic model, we further studied the impacts of testing-isolation on test sensitivities. Results show that the testing-isolation process could maintain a stable test sensitivity during the outbreak by removing most infected individuals, especially during the epidemic decline. Moreover, we compared the efficiency, accuracy, and cost of different screening methods during the pandemic. Our results show that PCR-based pooled screening is cost-effective in reversing the pandemic at low prevalence. When the prevalence is high, PCR-based pooled screening may not stop the outbreak. In contrast, antigen screening with sufficient frequency could reverse the epidemic, despite the high cost and the large numbers of false positives in the screening process.

Asymptomatic detection of SARS-CoV-2 among cancer patients receiving infusional anti-cancer therapy.

BackgroundLittle is known regarding the rate and clinical outcomes of asymptomatic carriers of SARS‐CoV‐2 among patients with cancer. Detection of asymptomatic carriers is important in this population given the use of myelosuppressive and immunomodulating therapies. Understanding the asymptomatic carrier rate will help to develop mitigation strategies in this high‐risk cohort.MethodsRetrospective cohort analysis of an asymptomatic screening protocol which required patients receiving infusional anti‐cancer therapy to undergo a symptom/exposure screen and SARS‐CoV‐2 PCR testing 24–96 h prior to their infusion. The primary outcome of this analysis was the rate of asymptomatic SARS‐CoV‐2 infection. Secondary outcomes included the rate of COVID‐19‐related hospitalization and mortality and delays in oncologic therapy.ResultsAmong a cohort of 2691 cancer patients who underwent asymptomatic screening, 1.6% (N = 43/2691) of patients were found to be SARS‐CoV‐2 positive on asymptomatic screening. 11.6% (N = 5/43) of the cohort ultimately developed COVID‐19‐related symptoms. Four patients required hospitalization for complications of COVID‐19 infection. No patient died from COVID‐related complications. 97.7% (N = 42/43) had their anti‐cancer therapy delayed or deferred with a median delay of 21 days (range: 7–77 days).ConclusionsOverall, among a cohort of active cancer patients receiving anti‐cancer therapy, an asymptomatic SARS‐CoV2 PCR‐based screening protocol detected a small cohort of asymptomatic carriers. The majority of these patients remained asymptomatic on long‐term follow‐up and outcomes were much more favorable compared to previously described outcomes of cancer patients with symptomatic COVID‐19 infection.

Fungus-originated glucanase and monooxygenase genes in creeping bent grass (Agrostis stolonifera L.).

Recent studies have revealed presence of fungus-originated genes in genomes of cool-season grasses, suggesting occurrence of multiple ancestral gene transfer events between the two distant lineages. The current article describes identification of glucanase-like and monooxygenase-like genes from creeping bent grass, as lateral gene transfer candidates. An in silico analysis suggested presence of the glucanase-like gene in Agrostis, Deyeuxia, and Polypogon genera, but not in other species belonging to the clade 1 of the Poeae tribe. Similarly, the monooxygenase-like gene was confined to Agrostis and Deyeuxia genera. A consistent result was obtained from PCR-based screening. The glucanase-like gene was revealed to be ubiquitously expressed in young seedlings of creeping bent grass. Although expression of the monooxygenase-like gene was suggested in plant tissues, the levels were considerably lower than those of the glucanase-like gene. A phylogenetic analysis revealed close relationships of the two genes between the corresponding genes in fungal endophyte species of the Epichloë genus, suggesting that the genes originated from the Epichloë lineage.