Liquid biopsy testing in metastatic or advanced breast cancer patients during the COVID-19 pandemic

Objective: During the COVID-19 pandemic, cancer patients had restricted access to standard of care tissue biopsy. Liquid biopsy assays using next generation sequencing technology provides a less invasive method for determining circulating tumour mutations (ctDNA) associated with targeted treatments or prognosis. As part of deploying technology to help cancer patients obtain molecular testing, a clinical program was initiated to offer liquid biopsy testing for Canadian patients with advanced or metastatic breast cancer. Method(s): Blood was drawn in two 10 mL StreckTM DNA BCTs and sent to the CAP/CLIA/DAP accredited Imagia Canexia Health laboratory for testing using the clinically validated Follow ItTM liquid biopsy assay. Plasma was isolated using a double spin protocol and plasma cell-free DNA (cfDNA) extracted using an optimized Promega Maxwell RSC method. Extracted cfDNA was amplified using the multiplex amplicon-based hotspot 30 or 38 gene panel and sequenced. An inhouse developed bioinformatics pipeline and reporting platform were used to identify pathogenic single nucleotide variants (SNVs), indels (insertions and deletions), and gene amplification. Included in the panel are genes associated with metastatic breast cancer: AKT1, BRAF, ERBB2, ESR1, KRAS, PIK3CA, TP53. Result(s): To identify biomarkers, 1214 metastatic or advanced breast cancer patient cfDNA samples were tested. There were 15 cases sent for repeat testing. We reported 48% of samples harboring pathogenic ctDNA mutations in TP53 (22%), PIK3CA (19%), ESR1 (18%), AKT1 (2%), ERBB2 (1.5%). Co-occurring variants were identified in samples with ESR1/PIK3CA as well as TP53/PIK3CA (both p-values <0.001). Interestingly, 29% of samples with mutated ESR1 harbored >= 2 ESR1 ctDNA mutations. In 56% of cases, previous molecular testing indicated the cancer subtype as hormone receptor (ER, PR) positive with/without HER2 negative status. In this specific subgroup, 49% harbored ctDNA mutations with 63% of those being PIK3CA and/or ESR1 mutations. Conclusion(s): A population of Canadian women with metastatic breast cancer were tested using a liquid biopsy gene panel during the COVID-19 pandemic for identification of biomarkers for targeted therapeutic options. Over 50% of the samples were identified as hormone positive, with greater than 60% harboring PIK3CA and ESR1 ctDNA mutations. Studies have shown that metastatic PIK3CA mutated ER-positive/HER2-negative tumors are predictive to respond to alpelisib therapy and have FDA and Health Canada approval. Additionally, ESR1 mutations are associated with acquired resistance to antiestrogen therapies, and interestingly we identified 29% of ESR1 mutated samples with multiple mutations possibly indicating resistance subclones. In future studies, longitudinal monitoring for presence of multiple targetable and resistance mutations could be utilized to predict or improve clinical management.

Randomized placebo-controlled trial of feline-origin Enterococcus hirae probiotic effects on preventative health and fecal microbiota composition of fostered shelter kittens.

Introduction: Diarrhea is the second most common cause of mortality in shelter kittens. Studies examining prevention strategies in this population are lacking. Probiotics are of particular interest but studies in cats are largely limited to healthy adults or those with induced disease. Only one study in domestic cats describes the use of host-derived bacteria as a probiotic. We previously identified Enterococcus hirae as a dominant species colonizing the small intestinal mucosa in healthy shelter kittens. Oral administration of a probiotic formulation of kitten-origin E. hirae (strain 1002-2) mitigated the increase in intestinal permeability and fecal water loss resulting from experimental enteropathogenic E. coli infection in purpose-bred kittens. Based on these findings, we hypothesized that administration of kitten-origin E. hirae to weaned fostered shelter kittens could provide a measurable preventative health benefit. Methods: We conducted a randomized, placebo-controlled, blinded clinical trial to determine the impact of a freeze-dried E. hirae probiotic on body weight gain, incidence of diarrhea, carriage of potential diarrheal pathogens, and composition of the intestinal microbiota in weaned fostered shelter kittens. Results: One-hundred thirty kittens completed the study. Fifty-eight kittens received the probiotic and 72 received the placebo. There were no significant differences in age, weight upon initiation of the study, number of days in the study, average daily gain in body weight, or weight at completion of the study. Kittens treated with E. hirae were 3.4 times less likely to develop diarrhea compared to kittens treated with placebo (odds ratio = 0.294, 95% CI 0.109-0.792, p = 0.022). A significant impact of E. hirae was not observed on the presence or abundance of 30 different bacterial, viral, protozoal, fungal, algal, and parasitic agents in feces examined by qPCR. With exception to a decrease in Megamonas, administration of the E. hirae probiotic did not alter the predominant bacterial phyla present in feces based on 16S rRNA gene amplicon sequencing. Discussion: Decreased incidence of diarrhea associated with preventative administration of E. hirae to foster kittens supports a rationale for use of E. hirae for disease prevention in this young population at high risk for intestinal disease though additional studies are warranted.

Long Term Circulation of Sars-Cov-2 Related Lineages in Bats in Cambodia

Intro: Recent evidence shows the Greater Mekong Subregion to be a hotspot for Sarbecoviruses in bats, especially insectivorous Horseshoe bats (genus Rhinolophus). However, prevalence, maintenance, and evolution of these viruses in Rhinolophids is still poorly understood. Sampling efforts are still limited and generally only cover cross-sectional surveillance at single points in time. Following the detection of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2)-related viruses in Rhinolophus shameli from 2010 in Steung Treng, Cambodia, further active longitudinal surveillance in the same area between 2020-2021 continued the detection of these viruses. Method(s): Live bat capture and sampling has been implemented in several sites located in Stung Treng province. All rectal swabs of bats were tested for the detection of SARS-CoV-2 or Sarbecoviruses by real time RT-PCR. RNA samples from positive RT-PCR bats were then sequenced using a highly multiplexed PCR amplicon approach using new designed primers set guided by the ARTIC Network multiplex PCR primers set (https://artic.network/ncov-2019), on Oxford Nanopore technology. Finding(s): The sarbecoviruses were detected in four Rhinolophus shameli bats, a percentage of similarity ranging at the nucleotide level between 98.8% - 99.1% when compared to two other Cambodian bat sarbecoviruses from 2010 and between 92.4% - 94.5% when compared to human SARS-CoV-2 across the whole genome. Discussion(s): The bat SARS-CoV-2 related virus recently detected in four positive bats in 2020-2021 are genetically homologous with the virus detected in 2010, indicating a geographically/host limited population that is stable over time in the past ten years. Conclusion(s): Overall, our findings indicate further complexity in the diversity and evolution of sarbecoviruses and add intricacy to the search for the origins of the Coronavirus Disease 2019 (COVID-19) pandemic.Copyright © 2023

Oral Microbiota in Children Who Started Antiretroviral Therapy at Young Ages

Background: Infancy is an important developmental period when the human microbiome is shaped. Given links between young age at antiretroviral treatment (ART) initiation and smaller persisting viral reservoirs, we hypothesized that earlier ART initiation may leave distinct microbial signatures in the oral cavity detectable in children living with HIV (CLWH). Method(s): Oral swab samples were collected from 477 CLWH and 123 children without HIV at two sites in Johannesburg, South Africa. CLWH had started ART < 2 years of age with 60% starting < 6 months of age. Most were wellcontrolled on ART at a median of 10 years of age when the swab was collected. Controls were age-matched and recruited from the same communities. Sequencing of the V4 amplicon of the 16S rRNA gene was done using established protocols. DADA2, decontam, and phyloseq were used for sequence inference, contaminant removal, and subsequent analyses. All p-values were adjusted for multiple testing using Benjamini-Hochberg false discovery rate method. Statistical analyses were performed with R. Result(s): CLWH had lower alpha diversity than uninfected children (Shannon index p< 0.0001). Genus-level abundances of Granulicatella, Streptococcus and Gemella were greater and Neisseria and Haemophilus were less abundant among CLWH compared to uninfected children. Associations were strongest among boys. There was no evidence of attenuation of associations with earlier ART initiation. In fact, decreased bacterial diversity and differences in taxa abundances in CLWH versus controls were consistent regardless of whether ART was started before or after 6 months of age. Shifts in genus-level taxa abundances relative to uninfected controls were most marked in children on regimens containing lopinavir/ritonavir;with few shifts seen if on regimens containing efavirenz. Conclusion(s): A distinct profile of less diverse oral bacterial taxa was observed in school-age CLWH on ART versus uninfected age-matched children suggesting persisting interference of HIV and its treatments on microbiota in the mouth. Any effects of earlier ART initiation were not detectable at this age. Studies of treated adults with HIV have observed similar shifts in taxa abundances. Oral microbiota have been linked to salivary cytokine levels with associations between Granulicatella and IL-8 and Neisseria and IL-6. Declines in Neisseria abundances in oral samples have been associated with more severe outcomes in influenza and COVID-19.

Emergence of a genotype I lineage 1 variant avian infectious bronchitis virus in Assam, India

Background: Infectious bronchitis (IB) is an acute and highly contagious viral disease of poultry affecting chicken of all ages. The causative agent IB virus (IBV) is a Gammacoronavirus within the family Coronaviridae. Viral genetic mutations and recombination events particularly in the spike protein (S1) of IBV constantly give rise to emerging IBV variants. Vaccination is considered as the most reliable approach for IBV control, but current vaccines have been found to be ineffective due to constant emergence of new variant viruses. Objective(s): The objective of our study was to detect IBV genotypes prevalent in Assam, India. Material(s) and Method(s): Oro-pharyngeal swabs and tissue samples from unvaccinated broiler chickens showing respiratory symptoms were tested using RT-PCR targeting the N gene of IBV. The virus was isolated from infected swab/tissue samples in 9 days old specific pathogen free embryonated chicken eggs through allantoic cavity route. Phylogenetic studies were done based on the S1 gene of IBV. Results and Conclusion(s): Clinically, the birds showed gasping and tracheal rales. Necropsy revealed distended ureters. Virus was isolated and identified by curling and dwarfing of the dead embryos and further confirmed by RT-PCR. Positive PCR amplicons were sequenced and phylogenetic analysis clustered the IBV isolate from Assam with genotype I lineage 1 IBV prototype sequence belonging to Beaudette and Mass 41 strains but the isolate exhibited a relatively high degree of sequence divergence with reference strains. Our findings suggest that the IBV isolate might have emerged from recombination with the local circulating virus or vaccine strains. This will have important implications for IB prevention strategies.

Reverse Transcription Recombinase Polymerase Amplification integrated with CRISPR Technology and LFA for point-of-care detection of SARS-CoV-2 virus

The field-deployable point-of-care diagnostic test for rapid detection of SARS-COV-2 is needed for implementation of the control measures. In this direction, recently developed CRISPR technology combined with isothermal recombinase polymerase amplification assay is a versatile highly sensitive detection platform for rapid diagnosis of infectious diseases. Here we report the development of RT-RPA-CRISPR based LFA assay for detection of SARS-CoV-2 targeting conserved RdRp and E genes. Various sets of primers and gRNAs were designed targeting conserved regions of the RdRp and E genes of different lineages of SARS-CoV-2 viruses. The isothermal RT-RPA based amplification reactions were standardized using invitro transcribed RNAs of the target regions. The optimum amplification was observed at 42degreeC for 30 min as confirmed by visualization of the amplicons in agarose gel. Subsequently, CRISPRCAS12 reaction was implemented for specific detection of amplicons. Different sets of gRNAs targeting RdRp and E genes were designed and synthesized by in-vitro transcription. The CRISP/CAS12-gRNA complex and single stranded fluorescence probe were added to the RT-RPA amplicons for cleavage of fluorescence probe in positive reaction. Subsequently, the cleaved probes were detected in precoated LFA strips. Upon probe cleavage reaction, the product was mixed with buffer and loaded into LFA strips. In positive reaction, test line showed strong band in test line and light band in control line. The standardized RT-RPA-CRISPR-LFA assay was tested for detection of SARS-CoV-2 using previously isolated RNAs from clinical cases of human SARS-CoV-2 infections. The developed assay successfully detected the positive cases. In conclusion, the developed assay could serve as versatile POC platform for rapid detection of SARS-CoV-2 nucleic acids in human as well as animals.

Pathogenic mutations in ethnic Lebanese Arab patients with high risk for hereditary breast cancer

Background: Breast cancer accounts for 35-40% of cancer in women in Lebanese and Arab countries with 50% of patients (pts) diagnosed before age 50. Prevalence of pathogenic BRCA variants in high-risk pts is 5.6-20% (Abulkhair and El Saghir 2021). 7 BRCA1 and 7 BRCA2 pathogenic variants were found in 5.6% of 250 pts with high hereditary risk breast cancer using amplicon sequencing and MLPA (El Saghir 2015;Poulet 2016). We report results of Next Generation Sequencing (NGS) on selected cases based on Manchester Score. First report in ethnic Lebanese Arab pts. Method(s): Pts prospectively enrolled in 2009-2012. IRB approval secured. Pts signed informed consent. Data collected from medical records. Amplicon and MLPA was done on 250 patients. NGS was done on 100 cases with Manchester Score 14-56. DNAs of the 14 pts previously found to have a pathogenic variant (Manchester Score 10-59) were not re-sequenced. NGS on remaining 150 pts was not done due to Covid-19 pandemic and lack of additional funding. Result(s): NGS showed 7 pathogenic variants, 4 in PALB2 and 3 in ATM. No new BRCA variants were found. Two BRCA2 mutations noted by Amplicon/MLPA reported as VUS in 2015 are reclassified as pathogenic. Total BRCA2 pathogenic variants becomes 9. Total pathogenic variants 23. Risk of having hereditary breast cancer in pts with MS 10-59 is 20% (23/ 114), and at least 9.2% in the entire cohort (23/250). Age <=40 with family history (FH) carries 18.9% risk of harboring a pathogenic mutation while no FH, 1.4% (Table 1). All BRCA1 pts had triple negative and 7/9 BRCA2 pts had hormone receptor positive breast cancer. 4 unrelated pts shared the same c.1056_1057delGA PALB2 pathogenic variant thus we suggest this is a founder mutation in Lebanese Ethnic Arab population. Conclusion(s): Mutation rates in high hereditary risk pts with Manchester Score range 10-59 is 20%. Age <=40 with positive FH can be used to select pts for testing when resources are limited. Our data suggests that c.1056_1057delGA is a PALB2 founder mutation. No conflict of interest.Copyright © 2022 Elsevier Ltd. All rights reserved

Carryover Contamination-Controlled Amplicon Sequencing Workflow for Accurate Qualitative and Quantitative Detection of Pathogens: a Case Study on SARS-CoV-2.

Carryover contamination during amplicon sequencing workflow (AMP-Seq) put the accuracy of the high-throughput detection for pathogens at risk. The purpose of this study is to develop a carryover contaminations-controlled AMP-Seq (ccAMP-Seq) workflow to enable accurate qualitative and quantitative detection for pathogens. By using the AMP-Seq workflow to detect SARS-CoV-2, Aerosols, reagents and pipettes were identified as potential sources of contaminations and ccAMP-Seq was then developed. ccAMP-Seq used filter tips and physically isolation of experimental steps to avoid cross contamination, synthetic DNA spike-ins to compete with contaminations and quantify SARS-CoV-2, dUTP/uracil DNA glycosylase system to digest the carryover contaminations, and a new data analysis procedure to remove the sequencing reads from contaminations. Compared to AMP-Seq, the contamination level of ccAMP-Seq was at least 22-folds lower and the detection limit was also about an order of magnitude lower-as low as one copy/reaction. By testing the dilution series of SARS-CoV-2 nucleic acid standard, ccAMP-Seq showed 100% sensitivity and specificity. The high sensitivity of ccAMP-Seq was further confirmed by the detection of SARS-CoV-2 from 62 clinical samples. The consistency between qPCR and ccAMP-Seq was 100% for all the 53 qPCR-positive clinical samples. Seven qPCR-negative clinical samples were found to be positive by ccAMP-Seq, which was confirmed by extra qPCR tests on subsequent samples from the same patients. This study presents a carryover contamination-controlled, accurate qualitative and quantitative amplicon sequencing workflow that addresses the critical problem of pathogen detection for infectious diseases. IMPORTANCE Accuracy, a key indicator of pathogen detection technology, is compromised by carryover contamination in the amplicon sequencing workflow. Taking the detection of SARS-CoV-2 as case, this study presents a new carryover contamination-controlled amplicon sequencing workflow. The new workflow significantly reduces the degree of contamination in the workflow, thereby significantly improving the accuracy and sensitivity of the SARS-CoV-2 detection and empowering the ability of quantitative detection. More importantly, the use of the new workflow is simple and economical. Therefore, the results of this study can be easily applied to other microorganism, which has great significance for improving the detection level of microorganism.

Identification of SARS-CoV-2 variants in wastewater using targeted amplicon sequencing during a low COVID-19 prevalence period in Japan.

Wastewater-based epidemiology is expected to be able to identify SARS-CoV-2 variants at an early stage via next-generation sequencing. In the present study, we developed a highly sensitive amplicon sequencing method targeting the spike gene of SARS-CoV-2, which allows for sequencing viral genomes from wastewater containing a low amount of virus. Primers were designed to amplify a relatively long region (599 bp) around the receptor-binding domain in the SARS-CoV-2 spike gene, which could distinguish initial major variants of concern. To validate the methodology, we retrospectively analyzed wastewater samples collected from a septic tank installed in a COVID-19 quarantine facility between October and December 2020. The relative abundance of D614G mutant in SARS-CoV-2 genomes in the facility wastewater increased from 47.5 % to 83.1 % during the study period. The N501Y mutant, which is the characteristic mutation of the Alpha-like strain, was detected from wastewater collected on December 24, 2020, which agreed with the fact that a patient infected with the Alpha-like strain was quarantined in the facility on this date. We then analyzed archived municipal wastewater samples collected between November 2020 and January 2021 that contained low SARS-CoV-2 concentrations ranging from 0.23 to 0.43 copies/qPCR reaction (corresponding to 3.30 to 4.15 log10 copies/L). The targeted amplicon sequencing revealed that the Alpha-like variant with D614G and N501Y mutations was present in municipal wastewater collected on December 4, 2020 and later, suggesting that the variant had already spread in the community before its first clinical confirmation in Japan on December 25, 2020. These results demonstrate that targeted amplicon sequencing of wastewater samples is a powerful surveillance tool applicable to low COVID-19 prevalence periods and may contribute to the early detection of emerging variants.

Association of Angiotensin Converting Enzyme 2 (ACE2) Gene Polymorphisms with Disease Severity in Indian Covid-19 Patients: A Next-gen Sequencing Approach

The clinical picture of COVID-19 ranges from asymptomatic to mild, moderate or severe disease sometimes leading to death. Differences in the interaction between SARS-CoV-2 Spike (S) protein and angiotensin converting enzyme 2 (ACE2) protein may lead to differences in disease severity. We studied whether ACE2 polymorphisms are associated with disease severity and outcome. We recruited 114 patients between July 2020 - March 2022 confirmed positive by RTPCR for COVID-19 with different degrees of severity (21 mild, 29 moderate, 34 severe, 30 death) and 30 controls (10 non-vaccinated+ 20 vaccinated) who were RT-PCR negative inspite of high-risk contact. Next-gen sequencing was done on MiSeq (Illumina) using amplicon-based targeted sequencing approach using a custom-designed panel to sequence all the exons of ACE2 gene. SPSS ver.26 was used for analysis. The following ACE2 variants were identified on the Local Run Manager (LRM) software from Illumina: (i) rs2285666 (c.439+4G>A) splice region variant, in controls (60%) and Patients (45.8%), (ii) rs4646140 (c.802+24G>A) intronic variant in 4/114 patients and 1/30 controls, (iii) rs41303171 ( c.2158A>G) missense variant in 2/114 patients, (iv) rs536749578 (c.2114+9T>C) intron variant, (v) rs763994205 (c.868A>C) missense variant and (vi) rs7595907 (c.656G>A) missense variant in 1/114 patient each only. rs2285666 was observed in equal frequency ( 60%) in vaccinated and non-vaccinated controls. rs2285666 was observed amongst different severity groups: Mild (80.95%), Moderate (37.93%), Severe (44.11%), and Death (56.67%) revealing association with disease severity, probably having a protective effect. However, these results need to be confirmed on larger sample sizes.

Emergence of BA.4/BA.5 Omicron Sub-lineages and Increased SARS-CoV-2 Incidence in Senegal

Background: The Omicron variant B.1.1.529 has led to a new dynamic in the COVID-19 pan-demic, with an increase in cases worldwide. Its rapid propagation favors the emergence of novel sub-lineages, including BA.4 and BA.5. The latter has shown increased transmissibility compared to other Omicron sub-lineages. In Senegal, the emergence of the Omicron variant in December 2021 characterized the triggering of a short and dense epidemiological wave that peaked at the end of February. This wave was followed by a period with a significant drop in the number of COVID-19 cases, but an upsurge in SARS-CoV-2 infection has been noted since mid-June. Objective(s): The purpose of this brief report is to give an update regarding the genomic situation of SARS-CoV-2 in Dakar during this phase of recrudescence of cases. Method(s): We performed amplicon-based SARS-CoV-2 sequencing on nasopharyngeal swab samples from declared COVID-19 patients and outbound travelers that tested positive. Result(s): Ongoing genomic surveillance activities showed that more than half of recent COVID-19 cases were due to the BA.4 and BA.5 sub-lineages that share two critical mutations associated with increased transmissibility and immune response escape. The circulation of recombinants between Omicron sub-lineages was also noted. Conclusion(s): Despite the lack of proven severity of BA.4 and BA.5 sub-lineages, their increased transmis-sibility causes a rapid spread of the virus, hence a surge in the number of cases. This rapid spread consti-tutes a greater risk of exposure for vulnerable patients. To tackle this issue, any increase in the number of cases must be monitored to support public health stakeholders. Therefore, genomic surveillance is an ever-essential element in managing this pandemic.Copyright © 2022 Bentham Science Publishers.

Analysis of the nasopharyngeal microbiome and respiratory pathogens in COVID-19 patients from Saudi Arabia.

BACKGROUND: Infection with SARS-CoV-2 may perturb normal microbiota, leading to secondary infections that can complicate the viral disease. The aim of this study was to probe the alteration of nasopharyngeal (NP) microbiota in the context of SARS-CoV-2 infection and obesity and to identify other respiratory pathogens among COVID-19 cases that may affect patients' health. METHODS: A total of 107 NP swabs, including 22 from control subjects and 85 from COVID-19 patients, were processed for 6S amplicon sequencing. The respiratory pathogens causing secondary infections were identified by RT-PCR assay, using a kit that contained specific primers and probes combinations to amplify 33 known respiratory pathogens. RESULTS: No significant (p > 0.05) difference was observed in the alpha and beta diversity analysis, but specific taxa differed significantly between the control and COVID-19 patient groups. Genera of Sphingomonas, Kurthia, Microbacterium, Methylobacterium, Brevibacillus, Bacillus, Acinetobacter, Lactococcus, and Haemophilus was significantly abundant (p < 0.05) in COVID-19 patients compared with a healthy control group. Staphylococcus was found in relatively high abundance (35.7 %) in the COVID-19 patient groups, mainly those treated with antibiotics. A relatively high percentage of Streptococcus was detected in COVID-19 patient groups with obesity or other comorbidities. Respiratory pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Salmonella species, along with Pneumocystis jirovecii fungal species were detected by RT-PCR mainly in the COVID-19 patients. Klebsiella pneumoniae was commonly found in most of the samples from the control and COVID-19 patients. Four COVID-19 patients had viral coinfections with human adenovirus, human rhinovirus, enterovirus, and human parainfluenza virus 1. CONCLUSIONS: Overall, no substantial difference was observed in the predominant NP bacterial community, but specific taxa were significantly changed between the healthy control and COVID-19 patients. Comparatively, an increased number of respiratory pathogens were identified in COVID-19 patients, and NP colonization by K. pneumoniae was probably occurring in the local population.

Gut and oral microbiota associations with viral mitigation behaviors during the COVID-19 pandemic.

Imposition of social and health behavior mitigations are important control measures in response to the coronavirus disease 2019 (COVID-19) pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Although postulated that these measures may impact the human microbiota including losses in diversity from heightened hygiene and social distancing measures, this hypothesis remains to be tested. Other impacts on the microbiota and host mental and physical health status associations from these measures are also not well-studied. Here we examine changes in stool and oral microbiota by analyzing 16S rRNA gene sequence taxonomic profiles from the same individuals during pre-pandemic (before March 2020) and early pandemic (May-November 2020) phases. During the early pandemic phase, individuals were also surveyed using questionnaires to report health histories, anxiety, depression, sleep and other lifestyle behaviors in a cohort of predominantly Caucasian adults (mean age = 61.5 years) with the majority reporting at least one underlying co-morbidity. We identified changes in microbiota (stool n = 288; oral n = 89) between pre-pandemic and early pandemic time points from the same subject and associated these differences with questionnaire responses using linear statistical models and hierarchical clustering of microbiota composition coupled to logistic regression. While a trend in loss of diversity was identified between pre-pandemic and early pandemic time points it was not statistically significant. Paired difference analyses between individuals identified fewer significant changes between pre-pandemic and early pandemic microbiota in those who reported fewer comorbidities. Cluster transition analyses of stool and saliva microbiota determined most individuals remained in the same cluster assignments from the pre-pandemic to early pandemic period. Individuals with microbiota that shifted in composition, causing them to depart a pre-pandemic cluster, reported more health issues and pandemic-associated worries. Collectively, our study identified that stool and saliva microbiota from the pre-pandemic to early pandemic periods largely exhibited ecological stability (especially stool microbiota) with most associations in loss of diversity or changes in composition related to more reported health issues and pandemic-associated worries. Longitudinal observational cohorts are necessary to monitor the microbiome in response to pandemics and changes in public health measures.

Intensity of sample processing methods impacts wastewater SARS-CoV-2 whole genome amplicon sequencing outcomes.

Wastewater SARS-CoV-2 surveillance has been deployed since the beginning of the COVID-19 pandemic to monitor the dynamics in virus burden in local communities. Genomic surveillance of SARS-CoV-2 in wastewater, particularly efforts aimed at whole genome sequencing for variant tracking and identification, are still challenging due to low target concentration, complex microbial and chemical background, and lack of robust nucleic acid recovery experimental procedures. The intrinsic sample limitations are inherent to wastewater and are thus unavoidable. Here, we use a statistical approach that couples correlation analyses to a random forest-based machine learning algorithm to evaluate potentially important factors associated with wastewater SARS-CoV-2 whole genome amplicon sequencing outcomes, with a specific focus on the breadth of genome coverage. We collected 182 composite and grab wastewater samples from the Chicago area between November 2020 to October 2021. Samples were processed using a mixture of processing methods reflecting different homogenization intensities (HA + Zymo beads, HA + glass beads, and Nanotrap), and were sequenced using one of the two library preparation kits (the Illumina COVIDseq kit and the QIAseq DIRECT kit). Technical factors evaluated using statistical and machine learning approaches include sample types, certain sample intrinsic features, and processing and sequencing methods. The results suggested that sample processing methods could be a predominant factor affecting sequencing outcomes, and library preparation kits was considered a minor factor. A synthetic SARS-CoV-2 RNA spike-in experiment was performed to validate the impact from processing methods and suggested that the intensity of the processing methods could lead to different RNA fragmentation patterns, which could also explain the observed inconsistency between qPCR quantification and sequencing outcomes. Overall, extra attention should be paid to wastewater sample processing (i.e., concentration and homogenization) for sufficient and good quality SARS-CoV-2 RNA for downstream sequencing.

Using Multiplex Amplicon PCR Technology to Efficiently and Timely Generate Rift Valley Fever Virus Sequence Data for Genomic Surveillance.

Rift Valley fever (RVF) is a febrile vector-borne disease endemic in Africa and continues to spread in new territories. It is a climate-sensitive disease mostly triggered by abnormal rainfall patterns. The disease is associated with high mortality and morbidity in both humans and livestock. RVF is caused by the Rift Valley fever virus (RVFV) of the genus Phlebovirus in the family Phenuiviridae. It is a tripartite RNA virus with three genomic segments: small (S), medium (M) and large (L). Pathogen genomic sequencing is becoming a routine procedure and a powerful tool for understanding the evolutionary dynamics of infectious organisms, including viruses. Inspired by the utility of amplicon-based sequencing demonstrated in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and Ebola, Zika and West Nile viruses, we report an RVFV sample preparation based on amplicon multiplex polymerase chain reaction (amPCR) for template enrichment and reduction of background host contamination. The technology can be implemented rapidly to characterize and genotype RVFV during outbreaks in a near-real-time manner. To achieve this, we designed 74 multiplex primer sets covering the entire RVFV genome to specifically amplify the nucleic acid of RVFV in clinical samples from an animal tissue. Using this approach, we demonstrate achieving complete RVFV genome coverage even from samples containing a relatively low viral load. We report the first primer scheme approach of generating multiplex primer sets for a tripartite virus which can be replicated for other segmented viruses.

Naso-oropharyngeal microbiome from breast cancer patients diagnosed with COVID-19.

Due to immunosuppressive cancer therapies, cancer patients diagnosed with COVID-19 have a higher chance of developing severe symptoms and present a higher mortality rate in comparison to the general population. Here we show a comparative analysis of the microbiome from naso-oropharyngeal samples of breast cancer patients with respect to SARS-CoV-2 status and identified bacteria associated with symptom severity. Total DNA of naso-oropharyngeal swabs from 74 women with or without breast cancer, positive or negative for SARS-CoV-2 were PCR-amplified for 16S-rDNA V3 and V4 regions and submitted to massive parallel sequencing. Sequencing data were analyzed with QIIME2 and taxonomic identification was performed using the q2-feature-classifier QIIME2 plugin, the Greengenes Database, and amplicon sequence variants (ASV) analysis. A total of 486 different bacteria were identified. No difference was found in taxa diversity between sample groups. Cluster analysis did not group the samples concerning SARS-CoV-2 status, breast cancer diagnosis, or symptom severity. Three taxa (Pseudomonas, Moraxella, and Klebsiella,) showed to be overrepresented in women with breast cancer and positive for SARS-CoV-2 when compared to the other women groups, and five bacterial groups were associated with COVID-19 severity among breast cancer patients: Staphylococcus, Staphylococcus epidermidis, Scardovia, Parasegitibacter luogiensis, and Thermomonas. The presence of Staphylococcus in COVID-19 breast cancer patients may possibly be a consequence of nosocomial infection.

In silico evaluation of the impact of Omicron variant of concern sublineage BA.4 and BA.5 on the sensitivity of RT-qPCR assays for SARS-CoV-2 detection using whole genome sequencing.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VoC) Omicron (B.1.1.529) has rapidly spread around the world, presenting a new threat to global public human health. Due to the large number of mutations accumulated by SARS-CoV-2 Omicron, concerns have emerged over potentially reduced diagnostic accuracy of reverse-transcription polymerase chain reaction (RT-qPCR), the gold standard diagnostic test for diagnosing coronavirus disease 2019 (COVID-19). Thus, we aimed to assess the impact of the currently endemic Omicron sublineages BA.4 and BA.5 on the integrity and sensitivity of RT-qPCR assays used for coronavirus disease 2019 (COVID-19) diagnosis via in silico analysis. We employed whole genome sequencing data and evaluated the potential for false negatives or test failure due to mismatches between primers/probes and the Omicron VoC viral genome. METHODS: In silico sensitivity of 12 RT-qPCR tests (containing 30 primers and probe sets) developed for detection of SARS-CoV-2 reported by the World Health Organization (WHO) or available in the literature, was assessed for specifically detecting SARS-CoV-2 Omicron BA.4 and BA.5 sublineages, obtained after removing redundancy from publicly available genomes from National Center for Biotechnology Information (NCBI) and Global Initiative on Sharing Avian Influenza Data (GISAID) databases. Mismatches between amplicon regions of SARS-CoV-2 Omicron VoC and primers and probe sets were evaluated, and clustering analysis of corresponding amplicon sequences was carried out. RESULTS: From the 1164 representative SARS-CoV-2 Omicron VoC BA.4 sublineage genomes analyzed, a substitution in the first five nucleotides (C to T) of the amplicon's 3'-end was observed in all samples resulting in 0% sensitivity for assays HKUnivRdRp/Hel (mismatch in reverse primer) and CoremCharite N (mismatch in both forward and reverse primers). Due to a mismatch in the forward primer's 5'-end (3-nucleotide substitution, GGG to AAC), the sensitivity of the ChinaCDC N assay was at 0.69%. The 10 nucleotide mismatches in the reverse primer resulted in 0.09% sensitivity for Omicron sublineage BA.4 for Thai N assay. Of the 1926 BA.5 sublineage genomes, HKUnivRdRp/Hel assay also had 0% sensitivity. A sensitivity of 3.06% was observed for the ChinaCDC N assay because of a mismatch in the forward primer's 5'-end (3-nucleotide substitution, GGG to AAC). Similarly, due to the 10 nucleotide mismatches in the reverse primer, the Thai N assay's sensitivity was low at 0.21% for sublineage BA.5. Further, eight assays for BA.4 sublineage retained high sensitivity (more than 97%) and 9 assays for BA.5 sublineage retained more than 99% sensitivity. CONCLUSION: We observed four assays (HKUnivRdRp/Hel, ChinaCDC N, Thai N, CoremCharite N) that could potentially result in false negative results for SARS-CoV-2 Omicron VoCs BA.4 and BA.5 sublineages. Interestingly, CoremCharite N had 0% sensitivity for Omicron Voc BA.4 but 99.53% sensitivity for BA.5. In addition, 66.67% of the assays for BA.4 sublineage and 75% of the assays for BA.5 sublineage retained high sensitivity. Further, amplicon clustering and additional substitution analysis along with sensitivity analysis could be used for the modification and development of RT-qPCR assays for detecting SARS-CoV-2 Omicron VoC sublineages.

Comparative Analysis of Library Preparation Approaches for SARS-CoV-2 Genome Sequencing on the Illumina MiSeq Platform.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for over two years of the COVID-19 pandemic and a global health emergency. Genomic surveillance plays a key role in overcoming the ongoing COVID-19 pandemic despite its relative successive waves and the continuous emergence of new variants. Many technological approaches are currently applied for the whole genome sequencing (WGS) of SARS-CoV-2. They differ in key stages of the process, and they feature some differences in genomic coverage, sequencing depth, and in the accuracy of variant-calling options. In this study, three different protocols for SARS-CoV-2 WGS library construction are compared: an amplicon-based protocol with a commercial primer panel; an amplicon-based protocol with a custom panel; and a hybridization capture protocol. Specific differences in sequencing depth and genomic coverage as well as differences in SNP number were found. The custom panel showed suitable results and a predictable output applicable for the epidemiological surveillance of SARS-CoV-2 variants.

Molecular Biology of SARS-CoV-2 and its Evolution within the Princeton University Campus Community

Background. SARS-CoV-2, a novel and highly pathogenic coronavirus, has caused unprecedented global disruption following its introduction into the human population. Beginning in January 2021, a NJ university invited all students to campus and initiated an asymptomatic testing protocol using weekly to twice-weekly PCR-based detection of human saliva samples. RNA extracted from PCR-positive human saliva samples was sequenced for surveillance purposes. Methods. Positive samples were submitted for RNA-Seq analysis (ARTIC amplicon sequencing protocol, Illumina MiSeq) and analyzed using Nextclade and USHER (comparison data from GISAID). Using sequencing data, the evolution, transmission, and emergence of SARS-CoV-2 variants were monitored over time in the campus community. Using sequencing data from NY, PA, and NJ in combination with University data, we performed an IQ-TREE based phylogenetic analysis. Results. Analyzing sequencing data of 1,011 University positive samples we demonstrate that SARS-CoV-2 variants Delta (B.1.617.2) and Omicron (BA.1 and BA.2) were first to emerge following widespread vaccination and, quickly, became predominant. These trends witnessed on campus preceded those same variants emerging in New Jersey, providing evidence of local campus spread distinct from the state-wide pandemic. The analysis of 2,359 total sequences from NY, PA, and NJ in combination with University data, provided evidence of the SARS-CoV-2 transmission chain on campus evolving from out-of-state (January 2021) to local (January 2022) spread over one year of the virus circulating within the community at large. Upon performing a Ct value analysis of 2,822 Princeton University sequences, no significant differences were discovered between N gene Ct values when grouped by age or vaccination status. However, there were significant differences in Ct values between strains. The Emergence of SARS-CoV-2 Variants at Princeton University This plot represents the emergence of SARS-CoV-2 clades at Princeton University, organized by Nextstrain clade and displayed as a proportion out of one. Dates of sample collection range from January 25, 2021, to March 1, 2022. X-axis represents SARS-CoV-2 sample test date (grouped by month);Y-axis represents the count per day organized by Nextstrain clade. Conclusion. Sequencing of positive SARS-CoV-2 samples from population screening of a highly vaccinated University campus community allowed the detection of emergence of new variants that became predominant on campus irrespective of the circulation of variants in the surrounding area.