Tracing Transmission of Sin Nombre Virus and Discovery of Infection in Multiple Rodent Species.

Sin Nombre orthohantavirus (SNV), a negative-sense, single-stranded RNA virus that is carried and transmitted by the North American deer mouse Peromyscus maniculatus, can cause infection in humans through inhalation of aerosolized excreta from infected rodents. This infection can lead to hantavirus cardiopulmonary syndrome (HCPS), which has an ∼36% case-fatality rate. We used reverse transcriptase quantitative PCR (RT-qPCR) to confirm SNV infection in a patient and identified SNV in lung tissues in wild-caught rodents from potential sites of exposure. Using viral whole-genome sequencing (WGS), we identified the likely site of transmission and discovered SNV in multiple rodent species not previously known to carry the virus. Here, we report, for the first time, the use of SNV WGS to pinpoint a likely site of human infection and identify SNV simultaneously in multiple rodent species in an area of known host-to-human transmission. These results will impact epidemiology and infection control for hantaviruses by tracing zoonotic transmission and investigating possible novel host reservoirs. IMPORTANCE Orthohantaviruses cause severe disease in humans and can be lethal in up to 40% of cases. Sin Nombre orthohantavirus (SNV) is the main cause of hantavirus disease in North America. In this study, we sequenced SNV from an infected patient and wild-caught rodents to trace the location of infection. We also discovered SNV in rodent species not previously known to carry SNV. These studies demonstrate for the first time the use of virus sequencing to trace the transmission of SNV and describe infection in novel rodent species.

Viral infection and allergy status impact severity of asthma symptoms in children with asthma exacerbations.

BACKGROUND: Although viral infection is known to be associated with asthma exacerbations, prior research has not identified reliable predictors of acute symptom severity in virus-related asthma exacerbations (VRAEs). OBJECTIVE: To determine the effect of asthma control and viral infection on the severity of current illness and evaluate biomarkers related to acute symptoms during asthma exacerbations. METHODS: We prospectively enrolled 120 children with physician-diagnosed asthma and current wheezing who presented to Arkansas Children's Hospital emergency department. The asthma control test (ACT) stratified controlled (ACT > 19) and uncontrolled (ACT ≤ 19) asthma, whereas pediatric respiratory symptom scores evaluated symptoms. Nasopharyngeal swabs were obtained for viral analysis, and inflammatory mediators were evaluated by nasal filter paper and Luminex assays. RESULTS: There were 33 children with controlled asthma and 87 children with uncontrolled asthma. In those with uncontrolled asthma, 77% were infected with viruses during VRAE compared with 58% of those with controlled asthma. Uncontrolled subjects with VRAE had more acute symptoms compared with the controlled subjects with VRAE or uncontrolled subjects without a virus. The uncontrolled subjects with VRAE and allergy had the highest acute symptom scores (3.363 point pediatric respiratory symptom; P = .04). Children with asthma with higher symptom scores had more periostin (P = .02). CONCLUSION: Detection of respiratory viruses is frequent in those with uncontrolled asthma. Uncontrolled subjects with viruses have more acute symptoms during exacerbations, especially in those with allergy. Periostin was highest in subjects with the most acute symptoms, regardless of control status. Taken together, these data imply synergy between viral infection and allergy in subjects with uncontrolled asthma when considering acute asthma symptoms and nasal inflammation during an exacerbation of asthma.

Complete genome sequence of a KI polyomavirus isolated from an otherwise healthy child with severe lower respiratory tract infection.

Unbiased, deep sequencing of a nasal specimen from an otherwise healthy 13-month-old boy hospitalized in intensive care revealed high gene expression and the complete genome of a novel isolate of KI polyomavirus (KIPyV). Further investigation detected minimal gene expression of additional viruses, suggesting that KIPyV was potentially the causal agent. Analysis of the complete genome of isolate NMKI001 revealed it is different from all previously reported genomes and contains two amino acid differences as compared to the closest virus isolate, Stockholm 380 (EF127908). J. Med. Virol. 89:926-930, 2017. © 2016 Wiley Periodicals, Inc.

Non-autophagy Role of Atg5 and NBR1 in Unconventional Secretion of IL-12 Prevents Gut Dysbiosis and Inflammation.

Intestinal myeloid cells play a critical role in balancing intestinal homeostasis and inflammation. Here, we report that expression of the autophagy-related 5 [Atg5] protein in myeloid cells prevents dysbiosis and excessive intestinal inflammation by limiting IL-12 production. Mice with a selective genetic deletion of Atg5 in myeloid cells [Atg5ΔMye] showed signs of dysbiosis preceding colitis, and exhibited severe intestinal inflammation upon colitis induction that was characterised by increased IFNγ production. The exacerbated colitis was linked to excess IL-12 secretion from Atg5-deficient myeloid cells and gut dysbiosis. Restoration of the intestinal microbiota or genetic deletion of IL-12 in Atg5ΔMye mice attenuated the intestinal inflammation in Atg5ΔMye mice. Additionally, Atg5 functions to limit IL-12 secretion through modulation of late endosome [LE] acidity. Last, the autophagy cargo receptor NBR1, which accumulates in Atg5-deficient cells, played a role by delivering IL-12 to LE. In summary, Atg5 expression in intestinal myeloid cells acts as an anti-inflammatory brake to regulate IL-12, thus preventing dysbiosis and uncontrolled IFNγ-driven intestinal inflammation.

Emergence in late 2020 of multiple lineages of SARS-CoV-2 Spike protein variants affecting amino acid position 677.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S) plays critical roles in host cell entry. Non-synonymous substitutions affecting S are not uncommon and have become fixed in a number of SARS-CoV-2 lineages. A subset of such mutations enable escape from neutralizing antibodies or are thought to enhance transmission through mechanisms such as increased affinity for the cell entry receptor, angiotensin-converting enzyme 2 (ACE2). Independent genomic surveillance programs based in New Mexico and Louisiana contemporaneously detected the rapid rise of numerous clade 20G (lineage B.1.2) infections carrying a Q677P substitution in S. The variant was first detected in the US on October 23, yet between 01 Dec 2020 and 19 Jan 2021 it rose to represent 27.8% and 11.3% of all SARS-CoV-2 genomes sequenced from Louisiana and New Mexico, respectively. Q677P cases have been detected predominantly in the south central and southwest United States; as of 03 Feb 2021, GISAID data show 499 viral sequences of this variant from the USA. Phylogenetic analyses revealed the independent evolution and spread of at least six distinct Q677H sub-lineages, with first collection dates ranging from mid-August to late November 2020. Four 677H clades from clade 20G (B.1.2), 20A (B.1.234), and 20B (B.1.1.220, and B.1.1.222) each contain roughly 100 or fewer sequenced cases, while a distinct pair of clade 20G clusters are represented by 754 and 298 cases, respectively. Although sampling bias and founder effects may have contributed to the rise of S:677 polymorphic variants, the proximity of this position to the polybasic cleavage site at the S1/S2 boundary are consistent with its potential functional relevance during cell entry, suggesting parallel evolution of a trait that may confer an advantage in spread or transmission. Taken together, our findings demonstrate simultaneous convergent evolution, thus providing an impetus to further evaluate S:677 polymorphisms for effects on proteolytic processing, cell tropism, and transmissibility.

Complete Genome Sequences of Four Novel Human Coronavirus OC43 Isolates Associated with Severe Acute Respiratory Infection.

We report here the complete genome sequences of four human coronavirus (HCoV) OC43 isolates generated using targeted viral nucleic acid capture and next-generation sequencing; the isolates were collected in New Mexico and Arkansas, USA, in February (HCoV-OC43/USA/TCNP_0070/2016) and March (HCoV-OC43/USA/ACRI_0052/2016) 2016 and January 2017 (HCoV-OC43/USA/TCNP_00204/2017 and HCoV-OC43/USA/TCNP_00212/2017).

The role of next generation sequencing in infection prevention in human parainfluenza virus 3 infections in immunocompromised patients.

BACKGROUND: Respiratory viral infections are a significant problem in patients with hematologic malignancies. We report a cluster of HPIV 3 infections in our myeloma patients, and describe the utility of next generation sequencing (NGS) to identify transmission linkages which can assist in infection prevention. OBJECTIVES: To evaluate the utility of NGS to track respiratory viral infection outbreaks and delineate between community acquired and nosocomial infections in our cancer units. STUDY DESIGN: Retrospective chart review conducted at a single site. All patients diagnosed with multiple myeloma who developed symptoms suggestive of upper respiratory tract infection (URTI) or lower respiratory tract infection (LRTI) along with a respiratory viral panel (RVP) test positive for HPIV 3 between April 1, 2016, to June 30, 2016, were included. Sequencing was performed on the Illumina MiSeq™. To gain understanding regarding community strains of HPIV 3 during the same season, we also performed NGS on HPIV3 strains isolated from pediatric cases. RESULTS: We saw a cluster of 13 cases of HPIV3 infections in the myeloma unit. Using standard epidemiologic criteria, 3 cases were considered community acquired, 7 cases developed infection during treatment in the cancer infusion center, while an additional 3 developed infections during hospital stay. Seven patients required hospitalization for a median duration of 20days. NGS enabled sensitive discrimination of the relatedness of the isolates obtained during the outbreak and provided evidence for source of transmission. Two hospital onset infections could be tracked to an index case; the genome sequences of HPIV 3 strains from these 3 patients only differed by a single nucleotide. CONCLUSIONS: NGS offers a significantly higher discriminatory value as an epidemiologic tool, and can be used to gather real-time information and identification of transmission linkages to assist in infection prevention in immunocompromised patients.

Complete Genome Sequence of a Novel Human WU Polyomavirus Isolate Associated with Acute Respiratory Infection.

We report here the complete genome sequence of a WU polyomavirus (WUPyV) isolate, NM040708, collected from a patient with an acute respiratory infection in New Mexico. The double-stranded DNA (dsDNA) genome of NM040708 is 5,229 bp in length and differs from the WUPyV reference with accession no. NC_009539 by 6 nucleotides and 2 amino acids.