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Microbiology Spectrum Aug 2022Mammarenaviruses establish a persistent infection in their rodent and bat hosts, and the evidence suggests that reptarenaviruses and hartmaniviruses found in captive...
Mammarenaviruses establish a persistent infection in their rodent and bat hosts, and the evidence suggests that reptarenaviruses and hartmaniviruses found in captive snakes act similarly. In snakes, reptarenaviruses cause boid inclusion body disease (BIBD), which is often associated with secondary infections. Snakes with BIBD usually carry more than a single pair of reptarenavirus S and L segments and occasionally demonstrate hartmanivirus coinfection. Here, we reported the generation of cell lines persistently infected with a single or two reptarenavirus(es) and a cell line with persistent reptarenavirus-hartmanivirus coinfection. By RT-PCR we demonstrated that the amount of viral RNA within the persistently infected cells remains at levels similar to those observed following initial infection. Using antibodies against the glycoproteins (GPs) and nucleoprotein (NP) of reptarenaviruses, we studied the levels of viral protein in cells passaged 10 times after the original inoculation and observed that the expression of GPs declines dramatically during persistent infection, unlike the expression of NP. Immunofluorescence (IF) staining served to demonstrate differences in the distribution of NP within the persistently infected compared to freshly infected cells. IF staining of cells inoculated with the viruses secreted from the persistently infected cell lines produced similar NP staining compared to cells infected with a traditionally passaged virus, suggesting that the altered NP expression pattern of persistently infected cells does not relate to changes in the virus. The cell cultures described herein can serve as tools for studying the coinfection and superinfection interplay between reptarenaviruses and studying the BIBD pathogenesis mechanisms. Mammarenaviruses cause a persistent infection in their natural rodent and bat hosts. Reptarenaviruses cause boid inclusion body disease (BIBD) in constrictor snakes, but it is unclear whether snakes are the natural host of these viruses. In this study, we showed that reptarenaviruses established a persistent infection in cultured Boa constrictor cells and that the persistently infected cells continued to produce infectious virus. Our results showed that persistent infection results from subsequent passaging of cells inoculated with a single reptarenavirus, two reptarenaviruses, or even when inoculating the cells with reptarenavirus and hartmanivirus (another arenavirus genus). The results further suggested that coinfection would not result in overt competition between the different reptarenaviruses, thus helping to explain the frequent reptarenavirus coinfections in snakes with BIBD. The established cell culture models of persistent infection could help to elucidate the role of coinfection and superinfection and potential immunosuppression as the pathogenic mechanisms behind BIBD.
Topics: Animals; Arenaviridae; Boidae; Cell Line; Chiroptera; Coinfection; Superinfection
PubMed: 35862992
DOI: 10.1128/spectrum.01585-22 -
Journal of Virology Sep 2022Reassortment, or genome segment exchange, increases diversity among viruses with segmented genomes. Previous studies on the limitations of reassortment have largely...
Reassortment, or genome segment exchange, increases diversity among viruses with segmented genomes. Previous studies on the limitations of reassortment have largely focused on parental incompatibilities that restrict generation of viable progeny. However, less is known about whether factors intrinsic to virus replication influence reassortment. Mammalian orthoreovirus (reovirus) encapsidates a segmented, double-stranded RNA (dsRNA) genome, replicates within cytoplasmic factories, and is susceptible to host antiviral responses. We sought to elucidate the influence of infection multiplicity, timing, and compartmentalized replication on reovirus reassortment in the absence of parental incompatibilities. We used an established post-PCR genotyping method to quantify reassortment frequency between wild-type and genetically barcoded type 3 reoviruses. Consistent with published findings, we found that reassortment increased with infection multiplicity until reaching a peak of efficient genome segment exchange during simultaneous coinfection. However, reassortment frequency exhibited a substantial decease with increasing time to superinfection, which strongly correlated with viral transcript abundance. We hypothesized that physical sequestration of viral transcripts within distinct virus factories or superinfection exclusion also could influence reassortment frequency during superinfection. Imaging revealed that transcripts from both wild-type and barcoded viruses frequently co-occupied factories, with superinfection time delays up to 16 h. Additionally, primary infection progressively dampened superinfecting virus transcript levels with greater time delay to superinfection. Thus, in the absence of parental incompatibilities and with short times to superinfection, reovirus reassortment proceeds efficiently and is largely unaffected by compartmentalization of replication and superinfection exclusion. However, reassortment may be limited by superinfection exclusion with greater time delays to superinfection. Reassortment, or genome segment exchange between viruses, can generate novel virus genotypes and pandemic virus strains. For viruses to reassort their genome segments, they must replicate within the same physical space by coinfecting the same host cell. Even after entry into the host cell, many viruses with segmented genomes synthesize new virus transcripts and assemble and package their genomes within cytoplasmic replication compartments. Additionally, some viruses can interfere with subsequent infection of the same host or cell. However, spatial and temporal influences on reassortment are only beginning to be explored. We found that infection multiplicity and transcript abundance are important drivers of reassortment during coinfection and superinfection, respectively, for reovirus, which has a segmented, double-stranded RNA genome. We also provide evidence that compartmentalization of transcription and packaging is unlikely to influence reassortment, but the length of time between primary and subsequent reovirus infection can alter reassortment frequency.
Topics: Animals; Coinfection; Genome, Viral; RNA, Double-Stranded; Reassortant Viruses; Reoviridae; Superinfection
PubMed: 36094315
DOI: 10.1128/jvi.00910-22 -
Current Problems in Diagnostic Radiology 2022New challenges in imaging and management of COVID-19 pneumonia emerge as the pandemic continues across the globe. These arise not only due to the COVID-19 pneumonia but... (Review)
Review
New challenges in imaging and management of COVID-19 pneumonia emerge as the pandemic continues across the globe. These arise not only due to the COVID-19 pneumonia but also related to various superinfections and co-infections. Limited use of bronchoscopic and other aerosol generating procedures to obtain representative lower respiratory samples from these patient groups for accurate identification of organism, increases the responsibility of radiologists in suggesting the most likely cause of secondary infection. Imaging features of many of these infections overlap with features of COVID-19 pneumonia. In this review, we highlight imaging findings that can aid in the diagnosis of superinfections and co-infections in patients with COVID-19 pneumonia, and also help in predicting the likely causative organism.
Topics: COVID-19; Coinfection; Humans; Pandemics; SARS-CoV-2; Superinfection
PubMed: 34903396
DOI: 10.1067/j.cpradiol.2021.09.009 -
Gut Jun 2023Chronic HBV/HDV infections are a major cause of liver cancer. Current treatments can only rarely eliminate HBV and HDV. Our previously developed preS1-HDAg immunotherapy...
OBJECTIVE
Chronic HBV/HDV infections are a major cause of liver cancer. Current treatments can only rarely eliminate HBV and HDV. Our previously developed preS1-HDAg immunotherapy could induce neutralising antibodies to HBV in vivo and raise HBV/HDV-specific T-cells. Here, we further investigate if a heterologous prime-boost strategy can circumvent T-cell tolerance and preclude HDV superinfection in vivo.
DESIGN
A DNA prime-protein boost strategy was evaluated for immunogenicity in mice and rabbits. Its ability to circumvent T-cell tolerance was assessed in immunocompetent hepatitis B surface antigen (HBsAg)-transgenic mice. Neutralisation of HBV and HDV was evaluated both in vitro and in immunodeficient human-liver chimeric mice upon adoptive transfer.
RESULTS
The prime-boost strategy elicits robust HBV/HDV-specific T-cells and preS1-antibodies that can effectively prevent HBV and HDV (co-)infection in vitro and in vivo. In a mouse model representing the chronic HBsAg carrier state, active immunisation primes high levels of preS1-antibodies and HDAg-specific T-cells. Moreover, transfer of vaccine-induced antibodies completely protects HBV-infected human-liver chimeric mice from HDV superinfection.
CONCLUSION
The herein described preS1-HDAg immunotherapy is shown to be immunogenic and vaccine-induced antibodies are highly effective at preventing HBV and HDV (super)infection both in vitro and in vivo. Our vaccine can complement current and future therapies for the control of chronic HBV and HDV infection.
Topics: Humans; Mice; Animals; Rabbits; Hepatitis delta Antigens; Hepatitis B Surface Antigens; Hepatitis B, Chronic; Superinfection; Hepatitis Delta Virus; Hepatitis B; Hepatitis B virus; Antibodies, Viral; Mice, Transgenic
PubMed: 35977815
DOI: 10.1136/gutjnl-2022-327216 -
PloS One 2021The recovery of other pathogens in patients with SARS-CoV-2 infection has been reported, either at the time of a SARS-CoV-2 infection diagnosis (co-infection) or... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The recovery of other pathogens in patients with SARS-CoV-2 infection has been reported, either at the time of a SARS-CoV-2 infection diagnosis (co-infection) or subsequently (superinfection). However, data on the prevalence, microbiology, and outcomes of co-infection and superinfection are limited. The purpose of this study was to examine the occurrence of co-infections and superinfections and their outcomes among patients with SARS-CoV-2 infection.
PATIENTS AND METHODS
We searched literature databases for studies published from October 1, 2019, through February 8, 2021. We included studies that reported clinical features and outcomes of co-infection or superinfection of SARS-CoV-2 and other pathogens in hospitalized and non-hospitalized patients. We followed PRISMA guidelines, and we registered the protocol with PROSPERO as: CRD42020189763.
RESULTS
Of 6639 articles screened, 118 were included in the random effects meta-analysis. The pooled prevalence of co-infection was 19% (95% confidence interval [CI]: 14%-25%, I2 = 98%) and that of superinfection was 24% (95% CI: 19%-30%). Pooled prevalence of pathogen type stratified by co- or superinfection were: viral co-infections, 10% (95% CI: 6%-14%); viral superinfections, 4% (95% CI: 0%-10%); bacterial co-infections, 8% (95% CI: 5%-11%); bacterial superinfections, 20% (95% CI: 13%-28%); fungal co-infections, 4% (95% CI: 2%-7%); and fungal superinfections, 8% (95% CI: 4%-13%). Patients with a co-infection or superinfection had higher odds of dying than those who only had SARS-CoV-2 infection (odds ratio = 3.31, 95% CI: 1.82-5.99). Compared to those with co-infections, patients with superinfections had a higher prevalence of mechanical ventilation (45% [95% CI: 33%-58%] vs. 10% [95% CI: 5%-16%]), but patients with co-infections had a greater average length of hospital stay than those with superinfections (mean = 29.0 days, standard deviation [SD] = 6.7 vs. mean = 16 days, SD = 6.2, respectively).
CONCLUSIONS
Our study showed that as many as 19% of patients with COVID-19 have co-infections and 24% have superinfections. The presence of either co-infection or superinfection was associated with poor outcomes, including increased mortality. Our findings support the need for diagnostic testing to identify and treat co-occurring respiratory infections among patients with SARS-CoV-2 infection.
Topics: Bacterial Infections; COVID-19; Coinfection; Hospitalization; Humans; Mycoses; Prevalence; SARS-CoV-2; Superinfection; Treatment Outcome; Virus Diseases
PubMed: 33956882
DOI: 10.1371/journal.pone.0251170 -
Pneumonia (Nathan Qld.) Apr 2021It has been recognised for a considerable time-period, that viral respiratory infections predispose patients to bacterial infections, and that these co-infections have a... (Review)
Review
BACKGROUND
It has been recognised for a considerable time-period, that viral respiratory infections predispose patients to bacterial infections, and that these co-infections have a worse outcome than either infection on its own. However, it is still unclear what exact roles co-infections and/or superinfections play in patients with COVID-19 infection.
MAIN BODY
This was an extensive review of the current literature regarding co-infections and superinfections in patients with SARS-CoV-2 infection. The definitions used were those of the Centers for Disease Control and Prevention (US), which defines coinfection as one occurring concurrently with the initial infection, while superinfections are those infections that follow on a previous infection, especially when caused by microorganisms that are resistant, or have become resistant, to the antibiotics used earlier. Some researchers have envisioned three potential scenarios of bacterial/SARS-CoV-2 co-infection; namely, secondary SARS-CoV-2 infection following bacterial infection or colonisation, combined viral/bacterial pneumonia, or secondary bacterial superinfection following SARS-CoV-2. There are a myriad of published articles ranging from letters to the editor to systematic reviews and meta-analyses describing varying ranges of co-infection and/or superinfection in patients with COVID-19. The concomitant infections described included other respiratory viruses, bacteria, including mycobacteria, fungi, as well as other, more unusual, pathogens. However, as will be seen in this review, there is often not a clear distinction made in the literature as to what the authors are referring to, whether true concomitant/co-infections or superinfections. In addition, possible mechanisms of the interactions between viral infections, including SARS-CoV-2, and other infections, particularly bacterial infections are discussed further. Lastly, the impact of these co-infections and superinfections in the severity of COVID-19 infections and their outcome is also described.
CONCLUSION
The current review describes varying rates of co-infections and/or superinfections in patients with COVID-19 infections, although often a clear distinction between the two is not clear in the literature. When they occur, these infections appear to be associated with both severity of COVID-19 as well as poorer outcomes.
PubMed: 33894790
DOI: 10.1186/s41479-021-00083-w -
European Journal of Ophthalmology Nov 2022Moraxella nonliquefaciens () is a low pathogenicity microorganism, which rarely causes ocular infections, unless there is a predisposing factor. The main clinical...
INTRODUCTION
Moraxella nonliquefaciens () is a low pathogenicity microorganism, which rarely causes ocular infections, unless there is a predisposing factor. The main clinical manifestation of ocular infections is endophthalmitis and only five cases of corneal infection have been reported. This work shows an update in corneal infections, and the first reported case of keratitis due to superinfecting herpes simplex infection.
CASE REPORT
A 84-year old woman with worsening of her herpes simplex keratitis, diagnosed, and treated 2 days before. The slit lamp showed deep paracentral infiltrate and hypopyon. A corneal sample was collected for culture prior to initiation of empiric antibiotic therapy with vancomycin and ceftazidime fortified, oral acyclovir, and cyclopentolate. The strain was identified as and topical antibiotic therapy was adjusted to ciprofloxacin and ceftazidime. After 2 weeks, the epithelial defect and the infiltrate were resolved and prednisolone was added to the regimen. As the corneal oedema and neovascularization decreased, acyclovir, and prednisolone were slowly tapered. About 4 months later, the visual outcome was 20/50 and the ophthalmic examination showed a clear cornea with a paracentral leucoma.
CONCLUSION
Keratitis due to is rare and should be suspected in patients with local predisposing factors such as corneal damage or previous corneal infection. Prompt and appropriate combined treatment for the predisposing lesions and the keratitis may improve the prognosis and avoid a more aggressive approach.
Topics: Acyclovir; Aged, 80 and over; Anti-Bacterial Agents; Ceftazidime; Ciprofloxacin; Cyclopentolate; Female; Humans; Keratitis, Herpetic; Moraxella; Prednisolone; Vancomycin
PubMed: 34015953
DOI: 10.1177/11206721211019565 -
Experimental and Therapeutic Medicine Jun 2023The future waves of COVID 19 infections will continue to raise serious problems in patients with severe forms of the disease. Bacterial infections associated with...
The future waves of COVID 19 infections will continue to raise serious problems in patients with severe forms of the disease. Bacterial infections associated with SARS-CoV-2 disease may complicate the progress of hospitalized patients with COVID-19. The present study aimed to evaluate the etiological spectrum of superinfection in adult patients with COVID-19 and to investigate the correlation between superinfection with multidrug-resistant (MDR) bacteria and serum procalcitonin (PCT). A total of 82 COVID-19 hospitalized patients with COVID-19 and bacterial superinfection were included. The superinfections were classified into early infections (3-7 days from admission) and late infections (>7 days from admission). Bacterial superinfection etiological spectrum, MDR bacteria profile and levels of serum PCT were studied. The most frequently isolated bacteria were , and MDR bacteria were involved in 73.17% of COVID-19 patients with bacterial superinfections. Most MDR bacteria superinfections (73.52%) occurred in the late infection period. , . and were the most common MDR bacteria identified in late infections after hospitalization in 20.43, 4.30 and 4.30% of all infections, respectively. Serum PCT values were significantly higher in patients with MDR bacteria superinfection compared with patients with sensitive bacteria superinfection (P=0.009). The principal findings of the present study were the high prevalence of superinfection with MDR bacteria among the COVID-19 patients with bacterial superinfections and the presence of a statistically significant association between serum PCT levels and the presence of superinfection with MDR bacteria. The most effective way to fight against microbial resistance to antibiotics, whether it occurs independently or overlaps with viral infections, is to pursue a national policy for the rational use of antibiotics.
PubMed: 37153889
DOI: 10.3892/etm.2023.11953 -
Retrovirology Aug 2023Using pigs as organ donors has advanced xenotransplantation to the point that it is almost ready for clinical use. However, there is still a zoonotic risk associated...
BACKGROUND
Using pigs as organ donors has advanced xenotransplantation to the point that it is almost ready for clinical use. However, there is still a zoonotic risk associated with xenotransplantation, and the potential transmission of porcine endogenous retroviruses needs to be surveyed. Despite significant attempts to eliminate this risk, by the selection of PERV-C free pigs with low expression of PERV-A, -B, and by the genome-wide inactivation of PERV using CRISPR/Cas9, the impact of superinfection resistance (SIR) was not investigated. SIR is a viral trait that prevents reinfection (superinfection). For PERV, the underlying mechanism is unclear, whether and how cells, that harbor functional PERV, are protected. Using PERV-C(5683) as a reference virus, we investigated SIR in a newly developed in vitro model to pursue the mechanism and confirm its protective effect.
RESULTS
We developed three PERV-C constructs on the basis of PERV-C(5683), each of which carries a hemagglutinin tag (HA-tag) at a different position of the envelope gene (SP-HA, HA-VRA, and RPep-HA), to distinguish between primary infection and superinfection. The newly generated PERV-C(5683)-HA viruses were characterized while quantifying the viral RNA, reverse transcriptase activity, protein expression analysis, and infection studies. It was demonstrated that SP-HA and RPep-HA were comparable to PERV-C(5683), whereas HA-VRA was not replication competent. SP-HA and RPep-HA were chosen to challenge PERV-C(5683)-positive ST-IOWA cells demonstrating that PERV-C-HA viruses are not able to superinfect those cells. They do not integrate into the genome and are not expressed.
CONCLUSIONS
The mechanism of SIR applies to PERV-C. The production of PERV-C particles serves as a defense mechanism from superinfection with exogenous PERV-C. It was demonstrated by newly generated PERV-C(5683)-HA clones that might be used as a cutting-edge tool. The HA-tagging of PERV-C is novel, providing a blueprint for the tagging of other human tropic PERV viruses. The tagged viruses are suitable for additional in vitro and in vivo infection studies and will contribute, to basic research on viral invasion and pathogenesis. It will maintain the virus safety of XTx.
Topics: Humans; Animals; Swine; Superinfection; Gammaretrovirus; Genes, env; Phenotype; RNA, Viral
PubMed: 37605152
DOI: 10.1186/s12977-023-00630-x -
Terapevticheskii Arkhiv Nov 2021To estimate graft function after kidney transplantation during active herpesviruses or superinfection Materials and methods. The study included 32 patients (men 21,...
AIM
To estimate graft function after kidney transplantation during active herpesviruses or superinfection Materials and methods. The study included 32 patients (men 21, women 11) with end-stage chronic kidney disease. The median age was 43 years. Cytomegalovirus (CMV), EpsteinBarr virus (EBV) and human herpes virus 6 (HHV-6) DNAs were screened by RT-PCR in the donor's transplant biopsy, and recipients peripheral blood and urine after kidney transplantation (KT) on 0, 1, 2, 4, 6, 12 months. Antiviral antibodies (IgM and IgG) were also screened by Enzyme-linked immunoassay analysis (ELISA) along with PCR. The 500 or less copies of viral DNA per 105 nuclear cells or 1 ml of urine was considered as low, more than 1000 copies high.
RESULTS
On the first month after KT CMV DNA was detected in 50% of pts., EBV DNA in 40% and HHV-6 DNA in 33%. During first year after KT two or three viruses simultaneously were found in 12 recipients: CMV, EBV, and HHV-6 were detected in 5 recipients; CMV and EBV in 4 patients; CMV and HHV-6 in 2 pts; EBV and HHV-6 in 1 pt. Graft dysfunction was observed in 9 patients with a high concentration of viral DNA of one, two or three viruses simultaneously. An upraise of the concentration of virus DNA (CMV, EBV and HHV 6) was detected primarily in the urine, while in the blood its concentration was less than 500 cop or undetectable. Renal dysfunction was not observed on the background of low concentrations of viral DNA in urine and blood. However, with an increase of DNA concentration, an impaired graft function in 8 of 12 patients appeared. Low viral DNA level proved to be a background for another virus activation or bacterial/fungal superinfection.
CONCLUSION
Graft dysfunction occurs at high viral DNA levels detection during mono-or superinfection. Low viral load can serve as a background for another virus activation and/or bacterial/fungal superinfection.
Topics: Male; Humans; Female; Adult; Kidney Transplantation; DNA, Viral; Cytomegalovirus Infections; Herpesvirus 4, Human; Superinfection; Cytomegalovirus; Herpesviridae; Herpesvirus 6, Human; Antiviral Agents; Immunoglobulin G; Immunoglobulin M
PubMed: 36286647
DOI: 10.26442/00403660.2021.11.201164