Dual Infection Research Articles

Concomitant Infection with <i>Leishmania donovani</i> and <i>Plasmodium berghei </i>Causes Pro-inflammatory Polarization Resulting in Malaria Exacerbation in BALB/c Mice

Malaria and visceral leishmaniasis coexist in the same geographical regions. However, dual co-infection with parasites causing these diseases and their impact on public health is poorly documented. Interactions between these parasites may play a role in disease outcome. The present study set out to evaluate the clinical and immunological parameters following Leishmania donovani and Plasmodium berghei co-infection in BALB/c mice. Mice were divided into four groups; L. donovani- only, L. donovani-P. berghei, P. berghei- only and naïve. Body weight, parasite burden, total IgG, IFN-γ and IL-4 responses were determined. To determine the survival rate, four mice were used from each group. Tissues for histological analysis were taken from spleen, liver and brain. Results indicated significant differences in body weight (PL. donovani parasite load (P), L. donovani IgG (PP. berghei parasitemia (P= 0.0222), P. berghei IgG (P= 0.002), IFN-γ (PL. donovani parasite load and IgG responses in single or dual infections, while there was a positive relationship of P. berghei parasitemia and IgG responses in the dual infection group only. Plasmodium berghei had the highest mortality rate compared to L. donovani- only and L. donovani- P. berghei infected mice groups. Histological analyses showed enlarged red and white pulps and pathological changes in the spleen, liver and brain tissues which were less pronounced in co-infected group. We conclude that L. donovani and P. berghei co-infection reduces disease severity and these changes seem to correlate with variation in serum IgG and cytokines (IFN-γ and IL-4). Therefore, the study recommends the importance of inclusion of early screening of malaria in Visceral Leishmaniasis patients in regions where malaria is co- endemic.

Viral hepatitis: Milestones, unresolved issues, and future goals.

In this review the current overall knowledge on hepatitis A, B, C, D, and E will be discussed. These diseases are all characterized by liver inflammation but have significant differences in distribution, transmission routes, and outcomes. Hepatitis B virus and hepatitis C virus are transmitted by exposure to infected blood, and in addition to acute infection, they can cause chronic hepatitis, which in turn can evolve into cirrhosis. It is estimated that more than 300 million people suffer from chronic hepatitis B or C worldwide. Hepatitis D virus, which is also transmitted by blood, only affects hepatitis B virus infected people, and this dual infection results in worse liver-related outcomes. Hepatitis A and E spread via the fecal–oral route, which corresponds mainly to the ingestion of food or water contaminated with infected stools. However, in developed countries hepatitis E is predominantly a zoonosis. Although hepatitis A virus and hepatitis E virus are usually responsible for a self-limiting hepatitis, a serious, rarely fatal illness is also possible, and in immunosuppressed patients, such as organ transplant recipients, hepatitis E virus infection can become chronic. The description of goals achieved, unresolved issues, and the latest research on this topic may make it possible to speculate on future scenarios in the world of viral hepatitis.

Classification of small ruminant lentivirus subtype A2, subgroups 1 and 2 based on whole genome comparisons and complex recombination patterns

Background: Small ruminant lentiviruses (SRLVs) cause a multisystemic chronic wasting disease in sheep across much of the world. SRLV subtype A2 is prevalent in North America and further classified into multiple subgroups based on variation in the group antigens gene (gag) and envelope (env) genes. In sheep, the ovine transmembrane protein 154 (TMEM154) gene is associated with SRLV susceptibility. Ewes with at least one copy of TMEM154 encoding a full-length protein with glutamate at position 35 (E35; haplotypes 2 and 3), are highly susceptible to SRLV infection while ewes with any combination of TMEM154 haplotypes which encodes lysine (K35; haplotype 1), or truncated proteins (haplotypes 4 and 6) are several times less so. A2 subgroups 1 and 2 are associated with host TMEM154 genotypes; subgroup 1 with the K35/K35 genotype and subgroup 2 with the E35/E35 genotype. Methods: Sequence variation within and among full-length assemblies of SRLV subtype A2 subgroups 1 and 2 was analyzed to identify genome-scale recombination patterns and subgroup-specific variants. Results: Consensus viral genomes were assembled from 23 infected sheep, including animals of assorted TMEM154 genotypes comprised of haplotypes 1, 2, or 3. Viral genome analysis identified viral subgroups 1 and 2 among the samples, and revealed additional sub-structure within subgroup 2 based on models predicting complex patterns of recombination between the two subgroups in several genomes. Animals with evidence of dual subgroup infection also possessed the most diverse quasi-species and the most highly recombined consensus genomes. After accounting for recombination, 413 subgroup diagnostic single nucleotide polymorphisms (SNPs) were identified. Conclusions: The viral subgroup framework developed to classify SRLV consensus genomes along a continuum of recombination suggests that animals with the TMEM154 E35/K35 genotype may represent a reservoir for producing viral genomes representing recombination between A2 subgroups 1 and 2.

Multiple infections of Entrerocytozoon hepatopenaei and Hepatopancreatic parvovirus in pond-reared Penaeus vannamei in India

Outbreaks of infectious disease affecting Penaeus vannamei (Pacific white shrimp), the most commonly cultured shrimp species in India, has led to severe economic loss. Five randomly selected P. vannamei samples were collected from 154 grow-out ponds located at Cuddalore and Nagapattinam Districts in Tamil Nadu where shrimp showed severe growth retardation over a two-year period. In addition to growth retardation, affected shrimp displayed an atrophied hepatopancreas (HP) and a white/empty gut and stomach. Histopathology revealed the various developmental stages (plasmodia to mature spores) of massive acidophilic microsporidian spores in the cytoplasm of hepatopancreatic (HP) tubule cells. Some of the microsporidian-infected shrimp also showed distinct hypertrophied nuclei within the HP tubular epithelial cells. TEM revealed different growth stages (meront to mature spores) of intracytoplasmic microsporidian parasites as well as icosahedral viral-like particles (VLP) ranging in diameter from 22 to 24 nm in the cytoplasm and nucleus of HP tubular epithelial cells and extracellular spaces. Among the pooled (five shrimp from each farm) HP samples from 154 farms, 53 (34.4%) farms were identified to be PCR-positive for Enterocytozoon hepatopenaei (EHP), whereas 11 (7.1%) were identified to be PCR-positive for Hepatopancreatic parvovirus (HPV). Among the PCR positives, eight (5.2%) farms were found to be positive for both EHP and HPV, indicating that some P. vannamei had dual infections with EHP and HPV. This is the first such report on the simultaneous occurrence of dual infections caused by EHP and HPV.

The prevalence and genotype distribution of human papilloma virus in cervical squamous intraepithelial lesion and squamous cell carcinoma in Taizhou, China.

Human papillomavirus (HPV) infection is a common sexually transmitted disease worldwide and the leading cause of cervical cancer. Current vaccines do not cover all HPV genotypes whereas the distribution of HPV genotypes varies in different geographic regions. The study aimed to investigate the distribution of HPV genotypes in patients with cervical squamous intraepithelial lesion (SIL) and cervical squamous cell carcinoma (SCC) in Taizhou City of Jiangsu Province, China. A total of 940 patients including 489 cases with cervical low-grade squamous intraepithelial lesions (LSIL), 356 cases with cervical high-grade squamous intraepithelial lesions (HSIL), and 95 cases with cervical SCC, underwent a biopsy or surgery in Taizhou People's Hospital between January 2019 and December 2019. The HPV testing results were retrospectively analyzed. The overall prevalence of any, high-risk, and low-risk HPV was 83.83%, 81.91%, and 12.13%, respectively. The 5 most common HPV genotypes were HPV16 (35.64%), HPV52 (16.91%), HPV58 (13.94%), HPV33 (8.94%), and HPV18 (7.98%). The prevalence of any and HR-HPV in SCC was significantly higher than those in LSIL and HSIL, while the prevalence of LR-HPV in SCC was significantly lower than those in LSIL and HSIL (P < .01). Single and dual HPV infections were prevalent in SCC, LSIL, and HSIL. Furthermore, the prevalence of dual HPV infection in SCC was significantly higher than those in LSIL and HSIL (P = .002). The HPV prevalence varied by age, being highest among women with SCC, LSIL, and HSIL aged 40 to 49 years, 40 to 49 years, and 50 to 59 years, respectively. In conclusion, the findings revealed a very high prevalence of HPV in women with cervical lesions in Taizhou. Routine HPV tests must cover all common HPV genotypes in clinical practice.

Classification of small ruminant lentivirus subtype A2, subgroups 1 and 2 based on whole genome comparisons and complex recombination patterns

Background: Small ruminant lentiviruses (SRLVs) cause a multisystemic chronic wasting disease in sheep across much of the world. SRLV subtype A2 is prevalent in North America and further classified into multiple subgroups based on variation in the group antigens gene (gag) and envelope (env) genes. In sheep, the ovine transmembrane protein 154 (TMEM154) gene is associated with SRLV susceptibility. Ewes with at least one copy of TMEM154 encoding a full-length protein with glutamate at position 35 (E35; haplotypes 2 and 3), are highly susceptible to SRLV infection while ewes with any combination of TMEM154 haplotypes which encodes lysine (K35; haplotype 1), or truncated proteins (haplotypes 4 and 6) are several times less so. A2 subgroups 1 and 2 are associated with host TMEM154 genotypes; subgroup 1 with the K35/K35 genotype and subgroup 2 with the E35/E35 genotype. Methods: Sequence variation within and among full-length assemblies of SRLV subtype A2 subgroups 1 and 2 was analyzed to identify genome-scale recombination patterns and subgroup-specific variants. Results: Consensus viral genomes were assembled from 23 infected sheep, including animals of assorted TMEM154 genotypes comprised of haplotypes 1, 2, or 3. Viral genome analysis identified viral subgroups 1 and 2 among the samples, and revealed additional sub-structure within subgroup 2 based on models predicting complex patterns of recombination between the two subgroups in several genomes. Animals with evidence of dual subgroup infection also possessed the most diverse quasi-species and the most highly recombined consensus genomes. After accounting for recombination, 413 subgroup diagnostic single nucleotide polymorphisms (SNPs) were identified. Conclusions: The viral subgroup framework developed to classify SRLV consensus genomes along a continuum of recombination suggests that animals with the TMEM154 E35/K35 genotype may represent a reservoir for producing viral genomes representing recombination between A2 subgroups 1 and 2.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Anti-HCV antibody titer highly predicts HCV viremia in patients with hepatitis B virus dual-infection

Hepatitis C Virus (HCV) infection is diagnosed by the presence of antibody to HCV and/or HCV RNA. This study aimed to evaluate the accuracy of anti-HCV titer (S/CO ratio) in predicting HCV viremia in patients with or without hepatitis B virus (HBV) dual infection. Anti-HCV seropositive patients who were treatment-naïve consecutively enrolled. Anti-HCV antibodies were detected using a commercially chemiluminescent microparticle immunoassay. HCV RNA was detected by real-time PCR method. A total of 1321 including1196 mono-infected and 125 HBV dually infected patients were analyzed. The best cut-off value of anti-HCV titer in predicting HCV viremia was 9.95 (AUROC 0.99, P<0.0001). Of the entire cohort, the anti-HCV cut-off value of 10 provided the best accuracy, 96.8%, with the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96.3%, 98.9%, 99.7% and 87.3% respectively. The best cut-off value of anti-HCV titer in predicting HCV viremia was 9.95 (AUROC 0.99, P<0.0001) and 9.36 (AUROC 1.00, P<0.0001) in patients with HCV mono-infection and HBV dual-infection respectively. Among the HBV dually infected patients, the accuracy of anti-HCV titer in predicting HCV viremia reached up to 100% with the cut-off value of 9. All the patients were HCV-viremic if their anti-HCV titer was greater than 9 (PPV 100%). On the other hand, all the patients were HCV non-viremic if their anti-HCV titer was less than 9 (NPV 100%). Anti-HCV titer strongly predicted HCV viremia. This excellent performance could be generalized to either HCV mono-infected or HBV dually infected patients.

Simultaneous Detection of Inflammatory Biomarkers by SERS Nanotag-Based Lateral Flow Assay with Portable Cloud Raman Spectrometer.

Inflammatory biomarkers are closely related to infectious diseases. However, traditional clinical tests of laboratory inspection are unable to achieve rapid and accurate detection of these biomarkers on-site due to shortcomings such as complex experimental operation, expensive equipment, and long test time. Herein, we proposed a lateral flow assay (LFA) strip based on surface-enhanced Raman scattering (SERS) nanotags (SERS-LFA strips) for the simultaneous and quantitative detection of dual infection biomarkers, serum amyloid A (SAA) and C-reactive protein (CRP), respectively. In practice, mesoporous silica (mSiO2)-coated Au nanoparticles (Au NPs) were used as the SERS substrate. Mercaptobenzoic acid (MBA) was embedded in the internal gap between Au NPs and the mSiO2 shell to prepare AuMBA@mSiO2 NPs, onto which SAA and CRP antibodies were modified to prepare two AuMBA@mSiO2 SERS nanotags. The Raman intensities of the test and control lines were simultaneously identified for the qualitative detection of SAA and CRP, with limits of detection (LODs) as low as 0.1 and 0.05 ng/mL for SAA and CRP, respectively. Finally, aiming at point-of-care testing (POCT) applications, we used a smartphone-based portable Raman spectrometer to quantitatively analyze the SERS-LFA strips. The Raman signal could still be accurately detected when the concentration of SAA and CRP was 10 ng/mL, which is lower than the LOD required in clinical practice for most diseases. Therefore, taking into account its simple operation and short analysis time, by using a portable Raman spectrometer which can be equipped with a 5G cloud-based healthcare management system, the current strategy based on SERS-LFA provides the potential for the quick and on-site diagnosis of infectious diseases such as sepsis, which is of great significance for medical guidance on the treatment of widely spread infection-related diseases in remote areas that lack well-developed medical resources.

Seropositivity for dengue and Leptospira IgM among patients with acute febrile illness: an indicator of co-infection?

Presentation of febrile illness with nonspecific features, overlapping manifestations of dengue and leptospirosis, limited laboratory diagnostic tests, make the clinical diagnosis of pyrexia a challenge. The present study aimed to determine the prevalence of Leptospira and dengue IgM co-infection among acute febrile illness patients. This is a retrospective hospital-based study which included patient data collected from June 2016 to May 2017. Inpatients' samples (n=2139) were tested for dengue and/or Leptospira IgM at the Microbiology Laboratory. Data like duration of fever, platelet count, hemoglobin, white blood cell count, erythrocyte sedimentation rate, results of liver and renal function tests, mode of treatment, were collected from medical records of laboratory-confirmed co-infection cases. Among 1612 serum samples tested for dengue IgM by ELISA, 382 (23.7%) were positive, 17 equivocal and 1213 were negative. Of the 811 Leptospira IgM ELISA done, 119 (14.7%) were positive, 17 equivocal and 675 negative. Two hundred eighty-four samples were tested for both infections and nine (3.2%) were positive for both and 275 were negative. These nine patients positive for dual infections showed elevated transaminases, alkaline phosphatase, serum bilirubin, creatinine, and blood urea, thrombocytopenia and leukocytosis. They received effective antibiotics along with supportive treatment and were cured of the infection. The study emphasizes the possibility of leptospirosis and dengue co-infection (3.2%) and need for confirmation by a highly specific test like PCR. If co-infection is suspected, treatment with specific antibiotics for leptospirosis and supportive treatment for dengue is mandatory, with due attention to complexity of organ involvement.

The contribution of the immune response to enhanced colibacillosis upon preceding viral respiratory infection in broiler chicken in a dual infection model

Colibacillosis in chickens caused by avian pathogenic Escherichia coli (APEC) is known to be aggravated by preceding infections with infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and avian metapneumovirus (aMPV). The mechanism behind these virus-induced predispositions for secondary bacterial infections is poorly understood. Here we set out to investigate the immunopathogenesis of enhanced respiratory colibacillosis after preceding infections with these three viruses. Broilers were inoculated intratracheally with APEC six days after oculonasal and intratracheal inoculation with IBV, NDV, aMPV or buffered saline. After euthanasia at 1 and 8 days post infection (dpi) with APEC, birds were macroscopically examined and tissue samples were taken from the trachea, lungs and air sacs. In none of the groups differences in body weight were observed during the course of infection. Macroscopic lesion scoring revealed most severe tissue changes after NDV-APEC and IBV-APEC infection. Histologically, persistent tracheitis was detected in all virus-APEC groups, but not after APEC-only infection. In the lungs, mostly APEC-associated transient pneumonia was observed. Severe and persistent airsacculitis was present after NDV-APEC and IBV-APEC infection. Bacterial antigen was detected by immunohistochemistry only at 1 dpi APEC, predominantly in NDV-APEC- and IBV-APEC-infected lungs. Higher numbers of CD4+ and CD8+ lymphocytes persisted over time in NDV-APEC- and IBV-APEC-infected tracheas, as did CD4+ lymphocytes in NBV-APEC- and IBV-APEC-infected air sacs. KUL01+ cells, which include monocytes and macrophages, and TCRγδ+ lymphocytes were observed mostly in lung tissue in all infected groups with transient higher numbers of KUL01+ cells over time and higher numbers of TCRγδ+ lymphocytes mainly at 8 dpi. qPCR analysis revealed mostly trends of transient higher levels of IL-6 and IFNγ mRNA in lung tissue after IBV-APEC and also NDV-APEC infection and persistent higher levels of IL-6 mRNA after aMPV-APEC infection. In spleens, transient higher levels of IL-17 mRNA and more persistent higher levels of IL-6 mRNA were observed after all co-infections. No changes in IL-10 mRNA expression were seen. These results demonstrate a major impact of dual infections with respiratory viruses and APEC, compared to a single infection with APEC, on the chicken respiratory tract and suggest that immunopathogenesis contributes to lesion persistence.

Comparison of outcomes in HIV-positive and HIV-negative patients with COVID-19

Background: South Africa has the highest prevalence of HIV in the world and to date has recorded the highest number of cases of COVID-19 in Africa. There is uncertainty as to what the significance of this dual infection is, and whether people living with HIV (PLWH) have worse outcomes compared to HIV-negative patients with COVID-19. This study compared the outcomes of COVID-19 in a group of HIV-positive and HIV-negative patients admitted to a tertiary referral centre in Johannesburg, South Africa.Methods: Data was collected on all adult patients with known HIV status and COVID-19, confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR), admitted to the medical wards and intensive care unit (ICU) between 6 March and 11 September 2020. The data included demographics, co-morbidities, laboratory results, severity of illness scores, complications and mortality, and comparisons were made between the HIV-positive and HIV negative groups.Results: Three-hundred and eighty-four patients, 108 HIV-positive and 276 HIV-negative, were included in the study. Median 4C score was significantly higher in the HIV-positive patients compared to the HIV-negative patients, but there was no significant difference in mortality between the HIV-positive and HIV-negative groups (15% vs 20%, p = 0.31). In addition, HIV-positive patients who died were younger than their HIV-negative counterparts, but this was not statistically significant (47.5 vs 57 years, p = 0.06).Conclusion: Our findings suggest that HIV is not a risk factor for moderate or severe COVID-19 disease neither is it a risk factor for mortality. However, HIV-positive patients with COVID-19 requiring admission to hospital are more likely to be younger than their HIV-negative counterparts. These findings need to be confirmed in future, prospective, studies.

An MHV-68 Mutator Phenotype Mutant Virus, Confirmed by CRISPR/Cas9-Mediated Gene Editing of the Viral DNA Polymerase Gene, Shows Reduced Viral Fitness.

Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed murine γ-herpesvirus-68 (MHV-68) that efficiently replicates in vitro as a model to study the antiviral resistance of γ-herpesviruses. In this study, we investigated the mechanism of resistance to nucleoside (ganciclovir (GCV)), nucleotide (cidofovir (CDV), HPMP-5azaC, HPMPO-DAPy) and pyrophosphate (foscarnet (PFA)) analogues and the impact of these drug resistance mutations on viral fitness. Viral fitness was determined by dual infection competition assays, where MHV-68 drug-resistant viral clones competed with the wild-type virus in the absence and presence of antivirals. Using next-generation sequencing, the composition of the viral populations was determined at the time of infection and after 5 days of growth. Antiviral drug resistance selection resulted in clones harboring mutations in the viral DNA polymerase (DP), denoted Y383SGCV, Q827RHPMP-5azaC, G302WPFA, K442TPFA, G302W+K442TPFA, C297WHPMPO-DAPy and C981YCDV. Without antiviral pressure, viral clones Q827RHPMP-5azaC, G302WPFA, K442TPFA and G302W+K442TPFA grew equal to the wild-type virus. However, in the presence of antivirals, these mutants had a growth advantage over the wild-type virus that was moderately to very strongly correlated with antiviral resistance. The Y383SGCV mutant was more fit than the wild-type virus with and without antivirals, except in the presence of brivudin. The C297W and C981Y changes were associated with a mutator phenotype and had a severely impaired viral fitness in the absence and presence of antivirals. The mutator phenotype caused by C297W in MHV-68 DP was validated by using a CRISPR/Cas9 genome editing approach.

Periprosthetic Fungal Infections in Severe Endoprosthetic Infections of the Hip and Knee Joint-A Retrospective Analysis of a Certified Arthroplasty Centre of Excellence.

The treatment of periprosthetic joint infections (PJI), and especially of re-infections, poses a highly complex problem in orthopaedic surgery. While fungal infections are rare, they present a special challenge. The therapy is often protracted and based on limited evidence. A total of 510 hip and knee revision surgeries were analysed for the occurrence of bacterial and fungal PJI. In patients with PJI, the duration of the hospital stay and the incidence of disarticulation of the infected joint were recorded. Out of the analysed revision arthroplasties, 43.5% were due to PJI. Monomicrobial infection occurred in 55.2%, dual microbial infection in 21.4%, and polymicrobial (≥3 different bacterial or fungal species) infection in 17.2% of the cases. Overall, Candida species were detected in 12.4% cases. Candida albicans was the main fungal pathogen. In 6.9% of cases, disarticulation of the joint was the only option to control PJI. The detection of polymicrobial infection more than doubled in follow-up revisions and there was a strong association between detection of Candida infection and disarticulation (OR 9.39). The majority of fungal infections were mixed infections of bacteria and Candida albicans. The choice of a biofilm penetrating antimycotic, e.g., caspofungin, together with a sufficient standard procedure for detection and surgical treatment can help to control the infection situation. Fungal infection often proves to be more difficult to treat than anticipated and is more frequent than expected.

KSHV infection drives poorly cytotoxic CD56-negative natural killer cell differentiation invivo upon KSHV/EBV dual infection.

Herpesvirus infections shape the human natural killer (NK) cell compartment. While Epstein-Barr virus (EBV) expands immature NKG2A+ NK cells, human cytomegalovirus (CMV) drives accumulation of adaptive NKG2C+ NK cells. Kaposi sarcoma-associated herpesvirus (KSHV) is a close relative of EBV, andboth are associated with lymphomas, including primary effusion lymphoma (PEL), which nearly always harbors both viruses. In this study, KSHV dual infection of mice with reconstituted human immunesystem components leads to the accumulation of CD56-CD16+CD38+CXCR6+ NK cells. CD56-CD16+ NK cells were also more frequently found in KSHV-seropositive Kenyan children. This NK cell subset is poorly cytotoxic against otherwise-NK-cell-susceptible and antibody-opsonized targets. Accordingly, NK cell depletion does not significantly alter KSHV infection in humanized mice. These data suggest that KSHV might escape NK-cell-mediated immune control by driving CD56-CD16+ NK cell differentiation.

Topical Application of Escherichia coli-Encapsulated dsRNA Induces Resistance in Nicotiana benthamiana to Potato Viruses and Involves RDR6 and Combined Activities of DCL2 and DCL4.

Exogenous application of double-stranded RNAs (dsRNAs) for inducing virus resistance in plants represents an attractive alternative to transgene-based silencing approaches. However, improvement of dsRNA stability in natural conditions is required in order to provide long-term protection against the targeted virus. Here, we tested the protective effect of topical application of Escherichia coli-encapsulated dsRNA compared to naked dsRNA against single and dual infection by Potato virus X expressing the green fluorescent protein (PVX-GFP) and Potato virus Y (PVY) in Nicotiana benthamiana. We found that, in our conditions, the effectiveness of E. coli-encapsulated dsRNA in providing RNAi-mediated protection did not differ from that of naked dsRNA. dsRNA vaccination was partly effective against a dual infection by PVX-GFP and PVY, manifested by a delay in the expression of the synergistic symptoms at early times after inoculation. Using PVX-GFP as a reporter virus together with a suite of RNAi knockdown transgenic lines, we have also shown that RNA-directed RNA polymerase 6 and the combined activities of DICER-like 2 (DCL2) and DCL4 act to promote efficient resistance to virus infection conferred by topical application of dsRNA in N. benthamiana. Our results provide evidence that exogenous dsRNA molecules are processed by the RNA silencing pathways commonly used by the host in response to virus infection.

Streptococcus pneumoniae serotype 22F infection in respiratory syncytial virus infected neonatal lambs enhances morbidity

Respiratory syncytial virus (RSV) is the primary cause of viral bronchiolitis resulting in hospitalization and a frequent cause of secondary respiratory bacterial infection, especially by Streptococcus pneumoniae (Spn) in infants. While murine studies have demonstrated enhanced morbidity during a viral/bacterial co-infection, human meta-studies have conflicting results. Moreover, little knowledge about the pathogenesis of emerging Spn serotype 22F, especially the co-pathologies between RSV and Spn, is known. Here, colostrum-deprived neonate lambs were divided into four groups. Two of the groups were nebulized with RSV M37, and the other two groups were mock nebulized. At day three post-RSV infection, one RSV group (RSV/Spn) and one mock-nebulized group (Spn only) were inoculated with Spn intratracheally. At day six post-RSV infection, bacterial/viral loads were assessed along with histopathology and correlated with clinical symptoms. Lambs dually infected with RSV/Spn trended with higher RSV titers, but lower Spn. Additionally, lung lesions were observed to be more frequent in the RSV/Spn group characterized by increased interalveolar wall thickness accompanied by neutrophil and lymphocyte infiltration and higher myeloperoxidase. Despite lower Spn in lungs, co-infected lambs had more significant morbidity and histopathology, which correlated with a different cytokine response. Thus, enhanced disease severity during dual infection may be due to lesion development and altered immune responses rather than bacterial counts.

The Prevalence of Ureaplasma Urealyticum and Mycoplasma Hominis Infections in Infertile Patients in the Northeast Region of Romania.

Background and objectives: Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) are two commensal microorganisms that form the urogenital microbiota. Under a state of dysbiosis, both bacteria cause intrauterine infection. Material and methods: Therefore, the purpose of the present study was to analyze the prevalence of UU and MH among four hundred and eleven infertile women. Results: Women between thirty and thirty-five years old were the most affected group, followed by those that were 25 and 30 years old, respectively. Cumulatively, the prevalence of single UU and MH, and coinfection, was 28.46% (n = 117), (n = 2) 0.48%, and 2.91% (n = 12), respectively, with an overall detection rate of 31.87% (n = 131). To assess the associated drug susceptibility, endocervical samples were unequally sent to Regina Maria (n = 281) and Synevo (n = 130) laboratories for further analyses. Pristinamycin (100% vs. 100%) and Josamycin (100% vs. 98.00%) were the most efficient antibiotics in eradicating UU and MH, several others also displaying a high efficiency, among which can be mentioned Doxycycline (98.23%), Minocycline (96.00%), Tetracycline (96.48% vs. 68.00%), and Erythromycin (70.17% vs. 92.00%). Based on antibiograms, Clarithromycin (88.00%), Roxithromycin (88.00%), Levofloxacin (82.00%), and Azithromycin (78.94%) can be further used in treating such infections. On the other hand, Clindamycin (4.00%) and Ciprofloxacin (12.27% vs. 2.00%) are no longer viable because both UU and MH display an intermediate response towards gained resistance. Interestingly, the efficiency of Ofloxacin (22.79% vs. 60.00%) was conflicting, this possibly suggesting a transient stage to a gradual adaptability of these microorganisms to Ofloxacin. Conclusions: The most susceptible age groups in each case were women that were between twenty and forty years old. It can be concluded that four antibiotics can be safely used for treating UU, MH, or dual infections whose efficiency was over 95%.

Malaria and helminth co-infections in children living in endemic countries: A systematic review with meta-analysis

Current knowledge on the burden of, and interactions between malaria and helminth co-infections, as well as the impact of the dual infections on anaemia, remains inconclusive. We have conducted a systematic review with meta-analysis to update current knowledge as a first step towards developing and deploying coordinated approaches to the control and, ultimately, elimination of malaria-helminth co-infections among children living in endemic countries. We searched Medline, Embase, Global Health and Web of Science from each database inception until 16 March 2020, for peer-reviewed articles reporting malaria-helminth co-infections in children living in endemic countries. No language restriction was applied. Following removal of duplicates, two reviewers independently screened the studies for eligibility. We used the summary odds ratio (OR) and 95% confidence intervals (CI) as a measure of association (random-effects model). We also performed Chi-square heterogeneity test based on Cochrane's Q and evaluated the severity of heterogeneity using I2 statistics. The included studies were examined for publication bias using a funnel plot and statistical significance was assessed using Egger's test (bias if p<0.1). Fifty-five of the 3,507 citations screened were eligible, 28 of which had sufficient data for meta-analysis. The 28 studies enrolled 22, 114 children in 13 countries across sub-Saharan Africa, Southeast Asia and South America. Overall, the pooled estimates showed a prevalence of Plasmodium-helminth co-infections of 17.7% (95% CI 12.7-23.2%). Summary estimates from 14 studies showed a lower odds of P. falciparum infection in children co-infected with Schistosoma spp (OR: 0.65; 95%CI: 0.37-1.16). Similar lower odds of P. falciparum infection were observed from the summary estimates of 24 studies in children co-infected with soil transmitted helminths (STH) (OR: 0.42; 95%CI: 0.28-0.64). When adjusted for age, gender, socio-economic status, nutritional status and geographic location of the children, the risk of P. falciparum infection in children co-infected with STH was higher compared with children who did not have STH infection (OR = 1.3; 95% CI 1.03-1.65). A subset of 16 studies showed that the odds of anaemia were higher in children co-infected with Plasmodium and STH than in children with Plasmodium infection alone (OR = 1.20; 95% CI: 0.59-2.45), and were almost equal in children co-infected with Plasmodium-Schistosoma spp or Plasmodium infection alone (OR = 0.97, 95% CI: 0.30-3.14). The current review suggests that prevalence of malaria-helminth co-infection is high in children living in endemic countries. The nature of the interactions between malaria and helminth infection and the impact of the co-infection on anaemia remain inconclusive and may be modulated by the immune responses of the affected children.

Brazilian Aedes aegypti as a Competent Vector for Multiple Complex Arboviral Coinfections.

Aedes aegypti is a highly competent vector in the transmission of arboviruses, such as chikungunya, dengue, Zika, and yellow fever viruses, and causes single and coinfections in the populations of tropical countries. The infection rate, viral abundance (VA), vector competence (VC), disseminated infection, and survival rate were recorded after single and multiple infections of the vector with 15 combinations of chikungunya, dengue, Zika, and yellow fever arboviruses. Infection rates were 100% in all single and multiple infection experiments, except in 1 triple coinfection that presented a rate of 50%. The VC and disseminated infection rate varied from 100% (in single and quadruple infections) to 40% (in dual and triple infections). The dual and triple coinfections altered the VC and/or VA of ≥1 arbovirus. The highest viral VAs were detected for a single infection with chikungunya. The VAs in quadruple infections were similar when compared with each respective single infection. A decrease in survival rates was observed in a few combinations. A. aegypti was able to host all single and multiple arboviral coinfections. The interference of the chikungunya virus suggests that distinct arbovirus families may have a significant role in complex coinfections.