Study of the Antiviral Mechanism of Cytovir®-3 Against Respiratory Viruses In Vitro

Background Human adenovirus (HAdV) is a common cause of acute respiratory illness (ARI) in children, ranging from asymptomatic to life-threatening disease. While previous studies have examined asymptomatic vs HAdV ARI infections, few have analyzed HAdV species and type. We compared frequencies of common HAdV ARI types among children with ARI vs. healthy controls (HCs). Comparison of demographics and HAdV detection between children with ARI and healthy controls: New Vaccine Surveillance Network 12/01/2016–11/30/2019 (N=1,393). Methods Data were analyzed from the New Vaccine Surveillance Network, a multicenter, prospective surveillance network at 7 U.S. children’s hospitals that enrolled children < 18 years with ARI (fever and/or respiratory symptoms) from emergency departments or inpatient settings during 12/01/16–11/30/19. HCs (ARI symptom free ≥3 days and no vomiting/diarrhea ≥14 days) were matched by age and near date of enrollment, and enrolled from outpatient clinics. Nasal and/or throat swabs were tested using molecular assays for HAdV and other respiratory viruses. HAdV-positive specimens were tested by real-time PCR for 11 common respiratory HAdV types representing species B, C, and E based on unique sequences in the hexon gene. Demographics, HAdV species, and HAdV types from HAdV-positive children with ARI were compared to those from HAdV-positive HCs. Percent of HAdV species detections stratified by ARI cases and healthy controls: New Vaccine Surveillance Network 12/01/2016–11/30/2019 Results 1,330 HAdV detections from ARI cases and 63 from HCs were included. Children with HAdV ARI were older, more frequently attended daycare, had higher viral load (based on cycle threshold value), and had more frequent viral co-detection compared to HCs (Table 1). HAdV-C predominated in both ARI and HC groups (Fig. 1); HAdV-C2 was most common, followed by HAdV-C1 (Fig. 2). Among HAdV-positive patients, those with ARI more frequently had HAdV-B detection than HCs (22.3% vs. 1.6%, p< 0.001). HAdV-positive HCs more frequently had HAdV-C detected than HAdV-positive ARI cases (95.2% vs 73.8%, p< 0.001). HAdV-C1 was more likely to be detected in HCs than those with ARI (28.9% vs. 41.3%, p=0.03), and HAdV-B3 was only detected in those with ARI. Percent of HAdV type detections stratified by ARI cases and healthy controls: NVSN, 12/01/2016–11/30/2019. Conclusion While HAdV-C was most frequent in all children, HAdV-B was more often detected in those with ARI than HCs, suggesting that different HAdV species and types have different symptom phenotypes, including HAdV-B3. Further investigations into the identification of specific HAdV types responsible for ARI are necessary. Disclosures Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Grant/Research Support|Abbott: Honoraria|BioMerieux: Grant/Research Support|Cepheid: Grant/Research Support|Diasorin: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Luminex: Grant/Research Support|Qiagen: Grant/Research Support Christopher J. Harrison, MD, GSK: Grant/Research Support|Medscape: Honoraria|Merck: Grant/Research Support|Pfizer: Grant/Research Support|UpToDate: Honoraria Pedro A. Piedra, MD, Merck: Grant/Research Support|Novavax: Grant/Research Support|Sanofi-Pasteur: Grant/Research Support|Shionogi: Grant/Research Support Mary A. Staat, MD, MPH, Cepheid: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Up-To-Date: Honoraria Elizabeth P. Schlaudecker, MD, MPH, Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Geoffrey A. Weinberg, MD, Inhalon: Advisor/Consultant|Merck & Company: Honoraria for textbook chapter preparation Janet A. Englund, MD, Abbvie: Advisor/Consultant|AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Advisor/Consultant|Pfizer: Board Member|Pfizer: Grant/Research Support|Pfizer: Speaker at meeting|SanofiPasteur: Advisor/Consultant|Shinogi: Advisor/Consultant James Chappell, MD, PhD, Merck: Grant/Research Support Natasha B. Halasa, MD, MPH, Merck: Grant/Research Support

Введение. Острые респираторные вирусные инфекции – это патология, которая чаще всего встречается в амбулаторной терапевтической практике (около 40 млн случаев в год). Термин «острая респираторная вирусная инфекция» является собирательным понятием и обозначает группу заболеваний вирусной этиологии с преимущественным поражением дыхательных путей. Общие эпидемиологические особенности возбудителей острых респираторных вирусных инфекций заключаются в единых путях передачи: воздушно-капельном и посредством контакта с зараженными предметами. Причины острых респираторных вирусных инфекций могут быть разными, однако у них есть общие эпидемиологические и клинические особенности, которые определяют единую стратегию лечения и профилактики. Результаты. Терапия острых респираторных вирусных инфекций направлена на снижение тяжести симптомов, предотвращение прогрессирования заболевания и достижение полного и стойкого выздоровления. Лабораторная этиологическая диагностика на амбулаторном этапе проводится молекулярно-генетическими методами только в отношении гриппа А и В, а также COVID-19; для идентификации других возбудителей острых респираторных вирусных инфекций ее проведение целесообразно только по клинико-эпидемиологическим показаниям, поскольку полученные результаты не влияют на дальнейшую тактику ведения пациента. Обязательным компонентом лечения является немедикаментозная терапия, включающая в себя постельный режим, диету и обильное питье. Медикаментозное лечение острых респираторных вирусных инфекций и гриппа включает этиотропные препараты, средства патогенетической и симптоматической терапии. В качестве этиотропной терапии применяют противовирусные препараты прямого и непрямого действия. Ингибиторы нейраминидазы, как и ингибиторы кэп-зависимой эндонуклеазы, используются в терапии гриппа А и В и, к сожалению, не активны в отношении других возбудителей острых респираторных вирусных инфекций. В связи с отсутствием препаратов прямого противовирусного действия, активных в отношении возбудителей острых респираторных вирусных инфекций, основными этиотропными препаратами выступают препараты непрямого (иммуномодулирующего) действия, обладающие широким противовирусным спектром, к которым, в частности, относятся индукторы интерферона. Заключение. В статье представлен анализ литературы на тему оптимизации терапии острых респираторных вирусных инфекций и гриппа в амбулаторных условиях за счет применения препаратов группы индукторов интерферона. В результате проведенного анализа был сделан вывод о необходимости комплексного подхода, включающего противовирусную терапию, в лечении любых форм острых респираторных вирусных инфекций и гриппа. Background. Acute respiratory viral infections are a pathology that most often occurs in outpatient therapeutic practice (about 40 million cases per year). The term acute respiratory viral infection is a collective concept and denotes a group of diseases of viral etiology with predominant damage to the respiratory tract.The general epidemiological features of acute respiratory viral infections pathogens consist in common transmission: airborne droplets and through contact with contaminated objects. Although the causes of acute respiratory viral infections may be different, they have common epidemiological and clinical features that determine a unified strategy for treatment and prevention. Results. Treatment of acute respiratory viral infections is aimed at reducing the severity of symptoms, preventing progression of the disease, and achieving a complete and lasting recovery. Laboratory etiological diagnosis at the outpatient stage is carried out using molecular genetic methods only for influenza A and B, as well as COVID-19; to identify other pathogens of acute respiratory viral infections, it is advisable only for clinical and epidemiological indications, since the results obtained do not affect further tactics of patient management. A required component of treatment is non-drug therapy, including bed rest, diet and plenty of fluids.Drug treatment of acute respiratory viral infections and influenza includes etiotropic drugs, pathogenetic and symptomatic therapy. Direct and indirect antiviral drugs are used as etiotropic therapy. Neuraminidase inhibitors, like cap-dependent endonuclease inhibitors, are used in the treatment of influenza A and B, and, unfortunately, are not active against other pathogens of acute respiratory viral infections. Due to the lack of drugs with direct antiviral action active against acute respiratory viral infections pathogens, the main etiotropic drugs are drugs of indirect (immunomodulatory) action with a wide antiviral spectrum, which include interferon inducers. Conclusion. The article presents an analysis of the literature on the topic of optimizing the treatment of acute respiratory viral infections and influenza in an outpatient setting using drugs from the group of interferon inducers.As a result of the analysis, it was concluded that an integrated approach is necessary, including antiviral therapy in the treatment of any forms of acute respiratory viral infections and influenza.

The human adenovirus (HAdV) is a common pathogen in children that can cause acute respiratory virus infection (ARVI). However, the molecular epidemiological and clinical information relating to HAdV among hospitalized children with ARVI is rarely reported in Russia. A 4-year longitudinal (2019–2022) study among hospitalized children (0–17 years old) with ARVI in Novosibirsk, Russia, was conducted to evaluate the epidemiological and molecular characteristics of HAdV. Statistically significant differences in the detection rates of epidemiological and virological data of all positive viral detections of HAdV were analyzed using a two-tailed Chi-square test. The incidence of HAdV and other respiratory viruses such as human influenza A and B viruses, respiratory syncytial virus, coronavirus, parainfluenza virus, metapneumovirus, rhinovirus, bocavirus, and SARS-CoV-2 was investigated among 3190 hospitalized children using real-time polymerase chain reaction. At least one of these respiratory viruses was detected in 74.4% of hospitalized cases, among which HAdV accounted for 4%. A total of 1.3% co-infections with HAdV were also registered. We obtained full-genome sequences of 12 HAdVs, which were isolated in cell cultures. Genetic analysis revealed the circulation of adenovirus of genotypes C1, C2, C5, C89, and 108 among hospitalized children in the period from 2019–2022.

Aim. To reveal peculiarities of acute respiratory viral infections (ARVI) incidence among population of the Far Eastern Federal District depending on viral etiology during two epidemic seasons (2017-2018 and 2018-2019). Materials and methods. Method of epidemiological analysis by means of ARVI incidence with weekly epidemic thresholds as utilized. Laboratory diagnosis of respiratory viruses was carried out by applying RT-PCR method and test-kits of the Central Research Institute of Epidemiology. In order to determine relations between ARVI incidence and viral etiological structure of ARVI correlation and regression analysis was performed. Results. Identical epidemical tendencies with differences in ARVI incidence intensity were registered in the evaluated constituent entities of the Russian Far East. Utmost intensity of epidemic process was revealed in the Republic Sakha (Yakutia) and Sakhalin Oblast. In the south regions (Khabarovsk and Primorsky Krai, Amur Oblast) ARVI incidence, occasionally excessing epidemic threshold was lower. Territorial and time irregularity is peculiar for etiology of infections in the Russian Far East. During the epidemic season of 2017-2018 statistically significant prevalence was determined for the influenza virus B in Primorsky and Khabarovsk Krai, influenza virus A(H3N2) ‒ in the Sakhalin Oblast, respiratory syncytial virus ‒ in the Republic Sakha (Yakutia), rhinoviruses were dominant in the Amur Oblast. During the 2018-2019 epidemic season influenza virus A(H1N1)pdm09 was mostly prevalent in most of the constituent entities of the Russian Far East. Compared to the other regions of the Far Eastern Federal District in the Amur Oblast were revealed differences in circulation of respiratory viruses predominantly of non-influenza origin during two observed epidemic seasons. Conclusion. Constant evaluation of ARVI epidemics under the conditions of constantly changing landscape of circulating viruses in a particular region can be useful for determination of strategies and tactics of epidemiological response.

BackgroundIn adults, the emerging human adenovirus (HAdV) type 55 (HAdV-55) has been reported to cause more severe cases of adenovirus induced acute lower respiratory tract infections (ALRTIs) compared to other HAdV serotypes (HAdV-3, HAdV-7, HAdV-14). However, there is a dearth of comparative studies in children that address differences in the clinical epidemiological features between HAdV-55 and other HAdV serotypes that can also induce severe infection (such as HAdV-7).MethodsWe conducted a retrospective review of pediatric patients hospitalized at Beijing Children’s Hospital with ALRTI from April 2008 to December 2013 who had adenovirus detected from nasopharyngeal or throat samples by PCR. We further compared pediatric patients infected with HAdV-55 to those infected with HAdV-7 using a case-control methodology by matching each subject with HAdV-55 infection to 4 patients with HAdV-7 infection within 2 months of each HAdV-55 infection. Demographic, clinical, and etiological data were collected and analyzed.ResultsOver the five-year period, HAdV was detected in 194 children. Of these, 8 were HAdV-55 positive. Epidemiological results showed that HAdV-55 infection was observed only in 4% of adenovirus infected children whereas HAdV-7 infection proportioned 53%. Most cases of HAdV-55 infection were identified during March and April, whereas HAdV-7 infection occurred throughout the year. Wheezing was significantly less frequent in the HAdV-55 group. No patients infected with HAdV-55 presented with vomiting or had any underlying disease. Coinfections with other respiratory tract pathogens were frequent among children infected with either HAdV-55 or HAdV-7.ConclusionsHAdV-55 circulated in Beijing during spring and appeared to cause pediatric respiratory infections that were as severe as HAdV-7 infections. Broader surveillance studies are needed.

Human adenoviruses (HAdVs) are nonenveloped, double-stranded DNA viruses in the family Adenoviridae; seven species (A-G) and >60 genotypes are known to cause human infection (1). Clinical manifestations associated with HAdV infection include fever, acute respiratory illness, gastroenteritis, and conjunctivitis. HAdV infection can be severe, particularly among immunocompromised patients, and can cause respiratory failure, disseminated infection, hemorrhagic cystitis, neurologic disease, and death (1,2). Illness tends to occur sporadically and without demonstrated seasonality. Outbreaks of HAdV have been reported globally in communities (3), and in closed or crowded settings, including dormitories, health care settings, and among military recruits, for whom a vaccine against HAdV type 4 (HAdV-4) and HAdV type 7 (HAdV-7) has been developed (4,5). CDC summarized HAdV detections voluntarily reported through the National Adenovirus Type Reporting System (NATRS) after initiation of surveillance in 2014 to describe trends in reported HAdVs circulating in the United States. Reporting laboratories were also encouraged to report available results for specimens collected before surveillance began. Overall, the number of reporting laboratories and HAdV type identifications reported to NATRS has increased substantially from the start of official reporting in 2014 through 2016; this report describes specimens collected during 2003-2016. The most commonly reported HAdV types were HAdV type 3 (HAdV-3) and HAdV type 2 (HAdV-2), although HAdV types reported fluctuated considerably from year to year. In the United States, information on recently circulating HAdV types is needed to inform diagnostic and surveillance activities by clinicians and public health practitioners. Routine reporting to NATRS by all U.S. laboratories with the capacity to type HAdVs could help strengthen this surveillance system.

Adenovirus infection occurs globally in the form of sporadic cases and isolated outbreaks. Human adenovirus type 55 (HAdV-55), endemic in China and South Korea, causes acute respiratory viral infections (ARVI) of varying severity, both among the civilian population and in military units in different countries of the world. Genomic research facilitates reliable identification of HAdV-55. The aim of this study was to identify HAdV isolated in Moscow in 2022, as well as to conduct whole-genome sequencing and comparative genomic research. HAdV-55 was isolated from a sample of a patient hospitalized with pneumonia and analyzed using restriction fragment length polymorphism analysis and whole-genome sequencing. Bioinformatics comparative analysis was performed on a sample of sequences of 83 isolates. The whole-genome sequencing of first isolated in Russia HAdV-55 was conducted. The sequence of isolate SCV3008:Ad55 was deposited in GenBank (Accession Number PQ641625). Unique mutations in the SCV3008:Ad55 genome were identified, one of which resulted in a conservative T29A substitution in the penton that did not affect its functions. Phylogenetic analysis showed clustering of SCV3008:Ad55 with isolates of clade II, which included representatives of 7 countries on different continents, indicating a wide distribution of HAdV-55. Isolates from endemic regions of China and South Korea formed separate clades. The study of microsatellite length polymorphism in untranslated regions of the genome became an additional tool for distinguishing closely related genomes. The obtained genomic information laid the foundation for further monitoring for HAdV-55 in Russia and demonstrated the informativeness and significance of whole-genome studies for monitoring adenoviruses. The development and implementation of genotyping methods aimed at detecting HAdV-55 and other clinically relevant genotypes will significantly improve the effectiveness of the diagnosis of adenovirus infections with the threat of developing bronchopneumonia.

Replication-defective adenoviruses are widely used as vectors for vaccines, but their efficacy may be compromised by the prevalence of pre-existing neutralizing antibodies from natural infections or prior vaccination with adenovirus-based vaccines. To overcome these limitations, less common human adenovirus (HAdV) types and simian adenoviruses (SAdV) have been explored as alternative vectors to the widely prevalent HAdV-C5. Despite their importance, there is limited information on the epidemiology of adenovirus immunity in many countries and geographical regions, including Mexico. In this study, we analyzed 2488 serum samples from healthy adults across all 32 states of Mexico to assess the prevalence of both total and neutralizing antibodies against various HAdV types from species A-F, and three related SAdVs. Our findings indicate a high prevalence of neutralizing antibodies against HAdV-C5 and HAdV-C6, with significant cross-reactivity observed among related adenoviruses. Notably, HAdV-D26 exhibited a lower prevalence of neutralizing antibodies, suggesting its potential suitability as a vector for vaccine development in populations with high pre-existing immunity to more common HAdV types. These results provide critical insights for optimizing adenovirus-based vaccine strategies in Mexico.

BACKGROUND: This study was conducted to determine the characteristics of various viral respiratory pathogens spreading during the epidemic season 20212022 and the frequency of co-infection with SARS-CoV-2 and influenza.
 AIM: To assess the development of the influenza epidemic and frequency of cases of co-infection with respiratory pathogens in patients with acute respiratory viral infections between 2021 and 2022.
 MATERIALS AND METHODS: Traditional and hospital epidemiological surveillance methods for acute respiratory viral infections were used.
 RESULTS: The epidemic season of 20212022 was characterized by the early activity of the influenza A(H3N2) virus and the emergence and rapid spread of the omicron variant of SARS-CoV-2. The distribution of different respiratory pathogens during the epidemic season 20212022 was clearly traced: SARS-CoV-2 (18.8%) was predominant, followed by influenza viruses (10.6%) and pathogens of other acute respiratory viral infections (0.43.7%). With respect to influenza A (H3N2) and B viruses, the heterogeneity of their populations and drift variability in relation to vaccine strains were noted.
 DISCUSSION: The frequency of co-infection with various respiratory pathogens was low, i.e., it was no more than 0.1%according to traditional surveillance, and no more than 9.2% in the hospital surveillance. The rationale for updating the composition of influenza vaccines for the countries in the Northern Hemisphere for 20222023 season was identified.
 CONCLUSION: At present, early diagnosis of influenza is important given the availability of effective drugs with a direct mechanism of action for the prevention and treatment of this pathogen. Timely use of anti-influenza drugs will reduce the risks of a severe course, complications, and death, including co-infection with SARS-CoV-2.

Detection of human adenoviruses (HAdVs) in nasopharyngeal swab samples by immunofluorescence assay (IFA) will be valuable for diagnosing HAdV infection, which is a leading cause of severe respiratory tract disease, and will help in curbing the spread of HAdV. Monoclonal antibodies employed in IFA for HAdV detection should ideally target highly conserved epitope types. Here, we describe the development of two antigen-binding fragments (Fabs) with specific reactivity to HAdV using phage antibody library technology. When tested with IFA, both Fabs recognized cells infected with several types of HAdV, some of which have been identified in epidemics globally, or associated with outbreaks of severe or fatal acute respiratory diseases. The specificity and cross-reactivity of both Fabs to HAdVs indicated that the generated Fabs could be applied in the development of IFAs to detect HAdVs. Both Fabs bound to the knob proteins, as shown by chemiluminescence enzyme immunoassay and western blot. In addition, epitope mapping showed that both Fabs recognized a conserved linear epitope among several types of HAdV. Two different Fabs recognized the same epitope, suggesting that the epitope triggered the production of at least two kinds of antibodies in the body. The generated Fabs exerted no neutralization against HAdVs. The results demonstrate that both Fabs bind to an epitope that plays no role in neutralization of HAdV.

Human adenovirus (HAdV) infection can result in a severe respiratory disease. The aim of this study was to identify HAdV types detected in patients hospitalized for severe respiratory illness. The study population consisted of 743 patients with severe respiratory disease admitted to four major hospitals in Kuwait between January 2013 and December 2016. Respiratory specimens were retrospectively screened for 20 respiratory viruses by real‐time PCR. The HAdV hexon gene was amplified and directly sequenced, and HAdV types were identified by performing Bayesian phylogenetic analysis. HAdV DNA was detected in 27 (3.6%) patients, with peaks in November and March. Most patients were infants and young children suffering from pneumonia or acute bronchiolitis. The detected HAdV types were C1, C2, C5, B3, and B7. Clusters of HAdV C1, C2, and C5 were observed with high posterior probability. All patients infected with HAdV C5 and 50% of patients infected with HAdV C2 or B7 were admitted to the intensive care unit (ICU). Co‐infection with other viruses was detected in 44.4% of patients. The most common co‐infecting virus was rhinovirus (HRV). HAdV/HRV co‐infection was detected in two children who presumably developed disseminated HAdV infection and died. This is the first report describing the circulation of HAdV types associated with severe outcomes in Kuwait. These findings highlight the need for a national surveillance system to monitor changes in predominant HAdV types and increased numbers of severe respiratory infections.

In the context of the wide range of products recommended for antiviral therapy, there is still a need for continuous evaluation of their effectiveness and safety in pediatrics. The work describes the experience of non-interventional study of the domestic drug umifenovir in the modern clinical practice. The authors studied 216 case histories of children hospitalized with acute respiratory viral infections at early stages of the disease. Against the background of the drug administration a significant reduction in the duration of all symptoms of the infectious process and the need to prescribe antibiotic therapy to patients, a reduction in the chances of complicated flu and acute respiratory viral infections, as well as a favorable safety spectrum and a high level of compliance during treatment.

BackgroundThe association between baseline seropositivity to human adenovirus (HAdV) type 5 and increased HIV acquisition in the Step HIV Vaccine Study has raised questions concerning frequency of acquired and/or persistent Adenovirus infections among adults at high risk of HIV-1 infection.MethodologyTo evaluate the frequency and pattern of HAdV shedding from the lower GI tract, we retrospectively tested rectal swabs for HAdVs in a cohort of 20 HSV-2 positive HIV-positive Peruvian men who have sex with men (MSM) undergoing rectal swabbing three times/week for 18 consecutive weeks, in a prospective study of HSV-2 suppression in HIV infection. Viral DNA was extracted and amplified using a sensitive multiplex PCR assay that detects all currently recognized HAdV types. Molecular typing of viruses was performed on selected samples by hexon gene sequencing. Baseline neutralizing antibody titers to HAdVs −5, −26, −35 and −48 were also assessed.Principal Findings15/20 individuals had HAdV detected during follow up. The median frequency of HAdV detection was 30% of samples (range 2.0% to 64.7%). HAdV shedding typically occurred on consecutive days in clustered episodes lasting a median of 4 days (range 1 to 9 days) separated by periods without shedding, suggesting frequent new infections or reactivation of latent infections over time. 8 of the 15 shedders had more than one type detected in follow-up. 20 HAdV types from species B, C, and D were identified, including HAdV-5, −26 and −48, HAdV types under development as potential vaccine candidates. 14/20 subjects were seropositive for HAdV-5; 15/20 for HAdV-26; 3/20 for HAdV-35; and 2/20 for HAdV-48. HAdV shedding did not correlate with CD4 count, plasma HIV-1 viral load, or titers to HAdV-5 or HAdV-35. The sole individual with HAdV-5 shedding was HAdV-5 seropositive.ConclusionsHAdV shedding was highly prevalent and diverse, including types presently under consideration as HIV vaccine vectors. Subclinical HAdV infection of the GI tract is common among MSM in Peru; the prevalence of HAdV in the enteric tract should be evaluated in other populations. The association between ongoing recent enteric HAdV and the immune response to recombinant HAdV vaccines should be evaluated.

The 293 cell line that was generated by transforming human embryonic kidney cells with human adenovirus type 5 (HAV5) early region 1 (E1) sequences is an excellent host for generating and growing HAV5 recombinants with E1 deleted, but it does not support the replication of bovine adenovirus type 3 (BAV3). Madin-Darby bovine kidney (MDBK), an established bovine cell line, is an excellent host for growing and plaquing BAV3. For the purpose of combining the unique characteristics of these two cell lines (293 and MDBK), we generated a number of bovine x human hybrid (BHH) cell lines. Comparison of three BHH hybrid clones-BHH3, BHH8, and BHH2C-with 293-Puro (puromycin-resistant 293 cells) and MDBK-Neo (G418-resistant MDBK cells) cell lines for total cellular DNA content, species-specific surface markers, isoenzyme analysis, and karyotyping indicate that they are hybrid in nature. BHH clones constitutively expressed the E1 proteins (E1A, E1B-21kDa, and E1B-55kDa) of HAV5 and efficiently supported the replication of both wild-type and replication-incompetent bovine or human adenoviruses. Transient gene expression experiments with a plasmid encoding the bacterial beta-galactosidase gene demonstrated that BHH cell hybrids seem to have better transfection efficiencies than either of the parental cell lines. These cell lines will be useful for isolating and growing replication-competent human or bovine adenovirus recombinants with E1 deleted and for the study of cellular or viral factors important for viral replication. The development of somatic cell hybrids appears to be a simple way of combining some of the desirable characteristics present separately in two parental cell lines.

BackgroundSevere community-acquired pneumonia (CAP) caused by human adenovirus (HAdV), especially HAdV type 55 (HAdV-55) in immunocompetent adults has raised increasing concerns. Clinical knowledge of severe CAP and acute respiratory distress syndrome induced by HAdV-55 is still limited, though the pathogen has been fully characterized by whole-genome sequencing.MethodsWe conducted a multicentre retrospective review of all consecutive patients with severe CAP caused by HAdV in immunocompetent adults admitted to the Emergency Department Intensive Care Unit of two hospitals in Northern China between February 2012 and April 2014. Clinical, laboratory, radiological characteristics, treatments and outcomes of these patients were collected and analyzed.ResultsA total of 15 consecutive severe CAP patients with laboratory-confirmed adenovirus infections were included. The median age was 30 years and all cases were identified during the winter and spring seasons. HAdV-55 was the most frequently (11/15) detected HAdV type. Persistent high fever, cough and rapid progression of dyspnea were typically reported in these patients. Significantly increased pneumonia severity index (PSI), respiratory rate, and lower PaO2/FiO2, hypersensitive CRP were reported in non-survivors compared to survivors (P = 0.013, 0.022, 0.019 and 0.026, respectively). The rapid development of bilateral consolidations within 10 days after illness onset were the most common radiographic finding, usually accompanied by adjacent ground glass opacities and pleural effusions. Total mortality was 26.7% in this study. Corticosteroids were prescribed to 14 patients in this report, but the utilization rate between survivors and non-survivors was not significant.ConclusionsHAdV and the HAdV-55 sub-type play an important role among viral pneumonia pathogens in hospitalized immunocompetent adults in Northern China. HAdV should be tested in severe CAP patients with negative bacterial cultures and a lack of response to antibiotic treatment, even if radiologic imaging and clinical presentation initially suggest bacterial pneumonia.