Human Papillomavirus 58 E7 T20I/G63S Variant Isolated from an East Asian Population Possesses High Oncogenicity.

Human papillomavirus (HPV) type 58 is the third most commonly detected HPV type in cervical cancer among Eastern Asians. Our previous international epidemiological studies revealed that HPV58 carrying an E7 natural variant, T20I/G63S (designated V1), was associated with a higher risk of cervical cancer. We recently showed that V1 possesses a greater ability to immortalize and transform primary cells, as well as degrading pRB more effectively, than the prototype and other common variants. In this study, we performed a series of phenotypic and molecular assays using physiologically relevant in vitro and in vivo models to compare the oncogenicity of V1 with that of the prototype and other common natural variants. Through activation of the AKT and K-Ras/extracellular signal-regulated kinase (ERK) signaling pathways, V1 consistently showed greater oncogenicity than the prototype and other variants, as demonstrated by increased cell proliferation, migration, and invasion, as well as induction of larger tumors in athymic nude mice. This study complements our previous epidemiological and molecular observations pinpointing the higher oncogenicity of V1 than that of the prototype and all other common variants. Since V1 is more commonly found in eastern Asia, our report provides insight into the design of HPV screening assays and selection of components for HPV vaccines in this region.IMPORTANCE Epidemiological studies have revealed that a wild-type variant of HPV58 carrying an E7 variation, T20I/G63S (V1), is associated with a higher risk of cervical cancer. We previously reported that this increased oncogenicity could be the result of the virus's greater ability to degrade pRB, thereby leading to an increased ability to grow in an anchorage-independent manner. In addition to this, this report further showed that this HPV variant induced activation of the AKT and K-Ras/ERK signaling pathways, thereby explaining its genuine oncogenicity in promoting cell proliferation, migration, invasion, and formation of tumors, all to a greater extent than the prototype HPV58 and other common variants.

SARS-CoV-2 RNA Detection on Disposable Wooden Chopsticks, Hong Kong.

We detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA on disposable wooden chopsticks used by 5 consecutive asymptomatic and postsymptomatic patients admitted for isolation and care at our hospital. Although we did not assess virus viability, our findings may suggest potential for transmission through shared eating utensils.

Serologic Responses in Healthy Adult with SARS-CoV-2 Reinfection, Hong Kong, August 2020.

In March 2020, mild signs and symptoms of coronavirus disease developed in a healthy 33-year-old man in Hong Kong. His first infection did not produce virus neutralizing antibodies. In August, he had asymptomatic reinfection, suggesting that persons without a robust neutralizing antibody response might be at risk for reinfection.

Frequent Genetic Mismatch between Vaccine Strains and Circulating Seasonal Influenza Viruses, Hong Kong, China, 1996-2012.

The World Health Organization selects influenza vaccine compositions biannually to cater to peaks in temperate regions. In tropical and subtropical regions, where influenza seasonality varies and epidemics can occur year-round, the choice of vaccine remains uncertain. Our 17-year molecular epidemiologic survey showed that most influenza A(H3N2) (9/11) and B (6/7) vaccine strains had circulated in East Asia >1 year before inclusion into vaccines. Northern Hemisphere vaccine strains and circulating strains in East Asia were closely matched in 7 (20.6%) of 34 seasons for H3N2 and 5 (14.7%) of 34 seasons for B. Southern Hemisphere vaccines also had a low probability of matching (H3N2, 14.7%; B, 11.1%). Strain drift among seasons was common (H3N2, 41.2%; B, 35.3%), and biannual vaccination strategy (Northern Hemisphere vaccines in November followed by Southern Hemisphere vaccines in May) did not improve matching. East Asia is an important contributor to influenza surveillance but often has mismatch between vaccine and contemporarily circulating strains.

Age-specific seroprevalence of dengue infection in Hong Kong.

A newly developed dengue virus vaccine (chimeric yellow fever virus-tetravalent dengue vaccine [CYD-TDV]) has recently been licensed for clinical use. The World Health Organization recommends vaccination for populations with seroprevalence of at least 70% to maximize public health impact. This study aimed to delineate the seroprevalence of dengue infection in Hong Kong. A total of 105 972 serum samples submitted for clinical testing during the period 2013-2015 were age-stratified and sex-stratified. For each year of collection, 25 samples were randomly selected from each age-sex group. Altogether, 2100 samples were tested for the dengue immunoglobulin G (IgG) antibody using a non-type-specific ELISA kit. The overall dengue IgG-positive rate was 4.6% and showed no significant change over the 3 years. The positive rate was not associated with sex, but a steep rise in seroprevalence for persons above 65 years (32.7%) was observed. The low dengue seroprevalence in Hong Kong does not support implementation of a national immunization program. Majority of the population in Hong Kong are susceptible to dengue infection, and a substantial proportion of persons older than 65 years could acquire secondary infection and are prone to develop severe dengue.

The role of human papillomavirus in laryngeal cancer in Southern China.

To delineate the role of human papillomavirus (HPV) in laryngeal cancer in Southern Chinese, a retrospective cross-sectional study was conducted in a major otorhinolaryngology referral center in Hong Kong. Eighty-five Chinese patients with histology-confirmed laryngeal squamous cell carcinoma (LSCC) diagnosed between 2005 and 2010 were examined for the status of HPV by PCR, and the expression of p16 and p53 by immunohistochemistry. The HPV, p16 and p53 findings were correlated with clinicopathological features, recurrence and 5-year survival. HPV DNA was detected in one patient (1.2%, 95%CI: 0.2-6.4%) who had glottic cancer and harbored HPV-6. Overexpression of p16 and p53 were detected in 11 (12.9%) and 47 (55.3%) cases, respectively. Recurrence occurred in 22.4% of patients at a median of 13 months. The 5-year overall survival and disease-specific survival were 55.7% and 72.4%, respectively. Overexpression of p16 or p53 was not associated with clinicopathological features, recurrence or overall survival. HPV plays a limited role in laryngeal cancer in Hong Kong Southern Chinese. In contrast to oropharyngeal cancer, p16 cannot be used as a surrogate marker for oncogenic involvement of HPV and cannot predict survival in laryngeal cancer.

First-In-Class Inhibitor of Ribosomal RNA Synthesis with Antimicrobial Activity against Staphylococcus aureus.

We report the discovery of the first bacterial ribosomal RNA (rRNA) synthesis inhibitor that has specific antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). A pharmacophore model was constructed on the basis of the protein-protein interaction between essential bacterial rRNA transcription factors NusB and NusE and employed for an in silico screen to identify potential leads. One compound, (E)-2-{[(3-ethynylphenyl)imino]methyl}-4-nitrophenol (MC4), demonstrated antimicrobial activity against a panel of S. aureus strains, including MRSA, without significant toxicity to mammalian cells. MC4 resulted in a decrease in the rRNA level in bacteria, and the target specificity of MC4 was confirmed at the molecular level. Results obtained from this work validated the bacterial rRNA transcription machinery as a novel antimicrobial target. This approach may be extended to other factors in rRNA transcription, and MC4 could be applied as a chemical probe to dissect the relationship among MRSA infection, MRSA growth rate, and rRNA synthesis, in addition to its therapeutic potential.

The role of human papillomavirus in head and neck squamous cell carcinoma: A case control study on a southern Chinese population.

HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor.

Influenza B lineage circulation and hospitalization rates in a subtropical city, Hong Kong, 2000-2010.

BACKGROUND: A need for quadrivalent vaccines to cover both lineages of influenza B has been raised. Information on the circulation status of influenza B lineages and the associated hospitalization rates is important to assist evidence-based decision making. This retrospective study revealed the situation in a subtropical city over a 10-year period. METHODS: Sequences of 268 influenza B isolates were analyzed to identify the circulating pool of virus lineages for each year. Hospital records and population census data were used to estimate annual age-specific hospitalization rates. RESULTS: Cocirculation with 2 influenza B lineages was found in 9 of the 10 years. Only in 6 of the 10 years had the vaccine strain successfully matched with the lineage that was found in >50% of the circulating pool. Six years were predominated by one lineage (occupying >80% of the circulating pool), and these years had higher (average, 1.4-fold) hospitalization rates. Matching between vaccine and circulating lineage was achieved only in 2 of the 6 "predominated years." The Yamagata lineage accounted for most (5/6) of the predominated years. Overall, 24% of influenza admissions were due to influenza B, and influenza B contributed to a higher proportion (41.9%) among children and young teenagers (5-14 years old). CONCLUSIONS: Cocirculation with 2 influenza B lineages is common in the subtropical region. To predict the next predominant lineage proves to be difficult. Influenza B accounts for a substantial fraction of influenza-associated hospitalizations, especially among children and young teenagers. Quadrivalent vaccines may improve the effectiveness of influenza vaccination programs.

Seroprevalence of hepatitis E virus in Hong Kong, 2008-2009.

The public health impact of hepatitis E virus (HEV) infection varies across the world. An HEV vaccine has been recently approved for clinical use in China. Population-specific seroprevalence data are essential for cost-effective assessment of vaccination programs. Here, a cross-sectional study was performed to provide an update on the local seroprevalence of HEV. An archive of serum samples submitted for virological investigation between 2008 and 2009 to a general hospital was used. A total of 450 samples with equal numbers from each gender covering the age groups from 1-10 to >80 years (25 samples per group) were tested for HEV immunoglobulin G (IgG) by enzyme-linked immunoassay. Age- and gender-specific seroprevalence were determined. The HEV IgG positive rate increased from 8% among 1-10 years to 56% among >80 years. The increase in prevalence was constant throughout all age groups without a steeper slope or plateau observed from any age group. The overall positive rate among males was significantly higher than among females (32.9% vs. 24.4%, P = 0.048). The best-fitted seroprevalence curves also suggested a higher positive rate for males across all age groups. Increased HEV IgG positivity was noted in comparison with historical local studies. Collectively, the prevalence of HEV in Hong Kong has increased over the past decade. A large proportion of the population is still susceptible to infection, and all age groups are at risk. Territory-wide vaccination program should be considered.

Extent of Oral-Gut Transmission of Bacterial and Fungal Microbiota in Healthy Chinese Adults.

Recent studies have provided evidence on the presence of an oral-gut microbiota axis in gastrointestinal diseases; however, whether a similar axis exists in healthy individuals is still in debate. Here, we characterized the bacterial and fungal microbiomes in paired oral rinse and stool samples collected from 470 healthy Chinese adults by sequencing the 16S rRNA V3-V4 and ITS1 regions, respectively. We hypothesized that there is limited oral-gut transmission of both the bacterial and fungal microbiota in healthy Chinese adults. Our results showed that the oral and gut microbiota in healthy individuals differed in taxonomic composition, alpha and beta diversity, metabolic potential, and network properties. Bayesian analysis showed that the vast majority of subjects had negligible or low bacterial and fungal oral-to-stool contribution. Detailed examination of the prevalent amplicon sequence variants (ASVs) also revealed limited cases of sharing between the oral and stool samples within the same individuals, except a few bacterial and fungal ASVs. Association analysis showed that sharing of the potentially transmissible fungal ASVs was associated with host factors, including an older age and a higher body mass index. Our findings indicate that oral-gut transmission of both bacterial and fungal microbiota in healthy adults is limited. Detection of a large amount of shared bacterial or fungal members between the oral and gut microbiome of an individual may indicate medical conditions that warrant detailed checkup. IMPORTANCE The oral-gut microbiota axis in health is a fundamentally important and clinically relevant topic; however, our current understanding of it remains biased and incomplete. By characterizing the bacterial and fungal microbiomes in paired oral rinse and stool samples from a large cohort of healthy Chinese adults, here we provided new evidence that oral-gut microbiota transmission is limited in non-Western population and across biological domains. Our study has established an important baseline of a healthy oral-gut microbiota axis, with which other disease conditions can be compared. Besides, our findings have practical implications that detection of a large amount of shared bacterial or fungal members between the oral cavity and gut within the same individual as an indicator of potential medical conditions.

Development of the early-life gut microbiome and associations with eczema in a prospective Chinese cohort.

IMPORTANCE: Eczema is a major allergic disease in children, which is particularly prevalent in Chinese children during their first year of life. In this study, we showed that alterations in the infant gut microbiota precede the development of eczema in a prospective Chinese cohort. In particular, we discovered enrichments of the genera Clostridium sensu stricto 1 and Finegoldia in the cases at 3 and 1 month of age, respectively, which may represent potential targets for intervention to prevent eczema. Besides, we identified a depletion of Bacteroides from 1 to 6 months of age and an enrichment of Clostridium sensu stricto 1 at 3 months in the eczema cases, patterns also observed in C-section-born infants within the same time frames, providing first evidence to support a role of the gut microbiota in previously reported associations between C-section and increased risk of eczema in infancy.

Effectiveness of mRNA and inactivated COVID-19 vaccines: A test-negative study in an infection-naïve Hong Kong population.

OBJECTIVE: Assess real-world effectiveness of vaccines against COVID-19. METHODS: A test-negative study was conducted in January-May 2022 during an Omicron BA.2 wave in Hong Kong. COVID-19 was identified by RT-PCR. 1-1 case-control matching was based on propensity score with vaccine effectiveness adjusted for confounders. RESULTS: Altogether, 1781 cases and 1737 controls aged 3-105 years were analysed. The mean lag time from the last dose of vaccination to testing for SARS-CoV-2 was 133.9 (SD: 84.4) days. Two doses of either vaccine within 180 days offered a low effectiveness against COVID-19 of all severity combined (VEadj [95% CI] for BNT162b2: 27.0% [4.2-44.5], CoronaVac: 22.9% [1.3-39.7]), and further decreased after 180 days. Two doses of CoronaVac were poorly protective 39.5% [4.9-62.5] against severe diseases for age ≥ 60 years, but the effectiveness increased substantially after the third dose (79.1% [25.7-96.7]). Two doses of BNT162b2 protected age ≥ 60 years against severe diseases (79.3% [47.2, 93.9]); however, the uptake was not high enough to assess three doses. CONCLUSIONS: The current real-world analysis indicates a high vaccine effectiveness of three doses of inactivated virus (CoronaVac) vaccines against Omicron variant, whereas the effectiveness of two doses is suboptimal.

Attribution of human papillomavirus types to cervical intraepithelial neoplasia and invasive cancers in Southern China.

The attribution of individual human papillomavirus (HPV) types to cervical neoplasia, especially intraepithelial lesions, varies ethnogeographically. Population-specific data are required for vaccine cost-effectiveness assessment and type replacement monitoring. HPV was detected from 2,790 Chinese women (444 invasive cervical cancers [ICC], 772 cervical intraepithelial neoplasia [CIN] grade 3, 805 CIN2 and 769 CIN1. The attribution of each HPV type found in multiple-type infections was approximated by the fractional contribution approach. Multiple-type infection was common and correlated inversely with lesion severity (54.7% for CIN1, 48.7% for CIN2, 46.2% for CIN3, 27.5% for ICC). Vaccine-covered high-risk types (HPV16/18) attributed to 59.5% of squamous cell carcinoma, 78.6% of adenocarcinoma, 35.9% of CIN3, 18.4% of CIN2 and 7.4% of CIN1. Distinct features compared to worldwide were a higher attribution of HPV52 and HPV58, and a much lower attribution of HPV45. Inclusion of HPV52 and HPV58 in future vaccines would provide the highest marginal increase in coverage with 11.7% for squamous cell carcinoma, 14.4% for CIN3, 22.6% for CIN2 and 17.7% for CIN1. The attribution of HPV types in southern China is different from elsewhere, which should be considered in prioritizing HPV types for vaccine and screening assay development.

Complications and outcomes of pandemic 2009 Influenza A (H1N1) virus infection in hospitalized adults: how do they differ from those in seasonal influenza?

BACKGROUND: It is unclear whether pandemic 2009 influenza A (pH1N1) infection caused more significant disease among hospitalized adults than seasonal influenza. METHODS: A prospective, observational study was conducted in adults hospitalized with polymerase chain reaction-confirmed pH1N1 infection in 2 acute-care general hospitals from June 2009 to May 2010 (n = 382). Complications and outcomes were described and compared with those in a seasonal influenza cohort (2007-2008, same hospitals; n = 754). RESULTS: Hospitalized patients with pH1N1 influenza were younger than those with seasonal influenza (mean age ± standard deviation, 47 ± 20 vs 70 ± 19 years) and fewer had comorbid conditions (48% vs 64%). The rate of positive immunofluorescence assay results was low (54% vs 84%), and antiviral use was frequent (96% vs 52%). Most patients in both cohorts developed complicated illnesses (67.8% vs 77.1%), but patients with pH1N1 influenza had higher rates of extrapulmonary complications (23% vs 16%; P = .004) and intensive care unit admission and/or death (patient age <35 years, 2.3% vs 0%; 35-65 years, 12.4% vs 3.2%; >65 years, 13.5% vs 8.5%; adjusted odds ratio [OR] 2.13; 95% confidence interval [CI], 1.25-3.62; P = .005). Patients who received antiviral treatment within 96 h after onset had better survival (log-rank test, P < .001). However, without timely treatment, the mortality risk was higher with pH1N1 infection (9.0% vs 5.8% for seasonal influenza; adjusted OR, 6.85; 95% CI, 1.64-28.65; P = .008]. Bacterial superinfection worsened outcomes. CONCLUSIONS: Adults hospitalized for pH1N1 influenza had significant complications and mortality despite being younger than patients with seasonal influenza. Antiviral treatment within 96 h may improve survival.

Determinants and Interactions of Oral Bacterial and Fungal Microbiota in Healthy Chinese Adults.

Numerous studies have examined the composition of and factors shaping the oral bacterial microbiota in healthy adults; however, similar studies on the less dominant yet ecologically and clinically important fungal microbiota are scarce. In this study, we characterized simultaneously the oral bacterial and fungal microbiomes in a large cohort of systemically healthy Chinese adults by sequencing the bacterial 16S rRNA gene and fungal internal transcribed spacer. We showed that different factors shaped the oral bacterial and fungal microbiomes in healthy adults. Sex and age were associated with the alpha diversity of the healthy oral bacterial microbiome but not that of the fungal microbiome. Age was also a major factor affecting the beta diversity of the oral bacterial microbiome; however, it only exerted a small effect on the oral fungal microbiome when compared with other variables. After controlling for age and sex, the bacterial microbiota structure was most affected by marital status, recent oral conditions and oral hygiene-related factors, whereas the fungal microbiota structure was most affected by education level, fruits and vegetables, and bleeding gums. Bacterial-fungal interactions were limited in the healthy oral microbiota, with the strongest association existing between Pseudomonas sp. and Rhodotorula dairenensis. Several bacterial amplicon sequence variants (ASVs) belonging to Veillonella atypica and the genera Leptotrichia, Streptococcus and Prevotella_7 and fungal ASVs belonging to Candida albicans and the genus Blumeria were revealed as putative pivotal members of the healthy oral microbiota. Overall, our study has facilitated understanding of the determining factors and cross-kingdom interactions of the healthy human oral microbiome. IMPORTANCE Numerous studies have examined the bacterial community residing in our oral cavity; however, information on the less dominant yet ecologically and clinically important fungal members is limited. In this study, we characterized simultaneously the oral bacterial and fungal microbial communities in a large cohort of healthy Chinese adults, examined their associations with an array of host factors, and explored potential interactions between the two microbial groups. We showed that different factors shape the diversity and structure of the oral bacterial and fungal microbial communities in healthy adults, with, for instance, sex and age only associated with the diversity of the bacterial community but not that of the fungal community. Besides, we found that bacterial-fungal interactions are limited in the healthy oral cavity. Overall, our study has facilitated understanding of the determining factors and bacterial-fungal interactions of the healthy human oral microbial community.

Cross-Clade Memory Immunity in Adults Following SARS-CoV-1 Infection in 2003.

Importance: Knowledge of the longevity and breath of immune response to coronavirus infection is crucial for the development of next-generation vaccines to control the COVID-19 pandemic. Objectives: To determine the profile of SARS-CoV-2 antibodies among persons infected with the closely related virus, SARS-CoV-1, in 2003 (SARS03 survivors) and to characterize their antibody response soon after the first and second doses of COVID-19 vaccines. Design, Setting, and Participants: This prospective cohort study examined SARS-CoV-2 antibodies among SARS03 survivors compared with sex- and age-matched infection-naive controls. Participants received the COVID-19 vaccines between March 1 and September 30, 2021. Interventions: One of the 2 COVID-19 vaccines (inactivated [CoronaVac] or messenger RNA [BNT162b2]) available in Hong Kong. Two doses were given according to the recommended schedule. The vaccine type administered was known to both participants and observers. Main Outcomes and Measures: SARS-CoV-2 antibodies were measured prevaccination, 7 days after the first dose, and 14 days after the second dose. Results: Eighteen SARS03 adult survivors (15 women and 3 men; median age, 46.5 [IQR, 40.0-54.3] years) underwent prevaccination serologic examination. The vast majority retained a detectable level of antibodies that cross-reacted with SARS-CoV-2 (16 of 18 [88.9%] with nucleocapsid protein antibodies and 17 of 18 [94.4%] with receptor-binding domain of spike protein antibodies); a substantial proportion (11 of 18 [61.1%]) had detectable cross-neutralizing antibodies. Twelve SARS03 adult survivors (10 women and 2 men) underwent postvaccination serologic examination. At 7 days after the first dose of vaccine, SARS03 survivors mounted significantly higher levels of neutralizing antibodies compared with controls (median inhibition: 89.5% [IQR, 77.1%-93.7%] vs 13.9% [IQR, 11.8%-16.1%] for BNT162b2; 64.9% [IQR, 60.8%-69.5%] vs 13.4% [IQR, 9.5%-16.8%] for CoronaVac; P < .001 for both). At 14 days after the second dose, SARS03 survivors generated a broader antibody response with significantly higher levels of neutralizing antibodies against variants of concern compared with controls (eg, median inhibition against Omicron variant, 52.1% [IQR, 35.8%-66.0%] vs 14.7% [IQR, 2.5%-20.7%]; P < .001). Conclusions and Relevance: The findings of this prospective cohort study suggest that infection with SARS-CoV-1 was associated with detectable levels of antibodies that cross-react and cross-neutralize SARS-CoV-2, which belongs to a distinct clade under the same subgenus Sarbecovirus. These findings support the development of broadly protective vaccines to cover sarbecoviruses that caused 2 devastating zoonotic outbreaks in humans over the last 2 decades.

Limited Impact of SARS-CoV-2 on the Human Naso-Oropharyngeal Microbiota in Hospitalized Patients.

Numerous studies have reported dysbiosis in the naso- and/or oro-pharyngeal microbiota of COVID-19 patients compared with healthy individuals; however, only a few small-scale studies have also included a disease control group. In this study, we characterized and compared the bacterial communities of pooled nasopharyngeal and throat swabs from hospitalized COVID-19 patients (n = 76), hospitalized non-COVID-19 patients with respiratory symptoms or related illnesses (n = 69), and local community controls (n = 76) using 16S rRNA gene V3-V4 amplicon sequencing. None of the subjects received antimicrobial therapy within 2 weeks prior to sample collection. Both COVID-19 and non-COVID-19 hospitalized patients differed in the composition, alpha and beta diversity, and metabolic potential of the naso-oropharyngeal microbiota compared with local controls. However, the microbial communities in the two hospitalized patient groups did not differ significantly from each other. Differential abundance analysis revealed the enrichment of nine bacterial genera in the COVID-19 patients compared with local controls; however, six of them were also enriched in the non-COVID-19 patients. Bacterial genera uniquely enriched in the COVID-19 patients included Alloprevotella and Solobacterium. In contrast, Mogibacterium and Lactococcus were dramatically decreased in COVID-19 patients only. Association analysis revealed that Alloprevotella in COVID-19 patients was positively correlated with the level of the inflammation biomarker C-reactive protein. Our findings reveal a limited impact of SARS-CoV-2 on the naso-oropharyngeal microbiota in hospitalized patients and suggest that Alloprevotella and Solobacterium are more specific biomarkers for COVID-19 detection. IMPORTANCE Our results showed that while both COVID-19 and non-COVID-19 hospitalized patients differed in the composition, alpha and beta diversity, and metabolic potential of the naso-oropharyngeal microbiota compared with local controls, the microbial communities in the two hospitalized patient groups did not differ significantly from each other, indicating a limited impact of SARS-CoV-2 on the naso-oropharyngeal microbiota in hospitalized patients. Besides, we identified Alloprevotella and Solobacterium as bacterial genera uniquely enriched in COVID-19 patients, which may serve as more specific biomarkers for COVID-19 detection.

Apoptosis, cytokine and chemokine induction by non-structural 1 (NS1) proteins encoded by different influenza subtypes.

BACKGROUND: Influenza pandemic remains a serious threat to human health. Viruses of avian origin, H5N1, H7N7 and H9N2, have repeatedly crossed the species barrier to infect humans. Recently, a novel strain originated from swine has evolved to a pandemic. This study aims at improving our understanding on the pathogenic mechanism of influenza viruses, in particular the role of non-structural (NS1) protein in inducing pro-inflammatory and apoptotic responses. METHODS: Human lung epithelial cells (NCI-H292) was used as an in-vitro model to study cytokine/chemokine production and apoptosis induced by transfection of NS1 mRNA encoded by seven infleunza subtypes (seasonal and pandemic H1, H2, H3, H5, H7, and H9), respectively. RESULTS: The results showed that CXCL-10/IP10 was most prominently induced (> 1000 folds) and IL-6 was slightly induced (< 10 folds) by all subtypes. A subtype-dependent pattern was observed for CCL-2/MCP-1, CCL3/MIP-1α, CCL-5/RANTES and CXCL-9/MIG; where induction by H5N1 was much higher than all other subtypes examined. All subtypes induced a similar temporal profile of apoptosis following transfection. The level of apoptosis induced by H5N1 was remarkably higher than all others. The cytokine/chemokine and apoptosis inducing ability of the 2009 pandemic H1N1 was similar to previous seasonal strains. CONCLUSIONS: In conclusion, the NS1 protein encoded by H5N1 carries a remarkably different property as compared to other avian and human subtypes, and is one of the keys to its high pathogenicity. NCI-H292 cells system proves to be a good in-vitro model to delineate the property of NS1 proteins.

Longitudinal Cytokine Profile in Patients With Mild to Critical COVID-19.

The cytokine release syndrome has been proposed as the driver of inflammation in coronavirus disease 2019 (COVID-19). However, studies on longitudinal cytokine profiles in patients across the whole severity spectrum of COVID-19 are lacking. In this prospective observational study on adult COVID-19 patients admitted to two Hong Kong public hospitals, cytokine profiling was performed on blood samples taken during early phase (within 7 days of symptom onset) and late phase (8 to 12 days of symptom onset). The primary objective was to evaluate the difference in early and late cytokine profiles among patient groups with different disease severity. The secondary objective was to assess the associations between cytokines and clinical endpoints in critically ill patients. A total of 40 adult patients (mild = 8, moderate = 15, severe/critical = 17) hospitalized with COVID-19 were included in this study. We found 22 cytokines which were correlated with disease severity, as proinflammatory Th1-related cytokines (interleukin (IL)-18, interferon-induced protein-10 (IP-10), monokine-induced by gamma interferon (MIG), and IL-10) and ARDS-associated cytokines (IL-6, monocyte chemoattractant protein-1 (MCP-1), interleukin-1 receptor antagonist (IL-1RA), and IL-8) were progressively elevated with increasing disease severity. Furthermore, 11 cytokines were consistently different in both early and late phases, including seven (growth-regulated oncogene-alpha (GRO-α), IL-1RA, IL-6, IL-8, IL-10, IP-10, and MIG) that increased and four (FGF-2, IL-5, macrophage-derived chemokine (MDC), and MIP-1α) that decreased from mild to severe/critical patients. IL-8, followed by IP-10 and MDC were the best performing early biomarkers to predict disease severity. Among critically ill patients, MCP-1 predicted the duration of mechanical ventilation, highest norepinephrine dose administered, and length of intensive care stay.