Effectiveness of the third dose of BNT162b2 vaccine on neutralizing Omicron variant in the Japanese population

Introduction

The vaccine against SARS-CoV-2 provides humoral immunity to fight COVID-19; however, the acquired immunity gradually declines. Booster vaccination restores reduced humoral immunity; however, its effect on newly emerging variants, such as the Omicron variant, is a concern. As the waves of COVID-19 cases and vaccine programs differ between countries, it is necessary to know the domestic effect of the booster.

Methods

Serum samples were obtained from healthcare workers (20–69 years old) in the Pfizer BNT162b2 vaccine program at the Toyama University Hospital 6 months after the second dose (6mA2D, n = 648) and 2 weeks after the third dose (2wA3D, n = 565). The anti-SARS-CoV-2 antibody level was measured, and neutralization against the wild-type and variants (Delta and Omicron) was evaluated using pseudotyped viruses. Data on booster-related events were collected using questionnaires.

Results

The median anti-SARS-CoV-2 antibody was >30.9-fold elevated after the booster (6mA2D, 710.0 U/mL [interquartile range (IQR): 443.0–1068.0 U/mL]; 2wA3D, 21927 U/mL [IQR: 15321.0–>25000.0 U/mL]). Median neutralizing activity using 100-fold sera against wild-type-, Delta-, and Omicron-derived variants was elevated from 84.6%, 36.2%, and 31.2% at 6mA2D to >99.9%, 99.1%, and 94.6% at 2wA3D, respectively. The anti-SARS-CoV-2 antibody levels were significantly elevated in individuals with fever ≥37.5 °C, general fatigue, and myalgia, local swelling, and local hardness.

Conclusion

The booster effect, especially against the Omicron variant, was observed in the Japanese population. These findings contribute to the precise understanding of the efficacy and side effects of the booster and the promotion of vaccine campaigns.

Escherichia coli ST131 isolated from urological patients can acquire plasmid-mediated extended spectrum β-lactamase from other bacteria with high frequency

OBJECTIVES

To investigate the prevalence of the clonal group Escherichia coli ST131 in urologic patients, and to clarify the mechanisms underlying the high prevalence of the antimicrobial resistant genes in ST131.

METHODS

We used 65 Escherichia coli strains collected from the Department of Urology, Nagasaki University Hospital, between January 2018 and December 2018. All of them underwent multilocus sequence typing and were analyzed for genes associated with quinolone resistance and extended-spectrum β-lactamases. To compare ST131 and non-ST131 strains, bacterial conjugation experiments and intestinal colonization evaluations were performed.

RESULTS

ST131 was the most dominant among all the strains, along with levofloxacin resistant strains, and extended-spectrum β-lactamases positive strains (32%, 63%, and 73%, respectively). 12 out of 15 extended-spectrum β-lactamases-producing Escherichia coli strains harbored CTX-M-9. In particular, all extended-spectrum β-lactamases-producing ST131 strains possessed CTX-M-9. The proportions of ST131 strains with or without quinolone resistance-determining region mutations were significantly higher and lower, respectively, than that of non-ST131 strains (P = 0.0002 and P < 0.0001, respectively). When Klebsiella pneumoniae was used as a donor, three ST131 strains acquired extended-spectrum β-lactamases a total of 16 times (six, four, and six times each), which was significantly more than that in one of the non-ST131 strains (two times). The amount of bacteria was significantly lower in the ST131 strains than in the non-ST131 strains administered to mice. Both the ST131 and non-ST131 strains increased again after the administration of vancomycin, even after the colony was not detected.

CONCLUSIONS

These results support the mechanisms underlying the prevalence of ST131 strains in hospitals, particularly in urologic patients.

Circulating Type I Interferon Levels in the Early Phase of COVID-19 Are Associated With the Development of Respiratory Failure

Background

The role of type I interferons (IFNs) in the early phase of COVID-19 remains unclear.

Objectives

To evaluate the relationship between IFN-I levels in patients with COVID-19 and clinical presentation, SARS-CoV-2 viral load, and other major pro-inflammatory cytokines.

Methods

This prospective observational study recruited patients hospitalized with COVID-19. The levels of interferon-alpha (IFN-α), interferon-beta (IFN-β), interleukin-6 (IL-6), and C-X-C motif chemokine ligand (CXCL10) within 5 days after symptom onset were measured using an ELISA, in serum from blood collected within 5 days after the onset of symptoms. The SARS-CoV-2 viral load was determined via qPCR using nasal-swab specimens and serum.

Results

The study enrolled 50 patients with COVID-19. IFN-α levels were significantly higher in patients who presented with pneumonia or developed hypoxemic respiratory failure (p &lt; 0.001). Furthermore, IFN-α levels were associated with viral load in nasal-swab specimens and RNAemia (p &lt; 0.05). In contrast, there was no significant association between IFN-β levels and the presence of pneumonia or RNAemia, despite showing a stronger association with nasal-swab viral load (p &lt; 0.001). Correlation analysis showed that the serum levels of IFN-α significantly correlated with those of IFN-β, IL-6, and CXCL10, while the levels of IFN-β did not correlate with those of IL-6 or CXCL10.

Conclusions

Serum IFN-I levels in the early phase of SARS-CoV-2 infection were higher in patients who developed hypoxemic respiratory failure. The association between IFN-α, IL-6, and CXCL10 may reflect the systemic immune response against SARS-CoV-2 invasion into pulmonary circulation, which might be an early predictor of respiratory failure due to COVID-19.

Novel super-neutralizing antibody UT28K is capable of protecting against infection from a wide variety of SARS-CoV-2 variants

Many potent neutralizing SARS-CoV-2 antibodies have been developed and used for therapies. However, the effectiveness of many antibodies has been reduced against recently emerging SARS-CoV-2 variants, especially the Omicron variant. We identified a highly potent SARS-CoV-2 neutralizing antibody, UT28K, in COVID-19 convalescent individuals who recovered from a severe condition. UT28K showed efficacy in neutralizing SARS-CoV-2 in an in vitro assay and in vivo prophylactic treatment, and the reactivity to the Omicron strain was reduced. The structural analyses revealed that antibody UT28K Fab and SARS-CoV-2 RBD protein interactions were mainly chain-dominated antigen-antibody interactions. In addition, a mutation analysis suggested that the emergence of a UT28K neutralization-resistant SARS-CoV-2 variant was unlikely, as this variant would likely lose its competitive advantage over circulating SARS-CoV-2. Our data suggest that UT28K offers potent protection against SARS-CoV-2, including newly emerging variants.

Age-Dependent Reduction in Neutralization against Alpha and Beta Variants of BNT162b2 SARS-CoV-2 Vaccine-Induced Immunity

Vaccines against severe acute respiratory syndrome coronavirus-2 have been introduced. To investigate the relationship between vaccine-induced humoral immunity and patient age, we measured antibody levels and neutralization in vaccinated sera. Sera from 13 to 17 days after the second dose of the BNT162b2 vaccine were collected from health care workers at the University of Toyama (n = 740). Antibody levels were measured by the anti-receptor binding domain antibody test (anti-RBD test), and neutralization against wild-type (WT), α- and β-variant pseudotyped viruses were assayed using a high-throughput chemiluminescent reduction neutralizing test (htCRNT; positivity cutoff, 50% neutralization at serum dilution 1:100). Basic clinical characteristics were obtained from questionnaires. Antibodies were confirmed in all participants in both the anti-RBD test (median, 2,112 U/ml; interquartile range [IQR], 1,275 to 3,390 U/ml) and the htCRNT against WT (median % inhibition, >99.9; IQR, >99.9 to >99.9). For randomly selected sera (n = 61), 100.0% had positive htCRNT values against the α- and β-derived variants. Among those who answered the questionnaire (n = 237), the values of the anti-RBD test were negatively correlated with age in females (P < 0.01). An age-dependent decline in neutralization was observed against the variants but not against the wild-type virus (wild type, P = 0.09; α, P < 0.01; β, P < 0.01). The neutralizing activity induced by BNT162b2 was obtained not only against the wild-type virus, but also against the variants; however, there was an age-dependent decrease in the latter. Age-related heterogeneity of vaccine-acquired immunity is a concern in preventive strategies in the era dominated by variants. IMPORTANCE Since mRNA vaccines utilize wild-type SARS-CoV-2 spike protein as an antigen, there are potential concerns about acquiring immunity to variants of this virus. The neutralizing activity in BNT162b2-vaccinated individuals was higher against the wild-type virus than against its variants; this effect was more apparent in older age groups. This finding suggests that one of the weaknesses of the mRNA vaccine is the high risk of variant infection in the elderly population. Because the elderly are at a higher risk of SARS-CoV-2 infection, the age-dependent decline of neutralization against viral variants should be considered while planning vaccination programs that include boosters.

The surveillance of colistin resistance and mobilized colistin resistance genes in multidrug-resistant Enterobacteriaceae isolated in Japan

BACKGROUND

The plasmid-mediated bacterial colistin-resistant gene, mcr, is of global concern in clinical healthcare. However, there are few reports of surveillance for mcr in Japan. The aim of this study was to assess the prevalence of colistin resistance by identifying nine mcr genes in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae (CRE) isolates in Japan.

METHODS

A total of 273 ESBL and CRE clinical isolates were collected from patients in five tertiary hospitals from August 2016 to March 2017. Minimum inhibitory concentration (MIC) of colistin was measured using the microdilution method. Polymerase chain reaction (PCR) was performed to detect mcr-1 to mcr-9 genes in all strains. Whole-genome sequencing (WGS) analysis was conducted for any mcr-genes identified that had not been previously reported in patients from Japan.

RESULTS

The rate of colistin resistance was 7.7% in all strains, with a higher rate in the CRE strains than in the ESBL-producing strains (20.4% versus 1.1%). The mcr-5 and mcr-9 gene were detected in one ESBL-producing Escherichia coli strain (1/273, 0.37%) and three CRE strains (3/273, 1.1%), respectively. As the ESBL-producing E. coli strain was the first clinical strain with mcr-5 in Japan, WGS analysis was performed for the strain. The sequence type of the mcr-5-positive strain was ST1642 and it carried two distinct plasmids, ESBL gene-carrying pN-ES-6-1, and mcr-5.1-carrying pN-ES-6-2.

CONCLUSIONS

The results of this study showed that the frequency of colistin resistance and mcr-positive strains is not high in Japan. As the MIC for colistin was low in the mcr-5.1 and mcr-9 gene-positive strain, continuous monitoring of mcr genes is necessary.

Conjunctival Sac Microbiome in Infectious Conjunctivitis

Acute bacterial conjunctival infections are common, and this study identified the conjunctival bacterial community in infectious conjunctivitis cases seen at the outpatient clinic of Khanh Hoa General Hospital in Nha Trang, Vietnam from October 2016 through December 2017. Conjunctival swabs were collected and tested using conventional culture, PCR, and 16S ribosomal RNA sequencing. The study included 47 randomly selected patients. More than 98% of all DNA reads represented five bacterial phyla. Three of these phyla constituted 92% of all sequences (Firmicutes (35%), Actinobacteria (31%), and Proteobacteria (26%)). At the genus level, there were 12 common genera that constituted about 61% of all sequence reads. Seven of those genera were common (Streptococcus (10%), Cutibacterium (10%), Staphylococcus (7%), Nocardioides (7%), Corynebacterium 1 (5%), Anoxybacillus (5%), and Acinetobacter (5%)), which encompassed 49% of all reads. As for diversity analysis, there was no difference on PERMANOVA analysis (unweighted UniFrac) for sex (p = 0.087), chemosis (p = 0.064), and unclassified eyedrops (p = 0.431). There was a significant difference in cases with bilateral conjunctivitis (p = 0.017) and for using antibiotics (p = 0.020). Of the predominant phyla, Firmicutes had the highest abundance in bacterial conjunctivitis in this study. Pseudomonas as a resident commensal microbiota may have an important role in the prevention of infection.

SARS-CoV-2 RNAemia with a higher nasopharyngeal viral load is strongly associated with disease severity and mortality in patients with COVID-19

This study aimed to determine the frequency of SARS‐CoV‐2 RNA in serum and its association with the clinical severity of COVID‐19. This retrospective cohort study performed at Toyama University Hospital included consecutive patients with confirmed COVID‐19. The prevalence of SARS‐CoV‐2 RNAemia and the strength of its association with clinical severity variables were examined. Fifty‐six patients were included in this study. RNAemia was detected in 19.6% (11/56) patients on admission, and subsequently in 1.0% (1/25), 50.0% (6/12), and 100.0% (4/4) moderate, severe, and critically ill patients, respectively. Patients with RNAemia required more frequent oxygen supplementation (90.0% vs. 13.3%), ICU admission (81.8% vs. 6.7%), and invasive mechanical ventilation (27.3% vs. 0.0%). Among patients with RNAemia, the median viral loads of nasopharyngeal (NP) swabs that were collected around the same time as the serum sample were significantly higher in critically ill (5.4 log₁₀ copies/μl; interquartile range [IQR]: 4.2–6.3) than in moderate‐severe cases (2.6 log₁₀ copies/μl; [IQR: 1.1–4.5]; p = 0.030) and were significantly higher in nonsurvivors (6.2 log₁₀ copies/μl [IQR: 6.0–6.5]) than in survivors (3.9 log₁₀ copies/μl [IQR: 1.6–4.6]; p = 0.045). This study demonstrated a relatively high proportion of SARS‐CoV‐2 RNAemia and an association between RNAemia and clinical severity. Moreover, among the patients with RNAemia, the viral loads of NP swabs were correlated with disease severity and mortality, suggesting the potential utility of combining serum testing with NP tests as a prognostic indicator for COVID‐19, with higher quality than each separate test.

Delayed neutralizing antibody response in the acute phase correlates with severe progression of COVID-19

Adaptive immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) dynamics remain largely unknown. The neutralizing antibody (NAb) levels in patients with coronavirus disease 2019 (COVID-19) are helpful for understanding the pathology. Using SARS-CoV-2 pseudotyped virus, serum sample neutralization values in symptomatic COVID-19 patients were measured using the chemiluminescence reduction neutralization test (CRNT). At least two sequential serum samples collected during hospitalization were analyzed to assess NAbs neutralizing activity dynamics at different time points. Of the 11 patients, four (36.4%), six (54.5%), and one (9.1%) had moderate, severe, and critical disease, respectively. Fifty percent neutralization (N50%-CRNT) was observed upon admission in 90.9% (10/11); all patients acquired neutralizing activity 2-12 days after onset. In patients with moderate disease, neutralization was observed at earliest within two days after symptom onset. In patients with severe-to-critical disease, neutralization activity increased, plateauing 9-16 days after onset. Neutralization activity on admission was significantly higher in patients with moderate disease than in patients with severe-to-critical disease (relative % of infectivity, 6.4% vs. 41.1%; P = .011). Neutralization activity on admission inversely correlated with disease severity. The rapid NAb response may play a crucial role in preventing the progression of COVID-19.

Prolonged viral clearance of severe acute respiratory syndrome coronavirus 2 in the older aged population

INTRODUCTION

The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) is the standard method for the diagnosis of coronavirus disease 2019 (COVID-19). This PCR test can be positive even in patients who have recovered from the disease, and the duration for achieving viral clearance has not been clarified yet.

METHODS

This study was conducted between April 3, 2020, and June 17, 2020, at the Toyama University Hospital and the Toyama Rehabilitation Home. We collected the data of patients with COVID-19, analyzing the duration until twice-consecutive negative qRT-PCR test.

RESULTS

A total of 42 patients were enrolled. The median duration of the twice-consecutive negative qRT-PCR test was 29.0 d (interquartile range: 25.75-35.25). The longest duration of viral shedding was 73 d. The duration of viral clearance was significantly longer in the older (>65 years) group than in the younger group (34.5 d vs. 25.0 d, P < 0.0001).

CONCLUSION

This study demonstrated that viral clearance tends to be sustained in the older adults.

M Segment-Based Minigenome System of Severe Fever with Thrombocytopenia Syndrome Virus as a Tool for Antiviral Drug Screening

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne bunyavirus that causes severe disease in humans with case fatality rates of approximately 30%. There are few treatment options for SFTSV infection. SFTSV RNA synthesis is conducted using a virus-encoded complex with RNA-dependent RNA polymerase activity that is required for viral propagation. This complex and its activities are, therefore, potential antiviral targets. A library of small molecule compounds was processed using a high-throughput screening (HTS) based on an SFTSV minigenome assay (MGA) in a 96-well microplate format to identify potential lead inhibitors of SFTSV RNA synthesis. The assay confirmed inhibitory activities of previously reported SFTSV inhibitors, favipiravir and ribavirin. A small-scale screening using MGA identified four candidate inhibitors that inhibited SFTSV minigenome activity by more than 80% while exhibiting less than 20% cell cytotoxicity with selectivity index (SI) values of more than 100. These included mycophenolate mofetil, methotrexate, clofarabine, and bleomycin. Overall, these data demonstrate that the SFTSV MGA is useful for anti-SFTSV drug development research.

Safety, efficacy, and analysis of key parameters after prophylactic administration of a sustained-release formulation of azithromycin in lung cancer surgery

BACKGROUND

The current use of prophylactic antibiotics for lung cancer surgery requires modification in aging individuals with impaired lung function. A sustained-release formulation of azithromycin (AZM-SR) could help resolve some of these challenges with its sustained antibacterial and anti-inflammatory effects. The aim of this study was to examine the safety and efficacy of AZM-SR in lung cancer surgery as well as its anti-inflammatory effect.

METHODS

Fifty patients were included in the study, and AZM-SR was administered 1 day prior to the surgery. The clinical course, including postoperative complications, was monitored, and the concentration of AZM, bacterial culture, and inflammatory cytokine levels of resected lung specimens were evaluated.

RESULTS

No side effects related to AZM-SR were observed. Five cases of postoperative pneumonia (10%) were observed; technical issues were involved in 3 cases. All patients recovered well. Four cases showed positive bacterial culture upon lung tissue examination; however, this was not significantly correlated with postoperative complications. A negative correlation was observed between AZM concentration in lung tissue and interleukin-6 (IL-6) expression.

CONCLUSIONS

Prophylactic utilization of AZM-SR in lung cancer surgery seems feasible. The anti-inflammatory effect of AZM might contribute additional beneficial effects in the perioperative management of lung cancer surgery.

Impact of daily wearing of fabric gloves on the management of hand eczema: A pilot study in health-care workers

Hand eczema is a major occupational disease, especially in medical workers, reducing their quality of life (QOL) and work productivity. Daily wearing of fabric gloves to prevent loss of moisture and lipids from the surface of the hands has been regarded as good in the management of hand eczema. However, limited evidence is available regarding the efficacy of moisturizing care with daily gloves on hand eczema. This pilot study was performed to evaluate the efficacy of moisturizing intervention with daily wearing of fabric gloves on skin barrier function, disease severity, and microbiome in health-care workers with hand eczema. Study 1: Nurses in the neonatal intensive care unit or growing care unit with and without hand eczema were recruited in the study. Subjects were instructed to apply moisturizer and wear two types of fabric gloves, common cotton gloves and moisturizing fabric gloves containing malate, for 4 weeks. Study 2: Physicians and health-care workers were recruited and instructed to wear a cotton glove on one hand at nighttime for 4 weeks. Disease severity, skin barrier function, QOL, and hand microbiome (Study 1) were evaluated. Study 1 found that daily wearing of both types of fabric gloves accompanied by use of topical moisturizers reduced the severity of hand eczema without changing the variation of microbiome. Study 2 found no apparent change between wearing and not wearing cotton gloves. In summary, topical moisturizer is of fundamental importance, and concomitant use of fabric gloves may merely enhance the efficacy of moisturizer in the management of hand eczema.

A case of COVID-19 diagnosed with favipiravir-induced drug fever based on a positive drug-induced lymphocyte stimulation test

As of October 2020, there is still no specific drug to treat COVID-19 as it rages worldwide. Favipiravir, indicated for the treatment of new and re-emerging influenza infections, has been suggested to be effective against SARS-CoV-2, although this is not yet fully validated. We administered favipiravir to a 64-year-old female patient with COVID-19. Her symptoms resolved quickly after the start of treatment, with reduction of SARS-CoV-2 viral load, but she developed a fever again on day 12. Since the fever was relieved by discontinuation of favipiravir, and based on positive results with a drug-induced lymphocyte stimulation test, we diagnosed her with favipiravir-induced drug fever. A decrease in the serum concentration of favipiravir was observed along with resolution of the fever. The present case suggests that drug fever should be considered in the differential diagnosis of relapsing fever episodes in COVID-19 patients receiving favipiravir.

Evaluation of a novel rapid TRC assay for the detection of influenza using nasopharyngeal swabs and gargle samples

We evaluated a novel transcription-reverse transcription concerted reaction (TRC) assay that can detect influenza A and B within 15 min using nasopharyngeal swab and gargle samples obtained from patients with influenza-like illness, between January and March 2018 and between January and March 2019. Based on the combined RT-PCR and sequencing results, in the nasal swabs, the sensitivity and specificity of TRC for detecting influenza were calculated as 1.000 and 1.000, respectively. In the gargle samples, the sensitivity and specificity of TRC were 0.946 and 1.000, respectively. The TRC assay showed comparable performance to RT-PCR in the detection of influenza viruses.

Multicenter evaluation of molecular point-of-care testing and digital immunoassays for influenza virus A/B and respiratory syncytial virus in patients with influenza-like illness

INTRODUCTION

Digital immunoassays (DIAs) and molecular point-of-care (POC) tests for influenza were recently developed. We aimed to evaluate and compare the positive rate with molecular POC tests and DIAs in detecting influenza virus A, B and respiratory syncytial virus (RSV).

METHODS

A prospective observational study was conducted in 2019-2020. Nasopharyngeal swab samples were collected from adult outpatients with influenza-like illness who visited four hospitals and clinics in Japan. DIAs were performed at each facility. The clinical diagnosis was determined based on the findings of DIAs, history taking, and physical assessment. Molecular POC test and reverse transcription polymerase chain reaction (RT-PCR) were performed later.

RESULTS

A total of 182 patients were evaluated. The positive rate for influenza virus with molecular POC test was significantly higher than that with DIAs (51.6% versus 40.7%, p = 0.046). In patients who tested positive for influenza virus with only molecular POC test, the presence of influenza virus was confirmed by RT-PCR. In a comparison between the patients who were positive for influenza virus with only molecular POC test and those with both molecular POC test and DIA, the percentage of patients who sought consultation within 18 h after the onset of symptoms was significantly higher in the molecular POC test only group than in the both methods group (70.0% versus 43.2%, p = 0.044).

CONCLUSIONS

A molecular POC test could contribute to the accurate diagnosis of influenza in patients with influenza-like illness, especially those who visited a hospital immediately after the onset of symptoms.

Evaluation of SARS-CoV-2 neutralizing antibodies using a vesicular stomatitis virus possessing SARS-CoV-2 spike protein

Background

SARS-CoV-2 is a novel coronavirus that emerged in 2019 and is now classified in the genus Coronavirus with closely related SARS-CoV. SARS-CoV-2 is highly pathogenic in humans and is classified as a biosafety level (BSL)-3 pathogen, which makes manipulating it relatively difficult due to its infectious nature.

Methods

To circumvent the need for BSL-3 laboratories, an alternative assay was developed that avoids live virus and instead uses a recombinant VSV expressing luciferase and possesses the full length or truncated spike proteins of SARS-CoV-2. Furthermore, to measure SARS-CoV-2 neutralizing antibodies under BSL2 conditions, a chemiluminescence reduction neutralization test (CRNT) for SARS-CoV-2 was developed. The neutralization values of the serum samples collected from hospitalized patients with COVID-19 or SARS-CoV-2 PCR-negative donors against the pseudotyped virus infection evaluated by the CRNT were compared with antibody titers determined from an enzyme-linked immunosorbent assay (ELISA) or an immunofluorescence assay (IFA).

Results

The CRNT, which used whole blood collected from hospitalized patients with COVID-19, was also examined. As a result, the inhibition of pseudotyped virus infection was specifically observed in both serum and whole blood and was also correlated with the results of the IFA.

Conclusions

In conclusion, the CRNT for COVID-19 is a convenient assay system that can be performed in a BSL-2 laboratory with high specificity and sensitivity for evaluating the occurrence of neutralizing antibodies against SARS-CoV-2.

Monitoring of viral load by RT-PCR caused decision making to continue ECMO therapy for a patient with COVID-19

Most patients with coronavirus disease 2019 (COVID-19) have just only mild symptoms, but about 5% are very severe. Although extracorporeal membranous oxygenation (ECMO) is sometimes used in critically patients with COVID-19, ECMO is only an adjunct, not the main treatment. If the patient's condition deteriorates and it is determined to be irreversible, it is necessary to decide to stop ECMO. A 54-year-old man was admitted on day 6 of onset with a chief complaint of high fever and cough. Computed tomography (CT) showed a ground glass opacity in both lungs, and reverse transcription-polymerase chain reaction (RT-PCR) diagnosed COVID-19. He was admitted to the hospital and started to receive oxygen and favipiravir. After that, his respiratory condition deteriorated, and he was intubated and ventilated on day 9 of onset, and ECMO was introduced on day 12. Two days after the introduction of ECMO, C-reactive protein (CRP) increased, chest X-p showed no improvement in pneumonia, and PaO2/FiO2 decreased again. As D-dimer rose and found a blood clot in the ECMO circuit, we had to decide whether to replace the circuit and continue with ECMO or stop ECMO. At this time, the viral load by RT-PCR was drastically reduced to about 1/1750. We decided to continue ECMO therapy and replaced the circuit. The patient's respiratory status subsequently improved and ECMO was stopped on day 21 of onset. In conclusion, viral load measurement by RT-PCR may be one of the indicators for promoting the treatment of severe COVID-19 patients.

Evaluation of GENECUBE Mycoplasma for the detection of macrolide-resistant Mycoplasma pneumoniae

Introduction. Resistance against macrolide antibiotics in Mycoplasma pneumoniae is becoming non-negligible in terms of both appropriate therapy and diagnostic stewardship. Molecular methods have attractive features for the identification of Mycoplasma pneumoniae as well as its resistance-associated mutations of 23S ribosomal RNA (rRNA).Hypothesis/Gap Statement. The automated molecular diagnostic sytem can identify macrolide-resistant M. pneumoniae.Aim. To assess the performance of an automated molecular diagnostic system, GENECUBE Mycoplasma, in the detection of macrolide resistance-associated mutations.Methodology. To evaluate whether the system can distinguish mutant from wild-type 23S rRNA, synthetic oligonucleotides mimicking known mutations (high-level macrolide resistance, mutation in positions 2063 and 2064; low-level macrolide resistance, mutation in position 2067) were assayed. To evaluate clinical oropharyngeal samples, purified nucleic acids were obtained from M. pneumoniae-positive samples by using the GENECUBE system from nine hospitals. After confirmation by re-evaluation of M. pneumoniae positivity, Sanger-based sequencing of 23S rRNA and mutant typing using GENECUBE Mycoplasma were performed.Results. The system reproducibly identified all synthetic oligonucleotides associated with high-level macrolide resistance. Detection errors were only observed for A2067G (in 2 of the 10 measurements). The point mutation in 23S rRNA was detected in 67 (26.9 %) of 249 confirmed M. pneumoniae-positive clinical samples. The mutations at positions 2063, 2064 and 2617 were observed in 65 (97.0 %), 2 (3.0 %) and 0 (0.0 %) of the 67 samples, respectively. The mutations at positions 2063 and 2064 were A2063G and A2064G, respectively. The results from mutant typing using GENECUBE Mycoplasma were in full agreement with the results from sequence-based typing.Conclusion. GENECUBE Mycoplasma is a reliable test for the identification of clinically significant macrolide-resistant M. pneumoniae.

Pathogenic Effect of Prevotella intermedia on a Mouse Pneumonia Model Due to Methicillin-Resistant Staphylococcus aureus With Up-Regulated α-Hemolysin Expression

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a common causative agent of pneumonia; however, the detailed mechanism underlying severe MRSA pneumonia, including association with oral hygiene or periodontitis, remains poorly characterized. In this study, we examined the pathogenic effect of Prevotella intermedia, a major periodontopathic pathogen, on MRSA pneumonia.

Methods: The pathogenic effect of the supernatant of P. intermedia (Pi Sup) was investigated in a murine MRSA pneumonia model, using several clinical strains; whereas the bactericidal activity of polymorphonuclear leukocytes (PMNs) was investigated in vitro. The effect of Pi Sup on messenger RNA (mRNA) expression of the toxin/quorum sensing system (rnaIII) was investigated by quantitative reverse transcription PCR both in vitro and in vivo.

Results: Mice infected by hospital-acquired MRSA (HA-MRSA) with Pi Sup exhibited a significantly lower survival rate, higher bacterial loads in the lungs, and higher α-hemolysin (hla) expression in the lungs, than those without Pi Sup. A similar effect of Pi Sup was not observed with MRSA strains producing Panton-Valentine leucocidin (PVL) or toxic shock syndrome toxin (TSST). In vitro, Pi Sup suppressed bactericidal activity of PMNs against the HA-MRSA strain. HA-MRSA was the clinical strain with the highest ability to proliferate in the lungs and was accompanied by time-dependent up-regulation of rnaIII and hla.

Conclusions: Our results provide novel evidence that the product of P. intermedia exerts a pathogenic effect on MRSA pneumonia, in particular with a strain exhibiting strong proliferation in the lower airway tract. Moreover, our results indicate that P. intermedia affects MRSA toxin expression via quorum sensing in a strain-dependent fashion, which might be important for understanding the pathogenesis of severe MRSA pneumonia.

Flow cytometry assay for the detection of single-copy DNA in human lymphocytes

Specific nucleic acid sequences can be detected in individual cells by in situ hybridization. However, when very few copies of a target sequence are present per cell, its signal is undetectable by flow cytometry. Although various approaches have been developed to increase fluorescence signals for in situ hybridization, flow cytometric detection of specific genomic DNA sequences has not been established. Here, we present a flow cytometry assay for detection of single-copy genomic sequences in human lymphocytes using in situ PCR with universal energy transfer-labelled primers.

A novel macrolide, solithromycin suppresses mucin overexpression induced by Pseudomonas aeruginosa LPS in airway epithelial cells

Some macrolides such as 14- and 15-membered macrolides have immunomodulatory effects such as suppression of mucin overproduction. Because a novel macrolide, solithromycin, was developed, we examined whether it suppresses the overexpression of mucin in vitro. A human airway epithelial cell line NCI-H292 was stimulated by Pseudomonas aeruginosa lipopolysaccharides to induce the overproduction of a major mucin, MUC5AC. Treatment with 10 μg/mL of solithromycin significantly inhibited LPS-induced MUC5AC in both mRNA and protein levels as well as a 15-membered macrolide, azithromycin. These findings support that solithromycin has a potential immunomodulatory effect.

Safety management in urgent endonasal trans-sphenoidal surgery for pituitary adenoma during the COVID-19 pandemic in Japan - A case report

We report a 72-year-old woman who required urgent endonasal trans-sphenoidal surgery (eTSS) because of progressive visual field disturbance due to pituitary adenoma, in whom we conducted reverse-transcriptase-polymerase-chain-reaction (RT-PCR) for COVID-19 and chest CT before eTSS. We took care of her by following the rule for suspected infection patient, and safely completed her treatment without medical staff infection. Under COVID-19 pandemic state, essentially careful management including RT-PCR test and chest CT should be taken for the high infection risk surgeries to avoid the outbreak through the hospital. And the cost of RT-PCR test for the patients should be covered by the government budget.

Effect of probiotics on gut microbiome in patients with administration of surgical antibiotic prophylaxis: A randomized controlled study

Surgical antibiotic prophylaxis (SAP) is recommended for the prevention of surgical site infections. However, there is a concern about adverse effects of SAP, such as antibiotic-associated diarrhea (AAD). To prevent AAD, administration of probiotics has been investigated. Although recent advances in next-generation sequencing makes it possible to analyze the gut microbiome, the effect of probiotics on the gut microbiome in the patients with SAP remains unknown. To test a hypothesis that SAP influences the gut microbiome and probiotics prevent the influence, a randomized controlled study was conducted with patients who underwent spinal surgery at Nagasaki University Hospital. After obtaining informed consent, the patients were automatically classified into the non-probiotics group and the probiotics group. In the probiotics group, the patients took 1 g of Enterococcus faecium 129 BIO 3B-R, 3 times a day on postoperative days (PODs) 1-5. The feces of all patients were sampled before administration of SAP and on PODs 5 and 10. We compared alpha and beta diversity and differential abundance analysis of the gut microbiome before and after SAP. During the study period, a total of 33 patients were evaluated, comprising 17 patients in the non-probiotics group and 16 in the probiotics group. There was no significant difference between the groups regarding patient characteristics. In alpha and beta diversity, there were no significant differences among all combinations. In differential abundance analysis at operational taxonomic unit level, Streptococcus gallolyticus and Roseburia were significantly increased in the non-probiotics group and significantly decreased in the probiotics group.