Clinical characteristics and antimicrobial susceptibility of Fusobacterium species isolated over 10 years at a Japanese university hospital.

PURPOSE: Anaerobic bacteria, existing on human skin and mucous membranes, can cause severe infections with complications or mortality. We examined the clinical characteristics of patients infected with Fusobacterium spp. and assessed their antibiotic susceptibility. METHODS: Clinical data were collated from patients diagnosed with Fusobacterium infections in a Japanese university hospital between 2014 and 2023. Antibiotic susceptibility tests were conducted following the Clinical and Laboratory Standards Institute guidelines. RESULTS: We identified 299 Fusobacterium isolates. The median age was 61 years (range, 14-95 years), with females constituting 43.1% of the patients. Most infections were community-acquired (84.6%, 253/299). Multiple bacterial strains were isolated simultaneously in 74.6% of cases. One-fourth of the patients had solid organ malignancies (25.4%, 76/299), and 14.5% (11/76) of those had colorectal cancer. The 30-day mortality rate was 1.3%. Fusobacterium species were isolated from blood cultures in 6% (18/299) of the patients. Patients, aged 75 years or older, with cerebrovascular disease or hematologic malignancy exhibited significantly higher prevalence of blood culture isolates in univariate analysis. Each Fusobacterium species had its characteristic infection site. Approximately 5% F. nucleatum and F. necrophorum isolates showed penicillin G resistance. Moxifloxacin resistance was observed in varying degrees across strains, ranging from 4.6 to 100% of isolates. All isolates were sensitive to ß-lactam/ß-lactamase inhibitors, carbapenems, and metronidazole. CONCLUSION: We show a link between Fusobacterium species and solid organ malignancies. We observed resistance to penicillin, cefmetazole, clindamycin, and moxifloxacin, warranting caution in their clinical use. This study offers valuable insights for managing Fusobacterium infections and guiding empirical treatments.

Clinical evaluation of a modified SARS-CoV-2 rapid molecular assay, ID NOW ™ COVID-19 2.0.

In the diagnosis of coronavirus disease 2019 (COVID-19), several types of instruments and reagents for SARS-CoV-2 nucleic acid testing have been introduced to meet clinical needs. We evaluated the clinical performances of ID NOW™ COVID-19 2.0 (ID NOW™ 2.0), which is capable of detecting SARS-CoV-2 within 12 min as part of point-of-care testing (POCT). Patients who displayed COVID-19 related symptoms, and who were tested for screening purposes, were recruited to this study. Two nasopharyngeal swabs were collected and tested using the ID NOW™ 2.0 test. Reference testing was performed using the cobas 8800 or 6800 (reagents: cobas SARS-CoV-2 and Flu A/B). A total of 38 samples and 46 samples were tested positive and negative, respectively, by the reference test. The ID NOW™ 2.0 showed a sensitivity of 94.7% (95% CI: 82.3-99.4) and a specificity of 100% (95% CI: 92.3-100). Samples that were positive by reference testing had cycle threshold (Ct) values ranging from 11.90 to 35.41. Among these reference positive samples, two samples were negative by ID NOW™ 2.0 with Ct values of 35.25 and 35.41. For samples with Ct values < 35, the sensitivity of ID NOW™ 2.0 was 100%. In Japan, the restrictions related to COVID-19 have been relaxed, however the COVID-19 epidemic still continues. ID NOW™ 2.0 is expected to be used as a rapid and reliable alternative to laboratory-based RT-PCR methods.

Epidemiological study of respiratory syncytial virus infection in adults during the pandemic of COVID-19.

INTRODUCTION: While respiratory syncytial virus (RSV) is one of the most common pathogens in adults admitted to the ICU due to respiratory diseases, no reports regarding the occurrence rate of RSV infections in adults in Japan during the COVID-19 pandemic exist. PATIENTS AND METHODS: We conducted this retrospective study to examine the exact occurrence rate of RSV infections in adults. We reviewed all patients (≥18 years) with any respiratory symptoms who received quantitative polymerase chain reaction (PCR) using nasopharyngeal samples for respiratory viruses by GeneLEAD at the Aichi Medical University Hospital between November 2022 and November 2023. RESULTS: A total of 541 adult patients who underwent PCR test were enrolled in this study. RSV was identified in 18 cases (3.3 %); 8 (1.5 %) upper and 10 (1.8 %) lower respiratory tract infections. Influenza A and SARS-CoV-2 were found in 10 (1.8 %) and 61 (11.3 %), respectively. Patients with RSV infections and COVID-19 had more comorbidities than those with Influenza virus infections. As for RSV-associated with lower respiratory tract infection cases, 10 developed acute respiratory failure, resulting in 1 fatal case due to pneumonia and 1 died of septic shock due to ileus. The 30-, 90-day mortality rates were 1 (6 %) and 2 (11 %) respectively. CONCLUSION: About 3 % of adults had RSV infections during the COVID-19 pandemic. The outcomes of RSV infections in adults were similar to those by COVID-19. Those with comorbidities should have a preventive method against RSV infections, the same as for COVID-19.

Complicated pyelonephritis caused by Proteus alimentorum in a woman with peritoneal cancer: a case report.

BACKGROUND: Proteus spp. are widespread in the environment and comprise a part of the normal flora of the human gastrointestinal tract. Only six species in this genus, including Proteus mirabilis, Proteus vulgaris, Proteus terrae, Proteus penneri, Proteus hauseri, and Proteus faecis, have been isolated from human clinical specimens. However, there are no reports of Proteus alimentorum isolated from humans, and the clinical characteristics of P. alimentorum infection are unknown. CASE PRESENTATION: An 85-year-old female patient with peritoneal cancer was hospitalized for complicated pyelonephritis and bacteremia caused by P. alimentorum. The patient received antimicrobial therapy and was discharged on day 7 of hospitalization. No recurrence was observed 14 days after the treatment. Various methods were used to identify the Proteus sp. Furthermore, the VITEK-2 GN ID card resulted in low discrimination between P. hauseri and P. penneri. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry showed P. hauseri with a spectral score of 2.22 as the best match. Nevertheless, the pathogen was identified as P. alimentorum based on genetic investigation using 16 S rRNA gene sequencing and biochemical tests. CONCLUSION: Proteus alimentorum is a human pathogen, and its infection has an excellent therapeutic response to antimicrobials based on antimicrobial susceptibility. Genomic methods may be helpful for the precise identification of P. alimentorum.

Usefulness of the FilmArray blood culture identification panel for identifying causative pathogens of bone and joint infections.

As bone and joint infections (BJIs) require long-term treatment, identifying their causative pathogens is vital. However, the detection rate of conventional culturing remains inadequate. This study aimed to evaluate the usefulness of the FilmArray blood culture identification (BCID) panel for identifying causative pathogens in patients with BJIs. We tested a BCID panel using collected samples, in addition to conventional cultures. The primary outcome was to evaluate the diagnostic performance of the BCID panel, calculated using conventional culturing methods. A total of 44 patients who underwent BJI-related specimen collection were enrolled. Of the 44 patients, 22 were diagnosed with a BJI. Conventional culture identified 15 of 22 organisms (68.2%), whereas the BCID panel identified 14 of 22 organisms (63.4%). The overall sensitivity and specificity of the BCID panel were 73.3% and 57.1%, respectively, compared to those of the conventional culture. However, the sensitivity reached 100% when only pathogens included in the BCID panel were considered. In seven culture-negative cases, the BCID panel identified three organisms (42.9%). The BCID panel also indicated the appropriate therapy against a BJI caused by methicillin-resistant Staphylococcus aureus by detecting the mecA gene. This study demonstrated that the BCID panel has the potential for early and accurate diagnosis of the causative organism of BJI using specimens such as joint fluid and bone tissue. Our results suggest that BCID panels, in addition to routine culture, may improve our ability to diagnose the causative microorganisms of BJI in clinical practice, thereby contributing to the selection of appropriate antimicrobial agents.

[Relationship between Serotypes and Biotypes of Yersinia enterocolitica and the Names of Identified Bacteria in the Microbial Identification and Susceptibility Testing Devices].

Yersinia enterocolitica is a causative agent of food poisoning and has been isolated from pork and stream water, causing Yersinia enterocolitica in humans. The bacterium is divided into multiple serotypes and biotypes, among which serotypes O3 and O8 and biotypes 1B, 3, and 4 are frequently isolated in Japan. Biotype 3 can be classified as [VP+, Suc+], [VP-, Suc+], [VP-, Suc-] based on the biochemical properties. Among them, [O3, 3, VP-, Suc-] has been reported to be identified as Yersinia kristensenii in a simple identification kit. An increasing number of facilities in the field of microbiological testing are currently using mass spectrometers to identify species of microorganisms. However, there are many facilities where mass spectrometers have not yet been installed and microbial identification and susceptibility testing devices are used to identify bacterial species. No reports have described how the [O3, 3, VP-, Suc-] type, which is identified as Y. kristensenii in the simple identification kit, is identified by the microbial identification and susceptibility testing devices. In this study, 15 strains of Y. enterocolitica, which were previously isolated, serotyped, and biotyped from fecal culture tests at our hospital, were analyzed to see how these strains were identified in RAISUS S4, Microscan WalkAway, VITEK2 Blue, and BD Phoenix. [O3, 3, VP-, Suc-] was identified as Y. kristensenii in RAISUS S4, Microscan WalkAway, and VITEK2 Blue and as Y. enterocolitica in BD Phoenix. [O3, 3, VP-, Suc+], [O3, 4] and [O8, 1B] were identified as Y. enterocolitica. Therefore, when a sample was identified as Y. kristensenii by RAISUS S4, Microscan WalkAway, or VITEK2 Blue, the possibility that it was actually [O3, 3, VP-, Suc-] could not be ruled out. The possibility of Y. enterocolitica should be informed to attending physicians.

Novel approach for rapid detection of extended spectrum ß-lactamase and metalloid-ß-lactamase using drug susceptibility testing microfluidic device (DSTM).

BACKGROUND/PURPOSE: Rapid detection of ß-lactamases is important in a recent situation where resistant bacteria are increasing. By using the drug susceptibility testing microfluidic device (DSTM), rapid screening of extended spectrum ß-lactamases (ESBLs) and metallo-ß-lactamases (MBLs) has become possible. METHODS: ß-lactams and ß-lactamase inhibitors were pre-fixed in the DSTM for use. A bacterial suspension in Mueller-Hinton broth (McF 0.25) was introduced into the device, and the effects of ß-lactamase inhibitor on morphological changes caused by ß-lactam were evaluated after 3 h incubation. RESULTS: Clinical isolates genetically confirmed to produce ß-lactamase were used. Of the 84 ESBL-producing strains, 80 strains (95%) turned to be ESBL positive, and five strains (6%) of them MBL were positive as well as ESBL. Four strains (5%) were negative for both ESBL and MBL. Of the 24 MBL-producing strains, 23 strains (96%) were positive for MBL. All the 43 AmpC-producing strains were negative for both ESBL and MBL. Of the 156 ESBL- and MBL-nonproducing strains, 155 strains (99%) were negative for both ESBL and MBL, and one strain was positive for ESBL. With this method, the detection sensitivity was 95% and the specificity was 100% for ESBL, whereas the detection sensitivity was 96% and the specificity was 98% for MBL. These results were not significantly different from the results of the disc diffusion method. CONCLUSION: The DSTM method allows rapid detection of ß-lactamases in 3 h and may be a useful replacement for the disc diffusion method.

Empyema and bacteremia caused by Aeromonas hydrophila: Case report and review of the literature.

INTRODUCTION: Despite the advance in antibiotics and widespread chest tube drainage, acute empyema still shows a high mortality rate, accounting for 10-25%. We experienced a case of acute empyema caused by A. hydrophila, which is extremely uncommon, and reviewed all previously published articles. CASE PRESENTATION: A 76-year older man with a medical history of liver cirrhosis (LC) due to chronic hepatitis C and hepatic cell carcinoma was admitted to our institute. Elevated inflammatory reaction and effusions on chest CT were seen, and he was suspected of having acute empyema. Although an empiric antibiotic therapy of meropenem with chest tube drainage was performed as an initial treatment, he died within 8 hours of admission. Postmortem, both blood and left pleural fluid cultures yielded Aeromonas hydrophila. The final diagnosis was acute empyema caused by A. hydrophila. We reviewed previously reported empyema caused by Aeromonas species cases (4 A. hydrophila, and 1 A. veronii) in 4 previous reports written in English, including ours. Of 5, all were male, and the mean age was 52 years (range 27-76 years). All patients had LC due to alcohol or viral infections. As for antibiotics initially prescribed, third-generation cephalosporins were most frequently used in 3/5 (60%). Thoracentesis was performed in all patients (100%). As for prognosis, 2 (40%) survived, and 3 (60%) died. CONCLUSION: Physicians should be aware of the possibility of acute empyema caused by A. hydrophila among patients with chronic hepatic disease.

Could quick SOFA and SOFA score be a predictive tool for 30-day and in-hospital mortality in acute empyema?

While acute empyema is a critical infectious disease showing a high mortality rate, there are no prognostic tools to evaluate the disease severity and prognosis for patients. We conducted a retrospective cohort to determine whether quick Sequential Organ Failure Assessment (qSOFA) and SOFA score can predict the disease severity and prognosis of acute empyema. A total of 53 patients were enrolled in the study. The mean age was 69 years and 41 patients (77%) were male. Twenty-two patients (42%) had multiple underlying diseases with the Charlson comorbidity index ≥3. The-30 days, and in-hospital deaths were 7 (13%) and 10 (19%), respectively. The area under the ROC curve of SOFA score and CCI for 30-day and in-hospital deaths were 0.814 (p = 0.073) and 0.752 (p = 0.082), 0.848 (p = 0.07) and 0.762 (p = 0.011), respectively. Univariate analysis showed that qSOFA ≥2 and SOFA score ≥2, isolation of potentially drug-resistant (PDR) pathogen, high CCI (≥3), performance status of 2-4, surgical intervention, and anaerobic bacteria involvement were prognostic factors. Of these, multivariate logistic regression analysis showed that qSOFA ≥2 and SOFA score ≥2 (p = 0.011), isolation of PDR pathogen (p = 0.005), and high CCI (≥3) (p = 0.015) were independently poor prognostic factors. We concluded that qSOFA and SOFA scores could predict the disease severity and prognosis in acute empyema. Additionally, isolation of PDR pathogens and high CCI could be poor prognostic factors for patients.

Efficacy and validity of guideline-concordant treatment according to the JRS guidelines for the managements of pneumonia in adults updated in 2017 for nursing and healthcare-associated pneumonia. A propensity-matching score analysis.

INTRODUCTION: Patients with nursing and healthcare-associated pneumonia (NHCAP) commonly receive empiric antibiotic therapy according to the guideline's recommendation corresponding to the patient's deteriorated conditions. However, it is unclear whether guideline-concordant treatment (GCT) could be effective or not. PATIENTS AND METHODS: To evaluate the efficacy and validity of GCT according to the current guideline for pneumonia, we conducted this retrospective study. NHCAP patients who were admitted to our institute between 2014 and 2017 were enrolled. Based on the initial antibiotic treatment, these patients were divided into two groups, the GCT group (n = 83) and the non-GCT group (n = 146). Propensity score matching (PSM) was used to balance the baseline characteristics and potential confounders between the two groups. After PSM, patients' characteristics, microbial profiles, and clinical outcomes were evaluated. RESULTS: Both groups were well-balanced after PSM, and 78 patients were selected from each group. There were no differences in patients' characteristics or microbial profiles between the two groups. As for outcomes, there were no differences in 30-day, in-hospital mortality rate, duration of antibiotic treatment, or admission. The severity of pneumonia was more severe in patients with the GCT group than those with the non-GCT group. Anti-pseudomonal agents as initial treatment were more frequently seen in patients with the GCT group than those in the non-GCT group. CONCLUSION: Unlike previous studies, GCT's recommendation for management of pneumonia by the JRS in 2017 would appear to be valid and does not increase the mortality rate.

Comparative study of SmartAmp assay and reverse transcription-polymerase chain reaction by saliva specimen for the diagnosing COVID-19.

INTRODUCTION: The pandemic of a novel coronavirus disease 2019 (COVID-19) caused by a severe acute respiratory coronavirus 2 (SARS-CoV-2) infection has been problematic worldwide. A new SARS-CoV-2 diagnostic test (SmartAmp) was licensed in Japan in July 2021. This method, which enables us to diagnose COVID-19 as well as a gene mutation on the virus, is promising to reduce medical costs and staff labor. PATIENTS AND METHODS: To analyze the diagnostic accuracy of the SmartAmp assay for diagnosing COVID-19, we performed this retrospective study at our institute during April and May 2021. We compared the results of the SmartAmp assay and real-time reverse transcription-polymerase chain reaction (rRT-PCR) using a saliva sample from individuals suspected as having COVID-19. RESULTS: Out of 70 samples tested, the SmartAmp assay had 50 (71%) positive and 20 (29%) negative results. Using rRT-PCR as a reference, the diagnostic accuracy displayed a sensitivity of 84%, a specificity of 95%, a positive predictive value of 97.7%, and a negative predictive value of 70.4%. On the other hand, false-negative cases were found in 7 (10%), and there was no significant difference of Ct-value between true positive and false negative cases (Mean Ct-value 25.2 vs. 27.5 cycles, p = 0.226 by Mann-Whitney U test). CONCLUSION: The SmartAmp assay is a valuable method to diagnose COVID-19 rapidly. However, the negative predictive value is not high enough to diagnose the disease, so that negative results should be considered for rRT-PCR testing if patients are suspected of having COVID-19.

Risk factors of first recurrence of Clostridioides difficile infection.

OBJECTIVES: Clostridioides difficile infection (CDI) often recurs. Approximately 25% of patients have recurrences after the initial treatment, and patients who have relapsed once are more likely to relapse. We aimed to identify the risk factors for initial CDI recurrence. METHODS: We performed a retrospective survey of patient backgrounds and treatment-related factors. Risk factors were analyzed using single and multiple logistic regression analyses. RESULTS: A total of 134 patients were included in the study. Prophylactic probiotic use and nasogastric tube feeding were independent risk factors for the initial recurrence of CDI. Patients using prophylactic probiotics had significantly higher recurrence rates than those not using prophylactic probiotics. CONCLUSION: Prophylactic probiotic use and nasogastric tube placement may be risk factors for the initial recurrence of CDI. It is noteworthy that CDI that occurs during the use of prophylactic probiotics may be prone to recurrence.

Combination of Sequential Organ Failure Assessment (SOFA) score and Charlson Comorbidity Index (CCI) could predict the severity and prognosis of candidemia more accurately than the Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) score.

BACKGROUND: Candidemia has emerged as an important nosocomial infection, with a mortality rate of 30-50%. It is the fourth most common nosocomial bloodstream infection (BSI) in the United States and the seventh most common nosocomial BSI in Europe and Japan. The aim of this study was to assess the performance of the Sequential Organ Failure Assessment (SOFA) score for determining the severity and prognosis of candidemia. METHODS: We performed a retrospective study of patients admitted to hospital with candidemia between September 2014 and May 2018. The severity of candidemia was evaluated using the SOFA score and the Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) score. Patients' underlying diseases were assessed by the Charlson Comorbidity Index (CCI). RESULTS: Of 70 patients enrolled, 41 (59%) were males, and 29 (41%) were females. Their median age was 73 years (range: 36-93 years). The most common infection site was catheter-related bloodstream infection (n=36, 51%).The 30-day, and in-hospital mortality rates were 36 and 43%, respectively. Univariate analysis showed that SOFA score ≥5, APACHE II score ≥13, initial antifungal treatment with echinocandin, albumin < 2.3, C-reactive protein > 6, disturbance of consciousness, and CCI ≥3 were related with 30-day mortality. Of these 7, multivariate analysis showed that the combination of SOFA score ≥5 and CCI ≥3 was the best independent prognostic indicator for 30-day and in-hospital mortality. CONCLUSIONS: The combined SOFA score and CCI was a better predictor of the 30-day mortality and in-hospital mortality than the APACHE II score alone.

An unexpected case of Cardiobacterium valvarum prosthetic arthritis without cardiac lesions: Case report and literature review.

We report a case of prosthetic arthritis caused by Cardiobacterium valvarum, which has been exclusively reported to cause intravascular infections. A 81-year-old Japanese female complained prosthetic knee joint pain. Arthrocentesis cultured no pathogen, and surgical replacement of the implant surface was performed. Modified Levinthal medium culture and 16S rRNA sequencing has finally led to diagnosis of C. valvarum prosthetic knee arthritis without cardiac lesions. Fastidious bacteria such as C. valvarum can be candidate pathogens of orthopedic infections whose causative agents are sometimes unidentified. Further development of molecular diagnostics is expected, but also the importance of conventional methods should be noted.

The combined score of quick SOFA and the charlson comorbidity index could be a poor prognostic indicator for in-hospital mortality among patients with necrotizing fasciitis.

INTRODUCTION: While necrotizing fasciitis (NF) is a rare but rapidly progressive devastating soft tissue infectious disease showing a high in-hospital mortality rate of 20-30%, there are no evidence-based predictive tools. PATIENTS AND METHODS: For the purpose of examining which predictive tools could correctly reflect the severity and prognosis of NF, we retrospectively reviewed all patients who were diagnosed with NF at our institute. The disease severity was evaluated by quick SOFA (qSOFA), SOFA score, SIRS score, APACHE II score, LRINEC score and the combined score of qSOFA and CCI. RESULTS: A total of 27 patients were enrolled in this study. The median age was 68 years (range 39-96 years). With respect to the predictive values for in-hospital mortality among NF patients, the area under the ROC curve for qSOFA, SOFA score, APACHE II score, the combined score of qSOFA and CCI were 0.653 (p = 0.192), 0.588 (p = 0.12), 0.709 (p = 0.075) and 0.782 (p = 0.016) respectively. A univariate analysis showed that the combined score of qSOFA and CCI≥5 and the initial treatment failure were poor prognostic indicators for the in-hospital death among NF patients. The appropriate cut-offs of qSOFA and CCI were based on the Youden Index. CONCLUSION: We concluded that the combined score of qSOFA and CCI could reflect the severity and prognosis of NF for in-hospital death.

Usefulness of serum procalcitonin for necrotizing fasciitis as an early diagnostic tool.

INTRODUCTION: While the early diagnosis of necrotizing fasciitis (NF) is crucial and could lead to a favorable outcome, it is difficult to differentiate NF from cellulitis, resulting in delay for the appropriate treatment. PATIENTS AND METHODS: For the purpose of examining which diagnostic tools could correctly differentiate NF from cellulitis, we conducted this case-control study. We retrospectively reviewed all patients who were diagnosed with NF at our institute during 2014-2019. The patients who were diagnosed with cellulitis were randomly selected during the study period as the control group. The severity of NF is evaluated by serum-procalcitonin (PCT), LRINEC score, NTSI assessment and SIARI score. RESULTS: A total of 25 NF patients were enrolled in this study. The median age was 68 years (range 39-79) and 18 (72%) were male. Comparing NF and cellulitis groups, NF group showed a higher LRINEC score and serum PCT than cellulitis group did, even though there was no statistical significance in serum PCT. With respect to the diagnostic value for differentiating NF from cellulitis, the area under the ROC curve for of serum PCT and LRINEC scores were 0.928 [95% confidential interval (CI) 0.864-0.992, p < 0.001] and 0.846 (95% CI 0.757-0.936, p < 0.001). The appropriate serum-PCT cutoff value was 1.0 and had a sensitivity of 88%, a specificity of 89%, a positive predictive value of 81%, and a negative predictive value of 93%. CONCLUSION: Serum-PCT could be a useful diagnostic marker for differentiating diagnosis of NF from cellulitis.

Ceftriaxone versus tazobactam/piperacillin and carbapenems in the treatment of aspiration pneumonia: A propensity score matching analysis.

INTRODUCTION: Aspiration pneumonia (AP) accounts for 5.0-53.2% of hospitalized pneumonia and the treatment commonly used is by broad-spectrum antibiotics to cover anaerobes. Since ceftriaxone (CTRX) could generally cover oral streptococcus and anaerobes implicated in AP, it could be a useful option in the treatment of AP, instead of piperacillin-tazobactam/(PIPC/TAZ) or Carbapenems. PATIENTS AND METHODS: For the purpose of examining whether CTRX is as effective as broad-spectrum antibiotics for the treatment of AP, this retrospective study included consecutive community-onset patients who were admitted to our institute between 2014 and 2017. These patients were divided into two groups, a CTRX group (n = 25) and a PIPC/TAZ or carbapenems group (n = 97) based on the initial antibiotic treatment. Propensity score matching (PSM) was used to balance the potential confounders, and 23 patients were selected from each group. Patients among CTXR group received CTRX, while those among PIPC/TAZ or carbapenems group received PIPC/TAZ, or carbapenems and/or other agents. RESULTS: Both groups were well-balanced after PSM. There were no differences in 30-day mortality, duration of hospital stay or antibiotic treatments in the between them. The medical costs were much more expensive in the PIPC/TAZ or carbapenems group than in the CTR group (35,582 v. s. 8678 Japanese yen, p < 0.001). CONCLUSION: CTRX is one of the most useful antibiotic treatment for AP, which is not inferior to broad-spectrum antibiotic treatment. In addition, usage of CTRX in the treatment of AP is more economical than broad-spectrum antibiotic treatment, and could contribute to reduction of medical costs.

Efficacy and validity of automated quantitative chemiluminescent enzyme immunoassay for SARS-CoV-2 antigen test from saliva specimen in the diagnosis of COVID-19.

INTRODUCTION: The pandemic of a novel coronavirus disease 2019 (COVID-19) caused by a severe acute respiratory coronavirus 2 (SARS-CoV-2) infection has been problematic worldwide. A new SARS-CoV-2 antigen test (LUMIPULSEⓇ) was licensed and widely used in Japan since May 2020. We conducted this study intending to whether the automated quantitative CLEIA antigen test using a saliva sample is effective and valid for the diagnosis of COVID-19. PATIENTS AND METHODS: We analyzed and compared the diagnostic accuracy of both the automated quantitative CLEIA antigen test and real-time RT-PCR (rRT-PCR) using a saliva sample from individuals suspected as having COVID-19. RESULTS: A total of 305 samples were collected and tested in Aichi Medical University Hospital and affiliated facilities from December 2020 until January 2021 at our institute. Using reverse-transcription PCR as a reference, the AUROC of the automated quantitative CLEIA antigen test was 0.903 (95% confidential interval 0.845-0.962, p < 0.001). The appropriate cut-off antigen level was 4.0 pg/mL and had a sensitivity of 77.8%, a specificity of 99.6%, a positive predictive value of 98%, and a negative predictive value of 94.5%. On the other hand, the diagnostic accuracy of the antigen test decreased among patients among patients with COVID-19 with threshold cycle (Ct-value)≥27, which shows the AUROC was 0.795 (95%CI 0.687-0.907, p < 0.001). CONCLUSION: While the automated quantitative CLEIA antigen test from saliva specimen could be one of the most useful diagnostic tests for the diagnosis of COVID-19 in general practice, clinicians should know the limitations of the antigen test.

Comparative evaluation of nasopharyngeal swab and saliva specimens for the molecular detection of SARS-CoV-2 RNA in Japanese patients with COVID-19.

Considering the issues of shortage of medical resources and the invasiveness and infection risk involved in the collection of nasopharyngeal swab specimens, there is a need for an effective alternative test specimen for SARS-CoV-2 RNA detection. Here, we investigated suitability of saliva as a non-invasively obtained specimen for molecular detection of SARS-CoV-2 RNA in Japanese patients with COVID-19. In total, 28 paired clinical specimens of saliva and nasopharyngeal swabs were collected from 12 patients at various time points after symptom onset. Each specimen was assayed using reverse transcription real-time polymerase chain reaction (rRT-PCR) on the BD MAX open system using primers and probes targeting the N-gene. The saliva and nasopharyngeal swab specimens showed 19 and 15 positive results, respectively. No invalid (PCR inhibition) result was observed for any specimen. The qualitative results of each specimen obtained in the period immediately after symptom onset were similar. Three convalescent patients presented saliva-positive results, whereas their nasopharyngeal swabs were negative at four different time points, suggesting that saliva may be superior to nasopharyngeal swabs in terms of obtaining stable assay result of SARS-CoV-2. In conclusion, our results suggest that saliva can potentially serve as an alternative to nasopharyngeal swabs as a specimen for SARS-CoV-2 rRT-PCR. As saliva can be collected by patients themselves, it may be an effective way to overcome the shortage of personal protective equipment and specimen sampling tools.

Could threshold cycle value correctly reflect the severity of novel coronavirus disease 2019 (COVID-19)?

The novel coronavirus disease 2019 (COVID-19) is diagnosed by positive result of reverse transcription polymerase chain reaction (RT-PCR) for the novel coronavirus. We concluded that cycle threshold value (Ct-value) of real-time RT-PCR (rRT-PCR) assay could decrease as patients recover. Results of rRT-PCR assay could remain positive among asymptomatic patients for longer than 2 weeks. The discharge criteria of COVID-19 patients using a negative result of rRT-PCR should be reconsidered.