Blood culture bottles for culturing cerebrospinal fluid in cases of bacterial meningitis caused by Enterococcus faecalis: A case report.

Pathogen identification is essential for the treatment of bacterial meningitis. However, cerebrospinal fluid (CSF) culture tests are often negative when antimicrobial agents are administered before CSF is collected. Therefore, it is necessary to improve the culturing process for such samples. Here, we report a case of bacterial meningitis where the causative bacteria were detected by inoculating that patient's CSF samples into blood culture bottles. A 52-year-old man developed a fever and headache after undergoing transnasal transsphenoidal surgery for a nonfunctioning pituitary neuroendocrine tumor. He was suspected of having a wound infection, for which he was treated with cefozopran and vancomycin. A CSF test was also performed, owing to persistent fever, and bacterial meningitis was suspected. Although conventional CSF culture tests were negative, CSF cultures using blood culture bottles detected Enterococcus faecalis. The antimicrobial agents were therefore changed to ampicillin and gentamicin, after which the patient's meningitis improved. The blood culture bottles used contained adsorbed polymer beads with antimicrobial neutralizing properties, which likely contributed to the isolation of the bacteria. In addition to conventional cultures, ones done in blood culture bottles may be useful for diagnosing bacterial meningitis via CSF samples-particularly in cases where antimicrobial agents have already been administered.

A case of bacteremia caused by Dialister micraerophilus with Enterocloster clostridioformis and Eggerthella lenta in a patient with pyometra.

BACKGROUND: Infection by Dialister micraerophilus, an obligate anaerobic gram-negative bacillus, has rarely been described, and its clinical characteristics remain unclear. CASE PRESENTATION: We report a case of bacteremia caused by D. micraerophilus, Enterocloster clostridioformis, and Eggerthella lenta in a 47-year-old woman, associated with pyometra. D. micraerophilus was identified using 16S rRNA gene sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. D. micraerophilus was detected by polymerase chain reaction using D. micraerophilus-specific primers and E. clostridioformis and E. lenta was isolated from the drainage pus sample obtained from the pyometra uterus. The patient achieved a cure after abscess drainage and 2-week antibiotic treatment. CONCLUSIONS: To the best of our knowledge, this is the first report of D. micraerophilus bacteremia. D. micraerophilus may be associated with gynecological infections. Clinicians should consider both oral and gynecological sites when searching to identify the focus of D. micraerophilus infection.

Fosfomycin as salvage therapy for persistent methicillin-resistant Staphylococcus aureus bacteremia: A case series and review of the literature.

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia can be persistent and refractory; however, the optimal approach for its treatment has not been determined. Although fosfomycin (FOM) has been shown to have synergistic effects with anti-MRSA agents in vitro, clinical experience with FOM combination therapy is limited. Thus, we present cases of persistent MRSA bacteremia that improved with the addition of FOM. In case 1, a 48-year-old man with prosthetic vascular graft infection developed persistent MRSA bacteremia despite vancomycin (VCM) and daptomycin (DAP) administration. On day 46, after the first positive blood culture, we added FOM to DAP. The blood culture became negative on day 53. In case 2, an 85-year-old woman presented with pacemaker-related MRSA bacteremia. She was treated with VCM, followed by DAP and DAP plus rifampicin. However, the bacteremia persisted for 32 days because of difficulties in immediate pacemaker removal. After adding FOM to DAP, the blood culture became negative on day 38. In case 3, a 57-year-old woman developed persistent MRSA bacteremia due to pulmonary valve endocarditis and pulmonary artery thrombosis after total esophagectomy for esophageal cancer. The bacteremia continued for 50 days despite treatment with DAP, followed by VCM, VCM plus minocycline, DAP plus linezolid (LZD), and VCM plus LZD. She was managed conservatively because of surgical complications. After adding FOM to VCM on day 51, the blood culture became negative on day 58. FOM combination therapy may be effective in eliminating bacteria and can serve as salvage therapy for refractory MRSA bacteremia.

In vitro anti-severe acute respiratory syndrome coronavirus 2 effect of Ephedra przewalskii Stapf extract.

ETHNOPHARMACOLOGICAL RELEVANCE: The terrestrial stems of Ephedra (Ephedra spp.; including Ephedra sinica Stapf and Ephedra przewalskii Stapf) extracts are used in traditional medicines in East Asia. In Japan, the Kampo formula containing E. sinica extract is prescribed for the treatment of the common cold, influenza virus infections, and mild symptoms of coronavirus disease 2019 (COVID-19). Although ephedrine alkaloids in E. sinica exert antitussive effects, they may have side effects associated with the sympathetic nervous system. E. przewalskii extract, a drug used in traditional Uyghur and Mongolian medicine, is considered to be free of ephedrine alkaloids and is a promising candidate for the treatment of infectious diseases. However, its use is currently limited because evidence of its antiviral efficacy remains inconclusive. AIM OF THE STUDY: We compared the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) effects of E. przewalskii and E. sinica extracts in vitro. Additionally, we examined the differences in their antiviral effects against different SARS-CoV-2 strains. MATERIALS AND METHODS: VeroE6/TMPRSS2 cells were infected with SARS-CoV-2 (Conventional, Delta, and Omicron strains-BA.1, BA.2, BA.4, and BA.5), and lysates prepared from each herbal extract were added. The infectious titer was determined using the 50% tissue culture infectious dose (TCID50) method; in turn, the half-maximal inhibitory concentration (IC50) was calculated for each extract to compare the antiviral efficacy of E. sinica and E. przewalskii extracts. Further, the extracts were compared with remdesivir for their antiviral efficacy against the conventional viral strain. To verify the effect of the inactivation of virus particles, these extracts were added to each SARS-CoV-2 strain, and the infectious titers were determined using the TCID50 method. RESULTS: The antiviral efficacy (i.e., IC50) of the E. przewalskii extract against each SARS-CoV-2 strain was 2.7-10.8-fold greater than that of the E. sinica extract. The antiviral efficacy of the E. przewalskii extract against conventional viral strains was compared with that of remdesivir, which was 1/27.6 of remdesivir's efficacy. The E. sinica extract showed minimal inactivation of virus particles of each strain, whereas the E. przewalskii extract resulted in substantial viral inactivation. CONCLUSIONS: The E. przewalskii extract showed higher antiviral activity against SARS-CoV-2 than the E. sinica extract. Overall, our study suggests that E. przewalskii extract can be used for the treatment of viral infections, including COVID-19.

Virus purification highlights the high susceptibility of SARS-CoV-2 to a chlorine-based disinfectant, chlorous acid.

Chlorous acid water (HClO2) is known for its antimicrobial activity. In this study, we attempted to accurately assess the ability of chlorous acid water to inactivate SARS-CoV-2. When using cell culture supernatants of infected cells as the test virus, the 99% inactivation concentration (IC99) for the SARS-CoV-2 D614G variant, as well as the Delta and Omicron variants, was approximately 10ppm of free chlorine concentration with a reaction time of 10 minutes. On the other hand, in experiments using a more purified virus, the IC99 of chlorous acid water was 0.41-0.74ppm with a reaction time of 1 minute, showing a strong inactivation capacity over 200 times. With sodium hypochlorite water, the IC99 was 0.54ppm, confirming that these chlorine compounds have a potent inactivation effect against SARS-CoV-2. However, it became clear that when using cell culture supernatants of infected cells as the test virus, the effect is masked by impurities such as amino acids contained therein. Also, when proteins (0.5% polypeptone, or 0.3% BSA + 0.3% sheep red blood cells, or 5% FBS) were added to the purified virus, the IC99 values became high, ranging from 5.3 to 76ppm with a reaction time of 10 minutes, significantly reducing the effect. However, considering that the usual usage concentration is 200ppm, it was shown that chlorous acid water can still exert sufficient disinfection effects even in the presence of proteins. Further research is needed to confirm the practical applications and effects of chlorous acid water, but it has the potential to be an important tool for preventing the spread of SARS-CoV-2.

Capture and neutralization of SARS-CoV-2 and influenza virus by algae-derived lectins with high-mannose and core fucose specificities.

We first investigated the interactions between several algae-derived lectins and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We created lectin columns using high-mannose (HM)-type glycan-specific lectins OAA and KAA-1 or core fucose-specific lectin hypninA-2 and conducted binding experiments with SARS-CoV-2. The results showed that these lectins were capable of binding to the virus. Furthermore, when examining the neutralization ability of nine different lectins, it was found that KAA-1, ESA-2, and hypninA-2 were effective in neutralizing SARS-CoV-2. In competitive inhibition experiments with glycoproteins, neutralization was confirmed to occur through HM-type or core fucose-type glycans. However, neutralization was not observed with other lectins, such as OAA. This trend of KAA-1 and ESA-2 having the neutralizing ability and OAA not having it was also similar to influenza viruses. Electron microscopy observations revealed that KAA-1 and hypninA-2 strongly aggregated SARS-CoV-2 particles, while OAA showed a low degree of aggregation. It is believed that the neutralization of SARS-CoV-2 involves multiple factors, such as glycan attachment sites on the S protein, the size of lectins, and their propensity to aggregate, which cause inhibition of receptor binding or aggregation of virus particles. This study demonstrated that several algae-derived lectins could neutralize SARS-CoV-2 and that lectin columns can effectively recover and concentrate the virus.

Clinical characteristics of extrapulmonary nontuberculous mycobacteria infections in comparison with pulmonary infections: A single-center, retrospective study in Japan.

INTRODUCTION: The prevalence of nontuberculous mycobacteria (NTM) infections is increasing worldwide. Although NTM can affect extrapulmonary organs, studies on the clinical characteristics of extrapulmonary NTM are rare. METHODS: We retrospectively analyzed patients who were newly diagnosed with NTM infections at Hiroshima University Hospital between 2001 and 2021 to investigate species distribution, infected sites, and risk factors of extrapulmonary NTM compared to pulmonary NTM. RESULTS: Of the 261 NTM infections, 9.6% and 90.4% had extrapulmonary and pulmonary NTM, respectively. The mean ages of patients with extrapulmonary and pulmonary NTM were 53.4 and 69.3 years, 64.0% and 42.8% were male, 36.0% and 9.3% received corticosteroids, 20.0% and 0% had acquired immune deficiency syndrome (AIDS), and 56.0% and 16.1% had any immunosuppressive conditions, respectively. Younger age, corticosteroid use, and AIDS were associated with extrapulmonary NTM. In pulmonary NTM, Mycobacterium avium complex (MAC) accounted for 86.4% of NTM species, followed by M. abscessus complex (4.2%), whereas in extrapulmonary NTM, M. abscessus complex, MAC, M. chelonae, and M. fortuitum accounted for 36.0%, 28.0%, 12.0%, and 8.0%, respectively. Compared to pulmonary NTM, extrapulmonary NTM were significantly more likely to be rapid-growing mycobacteria (RGM) (56.0% vs. 5.5%). The most common sites of infection were the skin and soft tissues (44.0%), followed by the blood (20.0%), tenosynovium, and lymph nodes (12.0%). CONCLUSION: Younger age and immunosuppressive conditions are associated with extrapulmonary NTM, with a higher prevalence of RGM in extrapulmonary NTM than in pulmonary NTM. These results provide a better understanding of extrapulmonary NTM.

Prevalence of Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum detection in urine and respiratory tract samples in Hiroshima, Japan.

Background: Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum are commensal bacteria that are associated with colonization and infection of the urogenital tract. However, colonization of the respiratory tract by these microorganisms in adults has not been fully investigated. Methods: Urine and respiratory tract samples (sputum, tracheal aspirates, and bronchoalveolar lavage) of patients aged 20-80 years were analyzed to detect the presence of M. hominis, U. parvum, and U. urealyticum using a conventional PCR method. The samples were submitted to the microbiological clinical laboratory of Hiroshima University Hospital from December 1, 2021 to May 31, 2022. Results: In total, 334 urine and 238 respiratory tract samples were analyzed. The overall detection rates of M. hominis, U. parvum, and U. urealyticum were 2.9%, 1.7%, and 2.3% in male urine; 7.0%, 13.8%, and 1.9% in female urine; 2.2%, 0%, and 2.2% in male respiratory tract; and 0%, 2.0%, and 0% in female respiratory tract, respectively. In urine samples, the detection rates of M. hominis, U. parvum, and U. urealyticum were significantly higher (p < 0.001) for women (29/159; 18.2%) than for men (10/175; 5.7%); however, in respiratory tract samples, the detection rates were not significantly different (p = 0.70) between women (2/101; 2.0%) and men (5/137; 3.7%). Further, both the urine and respiratory samples of 83 patients were analyzed. Three male samples were positive for M. hominis or U. urealyticum, and M. hominis and U. urealyticum were matched in both the urine and respiratory tract samples: M. hominis (n = 1), U. urealyticum (n = 1), M. hominis + U. urealyticum (n = 1). Conclusion: M. hominis, U. parvum, and U. urealyticum were detected in the respiratory tract of not only the young patients, but also of patients aged 50-60 years. Further studies are required to understand the relationship of these microorganisms in urogenital and respiratory tract samples with extra-genital infections.

Viable SARS-CoV-2 detected in the air of hospital rooms of patients with COVID-19 with an early infection.

OBJECTIVES: This study assessed the concentration of SARS-CoV-2 in the air of hospital rooms occupied by patients with COVID-19 who had viable SARS-CoV-2 in nasopharyngeal (NP) samples in early infection. METHODS: Between July and October 2021, NP swabs were collected from 20 patients with early SARS-CoV-2 infection admitted to a tertiary hospital in Japan. Air samples were collected from their rooms, tested for SARS-CoV-2 RNA, and cultured to determine potential infectivity. RESULTS: The NP swab samples of 18 patients were positive for viable SARS-CoV-2 (median concentration: 4.0 × 105 tissue culture infectious dose 50/ml). In the air samples, viral RNA (median concentration: 1.1 × 105 copies/m3) was detected in 12/18 (67%) patients, and viable virus (median concentration: 8.9 × 102 tissue culture infectious dose 50/m3) was detected in 5/18 (28%) patients. The median time between illness onset and sampling was 3 days. The RNA concentration was significantly higher in samples wherein viable SARS-CoV-2 was detected than in samples in which viable virus was not detected (P-value = 0.027). CONCLUSION: Viable SARS-CoV-2 can be detected in the air surrounding patients with early SARS-CoV-2 infection. Health care workers should pay attention to infection control when caring for patients with early SARS-CoV-2 infection.

Lung and Cerebral Nocardiosis Caused by Nocardia elegans in a Lung Transplant Recipient: A Case Report and Literature Review.

Patients after lung transplantation are at risk for Nocardia infections. We herein report a case of lung and cerebral nocardiosis caused by Nocardia elegans, a rare species of Nocardia, in a lung transplant recipient. Antibiotic therapy, including sulfamethoxazole-trimethoprim (ST), and brain abscess drainage improved symptoms and imaging findings. A literature review of N. elegans infections showed that 12 of 14 cases (85.7%) were reported from East Asia, particularly Japan (9 cases, 64.2%). The lungs were the predominant site (12/14 cases, 85.7%), and most of the cases were susceptible to ST (9/10 cases, 90%).

Virtual reality as a learning tool for improving infection control procedures.

BACKGROUND: Hand hygiene and donning personal protective equipment (PPE) are essential techniques for infection control; however, low compliance is an issue. The effectiveness of virtual reality (VR) in learning infection control procedures is unknown. METHODS: To verify the effectiveness of VR, medical students were categorized into VR or lecture groups (n=21 each). Each group was given the same curricular content; one group received the training through VR learning using a fully-immersive 360-degree video and the other was conventional lecture-style learning. Before and after the training, they were evaluated for the implementation of hand hygiene and PPE using an Objective Structured Clinical Examination method. Post-test questionnaires were administered. RESULTS: The scores for hand hygiene, donning PPE, and the total score increased after learning in both groups. There was no difference between the pre-test total scores of the two groups (7 [5-9] vs 6 [5-7.5], P=.352); however, the VR group had significantly higher post-test total scores than the lecture group (12 [9.5-12] vs 9 [8-12], P=.024). More students in the VR group responded that they enjoyed the training and would like to use the same learning method next time. CONCLUSIONS: VR can be a useful tool for learning and practicing appropriate infection control procedures.

In vitro Suppression of SARS-CoV-2 Infection by Existing Kampo Formulas and Crude Constituent Drugs Used for Treatment of Common Cold Respiratory Symptoms.

Several traditional Japanese Kampo formulas are known to have inhibitory effects on infections with viruses that cause respiratory symptoms. Although some herbs and their components have been reported to suppress SARS-CoV-2 replication in vitro, it is difficult to compare effective Kampo formulas because of the different methods used in studies. Thus, we carried out in vitro experiments on the suppression of SARS-CoV-2 infection by Kampo formulas and crude drugs used for the common cold to compare their suppressive effects on virus infection. After infecting VeroE6/TMPRSS2 cells with SARS-CoV-2, lysates of the Kampo formulas and crude drugs were added, and after 24 h, the infectious titer in the medium was measured by the TCID50 method. Maoto was the most effective among the Kampo formulas, and Ephedrae herba was the most effective among the constituent crude drugs. However, a comparison of the suppressive effects of Ephedrae herba and Kampo formulas containing Ephedrae herba showed that the suppressive effect on virus infection did not depend on the content of Ephedrae herba. Based on the results, we believe that the use of Maoto among Kampo formulas is suitable as a countermeasure against COVID-19.

Duration of infectious viral shedding in patients with mild to moderate COVID-19 treated with REGN-CoV2.

INTRODUCTION: New treatment methods, such as REGN-CoV2, have been approved for patients with coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the effect of the drug on the duration of infectious viral shedding and viral mutations is unknown. In this study, we investigated the clinical efficacy of REGN-CoV2 treatment in patients with mild to moderate disease and compared its antiviral effects against different strains of SARS-CoV-2. METHODS: Viral culture and PCR testing were performed on the pharyngeal swabs collected from 28 patients with COVID-19 who were admitted and treated at Hiroshima University Hospital during the study period. Of these, 23 patients were treated with REGN-CoV2. The patients were classified into the REGN-CoV2(+) and REGN-CoV2(-) groups, and the clinical course was compared between the groups. The 50% inhibitory concentrations (IC50) of REGN-CoV2 against the isolated virus strains were determined. RESULTS: After treatment with REGN-CoV2, the virus culture positivity rate was greatly reduced. The time to negative viral culture was significantly shorter in the REGN-CoV2(+) group than in the REGN-CoV2(-) group. In vitro evaluation of REGN-CoV2 against isolated virus strains also showed efficacy. CONCLUSIONS: REGN-CoV2 treatment was effective in patients with mild COVID-19 and could shorten the period of infectious viral shedding. This may be an important factor in preventing the spread of infection. It may be possible to revise the isolation period for patients with mild disease treated with REGN-CoV2.

Clinical characteristics of Actinotignum schaalii bacteremia in a Japanese tertiary hospital.

We retrospectively analyzed seven patients with Actinotignum schaalii bacteremia in a tertiary hospital in Japan. Pyelonephritis was the most frequent source of bacteremia, followed by Fournier's gangrene and pyometra. All patients with pyelonephritis had underlying urological conditions, ureteral stents, nephrostomy, ureteral stones, or ureterocele.

Adverse reactions to the BNT162b2 and mRNA-1273 mRNA COVID-19 vaccines in Japan.

INTRODUCTION: The BNT162b2 and mRNA-1273 COVID-19 vaccines are the main vaccines that have been used for mass vaccination in Japan. Information on adverse reactions to COVID-19 vaccines in the Japanese population is limited. METHODS: We conducted an online survey on self-reported adverse reactions in individuals who had received two doses of the BNT162b2 or mRNA-1273 vaccine. The incidence of adverse events after each dose of vaccine was investigated. Propensity score matching was used to compare the incidence of adverse reactions after the second dose of the BNT162b2 and mRNA-1273 vaccines. RESULTS: After the first and second doses of the BNT162b2 vaccine, and the first and second doses of the mRNA-1273 vaccine, 890, 853, 6401, and 3965 individuals, respectively, provided complete responses. Systemic reactions, including fever, fatigue, headache, muscle/joint pain, and nausea were significantly more common in females, individuals aged <50 years, and after the second dose. The incidence of injection site pain did not differ significantly according to the dose. The incidence of delayed injection site reactions after the first dose of mRNA-1273 vaccine was 3.9% and 0.8% among females and males, respectively, and 10.6% among females aged 40-69 years. Local and systemic reactions after the second dose, including fever, fatigue, headache, muscle/joint pain, nausea, and skin rash were more common in individuals who had received the mRNA-1273 vaccine. CONCLUSIONS: Adverse reactions were more frequently reported in females, younger individuals, and after the mRNA-1273 vaccine.

Duration of infectious virus shedding in patients with severe coronavirus disease 2019 who required mechanical ventilation.

BACKGROUND: Approximately 5% of patients with coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 develop severe COVID-19. Severe COVID-19 requires respiratory management with mechanical ventilation and an extended period of treatment. Prolonged infectious virus shedding is a concern in severe COVID-19 cases, but few reports have examined the duration of infectious virus shedding. Therefore, we investigated the duration of infectious virus shedding in patients transferred to Hiroshima University Hospital with severe COVID-19 requiring mechanical ventilation. METHODS: Nasopharyngeal swab specimens were collected and analyzed using both viral culture and reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) tests between December 2020 and February 2021. RESULTS: Of the 23 patients tested, the proportions of those with positive test results at first specimen collection (the median number of days to first specimen collection after symptom onset was 10) on RT-qPCR and viral culture tests were 95·7% and 30·4%, respectively. All six patients with positive viral culture test results who were followed-up tested negative 24 days after symptom onset but remained positive on RT-qPCR. Viral loads based on PCR testing did not decrease over time, but those determined via culture tests decreased over time. The longest negative conversion time was observed in a dialysis patient on immunosuppressive drugs. CONCLUSIONS: This study indicated that patients with severe COVID-19 remain culture positive for ≥ 10 days after symptom onset. Additionally, immunosuppressed patients with severe COVID-19 could consider isolation for ≥ 20 days.

Vertebral osteomyelitis caused by Mycobacteroides abscessus subsp. abscessus resulting in spinal cord injury due to vertebral body fractures.

Nontuberculous mycobacteria (NTM) rarely cause vertebral osteomyelitis; however, the clinical characteristics of vertebral osteomyelitis caused by NTM are poorly understood due to its rarity. A 74-year-old man with lung cancer was treated with prednisolone for immune checkpoint inhibitor-associated immune-related adverse events. He had been experiencing mild back pain without febrile episodes for five months, and was admitted to the hospital for worsening back pain and progressive paraplegia. Magnetic resonance imaging showed spinal cord compression at T4-5 due to fractures of the T5 and T7 vertebral bodies. The culture of a sample of pus from the T7 vertebral body obtained at the time of spinal fusion surgery yielded the Mycobacteroides abscessus (M. abscessus) complex. The patient was diagnosed with vertebral osteomyelitis caused by M. abscessus complex and treated with clarithromycin, amikacin, and imipenem; clarithromycin was later replaced by sitafloxacin because of inducible macrolide resistance. However, his neurologic deficits were irreversible, and he died due to a deteriorating general condition. The strain was identified up to subspecies level as M. abscessus subsp. abscessus by hsp65 and rpoB sequencing and nucleic acid chromatography. Although vertebral osteomyelitis due to NTM is rare, delayed diagnosis can lead to serious complications or poor outcomes. A prolonged clinical course, less frequent fever, vertebral destruction or spinal deformity, neurological deficits, or immunosuppressed conditions might be suggestive of NTM vertebral osteomyelitis.

Postoperative mediastinitis after cardiac surgery caused by Mycoplasma hominis: a case report.

BACKGROUND: Mycoplasma hominis is a human commensal bacterium of the urogenital tract, and extragenital infection caused by M. hominis has rarely been reported. The identification of M. hominis is challenging, and surgeons are generally not aware that this bacteria can cause postoperative infection. Here, we report a rare case of postoperative mediastinitis caused by M. hominis after cardiac surgery in an immunocompetent patient. CASE PRESENTATION: A 54-year-old man presented with pain and purulent discharge from the wound after aortic valve replacement and patent foramen ovale closure. However, Gram staining and culture of bacteria from the purulent discharge was negative, and empiric sulbactam/ampicillin therapy was not effective. This patient developed mediastinitis and rupture of a pseudoaneurysm of the ascending aorta caused by mediastinitis, and re-operation was performed. Then, postoperative mediastinitis caused by M. hominis or Ureaplasma species was suspected and bacterial cultures targeting these pathogens were performed. M. hominis was identified from abscess and tissue obtained from the surgical site and urine. A final diagnosis of postoperative mediastinitis caused by M. hominis was determined. The patient was initially treated with levofloxacin and then with minocycline for 3 weeks. The patient's clinical condition improved; the patient was transferred to another hospital. CONCLUSION: The role of M. hominis as a cause of postoperative infection might be underestimated in cardiac surgery. M. hominis should be considered when culture-negative purulent discharge is observed or there is no response to standard empiric treatment of postoperative infections.

Laboratory identification and clinical characteristics of Streptococcus bovis/Streptococcus equinus complex bacteremia: a retrospective, multicenter study in Hiroshima, Japan.

BACKGROUND: Bacteremia due to the Streptococcus bovis/Streptococcus equinus complex (SBSEC) is associated with specific diseases, such as colorectal cancer and infective endocarditis. This study aimed to evaluate the clinical characteristics of SBSEC bacteremia and the accuracy of identification of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and phenotypic identification systems for SBSEC isolates. METHODS: We analyzed patients with SBSEC bacteremia retrospectively between 2012 and 2019 at three hospitals in Japan. We re-identified each SBSEC isolate using sequencing superoxide dismutase (sodA) analysis, MALDI-TOF MS using the MALDI Biotyper, and phenotypic identification using the VITEK2. RESULTS: During the study period, 39 patients with SBSEC bacteremia were identified. S. gallolyticus subsp. pasteurianus (SGSP, n = 29), S. gallolyticus subsp. gallolyticus (SGSG, n = 5), S. lutetiensis (SL, n = 4), and S. infantarius subsp. infantarius (n = 1) were identified using sodA sequencing analysis. Primary bacteremia (36%) was the most common cause of bacteremia, followed by infective endocarditis (26%) and biliary tract infections (23%). Colorectal cancer was associated significantly with SGSG bacteremia, while the sources of bacteremia were similar in each SBSEC subspecies. The MALDI Biotyper was significantly more accurate in identifying the SBSEC isolates at the subspecies level compared to the VITEK2 (92% vs. 67%, P = 0.010). In contrast, there were no significant differences in the rates of correct identification of the SBSEC isolates at the species level between the MALDI Biotyper and the VITEK2 (100% vs. 87%, P = 0.055). CONCLUSIONS: Bacteremia with SGSG was associated with colorectal cancer, and the sources of bacteremia were similar in each SBSEC subspecies. The MALDI-TOF MS was significantly more accurate in identifying SBSEC isolates at the subspecies level than the phenotypic identification systems. The accurate identification of SBSEC isolates using the MALDI-TOF MS and phenotypic identification systems was sufficient at the species level, but it was insufficient at the subspecies level. Therefore, it may be reasonable for clinicians to perform echocardiographies and colonoscopies in all patients with SBSEC bacteremia.

Ethanol Susceptibility of SARS-CoV-2 and Other Enveloped Viruses.

Ethanol is an effective disinfectant against the novel coronavirus SARS-CoV-2. However, its effective concentration has not been shown, and we therefore analyzed the effects of different concentrations of ethanol on SARS-CoV-2. When SARS-CoV-2 was treated with varying ethanol concentrations and examined for changes in infectivity, the ethanol concentration at which 99% of the infectious titers were reduced was 24.1% (w/w) [29.3% (v/v)]. For reference, ethanol susceptibility was also examined with other envelope viruses, including influenza virus, vesicular stomatitis virus in the family Rhabdoviridae, and Newcastle disease virus in the family Paramyxoviridae, and the 99% inhibitory concentrations were found to be 28.8%(w/w) [34.8% (v/v)], 24.0% (w/w) [29.2% (v/v)], and 13.3% (w/w) [16.4% (v/v)], respectively. Some differences from SARS-CoV-2 were observed, but the differences were not significant. It was concluded that ethanol at a concentration of 30%(w/w) [36.2% (v/v)] almost completely inactivates SARS-CoV-2.