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.

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.

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.

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.

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.

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.

The effect of pulsed-xenon ultraviolet disinfection on surfaces contaminated with vancomycin-resistant Enterococci in a Japanese hospital.

INTRODUCTION: Recently, a worldwide outbreak of vancomycin-resistant Enterococci (VRE) was reported. However, due to the low incidence of VRE infection and colonization, VRE contamination of hospital environments has not been fully investigated in Japan. METHODS: Surfaces were swabbed, before and after manual cleaning and after pulsed xenon ultraviolet (PX-UV) disinfection, in five patient rooms that had been occupied by patients colonized with VRE. Difference in the number of VRE-positive samples and VRE colony forming units (CFUs), before and after disinfection, for each cleaning method was estimated. RESULTS: We detected VRE contamination in 22/60 (37%) and 14/60 (23%) samples collected before and after manual cleaning, respectively. In contrast, VRE contamination was not detected in the samples collected after PX-UV disinfection. In addition, 3/5 (60%) spray nozzles of electric warm-water bidet toilet seats were found to be contaminated with VRE before terminal cleaning. Manual cleaning caused a significant decrease in the number of VRE CFUs compared with that before cleaning (P = 0.031). PX-UV disinfection also caused a significant decrease in the number of VRE CFUs compared to that of manual cleaning (P < 0.001). CONCLUSION: We identified hot spots of severe contamination, such as private bathrooms in patient rooms and areas around the bed of patients using diapers and required assistance. VRE contamination persisted even after terminal disinfection; PX-UV disinfection in addition to terminal disinfection was effective at eliminating VRE contamination. These results can be useful in controlling the spread of VRE infections in Japanese hospitals.

Inhibiting SARS-CoV-2 infection in vitro by suppressing its receptor, angiotensin-converting enzyme 2, via aryl-hydrocarbon receptor signal.

Since understanding molecular mechanisms of SARS-CoV-2 infection is extremely important for developing effective therapies against COVID-19, we focused on the internalization mechanism of SARS-CoV-2 via ACE2. Although cigarette smoke is generally believed to be harmful to the pathogenesis of COVID-19, cigarette smoke extract (CSE) treatments were surprisingly found to suppress the expression of ACE2 in HepG2 cells. We thus tried to clarify the mechanism of CSE effects on expression of ACE2 in mammalian cells. Because RNA-seq analysis suggested that suppressive effects on ACE2 might be inversely correlated with induction of the genes regulated by aryl hydrocarbon receptor (AHR), the AHR agonists 6-formylindolo(3,2-b)carbazole (FICZ) and omeprazole (OMP) were tested to assess whether those treatments affected ACE2 expression. Both FICZ and OMP clearly suppressed ACE2 expression in a dose-dependent manner along with inducing CYP1A1. Knock-down experiments indicated a reduction of ACE2 by FICZ treatment in an AHR-dependent manner. Finally, treatments of AHR agonists inhibited SARS-CoV-2 infection into Vero E6 cells as determined with immunoblotting analyses detecting SARS-CoV-2 specific nucleocapsid protein. We here demonstrate that treatment with AHR agonists, including FICZ, and OMP, decreases expression of ACE2 via AHR activation, resulting in suppression of SARS-CoV-2 infection in mammalian cells.

Pilot study on the decontamination efficacy of an installed 222-nm ultraviolet disinfection device (Care222™), with a motion sensor, in a shared bathroom.

BACKGROUND: Toilet surfaces are contaminated with pathogens, and they may be a vector for disease transmission. In this study, we investigated the efficacy of an automated 222-nm ultraviolet C (UVC) disinfection device "Care222™," with a motion sensor, for removing bacterial contamination in a shared bathroom. METHODS: Two automated UVC devices, deactivated by motion sensors, were mounted on the ceiling of two bathrooms; the emission window of the UVC device was covered in the non-treated bathroom. After irradiation, samples were collected from five surfaces at four time points/day for 5 days, and colony-forming units (CFUs) of aerobic bacteria (AB) were determined. The irradiation time was also measured. RESULTS: UVC source deactivation time did not significantly differ between the bathrooms. There was a significant difference in the total AB CFUs between the treated and non-treated bathrooms. In the treated bathroom, the CFUs of AB of the toilet seat, control panel of the electric toilet seat, and top of the toilet paper holder were significantly lower than those of the control. The CFUs of AB at 9:00, 15:00, and 18:00 h in the treated bathroom were significantly lower than those of the control. CONCLUSIONS: The automated 222-nm UVC disinfection device with a motion sensor significantly reduced AB surface contamination of a shared bathroom.

Complicated cutaneous leishmaniasis caused by an imported case of Leishmania tropica in Japan: a case report.

BACKGROUND: Leishmaniasis is not endemic in Japan, and imported cases are rare. However, there are increasing concerns regarding imported cases of cutaneous leishmaniasis from endemic countries to Japan. This report describes a case of imported cutaneous leishmaniasis that was diagnosed and treated in Japan. CASE PRESENTATION: A 53-year-old Pakistani man presented with skin lesions on both malleoli of his right ankle and the dorsum of the left foot. The skin lesions manifested as erythematous nodules surrounding an ulcer in the center of the lesion. The lesions of the malleoli of his right ankle each measured 3 × 3 cm, and the lesion on the top of his left foot measured 5 × 4 cm. He had been living and working in Japan but had a history of a visit to Pakistan for about 2 months in 2018. The skin lesions were biopsied. Giemsa and hematoxylin and eosin staining of biopsy samples showed amastigotes of Leishmania in macrophages, and the presence of Leishmania was confirmed by skin tissue culture. Polymerase chain reaction using biopsy specimens identified Leishmania parasites, and DNA sequence analysis revealed that the species was Leishmania tropica. The patient was treated with intravenous liposomal amphotericin B for 6 days. The erythema disappeared, and the erythematous nodules resolved within 3 weeks. CONCLUSION: This is the first report of imported cutaneous leishmaniasis caused by L. tropica from Pakistan, and it is interesting that all three testing modalities showed positive results in this case.

Effect of intermittent irradiation and fluence-response of 222 nm ultraviolet light on SARS-CoV-2 contamination.

BACKGROUND: The effectiveness of 222 nm ultraviolet (UV) C light for disinfecting surfaces contaminated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported. The aim of this study was to evaluate the effect of the intermittent irradiation of 222 nm UVC on SARS-CoV-2 and the fluence-dependent effect of 222 nm UVC irradiation on SARS-CoV-2 inactivation. METHODS: We experimented with 5 min continuous and intermittent irradiation for 0.1, 0.05, 0.013, and 0.003 mW/cm2 of 222 nm UVC to evaluate the differences in the effect of the continuous and intermittent irradiation of 222 nm UVC on SARS-CoV-2 inactivation. For intermittent irradiation, we followed the on-off irradiation cycles with every 10-s irradiation followed by a 380-s interval. Thereafter, we evaluated the effects of 0.1, 0.013, and 0.003 mW/cm2 222 nm UVC irradiation on SARS-CoV-2 contamination at UV fluences of 1, 2, and 3 mJ/cm2 at each irradiance. RESULTS: At each irradiance, no significant difference was observed in the log reduction of SARS-CoV-2 between continuous and intermittent irradiation. At each UV fluence, no significant difference was observed in the log reduction of SARS-CoV-2 among the three different irradiance levels. CONCLUSION: There was no significant difference between continuous and intermittent irradiation with 222 nm UVC with regards to SARS-CoV-2 inactivation. Moreover, 222 nm UVC inactivates SARS-CoV-2 in a fluence-dependent manner. The efficacy of 222-nm UVC irradiation in reducing the contamination of SARS-CoV-2 needs to be further evaluated in a real-world setting.

Combining pulsed xenon ultraviolet disinfection with terminal manual cleaning helps reduce the acquisition rate of methicillin-resistant Staphylococcus aureus.

BACKGROUND: The clinical effectiveness of ultraviolet light (UV) disinfection remains unclear. This study aimed to investigate the effect of adding pulsed xenon UV (PX-UV) disinfection to the terminal cleaning protocol on the rate of methicillin-resistant Staphylococcus aureus (MRSA) acquisition at a Japanese hospital. METHODS: The use of a PX-UV disinfection device was added to the manual terminal cleaning protocol applied after the discharge or transfer of patients treated in the intensive and high care units. We used a Poisson regression model to examine the incidence of MRSA acquisition, based on the study period, PX-UV intervention status, unit type, and the rate of consumption of alcohol-based hand rub (ABHR). RESULTS: Approximately 86% of the rooms in the intervention units were terminally disinfected with the PX-UV device. In the intervention units, the incidence of MRSA acquisition decreased from 3.56 per 1,000 patient-days in the nonintervention period to 2.21 per 1,000 patient-days in the intervention period. Moreover, the use of PX-UV disinfection decreased the risk of MRSA acquisition (incident rate ratio: 0.556; 95% confidence interval, 0.309-0.999; P = .0497). ABHR consumption did not affect the risk of MRSA acquisition. CONCLUSIONS: Adding PX-UV disinfection to terminal manual cleaning reduced the rate of MRSA acquisition.

Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has emerged as a serious threat to human health worldwide. Efficient disinfection of surfaces contaminated with SARS-CoV-2 may help prevent its spread. This study aimed to investigate the in vitro efficacy of 222-nm far-ultraviolet light (UVC) on the disinfection of SARS-CoV-2 surface contamination. METHODS: We investigated the titer of SARS-CoV-2 after UV irradiation (0.1 mW/cm2) at 222 nm for 10-300 seconds using the 50% tissue culture infectious dose (TCID50). In addition, we used quantitative reverse transcription polymerase chain reaction to quantify SARS-CoV-2 RNA under the same conditions. RESULTS: One and 3 mJ/cm2 of 222-nm UVC irradiation (0.1 mW/cm2 for 10 and 30 seconds) resulted in 88.5 and 99.7% reduction of viable SARS-CoV-2 based on the TCID50 assay, respectively. In contrast, the copy number of SARS-CoV-2 RNA did not change after UVC irradiation even after a 5-minute irradiation. CONCLUSIONS: This study shows the efficacy of 222-nm UVC irradiation against SARS-CoV-2 contamination in an in vitro experiment. Further evaluation of the safety and efficacy of 222-nm UVC irradiation in reducing the contamination of real-world surfaces and the potential transmission of SARS-CoV-2 is needed.

Eligibility of Feline Calicivirus for a Surrogate of Human Norovirus in Comparison with Murine Norovirus, Poliovirus and Coxsackievirus.

Feline calicivirus (FCV) is frequently used as a surrogate of human norovirus. We investigated eligibility of FCV for anti-viral assay by investigating the stability of infectivity and pH sensitivity in comparison with other viruses. We found that infectivities of FCV and murine norovirus (MNV) are relatively unstable in infected cells compared with those of coxsackievirus (CoV) and poliovirus (PoV) , suggesting that FCV and MNV have vulnerability. Western blotting indicated that inactivation of FCV was not due to viral protein degradation. We also demonstrated sensitivity of FCV to low pH, the 50% inhibitory pH value being ca. 3.9. Since human norovirus is thought to persist longer, in infectivity and to be a resistant virus, CoV, which is robust and not restrained in use as PoV, may be more appropriate as a test virus for disinfectants, rather than FCV and MNV.