Association between Moraxella keratitis and advanced glycation end products.

Diabetes mellitus is recognized as a major predisposing factor for Moraxella keratitis. However, how diabetes mellitus contributes to Moraxella keratitis remains unclear. In this study, we examined Moraxella keratitis; based on the findings, we investigated the impact of advanced glycation end products (AGEs) deposition in the cornea of individuals with diabetic mellitus on the adhesion of Moraxella isolates to the cornea. A retrospective analysis of 27 culture-proven cases of Moraxella keratitis at Ehime University Hospital (March 2006 to February 2022) was performed. Moraxella isolates were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Among the patients, 30.4% had diabetes mellitus and 22.2% had the predominant ocular condition of using steroid eye drops. The species identified were Moraxella nonliquefaciens in 59.3% and Moraxella lacunata in 40.7% of patients. To investigate the underlying mechanisms, we assessed the effects of M. nonliquefaciens adherence to simian virus 40-immortalized human corneal epithelial cells (HCECs) with or without AGEs. The results demonstrated the number of M. nonliquefaciens adhering to HCECs was significantly increased by adding AGEs compared with that in controls (p < 0.01). Furthermore, in the corneas of streptozotocin-induced diabetic C57BL/6 mice treated with or without pyridoxamine, an AGE inhibitor, the number of M. nonliquefaciens adhering to the corneas of diabetic mice was significantly reduced by pyridoxamine treatment (p < 0.05). In conclusion, the development of Moraxella keratitis may be significantly influenced by the deposition of AGEs on the corneal epithelium of patients with diabetes mellitus.

Long-term transition of antibody titers in healthcare workers following the first to fourth doses of mRNA COVID-19 vaccine: Comparison of two automated SARS-CoV-2 immunoassays.

Anti-spike receptor binding domain (S-RBD) antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which best correlates with virus-neutralizing antibody is useful for estimating the period of protection and identifying the timing of additional booster doses. Long-term transition of the S-RBD antibody titer and the antibody responses among healthy individuals remain unclear. In the present study, therefore, we monitored the S-RBD antibody titers of 16 healthcare workers every 4 weeks for 76 weeks after vaccination with a fourth dose of mRNA-1273 (Moderna) following three doses of BNT162b2 (Pfizer/BioNTech) using two commercial automated immunoassays (Roche and Abbott). Two antibody responses to the vaccine were similar with an up-down change before and after the second (weeks 3), third (weeks 40) and fourth (week 72) vaccinations, but the titer did not fall below the assay's positivity threshold in any individual. The peak level of the geometric mean titer (GMT) in the Roche assay was highest after the third vaccination, and that in Abbott assay was highest after the fourth vaccination but almost equal to that after the third vaccination. Both the geometric mean fold rise (GMFR) demonstrated by the Roche and Abbott assays were highest after the third vaccination. Antibody titers determined by the Roche and Abbott assays showed a positive strong correlation (correlation coefficient: 0.70 to 0.99), but the ratio (Roche/Abbott) of antibodies demonstrated by both assays increased 0.46- to 8.26-fold between weeks 3 and 76. These findings will be helpful for clinicians when interpreting results for SARS-CoV-2 antibody levels and considering future vaccination strategies.

[Comparison of PVL-producing MRSA Showing POT Type 106-77-113 and POT Type 106-255-121 Detected in Materials Derived from Patients with Skin Infections].

Methicillin-resistant Staphylococcus aureus (MRSA) strains showing POT type 106-77-113 have been associated with USA300. Additionally, many strains produce Panton-Valentine Leukocidin (PVL). Until 2018, 106-77-113 was the most dominant POT-type PVL-producing bacteria isolated in our hospital; however, in 2018, one strain with POT type 106-255-121 was isolated, and thereafter, since 2019, an increasing trend towards isolation of this strain has been observed. In this study, we compared two PVL-producing strains detected in skin infections-derived materials from outpatients during the three-year period between 2019 and 2021 through genetic analysis using next-generation sequencers. Eight, each of POT types 106-77-113 (POT-A) and 106-255-121 (POT-B), strains were included in this study, and PVL productivity, drug susceptibility, multi-locus sequencing typing (MLST), and resistance genes and virulence genes were detected. Both the groups shared the same MLST profile (3-3-1-1-4-4-3), but a single nucleotide mutation of ARCC was detected in POT-B type strain, which was determined to be similar to ST 8 of POT-A and POT-B type strains. Only POT-B type strains harbored aac(6')-aph(2″) and erm(A) genes, consistent with the results of drug susceptibility tests. All the strains were resistant to GM and CAM and were positive to D-zone test. On the other hand, the POT-A strains were sensitive to GM, and 7 of 8 strains were sensitive to CLDM and MINO. However, one POT-A type strain was found to harbor erm(C), tet(K), and tet(M) genes and was resistant to CAM, CLDM, and MINO. Both groups of isolates harbored 17 genes including ACME, lukF-PV, and LukS-PV, and no difference in pathogenicity was observed. In our hospital, one strain of POT type 106-255-121 was isolated for the first time in 2018, and the number of isolates of this type has been increasing since then. The present study confirms that POT type 106-255-121 strains have the same virulence as POT type 106-77-113 strains have and have also acquired a drug resistance gene.

Two-Year Seroprevalence Surveys of SARS-CoV-2 Antibodies among Outpatients and Healthcare Workers in Ehime, Japan.

We conducted two-year seroprevalence surveys of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies among outpatients and healthcare workers (HCWs) at Ehime University Hospital. Data were collected for outpatients and HCWs in June 2020 (1st survey), December 2020 (2nd survey), July 2021 (3rd survey), and December 2021 (4th survey), focusing on demographics, occupation, and the seroprevalence of anti-SARS-CoV-2 antibodies. Blood samples were obtained from randomly selected outpatients who visited our hospital for medical care and HCWs undergoing regular medical checks with opt-out informed consent. SARS-CoV-2 antibody positivity was evaluated using two laboratory-based quantitative tests. The total number of participants enrolled was 6,369 (1st survey: 1,000 outpatients and 743 HCWs, 2nd survey: 1,000 outpatients and 407 HCWs, 3rd survey: 1,000 outpatients and 804 HCWs, 4th survey: 1,000 outpatients and 415 HCWs). The prevalence of SARS-CoV-2 antibodies among outpatients and HCWs was 0-0.1% and 0-0.124% during the research period, respectively, and changed little over time. These findings suggest that the magnitude of COVID-19 infection during the pandemic among outpatients and HCWs in this rural hospital might have been small.

Impact of Intestinal Bacteria on Levodopa Pharmacokinetics in LCIG Therapy.

Background: Levodopa-carbidopa intestinal gel (LCIG) therapy is used in advanced Parkinson's disease (PD) and consists of continuous administration of levodopa directly into the jejunum through a percutaneous endoscopic gastro-jejunal (PEG-J) tube. Recently, the metabolism of levodopa by Enterococcus faecalis (E. faecalis) has been reported. Intestinal bacteria can also affect this therapy. Objectives: To investigate intestinal bacteria and examine its impact on levodopa blood concentration in patients with PD receiving LCIG therapy. Methods: We enrolled 6 patients receiving LCIG therapy in our department. After PEG-J tube replacement, intestinal bacteria were collected from the tip of the tube and were identified using culture and polymerase chain reaction (PCR) tests. Moreover, the presence of tyrosine decarboxylase, which metabolizes levodopa, was also confirmed by PCR test. The ability of these bacteria to metabolize levodopa was confirmed in vitro. Levodopa blood concentrations were also examined before PEG-J tube replacement. Results: Bacteria were detected in all 6 patients. E. faecalis was present in 4 patients. Moreover, tyrosine decarboxylase was detected in 2 patients. The identified bacteria displayed in vitro metabolization to dopamine in the 4 E. faecalis positive samples. The addition of carbidopa did not inhibit the metabolism of levodopa. However, there was no difference in the mean blood concentration of levodopa, regardless of the presence of E. faecalis. Conclusions: We found bacteria, including E. faecalis in the PEG-J tube. We observed levodopa metabolism in vitro, but there was no association with levodopa blood concentration. The effect of intestinal bacteria may be limited in patients receiving LCIG therapy.

Properties of Staphylococcus lugdunensis in Children.

Background. Staphylococcus lugdunensis is one of the clinically important coagulase-negative staphylococci. The purpose of this study was to elucidate the microbiological features of S. lugdunensis in hospitalized children. Methods. From January 2012 to December 2019, all isolates were retrospectively screened for S. lugdunensis. Results. Twenty-five children were eligible for study. Nineteen and six children were classified into a critical care unit group (Group A) and a general medical ward group (Group B), respectively. The prevalence of methicillin-resistant S. lugdunensis was significantly higher in Group A than in Group B (68.4% vs 0%; P < .01). Eleven children (44%) had S. lugdunensis infections, while the remaining children were colonized. Six of the 11 infected children (55%) had healthcare-associated infections. Moreover, 3 isolates exhibited the methicillin resistance. Conclusions. The bacteriological characteristics of S. lugdunensis differ depending on patient background. Selection of antibiotic treatment should in part rely on patient background data.

A Catheter-Related Bloodstream Infection by Brevibacterium casei in a Child with Acute Myeloid Leukemia: Case Report and Literature Review.

The most common organisms isolated from pediatric catheter-related bloodstream infections (CRBSIs) are Gram-positive cocci, such as coagulase-negative staphylococci and Staphylococcus aureus. There are few formal reports of Brevibacterium casei infection and even fewer reports of CRBSI due to this Gram-positive rod. Here we report the first case of CRBSI due to B. casei in an 8-year-old girl with acute myeloid leukemia in Japan. The isolate exhibited decreased susceptibility to ß-lactam antibiotics. Antimicrobial therapy with meropenem and vancomycin, in addition to the removal of central venous catheter line, consequently led to a significant clinical improvement of the patient's symptoms. A literature review found available clinical courses in 16 cases (4 pediatric cases including our case) of B. casei infection. Our case and those in literature suggested that B. casei infection often occurs in patients with indwelling central venous catheters; the literature review further suggested that removal of central venous catheters is required in most cases. Special attention should be paid to the detection of opportunistic infections due to Brevibacterium spp. in immunocompromized children who are using a central venous catheter.

Presence of Acanthamoeba and diversified bacterial flora in poorly maintained contact lens cases.

Acanthamoeba can cause visually destructive Acanthamoeba keratitis (AK) in contact lens (CL) users. The purpose of this study was to determine whether Acanthamoeba was present in the CL cases of CL wearers and to develop techniques to prevent the contaminations. To accomplish this, 512 CL case samples were collected from 305 healthy CL wearers. Using real-time PCR, Acanthamoeba DNA was detected in 19.1% of CL cases, however their presence was not directly associated with poor CL case care. Instead, the presence of Acanthamoeba DNA was associated with significant levels of many different bacterial species. When the CL cases underwent metagenomic analysis, the most abundant bacterial orders were Enterobacteriales followed by Burkholderiales, Pseudomonadales, and Flavobacteriales. The presence of Acanthamoeba was characterized by Propionibacterium acnes and Rothia aeria and was also associated with an increase in the α diversity. Collectively, Acanthamoeba contamination occurs when a diversified bacterial flora is present in CL cases. This can effectively be prevented by careful and thorough CL case care.

Incidence and Antimicrobial Susceptibilities of Mycoplasma hominis in Pregnant Females, Ehime University Hospital.

OBJECTIVE: Mycoplasma hominis usually colonizes the lower urogenital tract and has been occasionally associated with pelvic inflammatory disease, postpartum fever, preterm labor in pregnant females. The aim of this study was to investigate the incidence and antimicrobial susceptibilities of M. hominis isolated from the urogenital tracts of pregnant females. METHODS: Specimens were obtained from the urogenital tract of pregnant females at Department of Obstetrics and Gynecology, Ehime University Hospital, between November 2014 and December 2017. The identification of M. hominis was confirmed by the polymerase chain reaction (PCR) methods. The minimum inhibitory concentrations (MICs) of antibiotics were measured using a broth microdilution assay. RESULTS: Of the 1074 specimens tested, 63 (5.9%) were positive for M. hominis. The M. hominis-positive rate was highest at 21.3% between 18 and 24 years old. The 21 (25.6%) of 82 patients with bacterial vaginosis were positive for M. hominis. The 17 (40.5%) of 42 patients delivered by cesarean section that occurred infections including of intrauterine infection and pelvic abscess were positive for M. hominis. They were all administered ß-lactam antibiotics before and after cesarean section. All patients recovered immediately following administration of clindamycin (CLDM). ß-lactam antibiotics, macrolides and fosfomycin (FOM) were all resistant against M. hominis strains. In contrast, M. hominis strains were susceptible to CLDM, minocycline (MINO) and quinolones. CONCLUSIONS: Our data suggests that the prevalence of genital M. hominis in pregnant females is high at younger age, bacterial vaginosis and infections after cesarean section with ß-lactam antibiotics administration. CLDM, MINO and quinolones may be recommended against M. hominis infection. Especially, CLDM can be used as the adequate agent for pregnant females because tetracycline and quinolones are undesirable during pregnancy and lactation.

[Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) by POT Method, Antimicrobial Susceptibility Patterns, and Toxin-Producing Types].

The PCR-based open reading frame typing (POT) is an important method for analyzing outbreak information. Many institutions use POT as a molecular epidemiological method for analyzing horizontal transmission in methicillin-resistant Staphylococcus aureus (MRSA). However, typing and analyzing MRSA only based on POT, with high detection frequency, has some limitations. In this study, we analyzed 62 strains of MRSA, isolated at Ehime University Hospital between January 2018 to December 2018 based on six POT types, toxin type, and antimicrobial susceptibility. Types of POT and strains used were as follows: 106-183-37 (28 strains), 106-137-80 (7 strains), 106-77-113 (7 strains), 106-9-80 (7 strains), 70-18-81 (7 strains), 106-247-33 (6 strains). Based on antimicrobial susceptibility patterns, 5 types of MRSA were detected, including types susceptible to gentamicin (GM), clarithromycin (CAM), and levofloxacin (LVFX). Strains belonging to the same POT type, showed differential antimicrobial susceptibility patterns and had different toxin productivity. These findings suggest that the combination of POT method with antimicrobial susceptibility patterns and toxin type may be a useful technique for MRSA typing.

Association between daptomycin susceptibility and teicoplanin resistance in Staphylococcus epidermidis.

Staphylococcus epidermidis infections are a common occurrence in hospitals, particularly in catheter-related bloodstream and surgical site infections and infective endocarditis. Higher daptomycin minimum inhibitory concentration (MIC) values may be associated with daptomycin treatment failure among patients with S. epidermidis infections. We therefore conducted a retrospective cohort study to determine the predictive value of daptomycin susceptibility. A retrospective study was undertaken in 1,337 patients with S. epidermidis infections. Data were collected from 1 January 2013 to 31 December 2016 at Ehime University Hospital, and included the following clinicopathological factors for evaluation: age, sex, resistance to vancomycin or teicoplanin, and history of antimicrobial therapy. Multiple analysis was performed using logistic regression to identify factors that independently and significantly affected the daptomycin resistance. Daptomycin-resistant S. epidermidis was identified in 38 (2.8%) patients. According to the multiple analysis, only higher MIC values (≥16 mg/L) for teicoplanin (P < 0.0001) were independently associated with an increased risk of developing daptomycin resistance. In conclusion, higher teicoplanin MIC values may predict resistance to daptomycin treatment in S. epidermidis infections.

Rapid identification of carbapenemase-type blaGES and ESBL-type blaGES using multiplex PCR.

Guiana extended-spectrum (GES) ß-lactamases are emerging in Japan. The GES family can be classified into 2 groups, one with extended-spectrum ß-lactamase (ESBL)-like activity, which hydrolyzes penicillins and cephalosporins, and the other with carbapenemase-like activity with an extended spectrum toward carbapenems. This difference is mediated by variations in a specific amino acid in the GES protein: G170 N or G170S substitutions. We developed an amplification refractory mutation system (ARMS) PCR assay that enabled rapid identification of these variant genes without sequencing.

Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients.

Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.

[Rapid Identification Method Positive Blood Culture Bottles with MALDI Biotyper].

Identification method positive blood culture bottles with MALDI Biotyper is the most important test on precisely and rapidly, for detamination the bacterial name in sepsis and bacteremia is very significant for decision a cure. This time, we devised a new method "blend" to identify the mixture hypostasis that were come into being by centrifuging blood culture broths and 70% formic acid with MALDI Biotyper (Bruker). This time, we identified 65 samples rapidly with MALDI biotyper by "on plate" and "blend," and verified their effectivity. As a result of six ways (on plate, blend-3, blend-6, blend-9, blend-12, blend-15), the highest detection rate was Gram negative rods: blend-15 (74.1%), Gram positive cocci: blend-9 (56.3%), total: blend-9 (55.4%). Moreover, we confirmed that the detection rate raised to 85.2% (GNR), 71.0% (GPC) and 77.6% (total), and the usefully was suggested. Our invented method is more excellently than recommended on Gram negative rods, especially Enterobacteriaceae, Staphylococcus aureus, and Enterococcus spp.

[Homologous Analysis Using Repetitive-sequence-based PCR Typing of Exfoliative Toxin-producing Staphylococcus aureus Isolated from Our Hospital].

We examined staphylococcal coagulase types and homologous analysis using the DiversiLab repetitive-sequence-based PCR system in exfoliative toxin (ET)-producing Staphylococcus aureus. Twenty-two isolates (17 methicillin-sensitive Staphylococcus aureus (MSSA) and 5 methicillin-resistant Staphylococcus aureus (MRSA) isolates) obtained in our hospital from January 2012 and December 2013 were used. Three groups were classified according to the coagulase types and serotypes of ET. The first group (4 MSSA) showed coagulase type I and ET-A, and the second group (3 MSSA and 2 MRSA) showed coagulase type I and ET-B. The third group (10 MSSA and 3 MRSA) showed coagulase type V and ET-B. An analysis by DiversiLab demonstrated that homology was high in both the first and second groups. The homogenousness was high among the third group isolates except for the ocular isolates. In our hospital, three important groups were present according to a coagulase type and an ET type, and the homology of ocular isolates could be different from other materials isolates.

[Pulmonary Nocardiosis due to Nocardia asiatica in a Patient with ANCA-associated Vasculitis].

Nocardia asiatica is a rare causative organism responsible for opportunistic infection, and was first reported by Kageyama et al. in 2004. We report herein on a very rare case of N. asiatica infection in a 76-year old male patient with ANCA-associated vasculitis and a history of pulmonary tuberculosis. The patient developed pulmonary nocardiosis due to N. asiatica while receiving glucocorticoid therapy. Chest computed tomography demonstrated multiple granules and cavity formation mainly in the left lower lobe. From the images, we suspected opportunistic infection, possibly pulmonary tuberculosis or pulmonary damage due to ANCA-associated vasculitis. Nocardia sp. was detected from a bronchoalveolar lavage culture and N. asiatica was identified by 16S ribosomal DNA gene sequencing. Cranial magnetic resonance imaging revealed no abnormality. Administration of Doripenem (1.5g/day) and sulfamethoxazole-trimethoprim (4g/day) was started, and the patient's clinical and imaging findings promptly improved. Thereafter, he received sulfamethoxazole-trimethoprim (2g/day) and prednisolone (10 mg/day) as maintenance therapy for ANCA-associated vasculitis for more than one year, and there has since been no recurrence of the Nocardia infection.

Clinical Characteristics and Bacteriological Profile of Moraxella Keratitis.

PURPOSE: Moraxella species are rare causative pathogens of severe sight-threatening keratitis. The aim of this study was to analyze the clinical presentation, predisposing risk factors, in vitro antimicrobial susceptibility, and treatment associated with Moraxella keratitis. METHODS: We retrospectively reviewed 30 culture-proven cases of Moraxella keratitis from multiple centers in Japan. RESULTS: The mean age of the patients was 58.4 ± 23.4 years. The most common ocular conditions were contact lens wearing (5 patients, 16.7%) and trauma (3 patients, 10.0%). Seven patients had diabetes mellitus. Sixteen patients exhibited hypopyon in association with the corneal focus. Ring-shaped infiltration was found in 9 patients (30.0%), and irregular or amoebic-shaped infiltration was observed in 13 patients (43.3%). Eight patients (26.7%) showed small round infiltrates. All Moraxella isolates were sensitive to fluoroquinolones and aminoglycosides. All were treated with a combination ophthalmic solution containing a fluoroquinolone, tobramycin, and cefmenoxime. Although no patients developed corneal perforation, the response to treatment was slow in all cases; the mean treatment period was 41.9 days. CONCLUSIONS: In Japan, Moraxella keratitis occurs in patients with contact lens wear, trauma, and diabetes mellitus. It presents as a small, round, ring-shaped, irregularly shaped, or amoebic-shaped focus. Moraxella species exhibit good susceptibility to fluoroquinolones and aminoglycosides. Because the treatment response may be very slow, these agents should be continued for a long period of time.

Tsukamurella inchonensis infection in a child with Hodgkin's lymphoma.

Tsukamurella spp. infection is a rare but important cause of bacteremia in immunocompromised patients. The organism is an aerobic, Gram-positive, weakly acid-fast bacillus that is difficult to differentiate from other aerobic Actinomycetales by standard laboratory methods. Here, we report on the case of a 14-year-old patient with Hodgkin's lymphoma who, after intensive chemotherapy, developed Tsukamurella inchonensis bacteremia, which was identified on the peripherally inserted central venous catheter (PICC) using 16S rRNA sequencing analysis. The bacteremia was successfully controlled with antimicrobial therapy and subsequent removal of the PICC. This is the first report of bacteremia by Tsukamurella inchonensis in immunocompromised children. Careful observation and prompt analysis of opportunistic infection, including Tsukamurella spp., is very important in immunocompromised children.