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.

[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.

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.

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.

[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.

[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.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2012].

The nationwide surveillance of antibacterial susceptibility to meropenem (MEPM) and other parenteral antibiotics against clinical isolates during 2012 in Japan was conducted. A total of 2985 strains including 955 strains of Gram-positive bacteria, 1782 strains of Gram-negative bacteria, and 248 strains of anaerobic bacteria obtained from 31 medical institutions were examined. The results were as follows; 1. MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). 2. Of all species tested, there were no species, which MIC90 of MEPM was more than 4-fold higher than those in our previous studies in 2009 or 2006. Therefore, the tendency to increase in antimicrobial resistance rates was not observed. 3. MEPM resistance against Pseudomonas aeruginosa was 17.8% (56/315 strains). Compared to our previous results, it was the lowest than that in 2006 and 2009. 4. Carbapenem-resistant Klebsiella pneumoniae, and multi-drug-resistant Acinetobacter species, which emerged in worldwide, were not observed. 5. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 6.2% (59/951 strains) in enterobacteriaceae, which increased compared with that of our previous studies in 2009 or before. Whereas, the proportion of metallo-beta-lactamase strains was 1.6% (5/315 strains) in P. aeruginosa, which was stable. In conclusion, the results from this surveillance suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 17 years passed after available for commercial use in Japan.

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.

Conjunctivitis caused by Neisseria gonorrhoeae isolates with reduced cephalosporin susceptibility and multidrug resistance.

We report two cases of conjunctivitis caused by Neisseria gonorrhoeae with reduced cephalosporin susceptibility. Patients showed no response to cefmenoxime eye drops and intravenous ceftriaxone administration. The patients' condition improved after the addition of oral minocycline. The isolates contained the mosaic penA for reduction of ß-lactam susceptibility.

Treatment with linezolid in a neonate with meningitis caused by methicillin-resistant Staphylococcus epidermidis.

UNLABELLED: Recent findings have focused on the possible role of linezolid (LZD) as a suitable candidate for the treatment of central nervous system infections. LZD treatment for meningitis has been sporadically reported in adults, but there are no reports in neonates or infants. We report a case of meningitis caused by methicillin-resistant Staphylococcus epidermidis (MRSE) in a neonatal girl. The patient had intraventricular hemorrhage on postnatal day 1 and was treated with ventricular drainage. Twenty-two days after drainage, the patient developed a fever and seizure. Although ampicillin and ceftriaxone were given empirically for meningitis, an increased cell count and protein were observed in cerebrospinal fluid (CSF). Vancomycin (VCM) was administered intravenously because MRSE was detected from CSF 2 days after the administration of ampicillin and ceftriaxone. However, intravenous administration of VCM did not show any effect. Subsequent treatment of LZD successfully reduced the cell count and protein in CSF. CONCLUSION: LZD may be a treatment option for neonates and infants for drain-associated meningitis caused by MRSE.

[Staphylococcal cassette chromosome mec types and antimicrobial susceptibilities of methicillin-resistant Staphylococcus aureus isolated from our hospital].

Reports of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have recently increased in Japan. To determine the status of MRSA infections in our hospital, we investigated their Staphylococcal cassette chromosome mec (SCCmec) types and prevalence of Panton-Valentine leukocidin (PVL). In addition, we investigated the relation between their SCCmec and antimicrobial susceptibility. The 191 strains were isolated from January to July in 2011 and were classified as SCCmec type I (2, 1.0％), type II (136, 71.2％), type IV (36, 18.8％), type V (4, 2.1％) and type VIII (2, 1.0％). Eleven isolates (5.8％) were designated as nontypable. No isolates were PVL-positive in this study. The SCCmec type IV strains were more susceptible to imipenem (MIC90, 0.25 µg/ml) than SCCmec type II strains (MIC90, >16 µg/ml). This difference was also observed between SCCmec type IV and SCCmec type II in susceptibility levels to clarithromycin, clindamycin, minocycline, and levofloxacin, but not to gentamicin. In particular, SCCmec type IV strains were susceptible to imipenem and minocycline. The result indicates these susceptibility is useful to discriminate CA-MRSA from Hospital-associated MRSA (HA-MRSA).

[Antimicrobial susceptibilityof clinical isolates of aerobic gram-negative bacteria in 2008].

We determined MICs of antibacterial agents against 1145 clinical strains of aerobic Gram-negative bacteria (22 species) isolated at 16 Japanese facilities in 2008. MICs were determined using mostly broth microdilution method and antibacterial activity was assessed. Strains producing extended-spectrum beta-lactamases (ESBL) accounted for 3.8% of Escherichia coli, 2.6% of Klebsiella pneumoniae, 6.8% of Klebsiella oxytoca, 5.5% of Proteus mirabilis and 1.8% of Proteus vulgaris. ESBL produced strains were 6.8% at K. oxytoca that increased compared with 3.2% and 5.5% at P. mirabilis that decreased compared with 18.8% in 2006. Among Haemophilus influenzae, 61.7% that decreased compared with 67.7% in 2006, equaled 58.7% in 2004, were strains when classified by penicillin-binding protein 3 mutation. Against Pseudomonas aeruginosa, the activity of most antibacterial agents was similar to that in 2006. Although two antibacterial agents that tobramycin showed an MIC90 of 1 microg/mL and doripenem showed an MIC90 of 4 microg/mL against P. aeruginosa have potent activity. Of all P. aeruginosa strains, 4.3% were resistant to six agents of nine antipseudomonal agents, that decreased compared to 12.2% in 2004 and 5.7% in 2006. Against other glucose-non-fermentative Gram-negative rods, the activity of most antibacterial agents was similar to that in 2006.

[Antimicrobial susceptibility of clinical isolates of aerobic gram-positive cocci and anaerobic bacteria in 2008].

The activity of antibacterial agents against aerobic Gram-positive cocci (25 genus or species, 1029 strains) and anaerobic bacteria (21 genus or species, 187 strains) isolated from clinical specimens in 2008 at 16 clinical facilities in Japan were studied using either broth microdilution or agar dilution method. The ratio of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis was 59.6% and 81.2%, suggesting that resistant strains were isolated at high frequency. Vancomycin (VCM), linezolid (LZD) and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activity against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of < or = 2 microg/mL. The ratio of penicillin (PC) intermediate and resistant strains classified by mutations of PC-binding proteins among Streptococcus pneumoniae was 92.0% that was highest among our previous reports. Cefpirome, carbapenems, VCM, teicoplanin (TEIC), LZD and QPR/DPR had MIC90s of < or = 1 microg/mL against PC-intermediate and resistant S. pneumoniae strains. Against all strains of Enterococcus faecalis and Enterococcus faecium, the MICs of VCM and TEIC were under 2 microg/mL, and no resistant strain was detected, suggesting that these agents had excellent activities against these species. 15.9% of E. faecalis strains and 1.2% of E. faecium strains showed intermediate to LZD. 17.1% of E. faecium strains showed intermediate or resistant to QPR/DPR. Against all strains of Clostridium difficile, the MIC of VCM was under 1 microg/mL, suggesting that VCM had excellent activity. Carbapenems showed good activity against Clostridiales, Bacteroides spp., and Prevotella spp., but one strain of Bacteroides fragilis showed resistant to carbapenems. And so, the susceptibility of this species should be well-focused in the future at detecting continuously.

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.

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.