Japanese journal of infectious diseases最新文献

The widespread prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli limits treatment options and is a worldwide problem. This study aimed to investigate the antimicrobial susceptibility and ESBL types of 204 strains of CTX-M-type ESBLsproducing E. coli isolated from 2011 to 2017 in the Chubu region of Japan and to identify factors correlated with susceptibility. Minimal inhibitory concentrations were determined in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Genes encoding β-lactamases were detected by PCR amplification. The CTX-M subtypes were determined using sequence analyses. CTX- M-15-producing strains showed significantly lower susceptibility rates to tazobactam/piperacillin (TAZ/ PIPC) than CTX-M-14 and -27-producing strains. Additional analyses of secondary β-lactamases revealed that most of the OXA-1-positive strains were CTX-M-15-producing strains (94.7%). The OXA-1-positive strains displayed significantly lower susceptibility to TAZ/PIPC (47.4%), sulbactam/ ampicillin (0.0%), and amikacin (73.7%) than the OXA-1-negative strains, suggesting that the high non-susceptibility rate of the CTX-M-15-producing strain was due to the co-carriage of OXA-1. Statistical analyses showed that OXA-1-positive strains were present in significant amounts in patients aged ≥65 years, suggesting that older patients have a higher risk of being refractory to treatment.

Campylobacter jejuni is one of the major bacterial strains that cause diarrhea in humans. It has been associated with many cases of food poisoning in Japan caused by eating raw, undercooked, and/or improperly prepared chicken meat, liver, and grilled chicken (Yakitori). Campylobacter jejuni is also known to be a preceding infectious pathogen of Guillain-Barré syndrome (GBS), which has a considerably negative health impact on humans. In a case of C. jejuni food poisoning that occurred at a restaurant in Tokyo (Japan) in January 2022, 1 of 4 patients with diarrhea developed GBS, which was presumed to have been caused by undercooked chicken, which has emerged as one of the most common causes of food poisoning in Japan. Moreover, C. jejuni isolates from 3 patients, including those with GBS, had the same genotypes (ST22, HS19, and LOS A). This genotype was frequently detected in patients with GBS in the authors' previous study. Findings confirmed that the patient developed GBS due to food poisoning after consuming undercooked chicken.

Japanese guidelines recommend metronidazole (MNZ) and vancomycin (VCM) for non-severe and severe cases of Clostridioides difficile infection (CDI), respectively. In the present study, we investigated the use of CDI antimicrobials and evaluated their clinical efficacy and validity using four severity classifications. A retrospective chart review was conducted using the data of 137 inpatients with initially positive C. difficile toxin test results and the initiation of CDI antimicrobials between April 2015 and March 2019. Patients treated with VCM or oral MNZ were included for clinical efficacy analysis of CDI antimicrobials and validation of severity classifications. The endpoints were CDI recurrence, 30-day mortality, and diarrhea cure rates. No significant differences were found between the VCM and oral MNZ groups in the CDI recurrence rate (10.4% vs. 12.7%, P = 0.707), 30-day mortality rate (12.5% vs. 5.6%, P = 0.162), and diarrhea cure rate (61.9% vs. 72.7%, P = 0.238), regardless of severity. Treatment with oral MNZ for non-severe cases was promising, confirming its usefulness according to Japanese guidelines. Further investigation of the clinical efficacy of oral MNZ in patients with first-episode CDI and evaluation of the preferred severity classification are warranted.

Patients with acquired immune deficiency syndrome (AIDS) are susceptible to numerous complications, such as sepsis and acute kidney injury (AKI), leading to adverse outcomes. Continuous renal replacement therapy (CRRT) is becoming increasingly popular for treating sepsis and AKI. This study aimed to verify the effectiveness of CRRT in the treatment of patients with AIDS with sepsis and AKI to provide new directions for the treatment of severe AIDS. Data of 74 people with AIDS, sepsis, and AKI were collected. The patients were divided into CRRT and non-CRRT groups. There was no difference in the indicators between the two groups at admission. Vital signs, pH, serum potassium level, renal function, blood lactate level, acute physiology and chronic health evaluation II score, and sequential organ failure assessment score in the CRRT group demonstrated significant improvements over those in the non-CRRT group at both 24 and 72 h after admission (P < 0.05). The levels of interleukin 6 and procalcitonin declined more significantly in the CRRT group at 72 h after admission (P < 0.05). The CRRT group had a higher 28-day survival rate than the non-CRRT group (P < 0.05). CRRT improves the clinical indicators and increases the short-term survival rate of patients with AIDS, sepsis, and AKI.

Respiratory samples from 139 hospitalized children were screened for the human bocavirus (HBoV) genome. Positive samples were sequenced for the partial VP1/VP2 gene followed by molecular and phylogenetic analyses. HBoV positivity was noted in 7.2% (10/139) of patients. All HBoV-positive children presented with fever, cough, and respiratory distress (90%, 9/10). Three children developed multisystemic viral illness, with one fatality. Eight children required intensive care management and five required mechanical ventilation. The nucleotide percent identity of the partial VP1/VP2 gene in the HBoV study strains ranged from 97.52% to 99.67%. Non-synonymous mutations in the VP1 protein were T591S (n = 8) and Y517S (n = 1) in the HBoV St1 strain and N475S (n = 8) and S591T (n = 2) in the HBoV St2 strain. One strain showed A556P, H556P, I561S, and M562R non-synonymous mutations. All the study strains belonged to the HBoV1 type. Seven HBoV strains belonged to the same lineage, and three belonged to another lineage. For evolutionary dynamics, GTR+I substitution model with uncorrelated relaxed lognormal clock and Bayesian Skyline tree prior showed 9.0 × 10^-4 (95% highest probability density interval: 3.1 × 10^-6, 2.1 × 10^-3) nucleotide substitutions per site per year. Clinical suspicion and virological screening are necessary to identify HBoV infections in children.

Escherichia coli is a Gram-negative bacterium that causes a variety of clinical infections in humans, including diarrhea, sepsis, and urinary tract infection. This bacterium is a common multidrug-resistant threat in community and hospital settings worldwide. This study examined the antimicrobial susceptibility and genetic relationship based on Clermont phylotyping and enterobacterial repetitive intergenic consensus (ERIC)-PCR of 84 E. coli urinary isolates from provincial and community hospitals in Thailand. All isolates were susceptible to nitrofurantoin, and almost all isolates were susceptible to carbapenem, fosfomycin, and amikacin. High resistance rates to fluoroquinolone, ampicillin, and trimethoprim/sulfamethoxazole were observed. Clermont phylogroup B2 was predominant (n = 58). Subtyping of the B2 phylogroup revealed diverse subgroups, of which subgroup V (n = 11), VII (n = 9), III (n = 6), and II (n = 6) were most prevalent. ERIC-PCR showed that the strains of the B2 subgroups III and V were spread between provincial and community hospitals and between hospital wards. This evidence suggests the need for comprehensive infection control monitoring, with strong active surveillance at all hospital levels.

We report the first case of necrotizing fasciitis caused by Pigmentibacter ruber. The isolated strain could not be identified by biochemical characterization or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry but was identified as P. ruber by 16S ribosomal RNA and whole-genome sequencing. Although much remains unknown about the pathogenicity of this bacterial species in humans, it has been shown to cause life-threatening infections such as septicemia and necrotizing fasciitis. Because the isolate was highly resistant to β-lactams, it was difficult to treat with antimicrobial therapy. Thus, further documentation of cases and analyses are required.

Biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococci (MR-CoNS) are a clinical challenge for the treatment of healthcare-associated infections. As alternative antimicrobial options are needed, we aimed to determine the effect of curcumin-chitosan magnetic nanoparticles on the biofilm of staphylococcal clinical isolates. MRSA and CoNS clinical isolates were identified by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing was performed by broth microdilution. Nanoparticles were synthesized by co-precipitation of magnetic nanoparticles (MNP) and encapsulation by ionotropic gelation of curcumin (Cur) and chitosan (Chi). Biofilm inhibition and eradication by nanoparticles with and without the addition of oxacillin was assessed on staphylococcal strains. Cur-Chi-MNP showed antimicrobial activity on planktonic cells of MRSA and MR-CoNS strains and inhibited biofilm of MRSA. The addition of OXA to Cur-Chi-MNP increased biofilm inhibition and eradication activity against all Staphylococci strains (p=0.0007); higher biofilm activity was observed in early biofilm stages. Cur-Chi-MNP showed antimicrobial and biofilm inhibition activity against S. aureus. The addition of OXA increased biofilm inhibition and eradication activity against all Staphylococci strains. A combination treatment of Cur-Chi-MNP and OXA could be potentially used to treat staphylococcal biofilm-associated infections in its early stages before the establishment of biofilm bacterial cells.

Since the COVID-19 pandemic has affected the epidemiological pattern of pharyngoconjunctival fever (PCF) caused by human adenovirus (HAdV), the prevalence and type distribution of HAdVs associated with PCF among children in Osaka, Japan, between 2019 and 2023 have been analyzed. The number of reported PCF cases in Osaka decreased from 2020 to 2022, followed by an unprecedented increase in 2023. HAdV-C strains, including types C1, C2, and C5, were annually detected in pathogen surveillance in Osaka. HAdV-B3 was not detected for 2 years and 9 months from March 2020, and the number of detections increased from July 2023. In total, HAdV-B3 was the most frequently detected (27 of 52 strains), and genetic analysis of its hexon hypervariable regions showed that, except for one strain, the HAdV-B3 strains identified after 2022 had different amino acid substitutions compared to those identified in 2019 and 2020. These results suggest that the PCF epidemic in 2023 was predominantly caused by variant strains of HAdV-B3, and children who have not acquired immunity against HAdV-B3 between 2020 and 2022 were thought to be infected. The impact of COVID-19 on the prevalence of HAdV infections needs to be continuously evaluated through surveillance.

The number of syphilis cases in Tokyo has been found to increase in recent years. We conducted a descriptive epidemiology to elucidate the actual status of syphilis. Data on age, sex, disease stage, and presumed sexual partner of syphilis cases reported in Tokyo were tabulated and analyzed. A total of 9,419 syphilis cases have been reported between 2019 and 2022. There was a particularly sharp rise in the number of reported cases from 2021 to 2022. Comparing 2020 to 2022, the number of syphilis cases among women in their 20s, rapidly increased, more than triple. Furthermore, the number of pregnant women among syphilis cases increased in 2022. Despite the rapid increase in the number of young women with syphilis, there has been no increase in cases of congenital syphilis. One of the reasons may be that syphilis was detected early in pregnancy due to the high antenatal checkup rate in Tokyo. However, the continued incidence of syphilis among young women may increase congenital syphilis in the future. Public health strategy should include educational activities targeting high-risk populations or adolescents, early and appropriate testing, and treatment for preventing progression of syphilis.