The first fatal case of Corynebacterium ulcerans infection in Japan

Corynebacterium ulcerans pneumonia treated with venovenous extracorporeal membrane oxygenation: a case report

We report the first case of airway obstruction due to toxin-producing Corynebacterium ulcerans, successfully managed with venovenous extracorporeal membrane oxygenation (V-V ECMO). A woman aged 73 years who was living with companion animals was intubated for pneumonia of unknown origin and treated with an empirical antimicrobial agent. Corynebacterium species were detected in the sputum and treated as commensal bacteria. Subsequently, the patient suddenly could not ventilate because of central airway obstruction caused by pseudomembrane formation. Therefore, V-V ECMO was initiated. Additional mass spectrometry identified the Corynebacterium species as C. ulcerans. After treatment with antitoxin, the patient was successfully weaned from V-V ECMO. Hence, in patients in contact with companion animals who present with respiratory failure and pseudomembrane formation, C. ulcerans pneumonia should be suspected and treated with antitoxin. C. ulcerans pneumonia may result in an inability to ventilate due to pseudomembrane formation. Therefore, treatment strategies including V-V ECMO should be considered in such cases.

Antimicrobial Activity of Xibornol and a Xibornol-Based Formulation Against Gram-Positive Pathogens of the Respiratory Tract

Xibornol is known since the 70s and a xibornol-based formulation is commercialized as spray suspension for the antisepsis of the oral cavity and as adjuvant in pharyngeal infections caused by Gram-positive microorganisms. Herein, we evaluated the antimicrobial activity of xibornol and the xibornol-based formulation against common pathogens of the upper and lower respiratory tract.Our results indicate that xibornol alone and the xibornol-based formulation have strong antibacterial action against Streptococcus pneumoniae, Streptococcus pyogenes, and Staphyloccus aureus, as well as against the two emerging pathogens Actinomyces israelii and Corynebacterium ulcerans. These findings highlight the antimicrobial potential of these drugs in the topical control of pathogenic Gram-positive bacteria of the respiratory tract.

Health Status of 'Community Cats' Living in the Tourist Area of the Old Town in Onomichi City, Japan

The "community cat program (CCP)" is a non-lethal control measure in which stray cats are owned and cared for as community cats at high welfare standards, while the Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) event is performed. The program is recommended by the Ministry of the Environment in Japan. Here, we evaluated the health status of community cats inhabiting a tourist area in Onomichi City. A medical check was conducted on 30 community cats as a part of the TTVARM event. The following health problems were identified: alopecia, gingivitis, incisor teeth loss, anemia, and urine glucose. An ELISA (the enzyme linked immunosorbent assay) showed that 16.7% of the cats were FIV-positive. The cats were also carriers of zoonoses (Capnocytophaga genus (100%) and Bartonella henselae (ITS, nested; 38.0%)), which pose a risk to tourists and residents. Our findings suggest that most cats require medical treatment. We recommend that friendly cats should be adopted rather than maintained as community cats and that a comprehensive review of the CCP is required.

Occupational Fatalities Due to Mammal-Related Accidents in Japan, 2000-2019

INTRODUCTION

Animal-related fatal accidents occur annually while individuals are outside working. This study intended to evaluate the trends of occupational fatal accidents related to mammals and compare them with nonoccupational accidents.

METHODS

We collected occupational and nonoccupational fatalities related to mammals between 2000 and 2019 from data on fatal occupational accident cases certified by the Ministry of Health, Labor and Welfare, Japan, in addition to other statistics from relevant ministries, media reports such as newspapers, and academic case reports.

RESULTS

A total of 109 fatal accidents related to mammals were confirmed as occurring during work, and 129 were confirmed as taking place outside of work. Of the former, accidents among livestock farmers and horse racing-related workers accounted for about half. Among the accidents not related to work, dog attacks, infectious diseases from cats or dogs, traffic accidents with wild animals, and bear attacks during wild vegetable picking were common. Deaths from infectious diseases caused by dogs and cats have rarely been reported in the mass media.

CONCLUSIONS

Although the number of fatal occupational accidents related to mammals is not large, we concluded that it is necessary to continue preventive measures centered on accidents at livestock farms and in horse racing-related workplaces. It is also necessary to inform people about the risks of infectious diseases mediated by dogs and cats.

Limitations of Ribotyping as Genotyping Method for Corynebacterium ulcerans

We conducted molecular typing of a Corynebacterium ulcerans isolate from a woman who died in Japan in 2016. Genomic DNA modification might have affected the isolate's ribotyping profile. Multilocus sequence typing results (sequence type 337) were more accurate. Whole-genome sequencing had greater ability to discriminate lineages at high resolution.

Corynebacterium species as one of the major causative pathogens of bacterial pneumonia

Recent advances using molecular methods, matrix-assisted laser desorption ionization time of flightmass spectrometry, and next-generation sequencers enable rapid and precise detection of bacterial species in the clinical samples, revealing bacterial diversities in the human body. Corynebacterium species are Gram-positive bacilli, which can cause pneumonia and have been reported as causative pathogens of lower respiratory tract infections since the 1970's. However, Corynebacterium spp. may be recognized and sorted as part of normal respiratory flora on Gram staining and culture, resulting in clinical under-recognition as pathogenic bacteria. The results of the clone library method using bacterial 16S ribosomal RNA gene sequence analysis in Japanese patients with hospital-acquired pneumonia revealed that bronchoalveolar lavage fluid obtained from the lung lesions contained 11.8% Corynebacterium spp., which was the second most predominant bacterial phylotype. Additionally, among patients in whom Corynebacterium spp. were detected, C. simulans was most commonly detected followed by C. striatum. In addition, almost half of the patients in whom C. simulans was detected was monophylotypic infection and/or co-detection of C. simulansand C. striatum. Further clinical information is expected on corynebacteria as pathogens of lower respiratory tract infection.

Mutation and Diversity of Diphtheria Toxin in Corynebacterium ulcerans

Corynebacterium ulcerans infection is emerging in humans. We conducted phylogenetic analyses of C. ulcerans and C. diptheriae, which revealed diverse diphtheria toxin in C. ulcerans. Diphtheria toxin diversification could decrease effectiveness of diphtheria toxoid vaccine and diphtheria antitoxin for preventing and treating illnesses caused by this bacterium.

Severe Pneumonia Caused by Toxigenic Corynebacterium ulcerans Infection, Japan

Corynebacterium ulcerans infection was recently recognized as a zoonosis. We present 2 cases of severe pneumonia complicated by diffuse pseudomembrane formation on the bronchus caused by C. ulcerans–producing diphtheria toxin. Our purpose is to alert medical professionals to the virulence of Corynebacterium species other than C. diphtheriae.

Genomic analyses reveal two distinct lineages of Corynebacterium ulcerans strains

Corynebacterium ulcerans is an important zoonotic pathogen which is causing diphtheria-like disease in humans globally. In this study, the genomes of three recently isolated C. ulcerans strains, 4940, 2590 and BR-AD 2649, respectively from an asymptomatic carrier, a patient with pharyngitis and a canine host, were sequenced to investigate their virulence potential. A comparative analysis was performed including the published genome sequences of 16 other C. ulcerans isolates. C. ulcerans strains belong to two lineages; 13 strains are grouped together in lineage 1, and six strains comprise lineage 2. Consistent with the zoonotic nature of C. ulcerans infections, isolates from both the human and canine hosts clustered in both the lineages. Most of the strains possessed spaDEF and spaBC gene clusters along with the virulence genes cpp, pld, cwlH, nanH, rpfI, tspA and vsp1. The gene encoding Shiga-like toxin was only present in one strain, and 11 strains carried the tox gene encoding the diphtheria-like toxin. However, none of strains 4940, 2590 and BR-AD 2649 carried any toxin genes. These strains varied in the number of prophages in their genomes, which suggests that they play an important role in introducing diversity in C. ulcerans. The pan-genomic analyses revealed a variation in the number of membrane-associated and secreted proteins that may contribute to the variation in pathogenicity among different strains.