Secondary hand infection with Eikenella corrodens and Staphylococcus aureus in a patient with Behcet's disease: a case report

We report the first case of a woman with Behcet's disease (BD) with multiple hand ulcers secondary to coninfection by Eikenella corrodens and Staphylococcus aureus resulting in necrotizing fasciitis. She had a long history of BD including long courses of prednisone and immunosuppressants. The patient was hospitalized for multiple superficial ulcers, swelling, and infection of the hands. After admission, pus culture examination revealed rare coinfection by E. corrodens and S. aureus. We administered moxifloxacin and vancomycin to control infection and methylprednisolone to control BD. We performed incision, drainage, and debridement of the ulcer surface on the hands to reduce the pus on the wound surface. E. corrodens infections occur in immunosuppressed patients and contribute to coinfections, particularly in patients with BD in whom destruction of the skin immune barrier increases risk to secondary infections. For severe and complicated hand infections, efforts should be made to identify pathogenic microorganisms so appropriate antibiotics and other interventions can be given to control the infection.

A 10-year-old child with acute torticollis due to polymicrobial deep neck infection

Torticollis in children can be a sign of a potentially dangerous disease; the correct diagnosis is not always obvious on history and physical examination. The use of point-of-care ultrasound (POCUS) helps to limit the differential diagnosis and direct appropriate further laboratory and radiology-performed evaluation. We present a case of a 10-year-old child whose deep neck infection (DNI) was timely diagnosed in the paediatric emergency department by early use of POCUS and drained under POCUS guidance after admission to the hospital. The culture from the fluid grew Eikenella corrodens, Streptococcus constellatus and Prevotella buccae. This case demonstrates that DNIs occur in children with acute acquired torticollis, even without fever and demonstrates the importance of early use of POCUS in cases where DNI is a potential diagnosis. Moreover, this case emphasises the importance of microbiological identification of DNIs that can be the key to successful treatment.

In Vitro Antibacterial Activity of Myrtus communis L. and Marrubium vulgare L. Leaves against Aggregatibacter actinomycetemcomitans and Eikenella corrodens

Background and Objectives. It has been shown that Myrtus communis and Marrubium vulgare have antibacterial activity against bacterial and fungal strains of different diseases. This study aimed to evaluate in vitro the antibacterial activity of aqueous and methanolic extracts of Myrtus communis and Marrubium vulgare leaves against selected periodontal pathogens. Materials and Methods. Clinical strains of Aggregatibacter actinomycetemcomitans and Eikenella corrodens and two reference strains of A. actinomycetemcomitans were tested. The antibacterial activity of each studied plant extract was evaluated using agar diffusion and broth microdilution assays. Results. Both aqueous and methanolic extracts of M. communis exhibited high antibacterial activity against periodontal pathogens as compared to M. vulgare extracts. At concentrations of 2.5-0.32 mg/disc, inhibition zones of the methanolic extract of M. communis ranged from 19.66 ± 0.57 to 12.33 ± 0.57 mm. The methanolic extract of M. vulgare showed at concentrations of 5-0.63 mg/disc inhibition zones ranging from 15.66 ± 0.57 to 12 ± 0.00 mm. Its aqueous extract at concentration of 0.63 mg/disc showed no antimicrobial activity against the clinical and reference strain of A. actinomycetemcomitans. Conclusion. This study showed that methanolic and aqueous extracts of M. communis and M. vulgare have in vitro an antibacterial activity against periodontal pathogens. They could be use as ingredients of an oral antimicrobial agent for prevention or treatment of periodontal diseases. Further research on isolating the compounds from these plant extracts and their toxicity effect could be conducted.

Resolving the Contradictory Functions of Lysine Decarboxylase and Butyrate in Periodontal and Intestinal Diseases

Periodontal disease is a common, bacterially mediated health problem worldwide. Mastication (chewing) repeatedly traumatizes the gingiva and periodontium, causing traces of inflammatory exudate, gingival crevicular fluid (GCF), to appear in crevices between the teeth and gingiva. Inadequate tooth cleaning causes a dentally adherent microbial biofilm composed of commensal salivary bacteria to appear around these crevices where many bacteria grow better on GCF than in saliva. We reported that lysine decarboxylase (Ldc) from Eikenella corrodens depletes the GCF of lysine by converting it to cadaverine and carbon dioxide. Lysine is an amino acid essential for the integrity and continuous renewal of dentally attached epithelium acting as a barrier to microbial products. Unless removed regularly by oral hygiene, bacterial products invade the lysine-deprived dental attachment where they stimulate inflammation that enhances GCF exudation. Cadaverine increases and supports the development of a butyrate-producing microbiome that utilizes the increased GCF substrates to slowly destroy the periodontium (dysbiosis). A long-standing paradox is that acid-induced Ldc and butyrate production support a commensal (probiotic) microbiome in the intestine. Here, we describe how the different physiologies of the respective tissues explain how the different Ldc and butyrate functions impact the progression and control of these two chronic diseases.

Effect of respiratory inhibitors and quinone analogues on the aerobic electron transport system of Eikenella corrodens

The effects of respiratory inhibitors, quinone analogues and artificial substrates on the membrane-bound electron transport system of the fastidious β-proteobacteriumEikenella corrodensgrown under O2-limited conditions were studied. NADH respiration in isolated membrane particles were partially inhibited by rotenone, dicoumarol, quinacrine, flavone, and capsaicin. A similar response was obtained when succinate oxidation was performed in the presence of thenoyltrifluoroacetone and N,N’-dicyclohexylcarbodiimide. NADH respiration was resistant to site II inhibitors and cyanide, indicating that a percentage of the electrons transported can reach O2without thebc1complex. Succinate respiration was sensitive to myxothiazol, antimycin A and 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). Juglone, plumbagin and menadione had higher reactivity with NADH dehydrogenase. The membrane particles showed the highest oxidase activities with ascorbate-TCHQ (tetrachlorohydroquinone), TCHQ alone, and NADH-TMPD (N,N,N’,N’-tetramethyl-p-phenylenediamine), and minor activity levels with ascorbate-DCPIP (2,6-dichloro-phenolindophenol) and NADH-DCPIP. The substrates NADH-DCPIP, NADH-TMPD and TCHQ were electron donors to cyanide-sensitivecbb'cytochromecoxidase. The presence of dissimilatory nitrate reductase in the aerobic respiratory system ofE.corrodensATCC 23834 was demonstrated by first time. Our results indicate that complexes I and II have resistance to their classic inhibitors, that the oxidation of NADH is stimulated by juglone, plumbagin and menadione, and that sensitivity to KCN is stimulated by the substrates TCHQ, NADH-DCPIP and NADH-TMPD.