Differences in mortality in Fusobacterium necrophorum and Fusobacterium nucleatum infections detected by culture and 16S rRNA gene sequencing

Mechanisms underlying the effects, and clinical applications, of oral microbiota in lung cancer: current challenges and prospects

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

[Impact of preservatives in topicals on the cutaneous microbiota]

Preservatives are used to stabilize topical preparations and protect the user from the influence of pathogenic microbes. After the application of a topical preparation, the matrix undergoes a metamorphosis, and by proportional evaporation of the hydrophilic phase the preservative may accumulate on the skin surface. This is believed to lead to antiseptic effects and may influence the diversity of the cutaneous microbiota. The regulation of the cutaneous microbiome and the associated influencing factors is a complex system that results in highly individualized conditions. Therefore, investigations on the influence of defined interventions are methodologically difficult. In the present proof-of-concept study, potential antiseptic effects of preservatives were investigated in a combination of in vitro and in vivo methods using microbiological culture tests. In addition, the investigations served to develop a clinical study design to answer further questions and use of an extended range of methods. The results support the hypothesis of an antiseptic effect of the tested preservatives (methyl-4-hydroxybenzoate and propyl-4-hydroxybenzoate, potassium sorbate and propylene glycol) on prominent reference bacteria, which could also be observed in clinical settings.

Clinical Differences in Patients Infected with Fusobacterium and Antimicrobial Susceptibility of Fusobacterium Isolates Recovered at a Tertiary-Care Hospital in Korea

Background

Fusobacterium species are obligately anaerobic, gram-negative bacilli. Especially, F. nucleatum and F. necrophorum are highly relevant human pathogens. We investigated clinical differences in patients infected with Fusobacterium spp. and determined the antimicrobial susceptibility of Fusobacterium isolates.

Methods

We collected clinical data of 86 patients from whom Fusobacterium spp. were isolated from clinical specimens at a tertiary-care hospital in Korea between 2003 and 2020. In total, 76 non-duplicated Fusobacterium isolates were selected for antimicrobial susceptibility testing by the agar dilution method, according to the Clinical and Laboratory Standards Institute guidelines (M11-A9).

Results

F. nucleatum was most frequently isolated from blood cultures and was associated with hematologic malignancy, whereas F. necrophorum was mostly prevalent in head and neck infections. Anti-anaerobic agents were more commonly used to treat F. nucleatum and F. varium infections than to treat F. necrophorum infections. We observed no significant difference in mortality between patients infected with these species. All F. nucleatum and F. necrophorum isolates were susceptible to the antimicrobial agents tested. F. varium was resistant to clindamycin (48%) and moxifloxacin (24%), and F. mortiferum was resistant to penicillin G (22%) and ceftriaxone (67%). β-Lactamase activity was not detected.

Conclusions

Despite the clinical differences among patients with clinically important Fusobacterium infections, there was no significant difference in the mortality rates. Some Fusobacterium spp. were resistant to penicillin G, ceftriaxone, clindamycin, or moxifloxacin. This study may provide clinically relevant data for implementing empirical treatment against Fusobacterium infections.