Pleuropulmonary infections caused by Eikenella corrodens

The Association of Periodontal Treatment and Decreased Pneumonia: A Nationwide Population-Based Cohort Study

Pneumonia is a common respiratory infectious disease that involves the inflammation of the pulmonary parenchyma. Periodontal disease is widespread and correlated with pneumonia. However, the relationship between periodontal treatment and clinical infectious outcomes in patients with pneumonia has remained undetermined. The aim of this study was to investigate the association between periodontal treatment and the risk of pneumonia events in the Taiwanese population. A nationwide population-based cohort study was conducted using data from the Taiwanese National Health Insurance Research Database (NHIRD). A total of 49,400 chronic periodontitis patients who received periodontal treatment from 2001 to 2012 were selected. In addition, 49,400 healthy individuals without periodontal diseases were picked randomly from the general population after propensity score matching according to age, gender, monthly income, urbanization, and comorbidities. The Cox proportional hazard regression analysis was adopted to assess the hazard ratio (HR) of pneumonia between the periodontal treatment cohort and the comparison cohort. The average ages of the periodontal treatment and comparison groups were 44.25 ± 14.82 years and 44.15 ± 14.5 years, respectively. The follow up durations were 7.66 and 7.41 years for the periodontal treatment and comparison groups, respectively. We found 2504 and 1922 patients with newly diagnosed pneumonia in the comparison cohort and the periodontal treatment cohort, respectively. The Kaplan–Meier plot revealed that the cumulative incidence of pneumonia was significantly lower over the 12 year follow-up period in the periodontal treatment group (using the log-rank test, p < 0.001). In conclusion, this nationwide population-based study indicated that the patients with periodontal treatment exhibited a significantly lower risk of pneumonia than the general population.

Bronchomediastinal fistula presenting as purulent pericarditis in a healthy 32-year-old man

Acute purulent pericarditis is rarely caused by anaerobic bacteria and it is almost always a complication of another disease process. Esophagomediastinal fistula, odontogenic, or pleuropulmonary infections have been reported to be the primary source of purulent pericarditis. If not diagnosed and treated promptly, purulent pericarditis is usually a fatal disease. We describe a case of bronchomediastinal fistula as sequels from a necrotizing parenchymal infection, leading on to secondary mediastinitis and pleuropericardial involvement in an immunocompetent patient. <Learning objective: Eikenella corrodens is an important pathogen associated with a spectrum of intrathoracic suppurative infections. Purulent pericarditis can be fatal if not recognized early enough. Physicians should be aware of such a presentation.>.

Eikenella corrodens in head and neck infections

BACKGROUND

Eikenella corrodens (E. corrodens) is a Gram-negative facultative anaerobic bacillus that originally was thought to be an attenuated and indigenous bacterium. In recent years, a number of reports have documented that E. corrodens can be a potential pathogen not only in immunocompromised patients but also in hosts with normal immunity. We herein study E. corrodens infections of the head and neck encountered in our department.

METHODS

Twenty-two consecutive patients treated in our department for E. corrodens infections of the head and neck were retrospectively analyzed. Microbial specimens were subjected to light microscopic examination, aerobic culture using chocolate and sheep blood agar media, and anaerobic culture using Brucella HK agar medium. Cultured bacteria were subjected to antimicrobial susceptibility tests by means of the broth microdilution method.

RESULTS

There were 16 males and 6 females with an average age of 29.9 years. Two patients had malignancy, while the other patients had no particular risk factors or underlying diseases. Infected sites were the ear in 6 cases, pharynx in 12 cases (tonsil in 10 cases), paranasal sinuses in 3 cases, and salivary gland in 1 case. Seventeen patients suffered polymicrobial infections. Staphylococcus and Streptococcus were the most frequently detected pathogens coexisting with E. corrodens, and mixed infections of E. corrodens and Streptococcus milleri group bacteria were prone to form abscesses. Isolated E. corrodens was susceptible to third-generation cephems (MIC90 = 0.15-0.25 microg/ml), carbapenems (MIC90 < or = 0.15 microg/ml), and new quinolones (MIC90 < or = 0.15 microg/ml), and resistant to oxacillin (MIC90 > 8 microg/ml), cefazolin (MIC90 > 4 microg/ml), macrolides (MIC90 = 4-8 microg/ml), and clindamycin (MIC90 > 4 microg/ml).

CONCLUSIONS

E. corrodens infections of the head and neck occur most frequently in the tonsil even in hosts with normal immunity. Coexistence with Streptococcus milleri group bacteria and the use of ineffective antibiotics can be exacerbating factors. First-choice drugs for E. corrodens infections should be third-generation cephems, carbapenems, or new quinolones.

Hypertrophic osteopathy associated with pulmonary Eikenella corrodens infection in a dog

CASE DESCRIPTION

A 4-year-old English Pointer was examined because of chronic, progressive signs of pulmonary disease and failure to respond to medical treatment.

CLINICAL FINDINGS

At examination, radiography of the thorax revealed increased pulmonary opacity and air bronchograms in the right caudal lung lobe, and radiography of the forelimbs revealed periosteal bone production typical of hypertrophic osteopathy. Attempts to isolate a causative organism included bacterial culture of bronchoalveolar lavage fluid and a lung tissue specimen obtained via fine-needle aspiration. Despite a cytologic diagnosis of septic suppurative inflammation in the lavage fluid, those specimens did not yield bacterial growth. However, a biopsy specimen obtained during a lung lobectomy procedure yielded growth of Eikenella corrodens.

TREATMENT AND OUTCOME

Despite successful surgical removal of the consolidated lung lobe and initiation of antimicrobial treatment, the dog died 6 days after surgery.

CLINICAL RELEVANCE

The authors are not aware of reports of pulmonary infection with E. corrodens in animals. Infection with the organism is rare, but it is possible that infections are underreported given that the organism is difficult to culture and biopsy may be necessary to obtain enough tissue to yield a diagnosis.

Eikenella corrodens infections in children and adolescents: case reports and review of the literature

Eikenella corrodens is a slow-growing, gram-negative, nonmotile, facultative rod that can cause infection in humans. Although the clinical characteristics of Eikenella infections in adults are well described, the literature regarding Eikenella infections in children is lacking. Thirteen cases of Eikenella infection in children and adolescents reported from a hospital and an additional 41 cases from the literature were reviewed. Eikenella species can be serious pediatric pathogens, particularly when there is an exposure to human oral secretions. Empirical therapy used to manage most oropharyngeal flora may be ineffective against Eikenella species. The treatment of choice for children and adolescents who are infected with Eikenella species includes a combination of surgical management and antibiotics.

Systemic diseases caused by oral infection

Recently, it has been recognized that oral infection, especially periodontitis, may affect the course and pathogenesis of a number of systemic diseases, such as cardiovascular disease, bacterial pneumonia, diabetes mellitus, and low birth weight. The purpose of this review is to evaluate the current status of oral infections, especially periodontitis, as a causal factor for systemic diseases. Three mechanisms or pathways linking oral infections to secondary systemic effects have been proposed: (i) metastatic spread of infection from the oral cavity as a result of transient bacteremia, (ii) metastatic injury from the effects of circulating oral microbial toxins, and (iii) metastatic inflammation caused by immunological injury induced by oral microorganisms. Periodontitis as a major oral infection may affect the host's susceptibility to systemic disease in three ways: by shared risk factors; subgingival biofilms acting as reservoirs of gram-negative bacteria; and the periodontium acting as a reservoir of inflammatory mediators. Proposed evidence and mechanisms of the above odontogenic systemic diseases are given.

Systemic diseases caused by oral infection

Recently, it has been recognized that oral infection, especially periodontitis, may affect the course and pathogenesis of a number of systemic diseases, such as cardiovascular disease, bacterial pneumonia, diabetes mellitus, and low birth weight. The purpose of this review is to evaluate the current status of oral infections, especially periodontitis, as a causal factor for systemic diseases. Three mechanisms or pathways linking oral infections to secondary systemic effects have been proposed: (i) metastatic spread of infection from the oral cavity as a result of transient bacteremia, (ii) metastatic injury from the effects of circulating oral microbial toxins, and (iii) metastatic inflammation caused by immunological injury induced by oral microorganisms. Periodontitis as a major oral infection may affect the host's susceptibility to systemic disease in three ways: by shared risk factors; subgingival biofilms acting as reservoirs of gram-negative bacteria; and the periodontium acting as a reservoir of inflammatory mediators. Proposed evidence and mechanisms of the above odontogenic systemic diseases are given.

Role of oral bacteria in respiratory infection

An association between oral conditions such as periodontal disease and several respiratory conditions has been noted. For example, recent evidence has suggested a central role for the oral cavity in the process of respiratory infection. Oral periodontopathic bacteria can be aspirated into the lung to cause aspiration pneumonia. The teeth may also serve as a reservoir for respiratory pathogen colonization and subsequent nosocomial pneumonia. Typical respiratory pathogens have been shown to colonize the dental plaque of hospitalized intensive care and nursing home patients. Once established in the mouth, these pathogens may be aspirated into the lung to cause infection. Other epidemiologic studies have noted a relationship between poor oral hygiene or periodontal bone loss and chronic obstructive pulmonary disease. Several mechanisms are proposed to explain the potential role of oral bacteria in the pathogenesis of respiratory infection: 1. aspiration of oral pathogens (such as Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, etc.) into the lung to cause infection; 2. periodontal disease-associated enzymes in saliva may modify mucosal surfaces to promote adhesion and colonization by respiratory pathogens, which are then aspirated into the lung; 3. periodontal disease-associated enzymes may destroy salivary pellicles on pathogenic bacteria to hinder their clearance from the mucosal surface; and 4. cytokines originating from periodontal tissues may alter respiratory epithelium to promote infection by respiratory pathogens.

Relationships between periodontal disease and bacterial pneumonia

Bacterial pneumonia is a prevalent and costly infection that is a significant cause of morbidity and mortality in patients of all ages. The continuing emergence of antibiotic-resistant bacteria (e.g., penicillin-resistant pneumococci) suggests that bacterial pneumonia will assume increasing importance in the coming years. Thus, knowledge of the pathogenesis of, and risk factors for, bacterial pneumonia is critical to the development of strategies for prevention and treatment of these infections. Bacterial pneumonia in adults is the result of aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which multiply in the lung and cause infection. It is recognized that community-acquired pneumonia and lung abscesses can be the result of infection by anaerobic bacteria; dental plaque would seem to be a logical source of these bacteria, especially in patients with periodontal disease. It is also possible that patients with high risk for pneumonia, such as hospitalized patients and nursing home residents, are likely to pay less attention to personal hygiene than healthy patients. One important dimension of this personal neglect may be diminished attention to oral hygiene. Poor oral hygiene and periodontal disease may promote oropharyngeal colonization by potential respiratory pathogens (PRPs) including Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Enterobacter species, etc.), Pseudomonas aeruginosa, and Staphylococcus aureus. This paper provides the rationale for the development of this hypothesis especially as it pertains to mechanically ventilated intensive care unit patients and nursing home residents, two patient groups with a high risk for bacterial pneumonia.

Pleuropulmonary infection with chest wall infiltration by Eikenella corrodens

Eikenella corrodens is a facultative anaerobic bacillus which is part of the normal flora of the oral cavity and has an unusual antibiotic sensitivity for an anaerobe. The case history is presented of a young man with chest wall infiltration by Eikenella corrodens.