Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures

Background: A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. Methods: A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. Results and Conclusions: The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.

Back to basics: a rare and aggressive case of Aggregatibacter aphrophilus endocarditis

ABSTRACT We present the case of a 25-year-old with a history of bicuspid aortic valve and ascending aortopathy who was successfully treated for infective endocarditis (IE) due to Aggregatibacter aphrophilus. His clinical course was complicated by a large aortic root abscess not initially visualised on transthoracic echocardiography or computerised tomography. The cardinal feature of progressive prolongation of the PR interval on serial electrocardiograms was the only sign associated with clinical deterioration and was the trigger for rapid investigation and urgent management. Our case emphasises the importance of simple bedside tests to identify dynamic clinical scenarios and the requirement for early further imaging in the management of IE.

An unusual case of multiple hepatic and pulmonary abscesses caused by Aggregatibacter aphrophilus in a young man: a case report

Background Aggregatibacter aphrophilus, formerly known as Haemophilus aphrophilus, belongs to the HACEK organisms, a group of pathogens classically associated with infectious endocarditis. A. aphrophilus is a rarely found pathogen, though abscess formation in various organs has been described, typically due to spread from an infected heart valve. Here we describe the unusual case of multiple hepatic abscesses caused by A. aphrophilus. Case presentation A 33-year-old Caucasian man presented at our hospital with fever and malaise, elevated inflammatory markers, and liver enzymes. Imaging was compatible with multiple liver and pulmonary abscesses, without evidence of endocarditis. Cultures of blood and liver abscess material remained without growth. Polymerase chain reaction finally revealed Aggregatibacter aphrophilus in the liver tissue. The patient recovered fully within 6 weeks of doxycycline treatment. Conclusions There are only a few case descriptions of liver abscesses caused by A. aphrophilus. As a ubiquitous organism in the gastrointestinal tract, A. aphrophilus may reach the liver via the portal venous system, as well as through hematogenous spread from the oropharynx. HACEK organisms are notoriously difficult to grow on culture, which highlights the diagnostic importance of eubacterial PCR.

Aggregatibacter aphrophilus spinal epidural abscess

A 76-year-old woman with a rare case of spinal epidural abscess (SEA) that had no risk factors for such type of infection, presented symptoms of back pain, progressive neurological deficit of the lower limb and loss of sphincter control. A gadolinium-enhanced MRI confirmed the diagnosis of an SEA. The patient underwent laminectomy with surgical drainage, where cultures showed the presence of Aggregatibacter aphrophilus, a bacterium of the HACEK group (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species), rarely involved in SEA. Following surgery, the patient was treated with intravenous ceftriaxone for 6 weeks, and this gave excellent results.