Actinobacillus actinomycetemcomitans Keratitis After Glaucoma Infiltration Surgery: A Clinical Report and Literature Review

Diaphragmatic mass caused by Aggregatibacter actinomycetemcomitams

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actinomycetemcomitans causes periodontitis, endocarditis and soft tissue abscess.

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First case of A. actinomycetemcomitans diaphragmatic infection without lung injury.

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Hematogenous spread of A. actinomycetemcomitans from oral mucosa to thorax.

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A 52-year-old man was evaluated in our outpatient facility because of a thoracic mass for one month. A needle biopsy of the chest mass was performed and microbiological culture showed growth of Aggregatibacter actinomycetemcomitans. Three months after starting antimicrobial therapy, acute phase reactants normalized, and chest CT showed a progressive reduction in the size of the phlegmon. To our knowledge, we report the first case of A. actinomycetemcomitans diaphragmatic and chest wall infection without pulmonary involvement. This supports the theory of hematogenous spread of the germ from oral mucosa to produce thoracic lesions.

The Spectrum of Microbial Keratitis: An Updated Review

Background:

In microbial keratitis, infection of the cornea can threaten vision through permanent corneal scarring and even perforation resulting in the loss of the eye. A literature review was conducted by Karsten, Watson and Foster (2012) to determine the spectrum of microbial keratitis. Since this publication, there have been over 2600 articles published investigating the causative pathogens of microbial keratitis.

Objective:

To determine the current spectrum of possible pathogens implicated in microbial keratitis relative to the 2012 study.

Methods:

An exhaustive literature review was conducted of all the peer-reviewed articles reporting on microbial pathogens implicated in keratitis. Databases including MEDLINE, EMBASE, Scopus and Web of Science were searched utilising their entire year limits (1950-2019).

Results:

Six-hundred and eighty-eight species representing 271 genera from 145 families were implicated in microbial keratitis. Fungal pathogens, though less frequent than bacteria, demonstrated the greatest diversity with 393 species from 169 genera that were found to cause microbial keratitis. There were 254 species of bacteria from 82 genera, 27 species of amoeba from 11 genera, and 14 species of virus from 9 genera, which were also identified as pathogens of microbial keratitis.

Conclusion:

The spectrum of pathogens implicated in microbial keratitis is extremely diverse. Bacteria were most commonly encountered and in comparison, to the review published in 2012, further 456 pathogens have been identified as causative pathogens of microbial keratitis. Therefore, the current review provides an important update on the potential spectrum of microbes, to assist clinicians in the diagnosis and treatment of microbial keratitis.

Antigen host response differences between the animal-type strain and human-clinical Pythium insidiosum isolates used for serological diagnosis in Thailand

The detection of Pythium insidiosum-specific-immunoglobulin-G antibody (Pi-Ab) with enzyme-linked immunosorbent assay (ELISA) test depends on the source of antigen. In this study, the Pi-Ab levels in 140 serum samples from patients with pythiosis were evaluated by ELISA using antigens from 10 P. insidiosum clinical isolates in comparison with antigen from the equine-standard-type strain. The ELISA values (EVs), calculated from antibody levels from serum of patients with pythiosis or other infections versus healthy controls, were significantly higher in the test with clinical-isolates antigen than the standard-equine-type strain (6.0 ± 2.6 vs 4.0 ± 1.7, respectively; P < .0001). ELISA with antigen from human source might be more proper diagnosis test.

Monitoring Anti-Pythium insidiosum IgG Antibodies and (1→3)-β-d-Glucan in Vascular Pythiosis

Despite aggressive treatment, vascular pythiosis has a mortality rate of 40%. This is due to delays in diagnosis and a lack of effective monitoring tools. To overcome this drawback, serum beta-d-glucan (BG) and P. insidiosum-specific antibody (Pi-Ab) were examined as potential monitoring markers in vascular pythiosis. A prospective cohort study of vascular pythiosis patients was carried out from January 2010 to July 2016. Clinical information and blood samples were collected and evaluated by the BG and Pi-Ab assays. Linear mixed-effect models were used to compare BG and Pi-Ab levels. The in vitro susceptibility test was performed with all P. insidiosum isolates from culture-positive cases. A total of 50 patients were enrolled: 45 survived and 5 died during follow-up. The survivors had a significantly shorter time to medical care (P < 0.0001) and a significantly shorter waiting time to the first surgery (P < 0.0001). There were no differences in BG levels among the groups at diagnosis (P = 0.33); however, BG levels among survivors were significantly lower than those of the deceased group at 0.5 months (P < 0.0001) and became undetectable after 3 months. Survivors were able to maintain an enzyme-linked immunosorbent assay (ELISA) value (EV) of Pi-Ab above 8, whereas the EV among deceased patients was less than 4. In vitro susceptibility results revealed no synergistic effects between itraconazole and terbinafine. This study showed that BG and Pi-Ab are potentially valuable markers to monitor the disease after treatment initiation. An unchanged BG level at 2 weeks after surgery should prompt an evaluation for residual disease.