Empyema caused by Prevotella bivia complicating an unusual case of spontaneous chylothorax

Anaerobic bacteria in chronic wounds: Roles in disease, infection and treatment failure

Infection is among the most common factors that impede wound healing, yet standard treatments routinely fail to resolve chronic wound infections. The chronic wound environment is largely hypoxic/anoxic, and wounds are predominantly colonised by facultative and obligate anaerobic bacteria. Oxygen (O2) limitation is an underappreciated driver of microbiota composition and behaviour in chronic wounds. In this perspective article, we examine how anaerobic bacteria and their distinct physiologies support persistent, antibiotic-recalcitrant infections. We describe the anaerobic energy metabolisms bacteria rely on for long-term survival in the wound environment, and why many antibiotics become less effective under hypoxic conditions. We also discuss obligate anaerobes, which are among the most prevalent taxa to colonise chronic wounds, yet their potential roles in influencing the microbial community and wound healing have been overlooked. All of the most common obligate anaerobes found in chronic wounds are opportunistic pathogens. We consider how these organisms persist in the wound environment and interface with host physiology to hinder wound healing processes or promote chronic inflammation. Finally, we apply our understanding of anaerobic physiologies to evaluate current treatment practices and to propose new strategies for treating chronic wound infections.

Seasonal variation significantly affected bacterioplankton and eukaryoplankton community composition in Xijiang River, China

Both bacterioplankton and eukaryoplankton communities play important roles in the geochemical cycles and energy flows of river ecosystems. However, whether a seasonal change in bacterioplankton and eukaryoplankton communities is synchronous remains unclear. To test the synchronicity and analyze how physical and chemical environmental factors affect these communities, we compared bacterioplankton and eukaryoplankton communities in surface water samples between March (dry season) and June (rainfall season) considering water environmental factors. Our results showed that there was no significant difference in operational taxonomic unit number, Shannon index, and Chao1 index in bacterioplankton and eukaryoplankton communities between March and June. However, principal component analysis showed that the communities were significantly different between the sampling times and sampling sites. Water temperature (WT), oxidation-reduction potential (ORP), water transparency (SD), NO₃-N, and NH₃ significantly influenced bacterioplankton communities, and WT, SD, ORP, and NH₄-N significantly influenced eukaryoplankton communities in the river. These results implied that compared with the sampling sites, sampling times more significantly affected the bacterioplankton and eukaryoplankton river communities by influencing WT, ORP, SD, and nitrogen forms.

A challenging case of thoracic empyema caused by Prevotella spp

We report here the case of a 49-year-old man admitted for a diagnostic work-up of bilateral lung nodules. Empyema rapidly developed after a chest computed-tomodensitometry guided lung puncture. Despite the lack of obvious aetiology after two biopsies, the diagnosis was reached by performing 16S ribosomal DNA (rDNA) sequence analysis, which identified Prevotella spp in the pleural liquid. The empyema and lung nodules resolved after appropriate antibiotic therapy.

Scrotal Abscess in a Japanese Patient Caused by Prevotella bivia and Streptococcus agalactiae, Successfully Treated with Cefazolin and Amoxicillin: A Case Report

Background

Infections caused by Prevotella bivia, a gram-negative anaerobic bacillus, are rare, with no reported cases in Japan. We present a novel case of scrotal abscess in a Japanese patient co-infected with Prevotella bivia and Streptococcus agalactiae.

Case Presentation

A 41-year-old uncontrolled diabetic man complained of swelling and pain in the scrotum. On examination, computed tomography revealed an abscess of 5-cm diameter in the scrotum. Then, the abscess was incised and drained. He was treated with cefazolin empirically. Prevotella bivia and Streptococcus agalactiae were identified in the pus cultures obtained from the abscess. However, the susceptibility tests for Prevotella bivia could not be submitted. Seven days following admission, the pain reduced, and the drainage slowed. The patient was discharged on day 14 when cefazolin was discontinued and oral amoxicillin (750 mg/day) was started. Amoxicillin was continued until day 42; improvement was confirmed.

Conclusion

To the best of our knowledge, this case is the first report of Prevotella bivia in Japan. We suggest that cephem antibiotics such as cefazolin may be effective against Prevotella bivia in Japan.

Pulmonary Kaposi's Sarcoma and Its Complications in the HAART Era: A Contemporary Case-Based Review

The early years of the acquired immunodeficiency syndrome (AIDS) epidemic introduced the global medical community to Kaposi's sarcoma (KS), a heretofore seldom encountered angiosarcomatous neoplasm associated with human herpesvirus-8. At that time, clinicians treating these KS patients were routinely exposed to the pulmonary manifestations of this malignancy, including characteristic airway lesions, peribronchovascular opacities, and the typically hemorrhagic pleural effusions. They also witnessed uncommon complications of pulmonary KS such as chylous effusions, diffuse alveolar hemorrhage, and immune reconstitution inflammatory syndrome. Since the advent of highly active antiretroviral therapy, the incidence of KS has steadily declined and with that so has clinician familiarity with this disease. Herein, we present four KS cases recently encountered at our institution that illustrate both typical manifestations of pulmonary KS as well as its thoracic complications. The case descriptions are followed by a review of these clinical entities with the aim of restoring awareness among frontline physicians of what is now a rare but not quite extinct AIDS-defining neoplasm.