Rapidly progressive necrotizing pneumonia: remember the Streptococcus anginosus group!

Streptococcus anginosus: a stealthy villain in deep odontogenic abscesses

Odontogenic infections (OIs) occasionally spread to deep facial and neck tissues. Our study aimed to explore the role of Streptococcus anginous group (SAG) in these severe OIs. A retrospective study of patients aged ≥ 18 years who required hospital care for acute OI was conducted. We analysed data of OI microbial samples and recorded findings of SAG and other pathogens. These findings were compared with data regarding patients' prehospital status and variables of infection severity. In total, 290 patients were included in the analyses. The most common (49%) bacterial finding was SAG. Other common findings were Streptococcus viridans and Prevotella species, Parvimonas micra, and Fusobacterium nucleatum. Infection severity variables were strongly associated with SAG occurrence. Treatment in an intensive care unit was significantly more common in patients with SAG than in patients without SAG (p < 0.001). In addition, SAG patients expressed higher levels of C-reactive protein (p = 0.001) and white blood cell counts (p < 0.001), and their hospital stays were longer than those of non-SAG patients (p = 0.001). SAG is a typical finding in severe OIs. Clinical features of SAG-related OIs are more challenging than in other OIs. Early detection of SAG, followed by comprehensive infection care with prompt and careful surgical treatment, is necessary due to the aggressive behaviour of this dangerous pathogen.

Streptococcus anginosus Lung Abscess With Complicated Parapneumonic Empyema

A 55-year-old female with hypertension presented to our facility with complicated pneumonia. She complained of progressively worsening shortness of breath and pleuritic chest pain. She was in her usual state of health except for an upper respiratory infection treated with oral antibiotics a month prior. At the presentation, she was febrile, tachycardic, and hypoxic on room air. A chest computed tomography (CT) showed near-complete opacification of the right lung, a cavitation with the fluid level in the right middle lobe, and moderate-to-large effusion. Broad-spectrum antibiotics were started. Sputum culture was later positive for methicillin-resistant Staphylococcus aureus, which prompted antibiotic de-escalation to vancomycin. A chest tube was placed into the right pleural space draining 700 mL of exudative fluid, which cultures grew Streptococcus anginosus group (SAG) bacteria. Due to persistent respiratory distress and residual effusion, right thoracotomy and decortication were performed. A right upper lobe abscess ruptured into the pleural space was noted during the procedure. Pathology revealed necrotic tissue, and the microbiological workup was negative. The patient clinically improved postoperatively and was discharged home with oral Linezolid.

High-Dose Tigecycline for the Treatment of Progressive Pneumonia Caused by Chlamydia psittaci: Case Series and Literature Review

Purpose

To summarize the clinical characteristics of progressive pneumonia caused by Chlamydia psittaci (C. psittaci) and to explore the effect of high-dose tigecycline on severe C psittaci.

Patients and Methods

We retrospectively analyzed the clinical characteristics, treatment, and outcomes of three progressive pneumonia patients caused by C. psittaci in our hospital in the past three years.

Results

All three patients showed high fever and progressive dyspnea, and all of them were finally diagnosed by bronchoalveolar lavage fluid (BALF) of metagenomic next-generation sequencing (mNGS). Case 1 rapidly developed into multilobar infiltration after raising a parrot with a normal appearance one week before. Respiratory failure occurred despite the use of moxifloxacin, requiring non-invasive ventilator-assisted ventilation. Case 2 developed discomfort one day after sightseeing in the forest park. Moxifloxacin was ineffective for her and she quickly developed respiratory failure, requiring invasive ventilator-assisted ventilation. Case 3 kept chickens and ducks at home. Respiratory failure and renal failure still occurred rapidly despite the use of doxycycline, requiring invasive ventilator-assisted ventilation and continuous renal replacement therapy (CRRT). After adjusting the antibiotic to high-dose tigecycline (100mg, I.V., q12h), all three patients were treated effectively and no side effects occurred.

Conclusion

C. psittaci pneumonia is one of the causes of progressive pneumonia. High-dose tigecycline is safe and effective for the treatment of severe C. psittaci.

An Unusual Case of Explosive Pleuritis without Mediastinal Shift

Explosive pleuritis (EP) is an under-reported condition. Although there is no agreed-upon definition, generally, the term EP denotes a dramatic clinical and radiologic progression of pleural space inflammation in the setting of pneumonia. The pleural space inflammation leads to the formation of loculated complex pleural effusion or empyema, and pleural adhesion within a matter of hours, typically in less than 24 hours. Radiologically, these changes are manifested as opacification of the hemithorax with or without contralateral mediastinal shift. Streptococcal pneumonia is the most common cause of EP. Here we present a case and discuss the clinical, microbiologic, radiologic, and treatment aspects of EP. We also scrutinize the medical literature to compare the previously reported cases.