Sepsis and Pleural Empyema Caused by Streptococcus pyogenes after Influenza A Virus Infection

Pro-inflammatory interactions of streptolysin O toxin with human neutrophils in vitro

The recent global resurgence of severe infections caused by the Group A streptococcus (GAS) pathogen, Streptococcus pyogenes, has focused attention on this microbial pathogen, which produces an array of virulence factors, such as the pore-forming toxin, streptolysin O (SOT). Importantly, the interactions of SOT with human neutrophils (PMN), are not well understood. The current study was designed to investigate the effects of pretreatment of isolated human PMN with purified SOT on several pro-inflammatory activities, including generation of reactive oxygen species (ROS), degranulation (elastase release), influx of extracellular calcium (Ca2+) and release of extracellular DNA (NETosis), using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of PMN to SOT alone caused modest production of ROS and elastase release, while pretreatment with the toxin caused significant augmentation of chemoattractant (fMLP)-activated ROS generation and release of elastase by activated PMN. These effects of treatment of PMN with SOT were associated with both a marked and sustained elevation of cytosolic Ca2+concentrations and significant increases in the concentrations of extracellular DNA, indicative of NETosis. The current study has identified a potential role for SOT in augmenting the Ca2+-dependent pro-inflammatory interactions of PMN, which, if operative in a clinical setting, may contribute to hyper-activation of PMN and GAS-mediated tissue injury.

Implementation of full-length 16S nanopore sequencing for bacterial identification in a clinical diagnostic setting

This study describes the implementation of 16S nanopore sequencing in a diagnostic lab for pathogen identification without prior enrichment. First, the universality of the test and taxonomic resolution was evaluated for 78 clinically relevant bacteria (69 known and 9 unknown bacterial cultures). Next, the diagnostic value of the test was evaluated based on clinical samples. It was shown that 16S sequencing can be used both for identification of unknown cultures and to find bacteria directly in the clinical sample without cultivation. All culture-positive samples (n=11) tested positive with 16S sequencing directly performed on the sample, but bacteria were found as well in 15/30 culture-negative samples. Pathogenic bacteria were found in a background of commensal flora, and even complex polymicrobial infections could be unraveled. This study demonstrates the feasibility of implementing 16S nanopore sequencing in a clinical diagnostic setting and demonstrates its value for the diagnosis of culture-negative and polymicrobial infections.

Streptococcus pyogenes Pneumonia: A Rare and Severe Presentation in a Patient With Asthma

Pneumonia is a common respiratory infection typically caused by pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. It is characterized by inflammation and infection in the lung parenchyma, often presenting with symptoms such as cough, fever, and difficulty breathing. Empyema, on the other hand, is a severe complication of pneumonia marked by the accumulation of pus in the pleural cavity. Streptococcus pyogenes (S. pyogenes), also known as group A Streptococcus (GAS), is a bacterium that can cause various infections, including pharyngitis and skin infections. In rare cases, it can lead to community-acquired pneumonia. In our case report, we describe a 32-year-old female with a history of mild persistent asthma who contracted influenza B virus, eventually developing pneumonia caused by GAS, S. pyogenes.

A case of severe bilateral empyema due to Streptococcus pyogenes

Bilateral empyema is a rare and severe condition and deciding on a treatment is quite difficult. Additionally, infections caused by group A Streptococcus (GAS [Streptococcus pyogenes]) are known to be invasive. We successfully treated without surgery a previously healthy 59-year-old woman with bilateral empyema due to GAS, with repeated drainages, antibiotics, and fibrinolytic therapy. To our knowledge, there have not been any published reports on cases of bilateral empyema due to GAS infection. In rare, severe cases of bilateral empyema caused by organisms such as GAS, physicians managing the condition should consider the overall condition of the patient.

Specialized pro-resolving lipid mediators regulate inflammatory macrophages: A paradigm shift from antibiotics to immunotherapy for mitigating COVID-19 pandemic

The most severe clinical manifestations of the horrifying COVID-19 disease, that claimed millions of lives during the pandemic time, were Acute respiratory distress syndrome (ARDS), Coagulopathies, septic shock leading eventually to death. ARDS was a consequence of Cytokine storm. The viral SARS-COV2infection lead to avalanche of cytokines and eicosanoids causing "cytokine storm" and "eicosanoid storm." Cytokine storm is one of the macrophage-derived inflammatory responses triggered by binding of virus particles to ACE2 receptors of alveolar macrophages, arise mainly due to over production of various pro-inflammatory mediators like cytokines, e.g., interleukin (IL)-1, IL-2, and tumor necrosis factor (TNF)- α, causing pulmonary edema, acute respiratory distress, and multi-organ failure. Cytokine storm was regarded as the predictor of severity of the disease and was deemed one of the causes of the high mortality rates due to the COVID-19. The basis of cytokine storm is imbalanced switching between an inflammation increasing - pro-inflammatory (M1) and an inflammation regulating-anti-inflammatory (M2) forms of alveolar macrophages which further deteriorates if opportunistic secondary bacterial infections prevail in the lungs. Lack of sufficient knowledge regarding the virus and its influence on co-morbidities, clinical treatment of the diseases included exorbitant use of antibiotics to mitigate secondary bacterial infections, which led to the unwarranted development of multidrug resistance (MDR) among the population across the globe. Antimicrobial resistance (AMR) needs to be addressed from various perspectives as it may deprive future generations of the basic health immunity. Specialized pro-resolving mediators (SPMs) are generated from the stereoselective enzymatic conversions of essential fatty acids that serve as immune resolvents in controlling acute inflammatory responses. SPMs facilitate the clearance of injured tissue and cell debris, the removal of pathogens, and augment the concentration of anti-inflammatory lipid mediators. The SPMs, e.g., lipoxins, protectins, and resolvins have been implicated in exerting inhibitory influence on with cytokine storm. Experimental evidence suggests that SPMS lower antibiotic requirement. Therefore, in this review potential roles of SPMs in enhancing macrophage polarization, triggering immunological functions, hastening inflammation resolution, subsiding cytokine storm and decreasing antibiotic requirement that can reduce AMR load are discussed.

Multi-omics association analysis reveals interactions between the oropharyngeal microbiome and the metabolome in pediatric patients with influenza A virus pneumonia

Children are at high risk for influenza A virus (IAV) infections, which can develop into severe illnesses. However, little is known about interactions between the microbiome and respiratory tract metabolites and their impact on the development of IAV pneumonia in children. Using a combination of liquid chromatography tandem mass spectrometry (LC-MS/MS) and 16S rRNA gene sequencing, we analyzed the composition and metabolic profile of the oropharyngeal microbiota in 49 pediatric patients with IAV pneumonia and 42 age-matched healthy children. The results indicate that compared to healthy children, children with IAV pneumonia exhibited significant changes in the oropharyngeal macrobiotic structure (p = 0.001), and significantly lower microbial abundance and diversity (p < 0.05). These changes came with significant disturbances in the levels of oropharyngeal metabolites. Intergroup differences were observed in 204 metabolites mapped to 36 metabolic pathways. Significantly higher levels of sphingolipid (sphinganine and phytosphingosine) and propanoate (propionic acid and succinic acid) metabolism were observed in patients with IAV pneumonia than in healthy controls. Using Spearman’s rank-correlation analysis, correlations between IAV pneumonia-associated discriminatory microbial genera and metabolites were evaluated. The results indicate significant correlations and consistency in variation trends between Streptococcus and three sphingolipid metabolites (phytosphingosine, sphinganine, and sphingosine). Besides these three sphingolipid metabolites, the sphinganine-to-sphingosine ratio and the joint analysis of the three metabolites indicated remarkable diagnostic efficacy in children with IAV pneumonia. This study confirmed significant changes in the characteristics and metabolic profile of the oropharyngeal microbiome in pediatric patients with IAV pneumonia, with high synergy between the two factors. Oropharyngeal sphingolipid metabolites may serve as potential diagnostic biomarkers of IAV pneumonia in children.

Bacterial co-infections with SARS-CoV-2

The pandemic coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide. To date, there are no proven effective therapies for this virus. Efforts made to develop antiviral strategies for the treatment of COVID-19 are underway. Respiratory viral infections, such as influenza, predispose patients to co-infections and these lead to increased disease severity and mortality. Numerous types of antibiotics such as azithromycin have been employed for the prevention and treatment of bacterial co-infection and secondary bacterial infections in patients with a viral respiratory infection (e.g., SARS-CoV-2). Although antibiotics do not directly affect SARS-CoV-2, viral respiratory infections often result in bacterial pneumonia. It is possible that some patients die from bacterial co-infection rather than virus itself. To date, a considerable number of bacterial strains have been resistant to various antibiotics such as azithromycin, and the overuse could render those or other antibiotics even less effective. Therefore, bacterial co-infection and secondary bacterial infection are considered critical risk factors for the severity and mortality rates of COVID-19. Also, the antibiotic-resistant as a result of overusing must be considered. In this review, we will summarize the bacterial co-infection and secondary bacterial infection in some featured respiratory viral infections, especially COVID-19.

A severe case of Streptococcal pyogenes empyema following influenza A infection

BACKGROUND

Any immunological mechanisms induced by influenza virus could cause severe secondary bacterial superinfection such as those by Streptococcus pyogenes [group A streptococcus (GAS)], Streptococcus pneumoniae or Staphylococcus aureus. Over recent years, the frequency of pleural empyema has increased in children with influenza infection. We present a severe case of acute empyema caused by S.pyogenes after influenza A infection.

CASE PRESENTATION

A previously healthy 39-year old woman was diagnosed as influenza A and received oral Oseltamivir 75 mg twice daily for 5 days. She had no vaccination of influenza A. Although her influenza A infection improved, she complained of fever and cough to our institute. Chest radiography showed encapsulated pleural effusion of the left lung and pleural effusion which was consistent with acute empyema. Then, she was diagnosed as having acute empyema and was admitted to our institute. Streptococcus pyogenes was identified by pleural fluid culture on day 4. thus, MNZ was changed to clindamycin (CLDM) 600 mg three times a day. While thoracic drainage with intrapleural urokinase and combination antibiotic therapy of ceftriaxone and CLDM were performed, her general condition and chest radiographic findings were not improved. She received video-assisted thoracic debridement on day 10. After the operation, the antibiotic therapy was changed to ABPC 6 g daily iv. Due to good clinical course, the antibiotic therapy was switched to oral amoxicillin 500 mg three times daily on day 28. Then, she was discharged.

CONCLUSION

Influenza A virus infection could lead to severe GAS infection, while the latter can occur in otherwise healthy individual as well. Physician must consider the possibility of severe GAS infection after influenza A infection.