Surfactant for a Patient with Refractory Pyopneumothorax and Acute Respiratory Distress Syndrome Due to Pneumococcal Necrotizing Pneumonia Complicated by a Bronchopleural Fistula.

Background: Necrotizing pneumonia rarely occurs in children, but when it does it can be complicated by bronchopleural fistula, empyema, pneumothorax, sepsis, and acute respiratory distress syndrome (ARDS). Antimicrobial therapy is the cornerstone of its management; however, surgery is necessary in some cases. Ideally, surgical interventions are kept to a minimum, but this is not always possible if there is a mass effect from air and fluid in the pleural space, pulmonary necrosis leading to massive hemoptysis, uncontrolled sepsis, or difficulties with assisted ventilation. Case Presentation: Herein we present a patient with refractory pyopneumothorax and ARDS due to pneumococcal necrotizing pneumonia complicated by a bronchopleural fistula. The patient's clinical condition deteriorated despite antibiotics, surgical drainage, and assisted ventilation. Owing to pneumothorax with a high percentage of air leakage, bilateral diffuse collapse of the lungs, and insufficient oxygenation, surgical treatment was considered, but because of the patient's lack of tolerance for surgery due to hemodynamic reasons and the complications associated with surgery, medical treatment was determined to be more appropriate. Surfactant treatment was administered to the patient, resulting in significant clinical improvement. Conclusion: To the best of our knowledge, this is the first report of the use of surfactant to treat ARDS due to necrotizing pneumonia. Based on the presented case, we think surfactant can be considered as a salvage treatment for such patients.

RIPK3 Activates MLKL-mediated Necroptosis and Inflammasome Signaling during Streptococcus Infection.

Community-acquired pneumonia is the most common type of pneumonia and remains a leading cause of morbidity and mortality worldwide. Although many different pathogens can contribute to pneumonia, Streptococcus pneumoniae is one of the common bacterial pathogens that underlie community-acquired pneumonia. RIPK3 (receptor-interacting protein kinase 3) is widely recognized as a key modulator of inflammation and cell death. To elucidate a potential role of RIPK3 in pneumonia, we examined plasma from healthy control subjects and patients positive for streptococcal pneumonia. In human studies, RIPK3 protein concentrations were significantly elevated and were identified as a potential plasma marker of pneumococcal pneumonia. To expand these findings, we used an in vivo murine model of pneumococcal pneumonia to demonstrate that RIPK3 deficiency leads to reduced bacterial clearance, severe pathological damage, and high mortality. Our results illustrated that RIPK3 forms a complex with RIPK1, MLKL (mixed-lineage kinase domain-like protein), and MCU (mitochondrial calcium uniporter) to induce mitochondrial calcium uptake and mitochondrial reactive oxygen species(mROS) production during S. pneumoniae infection. In macrophages, RIPK3 initiated necroptosis via the mROS-mediated mitochondrial permeability transition pore opening and NLRP3 inflammasome activation via the mROS-AKT pathway to protect against S. pneumoniae. In conclusion, our study demonstrated a mechanism by which RIPK3-initiated necroptosis is essential for host defense against S. pneumoniae.

More than Meets the Eye: Bacteremic Pneumococcal Pneumonia as the Initial Presentation of Multiple Myeloma.

BACKGROUND Increased susceptibility to bacterial infections is a hallmark of multiple myeloma (MM). Invasive infections with Streptococcus pneumoniae may be the first manifestation of underlying MM. Clinicians treating patients with invasive S. pneumoniae infections may consider searching for underlying MM in the presence of certain diagnostic findings. CASE REPORT A previously healthy 60-year-old man was referred from his general physician because of fever, cough, and chills despite treatment with clarithromycin. The patient had experienced night sweats, weight loss, and recurrent episodes of fever and cough during the last 3 months. Examination was significant for left-sided pulmonary rales. A chest X-ray showed a retrocardiac consolidation of the left lower lobe. The patient was started on empirical antimicrobial therapy for community-acquired pneumonia. Subsequently, blood and sputum cultures were positive for S. pneumoniae. Given the history of night sweats and weight loss, the discrepancy between elevated total protein and low albumin levels, and the diagnosis of pneumococcal bacteremia, multiple myeloma (MM) was suspected and confirmed by immunofixation and bone marrow biopsy. CONCLUSIONS This case showed that clinicians should be vigilant for features of MM, which are encountered during history (e.g., weight loss, bone pain) or routine laboratory workup (e.g., unexplained anemia, renal failure, hypercalcemia, or a discrepancy between elevated total protein and low albumin levels) in elderly patients presenting with invasive pneumococcal disease.

Exploration of Bacterial Bottlenecks and Streptococcus pneumoniae Pathogenesis by CRISPRi-Seq.

Streptococcus pneumoniae is an opportunistic human pathogen that causes invasive diseases, including pneumonia, with greater health risks upon influenza A virus (IAV) co-infection. To facilitate pathogenesis studies in vivo, we developed an inducible CRISPR interference system that enables genome-wide fitness testing in one sequencing step (CRISPRi-seq). We applied CRISPRi-seq to assess bottlenecks and identify pneumococcal genes important in a murine pneumonia model. A critical bottleneck occurs at 48 h with few bacteria causing systemic infection. This bottleneck is not present during IAV superinfection, facilitating identification of pneumococcal pathogenesis-related genes. Top in vivo essential genes included purA, encoding adenylsuccinate synthetase, and the cps operon required for capsule production. Surprisingly, CRISPRi-seq indicated no fitness-related role for pneumolysin during superinfection. Interestingly, although metK (encoding S-adenosylmethionine synthetase) was essential in vitro, it was dispensable in vivo. This highlights advantages of CRISPRi-seq over transposon-based genetic screens, as all genes, including essential genes, can be tested for pathogenesis potential.

Airway compromise and thyroglossal duct cysts in adulthood.

A 61-year-old man died suddenly after a brief history of shortness of breath and hemoptysis. At autopsy he had lobar pneumonia involving the right upper and left lower lobes of the lung. Significantly there was also a 30 × 20 mm (in cross-section) thyroglossal duct cyst compressing the upper airway. Death was attributed to respiratory failure due to the combined effects of lobar pneumonia (cultures positive for Streptococcus pneumoniae) and airway narrowing from a thyroglossal duct cyst. Although such cysts are usually found in childhood they may on occasion be diagnosed in adults. Despite being the most common congenital cyst in the neck cases associated with a lethal outcome are extremely rare.

Effectiveness of Streptococcus Pneumoniae Urinary Antigen Testing in Decreasing Mortality of COVID-19 Co-Infected Patients: A Clinical Investigation.

BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae urinary antigen (u-Ag) testing has recently gained attention in the early diagnosis of severe and critical acute respiratory syndrome coronavirus-2/pneumococcal co-infection. The aim of this study is to assess the effectiveness of Streptococcus pneumoniae u-Ag testing in coronavirus disease 2019 (COVID-19) patients, in order to assess whether pneumococcal co-infection is associated with different mortality rate and hospital stay in these patients. MATERIALS AND METHODS: Charts, protocols, mortality, and hospitalization data of a consecutive series of COVID-19 patients admitted to a tertiary hospital in northern Italy during COVID-19 outbreak were retrospectively reviewed. All patients underwent Streptococcus pneumoniae u-Ag testing to detect an underlying pneumococcal co-infection. Covid19+/u-Ag+ and Covid19+/u-Ag- patients were compared in terms of overall survival and length of hospital stay using chi-square test and survival analysis. RESULTS: Out of 575 patients with documented pneumonia, 13% screened positive for the u-Ag test. All u-Ag+ patients underwent treatment with Ceftriaxone and Azithromycin or Levofloxacin. Lopinavir/Ritonavir or Darunavir/Cobicistat were added in 44 patients, and hydroxychloroquine and low-molecular-weight heparin (LMWH) in 47 and 33 patients, respectively. All u-Ag+ patients were hospitalized. Mortality was 15.4% and 25.9% in u-Ag+ and u-Ag- patients, respectively (p = 0.09). Survival analysis showed a better prognosis, albeit not significant, in u-Ag+ patients. Median hospital stay did not differ among groups (10 vs. 9 days, p = 0.71). CONCLUSIONS: The routine use of Streptococcus pneumoniae u-Ag testing helped to better target antibiotic therapy with a final trend of reduction in mortality of u-Ag+ COVID-19 patients having a concomitant pneumococcal infection. Randomized trials on larger cohorts are necessary in order to draw definitive conclusion.

Inhibition of Necroptosis to Prevent Long-term Cardiac Damage During Pneumococcal Pneumonia and Invasive Disease.

BACKGROUND: Streptococcus pneumoniae infection can result in bacteremia with devastating consequences including heart damage. Necroptosis is a proinflammatory form of cell death instigated by pore-forming toxins such as S. pneumoniae pneumolysin. Necroptosis-inhibiting drugs may lessen organ damage during invasive pneumococcal disease (IPD). METHODS: In vitro experiments were carried out with human and mouse cardiomyocytes. Long-term cardiac damage was assessed using high-resolution echocardiography in ampicillin-rescued mice 3 months after challenge with S. pneumoniae. Ponatinib, a necroptosis-inhibiting and Food and Drug Administration-approved drug for lymphocytic leukemia treatment, was administered intraperitoneally alongside ampicillin to test its therapeutic efficacy. Histology of heart sections included hematoxylin-eosin staining for overt damage, immunofluorescence for necroptosis, and Sirius red/fast green staining for collagen deposition. RESULTS: Cardiomyocyte death and heart damage was due to pneumolysin-mediated necroptosis. IPD leads to long-term cardiac damage, as evidenced by de novo collagen deposition in mouse hearts and a decrease in fractional shortening. Adjunct necroptosis inhibition reduced the number of S. pneumoniae foci observed in hearts of acutely infected mice and serum levels of troponin I. Ponatinib reduced collagen deposition and protected heart function in convalescence. CONCLUSIONS: Acute and long-term cardiac damage incurred during IPD is due in part to cardiomyocyte necroptosis. Necroptosis inhibitors may be a viable adjunct therapy.

Pneumococcal superinfection in COVID-19 patients: A series of 5 cases.

BACKGROUND: In the context of the COVID-19 pandemic the risk of misdiagnosis of other causes of respiratory infection is likely. In this work we aim to describe the clinical characteristics, treatment and outcome of pneumococcal infection in COVID-19 patients. PATIENTS AND METHODS: Every COVID-19 patient presenting with concomitant pneumococcal pneumonia during March 2020 in a tertiary teaching Hospital In Barcelona, Spain. RESULTS: Five patients with PCR confirmed COVID19 or clinical and radiological suspicion were diagnosed of pneumococcal infection. In all cases chest X-ray were abnormal, with unilateral or bilateral infiltrates. Procalcitonin showed to be not sensitive enough to detect pneumococcal infection. Antibiotherapy was promptly started in all five cases with subsequent satisfactory evolution. CONCLUSION: International guidelines do not include the universal screening for bacterial co-infection. Radiological pattern of COVID-19 can be indistinguishable from that of pneumococcus pneumonia and frequency of co-infection is not well stablished, therefore clinicians should be aware of the possible SARS-CoV-2-pneumococcus association to avoid misdiagnosis and delay antibiotic therapy.

Influenza virus infection complicated by bacterial necrotising pneumonia: two case reports.

Necrotising pneumonia (NP) is a potentially severe complication of community-acquired pneumonia characterised by necrosis of consolidated lung tissue. A 7-year-old boy and a 6-year-old boy are presented, both of whom had a complicated influenza infection which evolved into severe NP caused by Streptococcus pneumoniae. Both needed intensive care for invasive respiratory support. Despite extensive pleural involvement in both cases, only one required thoracic surgery. Case 1 also developed anaemia, hyponatraemia and hypo-albuminaemia, resulting in generalised oedema. Despite the severe morbidity, both boys made a full recovery. The diagnosis of NP should always be considered in a child with pneumonia who remains unwell despite 72 hours of appropriate antibiotics, particularly if there is evidence of pleural disease. Although S. pneumoniae is the main agent for NP, the influenza virus may be a precipitating factor.

Incidence and Risk Factors for Invasive Pneumococcal Disease and Community-acquired Pneumonia in Human Immunodeficiency Virus-Infected Individuals in a High-income Setting.

BACKGROUND: Although people living with human immunodeficiency virus (PLWH) are at increased risk of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP), it is unclear whether this remains the case in the setting of early initiation of combination antiretroviral therapy (cART), at high CD4 cell counts. This is important, as pneumococcal vaccination coverage in PLWH is low in Europe and the United States, despite longstanding international recommendations. METHODS: We identified all CAP and IPD cases between 2008 and 2017 in a cohort of PLWH in a Dutch HIV referral center. We calculated incidence rates stratified by CD4 count and cART status and conducted a case-control study to identify risk factors for CAP in PLWH receiving cART. RESULTS: Incidence rates of IPD and CAP in PLWH were 111 and 1529 per 100 000 patient-years of follow-up (PYFU). Although IPD and CAP occurred more frequently in patients with CD4 counts <500 cells/µL (incidence rate ratio [IRR], 6.1 [95% confidence interval, 2.2-17] and IRR, 2.4 [95% confidence interval, 1.9-3.0]), the incidence rate in patients with CD4 counts >500 cells/µL remained higher compared with the general population (946 vs 188 per 100 000 PYFU). All IPD isolates were vaccine serotypes. Risk factors for CAP were older age, CD4 counts <500 cells/µL, smoking, drug use, and chronic obstructive pulmonary disease. CONCLUSIONS: The incidence of IPD and CAP among PLWH remains higher compared with the general population, even in those who are virally suppressed and have high CD4 counts. With all serotyped IPD isolates covered by pneumococcal vaccines, our study provides additional argumentation against the poor current adherence to international recommendations to vaccinate PLWH.

Clinically relevant model of pneumococcal pneumonia, ARDS, and nonpulmonary organ dysfunction in mice.

Pneumonia is responsible for more deaths in the United States than any other infectious disease. Severe pneumonia is a common cause of acute respiratory failure and acute respiratory distress syndrome (ARDS). Despite the introduction of effective antibiotics and intensive supportive care in the 20th century, death rates from community-acquired pneumonia among patients in the intensive care unit remain as high as 35%. Beyond antimicrobial treatment, no targeted molecular therapies have yet proven effective, highlighting the need for additional research. Despite some limitations, small animal models of pneumonia and the mechanistic insights they produce are likely to continue to play an important role in generating new therapeutic targets. Here we describe the development of an innovative mouse model of pneumococcal pneumonia developed for enhanced clinical relevance. We first reviewed the literature of small animal models of bacterial pneumonia that incorporated antibiotics. We then did a series of experiments in mice in which we systematically varied the pneumococcal inoculum and the timing of antibiotics while measuring systemic and lung-specific end points, producing a range of models that mirrors the spectrum of pneumococcal lung disease in patients, from mild self-resolving infection to severe pneumonia refractory to antibiotics. A delay in antibiotic treatment resulted in ongoing inflammation and renal and hepatic dysfunction despite effective bacterial killing. The addition of fluid resuscitation to the model improved renal function but worsened the severity of lung injury based on direct measurements of pulmonary edema and lung compliance, analogous to patients with pneumonia and sepsis who develop ARDS following fluid administration.

Streptococcus pneumoniae primary peritonitis mimicking acute appendicitis in an immunocompetent patient: a case report and review of the literature.

INTRODUCTION: Primary peritonitis without an identifiable intra-abdominal source is extremely rare in healthy individuals; it is commonly seen in cases of nephrotic syndrome, cirrhosis and end-stage liver disease, ascites, immunosuppression, and inflamed peritoneum due to pre-existing autoimmune and oncological conditions. CASE PRESENTATION: We present the case of a 68-year-old Caucasian woman operated on due to acute abdomen with a provisional diagnosis of acute appendicitis. During the operation a small amount of free intra-abdominal fluid was found. Her uterus, ovaries, and fallopian tubes were macroscopically normal. Therefore, with the suspicion of appendicitis, appendectomy was performed. Her blood cultures were negative while peritoneal fluid was positive for capsulated form of Streptococcus pneumoniae. A 30-day follow-up was performed and she was asymptomatic without any sign of infection. DISCUSSION: Streptococcus pneumoniae commonly causes upper respiratory tract infection and cutaneous infections. It very rarely causes gastrointestinal infection and it is very rarely responsible for primary peritonitis and septic shock syndrome. CONCLUSION: Pneumococcal peritonitis has a rare occurrence and represents a clinical challenge because of its subtle and non-specific clinical findings. The interest in our case lays in the relatively rare diagnosis of primary peritonitis mimicking acute appendicitis.

A 51-Year-Old Man With Unresolved Pulmonary Infiltrates Following Streptococcus pneumoniae Pneumonia.

CASE PRESENTATION: A 51-year-old man presented to the clinic 8 weeks after a 6-day hospital admission for severe multilobar pneumonia caused by Streptococcus pneumoniae. His productive cough resolved after antibiotics, but he reported persistent dyspnea. He recounted a lifelong history of recurrent sinusitis but no previous episodes of pneumonia. The patient denied fever, weight loss, or tobacco, alcohol, or drug use. He worked as an upholstery craftsman with no work-related exposures. He had no bird or exotic animal exposures, and no history of travel outside Sacramento, California, where he lived. Aside from the recently completed 2-week course of levofloxacin, he was not taking any medications.

Empyema necessitans in a six-month-old girl.

Empyema necessitans is a rare complication of acute bacterial pneumonia, especially in children. It is a complication of empyema characterised by the extension of pus from the pleural cavity into the thoracic wall to form a mass of purulent fluid in the adjacent soft tissue. An inflammatory chest wall mass following pneumonia caused by Streptococcus pneumonia in a six-month-old infant is reported. The case emphasises that children presenting with persistent fever and a painful chest wall mass following pneumonia should be investigated immediately as there might be an urgent need for surgery.

Predictive value of Thomsen-Friedenreich antigen activation for Streptococcus pneumoniae infection and severity in pediatric lobar pneumonia.

BACKGROUND: Most cases of complicated pneumonia in children are caused by pneumococcal infections. Thomsen-Friedenreich antigen (TA) is present on erythrocytes, platelets and glomeruli, and it can be activated during pneumococcal infection. The aim of this study was to investigate the predictive value of TA activation for pneumococcal infection and association with the severity of complicated pneumonia. MATERIALS AND METHODS: Patients with lobar pneumonia were routinely tested for TA at the Department of Pediatrics, Mackay Memorial Hospital from January 2010 to December 2015. We retrospectively reviewed and analyzed their charts and data including age, sex, etiology of infection, chest tube insertion or video-assisted thoracoscopic surgery, length of hospital stay, TA activation, white blood cell count and level of C reactive protein. RESULTS: A total of 142 children with lobar pneumonia were enrolled, including 35 with empyema, 31 with effusion, 11 with necrotizing pneumonia and four with lung abscess. Streptococcus pneumoniae was the most commonly identified pathogen. Twenty-two patients (15.4%) had activated TA, all of whom were infected with S. pneumoniae. TA activation had 100% specificity and 100% positive predictive value for pneumococcal infection. In the multivariate analysis in lobar pneumonia, TA activation (OR, 15.8; 95% CI, 3.0-83.5; p = 0.001), duration of fever before admission (OR, 1.2; 95% CI, 1.1-1.5; p = 0.013) and initial CRP level (OR, 1.1; 95% CI, 1.0-1.1; p = 0.004) were independent predictors of empyema. CONCLUSIONS: TA activation is a specific marker for pneumococcal pneumonia and might indicate higher risk for complicated pneumonia.

Quadruple valve infective endocarditis presenting with suspected Austrian syndrome: a case report and a case series of quadruple valve infective endocarditis.

OBJECTIVES: Austrian syndrome comprises the triad of pneumonia, meningitis, and endocarditis secondary to Streptococcus pneumonia. We present what we believe to be the first reported case of Austrian syndrome with quadruple heart valve involvement and review the literature detailing cases of quadruple valve infective endocarditis. CASE PRESENTATION AND RESULTS: A case is presented of a patient with radiographic evidence of a left lower lobe pneumonia. Sequential transthoracic followed by transesophageal echocardiogram done to evaluate the presence of a cardiac murmur revealed the presence of quadruple valve vegetations. Multiple blood cultures were persistently negative. The patient went on to develop seizures secondary to proven meningitis. Microbiological diagnosis was eventually established through positive Streptococcus pneumoniae antigen (Alere BinaxNOW®) from cerebrospinal fluid, establishing a presumptive clinical diagnosis of Austrian syndrome. A computerized PubMed search for reports of quadruple valve infective endocarditis and their references was collated. A total of 22 patients were found, including our patient. The median age of presentation was 47.5 years. Five patients had a history of intravenous drug abuse, another 5 had underlying congenital heart disease, and 1 had both. Two patients (9.1%) had 2 microorganisms isolated. Staphylococcus aureus and Streptococcus viridans (3 cases, 13.6% each) were the most commonly implicated microorganism. Heart failure was the commonest complication, afflicting 11 patients (50.0%). Ten patients (45.5%) underwent surgery. Overall case fatality rate was 50.0%. Cardiac surgery was of statistical significance in predicting survival (P = 0.009). CONCLUSION: Quadruple valve endocarditis is associated with a high mortality rate, and cardiac surgery may be protective.

Increased hypothalamic microglial activation after viral-induced pneumococcal lung infection is associated with excess serum amyloid A production.

BACKGROUND: It is well established that lung pathology and inflammation are more severe during respiratory infections complicated by the presence of both bacteria and viruses. Whilst co-infection can result in invasive pneumococcal disease and systemic inflammation, the neuroinflammatory consequences of co-infection are poorly characterised. METHODS: In this study, we utilised a mouse co-infection model involving Streptococcus pneumoniae (S. pneumoniae) and influenza A virus (IAV) lung infection, and we also isolated microglia for ex vivo stimulation with pneumococcus or serum amyloid A (SAA). RESULTS: Co-infection but not S. pneumoniae or IAV alone significantly increased the number of amoeboid-shaped microglia and expression of pro-inflammatory cytokines including tumour necrosis factor α (TNFα), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and C-C motif chemokine ligand-2 (CCL-2) in the hypothalamus. Pneumococcus was only detected in the hypothalamus of co-infected mice. In addition, the systemic inflammatory cytokines TNFα, IL-1ß and IL-6 were not elevated in co-infected mice relative to IAV-infected mice, whereas SAA levels were markedly increased in co-infected mice (p < 0.05). SAA and its functional receptor termed formyl peptide receptor 2 (Fpr2) transcript expression were also increased in the hypothalamus. In mouse primary microglia, recombinant SAA but not S. pneumoniae stimulated TNFα, IL-1ß, IL-6 and CCL-2 expression, and this response was completely blocked by the pro-resolving Fpr2 agonist aspirin-triggered resolvin D1 (AT-RvD1). CONCLUSIONS: In summary, lung co-infection increased the number of 'activated' amoeboid-shaped microglia and inflammatory cytokine expression in the hypothalamus. Whilst persistent pneumococcal brain infection was observed, SAA proved to be a much more potent stimulus of microglia than pneumococci, and this response was potently suppressed by the anti-inflammatory AT-RvD1. Targeting Fpr2 with pro-resolving eicosanoids such as AT-RvD1 may restore microglial homeostasis during severe respiratory infections.