Streptococcus constellatus Causing Empyema and Sepsis, Necessitating Early Surgical Decortication

Utilizing metagenomic next-generation sequencing for pathogen detection and diagnosis in lower respiratory tract infections in real-world clinical practice

BACKGROUND

Infectious etiologies of lower respiratory tract infections (LRTIs) by the conventional microbiology tests (CMTs) can be challenging. Metagenomic next-generation sequencing (mNGS) has great potential in clinical use for its comprehensiveness in identifying pathogens, particularly those difficult-to-culture organisms.

METHODS

We analyzed a total of 205 clinical samples from 201 patients with suspected LRTIs using mNGS in parallel with CMTs. mNGS results were used to guide treatment adjustments for patients who had negative CMT results. The efficacy of treatment was subsequently evaluated in these patients.

RESULTS

mNGS-detected microorganisms in 91.7% (188/205) of the clinical samples, whereas CMTs demonstrated a lower detection rate, identifying microorganisms in only 37.6% (77/205) of samples. Compared to CMT results, mNGS exhibited a detection sensitivity of 93.5% and 95.4% in all 205 clinical samples and 180 bronchoalveolar lavage fluid (BALF) samples, respectively. A total of 114 patients (114/201; 56.7%) showed negative CMT results, among which 92 received treatment adjustments guided by their positive mNGS results. Notably, 67.4% (62/92) of patients demonstrated effective treatment, while 25% (23/92) experienced a stabilized condition. Subgroup analysis of cancer patients revealed that 41.9% (13/31) exhibited an effective response to treatment, and 35.5% (11/31) maintained a stable condition following medication adjustments guided by mNGS.

CONCLUSION

mNGS demonstrated great potential in identifying microorganisms of clinical significance in LRTIs. The rapid turnaround time and reduced susceptibility to the impact of antimicrobial administration make mNGS a valuable supplementary tool for diagnosis and treatment decision-making for suspected LRTIs in clinical practice.

Successful Interventional Treatment of Pyopneumothorax Caused by Streptococcus constellatus Associated with Hashimoto's Thyroiditis: A Case Report and Literature Review

Background

Streptococcus constellatus rarely causes pyopneumothorax, which is a serious state and requires a surgery. However, not every patient can tolerate surgery and individualized solutions are needed. Furthermore, many known situations are risk factors of S. constellatus infection, but S. constellatus pyopneumothorax associated with Hashimoto's thyroiditis has not been reported.

Case Presentation

We present the case of a 74-year-old male with multiple encapsulated pyopneumothorax caused by S. constellatus. Given his respiratory failure, we provided two-stage percutaneous right empyema radiography for catheter drainage in the radiology interventional department instead of surgery. Moreover, an occult Hashimoto's thyroiditis was discovered in the patient, which was possibly associated with S. constellatus pyopneumothorax. Levothyroxine was administered to improve his situation.

Conclusion

To our knowledge, it is the first case described in this context. We provided an alternative treatment for S. constellatus encapsulated pyopneumothorax in patient who might not tolerate surgery. We also revealed the possible relationship between S. constellatus pyopneumothorax and Hashimoto's thyroiditis.

Intra-abdominal abscess caused by Streptococcus constellatus in an immunocompetent patient

Streptococcus constellatus is a Gram-positive commensal bacterium of the oropharyngeal, gastrointestinal and urogenital flora. It can cause abscesses in different parts of the body, especially in immunocompromised patients. We present the clinical case of a 33-year-old female patient with a previous history of one anastomosis gastric bypass, among others. The patient was hospitalized two years after surgery for peritonitis secondary to a perforation in the biliopancreatic loop, underwent laparoscopic surgery and was hospitalised for two weeks. Fifteen days after being discharged from the hospital, she went to the emergency service for abdominal pain and fever. An abdominal and pelvic computerized tomography (CT) scan showed a multiloculated pelvic collection with thickened and hypercapillary walls.

The Clinical Features and Management of Empyema Caused by Streptococcus constellatus

Background

Streptococcus constellatus, a commensal, plays an important role in purulent infections. It has been reported as aggressive pathogen causing pleural empyema. But the role of S. constellatus in empyema has not been taken seriously. There are no studies about clinical characteristics of empyema caused by S. constellatus domestically and abroad. This study aimed to explore the clinical features and management of empyema caused by S. constellatus.

Methods

A retrospective review of 9 patients diagnosed with empyema caused by S. constellatus in a hospital between January 2010 and August 2021 was performed.

Results

S. constellatus empyema were mostly seen in old males (66.7%) with comorbid diseases. The high-risk factors include diabetes mellitus, oral infection, and oral surgery. All were unilateral encapsulated empyema (right-side, 55.6%), diagnosed with pneumonia (bilateral pneumonia, 88.9%; ipsilateral lung abscess, 44.4%). 33.3% of patients had S. constellatus and anaerobes co-isolated. S. constellatus were sensitive to penicillin G, linezolid, levofloxacin, vancomycin, ceftriaxone, and chloramphenicol, resistant to erythromycin, tetracycline, and clindamycin. 33.3% of the patients needed ventilator support. The primary treatment to S. constellatus empyema was timely pus drainage, intravenous antibiotics, and enough nutrition support, intrapleural fibrinolytics and surgery (VAST recommended first) in necessity.

Conclusion

S. constellatus may cause pneumonia and lung abscess first and then spread to cause empyema mainly in old males with comorbid diseases. S. constellatus often co-isolated with anaerobes in empyema. Antibiotics should cover simultaneously both S. constellatus and anaerobes.

The Clinical View on Streptococcus anginosus Group – Opportunistic Pathogens Coming Out of Hiding

Three distinct streptococcal species: Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, belonging to the Streptococcus anginosus group (SAG), also known as Streptococcus milleri group, have been attracting clinicians and microbiologists, not only as oral commensals but also as opportunistic pathogens. For years they have been simply classified as so called viridans streptococci, and distinct species were not associated with particular clinical manifestations. Therefore, description of SAG members are clearly underrepresented in the literature, compared to other medically relevant streptococci. However, the increasing number of reports of life-threatening infections caused by SAG indicates their emerging pathogenicity. The improved clinical data generated with the application of modern molecular diagnostic techniques allow for precise identification of individual species belonging to SAG. This review summarizes clinical reports on SAG infections and systematizes data on the occurrence of individual species at the site of infection. We also discuss the issue of proper microbiological diagnostics, which is crucial for further clinical treatment.

Factors Affecting Patients with Concurrent Deep Neck Infection and Cervical Necrotizing Fasciitis

Deep neck infection (DNI) is a severe disease of the deep neck spaces, which has the potential for airway obstruction. Cervical necrotizing fasciitis (CNF) is a fatal infection of the diffuse soft tissues and fascia with a high mortality rate. This study investigated risk factors in patients with concurrent DNI and CNF. A total of 556 patients with DNI were included in this study between August 2016 and December 2021. Among these patients, 31 had concurrent DNI and CNF. The relevant clinical variables were assessed. In univariate analysis, age (> 60 years, odds ratio (OR) = 2.491, p = 0.014), C-reactive protein (CRP, OR = 1.007, p < 0.001), blood sugar (OR = 1.007, p < 0.001), and diabetes mellitus (DM, OR = 4.017, p < 0.001) were significant risk factors for concurrent DNI and CNF. In multivariate analysis, CRP (OR = 1.006, p < 0.001) and blood sugar (OR = 1.006, p = 0.002) were independent risk factors in patients with concurrent DNI and CNF. There were significant differences in the length of hospital stay and therapeutic management (intubation, tracheostomy, incision and drainage) between DNI patients with and without CNF (all p < 0.05). While there were no differences in pathogens between the DNI alone and concurrent DNI and CNF groups (all p > 0.05), the rate of specific pathogen non-growth from blood cultures was 16.95% (89/525) in the DNI alone group, in contrast to 0% (0/31) in the concurrent DNI and CNF group (p = 0.008). Higher CRP and blood sugar levels were independent risk factors for the concurrence of DNI and CNF. With regard to prognosis, there were significant differences in the length of hospital stay and therapeutic management between the groups with and without CNF. While there were no significant differences in pathogens (all p > 0.05), no cases in the concurrent DNI and CNF group showed specific pathogen non-growth, in contrast to 89/525 patients in the group with DNI alone.

Distribution, Diversity and Roles of CRISPR-Cas Systems in Human and Animal Pathogenic Streptococci

Streptococci form a wide group of bacteria and are involved in both human and animal pathologies. Among pathogenic isolates, differences have been highlighted especially concerning their adaptation and virulence profiles. CRISPR-Cas systems have been identified in bacteria and many streptococci harbor one or more systems, particularly subtypes I-C, II-A, and III-A. Since the demonstration that CRISPR-Cas act as an adaptive immune system in Streptococcus thermophilus, a lactic bacteria, the diversity and role of CRISPR-Cas were extended to many germs and functions were enlarged. Among those, the genome editing tool based on the properties of Cas endonucleases is used worldwide, and the recent attribution of the Nobel Prize illustrates the importance of this tool in the scientific world. Another application is CRISPR loci analysis, which allows to easily characterize isolates in order to understand the interactions of bacteria with their environment and visualize species evolution. In this review, we focused on the distribution, diversity and roles of CRISPR-Cas systems in the main pathogenic streptococci.

Factors Affecting Patients with Concurrent Deep Neck Infection and Acute Epiglottitis

Deep neck infection (DNI) is a serious disease of deep neck spaces that can lead to morbidities and mortality. Acute epiglottitis (AE) is a severe infection of the epiglottis, which can lead to airway obstruction. However, there have been no studies of risk factors in patients with concurrent DNI and AE. This study was performed to investigate this issue. A total of 502 subjects with DNI were enrolled in the study between June 2016 and August 2021. Among these patients, 30 had concurrent DNI and AE. The relevant clinical variables were assessed. In a univariate analysis, involvement of the parapharyngeal space (OR = 21.50, 95% CI: 2.905–158.7, p < 0.001) and involvement of the submandibular space (OR = 2.064, 95% CI: 0.961–4.434, p < 0.001) were significant risk factors for concurrent DNI and AE. In a multivariate analysis, involvement of the parapharyngeal space (OR = 23.69, 95% CI: 3.187–175.4, p = 0.002) and involvement of the submandibular space (OR = 2.465, 95% CI: 1.131–5.375, p < 0.023) were independent risk factors for patients with concurrent DNI and AE. There were no differences in pathogens, therapeutic managements (tracheostomy, intubation, surgical drainage), or hospital staying period between the 30 patients with concurrent DNI and AE and the 472 patients with DNI alone (all p > 0.05). However, we believe it is significant that DNI and AE are concurrent because both DNI and AE potentially cause airway obstruction, and concurrence of these two diseases make airway protection more difficult. The infections in critical spaces may cause the coincidence of these two diseases. Involvement of the parapharyngeal space and involvement of the submandibular space were independent risk factors associated with concurrent DNI and AE. There were no differences in pathogens between the concurrent DNI and AE group and the DNI alone group.