Invasive Streptococcus agalactiae (group B streptococcus) infection with toxic shock-like syndrome: A report of a fatal non-pregnant case and a review of the literature

Streptococcus agalactiae (group B streptococcus; GBS) is a Gram-positive coccus. It has emerged as a cause of significant infections in non-pregnant adults, particularly neonates and individuals aged 65 years or older, which can lead to fatal outcomes. Streptococcal toxic shock-like syndrome (STSS) is an acute illness, which is mainly caused by exotoxin-producing strains of Streptococcus pyogenes and may result in death. In this report, we present a fatal non-pregnant case of STSS induced by GBS in a 45-year-old healthy female. The patient presented with fever, polyarthralgia, myalgia, and skin erythema. Matrix Assisted Laser Desorption/Ionization‒Time of Flight Mass Spectrometry (MALDI-TOF-MS) and PCR identified GBS in colonies from her blood and urine cultures, and she was diagnosed with septicemia and STSS. On the sixth day of her illness, she died from acute respiratory distress syndrome and multiple organ dysfunction syndrome. Whole-genome sequencing revealed the presence of several virulence genes in the genome of the GBS strain detected in the blood cultures, which may have contributed to the development of STSS and the patient's death.

An incidentally discovered paraganglioma that caused sinus arrest after resection

Paragangliomas are neural-crest-derived nonepithelial neuroendocrine tumors distributed along the parasympathetic and sympathetic nerves. To our knowledge, no studies were reported regarding sinus arrest on day 4 after paraganglioma resection. A 66-year-old female patient with a history of pulmonary vein isolation visited our department for sigmoid colon cancer treatment. Enhanced computed tomography revealed an enhanced small nodule-like lymph node near the root of the inferior mesenteric artery. The patient underwent laparoscopic colectomy with regional lymph node dissection. Postoperatively, paroxysmal atrial fibrillation attacks developed, and the patient resumed oral medication. Additionally, sinus arrest after tachycardia developed. Changing the oral medication could maintain her circulatory dynamics. Pathological examination revealed that differentiated tubular adenocarcinoma infiltrated the submucosa. Immunohistochemically, the excised nodule as a lymph node was considered a functional paraganglioma. Our case indicates that paraganglioma resection and oral medication resumption may contribute to sinus arrest. When arrhythmias affecting the circulation occur perioperatively, the presence of a catecholamine-producing tumor should be considered in addition to cardiac disease. J. Med. Invest. 70 : 503-507, August, 2023.

Intra-familial transmission of Streptococcus dysgalactiae subsp. equisimilis (SDSE): A first case report and review of the literature

BACKGROUND

Concern about Streptococcus dysgalactiae infections has been increasing worldwide, and many cases of invasive infections have been reported. Streptococcus dysgalactiae has two main subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The epidemiology of invasive SDSE infections is not well understood, and the exact numbers of human SDSE infections are not known because standard laboratories are not able to identify Lancefield group C streptococci (GCS) or group G streptococci (GGS) to the species level. SDSE is often present in skin lesions, and sites of SDSE colonization and focal SDSE infections serve as the principal reservoirs for the transmission of skin and soft-tissue infections. Although the person-to-person transmission of S. pyogenes infections has been reported, the intra-familial transmission of SDSE has not been reported.

CASE PRESENTATION

We report two cases of cellulitis with bacteremia in a family. A 72-year-old female with cellulitis in her right lower extremity was hospitalized, and a 104-year-old male relative was hospitalized with cellulitis 2 days later. Two strains of Streptococcus dysgalactiae subsp. equisimilis were isolated from the blood of the patients. Single nucleotide polymorphism analysis of the bacterial genomes suggested that the two strains had the same origin. This is the first case report about the intra-familial transmission of Streptococcus dysgalactiae subsp. equisimilis.

CONCLUSIONS

This is the first case report about the intra-familial transmission of Streptococcus dysgalactiae subsp. equisimilis.

Morphological and genetic identification of fungal genus/species in formalin-fixed, paraffin-embedded specimens obtained from patients with histologically proven fungal infection

BACKGROUND

Although fungi are found relatively easily by microscopic examination of pathological samples, identification of fungal genus and species in pathological samples is not easy because the morphological features of fungi are similar among genera and species.

OBJECTIVES

A multiple real-time PCR was developed for identification of fungal genus/species, and morphological characterizations of fungi were analysed in pathological samples.

PATIENTS/METHODS

Seventy-five formalin-fixed paraffin-embedded (FFPE) samples morphologically proven to contain any fungus were examined. A multiple real-time PCR system was developed to identify 25 fungal genus/species in pathological samples. Morphology of fungus in the specimens was re-reviewed retrospectively based on the results of real-time PCR.

RESULTS

Real-time PCR identified fungal genus/species in 56 of 75 (74.6%) specimens with histologically proven fungal infection. In 53 specimens of filamentous fungi, Aspergillus spp. (22 specimens), Cladosporium (8), Scedosporium apiospermum (4), Malassezia sympodialis (1) and Candida albicans (1) were identified. Pseudohyphae of Candida were confused with filamentous fungus in a case. Morphological observation suggested differences in the presence of septated or non-septated hyphae, the filament size, and the branch angle among genus/species of filamentous fungi; however, genus/species was not able to be determined by their morphological features. In 22 specimens of yeasts, real-time PCR allowed for the identification of Candida albicans (12 specimens), Candida glabrata (2), Cladosporium (2), Scedosporium apiospermum (2), Pichia kudriavzevii (1) and Aspergillus sydowii (1).

CONCLUSIONS

These data suggest that it is difficult to identify fungal genus/species by morphological features alone. Real-time PCR is useful to identify fungal genus/species in pathological samples.

A case of protein-losing gastroenteropathy caused by systemic AA amyloidosis secondary to undifferentiated carcinoma of unknown primary origin

We report the case of a 61-year-old woman with Kartagener syndrome who presented with a 3-month history of chronic watery diarrhoea and severe hypoalbuminaemia. Histopathological examination of duodenum and large intestine biopsies showed amyloid A (AA) amyloid deposition. Scintigraphy and alpha-1 anti-trypsin clearance evaluations revealed protein-losing gastroenteropathy. Computed tomography with contrast and positron emission tomography showed a pelvic mass with multiple para-aortic lymph node enlargement. We suspected protein-losing gastroenteropathy secondary to AA amyloid produced related to malignant tumours. Following tumour resection, histopathological examination of the lesion revealed undifferentiated carcinoma of unknown origin. Postoperatively, the patient’s nutritional condition improved. There has been no recurrence of protein-losing gastroenteropathy 6 months postoperatively. This is the first report of protein-losing gastroenteropathy and AA amyloidosis secondary to undifferentiated carcinoma. Early recognition and intervention could increase the likelihood of amyloidosis remission.

Estimation of Arterial Mechanical Properties from Aortic and Tonometric Arterial Pressure Waveforms

Although arterial mechanical properties have been evaluated using arterial input impedance, the relative difficulty in accurate flow measurement made the value of impedance somewhat limited. To develop an alternative method to evaluate arterial mechanical properties, we analyzed the aortic pressure (AoP)-radial arterial pressure (RAP) relationship because of relative ease in obtaining peripheral pressure waveform by tonometry. In 8 patients we simultaneously recorded aortic root and radial arterial pressure waveforms. We calculated the transfer function from AoP to RAP. We then fitted the transfer function to a model of a lossless uniform elastic tube terminated with a modified Windkessel model. The fact that the model transfer function predicted AoP from RAP waveform with considerable accuracy indicated that the model represented the arterial mechanical properties well. We conclude that we can estimate the arterial mechanical properties by the pressure-pressure transfer function analysis.

Calcified Amorphous Tumor-Induced Acute Cerebral Infarction

We report the case of a 38-year-old woman who was admitted for acute cerebral infarction linked to a cardiac calcified amorphous tumor (CAT) and related mitral annular calcification (MAC). The cardiac mass was removed, and mitral valve replacement surgery was performed. Pathological examination revealed an amorphous accumulation of degenerating material within both lesions, indicating that build-up of calcium along the mitral annulus and subsequent rupture of the fibrotic tissue may be involved in the initiation and progression of CAT.

Mycotic pseudoaneurysm of a pulmonary artery branch caused by Cladosporium

We report the case of a 53-year-old male with a history of acute myelogenous leukemia, who suffered the rupturing of a right-sided pulmonary artery pseudoaneurysm combined with pneumonia. He underwent a right-sided lower lobectomy. The resected lung tissue demonstrated a mycotic pseudoaneurysm of a pulmonary artery branch together with a filamentous fungal infection. Pseudoaneurysms are caused by the breaching of all layers of a blood vessel wall. The extravasated blood is trapped by the surrounding extravascular tissue or clots. Cladosporium was detected during a polymerase chain reaction-based analysis followed by DNA sequencing of formalin-fixed paraffin-embedded lung tissue samples. Although previous cases of pulmonary artery pseudoaneurysms caused by fungal infections, e.g., Candida or Aspergillus sp., have been reported, to the best of our knowledge this is the first case to involve cladosporiosis.

Conserved sequences of BART and BHRF regions encoding viral microRNAs in Epstein-Barr virus-associated lymphoma

Objective

Epstein-Barr virus (EBV) encodes at least 25 pri-microRNAs (miRNAs) in two regions of its DNA genome, BART and BHRF. B95-8, an EBV reference strain, has a deletion in the BART region. However, no information is available on the deletions or mutations in the BART and BHRF regions in clinical samples of EBV-associated lymphoma.

Results

Nine DNA fragments encoding miR-BARTs and two coding miR-BHRF1s were amplified by PCR from DNA samples extracted from 16 cases of EBV-associated lymphoma. All the PCR products were sequenced directly. DNA fragments encoding miR-BARTs and miR-BHRF1-1 were successfully amplified from all samples. An adenine-to-guanine mutation in the DNA fragment encoding miR-BART2-3p was detected in four of the 16 cases, and a cytosine-to-thymidine mutation in the DNA fragment encoding miR-BART11-3p was detected in one of the 16 samples. These mutations were not associated with any histological categories of lymphoma. In conclusion, mutations were rarely observed in the DNA encoding viral miRNAs in cases of lymphoma. This suggests that the DNA sequences of EBV-encoded miR-BARTs and miR-BHRF1-1 are conserved in EBV-associated lymphoma.

Post-mortem detection of bacteremia using pairs of blood culture samples

AIM

The objective of this study was to assess the utility of examining pairs of blood culture samples obtained from separate sites (both ventricles or the aorta and vena cava) for detecting bacteremia in the post-mortem setting.

METHODS

Autopsy cases in which bacterial species were isolated from blood cultures were identified over a 4-year period. Ante-mortem and post-mortem records and the findings of pathological examinations were reviewed.

RESULTS

Overall, 23 bacterial species were detected in 18 autopsy cases. E. coli was the most commonly detected species (5 cases, 27.8%), followed by S. aureus and K. pneumoniae, respectively. Seven of the detected bacterial species (3 cases, 16.7%) were obligate anaerobes (Clostridium spp. and Bacteroides spp.). Among the 3 cases involving obligate anaerobes, multiple bacterial species were detected in 2 cases. Clinically, 2 of the 18 patients in which bacteria were detected were treated for significant infections (urosepsis, pneumonia, and catheter-related bloodstream infection) before their deaths. Seven cases exhibited evidence of significant infection during the post-mortem pathological examination. The differences between the aerobic and anaerobic bacteria positivity rates of the single and paired blood culture samples were significant (aerobic: p=0.013 and anaerobic: p=0.018).

CONCLUSION

Analyzing pairs of blood culture samples obtained from separate sites is useful for detecting bacteremia during post-mortem examinations.

Translational neurocardiology: preclinical models and cardioneural integrative aspects

Neuronal elements distributed throughout the cardiac nervous system, from the level of the insular cortex to the intrinsic cardiac nervous system, are in constant communication with one another to ensure that cardiac output matches the dynamic process of regional blood flow demand. Neural elements in their various 'levels' become differentially recruited in the transduction of sensory inputs arising from the heart, major vessels, other visceral organs and somatic structures to optimize neuronal coordination of regional cardiac function. This White Paper will review the relevant aspects of the structural and functional organization for autonomic control of the heart in normal conditions, how these systems remodel/adapt during cardiac disease, and finally how such knowledge can be leveraged in the evolving realm of autonomic regulation therapy for cardiac therapeutics.

Exercise training plus calorie restriction causes synergistic protection against cognitive decline via up-regulation of BDNF in hippocampus of stroke-prone hypertensive rats

One of the important organ damage of hypertension is cognitive decline. Cognitive function is determined by the function of hippocampus, and previous studies have suggested that the decrease in brain-derived neurotrophic factor (BDNF) in the hippocampus causes cognitive decline. Protection against cognitive decline is reported not only in pharmacological therapy but also in exercise training or calorie restriction. The aim of the present study was to determine whether exercise training plus calorie restriction cause synergistic protection against cognitive decline via BDNF in the hippocampus or not. Exercise training for 28 days improved cognitive decline determined by Morris water maze test via up-regulation of BDNF in the hippocampus of stroke-prone spontaneously hypertensive rats, whereas calorie restriction for 28 days did not. However, exercise training plus calorie restriction causes the protection against cognitive decline to a greater extent than exercise training alone. In conclusion, exercise training plus calorie restriction causes synergistic protection against cognitive decline via up-regulation of BDNF in the hippocampus of stroke-prone hypertensive rats.