Cold tolerance in Campylobacter jejuni and its impact on food safety.

Campylobacter jejuni is a major cause of foodborne illnesses worldwide and is primarily transmitted to humans through contaminated poultry meat. To control this pathogen, it is critical to understand its cold tolerance because poultry products are usually distributed in the cold chain. However, there is limited information regarding how this thermotolerant, microaerophilic pathogen can survive in cold and aerobic environments in the poultry cold chain. In this study, we investigated the cold tolerance of C. jejuni by measuring the viability of 90 C. jejuni strains isolated from retail raw chicken at 4 °C under aerobic and microaerobic conditions. Despite the microaerophilic nature of C. jejuni, under aerobic conditions, C. jejuni exhibited higher viability at 4 °C and required an extended inactivation time compared to microaerobic conditions. Some strains were highly tolerant to refrigeration temperatures and exhibited increased survival at 4 °C. These cold-tolerant strains mostly belonged to multilocus sequence typing (MLST) clonal complex (CC)-21 and CC-443, indicating that cold tolerance is associated with the phylogeny of C. jejuni. Notably, cold-tolerant strains had an increased probability of illness and were more likely to cause human infections due to their extended survival on refrigerated chicken meat compared to those sensitive to cold stress. Furthermore, the majority of cold-tolerant strains exhibited elevated aerotolerance, indicating that cold tolerance is related to aerotolerance. These findings suggest that refrigeration of chicken meat under aerobic conditions may not be effective at controlling C. jejuni and that cold-tolerant C. jejuni can pose an increased risk to food safety.

Tuberculous Pericarditis Mimicking a Malignant Pericardial Tumor: A Case Report.

Tuberculous pericarditis is an extrapulmonary manifestation of tuberculosis that is most commonly associated with pericardial thickening, effusion, and calcification. We present a case of tuberculous pericarditis mimicking a malignant pericardial tumor in a 77-year-old male. CT revealed an irregular and nodular pericardial thickening. MRI revealed high signal intensity on T1-weighted fat-suppressed images and peripheral rim enhancement after gadolinium administration. MRI can be helpful in determining the differential diagnoses in cases of tuberculous pericarditis with nonspecific imaging findings.

Glomerulonephritis following COVID-19 infection or vaccination: a multicenter study in South Korea.

BACKGROUND: Despite the widespread impact of the severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019, COVID-19) and vaccination in South Korea, our understanding of kidney diseases following these events remains limited. We aimed to address this gap by investigating the characteristics of glomerular diseases following the COVID-19 infection and vaccination in South Korea. METHODS: Data from multiple centers were used to identify de novo glomerulonephritis (GN) cases with suspected onset following COVID-19 infection or vaccination. Retrospective surveys were used to determine the COVID-19-related histories of patients who were initially not implicated. Bayesian structural time series and autoregressive integrated moving average models were used to determine causality. RESULTS: Glomerular diseases occurred shortly after the infection or vaccination. The most prevalent postinfection GN was podocytopathy (42.9%), comprising primary focal segmental glomerulosclerosis and minimal change disease, whereas postvaccination GN mainly included immunoglobulin A nephropathy (IgAN; 57.9%) and Henoch-Schönlein purpura nephritis (HSP; 15.8%). No patient progressed to end-stage kidney disease. Among the patients who were initially not implicated, nine patients with IgAN/HSP were recently vaccinated against COVID-19. The proportion of glomerular diseases changed during the pandemic in South Korea, with an increase in acute interstitial nephritis and a decrease in pauci-immune crescentic GN. CONCLUSION: This study showed the characteristics of GNs following COVID-19 infection or vaccination in South Korea. Understanding these associations is crucial for developing effective patient management and vaccination strategies. Further investigation is required to fully comprehend COVID-19's impact on GN.

Impact of nonspecific allograft biopsy findings in symptomatic kidney transplant recipients.

A for-cause biopsy is performed to diagnose the cause of allograft dysfunction in kidney transplantation. We occasionally encounter ambiguous biopsy results in symptomatic kidney transplant recipients. Yet, the allograft survival outcome in symptomatic recipients with nonspecific allograft biopsy findings remains unclear. The purpose of this study was to analyze the impact of nonspecific for-cause biopsy findings in symptomatic kidney transplant recipients. We retrospectively collected records from 773 kidney transplant recipients between January 2008 and October 2021. The characteristics of transplant recipients with nonspecific findings in the first for-cause biopsy were analyzed. Nonspecific allograft biopsy findings were defined as other biopsy findings excluding rejection, borderline rejection, calcineurin inhibitor toxicity, infection, glomerulonephritis, and diabetic nephropathy. The graft outcome was compared between recipients who had never undergone a for-cause biopsy and those who had a first for-cause biopsy with nonspecific findings. The graft survival in recipients with nonspecific for-cause biopsy findings was comparable to that in recipients who did not require the for-cause biopsy before and after propensity score matching. Even in symptomatic kidney transplant recipients, nonspecific allograft biopsy findings might not be a poor prognostic factor for allograft survival compared to recipients who did not require the for-cause biopsy.