Potential of Flow Cytometric Approaches for Rapid Microbial Detection and Chracterization in the Food Industry—A Review

As microbial contamination is persistent within the food and bioindustries and foodborne infections are still a significant cause of death, the detection, monitoring, and characterization of pathogens and spoilage microorganisms are of great importance. However, the current methods do not meet all relevant criteria. They either show (i) inadequate sensitivity, rapidity, and effectiveness; (ii) a high workload and time requirement; or (iii) difficulties in differentiating between viable and non-viable cells. Flow cytometry (FCM) represents an approach to overcome such limitations. Thus, this comprehensive literature review focuses on the potential of FCM and fluorescence in situ hybridization (FISH) for food and bioindustry applications. First, the principles of FCM and FISH and basic staining methods are discussed, and critical areas for microbial contamination, including abiotic and biotic surfaces, water, and air, are characterized. State-of-the-art non-specific FCM and specific FISH approaches are described, and their limitations are highlighted. One such limitation is the use of toxic and mutagenic fluorochromes and probes. Alternative staining and hybridization approaches are presented, along with other strategies to overcome the current challenges. Further research needs are outlined in order to make FCM and FISH even more suitable monitoring and detection tools for food quality and safety and environmental and clinical approaches.

Acute Effects of Ambient Air Pollution on Lower Respiratory Infections in Guangzhou Children of China

Daily concentrations of air pollution are associated with lower respiratory diseases. We investigated the short-term association of ambient air pollution with daily hospital admissions due to pneumonia among children aged 0−17 in Guangzhou city of China. Ambient air pollutants were all positively associated with children hospital admissions due to pneumonia of all ages. Significant associations were found for air pollutants except for inhalable particulate matter (PM) \(\le\)10 µm in aerodynamic diameter (PM10) in children of all ages. Increments of an interquartile range (IQR) (279.10µg/m3 and 28.42µg/m3, respectively) in the 7-day-average level of carbon monoxide (CO) and nitrogen dioxide (NO2) were associated with a 26.17% (95% confidence interval (CI) 1.40%-56.98%) and 25.09% (95%CI 0.54%-55.64%) increase in pneumonia hospitalizations for children aged 6−17, respectively. An IQR increase in CO concentrations was associated with a 15.15% (95%CI 4.34%-27.08%) increase in pneumonia hospitalizations for children aged 1−5. Daily cases of microbial detection for pneumonia were positively associated with daily NO2 concentration. The pneumonia hospitalizations due to Mycoplasma pneumonia, Flu A virus and Flu B virus, the predominant pathogenic microorganisms detected in children aged 0−5 are apparently associated with levels of PMs, CO, NO2 and O3.

Fatal septic shock due to Capnocytophaga canimorsus bacteremia masquerading as COVID-19 pneumonia - a case report

Background Capnocytophaga canimorsus (C. canimorsus) infections are rare and usually present with unspecific symptoms, which can eventually end in fatal septic shock and multiorgan failure. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) related coronavirus disease 2019 (COVID-19), on the other hand, is predominantly characterized by acute respiratory failure, although other organ complications can occur. Both infectious diseases have in common that hyperinflammation with a cytokine storm can occur. While microbial detection of C. canimorsus in blood cultures can take over 48 h, diagnosis of SARS-CoV-2 is facilitated by a widely available rapid antigen diagnostic test (Ag-RDT) the results of which are available within half an hour. These Ag-RDT results are commonly verified by a nucleic acid amplification test (NAAT), whose results are only available after a further 24 h. Case presentation A 68-year-old male patient with the diagnosis of COVID-19 pneumonia was referred to our Intensive Care Unit (ICU) from another hospital after testing positive on an Ag-RDT. While the initial therapy was focused on COVID-19, the patient developed a fulminant septic shock within a few hours after admission to the ICU, unresponsive to maximum treatment. SARS-CoV-2 NAATs were negative, but bacteremia of C. canimorsus was diagnosed post-mortem. Further anamnestic information suggest that a small skin injury caused by a dog leash or the subsequent contact of this injury with the patient’s dog could be the possible point of entry for these bacteria. Conclusion During the acute phase of hyperinflammation and cytokine storm, laboratory results can resemble both, sepsis of bacterial origin or SARS-CoV-2. This means that even in the light of a global SARS-CoV-2 pandemic, where this diagnosis provides the most salient train of thoughts, differential diagnoses must be considered. Ag-RDT can contribute to early detection of a SARS-CoV-2 infection, but false-positive results may cause fixation errors with severe consequences for patient outcome.

Liver Abscess Caused by Fusobacterium nucleatum: A Case Report

Introduction: Pyogenic liver abscess (PLA) is a serious infectious disease of the liver. PLA caused by Fusobacterium nucleatum is extremely rare. Here we report the first case of liver abscess caused by F. nucleatum in China. Case Presentation: The case was a 34-year-old female patient admitted to the hospital due to high fever. The diagnosis of liver abscess was confirmed by imaging studies and liver puncture. We finally confirmed the pathogen as F. nucleatum by next-generation sequencing (NGS). After the targeted anti-infective treatment, the patient recovered and discharged. Conclusions: As a new microbial detection method, NGS can still help in clinical practice. In addition, to improve the positive rate of anaerobic bacteria culture, we should pay attention to avoid contact with air in the process of specimen collection when the pathogenic bacteria are suspected to be anaerobic bacteria.