Clinical Microbiology Newsletter最新文献

Helicobacter pylori infection is a widespread worldwide infection that is the main cause of chronic gastritis and peptic ulcer disease. Accurate diagnosis is crucial for control and eradication of the infection. A greater need for effective management is looming due to increasing drug resistance. This review summarizes methods for H. pylori diagnostic testing and the algorithm for a clinically based diagnostic approach. In addition, cumulative antibiogram data are presented and demonstrate resistance patterns in the United States.

The global report on antibiotic resistance by the World Health Organization features the burden of antimicrobial resistance and the emerging risk of a post-antibiotic era, where therapeutic options will no longer exist for previously treatable diseases. The search for alternative avenues to combat multidrug-resistant (MDR) pathogens has sparked interest in the use of bacteriophages for the treatment of bacterial infections. The unique ability of bacteriophages to infect and kill bacteria without affecting mammalian cells makes them a promising avenue as biocontrol agents against bacterial pathogens. Phage therapy in both animal and human models has shown promising results. Further, the phage-derived proteins (lytic enzymes), such as endolysins, that are the key weapons used by phages to degrade the bacterial cell have been explored by the scientific community as viable therapeutic options themselves. This review focuses on the prospects of phage therapy; an overview of diverse phages isolated against MDR pathogens; phage-derived proteins as antibacterial agents; phage cocktail development; phage and antibiotic combinational therapy; and the application of phages as biocontrol agents in agriculture, veterinary science, synthetic biology, and aquaculture. The review emphasizes the therapeutic use of phages and how they might be applied on a large scale if certain limitations and challenges can be overcome.

Direct-to-consumer (DTC) testing continues to be a subject of debate throughout the medical community. DTC testing may be viewed as expanding access to health care. Additionally, caution is needed in defining the role of DTC testing in the overall health care continuum of the consumer, particularly with limited provider resources. The recent COVID-19 pandemic resulted in a shift of consumer health care expectations and triggered providers to restructure their health care delivery services to create a more consolidated care model. There are several benefits from DTC testing that can help address this new restructure of health care, such as easy access to an available product and decreased person-to-person contact. However, there have been controversies regarding ethical considerations, appropriate specimen sampling, and evidence-based practices. This article provides an overview of DTC testing, advantages and concerns, considerations around infectious disease, and the potential role of the clinical laboratory to ensure safe and effective DTC testing services.

Melioidosis is a tropical disease caused by the Gram-negative bacillus Burkholderia pseudomallei. High rates of mortality among acute melioidosis survivors remain an unresolved problem and require prompt and appropriate diagnosis and treatment. Currently, the diagnosis relies on conventional methods, including culture, Gram stain, and biochemical testing. However, a reliable point-of-care test could enable earlier treatment and improve outcomes. Several immunological and molecular assays have been developed to overcome the limitations of conventional methods and to improve the efficiency of detection. Genotyping assays have played an important role in tracking the source of acquired B. pseudomallei infection and predicted its molecular epidemiology. Here, we review currently applied diagnostic protocols and treatment regimens for melioidosis and provide updates with respect to future diagnostic methods for the pathogen.

The recent emergence of additional novel tick-borne viruses with the potential to cause severe disease is alarming. An awareness of the nature of these viruses, their transmitting vectors and geographical distribution, and the clinical presentations of associated infections is essential when considering these pathogens in the differential diagnoses. Currently, limited surveillance and inadequate diagnostic approaches limit a complete understanding of the spread of emerging tick-borne viruses. This article focuses on three emerging tick-borne viruses; Powassan, Heartland, and Bourbon.

Rapid diagnosis of tuberculosis (TB) and identification of antimicrobial resistance (AR) are critical to improving patient outcomes, especially for multidrug- and extensively drug-resistant TB (DR-TB) infections. Diagnosis can take weeks with traditional culture and growth-based antimicrobial susceptibility testing, delaying appropriate treatment, impacting transmission of resistant strains, and leading to additional health care costs. Next-generation sequencing (NGS) techniques are revolutionizing the diagnostic laboratory and provide rapid, comprehensive, and accurate detection of AR in one test. With NGS, the whole genome can be sequenced in as little as 4 days from identification of TB in a positive culture. Subsequent bioinformatic analysis of sequence data assesses nucleotide changes compared to a wild-type reference genome and can identify mutations known to cause AR. Additionally, data can be analyzed to determine the species and provide a genotype. Targeted NGS methods designed to detect DR-TB directly from clinical specimens hold promise for the future.

New infectious disease diagnostics are being introduced into clinical practice at high rates. For tests that are better, faster, and less expensive than what came before, adoption is easy. However, many new tests, though faster than conventional diagnostics, are more expensive. Whether they will add value to patient care must be evaluated and can best be assessed by randomized controlled clinical trials (RCTs). Here, an overview of RCTs of new blood culture diagnostics is presented. Operational logistics of executing RCTs of new diagnostics are presented based on the authors' experience. For tests that facilitate appropriate use of antibiotics, involvement of an antimicrobial stewardship team in the associated clinical trial is important.

The human and organizational burdens of sepsis can be reduced by early recognition, diagnosis, therapy, and systems that support more effective management. The World Health Organization's (WHO's) 2020 Global Report on the Epidemiology and Burden of Sepsis will add importance to the clinical laboratory's role of monitoring blood culture metrics. The report details strategies for future efforts to characterize the global impact of sepsis more accurately, to improve the characterization of and differences in epidemiology, and to make estimates of disease burden more accurate. As the WHO is working toward improved global sepsis monitoring, re-assessment of the way clinical laboratories can contribute to this effort are long overdue at the local, national, and global levels.

Clinical laboratory dogma describes the importance of blood cultures (BCs) and optimization of BC processes, with documented impact on patient care. The BC is considered a first-line investigation for the microbiological diagnosis of sepsis, bacteremia, and fungemia and can detect a wide variety of microorganisms at a relatively low cost. Once microbes are detected in BC broth, subcultures yield microbial colonies for subsequent identification and antimicrobial susceptibility testing, and information is incorporated into the final BC result. However, the impact of BCs and the speed at which BCs are collected, incubated, and reported are minimized in the “surviving sepsis” literature, except for BC collection prior to the administration of antibiotics. Most hospital quality efforts focus on compliance with the 1-, 3-, and 6-h sepsis bundles with limited focus on the contribution of microbiology's role in rapid incubation, pathogen reporting, and other diagnostics that drive antimicrobial de-escalation and escalation protocols.

Clinical microbiology and laboratory medicine bear responsibility to ensure that BCs are collected properly and in a timely manner; that they are rapidly transported to the laboratory and incubated quickly; and that results are achieved and reported in a timely, reproducible, and accurate fashion. The quality metrics we discuss are not all required by inspection agencies; however, considering the initiatives to reduce the human cost of sepsis, attention to best practices is useful to optimize BC performance and BC yield. Examples of blood culture quality monitors and metrics are listed for laboratory consideration. Each laboratory may have unique situations in which one or more of the monitors may prove to be useful.