Clinical Microbiology Newsletter最新文献

Onychomycosis is a fungal infection that can occur within the nails of the fingers and the toes. These infections can lead to discoloration and thickening of the nails, as well as separation of the nails from the bed and their splitting, and ultimately nail destruction. Although predominantly caused by dermatophytes, which have keratinolytic properties, several other groups of fungi can also cause this type of infection, including nondermatophyte molds (both hyaline and dematiaceous) and yeasts, such as Candida species. Proper identification of the etiologic agent is important, as it may influence the treatment of these infections. Here, we review the mycology of onychomycosis and describe recent changes in fungal taxonomy that have occurred with several of these fungi.

Diabetes mellitus is one of the most prevalent chronic diseases in the United States and is associated with a high incidence of infectious complications. These complications lead to increased morbidity, mortality, and utilization of the health care system by a large subset of the worldwide population. The mechanisms contributing to infection in a person living with diabetes are complex and include underlying pathology affecting physiologic functions ranging from adaptive immunity to skin integrity. In this review, we aim to summarize what is known about these pathologies. We highlight how common infections are unique and how certain unique infections are more common in persons with diabetes. Finally, we discuss the clinical presentations and diagnostic considerations pertinent to persons with diabetes.

Antimicrobial resistance (AMR) is a global health crisis, and the development of new antimicrobials is essential to reducing associated morbidity and mortality. Infections by multi-drug-resistant Gram-negative bacteria have been at the forefront of this AMR public health emergency, often overshadowing the importance of novel treatment options for multi-drug-resistant Gram-positive bacterial infections. Here, we introduce and review a number of antimicrobial agents with activity against clinically significant Gram-positive pathogens, including difficult-to-treat staphylococci, streptococci, enterococci, and Gram-positive anaerobes. We describe antimicrobial agents in late-stage development, those that are newly approved, and those with existing FDA-approved clinical indications for which more recently the FDA expanded approval for novel indications. Overall, the goal of this review is to provide clinical microbiologists, infectious disease physicians, and pharmacists with current, relevant information about novel antibiotic agents effective against Gram-positive bacteria.

Increasing rates of antibiotic resistance make selecting empiric therapy challenging for the treatment of sepsis and suspected bloodstream infections (BSIs). The time to initiation of effective therapy for BSIs is critical for positive patient outcomes. Recent advances in rapid diagnostics for the detection of BSIs directly from positive blood culture include rapid organism identification and rapid antimicrobial susceptibility testing (AST). Rapid AST methods include genotypic and phenotypic methods or a combination of both and provide important information to aid in the prompt initiation of effective therapy. Genotypic AST methods allow rapid direct detection of a resistance mechanism but may fail to accurately predict a full susceptibility profile, whereas phenotypic AST provides comprehensive results but is not rapid if conventional methods are used. Efforts to decrease the turnaround time of phenotypic AST are an important advancement for the treatment of BSIs. Here, we review currently available and in-development phenotypic methods for AST directly from positive blood culture and their potential benefits for antimicrobial stewardship and patient care.

Monkeypox virus (MPXV) has garnered recent attention as outbreaks are continually reported outside historic regions of endemicity in Africa. Consequently, MPXV is becoming routinely included in the differential diagnosis of rash illnesses, requiring clinicians and laboratorians alike to quickly adapt to a new public health emergency. This review discusses the epidemiology, clinical presentation, and laboratory testing of MPXV in the context of recent outbreaks.

The most common dimorphic fungi isolated from clinical specimens in North America are Coccidioides immitis, Coccidioides posadasii, Blastomyces dermatitidis species complex, and Histoplasma capsulatum. These organisms are typically definitively identified at reference or public health laboratories, as they are risk group 3 (RG3) pathogens requiring additional biosafety considerations compared to risk group 2 (RG2) pathogens. Reference and public health laboratories have been using organism-specific DNA probes since the early 1990s as the primary method of confirming the identification of morphologically suspect dimorphic fungi growing in culture. At the end of November 2021, manufacturing of these probes was discontinued, leaving clinical laboratories responsible for dimorphic fungus identification with the task of validating and implementing a new identification method for these pathogens. Here, we discuss alternatives to DNA probes for identification of Coccidioides spp., B. dermatitidis species complex, and H. capsulatum growing in culture, including the strengths and limitations of each method.