Faculty Bibliography

Rapid molecular assays guiding treatment of methicillin-resistant Staphylococcus aureus (MRSA) detect SCCmec (Xpert) or the SCCmec-orfX junction (BCID2). Sequence variation in this region can disrupt primer binding, yielding false-negative results. Investigation of a missed bloodstream infection linked escape to a CRISPR-Cas-associated SCCmec variant, leading to identification of 64 variants from 45 patients-2% of 2,432 screened. Misdiagnosis was restricted to clonal complex 5, a hospital-associated lineage; 11 of 40 SCCmec/junctions evaded detection by BCID2 or Xpert. Variants had mecA instability and circulated in healthcare settings. Our findings reveal a unique escape mechanism and underscore a threat to diagnostic accuracy.

Two unvaccinated infants residing in the same borough of New York, New York, USA, had Haemophilus influenzae type b meningitis develop 1 year apart. Whole-genome sequencing and phylogenetic analysis revealed the isolates shared a previously undescribed multilocus sequence type and were more closely related to each other than to other sequenced strains.

Syphilis screening during pregnancy is essential to prevent congenital syphilis, yet diagnostic challenges arise when clinical presentation, serologic results, and pathologic examination are discordant. We report the case of a 39-year-old pregnant patient with a reactive enzyme immunoassay (EIA) at delivery, despite prior nonreactive syphilis serologies and a negative confirmatory test postpartum. Placental examination revealed multiple intervillous abscesses and chronic villitis, raising concern for congenital syphilis. However, immunohistochemistry (IHC) for Treponema pallidum yielded conflicting results across laboratories. Despite the lack of confirmed maternal infection, the neonate underwent a full congenital syphilis evaluation and received penicillin treatment. This case highlights the complexities of interpreting isolated positive treponemal tests, the limitations of placental pathology in syphilis diagnosis, and the need for standardized management algorithms to prevent misclassification, overtreatment, and undue emotional and healthcare burden. Interdisciplinary communication and rapid confirmatory testing are critical to optimizing maternal and neonatal outcomes.

Inappropriate ordering practices, either under or over ordering of diagnostic tests, are recognized problems with possible negative downstream consequences. As the menu of clinical tests, especially molecular tests grows, it is becoming increasingly important to provide guidance to providers on the appropriate utilization. Diagnostic stewardship programs have been established at many institutions to help direct the appropriate utilization of laboratory testing to ultimately guide patient management and treatment decisions. Many molecular tests have now received Clinical Laboratory Improvement Amendments (CLIA)-waived status for use in a point-of-care (POC) setting; however, parallel diagnostic stewardship programs have not been established to help guide providers on how best to use these tests. In this article, we will discuss the available molecular POC tests and opportunities and challenges for establishing diagnostic stewardship programs for molecular testing performed in the POC setting.

We performed a retrospective survey of non-Candida albicans candidemia in patients with cancer, including those with solid tumors and those with hematological malignancies as well as transplants patients both, solid-organ transplant recipients and hematopoietic stem cell transplant recipients. The study was performed at two healthcare centers in New York City and covered the years 2018-2022. A total of 292 patients (318 isolates) were included in the study. In order of frequency, C. glabrata (38%) was the most common species recovered, followed by C. parapsilosis (19.2%), C. tropicalis (12.6%), C. krusei (10.7%), C. lusitaniae (5.7%), and C. guilliermondii (4.4%). Micafungin was the most common antifungal treatment and 18.5% of patients were on antifungal prophylaxis. The 30-day crude mortality was 40%. 4.5% of patients had more than one non-albicans species detected. In conclusion, this study represents one of the largest surveys of non-albicans species in cancer and transplant patients and provides data on the current epidemiology of these Candida species in this patient population.

Novel viral load monitoring strategies are needed to help individuals maintain an undetectable viral load (UVL). In 2018, U.S. MSM living with HIV with a past detectable VL received a dried blood spot (DBS) kit at baseline and 3-month follow-up and returned specimens to a research laboratory. Of 56 consenting participants, 91% returned specimens at baseline and 77% at 3-month follow-up; 74% who returned two specimens had UVL at both time points. At-home DBS collection and longitudinal VL monitoring is feasible among U.S. MSM with fluctuating viral load. This complementary approach to clinical care could improve viral suppression maintenance.

INTRODUCTION/BACKGROUND:Eikenella corrodens is a small, nonmotile Gram-negative rod that is part of the normal flora in the mouth, upper respiratory, gastrointestinal, and genitourinary tracts. It is classically found in human bite (fist to mouth) infections but is also seen in respiratory tract and head and neck infections. METHODS:We describe three cases of E. corrodens causing head and neck infections in children seen in our institution between 2013 and 2019. We also reviewed the available literature on pediatric head and neck infections caused by E. corrodens. RESULTS:All 3 children recovered and fit the trends identified in the 58 patients published in the literature from 1976 to 2019. CONCLUSIONS:E. corrodens is responsible for a range of head and neck infections in pediatric patients. It is a not infrequent cause of head and neck infections in children and should be considered when selecting presumptive antibiotic therapy.

BACKGROUND:Outsourcing of microbiology laboratory services is a growing trend in US medical centers. Data on the actual impact of outsourcing on patient care, safety, and medical education, including costs, are limited. The objective of this study was to examine the published literature on the potential benefits and harms when medical centers outsource common microbiology services. METHODS:We conducted a 16-step literature search of PubMed and Embase. Articles were selected for full-text review if their content matched our key questions: (1) What are the potential benefits of outsourcing core microbiology laboratory testing? (2) What are the potential harms to patient care and medical education when medical centers outsource essential microbiology services? RESULTS:The initial search yielded 6111 unique published articles; 36 were selected for full-text review, which resulted in the identification of 8 articles that addressed our key questions (2 editorials, 3 editorials with observational data, 1 survey, 1 case series, and 1 study of blood culture transport). These articles described a variety of issues, including longer turnaround times for blood cultures that resulted in delays in diagnosis and treatment, errors that resulted in patient morbidity, limited cost savings, and communication barriers. CONCLUSIONS:In this study, with the exception of the blood culture transport study, we found no published prospective studies that quantified the effects of outsourcing microbiology services on patient care, patient safety, or medical education. However, these largely anecdotal reports suggest that outsourcing microbiology services may have a detrimental impact on medical education, especially infectious disease training programs.