Helicobacter pylori Exposure in Nausea and Vomiting of Pregnancy Increases Risk of Preterm Delivery.

Background: Hyperemesis gravidarum (HG), a severe form of nausea and vomiting in pregnancy (NVP), is a leading indication for hospitalization in the first trimester. NVP and HG are associated with Helicobacter pylori (HP) infection in non-United States cohorts. How HP exposure and NVP interact to affect metabolic disturbance and pregnancy outcomes is not known. Materials and Methods: We designed a retrospective cohort study relating HP and NVP to serum electrolyte laboratory results, preterm delivery, and infant birth weight. Single academic institution discovery and independent multi-institutional validation cohorts included pregnant subjects with an HP test result. Associations of HP, NVP, and pregnancy outcomes were assessed with odds ratio calculations, Student's t-tests, and multivariate logistic regression. Results: Among subjects with positive HP test results, the prevalence of hyperemesis gravidarum (HG) was 0.025 (66 of 2671) and NVP was 0.27 (710 of 2671). Subjects with negative HP had prevalence of HG 0.015 (165 of 10,960) and NVP 0.22 (2392 of 10,960). History of HP exposure increased risk of NVP, including HG (odds ratio 1.3, 95% CI 1.1-1.4). Patients with HP exposure had lower serum potassium (mean difference 0.1 mEq/L) and bicarbonate (mean difference 0.3 mEq/L) during pregnancy than HP-negative patients (p < 0.01). Serum potassium was lowest in subjects with both NVP and HP exposure (mean 3.5 mEq/L [3.4-3.6], p < 0.0001). HP exposure alone carried increased risk for preterm delivery (OR 1.3 [1.1-1.4]). NVP alone increased risk of preterm delivery (OR 2.8 [2.5-3.1]) including second trimester delivery (OR 2.2 [1.7-2.8]). In multivariate analysis, HP exposure in the setting of NVP further increased risk of preterm delivery (adjusted OR 1.4 [1.0-1.9], p = 0.03). Conclusions: H. pylori exposure and diagnosis of NVP are individually associated with metabolic disturbances and adverse pregnancy outcomes such as preterm labor and delivery, and their combination further increases risk in US populations.

Antibiotic Recommendations for Treatment of Canine Stromal Corneal Ulcers.

The aim of the study was to identify the aerobic bacterial isolates and determine corresponding antibiotic susceptibility profiles in vitro in canine clinical specimens with stromal corneal ulcers, with the goal of providing recommendations for first-line treatment with antibiotics. A total of 198 canine corneal stromal ulcer samples were studied between 2018 and 2021. A corneal swab was collected and cultured under aerobic conditions. Bacterial organisms were identified at the species level by MALDI-TOF mass spectrometry. Antibiotic susceptibility testing for commonly used topical and systemic antibiotics was performed by disk diffusion. Bacterial growth was obtained from 80% of samples. A variety of bacterial species were identified wherein the most common specimens were represented by Staphylococcus pseudintermedius (22%), Staphylococcus epidermidis (12%), Staphylococcus capitis (11%), and Pseudomonas aeruginosa (10%). Based on the overall antibiotic susceptibility data, neopolybac alone (96%) or a combination of neopolybac with either ofloxacin or amikacin (each 99%) showed the best coverage for commonly isolated bacterial organisms from canine corneal stromal ulcers. Results of this study support the use of the combined antibiotics as the first-line response for the treatment of canine corneal stromal ulcers. A statically significant increase in acquired bacterial resistance was detected during the longitudinal data observation.

Does Antimicrobial Prophylaxis in Patients with Specific Comorbidities Reduce the Risk of Infection after Simple Cystourethroscopy?

INTRODUCTION: We evaluated whether antimicrobial prophylaxis decreases rates of post-procedural infection (urinary tract infection or sepsis) after simple cystourethroscopy for patients with specific comorbidities. METHODS: We utilized Epic® reporting software to conduct a retrospective review of all simple cystourethroscopy procedures performed by providers in our urology department from August 4, 2014 to December 31, 2019. Data collected included patient comorbidities, antimicrobial prophylaxis administration and incidence of post-procedural infection. Mixed effects logistic regression models were utilized to estimate the effects of antimicrobial prophylaxis and patient comorbidities on the odds of post-procedural infection. RESULTS: Antimicrobial prophylaxis was given for 7,001 (78%) of 8,997 simple cystourethroscopy procedures. Overall, 83 (0.9%) post-procedural infections occurred. The estimated odds of post-procedural infection were lower when antimicrobial prophylaxis was given compared to those without prophylaxis (OR 0.51, 95% CI 0.35-0.76; p <0.01). The number needed to treat with antimicrobial prophylaxis to prevent 1 post-procedural infection was 100. None of the comorbidities evaluated showed significant benefit from antimicrobial prophylaxis for prevention of post-procedural infection. CONCLUSIONS: Overall, the rate of post-procedural infection after simple office cystourethroscopy was low (0.9%). Though antimicrobial prophylaxis decreased the odds of post-procedural infection overall, the number needed to treat was high (100). Antibiotic prophylaxis was not shown to significantly reduce the risk of post-procedural infection in any of the comorbidity groups we evaluated. These findings suggest that the comorbidities evaluated in this study should not be used to recommend antibiotic prophylaxis for simple cystourethroscopy.

Meningitis Caused by the Live Varicella Vaccine Virus: Metagenomic Next Generation Sequencing, Immunology Exome Sequencing and Cytokine Multiplex Profiling.

Varicella vaccine meningitis is an uncommon delayed adverse event of vaccination. Varicella vaccine meningitis has been diagnosed in 12 children, of whom 3 were immunocompromised. We now report two additional cases of vaccine meningitis in twice-immunized immunocompetent children and we perform further testing on a prior third case. We used three methods to diagnose or investigate cases of varicella vaccine meningitis, none of which have been used previously on this disease. These include metagenomic next-generation sequencing and cytokine multiplex profiling of cerebrospinal fluid and immunology exome analysis of white blood cells. In one new case, the diagnosis was confirmed by metagenomic next-generation sequencing of cerebrospinal fluid. Both varicella vaccine virus and human herpesvirus 7 DNA were detected. We performed cytokine multiplex profiling on the cerebrospinal fluid of two cases and found ten elevated biomarkers: interferon gamma, interleukins IL-1RA, IL-6, IL-8, IL-10, IL-17F, chemokines CXCL-9, CXCL-10, CCL-2, and G-CSF. In a second new case, we performed immunology exome sequencing on a panel of 356 genes, but no errors were found. After a review of all 14 cases, we concluded that (i) there is no common explanation for this adverse event, but (ii) ingestion of an oral corticosteroid burst 3-4 weeks before onset of vaccine meningitis may be a risk factor in some cases.

Asymptomatic Pre-Operative COVID-19 Screening for Essential and Elective Surgeries: Early Results of Universal Screening at a Midwestern Academic Medical Center.

BACKGROUND: During the novel Coronavirus 2019 (COVID-19) worldwide pandemic, viral testing has largely focused on patients presenting with fever and respiratory symptoms. Although Centers for Disease Control has reported 1,551,095 cases in the United States as of May 21, 2020, asymptomatic infection rates remain unknown within the U.S., especially in geographically disparate regions. METHODS: On April 7, 2020 our hospital established universal SARS-CoV-2 screening using RT-PCR RNA detection from nasopharyngeal swabs from asymptomatic patients prior to essential and elective surgeries. This study included 1,997 asymptomatic patients undergoing surgical procedures and 1,797 admitted for medical management at a Midwestern academic hospital between April 7, 2020 and May 21, 2020. RESULTS: As of May 21, asymptomatic testing for SARS-CoV-2 infection had been completed for 1,997 surgical patients and 1,797 non-surgical patients. Initial testing was positive in 26 patients, with an additional four positive tests occurring during repeat testing when greater than 48 hours had elapsed since initial testing. Overall asymptomatic infection rate was 0.79%. Asymptomatic infection rate was significantly lower in surgical patients (0.35% vs. 1.28%, p=0.001). Surgical patients tended to be older than non-surgical patients, although this was not statistically significant (51, IQR 27-65 vsx 46, IQR 28-64, p=0.057). Orthopedic surgery patients were significantly younger than those from other surgical services (42 vs. 53 yrs, p<0.001), however orthopedic and non-orthopedic surgical patients had similar asymptomatic infection rates (0.70% vs. 0.25%, p=0.173). CONCLUSION: Among asymptomatic patients tested at a Midwestern academic medical center, 0.79% were infected with SARS-CoV-2 virus. These findings will help guide screening protocols at medical centers while providing essential and elective procedures during the COVID-19 pandemic. While the asymptomatic infection rate was low, this data substantiates the threat of asymptomatic infections and potential for community viral spread. These results may not be generalizable to large urban population centers or areas with high concentrations of COVID-19, each region must use available data to evaluate the risk-benefit ratio of universal testing vs universal contact precautions.Level of Evidence: IV.

Experience With Pretravel Testing for SARS-CoV-2 at an Academic Medical Center.

International travel has been a significant factor in the coronavirus disease 2019 pandemic. Many countries and airlines have implemented travel restrictions to limit the spread of the causative agent, severe acute respiratory syndrome coronavirus-2. A common requirement has been a negative reverse-transcriptase polymerase chain reaction performed by a clinical laboratory within 48 to 72 hours of departure. A more recent travel mandate for severe acute respiratory syndrome coronavirus-2 immunoglobulin M serology testing was instituted by the Chinese government on October 29, 2020. Pretravel testing for severe acute respiratory syndrome coronavirus-2 raises complications in terms of cost, turnaround time, and follow-up of positive results. In this report, we describe the experience of a multidisciplinary collaboration to develop a workflow for pretravel severe acute respiratory syndrome coronavirus-2 reverse-transcriptase polymerase chain reaction and immunoglobulin M serology testing at an academic medical center. The workflow primarily involved self-payment by patients and preferred retrieval of results by the patient through the electronic health record patient portal (Epic MyChart). A total of 556 unique patients underwent pretravel reverse-transcriptase polymerase chain reaction testing, with 13 (2.4%) having one or more positive results, a rate similar to that for reverse-transcriptase polymerase chain reaction testing performed for other protocol-driven asymptomatic screening (eg, inpatient admissions, preprocedural) at our medical center. For 5 of 13 reverse-transcriptase polymerase chain reaction positive samples, the traveler had clinical history, prior reverse-transcriptase polymerase chain reaction positive, and high cycle thresholds values on pretravel testing consistent with remote infection and minimal transmission risk. Severe acute respiratory syndrome coronavirus-2 immunoglobulin M was performed on only 24 patients but resulted in 2 likely false positives. Overall, our experience at an academic medical center shows the challenge with pretravel severe acute respiratory syndrome coronavirus-2 testing.

Practical Considerations for Implementation of SARS-CoV-2 Serological Testing in the Clinical Laboratory: Experience at an Academic Medical Center.

Molecular techniques, especially reverse transcriptase polymerase chain reaction (RT-PCR), have been the gold standard for the diagnosis of acute severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Serological tests for SARS-CoV-2 have been widely used for serosurveys, epidemiology, and identification of potential convalescent plasma donors. However, the clinical role of serologic testing is still limited and evolving. In this report, we describe the experience of selecting, validating, and implementing SARS-CoV-2 serologic testing for clinical purposes at an academic medical center in a rural state. Successful implementation involved close collaboration between pathology, infectious diseases, and outpatient clinics. The most common clinician concerns were appropriateness/utility of testing, patient charges/insurance coverage, and assay specificity. In analyzing test utilization, serologic testing in the first month after go-live was almost entirely outpatient and appeared to be strongly driven by patient interest (including health care workers and others in high-risk occupations for exposure to SARS-CoV-2), with little evidence that the results impacted clinical decision-making. Test volumes for serology declined steadily through October 31, 2020, with inpatient ordering assuming a steadily higher percentage of the total. In a 5-month period, SARS-CoV-2 serology test volumes amounted to only 1.3% of that of reverse transcriptase polymerase chain reaction. Unlike reverse transcriptase polymerase chain reaction, supply chain challenges and reagent availability were not major issues for serology testing. We also discuss the most recent challenge of requirements for SARS-CoV-2 testing in international travel protocols. Overall, our experience at an academic medical center shows that SARS-CoV-2 serology testing assumed a limited clinical role.

The Postmortem Features of Mucormycosis.

Mucormycosis is a rare and severe invasive fungal infection caused by ubiquitous fungi of the order Mucorales. Infection often occurs in immunocompromised hosts and includes cutaneous, pulmonary, gastrointestinal, rhinocerebral, and disseminated forms of disease. Although the clinical characteristics of mucormycosis are well established, infection can be difficult to diagnose antemortem, resulting in frequent postmortem diagnoses. Despite this, the gross appearance of mucormycosis at autopsy has not been well described. In the present report we illustrate the gross and histologic findings in four autopsy cases of mucormycosis, including one case of pulmonary disease and three cases of disseminated mucormycosis with cerebral, pulmonary, hepatic, renal, and gastrointestinal involvement. In all cases autopsy examination demonstrated characteristic hemorrhagic infarcts with a targetoid appearance in the affected organs. These findings are secondary to fungal angioinvasion with subsequent thrombosis and tissue necrosis. Mucormycosis should be suspected at autopsy when these characteristic infarcts are identified within the proper clinical context, and a high suspicion for atypical infections should be maintained postmortem in immunosuppressed patients.

Characteristics of Nontuberculous Mycobacterial Infections at a Midwestern Tertiary Hospital: A Retrospective Study of 365 Patients.

BACKGROUND: The prevalence of infections due to nontuberculous mycobacteria (NTM) is increasing worldwide, yet little is known about the epidemiology and pathophysiology of these ubiquitous environmental organisms. Pulmonary disease due to Mycobacterium avium complex is most prevalent, but many other NTM species can cause disease in virtually any organ system. As NTM becomes an increasingly common cause of morbidity and mortality, more information is needed about the epidemiology of NTM disease. METHODS: We conducted a retrospective chart review of all patients with cultures that grew NTM at a Midwestern tertiary hospital from 1996 to 2017. Information on demographics, medical history, clinical findings, treatment, and outcome was obtained from medical records of all NTM isolates. American Thoracic Society/Infectious Diseases Society of America criteria were used to define pulmonary NTM infections. RESULTS: We identified 1064 NTM isolates, 365 of which met criteria for NTM infection. Pulmonary cases predominated (185 of 365; 50.7%), followed by skin/soft tissue (56 of 365; 15.3%), disseminated (40 of 365; 11%), and lymphatic (28 of 365; 7.7%) disease. Mycobacterium avium complex was the most common species (184 of 365; 50.4%). Individuals aged >50 years were most affected (207 of 365; 56.7%). Common comorbidities included structural lung disease (116 of 365; 31.8%), use of immunosuppressive medications (78 of 365; 21.4%), malignancy (59 of 365; 16.2%), and human immunodeficiency virus (42 of 365; 11.5%). CONCLUSIONS: This large cohort provides information on the demographics, risk factors, and disease course of patients with pulmonary and extrapulmonary NTM infections. Most patients had medical comorbidities that resulted in anatomic, genetic, or immunologic risk factors for NTM infection. Further population-based studies and increased disease surveillance are warranted to further characterize NTM infection prevalence and trends.

Data on the relationship of signal-to-cutoff ratio of two HIV antigen/antibody combination assays to subsequent confirmation of HIV-1 infection in a low-prevalence population.

HIV-1/2 antigen/antibody (Ag/Ab) immunoassays that detect HIV-1 and HIV-2 antibodies and HIV-1 p24 antigen are commonly used in the diagnosis of HIV-1/HIV-2 infections in human plasma/serum. Samples from patients with positive screening results require confirmation by antibody differentiation and/or HIV PCR assays. HIV screening assays are commonly reported as positive or negative based on a signal-to-cutoff (S/CO) threshold. For some HIV screening assays, the strength of the S/CO value correlates with likelihood that confirmatory testing will be positive. The data in this article provide results from two HIV Ag/Ab combination assays (Abbott Architect HIV Ag/Ab Combo Assay, a 4th generation combination assay; Bio-Rad Bioplex 2200 HIV Ag-Ab Assay, a 5th generation assay). The data include 23,331 HIV screening results, S/CO ratios, antibody differentiation or Western blot results (for samples with positive HIV screens), HIV-1 PCR results (if performed), patient location at time of testing, age, and sex. Distribution of S/CO ratios for the Bio-Rad HIV screening assay data and the distribution of S/CO values for samples with positive screening results were analyzed.

Machine Learning Takes Laboratory Automation to the Next Level.

Clinical microbiology laboratories face challenges with workload and understaffing that other clinical laboratory sections have addressed with automation. In this issue of the Journal of Clinical Microbiology, M. L. Faron, B. W. Buchan, R. F. Relich, J. Clark, and N. A. Ledeboer (J Clin Microbiol 58:e01683-19, 2020, https://doi.org/10.1128/JCM.01683-19) evaluate the performance of automated image analysis software to screen urine cultures for further workup according to their total number of CFU. Urine cultures are the highest volume specimen type for most laboratories, so this software has the potential for tremendous gains in laboratory efficiency and quality due to the consistency of colony quantification.

Burden and Characteristics of Unsolicited Emails from Medical/Scientific Journals, Conferences, and Webinars to Faculty and Trainees at an Academic Pathology Department.

BACKGROUND: Professionals and trainees in the medical and scientific fields may receive high e-mail volumes for conferences and journals. In this report, we analyze the amount and characteristics of unsolicited e-mails for journals, conferences, and webinars received by faculty and trainees in a pathology department at an academic medical center. METHODS: With informed consent, we analyzed 7 consecutive days of e-mails from faculty and trainees who voluntarily participated in the study and saved unsolicited e-mails from their institutional e-mail address (including junk e-mail folder) for medical/scientific journals, conferences, and webinars. All e-mails were examined for characteristics such as reply receipts, domain name, and spam likelihood. Journal e-mails were specifically analyzed for claims in the message body (for example, peer review, indexing in databases/resources, rapid publication) and actual inclusion in recognized journal databases/resources. RESULTS: A total of 17 faculty (4 assistant, 4 associate, and 9 full professors) and 9 trainees (5 medical students, 2 pathology residents, and 2 pathology fellows) completed the study. A total of 755 e-mails met study criteria (417 e-mails from 328 unique journals, 244 for conferences, and 94 for webinars). Overall, 44.4% of e-mails were flagged as potential spam by the institutional default settings, and 13.8% requested reply receipts. The highest burden of e-mails in 7 days was by associate and full professors (maximum 158 or approximately 8200 per year), although some trainees and assistant professors had over 30 e-mails in 7 days (approximately 1560 per year). Common characteristics of journal e-mails were mention of "peer review" in the message body and low rates of inclusion in recognized journal databases/resources, with 76.4% not found in any of 9 journal databases/resources. The location for conferences in e-mails included 31 different countries, with the most common being the United States (33.2%), Italy (9.8%), China (4.9%), United Kingdom (4.9%), and Canada (4.5%). CONCLUSIONS: The present study in an academic pathology department shows a high burden of unsolicited e-mails for medical/scientific journals, conferences, and webinars, especially to associate and full professors. We also demonstrate that some pathology trainees and junior faculty are receiving an estimated 1500 unsolicited e-mails per year.

Improved Performance of a Rapid Immunochromatographic Assay for Detection of PBP2a in Non-Staphylococcus aureus Staphylococcal Species.

Non-Staphylococcus aureus staphylococcal species (non-SASS) are important pathogens in both animal and human populations. The development of ß-lactam resistance in non-SASS through acquisition and expression of penicillin-binding protein 2a (PBP2a) represents a significant clinical and public health threat. Here, we evaluated the diagnostic performance of two versions of a PBP2a immunochromatographic assay with non-SASS. Our data show that the revised version of the assay, the PBP2a SA culture colony test, has superior diagnostic sensitivity compared to the previous version of the assay, the PBP2a culture colony test, 100% (95% confidence interval [CI], 93.3 to 100%) versus 67.9% (95% CI, 53.7 to 80.1%), respectively, while both assays display a specificity of 100% (95% CI, 92.5 to 100%). Therefore, the PBP2a SA culture colony test offers a rapid, accurate, and relatively inexpensive method for detecting PBP2a-mediated ß-lactam resistance in clinically relevant non-SASS for the management of infections due to these organisms and for antimicrobial stewardship.

Angioinvasive fungal infections impacting the skin: Diagnosis, management, and complications.

As discussed in the first article in this continuing medical education series, angioinvasive fungal infections pose a significant risk to immunocompromised and immunocompetent patients alike, with a potential for severe morbidity and high mortality. The first article in this series focused on the epidemiology and clinical presentation of these infections; this article discusses the diagnosis, management, and potential complications of these infections. The mainstay diagnostic tests (positive tissue culture with histologic confirmation) are often supplemented with serum biomarker assays and molecular testing (eg, quantitative polymerase chain reaction analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry) to ensure proper speciation. When an angioinvasive fungal infection is suspected or diagnosed, further workup for visceral involvement also is essential and may partially depend on the organism. Different fungal organisms have varied susceptibilities to antifungal agents, and knowledge on optimal treatment regimens is important to avoid the potential complications associated with undertreated or untreated fungal infections.

Angioinvasive fungal infections impacting the skin: Background, epidemiology, and clinical presentation.

Angioinvasive fungal infections cause significant morbidity and mortality because of their propensity to invade blood vessel walls, resulting in catastrophic tissue ischemia, infarct, and necrosis. While occasionally seen in immunocompetent hosts, opportunistic fungi are emerging in immunosuppressed hosts, including patients with hematologic malignancy, AIDS, organ transplant, and poorly controlled diabetes mellitus. The widespread use of antifungal prophylaxis has led to an "arms race" of emerging fungal resistance patterns. As the at-risk population expands and new antifungal resistance patterns develop, it is critical for dermatologists to understand and recognize angioinvasive fungal pathogens, because they are often the first to encounter the cutaneous manifestations of these diseases. Rapid clinical recognition, histopathologic, and culture confirmation can help render a timely, accurate diagnosis to ensure immediate medical and surgical intervention. Superficial dermatophyte infections and deep fungal infections, such as blastomycosis and histoplasmosis, have been well characterized within the dermatologic literature, and therefore this article will focus on the severe infections acquired by angioinvasive fungal species, including an update on new and emerging pathogens. In the first article in this continuing medical education series, we review the epidemiology and cutaneous manifestations. The second article in the series focuses on diagnosis, treatment, and complications of these infections.

Cutaneous Infections Due to Nontuberculosis Mycobacterium: Recognition and Management.

Nontuberculous mycobacteria (NTM) are a diverse group of organisms that are ubiquitous in the environment, and the incidence of cutaneous infections due to NTM has been steadily increasing. Cutaneous infections due to NTM can be difficult to diagnose, due to their wide spectrum of clinical presentations and histopathological findings that are often nonspecific. A variety of modalities including tissue culture and polymerase chain reaction (PCR) assays may be necessary to identify the organism. Treatment can also be challenging, as it can depend on multiple factors, including the causative organism, the patient's immunological status, and the extent of disease involvement. In this review, we discuss the common presentations of cutaneous NTM infections, diagnostic tools, and treatment recommendations. A multi-disciplinary approach that involves good communication between the clinician, the histopathologist, the microbiologist, and infectious disease specialists can help lead to successful diagnosis and management.

Implementation of a Mobile Clinical Decision Support Application to Augment Local Antimicrobial Stewardship.

BACKGROUND: Medical applications for mobile devices allow clinicians to leverage microbiological data and standardized guidelines to treat patients with infectious diseases. We report the implementation of a mobile clinical decision support (CDS) application to augment local antimicrobial stewardship. METHODS: We detail the implementation of our mobile CDS application over 20 months. Application utilization data were collected and evaluated using descriptive statistics to quantify the impact of our implementation. RESULTS: Project initiation focused on engaging key stakeholders, developing a business case, and selecting a mobile platform. The preimplementation phase included content development, creation of a pathway for content approval within the hospital committee structure, engaging clinical leaders, and formatting the first version of the guide. Implementation involved a media campaign, staff education, and integration within the electronic medical record and hospital mobile devices. The postimplementation phase required ongoing quality improvement, revision of outdated content, and repeated staff education. The evaluation phase included a guide utilization analysis, reporting to hospital leadership, and sustainability and innovation planning. The mobile application was downloaded 3056 times and accessed 9259 times during the study period. The companion web viewer was accessed 8214 times. CONCLUSIONS: Successful implementation of a customizable mobile CDS tool enabled our team to expand beyond microbiological data to clinical diagnosis, treatment, and antimicrobial stewardship, broadening our influence on antimicrobial prescribing and incorporating utilization data to inspire new quality and safety initiatives. Further studies are needed to assess the impact on antimicrobial utilization, infection control measures, and patient care outcomes.

mecC-Harboring Methicillin-Resistant Staphylococcus aureus: Hiding in Plain Sight.

Previously there was scant data on the performance of laboratory testing to detect mecC-mediated beta-lactam resistance in Staphylococcus aureus Kriegeskorte and colleagues (J Clin Microbiol 56:e00826-17, 2018, https://doi.org/10.1128/JCM.00826-17) report the performance of various clinical tests for the detection of mecC-harboring methicillin-resistant S. aureus (MRSA), which failed to identify from 0 to 41% of tested mecC-harboring MRSA isolates. Changes in practice and new test development are necessary to address the challenge of mecC-harboring MRSA.