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.

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.

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.

Infection with a chlorophyllic eukaryote after a traumatic freshwater injury.

Infections with chlorophyllic algae are uncommon. Invasive infection with Desmodesmus armatus developed in two patients independently after they each sustained a penetrating freshwater injury.

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.

Identification of Low-Level Vancomycin Resistance in Staphylococcus aureus in the Era of Informatics.

Vancomycin-intermediateStaphylococcus aureus(VISA) and heteroresistant VISA (hVISA) are pathogens for which accurate antimicrobial susceptibility testing (AST) would rule out standard treatment with vancomycin. Unfortunately, AST for vancomycin is relatively slow and standard methods are unable to reliably detect VISA and hVISA. An article in this issue (C. A. Mather, B. J. Werth, S. Sivagnanam, D. J. SenGupta, and S. M. Butler-Wu, J Clin Microbiol 54:883-890, 2016, doi:http://dx.doi.org/10.1128/JCM.02428-15) describes a rapid whole-cell matrix-assisted laser desorption ionization-time of flight proxy susceptibility method that highlights current innovations and challenges with rapid AST, VISA/hVISA identification, and clinical bioinformatics.

POSITIVE TEST FOR ANTITHYROGLOBULIN ANTIBODIES DUE TO ADMINISTRATION OF IMMUNOGLOBULIN REPLACEMENT THERAPY IN A PATIENT WITH THYROID CANCER.

OBJECTIVE: Thyroglobulin (Tg) is used as a tumor marker to monitor differentiated thyroid cancer progression and recurrence. However, Tg measured by standard immunoassay (IMA) is not a reliable marker in the presence of anti-Tg antibodies (TgAbs) due to interference that may result in either false-positive or false-negative results. TgAbs levels can be high due to thyroid cancer and also exogenous immunoglobulin (Ig) administration, thus making it difficult to identify differentiated thyroid cancer recurrence. METHODS: We present an example of elevated TgAbs due to subcutaneous Ig (SCIg) administration in a patient with thyroid cancer. RESULTS: A 57-year-old male was diagnosed with stage I papillary thyroid cancer (PTC). His TgAbs were negative prior to the diagnosis of thyroid cancer and became positive after thyroidectomy and radioactive iodine administration. A detailed work-up including a whole body scan did not reveal recurrent disease. He had been diagnosed with common variable immune deficiency (CVID) and dermatomyositis at the age of 50 and was started on immunoglobulin (Ig) replacement therapy shortly after diagnosis. His Tg was negative when assessed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Therefore, elevated TgAb titers were attributed to concomitant SCIg treatment. We also demonstrated that SCIg treatment had TgAb activity that was removed by protein A column treatment. Dilutions of SCIg medication also caused positive IgG serologies for cytomegalovirus and herpes simplex, measles, mumps, rubella, and varicella zoster viruses. CONCLUSION: An exogenous source of TgAbs from SCIg led to extensive imaging work-up to assess for PTC recurrence. LC-MS/MS is a conceptually attractive approach to overcome TgAb interference with Tg IMA measurement.

Domain activities of PapC usher reveal the mechanism of action of an Escherichia coli molecular machine.

P pili are prototypical chaperone-usher pathway-assembled pili used by Gram-negative bacteria to adhere to host tissues. The PapC usher contains five functional domains: a transmembrane ß-barrel, a ß-sandwich Plug, an N-terminal (periplasmic) domain (NTD), and two C-terminal (periplasmic) domains, CTD1 and CTD2. Here, we delineated usher domain interactions between themselves and with chaperone-subunit complexes and showed that overexpression of individual usher domains inhibits pilus assembly. Prior work revealed that the Plug domain occludes the pore of the transmembrane domain of a solitary usher, but the chaperone-adhesin-bound usher has its Plug displaced from the pore, adjacent to the NTD. We demonstrate an interaction between the NTD and Plug domains that suggests a biophysical basis for usher gating. Furthermore, we found that the NTD exhibits high-affinity binding to the chaperone-adhesin (PapDG) complex and low-affinity binding to the major tip subunit PapE (PapDE). We also demonstrate that CTD2 binds with lower affinity to all tested chaperone-subunit complexes except for the chaperone-terminator subunit (PapDH) and has a catalytic role in dissociating the NTD-PapDG complex, suggesting an interplay between recruitment to the NTD and transfer to CTD2 during pilus initiation. The Plug domain and the NTD-Plug complex bound all of the chaperone-subunit complexes tested including PapDH, suggesting that the Plug actively recruits chaperone-subunit complexes to the usher and is the sole recruiter of PapDH. Overall, our studies reveal the cooperative, active roles played by periplasmic domains of the usher to initiate, grow, and terminate a prototypical chaperone-usher pathway pilus.

Septic arthritis of a native knee joint due to Corynebacterium striatum.

We report a case of septic arthritis of a native knee joint due to Corynebacterium striatum, a rare and unusual cause of septic arthritis of native joints. The isolate was identified by a combination of phenotypic, mass spectrometric, and nucleic acid-based assays and exhibited high-level resistance to most antimicrobials.

Optimization of routine identification of clinically relevant Gram-negative bacteria by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry and the Bruker Biotyper.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) might complement and one day replace phenotypic identification of bacteria in the clinical microbiology laboratory, but there is no consensus standard regarding the requirements for its validation prior to clinical use in the United States. The objective of this study was to assess the preanalytical variables influencing Gram-negative identification by use of the Bruker Biotyper MALDI-TOF MS system, including density of organism spotting on a stainless steel target plate and the direct overlay of organisms with formic acid. A heavy smear with formic acid overlay was either superior or equivalent to alternative smear conditions. Microbiological preanalytical variables were also assayed, such as culture medium, growth temperature, and use of serial subculture. Postanalytical analysis included the application of modified species-level identification acceptance criteria. Biotyper identifications were compared with those using traditional phenotypic methods, and discrepancies were resolved with 16S rRNA gene sequencing. Compared to the recommended score cutoffs of the manufacturer, the application of optimized Biotyper score cutoffs for species-level identification increased the rate of identification by 6.75% for the enteric Gram-negative bacteria and 4.25% for the nonfermenting Gram-negative bacteria. Various incubation temperatures, growth medium types, and repeat subcultures did not result in misidentification. We conclude that the Bruker MALDI Biotyper is a robust system for the identification of Gram-negative organisms in the clinical laboratory and that meaningful performance improvements can be made by implementing simple pre- and postanalytical techniques.

Two cases of Kerstersia gyiorum isolated from sites of chronic infection.

Kerstersia gyiorum is infrequently associated with human infection. We report the isolation of Kerstersia gyiorum from two patients: the first, a patient with chronic ear infections, and the second, a patient with a chronic leg wound. Both isolates were resistant to ciprofloxacin, which has not been previously reported.

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.

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.

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.

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.

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.

Intra-individual variability in serum hepcidin precludes its use as a marker of iron status in hemodialysis patients.

An accurate assessment of iron status in dialysis patients is important because both anemia and overtreatment with erythropoiesis-stimulating agents are associated with poor clinical outcomes. We have previously shown that both analytical and intra-individual (biological) variability in serum ferritin limits its utility as a proxy for iron stores in patients in this setting. As hepcidin is a direct regulator of iron status, its measurement might be useful for monitoring patients with iron dysregulation. We assessed short-term intra-individual variation of serum hepcidin in 28 patients with stable chronic kidney disease on hemodialysis. The intra-individual variability for serum hepcidin ranged from 9-79% during an initial 2-week to 12-85% over a 6-week period. The concentration of serum hepcidin was significantly correlated with serum C-reactive protein levels over the 6-week study period. Hence, significant intra-individual variability of hepcidin is likely dependent on short-term fluctuations in the inflammatory state. Thus, our results suggest that short-term measurement of serum hepcidin should not be used to guide clinical decisions regarding management of iron status in chronic hemodialysis patients.