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.

Real-World Impact of the Accelerate PhenoTest BC Kit on Patients With Bloodstream Infections in the Improving Outcomes and Antimicrobial Stewardship Study: A Quasiexperimental Multicenter Study.

BACKGROUND: Bloodstream infections (BSIs) are a leading cause of morbidity and mortality. The Improving Outcomes and Antimicrobial Stewardship study seeks to evaluate the impact of the Accelerate PhenoTest BC Kit (AXDX) on antimicrobial use and clinical outcomes in BSIs. METHODS: This multicenter, quasiexperimental study compared clinical and antimicrobial stewardship metrics, prior to and after implementation of AXDX, to evaluate the impact this technology has on patients with BSIs. Laboratory and clinical data from hospitalized patients with BSIs (excluding contaminants) were compared between 2 arms, 1 that underwent testing on AXDX (post-AXDX) and 1 that underwent alternative organism identification and susceptibility testing (pre-AXDX). The primary outcomes were time to optimal therapy (TTOT) and 30-day mortality. RESULTS: A total of 854 patients with BSIs (435 pre-AXDX, 419 post-AXDX) were included. Median TTOT was 17.2 hours shorter in the post-AXDX arm (23.7 hours) compared with the pre-AXDX arm (40.9 hours; P<.0001). Compared with pre-AXDX, median time to first antimicrobial modification (24.2 vs 13.9 hours; P<.0001) and first antimicrobial deescalation (36.0 vs 27.2 hours; P=.0004) were shorter in the post-AXDX arm. Mortality (8.7% pre-AXDX vs 6.0% post-AXDX), length of stay (7.0 pre-AXDX vs 6.5 days post-AXDX), and adverse drug events were not significantly different between arms. Length of stay was shorter in the post-AXDX arm (5.4 vs 6.4 days; P=.03) among patients with gram-negative bacteremia. CONCLUSIONS: For BSIs, use of AXDX was associated with significant decreases in TTOT, first antimicrobial modification, and time to antimicrobial deescalation.

Pelvic and central nervous system tuberculosis complicated by a paradoxical response manifesting as a spinal tuberculoma: a case report.

BACKGROUND: The post-partum period is a risk factor for tuberculosis (TB), possibly including the period after miscarriage as illustrated here. This case demonstrates how non-specific symptoms can hide widely disseminated TB. CASE PRESENTATION: A healthy 26-year-old female with a history of recent miscarriage presented to the emergency department with non-specific symptoms of headache, abdominal pain, and sub-acute fevers. She had immigrated to the United States from the Marshall Islands 9 years prior. Two months prior to presentation she had a miscarriage at 18 weeks of pregnancy. On admission, transvaginal ultrasound revealed retained products of conception and abdominal computed tomography revealed findings consistent with tubo-ovarian abscesses and peritonitis. The obstetrics and gynecology service performed dilation and curettage (D&C) to remove retained products of conception. Acid-fast bacilli cultures from cerebrospinal fluid as well as specimens from D&C and intra-abdominal abscesses subsequently all grew TB. She was diagnosed with TB meningitis, peritonitis, endometritis, and tubo-ovarian abscesses. Her treatment course was complicated by a paradoxical response resulting in a spinal tuberculoma causing lower extremity weakness. The tuberculoma was treated with surgical decompression as well as continuation of treatment with anti-tubercular chemotherapy and steroids. CONCLUSION: Disseminated and extrapulmonary TB can present with non-specific symptoms. Recognition of risk factors for TB is critical for prompt diagnostic evaluation and treatment of this deadly disease. A paradoxical reaction needs to be taken into consideration when any new neurological symptoms occur during TB treatment.

Coronavirus Disease 2019 Serial Testing Among Hospitalized Patients in a Midwest Tertiary Medical Center, July-September 2020.

We implemented serial coronavirus disease 2019 testing for inpatients with a negative test on admission. The conversion rate (negative to positive) on repeat testing was 1%. We identified patients during their incubation period and hospital-onset cases, rapidly isolated them, and potentially reduced exposures. Serial testing and infectiousness determination were resource intensive.

Improving outcomes and antibiotic stewardship (IOAS) for patients with Gram-positive bloodstream infections through use of rapid testing: a quasi-experimental multicentre study of the Accelerate PhenoTest™ BC Kit.

BACKGROUND: Data from the Improving Outcomes and Antibiotic Stewardship for Patients with Bloodstream Infections: Accelerate PhenoTest™ BC Kit (AXDX) Registry Study were analysed to determine the impact of rapid organism identification and antimicrobial susceptibility testing (AST) for Gram-positive bacteraemia. PATIENTS AND METHODS: This multicentre, quasi-experimental study evaluated clinical and antimicrobial stewardship metrics following the implementation of AXDX. Data from hospitalized patients with bacteraemia were compared between groups, one that underwent testing on AXDX (post-AXDX) and one that underwent traditional identification and AST (pre-AXDX). An analysis of patients with Gram-positive bacteraemia was performed. The primary outcome was time to optimal therapy (TTOT). Secondary outcomes included time to first antibiotic modification (overall and Gram-positive), duration of unnecessary MRSA coverage, incidence of adverse events, length of stay and mortality. RESULTS: A total of 219 (109 pre-AXDX, 110 post-AXDX) patients with Gram-positive bacteraemia were included. Median TTOT was 36.3 h (IQR, 16.9-56.7) in the pre-AXDX group and 20.4 h (IQR, 7.5-36.7) in the post-AXDX group (P = 0.01). Compared with pre-AXDX, median time to first antibiotic modification (29.1 versus 15.9 h; P = 0.002), time to first Gram-positive antibiotic modification (33.2 versus 17.2 h; P = 0.003) and median duration of unnecessary MRSA coverage (58.4 versus 29.7 h; P = 0.04) were reduced post-AXDX. A trend towards decreased acute kidney injury (24% versus 13%; P = 0.06) was observed in the post-AXDX group. Groups did not differ in other secondary outcomes. CONCLUSIONS: Implementation of AXDX testing for patients with Gram-positive bacteraemia shortened the TTOT and reduced unnecessary antibiotic exposure due to faster antibiotic modifications.

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.

Multicenter Evaluation of the Accelerate PhenoTest BC Kit for Rapid Identification and Phenotypic Antimicrobial Susceptibility Testing Using Morphokinetic Cellular Analysis.

We describe results from a multicenter study evaluating the Accelerate Pheno system, a first of its kind diagnostic system that rapidly identifies common bloodstream pathogens from positive blood cultures within 90 min and determines bacterial phenotypic antimicrobial susceptibility testing (AST) results within ∼7 h. A combination of fresh clinical and seeded blood cultures were tested, and results from the Accelerate Pheno system were compared to Vitek 2 results for identification (ID) and broth microdilution or disk diffusion for AST. The Accelerate Pheno system accurately identified 14 common bacterial pathogens and two Candida spp. with sensitivities ranging from 94.6 to 100%. Of fresh positive blood cultures, 89% received a monomicrobial call with a positive predictive value of 97.3%. Six common Gram-positive cocci were evaluated for ID. Five were tested against eight antibiotics, two resistance phenotypes (methicillin-resistant Staphylococcus aureus and Staphylococcus spp. [MRSA/MRS]), and inducible clindamycin resistance (MLSb). From the 4,142 AST results, the overall essential agreement (EA) and categorical agreement (CA) were 97.6% and 97.9%, respectively. Overall very major error (VME), major error (ME), and minor error (mE) rates were 1.0%, 0.7%, and 1.3%, respectively. Eight species of Gram-negative rods were evaluated against 15 antibiotics. From the 6,331 AST results, overall EA and CA were 95.4% and 94.3%, respectively. Overall VME, ME, and mE rates were 0.5%, 0.9%, and 4.8%, respectively. The Accelerate Pheno system has the unique ability to identify and provide phenotypic MIC and categorical AST results in a few hours directly from positive blood culture bottles and support accurate antimicrobial adjustment.

Rapid Detection of Urinary Tract Infections via Bacterial Nuclease Activity.

Rapid and accurate bacterial detection methods are needed for clinical diagnostic, water, and food testing applications. The wide diversity of bacterial nucleases provides a rich source of enzymes that could be exploited as signal amplifying biomarkers to enable rapid, selective detection of bacterial species. With the exception of the use of micrococcal nuclease activity to detect Staphylococcus aureus, rapid methods that detect bacterial pathogens via their nuclease activities have not been developed. Here, we identify endonuclease I as a robust biomarker for E. coli and develop a rapid ultrasensitive assay that detects its activity. Comparison of nuclease activities of wild-type and nuclease-knockout E. coli clones revealed that endonuclease I is the predominant DNase in E. coli lysates. Endonuclease I is detectable by immunoblot and activity assays in uropathogenic E. coli strains. A rapid assay that detects endonuclease I activity in patient urine with an oligonucleotide probe exhibited substantially higher sensitivity for urinary tract infections than that reported for rapid urinalysis methods. The 3 hr turnaround time is much shorter than that of culture-based methods, thereby providing a means for expedited administration of appropriate antimicrobial therapy. We suggest this approach could address various unmet needs for rapid detection of E. coli.

High clinical suspicion of donor-derived disease leads to timely recognition and early intervention to treat solid organ transplant-transmitted lymphocytic choriomeningitis virus.

Despite careful donor screening, unexpected donor-derived infections continue to occur in organ transplant recipients (OTRs). Lymphocytic choriomeningitis virus (LCMV) is one such transplant-transmitted infection that in previous reports has resulted in a high mortality among the affected OTRs. We report a LCMV case cluster that occurred 3 weeks post-transplant in three OTRs who received allografts from a common organ donor in March 2013. Following confirmation of LCMV infection at Centers for Disease Control and Prevention, immunosuppression was promptly reduced and ribavirin and/or intravenous immunoglobulin therapy were initiated in OTRs. The liver recipient died, but right kidney recipients survived without significant sequelae and left kidney recipient survived acute LCMV infection with residual mental status deficit. Our series highlights how early recognition led to prompt therapeutic intervention, which may have contributed to more favorable outcome in the kidney transplant recipients.

Crystal structure of the FimD usher bound to its cognate FimC-FimH substrate.

Type 1 pili are the archetypal representative of a widespread class of adhesive multisubunit fibres in Gram-negative bacteria. During pilus assembly, subunits dock as chaperone-bound complexes to an usher, which catalyses their polymerization and mediates pilus translocation across the outer membrane. Here we report the crystal structure of the full-length FimD usher bound to the FimC-FimH chaperone-adhesin complex and that of the unbound form of the FimD translocation domain. The FimD-FimC-FimH structure shows FimH inserted inside the FimD 24-stranded ß-barrel translocation channel. FimC-FimH is held in place through interactions with the two carboxy-terminal periplasmic domains of FimD, a binding mode confirmed in solution by electron paramagnetic resonance spectroscopy. To accommodate FimH, the usher plug domain is displaced from the barrel lumen to the periplasm, concomitant with a marked conformational change in the ß-barrel. The amino-terminal domain of FimD is observed in an ideal position to catalyse incorporation of a newly recruited chaperone-subunit complex. The FimD-FimC-FimH structure provides unique insights into the pilus subunit incorporation cycle, and captures the first view of a protein transporter in the act of secreting its cognate substrate.

Methylotroph Infections and Chronic Granulomatous Disease.

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by a defect in production of phagocyte-derived reactive oxygen species, which leads to recurrent infections with a characteristic group of pathogens not previously known to include methylotrophs. Methylotrophs are versatile environmental bacteria that can use single-carbon organic compounds as their sole source of energy; they rarely cause disease in immunocompetent persons. We have identified 12 infections with methylotrophs (5 reported here, 7 previously reported) in patients with CGD. Methylotrophs identified were Granulibacter bethesdensis (9 cases), Acidomonas methanolica (2 cases), and Methylobacterium lusitanum (1 case). Two patients in Europe died; the other 10, from North and Central America, recovered after prolonged courses of antimicrobial drug therapy and, for some, surgery. Methylotrophs are emerging as disease-causing organisms in patients with CGD. For all patients, sequencing of the 16S rRNA gene was required for correct diagnosis. Geographic origin of the methylotroph strain may affect clinical management and prognosis.

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.

The E. coli CsgB nucleator of curli assembles to ß-sheet oligomers that alter the CsgA fibrillization mechanism.

Curli are extracellular proteinaceous functional amyloid aggregates produced by Escherichia coli, Salmonella spp., and other enteric bacteria. Curli mediate host cell adhesion and invasion and play a critical role in biofilm formation. Curli filaments consist of CsgA, the major subunit, and CsgB, the minor subunit. In vitro, purified CsgA and CsgB exhibit intrinsically disordered properties, and both are capable of forming amyloid fibers similar in morphology to those formed in vivo. However, in vivo, CsgA alone cannot form curli fibers, and CsgB is required for filament growth. Thus, we studied the aggregation of CsgA and CsgB both alone and together in vitro to investigate the different roles of CsgA and CsgB in curli formation. We found that though CsgA and CsgB individually are able to self-associate to form aggregates/fibrils, they do so using different mechanisms and with different kinetic behavior. CsgB rapidly forms structured oligomers, whereas CsgA aggregation is slower and appears to proceed through large amorphous aggregates before forming filaments. Substoichiometric concentrations of CsgB induce a change in the mechanism of CsgA aggregation from that of forming amorphous aggregates to that of structured intermediates similar to those of CsgB alone. Oligomeric CsgB accelerated the aggregation of CsgA, in contrast to monomeric CsgB, which had no effect. The structured ß-strand oligomers formed by CsgB serve as nucleators for CsgA aggregation. These results provide insights into the formation of curli in vivo, especially the nucleator function of CsgB.