Salmonella enterica serovar Kentucky recovered from human clinical cases in Maryland, USA (2011-2015).

Salmonella Kentucky is among the most frequently isolated S. enterica serovars from food animals in the United States. Recent research on isolates recovered from these animals suggests there may be geographic and host specificity signatures associated with S. Kentucky strains. However, the sources and genomic features of human clinical S. Kentucky isolated in the United States remain poorly described. To investigate the characteristics of clinical S. Kentucky and the possible sources of these infections, the genomes of all S. Kentucky isolates recovered from human clinical cases in the State of Maryland between 2011 and 2015 (n = 12) were sequenced and compared to a database of 525 previously sequenced S. Kentucky genomes representing 12 sequence types (ST) collected from multiple sources on several continents. Of the 12 human clinical S. Kentucky isolates from Maryland, nine were ST198, two were ST152, and one was ST314. Forty-one per cent of isolates were recovered from patients reporting recent international travel and 58% of isolates encoded genomic characteristics similar to those originating outside of the United States. Of the five isolates not associated with international travel, three encoded antibiotic resistance genes conferring resistance to tetracycline or aminoglycosides, while two others only encoded the cryptic aac(6')-Iaa gene. Five isolates recovered from individuals with international travel histories (ST198) and two for which travel was not recorded (ST198) encoded genes conferring resistance to between 4 and 7 classes of antibiotics. Seven ST198 genomes encoded the Salmonella Genomic Island 1 and substitutions in the gyrA and parC genes known to confer resistance to ciprofloxacin. Case report data on food consumption and travel were, for the most part, consistent with the inferred S. Kentucky phylogeny. Results of this study indicate that the majority of S. Kentucky infections in Maryland are caused by ST198 which may originate outside of North America.

Nurses' work with interruptions: an objective model for testing interventions.

Interruptions experienced by nurses may lead to errors as their focus and attention to multiple patient needs are disrupted. As quantitative models to understand the dynamics of interruptions are lacking, the objective of this study is a model of a nurse's work with interruptions, generating insights into the onset of interruptions and evaluating suggested interventions. We observed nurses in a US Level I trauma center for 47.3 h, including 259 interruptions (9.1% of total time) across 580 nursing activities. A stochastic, non-stationary, model of a nurse's work was developed considering source and activity-dependent interruptions, with parameters clustered across similar periods of day. Two interventions emulating 'do not disturb' strategies were evaluated, along with a more focused intervention from suggestions that nurses' phone calls be 'triaged'. Modeled outcomes included the increase in interruptions in other activities due to deferment and changes to the beneficial/detrimental interruption (B/D) ratio. Across-the-board sequestering of nurses by deferring interruptions during medication increased the B/D ratio 17% (1.35 vs. 1.58), but resulted in an unforeseen 73% (1.04/h vs. 1.80/h) increase in interruptions during direct care. In contrast, the focused intervention (deferring only those interruptions arriving via cell phone during medication and direct care), netted a 31% improvement in the B/D ratio (1.29 vs. 1.69) and with moderated (< 0.13/h) impact on interruptions during other activities. Modeling the dynamics of the onset of interruptions reveals the potentially negative impact of across-the-board interventions, and the advantage of focused interventions anticipating unmet needs before they present as interruptions.

A Prospective Study of Acinetobacter baumannii Complex Isolates and Colistin Susceptibility Monitoring by Mass Spectrometry of Microbial Membrane Glycolipids.

Acinetobacter baumannii is a prevalent nosocomial pathogen with a high incidence of multidrug resistance. Treatment of infections due to this organism with colistin, a last-resort antibiotic of the polymyxin class, can result in the emergence of colistin-resistant strains. Colistin resistance primarily occurs via modifications of the terminal phosphate moieties of lipopolysaccharide-derived lipid A, which reduces overall membrane electronegativity. These modifications are readily identified by mass spectrometry (MS). In this study, we prospectively collected Acinetobacter baumannii complex clinical isolates from a hospital system in Pennsylvania over a 3-year period. All isolates were evaluated for colistin resistance using standard MIC testing by both agar dilution and broth microdilution, as well as genospecies identification and lipid A profiling using MS analyses. Overall, an excellent correlation between colistin susceptibility and resistance, determined by MIC testing, and the presence of a lipid A modification, determined by MS, was observed with a sensitivity of 92.9% and a specificity of 94.0%. Additionally, glycolipid profiling was able to differentiate A. baumannii complex organisms based on their membrane lipids. With the growth of MS use in clinical laboratories, a reliable MS-based glycolipid phenotyping method that identifies colistin resistance in A. baumannii complex clinical isolates, as well as other Gram-negative organisms, represents an alternative or complementary approach to existing diagnostics.

Genomic Variation and Evolution of Vibrio parahaemolyticus ST36 over the Course of a Transcontinental Epidemic Expansion.

Vibrio parahaemolyticus is the leading cause of seafood-related infections with illnesses undergoing a geographic expansion. In this process of expansion, the most fundamental change has been the transition from infections caused by local strains to the surge of pandemic clonal types. Pandemic clone sequence type 3 (ST3) was the only example of transcontinental spreading until 2012, when ST36 was detected outside the region where it is endemic in the U.S. Pacific Northwest causing infections along the U.S. northeast coast and Spain. Here, we used genome-wide analyses to reconstruct the evolutionary history of the V. parahaemolyticus ST36 clone over the course of its geographic expansion during the previous 25 years. The origin of this lineage was estimated to be in ~1985. By 1995, a new variant emerged in the region and quickly replaced the old clone, which has not been detected since 2000. The new Pacific Northwest (PNW) lineage was responsible for the first cases associated with this clone outside the Pacific Northwest region. After several introductions into the northeast coast, the new PNW clone differentiated into a highly dynamic group that continues to cause illness on the northeast coast of the United States. Surprisingly, the strains detected in Europe in 2012 diverged from this ancestral group around 2000 and have conserved genetic features present only in the old PNW lineage. Recombination was identified as the major driver of diversification, with some preliminary observations suggesting a trend toward a more specialized lifestyle, which may represent a critical element in the expansion of epidemics under scenarios of coastal warming.IMPORTANCEVibrio parahaemolyticus and Vibrio cholerae represent the only two instances of pandemic expansions of human pathogens originating in the marine environment. However, while the current pandemic of V. cholerae emerged more than 50 years ago, the global expansion of V. parahaemolyticus is a recent phenomenon. These modern expansions provide an exceptional opportunity to study the evolutionary process of these pathogens at first hand and gain an understanding of the mechanisms shaping the epidemic dynamics of these diseases, in particular, the emergence, dispersal, and successful introduction in new regions facilitating global spreading of infections. In this study, we used genomic analysis to examine the evolutionary divergence that has occurred over the course of the most recent transcontinental expansion of a pathogenic Vibrio, the spreading of the V. parahaemolyticus sequence type 36 clone from the region where it is endemic on the Pacific coast of North America to the east coast of the United States and finally to the west coast of Europe.

Nursing Interruptions in a Trauma Intensive Care Unit: A Prospective Observational Study.

OBJECTIVE: The aims of this study were to identify and analyze elements that affect duration of an interruption and likelihood of activity switch as experienced by nurses in an ICU. BACKGROUND: Although interruptions in the ICU impact patient safety, little is known regarding the complex situations that drive them. METHODS: RNs were observed in a 23-bed surgical ICU. We observed 206 interruptions, and analyzed for duration and activity switch. RESULTS: RNs were interrupted on the average every 21.8 minutes. Attending physicians/residents caused fewer, but longer, interruptions to the RN. Longer interruptions were more likely to result in an activity switch. During complex situations such as when an RN is documenting, interruptions by a physician led to longer durations. Interruptions by a device led to higher switches. CONCLUSIONS: A deeper understanding of individual factors and their complex interactions related to interruptions experienced by ICU RNs are vital to understanding the clinical significance of these interruptions and intervention design.

Likely Sexual Transmission of Zika Virus from a Man with No Symptoms of Infection - Maryland, 2016.

In June 2016, the Maryland Department of Health and Mental Hygiene (DHMH) was notified of a nonpregnant woman who sought treatment for a subjective fever and an itchy rash, which was described as maculopapular by her provider. Laboratory testing at the Maryland DHMH Laboratories Administration confirmed Zika virus infection. Case investigation revealed that the woman had not traveled to a region with ongoing transmission of Zika virus, but did have sexual contact with a male partner who had recently traveled to the Dominican Republic. The male partner reported exposure to mosquitoes while traveling, but no symptoms consistent with Zika virus infection either before or after returning to the United States. The woman reported no other sex partners during the 14 days before onset of her symptoms and no receipt of blood products or organ transplants.

Acute infections, cost and time to reporting of HIV test results in three U.S. State Public Health Laboratories.

OBJECTIVE: In three U.S. State Public Health Laboratories (PHLs) using a fourth-generation immunoassay (IA), an HIV-1/HIV-2 differentiation antibody IA and a nucleic acid test (NAT), we characterized the yield and time to reporting of acute infections, and cost per positive specimen. METHODS: Routine HIV testing data were collected from July 1, 2012-June 30, 2013 for Massachusetts and Maryland PHLs, and from November 27, 2012-June 30, 2013 for Michigan PHL. Massachusetts and Michigan used fourth-generation and differentiation IAs with NAT conducted by a referral laboratory. In Maryland, fourth-generation IA repeatedly reactive specimens were followed by a Western blot (WB), and those with negative or indeterminate results were tested with a differentiation IA and HIV-1 NAT, and if positive by NAT, confirmed by a different HIV-1 NAT. Specimens from WB-positive persons at risk for HIV-2 were tested with a differentiation IA and, if positive, with an HIV-2 WB and/or differential HIV-1/HIV-2 proviral DNA polymerase chain reaction. RESULTS: Among 7914 specimens from Massachusetts PHL, 6069 from Michigan PHL, and 36,266 from Maryland PHL, 0.10%, 0.02% and 0.05% acute infections were identified, respectively. Massachusetts and Maryland PHLs each had 1 HIV-2 positive specimen. The median time from specimen receipt to laboratory reporting of results for acute infections at Massachusetts, Michigan and Maryland PHLs was 8, 11, and 7 days respectively. The laboratory cost per HIV positive specimen was $336 (Massachusetts), $263 (Michigan) and $210 (Maryland). CONCLUSIONS: Acute and established infections were found by PHLs using fourth-generation IA in conjunction with antibody tests and NAT. Time to reporting of acute HIV test results to clients was suboptimal, and needs to be streamlined to expedite treatment and interrupt transmission.

A Nonautochthonous U.S. Strain of Vibrio parahaemolyticus Isolated from Chesapeake Bay Oysters Caused the Outbreak in Maryland in 2010.

UNLABELLED: In the summer of 2010, Vibrio parahaemolyticus caused an outbreak in Maryland linked to the consumption of oysters. Strains isolated from both stool and oyster samples were indistinguishable by pulsed-field gel electrophoresis (PFGE). However, the oysters contained other potentially pathogenic V. parahaemolyticus strains exhibiting different PFGE patterns. In order to assess the identity, genetic makeup, relatedness, and potential pathogenicity of the V. parahaemolyticus strains, we sequenced 11 such strains (2 clinical strains and 9 oyster strains). We analyzed these genomes by in silico multilocus sequence typing (MLST) and determined their phylogeny using a whole-genome MLST (wgMLST) analysis. Our in silico MLST analysis identified six different sequence types (STs) (ST8, ST676, ST810, ST811, ST34, and ST768), with both of the clinical and four of the oyster strains being identified as belonging to ST8. Using wgMLST, we showed that the ST8 strains from clinical and oyster samples were nearly indistinguishable and belonged to the same outbreak, confirming that local oysters were the source of the infections. The remaining oyster strains were genetically diverse, differing in >3,000 loci from the Maryland ST8 strains. eBURST analysis comparing these strains with strains of other STs available at the V. parahaemolyticus MLST website showed that the Maryland ST8 strains belonged to a clonal complex endemic to Asia. This indicates that the ST8 isolates from clinical and oyster sources were likely not endemic to Maryland. Finally, this study demonstrates the utility of whole-genome sequencing (WGS) and associated analyses for source-tracking investigations. IMPORTANCE: Vibrio parahaemolyticus is an important foodborne pathogen and the leading cause of bacterial infections in the United States associated with the consumption of seafood. In the summer of 2010, Vibrio parahaemolyticus caused an outbreak in Maryland linked to oyster consumption. Strains isolated from stool and oyster samples were indistinguishable by pulsed-field gel electrophoresis (PFGE). The oysters also contained other potentially pathogenic V. parahaemolyticus strains with different PFGE patterns. Since their identity, genetic makeup, relatedness, and potential pathogenicity were unknown, their genomes were determined by using next-generation sequencing. Whole-genome sequencing (WGS) analysis by whole-genome multilocus sequence typing (wgMLST) allowed (i) identification of clinical and oyster strains with matching PFGE profiles as belonging to ST8, (ii) determination of oyster strain diversity, and (iii) identification of the clinical strains as belonging to a clonal complex (CC) described only in Asia. Finally, WGS and associated analyses demonstrated their utility for trace-back investigations.

Differentiating between detrimental and beneficial interruptions: a mixed-methods study.

INTRODUCTION: Efforts to understand interruptions now span much of the last decade and a half. Often thought to negatively impact patient safety, some now acknowledge that interruptions may be beneficial and actually necessary for safety and high quality care. This study seeks a framework for differentiating between interruptions that are detrimental and those that are beneficial. METHODS: A mixed-methods approach at a US Level 1 trauma centre included direct observation of 13 registered nurses (RNs), survey of 47 RNs, retrospective observation of hands-free communication devices, and modelling of observed interruptions to key performance measures. RESULTS: On average, RNs were interrupted every 11 min, with 20.3% of their workload triggered by interruptions. While 85% of RNs agreed that interruptions place their patients at risk, only 21% agreed that all should be eliminated. During one 90-min period, 18 original events spawned 68 interruptions, 50 of these repeat messages. A statistical model, with patient measures of time and comfort, revealed that alarms and call lights returning RN's attention to the patient outside the patient room are beneficial, while interruptions in the patient room are generally detrimental. Triangulating the results, we present an emerging framework for differentiating between beneficial and detrimental interruptions based on the impact of interruptions on the RN's steady treatment and attention to the patient. CONCLUSIONS: A mixed-methods approach can help distinguish between detrimental and beneficial interruptions. While interruptions breaking the delivery of steady treatment and attention to the patient are detrimental, those returning the RN's focus to the patient, as well as those supporting patient-clinician and clinician-clinician communications are beneficial. This insight may be helpful to healthcare delivery teams tasked with improving interruption-laden processes.

Characterization of Vibrio parahaemolyticus clinical strains from Maryland (2012-2013) and comparisons to a locally and globally diverse V. parahaemolyticus strains by whole-genome sequence analysis.

Vibrio parahaemolyticus is the leading cause of foodborne illnesses in the US associated with the consumption of raw shellfish. Previous population studies of V. parahaemolyticus have used Multi-Locus Sequence Typing (MLST) or Pulsed Field Gel Electrophoresis (PFGE). Whole genome sequencing (WGS) provides a much higher level of resolution, but has been used to characterize only a few United States (US) clinical isolates. Here we report the WGS characterization of 34 genomes of V. parahaemolyticus strains that were isolated from clinical cases in the state of Maryland (MD) during 2 years (2012-2013). These 2 years saw an increase of V. parahaemolyticus cases compared to previous years. Among these MD isolates, 28% were negative for tdh and trh, 8% were tdh positive only, 11% were trh positive only, and 53% contained both genes. We compared this set of V. parahaemolyticus genomes to those of a collection of 17 archival strains from the US (10 previously sequenced strains and 7 from NCBI, collected between 1988 and 2004) and 15 international strains, isolated from geographically-diverse environmental and clinical sources (collected between 1980 and 2010). A WGS phylogenetic analysis of these strains revealed the regional outbreak strains from MD are highly diverse and yet genetically distinct from the international strains. Some MD strains caused outbreaks 2 years in a row, indicating a local source of contamination (e.g., ST631). Advances in WGS will enable this type of analysis to become routine, providing an excellent tool for improved surveillance. Databases built with phylogenetic data will help pinpoint sources of contamination in future outbreaks and contribute to faster outbreak control.

Meningococcal carriage among Georgia and Maryland high school students.

BACKGROUND: Meningococcal disease incidence in the United States is at an all-time low. In a previous study of Georgia high school students, meningococcal carriage prevalence was 7%. The purpose of this study was to measure the impact of a meningococcal conjugate vaccine on serogroup Y meningococcal carriage and to define the dynamics of carriage in high school students. METHODS: This was a prospective cohort study at 8 high schools, 4 each in Maryland and Georgia, during a school year. Students at participating schools received quadrivalent meningococcal conjugate vaccine that uses diphtheria toxoid as the protein carrier (MCV4-DT). In each state, 2 high schools were randomly assigned for MCV4-DT receipt by students at the beginning of the study, and 2 were randomly assigned for MCV4-DT receipt at the end. Oropharyngeal swab cultures for meningococcal carriage were performed 3 times during the school year. RESULTS: Among 3311 students, the prevalence of meningococcal carriage was 3.21%-4.01%. Phenotypically nongroupable strains accounted for 88% of carriage isolates. There were only 5 observed acquisitions of serogroup Y strains during the study; therefore, the impact of MCV4-DT on meningococcal carriage could not be determined. CONCLUSIONS: Meningococcal carriage rates in US high school students were lower than expected, and the vast majority of strains did not express capsule. These findings may help explain the historically low incidence of meningococcal disease in the United States.

Draft Genome Sequences of Clinical Vibrio parahaemolyticus Strains Isolated in Maryland (2010 to 2013).

Vibrio parahaemolyticus is the leading cause of food-borne illnesses associated with the consumption of raw shellfish worldwide. Here, we report 45 draft genomes of V. parahaemolyticus. Thirty-five of them are strains that were isolated from clinical cases in the state of Maryland from 2010 to 2013. The remaining 10 strains were historical isolates, isolated mostly from the West Coast of the United States during the period of 1988 to 2004. The availability of these genomes will allow for future phylogenetic analyses with other V. parahaemolyticus strains.

Scheduling of advanced practice providers at Level 1 trauma centers.

BACKGROUND: Advanced practice providers (APPs) are essential to the provision of trauma care services, particularly in the wake of residency hour restrictions. Demand for these APPs fluctuates with cyclic patient arrivals; however, most trauma teams continue to staff APPs in a linear fashion. Failure to plan for variable arrivals may contribute to excessive patient wait times and emergency department overcrowding. This study used both qualitative and quantitative approaches to evaluate the impact of APP scheduling on patient wait time and to find schedules minimizing delays in reaching the needed care at the right time. METHODS: A retrospective observation of the availability of APPs and the flow of 2,249 trauma patients at a Level 1 trauma center, using both visual overlays and computer modeling, allowed us to evaluate the baseline condition, two what-if schedules, and two model-generated schedules minimizing patient time without any additional APP hours. RESULTS: A visual overlay of APP staffing on 2010 patient arrivals indicated substantial times of mismatch. Trauma managers considered adding an APP during weekday evenings that would have resulted in a 14.8% increase in APP hours and yielded a 27% reduction in patient wait times according to our model. An alternate schedule was developed and implemented in 2012 with a 10.5% increase in APP hours and yielding a 73% reduction in wait times. We also delineated two schedule options with 57% and 78% reductions in wait time and no increase in APP work hours. CONCLUSION: Evaluating alternate shift times and assignments using visual overlays and computer modeling can provide APP staffing solutions with up to 78% reduction in trauma patient wait time without additional APP labor. Knowing that care at the right time is crucial to arriving patients, making sure APP staffing is synchronized with arriving patients is something trauma center managers cannot ignore. LEVEL OF EVIDENCE: Care management study, level IV.

Disseminated Mycobacterium sherrisii infection in a US-born, HIV-infected patient.

Mycobacterium sherrisii was first described as a novel species in 2004 but recently has begun to be more formally recognized with the use of new sequencing techniques. There have only been about 10 cases reported internationally, and we report the first case of M sherrisii in the United States. The mycobacterium was isolated from acid-fast bacilli cultures of a specimen obtained from a bronchoalveolar lavage and blood in a newly diagnosed HIV-infected, US-born patient presenting with sepsis. The patient was started on streptomycin, ethambutol, azithromycin, and rifampin with an improved clinical course. This report indicates the clinical presentation along with the varying drug susceptibilities to the emerging M sherrisii.

Diversity of factor H-binding protein in Neisseria meningitidis carriage isolates.

Several meningococcal vaccines under development for prevention of serogroup B disease target the factor H-binding protein (FHbp), an immunogenic lipoprotein expressed on the surface of Neisseria meningitidis. Based upon sequence and phylogenetic analyses, FHbp can be classified into 3 protein variants (1, 2 or 3) or 2 subfamilies (A or B). The potential effect of FHbp-containing vaccines on meningococcal carriage is not known. We determined the diversity of FHbp among a population of carriage isolates obtained from Georgia and Maryland high school students in 1998 and 2006-2007. Analysis of the fHbp gene sequence from 408 carriage isolates identified 30 different FHbp protein sequences. The majority of carriage isolates harbored FHbp proteins belonging to variant 2/subfamily A. Association between FHbp proteins and genetic lineage was observed among the carriage isolates. However, split decomposition analysis, together with tests of linkage disequilibrium and pairwise homoplasy suggest recombination at fHbp contribute to allelic diversity. Of note, the FHbp proteins in serogroup B vaccines under development are either absent or not well represented in this carriage population. The FHbp genetic repertoire observed in carriage isolate populations will be useful in understanding the potential impact of FHbp-containing vaccines on meningococcal carriage.

A 96-week comparison of lopinavir-ritonavir combination therapy followed by lopinavir-ritonavir monotherapy versus efavirenz combination therapy.

Antiretroviral-naive HIV-1-infected volunteers received zidovudine/lamivudine plus either lopinavir/ritonavir (n=104) or efavirenz (n=51). Lopinavir/ritonavir-treated subjects demonstrating 3 consecutive monthly HIV-1 RNA levels <50 copies/mL started lopinavir/ritonavir monotherapy. In previous-failure=failure analysis, 48% (lopinavir/ritonavir) and 61% (efavirenz) maintained HIV-1 RNA at <50 copies/mL through week 96, (P= .17; 95% confidence interval [CI] for the difference, -29% to 4%); in noncompletion=failure analysis, 60% (lopinavir/ritonavir) and 63% (efavirenz) maintained HIV-1 RNA at <50 copies/mL at week 96 (P= .73; 95% CI for the difference, -19% to 13%). Significant sparing of peripheral lipoatrophy was noted in the lopinavir/ritonavir simplification strategy. This study has provided important information for future studies using treatment simplified to lopinavir/ritonavir monotherapy.