RESUMO
Listeria monocytogenes is a foodborne pathogen that lives in nature as a saprophyte. Two of the three most common serotypes that cause foodborne listeriosis are 1/2a and 4b. Within serotype 4b, there is a variant called 4bv-1. In the last decade, several produce-related outbreaks (linked to leafy salad, caramel apples, and stone fruit) were linked to 4bv-1 strains, specifically those of Sequence Type 382. This study assessed the fitness of ST 382 strains on lettuce leaf sections to determine if they are more fit on produce than strains of other serotypes. Strains of serotypes 1/2a, 4b, and ST 382 were inoculated as mixtures onto lettuce and incubated at 4 °C for 7 days or 25 °C for 24 h. Thirty L. monocytogenes colonies resulting from the growth on each lettuce piece were characterized for serotype by multiplex PCR, and the percentages of each serotype recovered were compared. In the individual mixtures with three strains, none of the ST 382 strains showed better fitness for growth on lettuce at either 4 °C or 25 °C. Overall, ST 382 strains showed better recovery from lettuce sections grown at 4 °C than at 25 °C. Statistical analysis of the recovery of twelve strains tested in competition experiments indicated that ST 382 strains were less fit for lettuce growth when competing against the other serotypes. The data indicate that ST 382 strains do not have a competitive fitness advantage on cut lettuce sections.
RESUMO
The Infusion Therapy Standards of Practice provide evidence-based recommendations for infusion and access device related care in any healthcare setting. Developed and published by the Infusion Nurses Society, the Standards have increased the frequency of the revision process from an every 5-year cycle to a 3-year cycle due to the growing base of literature and to deliver the most updated and current practice recommendations. This article provides an overview of the development process and a brief description of selected standards. Notably, a new standard entitled Home Infusion Therapy was added in this latest edition. The Standards are an essential reference that should be available to every home care agency that provides home infusion therapy.
Assuntos
Terapia por Infusões no Domicílio , Humanos , Terapia por Infusões no Domicílio/normas , Terapia por Infusões no Domicílio/enfermagem , Guias de Prática Clínica como Assunto , Serviços de Assistência Domiciliar/normasRESUMO
Isolation of Salmonella from enrichment cultures of food or environmental samples is a complicated process. Numerous factors including fitness in various selective enrichment media, relative starting concentrations in pre-enrichment, and competition among multi-serovar populations and associated natural microflora, come together to determine which serovars are identified from a given sample. A recently developed approach for assessing the relative abundance (RA) of multi-serovar Salmonella populations (CRISPR-SeroSeq or Deep Serotyping, DST) is providing new insight into how these factors impact the serovars observed, especially when different selective enrichment methods are used to identify Salmonella from a primary enrichment sample. To illustrate this, we examined Salmonella-positive poultry pre-enrichment samples through the selective enrichment process in Tetrathionate (TT) and Rappaport Vassiliadis (RVS) broths and assessed recovery of serovars with each medium. We observed the RA of serovars detected post selective enrichment varied depending on the medium used, initial concentration, and competitive fitness factors, all which could result in minority serovars in pre-enrichment becoming dominant serovars post selective enrichment. The data presented provide a greater understanding of culture biases and lays the groundwork for investigations into robust enrichment and plating media combinations for detecting Salmonella serovars of greater concern for human health.
Assuntos
Salmonella enterica , Animais , Humanos , Salmonella enterica/genética , Sorogrupo , Aves Domésticas , Salmonella/genética , Sorotipagem/métodos , Meios de CulturaRESUMO
The surveillance of foods for Salmonella is hindered by bias in common enrichment media where serovars implicated in human illness are outgrown by less virulent serovars. We examined four Salmonella serovars, two common in human illness (Enteritidis and Typhimurium) and two that often dominate enrichments (Give and Kentucky), for factors that might influence culture bias. The four serovars had similar growth kinetics in Tryptic Soy Broth and Buffered Peptone Water. Phenotype microarray analysis with 950 chemical substrates to assess nutrient utilization and stress resistance revealed phenotype differences between serovars. Strains of S. Enteritidis had better utilization of plant-derived sugars such as xylose, mannitol, rhamnose, and fructose, while S. Typhimurium strains were able to metabolize tagatose. Strains of S. Kentucky used more compounds as phosphorus sources and grew better with inorganic phosphate as the sole phosphorus source. The sequences of nine genes involved in phosphate metabolism were compared, and there were differences between serovars in the catalytic ATP-binding domain of the histidine kinase phoR. Analysis of the predicted PhoR amino acid sequences from additional Salmonella genomes indicated a conservation of sequences each within the Typhimurium, Give, and Enteritidis serovars. However, three different PhoR versions were observed in S. Kentucky.
RESUMO
Infusion of fluids and medications is traditionally performed intravenously. However, venous depletion in patients has led to the quest for vessel health preservation. A safe, effective, acceptable, and efficient alternative is the subcutaneous route. A lack of organizational policies may contribute to the slow uptake of this practice. This modified e-Delphi (electronic) study aimed to derive international consensus on practice recommendations for subcutaneous infusions of fluids and medications. A panel of 11 international clinicians, with expertise in subcutaneous infusion research and/or clinical practice, rated and edited subcutaneous infusion practice recommendations from evidence, clinical practice guidelines, and clinical expertise within an Assessment, Best Practice, and Competency (ABC) domain guideline model. The ABC Model for Subcutaneous Infusion Therapy provides a systematic guideline of 42 practice recommendations for the safe delivery of subcutaneous infusions of fluids and medications in the adult population in all care settings. These consensus recommendations provide a guideline for health care providers, organizations, and policy makers to optimize use of the subcutaneous access route.
Assuntos
Veias , Humanos , Adulto , Técnica Delphi , Infusões Subcutâneas , Infusões ParenteraisRESUMO
Listeria monocytogenes is a Gram-positive, facultative intracellular foodborne pathogen capable of causing severe, invasive illness (listeriosis). Three serotypes, 1/2a, 1/2b, and 4b, are leading contributors to human listeriosis, with 4b including the major hypervirulent clones. The multiplex PCR scheme developed by Doumith and collaborators employs primers targeting specific lineages (e.g., lineage II-specific lmo0737, lineage I-specific LMOf2365_2059) or serotypes (e.g., serotype 4b-specific LMOf2365_1900). The Doumith scheme (DS) is extensively employed for molecular serotyping of L. monocytogenes due to its high accuracy, relative ease, and affordability. However, for certain strains, the DS serotype designations are in conflict with those relying on antibody-based schemes or whole-genome sequence (WGS) analysis. In the current study, all 27 tested serotype 4b strains with sequence type 782 (ST782) within the hypervirulent clonal complex 2 (CC2) were designated 1/2b/3b using the DS. These strains lacked the serotype 4b-specific gene LMOf2365_1900, while retaining LMOf2365_2059, which, together with prs, yields the DS 1/2b/3b profile. Furthermore, 15 serotype 1/2a strains of four STs, mostly from water, were designated 1/2b/3b using the DS. These strains lacked the lmo0737 cassette but harbored genomic islands with LMOf2365_2059, thus yielding the DS 1/2b/3b profile. Lastly, we investigated a novel, dual 1/2a-1/2b profile obtained using the DS with 21 serotype 1/2a strains of four STs harboring both the lmo0737 cassette and genomic islands with LMOf2365_2059. The findings suggest that for certain strains and clones of L. monocytogenes the DS designations should be viewed with caution and complemented with alternative tools, e.g., traditional serotyping or WGS analysis. IMPORTANCE Listeria monocytogenes is a foodborne pathogen responsible for severe illness (listeriosis), especially in pregnant women and their fetuses, immunocompromised individuals, and the elderly. Three serotypes, 1/2a, 1/2b, and 4b, account for most human listeriosis, with certain serotype 4b clonal complexes (CCs) overrepresented in human disease. Serotyping remains extensively employed in Listeria epidemiologic investigations, and a multiplex PCR-based serotyping scheme is widely used. However, the PCR gene targets can be lost or gained via horizontal gene transfer, leading to novel PCR profiles without known serotype designations or to incorrect serotype assignments. Thus, an entire serotype 4b clone of the hypervirulent CC2 would be misidentified as serotype 1/2b, and several strains of serotype 1/2a would be identified as serotype 1/2b. Such challenges are especially common in novel clones from underexplored habitats, e.g., wildlife and surface water. The findings suggest caution in application of molecular serotyping, while highlighting Listeria's diversity and potential for horizontal gene transfer.
Assuntos
Listeria monocytogenes , Listeriose , Gravidez , Feminino , Humanos , Idoso , Listeria monocytogenes/genética , Sorogrupo , Sorotipagem , Transferência Genética HorizontalRESUMO
A 5-year survey of public access surface waters in an agricultural region of the Central California Coast was done to assess the prevalence of the foodborne pathogen Listeria monocytogenes. In nature, L. monocytogenes lives as a saprophyte in soil and water, which are reservoirs for contamination of preharvest produce. Moore swabs were deployed biweekly in lakes, ponds, streams, and rivers during 2011 to 2016. L. monocytogenes was recovered in 1,224 of 2,922 samples, resulting in 41.9% prevalence. Multiple subtypes were isolated from 97 samples, resulting in 1,323 L. monocytogenes isolates. Prevalence was higher in winter and spring and after rain events in some waterways. Over 84% of the isolates were serotype 4b. Whole-genome sequencing was done on 1,248 isolates, and in silico multilocus sequence typing revealed 74 different sequence types (STs) and 39 clonal complexes (CCs). The clones most isolated, CC639, CC183, and CC1, made up 27%, 19%, and 13%, respectively, of the sequenced isolates. Other types were CC663, CC6, CC842, CC4, CC2, CC5, and CC217. All sequenced isolates contained intact copies of core L. monocytogenes virulence genes, and pathogenicity islands LIPI-3 and LIPI-4 were identified in 73% and 63%, respectively, of the sequenced isolates. The virulence factor internalin A was predicted to be intact in all but four isolates, while genes important for sanitizer and heavy metal resistance were found in <5% of the isolates. These waters are not used for crop irrigation directly, but they are available to wildlife and can flood fields during heavy rains. IMPORTANCE Listeria monocytogenes serotype 4b and 1/2a strains are implicated in most listeriosis, and hypervirulent listeriosis stems from strains containing pathogenicity islands LIPI-3 and LIPI-4. The waters and sediments in the Central California Coast agricultural region contain widespread and diverse L. monocytogenes populations, and all the isolates contain intact virulence genes. Emerging clones CC183 and CC639 were the most abundant clones, and major clones CC1, CC4, and CC6 were well represented. CC183 was responsible for three produce-related outbreaks in the last 7 years. Most of the isolates in the survey differ from those of lesser virulence that are often isolated from foods and food processing plants because they contain genes encoding an intact virulence factor, internalin A, and most did not contain genes for sanitizer and heavy metal resistance. This isolate collection is important for understanding L. monocytogenes populations in agricultural and natural regions.
Assuntos
Listeria monocytogenes , Listeriose , Humanos , Listeriose/epidemiologia , Tipagem de Sequências Multilocus , Prevalência , Fatores de Virulência/genéticaRESUMO
Prevalence and serovar diversity of Salmonella enterica were measured during a 5-year survey of surface waters in a 500-mi2 agricultural region of the Central California Coast. Rivers, streams, lakes, and ponds were sampled bimonthly resulting in 2,979 samples. Overall prevalence was 56.4% with higher levels detected in spring than in fall. Small, but significant, differences in prevalence were detected based on sample locations. Detection of Salmonella was correlated positively with both significant rain events and, in some environments, levels of generic Escherichia coli. Analysis of 1,936 isolates revealed significant serovar diversity, with 91 different serovars detected. The most common isolated serovars were S. enterica subsp. enterica serovars I 6,8:d:- (406 isolates, 21.0%, and potentially monophasic Salmonella Muenchen), Give (334 isolates, 17.3%), Muenchen (158 isolates, 8.2%), Typhimurium (227 isolates, 11.7%), Oranienburg (106 isolates, 5.5%), and Montevideo (78 isolates, 4%). Sixteen of the 24 most common serovars detected in the region are among the serovars reported to cause the most human salmonellosis in the United States. Some of the serovars were associated with location and seasonal bias. Analysis of XbaI pulsed field gel electrophoresis (PFGE) patterns of strains of serovars Typhimurium, Oranienburg, and Montevideo showed significant intraserovar diversity. PFGE pulsotypes were identified in the region for multiple years of the survey, indicating persistence or regular reintroduction to the region. IMPORTANCE Nontyphoidal Salmonella is among the leading causes of bacterial foodborne illness, and increasing numbers of outbreaks and recalls are due to contaminated produce. High prevalence and 91 different serovars were detected in this leafy green growing region. Seventeen serovars that cause most of the human salmonellosis in the United States were detected, with 16 of those serovars detected in multiple locations and multiple years of the 5-year survey. Understanding the widespread prevalence and diversity of Salmonella in the region will assist in promoting food safety practices and intervention methods for growers and regulators.
Assuntos
Infecções por Salmonella , Salmonella enterica , Eletroforese em Gel de Campo Pulsado , Humanos , Prevalência , Infecções por Salmonella/microbiologia , SorogrupoRESUMO
Antimicrobial resistance, the ability of microbes to become resistant to known antimicrobial medications, is a growing and serious global health concern. There are growing numbers of publications about efforts to educate nurses about antimicrobial resistance, and efforts to involve nurses in antimicrobial stewardship in acute and long-term care settings; however, this has not been the case in home care. Home care organizations are required to address infection control and surveillance, including patient, family, and staff education. Home care nurses play an important role in identifying infections, performing cultures, and teaching patients and families. This article provides an overview of antimicrobial resistance and antimicrobial stewardship and provides antimicrobial stewardship actions for home care nurses and agencies. In the interest of public health, home care agencies and nurses can, and should, educate themselves and patients about antimicrobial resistance and employ antimicrobial stewardship strategies.
Assuntos
Anti-Infecciosos , Gestão de Antimicrobianos , Serviços de Assistência Domiciliar , Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Atenção à Saúde , Farmacorresistência Bacteriana , HumanosRESUMO
The complete genome sequence of Enterobacter asburiae strain AEB30 is presented. The strain was isolated from store-bought ginger in Albany, CA, in 2016.
RESUMO
The Infusion Therapy Standards of Practice provide evidence-based recommendations as published by the Infusion Nurses Society every 5 years. This article provides a brief overview of the development process and short summaries of selected standards with attention to highlighting the relevance to home care agencies and nurses. The Standards should be reviewed by any home care organization that provides home infusion therapy.
Assuntos
Serviços de Assistência Domiciliar , Terapia por Infusões no Domicílio , HumanosRESUMO
ABSTRACT: The foodborne pathogen Listeria monocytogenes lives as a saprophyte in nature and can adhere to and grow on surfaces as diverse as leaves, sediment, and stainless steel. To discern the mechanisms used by L. monocytogenes for attachment and growth on various surfaces, we studied interactions between the pathogen on lettuce and stainless steel. A panel of 24 strains (23 L. monocytogenes and 1 Listeria innocua) were screened for attachment and growth on lettuce at 4 and 25°C and on stainless steel at 10 and 37°C. Overnight growth of attached cells resulted in a 0- to 3-log increase on lettuce, depending on the strain and the temperature. Among the worst-performing strains on lettuce were two from a large cantaloupe outbreak, indicating that factors important for interactions with cantaloupe may be different from those required on lettuce tissue. Strains that grew the best on lettuce belonged to serotypes 1/2a, 1/2b, and 4b and were from cheese, potatoes, and water-sediment near produce fields. Confocal microscopy of L. monocytogenes tagged with constitutively expressed green fluorescent protein indicated associations with the cut edges and veins of lettuce leaves. On stainless steel coupons, there was a 5- to 7-log increase at 10°C after 7 days and a 4- to 7-log increase at 37°C after 40 h. Statistically, surface growth on stainless steel was better for serotype 1/2a than for serotype 4b strains, even though certain serotype 4b strains grew well on the coupons. The latter included strains that originated from produce and water-sediment. Some strains were fit in both environments, whereas others showed variability between the two different surfaces. Further analysis of these strains should reveal molecular factors needed for adherence and surface growth of L. monocytogenes on different biotic and abiotic surfaces.
Assuntos
Listeria monocytogenes , Aço Inoxidável , Aderência Bacteriana , Biofilmes , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Lactuca , Listeria , Aço Inoxidável/análiseRESUMO
For assessing isolates of Listeria monocytogenes, serotype designation is the first subtyping method used. Methodologies used to assign serotype are currently evolving and will eventually be replaced with whole genome sequencing. Traditionally, serotyping has been done with agglutination reactions; however, alternative methods utilizing enzyme linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) are common. Described here are the three non-genomic methods and the advantages and disadvantages of each.
Assuntos
Testes de Aglutinação/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Listeria monocytogenes/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sorotipagem/métodos , Humanos , Listeria monocytogenes/classificação , Listeriose/diagnósticoRESUMO
Listeria monocytogenes is a foodborne pathogen that causes high rates of hospitalization and mortality in people infected. Contamination of fresh, ready to eat produce by this pathogen is especially troubling because of the ability of this bacterium to grow on produce under refrigeration temperatures. In this study, we created a library of over 8,000 plant phyllosphere-associated bacteria and screened them for the ability to inhibit the growth of L. monocytogenes in an in vitro fluorescence-based assay. One isolate, later identified as Bacillus amyloliquefaciens ALB65, was able to inhibit the fluorescence of L. monocytogenes by >30-fold in vitro. B. amyloliquefaciens ALB65 was also able to grow, persist, and reduce the growth of L. monocytogenes by >1.5 log CFU on cantaloupe melon rinds inoculated with 5 × 103 CFU at 30°C and was able to completely inhibit its growth at temperatures below 8°C. DNA sequence analysis of the B. amyloliquefaciens ALB65 genome revealed six gene clusters that are predicted to encode genes for antibiotic production; however, no plant or human virulence factors were identified. These data suggest that B. amyloliquefaciens ALB65 is an effective and safe biological control agent for the reduction of L. monocytogenes growth on intact cantaloupe melons and possibly other types of produce.IMPORTANCEListeria monocytogenes is estimated by the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration to cause disease in approximately 1,600 to 2,500 people in the United States every year. The largest known outbreak of listeriosis in the United States was associated with intact cantaloupe melons in 2011, resulting in 147 hospitalizations and 33 deaths. In this study, we demonstrated that Bacillus amyloliquefaciens ALB65 is an effective biological control agent for the reduction of L. monocytogenes growth on intact cantaloupe melons under both pre- and postharvest conditions. Furthermore, we demonstrated that B. amyloliquefaciens ALB65 can completely inhibit the growth of L. monocytogenes during cold storage (<8°C).
Assuntos
Bacillus amyloliquefaciens/fisiologia , Agentes de Controle Biológico/farmacologia , Cucumis melo/microbiologia , Microbiologia de Alimentos , Listeria monocytogenes/fisiologia , Temperatura Baixa , Manipulação de AlimentosRESUMO
We present here the complete genome sequences of three Salmonella enterica subsp. enterica serovar Muenchen strains, LG24, LG25, and LG26. All three strains were isolated from almond drupes grown in an orchard in San Joaquin County, California, in 2016. These genomic sequences are nonidentical and will contribute to our understanding of S. enterica genomics.
RESUMO
BACKGROUND: A consensus on a central line-associated bloodstream infection (CLABSI) surveillance definition in home infusion is needed to standardize measurement and benchmark CLABSI to provide data to drive improvement initiatives METHODS: Experts across fields including home infusion therapy, infectious diseases, and healthcare epidemiology convened to perform a 3-step modified Delphi approach to obtain input and achieve consensus on a candidate home infusion CLABSI definition. RESULTS: The numerator criterion was identified by participants as involving one of the 2 following: (1) recognized pathogen isolated from blood culture and pathogen is not related to infection at another site, or (2) one of the following signs or symptoms: fever of 38°C (100.4°F), chills, or hypotension (systolic blood pressure ≤90 mm Hg), and one of the 2 following: (A) common skin contaminant isolated from 2 blood cultures drawn on separate occasions and organism is not related to infection at another site, or (B) common skin contaminant isolated from blood culture from patient with intravascular access device and provider institutes appropriate antimicrobial therapy. The criteria for a denominator included days from the day of admission with a central venous catheter to day of removal of central venous catheter. In addition, 11 inclusion criteria and 4 exclusion criteria were included. DISCUSSION: Home infusion therapy and healthcare epidemiology experts developed candidate criteria for a home infusion CLABSI surveillance definition. CONCLUSIONS: Home care and home infusion agencies can use this definition to monitor their own CLABSI rates and implement preventative strategies.