scholarly journals Molecular Epidemiology of a Vancomycin-Intermediate Heteroresistant Staphylococcus epidermidis Outbreak in a Neonatal Intensive Care Unit

2016 ◽  
Vol 60 (10) ◽  
pp. 5673-5681 ◽  
Author(s):  
Jasmine Chong ◽  
Caroline Quach ◽  
Ana C. Blanchard ◽  
Philippe Guillaume Poliquin ◽  
George R. Golding ◽  
...  
Keyword(s):  
Intensive Care ◽  
Molecular Epidemiology ◽  
Staphylococcus Epidermidis ◽  
Population Analysis ◽  
Tertiary Care ◽  
Hospital Environment ◽  
Coagulase Negative Staphylococci ◽  
Time Curve ◽  
Content Type ◽  
The Impact

ABSTRACTCoagulase-negative staphylococci (CoNS) have become the leading cause of bloodstream infections (BSIs) in intensive care units (ICUs), particularly in premature neonates. Vancomycin-intermediate heteroresistant CoNS (hVICoNS) have been identified as sources of BSIs worldwide, and their potential to emerge as significant pathogens in the neonatal ICU (NICU) remains uncertain. This study describes the molecular epidemiology of an outbreak of vancomycin-heteroresistant (hV)Staphylococcus epidermidiscentral-line-associated BSI (CLABSI) in a single tertiary care NICU and compares it to a second tertiary care NICU that had not been associated with an outbreak. Between November 2009 and April 2014, 119S. epidermidisCLABSIs were identified in two tertiary care NICUs in Quebec, Canada. Decreased vancomycin susceptibility was identified in about 88% of all collected strains using Etest methods. However, discrepancies were found according to the Etest and population analysis profiling–area under the concentration-time curve (PAP-AUC) methods used. All strains were susceptible to linezolid, and a few isolates were nonsusceptible to daptomycin. Great genetic diversity was observed within the collection, with 31 pulsed-field gel electrophoresis (PFGE) patterns identified. The outbreak strains were all determined to be heteroresistant to vancomycin and were polyclonal. The study identified two major clones, PFGE patterns E and G, which were found in both NICUs across the 5-year study period. This suggests the persistence of highly successful clones that are well adapted to the hospital environment. hVS. epidermidisseems more common than currently realized in the NICU, and certain hVS. epidermidisclones can become endemic to the NICU. The reservoirs for these clones remain unknown at this time, and identification of the reservoirs is needed to better understand the impact of hVS. epidermidisin the NICU and to inform infection prevention strategies. In addition, there is a need to investigate and validate hV determination protocols for different species of CoNS.

scholarly journals Molecular Epidemiology of Staphylococcus epidermidis in a Neonatal Intensive Care Unit over a Three-Year Period

2000 ◽  
Vol 38 (5) ◽  
pp. 1740-1746 ◽  
Author(s):  
P. Villari ◽  
C. Sarnataro ◽  
L. Iacuzio
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Neonatal Intensive Care Unit ◽  
Staphylococcus Epidermidis ◽  
Neonatal Intensive Care ◽  
Population Analysis ◽  
Molecular Techniques ◽  
Detection Methods ◽  
Strict Adherence ◽  
The Impact

Coagulase-negative staphylococci, especially Staphylococcus epidermidis, are increasingly important nosocomial pathogens, particularly in critically ill neonates. A 3-year prospective surveillance of nosocomial infections in a neonatal intensive care unit (NICU) was performed by traditional epidemiologic methods as well as molecular typing of microorganisms. The aims of the study were (i) to quantify the impact of S. epidermidis on NICU-acquired infections, (ii) to establish if these infections are caused by endemic clones or by incidentally occurring bacterial strains of this ubiquitous species, (iii) to evaluate the use of different methods for the epidemiologic typing of the isolates, and (iv) to characterize the occurrence and the spread of staphylococci with decreased glycopeptide susceptibility. Results confirmed that S. epidermidis is one of the leading causes of NICU-acquired infections and that the reduced glycopeptide susceptibility, if investigated by appropriate detection methods such as population analysis, is more common than is currently realized. Typing of isolates, which can be performed effectively through molecular techniques such as pulsed-field gel electrophoresis but not through antibiograms, showed that many of these infections are due to clonal dissemination and, thus, are potentially preventable by strict adherence to recommended infection control practices and the implementation of programs aimed toward the reduction of the unnecessary use of antibiotics. These strategies are also likely to have a significant impact on the frequency of the reduced susceptibility of staphylococci to glycopeptides, since this phenomenon appears to be determined either by more resistant clones transmitted from patient to patient or, to a lesser extent, by strains that become more resistant as a result of antibiotic pressure.

The rate and impact of substance misuse in psychiatric intensive care units (PICUs) in the UK

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hattie Catherine Ann Moyes ◽  
Lana MacNaboe ◽  
Kate Townsend
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Substance Misuse ◽  
Well Being ◽  
Training Programme ◽  
Content Type ◽  
National Quality ◽  
Improvement Programme ◽  
The Uk ◽  
The Impact

Purpose This paper aims to understand the current scale of substance misuse in psychiatric intensive care units (PICUs), identify how substance misuse affects members of staff, patients and the running of wards and explore with staff what resources would be most useful to more effectively manage substance misuse and dual diagnosis on PICUs. Design/methodology/approach The paper used a mixed-methods approach, using a quantitative survey to determine the extent of substance use in PICUs and a co-design workshop to understand the impact of substance misuse on PICU wards, staff and patients. Findings The estimated rate of substance misuse in PICUs over a 12-month period is 67%, with cannabis the most frequently used substance. Despite the range of problems experienced on PICUs because of substance misuse, the availability of training and resources for staff was mixed. Research limitations/implications The findings may not be fully generalisable as research participants were members of a national quality improvement programme, and therefore, may not be representative of all PICUs. Data was collected from clinicians only; if patients were included, they might have provided another perspective on substance misuse on PICUs. Practical implications This paper emphasises the importance of substance misuse training for PICU staff to adequately respond to patients who misuse substances, improve the ward environment, staff well-being and patient outcomes. Originality/value This paper provides an updated estimation of rates of substance misuse in PICUs over a 12-month period and make suggestions for a training programme that can better support staff to address substance misuse on PICUs.

scholarly journals Tailoring Antimicrobial Susceptibility Testing to Individual Species of Coagulase-Negative Staphylococci: Next Up, Staphylococcus epidermidis

2019 ◽  
Vol 57 (12) ◽  
Author(s):  
C. Paul Morris ◽  
Patricia J. Simner
Keyword(s):  
Antimicrobial Susceptibility ◽  
Staphylococcus Epidermidis ◽  
Susceptibility Testing ◽  
Methicillin Resistance ◽  
Antimicrobial Susceptibility Testing ◽  
Individual Species ◽  
Beta Lactam ◽  
Coagulase Negative Staphylococci ◽  
Content Type ◽  
Species Specific

ABSTRACT Accurate detection of methicillin resistance among staphylococci is vital for patient care. Methicillin resistance is most commonly mediated by acquisition of the mecA gene, which encodes an altered penicillin binding protein, PBP2a. Application of phenotypic methods to detect mecA-mediated beta-lactam resistance in staphylococci is becoming more complex as species-specific differences are identified among coagulase-negative staphylococci (CoNS). Previously, interpretative criteria and antimicrobial susceptibility testing (AST) methods specific to the CoNS group were used to evaluate Staphylococcus epidermidis. A manuscript by S. N. Naccache, K. Callan, C.-A. D. Burnham, M. A. Wallace, et al. (J Clin Microbiol 57:e00961-19, 2019, https://doi.org/10.1128/JCM.00961-19) details experiments revealing that S. epidermidis, the most common clinically isolated CoNS, requires tailored use of previously described methods and interpretive criteria to reliably identify the presence of mecA-mediated methicillin resistance.

scholarly journals Apotransferrin in Combination with Ciprofloxacin Slows Bacterial Replication, Prevents Resistance Amplification, and Increases Antimicrobial Regimen Effect

2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Paul G. Ambrose ◽  
Brian D. VanScoy ◽  
Brian M. Luna ◽  
Jun Yan ◽  
Amber Ulhaq ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Bacterial Density ◽  
Infection Model ◽  
Time Curve ◽  
Content Type ◽  
Wide Range ◽  
Bacterial Replication ◽  
The Impact

ABSTRACT There has been renewed interest in combining traditional small-molecule antimicrobial agents with nontraditional therapies to potentiate antimicrobial effects. Apotransferrin, which decreases iron availability to microbes, is one such approach. We conducted a 48-h one-compartment in vitro infection model to explore the impact of apotransferrin on the bactericidal activity of ciprofloxacin. The challenge panel included four Klebsiella pneumoniae isolates with ciprofloxacin MIC values ranging from 0.08 to 32 mg/liter. Each challenge isolate was subjected to an ineffective ciprofloxacin monotherapy exposure (free-drug area under the concentration-time curve over 24 h divided by the MIC [AUC/MIC ratio] ranging from 0.19 to 96.6) with and without apotransferrin. As expected, the no-treatment and apotransferrin control arms showed unaltered prototypical logarithmic bacterial growth. We identified relationships between exposure and change in bacterial density for ciprofloxacin alone (R2 = 0.64) and ciprofloxacin in combination with apotransferrin (R2 = 0.84). Addition of apotransferrin to ciprofloxacin enabled a remarkable reduction in bacterial density across a wide range of ciprofloxacin exposures. For instance, at a ciprofloxacin AUC/MIC ratio of 20, ciprofloxacin monotherapy resulted in nearly 2 log10 CFU increase in bacterial density, while the combination of apotransferrin and ciprofloxacin resulted in 2 log10 CFU reduction in bacterial density. Furthermore, addition of apotransferrin significantly reduced the emergence of ciprofloxacin-resistant subpopulations compared to monotherapy. These data demonstrate that decreasing the rate of bacterial replication with apotransferrin in combination with antimicrobial therapy represents an opportunity to increase the magnitude of the bactericidal effect and to suppress the growth rate of drug-resistant subpopulations.

scholarly journals Generic Vancomycin Enriches Resistant Subpopulations of Staphylococcus aureus after Exposure in a Neutropenic Mouse Thigh Infection Model

2011 ◽  
Vol 56 (1) ◽  
pp. 243-247 ◽  
Author(s):  
Carlos A. Rodriguez ◽  
Maria Agudelo ◽  
Andres F. Zuluaga ◽  
Omar Vesga
Keyword(s):  
Staphylococcus Aureus ◽  
Population Analysis ◽  
Recovery Process ◽  
Control Group ◽  
Infection Model ◽  
Content Type ◽  
Sterile Saline ◽  
Generic Products ◽  
The Impact

ABSTRACTPrevious studies have shown that “bioequivalent” generic products of vancomycin are less effectivein vivoagainstStaphylococcus aureusthan the innovator compound. Considering that suboptimal bactericidal effect has been associated with emergence of resistance, we aimed to assessin vivothe impact of exposure to innovator and generic products of vancomycin onS. aureussusceptibility. A clinical methicillin-resistantS. aureus(MRSA) strain from a liver transplant patient with persistent bacteremia was used for which MIC, minimum bactericidal concentration (MBC), and autolytic properties were determined. Susceptibility was also assessed by determining a population analysis profile (PAP) with vancomycin concentrations from 0 to 5 mg/liter. ICR neutropenic mice were inoculated in each thigh with ∼7.0 log10CFU. Treatment with the different vancomycin products (innovator and three generics; 1,200 mg/kg of body weight/day every 3 h) started 2 h later while the control group received sterile saline. After 24 h, mice were euthanized, and the thigh homogenates were plated. Recovered colonies were reinoculated to new groups of animals, and the exposure-recovery process was repeated until 12 cycles were completed. The evolution of resistance was assessed by PAP after cycles 5, 10, 11, and 12. The initial isolate displayed reduced autolysis and higher resistance frequencies thanS. aureusATCC 29213 but without vancomycin-intermediateS. aureus(VISA) subpopulations. After 12 cycles, innovator vancomycin had significantly reduced resistant subpopulations at 1, 2, and 3 mg/liter, while the generic products had enriched them progressively by orders of magnitude. The great capacity of generic vancomycin to select for less susceptible organisms raises concerns about the role of therapeutic inequivalence of any antimicrobial on the epidemiology of resistance worldwide.

scholarly journals Genome Variation and Molecular Epidemiology ofSalmonella entericaSerovar Typhimurium Pathovariants

2018 ◽  
Vol 86 (8) ◽  
Author(s):  
Priscilla Branchu ◽  
Matt Bawn ◽  
Robert A. Kingsley
Keyword(s):  
Molecular Epidemiology ◽  
Host Range ◽  
Animal Health ◽  
Wide Distribution ◽  
Genomic Diversity ◽  
Broad Host Range ◽  
Wild Animals ◽  
Genome Variation ◽  
Content Type ◽  
The Impact

ABSTRACTSalmonella entericaserovar Typhimurium is one of approximately 2,500 distinct serovars of the genusSalmonellabut is exceptional in its wide distribution in the environment, livestock, and wild animals.S. Typhimurium causes a large proportion of nontyphoidalSalmonella(NTS) infections, accounting for a quarter of infections, second only toS. entericaserovar Enteritidis in incidence.S. Typhimurium was once considered the archetypal broad-host-rangeSalmonellaserovar due to its wide distribution in livestock and wild animals, and much of what we know of the interaction ofSalmonellawith the host comes from research using a small number of laboratory strains of the serovar (LT2, SL1344, and ATCC 14028). But it has become clear that these strains do not reflect the genotypic or phenotypic diversity ofS. Typhimurium. Here, we review the epidemiological record ofS. Typhimurium and studies of the host-pathogen interactions of diverse strains ofS. Typhimurium. We present the concept of distinct pathovariants ofS. Typhimurium that exhibit diversity of host range, distribution in the environment, pathogenicity, and risk to food safety. We review recent evidence from whole-genome sequencing that has revealed the extent of genomic diversity ofS. Typhimurium pathovariants, the genomic basis of differences in the level of risk to human and animal health, and the molecular epidemiology of prominent strains. An improved understanding of the impact of genome variation of bacterial pathogens on pathogen-host and pathogen-environment interactions has the potential to improve quantitative risk assessment and reveal how new pathogens evolve.

scholarly journals Cumulative Antimicrobial Susceptibility Data from Intensive Care Units at One Institution: Should Data Be Combined?

2016 ◽  
Vol 54 (4) ◽  
pp. 956-959 ◽  
Author(s):  
Aaron Campigotto ◽  
Matthew P. Muller ◽  
Linda R. Taggart ◽  
Reem Haj ◽  
Elizabeth Leung ◽  
...  
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Average Method ◽  
Tertiary Care ◽  
Empirical Therapy ◽  
Care Hospital ◽  
Content Type ◽  
Susceptibility Data ◽  
Minimum Number ◽  
Empirical Antibiotics

Cumulative susceptibility test data (CSTD) are used to guide empirical antimicrobial therapy and to track trends in antibiotic resistance. The Clinical and Laboratory Standards Institute recommends reporting CSTD at least annually and sets the minimum number of isolates per reported organism at 30. To comply, many hospitals combine data from multiple intensive care units (ICUs); however, this may not be appropriate to guide empirical therapy because of variations in patient populations. In this study, susceptibility data for two different ICUs at a tertiary care hospital in Toronto, Canada, were used to create a traditional CSTD report, which combined data from different ICUs, and a rolling-average CSTD report, which pooled 2 years of data for each ICU separately. For simplicity, data for only the most common Gram-negative organisms (Escherichia coli,Pseudomonas aeruginosa) and the most relevant antibiotics (ciprofloxacin, piperacillin-tazobactam) were examined. With the rolling-average method, significant differences in susceptibility were seen between the ICUs in 50% of the organism-antimicrobial combinations. Furthermore, the 3% median year-over-year difference in susceptibilities seen for the 16 organism-antibiotic combinations by using the traditional method was lower than the 14% median difference seen for the 20 between-ICU within-year comparisons obtained using the rolling-average method. Changes in our selection of empirical antibiotics resulted from this revised approach, and our results suggest that pooling data from ICUs with different patient populations may not be appropriate. A rolling-average method may be an appropriate strategy for the creation of individual-unit CSTD reports.

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