Evaluation of the NG-Test MCR-1 Lateral Flow Assay and EDTA-Colistin Broth Disk Elution Methods To Detect Plasmid-Mediated Colistin Resistance among Gram-Negative Bacterial Isolates

ABSTRACT Plasmid-mediated colistin resistance (PMCR) is a global public health concern, given its ease of transmissibility. The purpose of this study was to evaluate two methods for the detection of PMCR from bacterial colonies: (i) the NG-Test MCR-1 lateral flow immunoassay (LFA; NG Biotech, Guipry, France) and (ii) the EDTA-colistin broth disk elution (EDTA-CBDE) screening test method. These methods were evaluated using a cohort of contemporary, clinical Gram-negative bacillus isolates from 3 U.S. academic medical centers (126 isolates of the Enterobacterales, 50 Pseudomonas aeruginosa isolates, and 50 Acinetobacter species isolates; 1 isolate was mcr positive) and 12 mcr-positive CDC-FDA Antibiotic Resistance (AR) Isolate Bank isolates for which reference broth microdilution colistin susceptibility results were available. Eleven (4.6%) isolates were strongly positive by the MCR-1 LFA, with an additional 8 (3.4%) isolates yielding faintly positive results. The positive percent agreement (PPA) and negative percent agreement (NPA) for MCR-1 detection were 100% and 96.1%, respectively. Upon repeat testing, only a single false-positive MCR-2 producer remained, as the isolates with initially faintly positive results were negative. The EDTA-CBDE screening method had an overall PPA and NPA of 100% and 94.3%, respectively. The NPA for the EDTA-CBDE method was slightly lower at 94.2% with Enterobacterales, whereas it was 96.0% with P. aeruginosa. The MCR-1 LFA and EDTA-CBDE methods are both accurate and user-friendly methods for the detection of PMCR. Despite the rarity of PMCR among clinical isolates in the United States, these methods are valuable tools that may be implemented in public health and clinical microbiology laboratories to further discern the mechanism of resistance among colistin-resistant Gram-negative isolates and to detect PMCR for infection prevention and control purposes.

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Comparison of the Superpolymyxin and ChromID Colistin R Screening Media for the Detection of Colistin-Resistant Enterobacteriaceae from Spiked Rectal Swabs

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01618-18 ◽

2018 ◽

Vol 63 (1) ◽

Cited By ~ 7

Author(s):

Delphine Girlich ◽

Thierry Naas ◽

Laurent Dortet

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

Confidence Interval ◽

Enterobacter Cloacae ◽

Bacterial Isolates ◽

Colistin Resistance ◽

Gram Negative ◽

Content Type ◽

Rectal Swabs ◽

Stool Samples

ABSTRACT The dissemination of carbapenemase-producing Enterobacteriaceae (CPE) has led to the increased use of colistin, which has resulted in the emergence of colistin-resistant Enterobacteriaceae worldwide. One of the most threatening scenarios is the dissemination of colistin resistance in CPE, particularly the plasmid-encoded resistance element MCR. Thus, it has now become mandatory to possess reliable media to screen for colistin-resistant Gram-negative bacterial isolates, especially Enterobacteriaceae. In this study, we evaluated the performances of the Superpolymyxin medium (ELITechGroup) and the ChromID Colistin R medium (bioMérieux) to screen for colistin-resistant Enterobacteriaceae from spiked rectal swabs. Stool samples were spiked with a total of 94 enterobacterial isolates (Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Enterobacter cloacae), including 53 colistin-resistant isolates. ESwabs (Copan Diagnostics) were then inoculated with those spiked fecal suspensions, and culture proceeded as recommended by both manufacturers. The sensitivity of detection of colistin-resistant Enterobacteriaceae was 86.8% (95% confidence interval [95% CI] = 74.0% to 94.0%) using both the Superpolymyxin medium and the ChromID Colistin R plates. Surprisingly, the isolates that were not detected were not the same for both media. The specificities were high for both media, at 97.9% (95% CI = 87.3% to 99.9%) for the Superpolymyxin medium and 100% (95% CI = 90.4% to 100%) for the ChromID Colistin R medium. Both commercially available media, ChromID Colistin R and Superpolymyxin, provide useful tools to screen for colistin-resistant Enterobacteriaceae from patient samples (rectal swabs) regardless of the level and mechanism of colistin resistance.

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A Novel Phenotypic Method To Screen for Plasmid-Mediated Colistin Resistance among Enterobacteriales

Journal of Clinical Microbiology ◽

10.1128/jcm.00040-19 ◽

2019 ◽

Vol 57 (5) ◽

Cited By ~ 4

Author(s):

Drew T. Bell ◽

Yehudit Bergman ◽

Abida Q. Kazmi ◽

Shawna Lewis ◽

Pranita D. Tamma ◽

...

Keyword(s):

Public Health ◽

Sensitivity And Specificity ◽

Health Concern ◽

Colistin Resistance ◽

Public Health Concern ◽

Significant Public Health Concern ◽

Phenotypic Method ◽

Significant Public Health ◽

Clinical Pathogens

ABSTRACT Plasmid-mediated colistin resistance (PMCR), a consequence of the mcr genes, is a significant public health concern given its potential to easily spread among clinical pathogens. Recently, it was discovered that MCR enzymes require zinc for activity. Thus, we modified the colistin broth-disk elution (CBDE) test to screen for plasmid-mediated colistin resistance (PMCR) genes based on any reduction of colistin MIC in the presence of EDTA. Eighty-five isolates of the order Enterobacteriales (12 mcr positive) were tested by CBDE ± EDTA. The sensitivity and specificity of the EDTA-CBDE method to detect PMCR compared to the molecular genotype results were 100% and 95.8%, respectively. Isolates positive by the EDTA-CBDE test should be further evaluated to confirm the presence of mcr genes.

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Colistin resistance among Gram-negative isolates in Nepal: A review

Journal of Biomedical Sciences ◽

10.3126/jbs.v7i1.29851 ◽

2020 ◽

Vol 7 (1) ◽

pp. 33-39

Author(s):

Surya Prasad Devkota ◽

Ashmita Paudel

Keyword(s):

Public Health ◽

Public Health Problem ◽

Clinical Isolates ◽

Clinical Settings ◽

Drug Resistant ◽

Colistin Resistance ◽

Gram Negative ◽

Food Industries ◽

Animal Farms ◽

Animal Isolates

Background: Colistin resistance among Gram-negative isolates is a tremendous public health problem, and there are very few studies in Nepal about these pathogens. Hence, this review provides comprehensive data on colistin resistance among Gram-negative isolates from various samples in Nepal. Methods: Articles reporting colistin resistance among various Gram-negative isolates from Nepal before July 2019 were selected; analyzed and relevant data was collected. Results: Colistin resistance was low among clinical isolates (less than 6%) in comparison to food and animal isolates (up to 69%). A wide variety of clinical isolates were colistin-resistant in comparison to food and animal isolates. Many of these isolates were highly drug-resistant and also harbored various drug-resistant determinants. Conclusion: Increased colistin resistance among Gram-negative pathogens is a serious concern. Screening of these isolates in clinical settings, animal farms, and food industries, as well as cautious use of colistin in both clinical and animal farms, is imminent.

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Heterogeneous and Flexible Transmission ofmcr-1in Hospital-AssociatedEscherichia coli

mBio ◽

10.1128/mbio.00943-18 ◽

2018 ◽

Vol 9 (4) ◽

Cited By ~ 23

Author(s):

Yingbo Shen ◽

Zuowei Wu ◽

Yang Wang ◽

Rong Zhang ◽

Hong-Wei Zhou ◽

...

Keyword(s):

Escherichia Coli ◽

Genomic Analysis ◽

Multidrug Resistant ◽

Fluoroquinolone Resistance ◽

Gram Negative Bacteria ◽

Colistin Resistance ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Genes Encoding

ABSTRACTThe recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route ofmcr-1amongEnterobacteriaceaespecies in clinical settings is largely unknown. Here, we present a comprehensive genomic analysis ofEscherichia coliisolates collected in a hospital in Hangzhou, China. We found thatmcr-1-carrying isolates from clinical infections and feces of inpatients and healthy volunteers were genetically diverse and were not closely related phylogenetically, suggesting that clonal expansion is not involved in the spread ofmcr-1. Themcr-1gene was found on either chromosomes or plasmids, but in most of theE. coliisolates,mcr-1was carried on plasmids. The genetic context of the plasmids showed considerable diversity as evidenced by the different functional insertion sequence (IS) elements, toxin-antitoxin (TA) systems, heavy metal resistance determinants, and Rep proteins of broad-host-range plasmids. Additionally, the genomic analysis revealed nosocomial transmission ofmcr-1and the coexistence ofmcr-1with other genes encoding β-lactamases and fluoroquinolone resistance in theE. coliisolates. These findings indicate thatmcr-1is heterogeneously disseminated in both commensal and pathogenic strains ofE. coli, suggest the high flexibility of this gene in its association with diverse genetic backgrounds of the hosts, and provide new insights into the genome epidemiology ofmcr-1among hospital-associatedE. colistrains.IMPORTANCEColistin represents one of the very few available drugs for treating infections caused by extensively multidrug-resistant Gram-negative bacteria. The recently emergentmcr-1colistin resistance gene threatens the clinical utility of colistin and has gained global attention. Howmcr-1spreads in hospital settings remains unknown and was investigated by whole-genome sequencing ofmcr-1-carryingEscherichia coliin this study. The findings revealed extraordinary flexibility ofmcr-1in its spread among genetically diverseE. colihosts and plasmids, nosocomial transmission ofmcr-1-carryingE. coli, and the continuous emergence of novel Inc types of plasmids carryingmcr-1and newmcr-1variants. Additionally,mcr-1was found to be frequently associated with other genes encoding β-lactams and fluoroquinolone resistance. These findings provide important information on the transmission and epidemiology ofmcr-1and are of significant public health importance as the information is expected to facilitate the control of this significant antibiotic resistance threat.

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The ZKIR Assay, a Real-Time PCR Method for the Detection of Klebsiella pneumoniae and Closely Related Species in Environmental Samples

Applied and Environmental Microbiology ◽

10.1128/aem.02711-19 ◽

2020 ◽

Vol 86 (7) ◽

Cited By ~ 1

Author(s):

Elodie Barbier ◽

Carla Rodrigues ◽

Geraldine Depret ◽

Virginie Passet ◽

Laurent Gal ◽

...

Keyword(s):

Public Health ◽

Klebsiella Pneumoniae ◽

Real Time ◽

Real Time Pcr ◽

Environmental Samples ◽

Health Concern ◽

Complex Matrices ◽

Content Type ◽

Novel Method ◽

Pcr Method

ABSTRACT Klebsiella pneumoniae is of growing public health concern due to the emergence of strains that are multidrug resistant, virulent, or both. Taxonomically, the K. pneumoniae complex (“Kp”) includes seven phylogroups, with Kp1 (K. pneumoniae sensu stricto) being medically prominent. Kp can be present in environmental sources such as soils and vegetation, which could act as reservoirs of animal and human infections. However, the current lack of screening methods to detect Kp in complex matrices limits research on Kp ecology. Here, we analyzed 1,001 genome sequences and found that existing molecular detection targets lack specificity for Kp. A novel real-time PCR method, the ZKIR (zur-khe intergenic region) assay, was developed and used to detect Kp in 96 environmental samples. The results were compared to a culture-based method using Simmons citrate agar with 1% inositol medium coupled to matrix-assisted laser desorption ionization–time of flight mass spectrometry identification. Whole-genome sequencing of environmental Kp was performed. The ZKIR assay was positive for the 48 tested Kp reference strains, whereas 88 non-Kp strains were negative. The limit of detection of Kp in spiked soil microcosms was 1.5 × 10−1 CFU g−1 after enrichment for 24 h in lysogeny broth supplemented with ampicillin, and it was 1.5 × 103 to 1.5 × 104 CFU g−1 directly after soil DNA extraction. The ZKIR assay was more sensitive than the culture method. Kp was detected in 43% of environmental samples. Genomic analysis of the isolates revealed a predominance of phylogroups Kp1 (65%) and Kp3 (32%), a high genetic diversity (23 multilocus sequence types), a quasi-absence of antibiotic resistance or virulence genes, and a high frequency (50%) of O-antigen type 3. This study shows that the ZKIR assay is an accurate, specific, and sensitive novel method to detect the presence of Kp in complex matrices and indicates that Kp isolates from environmental samples differ from clinical isolates. IMPORTANCE The Klebsiella pneumoniae species complex Kp includes human and animal pathogens, some of which are emerging as hypervirulent and/or antibiotic-resistant strains. These pathogens are diverse and classified into seven phylogroups, which may differ in their reservoirs and epidemiology. Proper management of this public health hazard requires a better understanding of Kp ecology and routes of transmission to humans. So far, detection of these microorganisms in complex matrices such as food or the environment has been difficult due to a lack of accurate and sensitive methods. Here, we describe a novel method based on real-time PCR which enables detection of all Kp phylogroups with high sensitivity and specificity. We used this method to detect Kp isolates from environmental samples, and we show based on genomic sequencing that they differ in antimicrobial resistance and virulence gene content from human clinical Kp isolates. The ZKIR PCR assay will enable rapid screening of multiple samples for Kp presence and will thereby facilitate tracking the dispersal patterns of these pathogenic strains across environmental, food, animal and human sources.

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Technological advancements to address elderly loneliness: practical considerations and community resilience implications for COVID-19 pandemic

Working with Older People ◽

10.1108/wwop-07-2020-0036 ◽

2020 ◽

Vol 24 (4) ◽

pp. 257-264 ◽

Cited By ~ 1

Author(s):

Kristina M. Conroy ◽

Srikripa Krishnan ◽

Stacy Mittelstaedt ◽

Sonny S. Patel

Keyword(s):

Public Health ◽

Older Adults ◽

Environmental Factors ◽

Social Engagement ◽

The Elderly ◽

Advanced Technology ◽

Health Concern ◽

Specific Situation ◽

Content Type ◽

Elderly Populations

Purpose Loneliness has been a known severe public health concern among the elderly population during the COVID-19 pandemic. This paper aims to discuss the practicalities of using emerging technologies to address elderly loneliness and its implications and adaptations to the outbreak of corona virus disease–2019. Design/methodology/approach The authors draw on examples from the literature and their own observations from working with older adults, to provide an overview of possible ways technology could help this population in the current COVID-19 pandemic. Findings Technological advancements have offered remarkable opportunities to deliver care and maintain connections despite the need to stay physically separated. These tools can be integrated into crisis communications, public health responses and care programs to address loneliness among the elderly. However, it must be done strategically and informed by the type of loneliness at play, environmental factors, socioeconomics and technological literacy. Practical implications Care-providing organizations and policymakers should consider the risk of loneliness while responding to COVID-19 outbreak, particularly within elderly populations. As a part of a broader plan, technological solutions and low-tech approaches can make a difference in mitigating loneliness. Solutions should be accessible to and usable by older adults. Provision of equipment, training and guidance may be necessary to execute a technology-centric plan; for some communities and individuals, approaches that do not rely on advanced technology may be more effective. Originality/value Technological advancements can be a valuable tool in addressing known public health concerns, such as loneliness among the elderly populations. However, the use of this tool should be governed by the specific situation at hand, taking into consideration individual needs and environmental factors, especially the compounded effects caused by the coronavirus pandemic. Different technological programs and approaches are appropriate for different types of loneliness. For example, online therapy such as internet-based cognitive behavior therapy may mitigate loneliness caused by fear and online interaction such as videoconferencing may relieve loneliness caused by lack of social engagement.

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Lack of Antimicrobial Resistance in Yersinia pestis Isolates from 17 Countries in the Americas, Africa, and Asia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05043-11 ◽

2011 ◽

Vol 56 (1) ◽

pp. 555-558 ◽

Cited By ~ 19

Author(s):

Sandra K. Urich ◽

Linda Chalcraft ◽

Martin E. Schriefer ◽

Brook M. Yockey ◽

Jeannine M. Petersen

Keyword(s):

Public Health ◽

Multidrug Resistance ◽

Antimicrobial Resistance ◽

Yersinia Pestis ◽

Causative Agent ◽

Multidrug Resistant ◽

Antimicrobial Treatment ◽

Health Concern ◽

Public Health Concern ◽

Content Type

ABSTRACTYersinia pestisis the causative agent of plague, a fulminant disease that is often fatal without antimicrobial treatment. Plasmid (IncA/C)-mediated multidrug resistance inY. pestiswas reported in 1995 in Madagascar and has generated considerable public health concern, most recently because of the identification of IncA/C multidrug-resistant plasmids in other zoonotic pathogens. Here, we demonstrate no resistance in 392Y. pestisisolates from 17 countries to eight antimicrobials used for treatment or prophylaxis of plague.

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Shigella Vaccine Development: Finding the Path of Least Resistance

Clinical and Vaccine Immunology ◽

10.1128/cvi.00444-16 ◽

2016 ◽

Vol 23 (12) ◽

pp. 904-907 ◽

Cited By ~ 8

Author(s):

Wilbur H. Chen ◽

Karen L. Kotloff

Keyword(s):

Public Health ◽

Developing Countries ◽

Phase I ◽

Phase I Study ◽

Vaccine Development ◽

Shigella Flexneri ◽

Health Concern ◽

Childhood Diarrhea ◽

Public Health Concern ◽

Content Type

ABSTRACTShigellaspp. represent the second most common etiologic pathogen causing childhood diarrhea in developing countries. There are no licensedShigellavaccines, and progress for such vaccines has been limited. In this issue ofClinical and Vaccine Immunology, Riddle and colleagues (M. S. Riddle, R. W. Kaminski, C. Di Paolo, C. K. Porter, R. L. Gutierrez, et al., Clin Vaccine Immunol 23:908–917, 2016,http://dx.doi.org/10.1128/CVI.00224-16) report results from a phase I study of a parenterally administered monovalent O-polysaccharide “bioconjugate” directed againstShigella flexneri2a. Ultimately, the goal is to develop a broad-spectrumShigellavaccine to address this public health concern. A parenteralShigellavaccine capable of eliciting protection in children of developing countries would be an important tool to reach this goal.

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Structural Modification of Lipopolysaccharide Conferred by mcr-1 in Gram-Negative ESKAPE Pathogens

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00580-17 ◽

2017 ◽

Vol 61 (6) ◽

Cited By ~ 49

Author(s):

Yi-Yun Liu ◽

Courtney E. Chandler ◽

Lisa M. Leung ◽

Christi L. McElheny ◽

Roberta T. Mettus ◽

...

Keyword(s):

Structural Changes ◽

Lipid A ◽

Colistin Resistance ◽

Gram Negative ◽

Content Type ◽

Clinical Strains ◽

E Coli ◽

The Family ◽

Phosphoethanolamine Transferases ◽

Eskape Pathogens

ABSTRACT mcr-1 was initially reported as the first plasmid-mediated colistin resistance gene in clinical isolates of Escherichia coli and Klebsiella pneumoniae in China and has subsequently been identified worldwide in various species of the family Enterobacteriaceae. mcr-1 encodes a phosphoethanolamine transferase, and its expression has been shown to generate phosphoethanolamine-modified bis-phosphorylated hexa-acylated lipid A in E. coli. Here, we investigated the effects of mcr-1 on colistin susceptibility and on lipopolysaccharide structures in laboratory and clinical strains of the Gram-negative ESKAPE (Enterococcus faecium, Staphylococcus aureus, K. pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens, which are often treated clinically by colistin. The effects of mcr-1 on colistin resistance were determined using MIC assays of laboratory and clinical strains of E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. Lipid A structural changes resulting from MCR-1 were analyzed by mass spectrometry. The introduction of mcr-1 led to colistin resistance in E. coli, K. pneumoniae, and A. baumannii but only moderately reduced susceptibility in P. aeruginosa. Phosphoethanolamine modification of lipid A was observed consistently for all four species. These findings highlight the risk of colistin resistance as a consequence of mcr-1 expression among ESKAPE pathogens, especially in K. pneumoniae and A. baumannii. Furthermore, the observation that lipid A structures were modified despite only modest increases in colistin MICs in some instances suggests more sophisticated surveillance methods may need to be developed to track the dissemination of mcr-1 or plasmid-mediated phosphoethanolamine transferases in general.

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Infective endocarditis caused by Cardiobacterium valvarum

Access Microbiology ◽

10.1099/acmi.0.000040 ◽

2019 ◽

Vol 1 (8) ◽

Author(s):

Yohei Washio ◽

Shun-ichiro Sakamoto ◽

Ryoichi Saito ◽

Takahito Nei ◽

Masayo Morishima ◽

...

Keyword(s):

Infective Endocarditis ◽

Ribosomal Rna ◽

Transthoracic Echocardiography ◽

Type Species ◽

Blood Cultures ◽

Gram Negative ◽

Content Type ◽

Link Type ◽

Conventional Methods ◽

Positive Results

We report a case with infective endocarditis (IE) due to Cardiobacterium valvarum . The patient was a 57-year-old male, who was referred to our hospital based on suspected IE detected by transthoracic echocardiography at a neighbourhood clinic. Three sets of blood cultures obtained on admission yielded positive results, and revealed rather slender and linear Gram-negative bacilli with a rosette formation that dyed minimally, with a pale white appearance. Although no isolates were identified by conventional methods, C. valvarum was ultimately identified by 16 S ribosomal RNA genotyping. HACEK group strains are difficult to identify by conventional methods. Therefore, if Gram-negative bacilli are isolated from IE patients, 16 S ribosomal RNA genotyping will be necessary. Furthermore, IE due to C. valvarum is very rare. We thus discuss our case in comparison with previous reports.

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