A rare case of Colistin-resistant Salmonella Enteritidis meningitis in an HIV-seropositive patient

Abstract Background Non-typhoidal salmonellae (NTS) have been associated with invasive disease, notably meningitis, in immunocompromised individuals. Infections of this nature carry high rates of morbidity and mortality. Colistin resistance in salmonellae is a rare finding, more so in an invasive isolate such as cerebrospinal fluid (CSF). Colistin resistance has important infection control implications and failure to manage this phenomenon may lead to the loss of our last line of defence against multi-drug resistant Gram-negative organisms. To our knowledge, this is the first reported clinical case of colistin-resistant Salmonella Enteritidis meningitis in South Africa. Case presentation We report a case of a young male patient with advanced human immunodeficiency virus (HIV) infection who presented to hospital with symptoms of meningitis. Cerebrospinal fluid (CSF) cultured a Salmonella Enteritidis strain. Antimicrobial susceptibility testing (AST) of the isolate, revealed the strain to be colistin resistant. Despite early and aggressive antimicrobial therapy, the patient succumbed to the illness after a short stay in hospital. Subsequent genomic analysis of the isolate showed no presence of the mcr genes or resistance-conferring mutations in phoPQ, pmrAB, pmrHFIJKLME/arnBCADTEF, mgrB, and acrAB genes, suggesting the presence of a novel colistin resistance mechanism. Conclusion Invasive non-typhoidal salmonellae infection should be suspected in patients with advanced immunosuppression who present with clinical features of meningitis. Despite early and appropriate empiric therapy, these infections are commonly associated with adverse outcomes to the patient. Combination therapy with two active anti-Salmonella agents may be a consideration in the future to overcome the high mortality associated with NTS meningitis. Colistin resistance in clinical Salmonella isolates, although a rare finding at present, has significant public health and infection control implications. The causative mechanism of resistance should be sought in all cases.

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Genomic Analysis of Hospital Plumbing Reveals Diverse Reservoir of Bacterial Plasmids Conferring Carbapenem Resistance

mBio ◽

10.1128/mbio.02011-17 ◽

2018 ◽

Vol 9 (1) ◽

Cited By ~ 68

Author(s):

Rebecca A. Weingarten ◽

Ryan C. Johnson ◽

Sean Conlan ◽

Amanda M. Ramsburg ◽

John P. Dekker ◽

...

Keyword(s):

Infection Control ◽

Control Strategies ◽

Resistance Mechanism ◽

Genomic Analysis ◽

Carbapenem Resistance ◽

Epidemiological Survey ◽

Hospital Environment ◽

Potential Reservoir ◽

Environmental Reservoir ◽

Comprehensive Survey

ABSTRACT The hospital environment is a potential reservoir of bacteria with plasmids conferring carbapenem resistance. Our Hospital Epidemiology Service routinely performs extensive sampling of high-touch surfaces, sinks, and other locations in the hospital. Over a 2-year period, additional sampling was conducted at a broader range of locations, including housekeeping closets, wastewater from hospital internal pipes, and external manholes. We compared these data with previously collected information from 5 years of patient clinical and surveillance isolates. Whole-genome sequencing and analysis of 108 isolates provided comprehensive characterization of bla KPC/bla NDM-positive isolates, enabling an in-depth genetic comparison. Strikingly, despite a very low prevalence of patient infections with bla KPC-positive organisms, all samples from the intensive care unit pipe wastewater and external manholes contained carbapenemase-producing organisms (CPOs), suggesting a vast, resilient reservoir. We observed a diverse set of species and plasmids, and we noted species and susceptibility profile differences between environmental and patient populations of CPOs. However, there were plasmid backbones common to both populations, highlighting a potential environmental reservoir of mobile elements that may contribute to the spread of resistance genes. Clear associations between patient and environmental isolates were uncommon based on sequence analysis and epidemiology, suggesting reasonable infection control compliance at our institution. Nonetheless, a probable nosocomial transmission of Leclercia sp. from the housekeeping environment to a patient was detected by this extensive surveillance. These data and analyses further our understanding of CPOs in the hospital environment and are broadly relevant to the design of infection control strategies in many infrastructure settings. IMPORTANCE Carbapenemase-producing organisms (CPOs) are a global concern because of the morbidity and mortality associated with these resistant Gram-negative bacteria. Horizontal plasmid transfer spreads the resistance mechanism to new bacteria, and understanding the plasmid ecology of the hospital environment can assist in the design of control strategies to prevent nosocomial infections. A 5-year genomic and epidemiological survey was undertaken to study the CPOs in the patient-accessible environment, as well as in the plumbing system removed from the patient. This comprehensive survey revealed a vast, unappreciated reservoir of CPOs in wastewater, which was in contrast to the low positivity rate in both the patient population and the patient-accessible environment. While there were few patient-environmental isolate associations, there were plasmid backbones common to both populations. These results are relevant to all hospitals for which CPO colonization may not yet be defined through extensive surveillance.

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Mobile Colistin Resistance Gene mcr-1 Detected on an IncI2 Plasmid in Salmonella Typhimurium Sequence Type 19 from a Healthy Pig in South Korea

Microorganisms ◽

10.3390/microorganisms9020398 ◽

2021 ◽

Vol 9 (2) ◽

pp. 398

Author(s):

Dong Chan Moon ◽

Su-Jeong Kim ◽

Abraham Fikru Mechesso ◽

Hee Young Kang ◽

Hyun-Ju Song ◽

...

Keyword(s):

South Korea ◽

Salmonella Typhimurium ◽

Bacterial Infections ◽

Salmonella Enteritidis ◽

Sequence Type ◽

Intestinal Epithelial ◽

Colistin Resistance ◽

Salmonella Gallinarum ◽

Additional Resistance ◽

Food Animals

Colistin is considered the last resort for the treatment of multi-drug resistant Gram-negative bacterial infections. We studied colistin resistance and the mcr-1 gene carriage in Salmonella isolates recovered from food animals in South Korea between 2010 and 2018. Colistin resistance was found in 277 isolates, predominantly in Salmonella Enteritidis (57.1%) and Salmonella Gallinarum (41.9%). However, the mcr-1 gene was identified in only one colistin-resistant Salmonella Typhimurium (MIC = 16 µg/mL) isolated from a healthy pig. The mcr-1 carrying isolate presented additional resistance to multiple antimicrobials. The strain belonged to sequence type (ST)19 and carried various virulence factor genes that are associated with adhesion and invasion of Salmonella into intestinal epithelial cells, as well as its survival in macrophages. The mcr-1 gene was identified on an IncI2 plasmid and it was also transferred to the E. coli J53 recipient strain. The mcr-1-carrying plasmid (pK18JST013) in this study was closely related to that previously reported in S. Indiana (pCFSA664-3) from chicken in China. This is the first report of mcr-1 carrying S. Typhimurium in South Korea. The finding indicates the importance of regular screening for the presence of the mcr-1 gene in S. Typhimurium in food animals to prevent the spread to humans.

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Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

BMC Microbiology ◽

10.1186/s12866-021-02250-x ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Shixing Liu ◽

Renchi Fang ◽

Ying Zhang ◽

Lijiang Chen ◽

Na Huang ◽

...

Keyword(s):

Lipid A ◽

Efflux Pump ◽

Resistance Mechanism ◽

Carbapenem Resistance ◽

Enterobacter Cloacae ◽

Resistance Mechanisms ◽

Colistin Resistance ◽

Carbapenem Resistant ◽

Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

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Protocol for a mixed method acceptability evaluation of a codesigned bundled COmmunication intervention for use in the adult ICU during the COVID-19 PandEmic: the COPE study

BMJ Open ◽

10.1136/bmjopen-2021-050347 ◽

2021 ◽

Vol 11 (9) ◽

pp. e050347

Author(s):

Laura Istanboulian ◽

Louise Rose ◽

Yana Yunusova ◽

Craig M Dale

Keyword(s):

Infection Control ◽

Mixed Method ◽

Phase 1 ◽

Invasive Mechanical Ventilation ◽

Healthcare Providers ◽

Adverse Outcomes ◽

Advisory Council ◽

Communication Intervention ◽

Adult Intensive Care Unit ◽

Study Setting

IntroductionPatients requiring invasive mechanical ventilation via an artificial airway experience sudden voicelessness placing them at risk for adverse outcomes and increasing provider workload. Infection control precautions during the COVID-19 pandemic, including the use of personal protective equipment (eg, gloves, masks, etc), patient isolation, and visitor restrictions may exacerbate communication difficulty. The objective of this study is to evaluate the acceptability of a codesigned communication intervention for use in the adult intensive care unit when infection control precautions such as those used during COVID-19 are required.Methods and analysisThis three-phased, prospective study will take place in a medical surgical ICU in a community teaching hospital in Toronto. Participants will include ICU healthcare providers, adult patients and their family members. Qualitative interviews (target n: 20–25) will explore participant perceptions of the barriers to and facilitators for supporting patient communication in the adult ICU in the context of COVID-19 and infection control precautions (phase 1). Using principles of codesign, a stakeholder advisory council of 8–10 participants will iteratively produce an intervention (phase 2). The codesigned intervention will then be implemented and undergo a mixed method acceptability evaluation in the study setting (phase 3). Acceptability, feasibility and appropriateness will be evaluated using validated measures (target n: 60–65). Follow-up semistructured interviews will be analysed using the theoretical framework of acceptability (TFA). The primary outcomes of this study will be acceptability ratings and descriptions of a codesigned COmmunication intervention for use during and beyond the COVID-19 PandEmic.Ethics and disseminationThe study protocol has been reviewed, and ethics approval was obtained from the Michael Garron Hospital. Results will be made available to healthcare providers in the study setting throughout the study and through publications and conference presentations.

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Cerebrospinal Fluid Eosinophilia and Sterile Shunt Malfunction

Neurosurgery ◽

10.1227/00006123-198811000-00019 ◽

1988 ◽

Vol 23 (5) ◽

pp. 645-649 ◽

Cited By ~ 20

Author(s):

Vincent C. Traynelis ◽

Randell G. Powell ◽

William Koss ◽

Sydney S. Schochet ◽

Howard H. Kaufman

Keyword(s):

Central Nervous System ◽

Cerebrospinal Fluid ◽

Shunt Malfunction ◽

Cotton Fibers ◽

Foreign Material ◽

Surgical Glove ◽

Rare Finding ◽

Inflammatory Processes ◽

Mycotic Infections

Abstract Cerebrospinal fluid (CSF) eosinophilia is a rare finding most often associated with central nervous system inflammatory processes, including parasitic, bacterial, and mycotic infections. It has also been seen as an allergic phenomenon. We present two cases of CSF eosinophilia occurring concurrently with sterile shunt malfunction. We speculate that CSF eosinophilia in our patients might have resulted from an allergic response to a foreign material such as suture, surgical glove powder, hair, cotton fibers, antibiotics, or silicone rubber. The incidence of sterile CSF eosinophilia after shunting is not known. Information concerning the role of eosinophilia in the development of shunt malfunctions is also lacking. An increased awareness of this possibility and further investigation are warranted.

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A common complication of myelofibrosis presenting as a rare finding in cerebrospinal fluid cytology

Diagnostic Cytopathology ◽

10.1002/dc.23768 ◽

2017 ◽

Vol 45 (11) ◽

pp. 1039-1041

Author(s):

Roberto Ruiz-Cordero ◽

Jeffrey L. Jorgensen ◽

Savitri Krishnamurthy ◽

Gene Landon

Keyword(s):

Cerebrospinal Fluid ◽

Common Complication ◽

Rare Finding ◽

Cerebrospinal Fluid Cytology ◽

Fluid Cytology

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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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Giant Dissecting Aortic Aneurysm in an Asymptomatic Young Male

Case Reports in Vascular Medicine ◽

10.1155/2015/958464 ◽

2015 ◽

Vol 2015 ◽

pp. 1-2 ◽

Cited By ~ 3

Author(s):

Priyank Shah ◽

Nishant Gupta ◽

Irvin Goldfarb ◽

Fayez Shamoon

Keyword(s):

Aortic Aneurysm ◽

Giant Cell Arteritis ◽

Giant Cell ◽

Hereditary Hemorrhagic Telangiectasia ◽

Surgical Intervention ◽

Young Male ◽

Physical Exam ◽

Ascending Aortic Aneurysm ◽

Rare Finding ◽

Dissecting Aortic Aneurysm

Giant aortic aneurysm is defined as aneurysm in the aorta greater than 10 cm in diameter. It is a rare finding since most patients will present with complications of dissection or rupture before the size of aneurysm reaches that magnitude. Etiological factors include atherosclerosis, Marfan’s syndrome, giant cell arteritis, tuberculosis, syphilis, HIV-associated vasculitis, hereditary hemorrhagic telangiectasia, and medial agenesis. Once diagnosed, prompt surgical intervention is the treatment of choice. Although asymptomatic unruptured giant aortic aneurysm has been reported in the literature, there has not been any case of asymptomatic giant dissecting aortic aneurysm reported in the literature thus far. We report a case of giant dissecting ascending aortic aneurysm in an asymptomatic young male who was referred to our institution for abnormal findings on physical exam.

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Investigation of Novel pmrB and eptA Mutations in Isogenic Acinetobacter baumannii Isolates Associated with Colistin Resistance and Increased Virulence In Vivo

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01586-18 ◽

2019 ◽

Vol 63 (3) ◽

Cited By ~ 18

Author(s):

Stefanie Gerson ◽

Jonathan W. Betts ◽

Kai Lucaßen ◽

Carolina Silva Nodari ◽

Julia Wille ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Lipid A ◽

Galleria Mellonella ◽

Resistance Mechanism ◽

Resistant Isolate ◽

Infection Model ◽

Colistin Resistance ◽

Strain Specificity ◽

Content Type

ABSTRACT Colistin resistance in Acinetobacter baumannii is of great concern and is a threat to human health. In this study, we investigate the mechanisms of colistin resistance in four isogenic pairs of A. baumannii isolates displaying an increase in colistin MICs. A mutation in pmrB was detected in each colistin-resistant isolate, three of which were novel (A28V, I232T, and ΔL9-G12). Increased expression of pmrC was shown by semi-quantitative reverse transcription-PCR (qRT-PCR) for three colistin-resistant isolates, and the addition of phosphoethanolamine (PEtN) to lipid A by PmrC was revealed by mass spectrometry. Interestingly, PEtN addition was also observed in some colistin-susceptible isolates, indicating that this resistance mechanism might be strain specific and that other factors could contribute to colistin resistance. Furthermore, the introduction of pmrAB carrying the short amino acid deletion ΔL9-G12 into a pmrAB knockout strain resulted in increased pmrC expression and lipid A modification, but colistin MICs remained unchanged, further supporting the strain specificity of this colistin resistance mechanism. Of note, a mutation in the pmrC homologue eptA and a point mutation in ISAba1 upstream of eptA were associated with colistin resistance and increased eptA expression, which is a hitherto undescribed resistance mechanism. Moreover, no cost of fitness was observed for colistin-resistant isolates, while the virulence of these isolates was increased in a Galleria mellonella infection model. Although the mutations in pmrB were associated with colistin resistance, PEtN addition appears not to be the sole factor leading to colistin resistance, indicating that the mechanism of colistin resistance is far more complex than previously suspected and is potentially strain specific.

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