Antibiotic Resistance and Detection of the Most Common Mechanism of Resistance (MLSB) of Opportunistic Corynebacterium

Olender, Alina

doi:10.1159/000357467

Cited by 28 publications

(18 citation statements)

References 89 publications

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“…In relation to antimicrobial susceptibility, the VITEK 2 technology used for AST in this study is not available for these bacterial genera yet, and therefore the analyses of their antimicrobial resistance profiles will be part of a future study. It is of utmost importance since many medically relevant species have shown broad-spectrum antibiotic resistance which has important therapeutic implications (Olender, 2013; Dobinson et al, 2015). …”

Section: Discussionmentioning

confidence: 99%

Identification of Emerging Human Mastitis Pathogens by MALDI-TOF and Assessment of Their Antibiotic Resistance Patterns

Marín

Arroyo²,

Espinosa-Martos³

et al. 2017

Front. Microbiol.

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Lactational mastitis constitutes one of the main causes of undesired weaning, depriving the mother–infant pair from the benefits of breastfeeding; therefore, this condition should be considered a relevant public health issue. The role of specific microorganisms remains unclear since human milk cultures and antibiotic susceptibility testing (AST) are not routinely performed, despite the fact that this would be key to ensure an early and effective diagnosis and treatment. The objective of this study was to describe the culturable microbial diversity in 647 milk samples from breastfeeding women with clinical symptoms of mastitis by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) VITEK MS technology and to analyze the antimicrobial susceptibility profiles of a collection of isolates from these samples by the VITEK 2 AST system. Staphylococcus epidermidis was the most common species isolated from mastitis samples (87.6%), while Staphylococcus aureus was detected in 22.1%. Streptococci constituted the second (68.6%) most prevalent bacterial group, with Streptococcus mitis/oralis, Streptococcus salivarius, and Streptococcus parasanguinis detected with frequencies of 40.8, 36.8, and 14.4%, respectively. The antibiotic susceptibility profiles of 642 staphylococcal isolates indicated a remarkable resistance to benzylpenicillin (88.3%) and erythromycin (67.3%) with differences between species. A high percentage of Staphylococcus isolates were resistant to at least one antibiotic (Staphylococcus hominis, 100%; S. epidermidis, 98.2%; S. aureus, 92.9%; Staphylococcus lugdunensis, 90.5%) and the percentage of multidrug-resistance (MDR) isolates was noticeable (S. hominis, 81%; S. epidermidis, 64.4%; S. aureus, 11.5%; S. lugdunensis, 10.5%). In relation to streptococcal isolates (n = 524), AST revealed high or moderate percentages of resistance to erythromycin (68.7%), benzylpenicillin (63.7%), ampicillin (51.5%), and tetracycline (30.8%). Antibiotic resistance to at least one antibiotic was detected in 97.6% of S. parasanguinis, 92.6% of S. salivarius, 83.3% of S. mitis/oralis, and 72.4% of Streptococcus vestibularis isolates. A significant number of MDR streptococcal isolates was also found (S. parasanguinis, 51.2%; S. salivarius, 39.3%; S. mitis/oralis, 34.6%; and S. vestibularis, 19%). The results highlight the important role of coagulase-negative staphylococci and streptococci as human mastitis-causing agents. Moreover, the high rates of antimicrobial resistance among these microorganisms must be contemplated as an issue of clinical relevance in relation to treatment options.

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Section: Discussionmentioning

confidence: 99%

Identification of Emerging Human Mastitis Pathogens by MALDI-TOF and Assessment of Their Antibiotic Resistance Patterns

Marín

Arroyo²,

Espinosa-Martos³

et al. 2017

Front. Microbiol.

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“…C. xerosis is rare in clinical specimens; however, C. amycolatum is common, and thus, the majority of these isolates were likely C. amycolatum (2). C. amycolatum is a pathogen of soft tissues, blood, sterile sites, and the urinary tract and is frequently multidrug resistant (MDR) (2,15). Failure to accurately identify these organisms is a significant limitation of the present study, and future bioMérieux protein spectrum database updates should focus on resolving these ambiguities.…”

Section: Discussionmentioning

confidence: 99%

Clinical Significance of Commensal Gram-Positive Rods Routinely Isolated from Patient Samples

2016

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Commensal bacteria from the skin and mucosal surfaces are routinely isolated from patient samples and considered contaminants. The majority of these isolates are catalase-positive Gram-positive rods from multiple genera routinely classified as diphtheroids. These organisms can be seen upon Gram staining of clinical specimens or can be isolated as the predominant or pure species in culture, raising a priori suspicion of a possible involvement in infection. With the development and adoption of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), suspicious isolates are now routinely identified to the species level. In this study, we performed a retrospective data review (2012 to 2015) and utilized site-specific laboratory criteria and chart reviews to identify species within the diphtheroid classification representative of true infection versus contamination. Our data set included 762 isolates from 13 genera constituting 41 bacterial species. Only 18% represented true infection, and 82% were deemed contaminants. Clinically significant isolates were identified in anaerobic wounds (18%), aerobic wounds (30%), blood (5.5%), urine (22%), cerebrospinal fluid (24%), ophthalmologic cultures (8%), and sterile sites (20%). Organisms deemed clinically significant included multiple Actinomyces species in wounds, Propionibacterium species in joints and cerebrospinal fluid associated with central nervous system hardware, Corynebacterium kroppenstedtii (100%) in breast, and Corynebacterium striatum in multiple sites. Novel findings include clinically significant urinary tract infections by Actinomyces neuii (21%) and Corynebacterium aurimucosum (21%). Taken together, these findings indicate that species-level identification of diphtheroids isolated with a priori suspicion of infection is essential to accurately determine whether an isolate belongs to a species associated with specific types of infection. C linical microbiology specimens frequently grow variable levels of commensal bacteria from the skin and mucosal surfaces in addition to true pathogens (1). The majority of these isolates are aerobic, asporogenic, irregularly shaped, non-partially-acid-fast, catalase-positive, Gram-positive rods from multiple genera with nondistinct colony morphology, routinely classified as diphtheroids (2). The term diphtheroid and coryneform are interchangeable, and for a comprehensive review of bacterial genera classified as coryneform bacteria, see two excellent reviews by Bernard et al. (2,3). In brief, the medically relevant genera whose morphological and biochemical descriptions fit in the diphtheroid classification include Arcanobacterium, Arthrobacter, Brevibacterium, Cellulomonas, Cellulosimicrobium, Corynebacterium (non-diphtheriae), Curtobacterium, Dermabacter, Exiguobacterium, Helcobacillus, Janibacter, Knoellia, Leifsonia, Microbacterium, Pseudoclavibacter, and Trueperella (2-4).Additionally, certain species within other genera share some but not all features of diphtheroids, are part of t...

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“…Despite these potential obstacles, tests for AMR genes are in successful widespread clinical use today, with reported sensitivity and specificity of 72.3-100 and 55-100 %, respectively (Tuite et al, 2014). Olender (2013) reported 'very high' concordance between the phenotypic method (MIC determination) and the presence of the ermX gene for Corynebacterium isolated from the nasal mucosa, noting that this was the most common mechanism of resistance. Similarly, the Clinical and Laboratory…”

Section: G Bostwick and Othersmentioning

confidence: 99%

Antimicrobial resistance genes and modelling of treatment failure in bacterial vaginosis: clinical study of 289 symptomatic women

Bostwick¹,

J²,

Hunt³

et al. 2016

Journal of Medical Microbiology

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Clinical management of bacterial vaginosis (BV) is difficult owing to inaccurate diagnostic tests, limited drug choices, and a high rate of recurrence. To our knowledge, there has not been a previous study of antimicrobial resistance (AMR) genes in community practice using nextgeneration sequencing (NGS). A case-control study (1 : 1 age-matched with and without BV) was undertaken in a series of 326 nongravid women of reproductive age with symptoms of BV to determine the prevalence of AMR genes. NGS was used to describe the complete vaginal microbiota and identify bacterial genes associated with resistance to: macrolides and/or lincosamides -ermA, ermB, ermC, erM, ermTR and mefA; tetracyclines, b-lactams, streptomycin, gentamicin and/or tobramycin -acrA, acrB, mecA, tet, tetA, tolC and aac2; 5-nitroimadazoles -nim and nimB; and triazoles -cdr1 and mdr1. An evidence base was created to inform treatment decisions applicable to individual patients. AMR genes were identified in all drug classes: macrolides, 35.2 %; lincosamides, 35.6 %; tetracyclines, 21.8 %; aminoglycosides (streptomycin, gentamicin and tobramycin), 5.2 % each; 5-nitroimidazoles, 0.3 %; and triazoles, 18.7 %. There was more than a fourfold-higher frequency of AMR genes in pathogens from BV than from non-BV patients for macrolides (58.2 versus 12.3 %, respectively), lincosamides (58.9 versus 12.3 %) and tetracyclines (35.6 versus 8.0 %) (Fisher's exact test; all p,0.001). For each patient with BV, the spectrum of resistance genes was matched to the pathogens present. AMR genes were present in the majority of vaginal microbiomes of patients with symptoms of BV.

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Antibiotic Resistance and Detection of the Most Common Mechanism of Resistance (MLSB) of Opportunistic Corynebacterium

Cited by 28 publications

References 89 publications

Identification of Emerging Human Mastitis Pathogens by MALDI-TOF and Assessment of Their Antibiotic Resistance Patterns

Identification of Emerging Human Mastitis Pathogens by MALDI-TOF and Assessment of Their Antibiotic Resistance Patterns

Clinical Significance of Commensal Gram-Positive Rods Routinely Isolated from Patient Samples

Antimicrobial resistance genes and modelling of treatment failure in bacterial vaginosis: clinical study of 289 symptomatic women

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