scholarly journals CRISPR Typing Increases the Discriminatory Power of Streptococcus agalactiae Typing Methods

2021 ◽  
Vol 12 ◽  
Author(s):  
Clémence Beauruelle ◽  
Ludovic Treluyer ◽  
Adeline Pastuszka ◽  
Thierry Cochard ◽  
Clément Lier ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Diversity Index ◽  
Reference Method ◽  
Direct Repeat ◽  
Discriminatory Power ◽  
High Discriminatory Power ◽  
Typing Methods ◽  
Group B ◽  
Reduced Time ◽  
Capsular Typing

We explored the relevance of a Clustered regularly interspaced short palindromic repeats (CRISPR)-based genotyping tool for Streptococcus agalactiae typing and we compared this method to current molecular methods [multi locus sequence typing (MLST) and capsular typing]. To this effect, we developed two CRISPR marker schemes (using 94 or 25 markers, respectively). Among the 255 S. agalactiae isolates tested, 229 CRISPR profiles were obtained. The 94 and 25 markers made it possible to efficiently separate isolates with a high diversity index (0.9947 and 0.9267, respectively), highlighting a high discriminatory power, superior to that of both capsular typing and MLST (diversity index of 0.9017 for MLST). This method has the advantage of being correlated with MLST [through analysis of the terminal direct repeat (TDR) and ancestral spacers] and to possess a high discriminatory power (through analysis of the leader-end spacers recently acquired, which are the witnesses of genetic mobile elements encountered by the bacteria). Furthermore, this “one-shot” approach presents the benefit of much-reduced time and cost in comparison with MLST. On the basis of these data, we propose that this method could become a reference method for group B Streptococcus (GBS) typing.

scholarly journals Comparison of Multilocus Variable-Number Tandem-Repeat Analysis with Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis for Enterococcus faecalis

2011 ◽  
Vol 60 (4) ◽  
pp. 335-339 ◽  
Author(s):  
EWA SADOWY ◽  
ALEKSANDRA SIEŃKO ◽  
WALERIA HRYNIEWICZ
Keyword(s):  
Enterococcus Faecalis ◽  
Gel Electrophoresis ◽  
Tandem Repeats ◽  
Diversity Index ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Pulsed Field Gel Electrophoresis ◽  
Discriminatory Power ◽  
Pulsed Field ◽  
High Discriminatory Power

Enterococcus faecalis represents recently an important etiological agent of health care-associated infections (HAIs) and there is a need for evaluation and comparison of typing methods available for this microorganism. We tested multilocus VNTR (variable-number tandem repeats) analysis (MLVA) on a well-characterized collection of 153 clinical isolates of E. faecalis, corresponding to 52 multilocus sequence types and 67 pulsed-field gel electrophoresis (PFGE) profiles. MLVA showed high discriminatory power, discerning 111 different types (diversity index equal 98.9%). The concordance MLVA/MLST and MLVA/PFGE was 0.95 and 0.74, respectively. High discriminatory power of MLVA indicates its utility for local epidemiology such as outbreak investigation, and for differentiation of clones defined by other methods.

scholarly journals High-Resolution Genotyping of Streptococcus pyogenesSerotype M1 Isolates by Fluorescent Amplified-Fragment Length Polymorphism Analysis

1999 ◽  
Vol 37 (6) ◽  
pp. 1948-1952 ◽  
Author(s):  
Meeta Desai ◽  
Androulla Efstratiou ◽  
Robert George ◽  
John Stanley
Keyword(s):  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Geographic Origin ◽  
Amplified Fragment Length Polymorphism ◽  
Discriminatory Power ◽  
Polymorphism Analysis ◽  
Worldwide Distribution ◽  
High Discriminatory Power ◽  
Typing Methods

We have used fluorescent amplified-fragment length polymorphism (FAFLP) analysis to subtype clinical isolates of Streptococcus pyogenes serotype M1. Established typing methods define most M1 isolates as members of a clone that has a worldwide distribution and that is strongly associated with invasive diseases. FAFLP analysis simultaneously sampled 90 to 120 loci throughout the M1 genome. Its discriminatory power, precision, and reproducibility were compared with those of other molecular typing methods. Irrespective of disease symptomatology or geographic origin, the majority of the clinical M1 isolates shared a single ribotype, pulsed-field gel electrophoresis macrorestriction profile, and emm1 gene sequence. Nonetheless, among these isolates, FAFLP analysis could differentiate 17 distinct profiles, including seven multi-isolate groups. The FAFLP profiles of M1 isolates reproducibly exhibited between 1 and more than 20 amplified fragment differences. The high discriminatory power of genotyping by FAFLP analysis revealed genetic microheterogeneity and differentiated otherwise “identical” M1 isolates as members of a clone complex.

scholarly journals Streptococcus agalactiaepulsed-field gel electrophoresis patterns cross capsular types

2009 ◽  
Vol 137 (10) ◽  
pp. 1420-1425 ◽  
Author(s):  
P. PILLAI ◽  
U. SRINIVASAN ◽  
L. ZHANG ◽  
S. M. BORCHARDT ◽  
J. DEBUSSCHER ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Gel Electrophoresis ◽  
Diversity Index ◽  
Geographic Area ◽  
Pulsed Field Gel Electrophoresis ◽  
Capsular Type ◽  
Healthy Individuals ◽  
Pulsed Field ◽  
Capsular Typing

SUMMARYStreptococcus agalactiaeis a genetically diverse organism; when typed by pulsed-field gel electrophoresis (PFGE), multiple types appear within a single serotype. We tested whetherS. agalactiaePFGE types correspond to a specific serotype within individuals, and different individuals from the same geographic area. A total of 872S. agalactiaeisolates from 152 healthy individuals were classified by PFGE and capsular serotype. Serotype V was the most homogeneous (Simpson's diversity index 0·54); and types III, II and Ib were mostly heterogeneous (Simpson's diversity index ⩾0·90). Within an individual, isolates with the same PFGE patterns had identical capsular types, but across individuals the same PFGE types sometimes occurred in different serotypes. Capsular type alone is insufficient to define epidemiological relatedness. Although PFGE types appear to be a valid surrogate for capsular typing of isolates from the same individual, it is not a valid surrogate for serotype in isolates from different individuals.

scholarly journals Comparison of four molecular typing methods to assess genetic relatedness of Candida albicans clinical isolates in Taiwan

2005 ◽  
Vol 54 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Kuo-Wei Chen ◽  
Hsiu-Jung Lo ◽  
Yu-Hui Lin ◽  
Shu-Ying Li
Keyword(s):  
Candida Albicans ◽  
Molecular Typing ◽  
Genetic Relatedness ◽  
Geographic Origin ◽  
Discriminatory Power ◽  
Patient Specific ◽  
High Discriminatory Power ◽  
Typing Methods ◽  
Pcr Method ◽  
Genetic Profiles

This report describes the investigation of the genetic profiles of 53 Candida albicans isolates collected from 18 hospitals in Taiwan using three PFGE-based typing methods (PFGE karyotyping, and PFGE of SfiI and BssHII restriction fragments) and one repetitive-sequence-PCR (rep-PCR) method. All four methods were able to identify clonal related isolates from the same patients. PFGE-BssHII exhibited the highest discriminatory power by discriminating 40 genotypes, followed by PFGE-SfiI (35 genotypes) and then by rep-PCR (31 genotypes), while PFGE karyotyping exhibited the lowest discriminatory power (19 genotypes). High discriminatory power can also be achieved by combining typing methods with different typing mechanisms, such as rep-PCR and PFGE-based typing methods. The results also showed that the genotype of each isolate was patient-specific and not associated with the source of the isolation, geographic origin or antifungal resistance.

An Emerging Infection: Streptococcal Toxic Shock-Like Syndrome Caused By Group B Streptococcus (GBS), Streptococcus Agalactiae

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S140-S140
Author(s):  
F Rajack ◽  
A Afsari ◽  
A M Ramadan ◽  
T J Naab
Keyword(s):  
Soft Tissue ◽  
Necrotizing Fasciitis ◽  
Streptococcus Agalactiae ◽  
Group A Streptococcus ◽  
Multiorgan Failure ◽  
Group B Streptococcus ◽  
Stage Iii ◽  
Streptococcal Toxic Shock Syndrome ◽  
Toxic Shock ◽  
Group B

Abstract Introduction/Objective Streptococcus agalactiae, Group B Streptococcus (GBS), is a major cause of neonatal sepsis and infections in pregnant women. However, incidence of invasive GBS infections has more than doubled in the last two decades with highest risk in adults 65 years or older. Other risk factors are diabetes, malignancy, and immunocompromised state. Bacteremia and skin soft tissue infections are the most common invasive infections in nonpregnant adults. Rarely GBS infection has a fulminating pyrogenic exotoxin-mediated course characterized by acute onset, multiorgan failure, shock, and sometimes death, referred to as toxic shock-like syndrome. Methods A 77-year-old hypertensive female with uncontrolled type 2 diabetes mellitus and a history of bilateral foot ulcers presented to the hospital in probable septic shock. Clinical diagnosis of necrotizing fasciitis was made and she underwent bilateral lower limb amputations. Results Grossly soft tissue appeared gray. Microscopically fascia was necrotic without neutrophils present and Gram stain revealed sheets of Gram positive cocci. These findings reflected histopathologic Stage III necrotizing fasciitis, which is associated with 47% mortality. Autopsy showed a similar histology of Stage III necrotizing fasciitis involving the surgical stump. Erythema and desquamation of the upper limbs bilaterally and multi-organ failure met the clinical picture of Streptococcal Toxic Shock Syndrome (STSS) and fulfilled the criteria for TSS due to Group A Streptococcus (GAS), defined by The Working Group on Severe Streptococcal Infections. Conclusion Group B Streptococcal Toxic Shock-Like Syndrome may have a similar outcome to STSS caused by GAS and other pathogens and, in limited studies, mortality has been 30% or greater.

scholarly journals Streptococcus agalactiae Induces Placental Macrophages To Release Extracellular Traps Loaded with Tissue Remodeling Enzymes via an Oxidative Burst-Dependent Mechanism

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Ryan S. Doster ◽  
Jessica A. Sutton ◽  
Lisa M. Rogers ◽  
David M. Aronoff ◽  
Jennifer A. Gaddy
Keyword(s):  
Bacterial Infection ◽  
Streptococcus Agalactiae ◽  
Preterm Labor ◽  
Fetal Membrane ◽  
Content Type ◽  
Membrane Rupture ◽  
Extracellular Traps ◽  
Placental Macrophages ◽  
Group B ◽  
Placental Macrophage

ABSTRACT Streptococcus agalactiae, or group B Streptococcus (GBS), is a common perinatal pathogen. GBS colonization of the vaginal mucosa during pregnancy is a risk factor for invasive infection of the fetal membranes (chorioamnionitis) and its consequences such as membrane rupture, preterm labor, stillbirth, and neonatal sepsis. Placental macrophages, or Hofbauer cells, are fetally derived macrophages present within placental and fetal membrane tissues that perform vital functions for fetal and placental development, including supporting angiogenesis, tissue remodeling, and regulation of maternal-fetal tolerance. Although placental macrophages as tissue-resident innate phagocytes are likely to engage invasive bacteria such as GBS, there is limited information regarding how these cells respond to bacterial infection. Here, we demonstrate in vitro that placental macrophages release macrophage extracellular traps (METs) in response to bacterial infection. Placental macrophage METs contain proteins, including histones, myeloperoxidase, and neutrophil elastase similar to neutrophil extracellular traps, and are capable of killing GBS cells. MET release from these cells occurs by a process that depends on the production of reactive oxygen species. Placental macrophage METs also contain matrix metalloproteases that are released in response to GBS and could contribute to fetal membrane weakening during infection. MET structures were identified within human fetal membrane tissues infected ex vivo, suggesting that placental macrophages release METs in response to bacterial infection during chorioamnionitis. IMPORTANCE Streptococcus agalactiae, also known as group B Streptococcus (GBS), is a common pathogen during pregnancy where infection can result in chorioamnionitis, preterm premature rupture of membranes (PPROM), preterm labor, stillbirth, and neonatal sepsis. Mechanisms by which GBS infection results in adverse pregnancy outcomes are still incompletely understood. This study evaluated interactions between GBS and placental macrophages. The data demonstrate that in response to infection, placental macrophages release extracellular traps capable of killing GBS. Additionally, this work establishes that proteins associated with extracellular trap fibers include several matrix metalloproteinases that have been associated with chorioamnionitis. In the context of pregnancy, placental macrophage responses to bacterial infection might have beneficial and adverse consequences, including protective effects against bacterial invasion, but they may also release important mediators of membrane breakdown that could contribute to membrane rupture or preterm labor.

scholarly journals Prevalence and Serotype Determination of Streptococcus agalactiae Isolated From Non-Pregnant Women in Tehran, Iran

2020 ◽  
Author(s):  
Leila Goudarzi ◽  
Mohammad Bagher Khalili ◽  
Mahmood Vakili ◽  
Maryam Sadeh
Keyword(s):  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Cross Sectional Study ◽  
Chi Square ◽  
Cross Sectional ◽  
Specific Pcr ◽  
Pcr Method ◽  
Group B ◽  
Tehran Area

Consequence of Streptococcus agalactiae, Group B Streptococcus (GBS) relating infant’s diseases are well documented. Although many women carry this bacterium in their vagina, they may transfer to their infant during delivery and may result in different neonatal invasive diseases. The aim of this study was to determine the prevalence of GBS and serotyping the isolated species among un-selective non-pregnant women who attended two gynecology clinics in Tehran. In this cross-sectional study, a total of 560 vaginal samples collected from non-pregnant women. Following inoculation of the specimen on Blood Agar, the standard technology was applied for the final identification of GBS. Detected GBS species were further confirmed using specific PCR directed on dlts gene. Capsular serotyping was done by using the multiplex PCR method. The chi-square method was used for statistical analysis. Fifty (8.9%) out of 560 non-pregnant women were carriers of GBS. The most common types were III (36%), followed by type II (32%), Ia (26%), and Ib (6%), respectively. Results represent that the prevalence rate of GBS in non-pregnant women was reliable and similar to what obtained from pregnant women. In addition, the serotype III was found the most dominant types, as well as other investigations in the Tehran area. Therefore, vaccine designation based on type III is recommended.

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