scholarly journals Serotype Emergence and Genotype Distribution among Macrolide-Resistant Invasive Streptococcus Pneumoniae Isolates in the Postconjugate Vaccine (PCV-7) Era

2011 ◽  
Vol 56 (2) ◽  
pp. 743-750 ◽  
Author(s):  
Zhenying Liu ◽  
Irving Nachamkin ◽  
Paul H. Edelstein ◽  
Ebbing Lautenbach ◽  
Joshua P. Metlay
Keyword(s):  
Streptococcus Pneumoniae ◽  
Gel Electrophoresis ◽  
Molecular Mechanisms ◽  
Population Based ◽  
Resistance Rate ◽  
Pulsed Field Gel Electrophoresis ◽  
Genotype Distribution ◽  
Erythromycin Resistance ◽  
Content Type ◽  
Pneumococcal Bacteremia

ABSTRACTWe conducted population-based surveillance for pneumococcal bacteremia within a 5-county region surrounding Philadelphia from October 2001 through September 2008, the period following introduction of the seven-valent pneumococcal conjugate vaccine. Erythromycin resistance increased from 14.7% in 2001-2002 to 20.3% in 2007-2008, while the resistance rate to penicillin (MIC, ≥2 μg/ml) decreased from 7.2% to 4.2% during the same period. The most predominant serotypes associated with erythromycin resistance in 2007-2008 included 19A (29.7%), 15A (29.2%), 6C (10.1%), 3 (5.6%), and 6A (4.5%). The molecular mechanisms for the increasing erythromycin resistance were mainly due to the growing presence ofmef(A)negativeerm(B)+andmef(A)+erm(B)+genotypes, which increased from 20.0% to 46.1% and from 1.8% to 19.1%, respectively, from 2001-2002 to 2007-2008. However,mef(A)-mediated erythromycin resistance decreased from 72.7% in 2001-2002 to 34.8% in 2007-2008. Serotypes related to theerm(B) gene were 15A (45.6%), 19A (20.9%), 3 (10.1%), and 6B (6.3%); serotypes related to themef(A)gene were 6A (18.6%), 19A (15.0%), 6C (9.3%), and 14(8.4%); serotypes associated with the presence of botherm(B) andmef(A)were 19A (81.5%), 15A (7.7%), and 19F (6.2%). Pulsed-field gel electrophoresis analysis demonstrated that erythromycin-resistant isolates within the 19A serotype were genetically diverse and related to several circulating international clones. In contrast, erythromycin-resistant isolates within the 15A serotype consisted of clonally identical or closely related isolates.

scholarly journals A Novel Multiresistant Streptococcus pneumoniae Serogroup 19 Clone from Washington State Identified by Pulsed-Field Gel Electrophoresis and Restriction Fragment Length Patterns

2000 ◽  
Vol 38 (4) ◽  
pp. 1575-1580 ◽  
Author(s):  
Vicki A. Luna ◽  
Daniel B. Jernigan ◽  
Alan Tice ◽  
James D. Kellner ◽  
Marilyn C. Roberts
Keyword(s):  
Streptococcus Pneumoniae ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Gel Electrophoresis ◽  
Washington State ◽  
Pulsed Field Gel Electrophoresis ◽  
Erythromycin Resistance ◽  
Eastern Canada ◽  
Pulsed Field ◽  
Restriction Fragment Length

In 1997, a cluster of multiresistant invasive serogroup 19 pneumococcus infections, including two fatalities, was reported in Washington State. Further investigation identified other cases. Fourteen Washington Streptococcus pneumoniae isolates, four from Alaska, and eight isolates from eastern Canada with reduced penicillin susceptibility (MIC of ≥1 μg/ml) were included in the study. Pulsed-field gel electrophoresis (PFGE) with ApaI,SacII, and SmaI restriction enzymes and IS1167 and mef restriction fragment length polymorphism (RFLP) pattern analysis were performed. Twenty of the 26 isolates had identical or related PFGE patterns, with two or all three enzymes, and identical or related IS1167 RFLP patterns, indicating that they were genetically related. These 20 isolates contained the mef gene conferring erythromycin resistance and had identical mef RFLP patterns. The PFGE and RFLP patterns were distinct from those of six multiresistant clones previously described and suggest that a new multiresistant clone has appeared in Washington, Alaska, and eastern Canada. This newly characterized clone should be included in the Pneumococcal Molecular Epidemiology Network.

scholarly journals Rapid Emergence and Evolution of Staphylococcus aureus Clones HarboringfusC-Containing Staphylococcal Cassette Chromosome Elements

2016 ◽  
Vol 60 (4) ◽  
pp. 2359-2365 ◽  
Author(s):  
Sarah L. Baines ◽  
Benjamin P. Howden ◽  
Helen Heffernan ◽  
Timothy P. Stinear ◽  
Glen P. Carter ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Fusidic Acid ◽  
Molecular Mechanisms ◽  
Population Based ◽  
Resistance Rate ◽  
Content Type ◽  
Fitness Advantage ◽  
Genotypic Association ◽  
Rapid Emergence ◽  
Staphylococcal Cassette Chromosome

ABSTRACTThe prevalence of fusidic acid (FA) resistance amongStaphylococcus aureusstrains in New Zealand (NZ) is among the highest reported globally, with a recent study describing a resistance rate of approximately 28%. Three FA-resistantS. aureusclones (ST5 MRSA, ST1 MSSA, and ST1 MRSA) have emerged over the past decade and now predominate in NZ, and in all three clones FA resistance is mediated by thefusCgene. In particular, ST5 MRSA has rapidly become the dominant MRSA clone in NZ, although the origin of FA-resistant ST5 MRSA has not been explored, and the genetic context offusCin FA-resistant NZ isolates is unknown. To better understand the rapid emergence of FA-resistantS. aureus, we used population-based comparative genomics to characterize a collection of FA-resistant and FA-susceptible isolates from NZ. FA-resistant NZ ST5 MRSA displayed minimal genetic diversity and represented a phylogenetically distinct clade within a global population model of clonal complex 5 (CC5)S. aureus. In all lineages,fusCwas invariably located within staphylococcal cassette chromosome (SCC) elements, suggesting that SCC-mediated horizontal transfer is the primary mechanism offusCdissemination. The genotypic association offusCwithmecAhas important implications for the emergence of MRSA clones in populations with high usage of fusidic acid. In addition, we found thatfusCwas colocated with a recently described virulence factor (tirS) in dominant NZS. aureusclones, suggesting a fitness advantage. This study points to the likely molecular mechanisms responsible for the successful emergence and spread of FA-resistantS. aureus.

scholarly journals Serotype 19F Multiresistant Pneumococcal Clone Harboring Two Erythromycin Resistance Determinants [erm(B) and mef(A)] in South Africa

2001 ◽  
Vol 45 (5) ◽  
pp. 1595-1598 ◽  
Author(s):  
Lesley McGee ◽  
Keith P. Klugman ◽  
Avril Wasas ◽  
Thora Capper ◽  
Adrian Brink
Keyword(s):  
South Africa ◽  
Streptococcus Pneumoniae ◽  
Private Sector ◽  
Dna Fingerprinting ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Erythromycin Resistance ◽  
Pulsed Field ◽  
Resistance Determinants ◽  
Genes Encoding

ABSTRACT One hundred eighteen erythromycin-resistant Streptococcus pneumoniae (ERSP) strains (MICs of ≥0.5 μg/ml) from five laboratories serving the private sector in South Africa were analyzed for the genes encoding resistance to macrolides. Sixty-seven ERSP strains (56.8%) contained the erm(B) gene, and 15 isolates (12.7%) contained the mef(A) gene. Thirty-six isolates (30.5%) harbored both the erm(B) and mef(A) genes and were highly resistant to erythromycin and clindamycin. DNA fingerprinting by BOX-PCR and pulsed-field gel electrophoresis identified 83% of these strains as belonging to a single multiresistant serotype 19F clone.

scholarly journals Phenotypic and Molecular Analysis of Penicillin-Nonsusceptible Streptococcus pneumoniae Isolates in Poland

2006 ◽  
Vol 51 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Ewa Sadowy ◽  
Radosław Izdebski ◽  
Anna Skoczyńska ◽  
Paweł Grzesiowski ◽  
Marek Gniadkowski ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Analysis ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Susceptibility Testing ◽  
Bacterial Pathogen ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Related Clone ◽  
Sequence Types

ABSTRACT β-Lactams are the drugs of choice for the treatment of infections caused by the important bacterial pathogen Streptococcus pneumoniae. The recent growth of resistance of this organism to penicillin observed worldwide is of the highest concern. In this study, using 887 surveillance pneumococcal isolates recovered in Poland from 1998 to 2002, we observed the increase in penicillin nonsusceptibility from 8.7% to 20.3%. All of the 109 penicillin-nonsusceptible S. pneumoniae (PNSP) isolates identified, together with 22 archival PNSP isolates from 1995 to 1997, were subsequently analyzed by susceptibility testing, serotyping, profiling of pbp genes, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Four predominant serotypes, serotypes 6B, 9V, 14, and 23F, characterized 85.5% of the isolates. MLST revealed the presence of 34 sequence types, 15 of which were novel types. Representatives of seven multiresistant international clones (Spain23F-1, Spain6B-2, Spain9V-3, Taiwan23F-15, Poland23F-16, Poland6B-20, and Sweden15A-25) or their closely related variants comprised the majority of the study isolates. The spread of Spain9V-3 and its related clone of serotype 14/ST143 has remarkably contributed to the recent increase in penicillin resistance in pneumococci in the country.

scholarly journals Plasmid-Borne Type E Neurotoxin Gene Clusters in Clostridium botulinum Strains

2013 ◽  
Vol 79 (12) ◽  
pp. 3856-3859 ◽  
Author(s):  
Zhen Zhang ◽  
Hannamari Hintsa ◽  
Ying Chen ◽  
Hannu Korkeala ◽  
Miia Lindström
Keyword(s):  
Gene Cluster ◽  
Gel Electrophoresis ◽  
Clostridium Botulinum ◽  
Southern Hybridization ◽  
Gene Clusters ◽  
Pulsed Field Gel Electrophoresis ◽  
Content Type ◽  
Pulsed Field ◽  
Large Plasmids

ABSTRACTA collection of 36Clostridium botulinumtype E strains was examined by pulsed-field gel electrophoresis (PFGE) and Southern hybridization with probes targeted tobotEandorfX1in the neurotoxin gene cluster. Three strains were found to contain neurotoxin subtype E1 gene clusters in large plasmids of about 146 kb in size.

scholarly journals Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States

2016 ◽  
Vol 54 (7) ◽  
pp. 1871-1876 ◽  
Author(s):  
Pamela R. F. Adkins ◽  
John R. Middleton ◽  
Lawrence K. Fox
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Virulence Gene ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Gene Identification ◽  
Content Type ◽  
Pulsed Field

Staphylococcus aureusis one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently describedS. aureusgenotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing ofS. aureusstrains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection ofS. aureusisolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) andN-acetyl-β-d-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing ofS. aureusisolates of bovine origin.

scholarly journals Genetic Relatedness of Recently Collected Spanish Respiratory Tract Streptococcus pneumoniae Isolates with Reduced Susceptibility to Amoxicillin

2003 ◽  
Vol 47 (11) ◽  
pp. 3637-3639 ◽  
Author(s):  
E. Pérez-Trallero ◽  
J. M. Marimón ◽  
A. González ◽  
C. García-Rey ◽  
L. Aguilar
Keyword(s):  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Gel Electrophoresis ◽  
Genetic Relatedness ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field

ABSTRACT Of Streptococcus pneumoniae isolates from 17 hospitals, 9.8% were amoxicillin nonsusceptible (MIC ≥ 4 μg/ml). The genetic relatedness of 138 isolates was studied by pulsed-field gel electrophoresis. Although 44 different clones were detected, more than 62% of these isolates were related to four clones (Spain23F-1, Spain6B-2, Spain9V-3, and Spain14-5).

scholarly journals Pulsed-Field Gel Electrophoresis and PCR Characterization of Environmental Vibrio parahaemolyticus Strains of Different Origins

2011 ◽  
Vol 77 (17) ◽  
pp. 6301-6304 ◽  
Author(s):  
E. Suffredini ◽  
C. Lopez-Joven ◽  
L. Maddalena ◽  
L. Croci ◽  
A. Roque
Keyword(s):  
Gel Electrophoresis ◽  
Vibrio Parahaemolyticus ◽  
Genetic Relationships ◽  
Pulsed Field Gel Electrophoresis ◽  
Environmental Isolates ◽  
Content Type ◽  
Pulsed Field ◽  
Intraspecies Variability ◽  
Different Origins

ABSTRACTThe present study used pulsed-field gel electrophoresis (PFGE) characterization to examine the intraspecies variability and genetic relationships among environmental isolates ofVibrio parahaemolyticusfrom different European countries. This is first study performed on environmentalV. parahaemolyticusthat included more than one European country.

scholarly journals Population Structure Analysis of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates from Brazil Reveals Predominance of Clonal Complexes 1, 15, and 79

2016 ◽  
Vol 60 (4) ◽  
pp. 2545-2547 ◽  
Author(s):  
Carlos Henrique Camargo ◽  
Monique Ribeiro Tiba ◽  
Marta Regina Saes ◽  
Francielli Mahnic de Vasconcellos ◽  
Luis Fernando dos Santos ◽  
...  
Keyword(s):  
Population Structure ◽  
Acinetobacter Baumannii ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Isolates ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Population Structure Analysis

ABSTRACTThe population structure of 71 carbapenem-resistantAcinetobacter baumanniiclinical isolates from several hospitals in Brazil was investigated by ApaI pulsed-field gel electrophoresis,blaOXA-51-like subtyping, and multilocus sequence typing (Institute Pasteur scheme). In addition to the predominance of strains carryingblaOXA-23, we detected the presence ofblaOXA-72andblaOXA-231. We observed a predominance of clonal complex 1 (CC1), CC15, and CC79 and representative strains of the worldwide-disseminated international clone I.

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