Identification of Three Major Clones of Multiply Antibiotic-Resistant Streptococcus pneumoniae in Taiwanese  Hospitals by Multilocus Sequence Typing

In this paper we demonstrate the advantages of a new molecular typing procedure, multilocus sequence typing, for the unambiguous characterization of penicillin-resistant pneumococci. The sequences of ∼450-bp fragments of seven housekeeping genes were determined for 74 penicillin-resistant Taiwanese isolates of Streptococcus pneumoniae (MIC of penicillin > 0.5 μg/ml). The combination of alleles at the seven loci defined an allelic profile for each strain, and a dendrogram, based on the pairwise mismatches in allelic profiles, grouped 86% of the isolates into one of three penicillin-resistant clones for which the MICs of penicillin were 1 to 2 μg/ml. Isolates within each clone had identical alleles at all seven loci or differed at only a single locus, and the fingerprints of their pbp1A, pbp2B, and pbp2X genes were uniform. Isolates of the Taiwan-19F clone and the Taiwan-23F clone were resistant to penicillin, tetracycline, and erythromycin but were susceptible to chloramphenicol. A second serotype 23F clone and serotype 19F variants of this clone were resistant to penicillin, tetracycline, chloramphenicol, and, in some cases, erythromycin. Comparisons of the allelic profiles of the three major clones with those of reference isolates of the known penicillin-resistant clones showed that the Taiwan-19F and Taiwan-23F clones were previously undescribed, whereas the second serotype 23F clone was indistinguishable from the Spanish multidrug-resistant serotype 23F clone. Single isolates of the Spanish penicillin-resistant serotype 9V clone and the Spanish multidrug-resistant serotype 6B clone were also identified in the collection.

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Identification of the Major Spanish Clones of Penicillin-Resistant Pneumococci via the Internet Using Multilocus Sequence Typing

Journal of Clinical Microbiology ◽

10.1128/jcm.38.3.977-986.2000 ◽

2000 ◽

Vol 38 (3) ◽

pp. 977-986 ◽

Cited By ~ 33

Author(s):

Jiaji Zhou ◽

Mark C. Enright ◽

Brian G. Spratt

Keyword(s):

Molecular Typing ◽

Multilocus Sequence Typing ◽

Multidrug Resistant ◽

Single Locus ◽

The Internet ◽

Penicillin Binding Protein ◽

Allelic Profile ◽

Antibiotic Resistant ◽

Almost All ◽

Typing Procedure

Multilocus sequence typing was used to characterize isolates of the major Spanish clones of penicillin-resistant and multiple-antibiotic-resistant Streptococcus pneumoniae. Isolates of the multidrug-resistant Spanish serotype 23F clone and serotype variants of this clone either had identical allelic profiles or their allelic profiles differed from this typical allelic profile at only one of the seven housekeeping loci. Similarly, isolates of the Spanish serotype 6B and 14 clones and the penicillin-resistant serotype 9V clone (and serotype variants of this clone) each had the same allelic profiles or profiles that differed at a single locus. Multilocus sequence typing therefore allows resistant pneumococci to be assigned to the Spanish clones if they have the typical allelic profile of the clone or if their profiles differ from that profile at a single locus. A few resistant isolates that had allelic profiles typical of that of a Spanish clone or whose profiles differed from that of the typical profile at only a single locus possessed penicillin-binding protein pbp1a, pbp2b, or pbp2xgenes that differed from those that are characteristic of the clone. In most cases these isolates could be assigned as variant members of the clone. Since almost all serotype 9V isolates have very similar genotypes, independently emerging penicillin-resistant clones of this serotype will inevitably appear to be similar by molecular typing procedures. Analysis of the pbp genes, in addition to multilocus sequence typing (or any other molecular typing procedure), is therefore required to assign isolates unambiguously to the penicillin-resistant Spanish serotype 9V clone.

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Multilocus Sequence Typing for Characterization of Methicillin-Resistant and Methicillin-Susceptible Clones ofStaphylococcus aureus

Journal of Clinical Microbiology ◽

10.1128/jcm.38.3.1008-1015.2000 ◽

2000 ◽

Vol 38 (3) ◽

pp. 1008-1015 ◽

Cited By ~ 1865

Author(s):

Mark C. Enright ◽

Nicholas P. J. Day ◽

Catrin E. Davies ◽

Sharon J. Peacock ◽

Brian G. Spratt

Keyword(s):

Multilocus Sequence Typing ◽

Reference Strain ◽

Housekeeping Genes ◽

Invasive Disease ◽

Healthy Individuals ◽

Allelic Profile ◽

Methicillin Resistant ◽

Mlst Scheme ◽

Hospital Acquired

A multilocus sequence typing (MLST) scheme has been developed forStaphylococcus aureus. The sequences of internal fragments of seven housekeeping genes were obtained for 155 S. aureusisolates from patients with community-acquired and hospital-acquired invasive disease in the Oxford, United Kingdom, area. Fifty-three different allelic profiles were identified, and 17 of these were represented by at least two isolates. The MLST scheme was highly discriminatory and was validated by showing that pairs of isolates with the same allelic profile produced very similar SmaI restriction fragment patterns by pulsed-field gel electrophoresis. All 22 isolates with the most prevalent allelic profile were methicillin-resistant S. aureus (MRSA) isolates and had allelic profiles identical to that of a reference strain of the epidemic MRSA clone 16 (EMRSA-16). Four MRSA isolates that were identical in allelic profile to the other major epidemic MRSA clone prevalent in British hospitals (clone EMRSA-15) were also identified. The majority of isolates (81%) were methicillin-susceptible S. aureus (MSSA) isolates, and seven MSSA clones included five or more isolates. Three of the MSSA clones included at least five isolates from patients with community-acquired invasive disease and may represent virulent clones with an increased ability to cause disease in otherwise healthy individuals. The most prevalent MSSA clone (17 isolates) was very closely related to EMRSA-16, and the success of the latter clone at causing disease in hospitals may be due to its emergence from a virulent MSSA clone that was already a major cause of invasive disease in both the community and hospital settings. MLST provides an unambiguous method for assigning MRSA and MSSA isolates to known clones or assigning them as novel clones via the Internet.

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Estimating Recombinational Parameters in Streptococcus pneumoniae From Multilocus Sequence Typing Data

Genetics ◽

10.1093/genetics/154.4.1439 ◽

2000 ◽

Vol 154 (4) ◽

pp. 1439-1450 ◽

Cited By ~ 1

Author(s):

Edward J Feil ◽

John Maynard Smith ◽

Mark C Enright ◽

Brian G Spratt

Keyword(s):

Streptococcus Pneumoniae ◽

Multilocus Sequence Typing ◽

Clonal Complex ◽

Average Length ◽

Housekeeping Genes ◽

Single Locus ◽

Recent Common Ancestor ◽

Typing Method ◽

Molecular Events ◽

Molecular Typing Method

Abstract Multilocus sequence typing (MLST) is a highly discriminatory molecular typing method that defines isolates of bacterial pathogens using the sequences of ~450-bp internal fragments of seven housekeeping genes. This technique has been applied to 575 isolates of Streptococcus pneumoniae and identifies a number of discrete clonal complexes. These clonal complexes are typically represented by a single group of isolates sharing identical alleles at all seven loci, plus single-locus variants that differ from this group at only one out of the seven loci. As MLST is highly discriminatory, the members of each clonal complex can be assumed to have a recent common ancestor, and the molecular events that give rise to the single-locus variants can be used to estimate the relative contributions of recombination and mutation to clonal divergence. By comparing the sequences of the variant alleles within each clonal complex with the allele typically found within that clonal complex, we estimate that recombination has generated new alleles at a frequency ~10-fold higher than mutation, and that a single nucleotide site is ~50 times more likely to change through recombination than mutation. We also demonstrate how to estimate the average length of recombinational replacements from MLST data.

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Characterization of major clones of antibiotic-resistant Streptococcus pneumoniae in New Zealand by multilocus sequence typing

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dki001 ◽

2005 ◽

Vol 55 (3) ◽

pp. 375-378 ◽

Cited By ~ 14

Author(s):

David C. Bean ◽

John D. Klena

Keyword(s):

New Zealand ◽

Streptococcus Pneumoniae ◽

Multilocus Sequence Typing ◽

Antibiotic Resistant

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The Three Major Spanish Clones of Penicillin-Resistant Streptococcus pneumoniae Are the Most Common Clones Recovered in Recent Cases of Meningitis in Spain

Journal of Clinical Microbiology ◽

10.1128/jcm.37.10.3210-3216.1999 ◽

1999 ◽

Vol 37 (10) ◽

pp. 3210-3216 ◽

Cited By ~ 32

Author(s):

Mark C. Enright ◽

Asunción Fenoll ◽

David Griffiths ◽

Brian G. Spratt

Keyword(s):

Streptococcus Pneumoniae ◽

Multilocus Sequence Typing ◽

Pneumococcal Meningitis ◽

Multidrug Resistant ◽

The Other ◽

Antibiotic Resistant ◽

The United Kingdom ◽

Life Threatening ◽

Globally Distributed ◽

Sequence Types

One hundred six isolates of Streptococcus pneumoniaerecovered in Spain from patients with meningitis in 1997 and 1998 were characterized by multilocus sequence typing. A heterogeneous collection of genotypes was associated with meningitis in Spain: 65 different sequence types were resolved and, even at a genetic distance of 0.43, there were 37 distinct lineages. Thirty-eight percent of the isolates, including all isolates of serotypes 6B, 9V, 14, and 23F, were resistant to penicillin, and 24% of the isolates were members of the three major Spanish penicillin-resistant or multidrug-resistant clones of serotypes 6B, 9V, and 23F or serotype variants of these clones. These three clones (MICs, 1 to 2 μg of penicillin/ml) were the most common clones associated with pneumococcal meningitis in Spain during 1997 and 1998. Only two of the other clones associated with meningitis were penicillin resistant (MICs, 0.12 to 0.5 μg/ml). One of the two most prevalent penicillin-susceptible clones causing meningitis (serotype 3) has not been detected outside of Spain, whereas the other (serotype 18C) has been recovered from patients with meningitis in the United Kingdom, The Netherlands, and Denmark. The prevalence of meningitis caused by isolates of the three major Spanish penicillin-resistant or multiply antibiotic-resistant clones, which are now globally distributed, is disturbing and clearly establishes their ability to cause life-threatening disease.

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Streptococcus pneumoniae carriage in school children

Medical alphabet ◽

10.33667/2078-5631-2021-30-57-60 ◽

2021 ◽

Vol 1 (30) ◽

pp. 57-60

Author(s):

I. N. Protasova ◽

N. V. Bakhareva ◽

N. A. Ilyenkova ◽

E. S. Sokolovskaya ◽

T. A. Elistratova ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Antimicrobial Resistance ◽

School Children ◽

Clonal Diversity ◽

Multidrug Resistant ◽

Clonal Structure ◽

Serotype Distribution ◽

Antibiotic Resistant ◽

Oropharyngeal Swab ◽

Resistant Strains

Purpose. To investigate the serotype distribution, clonal structure and antimicrobial resistance of pneumococci isolated from schoolchildren.Materials and methods. During the period from 2012 to 2018 we examined 498 healthy school children aged 6 to 17 years. Oropharyngeal swab was taken from each child for culture, after that all S. pneumoniae strains were genotyped for serotype and ST-type deduction (PCR and sequencing, respectively). Antimicrobial resistance was also determined.Results. Pneumococcal culture was positive in 10.6 % of children. S. pneumoniae isolates belonged to seven serogroups and seven serotypes. Serogroup 6 and serotype 19F strains (15.1% each), and serogroup 9 strains (13.2%) were the most prevalent. S. pneumoniae33FA/37 and 3 (9.4 and 5.7%), serogroups 15 and 18 (7.6 and 5.7%), and 10A serotype (3.8%) were determined at a lower frequency. 20 detected ST-types belonged to 14 clonal complexes (CCs); CC156, CC447, and CC320 were predominant. 1.9% of isolates were penicillin-resistant; 13.2% – macrolide-, clindamycin-, and tetracycline-resistant. S. pneumoniae antibiotic resistant strains belonged to multidrug-resistant CCs 320, 315, and 156.Conclusion. S. pneumoniae prevalence in school children is not high. Pneumococcal population is characterized by serotype and clonal diversity including ‘invasive’ serotypes and genotypes. Most of strains are susceptible to antimicrobials.

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Ceftaroline Activity Against Multidrug-Resistant Streptococcus pneumoniae from U.S. Medical Centers (2014) and Molecular Characterization of a Single Ceftaroline Nonsusceptible Isolate

Microbial Drug Resistance ◽

10.1089/mdr.2016.0258 ◽

2017 ◽

Vol 23 (5) ◽

pp. 571-579 ◽

Cited By ~ 6

Author(s):

Michael A. Pfaller ◽

Rodrigo E. Mendes ◽

Robert K. Flamm ◽

Ronald N. Jones ◽

Helio S. Sader

Keyword(s):

Streptococcus Pneumoniae ◽

Molecular Characterization ◽

Multidrug Resistant ◽

Medical Centers

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Genetic diversity in Italian Lactobacillus sanfranciscensis strains assessed by multilocus sequence typing and pulsed-field gel electrophoresis analyses

Microbiology ◽

10.1099/mic.0.037341-0 ◽

2010 ◽

Vol 156 (7) ◽

pp. 2035-2045 ◽

Cited By ~ 54

Author(s):

Claudia Picozzi ◽

Gaia Bonacina ◽

Ileana Vigentini ◽

Roberto Foschino

Keyword(s):

Multilocus Sequence Typing ◽

Geographical Area ◽

Housekeeping Genes ◽

Processing Conditions ◽

Clonal Population ◽

Factors Affecting ◽

Lactobacillus Sanfranciscensis ◽

Mlst Scheme ◽

Sequence Types

Lactobacillus sanfranciscensis is a lactic acid bacterium that characterizes the sourdough environment. The genetic differences of 24 strains isolated in different years from sourdoughs, mostly collected in Italy, were examined and compared by PFGE and multilocus sequence typing (MLST). The MLST scheme, based on the analysis of six housekeeping genes (gdh, gyrA, mapA, nox, pgmA and pta) was developed for this study. PFGE with the restriction enzyme ApaI proved to have higher discriminatory power, since it revealed 22 different pulsotypes, while 19 sequence types were recognized through MLST analysis. Notably, restriction profiles generated from three isolates collected from the same firm but in three consecutive years clustered in a single pulsotype and showed the same sequence type, emphasizing the fact that the main factors affecting the dominance of a strain are correlated with processing conditions and the manufacturing environment rather than the geographical area. All results indicated a limited recombination among genes and the presence of a clonal population in L. sanfranciscensis. The MLST scheme proposed in this work can be considered a useful tool for characterization of isolates and for in-depth examination of the strain diversity and evolution of this species.

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