Molecular Characterization of Penicillin-Resistant  Streptococcus pneumoniae Isolates from Bulgaria

As part of an ongoing surveillance program of antibiotic-resistantStreptococcus pneumoniae in Sofia, Bulgaria, 120 penicillin-resistant strains (PRSP) (most of them recovered from children hospitalized with pneumococcal disease) were analyzed by microbiological and molecular methods. Several unique features of this collection are of particular interest. (i) Most isolates (112 of 120) were also resistant to trimethoprim-sulfamethoxazole (SXT) (97 of 120 isolates, or 80%), and over 70% (86 of 120) of the isolates were resistant to at least three antibiotics in addition to penicillin. (ii) Close to 80% of all isolates were represented by large clusters of bacteria, each with a unique serotype, antibiotype, and chromosomal macrorestriction pattern (determined by pulsed-field gel electrophoresis), as well as unique restriction fragmentation length polymorphisms of the penicillin-binding protein genespbp1a, pbp2x, and pbp2b. (iii) A large proportion (45 of 120, or 38%) of the strains belonged to two internationally spread epidemic clones of S. pneumoniae, the first expressing capsular type 23F and the second expressing serotype 9. (iv) A unique Bulgarian cluster composed of eight serotype 19F isolates was resistant to tetracycline, SXT, cefotaxime, and extremely high levels of penicillin and erythromycin. Nevertheless, this clone did not react with either the erm or the mef DNA probes, and thus the mechanism of macrolide resistance in this group of PRSP remains to be elucidated.

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In Vitro Evaluation of the Antimicrobial Activity of Ceftaroline against Cephalosporin-Resistant Isolates of Streptococcus pneumoniae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01324-08 ◽

2008 ◽

Vol 53 (2) ◽

pp. 552-556 ◽

Cited By ~ 45

Author(s):

Lesley McGee ◽

Donald Biek ◽

Yigong Ge ◽

Magderie Klugman ◽

Mignon du Plessis ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Vitro Activity ◽

Clinical Isolates ◽

Surveillance Program ◽

In Vitro Activity ◽

Penicillin Binding Protein ◽

Control And Prevention ◽

Cephalosporin Resistance ◽

Resistant Strains

ABSTRACT Increasing pneumococcal resistance to extended-spectrum cephalosporins warrants the search for novel agents with activity against such resistant strains. Ceftaroline, a parenteral cephalosporin currently in phase 3 clinical development, has demonstrated potent in vitro activity against resistant gram-positive organisms, including penicillin-resistant Streptococcus pneumoniae. In this study, the activity of ceftaroline was evaluated against highly cefotaxime-resistant isolates of pneumococci from the Active Bacterial Core surveillance program of the Centers for Disease Control and Prevention and against laboratory-derived cephalosporin-resistant mutants of S. pneumoniae. The MICs of ceftaroline and comparators were determined by broth microdilution. In total, 120 U.S. isolates of cefotaxime-resistant (MIC ≥ 4 μg/ml) S. pneumoniae were tested along with 18 laboratory-derived R6 strains with known penicillin-binding protein (PBP) mutations. Clinical isolates were characterized by multilocus sequence typing, and the DNAs of selected isolates were sequenced to identify mutations affecting pbp genes. Ceftaroline (MIC90 = 0.5 μg/ml) had greater in vitro activity than penicillin, cefotaxime, or ceftriaxone (MIC90 = 8 μg/ml for all comparators) against the set of highly cephalosporin-resistant clinical isolates of S. pneumoniae. Ceftaroline was also more active against the defined R6 PBP mutant strains, which suggests that ceftaroline can overcome common mechanisms of PBP-mediated cephalosporin resistance. These data indicate that ceftaroline has significant potency against S. pneumoniae strains resistant to existing parenteral cephalosporins and support its continued development for the treatment of infections caused by resistant S. pneumoniae strains.

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Ceftaroline Activity against Bacterial Pathogens Frequently Isolated in U.S. Medical Centers: Results from Five Years of the AWARE Surveillance Program

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04614-14 ◽

2015 ◽

Vol 59 (4) ◽

pp. 2458-2461 ◽

Cited By ~ 22

Author(s):

Helio S. Sader ◽

Robert K. Flamm ◽

Jennifer M. Streit ◽

David J. Farrell ◽

Ronald N. Jones

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Bacterial Pathogens ◽

Surveillance Program ◽

Broth Microdilution ◽

Methicillin Resistant ◽

Content Type ◽

Medical Centers ◽

Resistant Strains

ABSTRACTA total of 84,704 isolates were collected from 191 medical centers in 2009 to 2013 and tested for susceptibility to ceftaroline and comparator agents by broth microdilution methods. Ceftaroline inhibited allStaphylococcus aureusisolates at ≤2 μg/ml and was very active against methicillin-resistant strains (MIC at which 90% of the isolates tested are inhibited [MIC90], 1 μg/ml; 97.6% susceptible). AmongStreptococcus pneumoniaeisolates, the highest ceftaroline MIC was 0.5 μg/ml, and ceftaroline activity against the most commonEnterobacteriaceaespecies (MIC50, 0.12 μg/ml; 78.9% susceptible) was similar to that of ceftriaxone (MIC50, ≤0.25 μg/ml; 86.8% susceptible).

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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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Identification and Characterization of the Penicillin-Binding Protein 2a of Streptococcus pneumoniae and Its Possible Role in Resistance to β-Lactam Antibiotics

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.6.1745-1748.2000 ◽

2000 ◽

Vol 44 (6) ◽

pp. 1745-1748 ◽

Cited By ~ 20

Author(s):

Genshi Zhao ◽

Timothy I. Meier ◽

Joann Hoskins ◽

Kelly A. McAllister

Keyword(s):

Streptococcus Pneumoniae ◽

Binding Protein ◽

Penicillin Resistance ◽

Penicillin Binding Protein ◽

Insertional Mutant ◽

Identification And Characterization

ABSTRACT To further understand the role of penicillin-binding protein 2a (PBP 2a) of Streptococcus pneumoniae in penicillin resistance, we confirmed the identity of the protein as PBP 2a. The PBP 2a protein migrated electrophoretically to a position corresponding to that of PBP 2x, PBP 2a, and PBP 2b of S. pneumoniae and was absent in a pbp2ainsertional mutant of S. pneumoniae. We found that the affinities of PBP 2a for penicillins were lower than for cephalosporins and a carbapenem. When compared with other S. pneumoniae PBPs, PBP 2a exhibited lower affinities for β-lactam antibiotics, especially penicillins. Therefore, PBP 2a is a low-affinity PBP for β-lactam antibiotics in S. pneumoniae.

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Genetic Characterization of Fluoroquinolone-Resistant Streptococcus pneumoniae Strains Isolated during Ciprofloxacin Therapy from a Patient with Bronchiectasis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.47.4.1419-1422.2003 ◽

2003 ◽

Vol 47 (4) ◽

pp. 1419-1422 ◽

Cited By ~ 16

Author(s):

Adela G. de la Campa ◽

María-José Ferrandiz ◽

Fe Tubau ◽

Román Pallarés ◽

Federico Manresa ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Genetic Characterization ◽

Susceptible Strain ◽

Low Level ◽

Resistant Strains ◽

Resistant Mutants ◽

High Level ◽

Level Resistance

ABSTRACT Five Spain9V-3 Streptococcus pneumoniae strains were isolated from a patient with bronchiectasis who had received long-term ciprofloxacin therapy. One ciprofloxacin-susceptible strain was isolated before treatment, and four ciprofloxacin-resistant strains were isolated during treatment. The resistant strains were derived from the susceptible strain either by a parC mutation (low-level resistance) or by parC and gyrA mutations (high-level resistance). This study shows that ciprofloxacin therapy in a patient colonized by susceptible S. pneumoniae may select fluoroquinolone-resistant mutants.

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The Emergence of Invasive Streptococcus pneumoniae Serotype 24F in Lebanon: Complete Genome Sequencing Reveals High Virulence and Antimicrobial Resistance Characteristics

Frontiers in Microbiology ◽

10.3389/fmicb.2021.637813 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lina Reslan ◽

Marc Finianos ◽

Ibrahim Bitar ◽

Mohamad Bahij Moumneh ◽

George F. Araj ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Antimicrobial Resistance ◽

Tetracycline Resistance ◽

Virulence Gene ◽

Surveillance Program ◽

Virulence Determinants ◽

Tetracycline Resistance Genes ◽

Long Reads ◽

Genomic Characterization

BackgroundInvasive pneumococcal disease (IPD) remains a global health problem. IPD incidence has significantly decreased by the use of pneumococcal conjugate vaccines (PCV). Nevertheless, non-PCV serotypes remain a matter of concern. Eight Streptococcus pneumoniae serotype 24F isolates, belonging to a non-PCV serotype, were detected through the Lebanese Inter-Hospital Pneumococcal Surveillance Program. The aim of the study is to characterize phenotypic and genomic features of the 24F isolates in Lebanon.MethodsWGS using long reads sequencing (PacBio) was performed to produce complete circular genomes and to determine clonality, antimicrobial resistance and virulence determinants.ResultsThe sequencing results yielded eight closed circular genomes. Three multilocus sequence typing (MLST) types were identified (ST11618, ST14184, ST15253). Both MLST and WGS analyses revealed that these isolates from Lebanon were genetically homogenous belonging to clonal complex CC230 and clustered closely with isolates originating from Canada, United States of America, United Kingdom and Iceland. Their penicillin binding protein profiles correlated with both β-lactam susceptibility patterns and MLST types. Moreover, the isolates harbored the macrolide and tetracycline resistance genes and showed a similar virulence gene profile. To our knowledge, this study represents the first report of complete phenotypic and genomic characterization of the emerging Streptococcus pneumoniae, serotype 24F, in the Middle East and North Africa region.

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Molecular Epidemiology of Penicillin-NonsusceptibleStreptococcus pneumoniae among Children in Greece

Journal of Clinical Microbiology ◽

10.1128/jcm.38.12.4361-4366.2000 ◽

2000 ◽

Vol 38 (12) ◽

pp. 4361-4366 ◽

Cited By ~ 6

Author(s):

Debby Bogaert ◽

George A. Syrogiannopoulos ◽

Ioanna N. Grivea ◽

Ronald de Groot ◽

Nicholas G. Beratis ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Molecular Epidemiology ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Genetic Relatedness ◽

Antibiotic Susceptibility Testing ◽

Penicillin Binding Protein ◽

Genetic Clusters

A total of 145 penicillin-nonsusceptible Streptococcus pneumoniae strains were isolated from young carriers in Greece and analyzed by antibiotic susceptibility testing, serotyping, restriction fragment end labeling (RFEL), and penicillin-binding protein (PBP) genotyping. The serotypes 23A and 23F (54%), 19A and 19F (25%), 9V (5%), 15A, 15B, and 15C (4%), 6A and 6B (4%), and 21 (4%) were most prevalent in this collection. Fifty-three distinct RFEL types were identified. Sixteen different RFEL clusters, harboring 2 to 32 strains each, accounted for 82% of all strains. Eight of these genetic clusters representing 60% of the strains were previously identified in other countries. A predominant lineage of 66 strains (46%) harboring five RFEL types and the serotypes 19F and 23F was closely related to the pandemic clone Spain23F-1 (genetic relatedness of ≥85%). Another lineage, representing 11 strains, showed close genetic relatedness to the pandemic clone France9V-3. Another lineage of 8 serotype 21 strains was Greece specific since the RFEL types were not observed in an international collection of 193 genotypes from 16 different countries. Characterization of the PBP genes pbp1a, pbp2b, and pbp2x revealed 20 distinct PBP genotypes of which PBP type 1-1-1, initially observed in the pandemic clones 23F and 9V, was predominantly present in 11 RFEL types in this Greek collection of penicillin-nonsusceptible strains (55%). Sixteen PBP types covering 52 strains (36%) were Greece specific. This study underlines the strong contribution of penicillin-resistant international clones to the prevalence and spread of penicillin-nonsusceptible pneumococci among young children in Greece.

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Molecular Characterization of Pneumococcal Nasopharynx Isolates Collected from Children during Their First 2 Years of Life

Journal of Clinical Microbiology ◽

10.1128/jcm.36.8.2248-2253.1998 ◽

1998 ◽

Vol 36 (8) ◽

pp. 2248-2253 ◽

Cited By ~ 15

Author(s):

Marcel Sluijter ◽

Howard Faden ◽

Ronald de Groot ◽

Nicole Lemmens ◽

Wil H. F. Goessens ◽

...

Keyword(s):

Molecular Characterization ◽

Horizontal Transfer ◽

Capsular Type ◽

Penicillin Binding Protein ◽

Resistant Strains ◽

Pneumococcal Colonization ◽

Different Strains ◽

Culture Positive ◽

Capsular Typing

Pneumococcal colonization was studied in 19 children monitored from birth through the age of 2 years. For this purpose, pneumococcal isolates were characterized by capsular typing, restriction fragment end labeling (RFEL), and penicillin-binding protein (PBP) genotyping. Fifty-eight isolates were collected and were found to belong to 10 capsular types, 31 RFEL types, and 7 PBP genotypes. Thirty-nine percent of the isolates had reduced susceptibility to penicillin. All seven highly resistant strains (MICs, >1 μg/ml) were identical to the pandemic clone 23F. Children were culture positive between one and eight times at 13 scheduled visits. Although the infants were frequently recolonized with different strains, colonization with one particular strain often persisted for several months. Isolation of a previously detected capsular type was common, and the chromosomal homogeneity tended to be high when it occurred. Horizontal transfer of capsular genes between strains of different RFEL types was demonstrated in one child. The ecological advantage of transfer of capsular genes is unclear unless survival of the organism on a mucosal surface may be linked to immunoprotective pressure against particular capsular types.

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