scholarly journals Genome analysis of a MDR Streptococcus pneumoniae 23F serotype causing meningoencephalitis in a 10-months refugee infant

2018 ◽  
Vol 12 (03) ◽  
pp. 196-203
Author(s):  
Tamara Salloum ◽  
Elie Tannous ◽  
Samar Merheb-Ghoussoub ◽  
Elie Ghoussoub ◽  
Sima Tokajian
Keyword(s):  
Streptococcus Pneumoniae ◽  
Virulence Factors ◽  
Genome Analysis ◽  
Reference Strain ◽  
Clinical Diagnostics ◽  
Penicillin Binding Proteins ◽  
Multiple Components ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Reference Strains

Purpose: Streptococcus pneumoniae is an important human pathogen causing invasive pneumococcal diseases (IPD). The re-emergence of eradicated S. pneumoniae-associated meningoencephalitis in Lebanon is a major point of concern. Methods: We aimed at conducting a comparative genome analysis of a multi-drug resistant S. pneumoniae, LAU-23F, linked to meningoencephalitis and fatality in a 10-months Syrian refugee infant in Lebanon, and 24 related publically available genome sequences. Serotype, capsular genes, MLST, SNPs, phylogenetic relatedness and repertoire of resistance genes were investigated. Genes encoding penicillin binding proteins (PBPs) were examined for mosaicity. Virulence factors were screened for SNPs as compared to reference strains. Results: The isolate belonged to ST-277 and was of serotype 23F. It showed an intermediate resistance to ciprofloxacin, cefuroxime and penicillin and carried multiple components of different efflux pumps. Gene mosaicity was observed in pbp2x, it was also distinct from other penicillin-resistant strains; pbp1a and pbp2b appeared to be conserved between LAU-23F and the reference strain SP49. The arrangement of capsular gene loci was similar to ATCC 700669 though polymorphism was detected in the cpsABCD region, believed to be conserved among different Streptococcus species. Amplitude of virulence factors was detected showing varying degrees of conservation compared to reference strains. Observed zones of high heterogeneity were associated with phage encoded regions. Conclusions: The fine levels of diversity throughout the genome could account for the pronounced invasiveness of this isolate. The genomics-based methods used support the importance of implementing WGS in routine clinical diagnostics and surveillance of streptococcal diseases.

scholarly journals Highly Variable Penicillin Resistance Determinants PBP 2x, PBP 2b, and PBP 1a in Isolates of Two Streptococcus pneumoniae Clonal Groups, Poland23F-16 and Poland6B-20

2007 ◽  
Vol 52 (3) ◽  
pp. 1021-1027 ◽  
Author(s):  
Radosław Izdebski ◽  
Jens Rutschmann ◽  
Janusz Fiett ◽  
Ewa Sadowy ◽  
Marek Gniadkowski ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Reference Strain ◽  
Pattern Analysis ◽  
Profile Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Reactivity Pattern ◽  
Multiple Gene ◽  
Penicillin Binding Proteins ◽  
Resistance Determinants

ABSTRACT Penicillin-binding proteins (PBPs) in representatives of two Streptococcus pneumoniae clonal groups that are prevalent in Poland, Poland23F-16 and Poland6B-20, were investigated by PBP profile analysis, antibody reactivity pattern analysis, and DNA sequence analysis of the transpeptidase (TP) domain-encoding regions of the pbp2x, pbp2b, and pbp1a genes. The isolates differed in their MICs of β-lactam antibiotics. The majority of the 6B isolates were intermediately susceptible to penicillin (penicillin MICs, 0.12 to 0.5 μg/ml), whereas all 23F isolates were penicillin resistant (MICs, ≥2 μg/ml). The 6B isolates investigated had the same sequence type (ST), determined by multilocus sequence typing, as the Poland6B-20 reference strain (ST315), but in the 23F group, isolates with three distinct single-locus variants (SLVs) in the ddl gene (ST173, ST272, and ST1506) were included. None of the isolates showed an identical PBP profile after labeling with Bocillin FL and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and only one pair of 6B isolates and one pair of 23F isolates (ST173 and ST272) each contained an identical combination of PBP 2x, PBP 2b, and PBP 1a TP domains. Some 23F isolates contained PBP 3 with an apparently higher electrophoretic mobility, and this feature also did not correlate with their STs. The data document a highly variable pool of PBP genes as a result of multiple gene transfer and recombination events within and between different clonal groups.

scholarly journals In Vitro Activity of Sanfetrinem and Affinity for the Penicillin-Binding Proteins of Streptococcus pneumoniae

1998 ◽  
Vol 42 (1) ◽  
pp. 173-175 ◽  
Author(s):  
Farid Sifaoui ◽  
Emmanuelle Varon ◽  
Marie-Dominique Kitzis ◽  
Laurent Gutmann
Keyword(s):  
Streptococcus Pneumoniae ◽  
Binding Proteins ◽  
Susceptible Strain ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Penicillin Binding Proteins ◽  
Resistant Strains

ABSTRACT Against penicillin-susceptible pneumococci, the activity of sanfetrinem was similar to those of penicillin, amoxicillin, cefotaxime, imipenem, and meropenem, while against penicillin-resistant strains, sanfetrinem and the carbapenems exhibited superior activity (MICs at which 90% of strains are inhibited, ≤1 μg/ml). PBP 1a in the penicillin-susceptible strain and PBP 1a and PBP 2b in the more resistant isolates seemed to be the essential penicillin-binding proteins for imipenem and sanfetrinem.

scholarly journals Identical Penicillin-Binding Domains in Penicillin-Binding Proteins of Streptococcus pneumoniae Clinical Isolates with Different Levels of β-Lactam Resistance

2005 ◽  
Vol 49 (7) ◽  
pp. 2895-2902 ◽  
Author(s):  
Laurent Chesnel ◽  
Raphaël Carapito ◽  
Jacques Croizé ◽  
Otto Dideberg ◽  
Thierry Vernet ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Binding Proteins ◽  
Laboratory Strain ◽  
Clinical Isolates ◽  
Penicillin G ◽  
Resistance Level ◽  
Penicillin Binding Proteins ◽  
Binding Domains ◽  
Wide Range ◽  
Genes Encoding

ABSTRACT We have sequenced the penicillin-binding domains of the complete repertoire of penicillin-binding proteins and MurM from 22 clinical isolates of Streptococcus pneumoniae that span a wide range of β-lactam resistance levels. Evidence of mosaicism was found in the genes encoding PBP 1a, PBP 2b, PBP 2x, MurM, and, possibly, PBP 2a. Five isolates were found to have identical PBP and MurM sequences, even though the MICs for penicillin G ranged from 0.25 to 2.0 mg/liter. When the sequences encoding PBP 1a, PBP 2b, and PBP 2x from one of these isolates were used to transform laboratory strain R6, the resulting strain had a resistance level higher than that of the less resistant isolates carrying that PBP set but lower than that of the most resistant isolates carrying that PBP set. This result demonstrates that if the R6 strain is arbitrarily defined as the standard genotype, some wild genetic backgrounds can either increase or decrease the PBP-based resistance phenotype.

Gene Disruption Studies of Penicillin-Binding Proteins 1a, 1b, and 2a in Streptococcus pneumoniae

1999 ◽  
Vol 181 (20) ◽  
pp. 6552-6555 ◽  
Author(s):  
JoAnn Hoskins ◽  
Patti Matsushima ◽  
Deborah L. Mullen ◽  
Joseph Tang ◽  
Genshi Zhao ◽  
...  
Keyword(s):  
Growth Rate ◽  
Streptococcus Pneumoniae ◽  
Gene Disruption ◽  
Binding Proteins ◽  
The Other ◽  
Penicillin Binding Protein ◽  
Disruption Mutant ◽  
Penicillin Binding Proteins ◽  
Genes Encoding

ABSTRACT The effects of inactivation of the genes encoding penicillin-binding protein 1a (PBP1a), PBP1b, and PBP2a inStreptococcus pneumoniae were examined. Insertional mutants did not exhibit detectable changes in growth rate or morphology, although a pbp1a pbp1b double-disruption mutant grew more slowly than its parent did. Attempts to generate a pbp1a pbp2a double-disruption mutant failed. The pbp2amutants, but not the other mutants, were more sensitive to moenomycin, a transglycosylase inhibitor. These observations suggest that individually the pbp1a, pbp1b, andpbp2a genes are dispensable but that eitherpbp1a or pbp2a is required for growth in vitro. These results also suggest that PBP2a is a functional transglycosylase in S. pneumoniae.

scholarly journals Reference genome for the WHO reference strain for Mycobacterium bovis BCG Danish, the present tuberculosis vaccine

2019 ◽  
Author(s):  
Katlyn Borgers ◽  
Jheng-Yang Ou ◽  
Po-Xing Zheng ◽  
Petra Tiels ◽  
Annelies Van Hecke ◽  
...  
Keyword(s):  
Mycobacterium Bovis ◽  
Vaccine Strain ◽  
Genome Analysis ◽  
Reference Strain ◽  
Reference Genome ◽  
Bacillus Calmette Guerin ◽  
Genome Duplications ◽  
Analysis Workflow ◽  
Derivatives Of ◽  
Reference Strains

ABSTRACTMycobacterium bovis bacillus Calmette-Guérin (M. bovis BCG) is the only vaccine available against tuberculosis (TB). This study reports on an integrated genome analysis workflow for BCG, resulting in the completely assembled genome sequence of BCG Danish 1331 (07/270), one of the WHO reference strains for BCG vaccines. We demonstrate how this analysis workflow enables the resolution of genome duplications and of the genome of engineered derivatives of this vaccine strain.

Quintuplex PCR to Detect Antibiotic Resistance Genes in Streptococcus pneumoniae

2016 ◽  
Vol 1 (2) ◽  
pp. 22 ◽  
Author(s):  
Navindra Kumari Palanisamy ◽  
Parasakthi Navaratnam ◽  
Shamala Devi Sekaran
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pneumoniae ◽  
Resistance Genes ◽  
Bacterial Pathogen ◽  
Antibiotic Resistance Genes ◽  
Pcr Amplification ◽  
Penicillin Resistance ◽  
Penicillin Binding Proteins ◽  
Efflux Mechanism ◽  
Mic Value

Introduction: Streptococcus pneumoniae is an important bacterial pathogen, causing respiratory infection. Penicillin resistance in S. pneumoniae is associated with alterations in the penicillin binding proteins, while resistance to macrolides is conferred either by the modification of the ribosomal target site or efflux mechanism. This study aimed to characterize S. pneumoniae and its antibiotic resistance genes using 2 sets of multiplex PCRs. Methods: A quintuplex and triplex PCR was used to characterize the pbp1A, ermB, gyrA, ply, and the mefE genes. Fifty-eight penicillin sensitive strains (PSSP), 36 penicillin intermediate strains (PISP) and 26 penicillin resistance strains (PRSP) were used. Results: Alteration in pbp1A was only observed in PISP and PRSP strains, while PCR amplification of the ermB or mefE was observed only in strains with reduced susceptibility to erythromycin. The assay was found to be sensitive as simulated blood cultures showed the lowest level of detection to be 10cfu. Conclusions: As predicted, the assay was able to differentiate penicillin susceptible from the non-susceptible strains based on the detection of the pbp1A gene, which correlated with the MIC value of the strains.

scholarly journals Streptococcus pneumoniae and Its Virulence Factors H2O2 and Pneumolysin Are Potent Mediators of the Acute Chest Syndrome in Sickle Cell Disease

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 157
Author(s):  
Joyce Gonzales ◽  
Trinad Chakraborty ◽  
Maritza Romero ◽  
Mobarak Abu Mraheil ◽  
Abdullah Kutlar ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Sickle Cell Disease ◽  
Virulence Factors ◽  
Sickle Cell ◽  
Biological Activities ◽  
Acute Chest Syndrome ◽  
Antibiotics Resistance ◽  
Cell Disease ◽  
Antibiotic Drug ◽  
Tract Infections

Sickle cell disease (SCD) is one of the most common autosomal recessive disorders in the world. Due to functional asplenia, a dysfunctional antibody response, antibiotic drug resistance and poor response to immunization, SCD patients have impaired immunity. A leading cause of hospitalization and death in SCD patients is the acute chest syndrome (ACS). This complication is especially manifested upon infection of SCD patients with Streptococcus pneumoniae (Spn)—a facultative anaerobic Gram-positive bacterium that causes lower respiratory tract infections. Spn has developed increased rates of antibiotics resistance and is particularly virulent in SCD patients. The primary defense against Spn is the generation of reactive oxygen species (ROS) during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn itself produces high levels of the ROS hydrogen peroxide (H2O2) as a virulence strategy. Apart from H2O2, Spn also secretes another virulence factor, i.e., the pore-forming exotoxin pneumolysin (PLY), a potent mediator of lung injury in patients with pneumonia in general and particularly in those with SCD. PLY is released early on in infection either by autolysis or bacterial lysis following the treatment with antibiotics and has a broad range of biological activities. This review will discuss recent findings on the role of pneumococci in ACS pathogenesis and on strategies to counteract the devastating effects of its virulence factors on the lungs in SCD patients.

Sign in / Sign up

Export Citation Format

Share Document