Molecular analysis of antibiotic tolerance in pneumococci

Mitchell, Lauren; Tuomanen, Elaine

doi:10.1078/1438-4221-00193

Cited by 9 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early reports showed the vex-vnc locus plays a major role in autolysis and vancomycin tolerance in S. pneumoniae [71], [72], [73], [74]. The proposed mechanism of autolysin activation and vancomycin tolerance involves the vex / pep 27 / vncSR locus whereby upon binding of vancomycin onto the bacterial cell wall, it triggers the expression of the locus, the death signal peptide pep 27 produced is transported into the extracellular space via Vex123 transporter system.…”

Section: Resultsmentioning

confidence: 99%

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence

Lin¹,

Liu²,

Teng³

et al. 2011

PLoS ONE

View full text Add to dashboard Cite

Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I) and S. pasteurianus ATCC 43144 (biotype II.2). The genomic differences between the two biotypes were characterized with comparative genomic analyses. The chromosome of ATCC 43143 and ATCC 43144 are 2,36 and 2,10 Mb in length and encode 2246 and 1869 CDS respectively. The organization and genomic contents of both genomes were most similar to the recently published S. gallolyticus UCN34, where 2073 (92%) and 1607 (86%) of the ATCC 43143 and ATCC 43144 CDS were conserved in UCN34 respectively. There are around 600 CDS conserved in all Streptococcus genomes, indicating the Streptococcus genus has a small core-genome (constitute around 30% of total CDS) and substantial evolutionary plasticity. We identified eight and five regions of genome plasticity in ATCC 43143 and ATCC 43144 respectively. Within these regions, several proteins were recognized to contribute to the fitness and virulence of each of the two subspecies. We have also predicted putative cell-surface associated proteins that could play a role in adherence to host tissues, leading to persistent infections causing sub-acute and chronic diseases in humans. This study showed evidence that the S. gallolyticus still possesses genes making it suitable in a rumen environment, whereas the ability for S. pasteurianus to live in rumen is reduced. The genome heterogeneity and genetic diversity among the two biotypes, especially membrane and lipoproteins, most likely contribute to the differences in the pathogenesis of the two S. gallolyticus biotypes and the type of disease an infected patient eventually develops.

show abstract

Section: Resultsmentioning

confidence: 99%

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence

Lin¹,

Liu²,

Teng³

et al. 2011

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…The microbial ability to withstand chemical stress is attributed to different adaptive responses exhibited by tolerant microorganisms (Bradley & Fraise, 1996;Isken & de Bont, 1998). The molecular and biochemical mechanisms of bacterial resistance to toxic chemicals have been studied in detail for antibiotics, where the resistance is exerted by mechanisms for example enzymatic inactivation, passive exculsion from the cell or active efflux of the antibiotic molecule (Goessens, 1993;McManus, 1997;Charpentier & Tuomanen, 2000;Mitchell & Tuomanen, 2002). Bacterial resistance to biocidal chemicals including organic chemicals and solvents also follows a similar mechanism (Isken & de Bont, 1998;Ng et al, 2002;Sardessai & Bhosle, 2002).…”

Section: Biotic Factorsmentioning

confidence: 99%

Integrative approaches for assessing the ecological sustainability ofin situbioremediation

2009

View full text Add to dashboard Cite

Application of microbial metabolic potential (bioremediation) is accepted as an environmentally benign and economical measure for decontamination of polluted environments. Bioremediation methods are generally categorized into ex situ and in situ bioremediation. Although in situ bioremediation methods have been in use for two to three decades, they have not yet yielded the expected results. Their limited success has been attributed to reduced ecological sustainability under environmental conditions. An important determinant of sustainability of in situ bioremediation is pollutant bioavailability. Microbial chemotaxis is postulated to improve pollutant bioavailability significantly; consequently, application of chemotactic microorganisms can considerably enhance the performance of in situ degradation. The environmental fate of degradative microorganisms and the ecological consequence of intervention constitute other important descriptors for the efficiency and sustainability of bioremediation processes. Integrative use of culture-dependent, culture-independent methods (e.g. amplified rDNA restriction analysis, terminal restriction fragment length polymorphism, denaturing/thermal gradient gel electrophoresis, phospholipid fatty acid, etc.), computational and statistical analyses has enabled successful monitoring of the above aspects. The present review provides a detailed insight into some of the key factors that affect the efficiency of in situ bioremediation along with a comprehensive account of the integrative approaches used for assessing the ecological sustainability of processes. The review also discusses the possibility of developing suicidal genetically engineered microorganisms for optimized and controlled in situ bioremediation.

show abstract

“…It is clear that the triggering of autolytic enzymes by cell wall acting antibiotics is the basis of bacterial lysis (and death) (Tomasz et al ., 1970). Direct evidence showing that mutation of the LytA autolysin prevents autolysis and causes tolerance to killing by antibiotics that inhibit cell wall synthesis has been provided (Sánchez‐Puelles et al ., 1986; Ronda et al ., 1987; Henriques Normark and Normark, 2002; Mitchell and Tuomanen, 2002). However, the signal and trigger pathway for this event is unknown.…”

Section: Introductionmentioning

confidence: 99%

Vancomycin tolerance in clinical and laboratory Streptococcus pneumoniae isolates depends on reduced enzyme activity of the major LytA autolysin or cooperation between CiaH histidine kinase and capsular polysaccharide

Moscoso¹,

Domenech²,

Garcı́a³

2010

Molecular Microbiology

View full text Add to dashboard Cite

SummaryVancomycin is frequently added to standard therapy for pneumococcal meningitis. Although vancomycinresistant Streptococcus pneumoniae strains have not been isolated, reports on the emergence of vancomycin-tolerant pneumococci are a cause of concern. To date, the molecular basis of vancomycin tolerance in S. pneumoniae is essentially unknown. We examined two vancomycin-tolerant clinical isolates, i.e. a purported autolysin negative (LytA -), serotype 23F isolate (strain S3) and the serotype 14 strain 'Tupelo', which is considered a paradigm of vancomycin tolerance. S3 was characterized here as carrying a frameshift mutation in the lytA gene encoding the main pneumococcal autolysin. The vancomycin tolerance of strain S3 was abolished by transformation to the autolysin-proficient phenotype. The original Tupelo strain was discovered to be a mixture: a strain showing a vancomycin-tolerant phenotype (Tupelo_VT) and a vancomycinnontolerant strain (Tupelo_VNT). The two strains differed only in terms of a single mutation in the ciaH gene present in the VT strain. Most interestingly, although the vancomycin tolerance of Tupelo_VT could be overcome by increasing the LytA dosage upon transformation by a multicopy plasmid or by externally adding the autolysin, we show that vancomycin tolerance in S. pneumoniae requires the simultaneous presence of a mutated CiaH histidine kinase and capsular polysaccharide.

show abstract

Molecular analysis of antibiotic tolerance in pneumococci

Cited by 9 publications

References 16 publications

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence

Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence

Integrative approaches for assessing the ecological sustainability ofin situbioremediation

Vancomycin tolerance in clinical and laboratory Streptococcus pneumoniae isolates depends on reduced enzyme activity of the major LytA autolysin or cooperation between CiaH histidine kinase and capsular polysaccharide

Contact Info

Product

Resources

About