scholarly journals Newly identified bacteriolytic enzymes that target a wide range of clinical isolates of Clostridium difficile

2016 ◽  
Vol 113 (12) ◽  
pp. 2568-2576 ◽  
Author(s):  
Krunal K. Mehta ◽  
Elena E. Paskaleva ◽  
Xia Wu ◽  
Navdeep Grover ◽  
Ruchir V. Mundra ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Clinical Isolates ◽  
Bacteriolytic Enzymes ◽  
Wide Range

scholarly journals Analysis of virulence factors and emm typing of Streptococcus pyogenes clinical isolates.

2019 ◽  
Author(s):  
Gustavo Enck Sambrano ◽  
Gustavo P Riboldi ◽  
Keli C Reiter ◽  
Thiago Galvão da Silva Paim ◽  
Neidmar Correa Tolfo ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Pcr Analysis ◽  
Tissue Tropism ◽  
Factors Analysis ◽  
Wide Range ◽  
Group A ◽  
Micro Organisms

Background: Streptococcus pyogenes, a Group A streptococci (GAS), is an important human pathogen that causes a wide range of infections. Methods: Twenty five clinical isolates of S. pyogenes were submitted to an emm typing and to a Real-time PCR analysis for 23 important virulence factors. Results: Fourteen emm types were found and the emm1 type was the most prevalent. The majority of the isolates were classified as emm pattern E, followed by A-C3. No pattern D was found. Among the virulence factors, the most prevalent were SpeG, Slo, C5a-peptidase and SPNA. Phage encoded virulence genes were also found among the strains, such as mf-2, SpeJ and SpeL. Discussion: The emm1 type was the most prevalent while the 13 others M types were distributed along the strains. No tissue tropism was found on the isolates. The virulence factors analysis demonstrated that chromosomally and phage-encoded genes were found, which confers a potential for high virulent micro-organisms.

scholarly journals Analysis of virulence factors and emm typing of Streptococcus pyogenes clinical isolates.

2019 ◽  
Author(s):  
Gustavo Enck Sambrano ◽  
Gustavo P Riboldi ◽  
Keli C Reiter ◽  
Thiago Galvão da Silva Paim ◽  
Neidmar Correa Tolfo ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Pcr Analysis ◽  
Tissue Tropism ◽  
Factors Analysis ◽  
Wide Range ◽  
Group A ◽  
Micro Organisms

Background: Streptococcus pyogenes, a Group A streptococci (GAS), is an important human pathogen that causes a wide range of infections. Methods: Twenty five clinical isolates of S. pyogenes were submitted to an emm typing and to a Real-time PCR analysis for 23 important virulence factors. Results: Fourteen emm types were found and the emm1 type was the most prevalent. The majority of the isolates were classified as emm pattern E, followed by A-C3. No pattern D was found. Among the virulence factors, the most prevalent were SpeG, Slo, C5a-peptidase and SPNA. Phage encoded virulence genes were also found among the strains, such as mf-2, SpeJ and SpeL. Discussion: The emm1 type was the most prevalent while the 13 others M types were distributed along the strains. No tissue tropism was found on the isolates. The virulence factors analysis demonstrated that chromosomally and phage-encoded genes were found, which confers a potential for high virulent micro-organisms.

scholarly journals Molecular Analysis of the gyrA and gyrB Quinolone Resistance-Determining Regions of Fluoroquinolone-Resistant Clostridium difficile Mutants Selected In Vitro

2009 ◽  
Vol 53 (6) ◽  
pp. 2463-2468 ◽  
Author(s):  
Patrizia Spigaglia ◽  
Fabrizio Barbanti ◽  
Thomas Louie ◽  
Frédéric Barbut ◽  
Paola Mastrantonio
Keyword(s):  
Clostridium Difficile ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Toxin B ◽  
Relevant Role ◽  
Vitro Development ◽  
Selection Of

ABSTRACT Recent studies have suggested that exposure to fluoroquinolones represents a risk factor for the development of Clostridium difficile infections and that the acquisition of resistance to the newer fluoroquinolones is the major reason facilitating wide dissemination. In particular, moxifloxacin (MX) and levofloxacin (LE) have been recently associated with outbreaks caused by the C. difficile toxinotype III/PCR ribotype 027/pulsed-field gel electrophoresis type NAP1 strain. In this study, we evaluated the potential of MX and LE in the in vitro development of fluoroquinolone resistance mediated by GyrA and GyrB alterations. Resistant mutants were obtained from five C. difficile parent strains, susceptible to MX, LE, and gatifloxacin (GA) and belonging to different toxinotypes, by selection in the presence of increasing concentrations of MX and LE. Stable mutants showing substitutions in GyrA and/or GyrB were obtained from the parent strains after selection by both antibiotics. Mutants had MICs ranging from 8 to 128 μg/ml for MX, from 8 to 256 μg/ml for LE, and from 1.5 to ≥32 μg/ml for GA. The frequency of mutation ranged from 3.8 × 10−6 to 6.6 × 10−5 for MX and from 1.0 × 10−6 to 2.4 × 10−5 for LE. In total, six different substitutions in GyrA and five in GyrB were observed in this study. The majority of these substitutions has already been described for clinical isolates or has occurred at positions known to be involved in fluoroquinolone resistance. In particular, the substitution Thr82 to Ile in GyrA, the most common found in resistant C. difficile clinical isolates, was observed after selection with LE, whereas the substitution Asp426 to Val in GyrB, recently described in toxin A-negative/toxin B-positive epidemic strains, was observed after selection with MX. Interestingly, a reduced susceptibility to fluoroquinolones was observed in colonies isolated after the first and second steps of selection by both MX and LE, with no substitution in GyrA or GyrB. The results suggest a relevant role of fluoroquinolones in the emergence and selection of fluoroquinolone-resistant C. difficile strains also in vivo.

scholarly journals Microevolution ofStreptococcus agalactiaeST-261 from Australia Indicates Dissemination via Imported Tilapia and Ongoing Adaptation to Marine Hosts or Environment

2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Minami Kawasaki ◽  
Jerome Delamare-Deboutteville ◽  
Rachel O. Bowater ◽  
Mark J. Walker ◽  
Scott Beatson ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Core Genome ◽  
Minimum Spanning Tree ◽  
Vaccine Development ◽  
The United States ◽  
Wild Fish ◽  
Clinical Isolates ◽  
Global Trade ◽  
Content Type ◽  
Wide Range

ABSTRACTStreptococcus agalactiae(group BStreptococcus[GBS]) causes disease in a wide range of animals. The serotype Ib lineage is highly adapted to aquatic hosts, exhibiting substantial genome reduction compared with terrestrial conspecifics. Here, we sequence genomes from 40 GBS isolates, including 25 isolates from wild fish and captive stingrays in Australia, six local veterinary or human clinical isolates, and nine isolates from farmed tilapia in Honduras, and compared them with 42 genomes from public databases. Phylogenetic analysis based on nonrecombinant core-genome single nucleotide polymorphisms (SNPs) indicated that aquatic serotype Ib isolates from Queensland were distantly related to local veterinary and human clinical isolates. In contrast, Australian aquatic isolates are most closely related to a tilapia isolate from Israel, differing by only 63 core-genome SNPs. A consensus minimum spanning tree based on core-genome SNPs indicates the dissemination of sequence type 261 (ST-261) from an ancestral tilapia strain, which is congruent with several introductions of tilapia into Australia from Israel during the 1970s and 1980s. Pangenome analysis identified 1,440 genes as core, with the majority being dispensable or strain specific, with non-protein-coding intergenic regions (IGRs) divided among core and strain-specific genes. Aquatic serotype Ib strains have lost many virulence factors during adaptation, but six adhesins were well conserved across the aquatic isolates and might be critical for virulence in fish and for targets in vaccine development. The close relationship among recent ST-261 isolates from Ghana, the United States, and China with the Israeli tilapia isolate from 1988 implicates the global trade in tilapia seed for aquaculture in the widespread dissemination of serotype Ib fish-adapted GBS.IMPORTANCEStreptococcus agalactiae(GBS) is a significant pathogen of humans and animals. Some lineages have become adapted to particular hosts, and serotype Ib is highly specialized to fish. Here, we show that this lineage is likely to have been distributed widely by the global trade in tilapia for aquaculture, with probable introduction into Australia in the 1970s and subsequent dissemination in wild fish populations. We report here the variability in the polysaccharide capsule among this lineage but identify a cohort of common surface proteins that may be a focus of future vaccine development to reduce the biosecurity risk in international fish trade.

scholarly journals Clostridium difficile erm(B)-containing elements and the burden on the in vitro fitness

2013 ◽  
Vol 62 (9) ◽  
pp. 1461-1467 ◽  
Author(s):  
François Wasels ◽  
Patrizia Spigaglia ◽  
Fabrizio Barbanti ◽  
Paola Mastrantonio
Keyword(s):  
Clostridium Difficile ◽  
Clinical Isolates ◽  
Surveillance Study ◽  
Conjugative Transposon ◽  
Genetic Organization ◽  
Ribotype 027 ◽  
Pcr Ribotype 027

In Clostridium difficile, resistance to the macrolide-lincosamide-streptogramin B group of antibiotics generally relies on erm(B) genes. In this study, we investigated elements with a genetic organization different from Tn5398, the mobilizable non-conjugative element identified in C. difficile strain 630. Our results suggested that the elements most frequently found in strains isolated during the European surveillance study in 2005 were related to Tn6194, the conjugative transposon recently detected in different C. difficile types, including PCR-ribotype 027. We characterized a Tn6194-like and a novel element rarely found in clinical isolates. A burden on the in vitro fitness of C. difficile was observed after the acquisition of these elements as well as of Tn5398.

Molecular characterization of moxifloxacin resistance from Canadian Clostridium difficile clinical isolates

2010 ◽  
Vol 66 (4) ◽  
pp. 419-424 ◽  
Author(s):  
Andrew Walkty ◽  
David A. Boyd ◽  
Denise Gravel ◽  
Jim Hutchinson ◽  
Allison McGeer ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Molecular Characterization ◽  
Clinical Isolates

scholarly journals Volatile Oils ofNepeta tenuifolia(Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  
Keyword(s):  
Essential Oils ◽  
In Vitro Study ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Gram Negative ◽  
E Coli ◽  
Wide Range ◽  
Main Component ◽  
Reference Strains

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.

Zoonoses

2020 ◽  
Vol 41 (1) ◽  
pp. 3
Author(s):  
John S Mackenzie ◽  
David Williams
Keyword(s):  
Clostridium Difficile ◽  
Ancient Greece ◽  
Zoonotic Diseases ◽  
Zoonotic Pathogen ◽  
The Past ◽  
Wide Range ◽  
Ancient Times ◽  
Ancient Mesopotamia ◽  
Selection Of

The selection of papers included in this issue of Microbiology Australia present a broad brush of zoonotic diseases, from those known or described in ancient times such as rabies, first described in the Eshnunna cuneiform law tablets from ancient Mesopotamia dating back to the 18th–19th centuries BC, and glanders, thought to be first described in donkeys by Aristotle in Ancient Greece in 420–450 BC and subsequently by the Romans, to some discovered or recognised as zoonotic within the past 30 years, such as the recently described zoonotic bat-borne pathogens in Australia, and Clostridium difficile, only recently recognised as a zoonotic pathogen. The selection of papers also demonstrates the wide range of zoonotic origins, including arthropod-borne viruses and potentially seafood-borne parasites.

Diarrheal Disease in the Hospitalized Patient

1986 ◽  
Vol 7 (12) ◽  
pp. 607-609 ◽  
Author(s):  
Peter H. Gilligan
Keyword(s):  
Escherichia Coli ◽  
Clostridium Difficile ◽  
Diarrheal Disease ◽  
Cost Effective ◽  
Etiologic Agent ◽  
The Past ◽  
Wet Mount ◽  
Etiologic Agents ◽  
Wide Range ◽  
Hospitalized Patient

In the past 15 years, our knowledge of the pathogenesis and etiologic agents of diarrheal disease has expanded rapidly. No longer is it scientifically appropriate or cost effective for the laboratory simply to culture a stool for Salmonella and Shigella and to do a wet mount for amebae. Today we have a plethora of agents including, but not limited to, Campylobacter, Yersinia, Clostridium difficile, Escherichia coli, Aeromonas, Plesiomonas, vibrios, rotavirus, Norwalk agent, Giardia, and Cryptosporidium, which have all been suggested to be agents of diarrheal disease. Given such a wide range of possibilities, what approaches should be taken to determine the etiologic agent of diarrheal disease in the hospitalized patient in an era of cost containment?

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