Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates

Streptococcus pyogenes or group A streptococcus (GAS) is commonly known as a flesh-eating bacterium. Several virulence genes are responsible for this phenomenon and other clinical diseases ranging from mild to life threatening infections. Extracellular toxins such as superantigen...

Full description

Saved in:

Bibliographic Details
Main Author:	Hamzah, Siti Nur Adila
Format:	Thesis
Language:	English
Published:	2019
Subjects:	Streptococcus pyogenes - isolation & purification Streptococcus pyogenes - pathogenicity
Online Access:	http://psasir.upm.edu.my/id/eprint/89854/1/FPSK%28m%29%202020%2026%20-%20ir.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.89854
record_format	uketd_dc
spelling	my-upm-ir.898542021-12-06T07:59:27Z Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates 2019-05 Hamzah, Siti Nur Adila Streptococcus pyogenes or group A streptococcus (GAS) is commonly known as a flesh-eating bacterium. Several virulence genes are responsible for this phenomenon and other clinical diseases ranging from mild to life threatening infections. Extracellular toxins such as superantigen streptococcal pyrogenic exotoxins are commonly associated with tissue invasion and initiate the release of cytokinesin S. pyogenes pathogenesis. This study aimed to determine the virulence characteristics of S. pyogenes by haemolysin test and DNase test and the detection of selected toxin genes (speA, speB, speJ, ssa and sdaB) in S. pyogenes isolates. Its genetic relatedness was determined by multilocus sequence typing (MLST). A total of 42 S. pyogenes clinical isolates were collected from Hospital Kuala Lumpur and Hospital Serdang. The isolates were obtained from five different sources which were blood (23.8%), pus (52.4%), tissue (16.7%), wound (4.8%) and throat (2.4%). Regardless of the type of invasiveness, all S. pyogenes produced positive result in haemolysin test. A total of 81.0% of GAS hydrolyzed DNA while only 19.0% negative toward DNase test. Among those with positive DNase, all GAS isolates from throat, tissue and wound contributed positive detection. The highest virulence gene detected was sdaB(83.3%), followed by speB(64.3%), ssa(54.8%), speA(52.4%) and speJ(52.4%). In blood isolates, sdaB gene was highly detected with (80.0%) while in wound isolates, (100.0%) of sdaB, speA, and speB genes were detected as positive findings. All five different virulent genes were detected in all types of samples except speA gene which not been detected in an isolate from throat sample. MLST analysis showed that the most predominant STs were in descending order as follows: ST28, ST473, ST402, ST13 and ST318 (7.14% for each), ST60, ST313, ST205, ST101, ST55 (4.76% for each) and ST300, ST599, ST36, ST25, ST168, ST5, ST426, ST408, ST156, ST31, ST442, ST306, ST147, ST114, ST549, ST89, ST83 (2.38% for each). Based on the phylogenetic tree analysis, eleven pairs of S. pyogenes isolates shared the same branches with the current ancestor such as (HKL14 and HKL23), (HKL1 and HKL22), (HKL17 and HS2), (HKL18 and HS15), (HKL20 and HS18), (HKL2 and HKL6), (HKL5 and HS4), (HS6 and HKL4), (HKL9 and HS5), (HKL10 and HS9) and (HKL19 and HS21).Diverse genetic heterogeneity of GAS isolates in the present study was observed with high distribution of virulence genes. Similarities and differences in ST numbers among GAS isolates shared one common ancestor despite they were isolated from two different locations were also observed. The presence of emm1/(ST28) which is associated with hospital outbreaks worldwide deserves continuous surveillance in Malaysian hospitals. Streptococcus pyogenes - isolation & purification Streptococcus pyogenes - pathogenicity 2019-05 Thesis http://psasir.upm.edu.my/id/eprint/89854/ http://psasir.upm.edu.my/id/eprint/89854/1/FPSK%28m%29%202020%2026%20-%20ir.pdf text en public masters Universiti Putra Malaysia Streptococcus pyogenes - isolation & purification Streptococcus pyogenes - pathogenicity Awang Hamat, Rukman
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Awang Hamat, Rukman
topic	Streptococcus pyogenes - isolation & purification Streptococcus pyogenes - pathogenicity
spellingShingle	Streptococcus pyogenes - isolation & purification Streptococcus pyogenes - pathogenicity Hamzah, Siti Nur Adila Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
description	Streptococcus pyogenes or group A streptococcus (GAS) is commonly known as a flesh-eating bacterium. Several virulence genes are responsible for this phenomenon and other clinical diseases ranging from mild to life threatening infections. Extracellular toxins such as superantigen streptococcal pyrogenic exotoxins are commonly associated with tissue invasion and initiate the release of cytokinesin S. pyogenes pathogenesis. This study aimed to determine the virulence characteristics of S. pyogenes by haemolysin test and DNase test and the detection of selected toxin genes (speA, speB, speJ, ssa and sdaB) in S. pyogenes isolates. Its genetic relatedness was determined by multilocus sequence typing (MLST). A total of 42 S. pyogenes clinical isolates were collected from Hospital Kuala Lumpur and Hospital Serdang. The isolates were obtained from five different sources which were blood (23.8%), pus (52.4%), tissue (16.7%), wound (4.8%) and throat (2.4%). Regardless of the type of invasiveness, all S. pyogenes produced positive result in haemolysin test. A total of 81.0% of GAS hydrolyzed DNA while only 19.0% negative toward DNase test. Among those with positive DNase, all GAS isolates from throat, tissue and wound contributed positive detection. The highest virulence gene detected was sdaB(83.3%), followed by speB(64.3%), ssa(54.8%), speA(52.4%) and speJ(52.4%). In blood isolates, sdaB gene was highly detected with (80.0%) while in wound isolates, (100.0%) of sdaB, speA, and speB genes were detected as positive findings. All five different virulent genes were detected in all types of samples except speA gene which not been detected in an isolate from throat sample. MLST analysis showed that the most predominant STs were in descending order as follows: ST28, ST473, ST402, ST13 and ST318 (7.14% for each), ST60, ST313, ST205, ST101, ST55 (4.76% for each) and ST300, ST599, ST36, ST25, ST168, ST5, ST426, ST408, ST156, ST31, ST442, ST306, ST147, ST114, ST549, ST89, ST83 (2.38% for each). Based on the phylogenetic tree analysis, eleven pairs of S. pyogenes isolates shared the same branches with the current ancestor such as (HKL14 and HKL23), (HKL1 and HKL22), (HKL17 and HS2), (HKL18 and HS15), (HKL20 and HS18), (HKL2 and HKL6), (HKL5 and HS4), (HS6 and HKL4), (HKL9 and HS5), (HKL10 and HS9) and (HKL19 and HS21).Diverse genetic heterogeneity of GAS isolates in the present study was observed with high distribution of virulence genes. Similarities and differences in ST numbers among GAS isolates shared one common ancestor despite they were isolated from two different locations were also observed. The presence of emm1/(ST28) which is associated with hospital outbreaks worldwide deserves continuous surveillance in Malaysian hospitals.
format	Thesis
qualification_level	Master's degree
author	Hamzah, Siti Nur Adila
author_facet	Hamzah, Siti Nur Adila
author_sort	Hamzah, Siti Nur Adila
title	Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
title_short	Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
title_full	Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
title_fullStr	Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
title_full_unstemmed	Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates
title_sort	virulence factor and genetic characterization of streptococcus pyogenes from clinical isolates
granting_institution	Universiti Putra Malaysia
publishDate	2019
url	http://psasir.upm.edu.my/id/eprint/89854/1/FPSK%28m%29%202020%2026%20-%20ir.pdf
_version_	1747813585884545024

Virulence factor and genetic characterization of Streptococcus pyogenes from clinical isolates

Similar Items