Distribution of virulence genes and the molecular epidemiology of Streptococcus pyogenes clinical isolates by emm and multilocus sequence typing methods

2020 ◽  
Author(s):  
Siti Nur Adila Hamzah ◽  
Mohd Nasir Mohd Desa ◽  
Azmiza Syawani Jasni ◽  
Niazlin Mohd Taib ◽  
Siti Norbaya Masri ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Multilocus Sequence Typing ◽  
Virulence Genes ◽  
Clinical Samples ◽  
Pcr Analysis ◽  
Gold Standard Method ◽  
Non Invasive ◽  
Typing Methods

Abstract Background: Streptococcus pyogenes has a variety of virulence factors and the predominant invasive strains differ according to specific emm types and geographical orientation. Although emm typing is commonly used as the gold standard method for the molecular characterization, multilocus sequence typing (MLST) has become an important tool for comparing the genetic profiles globally. This study aimed to screen selected virulence genes from invasive and non-invasive clinical samples and to characterize the molecular epidemiology by emm typing and MLST methods. Methods: A total of 42 S. pyogenes isolates from invasive and non-invasive samples collected from 2014 to 2015 from two different tertiary hospitals were investigated for the distribution of virulence factors and their molecular epidemiology by emm and multilocus sequence typing methods. Detection of five virulence genes (speA , speB , speJ , ssa and sdaB) was performed using multiplex polymerase chain reaction (PCR) using the standard primers and established protocol. Results: Multiplex PCR analysis revealed that sdaB/speF (78.6%) and speB (61.9%) were the predominant virulence genes. Regardless of the type of invasiveness, diverse distribution of emm types/subtypes was noted which comprised of 27 different emm types/subtypes. The predominant emm types/subtypes were emm63 and emm18 with each gene accounted for 11.8% whereas 12% for each gene was noted for emm28, emm97.4 and emm91. The MLST revealed that the main sequence type (ST) in invasive samples was ST402 (17.7%) while ST473 and ST318 (12% for each ST) were the major types in non-invasive samples. Out of 18 virulotypes, Virulotype A (five genes, 55.6%) and Virulotype B (two genes, 27.8%) were the major virulotypes found in this study. Phylogenetic analysis indicated the presence of seven different clusters of S. pyogenes. Interestingly, Cluster VI showed that selected emm/ST types such as emm71/ST318 (n=2), emm70.1/ST318 (n=1), emm44/ST31 (n=1) and emm18/ST442 (n=1) have clustered within a common group (Virulotype A) for both hospitals studied. Conclusion: The present study showed that group A streptococci (GAS) are genetically diverse and possess virulence genes regardless of their invasiveness. Majority of the GAS exhibited no restricted pattern of virulotypes except for a few distinct clusters. Therefore, it can be concluded that virulotyping is partially useful for characterizing a heterogeneous population of GAS in hospitals.

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 Analysis of virulence factors and antibiotic resistance genes in Group B Streptococcus from clinical samples

2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe
Keyword(s):  
Antibiotic Resistance ◽  
Pregnant Women ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Group B Streptococcus ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Clinical Samples ◽  
Group B

Abstract Background: Streptococcus agalacticae is one of the most important causative agents of serious infections among neonates. Group B Streptococcus (GBS) virulence factors are important in the development of vaccines, whilst antibiotic resistance genes are necessary in understanding the resistance mechanisms used by these pathogens. This study was carried out to identify the virulence genes and antibiotic resistance genes associated with GBS isolated from pregnant women.Methods: A total of 43 GBS isolates were obtained from vaginal samples that were collected from all HIV positive and HIV negative women who were 13-35 weeks pregnant attending Antenatal Care at both Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods including molecular tests. Antibiotic susceptibility testing using 3 antibiotics was done using the modified Kirby-Bauer method. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes in the isolates. Data was fed into SPSS 24.0 and the Spearman rank correlation test used to determine any correlation among genes.Results: Nine distinct virulence gene profiles were identified. The profiles hly-scpB-bca-rib 37.2% (16/43) and hly-scpB-bca 18.6% (8/43) were common among GBS isolates. The following virulence gene frequencies were obtained namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). Antibiotic resistance genes showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene amplification yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded a low 9.3% (4/43).Conclusion: The study showed a high prevalence of multiple virulence genes hly, scpB, bca and rib in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was found to be predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.

scholarly journals M genotyping and DNA fingerprinting of Streptococcus pyogenes isolates from an area of central Italy

1998 ◽  
Vol 121 (1) ◽  
pp. 77-84 ◽  
Author(s):  
M. MENCARELLI ◽  
R. CORBISIERO ◽  
B. MARZOCCHI ◽  
A. GISTRI ◽  
R. SIGNORI ◽  
...  
Keyword(s):  
Dna Fingerprinting ◽  
Streptococcus Pyogenes ◽  
Central Italy ◽  
Geographic Area ◽  
Non Invasive ◽  
Serological Typing ◽  
Typing Methods ◽  
M1 Type ◽  
Epidemiological Information

M protein gene typing was used to analyse Streptococcus pyogenes clinical isolates collected between 1983 and 1995 in an area of central Italy from patients presenting different types of infections; the same isolates were also characterized by means of DNA fingerprinting.M type 1 was the most common (50% of study strains), followed by M types 4, 12 and 6. The proportion of M type 12 decreased with time, whereas M type 1 increased, in agreement with data obtained in many different areas. Most invasive strains belonged to types M1 (30%) and M12 (30%); on the other hand, the M1 type did frequently occur also among non-invasive isolates. DNA fingerprinting showed a correlation between M types and DNA patterns. This report provides epidemiological information from a geographic area not sampled recently, and further shows the usefulness of the M genotyping technique, which offers potential advantages over conventional serological typing methods.

scholarly journals Analysis of virulence factors and antibiotic resistance genes in Group B Streptococcus from clinical samples

2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe
Keyword(s):  
Antibiotic Resistance ◽  
Pregnant Women ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Group B Streptococcus ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Clinical Samples ◽  
Group B

Abstract Background : Streptococcus agalacticae (Group B Streptococcus, GBS) is one of the most important causative agents of serious infections among neonates. GBS virulence factors are important in vaccine development, whilst antibiotic resistance genes are necessary in understanding the resistance mechanisms used by pathogens. This study was carried out to identify virulence genes and antibiotic resistance genes associated with GBS isolated from pregnant women. Methods: A total of 43 GBS isolates were obtained from 420 vaginal samples collected from HIV positive and negative women who were 13-35 weeks pregnant attending Antenatal Care at Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods including molecular tests. Antibiotic susceptibility testing using 3 antibiotics was done using the modified Kirby-Bauer method. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes. Data was fed into SPSS 24.0 and the Spearman rank correlation test used to determine correlation among genes. Results: Nine distinct virulence gene profiles were identified. The profiles hly-scpB-bca-rib 37.2% (16/43) and hly-scpB-bca 18.6% (8/43) were common. The following virulence gene frequencies were obtained namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). High resistance to tetracycline 97.7% (42/43) was reported followed by clindamycin 55.8% (24/43) and erythromycin 30.2% (13/43). Antibiotic resistance genes among the resistant and intermediate-resistant isolates showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded 9.3% (4/43). Conclusion: The study showed high prevalence of multiple virulence genes hly, scpB, bca and rib in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was found to be predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.

scholarly journals Age as a Factor Influencing Diversity of Commensal E. coli Microflora in Pigs

2013 ◽  
Vol 62 (2) ◽  
pp. 165-171 ◽  
Author(s):  
EWA BOK ◽  
JUSTYNA MAZUREK ◽  
PAWEŁ PUSZ ◽  
MICHAŁ STOSIK ◽  
KATARZYNA BALDY-CHUDZIK
Keyword(s):  
Virulence Factors ◽  
Virulence Genes ◽  
Phylogenetic Group ◽  
Pcr Analysis ◽  
Weaned Piglets ◽  
Phylogenetic Groups ◽  
Phylogenetic Structure ◽  
E Coli ◽  
Phylogenetic Grouping ◽  
Group A

Commensal, intestinal E. coli microflora plays a role in maintenance of intestinal balance of the host, is responsible for defending against pathogenic E. coli. This study encompasses the analysis of BOX-PCR fingerprinting patterns, phylogenetic grouping and virulence genes prevalence among commensal E. coli isolates derived from healthy pigs. Altogether, 274 unique E. coli isolates were identified, 110 from weaned piglets (Piglets I and Piglets II) and 164 from adult sows (Sows I and Sows II). BOX-PCR analysis distinguished isolates from pigs in different age and indicated that during maturation the changes in E. coli microflora occurred. Phylogenetic grouping revealed significant differences between distribution of four phylogenetic groups among isolates derived from piglets and sows. In phylogenetic structure of isolates from the piglets group B1 prevailed significantly, while among isolates derived from the sows the majority of them were classified into phylogenetic group A. The identification of 17 virulence factors in E. coli isolates derived from healthy pigs was performed. Three of 13 intestinal (escV, ehxA, estII) and four extra-intestinal virulence genes (VGs) (hlyA, fimH, papA, sfaS) were detected in the porcine isolates. The percentage of VGs positive isolates among piglets is higher than among sows, moreover, the VGs occurring in E. coli isolates from piglets revealed greater diversity than that detected among isolates from sows.

scholarly journals Molecular Epidemiology of Hypervirulent Carbapenemase-Producing Klebsiella pneumoniae

2021 ◽  
Vol 11 ◽  
Author(s):  
Dakang Hu ◽  
Yuming Li ◽  
Ping Ren ◽  
Dongxing Tian ◽  
Wenjie Chen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Molecular Epidemiology ◽  
Multilocus Sequence Typing ◽  
Virulence Genes ◽  
Molecular Serotyping ◽  
Plasmid Replicon ◽  
Complete Genomes

ObjectiveTo investigate the overall distributions of key virulence genes in Klebsiella pneumoniae, especially the hypervirulent blaKPC-positive K. pneumoniae (Hv-blaKPC(+)-KP).MethodsA total of 521 complete genomes of K. pneumoniae from GenBank were collected and analyzed. Multilocus sequence typing, molecular serotyping, antibiotic-resistance, virulence genes and plasmid replicon typing were investigated.ResultsPositive rates of virulence genes highly varied, ranging from 2.9 (c-rmpA/A2) to 99.6% (entB). Totally 207 strains presented positive fimH, mrkD, entB and wzi and 190 showed positive fimH, mrkD, entB, irp2 and wzi, which were the two primary modes. A total of 94, 165 and 29 strains were denoted as hypervirulent K. pneumoniae (HvKP), blaKPC(+)-KP and Hv-blaKPC(+)-KP. ST11 accounted for 17 among the 29 Hv-blaKPC(+)-KP strains; Genes iucA, p-rmpA2 and p-rmpA were positive in 28, 26 and 18 Hv-blaKPC(+)-KP strains respectively. Among the 29 Hv-blaKPC(+)-KP strains exhibiting four super clusters from GenBank, IncHI1B plasmids carrying virulence genes and IncFII ones with blaKPC were responsible for both 23 strains respectively.ConclusionsPositive rates of virulence genes vary remarkably in K. pneumoniae. Genes iucA, p-rmpA2 and p-rmpA were primary ones inducing Hv-blaKPC(+)-KP. IncHI1B plasmids carrying virulence genes and IncFII ones with blaKPC constitute the primary combination responsible for Hv-blaKPC(+)-KP. The making of Hv-blaKPC(+)-KP is mostly via blaKPC(+)-KP acquiring another plasmid harboring virulence genes.

scholarly journals Multilocus Sequence Typing of Streptococcus pyogenes and the Relationships between emm Type and Clone

2001 ◽  
Vol 69 (4) ◽  
pp. 2416-2427 ◽  
Author(s):  
Mark C. Enright ◽  
Brian G. Spratt ◽  
Awdhesh Kalia ◽  
John H. Cross ◽  
Debra E. Bessen
Keyword(s):  
Genetic Structure ◽  
Streptococcus Pyogenes ◽  
Multilocus Sequence Typing ◽  
Population Genetic ◽  
The Internet ◽  
Immune Selection ◽  
Mlst Database ◽  
Mlst Scheme ◽  
Typing Methods ◽  
Emm Type

ABSTRACT Multilocus sequence typing (MLST) is a tool that can be used to study the molecular epidemiology and population genetic structure of microorganisms. A MLST scheme was developed for Streptococcus pyogenes and the nucleotide sequences of internal fragments of seven selected housekeeping loci were obtained for 212 isolates. A total of 100 unique combinations of housekeeping alleles (allelic profiles) were identified. The MLST scheme was highly concordant with several other typing methods. The emm type, corresponding to a locus that is subject to host immune selection, was determined for each isolate; of the >150 distinct emm types identified to date, 78 are represented in this report. For a given emmtype, the majority of isolates shared five or more of the seven housekeeping alleles. Stable associations between emm type and MLST were documented by comparing isolates obtained decades apart and/or from different continents. For the 33 emm types for which more than one isolate was examined, only five emmtypes were present on widely divergent backgrounds, differing at four or more of the housekeeping loci. The findings indicate that the majority of emm types examined define clones or clonal complexes. In addition, an MLST database is made accessible to investigators who seek to characterize other isolates of this species via the internet (http://www.mlst.net ).

scholarly journals Virulence Factors and Molecular Epidemiology of Pyogenic Liver Abscess Causing Multidrug Resistant Klebsiella pneumoniae in Wenzhou, China

2020 ◽  
Author(s):  
Zhongyong Wang ◽  
Siqin Zhang ◽  
Na Huang ◽  
Shixing Liu ◽  
Ye Xu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Molecular Epidemiology ◽  
Liver Abscess ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Pyogenic Liver Abscess ◽  
Multidrug Resistant ◽  
Carbapenem Resistant ◽  
Tertiary Teaching ◽  
Tertiary Teaching Hospital

Abstract Background: To date, little is known about virulence characteristics of pyogenic liver abscess (PLA) causing multidrug resistant (MDR) Klebsiella pneumoniae (K. pneumoniae). It may be these strains are rare. The aim of this study was to analyze the virulence and molecular epidemiology of 12 MDR strains from 163 PLA cases in a tertiary teaching hospital from the perspective of clinical characteristics, virulence phenotypes and genotypes.Results: The virulence phenotypes of the twelve PLA-causing MDR K. pneumoniae were similar or even more obvious than those of sensitive hypervirulent Klebsiella pneumoniae control strains. These MDR strains were mainly non-K1/K2 serotypes and carried multiple virulence genes. Multilocus sequence typing (MLST) revealed the PLA-causing MDR strains had low clone correlation.Conclusions: This study was the first analysis on virulence factors of PLA-causing MDR strains. The virulent factors exhibited the coexistence of hypervirulence and multidrug resistance in PLA-causing MDR K. pneumoniae strains, and these MDR strains were mainly polyclonal spread and there was firstly found one ST11 carbapenem-resistant hypervirulent strain in PLA.

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