P515 Analysis of antimicrobial susceptibility and virulence factors in Helicobacter pylori clinical isolates in the United Arab Emirates

2007 ◽  
Vol 29 ◽  
pp. S113
Author(s):  
M. Alfaresi ◽  
A. Elkouch ◽  
A. Abdulsalam
Keyword(s):  
Helicobacter Pylori ◽  
United Arab Emirates ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Clinical Isolates

scholarly journals vacA Genotypes and Genetic Diversity in Clinical Isolates of Helicobacter pylori

1998 ◽  
Vol 5 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Shan-Rui Han ◽  
Hans-Joachim Schreiber ◽  
Sucharit Bhakdi ◽  
Michael Loos ◽  
Markus J. Maeurer
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Signal Sequence ◽  
Genotypic Variation ◽  
Rflp Analysis ◽  
Amino Acid Sequences ◽  
Clinical Isolates ◽  
Gastric Ulcers ◽  
H Pylori

ABSTRACT Genetic diversity in Helicobacter pylori strains may affect the function and antigenicity of virulence factors associated with bacterial infection and, ultimately, disease outcome. In this study, DNA diversity of H. pylori isolates was examined by analysis of vacA genotypes and by restriction fragment length polymorphism (RFLP) analysis of H. pylori-associated genes (vacA, cagA, flaA,ureAB, and ureCD). Thirty-seven H. pylori isolates from 26 patients were successfully classified into distinct vacA allelic genotypes. The signal sequence allele s1 (31 of 37) predominated over the s2 allele (6 of 37) and was significantly associated with the occurrence (past or present) of gastric ulcers. A novel midregion allele, designated as m3, has been identified in two H. pylori isolates which could not be typed with midregion allele m1- or m2-specific primers. Additionally, significant nucleotide diversity yielding different amino acid sequences was demonstrated by DNA sequencing of vacAfragments from clinical isolates of H. pylori. Furthermore, RFLP analysis of 45 H. pylori isolates (including 15 paired isolates) obtained from antrum and corpus biopsy specimens from 30 individual patients showed remarkably high interhost diversity (one patient, one H. pylori strain) and intrahost identity in gene sequences coding for VacA, CagA, flagellin, and urease. Only in a single patient was a minor genotypic variation at different anatomic sites within the stomach identified. These data warrant the detailed analysis of the effect of genetic diversity on the function and antigenicity of H. pylori-associated virulence factors.

Relationship between nuclear factor-kappaB activation and virulence factors of Helicobacter pylori in Japanese clinical isolates

2002 ◽  
Vol 17 (5) ◽  
pp. 556-562 ◽  
Author(s):  
SHIN MAEDA ◽  
JAZAG ANARSANAA ◽  
YUZO MITSUNO ◽  
YOSHIHIRO HIRATA ◽  
MASAO AKANUMA ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Clinical Isolates ◽  
Nuclear Factor Kappab ◽  
Nuclear Factor

scholarly journals Antimicrobial susceptibility, serotype distribution, virulence profile and molecular typing of piliated clinical isolates of pneumococci from east coast, Peninsular Malaysia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nurul Diana Dzaraly ◽  
Mohd Nasir Mohd Desa ◽  
AbdulRahman Muthanna ◽  
Siti Norbaya Masri ◽  
Niazlin Mohd Taib ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Antimicrobial Susceptibility ◽  
East Coast ◽  
Tertiary Hospital ◽  
Multidrug Resistant ◽  
Peninsular Malaysia ◽  
Clinical Isolates ◽  
Serotype Distribution ◽  
Antimicrobial Susceptibility Test ◽  
Conjugate Vaccines

AbstractPilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.

scholarly journals Helicobacter pylori Virulence Factors—Mechanisms of Bacterial Pathogenicity in the Gastric Microenvironment

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Jacek Baj ◽  
Alicja Forma ◽  
Monika Sitarz ◽  
Piero Portincasa ◽  
Gabriella Garruti ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Virulence Factors ◽  
Premalignant Lesions ◽  
Bacterial Pathogenicity ◽  
Current State ◽  
Genetic And Environmental Factors ◽  
H Pylori ◽  
Stimulation Of

Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is associated with the interaction between genetic and environmental factors, among which infection by Helicobacter pylori (H. pylori) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of H. pylori pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding H. pylori virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.

Sign in / Sign up

Export Citation Format

Share Document