Analysis of Antimicrobial Susceptibility and Virulence Factors in<i>Helicobacter pylori</i>Clinical Isolates

Basaglia, Giancarlo; Sperandio, P.; Tomasini, M.L.; Calzavara, S. Stocco; Giordari, F.; Paoli, Paolo De

doi:10.1179/joc.2004.16.5.504

Cited by 3 publications

(4 citation statements)

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“…Hence, eradication therapy may be indicated in a subset of these patients, especially in the presence of signs of atrophy or old age. However, it must be kept in mind that the intactness or deletions of specific virulence factors, such as CagPAI and cagA, or the presence of less virulent forms of vacA, could be associated with phenotypic resistance to antibiotics [19,88,89,90,91] and high risk of eradication failure [92]. These data imply that, in the presence of diversity within single H. pylori strains, antibiotics therapies could select resistant subtypes and, in addition, they stimulate research on feasible methods to assess the presence of resistance within heterogeneous populations.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies suggested a functional relation of particular combinations of genes and proteins, determining certain traits of H. pylori and specific pre-cancerous or pathological conditions [10,11,12,13,14,15]. In particular, the composition of the Cytotoxin-associated gene A Pathogenicity Island (CagPAI) modulates bacterial motility, survival, production of proinflammatory cytokines and antimicrobial susceptibility [16,17,18,19,20]. It has been highlighted that a single H. pylori strain may include variable proportions of subtypes with different CagPAI genotypes [21,22].…”

Section: Introductionmentioning

confidence: 99%

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Differential Helicobacter pylori Plasticity in the Gastric Niche of Subjects at Increased Gastric Cancer Risk

et al. 2019

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Helicobacter pylori (H. pylori) represents an independent risk factor for Gastric Cancer (GC). First Degree Relatives (FDR) of GC subjects and Autoimmune Gastritis (AG) patients are both at increased risk for GC. H. pylori genetic heterogeneity within the gastric niche of FDR and AG individuals has been little explored. To understand whether they exploit an increased H. pylori stability and virulence, 14 AG, 25 FDR, 39 GC and 13 dyspeptic patients (D) were investigated by a cultural PCR-based approach characterizing single colonies-forming-units. We chose three loci within the Cytotoxin-associated gene-A Pathogenicity Island (CagPAI) (cagA,cagE,virB11), vacA, homA and homB as markers of virulence with reported association to GC. Inflammatory/precancerous lesions were staged according to Sydney System. When compared to D, FDR, similarly to GC patients, were associated to higher atrophy (OR = 6.29; 95% CI:1.23–31.96 in FDR; OR = 7.50; 95% CI:1.67–33.72 in GC) and a lower frequency of mixed infections (OR = 0.16; 95% CI:0.03–0.81 in FDR; OR = 0.10; 95% CI:0.02–0.48 in GC). FDR presented also an increased neutrophil infiltration (OR = 7.19; 95% CI:1.16–44.65). Both FDR and GC carried a higher proportion of CagPAI+vacAs1i1mx+homB+ profiles (OR = 2.71; 95% CI: 1.66–4.41 and OR = 3.43; 95% CI: 2.16–5.44, respectively). Conversely, AG patients presented a lower frequency of subtypes carrying a stable CagPAI and vacAs1i1mx. These results underline different H. pylori plasticity in FDR and AG individuals, and thus, a different host-bacterium interaction capacity that should be considered in the context of eradication therapies.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Differential Helicobacter pylori Plasticity in the Gastric Niche of Subjects at Increased Gastric Cancer Risk

et al. 2019

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“…The phenotypic and genotypic characteristics of each colony were then studied in parallel. The results showed that a proportion of the patients carried mixed populations of antibiotic-sensitive and antibiotic-resistant microorganisms [6]. More interestingly, the distribution of these subpopulations was highly variable within patients, with metronidazole-resistant colonies accounting for 40-90% of the entire bacterial population.…”

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confidence: 95%

“…More interestingly, the distribution of these subpopulations was highly variable within patients, with metronidazole-resistant colonies accounting for 40-90% of the entire bacterial population. It was also demonstrated that metronidazole resistance was associated significantly with an intact cag pathogenicity island, although the composition of this gene cluster did not affect resistance to clarithromycin or amoxycillin [6]. Based on these observations, it can be hypothesised that the differences in susceptibility testing observed by Henriksen et al…”

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confidence: 96%