RESUMEN
The molecular mechanism of Helicobacter pylori resistance to tetracycline involves mutations in the primary binding site of the ribosome. A resistance or reduced susceptibility to tetracycline could be the result of single, double or triple mutations in the 16S rRNA gene of H. pylori. We investigated if the genotype was correlated to tetracycline resistance as determined phenotypically in vitro for 96 H. pylori isolates in the gastroesophageal mucosa of Venezuelan individual hosts. E-test for antimicrobial susceptibility test and real-time PCR for the detection of 16S rRNA gene mutations were performed in 96 H. pylori isolates (48 obtained from antrum, and 48 from oesophagus) from eight dyspeptic patients. In the gastric mucosa, 38 isolates were identified sensitive and 10 resistant to tetracycline by E-test, whereas 44 sensitive and 4 resistant isolates were found in the oesophagus. Real-time PCR detection of the 16S rRNA gene exhibited mutants with a single base-pair substitution (AGA926GGA) in six antrum isolates and seven oesophagus isolates, whereas only three harboured a low level of tetracycline resistance in vitro. Our results indicate that real-time PCR detection of 16S rRNA is a reliable method to classify among tetracycline-resistant genotypes and useful in patients who have experienced a first-line treatment failure with triple therapy.
Asunto(s)
Infecciones por Helicobacter/microbiología , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/genética , ARN Ribosómico 16S/genética , Resistencia a la Tetraciclina/genética , Tetraciclina/farmacología , Antibacterianos/farmacología , Mucosa Esofágica/microbiología , Mucosa Gástrica/microbiología , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Mutación , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Helicobacter pylori (H. pylori) is a highly prevalent bacterium in our environment, directly involved in various upper digestive tract diseases, such as gastritis, peptic ulcer, and gastric cancer. Several molecules activating the immune system have been reported to be involved in containing H. pylori infection. This study is aimed at analyzing the mRNA expression of the cytokines IFN-γ, IL-17, IL-10, TGF-ß, IL-6, IL-22, IL-23, and IL-33; transcription factors T-bet, RORC, and FOXP3; enzymes ARG1, ARG2, and NOS2; and neuropeptides VIP and TAC and their respective receptors VIPR1 and TACR1 in the stomach lining of patients with severe digestive disorders. One hundred and twenty six patients have been evaluated, presenting with symptoms in the upper digestive tract, with the clinical indication for an Upper Digestive Endoscopy exam. Two fragments of the mucosa of the gastric body and antrum have been collected for anatomopathological examination and to analyze the expression of enzymes, cytokines, and transcription factors using qPCR. Expression of the ARG1 gene was seen as significantly higher in the group of patients with chronic inactive gastritis than in the control group. Expression of the TGF-ß gene and its FOXP3 transcription factor was significantly higher in the group of chronic inactive gastritis patients than in the control. Expression of IFN-γ, IL-17, IL-10, and TGF-ß and the transcription factors, T-bet and RORC, in the presence or absence of H. pylori showed no significant difference. However, the expression of FOXP3 was significantly lower in H. pylori-positive patients than that in H. pylori-negative patients. ARG1 and Treg profile appeared to be modulating the inflammatory process, protecting patients from the tissue lesions with chronic inactive gastritis. Furthermore, we suggest that IL-33 may be a crucial mediator of the immune response against an infection, after gastric mucosal damage.
Asunto(s)
Arginasa/metabolismo , Infecciones por Helicobacter/inmunología , Interleucina-33/metabolismo , Linfocitos T Reguladores/inmunología , Adulto , Biopsia , Citocinas/metabolismo , Mucosa Esofágica/inmunología , Mucosa Esofágica/microbiología , Femenino , Mucosa Gástrica/inmunología , Mucosa Gástrica/microbiología , Gastritis/inmunología , Gastritis/microbiología , Perfilación de la Expresión Génica , Helicobacter pylori , Humanos , Inflamación/inmunología , Masculino , Persona de Mediana Edad , Antro Pilórico/inmunología , Antro Pilórico/microbiologíaRESUMEN
The treatment of Helicobacter pylori infection is complicated by antibiotic resistance. A high levofloxacin (LVX) resistance rate was previously demonstrated in H. pylori isolates from gastric mucosa (40%) and esophagus (19%) in individual hosts of a Venezuelan population. We aimed to assess the molecular mechanisms of LVX resistance and susceptibility in isolates from the gastroesophageal mucosa, by studying point mutations in the quinolone resistance-determining region of gyrA and gyrB genes. Sequencing of gyrA and gyrB genes (N = 120) helped to identify point mutations in 60 isolates (30 from antrum and 30 from esophagus) of five dyspeptic patients. Double (Asn87Thr and Asp91Asn) and single (Asn87Ile or Asn87Thr) mutations in the gyrA gene were identified in the esophageal mucosa. These mutations have been commonly found in the stomach. Occurrence of a single (Asn87Ile) mutation was associated with high resistance (minimum inhibitory concentration ≥ 32 µg/mL) to LVX. Only a single (Ser479Gly) mutation was found in the gyrB gene in both mucosae. One patient presented isolates with no mutations in the two genes studied. Isolates with the same mutation pattern in individual hosts revealed identical genetic profiles for these genes, confirming that isolates identified in the esophageal mucosa come from isolates colonizing the stomach. Helicobacter pylori resistance to LVX in the esophagus is related to double- and single-point mutations in gyrA and gyrB genes, such as those found in the stomach. Levofloxacin should be applied with caution, because its antibiotic effect on H. pylori is decreasing in Latin America, perhaps owing to high prescription rates.
Asunto(s)
Antibacterianos/farmacología , Girasa de ADN/genética , Farmacorresistencia Bacteriana/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Levofloxacino/farmacología , Sustitución de Aminoácidos , Mucosa Esofágica/microbiología , Mucosa Gástrica/microbiología , Gastroenterología , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/aislamiento & purificación , Humanos , Pruebas de Sensibilidad Microbiana , Mutación Puntual , Quinolinas/farmacología , Venezuela/epidemiologíaRESUMEN
Endoscopy is a visual examination of internal structures with the aid of an endoscope. In some cases, it is possible to define the etiology of the diseases and the patient's response to a particular disease, helping to define specific prognoses and therapies. It is minimally invasive, reducing surgical time and consequently the duration of anesthesia, which is desirable mainly in debilitated patients and is indicated for visualization and / or sampling of an organ or site with additional diagnostic information. In the present case, the objective was to perform endoscopic examination in a boa constrictor. This patient was anesthetized for digestive endoscopy and sample collection for histopathological examinations that allowed the definitive diagnosis of chronic histiolymphoplasmacytic esophagitis of probable bacterial origin. It was concluded that this technique made it possible, in a non-traumatic way, to obtain samples that, on histopathological examination, determined the definitive diagnosis.
Asunto(s)
Animales , Boidae , Endoscopía/veterinaria , Esofagitis/diagnóstico , Esofagitis/veterinaria , Mucosa Esofágica/microbiología , PóliposRESUMEN
Endoscopy is a visual examination of internal structures with the aid of an endoscope. In some cases, it is possible to define the etiology of the diseases and the patient's response to a particular disease, helping to define specific prognoses and therapies. It is minimally invasive, reducing surgical time and consequently the duration of anesthesia, which is desirable mainly in debilitated patients and is indicated for visualization and / or sampling of an organ or site with additional diagnostic information. In the present case, the objective was to perform endoscopic examination in a boa constrictor. This patient was anesthetized for digestive endoscopy and sample collection for histopathological examinations that allowed the definitive diagnosis of chronic histiolymphoplasmacytic esophagitis of probable bacterial origin. It was concluded that this technique made it possible, in a non-traumatic way, to obtain samples that, on histopathological examination, determined the definitive diagnosis.(AU)