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1.
World J Hepatol ; 16(4): 517-536, 2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38689748

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic has caused changes in the global health system, causing significant setbacks in healthcare systems worldwide. This pandemic has also shown resilience, flexibility, and creativity in reacting to the tragedy. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection targets most of the respiratory tract, resulting in a severe sickness called acute respiratory distress syndrome that may be fatal in some individuals. Although the lung is the primary organ targeted by COVID-19 viruses, the clinical aspect of the disease is varied and ranges from asymptomatic to respiratory failure. However, due to an unorganized immune response and several affected mechanisms, the liver may also experience liver cell injury, ischemic liver dysfunction, and drug-induced liver injury, which can result in respiratory failure because of the immune system's disordered response and other compromised processes that can end in multisystem organ failure. Patients with liver cirrhosis or those who have impaired immune systems may be more likely than other groups to experience worse results from the SARS-CoV-2 infection. We thus intend to examine the pathogenesis, current therapy, and consequences of liver damage concerning COVID-19.

2.
World J Gastroenterol ; 29(19): 2950-2960, 2023 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-37274796

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis. AIM: To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen. METHODS: H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation. RESULTS: The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%-70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175-0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: -0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026-0.537). CONCLUSION: This study's low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Humanos , Claritromicina/uso terapéutico , Metronidazol/uso terapéutico , Antibacterianos/uso terapéutico , Helicobacter pylori/genética , Virulencia/genética , Egipto/epidemiología , Quimioterapia Combinada , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/epidemiología , Amoxicilina/uso terapéutico , Genotipo
3.
J Clin Med ; 11(11)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35683528

RESUMEN

Helicobacter pylori colonize the gastric mucosa of at least half of the world's population. Persistent infection is associated with the development of gastritis, peptic ulcer disease, and an increased risk of gastric cancer and gastric-mucosa-associated lymphoid tissue (MALT) lymphoma. In vivo studies using several animal models have provided crucial evidence for understanding the pathophysiology of H. pylori-associated complications. Numerous animal models, such as Mongolian gerbils, transgenic mouse models, guinea pigs, and other animals, including non-human primates, are being widely used due to their persistent association in causing gastric complications. However, finding suitable animal models for in vivo experimentation to understand the pathophysiology of gastric cancer and MALT lymphoma is a complicated task. In this review, we summarized the most appropriate and latest information in the scientific literature to understand the role and importance of H. pylori infection animal models.

4.
Clin Microbiol Rev ; 35(3): e0025821, 2022 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-35404105

RESUMEN

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas Respiratorias/métodos , Técnicas de Laboratorio Clínico , Farmacorresistencia Bacteriana , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Humanos , Sensibilidad y Especificidad
5.
World J Emerg Surg ; 17(1): 17, 2022 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-35300731

RESUMEN

BACKGROUND: The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. METHODS: A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. RESULTS: Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. CONCLUSION: Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened.


Asunto(s)
Antiinfecciosos , COVID-19 , Antibacterianos/uso terapéutico , Estudios Transversales , Humanos , Modelos Organizacionales , Pandemias/prevención & control
6.
World J Emerg Surg ; 16(1): 46, 2021 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-34507603

RESUMEN

On January 2020, the WHO Director General declared that the outbreak constitutes a Public Health Emergency of International Concern. The world has faced a worldwide spread crisis and is still dealing with it. The present paper represents a white paper concerning the tough lessons we have learned from the COVID-19 pandemic. Thus, an international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making. With the present paper, international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making.


Asunto(s)
COVID-19/epidemiología , Salud Global , Pandemias , Investigación Biomédica , COVID-19/diagnóstico , COVID-19/terapia , Vacunas contra la COVID-19 , Atención a la Salud/organización & administración , Política de Salud , Accesibilidad a los Servicios de Salud , Disparidades en el Estado de Salud , Disparidades en Atención de Salud , Humanos , Cooperación Internacional , Vacunación Masiva/organización & administración , Pandemias/prevención & control , Política , Atención Primaria de Salud/organización & administración , Telemedicina/organización & administración
7.
Diagnostics (Basel) ; 11(8)2021 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-34441303

RESUMEN

The use of serum anti-Helicobacter pylori IgG and pepsinogen (PG) detection as a diagnostic method was evaluated in Sri Lanka. Gastric biopsies were performed (353 patients), and the prevalence of H. pylori infection was 1.7% (culture) and 2.0% (histology). IgG serology testing showed an area under the curve (AUC) of 0.922 (cut-off, 2.95 U/mL; specificity, 91.56%; sensitivity, 88.89%). Histological evaluation showed mild atrophy (34.3%), moderate atrophy (1.7%), metaplasia (1.7%), chronic gastritis (6.2%), and normal tissue (56%). The PGI/PGII ratio was significantly higher in H. pylori-negative patients (p < 0.01). PGII and PGI/PGII levels were lower in patients with metaplasia than in those with normal mucosa (p = 0.049 and p < 0.001, respectively). The PGI/PGII ratio best discriminated metaplasia and moderate atrophy (AUC 0.88 and 0.76, respectively). PGI and PGII alone showed poor discriminative ability, especially in mild atrophy (0.55 and 0.53, respectively) and chronic gastritis (0.55 and 0.53, respectively). The best cut-off to discriminate metaplasia was 3.25 U/mL (95.19% specificity, 83.33% sensitivity). Anti-H. pylori IgG and PG assessment (ABC method) was performed (group B, 2.0%; group A, 92.1%). The new cut-off more accurately identified patients with metaplasia requiring follow-up (group B, 5.4%). Assessment of anti-H. pylori IgG and PG is valuable in countries with a low prevalence of H. pylori infection.

8.
JAC Antimicrob Resist ; 3(2): dlab038, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34192258

RESUMEN

The COVID-19 pandemic presents a serious public health challenge in all countries. However, repercussions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on future global health are still being investigated, including the pandemic's potential effect on the emergence and spread of global antimicrobial resistance (AMR). Critically ill COVID-19 patients may develop severe complications, which may predispose patients to infection with nosocomial bacterial and/or fungal pathogens, requiring the extensive use of antibiotics. However, antibiotics may also be inappropriately used in milder cases of COVID-19 infection. Further, concerns such as increased biocide use, antimicrobial stewardship/infection control, AMR awareness, the need for diagnostics (including rapid and point-of-care diagnostics) and the usefulness of vaccination could all be components shaping the influence of the COVID-19 pandemic. In this publication, the authors present a brief overview of the COVID-19 pandemic and associated issues that could influence the pandemic's effect on global AMR.

9.
Can J Infect Dis Med Microbiol ; 2021: 4767429, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33897921

RESUMEN

Infections due to extended-spectrum ß-lactamase- (ESBL-) producing Gram-negative bacteria have led to increased mortality, morbidity, and economic burden worldwide. These bacteria can colonize the healthy intestine of human beings and can disseminate in communities and hospital. This study aimed to investigate the prevalence of fecal carriage of ESBL-producing Escherichia coli and Klebsiella species among health science (HS) and non-health science (NHS) students. This descriptive cross-sectional study was conducted on 104 HS and 104 NHS students in which one stool sample from each student was collected and processed for bacterial culture and sensitivity testing according to standard bacteriological procedures. Each morphotype was identified and characterized phenotypically. The antimicrobial sensitivity profile of bacterial isolates was determined by the Kirby-Bauer disk diffusion technique. ESBL production was tested by combination disk method as recommended by the Clinical and Laboratory Standards Institute. Out of 208 stool samples, E. coli and Klebsiella spp. were recovered from 203 (86.8%) and 31 (13.2%) stool samples, respectively. Among those 234 isolates, 69 were positive for ESBL which included E. coli (n = 66, 95.7%) and Klebsiella spp. (n = 3, 4.3%). Fifty (42.4%) out of 118 isolates from HS students and 19 (16.4%) out of 116 from NHS students were colonized by ESBL-producers. Compared to non-ESBL producers, a higher number of ESBL-producing isolates were resistant to ciprofloxacin (14.5% vs. 1.8%, p < 0.001), cotrimoxazole (59.4% vs. 16.4%, p < 0.001), and amikacin (10.1% vs 4.2%, p < 0.001). All E. coli and Klebsiella species isolates were susceptible to meropenem. The prevalence of fecal carriage of ESBL-producing bacteria was higher in HS students; however, there was a considerable number of these strains colonizing NHS students as well. This "iceberg phenomenon" of asymptomatic carriage of ESBL-producing pathogens might act as a source of infection in both the community and hospitals. Therefore, surveillance of carriage of drug-resistant bacteria should be performed regularly.

10.
Infect Drug Resist ; 14: 709-717, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33654415

RESUMEN

OBJECTIVE: This cross-sectional study aims to determine the prevalence and associated risk factors of biofilm-producing A. baumannii nosocomial isolates from a tertiary care hospital, as well as to investigate any possible association of biofilm formation with the distribution of biofilm-related genotypes and antibiotic resistance phenotypes. METHODS: A total of 94 non-duplicate A. baumannii nosocomial isolates were identified, their biofilm formation was quantitatively detected using the modified microtiter plate assay, and their susceptibilities to different antibiotics were determined using the breakpoint method. Isolates were then subjected to PCR assays targeting bap, ompA and bla PER-1 genes. RESULTS: The majority (70.1%) of isolates were biofilm producers. The most prevalent biofilm gene was ompA (63.8%), followed by bap (13.8%) and bla PER-1 (10.6%). The presence of multi- and extensive-drug resistance (MDR and XDR) was significantly associated with biofilm producers (p = 0.017 and 0.002, respectively). The length of hospital stay (aOR= 0.023), the presence of ompA gene (aOR = 0.286) or bap gene (aOR = 0.346), ampicillin/sulbactam resistance (aOR = 1), and the presence of MDR (aOR = -0.329) or XDR (aOR = -0.252) were considered significant risk factors associated with biofilm-producing isolates. CONCLUSION: The high prevalence of biofilm-producing MDR and XDR nosocomial isolates in this study is worrisome and alarming. Characterization of risk factors could help control the continuous selection and transfer of this serious A. baumannii phenotype inside hospitals and improve the quality of patients' care.

11.
J Gastroenterol Hepatol ; 36(8): 2198-2209, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33609333

RESUMEN

BACKGROUND AND AIM: To determine the application range of diagnostic kits utilizing anti-Helicobacter pylori antibody, we tested a newly developed latex aggregation turbidity assay (latex) and a conventional enzyme-linked immunosorbent assay (E-plate), both containing Japanese H. pylori protein lysates as antigens, using sera from seven Asian countries. METHODS: Serum samples (1797) were obtained, and standard H. pylori infection status and atrophy status were determined by culture and histology (immunohistochemistry) using gastric biopsy samples from the same individuals. The two tests (enzyme-linked immunosorbent assay and latex) were applied, and receiver operating characteristics analysis was performed. RESULTS: Area under the curve (AUC) from the receiver operating characteristic of E-plate and latex curves were almost the same and the highest in Vietnam. The latex AUC was slightly lower than the E-plate AUC in other countries, and the difference became statistically significant in Myanmar and then Bangladesh as the lowest. To consider past infection cases, atrophy was additionally evaluated. Most of the AUCs decreased using this atrophy-evaluated status; however, the difference between the two kits was not significant in each country, but the latex AUC was better using all samples. Practical cut-off values were 3.0 U/mL in the E-test and 3.5 U/mL in the latex test, to avoid missing gastric cancer patients to the greatest extent possible. CONCLUSIONS: The kits were applicable in all countries, but new kits using regional H. pylori strains are recommended for Myanmar and Bangladesh. Use of a cut-off value lower than the best cut-off value is essential for screening gastric cancer patients.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Adulto , Anciano , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Asia , Atrofia , Biopsia , Detección Precoz del Cáncer , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/etiología , Helicobacter pylori/inmunología , Helicobacter pylori/aislamiento & purificación , Humanos , Pruebas de Fijación de Látex/métodos , Linfoma de Células B de la Zona Marginal/sangre , Linfoma de Células B de la Zona Marginal/diagnóstico , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Neoplasias Gástricas/sangre , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/etiología
12.
Int J Mol Sci ; 21(19)2020 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-33050101

RESUMEN

Helicobacter pylori causes persistent infection in the gastric epithelium of more than half of the world's population, leading to the development of severe complications such as peptic ulcer diseases, gastric cancer, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Several virulence factors, including cytotoxin-associated gene A (CagA), which is translocated into the gastric epithelium via the type 4 secretory system (T4SS), have been indicated to play a vital role in disease development. Although infection with strains harboring the East Asian type of CagA possessing the EPIYA-A, -B, and -D sequences has been found to potentiate cell proliferation and disease pathogenicity, the exact mechanism of CagA involvement in disease severity still remains to be elucidated. Therefore, we discuss the possible role of CagA in gastric pathogenicity.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/genética , Helicobacter pylori/patogenicidad , Úlcera Péptica/microbiología , Neoplasias Gástricas/microbiología , Factores de Virulencia/genética , Antígenos Bacterianos/química , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/microbiología , Humanos , Úlcera Péptica/metabolismo , Fosforilación , Neoplasias Gástricas/metabolismo , Sistemas de Secreción Tipo IV/genética , Tirosina/metabolismo , Virulencia/genética
13.
Expert Rev Anti Infect Ther ; 18(10): 987-996, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32536287

RESUMEN

Introduction Helicobacter pylori causes, via the influence of several virulence factors, persistent infection of the stomach, which leads to severe complications. Vacuolating cytotoxin A (VacA) is observed in almost all clinical strains of H. pylori; however, only some strains produce the toxigenic and pathogenic VacA, which is influenced by the gene sequence variations. VacA exerts its action by causing cell vacuolation and apoptosis. We performed a PubMed search to review the latest literatures published in English language. Areas covered Articles regarding H. pylori VacA and its genotypes, architecture, internalization, and role in gastric infection and pathogenicity are reviewed. We included the search for recently published literature until January 2020. Expert opinion H. pylori VacA plays a crucial role in severe gastric pathogenicity. In addition, VacA mediated in vivo bacterial survival leads to persistent infection and an enhanced bacterial evasion from the action of antibiotics and the innate host defense system, which leads to drug evasion. VacA as a co-stimulator for the CagA phosphorylation may exert a synergistic effect playing an important role in the CagA-mediated pathogenicity.


Asunto(s)
Proteínas Bacterianas/metabolismo , Infecciones por Helicobacter/fisiopatología , Helicobacter pylori/patogenicidad , Animales , Apoptosis/fisiología , Genotipo , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Humanos , Gastropatías/microbiología , Gastropatías/fisiopatología
14.
Toxins (Basel) ; 11(11)2019 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-31752394

RESUMEN

Helicobacter pylori colonizes the gastric epithelial cells of at least half of the world's population, and it is the strongest risk factor for developing gastric complications like chronic gastritis, ulcer diseases, and gastric cancer. To successfully colonize and establish a persistent infection, the bacteria must overcome harsh gastric conditions. H. pylori has a well-developed mechanism by which it can survive in a very acidic niche. Despite bacterial factors, gastric environmental factors and host genetic constituents together play a co-operative role for gastric pathogenicity. The virulence factors include bacterial colonization factors BabA, SabA, OipA, and HopQ, and the virulence factors necessary for gastric pathogenicity include the effector proteins like CagA, VacA, HtrA, and the outer membrane vesicles. Bacterial factors are considered more important. Here, we summarize the recent information to better understand several bacterial virulence factors and their role in the pathogenic mechanism.


Asunto(s)
Helicobacter pylori/patogenicidad , Estómago/microbiología , Factores de Virulencia/metabolismo , Gastritis/microbiología , Helicobacter pylori/crecimiento & desarrollo , Humanos , Concentración de Iones de Hidrógeno , Úlcera Péptica/microbiología
15.
Infect Drug Resist ; 12: 1243-1255, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31190912

RESUMEN

Staphylococcus aureus normally colonizes the nasal cavity and pharynx. After breaching the normal habitat, the organism is able to cause a number of infections at any site of the body. The development of antibiotic resistance has created a global challenge for treating infections. Therefore, protection by vaccines may provide valuable measures. Currently, several vaccine candidates have been prepared which are either in preclinical phase or in early clinical phase, whereas several candidates have failed to show a protective efficacy in human subjects. Approaches have also been made in the development of monoclonal or polyclonal antibodies for passive immunization to protect from S. aureus infections. Therefore, in this review we have summarized the findings of recently published scientific literature to make a concise report.

16.
J Gastroenterol ; 54(12): 1039-1051, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31049715

RESUMEN

BACKGROUND: Helicobacter pylori CagA has been found to be immuno-dominant protein and utilized for the diagnosis of the infection with cagA-positive strains. It is important to characterize the peptide epitopes capable of detecting serum anti-CagA antibodies to understand CagA immunogenicity. METHODS: Sera from 171 Japanese patients were subjected for the epitope mapping study. Eighty seven peptides were designed from the CagA consensus sequence and were used for ELISA protocol to test the serum samples. The reacting anti-CagA IgG amounts to specific peptides were measured and compared. RESULTS: The study revealed a strong reactivity of two peptides (c7-NNTEPIYAQVNKKKAGQAT and c8-AGQATSPEEPIYAQVAKKV) in H. pylori-infected group. Interestingly, these two peptides contained the well-known EPIYA-A and EPIYA-B region, respectively, which are two out of three CagA phosphorylation domains. Tyrosine-phosphorylation of these peptides reduced their reactivity in most sera. Moreover, additional peptides' mapping and chimeric-peptides' experiments indicated that the amino acids (QV and KK) accommodated in right-side flanking regions of both EPIYA-motifs were essential for their strong reactivity, whereas the third EPIYA-motif containing peptide (c12-GRSASPEPIYATIDFDEA) with differing flanking amino acids was not reactive in most cases. CONCLUSIONS: Our results suggest that the amino acid sequences constituted in the two reactive peptides are the important immunogenic regions of CagA which would be useful to develop next-generation peptide-based diagnostic assays.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Adulto , Secuencia de Aminoácidos , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Pueblo Asiatico , Proteínas Bacterianas/genética , Epítopos/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Humanos , Mapeo Peptídico
17.
Int J Mol Sci ; 19(8)2018 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-30115886

RESUMEN

Gastric cancer is the third leading cause of cancer-related deaths and ranks as the fifth most common cancer worldwide. Incidence and mortality differ depending on the geographical region and gastric cancer ranks first in East Asian countries. Although genetic factors, gastric environment, and Helicobacter pylori infection have been associated with the pathogenicity and development of intestinal-type gastric cancer that follows the Correa's cascade, the pathogenicity of diffuse-type gastric cancer remains mostly unknown and undefined. However, genetic abnormalities in the cell adherence factors, such as E-cadherin and cellular activities that cause impaired cell integrity and physiology, have been documented as contributing factors. In recent years, H. pylori infection has been also associated with the development of diffuse-type gastric cancer. Therefore, in this report, we discuss the host factors as well as the bacterial factors that have been reported as associated factors contributing to the development of diffuse-type gastric cancer.


Asunto(s)
Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Mutación de Línea Germinal/genética , Infecciones por Helicobacter/patología , Humanos , Modelos Biológicos , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/microbiología
18.
F1000Res ; 72018.
Artículo en Inglés | MEDLINE | ID: mdl-29946428

RESUMEN

In addition to its role in gastric conditions, Helicobacter pylori has been found to contribute to the development of several non-gastric issues in recent years. Eradication therapy is the only effective management strategy to minimize the H. pylori-related gastric cancer and extra-gastric complications. For an effective "test and treat" strategy, diagnosis and therapy are both important. Because the infection is usually asymptomatic, patient selection is a critical issue for timely diagnosis and many clinical and demographic factors should be considered. Clarithromycin and metronidazole resistance rates also need to be considered while eradication therapy is offered. In this report, we discuss the issues which must be taken into account for the correct and timely diagnosis and for the antibiotic therapy-based management of H. pylori infection.

19.
PLoS One ; 12(11): e0187225, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29107979

RESUMEN

BACKGROUND: Helicobacter pylori BabA is an important outer membrane protein that involves in the attachment to the gastric mucosa and enhances the virulence property of the bacterium. This study was aimed to characterize the bab genotypes, to evaluate its association with cagA, vacA and clinical diseases as well as degree of gastric inflammation. METHODS: H. pylori isolates from four countries were subjected for the characterization of bab. The locus specific forward and bab specific reverse primers were used to get the specific products by PCR, which could distinguish the three locus (A, B and C). The histological activities were evaluated according to the Updated Sydney system. RESULT: In patients from high risk countries (Bhutan and Myanmar) relatively higher frequencies of strains with babA-positivity (91.8% and 90.7%, respectively), babA at locus A (98% and 91.2%, respectively) and with single babA (96.8% and 91.2%, respectively) were found. Strains with two loci occupied were the most prevalent in Bhutan (84.6%), Myanmar (74.7%), Nepal (58.3%) and Bangladesh (56.9%). The genotype babA at locus A/babB at locus B/bab-negative at locus C (babA/babB/-) was the most common genotype isolated from Bhutan (82.7%), Myanmar (58.7%), Nepal (32%) and Bangladesh (31.4%) among all genotypes assessed. This genotype was also associated with the peptic ulcer disease (P = 0.013) when compared to gastritis. babA-positive characteristics and the genotype babA/babB/- exhibited the enhanced histological activities. CONCLUSIONS: The higher prevalence of virulence associated babA-positive characteristics and enhanced histological activities in Bhutan than in Myanmar, Nepal and Bangladesh might partly explain why the peoples in Bhutan are at higher risk for developing severe gastric complications.


Asunto(s)
Helicobacter pylori/aislamiento & purificación , Bangladesh , Bután , Gastritis/microbiología , Gastritis/patología , Genes Bacterianos , Genotipo , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/patología , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Mianmar , Nepal , Virulencia
20.
BMJ Open Respir Res ; 4(1): e000203, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29071076

RESUMEN

INTRODUCTION: Respiratory tract infections are one of the most common human infections in all age group and important cause of mortality and morbidity worldwide. Most bacterial upper respiratory tract infections are vaccine preventable. This study aimed to determine the prevalence of carrier state of bacterial upper respiratory tract pathogens among school children. It also aimed to study their antibiograms. METHODS: The specimen from posterior pharyngeal wall and tonsils were collected from 204 participants on calcium alginate coated swabs (HiMedia). Isolates were identified by standard microbiological methods and tested for in vitro antibiotic susceptibility testing by modified Kirby-Bauer disc diffusion method. RESULTS: In this study, Streptococcus pneumoniae (16.6%) was the most common bacterial pathogen recovered, followed by Staphylococcus aureus (14.7%), ß-haemolytic streptococci (non-Group A) (8.8%), Streptococcus pyogenes (5.3%) and Corynebacterium diphtheriae (3.4%). The Gram negative bacteria were Klebsiella pneumoniae (4.9%), Haemophilus influenzae (3.4%) and Neisseria meningitidis (1.4%). Important findings in antibiogram include high resistance of Streptococcus pneumoniae to penicillin (91.17%) and resistance of S. aureus to oxacillin (23.3%). CONCLUSION: Pharyngeal colonisation by S. pneumoniae was found high among school children and this calls for an urgent need to include pneumococcal vaccine in routine national immunisation schedule of Nepal given the high burden of invasive pneumococcal disease. Despite expected universal vaccination, pharyngeal colonisation by C. diphtheriae is possible and there is possibility of transmission of these respiratory pathogens to other healthy children.

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