Antibiotic resistance of Helicobacter pylori in Chinese children: A multicenter study from 2016 to 2023.

BACKGROUND: To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children. MATERIALS AND METHODS: This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method. RESULTS: Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole. CONCLUSIONS: The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.

Relationship between antibiotic resistance and the cagA and vacA genotypes among Helicobacter pylori strain isolates from patients in Xi'an.

The issue of drug resistance of Helicobacter pylori is becoming increasingly serious. To analyze the correlation between the cagA and vacA genotypes of H. pylori strains and their resistance to metronidazole, levofloxacin, and clarithromycin in patients in Xi'an, we studied 117 H. pylori strains isolated from patients in Xi'an. Antibiotic susceptibility testing of H. pylori was performed. The cagA and vacA genotypes were investigated using PCR. Among 117 strains of H. pylori, the rate of detection of cagA was 91.45% (107/117), among which the detection rate of East Asian-type cagA was 85.05% (91/107) and that of Western-type cagA was 14.95% (16/107). There were only two genotypes of vacA: s1m1 and s1m2. The detection rate of vacAs1m1 was 47.01% (55/117) and that of vacAs1m2 was 52.99% (62/117). The dominant strains in Xi'an were cagA + vacAs1m2 strains. The metronidazole resistance rate of vacAs1m2 H. pylori strains was significantly higher than that of vacAs1m1 H. pylori strains (91.94% vs. 69.09%, P = 0.002). The levofloxacin resistance rate of Western-type cagA strains was significantly higher than that of East Asian-type cagA strains (56.25% vs. 20.88%, P = 0.004). The metronidazole resistance rate of cagA + vacAs1m2 H. pylori strains was significantly higher than that of cagA + vacAs1m1 H. pylori strains (91.23% vs. 66.00%, P = 0.001). Our results showed that Western-type cagA strains were more likely to develop levofloxacin resistance than East Asian-type cagA strains. VacAs1m2 strains were more prone to metronidazole resistance than vacAs1m1 strains.

Antibiotic Resistance of Helicobacter pylori Isolated from Patients after Partial Gastrectomy: A Retrospective Study.

BACKGROUND: To determine the prevalence of Helicobacter pylori infection and the antibiotic susceptibility of H. pylori in patients after partial gastrectomy. METHODS: Patients who underwent gastroscopy from January 2009 to November 2017 and had a history of partial gastrectomy were retrospectively enrolled in the remnant stomach group. Contemporary non-gastrectomized patients with an endoscopic diagnosis of chronic gastritis were enrolled in the non-operated stomach group. The detection of H. pylori infection was performed by culture and histology. The in vitro antimicrobial susceptibility was examined by the agar dilution method on strains from gastric biopsies. RESULTS: In this study, a total of 728 gastrectomized and 5035 non-gastrectomized patients were included. There was a significantly lower prevalence of H. pylori infection in the gastric-remnant patients (8.65%) than in the non-gastrectomized patients (17.76%) (P < .001) with the diagnostic method of culture. In the gastric-remnant patients, the H. pylori strains had resistance rates to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone of 100%, 20.63%, 22.22%, 0%, and 0%, respectively. In the nongastrectomized patients, H. pylori resistance to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone was 90.49%, 24.61%, 21.70%, 0.22%, and 0.11%, respectively. Gastric-remnant patients had a significantly higher metronidazole resistance rate than non-gastrectomized patients (P = .005). Moreover, no significant changes in the resistance to 5 antibiotics were observed among the gastric-remnant patients from different age, gender, and surgical indication groups. CONCLUSION: Patients after partial gastrectomy showed a lower prevalence of H. pylori infection. Gastric-remnant patients were more likely to harbor metronidazole-resistant H. pylori strains.

Efficacy of tailored second-line therapy of Helicobacter pylori eradication in patients with clarithromycin-based treatment failure: a multicenter prospective study.

BACKGROUND: After the failure of clarithromycin- and bismuth-based quadruple therapy (CBQT), levofloxacin- and bismuth-based quadruple therapy (LBQT) is recommended for Helicobacter pylori eradication. We compared the efficacies of second-line tailored bismuth-based quadruple therapy (TBQT) and empirical LBQT. METHODS: Patients with CBQT failure were randomly assigned to receive TBQT or LBQT for 14 days. All patients underwent endoscopy for culture-based antibiotic susceptibility testing. Patients in the TBQT group exhibiting levofloxacin susceptibility were randomized to receive amoxicillin, levofloxacin, esomeprazole, and colloidal bismuth pectin (ALEB) or amoxicillin, furazolidone, esomeprazole, and colloidal bismuth pectin (AFEB) for 14 days; patients with levofloxacin resistance received AFEB. RESULTS: From May 2016 to June 2019, 364 subjects were enrolled. Eradication rates were significantly higher in the TBQT group (n = 182) than in the LBQT group (n = 182) according to both intention-to-treat (ITT) analysis (89.6% vs. 64.8%, P < 0.001) and per protocol (PP) analysis (91.1% vs. 67.8%, P < 0.001). Among patients in the TBQT group with levofloxacin susceptibility, eradication rates were similar in the ALEB (n = 51) and AFEB (n = 50) subgroups according to both the ITT (86.3% vs. 90.0%, P = 0.56) and PP (88.0% vs. 90.0%, P = 0.75) analyses. Isolated clarithromycin and levofloxacin resistance rates were 57.7% and 44.5%, respectively. The total clarithromycin and levofloxacin resistance rate in strains with dual or triple resistance was 35.7%. CONCLUSIONS: TBQT was more effective than LBQT as a second-line strategy after CBQT failure. In the absence of antibiotic susceptibility testing, AFEB therapy might be used as a rescue therapy to eradicate H. pylori and avoid levofloxacin resistance.Trial registration: Chinese Clinical Trial Registry (www.chictr.org.cn): ChiCTR1900027743.

Is tailored therapy based on antibiotic susceptibility effective ? a multicenter, open-label, randomized trial.

An effective eradication therapy of Helicobacter pylori (H. pylori) should be used for the first time. In this study, we assessed whether tailored therapy based on antibiotic susceptibility testing is more effective than traditional therapy. We also evaluated the factors that cause treatment failure in high-resistance areas. For this multicenter trial, we recruited 467 H. pylori-positive patients. The patients were randomly assigned to receive tailored triple therapy (TATT), tailored bismuth-containing quadruple therapy (TABQT), or traditional bismuth-containing quadruple therapy (TRBQT). For the TATT and TABQT groups, antibiotic selection proceeded via susceptibility testing using an agar-dilution test. The patients in the TRBQT group were given amoxicillin, clarithromycin, esomeprazole, and bismuth. Successful eradication was defined as a negative 13C-urea breath test at least eight weeks after the treatment ended. Susceptibility testing was conducted using an agar-dilution test. The eradication rate was examined via intention-to-treat (ITT) and per-protocol (PP) analyses. The clarithromycin, levofloxacin, and metronidazole resistance rates were 26.12%, 28.69%, and 96.79%, respectively. Resistance against amoxicillin and furazolidone was rare. The eradication rates for TATT, TRBQT, and TABQT were 67.32%, 63.69%, and 85.99% in the ITT analysis (P 0.001) and 74.64%, 68.49%, and 91.22% in the PP analysis (P 0.001), respectively. The efficacy of TABQT was affected by clarithromycin resistance, and bismuth exerted a direct influence on TATT failure. TABQT was the most efficacious regimen for use in high-resistance regions, especially among clarithromycin-susceptible patients.

Microarray-Based Detection and Clinical Evaluation for Helicobacter pylori Resistance to Clarithromycin or Levofloxacin and the Genotype of CYP2C19 in 1083 Patients.

Background. Helicobacter pylori (H. pylori) is one of the most frequent and persistent bacterial infections that affect nearly half of the world's population. Antibiotic resistance is a constantly evolving process and local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. The aim of this study was to establish a microarray-based detection to identify H. pylori infection, clarithromycin and levofloxacin susceptibility, and CYP2C19 genetic polymorphism and guide to potential choice of proton pump inhibitor (PPI), antibiotic administration for tailored H. pylori eradication therapy. Methods. By analyzing the sequence of human genomic CYP2C19⁎2 and CYP2C19⁎3 and mutations within the 23S rRNA and gyrA gene regions conferring clarithromycin and levofloxacin resistance, respectively, we developed a microarray for individual therapy detection of H. pylori infection. Plasmids were established as positive or limit of detection (LOD) reference materials. The specificity and sensitivity of the microarray had been performed. And a total of 1083 gastric biopsy samples were tested and the Kappa value had been calculated between the array and Sanger sequencing. We also analyzed the resistance to clarithromycin and levofloxacin in China, as well as the CYP2C19 polymorphisms. Results. The LOD of detecting H. pylori was 103 CFU/mL and human genome DNA was 2 ng/µL. The detection results of 1083 gastric biopsy samples showed that 691 (63.80%) were H. pylori positive, of which 266 (38.49%) were resistant to clarithromycin, 192 (27.79%) were resistant to levofloxacin, and 61 (8.83%) were resistant to both of them. For the type of CYP2C19 polymorphism, 412 (38.04%) were homozygous fast type (HomEM), 574 (53%) were heterozygous EM (HetEM), and 97 (8.96%) were poor metabolizer (PM). Conclusions. The proposed microarray-based detection has high specificity, sensitivity, and reproducibility for detecting the resistance of clarithromycin or levofloxacin as well as CYP2C19 polymorphism, which may help to improve the clinical eradication rate of H. pylori.

Simultaneous detection of human CYP2C19 polymorphisms and antibiotic resistance of Helicobacter pylori using a personalised diagnosis kit.

OBJECTIVES: A personalised diagnosis kit for Helicobacter pylori that employs visual gene chip technology for the simultaneous detection of CYP2C19 polymorphisms and clarithromycin/levofloxacin antibiotic resistance was evaluated. METHODS: Gastric antrum mucosa biopsy specimens of 394 patients were tested using the kit. DNA sequencing and antibiotic susceptibility testing of the H. pylori were also performed. RESULTS: In total, 267 (67.8%) of the 394 specimens were positive for H. pylori using the kit and DNA sequencing, and 136 (34.5%) were positive by culturing. For human CYP2C19 and the bacterial 23S rRNA and gyrA genes, the concordance rates were 92.4% (364/394), 96.6% (258/267) and 97.0% (259/267) between the kit and DNA sequencing results, respectively. For clarithromycin and levofloxacin resistance, the concordance rates were 90.4% (123/136) and 81.6% (111/136) between the kit and antibiotic susceptibility testing results. CONCLUSIONS: The personalised diagnosis kit for H. pylori provides useful information for the choice of proton pump inhibitor and antibiotic in combination therapy.

Analysis of microbial community composition and diversity in postoperative intracranial infection using high­throughput sequencing.

Intracranial infection is one of the most serious complications following neurosurgery. It is well acknowledged that bacteria and fungi are the main pathogens responsible for postoperative intracranial infection. However, the microbial community structure, including composition, abundance and diversity, in postoperative intracranial infection is not fully understood, which greatly compromises our understanding of the necessity and effectiveness of postoperative antibiotic treatment. The present study collected eight cerebrospinal fluid (CSF) samples from patients with intracranial infection following neurosurgical procedures. High­throughput amplicon sequencing for 16S rDNA and internal transcribed spacer (ITS) was performed using the Illumina MiSeq platform to investigate the microbial community composition and diversity between treated and untreated patients. Bioinformatics analysis revealed that the microbial composition and diversity in each patient group (that is, with or without antibiotic treatment) was similar; however, the group receiving antibiotic treatment had a comparatively lower species abundance and diversity compared with untreated patients. At the genus level, Acinetobacter and Staphylococcus were widely distributed in CSF samples from patients with postoperative intracranial infection; in particular, Acinetobacter was detected in all CSF samples. In addition, five ITS fungal libraries were constructed, and Candida was detected in three out of four patients not receiving antibiotic treatment, indicating that the fungal infection should be given more attention. In summary, 16S and ITS high­throughput amplicon sequencing were practical methods to identify pathogens in the different periods of treatment in patients with postoperative intracranial infection. There was a notable difference in microbial composition and diversity between the treated and untreated patients. Alterations in the microbial community structure may provide a signal whether antibiotic treatment worked in postoperative intracranial infection and may assist surgeons to better control the progression of infection.

Partners of patients with ulcerative colitis exhibit a biologically relevant dysbiosis in fecal microbial metacommunities.

AIM: To investigate alterations in the fecal microbiome using 16S rRNA amplicon sequencing in couples in the same cohabitation environment. METHODS: Fecal samples were collected from eight ulcerative colitis (UC) patients and their healthy partners at Lishui People's Hospital, Zhejiang Province, China. DNA was extracted and the variable regions V3 and V4 of the 16S rRNA genes were PCR amplified using a two-step protocol. Clear reads were clustered into operational taxonomic units (OTUs) at the 97% sequence similarity level using UCLUST v1.2.22. The Wilcoxon rank-sum test (R v3.1.2) was used to compare inter-individual differences. Differences with a P value < 0.05 were considered statistically significant. RESULTS: Fecal microbial communities were more similar among UC patients than their healthy partners (P = 0.024). UC individuals had a lower relative abundance of bacteria belonging to the Firmicutes, especially Blautia, Clostridium, Coprococcus and Roseburia (P < 0.05). Microbiota dysbiosis was detected in UC patients and their healthy partners. Relevant genera included Akkermansiam, Bacteroides, Escherichia, Lactobacillales, Klebsiella and Parabacteroides. The enriched pathways in fecal samples of UC patients were related to lipid and nucleotide metabolism. Additionally, the pathways involved in membrane transport and metabolism of cofactors and vitamins were more abundant in the healthy partners. CONCLUSION: Our results suggested that the microbial composition might be affected in healthy partners cohabiting with UC patients, especially in terms of microbiota dysbiosis.

Antibiotic resistance of Helicobacter pylori in Chinese children: A multicenter retrospective study over 7 years.

BACKGROUND: To determine the prevalence of resistance to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone in Helicobacter pylori isolated from Chinese children. MATERIALS AND METHODS: This multicenter retrospective study was conducted from January 2009 to December 2015. A total of 1746 isolates of H. pylori were collected from nine areas of Zhejiang province in the southeast coastal region of China. H. pylori strains were examined for antibiotics susceptibility by agar dilution method. RESULTS: The resistance rates were 75.20% for metronidazole, 16.38% for clarithromycin, 6.70% for levofloxacin, 0.06% for amoxicillin, and 0.06% for furazolidone. The pattern of H. pylori antibiotic resistance demonstrated no significant changes in the rates of resistance to clarithromycin, amoxicillin, furazolidone, and metronidazole over 7 years. A significant trend of increasing resistance to metronidazole was observed as children aged, but a downward trend in clarithromycin resistance was observed as children aged. No difference in the resistance to other antibiotics was observed among different age groups. Also, there was no significant difference between male and female subjects in rates of resistance to these five types of antibiotics. The predominant dual resistance to metronidazole and clarithromycin was presented in 10.65% of the isolates. CONCLUSIONS: The resistance rates of H. pylori in children from southeast coastal region of China were very high to metronidazole, moderate to clarithromycin and levofloxacin, and low to amoxicillin and furazolidone. It is important to continue monitoring the resistance profiles of H. pylori isolated in this region.

The Association of Age and Antibiotic Resistance of Helicobacter Pylori: A Study in Jiaxing City, Zhejiang Province, China.

The antibiotic resistance of Helicobacter pylori (H pylori) is steadily increasing worldwide, resulting in the low efficiency of the current therapeutic approaches for eradication. In this study, we investigated the relationship between antibiotic resistances, the year of sample collection, and the ages of the infected individuals.A total of 29,034 gastric mucosa biopsy samples were randomly collected from January 1, 2009 to December 9, 2014 in Jiaxing City, Zhejiang Province, China. An antibiotic susceptibility testing was determined using an agar-dilution method. The statistical significance was tested using the chi-squared (χ) test.A total of 9687 strains were isolated. The resistance rate to clarithromycin, levofloxacin, and metronidazole were 17.76%, 19.66%, and 95.5%, respectively. Resistance was rare against amoxicillin, gentamicin, and furazolidone. The metronidazole resistance rate stayed at a consistently high level. In contrast, the resistance rates of clarithromycin and levofloxacin increased rapidly from 2009 to 2011, gradually decreased from 2012 to 2013, and then increased again in 2014. Although patients ages 31 to 50 and 71 to 80 years had lower infection rates of H pylori, they also had higher resistance rates to clarithromycin and levofloxacin. The highest antibiotic resistance rate was observed in patients' ages 71 to 80 years old. Younger patients (below 30 years old) had a lower resistance to levofloxacin. Patients' ages 51 to 60 years old may thus represent an important category for the future study of H pylori infection.Age plays a key element in H pylori resistance to clarithromycin and levofloxacin. It is therefore necessary to consider individualized therapy for the optimized treatment of H pylori-infected patients.

Seven-day triple therapy is a better choice for Helicobacter pylori eradication in regions with low antibiotic resistance.

AIM: To investigate whether 7-d triple therapies are still valid in populations with low levels of resistance. METHODS: A total of 1106 Helicobacter pylori (H. pylori)-positive patients were divided into three groups, each of which received one type of 7-d triple therapy. Therapeutic outcomes of the patients were assessed by the (13)C-urea breath test at 8 wk after treatment. The susceptibility of H. pylori to antibiotics was determined by an agar-dilution method. Data analysis was performed by χ(2) tests. RESULTS: The eradication rates in groups A, B and C were 90.71% (332/366), 90.46% (313/346) and 90.87% (189/208), respectively (P = 0.986). The resistance rates were 8.91% for clarithromycin, 14.78% for levofloxacin and 0% for amoxicillin. The eradication rate was significantly different between clarithromycin- and levofloxacin-resistant patients (P < 0.05) in group A. Patients whose treatment failed in group A also had a higher clarithromycin resistance rate than did successive patients (P = 0.034). However, levofloxacin resistance had no obvious influence on the eradication rate. Furthermore, three main antibiotics (clarithromycin, levofloxacin and amoxicillin) had lower DID (defined daily dose per 1000 inhabitants per day) in this city. CONCLUSION: Clarithromycin resistance is the main reason for the failure of 7-d triple therapy. In populations with low levels of resistance, a 7-d triple therapy is a viable choice. The choice of therapy should not be influenced by conditions in high antibiotic resistance regions.

Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences.

AIM: To evaluate the efficacy of centralized culture and possible influencing factors. METHODS: From January 2010 to July 2012, 66452 patients with suspected Helicobacter pylori (H. pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy. Gastric mucosal biopsies were taken from the antrum for culture. These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time: 5, 24 and 48 h. The culture results were reported after 72 h and the positive culture rates were analyzed by a χ (2) test. An additional 5736 biopsies from H. pylori-positive patients (5646 rapid urease test-positive and 90 (14)C-urease breath test-positive) were also cultured for quality control in the central laboratory setting. RESULTS: The positive culture rate was 31.66% (21036/66452) for the patient samples and 71.72% (4114/5736) for the H. pylori-positive quality control specimens. In the 5 h transport group, the positive culture rate was 30.99% (3865/12471), and 32.84% (14960/45553) in the 24 h transport group. In contrast, the positive culture rate declined significantly in the 48 h transport group (26.25%; P < 0.001). During transportation, the average natural temperature increased from 4.67 to 29.14 °C, while the positive culture rate declined from 36.67% (1462/3987) to 24.12% (1799/7459). When the temperature exceeded 24 °C, the positive culture rate decreased significantly, especially in the 48 h transport group (23.17%). CONCLUSION: Transportation of specimens within 24 h and below 24 °C is reasonable and acceptable for centralized culture of multicenter H. pylori samples.

[Epidemiological study on antibiotic resistance among Helicobacter pylori in Taizhou district, Zhejiang, 2010-2013].

OBJECTIVE: To study the infection status of Helicobacter pylori (H. pylori) and sensitivity to commonly used antibiotics in Taizhou district,Zhejiang province. METHODS: 39 099 cases aged between 5 and 95 years old (mean as 48.42 years) were involved during January 2010 to December, 2013 for this study. Sex ratio was 1 : 0.95. Yearly distribution of the number of cases were 5 031, 6 709, 11 902 and 15 457 in 2010, 2011, 2012 and 2013, respectively. Gastric mucosal specimens were collected and H. pylori strains were isolated and cultured in the same platform in Zhiyuan Medical Inspection Institute of Hangzhou. Resistance tests of all the H. pylori isolates were performed to 6 commonly used antibiotics:metronidazole, clarithromycin, amoxicillin, gentamicin, levofloxacin and furazolidone with the agar dilution method. The antibiotic resistance rates of H. pylori strains isolated during year 2010-2013 and the changing trends were analyzed. RESULTS: Resistance rates to levofloxacin and clarithromycin kept at higher level and the highest was in 2011 and then decreased in both 2012 and 2013 (P < 0.01). The resistance rates to both levofloxacin and clarithromycin reached the highest in 2011 (P < 0.01), and decreased thereafter, with no significant change in 2013 to 2012 (P > 0.05). CONCLUSION: Antibiotic resistance rate against metronidazole for HP isolate was highest. Resistance rate against amoxicillin and furazolidone, gentamicin was low. Clinical treatment should choose amoxicillin and furazolidone, gentamicin. The resistance rates to levofloxacin and clarithromycin had been seen at a significantly downward trend since 2011. However, the combined resistance rates to levofloxacin and clarithromycin did not seem to reduce since 2012.

Helicobacter pylori induces increased expression of the vitamin d receptor in immune responses.

BACKGROUND: Vitamin D receptor (VDR) is a member of the nuclear receptor family of transcription factors that play a critical role in innate immunity. This study examined the role of VDR in gastric innate immune defence against the gastric pathogen Helicobacter pylori. MATERIALS AND METHODS: Seventeen H. pylori-infected patients and sixteen controls participated in the study. The GES-1 cells were transfected with siRNA or incubated with or without 1α,25(OH)2 D3 (100 nmol/L) then infected with H. pylori. VDR, cathelicidin antimicrobial protein (CAMP), and cytokine mRNA expression levels in normal and H. pylori-infected gastric mucosa and GES-1 cells was determined by qRT-PCR and correlated with the histopathologic degree of gastritis. Bactericidal activity was measured by using a colony-forming unit assay. RESULTS: Vitamin D receptor mRNA expression levels were significantly upregulated in H. pylori-infected patients and positively correlated with chronic inflammation scores. There was a significant positive correlation between VDR and CAMP mRNA expression in H. pylori-positive gastric mucosa. VDR siRNA reduced H. pylori-induced CAMP production and conversely increased IL-6 and IL8/CXCL8 expression levels. The vitamin D agonist 1α,25(OH)2 D3 increased CAMP expression and reduced cytokine activation in GES-1 cells infected with H. pylori. 1α,25(OH)2 D3 could enhance the intracellular killing of the replicating bacteria, but the presence of siVDR and siCAMP led to a decline in its bactericidal ability. CONCLUSIONS: The expression of VDR and CAMP in the gastric epithelium is up-regulated in the case of H. pylori infection; thus, VDR plays an important role in gastric mucosa homeostasis and host protection from H. pylori infection.

Antibiotic resistance of Helicobacter pylori isolated in the Southeast Coastal Region of China.

BACKGROUND: The resistance of Helicobacter pylori (H. pylori) to antibiotics is increasing worldwide, lowering its efficacy in current eradication therapies. This study evaluated H. pylori resistance to antibiotics in the southeast coastal region of China and suggests appropriate alternatives. MATERIALS AND METHODS: Seventeen thousand seven hundred and thirty one H. pylori strains were collected from eight areas of two provinces in coastal southeast China from 2010 to 2012. The resistance of these strains to six antibiotics was tested using the agar dilution method. RESULTS: The resistance rates to clarithromycin, metronidazole, levofloxacin, amoxicillin, gentamicin and furazolidone were 21.5, 95.4, 20.6, 0.1, 0.1 and 0.1%, respectively. Double, triple and quadruple antibacterial resistant percentages were 25.5, 7.5 and 0.1%, respectively. A positive association between the resistance to levofloxacin and to clarithromycin was found, but there was a negative correlation in the resistances to levofloxacin and to metronidazole. CONCLUSIONS: The prevalence of H. pylori resistance to clarithromycin, metronidazole, levofloxacin and multiple antibiotics in coastal southeast China is high. Choice of therapy should be individualized based on a susceptibility test in this region of the country.

Levofloxacin susceptibility testing for Helicobacter pylori in China: comparison of E-test and disk diffusion method.

BACKGROUND: The aims of this study were to compare disk diffusion with E-test method for levofloxacin susceptibility testing of Helicobacter pylori and standardized breakpoints for disk diffusion as a stable and reliable method for determining qualitative levofloxacin susceptibility. MATERIALS AND METHODS: We determined the levofloxacin susceptibility of 45 H. pylori strains isolated from Chinese patients by the E-test method. Disk diffusion was evaluated as an alternative method to determine susceptibility and compared with the E-test results by linear regression analysis. RESULTS: The minimum inhibitory concentration (MIC) values tested by E-test method ranged from 0.047 to 32 µg/mL. Resistance to levofloxacin was detected in 16 (35.6%) isolates. The levofloxacin disk zone sizes obtained by disk diffusion method correlated well (r² = .877) with the MICs obtained by E-test method. As a consequence of regression analysis, isolates with inhibition diameters < 12 mm were considered resistant to levofloxacin. There was 100% agreement between the two methods for levofloxacin, applying the regression-based breakpoints. CONCLUSIONS: The disk diffusion method is equivalent to the E-test method for testing levofloxacin susceptibility of H. pylori strains; it is more practical and inexpensive, and it is suitable for the analysis of a small number of isolates compared with the E-test method.

ELISAs using human bocavirus VP2 virus-like particles for detection of antibodies against HBoV.

Human bocavirus (HBoV) has been identified worldwide in children with lower respiratory tract infections with an incidence of approximately 2-11%. The role of HBoV in pathogenesis, however, is largely unknown, and little is known about the epidemiology of the virus. To study the seroepidemiology of HBoV infection, the capsid protein was expressed in insect cells. Expression of the putative major capsid protein VP2 in insect cells led to the formation of virus-like particles exhibiting the typical icosahedral appearance of parvoviruses with a diameter of approximately 20 nm. The expressed particles were used to establish an enzyme-linked immunosorbent assay (ELISA) method, and serum samples from groups of children of various ages in China were tested for IgG antibodies against HBoV. HBoV antibodies were detected in as high as 36% of healthy children under 9 years. Of children hospitalized with lower respiratory tract infections, 31% were seropositive, and all age groups of these children showed a significantly higher level of HBoV IgG antibody than their healthy counterparts. When divided into age cohorts, results showed that more than 48% of healthy children had seroconverted by age of 4. Thus, HBoV appears to be a common infection in children. The potential pathogenesis of this virus, especially its role in lower respiratory tract infections in children warrants further investigation.

[Sequence analysis of the complete genome of bocavirus WLL-1].

Human bocavirus, which was firstly discovered in 2005, is a new human parvovirus associated with lower respiratory tract infection in children. In this study, a human bocavirus, named WLL-1 isolate, was identified in Wenlin County, Zhejiang Province. The genome of bocavirus WLL-1 has been sequenced and analyzed. Phylogenetic analyses showed that WLL-1 shares 99% homology with other bocaviruses recently reported, but also has some special variations.