Ottowia cancrivicina sp. nov., isolated from human stomach.

A Gram-negative, facultative anaerobic, non-motile and rod-shaped bacterium, designated 10c7w1T, was isolated from a human gastrointestinal tract. Colonies on agar plates were small, circular, smooth and beige. The optimal growth conditions were determined to be 37 °C, pH 7.0-7.5 and 0 % (w/v) NaCl. Comparative analysis of complete 16S rRNA gene sequences revealed that strain 10c7w1T showed the highest sequence similarity of 95.8 % to Ottowia beijingensis MCCC 1A01410T, followed by Ottowia thiooxydans (95.2 %) JCM 11629T. The average amino acid identity values between 10c7w1T and O. beijingensis MCCC 1A01410T and O. thiooxydans JCM 11629T were above 60 % (71.4 and 69.5 %). The average nucleotide identity values between strain 10c7w1T and O. beijingensis MCCC 1A01410T and O. thiooxydans JCM 11629T were 76.9 and 72.5 %, respectively. The dominant fatty acids (≥10 %) were straight chain ones, with summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c) and C16 : 00 being the most abundant. Q-8 was the only respiratory quinone. The major polar lipids of strain 10c7w1T were phosphatidylethanolamine, diphosphatidylglycerol and unknown lipids. The DNA G+C content of strain 10c7w1T was 63.6 mol%. On the basis of phylogenetic, phenotypic and chemotaxonomic data, strain 10c7w1T is considered to represent a novel species within the genus Ottowia, for which the name Ottowia cancrivicina sp. nov. is proposed. The type strain is 10c7w1T (=MCCC 1H01399T=KCTC 92200T).

Tumebacillus lacus sp. nov., isolated from lake water.

A Gram-stain-positive, aerobic, rod-shaped, endospore-forming and motile, by means of peritrichous flagella, bacterium, designated DT12T, was isolated from a lake water sample from Datun Lake of Yunnan Province, PR China. The results of phylogenetic analysis based on 16S rRNA gene sequence and the concatenated alignment of 120 ubiquitous single-copy proteins indicated that the novel strain represented a member of the genus Tumebacillus. The sole quinone was menaquinone-7 and the cell-wall peptidoglycan was type-A1γ. The major fatty acids (>10 %) of the novel strain were iso-C15 : 0 and anteiso-C15 : 0, while the major polar lipids were phosphatidylmonomethylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The results of phylogenetic analyses combined with phylogenetic, phenotypic and chemotaxonomic features, strongly supported the hypothesis that the strain should be classified as representing a novel species of the genus Tumebacillus, for which the name Tumebacillus lacus sp. nov. is proposed. The type strain is DT12T (=KCTC 33958T= MCCC 1H00320T). The genomic analysis revealed that DT12T has various biosynthetic gene clusters for secondary metabolites, and members of the genus Tumebacillus may represent a promising source of new natural products. Our study also showed that members of the genus Tumebacillus are widely distributed in a variety of habitats throughout the globe, particularly in soils, human-, animal- and plant-associated environments. Members of the genus Tumebacillus may have an important role in the growth and health of humans, plants and animals.

Marinicella marina sp. nov. and Marinicella gelatinilytica sp. nov., isolated from coastal sediment, and genome analysis and habitat distribution of the genus Marinicella.

Three Marinicella strains, X102, S1101T and S6413T, were isolated from sediment samples from different coasts of Weihai, PR China. All strains were Gram-stain-negative, rod-shaped and non-motile. The predominant fatty acids of all strains were iso-C15 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and the major polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Strains X102 and S1101T shared 100 % 16S rRNA gene sequence similarity, and strains S1101T/X102 and S6413T had 95.4 % similarity. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strains S1101T and X102 were 99.9 and 99.2 %, respectively. Strain S1101T had ANI values of 69.1-72.9% and dDDH values of 17.9-20.5 % to members of the genus Marinicella. Strain S6413T had ANI values of 69.1-77.5% and dDDH values of 17.6-21.5 % to members of the genus Marinicella. The results of phylogenetic and comparative genomic analysis showed that the three strains belong to two novel species in the genus Marinicella, and strains X102 and S1101T represented one novel species, and strain S6413T represented another novel species. The result of BOX-PCR and genomic analysis showed that X102 and S1101T were not the same strain. The phylogenetic analyses and genomic comparisons, combined with phylogenetic, phenotypic and chemotaxonomic features, strongly supported that the three strains should be classified as representing two novel species of the genus Marinicella, for which the names Marinicella marina sp. nov. and Marinicella gelatinilytica sp. nov. are proposed, respectively. The type strains of the two novel species are S1101T (=KCTC 92642T=MCCC 1H01359T) and S6413T (=KCTC 92641T=MCCC 1H01362T), respectively. In addition, all previously described isolates of Marinicella were isolated from marine environments, but our study showed that Marinicella is also distributed in non-/low-saline habitats (e.g. animal gut, soil and indoor surface), which broadened our perception of the environmental distribution of Marinicella.

Huntingtin-associated protein 1 is a potential tumor suppressor for gastric cancer.

BACKGROUND: Gastric cancer is heterogeneous cancer and the causes of this disease are complex. New diagnostic and therapeutic targets are urgently needed to explore. Huntingtin-associated protein 1 (HAP1) is directly related to Huntington's disease (HD). However, patients with Huntington's disease have a lower incidence of cancer. Therefore, we are committed to studying the correlation between HAP1 and gastric carcinogenesis and development. METHODS AND RESULTS: Immunohistochemical staining, western blot analysis, and RT-qPCR were conducted to explore the localization and expression of HAP1 in gastric cancer. To study the biological significance of HAP1, we overexpressed HAP1 in both MKN28 and AGS cell lines by lentivirus infection. To explore the role of HAP1 in cell proliferation, the cells counting assay, EdU incorporation assay, and colony formation assay were carried out. We performed the wound healing assay and transwell assay to study the cell migration and invasion. To further investigate whether HAP1 could regulate gastric cancer cell death during glucose deprivation, Annexin V-FITC/PI staining was performed. In our study, we elucidated that HAP1 was downregulated in gastric cancer. What's more, overexpressing HAP1 inhibited cell proliferation, cell migration and invasion, and triggered apoptosis during glucose deprivation. More importantly, the antitumor properties and mechanisms of HAP1 have been elucidated further in gastric cancer. CONCLUSIONS: Taken together, the available evidence implies that HAP1 may serve as a potential tumor suppressor, making it a significant target in preventing and treating gastric cancer. This research provides a theoretical basis for the early diagnosis, clinical targeted therapy, and prognosis evaluation of gastric cancer.

Predation capacity of Bradymonabacteria, a recently discovered group in the order Bradymonadales, isolated from marine sediments.

Bacterial predation is a vital feeding behavior that affects community structure and maintains biodiversity. However, predatory bacterial species in coastal sediments are comparatively poorly described. In this study, the predation capacity of all nine culturable Bradymonabacteria strains belonging to the recently discovered order Bradymonadales was determined against different types of prey. The predatory efficiency of Bradymonabacteria increased as the initial prey proportion in a mixed culture decreased. When the initial prey proportion was 0.5, the number of surviving prey bacterial cells significantly decreased after 4 h of predation with the Bradymonabacteria strains TMQ1, SEH01, B210 and FA350. However, growth of the prey strain occurred in the presence of the Bradymonabacteria strains TMQ4, TMQ2, TMQ3, V1718 and YN101. When the initial prey proportion decreased to 0.1 or 0.01, most of the Bradymonabacteria strains preyed efficiently. Furthermore, established neighboring colonies of prey were destroyed by Bradymonabacteria. This invading predation capacity was determined by the predation ability of the strain and its motility on the agar surface. Our findings provide new insights into the potential ecological significance of predatory Bradymonabacteria, which may serve as a potential probiotic for use in the aquaculture.

Acute and chronic infection of H. pylori caused the difference in apoptosis of gastric epithelial cells.

Helicobacter pylori (H. pylori) is one of the most important pathogenic bacteria associated with various gastrointestinal diseases. At present, its apoptotic or antiapoptotic mechanism on gastric epithelial cells remains unknown and needs further illustrated. In this study, acute infection model (H. pylori and GES-1 cells were co-cultured for 24 h at a multiplicity of infection MOI of 100:1) and chronic infection model (GES-1 cells were infected repeatedly every 24 h at a multiplicity of infection MOI of 100:1 for approximately 8 weeks) were established, respectively. the chronic H. pylori infected GES-1 cells underwent a typically morphological change and Western Blot results showed that there was slight decrease in expression of E-cadherin, and obvious increase in expression of Vimentin. Apoptosis of these two models were analyzed by flow cytometry compared with the control cells, meanwhile, apoptosis associated markers (Bcl-xL, Bcl-2, Bax, etc) were detected by Western blot, additional in clinical H. pylori-positive gastric cancer tissues. Results showed that compared with the control cells, acute infection of H. pylori significantly accelerated the apoptosis of GES-1, increased the expression of Bax and Cleaved caspase-3, down-regulated expression of Bcl-xL and Bcl-2. Moreover, an opposite result was found in chronic infection of model and clinical gastric cancer tissues, and enhanced expression of NF-κB p65. Taken together, these findings suggest that H. pylori infection plays differential effects on apoptosis of gastric epithelial cells.

Sulfitobacter algicola sp. nov., isolated from green algae.

A novel Gram-stain-negative, aerobic, non-flagellated, non-motile, oval-rod-shaped and light pink to light tawny-pigmented bacterial strain (designated 1151T) were isolated from marine green algae obtained from the coastal seawater of Weihai, China. Strain 1151T was found to grow at 15-37 °C (optimum, 33 °C), pH 7.0-9.5 (optimum, 7.5-8.5) and in the presence of 1-6% (w/v) NaCl (optimum, 3%). Cells were oxidase-positive and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 1151T was a member of the genus Sulfitobacter and exhibited the hightest sequence similarity to Sulfitobacter indolifex DSM 14862T (96.6%), followed by the sequence similarity to Sulfitobacter aestuarii hydD52T (96.5%) and Sulfitobacter profundi SAORIC-263T (96.5%). The average nucleotide identity and digital DDH values between strain 1151T and Sulfitobacter indolifex DSM 14862T were 69.9% and 20.9%, respectively. The average amino acid identity between strain 1151T and Sulfitobacter pontiacus DSM 10014T (type strain of the type species) was 62.3%. Q-10 was detected as the sole respiratory quinone. The dominant cellular fatty acids were sum feature 8 (C18: 1ω7c; 44.1%), C20: 1ω7c (29.7%) and C18: 0 (11.7%). The DNA G + C content of strain 1151T was 51.8 mol%. The polar lipids included phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and three unidentified lipids (L1, L2 and L3). Based on the phylogenetic and phenotypic characteristics, strain 1151T is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter algicola sp. nov. is proposed. The type strain is 1151T (= KCTC 72513T = MCCC 1H00384T).

Ostreibacterium oceani gen. nov., sp. nov., isolated from oyster, and description of Ostreibacteriaceae fam. nov.

A novel Gram-stain-negative, short rod-shaped, facultatively anaerobic, non-motile, non-gliding, oxidase-positive and catalase-negative bacterium, designated ML27T, was isolated from oyster homogenate in Rushan, Weihai, PR China. Growth occurred at 20-33 °C (optimum, 30 °C), at pH 7.0-9.0 (optimum, pH 7.5-8.0) and in the presence of 1-6 % (w/v) NaCl (optimum, 3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ML27T was 90.7 % similar to Suttonella ornithocola DSM 18249T, 89.2 % to Suttonella indologenes JCM 1478T and 88.2 % to Cardiobacterium hominis DSM 8339T; similarities to other species were less than 90 %. The average amino acid identity between strain ML27T, S. indologenes JCM 1478T, S. ornithocola DSM 18249T, C. hominis DSM 8339T and Dichelobacter nodosus ATCC 25549T were 46.23, 45.86, 45.54 and 45.84 %, respectively. Phylogenomic tree and phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate formed a novel family-level clade in the order Cardiobacteriales. The sole respiratory quinone was ubiquinone-7 (Q-7). The dominant cellular fatty acids were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c; 46.3 %), C16 : 0 (17.8 %) and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c; 13.5 %). The DNA G+C content of strain ML27T was 45.6 mol%. Polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unidentified lipid. Comparative analyses of 16S rRNA gene sequences, genomic distinctiveness and characterization indicated that strain ML27T represents a novel species of a new genus within a novel family of the order Cardiobacteriales, for which the name Ostreibacterium oceani gen. nov., sp. nov. is proposed. The type strain of Ostreibacterium oceani is ML27T (=MCCC 1H00372T=KCTC 72155T). In addition, a novel family, Ostreibacteriaceae fam. nov., is proposed to accommodate the genus Ostreibacterium.

Moheibacter lacus sp. nov., Isolated from Freshwater Lake Sediment.

A Gram-stain-negative, yellow-pigmented, rod-shaped, strictly aerobic, non-motile bacterium, designated BDHS18T, was isolated from the sediment of the Hasuhai Lake, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain belongs to the genus Moheibacter in the family Flavobacteriaceae and its closest relative was Moheibacter sediminis JCM 19634T (96.0%), followed by Moheibacter stercoris DSM 29388T (95.3%). Cells of strain BDHS18T were catalase-positive and oxidase-negative. Strain BDHS18T was found to grow optimally at 28-33 â„ƒ, pH 7.5-8.0, and in the presence of approximately 1.0% (w/v) NaCl. Major cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, Summed feature 4 and Summed feature 9. The predominant respiratory quinone was MK-6. The predominant polar lipids in strain BDHS18T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G + C content was 36.9 mol%. According to the phylogenetic analysis, physiological and phenotypic characteristics, strain BDHS18T represents a novel species of the genus Moheibacter, for which the name Moheibacter lacus sp. nov. is proposed. The type strain is BDHS18T (= KCTC 72160T = MCCC 1H00369T).

virB11 gene potentially involves in ATP metabolism to provide energy in H. pylori infection.

Helicobater pylori (H. pylori) is the most important bacteria known to be associated with various gastroduodenal diseases. virB11 gene is a structural gene of tfs3a genes cluster in the plasticity region of H. pylori. In this study, the structure and biology of virB11 gene were analyzed and elucidated with bioinformatics analysis. After cloning, expression and purification, VirB11 protein was generated for the cytotoxicity to GES-1 cells and the anti-VirB11 protein antibody production for localization and interaction proteins analysis. The results showed that VirB11 protein is a hydrophilic protein, mainly locates in cell membrane. IL-8 productions from GES-1 cells co-culture with VirB11 protein were increased gradually with time (p < 0.001). The interaction proteins of VirB11 protein were F0F1 ATP synthase subunit alpha, ATP synthase subunit beta and isocitrate dehydrogenase. We demonstrate that VirB11 protein possesses cytotoxicity and potentially plays important roles in ATP metabolism to provide energy in the course of H. pylori infection.

Population structure and genetic diversity of Vibrio parahaemolyticus from a coastal area of China based on a multi-locus sequence typing (MLST) scheme.

The Gram-negative marine bacterium Vibrio parahaemolyticus has been identified as a major cause of bacterial food poisoning in China. Here, the population structure and genetic diversity of V. parahaemolyticus from Weihai, a coastal city in China, was studied by the multi-locus sequence typing (MLST) method. In this survey, we isolated 40 strains including environmental and clinical samples of patients with acute gastroenteritis or diarrhea; isolates from other countries were also included for comparison. DnaSP Version5, START V2, eBURST version3 and Mega 6 were used to analyse the data. We found that ST3 and ST332 were the most prevalent clones and that they were closely associated with acute diarrhoeal diseases. These STs showed a low dN/dS ratio and significant linkage disequilibrium. All isolates were divided into four clonal complexes, six groups and nine singletons, showing a high degree of genetic diversity. 18 STs, mostly from environmental isolates, were recognised by the MLST analysis for the first time. In conclusion, ST3 and ST332 were the epidemic STs in the coastal area. ST332 might be a region-specific ST, which needs to be confirmed by further analysis. Thus, the long-term monitoring of V. parahaemolyticus plays an important role in preventing and controlling the transmission between environment and people in Weihai.

WITHDRAWN: A Randomized Controlled Trial Comparing Between Titanium Osteosynthesis and Biodegradable Osteosynthesis in Access Mandibulotomy for Oral Malignancy.

Available online April 7, 2018. This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Biological function of hpsh4590 localized in the plasticity zone of Helicobacter pylori.

The aim of this study was to determine the biological function of hpsh4590 in Helicobacter pylori. After Hpsh4590 was expressed using a prokaryotic expression system, the cytotoxic effects and IL-8 production of Hpsh4590 were analyzed by co-culturing with GES-1 cells. Meanwhile, the antibody of rHpsh4590, produced by immunizing rabbit, was used for localization and protein interaction studies. Hpsh4590 fusion protein was expressed successfully in Escherichia coli Rosetta (DE3), and the polyclonal antibody was produced at high titers. The MTT assay showed that the inhibition ratio of GES-1 cells cultured with 0.1 µg/mL rHpsh4590 (3.02% ± 0.02%) was significantly lower than that of 20 µg/mL rHpsh4590 (57.57% ± 0.03%, p < 0.01), while DAPI staining showed the cytotoxic effects of rHpsh4590 for GES-1 cells. The up-regulation of cleaved caspase-3 and cleaved PARP was observed after GES-1 cells co-cultured with rHpsh4590 by Western blot. Co-culturing of GES-1 cells with rHpsh0459 (20 µg/mL) led to significant production of IL-8 at 12 h(1097.74 ± 212.37 pg/mL) and 24 h (1379.55 ± 209.58 pg/mL) then at 6 h(134.68 ± 14.64 pg/mL, p < 0.01). These observations suggest that the cytotoxicity of Hpsh4590 occurred in a concentration dependent manner, which is related with IL-8 secretion from gastric mucosal epithelial cells. Hpsh4590 was found localized in the membrane and the periplasm of H. pylori, interacted with zinc finger protein and methionine ABC transporter ATP-binding protein, and potentially regulates DNA uptake or transfer.

Intact long-type DupA protein in Helicobacter pylori is an ATPase involved in multifunctional biological activities.

The function of intact long-type DupA protein in Helicobacter pylori was analyzed using immunoblotting and molecular biology techniques in the study. After cloning, expression and purification, ATPase activity of DupA protein was detected. Antibody was produced for localization and interaction proteins analysis. The dupA-deleted mutant was generated for adhesion and CagA protein translocation assay, susceptibility to different pH, IL-8 secretion assay, cytotoxicity to MKN-45 cells and proteins-involved apoptosis analysis. DupA protein exhibited an ATPase activity (129.5±17.8 U/mgprot) and located in bacterial membrane, while it did not involve the adhesion and CagA protein delivery of H. pylori. DupA protein involved the urease secretion as the interaction proteins. The wild type strain had a stronger growth in low pH than the dupA-deleted mutant (p < 0.001). IL-8 productions from GES-1 cells infected with the wild type strain were significantly higher than from those with the mutant (p < 0.001). The amounts of vital MKN-45 cells were decreased and the numbers of apoptotic cells were increased with the wild type strain, compared to those with the mutant after 12 h (p < 0.05). The increase of cleaved Caspase-3 and Bax was significantly higher and the decrease of Bcl-2 was more obvious in MKN-45 cells exposed to the wild type strain than that exposed to the mutant after 6 h. We demonstrate that intact long-type DupA protein located in membrane as ATPase is a true virulence factor associated with duodenal ulcer development involving the IL-8 induction and urease secretion, while it inhibits gastric cancer cell growth in vitro by activating the mitochondria-mediated apoptotic pathway.

Helicobacter pylori with the Intact dupA Cluster is more Virulent than the Strains with the Incomplete dupA Cluster.

The duodenal ulcer promoting gene (dupA), located in the plasticity region of Helicobacter pylori (H. pylori), is predicted to form a type IV secretory system (T4SS) with vir genes around dupA. In the study, we investigated the association between the dupA cluster status and the virulence of H. pylori in a littoral region of Northeast China. Two hundred and sixty-two H. pylori strains isolated from the chronic gastritis were examined to evaluate the dupA cluster status, cag PAI genes and vacA genotype using PCR and Western blot. Histopathologic evaluations of biopsy specimens were performed to analysis the association between the dupA cluster and the inflammatory response. IL-8 productions in gastric mucosa and from GES-1 cells co-cultured with H. pylori were measured, respectively, to analysis the association between the dupA cluster status and IL-8 production. We found that gastric mucosal inflammatory cell infiltration was significantly higher in patients with dupA-positive H. pylori, including H. pylori with complete dupA cluster (2.71 ± 0.79) and incomplete dupA cluster (2.09 ± 0.61) than in patients with dupA-negative strain (1.73 ± 0.60, p < 0.01), whereas no significant difference in the gastric mucosal atrophy was found according to the status of dupA cluster. Gastric mucosal IL-8 levels were higher in the complete dupA cluster group than in other groups (p < 0.01), and IL-8 production from GES-1 cells was also significantly higher in strains with a complete dupA cluster (1527.9 ± 180.0 pg/ml) than in those with an incomplete dupA cluster (1229.4 ± 75.3 pg/ml, p < 0.01) or those with dupA negative (1201.9 ± 92.3 pg/ml, p < 0.01). In conclusion, the complete dupA cluster in H. pylori is associated with inflammatory cell infiltration and IL-8 secretion, and H. pylori strain with a complete dupA cluster seems to be more virulent than other strains with the incomplete dupA cluster or dupA negative.

Characterization of integrons among Escherichia coli in a region at high incidence of ESBL-EC.

Objective : The aim of study was to investigate the distribution of the integrons in Escherichia coli (E. coli) isolates, and analyze the possible relationship between the antimicrobial resistance profiles and the integrons. Methods : The antimicrobial profiles of 376 E. coli strains were analysed by disk diffusion test. The integron genes and variable regions were detected by PCR. Some amplicons were sequenced to determine the gene cassettes style. Results : Of 376 isolates, 223 isolates (59.3%) were confirmed as ESBL-EC. Comparison to ESBL-negative E. coli, the high rates of resistance to the third and fourth generation of cephalosporins, penicillins and amikacin were found in ESBL-EC. Only class 1 was integron detected in the isolates, and the prevalence of it was 66.5%. It was commonly found in ESBL-EC (77.6%, 173/223), which was higher than that of ESBL-negative E. coli (50.3%, 77/153) (p<0.001). Six different genes cassettes were detected in this study and were classified into three groups: dfr17-aadA5, dfrA12-aadA2 and aacA4-CmlA1. Additionally, more than one gene array harboured in 13.9% isolates of ESBL-EC, while in 9.1% isolates of ESBL-negative E.coli. Conclusion : The high incidence of ESBL-EC with resistance to multiple antibiotics were detected in the isolates from Blood stream infection (BSI). More resistant gene cassettes in ESBL-EC may partially underlie the high resistance to amikacin, while no relation exists between the high incidence of ESBL-EC and classes 1~ 3 integrons in this region.

CagA status & genetic characterization of metronidazole resistant strains of H. pylori from: A region at high risk of gastric cancer.

OBJECTIVE: The aim of study was to determine relationship between cagA and genetic characterization of metronidazole (MTZ) resistant H. pylori strains from a region at high risk of gastric cancer. METHODS: 172 H. pylori strains were isolated from the patients with dyspeptic symptoms, and antimicrobial susceptibility testing for MTZ was assessed by E-test. rdxA and frxA genes were amplified using PCR among the MTZ resistant isolates. The status of the plasmid and classes 1～3 integrons were investigated in all isolates. RESULTS: MTZ was detected in 88 isolates (51.16%). Variations in the rdxA gene leading to alterations of amino acids in RdxA proteins were identified in all MTZ resistant strains. FrxA contained missense alterations in 55 MTZ resistant isolates, while the premature truncation of FrxA was caused by frameshift mutations in 9 MTZ resistant strains. Plasmid was found in one MTZ sensitive strain (0.58%), and none of Class 1～3 integrases gene was detected in the studied isolates. The conservative cagA fragment was obtained from all clinical isolates of H. pylori. The sequence of cagA 3' variable region in 164 strains were obtained, including East Asian-type (122, 74.39%) and Western-type (42, 25.61%). Prevalence of Western-type cagA 3' variable region was significantly higher in MTZ resistant (33.73%, 28/83) than those of MTZ-sensitive strains (17.28%, 14/81) (p=0.02). CONCLUSION: A high prevalence of MTZ resistance was found in the region, and bacterial chromosome mutations in the rdxA and frxA gene still contribute to the high-level MTZ resistance. H. pylori strains characterized with West-type cagA 3' variable region tend to acquire MTZ resistance in the region.

Deciphering the population structure and genetic basis of growth traits from whole-genome resequencing of the leopard coral grouper ( Plectropomus leopardus).

The leopard coral grouper ( Plectropomus leopardus) is a species of significant economic importance. Although artificial cultivation of P. leopardus has thrived in recent decades, the advancement of selective breeding has been hindered by the lack of comprehensive population genomic data. In this study, we identified over 8.73 million single nucleotide polymorphisms (SNPs) through whole-genome resequencing of 326 individuals spanning six distinct groups. Furthermore, we categorized 226 individuals with high-coverage sequencing depth (≥14×) into eight clusters based on their genetic profiles and phylogenetic relationships. Notably, four of these clusters exhibited pronounced genetic differentiation compared with the other populations. To identify potentially advantageous loci for P. leopardus, we examined genomic regions exhibiting selective sweeps by analyzing the nucleotide diversity ( θπ) and fixation index ( F ST) in these four clusters. Using these high-coverage resequencing data, we successfully constructed the first haplotype reference panel specific to P. leopardus. This achievement holds promise for enabling high-quality, cost-effective imputation methods. Additionally, we combined low-coverage sequencing data with imputation techniques for a genome-wide association study, aiming to identify candidate SNP loci and genes associated with growth traits. A significant concentration of these genes was observed on chromosome 17, which is primarily involved in skeletal muscle and embryonic development and cell proliferation. Notably, our detailed investigation of growth-related SNPs across the eight clusters revealed that cluster 5 harbored the most promising candidate SNPs, showing potential for genetic selective breeding efforts. These findings provide a robust toolkit and valuable insights into the management of germplasm resources and genome-driven breeding initiatives targeting P. leopardus.

Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in a region at high risk of gastric cancer.

ABSTRACT BACKGROUND: Helicobacter pylori (H. pylori) is a major human pathogen that is responsible for various gastroduodenal diseases. We investigated the prevalence of H. pylori virulence markers in a region at high risk of gastric cancer. METHODS: One hundred and sixteen H. pylori strains were isolated from patients with gastroduodenal diseases. cagA, the cagA 3' variable region, cagPAI genes, vacA, and dupA genotypes were determined by PCR, and some amplicons of the cagA 3' variable region, cagPAI genes and dupA were sequenced. RESULTS: cagA was detected in all strains. The cagA 3' variable region of 85 strains (73.3%) was amplified, and the sequences of 24 strains were obtained including 22 strains possessing the East Asian-type. The partial cagPAI presented at a higher frequency in chronic gastritis (44.4%) than that of the severe clinical outcomes (9.7%, p < 0.001). The most prevalent vacA genotypes were s1a/m2 (48.3%) and s1c/m2 (13.8%). Thirty-six strains (31.0%) possessed dupA and sequencing of dupA revealed an ORF of 2449-bp. The prevalence of dupA was significantly higher in strains from patients with the severe clinical outcomes (40.3%) than that from chronic gastritis (20.4%, p = 0.02). CONCLUSION: The high rate of East Asian-type cagA, intact cagPAI, virulent vacA genotypes, and the intact long-type dupA may underlie the high risk of gastric cancer in the region.