Association between Bacteroides fragilis and Fusobacterium nucleatum infection and colorectal cancer in Vietnamese patients.

BACKGROUND: Colorectal cancer (CRC) is a significant global health concern, and understanding the role of specific bacterial infections in its development and progression is of increasing interest. This cross-sectional study investigated the associations between Bacteroides fragilis (B. fragilis) and Fusobacterium nucleatum (F. nucleatum) infections and Vietnamese CRC patients. METHODS: 192 patients with either polyps or CRC at varying stages were recruited from May 2017 to December 2020. Real-time PCR assessed infection rates and bacterial loads in CRC tissues. RESULTS: B. fragilis infection was notably higher in CRC tissues (51.6 %) than polyps (9.4 %), with a fivefold higher relative load. Positive associations were found in stages II and III, indicating a fivefold increase in CRC progression risk. F. nucleatum infection rates were significantly higher in CRC tissues (55.2 %) than in polyps (10.5 %). In stage II, the infection rate exceeded that in adjacent tissues. The relative load of F. nucleatum was higher in stage III than in stages I and II. Positive F. nucleatum patients had a 3.2 times higher risk of CRC progression. CONCLUSION: These findings suggest associations between loading of F. nucleatum or/and B. fragilis with the advanced stages of CRC.

Spectrum and antimicrobial resistance in acute exacerbation of chronic obstructive pulmonary disease with pneumonia: a cross-sectional prospective study from Vietnam.

BACKGROUND: Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined. METHODS: This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses. RESULTS: The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78). CONCLUSION: Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.

Whole-genome sequence and resistance determinants of four Elizabethkingia anophelis clinical isolates collected in Hanoi, Vietnam.

Four isolates of the opportunistic pathogen Elizabethkingia anophelis were identified for the first time in a Vietnamese hospital and underwent antimicrobial susceptibility testing and genomic characterization by whole-genome sequencing. Complete, fully circularized genome sequences were obtained for all four isolates. Average Nucleotide Identity analysis and single nucleotide polymorphism phylogenetic analysis on the core genome showed that three of the four isolates were genetically distinct, ruling out the hypothesis of a single strain emergence. Antibiotic susceptibility testing highlighted multi-resistant phenotypes against most antimicrobial families, including beta-lactams, carbapenems, aminoglycosides, quinolones, macrolides, amphenicols, rifamycins and glycopeptides. Additionally, in silico genomic analysis was used to correlate the phenotypic susceptibility to putative resistance determinants, including resistance genes, point mutations and multidrug efflux pumps. Nine different resistance genes were located inside a single resistance pocket predicted to be a putative Integrative and Conjugative Element (ICE). This novel ICE was shared by three isolates from two different lineages and displayed similarity with ICEs previously reported in various Elizabethkingia and Chryseobacterium species. The role of such ICEs in pathogenicity, genome plasticity and antimicrobial resistance gene spread within the Flavobacteriaceae family needs to be further elucidated.

Novel Adiponectin Receptor Agonist Inhibits Cholangiocarcinoma via Adenosine Monophosphate-activated Protein Kinase.

BACKGROUND: Cholangiocarcinoma (CCA) has a poor prognosis and only limited palliative treatment options. The deficiency of adiponectin and adenosine monophosphate-activated protein kinase (AMPK) signaling was reported in several malignancies, but the alteration of these proteins in CCA is still unclear. OBJECTIVES: This study aimed to assess the role of adiponectin and AMPK signaling in CCA. Furthermore, AdipoRon, a novel adiponectin receptor (AdipoR) agonist, was evaluated in vitro and in vivo as a new anti-tumor therapy for CCA. METHODS: The expression of AdipoR1 and p-AMPKα in human tissue microarrays (TMAs) was evaluated by immunohistochemistry staining (IHC). The effect of 2-(4-Benzoylphenoxy)-N-[1-(phenylmethyl)- 4-piperidinyl]-acetamide (AdipoRon) was investigated in vitro with proliferation, crystal violet, migration, invasion, colony formation, senescence, cell cycle and apoptosis assays and in vivo using a CCA engineered mouse model (AlbCre/LSL-KRASG12D/p53L/L). RT-qPCR and western blot methods were applied to study molecular alterations in murine tissues. RESULTS: AdipoR1 and p-AMPKα were impaired in human CCA tissues, compared to adjacent non-tumor tissue. There was a positive correlation between the AdipoR1 and p-AMPKα levels in CCA tissues. Treatment with AdipoRon inhibited proliferation, migration, invasion and colony formation and induced apoptosis in a time- and dose-dependent manner in vitro(p<0.05). In addition, AdipoRon reduced the number of CCA and tumor volume, prolonged survival, and decreased metastasis and ascites in the treated group compared to the control group (p<0.05). CONCLUSIONS: AdipoR1 and p-AMPKα are impaired in CCA tissues, and AdipoRon effectively inhibits CCA in vitro and in vivo. Thus, AdipoRon may be considered as a potential anti-tumor therapy in CCA.

Genomic insights into an extensively drug-resistant and hypervirulent Burkholderia dolosa N149 isolate of a novel sequence type (ST2237) from a Vietnamese patient hospitalised for stroke.

OBJECTIVES: Burkholderia dolosa is a clinically important opportunistic pathogen in inpatients. Here we characterised an extensively drug-resistant and hypervirulent B. dolosa isolate from a patient hospitalised for stroke. METHODS: Resistance to 41 antibiotics was tested with the agar disc diffusion, minimum inhibitory concentration, or broth microdilution method. The complete genome was assembled using short-reads and long-reads and the hybrid de novo assembly method. Allelic profiles obtained by multilocus sequence typing were analysed using the PubMLST database. Antibiotic-resistance and virulence genes were predicted in silico using public databases and the 'baargin' workflow. B. dolosa N149 phylogenetic relationships with all available B. dolosa strains and Burkholderia cepacia complex strains were analysed using the pangenome obtained with Roary. RESULTS: B. dolosa N149 displayed extensive resistance to 31 antibiotics and intermediate resistance to 4 antibiotics. The complete genome included three circular chromosomes (6 338 630 bp in total) and one plasmid (167 591 bp). Genotypic analysis revealed various gene clusters (acr, amr, amp, emr, ade, bla and tet) associated with resistance to 35 antibiotic classes. The major intrinsic resistance mechanisms were multidrug efflux pump alterations, inactivation and reduced permeability of targeted antibiotics. Moreover, 91 virulence genes (encoding proteins involved in adherence, formation of capsule, biofilm and colony, motility, phagocytosis inhibition, secretion systems, protease secretion, transmission and quorum sensing) were identified. B. dolosa N149 was assigned to a novel sequence type (ST2237) and formed a mono-phylogenetic clade separated from other B. dolosa strains. CONCLUSIONS: This study provided insights into the antimicrobial resistance and virulence mechanisms of B. dolosa.

Silencing of Kangai 1 C-terminal interacting tetraspanin suppresses progression of cholangiocarcinoma.

Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy. CC treatment options are very limited especially for patients with distant metastasis. Kangai 1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in numerous cancers, but the role of KITENIN in CC remains unknown. Here, we have investigated for the first time the function of KITENIN in human CC cell lines (TFK-1, SZ-1), tissues and a CC mouse model (Alb-Cre/LSL-KRASG12D/p53L/L). KITENIN was expressed in 92.2% of human CC tissues, in murine CC samples and also in human CC cell lines. Knockdown of KITENIN by small interfering RNA (siRNA) effectively reduced proliferation, migration, invasion and colony formation in both intra- and extra-hepatic CC cells. The expression of epithelial-mesenchymal transition (EMT) markers like N-cadherin, Vimentin, Snail and Slug were suppressed in KITENIN knockdown CC cells. Our results indicate that KITENIN is crucial for cholangiocarcinogenesis and it might become a potential therapeutic target for human CC treatment.