Gastric cancer prevention targeted on risk assessment: Gastritis OLGA staging

Gastric cancer (GC) ranks among the most lethal epithelial malignancies, and its striking mortality rate prompts a global prevention strategy. Helicobacter pylori (H. pylori) gastritis is the main GC promoter, and the 2014 Global Kyoto conference recognized H. pylori gastritis as a (treatable) infectious disease. It is therefore plausible that any large‐scale intervention for H. pylori eradication would result in cleansing the world of the fifth cause of cancer‐related death. Atrophic gastritis is the cancerization field in which GCs (both intestinal and diffuse histotypes) mainly develop. Discontinuing the inflammatory cascade triggered by H. pylori is tantamount to preventing GC. For patients (still infected or eradicated) who have already developed gastric atrophy, the severity/topography of the atrophic changes correlates with their cancer risk. Gastritis OLGA (Operative Link for Gastritis Assessment) staging consistently ranks the atrophy‐associated cancer risk, providing a solid clinical/biological rationale for establishing patient‐specific surveillance programs. By combining primary and secondary prevention strategies, gastric cancer is a preventable disease.     

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

The tick Haemaphysalis flava is one of the most significant blood‐feeding arthropod parasites and is a vector for numerous human and animal pathogens. However, a comprehensive investigation of the microbial communities found in the saliva of this tick species is lacking. This study used 16S rRNA Illumina sequencing to characterize the compositions of microbiomes present in saliva and whole tick samples isolated from engorged and partially fed adult H. flava females. This revealed that the bacterial diversity present in tick saliva increased after a prolonged blood meal, and that the species diversity found in saliva was significantly higher than that of whole ticks. Three bacteria phyla, in particular, made up more than 80% of the microbial community across all samples—Proteobacteria, Firmicutes and Actinobacteria. Furthermore, some of the genera identified in this study had not previously been reported in ticks before, such as Facklamia, Vagococcus, Ruminococcus, Lachnospira, Bradyrhizobium, Peptostreptococcus, Jeotgalicoccus, Roseburia, Brachybacterium, Sporosarcina, u114, Megamonas and Dechloromonas. Finally, we found that many of the isolated bacteria were opportunistic pathogens, indicating a potential risk to humans and livestock exposed to H. flava. These results will contribute to fully understanding the transmission of tick‐borne pathogens.     

A Comparison of Pathogen Isolation in Culture and Injection–infiltration Bioassay of Citrus Leaves for Detecting Xanthomonas citri subsp. citri

Citrus canker [caused by Xanthomonas citri subsp. citri (Xcc)] can cause yield loss of susceptible citrus and result in trade restrictions of fresh fruit. For both regulatory purposes and epidemiological studies, accurate detection and quantification of viable inoculum are critical. Two accepted methods used to detect and quantify Xcc are injection–infiltration bioassay and culture, but these two methods have not been directly compared using field‐obtained samples. The two methods were compared using washates of lesions taken from fruit, leaves and shoots in a commercial orchard in Florida in 2009–2010 and 2010–2011, with bioassay being the assumed standard. Despite some misclassifications, true positives (sensitivity) and true negatives (specificity) were the dominant classes using culture. False positives for lesions from shoots ranged from 13.1 to 21.4% in 2009–2010 and 2010–2011, respectively, and false positives for lesions from fruit and leaves ranged from 4.3 to 15.7%, in the two seasons, respectively. The false positive rate for culture compared with injection–infiltration bioassay was highest (0.16–0.55), due to more frequent recovery of Xcc by culture at ≤10³ colony‐forming units (CFU) Xcc per ml. The false negative rate was consistently lower (0.02–0.21), confirming that in only a few cases did culture fail to detect Xcc when it was present. The area under the curve for receiver operator characteristic analysis ranged from 0.80 to 0.97, confirming that culture provided an accurate diagnosis in most cases. There was a higher frequency of lesions from shoots with a CFU ≤10³ Xcc compared with lesions from fruit or leaves, making culture more effective at detecting these. The data demonstrate that culture is a reliable way to detect and quantify Xcc compared with injection–infiltration bioassay, particularly when the CFU is ≤10³ Xcc per ml.     

Antimicrobial Compounds from Drypetes staudtii

Antimicrobial‐directed phytochemical investigation of the MeOH extract of Drypetes staudtii afforded two new compounds, 4,5‐(methylenedioxy)‐o‐coumaroylputrescine ( 1 ), 4,5‐(methylenedioxy)‐o‐coumaroyl‐4′‐N‐methylputrescine ( 2 ), along with seven known natural products 4α‐hydroxyeremophila‐1,9‐diene‐3,8‐dione ( 3 ), drypemolundein B ( 4 ), friedelan‐3β‐ol ( 5 ), erythrodiol ( 6 ), ursolic acid ( 7 ), p‐coumaric acid ( 8 ), and β‐sitosterol ( 9 ). Structures of compounds 1 – 9 were elucidated with the aid of extensive NMR and mass spectral studies. All of the isolates exhibited antibacterial activity against Gram‐positive and Gram‐negative bacteria with minimum inhibitory concentration (MIC) in the range of 8 – 128 μg/ml. Compounds 1 – 2 were also moderately active against Candida albicans with an MIC value of 32 μg/ml.     

Identification of Intracellular Bacteria in the Ciliate Balantidium ctenopharyngodoni (Ciliophora,Litostomatea)

The ciliate Balantidium ctenopharyngodoni is the most prominent protist in the guts of grass carp, where it mainly inhabits the creamy luminal contents of the hindgut. Ciliates are generally colonized by microorganisms via phagotrophic feeding. In order to study the intracellular bacteria in this ciliate, we have successfully established it in in vitro culture. Herein, we investigated and compared the bacterial community structures of cultured and freshly collected B. ctenopharyngodoni. The results showed that these two groups exhibited different bacterial communities. The most abundant bacterial family in freshly collected samples was Enterobacteriaceae, while in cultured samples it was Fusobacteriaceae. In addition, a key intracellular bacterium, Cetobacterium somerae, was identified in the cytoplasm of cultured ciliates using fluorescence in situ hybridization (FISH). This study shows that ciliates can retain the intracellular bacteria acquired in the natural habitat for quite a long time, but the bacterial community structure of ciliates eventually changes after a long period of cultivation.