Microbiome-derived cobalamin and succinyl-CoA as biomarkers for improved screening of anal cancer.

Human papillomavirus can cause preinvasive, high-grade squamous intraepithelial lesions (HSILs) as precursors to cancer in the anogenital area, and the microbiome is suggested to be a contributing factor. Men who have sex with men (MSM) living with human immunodeficiency virus (HIV) have a high risk of anal cancer, but current screening strategies for HSIL detection lack specificity. Here, we investigated the anal microbiome to improve HSIL screening. We enrolled participants living with HIV, divided into a discovery (n = 167) and validation cohort (n = 46), and who were predominantly (93.9%) cisgender MSM undergoing HSIL screening with high-resolution anoscopy and anal biopsies. We identified no microbiome composition signatures associated with HSILs, but elevated levels of microbiome-encoded proteins producing succinyl coenzyme A and cobalamin were significantly associated with HSILs in both cohorts. Measurement of these candidate biomarkers alone in anal cytobrushes outperformed anal cytology as a diagnostic indicator for HSILs, increasing the sensitivity from 91.2% to 96.6%, the specificity from 34.1% to 81.8%, and reclassifying 82% of false-positive results as true negatives. We propose that these two microbiome-derived biomarkers may improve the current strategy of anal cancer screening.

Validation of standard method EN ISO 22964:2017 - Microbiology of the food chain - Horizontal method for the detection of Cronobacter spp.

The new version of the ISO standard method for detection of Cronobacter spp. (EN ISO 22964:2017) was validated in the frame of the European Commission Mandate M381 to CEN. Seventeen laboratories from nine countries participated in the interlaboratory studies to determine the performance characteristics of the method. The performance of the method was evaluated using matrices for which the presence of Cronobacter spp. is considered to be of serious concern, such as infant formula and its ingredients and representatives of categories cited in the EC Regulation 2073/2005 on microbiological criteria for foodstuffs for Cronobacter spp. The five matrices included in the validation were: two types of powdered infant food formulas (with and without probiotics); lactose; starch and environmental samples (swabs). The samples were each tested at two different levels of contamination, plus a negative control. Inoculation levels ranged from 4 to 95 CFU/sample. Each participant examined eight replicates of each level of inoculation, a total of 24 samples per matrix type. Specificity was calculated for each matrix used in the validation, with results ranging between 99 and 100%. Sensitivity of the method was calculated for samples in which no fractional recovery was expected and the values that were obtained ranged between 65 and 100%, depending on the matrix, the inoculation level and the interfering microbiota present in the samples. LOD50 value was calculated for three food items (the two powdered infant formulas and the starch) with values between 0.8 and 1.1 CFU/sample.

Screening for precancerous anal lesions with P16/Ki67 immunostaining in HIV-infected MSM.

BACKGROUND: Screening of anal cancer in HIV-infected MSM with anal cytology results in high rates of false positive results and elevated burden of high-resolution anoscopies. High-risk HPV up-regulates p16 and Ki67 expression in epithelial cells. We assessed the usefulness of P16/Ki-67 immunostaining cytology for the diagnosis of precancerous anal lesions. METHODOLOGY: Cross-sectional multicenter study. Concomitant anal liquid cytology with p16/Ki-67 immunostaining and HRA with biopsy of acetowhite lugol-negative lesions was performed in HIV-infected MSM. We compared the diagnostic performance of an abnormal anal cytology and p16/Ki-67 immunostaining relative to HRA-guided biopsy by logistic regression and comparison of ROC areas. RESULTS: We included 328 HIV-infected MSM. HSIL was histologically diagnosed in 72 subjects (25.1%), and 2 (0.6%) were diagnosed with anal cancer. An abnormal cytology showed a sensitivity of 95.6% and a specificity of 58.8% for the diagnosis of biopsy-proven HSIL. P16/Ki67 positivity was associated with the presence of biopsy-proven HSIL (P trend = 0.004) but with low sensitivity (41.2%) and specificity (71%). The combination of standard cytology with P16/Ki67 immunostaining did not increment the predictive value of standard cytology alone (AUC 0.685 vs. 0.673, respectively, P = 0.688). CONCLUSION: In HIV-infected MSM P16/Ki67 immunostaining does not improve the diagnostic accuracy of anal cytology, which shows a high sensitivity yet poor specificity. Other approaches aimed at improving the diagnostic accuracy of current techniques for the diagnostic of precancerous HSIL are warranted.

HIV, HPV, and microbiota: partners in crime?

Altered interplay between gut mucosa and dysbiotic bacteria during HIV infection seems to fuel chronic immune dysfunction and might explain the excess rates of human papillomavirus (HPV)-associated anal cancer in HIV-infected individuals. Here, we show in HIV-infected MSM undergoing screening for HPV-related cancer that specific fecal and mucosal bacteria are able to predict the existence of precancerous anal lesions. If confirmed, these bacterial biomarkers could be exploited either as diagnostic tools or therapeutic targets.

Assessment of different pre-treatment methods for the removal of limonene in citrus waste and their effect on methane potential and methane production rate.

The objective of this study was to assess the limonene removal efficiency of three pre-treatment methods when applied to citrus waste and to evaluate their effects on the biochemical methane potential and the methane production rate using batch anaerobic tests. The methods tested were based on removal (biological pretreatment by fungi) or recovery (steam distillation and ethanol extraction) of limonene. All the treatments decreased the concentration of limonene in orange peel, with average efficiencies of 22%, 44% and 100% for the biological treatment, steam distillation and ethanol extraction, respectively. By-products from limonene biodegradation by fungi exhibited an inhibitory effect also, not making interesting the biological pretreatment. The methane potential and production rate of the treated orange peel increased significantly after applying the recovery strategies, which separated and recovered simultaneously other inhibitory components of the citrus essential oil. Apart from the high recovery efficiency of the ethanol extraction process, it presented a favourable energy balance.