Determinants of Repeating an HIV Test Among Gay, Bisexual, and Other Men Who have Sex with Men, and Transgender People Who Use an Online-Requested Self-Sampling Program and Attending Community-Based Testing Venues in Spain (2018-2021).

Our aims were: (1) to characterize gay, bisexual and other men who have sex with men (GBMSM) and transgender (TG) populations using internet-based self-sampling services in the TESTATE project or attending community-based STI/HIV voluntary counselling and testing (CBVCT) services as alternative strategies to formal HIV testing within the Spanish national health system, and (2) to identify factors associated with repeat use of the same screening strategy from November 2018 to December 2021. Demographic, health, and behavioral characteristics of users using complementary strategies were analyzed. We developed a cross-sectional study, with descriptive analysis, HIV cascade, and a multivariate logistic model to identify factors associated with participants' repeated use of the same screening strategy. We included 9939 users, of whom 94.1% were GBMSM (n = 9348) and 5.9% TG (n = 580), with a high representation of migrants. Reactive results were 3.4% (n = 340), with 3.0% in GBMSM (n = 277/9348) and 10.7% in TG (n = 63/591). 73.8% (n = 251) were confirmed HIV positive and 76.7% (n = 194) were linked to health services. Users repeated the online screening strategy more than CBVCT (44.3% vs. 31.8%), but TG population used face-to-face community services more (8.4% vs. 0.6%). Factors influencing the repetition of the online self-sampling strategy included older age, non-migrant status, and recent HIV testing. In the CBVCT strategy, factors included older age, TG identity, non-migrant status, condom use during the last sexual encounter, and recent HIV testing. In conclusion, both CBVCT and online-requested self-sampling at home are important alternatives to the health system for the provision of HIV testing to GBMSM and TG.

A clinical utility evaluation of dual HIV/Syphilis point-of-care tests in non-clinical settings for screening for HIV and syphilis in men who have sex with men.

BACKGROUND: Dual point-of-care tests (POCTs) for the simultaneous detection of antibodies to HIV and syphilis have been developed. Since community-based organisations (CBO) are effective providers of HIV and syphilis testing among men who have sex with men (MSM), evaluation of the utility of these dual tests at CBO testing services is a high priority. The aim of this study is to determine the feasibility of performing dual HIV-syphilis POCT testing among both users and providers at these non-clinical sites. METHODS: This evaluation assessed the utility of two lateral flow immunochromatographic antibody technologies for dual screening for HIV/syphilis among MSM seeking testing in four CBO testing services in Spain, Slovenia, Latvia, and Ukraine. The study's conceptual framework divides the concept of feasibility into two inter-related domains, acceptability, and usability and further breaks it down into six subdomains: learnability, willingness, suitability, satisfaction, efficacy, and effectiveness. The feasibility analysis was performed by calculating the median score in 3 stages (for individual questions, subdomains, and domains), using a summated scores method. RESULTS: The final sample included 844 participants, 60 of which were found to be HIV test positive (7.1%) and 61 (7.2%) positive on testing for syphilis. There was a small difference (1.1%) when comparing the results of the two dual POCTs under evaluation to the tests routinely used at each site. The inter-rater agreement showed a high concordance between two independent readings. The analysis of the feasibility for the users of the services indicated good satisfaction, suitability, and willingness. In addition, among 18 providers the total mean score showed good acceptability and usability, good willingness, easy learnability, high suitability, and good efficacy, but lower satisfaction and effectiveness. The operational characteristics of both dual study POCTs were well evaluated by providers. CONCLUSIONS: The introduction of dual HIV and syphilis  POCTs in CBO testing services for screening of MSM is feasible, with a high acceptability and usability both for users and providers. Implementation of dual POCTs for HIV and syphilis in CBO testing services is an opportunity for scaling up integrated HIV/syphilis testing for MSM.

Trends in Sexual Health of Gay, Bisexual, and Other Men Who Have Sex with Men, and Transgender Individuals: Apps Driven Testing Program for HIV and Other STIs in Barcelona, Spain (2016-2023).

Gay, bisexual and other men who have sex with men (GBMSM) and transgender individuals face heightened risks of HIV and other sexually transmitted infections (STIs). Surveillance within these populations is critical, and community testing services play a pivotal role in preventing and controlling HIV and STIs. This study investigates the trends in HIV, syphilis and hepatitis C (HCV) infections among participants in an apps-driven rapid test program from 2016 to 2023 in Barcelona, Spain, examining associated factors. Trend analysis utilized Wilcoxon-type test and associated factors were determined through multivariate logistic analysis. The prevalence of new HIV diagnosis was 1.81% (CI 1.18-2.64), active syphilis was 3.37% (CI 2.46-4.50) and acute HCV was 0.40% (CI 0.11-1.02). While infection rates showed no significant changes, there was significant increasing in sex work and chemsex and decreasing in condom use. Additionally, a peak in dating apps use for sex and a specific reduction in number of sexual partners were observed in 2020. Factors associated with HIV diagnoses included migrant status (aOR = 11.19; CI 2.58-48.53) and inconsistent condom use during the previous 12 months (aOR = 3.12; CI 1.02-9.51). For syphilis, associated factors were migrant status (aOR = 2.46; CI 1.14-5.29), inconsistent condom use (aOR = 3.38; CI 1.37-8.36), and chemsex practice during the previous 12 months (aOR = 2.80; CI 1.24-6.30). Our findings emphasize the need for tailored interventions, including culturally sensitive outreach for migrants and comprehensive strategies addressing substance use in sexual contexts. Technological innovations and targeted educational initiatives could reduce the burden of HIV and STIs within the GBMSM and transgender communities, providing valuable insights for public health strategies.

Impact of the COVID-19 pandemic on community-based testing for HIV, viral hepatitis and sexually transmitted infections in the WHO European Region, March to August 2020.

BACKGROUND: COVID-19 affected testing for HIV, viral hepatitis and sexually transmitted infections (STIs) worldwide. We aimed to assess the impact of the COVID-19 pandemic on community-based voluntary, counselling and testing (CBVCT) services for those infections in the WHO European Region. METHODS: An online survey was distributed between 14 October and 13 November 2020 to testing providers in the WHO European Region. Key questions included: impact on testing volume, reasons for this impact, measures to mitigate, economic effects, areas where guidance or support were needed. A descriptive analysis on data reported by CBVCT services was performed. RESULTS: In total, 71 CBVCT services from 28 countries completed the survey. From March to May 2020, compared to the same period in 2019, most respondents reported a very major decrease (>50%) in the volume of testing for all the infections, ranging from 68% (Chlamydia) to 81% (HCV), and testing levels were not recovered during post-confinement. Main reasons reported were: site closure during lockdown (69.0%), reduced attendance and fewer appointments scheduled (66.2%), reduced staff (59.7%), and testing only by appointment (56.7%). Measures implemented to mitigate the decreased testing were remote appointments (64.8%), testing by appointment (50.7%), referral to other sites (33.8%), testing campaigns (35.2%) and promotion of self-testing (36.6%). Eighty-two percent of respondents reported a need for guidance/support. CONCLUSION: Results suggest that people attending CBVCT services experienced reductions in access to testing compared to before the pandemic. National governmental agencies need to support European CBVCT services to ensure recovery of community counselling and testing.

Enhancing the Hydrolytic Activity of a Lipase towards Larger Triglycerides through Lid Domain Engineering.

Lipases have valuable potential for industrial use, particularly those mostly active against water-insoluble substrates, such as triglycerides composed of long-carbon chain fatty acids. However, in most cases, engineered variants often need to be constructed to achieve optimal performance for such substrates. Protein engineering techniques have been reported as strategies for improving lipase characteristics by introducing specific mutations in the cap domain of esterases or in the lid domain of lipases or through lid domain swapping. Here, we improved the lipase activity of a lipase (WP_075743487.1, or LipMRD) retrieved from the Marine Metagenomics MarRef Database and assigned to the Actinoalloteichus genus. The improvement was achieved through site-directed mutagenesis and by substituting its lid domain (FRGTEITQIKDWLTDA) with that of Rhizopus delemar lipase (previously R. oryzae; UniProt accession number, I1BGQ3) (FRGTNSFRSAITDIVF). The results demonstrated that the redesigned mutants gain activity against bulkier triglycerides, such as glyceryl tridecanoate and tridodecanoate, olive oil, coconut oil, and palm oil. Residue W89 (LipMRD numbering) appears to be key to the increase in lipase activity, an increase that was also achieved with lid swapping. This study reinforces the importance of the lid domains and their amino acid compositions in determining the substrate specificity of lipases, but the generalization of the lid domain swapping between lipases or the introduction of specific mutations in the lid domain to improve lipase activity may require further investigation.

Design and Characterization of In-One Protease-Esterase PluriZyme.

Proteases are abundant in prokaryotic genomes (~10 per genome), but their recovery encounters expression problems, as only 1% can be produced at high levels; this value differs from that of similarly abundant esterases (1-15 per genome), 50% of which can be expressed at good levels. Here, we design a catalytically efficient artificial protease that can be easily produced. The PluriZyme EH1AB1 with two active sites supporting the esterase activity was employed. A Leu24Cys mutation in EH1AB1, remodelled one of the esterase sites into a proteolytic one through the incorporation of a catalytic dyad (Cys24 and His214). The resulting artificial enzyme, EH1AB1C, efficiently hydrolysed (azo)casein at pH 6.5-8.0 and 60-70 °C. The presence of both esterase and protease activities in the same scaffold allowed the one-pot cascade synthesis (55.0 ± 0.6% conversion, 24 h) of L-histidine methyl ester from the dipeptide L-carnosine in the presence of methanol. This study demonstrates that active sites supporting proteolytic activity can be artificially introduced into an esterase scaffold to design easy-to-produce in-one protease-esterase PluriZymes for cascade reactions, namely, the synthesis of amino acid esters from dipeptides. It is also possible to design artificial proteases with good production yields, in contrast to natural proteases that are difficult to express.

A Plurizyme with Transaminase and Hydrolase Activity Catalyzes Cascade Reactions.

Engineering dual-function single polypeptide catalysts with two abiotic or biotic catalytic entities (or combinations of both) supporting cascade reactions is becoming an important area of enzyme engineering and catalysis. Herein we present the development of a PluriZyme, TR2 E2 , with efficient native transaminase (kcat : 69.49±1.77 min-1 ) and artificial esterase (kcat : 3908-0.41 min-1 ) activities integrated into a single scaffold, and evaluate its utility in a cascade reaction. TR2 E2 (pHopt : 8.0-9.5; Topt : 60-65 °C) efficiently converts methyl 3-oxo-4-(2,4,5-trifluorophenyl)butanoate into 3-(R)-amino-4-(2,4,5-trifluorophenyl)butanoic acid, a crucial intermediate for the synthesis of antidiabetic drugs. The reaction proceeds through the conversion of the ß-keto ester into the ß-keto acid at the hydrolytic site and subsequently into the ß-amino acid (e.e. >99 %) at the transaminase site. The catalytic power of the TR2 E2 PluriZyme was proven with a set of ß-keto esters, demonstrating the potential of such designs to address bioinspired cascade reactions.

Recommendations for collection and integration of community-based testing and linkage to care data into national surveillance, monitoring and evaluation systems for HIV, viral hepatitis and sexually transmitted infections: results from the INTEGRATE Joint Action.

BACKGROUND: National testing strategy, including monitoring and evaluation, is critical in responding to HIV, sexually transmitted infections, and viral hepatitis. Community-based voluntary counselling and testing contributes to early HIV diagnoses among key populations. Countries providing community-based testing, should integrate some core data on testing and linkage to care in these services into national surveillance and monitoring and evaluation systems. This study aimed to support the integration of community-based voluntary counselling and testing data into respective national surveillance and M&E systems for those infections. METHODS: Preliminary consensus on indicators for the integration of community-based voluntary counselling and testing data into respective national surveillance and monitoring and evaluation systems was reached. Pilot studies were conducted in Estonia, Poland, Serbia, Slovakia, Slovenia and Spain. After pilot activities were implemented, the final consensus on indicators was reached. An analysis of the facilitators and barriers faced during pilot studies was conducted to inform the final recommendations for implementation. RESULTS: The minimum set of six indicators to be integrated into national surveillance and monitoring and evaluation systems were: number of tests, number of clients tested, reactivity rate for tests and clients, positivity (active infection) rates for tests and clients, linkage to care rates for clients with reactive and/or positive test result, proportion of all new diagnoses in a country with first reactive test result at community-based voluntary counselling and testing service. Seven additional indicators were identified. Each indicator should be disaggregated by key population, sex and age group. A list of 10 recommendations for the collection and integration of community-based voluntary counselling and testing data into national surveillance and monitoring and evaluation systems for HIV, sexually transmitted infections and viral hepatitis was identified. CONCLUSIONS: Integration of some community-based voluntary counselling and testing monitoring and evaluation data into national surveillance and monitoring and evaluation systems in all pilot countries was achieved. The recommendations will support such integration in other European countries. European Centre for Prevention and Control of Diseases included questions from the minimum list of indicators into their Dublin Declaration questionnaire 2020 to contribute to evidence based community testing policies in European countries.

Integration of community-based testing data into national HIV surveillance in Poland, Serbia and Slovakia within the framework of INTEGRATE project.

BACKGROUND: Community-based voluntary counselling and testing contributes to early HIV diagnoses among key populations. Testing data from such decentralized services is however often not standardized nor linked to national surveillance systems. This study aimed to support the integration of community testing data into respective national surveillance and monitoring and evaluation systems for those infections. We present results from three national pilots, focused on improved data collection and transfer. METHODS:  Within the Joint Action INTEGRATE different pilot activities were planned and implemented according to the local context. In Slovakia, standardised data collection tools were implemented in three community testing services. The data generated was used to calculate the proposed indicators. In Poland, positive test results from the community testing database were linked to the national case-based surveillance database using confirmatory test number, to improve the completeness of behavioural data in the national database. In Serbia, voluntary counselling and testing forms were improved enabling identification of community-based testing. A system to generate unique client identifiers was initiated in the National registry of HIV cases to monitor linkage to care. RESULTS: All three sites were able to estimate most of the agreed indicators. In Slovakia during the study period 675 people were tested for HIV, 410 for hepatitis C and 457 for syphilis, with reactivity rates of 0.4, 2.5 and 1.8%, respectively. For HIV, 66.7% of reactive cases were confirmed and linked to care. In Poland, 28.9% of the community testing sites' records were linked to the national surveillance database (and accounted for 14.3% of all new diagnoses registered here during 2017-2018). Reactivity rate ranged between 1.9% and 2.1%. In Serbia, 80 persons were tested at community sites, from which two had a reactive HIV test result. By linking unique client identifiers from voluntary counselling and testing and National Registry of HIV cases databases, linkage to care within a two-month period was observed for one of two people with reactive HIV test result. CONCLUSIONS:  Pilot activities in the three countries demonstrate that integration of community-based testing data into surveillance systems is feasible and can help improve national surveillance data by providing key information.

Hepatitis C Screening in Community-Based Voluntary Counselling and Testing Services in Europe: An Observational Study from the COBATEST Network 2014-2018.

The COBATEST Network links community-based voluntary counselling and testing (CBVCT) services in the European region and collects testing data using standardised data collection tools. This study aims to describe the population being screened for anti-HCV antibodies in the COBATEST Network and identify risk factors associated with a reactive HCV screening test result in the period 2014-2018. Clients aged > 16 screened for HCV in the period 2014-2018 at one of the Network's CBVCT services were included in the study. In the 5 year period, 7426 clients were screened for HCV in 22 centres in 10 countries and anti-HCV antibodies were detected in 113 (1.5%). The majority of people screened were aged 25-44, men who have sex with men (MSM), not HIV+ , not reporting a history of injecting drug use or sex work. Detection of anti-HCV antibodies was associated with being HIV + MSM (aOR 9.1, 95% CI 3.8; 21.8 compared to HIV-clients) and being a person who injects drugs (PWID, aOR 28.1, 95% CI 17.6; 45.0, compared to people with no history of injecting drug use). This study demonstrates that HIV-MSM with no history of injection drug use are using CBVCT services for HCV screening, but reactive screening test is associated with being HIV+ or PWID. The integration of HCV screening into the CBVCT service model may widen access to testing for populations that may otherwise not be tested.

The contribution of HIV point-of-care tests in early HIV diagnosis: community-based HIV testing monitoring in Catalonia, 1995 to 2018.

BackgroundCommunity-based HIV testing services combined with the use of point-of-care tests (POCT) have the potential to improve early diagnosis through increasing availability, accessibility and uptake of HIV testing.AimTo describe community-based HIV testing activity in Catalonia, Spain, from 1995 to 2018, and to evaluate the impact of HIV POCT on the HIV continuum of care.MethodsA community-based network of voluntary counselling and testing services in Catalonia, Spain has been collecting systematic data on activity, process and results since 1995. A descriptive analysis was performed on pooled data, describing the data in terms of people tested and reactive screening test results.ResultsBetween 1995 and 2018, 125,876 HIV tests were performed (2.1% reactive). Since the introduction of HIV POCT in 2007, a large increase in the number of tests performed was observed, reaching 14,537 tests alone in 2018 (1.3% reactive). Men who have sex with men (MSM), as a proportion of all people tested, has increased greatly over time reaching 74.7% in 2018. The highest percentage of reactive tests was found in people who inject drugs followed by MSM. The contribution of community-based HIV testing to the overall total notified cases in the Catalonia HIV registry has gradually increased, reaching 37.9% in 2018, and 70% of all MSM cases. In 2018, the percentage of individuals with a reactive screening test who were linked to care was 89.0%.ConclusionOur study reinforces the important role that community-based HIV POCT has on the diagnosis of HIV in key populations.

Economic evaluation of HIV testing for men who have sex with men in community-based organizations - results from six European cities.

The non-decreasing incidence of HIV among men who have sex with men (MSM) has motivated the emergence of Community Based Voluntary Counselling and Testing (CBVCT) services specifically addressed to MSM. The CBVCT services are characterized by facilitated access and linkage to care, a staff largely constituted by voluntary peers, and private not-for-profit structures outside the formal health system institutions. Encouraging results have been measured about their effectiveness, but these favourable results may have been obtained at high costs, questioning the opportunity to expand the experience. We performed an economic evaluation of HIV testing for MSM at CBVCT services, and compared them across six European cities. We collected retrospective data for six CBVCT services from six cities (Copenhagen, Paris, Lyon, Athens, Lisbon, and Ljubljana), for the year 2014, on the number of HIV tests and HIV reactive tests, and on all expenditures to perform the testing activities. The total costs of CBVCTs varied from 54,390€ per year (Ljubljana) to 245,803€ per year (Athens). The cost per HIV test varied from to 41€ (Athens) to 113€ (Ljubljana). The cost per HIV reactive test varied from 1966€ (Athens) to 9065€ (Ljubljana). Our results show that the benefits of CBVCT services are obtained at an acceptable cost, in comparison with the literature (values, mostly from the USA, range from 1600$ to 16,985$ per HIV reactive test in clinical and non-clinical settings). This result was transversal to several European cities, highlighting that there is a common CBVCT model, the cost of which is comparable regardless of the epidemiological context and prices. The CBVCT services represent an effective and "worth it" experience, to be continued and expanded in future public health strategies towards HIV.

Level of impact on the public health of universal human immunodeficiency virus screening in an Emergency Department. / Estudio del impacto a nivel de salud pública del cribado universal del virus de la inmunodeficiencia humana en un servicio de Urgencias.

INTRODUCTION: The aim of this study was to determine the prevalence of HIV and the acceptability of rapid testing in an emergency department (ED), Barcelona (6/07/2011 to 8/03/2013). METHOD: A convenience sample was used, depending on nurse availability in the ED. Participants signed an informed consent. Results were confirmed by conventional methods. RESULT: A total of 2,140 individuals were offered testing, and 5% rejected taking part (107/2,140). Three subjects (3/2,033 [0.15%]) had confirmed reactive test. Individuals with a higher education were more likely to perform a rapid HIV test in ED (P<.005). CONCLUSION: A low prevalence of new HIV diagnoses was found among participants, although there was a high acceptability rate to perform rapid testing in the ED.

Desorption of Lipases Immobilized on Octyl-Agarose Beads and Coated with Ionic Polymers after Thermal Inactivation. Stronger Adsorption of Polymers/Unfolded Protein Composites.

Lipases from Candida antarctica (isoform B) and Rhizomucor miehei (CALB and RML) have been immobilized on octyl-agarose (OC) and further coated with polyethylenimine (PEI) and dextran sulfate (DS). The enzymes just immobilized on OC supports could be easily released from the support using 2% SDS at pH 7, both intact or after thermal inactivation (in fact, after inactivation most enzyme molecules were already desorbed). The coating with PEI and DS greatly reduced the enzyme release during thermal inactivation and improved enzyme stability. However, using OC-CALB/RML-PEI-DS, the full release of the immobilized enzyme to reuse the support required more drastic conditions: a pH value of 3, a buffer concentration over 2 M, and temperatures above 45 °C. However, even these conditions were not able to fully release the thermally inactivated enzyme molecules from the support, being necessary to increase the buffer concentration to 4 M sodium phosphate and decrease the pH to 2.5. The formation of unfolded protein/polymers composites seems to be responsible for this strong interaction between the octyl and some anionic groups of OC supports. The support could be reused five cycles using these conditions with similar loading capacity of the support and stability of the immobilized enzyme.

Implementation of rapid HIV and HCV testing within harm reduction programmes for people who inject drugs: a pilot study.

UNLABELLED: Including HCV and HIV rapid tests in harm reduction programmes (HRP) for people who inject drugs (PWID) can increase detection of these infections in high-risk populations who do not seek conventional health care. AIMS: To assess acceptability and feasibility of rapid HIV and HCV tests in HRP; to identify HIV and HCV prevalence rates in HRP; to identify the percentage of PWID with a reactive test that attend hospital for confirmation and follow-up. Rapid oral tests for HCV and HIV were offered to users of 13 HRP from both mobile units and facility-based centres. A total of 172 HCV and 198 HIV tests were performed, with a refusal rate of 1.7% and 10.4%, respectively. Injectors made up 64.9% of all drug users and 35.1% did not inject drugs. Overall, 20.3% of HCV tests and 2.5% of HIV test were reactive. Only 24 of the 35 reactive HCV could be confirmed (68.6%) and one was false-negative. Of the five HIV reactive cases, only two could be confirmed (40%) with 1 false-positive case. Acceptability of rapid HIV and HCV tests among HRP users was high. The usefulness of oral rapid tests in HRP has been demonstrated, especially in mobile HRP.

Reversible Immobilization of Lipases on Heterofunctional Octyl-Amino Agarose Beads Prevents Enzyme Desorption.

Two different heterofunctional octyl-amino supports have been prepared using ethylenediamine and hexylendiamine (OCEDA and OCHDA) and utilized to immobilize five lipases (lipases A (CALA) and B (CALB) from Candida antarctica, lipases from Thermomyces lanuginosus (TLL), from Rhizomucor miehei (RML) and from Candida rugosa (CRL) and the phospholipase Lecitase Ultra (LU). Using pH 5 and 50 mM sodium acetate, the immobilizations proceeded via interfacial activation on the octyl layer, after some ionic bridges were established. These supports did not release enzyme when incubated at Triton X-100 concentrations that released all enzyme molecules from the octyl support. The octyl support produced significant enzyme hyperactivation, except for CALB. However, the activities of the immobilized enzymes were usually slightly higher using the new supports than the octyl ones. Thermal and solvent stabilities of LU and TLL were significantly improved compared to the OC counterparts, while in the other enzymes the stability decreased in most cases (depending on the pH value). As a general rule, OCEDA had lower negative effects on the stability of the immobilized enzymes than OCHDA and while in solvent inactivation the enzyme molecules remained attached to the support using the new supports and were released using monofunctional octyl supports, in thermal inactivations this only occurred in certain cases.

Approval and potential use of over-the-counter HIV self-tests: the opinion of participants in a street based HIV rapid testing program in Spain.

HIV self-testing, not yet available in Spain, is a strategy thought to be able to increase the number of people tested and testing frequency. 3,373 attenders of a street-based HIV rapid-testing program gave their opinion on authorizing over-the-counter self-tests and a potentially shorter lead time if self-tests were available. 88.0 % of participants were in favor of authorization, 9.2 % had no clear opinion and 2.8 % were against. 54.6 % of men who have sex with men (MSM), 38.4 % of men who have sex with women and 36.3 % of women acknowledged a potential for lead time reduction. Potential lead time was associated with being ≥35 years, having a university degree, never injected drugs, previous HIV tests and being concerned about an HIV positive result, and in MSM, also having ≥5 partners. Self-testing seems a promising strategy for Spain: its authorization is supported by nearly all potential users and almost three quarters of MSM would have opted to advance their current testing if self-tests were available.

Assigning Functions of Unknown Enzymes by High-Throughput Enzyme Characterization.

The discovery of new enzymes is strongly enabled by the implementation of high-throughput screening methods to detect enzymatic activity in single organisms or clone expression libraries, or to benchmark their performances against known prototypes. In this chapter, a number of methods, applicable at high-throughput scale, are described that allow the screening and characterization of enzymes relevant to biotechnology, particularly, ester-hydrolases (esterases, lipases, phospholipases, and polyester hydrolases).

Transforming an esterase into an enantioselective catecholase through bioconjugation of a versatile metal-chelating inhibitor.

Metal complexes introduced into protein scaffolds can generate versatile biomimetic catalysts endowed with a variety of catalytic properties. Here, we synthesized and covalently bound a bipyridinyl derivative to the active centre of an esterase to generate a biomimetic catalyst that shows catecholase activity and enantioselective catalytic oxidation of (+)-catechin.

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.