Characterization of Bacterial Membrane Fatty Acid Profiles for Biofilm Cells.

When submitted to environmental stresses, bacteria can modulate its fatty acid composition of membrane phospholipids in order to optimize membrane fluidity. Characterization of bacterial membrane fatty acid profiles is thus an interesting indicator of cellular physiological state. The methodology described here aims to improve the recovering of biofilm cells for the characterization of their fatty acid profiles. The saponification reagent is directly applied on the whole biofilm before the removal of cells from the inert surface. In this way, maximum of the cells and their fatty acids can be recovered from the deepest layers of the biofilm.

Enhanced protection for interfacial lipid ozonolysis by sulfur-containing amino acids.

Sulfur-containing amino acids have been proposed as drugs for lipid oxidation associated with diseases for a long time, but the molecular-level mechanism on the effectiveness of sulfur-containing amino acids against lipid oxidation remains elusive. In this work, with the interfacial sensitivity mass spectrometry method, oxidation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG), a widely used model lipid, was significantly inhibited on hung droplet surface in presence of sulfur-containing amino acids, such as cysteine (Cys) and methionine (Met). Both the Cys and Met showed a self-sacrificing protection. The amino acids with -S-R tails (R referring to methyl or t-butyl group) showed more effective against POPG oxidation than those with -SH tails, and this process was not related to the conformations of amino acids. The low effectiveness of Cys during the interfacial chemistry was proved to arise from the formation of disulfide bond. This study extends the current understanding of chemistry of sulfur-containing amino acids and provides insights to aid the sulfur-containing amino acids against cell oxidation.

Influence of critical micelle concentration of choline-based long chain fatty acid soaps on their antibacterial activity against Methicillin resistant Staphylococcus aureus.

HYPOTHESIS: Antimicrobial resistance (AMR) is a pressing global health concern. ESKAPEE pathogens, such as Methicillin-resistant Staphylococcus aureus (MRSA) are notable of concern in healthcare settings due to their resistance to critical antibiotics. To combat AMR, the development of alternatives such as bacterial membrane-active agents is crucial. Fatty acids (FAs) have emerged as a sustainable, antibiotic-free solution with inherent antibacterial activity. However, long chain saturated fatty acids (LCFAs) sodium soaps exhibit poorly antibacterial properties in comparison to short chain FAs, believed to be linked to limited solubility in aqueous media. EXPERIMENTS: We employed choline as a chaotropic organic counter-ion to enhance the solubility of LCFAs and investigated their antibacterial effects against MRSA. The optimal medium conditions for micelle formation for LCFAs was first investigated. Then, we determined the critical micelle concentration (CMC), micellar morphology, and aggregation number through surface tension measurements and small angle neutron scattering experiments. Antimicrobial activity was assessed using minimum bactericidal concentration (MBC) assays and time-kill experiments. FINDINGS: We have identified conditions where LCFAs are effective against MRSA for the first time, providing valuable insights for developing new antibacterial agents to fight AMR. LCFAs need to be used above their Krafft temperatures and CMC to exhibit antibacterial efficacy.

Re-evaluating the necessity of routine laboratory monitoring during isotretinoin therapy for acne.

In this letter, we discuss the topic of necessity of routine laboratory monitoring during isotretinoin treatment for acne. According to Park and colleagues, it is advisable to monitor the levels of triglycerides, alanine aminotransferase, and aspartate aminotransferase every 5 to 6 months. Additionally, the levels of total cholesterol and low-density lipoprotein should be checked within the first two months of treatment. Isotretinoin is a commonly prescribed agent mainly used to treat acne. Despite its high effectiveness, it necessitates regular monitoring of laboratory parameters due to its side effect profile. Currently, there remains a lack of consensus on the appropriate frequency for monitoring these parameters during treatment with isotretinoin. This letter will provide insight into this complex and controversial topic. Based on existing literature, we concluded that the incidence of changes in lipid and liver aminotransferase levels during isotretinoin treatment for acne was low and likely clinically insignificant. For generally healthy people, we recommend testing lipid and liver profiles once at baseline and a second time at the peak dosage. However, frequent testing might still be beneficial in certain populations of patients.

Drought stress reduces arbuscular mycorrhizal colonization of Poncirus trifoliata (L.) roots and plant growth promotion via lipid metabolism.

Drought stress poses increasingly serious threats to agricultural production in the era of global climate change. Arbuscular mycorrhizal (AM) fungi are well-recognized biostimulants promoting plant tolerance to drought stress. Lipids are indispensable for AM fungal colonization, however, the involvement of lipid metabolism in the drought tolerance conferred by AM fungi is largely unknown. In this study, we inoculated Poncirus trifoliata (L.) with Rhizophagus irregularis DAOM197198 under no drought stress, medium drought stress and severe drought stress, with non-inoculation under respective treatments as control. Results indicated that AM fungal inoculation significantly promoted the drought tolerance of P. trifoliata (L.), with the effect size decreasing along with drought severity. Moreover, the effect size was significantly related to arbuscule abundance. Fatty acid profiling showed that the arbuscule abundance was determined by the AM-specific phospholipids (PLs), whose biosynthesis and delivery were inhibited by drought stress as revealed by qRT-PCR of FatM, RAM1 and STR/STR2. More interestingly, AM fungal inoculation increased the lipid allocation to total PLs and the unsaturation rate of total neutral lipids (NLs), probably indicating the involvement of non-AM-specific lipids in the increased drought tolerance. Taken together, our results demonstrate that lipid metabolism in AM mediates the increased drought tolerance conferred by AM fungal inoculation, with AM-specific and non-AM-specific lipids functioning therein in different ways.

Impact of Lipid Tail Length on the Organ Selectivity of mRNA-Lipid Nanoparticles.

The delivery of mRNA molecules to organs beyond the liver is valuable for therapeutic applications. Functionalized lipid nanoparticles (LNPs) using exogenous mechanisms can regulate in vivo mRNA expression profiles from hepatocytes to extrahepatic tissues but lead to process complexity and cost escalation. Here, we report that mRNA expression gradually shifts from the liver to the spleen in an ionizable lipid tail length-dependent manner. Remarkably, this simple chemical strategy held true even when different ionizable lipid head structures were employed. As a potential mechanism underlying this discovery, our data suggest that 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) is enriched on the surface of mRNA/LNPs with short-tail lipids. This feature limits their interaction with biological components, avoiding their rapid hepatic clearance. We also show that spleen-targeting LNPs loaded with SARS-CoV-2 receptor-binding domain (RBD) mRNA can efficiently induce immune responses and neutralize activity following intramuscular vaccination priming and boosting.

Mobile Phase Contaminants Affect Neutral Lipid Analysis in LC-MS-Based Lipidomics Studies.

Lipidomics is a well-established field, enabled by modern liquid chromatography mass spectrometry (LC-MS) technology, rapidly generating large amounts of data. Lipid extracts derived from biological samples are complex, and most spectral features in LC-MS lipidomics data sets remain unidentified. In-depth analyses of commercial triacylglycerol, diacylglycerol, and cholesterol ester standards revealed the expected ammoniated and sodiated ions as well as five additional unidentified higher mass peaks with relatively high intensities. The identities and origin of these unknown peaks were investigated by modifying the chromatographic mobile-phase components and LC-MS source parameters. Tandem MS (MS/MS) of each unknown adduct peak yielded no lipid structural information, producing only an intense ion of the adducted species. The unknown adducts were identified as low-mass contaminants originating from methanol and isopropanol in the mobile phase. Each contaminant was determined to be an alkylated amine species using their monoisotopic masses to calculate molecular formulas. Analysis of bovine liver extract identified 33 neutral lipids with an additional 73 alkyl amine adducts. Analysis of LC-MS-grade methanol and isopropanol from different vendors revealed substantial alkylated amine contamination in one out of three different brands that were tested. Substituting solvents for ones with lower levels of alkyl amine contamination increased lipid annotations by 36.5% or 27.4%, depending on the vendor, and resulted in >2.5-fold increases in peak area for neutral lipid species without affecting polar lipid analysis. These findings demonstrate the importance of solvent selection and disclosure for lipidomics protocols and highlight some of the major challenges when comparing data between experiments.

Safety and Efficacy of a Composite Lipid Emulsion with Fish Oil in Hospitalized Neonates and Infants Requiring Prolonged Parenteral Nutrition - A Randomized, Double-Blind, Multicenter, Controlled Trial.

BACKGROUND: Intravenous lipids are critical to the care of extremely premature and other high-risk infants. OBJECTIVE: The study evaluated safety and efficacy of parenteral nutrition (PN) with composite intravenous lipid emulsion (CO-ILE) with fish oil compared to pure soybean oil lipid emulsion (SOLE). METHODS: Randomized, controlled, double-blind, multicenter study (NCT02579265) in neonates/ infants anticipated to require ≥28 days of PN due to gastrointestinal malformations or injury. Duration of the initial and extended treatment phase was 28 days and 84 days (for patients with PN indication after day 28). RESULTS: 83/ 78 patients (mean postnatal age: 11.4/ 8.3 days, 54/ 59 preterm) received CO-ILE and SOLE, respectively. 33 patients per group completed 28 days on treatment. Risk of having conjugated bilirubin values > 2 mg/dL confirmed by a second sample 7 days after the first during the initial treatment phase (primary outcome) was 2.4% (2 of 83) with CO-ILE and 3.8% (3 of 78) with SOLE (risk ratio 0.59 [95% CI: 0.09, 3.76]). Between days 29 and 84, the number of patients with confirmed conjugated bilirubin values > 2 mg/dL did not increase in the CO-ILE group (n=2) and increased in the SOLE group (n=9). At the end of the initial treatment phase, conjugated bilirubin concentrations were 45.6% lower under CO-ILE than under SOLE (p=0.006). There was no clinical or laboratory evidence of essential fatty acid deficiency in patients in the CO-ILE group. Median time to discharge alive was 56.7 and 66.4 days with CO-ILE and SOLE, respectively (hazard ratio: 1.16; 95% CI: 0.81, 1.68). CONCLUSIONS: CO-ILE was associated with a possible lower risk of cholestasis and significantly lower conjugated bilirubin at the end of the initial treatment phase in high-risk neonates and infants as compared to patients treated with SOLE. In summary, these data indicate that CO-ILE can be considered safe and may be preferable over SOLE in high-risk neonates. CLINICAL TRIAL REGISTRY NUMBER: Clinicaltrials.gov, study ID NCT02579265.

Assessment of correlation between lipid ratios and body mass index in patients with type 2 diabetes mellitus in Sarajevo, Bosnia and Herzegovina.

Objective. Studies that have evaluated correlation between body mass index (BMI) and novel lipid indices such as triglycerides (TG)/high-density lipoprotein-cholesterol (HDL-C), total cholesterol (TC)/HDL-C, and low-density lipoprotein cholesterol (LDL-C)/HDL-C in type 2 diabetes mellitus (T2DM) are scarce. Hence, the aim of the present study was to explore the correlation between BMI and novel lipid indices in Bosnian patients with T2DM. Methods. Present study included 117 patients with T2DM (mean age: 66.51 years) and 68 controls (mean age: 68.37 years). BMI was calculated as weight/height². Lipids were measured by standard methods. TG/HDL-C, TC/HDL-C, and LDL-C/HDL-C ratios were separately calculated. The differences between the groups were assessed by Student's t-test or Man Whitney U test. Correlations were determined by Spearman's test. Results. In a total sample of T2DM patients, 41.0% were overweight and 44.4% were obese. In the control group, 51.5% of subjects were overweight and 25.0% were obese. In T2DM group, a significant correlation was observed between BMI and HDL-C, LDL-C, TG/HDL, TC/HDL-C, and LDL-C/HDL-C ratios. In the control group, there was a significant correlation found between BMI and HDL-C, TG, TG/HDL, TC/HDL-C, and LDL-C/HDL-C-ratios. Correlation between BMI and other lipid parameters in T2DM and the control group was not determined. Conclusion. The present study showed significant correlation between BMI and novel lipid indices in both T2DM patients and the control group of subjects. Possible explanation for the observed results might be prevalence of overweight and obese participants in this study sample. Since novel lipid indices are used in the prediction of cardiometabolic risk, results obtained in the present study have valuable clinical implications.

Lipid remodeling in acrosome exocytosis: unraveling key players in the human sperm.

It has long been thought that exocytosis was driven exclusively by well-studied fusion proteins. Some decades ago, the role of lipids became evident and escalated interest in the field. Our laboratory chose a particular cell to face this issue: the human sperm. What makes this cell special? Sperm, as terminal cells, are characterized by their scarcity of organelles and the complete absence of transcriptional and translational activities. They are specialized for a singular membrane fusion occurrence: the exocytosis of the acrosome. This unique trait makes them invaluable for the study of exocytosis in isolation. We will discuss the lipids' role in human sperm acrosome exocytosis from various perspectives, with a primary emphasis on our contributions to the field. Sperm cells have a unique lipid composition, very rare and not observed in many cell types, comprising a high content of plasmalogens, long-chain, and very-long-chain polyunsaturated fatty acids that are particular constituents of some sphingolipids. This review endeavors to unravel the impact of membrane lipid composition on the proper functioning of the exocytic pathway in human sperm and how this lipid dynamic influences its fertilizing capability. Evidence from our and other laboratories allowed unveiling the role and importance of multiple lipids that drive exocytosis. This review highlights the role of cholesterol, diacylglycerol, and particular phospholipids like phosphatidic acid, phosphatidylinositol 4,5-bisphosphate, and sphingolipids in driving sperm acrosome exocytosis. Furthermore, we provide a comprehensive overview of the factors and enzymes that regulate lipid turnover during the exocytic course. A more thorough grasp of the role played by lipids transferred from sperm can provide insights into certain causes of male infertility. It may lead to enhancements in diagnosing infertility and techniques like assisted reproductive technology (ART).

Maternal Lipids in Pregnancy and Later Life Dyslipidemia: The POUCHmoms Longitudinal Cohort Study.

OBJECTIVE: Maternal lipid levels increase in normal pregnancies. Here, we examine whether pregnancies with the highest total cholesterol, low-density lipoprotein (LDL) or triglyceride levels or the lowest high-density lipoprotein (HDL) levels predict future dyslipidemia post-pregnancy. DESIGN: Longitudinal cohort study. SETTING: Five communities in Michigan, USA. SAMPLE: Pregnant women (n = 649) with blood lipid levels measured at mid-pregnancy in the Pregnancy Outcomes and Community Health (POUCH) Study and at the POUCHmoms Study follow-up, 7-15 years later. METHODS: Maternal mid-pregnancy lipid levels were defined as 'high' (upper quartile of triglycerides ≥ 216 mg/dL, LDL ≥ 145 mg/dL and total cholesterol ≥ 256 mg/dL) or 'low' (lower quartile, HDL < 58 mg/dL) using whole sample lipid distributions. At follow-up, dyslipidemia was classified by the clinical cutoffs of triglycerides and total cholesterol ≥ 200 mg/dL, LDL ≥ 130 mg/dL and HDL < 50 mg/dL. Weighted regression models estimated the risk of dyslipidemia at follow-up in relation to pregnancy lipid levels, adjusted for baseline confounders. MAIN OUTCOME MEASURE: Dyslipidemia later in life. RESULTS: Mid-pregnancy triglycerides, LDL, and total cholesterol levels at the upper quartile were associated with at least threefold increase in the risk of abnormal triglycerides, LDL and total cholesterol levels later in life. Women with low mid-pregnancy HDL levels had just over a twofold increased risk of abnormally low HDL levels at follow-up. These associations persisted following adjustment for covariates, i.e. demographics, lifestyle, and years of follow-up. CONCLUSIONS: Higher mid-pregnancy LDL, total cholesterol and triglycerides and lower levels of HDL may signal future dyslipidemia risk and the need for closer lipid monitoring to ensure timely interventions that can attenuate cardiovascular disease risk.

Ursodeoxycholic Acid for Trans Intestinal Cholesterol Excretion Stimulation: A Randomized Placebo Controlled Crossover Study.

BACKGROUND: The trans intestinal cholesterol excretion (TICE) pathway is a potential therapeutic target to reduce plasma low-density lipoprotein (LDL) cholesterol levels. TICE encompasses the direct excretion of cholesterol by enterocytes into feces. In mice, TICE has been shown to be stimulated by a hydrophilic bile acid pool, resulting in increased fecal neutral sterol loss and reduced plasma cholesterol levels. We investigated whether treatment with a hydrophilic bile acid, ursodeoxycholic acid (UDCA), would increase fecal neutral sterols in humans as a proxy for TICE. METHODS AND RESULTS: We performed a randomized, double-blind, placebo-controlled, cross-over trial in 20 male participants aged >18 years, with plasma LDL cholesterol levels ≥2.6 mmol/L. After a run-in period of ezetimibe 20 mg once daily for 3 weeks, patients were randomized to UDCA 600 mg or placebo orally once daily for 2 weeks. After a 3 week washout, patients underwent the alternate treatment. At baseline, mean (SD) age, body mass index, and plasma LDL cholesterol were 59±11.3 years, 26.4±3.1 kg/m2, and 3.9±0.8 mmol/L, respectively. After UDCA treatment, the plasma bile acid hydrophobicity index was reduced compared with placebo (-118.7% versus +2.3%, P<0.001). The fecal neutral sterols did not change (-5.8% versus +18.8%, P=0.51) and treatment with UDCA increased LDL cholesterol with 0.39 mmol/L (+8.1% versus -3.64%, P=0.002) when compared with placebo. CONCLUSIONS: UDCA in combination with ezetimibe increased plasma bile acid hydrophilicity in healthy subjects with LDL cholesterol levels >2.6 mmol/L but did not result in increased fecal neutral sterols or decreased LDL cholesterol. This suggests that TICE is not stimulated by an increase in the hydrophilicity of the bile acid pool in humans.

Metagenomic, metabolomic, and lipidomic shifts associated with fecal microbiota transplantation for recurrent Clostridioides difficile infection.

Recurrent C. difficile infection (rCDI) is an urgent public health threat, for which the last resort and lifesaving treatment is a fecal microbiota transplant (FMT). However, the exact mechanisms that mediate a successful FMT are not well-understood. Here, we use longitudinal stool samples collected from patients undergoing FMT to evaluate intra-individual changes in the microbiome, metabolome, and lipidome after successful FMTs relative to their baselines pre-FMT. We show changes in the abundance of many lipids, specifically a decrease in acylcarnitines post-FMT, and a shift from conjugated bile acids pre-FMT to deconjugated secondary bile acids post-FMT. These changes correlate with a decrease in Enterobacteriaceae, which encode carnitine metabolism genes, and an increase in Lachnospiraceae, which encode bile acid altering genes such as bile salt hydrolases (BSHs) and the bile acid-inducible (bai) operon, post-FMT. We also show changes in gut microbe-encoded amino acid biosynthesis genes, of which Enterobacteriaceae was the primary contributor to amino acids C. difficile is auxotrophic for. Liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) revealed a shift from microbial conjugation of primary bile acids pre-FMT to secondary bile acids post-FMT. Here, we define the structural and functional changes associated with a successful FMT and generate hypotheses that require further experimental validation. This information is meant to help guide the development of new microbiota-focused therapeutics to treat rCDI.IMPORTANCERecurrent C. difficile infection is an urgent public health threat, for which the last resort and lifesaving treatment is a fecal microbiota transplant. However, the exact mechanisms that mediate a successful FMT are not well-understood. Here, we show changes in the abundance of many lipids, specifically acylcarnitines and bile acids, in response to FMT. These changes correlate with Enterobacteriaceae pre-FMT, which encodes carnitine metabolism genes, and Lachnospiraceae post-FMT, which encodes bile salt hydrolases and baiA genes. There was also a shift from microbial conjugation of primary bile acids pre-FMT to secondary bile acids post-FMT. Here, we define the structural and functional changes associated with a successful FMT, which we hope will help aid in the development of new microbiota-focused therapeutics to treat rCDI.

Key biomarkers in type 2 diabetes patients: A systematic review.

Type 2 diabetes mellitus (T2DM) is not just a local health issue but a significant global health burden, affecting patient outcomes and clinical management worldwide. Despite the wealth of studies reporting T2DM biomarkers, there is an urgent need for a comparative review. This review aims to provide a comprehensive analysis based on the reported T2DM biomarkers and how these are linked with other conditions, such as inflammation and wound healing. A comparative review was conducted on 24 001 study participants, including 10 024 T2DM patients and 13 977 controls (CTL; age 30-90 years). Four main profiles were extracted and analysed from the clinical reports over the past 11 years: haematological (1084 cases vs. 1458 CTL), protein (6753 cases vs. 9613 CTL), cytokine (975 cases vs. 1350 CTL) and lipid (1212 cases vs. 1556 CTL). This review provides a detailed analysis of the haematological profile in T2DM patients, highlighting fundamental changes such as increased white blood cells and platelet counts, accompanied by decreases in red blood cell counts and iron absorption. In the serum protein profile, a reduction in albumin and anti-inflammatory cytokines was noted along with an increase in globulin levels and pro-inflammatory cytokines. Furthermore, changes in lipid profiles were discussed, specifically the decreases in high-density lipoprotein (HDL) and the increases in low-density lipoprotein (LDL) and triglycerides. Understanding the changes in these four biomarker profiles is essential for developing innovative strategies to create diagnostic and prognostic tools for diabetes management.

Revolutionizing Brain Drug Delivery: Buccal Transferosomes on the Verge of a Breakthrough.

The buccal cavity, also known as the oral cavity, is a complex anatomical structure that plays a crucial role in various physiological processes. It serves as a gateway to the digestive system and facilitates the initial stages of food digestion and absorption. However, its significance extends beyond mere digestion as it presents a promising route for drug delivery, particularly to the brain. Transferosomes are lipid-based vesicles that have gained significant attention in the field of drug delivery due to their unique structure and properties. These vesicles are composed of phospholipids that form bilayer structures capable of encapsulating both hydrophilic and lipophilic drugs. Strategies for the development of buccal transferosomes for brain delivery have emerged as promising avenues for pharmaceutical research. This review aims to explore the various approaches and challenges associated with harnessing the potential of buccal transferosomes as a means of enhancing drug delivery to the brain. By understanding the structure and function of both buccal tissue and transferosomes, researchers can develop effective formulation methods and characterization techniques to optimize drug delivery. Furthermore, strategic approaches and success stories in buccal transferosome development are highlighted, showcasing inspiring examples that demonstrate their potential to revolutionize brain delivery.

Serum lipid profile in adolescents and adults with acne vulgaris receiving isotretinoin.

Background: Acne vulgaris is a chronic, inflammatory disease and one of the most common skin diseases. Isotretinoin is the best treatment for severe nodulocystic acne compared to other systemic medicine. Although serum lipids elevation is one of the side effects of this medicine; recent studies have shown controversial results. This study aimed to assess the serum lipid profile in adolescents and adults with acne vulgaris receiving isotretinoin. Methods: This is a cross-sectional study on 65 adolescents and adults older than 16 years old (55 females and 10 males) with moderate to severe degrees of acne vulgaris under a fixed low dose of 20 mg/day Isotretinoin treatment for 120 days. We analyzed the data using the SPSS software Version 16 using paired sample t-test, Wilcoxon, and ANCOVA test. Results: In this study, 65 records of patients with a mean age of 22.21±6.25 years were assessed. There was a significant elevation in Cholesterol and LDL levels, but in HDL and triglyceride levels no significant change occurred. A significant change in cholesterol levels was noticed in the adolescent age group, the female sex, and the normal weight group. Triglyceride had a significant change in the female sex and normal weight group and HDL significantly increased in male patients. Conclusion: Although a low dose of isotretinoin can be used with minimal concern for changes in lipid profile in acne vulgaris patients, in the long-term follow-up and treatment, it seems that we have to administer it cautiously.

Skin Lipid Barrier: Structure, Function and Metabolism.

Lipids are important skin components that provide, together with proteins, barrier function of the skin. Keratinocyte terminal differentiation launches unique metabolic changes to lipid metabolism that result in the predominance of ceramides within lipids of the stratum corneum (SC)-the very top portion of the skin. Differentiating keratinocytes form unique ceramides that can be found only in the skin, and generate specialized extracellular structures known as lamellae. Lamellae establish tight hydrophobic layers between dying keratinocytes to protect the body from water loss and also from penetration of allergens and bacteria. Genetic and immunological factors may lead to the failure of keratinocyte terminal differentiation and significantly alter the proportion between SC components. The consequence of such changes is loss or deterioration of skin barrier function that can lead to pathological changes in the skin. This review summarizes our current understanding of the role of lipids in skin barrier function. It also draws attention to the utility of testing SC for lipid and protein biomarkers to predict future onset of allergic skin diseases.

Early antibody responses to lipid antigens in red deer infected with Mycobacterium bovis.

THE PROBLEM: Early and rapid diagnosis of bovine tuberculosis remains an issue of great interest. AIM: The aim of this study was to evaluate the use of synthetic lipid antigens for diagnosis of tuberculosis in red deer (Cervus elaphus). The proposition: Synthetic mycolic acid derivatives, identical to components of mycobacterial cells, bind to antibodies to lipids produced in active human tuberculosis. Experimental infection studies in red deer (Cervus elaphus) allow the evaluation of such antigens for the serodiagnosis of bovine tuberculosis. RESULTS: Antibody levels in plasma from deer experimentally infected with Mycobacterium bovis were evaluated in ELISA using synthetic antigens based on several classes of mycolic acid, using protein G as conjugate. All antigens gave significantly increased responses 60 days post-infection, when all animals had active disease. A significantly increased response was also observed with four antigens 15 days after infection. CONCLUSION: ELISA using synthetic lipid antigens not only detects antibodies in the plasma of deer experimentally infected with M. bovis, but a strong response occurs early in the infection. With a full analysis of responses with naturally infected animals, this may offer a useful supplement to current diagnostic methods.