Evidence of Transfer by Conjugation of Type IV Secretion System Genes between Bartonella Species and Rhizobium radiobacter in Amoeba

Background: Bartonella species cospeciate with mammals and live within erythrocytes. Even in these specific niches, it has been recently suggested by bioinformatic analysis of full genome sequences that Lateral Gene Transfer (LGT) may occur but this has never been demonstrated biologically. Here we describe the sequence of the B. rattaustraliani (AUST/NH4 T) circular plasmid (pNH4) that encodes the tra cluster of the Type IV secretion system (T4SS) and we eventually provide evidence that Bartonella species may conjugate and exchange this plasmid inside amoeba. Principal Findings: The T4SS of pNH4 is critical for intracellular viability of bacterial pathogens, exhibits bioinformatic evidence of LGT among bacteria living in phagocytic protists. For instance, 3 out of 4 T4SS encoding genes from pNH4 appear to be closely related to Rhizobiales, suggesting that gene exchange occurs between intracellular bacteria from mammals (bartonellae) and plants (Rhizobiales). We show that B. rattaustraliani and Rhizobium radiobacter both survived within the amoeba Acanthamoeba polyphaga and can conjugate together. Our findings further support the hypothesis that tra genes might also move into and out of bacterial communities by conjugation, which might be the primary means of genomic evolution for intracellular adaptation by cross-talk of interchangeable genes between Bartonella species and plant pathogens. Conclusions: Based on this, we speculate that amoeba favor the transfer of genes as phagocytic protists, which allows fo

Perspectives and Potential Applications of Mitochondria-Targeted Antioxidants in Cardiometabolic Diseases and Type 2 Diabetes

There is abundant evidence to suggest that mitochondrial dysfunction is a main cause of insulin resistance and related cardiometabolic comorbidities. On the other hand, insulin resistance is one of the main characteristics of type 2 diabetes, obesity, and metabolic syndrome. Lipid and glucose metabolism require mitochondria to generate energy, and when O2 consumption is low due to inefficient nutrient oxidation, there is an increase in reactive oxygen species, which can impair different types of molecules, including DNA, lipids, proteins, and carbohydrates, thereby inducing proinflammatory processes. Factors which contribute to mitochondrial dysfunction, such as mitochondrial biogenesis and genetics, can also lead to insulin resistance in different insulin-target tissues, and its association with mitochondrial dysfunction can culminate in the development of cardiovascular diseases. In this context, therapies that improve mitochondrial function may also improve insulin resistance. This review explains mechanisms of mitochondrial function related to the pathological effects of insulin resistance in different tissues. The pathogenesis of cardiometabolic diseases will be explained from a mitochondrial perspective and the potential beneficial effects of mitochondria-targeted antioxidants as a therapy for modulating mitochondrial function in cardiometabolic diseases, especially diabetes, will also be considered.Contract grant sponsor: PI10/1195; Contract grant sponsor: PI 12/1984; Contract grant sponsor: CIBERehd CB06/04/0071; Contract grant sponsor: PROMETEO 2010/060; Contract grant sponsor: ACOMP/2012/042; Contract grant sponsor: ACOMP/2012/045; Contract grant sponsor: ACOMP2013/061; Contract grant sponsor: European Regional Development Fund (ERDF)

Anthropometric studies in diabetes in the tropics

Anthropometric studies were carried out in three groups of diabetics seen in southern India, namely fibrocalculous pancreatic diabetes (FCPD) (n=49) (a subtype of malnutrition related diabetes), insulin dependent diabetes mellitus (IDDM) (n=55) and non-insulin dependent diabetes mellitus (NIDDM) (n=104). Both FCPD and IDDM had significantly lower body mass index, skinfold thickness (triceps, biceps, subscapular and suprailiac), mid-arm circumference and fat mass compared to controls and NIDDM patients, (p<0.001 for all parameters). FCPD and IDDM males did not show any significant differences in any of the anthropometric parameters studied. Among the females, FCPD had lower triceps skinfold measurements (p=0.007) and mid-arm circumferences (p<0.05) compared to IDDM patients. Patients with NIDDM did not show any significant difference compared to the control group. This study shows that both FCPD and IDDM patients have lower body mass and fat mass compared to NIDDM patients and control subjects

Xenobiotics and tropical chronic pancreatitis

The prevalence of chronic pancreatitis in tropical zones is far higher than in temperate zones, but there is no explanation for this difference. Detailed social, occupational, and dietary histories were taken from 79 patients attending two hospitals in Madras, South India. There were 53 apparently sporadic cases with both pancreatic calculi and diabetes; six apparently sporadic cases with noncalcific disease, usually with diabetes; four pairs of first-degree relatives with either calcific or noncalcific disease, with or without diabetes; and two families in which several members had one or another variant of the disease. Three trends emerged from these histories: 1. Regular exposure to a xenobiotic inducer of cytochromes P450I (smoke from cigarets, burning firewood, or vehicle emissions; a cooking oil composed of C18:2 fatty acids); 2. Concurrent exposure to a chemical that undergoes metabolic activation (petroleum products, notably kerosene fumes; cyanogenic glycosides; solvents; paint); and 3. Low intakes of micronutrients required to synthesize/refurbish glutathione. These trends, similar to those noted at Manchester, North West England, suggest a unifying template for tissue damage in chronic pancreatitis, namely, heightened but unmitigated oxidative detoxification reactions mediated by cytochromes P450. The higher prevalence of the disease in underprivileged communities of the tropics may reflect poorer dietary availability of micronutrient antioxidants