Saccharomyces cerevisiae fermentation products reduce bacterial endotoxin concentrations and inflammation during grain-based subacute ruminal acidosis in lactating dairy cows.

Subacute ruminal acidosis (SARA) is a metabolic disorder in dairy cows that is associated with dysbiosis of rumen and hindgut microbiomes, translocation of immunogenic compounds from the gut lumen into blood circulation, and systemic inflammatory response. In this study we hypothesized that Saccharomyces cerevisiae fermentation products (SCFP) attenuate the increases in ruminal and peripheral bacterial endotoxin concentrations and the inflammation resulting from repeated induction of SARA. Lactating Holstein dairy cows (parity 2 and 3+, n = 32) were fed diets with or without SCFP (all from Diamond V) and subjected to 2 episodes of SARA challenges. Cows received a basal total mixed ration (TMR) containing 34% neutral detergent fiber and 18.6% starch, dry matter (DM) basis. Treatments were randomly assigned to control (basal TMR and 140 g/d of ground corn with no SCFP) or 1 of 3 SCFP treatments: basal TMR and 14 g/d Original XPC (SCFPa), 19 g/d NutriTek (SCFPb-1×), or 38 g/d NutriTek (SCFPb-2×) mixed with 126, 121, or 102 g/d of ground corn, respectively. Treatments were implemented from 4 wk before until 12 wk after parturition. During wk 5 (SARA1) and wk 8 of lactation (SARA2), grain-based SARA challenges were conducted by gradually replacing 20% of DM of the basal TMR over 3 d with pellets containing 50% wheat and 50% barley. Ruminal fluid, fecal, and blood samples were collected weekly during Pre-SARA1 (wk 4, as baseline), Post-SARA1 (wk 7), and Post-SARA2 (wk 10 for blood and wk 12 for rumen and fecal parameters) stages, and twice a week during the challenges SARA1 and SARA2. Rumen papillae samples were taken only during Pre-SARA1 and Post-SARA2. We measured the concentrations of free lipopolysaccharides (LPS) in the rumen fluid and feces; free LPS and lipoteichoic acid (LTA) endotoxins in peripheral plasma; interleukin (IL)-1ß and IL-6 in peripheral serum; acute-phase proteins, serum amyloid A (SAA), and LPS-binding protein in peripheral plasma; haptoglobin (Hp) in peripheral serum; and myeloperoxidase (MPO) in rumen papillae. Induction of SARA episodes increased free LPS concentrations in rumen fluid and tended to increase LTA in peripheral plasma. The SARA episodes increased concentration of circulating SAA and tended to increase that of IL-1ß compared with Pre-SARA1. Induction of SARA did not affect the concentrations of circulating IL-6, Hp, and MPO. The SCFP supplementation reduced plasma concentrations of LTA and SAA and serum concentration of IL-1ß compared with control. Additionally, SCFPb-2× tended to reduce ruminal LPS in second-parity cows compared with control. Overall, SCFP supplementation appeared to stabilize the rumen environment and reduce proinflammatory status, hence attenuating adverse digestive and inflammatory responses associated with SARA episodes.

Patterns of drug resistance and RFLP analysis of Mycobacterium tuberculosis strains isolated from recurrent tuberculosis patients in Sri Lanka.

The aim of the study was to determine drug sensitivity and DNA fingerprints of Mycobacterium tuberculosis strains from retreatment cases of pulmonary tuberculosis. The study population consisted of 131 culture positive, retreatment tuberculosis patients admitted to the Chest Hospital, Welisara, Sri Lanka who had taken anti-tuberculosis drugs previously. Forty-eight percent of the isolates were susceptible to all 12 drugs tested. Twenty isolates were resistant to first line drugs, 28 to both first and second line drugs and 17 to second line drugs. Forty-six percent were resistant to a single drug, 23% to two and 19% to 3 drugs, respectively. Resistance to p-aminosalicylic acid (15%) was most common followed by ethambutol (14%), isoniazid and pyrazinamide (12%). Multi-drug resistance was present in four isolates. Using RFLP analysis the copy number and IS 6110 element in M. tuberculosis strains varied from one to seven, the majority having 3 to 5 copies. The prevalence of acquired drug resistance to individual drugs was comparatively lower except resistance to ethambutol. The majority of retreatment patients belonged to the defaulter category and this stresses the importance of implementing directly observed treatment short course and susceptibility testing of isolates in retreatment TB patients to prevent the spread of drug resistance. By using the IS 6110 genetic marker it was possible to differentiate most of the M. tuberculosis isolates. However, for an unambiguous confirmation of the identities of strains, additional genetic markers should be employed in strain typing such as spoligotyping.

The electrode reaction of Euglena gracilis cytochrome c-552 at edge-oriented pyrolytic graphite.

The direct electron transfer reaction of Euglena gracilis cytochrome c-552 at edge-oriented pyrolytic graphite electrodes was determined by cyclic voltammetry to be quasi-reversible, stable and reproducible. The presence of a persistent layer of irreversibly adsorbed cytochrome c-552 on the electrode surface was detected in these experiments. Heterogeneous electron transfer rate constants for both the diffusing and adsorbed forms of the protein are reported, and mechanistic aspects are addressed. The applicability of cytochrome c-552 as a complementarily charged analog of eucaryotic cytochrome c in interfacial bioelectrochemical studies is discussed.