The Abundance of Lactic Acid Bacteria in the Gastrointestinal Tract of Lake Victoria Nile Perch

This study was carried out to determine the presence and abundance of lactic acid from gastrointestinal tracts of Latesniloticus fish with the specific objective of determining fish size effect on lactic acid bacteria (LAB) population. The study was conducted in Lake Victoria between April-June and July-September, 2014. Statistical analysis was performed by using Minitab 9.1.3 software version. Analysis of Variance (ANOVA) and east significant difference (LSD) was used for statistical comparisons. Differences were considered significant at α=0.05 level.  The average weight of small fish sampled during the wet season was 667.9g that gave an average colony forming units/g of 9.2x 103; medium averaging 1485.1g had an average of 2.1x104cfu and big averaging 3210.8g had 4.9 x 104cfu. In the dry spells, the small fish averaging 614.6g had 6.7 x 103, medium averaging 1392.9g had an average of 1.7x104cfu and big averaging 2756.3g had 3.4 x 104cfu. The mean of counts of LABs are significantly different for the three sizes tested, with the big size giving the highest followed by medium and small respectively. This could be due to ability to access more variety of foods. The means of counts of LABs are insignificantly different for the eight sites tested. The mean of counts of LABs are significantly different for the wet and dry seasons tested. In conclusion, this study showed availability of lactic acid bacteria in the gut of Lake Victoria Nile perch which can be used as a source of potential bio preservative. Key words: Lactic Acid Bacteria (LAB), Gastrointestinal tracts, Nile perch, L. Victoria, ANOVA

Chitosan nanoencapsulation of flavonoids enhances their quorum sensing and biofilm formation inhibitory activities against an E.coli Top 10 biosensor

Phytochemicals have been found to be promising alternatives to conventional antibiotic therapies for the control of bacterial infections, as they may entail less selective pressure and hence reduce the development of resistance. This study involved examining the inhibition of biofilm formation and of quorum sensing (QS), and the cytotoxicity on mammalian cells of two flavonoids, quercetin and baicalein, in freeform and associated into chitosan-based nanocapsules. This was done by use of a transformed E. coli Top10 biosensor strain, while the cytotoxicity was evaluated on MDCK-C7 cells. In free form, application both flavonoids exhibited slight inhibitory activity on the QS response and biofilm formation, a scenario that was improved positively upon encapsulation with chitosan (Mw ∼115,000 g/mol and DA ∼42%). The association efficiency of 99% (quercetin) and 87% (baicalein) was determined, and each formulation had an average diameter of 190 ± 4 and 187 ± 2 nm, and zeta ( ) potential of +48.1 ± 2.03 and +48.4 ± 3.46 mV, respectively. Both types of systems were stable against aggregation in M9 and MEM media. The in vitro release kinetics data of both flavonoids seemed to be similar with only ∼20% released over the first 5 h, or∼10% over the first 4 h, respectively, with subsequent sudden release increase up to ∼40% in both cases.The free phytochemicals seemed to be cytotoxic to MDCK-C7 cells at higher doses, however, upon nanoencapsulation, a cytoprotective effect was evidenced. We have gained proof-of-principle of the advantages of encapsulation of two bioactive flavonoids

Antimicrobial, cytotoxicity and preliminary phytochemical determination of commonly used medicinal plants to treat oral cavity, urinary tract and gut infections by inhabitants of Borabu sub-county, Nyamira County, Kenya

Aims: The study aimed at determining the antimicrobial activities and cytotoxicity properties of medicinal plants collected from southwestern Kenya. Methods and results: A total of 23 ethanol extracts of selected medicinal plants were bio-assayed against Gram-negative bacterial strains (Escherichia coli NU14, Helicobacter pylori ATCC 700824, and Porphyromonas gingivalis ATCC 33277). Cytotoxicity tests were also carried out on mammalian cell lines (AGS, KB, and TR146). Preliminary type of phytochemical compounds present in the extracts was determined by thin-layer chromatography. Cassia didymobotrya plant extract (1 mg/mL) had strong antimicrobial activity against P. gingivalis (average zone of inhibition of 21.70 ± 0.88 mm, MIC 0.13 ± 0.00 mg/mL and MBC 0.50 ± 0.00 mg/mL). E. coli was resistant to all the extracts bioassayed. Leonotis nepetifolia (15.80 ± 0.20 mm) and Clerodendrum myriacoides (14.20 ± 0.44 mm) showed only moderate activity against H. pylori. Cell cytotoxicity results indicated a dose-dependent response against KB, TR146 and AGS cell lines with C. didymobotrya having IC50 values of 47.64 and 704.00 µg/mL on KB and TR146 cell lines, respectively. L. nepetifolia and C. myriacoides did produce IC50 of 0.1883 mg/mL and 0.1061 mg/mL against the AGS cell line respectively. Conclusion, significance and impact of the study: Most of the extracts had no or weak activity against test isolates, but C. didymobotrya leaves extracts showed strong activity against P. gingivalis. C. didymobotrya can offer alternative medicare to P. gingivalis conditions

Distinct microRNA and protein profiles of extracellular vesicles secreted from myotubes from morbidly obese donors with type 2 diabetes in response to electrical pulse stimulation

Lifestyle disorders like obesity, type 2 diabetes (T2D), and cardiovascular diseases can be prevented and treated by regular physical activity. During exercise, skeletal muscles release signaling factors that communicate with other organs and mediate beneficial effects of exercise. These factors include myokines, metabolites, and extracellular vesicles (EVs). In the present study, we have examined how electrical pulse stimulation (EPS) of myotubes, a model of exercise, affects the cargo of released EVs. Chronic low frequency EPS was applied for 24 h to human myotubes isolated and differentiated from biopsy samples from six morbidly obese females with T2D, and EVs, both exosomes and microvesicles (MV), were isolated from cell media 24 h thereafter. Size and concentration of EV subtypes were characterized by nanoparticle tracking analysis, surface markers were examined by flow cytometry and Western blotting, and morphology was confirmed by transmission electron microscopy. Protein content was assessed by high-resolution proteomic analysis (LC-MS/MS), non-coding RNA was quantified by Affymetrix microarray, and selected microRNAs (miRs) validated by real time RT-qPCR. The size and concentration of exosomes and MV were unaffected by EPS. Of the 400 miRs identified in the EVs, EPS significantly changed the level of 15 exosome miRs, of which miR-1233-5p showed the highest fold change. The miR pattern of MV was unaffected by EPS. Totally, about 1000 proteins were identified in exosomes and 2000 in MV. EPS changed the content of 73 proteins in exosomes, 97 in MVs, and of these four were changed in both exosomes and MV (GANAB, HSPA9, CNDP2, and ATP5B). By matching the EPS-changed miRs and proteins in exosomes, 31 targets were identified, and among these several promising signaling factors. Of particular interest were CNDP2, an enzyme that generates the appetite regulatory metabolite Lac-Phe, and miR-4433b-3p, which targets CNDP2. Several of the regulated miRs, such as miR-92b-5p, miR-320b, and miR-1233-5p might also mediate interesting signaling functions. In conclusion, we have used a combined transcriptome-proteome approach to describe how EPS affected the cargo of EVs derived from myotubes from morbidly obese patients with T2D, and revealed several new factors, both miRs and proteins, that might act as exercise factors

Lifestyle and diet in relation to risk of type 2 diabetes in Vietnam: a hospital-based case-control study.

BACKGROUND: Lifestyle and diet are important determinants of type 2 diabetes (T2D). Their impact on T2D can be evaluated using clinical and epidemiological approaches. Randomised controlled trials are the most rigorous design but expensive to conduct, whereas prospective cohort studies are time-consuming and less powerful for populations with a low incidence of the disease. Case-control studies are considered appropriate in resource-limited settings. A hospital-based case-control study protocol has been developed to investigate the role of lifestyle and dietary factors in T2D aetiology for adults in Vietnam. METHODS: A total of 1100 patients aged 40-65 years (550 T2D cases and 550 controls) will be recruited from a tertiary hospital in Hanoi, the capital city of Vietnam. Cases and controls will be frequency-matched on age (±3 years), gender, and residential location. T2D will be diagnosed according to the 2006 World Health Organisation criteria. Habitual physical activity will be assessed by the Vietnamese version of the International Physical Activity Questionnaire-Short Form. Food and beverage consumption will be ascertained using a Validated Food Frequency Questionnaire, specifically developed for the Vietnamese population. Information on demographic and other personal characteristics will be collected, together with anthropometric and blood pressure measurements. Descriptive statistics and unconditional logistic regression analyses will be performed to examine factors associated with the T2D prevalence. DISCUSSION: The proposed study will elucidate the role of lifestyle and diet in T2D prevalence among Vietnamese adults. Findings concerning pertinent factors will provide epidemiological evidence for the development of focused interventions, and contribute to the formulation of national policies to prevent and control T2D in Vietnam

Risk factors and control strategies for antibiotic residues in milk at farm level in Kenya

Antibiotic residues in milk in Kenya constitute a problem and there is strong interest to enhance milk safety. The research sought to establish whether the prevention of residues in milk was viable at the farm level. It also evaluated implications of non-restricted use of antibiotics in terms of resistance among Staphylococcus aureus isolates from the small and large-scale farms, which are the two main producer categories in the country. The research demonstrated the possible use of a low cost microbiological screening assay (two-tube test) for detection of antibiotic residues in a local dairy. The verified limits of detection for selected antibiotics were below or near established Codex Alimentarius standards. During 2000–2001, 14.9% of the analysed 1109 herd milk samples caused inhibition in the microbial test. Eleven percent (n=118) of the samples had ß-lactam type residues in concentrations ≥ 10µg/kg exceeding established limits two fold and the contamination differed significantly (p<0.001) among the two types of producers. Circumstantial evidence was provided between rising incidence of antibiotics and prevalence of drug resistant S. aureus isolates from mastitis milk. The isolates were tested for susceptibility to five antibiotics from different families. The overall mean prevalence of multidrug resistance from 402 isolates was 34.3% for small and 18.0% for large-scale farms (p < 0.05). Five characteristics were identified based on Hazard Analysis Critical Control Point principles, which predicted residue contamination on farms and were associated with a higher risk (p < 0.05). The characteristics were used to develop a simple risk assessment tool, which was validated in local and remote cohort farms. The tool was then applied in a single blind randomised control study on small-scale farms (42 cases and 42 controls) alongside the two-tube test. A 52% reduction in incidence of antibiotic residue violation was observed in the treatment group compared to the control farms (p < 0.05). The risk assessment tool and the two-tube screening assay were concluded to offer a viable strategy to minimize violative antibiotic residues in farm milk within a control program. The results suggest that this approach could also be implemented on other farms in low-income countries

Sensitivity of the improved Dutch tube diffusion test for detection of antimicrobial residues in Kenyan Milk.

The sensitivity of the improved two-tube test for detection of antimicrobial residues in Kenyan milk was investigated by comparison with the commercial Delvo test SP. Suspect positive milk samples (n =244) from five milk collection centers, were analyzed with the improved two-tube and the commercial Delvo SP test as per manufacturer, weekly over a ten-week period. The 't' test statistic was utilised based on the hypothesis: H0: Ud = 0 (U2 - U1 = Ud) and Ha: Ud > 0 (one-sided test) to analyse the results. The t calculated was compared to the tabulated t value at p = 0.05 for ten degrees of freedom. The results suggest that the improved two-tube test has some improved effect on the sensitivity for antimicrobials residues in comparison to the commercial Delvo test. Utilizing the improved two-tube test could lead to an improvement in sensitivity for antimicrobial residues. The Journal of Food Technology in Africa Volume 6 Number 1 (January-March 2001), pp. 5-7 KEY WORDS: milk, antimicrobial residues, Bacillus stearothermophilus var. calidolactis. Maximum residual limits (MRLs), Improved two-tube test

Sensitivity of the improved Dutch tube diffusion test for detection of antimicrobial residues in Kenyan milk

The sensitivity of the improved two-tube test for detection of antimicrobial residues in Kenyan milk was investigated by comparison with the commercial Delvo test SP. Suspect positive milk samples (n =244) from five milk collection centers, were analyzed with the improved two-tube and the commercial Delvo SP test as per manufacturer, weekly over a ten-week period. The 't' test statistic was utilised based on the hypothesis: H0: Ud = 0 (U2 ­ U1 = Ud) and Ha: Ud > 0 (one-sided test) to analyse the results. The t calculated was compared to the tabulated t value at p = 0.05 for ten degrees of freedom. The results suggest that the improved two-tube test has some improved effect on the sensitivity for antimicrobials residues in comparison to the commercial Delvo test. Utilizing the improved two-tube test could lead to an improvement in sensitivity for antimicrobial residues