<Emphasis Type="Italic">Staphylococcus epidermidis</Emphasis>: A differential trait of the fecal microbiota of breast-fed infants

Background  

Breast milk is an important source of staphylococci and other bacterial groups to the infant gut. The objective of this work was to analyse the bacterial diversity in feces of breast-fed infants and to compare it with that of formula-fed ones. A total of 23 women and their respective infants (16 breast-fed and 7 formula-fed) participated in the study. The 16 women and their infants provided a sample of breast milk and feces, respectively, at days 7, 14, and 35. The samples were plated onto different culture media. Staphylococcal and enterococcal isolates were submitted to genetic profiling and to a characterization scheme, including detection of potential virulence traits and sensitivity to antibiotics.     

Phylogenetic dimension of tree communities reveals high conservation value of disturbed tropical rain forests

Aim

The conversion of old‐growth tropical forests into human‐modified landscapes threatens biodiversity worldwide, but its impact on the phylogenetic dimension of remaining communities is still poorly known. Negative and neutral responses of tree phylogenetic diversity to land use change have been reported at local and landscape scales. Here, we hypothesized that such variable responses to disturbance depend on the regional context, being stronger in more degraded rain forest regions with a longer history of land use.

Location

Six regions in Mexico and Brazil.

Methods

We used a large vegetation database (6,923 trees from 686 species) recorded in 98 50‐ha landscapes distributed across two Brazilian and four Mexican regions, which exhibit different degrees of disturbance. In each region, we assessed whether phylogenetic alpha and beta diversities were related to landscape‐scale forest loss, the percentage of shade‐intolerant species (a proxy of local disturbance) and/or the relatedness of decreasing (losers) and increasing (winners) taxa.

Results

Contrary to our expectations, the percentage of forest cover and shade‐intolerant species were weakly related to phylogenetic alpha and beta diversities in all but one region. Loser species were generally as dispersed across the phylogeny as winner species, allowing more degraded, deforested and species‐poorer forests to sustain relatively high levels of evolutionary (phylogenetic) diversity.

Main conclusion

Our findings support previous evidence indicating that traits related to high susceptibility to forest disturbances are convergent or have low phylogenetic signal. More importantly, they reveal that the evolutionary value of disturbed forests is (at least in a phylogenetic sense) much greater than previously thought.

     

Effect of high pressure on the reduction of microbial populations in vegetables

Resistance of micro-organisms to high pressure is variable and directly related to extrinsic and intrinsic factors. Pressures of 100, 200, 300, 350 and 400 MPa were applied at 20°C for 10 min and at 10°C for 20 min using strains of Gram-positive and Gram-negative bacteria, moulds and yeasts, as well as spores of Gram-positive bacteria. The results showed that at pressures of 100 and 200 MPa, decreases in microbial populations were not significant, whereas the populations of all the micro-organisms tested decreased considerably at a pressure of 300 MPa. A pressure of 300 MPa at 10°C for 20 min was required to completely reduce the population of Saccharomyces cerevisiae , and a pressure of 350 MPa was needed to reduce most of the Gram-negative bacteria and moulds. The Gram-positive bacteria were more resistant, and pressures of 400 MPa were unable to completely reduce their populations. The different pressures employed had little effect on the initial numbers of spores. The initial populations of viable aerobic mesophiles and moulds and yeasts in vegetables (lettuce and tomatoes) decreased 1 log unit at pressures of 300 MPa and above under both sets of experimental treatment conditions. However, treatment at that pressure also resulted in alterations in the organoleptic properties of the samples. In the tomatoes, the skin loosened and peeled away, though the flesh remained firm, and colour and flavour were unchanged. The lettuce remained firm but underwent browning; flavour was unaffected. In vegetables use of moderate pressures in combination with other treatment conditions would appear to be required to reduce the populations of contaminating micro-organisms while avoiding the undesirable alterations in organoleptic properties that take place at 300 MPa.     

A New species of Periandra (Leguminosae: Lotoideae) from the Planalto of Brazil

Periandra gracilis is described, the type locality of this very rare species being the Parque Municipal do Gama, Distrito Federal. Thus far this species is known only from the type locality.     

A new species of Camptosema (Leguminosae: Lotoideae) from the Planalto of Brazil

Camptosema douradense (Leguminosae: Lotoideae) is described. The species is known only from the type locality and its vicinity, the summit of the Serra Dourada near the town of Goiás Velho in the State of Goiás, Brazil.