Conditions that sustain constant bacterial growth are seldom found in nature. Oligotrophic environments and competition among microorganisms force ba

In gram-negative bacteria, a pathway for aerobic degradation of phenylacetic acid (PAA) that proceeds via phenylacetyl-coenzyme A (CoA) and hydrolytic ring fission plays a central role in the degradation of a range of aromatic compounds. In contrast, the PAA pathway and its role are not well characterized in gram-positive bacteria. A cluster including 13 paa genes encoding enzymes orthologous to those of gram-negative bacteria was identified on the chromosome of Rhodococcus sp. strain RHA1. These genes were transcribed during growth on PAA, with 11 of the genes apparently in an operon yielding a single transcript. Quantitative proteomic analyses revealed that at least 146 proteins were more than twice as abundant in PAA-grown cells of RHA1 than in pyruvate-grown cells. Of these proteins, 29 were identified, including 8 encoded by the paa genes. Knockout mutagenesis indicated that paaN , encoding a putative ring-opening enzyme, was essential for growth on PAA. However, paaF , encoding phenylacetyl-CoA ligase, and paaR , encoding a putative regulator, were not essential. paaN was also essential for growth of RHA1 on phenylacetaldehyde, phenylpyruvate, 4-phenylbutyrate, 2-phenylethanol, 2-phenylethylamine, and l -phenylalanine. In contrast, growth on 3-hydroxyphenylacetate, ethylbenzene, and styrene was unaffected. These results suggest that the range of substrates degraded via the PAA pathway in RHA1 is somewhat limited relative to the range in previously characterized gram-negative bacteria.

Background: The practice of Female Genital Mutilation (FGM), a deeply-rooted tradition in 28 countries in Sub-Saharan Africa, carries important negative consequences for the health and quality of life of women and children. Migratory movements have brought this harmful traditional practice to our medical offices, with the subsequent conflicts related to how to approach this healthcare problem, involving not only a purely healthcare-related event but also questions of an ethical, cultural identity and human rights nature. Methods: The aim of this study was to analyse the perceptions, degree of knowledge, attitudes and practices of the primary healthcare professionals in relation to FGM. A transversal, descriptive study was performed with a self-administered questionnaire to family physicians, paediatricians, nurses, midwives and gynaecologists. Trends towards changes in the two periods studied (2001 and 2004) were analysed. Results: A total of 225 (80%) professionals answered the questionnaire in 2001 and 184 (62%) in 2004. Sixteen percent declared detection of some case in 2004, rising three-fold from the number reported in 2001. Eighteen percent stated that they had no interest in FGM. Less than 40% correctly identified the typology, while less than 30% knew the countries in which the practice is carried out and 82% normally attended patients from these countries. Conclusion: Female genital mutilations are present in primary healthcare medical offices with paediatricians and gynaecologists having the closest contact with the problem. Preventive measures should be designed as should sensitization to promote stands against these practices.

This paper reports physiological and genetic data about the type strain Gordonia cholesterolivorans , a strain that is able to degrade steroid compounds containing a long carbon side chain such as cholesterol (C ₂₇ ), cholestenone (C ₂₇ ), ergosterol (C ₂₈ ), and stigmasterol (C ₂₉ ). The length of the carbon side chain appears to be of great importance for this bacterium, as the strain is unable to grow using steroids with a shorter or nonaliphatic carbon side chain such as cholic acid (C ₂₄ ), progesterone (C ₂₁ ), testosterone, androsterone, 4-androstene-3,17-dione (all C ₁₉ ), and further steroids. This study also demonstrates that the degradation of cholesterol is a quite common feature of the genus Gordonia by comparing Gordonia cholesterolivorans with some other species of this genus (e.g., G. sihwensis , G. hydrophobica , G. australis , and G. neofelifaecis ). Pyrosequencing of the genome of G. cholesterolivorans led to the identification of two conventional cholesterol oxidase genes on an 8-kb and a 12.8-kb genomic fragment with genetic organizations that are quite unique as compared to the genomes of other cholesterol-degrading bacteria sequenced so far. The identified two putative cholesterol oxidases of G. cholesterolivorans are both intracellularly acting enzymes of the class I type. Whereas one of these two cholesterol oxidases (ChoOx-1) shows high identity with an oxidoreductase of the opportunistic pathogen G. bronchialis and is not transcribed during growth with cholesterol, the other one (ChoOx-2) appears phylogenetically closer to cholesterol oxidases from members of the genus Rhodococcus and is transcribed constitutively. By using targeted gene disruption, a G. cholesterolivorans ChoOx-2 gene mutant strain that was unable to grow with steroids was obtained.