Myxobacteria isolated in Israel as potential source of new anti-infectives.

AIMS: To evaluate the patterns of the production of antimicrobial compounds by Israeli myxobacteria newly isolated from soil samples and barks by a battery of isolation and purification methods. METHODS AND RESULTS: A total of 100 myxobacteria belonging to five of the 12 described genera, were isolated from 48 soil and 45 tree bark samples collected in different areas inside the State of Israel. Four isolation methods based on the peculiar metabolic and cell cycle aspects of myxobacteria, were combined with purification procedures and optimization of cultivation conditions. Ninety-seven strains were fermented and screened for antimicrobial activities. Production of antimicrobial activities was detected in 62 isolates. More than 50% of the collection (54 strains) was able to inhibit Escherichia coli growth. CONCLUSIONS: The results of this study support the idea that myxobacterial strains can be isolated from particular habitats and then cultivated and screened for their capacity to produce secondary metabolites endowed with antibacterial and antifungal activities. Myxovirescin, a typical poliketide myxobacterial antibiotic, has been identified in one Israeli isolate. Althiomycin, a thiazolyl peptide, which inhibits prokaryotic protein synthesis, usually produced by actinomycetes, was detected in three strains selected in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: The results confirm that myxobacteria are prolific producers of a variety of bioactive secondary metabolites including antibacterial and antifungal compounds, being their high frequency of anti-Gram-negative activities particularly appealing for the current anti-infective research. So far their screening has often been hampered because their isolation is time-consuming and are quite difficult to handle and cultivate. In this paper we demonstrate that a proper combination of isolation, purification and cultivation methods allow their pharmaceutical exploitation.

The sick neonate as centre of parents/health staff relationship.

In this research we analyze which psychical reaction a neonate's hospitalization can have on parents, the evolution of their feelings, which functions doctors and nurses fulfil towards the baby and his/her parents. Disappointment and psychical suffering make to the mother difficult to put the attachment's process to the child into practice. A refusal reaction generally follows the shock and responsibilities are frequently projected on an external object, for instance the gynaecologist, rather than to search the guilt into herself. The mother can evade treatments, because she considers herself not able to take care of him/her. The father usually lets his baby to become a member of the family, he is the first one who becomes fond of the child. Mothers become estranged from the neonate to avoid becoming fond of him/her: they are afraid he/she dies and they keep an emotional distance to shelter themselves from pain. The doctor is invested by parents and nurses with full powers and aggressiveness when things go wrong. It is helpful to the mother to externalize the blame on him/her, but he/she protects himself/herself from being involved, because his/her function is to attend physical health and to remedy child's damages. Treatment of parent's suffering does not concern the doctor or the nurse. It is necessary a different professional figure to recover and reconstruct the relationship between child and parents. The nurse attends children applying their efforts for him/her. Each mother chooses a nurse with whom she identifies herself. In the most serious pathologies the mother identifies herself with a professional nurse: when a mother expresses sentiments of jealousy towards nurses we can be satisfied with the work done.

Antimicrobial activity of MDL 63,246, a new semisynthetic glycopeptide antibiotic.

MDL 63,246 is a semisynthetic derivative of the naturally occurring glycopeptide antibiotic MDL 62,476 (A40926). It was more active in vitro against Staphylococcus aureus and coagulase-negative staphylococci than MDL 62,476, teicoplanin, and vancomycin and was more active than mideplanin (MDL 62,873) against some isolates. MDL 63,246 had excellent activity against streptococci and teicoplanin-susceptible enterococci, and it also had in vitro activity against some VanA enterococcal isolates. It was more active than teicoplanin and vancomycin against acute staphylococcal, streptococcal, and enterococcal septicemia in immunocompetent and neutropenic mice. It was highly efficacious in reducing the bacterial load in the hearts of rats in staphylococcal endocarditis experiments and the bacterial load of Staphylococcus epidermis in a high infection model in neutropenic mice. The excellent in vivo activity of MDL 63,246 appears to correlate both with its in vitro antibacterial activity and with its long half-life in rodents.