Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microbial cooperation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Microbial contamination in allografted wound beds in patients with burns.

Microbial wound contamination has been recognized as a cause of autograft skin graft failure. Human cadaver allograft is believed to decrease or control microbial wound contamination, and by its adherence to the wound bed, to indicate a sufficiently low microbial count to allow successful application of autograft. Suboptimal "take" of more fragile cultured skin grafts after removal of adherent allograft led us to reexamine the microbial population of these wound beds. Immediately before autografts were placed, wound beds beneath adherent allograft were biopsied for quantitative microbiologic analysis. Eighty tissue biopsy specimens from 21 patients were examined. No patients had signs of infection or sepsis at the time of biopsy. Fifty-seven percent of all patients had positive cultures beneath adherent allograft skin. Twenty-one percent of all cultures revealed "infected" wound beds (greater than 100,000 colonies per gram), and 30% of all wounds were "colonized" (less than 100,000 colonies per gram). These data suggest that take and vascularization of allograft does not guarantee that a wound bed is free of microbial contamination.

Adolescent↗

The immune self: a selectionist theory of recognition, learning, and remembering within the immune system.

In this paper, I have briefly explored metaphors shared by the immune and nervous systems and shown that this exercise can lead to the elucidation of common principles of organization, as well as to predictions concerning how the immune system functions. Metaphor itself undoubtedly reflects the way in which we categorize and retrieve information 44], so it is not surprising that the deep processes of language tend to sample information from related data categories. Although the nervous and immune systems are obviously not the same and metaphors are indeed just that, my primary goal has been to suggest that by virtue of their having evolved in parallel over millions of years, the nervous and immune systems currently use the same archetypal principles and strategies to address related challenges in information processing and retrieval. Ultimately, nature is conservative. One need only look at a tree, a river, the airways, or the vascular bed in order to see how a fractal pattern of repetitive dichotomous branching has been used by each, in order to optimize the transport of fluids over large distances [45]. While each system has had to adopt different materials in order to solve the problem, the shape of their solutions is remarkably alike. In the immune and nervous systems, the elements used to produce optimal functional responses are also quite different, but again the solutions have been achieved by comparable strategies. I am certain that these two great systems of information processing, each responding with vastly different kinetics, will prove to be far more integrally interdependent than has been previously recognized. For example, should a swift response by the immune system be required in an overwhelming invasion by microbial pathogens, the immune system may be able to cooperate with the rapidly reacting nervous system to rid the host of the invaders. In this regard, we have shown that the beta-adrenergic hormone epinephrine rapidly increases the traffic of memory T-cells to mucosal sites, presumably representing an immune component of the fight-or-flight response [46]. Neural evolution appears to have as its goal the development of more efficient information processing systems that lead to higher levels of consciousness. However, in modern times, technologic advances in information processing have rapidly outstripped the slower adaptations that can be made by evolution. In order to satisfy his compulsive quest for information, man has recently developed and recruited the aid of computers.(ABSTRACT TRUNCATED AT 400 WORDS)

Association Learning↗

Health-associated key gut microbiota drives the variation in community metabolic interactions in non-human primates.

Gut microbiota often undergo metabolic cross-feeding and resource competition. However, our understanding of global variations in these interactions and their implications for host health remain elusive. By analyzing a microbial genome catalog from 841 fecal metagenomes across 53 primate species worldwide, we identified key microbiota assigned to two taxa, i.e., Bacillota_A and Pseudomonadota, which well predicted the trade-off of community-level interaction types between metabolic competition and cooperation. Specifically, Bacillota_A species were inherently competitive and amino acid auxotrophic and typically found in anaerobic habitats. In contrast, members of Pseudomonadota were inherently cooperative, siderophore producers, and more abundant in aerobic conditions. Random forest models successfully distinguished unhealthy gut samples from healthy samples through the key competitive and cooperative microbiota, suggesting potential links between community metabolic interactions and host health. Together, this study enhances our mechanistic understanding of microbial interaction dynamism within complex gut ecosystems, offering new targets for understanding host health.

Animals↗

Systematic review of Propionibacterium acnes resistance to systemic antibiotics.

OBJECTIVE: To document changes in the prevalence of resistance of Propionibacterium acnes to antibiotics used for treating acne. DATA SOURCES: MEDLINE and EMBASE were searched for publications on P. acnes resistance to systemic antibiotics. The search strategy mapped "acne" or "acne vulgaris" with the terms "antibiotic resistance" or "drug resistance, microbial". Only papers published in English during 1976 to 1997 were included in the search. STUDY SELECTION: 53 publications met the search criteria. The search output was refined by selecting papers that specifically addressed P. acnes resistance patterns. Additional studies (not included in the search output) were identified from review articles and references of the retrieved articles. Twelve articles were reviewed. DATA EXTRACTION: Data on the prevalence of antibiotic-resistant propionibacteria, the incidence of individual resistance phenotypes, mixed resistance, and correlation between poor therapeutic response and resistant propionibacteria were extracted. DATA SYNTHESIS: Research since 1978 has suggested an association between poor therapeutic response and antibiotic-resistant propionibacteria. The overall incidence of P. acnes antibiotic resistance has increased from 20% in 1978 to 62% in 1996. Resistance to specific antibiotics varied and was most commonly reported with erythromycin and clindamycin, tetracycline and doxcycline, and trimethoprim. Resistance to minocycline is rare. CONCLUSIONS: In many patients with acne, continued treatment with antibiotics can be inappropriate or ineffective. It is important to recognise therapeutic failure and alter treatment accordingly. The use of long-term rotational antibiotics is outdated and will only exacerbate antibiotic resistance.

Acne Vulgaris↗

Linezolid eradicates MRSA better than vancomycin from surgical-site infections.

BACKGROUND: The purpose of this analysis was to compare the efficacy of linezolid versus vancomycin in patients with suspected or proven gram-positive methicillin-resistant Staphylococcus aureus (MRSA) surgical-site infections. METHODS: An open-label, randomized, comparator-controlled, multicenter, multinational study was conducted in hospitalized patients. Patients were randomized 1:1 to receive linezolid 600 mg (intravenous [IV] or oral) every 12 hours (n = 66) or vancomycin 1 g every 12 hours IV (n = 69) for 7 to 21 days. Patients were assessed at the test-of-cure (TOC) visit, 7 days after completing therapy. RESULTS: Clinical success at TOC was documented in similar proportions of patients treated with linezolid or vancomycin. Of those with MRSA isolated, significantly more patients who received linezolid compared with those who received vancomycin were microbiologically cured (87% vs 48%, respectively; 95% confidence interval 16.51 to 60.27; P = 0.0022). CONCLUSION: Intravenous or oral linezolid was well tolerated and superior to vancomycin in treating patients with MRSA-infected surgical-site infections.

Acetamides↗

Quality control of Aspergillus flavus and A. parasiticus agar and comparison with dichloran 18% glycerol agar: a collaborative study.

AFPA culture medium, which is used for recognition of Aspergillus flavus and A. parasiticus, has been validated in a collaborative study including nine laboratories located in Australia, Brazil, Denmark, The Netherlands, Sweden and United Kingdom. Three freeze-dried fungal mixtures, containing A. flavus/A. parasiticus and background fungi, were produced and checked for homogeneity. The coefficients of variance were low, ranging from 0.81% to 1.09% for total fungal counts and between 2.50% and 2.72% for counts of A. flavus/A. parasiticus. The laboratories analysed the contents of two vials of each mixture on commercial A. flavus and A. parasiticus agar (AFPA), in-house-made AFPA, and on a standard media, dichloran 18% glycerol agar (DG18). Reproducibility values for counts of A. flavus/A. parasiticus indicated no differences between the commercial AFPA and the in-house-made AFPA. Variation between laboratories was low, indicating that the medium was effective in use. Reproducibility values for DG18 were higher. There were no differences in counts of A. flavus/A. parasiticus on AFPA and DG18. However, DG18 gave slightly higher total fungal counts compared to AFPA.

Agar↗

Surveillance of hospital-acquired infection in the Republic of Ireland: past, present and future.

There is increasing interest in the surveillance of hospital-acquired infection (HAI) in the Republic of Ireland due to a greater awareness of the consequences of antibiotic resistance, and consumer pressure in the form of public expectations of the quality of health care. To date there have been no nationwide prospective surveillance projects but surveillance has taken place in the form of participation in international and national studies, and the description of local outbreaks. Infection control teams and others have participated in projects such as a European study of HAI in intensive care units conducted in 1992, the second national prevalence study conducted in the UK in 1993 and two surveys of methicillin-resistant Staphylococcus aureus (MRSA) carried out in 1995 and 1999, the latter involving colleagues in Northern Ireland. There have been a number of local surveys of antibiotic-resistant bacteria including the molecular characterization of MRSA in Dublin hospitals, vancomycin-resistant enterococci, and Gram-negative bacteria such as Enterobacter spp. and Serratia spp. affecting compromised patients such as bone marrow transplant recipients. In the future, it is hoped to standardize case definitions, automate data entry, increase collaboration with surveillance initiatives in Northern Ireland and link in with European networks such as EARSS and HELICS. Apart from the need to improve the quality of health care in Irish hospitals, approximate costings suggest that there are potential savings of 7.5 pounds sterling -15 pounds sterling m to be made following a reduction of HAI rates of 15%.

Cross Infection↗

CD95 signaling is not required for the down regulation of cellular responses to systemic Mycobacterium tuberculosis infection.

There is a tendency among tuberculosis patients to have reduced cellular responses to mycobacterial antigens and this loss has been associated with apoptosis of CD4 T cells. In order to determine the role of CD95 in mediating apoptosis of antigen-specific lymphocytes in tuberculosis, mice with a mutated CD95L molecule were infected systemically with virulent Mycobacterium tuberculosis. Both control and CD95L mutant mice exhibited the expected loss of response to mycobacterial antigens, with the only difference being a slight delay in the loss of the response in the mutant mice. The limited persistence of the response in the mutant mice suggests that, while antigen-specific cellular responses do decline in mice infected with mycobacteria, this decline is not dependent upon CD95L.

Animals↗

Evolving concepts of pharmaceutical company-sponsored surveillance studies.

As a result of increasing bacterial resistance to antimicrobial agents, there is a need to conduct studies that monitor changes in susceptibility. In addition to studying the emergence and dissemination of antibacterial resistance, pharmaceutical companies perform surveillance studies for a number of reasons. As an example, the Alexander Project was conducted to study community-acquired respiratory infections internationally over 10 years. The project's findings have been valuable in the study of antimicrobial resistance. The Alexander Project has also been instrumental in the study of the evolution of resistance genes and in predictions of future rates of resistance, as well as in establishing the importance of high-quality data, the complexity of the evolution of resistance, and the need to disseminate the results in a variety of formats. Although there has been a reduction in pharmaceutical company studies, consolidated efforts between industry, government, and private groups have increased. Future surveillance efforts by pharmaceutical companies will likely be more targeted and disease directed.

Bacteria↗