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PubMed1996

United States geographic bacteria susceptibility patterns. 1995 ASCP Susceptibility Testing Group.

Drug resistance in microbial pathogens once considered "conquered" is now recognized as a major emerging health-care issue in many parts of the United States. There is a very real possibility this problem will continue to spread throughout our country, heralding the beginning of the "post-antibiotic era." A significant issue in dealing with this rapidly developing problem is a lack of national data presented in a reasonably rapid manner that highlights the geographic distribution of increasing resistance to antimicrobial agents. In the Fall of 1994, the Microbiology Council of the American Society of Clinical Pathologists (ASCP) adopted a proposal to present geographic susceptibility and resistance patterns for selected pathogens on at least an annual basis. The American Journal of Clinical Pathology subsequently agreed to publish this information as a service to its readers. The following report is the first of these annual surveys. All laboratories submitting this information expended considerable effort to voluntarily compile the information. These data are sent to the AJCP in the spirit that all our cooperation will be needed to begin developing solutions for combating the problem of growing drug resistance in microbial pathogens. All were enthusiastic participants in this project and are to be commended, along with the ASCP, for supporting this project! We plan to continue this annual survey as long as the interest continues, and the need persists. It is clear the future of infectious diseases and clinical microbiology is filled with challenge. Only time will tell if we are able and ready to meet this new threat to our medical well-being with cooperation, energy, sufficient resources, and creative solutions.

Data Collection↗
PubMed2026

Cooperative anaerobic catabolism of chlorinated organic compounds: implications for sustainable bioremediation.

Biodegradation research historically followed a reductionist approach focused on axenic (pure) cultures capable of catabolizing the specific contaminant(s) of interest. While this approach has substantially advanced our understanding of the microbiology, physiology, biochemistry, and genetics of contaminant degradation under laboratory conditions, it does not capture the complexity of natural and engineered environments. During in situ bioremediation, microbiomes are exposed to mixtures of contaminants, and microbial interactions profoundly influence contaminant transformation and fate. In anoxic environments, degradation of chlorinated compounds is often sustained by metabolic cooperation among taxonomically and physiologically distinct microorganisms. Through the exchange of metabolites such as hydrogen, formate, acetate, and other nutrients, microbial populations establish interdependent networks that overcome thermodynamic and physiological constraints, enabling self-sustaining systems of contaminant transformations that would be inefficient or impossible with individual organisms. We highlight examples of microbial interactions that underpin anaerobic catabolism of chlorinated contaminants, including systems resulting in self-sustained anaerobic bioremediation.

Biodegradation, Environmental↗
PubMed2026

Genome-resolved analysis reveals disruption of gut microbial vitamin B and K2 biosynthesis during Toxoplasma gondii infection in mice.

UNLABELLED: Toxoplasma gondii infection remodels the gut microbiome, yet its impact on microbial vitamin biosynthetic potential and host redox metabolism remains unclear. Here, we integrated mouse gut metagenomes with publicly available metagenome-assembled genomes (MAGs) to construct a genome-resolved atlas of B-vitamin and vitamin K2 biosynthesis. From 45,697 MAGs, we curated 4,771 representative genomes, of which 2,682 met high-quality criteria (completeness &#x2265;90%, contamination <5%). Functional annotation identified 229,717 vitamin-related genes corresponding to 177 Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs across de novo pathways for eight B vitamins, thiamine (B1), riboflavin (B2), niacin (B3), pantothenate (B5), pyridoxine (B6), biotin (B7), folate (B9), cobalamin (B12), and vitamin K2. Among the high-quality genomes, 1,665 encoded complete de novo pathways for at least one vitamin, highlighting functional specialization and community-level complementarity. Transcripts per million-normalized metagenomic read counts revealed significant differences in KEGG ortholog abundances across six of the nine vitamin pathways. Reanalysis of metagenomic data from infected mice (acute, chronic, and control; n = 10 per group) revealed a stage-dependent reduction in &#x3b1;-diversity of vitamin biosynthesis pathways during acute infection, and a clear &#x3b2;-diversity separation from chronic and control groups. Core niacin biosynthesis genes (nadB, nadA, nadC) displayed phylum-specific redistribution, indicating selective remodeling of microbial NAD+ precursor production under infection-induced metabolic stress. These results suggest that T. gondii infection disrupts cooperative vitamin biosynthetic networks while specifically modulating niacin pathways linked to host NAD+ metabolism. IMPORTANCE: Gut microbes can synthesize essential vitamins, but how infection alters this function is poorly understood. By integrating mouse gut metagenomes with genome-resolved microbial data, we show that Toxoplasma gondii infection reshapes the vitamin biosynthetic potential of the gut microbiome in a stage-dependent manner. Acute infection reduces the diversity of vitamin biosynthesis pathways and shifts the taxonomic distribution of key niacin biosynthesis genes involved in microbial NAD+ precursor production. These findings identify vitamin metabolism, especially niacin-related pathways, as a sensitive functional axis of microbiome remodeling during infection. Our work links microbial taxonomic changes to functional metabolic consequences and suggests that microbiome-mediated regulation of NAD+-related metabolism may contribute to host redox adaptation during T. gondii infection.

B vitamins↗
PubMed2002

Synergistic interactions in the microbial world.

After several decades of microbiological research has focused on pure cultures, synergistic effects between different types of microorganisms find increasing interest. Interspecies interactions between prokaryotic cells have been studied into depth mainly with respect to syntrophic cooperations involved in methanogenic degradation of electron-rich substrates such as fatty acids, alcohols, and aromatics. Partners involved in these processes have to run their metabolism at minimal energy increments, with only fractions of an ATP unit synthesized per substrate molecule metabolized, and their cooperation is intensified by close proximity of the partner cells. New examples of such syntrophic activities are anaerobic methane oxidation by presumably methanogenic and sulfate-reducing prokaryotes, and microbially mediated pyrite formation. Syntrophic relationships have also been discovered to be involved in the anaerobic metabolization of amino acids and sugars where energetical restrictions do not necessarily force the partner organisms into strict interdependencies. The most highly developed cooperative systems among prokaryotic cells appear to be the structurally organized phototrophic consortia of the Chlorochromatium and Pelochromatium type in which phototrophic and chemotrophic bacteria not only exchange metabolites but also interact at the level of growth coordination and tactic behaviour.

Bacteria↗
PubMed1985

Etiology of rheumatoid arthritis.

Definite genetic associations with immunological cooperative HLA-D(R) antigens have been demonstrated for rheumatoid arthritis (RA). Microbial etiology has not been proven, but some hope for the supporters of this view is still given by small viruses, plasmids of enteric bacteria or perhaps oncogen-like DNA-sequences. Yet, electrophoretical analysis of membrane proteins or surface glycoproteins of RA synovial cells does not show any differences compared to reference cells. Autoimmunity to several tissue elements has been demonstrated, but most of it is of secondary nature. Antigenicities of type II and III collagens are probably only contributory factors for HLA-DR4 positive individuals. Proteoglycans or minor cartilage collagens have not been extensively studied, so far. Endocrine, dietary or psychological influences might be triggering events for otherwise 'preloaded' individuals.

Animals↗
PubMed2005

Monitoring of microbial metal transformations in the environment.

The biotransformation of metals is an exciting, developing strategy to treat metal contamination, especially in environments that are not accessible to other remediation technologies. However, our ability to benefit from these strategies hinges on our ability to monitor these transformations in the environment. This involves monitoring metals in both solid and aqueous samples, distinguishing between different chemical states, and obtaining information on the activities of specific microbial taxa in communities that inhabit the treated site. Accomplishing these goals requires cooperation among scientists from various disciplines and would benefit from both new, innovative approaches and the tailoring of established methods to control metal mobility in the environment.

Archaea↗
PubMed1999

N-acyl homoserinelactone-mediated gene regulation in gram-negative bacteria.

The view of bacteria as unicellular organisms has strong roots in the tradition of culturing bacteria in liquid media. However, in nature microbial activity is mainly associated with surfaces where bacteria form highly structured and cooperative consortia which are commonly referred to as biofilms. The ability of bacteria to organize structurally and to distribute metabolic activities between the different members of the consortium demands a high degree of coordinated cell-cell interaction. Recent work has established that many bacteria employ sophisticated intercellular communication systems that rely on small signal molecules to control the expression of multiple target genes. In Gram-negative bacteria, the most intensively investigated signal molecules are N-acyl-L-homoserine lactones (AHLs), which are utilized by the bacteria to monitor their own population densities in a process known as 'quorum sensing'. These density-dependent regulatory systems rely on two proteins, an AHL synthase, usually a member of the LuxI family of proteins, and an AHL receptor protein belonging to the LuxR family of transcriptional regulators. At low population densities cells produce a basal level of AHL via the activity of an AHL synthase. As the cell density increases, AHL accumulates in the growth medium. On reaching a critical threshold concentration, the AHL molecule binds to its cognate receptor which in turn leads to the induction/repression of AHL-regulated genes. To date, AHL-dependent quorum sensing circuits have been identified in a wide range of gram-negative bacteria where they regulate various functions including bioluminescence, plasmid conjugal transfer, biofilm formation, motility, antibiotic biosynthesis, and the production of virulence factors in plant and animal pathogens. Moreover, AHL signal molecules appear to play important roles in the ecology of complex consortia as they allow bacterial populations to interact with each other as well as with their eukaryotic hosts.

4-Butyrolactone↗
PubMed1991

Conventional antigen and superantigen may be coupled to distinct and cooperative T-cell activation pathways.

CD4+ T cells are equipped to detect two major classes of ligands. Infectious microbial agents, including bacteria and retroviruses, carry a class of proteins termed superantigens that are recognized by the T-cell receptor in association with class II products of the major histocompatibility complex. Proteins expressed by other cells and organisms are processed by macrophages into peptides that are presented to CD4+ T cells by class II molecules. We have examined CD4+ T-cell clones that proliferate vigorously in response both to conventional peptide antigens and to bacterial or retroviral superantigens. The response to peptide antigen is characterized by a rapid and sustained increase in the levels of intracellular free Ca2+ and a vigorous cytokine response. In contrast, the proliferative response of these clones to bacterial or retroviral superantigen is not accompanied by detectable increases in intracellular Ca2+ or by significant cytokine production. Further analysis of T-cell activation indicates that interaction of a single T-cell receptor with the two types of ligand may be coupled to functionally distinct signaling pathways that interact in a synergistic fashion to achieve T-cell activation.

Animals↗
PubMed2001

Infection control practice: global preparedness for future challenges.

The modern infection control profession emerged in the 1960s in England and the US in response to a pandemic of infections in hospitalized patients from a virulent strain of Staphylococcus aureus. The need for better patient care practices to prevent infections in this setting was evident, and the nursing, medical and microbiology professions responded. Both governmental and non-governmental agencies and professional organizations supported their efforts. During the past 3 decades infection control programs and professionals have multiplied and flourished throughout the world. At first, each country worked primarily within its own borders. In recent years collaboration among countries has increased dramatically, especially as related to education and training, research, and publishing. This article describes two examples of these partnerships. In the US, the Society for Healthcare Epidemiology of America (SHEA) and the Association for Professionals in Infection Control and Epidemiology, Inc (APIC) have joined with the King Fahad National Guard Hospital (KFNGH), a center-of-excellence for infection control in Riyadh, Saudi Arabia for educational meetings and infection control certification. The information exchanged and relationships developed through these activities will further efforts of both countries toward meeting infection prevention and control challenges of the future.

Disaster Planning↗