antibiotic resistance
PhysiologyInsights into the Function of the N-Acetyltransferase SatA That Detoxifies Streptothricin in Bacillus subtilis and Bacillus anthracisThis work provides insights into how an abundant antibiotic found in soil is bound to the enzyme that inactivates it. This work identifies residues for the binding of the antibiotic and probes the contributions of substituting side chains for those in the native protein, providing information regarding hydrophobicity, size, and flexibility of the antibiotic binding site.
Genetics and Molecular BiologyExperimental Evolution of Escherichia coli K-12 in the Presence of Proton Motive Force (PMF) Uncoupler Carbonyl Cyanide m-Chlorophenylhydrazone Selects for Mutations Affecting PMF-Driven Drug Efflux PumpsThe genetic responses of bacteria to depletion of proton motive force (PMF), and their effects on drug resistance, are poorly understood. PMF drives export of many antibiotics, but the energy cost may decrease fitness when antibiotics are absent. Our evolution experiment reveals genetic mechanisms of adaptation to the PMF uncoupler CCCP, including selection for increased CCCP efflux but also against the expression of PMF-driven pumps...
Evolutionary and Genomic Microbiology | SpotlightResistance Gene Carriage Predicts Growth of Natural and Clinical Escherichia coli Isolates in the Absence of AntibioticsManaging the spread of antibiotic resistance in bacterial pathogens is a major challenge for global public health. Central to this challenge is understanding whether resistance is linked to impaired bacterial growth in the absence of antibiotics, because this determines whether resistance declines when bacteria are no longer exposed to antibiotics. We studied 92 isolates of the key bacterial pathogen...
Evolutionary and Genomic MicrobiologyA Type I Restriction-Modification System Associated with Enterococcus faecium Subspecies SeparationEnterococcus faecium is a leading cause of hospital-acquired infections around the world. Rising antibiotic resistance in certain E. faecium lineages leaves fewer treatment options. The overarching aim of this work was to determine whether restriction-modification (R-M) systems contribute to the...
Microbial Ecology | SpotlightAssessing Transmission of Antimicrobial-Resistant Escherichia coli in Wild Giraffe Contact NetworksAntimicrobial resistance represents a significant threat to human health, food security, and the global economy. To fully understand the evolution and dissemination of resistance genes, a complete picture of antimicrobial resistance in all biological compartments, including natural ecosystems, is required. The environment and wild animals may act as reservoirs for anthropogenically derived resistance genes that could be transferrable to...
Food MicrobiologyTranscriptional and Functional Analysis of Bifidobacterium animalis subsp. lactis Exposure to TetracyclineBifidobacterium animalis subsp. lactis is widely used in human food and dietary supplements. Although well documented to be safe, B. animalis subsp. lactis strains must not contain transferable antibiotic resistance...
Public and Environmental Health MicrobiologyAntibiotic-Resistant Escherichia coli and Class 1 Integrons in Humans, Domestic Animals, and Wild Primates in Rural UgandaAntibiotic resistance is a global problem. This study, conducted in rural western Uganda, describes antibiotic resistance patterns in Escherichia coli bacteria near two forested national parks. Resistance was present not only in people, but also in their livestock and in nearby wild nonhuman primates. Multidrug resistance and class 1 integrons containing genes that...
Environmental MicrobiologyEvidence for Multidrug Resistance in Nonpathogenic Mycoplasma Species Isolated from South African PoultryNonpathogenic poultry Mycoplasma species are often overlooked due to their lesser impact on poultry health and production compared to the OIE-listed pathogenic strains M. gallisepticum and M. synoviae. The use of antimicrobials as in-feed growth promoters and for the control of mycoplasmosis is common in poultry production across the world. Here, we...
Public and Environmental Health MicrobiologyAntimicrobial Susceptibility Testing and Tentative Epidemiological Cutoff Values for Five Bacillus Species Relevant for Use as Animal Feed Additives or for Plant ProtectionWhen commercializing bacterial strains, like Bacillus spp., for feed applications or plant bioprotection, it is required that the strains are free of acquired antimicrobial resistance genes that could potentially spread to pathogenic bacteria, thereby adding to the pool of resistance genes that may cause treatment failures in humans or animals. Conversely, if...
- Microbial EcologyLong-Term Colonization Dynamics of Enterococcus faecalis in Implanted Devices in Research Macaques
Enterococcus faecalis is a common cause of health care-associated infections in humans, largely due to its ability to persist in the hospital environment, colonize patients, acquire antimicrobial resistance, and form biofilms. Understanding how enterococci evolve in health care settings provides insight into factors affecting enterococcal survival and persistence....