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Bacteria, antibiotic resistance

Michael Wesbrook Staude, David A Leonard, Jeffrey W Peng
Gram-negative bacteria resist β-lactam antibiotics primarily by deploying β-lactamase proteins that hydrolytically destroy the antibiotics. In clinical settings, these bacteria are producing variant β-lactamases with "gain of activity" mutations that inactivate a broader range of β-lactams. Learning how these mutations broaden substrate activity is important for coping with β-lactam resistance. Here, we investigate a gain of activity mutation in OXA-24/40, a carbapenem-hydrolyzing Class D β-lactamase (CHDL) in Acinetobacter baumannii...
October 26, 2016: Biochemistry
Dhiviya Prabaa Muthuirulandi Sethuvel, Naveen Kumar Devanga Ragupathi, Shalini Anandan, Balaji Veeraraghavan
Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms, and organism-shedding time. However, In India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp is becoming a major issue as these strains are non-typeable by conventional serotyping...
October 26, 2016: Letters in Applied Microbiology
Leslie E Cohen, Thomas A Imahiyerobo, Jeffrey R Scott, Jason A Spector
BACKGROUND: The objective of this study was to evaluate the antimicrobial performance of a rifampin/minocycline-coated, non-cross-linked, acellular porcine dermal matrix (XenMatrix AB) compared to an uncoated, non-cross-linked, acellular porcine dermal matrix (Strattice) after implantation/inoculation with methicillin-resistant Staphylococcus aureus or Escherichia coli in a dorsal rabbit model. METHODS: Forty male New Zealand White rabbits were bilaterally implanted with XenMatrix AB or Strattice grafts and inoculated with clinically isolated methicillin-resistant S...
November 2016: Plastic and Reconstructive Surgery
Moses Abiala, John Olayiwola, Oluwatoyin Babatunde, Olapeju Aiyelaagbe, Sunday Akinyemi
BACKGROUND: Plant extracts were evaluated on poultry bacteria known to be threatening public health. This is to develop better bio-therapeutic agents from plant origin. METHODS: Bacteria were isolated from water, feed, crop, gizzard and faeces of layer chicken. Isolates of interest (Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa and Klebsiella oxytoca) were subjected to antibiotic susceptibility test. Resistant strains were further evaluated against different plant extracts in comparison to Meropenem (control) using agar diffusion method...
October 26, 2016: BMC Complementary and Alternative Medicine
Joanna Krysiak, Stephan A Sieber
Understanding the molecular mechanisms of bacterial pathogenesis and virulence is of great importance from both an academic and clinical perspective, especially in view of an alarming increase in bacterial resistance to existing antibiotics and antibacterial agents. Use of small molecules to dissect the basis of these dynamic processes is a very attractive approach due to their ability for rapid spatiotemporal control of specific biochemical functions. Activity-based protein profiling (ABPP), employing small molecule probes to interrogate enzyme activities in complex proteomes, has emerged as a powerful tool to study bacterial pathogenesis...
2017: Methods in Molecular Biology
Changsheng Guo, Kai Wang, Song Hou, Li Wan, Jiapei Lv, Yuan Zhang, Xiaodong Qu, Shuyi Chen, Jian Xu
Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO2 was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively...
October 19, 2016: Journal of Hazardous Materials
Cristina Prat, Alicia Lacoma
BACKGROUND: Acute and chronic respiratory tract infections are a common cause of inappropriate antimicrobial prescription. Antimicrobial therapy leads to the development of resistance and the emergence of opportunistic pathogens that substitute the indigenous microbiota. METHODS: This review explores the major challenges and lines of research to adequately establish the clinical role of bacteria and the indications for antimicrobial treatment, and reviews novel therapeutic approaches...
October 2016: International Journal of Infectious Diseases: IJID
Slavica Stankic, Sneha Suman, Francia Haque, Jasmina Vidic
Th antibacterial activity of metal oxide nanoparticles has received marked global attention as they can be specifically synthesized to exhibit significant toxicity to bacteria. The importance of their application as antibacterial agents is evident keeping in mind the limited range and effectiveness of antibiotics, on one hand, and the plethora of metal oxides, on the other, along with the propensity of nanoparticles to induce resistance being much lower than that of antibiotics. Effective inhibition against a wide range of bacteria is well known for several nano oxides consisting of one metal (Fe3O4, TiO2, CuO, ZnO), whereas, research in the field of multi-metal oxides still demands extensive exploration...
October 24, 2016: Journal of Nanobiotechnology
Appiah-Korang Labi, Noah Obeng-Nkrumah, Stephanie Bjerrum, Christabel Enweronu-Laryea, Mercy Jemima Newman
BACKGROUND: Diagnosis of bloodstream infections (BSI) in neonates is usually difficult due to minimal symptoms at presentation; thus early empirical therapy guided by local antibiotic susceptibility profile is necessary to improve therapeutic outcomes. METHODS: A review of neonatal blood cultures submitted to the microbiology department of the Korle-Bu Teaching Hospital was conducted from January 2010 through December 2013. We assessed the prevalence of bacteria and fungi involved in BSI and the susceptibility coverage of recommended empiric antibiotics by Ghana Standard Treatment guidelines and the WHO recommendations for managing neonatal sepsis...
October 24, 2016: BMC Infectious Diseases
Anthony A Iwuafor, Folasade T Ogunsola, Rita O Oladele, Oyin O Oduyebo, Ibironke Desalu, Chukwudi C Egwuatu, Agwu U Nnachi, Comfort N Akujobi, Ita O Ita, Godwin I Ogban
BACKGROUND: Infections are common complications in critically ill patients with associated significant morbidity and mortality. AIM: This study determined the prevalence, risk factors, clinical outcome and microbiological profile of hospital-acquired infections in the intensive care unit of a Nigerian tertiary hospital. MATERIALS AND METHODS: This was a prospective cohort study, patients were recruited and followed up between September 2011 and July 2012 until they were either discharged from the ICU or died...
2016: PloS One
Vera Pader, Sanika Hakim, Kimberley L Painter, Sivaramesh Wigneshweraraj, Thomas B Clarke, Andrew M Edwards
Daptomycin is a bactericidal antibiotic of last resort for serious infections caused by methicillin-resistant Staphylococcus aureus (MRSA)(1,2). Although resistance is rare, treatment failure can occur in more than 20% of cases(3,4) and so there is a pressing need to identify and mitigate factors that contribute to poor therapeutic outcomes. Here, we show that loss of the Agr quorum-sensing system, which frequently occurs in clinical isolates, enhances S. aureus survival during daptomycin treatment. Wild-type S...
October 24, 2016: Nature Microbiology
Jessica M Andriolo, Richard J Rossi, Casey A McConnell, Baili I Connors, Kevin Trout, M K Hailer, Marisa L Pedulla, Jack L Skinner
The Centers for Disease Control and Prevention have estimated that each year, two million people in the United States become infected with antibiotic-resistant bacteria, of which, approximately 23 000 die as a direct result of these infections. Phage therapy, or the treatment of bacterial infection by specific, antagonistic viruses, provides one alternative to traditional antibiotics. Bacteriophages, or phages, are bacteriaspecific viruses that possess biological traits that allow for not only the removal of bacterial infection, but also the evasion of bacterial resistance which renders antibiotics ineffective...
October 19, 2016: IEEE Transactions on Nanobioscience
Christen Ravn, Ulrika Furustrand Tafin, Bertrand Bétrisey, Søren Overgaard, Andrej Trampuz
Background and purpose - Antibiotic treatment of patients before specimen collection reduces the ability to detect organisms by culture. We investigated the suppressive effect of antibiotics on the growth of non-adherent, planktonic, and surface-related biofilm bacteria in vitro by using sonication and microcalorimetry methods. Patients and methods - Biofilms of Staphylococcus aureus, S. epidermidis, Escherichia coli, and Propionibacterium acnes were formed on porous glass beads and exposed for 24 h to antibiotic concentrations from 1 to 1,024 times the minimal inhibitory concentration (MIC) of vancomycin, daptomycin, rifampin, flucloxacillin, or ciprofloxacin...
October 24, 2016: Acta Orthopaedica
Nadine Czekalski, Stefanie Imminger, Elisabeth Salhi, Marjan Veljkovic, Karolin Kleffel, David Drissner, Frederik Hammes, Helmut Bürgmann, Urs von Gunten
Ozone, a strong oxidant and disinfectant, seems ideal to cope with future challenges of water treatment, such as micropollutants, multiresistant bacteria (MRB) and even intracellular antibiotic resistance genes (ARG), but information on the latter is scarce. In ozonation experiments we simultaneously determined kinetics and dose-dependent inactivation of Escherichia coli and its plasmid-encoded sulfonamide resistance gene sul1 in different water matrixes. Effects in E. coli were compared to an autochthonous wastewater community...
October 24, 2016: Environmental Science & Technology
Liis Andresen, Vallo Varik, Yuzuru Tozawa, Steffi Jimmy, Stina Lindberg, Tanel Tenson, Vasili Hauryliuk
The stringent response is a central adaptation mechanism that allows bacteria to adjust their growth and metabolism according to environmental conditions. The functionality of the stringent response is crucial for bacterial virulence, survival during host invasion as well as antibiotic resistance and tolerance. Therefore, specific inhibitors of the stringent response hold great promise as molecular tools for disarming and pacifying bacterial pathogens. By taking advantage of the valine amino acid auxotrophy of the Bacillus subtilis stringent response-deficient strain, we have set up a High Throughput Screening assay for the identification of stringent response inhibitors...
October 24, 2016: Scientific Reports
Marta Martins, Matthew P McCusker
No abstract text is available yet for this article.
2016: Frontiers in Microbiology
Glenn S Tillotson
Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapting known antibiotic classes by altering their chemical structure could be a way forward...
2016: Infectious Diseases
Kazufumi Kasuya, Tilusha Manchanayake, Kei Uenoyama, Sayaka Kawa, Kou Takayama, Naoto Imai, Tomoyuki Shibahara
An imported crossbred Angus beef steer aged eight to twelve months died suddenly on the eighth day of a quarantine period in Japan. Gross examination showed the peritoneum and mesentery consisted of numerous nodules of various sizes. Histological examination revealed chronic suppurative granulomatous peritonitis with eosinophilic rosettes surrounding colonies of Gram-negative bacilli. The bacteria isolated from the nodules were confirmed to be Actinobacillus lignieresii based on the results of 16S rRNA gene sequencing and immunohistochemistry...
October 21, 2016: Journal of Veterinary Medical Science
Yuliang Dong, Weiqing Liu, Yiling Lei, Tingxi Wu, Shiwen Zhang, Yuchen Guo, Yuan Liu, Demeng Chen, Quan Yuan, Yongyue Wang
Oral infectious diseases may lead to bone loss, which makes it difficult to achieve satisfactory restoration. The rise of multidrug resistant bacteria has put forward severe challenges to the use of antibiotics. Silver (Ag) has long been known as a strong antibacterial agent. In clinic, gelatin sponge with colloid silver is used to reduce tooth extraction complication. To investigate how this material affect infected bone defects, methicillin-resistant Staphylococcus aureus (MRSA) infected 3-mm-diameter cranial defects were created in adult female Sprague-Dawley rats...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
A N Severyukhina, N V Petrova, A M Yashchenok, D N Bratashov, K Smuda, I A Mamonova, N A Yurasov, D M Puchinyan, R Georgieva, H Bäumler, A Lapanje, D A Gorin
Increasing antimicrobial resistance requires the development of novel materials and approaches for treatment of various infections. Utilization of photodynamic therapy represents an advanced alternative to antibiotics and metal-based agents. Here, we report the fabrication of electrospun material that possesses benefits of both topical antimicrobial and photodynamic therapies. This material combines chitosan, as a biocompatible polymer, and a second generation photosensitizer. The incorporation of photosensitizer doesn't affect the material morphology and its nearly uniform distribution in fibers structure was observed by confocal Raman microscopy...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
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