Bacterial Infections and Mycoses Commons^™

Reiq-Mediated Alarmone Signalling Regulates Growth, Stress-Induced Biofilm Formation And Spore Accumulation In Clostridioides Difficile, Areej Malik, Adenrele Oludiran, Asia Poudel, Orlando Berumen Alvarez, Charles Woodward, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm …

Comparison Of Bacterial Culture With Biofire® Filmarray® Multiplex Pcr Screening Of Archived Cerebrospinal Fluid Specimens From Children With Suspected Bacterial Meningitis In Nigeria, S Obaro, F Hassan-Hanga, N Medugu, Rasaq Olaosebikan, G Olanipekun, B Jibir, S Gambo, Theresa Ajose, Carissa Duru, B Ebruke, H D Davies

Department of Pharmacology and Experimental Therapeutics Faculty Papers

BACKGROUND: Diagnosis of bacterial meningitis remains a challenge in most developing countries due to low yield from bacterial culture, widespread use of non-prescription antibiotics, and weak microbiology laboratories. The objective of this study was to compare the yield from standard bacterial culture with the multiplex nested PCR platform, the BioFire® FilmArray® Meningitis/Encephalitis Panel (BioFire ME Panel), for cases with suspected acute bacterial meningitis.

METHODS: Following Gram stain and bacterial culture on cerebrospinal fluid (CSF) collected from children aged less than 5 years with a clinical suspicion of acute bacterial meningitis (ABM) as defined by the WHO guidelines, residual CSF specimens …

Evolving Antibiotic Resistance In Group B Streptococci Causing Invasive Infant Disease: 1970–2021, Elizabeth Marie Sabroske, Misu Ailin Sanson Iglesias, Marcia Rench, Trevor Moore, Hanna Harvey, Morven Edwards, Carol J Baker, Anthony R Flores

Student and Faculty Publications

BACKGROUND: We sought to define the frequency of antibiotic resistance over time in a collection of invasive GBS isolates derived from infant early-onset disease (EOD), late-onset disease (LOD), and late-late onset disease (LLOD).

METHODS: A multicenter retrospective review of infants born from 1970 to 2021 with GBS isolated from blood, cerebrospinal fluid, synovial fluid, cellulitis, or bone. All isolates were serotyped and antimicrobial susceptibility testing performed using disk diffusion.

RESULTS: The most common serotypes in our 2017 isolates were III (n = 1112, 55.1%), Ia (n = 445, 22%), Ib (n = 182, 9%) and II (n = 146, 7.2%). …

Combating Antibiotic Resistance In The 21st Century, Kevin Krivanek, Brian Heilbronner, Brendan Rasor, Kelsey Lindsley, Andrew Roecker

Pharmacy and Wellness Review

Antibiotic resistance is one of the most significant challenges facing the medical community today. In response, the Centers for Disease Control and Prevention (CDC) created a list of the greatest antibiotic resistance threats, a number of which are gram-positive bacteria. The cell wall of these organisms has long been a favored target of antibiotic therapies, but the development of numerous resistance mechanisms has led to widespread resistance against nearly all major antibiotic compounds on the market. The medical community is faced with the task of developing better antibiotic compounds that preclude the spread of bacterial resistance and also increasing the …

Enhanced Control Of Mycobacterium Tuberculosis Extrapulmonary Dissemination In Mice By An Arabinomannan-Protein Conjugate Vaccine, R Prados-Rosales, L Carreno, T Cheng, C Blanc, B Weinrick, Aharona Glatman-Freedman, A Casadevall, S Hung, A Tripathi, J Xu, Aharona Glatman-Freedman, W Jacobs Jr., J Chan, S Porcelli, J Achkar, A Casadevall

NYMC Faculty Publications

Currently there are a dozen or so of new vaccine candidates in clinical trials for prevention of tuberculosis (TB) and each formulation attempts to elicit protection by enhancement of cell-mediated immunity (CMI). In contrast, most approved vaccines against other bacterial pathogens are believed to mediate protection by eliciting antibody responses. However, it has been difficult to apply this formula to TB because of the difficulty in reliably eliciting protective antibodies. Here, we developed capsular polysaccharide conjugates by linking mycobacterial capsular arabinomannan (AM) to either Mtb Ag85b or B. anthracis protective antigen (PA). Further, we studied their immunogenicity by ELISA and …

Β-Lactams Interfering With Pbp1 Induce Panton-Valentine Leukocidin Expression By Triggering Sara And Rot Global Regulators Of Staphylococcus Aureus, Oana Dumitrescu, Priya Choudhury, Sandrine Boisset, Cedric Badiou, Michele Bes, Yvonne Benito, Christiane Wolz, Francois Vandenesch, Jerome Etienne, Ambrose L. Cheung

Dartmouth Scholarship

Previous articles reported that beta-lactam antibiotics increase the expression of Staphylococcus aureus Panton-Valentine leukocidin (PVL) by activating its transcription. We investigated the mechanisms underlying the inductor effect of beta-lactams on PVL expression by determining targets and regulatory pathways possibly implicated in this process. We measured PVL production in the presence of oxacillin (nonselective), imipenem (penicillin-binding protein 1 [PBP1] selective), cefotaxime (PBP2 s

Polysorbate 80 Inhibition Of Pseudomonas Aeruginosa Biofilm Formation And Its Cleavage By The Secreted Lipase Lipa, C M. Toutain-Kidd, S C. Kadivar, C T. Bramante, S A. Bobin, Michael E. Zegans

Dartmouth Scholarship

Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses.