A5102907798- Antimicrobial Resistance in Staphylococcus
- Bacterial Identification and Susceptibility Testing
- Bacterial biofilms and quorum sensing
- Antibiotic Resistance in Bacteria
- Streptococcal Infections and Treatments
- Mycobacterium research and diagnosis
- Antifungal resistance and susceptibility
- Antibiotics Pharmacokinetics and Efficacy
- Biochemical and Structural Characterization
- Infective Endocarditis Diagnosis and Management
- Microbial Metabolism and Applications
- Oral microbiology and periodontitis research
- Nosocomial Infections in ICU
- Plant Pathogenic Bacteria Studies
- Blood disorders and treatments
- Otolaryngology and Infectious Diseases
- Liver Disease and Transplantation
- Bacteriophages and microbial interactions
- Medical Device Sterilization and Disinfection
- Liver Disease Diagnosis and Treatment
- Surgical site infection prevention
- Sinusitis and nasal conditions
- Molecular Biology Techniques and Applications
- Neonatal and Maternal Infections
- Respiratory and Cough-Related Research
Icahn School of Medicine at Mount Sinai
2019-2023
Rockefeller University
2004-2018
Eulji General Hospital
2010
Hvidovre Hospital
2001
Statens Serum Institut
2001
Universidade Nova de Lisboa
2001
Instituto de Tecnología Química
2000
Memorial Sloan Kettering Cancer Center
1996-1998
Cornell University
1998
NewYork–Presbyterian Hospital
1998
The key genetic component of methicillin resistance, the mecA determinant, is not native to Staphylococcus aureus . Thus, evolution methicillin-resistant S. (MRSA) must have begun with acquisition determinant from an unknown heterologous source some time before first reported appearance MRSA isolates in clinical specimens U.K. and Denmark (in early 1960s). We compared backgrounds phenotypes a group methicillin-susceptible (MSSA) properties strains isolated during same period, also profiles...
Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations. In spite its high resolving power, use method been hampered by inadequate laboratory-to-laboratory reproducibility. project described here we have addressed this problem organizing a multilaboratory effort which same bacterial strains (subtype variants Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed twenty investigators...
The epidemic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 lineage has recently become a leading cause of hospital-associated bloodstream infections (BSIs). Here, we leveraged this recent introduction into hospitals and the limited genetic variation across isolates to identify mutations that contribute its success in new environment. We found BSI exhibit altered virulence regulation. Using comparative genomics delineate genes involved phenotype, discovered...
Abstract Objective: To determine the incidence, duration, and genetic diversity of colonization with vancomycin-resistant Enterococcus faecium (VREF). Setting: Oncology unit a 650-bed university hospital. Methods: Surveillance perianal swab cultures were performed on admission weekly. The molecular relatedness VREF isolates was determined by pulsed-field gel electrophoresis hybridization pattern vanA resistance determinant. Results: During 8 months surveillance, rate 16.6 patients per 1,000...
All methicillin resistant S. aureus (MRSA) strains carry an acquired genetic determinant--mecA or mecC--which encode for a low affinity penicillin binding protein -PBP2A PBP2A'--that can continue the catalysis of peptidoglycan transpeptidation in presence high concentrations beta-lactam antibiotics which would inhibit native PBPs normally involved with synthesis staphylococcal cell wall peptidoglycan. In contrast to this common and biochemical mechanism carried by all MRSA strains, level...
We identified mutated genes in highly resistant subpopulations of methicillin-resistant Staphylococcus aureus (MRSA) that are most likely responsible for the historic failure β-lactam family antibiotics as therapeutic agents against these important pathogens. Such produced during growth clinical MRSA strains, including four historically early isolates studied here. Chromosomal DNA was prepared from cells along with majority (poorly cells) followed by full genome sequencing. In cells,...
The overwhelming majority of methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates exhibit a peculiar heterogeneous resistance to β-lactam antibiotics: in cultures such strains, the cells display only low level methicillin resistance--often close MIC breakpoint susceptible strains. Yet, same cultures, subpopulations bacteria exhibiting very high levels are also present with variable frequencies, which characteristic particular MRSA lineage. mechanism is not understood. We...
Objective To determine the duration of stool shedding and incidence clinical infection among pediatric oncology patients colonized with vancomycin-resistant Enterococcus faecium (VRE) in our institution. Methods Stool cultures were obtained from all admitted May 15 to August 2, 1994. Patients followed for evidence VRE surveillance results through 15, 1995. Genetic relatedness stool-clinical isolate pairs serial samples was evaluated using pulsed field gel electrophoresis. Results...
Recently, for the first time in history of this bacterial species, methicillin-resistant Staphylococcus aureus (MRSA) carrying enterococcal vanA gene complex and expressing high level resistance to vancomycin was identified clinical specimens (CDC (2002) MMWR 51, 565-567). The purpose our studies understand how is expressed heterologous background S. it interacts with mecA-based mechanism, which also present these strains targeted on cell wall biosynthesis. vanA-containing staphylococcal...
ABSTRACT Penicillin-binding protein 4 (PBP4), a nonessential, low-molecular-weight penicillin-binding of Staphylococcus aureus , has been implicated in low-level resistance to β-lactam antibiotics, although the mechanism is unknown. Mutations PBP4 and its promoter were identified laboratory-generated mutant strain, CRB, which expresses high-level β-lactams, including new-generation cephalosporins active against methicillin-resistant strains S. . These mutations did not appreciably alter...
ABSTRACT A total of 202 methicillin-resistant Staphylococcus aureus (MRSA) single-patient isolates recovered between January and June 1998 in two hospitals Miami, Florida, were characterized by a combination several molecular typing techniques: multilocus sequence typing, spaA pulsed-field gel electrophoresis, determination the structure SCC mec element. The overwhelming majority isolates—187of 202, or 93%—belonged to one three internationally spread epidemic clones which identified on basis...
In November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology Infectious Diseases, Directors Network (CDN) launched a research learning collaborative project with six community health centers in New York City metropolitan area to determine nature (clonal type) community-acquired Staphylococcus aureus strains causing skin soft tissue infections (SSTIs). Between 2011 March 2013, wound nasal samples from 129 patients active...
The multidrug-resistant "Iberian" clone of methicillin-resistant Staphylococcus aureus (MRSA) was first identified on the basis its unique DNA fingerprints as strain responsible for massive 1989 outbreak MRSA disease in hospital Princeps d'Espanya, Barcelona, Spain. Most Iberian carry a constitutive β-lactamase. They are resistant to most β-lactam antibiotics, macrolides, aminoglycosides, tetracycline, rifampin and ciprofloxacin susceptible fosfomycin, fusidic acid, mupirocin,...
Recent surveillance of MRSA colonizing patients and healthcare workers in two African countries (Angola São Tomé Príncipe) reported the frequent recovery oxacillin-susceptible (OS-MRSA): Staphylococcus aureus strains that gave positive results with mecA DNA probe, but had low oxacillin MIC values characteristic susceptible S. aureus. This apparent dissociation drug-resistant phenotype from mecA—the primary genetic determinant resistance—prompted us to perform a more detailed analysis on nine...
Methicillin-resistant Staphylococcus aureus (MRSA) isolated in the 1960s Denmark are among historically earliest samples of these bacteria. We determined microbiological and molecular properties 46 such isolates. They showed remarkably uniform properties, which included: (i) low methicillin MIC value (6–25 μg/ml); (ii) heterogeneous expression resistance; (iii) presence a single, common, mecA polymorph II; (iv) lack regulatory gene mecI; (v) frequent Tn554; (vi) common pulsed-field gel...
A previous surveillance study conducted in 12 hospitals New York City 1996 identified a unique multidrug-resistant genetic lineage of methicillin-resistant Staphylococcus aureus (MRSA) that was widespread and accounted for as much 42% all the MRSA isolates. The purpose described here to determine possible geographic spread this clone neighboring states. Single-patient isolates (258) from 29 health care facilities Connecticut (CT), Jersey (NJ), Pennsylvania (PA) were collected during calendar...
ABSTRACT Multidrug-resistant strains of Staphylococcus aureus continue to increase in frequency worldwide, both hospitals and the community, raising serious problems for chemotherapy staphylococcal disease. Ceftobiprole (BPR; BAL9141), active constituent prodrug ceftobiprole medocaril (BAL5788), is a new cephalosporin which was already shown have powerful activity against number bacterial pathogens, including S. . In an effort test possible limits antibacterial spectrum efficacy BPR, we...
During a 36-month period between 1993 and 1995 in the Pediatric Oncology Unit of Memorial Sloan Kettering Cancer Center, 74 patients experienced episodes infection or colonization caused by vancomycin-resistant enterococci (VRE). Characterization bacterial isolates microbiological molecular techniques (pulsed-field gel electrophoresis hybridization with DNA probes specific for vanA vanB genes IS1251) identified 73 Enterococcus faecium one faecalis (vanB) among primary VRE isolates. Most...
Background. Between 1990 to 1992 and 1993 1995 there was a >5-fold increase (16.7% 89.8%) in vancomycin-resistant Enterococcus faecium isolates as percentage of all enterococci on the pediatric units The New York Hospital-Cornell Medical Center (NYH-CMC). A molecular epidemiologic investigation undertaken determine extent which this associated with spread vanA-containing clone E. that had been previously defined adults hospitalized at NYH-CMC or another vanA children service Memorial...
Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA- or mecC-mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression shows extensive strain-to-strain variation. In recent communications, we identified genetic determinants associated with stringent stress response that play major role in antibiotic resistant phenotype historically earliest "archaic" clone MRSA mecC-carrying strain LGA251. Here, sought test whether not same also...
Abstract Background Whole-genome sequencing (WGS) is increasingly used to map the spread of bacterial and viral pathogens in nosocomial settings. A limiting factor for more widespread adoption WGS hospital infection prevention practices availability standardized tools genomic epidemiology. Methods We developed Pathogen Sequencing Phylogenomic Outbreak Toolkit (PathoSPOT) automate integration medical record data rapid detection tracing outbreaks. To demonstrate its capabilities, we applied...
Persons with acquired immune deficiency syndrome (AIDS) who use drugs appear to be at increased risk for colonization and infection Staphylococcus aureus. Little is known about the nature of factors responsible this association. This study among first prospectively follow carriage in uniquely high-risk population.We followed cases 75 patients AIDS a residential drug treatment facility screened S. aureus nasal infection.Thirty-seven baseline cultures (49%) were positive aureus, 81% subjects...
Addition of β-lactam antibiotics to growing cultures bacteria inhibit synthesis the bacterial cell wall peptidoglycan accompanied by killing (loss viable titer) and lysis (physical disintegration) cells. However, it has also been well established that these are not effective in non-growing or slow-growing mechanism this "antibiotic tolerance" is understood. In study, we report on genetic basis phenotypic properties an antibiotic tolerant derivative methicillin susceptible S. aureus strain...
We describe a case of Lemierre's syndrome (LS) caused by hypervirulent strain Klebsiella pneumoniae in 63-year-old female with hypertension, hyperlipidemia, and diabetes mellitus, who presented right neck pain fevers. Computerized tomography the chest revealed an occluded internal jugular vein secondary to thrombosis septic emboli lungs. Blood cultures grew K. pneumoniae. The patient was treated ampicillin-sulbactam then transitioned amoxicillin-clavulanate complete 6-week course...