Biomedical subjects

Joan Pawlak

Publications and source records attributed to Joan Pawlak.

6 recordsLinked to original sources

PubMed2006

Emergence of community-associated methicillin-resistant Staphylococcus aureus infection among patients with end-stage renal disease.

OBJECTIVE: To evaluate the frequency of infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains among our patients with end-stage renal disease. DESIGN: Prospective observational clinical and laboratory study of patients in 2005. Molecular features of isolates recovered from these patients were compared with those of isolates recovered in 2000 from patients with end-stage renal disease. SETTING: A 600-bed urban academic medical center. PATIENTS: Thirty-two patients with end-stage renal disease and MRSA infection at the time of hospitalization from 2005 were evaluated. For comparison, laboratory analysis was performed for 17 MRSA isolates recovered from patients with end-stage renal disease in 2000. RESULTS: The patients from 2005 were more likely than the patients from 2000 to have infection with strains that carried the staphylococcal cassette chromosome (SCC) mec type IV complex (50% vs 11.8%; relative risk, 4.25 [95% confidence interval, 1.17-25.98]; P = .012) and the Panton-Valentine leukocidin toxin genes (25% vs 0%; P = .038). Eight patients from 2005 were infected with a strain that is identical to MRSA clone USA300 in terms of molecular type and presence of SCCmec type IV and Panton-Valentine leukocidin genes. Among the patients from 2005, those infected with SCCmec type IV strains (ie, CA-MRSA strains) and those infected with SCCmec type II strains (ie, healthcare-associated MRSA [HA-MRSA] strains) were similar with respect to demographic characteristics, risk factors, and outcomes. CONCLUSIONS: We documented an increased proportion of infections with CA-MRSA strains, including clone USA300, among our population of patients undergoing dialysis. Patients infected with CA-MRSA strains and HA-MRSA strains were similar with respect to presenting illness and outcomes.

Bacterial Toxins↗

PubMed2006

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Adult↗

PubMed2006

Clinical and laboratory features of community-associated methicillin-resistant Staphylococcus aureus: is it really new?

OBJECTIVE: To review the epidemiologic and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Detroit, Michigan, to assess the risk factors for infection and the response to therapy. DESIGN: Prospective clinical and laboratory study of 2003-2004 CA-MRSA isolates. Molecular features were compared with CA-MRSA isolates from 1980. SETTING: A 600-bed urban academic medical center. PATIENTS: Twenty-three patients with CA-MRSA infections from 2003-2004 were evaluated. In addition, laboratory analysis was performed on 13 CA-MRSA isolates from 1980. MAIN OUTCOME MEASURES: Laboratory analysis of isolates included antimicrobial susceptibility testing, pulsed-field genotyping, testing for Panton-Valentine leukocidin (PVL) genes, and staphylococcal cassette chromosome mec typing. RESULTS: Patients were predominantly young African American males and presented with skin and soft-tissue infections. All isolates were resistant to erythromycin and highly susceptible to other agents. Patients were generally treated successfully with combination incision and drainage and systemic antibiotics. Among the 23 isolates, 20 (87%) were the same strain. This strain carried the staphylococcal cassette chromosome mec type IV and PVL genes and is genetically identical to USA 300. Thirteen isolates of patients from our community who presented with CA-MRSA infections in 1980 represented a single clone that is unique compared with the 2003-2004 isolates. This strain carried staphylococcal cassette chromosome mec type IVA but did not carry the PVL genes. CONCLUSIONS: In our community, CA-MRSA is largely due to a single clone with a type IV mec gene and PVL gene. The type IV staphylococcal cassette chromosome mec type can be demonstrated in CA-MRSA isolates from a remote period, suggesting that earlier outbreaks were not related to healthcare exposure.

Academic Medical Centers↗

PubMed2005

Antimicrobial activity and a comparison of published pharmacodynamics of gemifloxacin and eight fluoroquinolones against Streptococcus pneumoniae.

Gemifloxacin was evaluated for its in vitro activity and was compared with eight fluoroquinolones. Pharmacodynamic comparisons were made based on published pharmacokinetic information. Gemifloxacin demonstrated excellent in vitro activity (minimum inhibitory concentration necessary to inhibit 90% of the strains tested, MIC90 = 0.03 mg/L (range 0.0019-0.03 mg/L)) against 199 strains of Streptococcus pneumoniae. Its activity was not influenced by penicillin or ciprofloxacin non-susceptibility. Gemifloxacin demonstrated excellent pharmacodynamic parameters, with a Cmax/MIC90 of 67 (where Cmax is the peak serum level) and an AUC/MIC90 of 297 (where AUC is the area under the curve). Compared with the other eight fluoroquinolones tested, gemifloxacin demonstrated the best in vitro activity and Cmax/MIC90.

Anti-Bacterial Agents↗

PubMed2003

Changing epidemiology of community-onset methicillin-resistant Staphylococcus aureus bacteremia.

OBJECTIVES: To review cases of community-onset Staphylococcus aureus bacteremia and to evaluate whether the risk factors and epidemiology of methicillin-resistant S. aureus (MRSA) bacteremia have changed from early reports. DESIGN: Retrospective case-comparison study of community-onset MRSA (n = 26) and methicillin-susceptible S. aureus (MSSA) (n = 26) bacteremias at our institution. SETTING: A 600-bed urban academic medical center. PATIENTS: Twenty-six patients with community-onset MRSA bacteremia were compared with 26 patients with community-onset MSSA bacteremia. Molecular analysis was performed on S. aureus isolates from the 26 MRSA cases as well as from 13 cases of community-onset S. aureus bacteremia from 1980 and 9 cases of nosocomial S. aureus bacteremia from 2001. RESULTS: The two groups were similar except that patients with MRSA bacteremia were more likely to have presented from a long-term-care facility (26.9% vs 4%; P = .05) and to have had multiple admissions within the preceding year (46% vs 15%; P = .03). Clamped homogeneous electric fields analysis of MRSA isolates from 1982 revealed predominantly that one clone was the epidemic strain, whereas there were 14 unique strains among current community-onset isolates. Among current nosocomial isolates, 3 patterns were identified, all of which were present in the community-onset cases. CONCLUSIONS: Previously described risk factors for MRSA acquisition may not be helpful in predicting disease due to the polyclonal spread of MRSA in the community. Unlike early outbreaks of MRSA in patients presenting from the community, current acquisition appears to be polyclonal and is usually related to contact with the healthcare system.

Academic Medical Centers↗

PubMed2002

Broad-range bacterial polymerase chain reaction for early detection of bacterial meningitis.

The diagnosis of bacterial meningitis often depends on isolation of bacteria on culture, which may take 24-48 h. DNA amplification techniques could provide rapid diagnosis, which would guide the clinician in antimicrobial therapy decisions. This study determined the clinical utility of polymerase chain reaction (PCR) for the diagnosis of meningitis with use of a broad range of bacterial primers. Seventy-four cerebrospinal fluid specimens obtained from 70 patients were subjected to PCR with use of primers derived from conserved regions of the bacterial 16S RNA gene. The test characteristics for the broad-range bacterial PCR were as follows: sensitivity, 100%; specificity, 98.2%; positive predictive value, 94.4%; and negative predictive value, 100%. Broad-range bacterial PCR may be useful for excluding the diagnosis of meningitis, and the results may influence the decision to initiate or discontinue antimicrobial therapy.

Adolescent↗