Biomedical subjects

Bette Jensen

Publications and source records attributed to Bette Jensen.

12 recordsLinked to original sources

PubMed2006

High-level vancomycin-resistant Staphylococcus aureus isolates associated with a polymicrobial biofilm.

Glycopeptides such as vancomycin are the treatment of choice for infections due to methicillin-resistant Staphylococcus aureus. This study describes the identification of high-level vancomycin-resistant S. aureus (VRSA) isolates in a polymicrobial biofilm within an indwelling nephrostomy tube in a patient in New York. S. aureus, Enterococcus faecalis, Enterococcus faecium, Micrococcus species, Morganella morganii, and Pseudomonas aeruginosa were isolated from the biofilm. For VRSA isolates, vancomycin MICs ranged from 32 to >128 microg/ml. VRSA isolates were also resistant to aminoglycosides, fluoroquinolones, macrolides, penicillin, and tetracycline but remained susceptible to chloramphenicol, linezolid, rifampin, and trimethoprim-sulfamethoxazole. The vanA gene was localized to a plasmid of approximately 100 kb in VRSA and E. faecium isolates from the biofilm. Plasmid analysis revealed that the VRSA isolate acquired the 100-kb E. faecium plasmid, which was then maintained without integration into the MRSA plasmid. The tetracycline resistance genes tet(U) and tet(S), not previously detected in S. aureus isolates, were identified in the VRSA isolates. Additional resistance elements in the VRSA isolate included a multiresistance gene cluster, ermB-aadE-sat4-aphA-3, msrA (macrolide efflux), and the bifunctional aminoglycoside resistance gene aac(6')-aph(2")-Ia. Multiple combinations of resistance genes among the various isolates of staphylococci and enterococci, including vanA, tet(S), and tet(U), illustrate the dynamic nature of gene acquisition and loss within and between bacterial species throughout the course of infection. The potential for interspecies transfer of antimicrobial resistance genes, including resistance to vancomycin, may be enhanced by the microenvironment of a biofilm.

Acetamides↗

PubMed2006

Emergence of community-associated methicillin resistant Staphylococcus aureus in Hawaii, 2001-2003.

OBJECTIVES: We conducted a retrospective study to determine trends and characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Hawaii. METHODS: We reviewed medical records of patients with MRSA infections during July 2001-June 2003 in four healthcare facilities. A case was defined as a patient with MRSA infection (colonization excluded), diagnosed in ambulatory settings or < or = 48 h after hospitalization, without previous MRSA or healthcare risk factors. Pulsed-field gel electrophoresis (PFGE) and typing of resistance and toxin genes was performed in 40 MRSA isolates. RESULTS: CA-MRSA infections increased from 28 (23% of MRSA infections) to 65 (32%) per quarter over the 2-year period (P<0.05). Pacific islanders accounted for 51% of 389 case-patients, but only 24% of the Hawaii population. In the pediatric hospital, Pacific Islanders represented 76% of 90 case-patients versus 35% of the hospital population. Hospital admission, required for 40% (154/389), was associated with prior antimicrobial treatment (P<0.01). The staphylococcal cassette chromosome mec type IV was detected in 38/40 isolates; 31 isolates carried Panton-Valentine leukocidin genes and 22 belonged to the same staphylococcal lineage. CONCLUSIONS: In Hawaii, prevention strategies for CA-MRSA infections should focus on Pacific Islanders. CA-MRSA infections in Hawaii appear to be related to strains causing disease throughout the United States.

Adolescent↗

PubMed2006

Life-threatening sepsis caused by Burkholderia cepacia from contaminated intravenous flush solutions prepared by a compounding pharmacy in another state.

We report 2 life-threatening cases of Burkholderia cepacia sepsis caused by infusate contamination during compounding. Bacterial isolates from the patients' blood cultures and the infusate were indistinguishable by pulsed-field gel electrophoresis. Proper quality controls at a local and national level are important for ensuring safe delivery of compounded medications to patients in all settings, including those outside health care facilities.

Bacteremia↗

PubMed2006

An outbreak of Burkholderia cepacia associated with contamination of albuterol and nasal spray.

BACKGROUND: Species within the Burkholderia cepacia complex (Bcc) can contaminate medications and disinfectants and cause severe pneumonia in critically ill patients or persons with cystic fibrosis. In March 2004, we investigated a hospital outbreak of Bcc possibly associated with a contaminated nasal spray. METHODS: We conducted a matched case-control study, environmental sampling, and observations of infection control practices. Case patients had infection or colonization with Bcc, and control patients had sputum culture not yielding Bcc. Isolates from patients and environmental samples were compared by pulsed-field gel electrophoresis (PFGE). RESULTS: Bcc was recovered from sputum in 18 patients. Compared with matched control patients (n = 18), case patients were more likely to be receiving mechanical ventilation (p = 0.01), to have been hospitalized > 6 days (p = 0.01), and to have received antimicrobial treatment within 7 days before sputum collection (p = 0.03). Bcc was cultured from opened, but not unopened, multidose albuterol bottles, a nebulizer attached to a ventilator, and opened and unopened nasal spray bottles from contaminated lots. PFGE showed that isolates from albuterol samples and from patients were indistinguishable but unrelated to the nasal spray strain. Observations revealed improper aseptic techniques during respiratory therapy procedures and inadequate nebulizer cleaning. CONCLUSIONS: Despite a temporal association with use of a contaminated nasal spray, this outbreak was caused by extrinsic contamination of multidose albuterol used for nebulization treatments and lack of adherence to infection control precautions. Implementation and re-enforcement of infection control measures successfully terminated the outbreak.

Administration, Intranasal↗

PubMed2005

Prevalence of Staphylococcus aureus nasal colonization in the United States, 2001-2002.

BACKGROUND: Staphylococcus aureus is a common cause of disease, particularly in colonized persons. Although methicillin-resistant S. aureus (MRSA) infection has become increasingly reported, population-based S. aureus and MRSA colonization estimates are lacking. METHODS: Nasal samples for S. aureus culture and sociodemographic data were obtained from 9622 persons > or = 1 year old as part of the National Health and Nutrition Examination Survey, 2001-2002. After screening for oxacillin susceptibility, MRSA and selected methicillin-susceptible S. aureus isolates were tested for antimicrobial susceptibility, pulsed-field gel electrophoresis clonal type, toxin genes (e.g., for Panton-Valentine leukocidin [PVL]), and staphylococcal cassette chromosome mec (SCCmec) type I-IV genes. RESULTS: For 2001-2002, national S. aureus and MRSA colonization prevalence estimates were 32.4% (95% confidence interval [CI], 30.7%-34.1%) and 0.8% (95% CI, 0.4%-1.4%), respectively, and population estimates were 89.4 million persons (95% CI, 84.8-94.1 million persons) and 2.3 million persons (95% CI, 1.2-3.8 million persons), respectively. S. aureus colonization prevalence was highest in participants 6-11 years old. MRSA colonization was associated with age > or = 60 years and being female but not with recent health-care exposure. In unweighted analyses, the SCCmec type IV gene was more frequent in isolates from participants of younger age and of non-Hispanic black race/ethnicity; the PVL gene was present in 9 (2.4%) of 372 of isolates tested. CONCLUSIONS: Many persons in the United States are colonized with S. aureus; prevalence rates differ demographically. MRSA colonization prevalence, although low nationally in 2001-2002, may vary with demographic and organism characteristics.

Adolescent↗

PubMed2005

A clone of methicillin-resistant Staphylococcus aureus among professional football players.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of infections outside of health care settings. We investigated an outbreak of abscesses due to MRSA among members of a professional football team and examined the transmission and microbiologic characteristics of the outbreak strain. METHODS: We conducted a retrospective cohort study and nasal-swab survey of 84 St. Louis Rams football players and staff members. S. aureus recovered from wound, nasal, and environmental cultures was analyzed by means of pulsed-field gel electrophoresis (PFGE) and typing for resistance and toxin genes. MRSA from the team was compared with other community isolates and hospital isolates. RESULTS: During the 2003 football season, eight MRSA infections occurred among 5 of the 58 Rams players (9 percent); all of the infections developed at turf-abrasion sites. MRSA infection was significantly associated with the lineman or linebacker position and a higher body-mass index. No MRSA was found in nasal or environmental samples; however, methicillin-susceptible S. aureus was recovered from whirlpools and taping gel and from 35 of the 84 nasal swabs from players and staff members (42 percent). MRSA from a competing football team and from other community clusters and sporadic cases had PFGE patterns that were indistinguishable from those of the Rams' MRSA; all carried the gene for Panton-Valentine leukocidin and the gene complex for staphylococcal-cassette-chromosome mec type IVa resistance (clone USA300-0114). CONCLUSIONS: We describe a highly conserved, community-associated MRSA clone that caused abscesses among professional football players and that was indistinguishable from isolates from various other regions of the United States.

Abscess↗

PubMed2005

Emerging infections with community-associated methicillin-resistant Staphylococcus aureus in outpatients at an Army Community Hospital.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infection typically occurs in chronically ill patients requiring long-term antimicrobial therapy or hospitalization. However, community-associated MRSA (CA-MRSA) necrotizing soft tissue infections seem to be increasing in incidence. Our aim was to describe the incidence and microbiologic characteristics of CA-MRSA isolates collected at an army community hospital. METHODS: We report a retrospective review of MRSA isolates identified during 1998-2003 at the microbiology laboratory of Moncrief Army Community Hospital that serves a community of approximately 40,000 transient residents yearly in Fort Jackson, South Carolina. We evaluated the incidence of MRSA in our laboratory during 1998-2003. For MRSA isolates from 2003, we evaluated antimicrobial susceptibility patterns. Six selected isolates were evaluated by molecular typing, resistance gene analysis, and toxin analysis. RESULTS: During 1998-2003, 241 (23%) of 1041 S. aureus isolates identified at the hospital microbiology laboratory were resistant to methicillin. Of these 241 MRSA isolates, 223 were cultured from outpatients. The incidence of MRSA in our population increased from 12% of S. aureus isolates in 1998 to 43% in 2003. In 2003, MRSA was cultured from 76 different patients. Isolates of MRSA were often resistant to erythromycin (91%), although resistance to other agents was less common: Ciprofloxacin (14%), levofloxacin (14%), clindamycin (3%), tetracycline (3%), and trimethoprim sulfamethoxazole (1%). No isolates were resistant to vancomycin, gentamicin, nitrofurantoin, or rifampin. Six CA-MRSA isolates were compared by pulsed-field gel electrophoresis (PFGE). Five were PFGE type USA300, and one was PFGE type USA100, based on the U.S. Centers for Disease Control and Prevention (CDC) classification scheme. The five USA300 isolates carried SCCmec type IV, and the USA100 carried SCCmec II. None of the isolates were positive by PCR for genes encoding enterotoxins A-E and H, or toxic shock syndrome toxin (TSST-1), but the five USA300 isolates carried the gene coding for Panton-Valentine leukocidin toxin. CONCLUSIONS: The incidence of MRSA at our institution is increasing. Isolates of MRSA show resistance patterns and microbiologic characteristics consistent with CA-MRSA isolates from the United States. Clinicians should consider the possibility of CA-MRSA in patients with soft-tissue infections who do not respond to initial therapy with beta-lactam antimicrobial agents.

Community-Acquired Infections↗

PubMed2005

Chlorine inactivation of bacterial bioterrorism agents.

Seven species of bacterial select agents were tested for susceptibility to free available chlorine (FAC). Under test conditions, the FAC routinely maintained in potable water would be sufficient to reduce six species by 2 orders of magnitude within 10 min. Water contaminated with spores of Bacillus anthracis spores would require further treatment.

Bacillus anthracis↗

PubMed2004

Swab materials and Bacillus anthracis spore recovery from nonporous surfaces.

Four swab materials were evaluated for their efficiency in recovery of Bacillus anthracis spores from steel coupons. Cotton, macrofoam, polyester, and rayon swabs were used to sample coupons inoculated with a spore suspension of known concentration. Three methods of processing for the removal of spores from the swabs (vortexing, sonication, or minimal agitation) and two swab preparations (premoistened and dry) were evaluated. Results indicated that premoistened swabs were more efficient at recovering spores than dry swabs (14.3% vs. 4.4%). Vortexing swabs for 2 min during processing resulted in superior extraction of spores when compared to sonicating them for 12 min or subjecting them to minimal agitation. Premoistened macrofoam and cotton swabs that were vortexed during processing recovered the greatest proportions of spores with a mean recovery of 43.6% (standard deviation [SD] 11.1%) and 41.7% (SD 14.6%), respectively. Premoistened and vortexed polyester and rayon swabs were less efficient, at 9.9% (SD 3.8%) and 11.5% (SD 7.9%), respectively.

Anthrax↗

PubMed2004

Mycobacterium goodii infections associated with surgical implants at Colorado hospital.

From February to October 2003, Mycobacterium goodii wound infections were identified among three patients who received surgical implants at a Colorado hospital. This report summarizes the investigation of the first reported nosocomial outbreak of M. goodii. Increased awareness is needed about the potential for nontuberculous mycobacteria to cause postoperative wound infections.

Aged↗

PubMed2003

Enterobacter cloacae bloodstream infections in pediatric patients traced to a hospital pharmacy.

The sources of an outbreak of Enterobacter cloacae bloodstream infections in a pediatric hospital were investigated, as were the risk factors for acquiring the infection: Two retrospective case-control studies were conducted. The study sample included all patients admitted to the general pediatric wards from February 5 through March 30, 2001, who had a positive blood culture for E. cloacae. Pediatric ward and pharmacy infection-control practices were reviewed, personnel and environmental cultures were obtained, and pulsed-field gel electrophoresis (PFGE) molecular typing of the bloodstream isolates was conducted. Four subjects were identified. These infants were more likely than control patients to receive i.v. ranitidine (p < 0.01). Among patients receiving i.v. ranitidine, subjects were more likely than controls to receive i.v. ranitidine prepared by a pharmacist. No environmental or personnel cultures yielded E. cloacae. Patients' E. cloacae isolates had four different PFGE patterns, suggesting environmental rather than point-source contamination. Ranitidine multidose vials were kept connected to an automatic compounding machine for up to 48 hours at room temperature after the first dose was drawn, contrary to manufacturer recommendations. Further, preparation of ranitidine infusions was not conducted in accordance with recommendations for risk level 2 sterile i.v. products. The use of contaminated ranitidine multidose vials was the most likely cause of an outbreak of E. cloacae. However, a combination of other factors such as inadequate hand-washing techniques, presence of E. cloacae in the environment, noncompliance with guidelines for the preparation of sterile infusions and medications, and a susceptible population may have contributed to the infections.

Case-Control Studies↗

PubMedDate not supplied

A hospital outbreak of diarrhea due to an emerging epidemic strain of Clostridium difficile.

BACKGROUND: Increased Clostridium difficile-associated disease (CDAD) in a hospital and an affiliated long-term care facility continued despite infection control measures. We investigated this outbreak to determine risk factors and transmission settings. METHODS: The CDAD cases were compared according to where the disease was likely acquired based on health care exposure and characterization of isolates from case patients, asymptomatic carriers, and the environment. Antimicrobial susceptibility testing, strain typing using pulsed-field gel electrophoresis, and toxinotyping were performed, and toxins A and B, binary toxin, and deletions in the tcdC gene were detected using polymerase chain reaction. Risk factors were examined in a case-control study, and overall antimicrobial use was compared at the hospital before and during the outbreak. RESULTS: Significant increases were observed in hospital-acquired (0.19 vs 0.86; P < .001) and long-term care facility-acquired (0.04 vs 0.31; P = .004) CDAD cases per 100 admissions as a result of transmission of a toxinotype III strain at the hospital and a toxinotype 0 strain at the long-term care facility. The toxinotype III strain was positive for binary toxin, an 18-base pair deletion in tcdC, and increased resistance to fluoroquinolones. Independent risk factors for CDAD included use of fluoroquinolones (odds ratio [OR], 3.22; P = .04), cephalosporins (OR, 5.19; P = .006), and proton pump inhibitors (OR, 5.02; P = .02). A significant increase in fluoroquinolone use at the hospital took place during the outbreak (185.5 defined daily doses per 1000 patient-days vs 200.9 defined daily doses per 1000 patient-days; P < .001). CONCLUSIONS: The hospital outbreak of CDAD was caused by transmission of a more virulent, fluoroquinolone-resistant strain of C difficile. More selective fluoroquinolone and proton pump inhibitor use may be important in controlling and preventing such outbreaks.

Adult↗