Biomedical subjects

Phyllis Della-Latta

Publications and source records attributed to Phyllis Della-Latta.

35 records · Page 2Linked to original sources

PubMed2004

Molecular epidemiology of Serratia marcescens outbreaks in two neonatal intensive care units.

OBJECTIVE: Serratia marcescens can cause serious infections in patients in neonatal intensive care units (NICUs), including sepsis, pneumonia, urinary tract infection, and conjunctivitis. We report the utility of genetic fingerprinting to identify, investigate, and control two distinct outbreaks of S. marcescens. DESIGN: An epidemiologic investigation was performed to control two clusters of S. marcescens infections and to determine possible routes of transmission. Molecular typing by pulsed-field gel electrophoresis determined the relatedness of S. marcescens strains recovered from neonates, the environment, and the hands of healthcare workers (HCWs). SETTING: Two geographically distinct level III-IV NICUs (NICU A and NICU B) in two university-affiliated teaching hospitals in New York City. RESULTS: In NICU A, one major clone, "F," was detected among isolates recovered from four neonates and the hands of one HCW. A second predominant clone, "A," was recovered from four sink drains and one rectal surveillance culture from an asymptomatic neonate. In NICU B, four neonates were infected with clone "D," and three sink drains harbored clone "H." The attributable mortality rate from bloodstream infections was 60% (3 of 5 infants). The antimicrobial susceptibilities of clone F strains varied for amikacin, cefepime, and piperacillin/tazobactam. CONCLUSIONS: S. marcescens causes significant morbidity and mortality in preterm neonates. Cross-transmission via transient hand carriage of a HCW appeared to be the probable route of transmission in NICU A. Sinks did not harbor the outbreak strains. Antimicrobial susceptibility patterns did not prove to be an accurate predictor of strain relatedness for S. marcescens.

Cross Infection↗

PubMed2004

Relationship between triclosan and susceptibilities of bacteria isolated from hands in the community.

The possible association between triclosan and bacterial susceptibility to antibiotic was examined among staphylococci and several species of gram-negative bacteria (GNB) isolated from the hands of individuals in a community setting. Hand cultures from individuals randomized to using either antibacterial cleaning and hygiene products (including a hand soap containing 0.2% triclosan) or nonantibacterial cleaning and hygiene products for a 1-year period were taken at baseline and at the end of the year. Although there was no statistically significant association between triclosan MICs and susceptibility to antibiotic, there was an increasing trend in the association the odds ratios (ORs) for all species were compared at baseline (OR = 0.65, 95% confidence interval [95%CI] = 0.33 to 1.27) versus at the end of the year (OR = 1.08, 95%CI = 0.62 to 1.97) and for GNB alone at baseline(OR = 0.66, 95%CI = 0.29 to 1.51) versus the end of year (OR = 2.69, 95%CI = 0.78 to 9.23) regardless of the hand-washing product used. Moreover, triclosan MICs were higher in some of the species compared to earlier reports on household, clinical, and industrial isolates, and some of these isolates had triclosan MICs in the range of concentrations used in consumer products. The absence of a statistically significant association between elevated triclosan MICs and reduced antibiotic susceptibility may indicate that such a correlation does not exist or that it is relatively small among the isolates that were studied. Still, a relationship may emerge after longer-term or higher-dose exposure of bacteria to triclosan in the community setting.

Anti-Bacterial Agents↗

PubMed2004

Molecular characterization of fluconazole resistance in a case of Candida albicans ocular infection.

Ocular yeast infections in diabetics are a therapeutic challenge. Drug resistance and reduced azole susceptibility are major concerns. The case we describe characterizes a Candida albicans strain from a vitrectomy specimen that was susceptible to fluconazole by in vitro testing but recalcitrant to therapy. Molecular studies revealed transient overexpression of CDR1 and ERG11 mRNA in the presence of fluconazole that may have contributed to poor clinical response in this patient.

Antifungal Agents↗

PubMed2004

Rapid detection of cytomegalovirus infection in transplant patients.

Human cytomegalovirus (CMV) is a well-known cause of morbidity and mortality in transplantation patients. Monitoring of CMV reactivation from latency is critical for these patients. The key to efficient and effective management of CMV infection is a test capable of rapidly monitoring and quantifying the presence of CMV in the blood. This is essential for the identification of subjects at high risk of developing CMV disease, for example, patients receiving steroid or immunosuppressive compounds for accelerated graft-versus-host disease, transplant rejection and also for the application and monitoring of pre-emptive antiviral therapeutic strategies. The assays presently available and frequently used in this setting include conventional and shell vial culture, the CMV antigenemia assay, PCR for CMV DNA, hybrid capture assay for CMV DNA and detection of CMV RNA by nucleic acid sequence-based amplification. The low sensitivity and low reproducibility of conventional cell culture and shell vial assays limit their role in the management of CMV infection to one of disease diagnosis. Diagnostic assays, such as the pp65 antigenemia and other molecular assays, have improved the ability to diagnose CMV disease quickly and accurately. These methods fulfill the requirements for a good diagnostic assay: they have high sensitivity, most can quantify viral load and they are rapid and reproducible. Their characteristics allow these assays to be used to predict the development of CMV disease and monitor response to therapy.

Antigens, Viral↗

PubMed2003

Hospital transmission of community-acquired methicillin-resistant Staphylococcus aureus among postpartum women.

Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are being increasingly observed in patients who lack traditional risk factors. We described 8 postpartum women who developed skin and soft-tissue infections caused by MRSA at a mean time of 23 days (range, 4-73 days) after delivery. Infections included 4 cases of mastitis (3 of which progressed to breast abscess), a postoperative wound infection, cellulitis, and pustulosis. The outbreak strains were compared with the prototype CA-MRSA strain MW2 and found to be indistinguishable by pulsed-field gel electrophoresis. All were spa type 131, all contained the staphylococcal chromosomal cassette mec type IV, and all expressed Panton-Valentine leukocidin and staphylococcal enterotoxins C and H. The route of transmission was not discovered: the results of surveillance cultures of samples obtained from employees of the hospital, the hospital environment, and newborns were negative for the outbreak strain. We report that MW2, which was previously limited to the midwestern United States, has spread to the northeastern United States and has become a health care-associated pathogen.

Anti-Bacterial Agents↗

PubMed2003

Intracameral antibiotic agents for endophthalmitis prophylaxis: a pharmacokinetic model.

PURPOSE: To assess in vitro whether intracameral antibiotic agents are plausibly effective prophylaxis against Staphylococcus aureus endophthalmitis. SETTING: University research laboratory.Staphylococcus aureus was cultured for 8 hours with vancomycin (50 microg/mL) or piperacillin/tazobactam (512/64 microg/mL). Without reducing the bacterial counts, the antibiotic concentration was halved every 2 hours to simulate the half-life of antibiotic agents in the anterior chamber. The number of colony forming units (CFU)/mL was measured at 0, 2, 4, 6, and 8 hours. RESULTS: Vancomycin inhibited the growth of methicillin-resistant S aureus such that the CFU/mL was 1000 times higher in the control group after 8 hours. Piperacillin/tazobactam nearly eliminated 1 oxacillin-susceptible strain and reduced the CFU/mL of another strain 1000-fold. CONCLUSIONS: Intracameral vancomycin may inhibit the growth of S aureus in the anterior chamber after surgery. Inhibiting the growth could increase the chances that the eye's innate defenses would eliminate the bacterial contamination that could cause endophthalmitis.

Anti-Bacterial Agents↗

PubMed2003

Short- and long-term effects of handwashing with antimicrobial or plain soap in the community.

Little is known about effects of public use of antimicrobial handwashing soap. A double-blinded, randomized clinical trial of hands of primary caretakers in 238 inner city households was conducted in which effects of plain or antimicrobial (containing 0.2% triclosan) handwashing soap on bacterial counts of the hands were compared before and after a single wash and before and after handwashing following a year of product use. The randomly assigned product was provided without cost to each household during monthly home visits, and compliance with product use was monitored. Households were contacted by telephone weekly and with a home visit monthly for 11 months. Hand cultures were obtained before and after handwashing at baseline and after 11 months, using a modified glove juice technique. Overall, there were no significant differences in pre-to-post handwashing counts at baseline (p = 0.41), but by the end of one year, post-wash counts were significantly lower than pre-wash (p = 0.000) for those using either antimicrobial or plain soap. There were no significant differences in mean log counts either before or after handwashing between those using the antimicrobial or plain soap at baseline or after a year of use (all p values > 0.28). For the group using antimicrobial soap, higher counts were observed post-handwashing in 31.3% of paired samples at baseline and 26.7% after one year (p = 0.03). A single handwash had minimal effect on quantity of hand flora, but there were significant effects over time, regardless of whether antimicrobial or plain soap was used. In the absence of more definitive evidence, the risk-benefit ratio argues in favor of targeted rather than ubiquitous, general household use of antimicrobial soap.

Anti-Infective Agents, Local↗

PubMed2003

Microbial flora of hands of homemakers.

OBJECTIVES AND METHODS: Because of increasing concern about antimicrobial resistance in the community, aerobic flora of hands of 224 healthy homemakers in northern Manhattan, New York, were examined. RESULTS: Mean log colony-forming unit counts before and after handwashing were 5.72 and 5.69, respectively, P =.60; mean number of species identified/sample was 3.6 before washing and 3.3 after (P =.02). After handwashing gram-negative bacteria were isolated from 75.1% of subjects; yeast from 32.9%; and Staphylococcus aureus from 18.5%, 1 of which (2.4%) was oxacillin-resistant. Generally, these community isolates were more sensitive than isolates from inpatients in the local hospital, although community isolates of Pseudomonas aeruginosa were significantly more resistant than inpatient isolates for 4/10 agents tested. CONCLUSIONS: Hands of healthy persons in the community were usually colonized with gram-negative bacteria, a single handwash had little impact on microbial counts, and hands of healthy adults may increasingly become one reservoir for antimicrobial resistance.

Adult↗

PubMed2003

The epidemiology of multidrug-resistant Acinetobacter baumannii: does the community represent a reservoir?

OBJECTIVE: To explore the role of the community as a potential reservoir for Acinetobacter baumannii. DESIGN: Antimicrobial resistance patterns and genotypes of A. baumannii isolates from patients in two Manhattan hospitals were compared with those of A. baumannii isolates from the hands of community members. RESULTS: A total of 103 isolates from two hospitals (hospital A, 81; hospital B, 22) and 23 isolates from community residents were studied. Of the hospital isolates, 36.6% were multidrug resistant (hospital A, 68.2%; hospital B, 27.8%). In contrast, there were no multidrug-resistant isolates from the community (P < .005 between hospital and community). The prevalence of A. baumannii on the hands of community residents was 10.4% (23 of 222). By molecular typing, 42 strains of A. baumannii were identified. Of the isolates from hospital A and hospital B, 55.6% (45 of 81) and 68.2% (15 of 22), respectively, were indistinguishable or closely related. In contrast, most community (83.3%) isolates were unrelated (P = .001 between hospital and community). CONCLUSION: Acinetobacter isolates from the community, characterized by a large variety of unrelated strains (83.3%), were distinct from the hospital isolates, of which 58.3% were closely related. The absence of multidrug-resistant strains in the community compared with 36.8% prevalence among hospital isolates suggests that the reservoir for epidemic strains resides in the hospital environment itself. To our knowledge, this is the first study to examine the community as a potential reservoir for hospital strains of A. baumannii.

Acinetobacter Infections↗

PubMed2003

An outbreak of methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit.

OBJECTIVE: To describe the epidemiologic and molecular investigations that successfully contained an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in a neonatal intensive care unit (NICU). DESIGN: Isolates of MRSA were typed by pulsed-field gel electrophoresis (PFGE) and S. aureus protein A (spa). SETTING: A level III-IV, 45-bed NICU located in a children's hospital within a medical center. PATIENTS: Incident cases had MRSA isolated from clinical cultures (eg, blood) or surveillance cultures (ie, anterior nares). INTERVENTIONS: Infected and colonized infants were placed on contact precautions, cohorted, and treated with mupirocin. Surveillance cultures were performed for healthcare workers (HCWs). Colonized HCWs were treated with topical mupirocin and hexachlorophene showers. RESULTS: From January to March 2001, the outbreak strain of MRSA, PFGE clone B, was harbored by 13 infants. Three (1.3%) of 235 HCWs were colonized with MRSA. Two HCWs, who rotated between the adult and the pediatric facility, harbored clone C. One HCW, who exclusively worked in the children's hospital, was colonized with clone B. From January 1999 to November 2000, 22 patients hospitalized in the adult facility were infected or colonized with clone B. Spa typing and PFGE yielded concordant results. PFGE clone B was identified as spa type 16, associated with outbreaks in Brazil and Hungary. CONCLUSIONS: A possible route of MRSA transmission was elucidated by molecular typing. MRSA appears to have been transferred from our adult facility to our pediatric facility by a rotating HCW. Spa typing allowed comparison of our institution's MRSA strains with previously characterized outbreak clones.

Cross Infection↗

PubMed2003

Attributable costs and length of stay of an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae outbreak in a neonatal intensive care unit.

OBJECTIVES: To determine the costs of the interventions aimed at controlling the 4-month outbreak and to determine the attributable length of stay (LOS) associated with infection and colonization with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae. DESIGN: A retrospective cost analysis was conducted from the hospital perspective. A micro-costing approach was employed. The LOS of four groups of hospitalized patients were compared with each other. National Perinatal Information Center criteria were used to stratify infants for severity of risk. The LOS of each group was compared with that of a national sample of similarly stratified infants. SETTING: A level III-IV, 45-bed neonatal intensive care unit. PATIENTS: Infant groups were infected (n = 8), colonized (n = 14), concurrent cohort (n = 54), and prior cohort (n = 486). RESULTS: The cost of the outbreak totaled 341,751 dollars. The largest proportion of costs was related to healthcare worker time providing direct patient care (2,489 hours at a cost of 146,331 dollars). Infected and colonized neonates had longer LOS than either the concurrent cohort or the prior cohort (P < .001). Compared with the national sample, infected infants had a 48.5-day longer mean LOS (95% confidence interval [CI95], 1.7 to 95.2), whereas the prior cohort's mean LOS was 6 days shorter (CI95, -9.4 to -2.9). CONCLUSIONS: This study increases the understanding of the burden of these multidrug-resistant organisms. Further research is needed to estimate the societal costs of these infections and the cost-effectiveness of preventive interventions.

Anti-Bacterial Agents↗

PubMed2003

Transfusion-associated babesiosis after heart transplant.

We describe a 54-year-old spleen-intact man with transfusion-associated Babesia microti infection after a heart transplant. Adult respiratory distress syndrome developed in the patient, and he required mechanical ventilation. Our experiences with this patient suggest that babesiosis should be considered in the differential diagnosis of transplant patients who have fever and hemolytic anemia.

Babesia microti↗

PubMed2002

Linezolid-resistant Enterococcus faecium isolated from a patient without prior exposure to an oxazolidinone: report from the SENTRY Antimicrobial Surveillance Program.

A patient case report describes an Enterococcus faecium strain isolated from a blood culture that was resistant to linezolid (MIC, 8 microg/mL; G2576U mutation of 23S rRNA). Co-resistances were identified for vancomycin, ampicillin, macrolides, fluoroquinolones, chloramphenicol, rifampin, gentamicin (high-level), nitrofurantoin and trimethoprim/sulfamethoxazole. Etest (AB BIODISK, Solna, Sweden) and disk diffusion results also detected the oxazolidinone resistance pattern. Laboratories should be aware of the rare possibility of these strains occurring during linezolid therapy or spontaneously (this case) in contemporary practice, and have in vitro susceptibility methods available capable of detecting oxazolidinone resistance.

Acetamides↗

PubMed2002

Molecular typing strategies.

Nosocomial infections among infants in neonatal intensive care units are an increasing cause of morbidity and mortality. Efforts to rapidly detect, contain and ultimately prevent cross-transmission of these pathogens require constant vigilance by members of the epidemiology team. A vital component of an epidemiological evaluation is the ability to assess the interrelatedness of clinical isolates. This review focuses on the basic principles, strengths and weaknesses of some of the most commonly used molecular-based procedures, which determine clonal identity of outbreak strains in neonatal settings. Published evidence for the cogent selection of the method best suited for studying a particular organism and technological advances that await the new science of Molecular Epidemiology are also presented. The appropriate use of molecular typing technologies should enable reliable tracking of epidemic clones and thereby enhance the effectiveness of infection control strategies.

Bacteriophage Typing↗

PubMed2002

Nosocomial transmission of methicillin-resistant Staphylococcus aureus from a mother to her preterm quadruplet infants.

BACKGROUND: Patient-to-patient transmission of methicillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs) has been well described. We report the first documented outbreak of probable transmission of MRSA from a mother to 3 of her preterm quadruplet infants postnatally. METHODS: Routine surveillance of clinical microbiologic laboratory reports revealed an increased incidence of MRSA infections in our NICU, including 3 of 4 preterm quadruplets. Surveillance cultures of the anterior nares of all patients and the quadruplets' parents were performed to detect MRSA carriage. The isolates were typed by pulsed-field gel electrophoresis with the restriction endonuclease SmaI. Infection control strategies included mupirocin treatment and contact isolation precautions for infected/colonized infants. RESULTS: Clinical cultures from infants A, C, and D and surveillance cultures of the quadruplets' mother and 2 additional unrelated infants grew the same clone of MRSA. The mother's only identified risk factors for MRSA acquisition were 2 prepartum hospitalizations related to the multiple gestation and previous treatment with antibiotics. All anterior nares cultures were negative for MRSA after mupirocin treatment. CONCLUSIONS: Use of gowns and gloves by the family members of women with multiple gestations should be recommended to prevent transmission of potential pathogens in the NICU.

Adult↗

PubMed2002

Epidemiology of methicillin-susceptible Staphylococcus aureus in the neonatal intensive care unit.

OBJECTIVE: When the incidence of methicillin-susceptible Staphylococcus aureus (MSSA) infection or colonization increased in our neonatal intensive care unit (NICU), we sought to further our understanding of the relationship among colonization with MSSA, endemic infection, and clonal spread. DESIGN: A retrospective cohort study was used to determine risk factors for acquisition of a predominant clone of MSSA (clone "B"). SETTING: A 45-bed, university-affiliated, level III-IV NICU. PATIENTS: Infants hospitalized in the NICU from October 1999 to September 2000. INTERVENTIONS: Infection control strategies included surveillance cultures of infants, cohorting infected or colonized infants, contact precautions, universal glove use, mupirocin treatment of the anterior nares of all infants in the NICU, and a hexachlorophene bath for infants weighing 1,500 g or more. RESULTS: During the 1-year study period, three periods of increased incidence of MSSA colonization or infection, ranging from 6.4 to 13.5 cases per 1,000 patient-days per month, were observed. Molecular typing using pulsed-field gel electrophoresis demonstrated two predominant clones, clone "B" and clone "G," corresponding to two periods of increased incidence. Multivariate analysis demonstrated that length of stay (OR, 1.035; 95% confidence interval [CI95], 1.008 to 1.062; P = .010) increased risk per day) and the use of H2-blockers (OR, 20.44; CI95, 2.48 to 168.26; P = .005) were risk factors for either colonization or infection with clone "B," and that the use of peripheral catheters was protective (OR, 0.06; CI95, 0.01 to 0.43; P= .005). CONCLUSIONS: Control of MSSA represents unique challenges as colonization is expected, endemic infections are tolerated, and surveillance efforts generally focus on multidrug-resistant pathogens. Future studies should address cost-effective surveillance strategies for endemic infections.

Cohort Studies↗

PubMedDate not supplied

Prevalence and antimicrobial patterns of Acinetobacter baumannii on hands and nares of hospital personnel and patients: the iceberg phenomenon again.

OBJECTIVE: To determine the prevalence and antimicrobial susceptibility patterns of Acinetobacter baumannii on the hands and nares of health care workers and patients from intensive care and rehabilitation units at two hospitals in northern Manhattan, New York. DESIGN: Prevalence survey of Acinetobacter on the hands and anterior nares of staff (n = 184) and patients (n = 98) in rehabilitation and intensive care units of two hospitals. RESULTS: Twenty subjects (7.1%) had positive test results for A baumannii (6 staff [3.3%] and 14 patients [14.3%]). Five patients had positive test results at both sites, four in the nares only, and 11 on hands only. Among patients, four significant predictors of A baumannii were days on unit (P = .003), location (hospital A or B) (P = .01), surgery (P = .04), and receiving an antifungal agent (P = .02; OR, 5.6; 95% CI, 1.25-24.52). Among staff, predictors were skin damage (P = .02) and employment in hospital B (P = .03). Nine of the 20 subjects (45%) had positive test results for multiresistant strains, one from a staff member and eight from patients. CONCLUSION: Patients whose conditions are not clinically symptomatic for A baumannii, as well as staff, are often colonized. Staff with damaged skin are more likely to be colonized. Control of this organism will only be possible when the principle of the iceberg phenomenon--all patients (and staff) treated with standard, Universal Precautions--is strictly followed. Further, the endemic prevalence of multiresistant strains may be higher than previously appreciated.

Acinetobacter Infections↗