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Biomedical subjects

A S Levin

Publications and source records attributed to A S Levin.

At least 19 recordsLinked to original sources

Investigation of the possible association between nosocomial candiduria and candidaemia.

This study aimed to determine whether candiduria is associated with the occurrence of nosocomial candidaemia. In the case-control part of the study, 115 cases (nosocomial candidaemia) and 115 controls (nosocomial bacteraemia) were similar in age, severity of condition and time of hospitalisation. There was a significant association of candidaemia with candiduria (OR 9.79; 95% CI 2.14-44.76). In the microbiology part of the study, 23 pairs of Candida-positive urine and blood cultures were obtained from 23 patients. In ten (43%) cases, the urine and blood culture isolates belonged to different species, and molecular typing showed a difference in two of the 13 cases yielding the same species from both specimens. Overall, there was a significant association between candiduria and candidaemia, but the Candida isolates from urine and blood were different for 52% of the patients. Thus, the data indicated that the urinary tract was probably not a source for the candidaemia.

Adolescent↗

Clonal dissemination of VanA-type glycopeptide-resistant Enterococcus faecalis between hospitals of two cities located 100 km apart.

Nosocomial dissemination of glycopeptide-resistant enterococci represents a major problem in hospitals worldwide. In Brazil, the dissemination among hospitals in the city of São Paulo of polyclonal DNA profiles was previously described for vancomycin-resistant Enterococcus faecium. We describe here the dissemination of VanA phenotype E. faecalis between two hospitals located in different cities in the State of São Paulo. The index outbreak occurred in a tertiary care university hospital (HCUSP) in the city of São Paulo and three years later a cluster caused by the same strain was recognized in two patients hospitalized in a private tertiary care hospital (CMC) located 100 km away in the interior of the state. From May to July 1999, 10 strains of vancomycin-resistant E. faecalis were isolated from 10 patients hospitalized in the HCUSP. The DNA genotyping using pulsed-field gel electrophoresis (PFGE) showed that all isolates were originated from the same clone, suggesting nosocomial dissemination. From May to July 2002, three strains of vancomycin-resistant E. faecalis were isolated from two patients hospitalized in CMC and both patients were colonized by the vancomycin-resistant Enterococcus in skin lesions. All isolates from CMC and HCUSP were highly resistant to vancomycin and teicoplanin. The three strains from CMC had minimum inhibitory concentration >256 micro g/ml for vancomycin, and 64 (CMC 1 and CMC 2) and 96 micro g/ml (CMC 3) for teicoplanin, characterizing a profile of VanA resistance to glycopeptides. All strains had the presence of the transposon Tn1546 detected by PCR and were closely related when typed by PFGE. The dissemination of the E. faecalis VanA phenotype among hospitals located in different cities is of great concern because E. faecalis commonly colonizes the gastrointestinal tract of patients and healthy persons for periods varying from weeks to years, which, together with the persistence of vancomycin-resistant Enterococcus in hospital rooms after standard cleaning procedures, increases the risk of the dissemination and reservoir of the bacteria.

Anti-Bacterial Agents↗

A nosocomial outbreak of Salmonella enteritidis associated with lyophilized enteral nutrition.

Outbreaks of Salmonella spp. gastro-enteritis in hospitals are of concern because of the increased susceptibility of patients and associated high morbidity. This study is a report of a nosocomial outbreak of Salmonella enteritidis associated with enteral nutrition. In December 1999, one sample of enteral feed tested positive for S. enteritidis. During the subsequent 6 weeks, eight cases of nosocomial salmonellosis occurred. Patients involved in the outbreak were aged 19-79 years (median = 36.5), and salmonella was isolated from the blood of two patients. All patients were receiving enteral nutrition at the time and all had diarrhoea. Three patients died. All 13 employees of the Nutrition Department were asymptomatic and their stool samples were negative. Environmental and water samples were also negative. The diet, however, contained lyophilized egg albumin. Molecular typing showed that the isolates of seven patients were indistinguishable from the one obtained from the enteral diet. It was thought that the nosocomial salmonellosis probably occurred due to the use of a commercial lyophilized diet. Another method of processing diets may be necessary to ensure patient safety.

Adult↗

Factors associated with penicillin-nonsusceptible pneumococcal infections in Brazil.

Resistance of Streptococcus pneumoniae is a worldwide, growing problem. Studies of factors associated with resistance to penicillin have not been conducted in Brazil. The objective of the present study was to evaluate factors associated with infection by S. pneumoniae not susceptible to penicillin. A prevalence study was conducted including all patients with a positive culture for S. pneumoniae in a hospital from July 1991 to December 1992 and the year 1994. Of 165 patients identified, 139 were considered to have clinically relevant infections and 88% of them had invasive infections. All infections were community acquired and consisted of pneumonia (44%) and of central nervous system (19%), pelvic or abdominal (12%), upper airway or ocular (12%), primary bloodstream (9%) and skin and soft tissue (5%) infections. Mortality was 25%. Susceptibility to penicillin was present in 77.6% of the isolates; 21.8% were relatively resistant, and one isolate was resistant (minimal inhibitory concentration = 4 micro g/ml). Multivariate analysis showed that age below 4 years (odds ratio (OR): 3.53, 95% confidence interval (95%CI): 1.39-8.96) and renal failure (OR: 5.50, 95%CI: 1.07-28.36) were associated with lack of susceptibility to penicillin. Bacteremia occurred significantly less frequently in penicillin-nonsusceptible infections (OR: 0.34, 95%CI: 0.14-0.84), possibly suggesting that lack of penicillin susceptibility is associated with lower virulence in S. pneumoniae.

Adolescent↗

Comparative performance of two air samplers for monitoring airborne fungal propagules.

Many studies have attempted to evaluate the importance of airborne fungi in the development of invasive fungal infection, especially for immunocompromised hosts. Several kinds of instruments are available to quantitate fungal propagule levels in air. We compared the performance of the most frequently used air sampler, the Andersen sampler with six stages, with a portable one, the Reuter centrifugal sampler (RCS). A total of 84 samples were analyzed, 42 with each sampler. Twenty-eight different fungal genera were identified in samples analyzed with the Andersen instrument. In samples obtained with the RCS only seven different fungal genera were identified. The three most frequently isolated genera in samples analyzed with both devices were Penicillium, Aspergillus and Cladophialophora. In areas supplied with a high efficiency particulate air filter, fungal spore levels were usually lower when compared to areas without these filters. There was a significant correlation between total fungal propagule measurements taken with both devices on each sampling occasion (Pearson coefficient = 0.50). However, the Andersen device recovered a broader spectrum of fungi. We conclude that the RCS can be used for quantitative estimates of airborne microbiological concentrations. For qualitative studies, however, this device cannot be recommended.

Air Microbiology↗

Infections in a burn intensive care unit: experience of seven years.

The objective of this study is to describe infections in a specialized burns intensive care unit from 1993 to 1999. The criteria for admission to the unit are: children with burns involving at least 10% or adults with burns involving at least 20% of total body surface; burns affecting face, perineum or feet; suspected or proven airway injury; electric or chemical burns; age less than one year or above 50; or pre-existing disease with any extent of burns. Surveillance of hospital-acquired infection was prospective. Hospital-acquired infection criteria used were those modified from the Centers for Disease Control and Prevention. Diagnosis of infection using skin biopsy was not done. Over the study period, 320 patients were admitted to our burns intensive care unit. One hundred and seventy-five (55%) developed 388 hospital-acquired infections. The rate for vascular catheter-associated bloodstream infections was 34 per 1,000 central line-days. The rate of ventilator associated pneumonia was 26 infections per 1,000 ventilator-days. Primary bloodstream was the most common infection with 189 episodes (49%); followed by 83 burn wound infections (21%) and 56 pneumonias (14%). In 76% of these infections and in 97% of the primary bloodstream infections, aetiological agents were identified. The micro-organisms causing infections were S taphylococcus aureus (24%), Pseudomonas aeruginosa (18%), Acinetobacter spp. (14%) and coagulase-negative staphylococci (12%). Candida spp. caused 8% of infections. Gram-positive and Gram-negative organisms exhibited resistance to most antimicrobial agents used for therapy. During the first three days of hospitalization in the burns intensive care unit there were eight infections caused by S. aureus and three of these were resistant to oxacillin. These data provide background information regarding extensive burn patients on which decisions for control and prevention of hospital-acquired infections can be made.

Adolescent↗

Multiresistant Acinetobacter infections: a role for sulbactam combinations in overcoming an emerging worldwide problem.

Recent studies have highlighted the emergence of infections involving multiresistant Acinetobacter clinical isolates. Sulbactam offers direct antimicrobial activity against Acinetobacter species. Accordingly, co-administration of sulbactam with ampicillin or cefoperazone offers the potential of effective empirical therapy against Acinetobacter and other bacteria such as Enterobacteriaceae in institutions in which they are susceptible. Many in vitro studies have indicated that Acinetobacter remains fully susceptible to ampicillin-sulbactam or cefoperazone-sulbactam. Furthermore, ampicillin-sulbactam has proven clinically effective and well tolerated in the treatment of severe acinetobacter infections, including bacteremia. Therefore, ampicillin-sulbactam is a sensible option for the treatment of life-threatening acinetobacter infections.

Acinetobacter↗

Nosocomial pneumonia: importance of recognition of aetiological agents to define an appropriate initial empirical therapy.

Of the 16,024 patients hospitalized from January 1995 to October 1997, 397 (2.4%) acquired nosocomial pneumonia and the aetiological agent was defined in 101 (25%). About 82% developed late onset pneumonia (>7 days of hospitalization). The site of isolation of microorganisms was bronchoalveolar lavage (BAL) (49%), blood culture (39%), pleural effusion (10%) and (2%) pulmonary tissue. Gram-negative bacteria were responsible for 54% of infections. Staphylococcus aureus (34%) was the most frequent microorganism isolated followed by Acinetobacter baumannii (29%) and Pseudomonas aeruginosa and Klebsiella pneumoniae, responsible for 7% of nosocomial pneumonia. Monotherapy gave good cover for early onset pneumonia, but not for late onset pneumonia. Based on our selection criteria, ciprofloxacin was the best monotherapy for early (50%) and late (31%) onset pneumonia. Vancomycin plus ciprofloxacin gave cover of 85% of early and 64% of late onset pneumonia. Monotherapy with ciprofloxacin and also combination therapy of ciprofloxacin plus vancomycin may be good options as initial empirical therapy for nosocomial pneumonia.

Anti-Bacterial Agents↗

Environmental contamination by multidrug-resistant Acinetobacter baumannii in an intensive care unit.

Contamination in an intensive care unit caused by multidrug-resistant Acinetobacter baumannii complex (MRAB)-colonized patients was evaluated using environmental and patient cultures. MRAB occurred in 21% of patients' cultures, 2.1% of 513 areas surrounding MRAB-patients, and one of 372 common areas. No transmission to other patients occurred. Barrier precautions and ethanol disinfection may prevent dissemination.

Acinetobacter Infections↗

Pichia anomala outbreak in a nursery: exogenous source?

BACKGROUND: Pichia anomala is a rare cause of fungemia. From February to April, 1998, eight cases of fungemia occurred in the intensive care and high risk units of the Nursery. There were four infants with P. anomala infection, one of whom also had Candida parapsilosis infection, two cases with C. parapsilosis infection and two with Candida albicans infection. OBJECTIVE: To determine factors associated with fungemia in the intensive care and high risk units of the Nursery, especially P. anomala. METHODS: A cohort study with 59 newborns. RESULTS: Factors associated with fungemia were: central venous catheter (CVC) (P = 0.0006); total parenteral nutrition (TPN) (P = 0.0005); lipid emulsion (P = 0.002); previous antimicrobial use (P = 0.002); and other invasive procedures (P = 0.002). Factors associated with P. anomala fungemia were: CVC (P = 0.004); TPN (P = 0.018); previous antibiotic use (P = 0.037); and other invasive procedures (P = 0.037). Evaluation of the units demonstrated that there were several technical problems involving administration of TPN that was manipulated in the Nursery without precautions. Changes in TPN formulation and education as to adequate technique were implemented. During follow-up (1998 to 1999) only two fungemias occurred that were caused by C. albicans. Cultures of hands of personnel were negative for P. anomala. Electrophoretic karyotyping of P. anomala showed three profiles. CONCLUSIONS: Factors associated with fungemia were catheter use, invasive procedures and total parenteral nutrition, suggesting that the acquisition of P. anomala was exogenous.

Analysis of Variance↗

Outer-membrane proteins pattern and detection of beta-lactamases in clinical isolates of imipenem-resistant Acinetobacter baumannii from Brazil.

In order to compare imipenem-sensitive and -resistant Acinetobacter baumannii strains isolated from three patients, ribotyping, plasmid, beta-lactamase detection and outer-membrane analysis were performed. Ribotyping and the use of a beta-lactam during the period when the strains were isolated suggested that they had a common origin and that resistance occurred in vivo. Outer membrane analysis showed no difference between susceptible and resistant strains with the exception of an A2 imipenem-resistant strain that lost a protein band of 31-36 kDa. Beta-lactamases were detected using isoelectric focusing in all strains (pI of 7.4). In addition, two beta-lactamases (pI of 5.9 and 6.7) were found in imipenem-resistant isolates. The double-disc technique demonstrated the presence of a beta-lactamase capable of imipenem inactivation in resistant strains. Plasmid analysis showed that all susceptible strains had the same pattern, one resistant strain did not have any plasmid, one had the same plasmid pattern of its susceptible pair and only one had a different pattern when compared with its susceptible pair.

Acinetobacter↗

Nosocomial fungaemia: a 2-year prospective study.

Eighty-six consecutive patients with fungaemia were studied during a period of 2 years, 81% had two or more positive blood cultures. Gastrointestinal tract (28%) and haematological diseases (17%) were the most common underlying conditions. The majority of cases had received vancomycin and/or imipenem (87%) and a central venous catheter (78%). Candida albicans (50%) and Candida parapsilosis (17%) were the most frequent isolates. Overall mortality was 41%, and for patients with Candida tropicalis was 71%. There was not significant difference in survival with gender, age and days of treatment with antifungal drugs. Haematological diseases, neutropenia and a higher number of positive blood cultures were associated with poor outcome.

Adolescent↗

Nosocomial infections caused by multiresistant Pseudomonas aeruginosa.

A case-control study was done to evaluate factors associated with nosocomial infections by multiresistant Pseudomonas aeruginosa (MRPA). Results showed that MRPA was associated with the use of immunosuppressive and antimicrobial drugs. Five typing methods indicated that the MRPA infections were due to multiple strains rather than a single strain.

APACHE↗

Intravenous colistin as therapy for nosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii.

Sixty nosocomial infections caused by Pseudomonas aeruginosa and Acinetobacter baumannii resistant to aminoglycosides, cephalosporins, quinolones, penicillins, monobactams, and imipenem were treated with colistin (one patient had two infections that are included as two different cases). The infections were pneumonia (33% of patients), urinary tract infection (20%), primary bloodstream infection (15%), central nervous system infection (8%), peritonitis (7%), catheter-related infection (7%), and otitis media (2%). A good outcome occurred for 35 patients (58%), and three patients died within the first 48 hours of treatment. The poorest results were observed in cases of pneumonia: only five (25%) of 20 had a good outcome. A good outcome occurred for four of five patients with central nervous system infections, although no intrathecal treatment was given. The main adverse effect of treatment was renal failure; 27% of patients with initially normal renal function had renal failure, and renal function worsened in 58% of patients with abnormal baseline creatinine levels. Colistin may be a good therapeutic option for the treatment of severe infections caused by multidrug-resistant P. aeruginosa and A. baumannii.

Acinetobacter Infections↗

Candida parapsilosis fungemia associated with implantable and semi-implantable central venous catheters and the hands of healthcare workers.

A cluster of six cases of fungemia among hematology, bone marrow transplant, and oncology patients was investigated in a case-control study (18 controls). The use of implantable and semi-implantable central venous catheters was significantly associated with cases (p = 0.016). The hands of three healthcare workers (HCWs) were positive for Candida parapsilosis. Electrophoretic karyotyping showed two profiles among patients and HCWs, and five among six unrelated strains. The profiles of two HCWs matched the ones of the patients they had handled. The patients' strains were moderate or strong slime producers, whereas none of the HCWs' were strong producers. In conclusion, our results indicated the occurrence of an outbreak C. parapsilosis fungemia related to long-term central venous catheters in which the hands of HCWs were implicated. The amount of slime production might be associated with the pathogenicity of the strains.

Adolescent↗

Electric showers as a control measure for Legionella spp. in a renal transplant unit in São Paulo, Brazil. Legionellosis Study Team.

After an outbreak of legionnaires' disease Legionella pneumophila serogroup 1 in a renal transplant unit in São Paulo, Brazil, periodic hyperchlorination and flushing of pipes were instituted as control measures. These were only partially effective as every two to five months water cultures turned positive or new cases of the disease occurred. In November 1993 the hot water was disconnected from the unit and small, plastic electric showers were installed in each bathroom. Over a period of 12 months water from showers and taps was cultured for Legionella spp. every two weeks. On only one occasion was a water culture positive for L. pneumophila from a sink tap. No water sample obtained from showers was positive during the study period. No cases of legionnaires' disease occurred. We considered the use of electric showers an inexpensive and effective method of controlling the problem of Legionella spp. in the water system of our renal transplant unit.

Baths↗