Why is there an analytical culture in a medical laboratory?]

During a seven-year period (1998-94) 68 patients with infectious endocarditis were diagnosed at a university hospital. Staphylococcus aureus was the most common etiological agent (38%), followed by Streptococcus viridans (21%). In seven patients the diagnosis infectious endocarditis was first made during autopsy, all seven of them had the clinical diagnosis septicaemia. Surgery was performed on 41% of the patients. Case fatality was 34%. Case fatality was significantly higher for S aureus endocarditis than for S viridans endocarditis, 48% vs. 7% (p = 0.01). The advantages of transthoracic and transoesophageal echocardiography in the diagnosis and follow up of patients with infectious endocarditis is emphasized. In spite of these new diagnostic tools a definitive clinical diagnosis of infectious endocarditis was not made for 23% of the patients.     

N-acetylcysteine prevents development of the hyperdynamic circulation in the portal hypertensive rat

Infective endocarditis, defined as pathologically or clinically definite by the Duke criteria, was observed in 14 transplant recipients at our institutions. In addition, we reviewed 32 previously reported cases in solid organ transplant recipients. The spectrum of organisms causing infective endocarditis was clearly different in transplant recipients than in the general population; 50% of the infections were due to Aspergillus fumigatus or Staphylococcus aureus, but only 4% were due to viridans streptococci. Fungal infections predominated early (accounting for six of 10 cases of endocarditis within 30 days of transplantation), while bacterial infections caused most cases (80%) after this time. In 80% (37) of the 46 cases in transplant recipients, there was no underlying valvular disease. Seventy-four percent (34) of the 46 cases were associated with previous hospital-acquired infection, notably venous access device and wound infections. Three patients with S. aureus endocarditis had had an episode of S. aureus bacteremia > 3 weeks prior to the diagnosis of endocarditis and had received treatment for the initial bacteremia of < 14 days' duration. The overall mortality rate was 57% (26 of 46 patients died), with 58% (15) of the 26 fatal cases not being suspected during life. Endocarditis is an underappreciated sequela of hospital-acquired infection in transplant recipients.     

Epidemiological changes in infectious endocarditis. A prospective study, 1992-96

BACKGROUND: To know the present epidemiological situation of the infective endocarditis in our environment and its evolution in the last few years. RESULTS: The incidence of infective endocarditis was 0.85 per thousand patients admitted to hospital, with a mean age of 43 years. The predisposed factors more frequently found were: drug addiction (32%) and cardiac prosthetic valves (23%). In the greatest number of our patients the cardiac valves involved were: tricuspid (28%), mitral (27%) and prosthetic valves (23%). The causative organism were: S. aureus (19 cases), Streptococcus (15 cases) and S. epidermidis (11 cases). The echocardiography study resulted diagnostic in 90% of the patients, valve replacements were performed in 22% of the cases. The overall mortality rate was 10%. CONCLUSIONS: The current profile of infective endocarditis is characterized by a high incidence of parenterally drug addict patients or prosthetic valves carriers. Increase of the infections of S aureus and a decrease of Streptococcus infections, as well as a less overall mortality.     

Physiopathology of leg ulcers]

Polymicrobial endocarditis (PE) is uncommon, whether in series of cases of polymicrobial bacteriemia or of endocarditis. Among the 201 cases of infective endocarditis seen between 1986 and 1995 by an infectious diseases service, 12 patients had PE (6%). Nine were males, mean age was 28 years and ten were active intravenous drug users. All of them were HIV (+) and 50% had AIDS. Eleven subjects had infection of the tricuspid valve and 58% developed septic pulmonary emboli. The most common organism encountered was Staphylococcus aureus in 8 patients followed by Streptococcus viridans and S. pneumoniae in three. The most common combinations of organisms were S. aureus and S. pneumoniae in 3 cases and S. aureus and Pseudomonas aeruginosa in two. Two patients died, one with Xantomona maltophilia and another with Candida albicans. The symptoms of PE were usually indistinguishable from endocarditis caused by a single organism and the prognosis depended on the species rather than the number of organisms isolated.     

Antibiotic susceptibility to microorganisms isolated in blood cultures of patients an the Ignacio Chavez National Institute of Cardiology

A microdilution method was utilized for determining susceptibility to several antimicrobial agents in 142 bacterial blood culture isolates obtained during a one year period. Associated clinical features were also identified. Three cases of polymicrobial bacteriemia were found. Endocarditis was the most frequent source of bacteriemia (28.5%) and the viridans streptococci were the most frequently isolated microorganism (53%). Surprisingly, half of the bacteriemic episodes corresponded to a nosocomial infection most of which were due to staphylococci (25%) and Enterobacter sp (22%). Viridans streptococci group were 61.5% resistant to penicillin (MIC > 0.12 micrograms/mL). These strains also showed a 31% resistance to ceftriaxone (MIC > 8 micrograms/mL). The staphylococcal strains showed a 19% resistance to oxacillin; this resistance occurred for coagulase negative staphylococcis in 32% (6/19) and for S. aureus in 9% (2/22). All Gram-positive microorganisms were susceptible to vancomycin. The enterobacteria group were susceptible to most antimicrobial agents; nevertheless this group showed a 45% resistance to amikacin. In contrast, the non enterobacteria group were resistant to most of the antimicrobial agents tested except to imipenem, ceftazidime and ciprofloxacin. When comparing susceptibility longitudinally, no significative changes were identified, but a significant increase was found in MIC50-90 to amikacin and cephalothin when testing S. aureus, and cefoperazone in the non enterobacteria group.     

Infective endocarditis in adolescents. Analysis of risk factors for hospital mortality

PURPOSE: To study the epidemiological, clinical, therapeutic and evolutive aspects of endocarditis in a group of patients aging 12 to 20 years-old (mean 15.5). METHODS: Thirty-three consecutive patients (14 males, 19 females) admitted with infective endocarditis were retrospectively studied. RESULTS: Infective endocarditis mortality was 42%. Rheumatic heart disease was the predominant underlying condition in 63% of patients. Congenital heart disease (24%) and cardiac prosthesis (12%) were the other affections involved. The majority of patients (78%) were in functional class III and IV, with more deaths than the 22% who were in functional class I and II (p = 0.01). Staphylococcus aureus was the most frequently isolated agent (42% of the positive blood cultures, followed by Staphylococcus viridans, 21%). Multivariate analysis identified total leukocyte count above 10,000/mm3 and functional class, both at admission (p = 0.01 and p = 0.004, respectively), and the occurrence of embolic complications (p = 0.03) as independent predictors of in-hospital mortality. CONCLUSION: Rheumatic heart disease remains, as in adults, the main predisposing factor for infective endocarditis in adolescents, and S. aureus is, like in children, the leading agent. Mortality is high and functional class at hospital admission, embolic complications and leukocytosis are independent predictors of in-hospital mortality.     

Infective endocarditis at a large community teaching hospital, 1980-1990. A review of 210 episodes

We studied 210 episodes of infective endocarditis in 204 patients. The prevalence of this disease in our series ranged from 0.32 to 1.30 (mean, 0.75) episodes per 1000 admissions per year. There were 115 male and 89 female patients, whose ages ranged from newborn to 91 years (median, 60-70). One-hundred-and-forty-eight episodes involved host valves and another 33 episodes occurred in intravenous drug users. There were 2 episodes of early and 27 episodes of late prosthetic valve endocarditis. Staphylococcus aureus accounted for 99 episodes (47.1%), alpha-hemolytic streptococci for 29 episodes (13.8%), enterococci for 11 episodes (5.2%), culture-negative endocarditis for 11 episodes (5.2%), and other organisms for 60 episodes (28.6%). Severe back pain was the chief complaint in 15 patients. 2-D echocardiography was performed in 164 episodes, results in 67 (40.9%) of which were positive. Valve surgery was performed in 29 episodes (23 host valves and 6 prosthetic valves). The overall mortality was 21.4%. Autopsy was performed in 22 of the 45 patients who died (48.9%). The mortality rate increased with age, (10.1% and 31.5% for patients < 60 years old and 60 years or older, respectively (p < 0.001).     

Generation of chromosome fragment specific bovine DNA sequences by microdissection and DOP-PCR

Trends in causative organisms and sources of infection were studied in a series of 288 episodes of bacteremia in neutropenic cancer patients observed in a single institution from 1986 to 1993. The incidence of bacteremia increased significantly from 20 episodes per 1000 admissions in 1986 to 50 episodes per 1000 admissions in 1993 (p = 0.00001). Over the study period, a continuous increment in gram-positive bacteremia, which reached 81% of episodes in 1993 (p = 0.000001), was observed. Conversely, the incidence of gram-negative bacteremia remained stable. Coagulase-negative staphylococci and viridans group streptococci were the most commonly isolated pathogens. Bacteremia caused by coagulase-negative staphylococci increased from 3 episodes per 1000 admissions to 19 episodes per 1000 admissions (p = 0.0001), and viridans group streptococci bacteremia increased from 0 episodes per 1000 admissions to 19 episodes per 1000 admissions (p = 0.000001). The upward trend in gram-positive bacteremia appeared to be related to a significant increase in both intravascular catheters (p = 0.003) and oral mucositis (p = 0.003) as sources of infection. Specific strategies to prevent chemotherapy-induced mucositis and catheter-related bacteremia merit further investigations.     

Intramuscular clindamycin for therapy of infective endocarditis. Report of 23 cases and review of the literature

Twenty-three patients with infective endocarditis received intramuscular clindamycin (Cleocin) for treatment. Thirteen had acute Staphylococcus (S.) aureus endocarditis but none had involvement of the aortic valve. Eleven of these 13 infections were heroin-related and involved the tricuspid valve.Twenty-one patients were successfully treated. Two patients with heroin-related S. aureus infection failed to respond to intramuscularly administered clindamycin, but responded to retreatment with methicillin. There have been 34 reported cases of endocarditis treated with clindamycin. Although 80 percent of all cases due to staphylococci responded favorably, almost all were heroin-related tricuspid valve infections. In addition 91 percent of cases due to aerobic streptococci responded but, surpisingly, treatment failed in three of four cases of anaerobic endocarditis. Although clindamycin can be useful in streptococcal endocarditis and in some cases of heroin-related S. aureus tricuspid endocarditis, caution should be exercised in its use. It is "less" bactericidal than the penicillins or cephalosporins, and organisms have become resistant during treatment. Furthermore, patients with anaerobic endocarditis have not responded well, and data are not available to recommend administration of clindamycin for acute S. aureus infections engrafted on the aortic or mitral valve.     

Occurrence and etiology for subclinical mastitis in cows

Studied were a total of 16,571 cows on 89 farms by means of the Bernburg test. Milk was sampled from the positively reacting quarters of the udder by taking 18,047 samples intended for bacteriologic investigation. The demonstration of mastitis streptococci was carried out on "TKT" agar Merk, of pathogenic staphylococci, hemolytic streptococci, and Corinebacteria--on dextrose agar Oxoid containing 7.5% citrated calf blood. The isolated hemolytic streptococcus bacteria from the two nutrient media were differentiated through the CAMP test as well as serologically by the precipitation agar gel and Difco sera. The pathogenicity of Staphylococcus bacteria, in addition through hemolysis, was tested by the use of plasma coagulase with citrated rabbit plasma. In 53.95% of the cases there were secretory lesions due to Sc. agalactiae (6.23%) to Sc. dysgalactiae (5.69%) to Sc. uberis (8.47%), to Staph. aureus (2.44%), to hemolytic streptococci of the C, G and L groups (0.28%), to Sc. viridans (0.03%), to Corynebacterium pyogenes (0.41%), and catarrhal mastitis (30.4%). Some of the causative agents, such as Sc. agalactiae, Staph. aureus, and others have proved of epidemiologic importance to humans.     

Body site distribution of cutaneous malignant melanoma in relationship to patterns of sun exposure

AIM: To compare the clinical and morphological characteristics of patients with Streptococcus bovis endocarditis with those of patients with endocarditis caused by other microorganisms. METHODS: 177 consecutive patients (Streptococcus bovis, 22; other streptococci, 94; staphylococci, 44; other, 17) with definite infective endocarditis according to the Duke criteria were included. All patients underwent transthoracic and transoesophageal echocardiography. In 88 patients, findings from surgery/necropsy were obtained. RESULTS: S bovis endocarditis was associated with older patients, with a higher mortality (p = 0.04), and with a higher rate of cardiac surgery (p < 0.001) than other microorganisms, although embolic events were observed less often (p = 0.02). Pathological gastrointestinal lesions were detected in 45% of the patients. Multiple valves were affected in 68% of the patients with S bovis endocarditis and in 20% of those with other organisms (p < 0.001). Moderate or severe regurgitation occurred more often in S bovis endocarditis than with other microorganisms (p = 0.05). When surgery or necropsy was performed, infectious myocardial infiltration of the left ventricle was confirmed histopathologically in 36% of the patients with S bovis endocarditis and in 10% of those with other organisms (p = 0.002). CONCLUSIONS: S bovis endocarditis is a severe illness because of the more common involvement of multiple valves, and of the frequent occurrence of haemodynamically relevant valvar regurgitation and infectious myocardial infiltration.     

Viridans streptococci in blood cultures. Can we see any patterns of species related to patient category? Review of 229 cases of positive cultures with viridans streptococci

We present a review of 229 blood cultures with viridans streptococci collected during a period of eight and a half years from 1986 to 1994 at a teaching hospital in Sweden. The clinical significance of the growth of viridans streptococci is always uncertain, since these bacteria can be contaminants from the skin flora. Growth in more than one culture bottle strengthens the clinical value of the finding. The question was whether species identification might also help in the assessment of the clinical relevance of the finding. The results show that Streptococcus mitis occurs significantly more frequently in blood cultures from the departments dealing with cancer patients. Even with polymicrobial growth in blood cultures, S. mitis should be considered a pathogen of clinical relevance, not a contaminant.     

Characterization of progesterone membrane binding sites from porcine liver probed with a novel azido-progesterone radioligand

BACKGROUND: Global hospital mortality for infective endocarditis ranges from 13 to 40%. AIM: To compare clinical, microbiological, echocardiographic factors and complications between patients that died during an episode of infective endocarditis and those who survived. PATIENTS AND METHODS: We followed during their hospital stay, 129 patients, aged 14 to 74 years old, who had 131 episodes of infective endocarditis. Clinical assessment, echocardiography and microbiological study was done to all patients. Surgical indications were those derived from complications. RESULTS: Thirty three patients died during hospital stay (25.2%). There were no differences between survivors and deceased patients in the lapse between onset of symptoms and hospital admission, presence of fever, dyspnea or heart murmurs. Skin and mucosal septic manifestations occurred with higher frequency in deceased patients (57.1 and 24.3% respectively). Blood cultures were positive in 55% in survivors and 48% in those who died. The most frequent infecting organisms were staphilococci and streptococci. Vegetations were found with greater frequency in aortic position in both groups of patients. Deceased patients had a higher frequency of cardiac failure (84 and 65% respectively) and embolic episodes (77 and 46% respectively) than survivors. Antimicrobial treatment was successful in 94% of survivors and 15% of those who died. Forty percent of survivors and 54% of deceased patients were subjected to surgical procedures. CONCLUSIONS: The most important predictor of hospital mortality in this series of patients with infective endocarditis was antimicrobial treatment failure.     

Multiple promoters direct stimulus and temporal specific expression of brain-derived neurotrophic factor in the somatosensory cortex

Patients operated on for infective endocarditis (n = 69) at two regional hospitals between 1988 and 1994 are reviewed. 70% had a known valvular heart disease and 16% had prosthetic valve endocarditis. In 28% the offending microorganism was Staphylococcus aureus; in 26% Streptococcus viridans. Therapy was intended to be a six-week antibiotic course before operating, but 55% of the patients had to be operated on earlier. The postoperative course was uncomplicated in 59%, mortality was 16% and one-year survival 81%. Increased risk of death was associated with operating before the six-week course of antibiotics was completed (p = 0.005), with preoperative renal failure (p = 0.006) or lung failure (p = 0.008), with the growth of microorganisms from tissue samples extirpated during the operation (p = 0.01), with additional surgical procedures concomitant to valvular replacement (p = 0.02), S. aureus endocarditis (p = 0.03), and with the presence of paravalvular abscesses or intracardial fistulas (p = 0.03). The study shows that infective endocarditis is a serious disease. Wherever clinically feasible, all patients should be given antibiotics for six weeks before evaluating surgery. However, close surveillance of infection and haemodynamics is necessary to allow for the possibility of acute surgery before the development of organ failure. Special attention must be paid to cases of S. aureus endocarditis.     

Hydrolysis of androgen receptor by cathepsin D: its biological significance in human prostate cancer

Risk factors, etiology, and outcome of 180 cases of infective endocarditis (IE) in the Slovak Republic for 5 years were prospectively studied in a national survey. According to the Duke Endocarditis Service Criteria (1994), 169 cases were considered definitive and 21 possible/probable. The aortic valve was infected in 46.7%, mitral in 47.2%, and tricuspidal/pulmonary in 6.1% of cases. The majority of endocarditis cases was caused by Staphylococcus aureus and coagulase-negative staphylococci (CNS) (33.3%); only 12.2% were due to viridans streptococci; 11.7% were due to Enterococcus faecalis; 6.1% due to Haemophilus spp.; 10.1% due to other organisms; and 26.7% were culture negative. Single positive cultures of CNS were not considered clinically significant. More than 25% of 180 patients were older than 60 years. Rheumatic fever was a risk factor in 35.5%, dental surgery in 20.5%, prior cardiosurgery in 7.8%, and neoplasia in 6.7%. All patients were treated with antimicrobials (average length of therapy was 29.5 days) and 33.3% of patients also had surgery (valvular prosthesis replacement). Forty (22.2%) died, and 140 (77.8%) survived at day 60 after the diagnosis of endocarditis was made. All 40 deaths were attributable to infection. Univariate analysis comparing deaths and survivors did not show significant differences in most of the recorded risk factors between both groups, except age > 60 (40.0% versus 21.4%, p < 0.05), staphylococcal etiology (55.0% versus 27.1%, p < 0.04), and antibiotic therapy < 21 days (without surgery) (65.0% versus 3.6%, p < 0.01). These risk factors were significantly more frequently associated with deaths. Viridans streptococcal IE and surgical therapy in addition to antibiotics were associated with lower mortality in comparison to staphylococcal endocarditis (p < 0.045) or to cases treated with antibiotics only (p < 0.05). In comparison to other nationally based surveys in Europe (Greece, Croatia, France), the percentage of culture-negative endocarditis and spectrum of pathogens differed significantly.     

Bacteremic pneumonia in neutropenic patients with cancer: causes, empirical antibiotic therapy, and outcome

BACKGROUND: Bacteremic pneumonia is a major cause of death among neutropenic patients with cancer. METHODS: We analyzed the causes, empirical antibiotic therapy, and outcome of 40 consecutive cases of bacteremic pneumonia identified among 408 episodes of bacteremia in adult neutropenic patients with cancer, prospectively documented from 1986 to 1995. RESULTS: The most frequent causative organisms were Pseudomonas aeruginosa (17 cases), Streptococcus pneumoniae (12 cases), Escherichia coli (5 cases), and Streptococcus mitis (3 cases). Overall, P. aeruginosa and S. pneumoniae caused 72.5% of all episodes of bacteremic pneumonia, compared with 11.4% of bacteremic episodes from other sources (P< .001). Thirty patients received ceftazidime and 10 patients received imipenem as the beta-lactam component of the initial empirical treatment. All strains of P. aeruginosa were susceptible to both agents. Forty-seven percent of streptococcal strains were penicillin resistant and showed a decreased susceptibility to ceftazidime (minimum inhibitory concentration ranged from 1 to 64 microg/mL). Five patients (12.5%) were considered to have received inappropriate empirical antibiotic therapy. Attributable mortality in patients with bacteremic pneumonia was higher than in patients with bacteremia from other sources; 22 (55%) of the 40 patients with bacteremic pneumonia died, whereas 39 (10.6%) of the 368 patients with bacteremia from other sources died (P<.001). CONCLUSIONS: Our data suggest that bacteremic pneumonia in neutropenic cancer patients is associated with a poor outcome and that empirical antibiotic therapy for neutropenic patients with pneumonia should include agents active against both P. aeruginosa and cephalosporin-resistant streptococci.     

Pulmonary cavitation lesions in patients infected with the human immunodeficiency virus: an analysis of a series of 78 cases

BACKGROUND: To assess the clinical, radiologic and microbiological features of lung cavitation and HIV infection. Evaluation of the differences related to this disease in the last years. PATIENTS AND METHODS: Retrospective review of all patients with lung cavitation and HIV infection admitted at our hospital from January 1989 until December 1994 and prospective study of all patients with the same characteristics during 1995 and 1996. Lung cavitation was defined as any parenchymal lesion, with air content, visible in a simple X-ray and greater than 1 cm of diameter. Criteria for confirmed, probable or possible diagnosis were defined. RESULTS: 78 cases of lung cavitation have been identified in 73 patients. The radiologic patterns included unilobar and multilobular involvement in 31 and 47 cases, respectively. Cavities were multiple and single in 40 and 38 cases respectively. Findings with fine needle aspiration biopsy (FNAB) were diagnostic in 11 out of 14 cases. A clinical diagnosis was performed in all 78 cases, with microbiological results in 69 cases (88.5%): Mycobacterium tuberculosis in 20, Pneumocystis carinii in nine, Pseudomonas aeruginosa in nine, Staphylococcus aureus in eight (5 endocarditis with cavitary septic emboli), Rhodococcus equi in six, P. aeruginosa and S. aureus in three, Salmonella enteritidis in three, Cryptococcus neoformans in two, Aspergillus fumigatus in two and others in 7 cases. Confirmed, probable and possible diagnosis was considered in 54, 15 and 9 cases, respectively. Thirteen episodes of spontaneous pneumothorax were found. CONCLUSIONS: The lung cavitation rate is low, compared with the number of admissions related to HIV infection; nevertheless, many of them are in close relationship with HIV infection, and most of them are caused by treatable infections. It is important to know the clinical and radiological characteristics, in order to establish an early diagnosis and an appropriate therapy. Pseudomonas aeruginosa is becoming an important cause of lung cavitation. In our series, spontaneous pneumo-thorax was not related to Pneumocystis carinii pneumonia in 61.5% of cases.     

Characteristics and treatment of Staphylococcus aureus endocarditis

In order to evaluate whether there were changes of the clinical features of Staphylococcus (Staph.) aureus endocarditis in recent years, the data of 21 cases of Staph. aureus endocarditis diagnosed from 1977 to 1994 were analyzed and compared with those of 11 cases of Staph. aureus endocarditis from 1957 to 1977. The results showed the following changes in recent years. The incidence of Staph. aureus endocarditis cases has been increasing. Cases of right-sided endocarditis increased in the recent two decades and this increase was related to intravenous drug abuse and increased use of vascular intervention. Right-sided endocarditis was different from left-sided endocarditis in their risk factors, underlying heart diseases, clinical manifestations and prognosis. The clinical manifestations of ventricular-wall endocarditis were atypical and it could be definitely diagnosed only with echocardiogram. Complications of Staph. aureus endocarditis became more common and serious, in recent decades but hospital mortality decreased markedly due to effective antibiotic management. The authors believe that sound knowledge of Staph. aureus endocarditis is essential for the proper diagnosis and treatment of Staph. aureus endocarditis.     

Incidence and outcome of Staphylococcus aureus bacteremia in hemodialysis patients

BACKGROUND: Staphylococcus aureus bacteremia is frequently associated with metastatic complications and infective endocarditis (IE). The Duke criteria for the diagnosis of IE utilize echocardiographic techniques and are more sensitive than previous criteria. The documentation of IE in patients undergoing hemodialysis (HD) has become increasingly important in order to avoid the overuse of empiric vancomycin and the emergence of antibiotic resistance. METHODS: Patients who developed S. aureus bacteremia while undergoing HD at a tertiary medical center or one of four affiliated outpatient HD units were identified. Clinical outcome (death, metastatic complications, IE, and microbiologic recurrence) was assessed during hospitalization and at three months after discharge. Transthoracic and transesophageal echocardiograms were performed and the Duke criteria were used to diagnose IE. Pulse field gel electrophoresis was performed to confirm genetic similarity of recurrent isolates. RESULTS: Four hundred and forty-five patients underwent hemodialysis for 5431.8 patient-months. Sixty-two developed 65 episodes of S. aureus bacteremia (1.2 episodes/100 patient-months). Complications occurred in 27 (44%) patients. Bacteremia recurred in patients who dialyzed through polytetrafluorethylene grafts (44.4% vs. 7.1%, P = 0.0.01), and there was a trend to increased recurrence in patients who received only vancomycin (19.5% vs. 7.1%, P = 0.4). IE was diagnosed in 8 patients (12%), six of whom had normal transthoracic echocardiograms. CONCLUSIONS: Sensitive echocardiographic techniques and the Duke criteria for the diagnosis of IE should be used to determine the proper duration of antibiotic therapy in hemodialysis patients with S. aureus bacteremia. This diagnostic approach, coupled with early removal of hardware, may assist in improving outcomes.     

Controlled clinical evaluation of Isolator and ESP aerobic blood culture systems for detection of bloodstream infections

A controlled clinical evaluation comparing the Isolator system (Wampole Laboratories, Cranbury, N.J.) and the ESP 80A blood culture bottle in the automated ESP system (Difco Laboratories, Detroit, Mich.) was performed with 10,535 blood culture sets from patients with suspected septicemia. Of 1,150 positive cultures, 844 positive cultures from 285 patients with 394 septic episodes fulfilled the study criteria for minimum blood sample requirements in each system and clinical significance of isolates. The Isolator system detected statistically significantly more positive cultures of Staphylococcus aureus (P < 0.001), Enterococcus spp. (P = 0.007), Escherichia coli (P = 0.001), Alcaligenes xylosoxidans (P = 0.02), Xanthomonas maltophilia (P = 0.01), Candida albicans (P < 0.001), and Candida glabrata (P = 0.05). The Isolator system detected significantly more septic episodes due to S. aureus (P < 0.001), X. maltophilia (P = 0.02), and C. albicans (P = 0.004) than did the ESP 80A bottle; however, the two systems did not otherwise significantly differ in their abilities to detect septic episodes due to other organisms.