Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BACTEREMIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources

An infant rat model of bacteremia with Brazilian purpuric fever isolates of Hemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

Brazilian purpuric fever (BPF) is a newly recognized fulminant pediatric infection caused by bacteremia with Hemophilus influenzae biogroup aegyptius (Hae). Following intraperitoneal inoculation, each of five disease isolates caused bacteremia more frequently than control, conjunctival isolates of Hae in complement-depleted 6-d-old rats. Sustained but self-limited bacteremia was observed in normal infant rats after inoculation with a disease strain. These rats developed meningitis and had depressed hemoglobin concentration and platelet counts. Pathologic examination showed meningitis and contiguous otitis. Pretreatment of infant rats with immune adult rat serum raised against disease isolates protected rats from bacteremia. Normal adult rat serum or immune rat serum against control strains failed to protect infant rats. Thus, strains of Hae isolated from patients with BPF are more virulent than control strains. Antibody against antigens unique to disease isolates protects infant rats from bacteremia.

Animals↗

Beta-lactam-resistant Enterobacter bacteremia in febrile neutropenic patients receiving monotherapy.

Bacteremia with resistant Enterobacter species has been reported in febrile, neutropenic cancer patients receiving beta-lactam antibiotics. To assess the relationship between enterobacter bacteremia and ceftazidime monotherapy, medical records were reviewed and isolates were tested from 16 neutropenic and 35 nonneutropenic patients with Enterobacter bacteremia. Fifteen isolates from the neutropenic patients were resistant to extended spectrum cephalosporins; only 12 of 35 isolates from the nonneutropenic patients were resistant to Enterobacter species. The neutropenic patients also had more beta-lactam therapy, both immediately before bacteremia and in the preceding year, than did nonneutropenic patients. Prior beta-lactam antibiotic exposure may predispose neutropenic patients to develop resistant Enterobacter bacteremia.

Adolescent↗

Mycobacterium avium complex in the respiratory or gastrointestinal tract and the risk of M. avium complex bacteremia in patients with human immunodeficiency virus infection.

Mycobacterium avium complex (MAC) is frequently isolated from the respiratory or gastrointestinal tract of patients with advanced human immunodeficiency virus (HIV) infection. Whether they are at increased risk of MAC bacteremia and whether culture of respiratory tract or stool specimens is useful for predicting bacteremia are unclear. HIV-infected patients with < or = 50 CD4+ cells/microL were prospectively studied. The risk of MAC bacteremia was approximately 60% within 1 year for patients with MAC in either the respiratory or gastrointestinal tract and was greater than for those without MAC in these sites (relative hazards for respiratory and gastrointestinal tract, 2.3 and 6.0; 95% confidence intervals, 1.1-4.6 and 2.5-14.6, respectively). Both respiratory tract specimen and stool culture had poor sensitivities (22% and 20%, respectively) but good positive predictive values (approximately 60%) for bacteremia. Symptomatic HIV-infected patients with MAC in the respiratory or gastrointestinal tract are at a substantial risk for developing MAC bacteremia; culture of these sites has limited usefulness as a screening test.

Adult↗

Neutropenia is a risk factor for gram-negative bacillus bacteremia in human immunodeficiency virus-infected patients: results of a nested case-control study.

A previous cohort study demonstrated a relation between neutropenia and bacteremia due to gram-negative bacilli among patients infected with human immunodeficiency virus (HIV). To explore further the relation between neutropenia and bacteremia due to Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa among HIV-infected patients, controlling for confounding factors, the authors conducted a nested case-control study with matching and risk-set sampling of controls. The cohort included 1,645 HIV-infected patients followed at the University of California, San Diego, Medical Center in San Diego, California, between 1991 and 1995. Absolute neutrophil count (ANC) was summarized as mean ANC during the 7-day interval preceding the index date of bacteremia. Covariates were ascertained by medical record review. The matching ratio was 6:1 (controls:cases). Odds ratios were estimated using conditional logistic regression. Forty-four incident cases of bacteremia were identified. After adjustment for covariates, the estimated odds ratio for the effect of neutropenia (ANC=500 vs. >500/microl) during the 7 days preceding the index date was 8.1 (95% confidence interval confidence interval 1.5-43.1). The rate of bacteremia due to E. coli, K. pneumoniae, or P. aeruginosa is increased eightfold if the average current-week ANC is less than or equal to 500/microl compared with more than 500/microl.

AIDS-Related Opportunistic Infections↗

Bacteremia following dental extractions in patients with and without penicillin prophylaxis.

This study describes the type, rate and magnitude of bacteremia in 128 patients undergoing dental extractions with and without penicillin prophylaxis. The most prolonged and highest rates of bacteremia occurred in patients undergoing extractions and alveoplasty while under general anesthesia following nasotracheal intubation. The most common aerobes in patients receiving no penicillin were streptococci. Bacteroides sp. were detected most often in patients receiving penicillin prophylaxis. The overall bacteremia, streptococcal and polymicrobial bacteremia rates were lowest for the patients receiving penicillin. Only two of 66 patients given penicillin prophylaxis had recoverable streptococci in blood cultures. Our study indicates that both intravenous and oral penicillin G prophylaxis for dental extractions decreased bacteremia rates significantly, including the recovery of streptococci.

Alveoloplasty↗

The effects of Escherichia coli bacteremia on in vitro perfused kidneys.

The renal response to sepsis results in increased renal blood flow, decreased renal vascular resistance, polyuric renal failure and a change in intracortical renal blood distribution. Prior reports used whole animal preparations, where the effects of sepsis on other organs may have led to systemic vasoactive changes altering the experimental model. To elucidate the direct effect of gram negative bacteremia on the kidney, intracortical hemodynamics and urinary flow were investigated using isolated canine kidneys perfused with a nonpulsatile pump oxygenator primed with modified dog plasma. Bacteremia was produced by 2.5 x 10(11) live Escherichia coli organisms infused directly into the perfusate. Intracortical blood flow distribution was measured by radioactive microsphere trapping using 15 microns diameter plastic radioactive microspheres. Urine flow increased 157% (p less than 0.05) following E. coli bacteremia while intracortical blood distribution was unchanged. The polyuric renal failure of sepsis is therefore, a direct result of bacteremia and not secondary to a change in intracortical flow as previously reported. The changes in intracortical blood distribution reported previously in sepsis using intact animal models probably reflect the renal response to release of vasoactive compounds originating in other organs rather than an intrinsic renal reaction to bacteremia.

Animals↗

Nontyphoidal Salmonella enteric infections and bacteremia.

Antimicrobial treatment of nontyphoidal Salmonella gastroenteritis is usually advocated for infants younger than 3 months of age based on published data showing that infants in this age group are more prone to have bacteremia and develop extraintestinal focal infections. A review of nontyphoidal Salmonella isolates from our institution from January, 1981, through March, 1988, was undertaken to assess the role of age and specific serovar on the incidence of bacteremia. Two hundred twenty isolates were identified: one cerebrospinal fluid, 14 blood and 205 stool. The mean age of patients with bacteremia was 182 months, not significantly different from the mean age of 142 months for patients with stool isolates. Salmonella weltevreden was the most frequent isolate accounting for 23% of all isolates and all isolates of this organism were from stool cultures. Patients with S. weltevreden infections had mean and median ages of 50 and 2.5 months and were younger than patients with stool isolates from other serovars who had mean and median ages of 174 and 38 months. Infants younger than 3 or 6 months of age with positive stool cultures in whom blood cultures were obtained did not demonstrate a higher incidence of bacteremia than did older patients. We conclude that the incidence of bacteremia in patients with nontyphoidal Salmonella gastroenteritis is highly related to the invasiveness of the infecting specific Salmonella serovar.

Adolescent↗

Occurrence of bacteremia in febrile children seen in a hospital outpatient department and private practice.

Blood cultures were obtained during a one-year period from 147 febrile children seen in the hospital outpatient clinic (group 1), and 42 seen in a private practice office (group 2). Although the two clinics were located in the same geographic area, they served different socioeconomic groups. Bacteremia was detected in 12 (8.2%) of the children in group 1; the organisms recovered were Streptococcus pneumoniae in nine and Haemophilus influenzae in three. Bacteremia was observed in two (4.8%) of the children seen in group 2, and both cases were due to S pneumoniae. The difference in prevalence rates for bacteremia between groups was not significant by chi-square testing (P = .46). The age of all the 13 patients with bacteremia was less than 24 months, their temperature was above 104 F (40 C), their polymorphonuclear leukocyte count was above 15,000/cu mm, and a localized site of infection was present in ten of them. These data suggest that the presence of bacteremia in febrile children depends more on the patients' clinical and laboratory findings than on the medical facility in which they are seen.

Child, Preschool↗

Staphylococcus aureus bacteremia in patients with hematological malignancies and/or agranulocytosis.

A total of 6,253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975-1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p less than 0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p less than 0.01), the lowest in patients with acute lymphocytic leukemia (28%, p less than 0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent.

Aged↗

Pneumococcal bacteremia. Update from an adult hospital with a high rate of nosocomial cases.

Eighty-nine episodes of pneumococcal bacteremia were reviewed over a 66-month period at a Veterans Administration Medical Center. Forty-one percent of these episodes were nosocomial in origin, and 59% of the patients were elderly (60 years of age or older). Nosocomial infection occurred more often in the elderly (55%) compared to those less than 60 years of age (32%; P less than 0.05). Within the elderly group, those older than 75 years of age had a higher rate of nosocomial bacteremia than those 60 to 75 years of age (76 versus 44%; P less than 0.05). The clinical presentation of the elderly and younger groups was not significantly different. All but one patient had serious underlying diseases. Eighty-three percent of the episodes were due to pneumonia, and penicillin alone was prescribed for only 21% of all cases. The mortality rate directly due to the bacteremia was 22%, while the overall mortality during the hospitalization was 47%. In the elderly, the percentage of deaths due to infection was similar to the younger group, but overall mortality during the hospitalization was significantly higher in the elderly (74 versus 26%; P less than 0.01). Physicians showed poor recognition of the significance of pneumococcal disease, as demonstrated by inclusion of the diagnosis of pneumococcal infection or bacteremia in only 27% of the discharge summaries and by predischarge vaccination of only 7% (6 of 82) of those without previous pneumococcal vaccination. In conclusion, the rate of nosocomial pneumococcal bacteremia was high in a predominantly elderly male population; it may be appropriate to consider a hospital-based vaccine program in similar populations.

Age Factors↗

[Pseudomonas aeruginosa bacteremia associated with hematologic disorders [II]. Blood culture isolates and surveillance cultures].

We experienced 57 episodes of Pseudomonas aeruginosa bacteremia in 55 patients with hematologic disorders such as acute leukemia over a 16-year period. All the patients were treated on the same hospital ward. A total of 57 blood culture isolates of P. aeruginosa were divided into nine serogroups. Seventy-four percent of the isolates belonged to four serogroups, which became preponderant one after the other. Surveillance throat and/or stool cultures grew the organisms identical to the isolates from the blood at or prior to the onset of bacteremia in 75% of the episodes. Only 11% of the patients had had P. aeruginosa cultured at admission. The acquisition of the organism was closely associated with antibiotic therapy for other presumed or proved infection. On the other hand, 60% of the episodes occurred during the administration of at least one in vitro effective antibiotic. In five episodes, the patients had received an antipseudomonal penicillin and an aminoglycoside in combination, both of which proved effective in vitro against the infecting organism, when bacteremia occurred. In managing P. aeruginosa bacteremia complicating hematologic disorders, it was thus suggested that surveillance cultures should be regularly carried out, and that attention should be drawn to the occurrence of "breakthrough" bacteremia.

Acute Disease↗

Experimental production of lethal Escherichia coli bacteremia of pelvic origin.

To reproduce the syndrome of overwhelming Escherichia coli bacteremia and shock after pelvic instrumentation, a model was developed by feeding E. coli via drinking water to coliform-free rabbits, injecting nitrogen mustard intravenously, and inserting a temperature probe into the rectum. The temperature probe was inserted to mimic pelvic instrumentation of patients and to detect fever. Rabbits fed invasive serotypes of E. coli all suffered overwhelming bacteremia with high fever and fatal vascular collapse secondary to invasion of pelvic veins as the granulocyte count approached zero. In the absence of granulocytopenia, the rectal temperature probe produced an intensive inflammation with numerous polymorphonuclears and bacteremia did not develop. In the absence of rectal probing, granulocytopenic rabbits developed high fever without bacteremia. This model resembles human bacteremic shock with respect to the endogenous source of the bacteria, the high frequency of bacteremia due to E. coli and other enteric bacilli, the importance of pelvic instrumentation, and the associated immune disturbances such as granulocytopenia.

Animals↗

Comparison of radiometric and conventional culture systems in detecting Haemophilus influenzae type b bacteremia in rats.

To compare the efficiency of detecting Haemophilus influenzae type b bacteremia by the BACTEC radiometric system (RS; Johnston Laboratories, Inc., Towson, Md.) and a conventional Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) blood culture system (TSB), we developed an in vivo model of bacteremia in rats. After intravenous injection of 50 to 200 CFU into adult rats, there was a linear logarithmic increase in CFU per milliliter of rat blood during the first 10 h (r = 0.98), allowing accurate prediction of the level of bacteremia with time. Culture bottles were inoculated with 0.5 ml of blood obtained by cardiac puncture and processed as clinical samples in the microbiology laboratory with our RS and conventional protocols. We found the following. (i) The first detection of bacteremia by RS was similar to that by TSB if a Gram stain of the TSB was done on day 1 and was superior if that smear was omitted (P less than 0.01). (ii) The detection times in both systems were comparable at different magnitudes of bacteremia (10(1) to 10(4) CFU/ml). (iii) Supplementation of inoculated bottles with 2 ml of sterile rat blood interfered with Gram stain detection in TSB but resulted in increased 14CO2 production in RS. (iv) No difference in detection time was found between RS and TSB for four different clinical isolates. These studies show that, in a biologically relevant model, the detection of positive blood cultures for H. influenzae type b by RS was comparable to or better than detection by TSB when blood was processed analogously to clinical specimens.

Animals↗

Comparison of the Du Pont Isolator 1.5 Microbial Tube and Trypticase soy broth for the recovery of Haemophilus influenzae type b in experimental bacteremia.

The isolator 1.5 Microbial Tube (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) is a new blood culture system for detection of bacteremia in children which involves lysis of blood cells and direct plating of blood lysate on agar media. Haemophilus influenzae type b is a major pediatric pathogen and may be associated with low-density bacteremia (less than or equal to 50 CFU per ml), yet the clinical data on the efficacy of this system for recovery of H. influenzae b are limited. We used a rat model of H. influenzae b bacteremia and fresh, whole human blood inoculated in vitro with H. influenzae b to compare the 1.5 Microbial Tube and conventional Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) for the detection of low-density H. influenzae b bacteremia. There was a significantly lower recovery of H. influenzae b from blood of bacteremic rats and from in vitro-inoculated human blood by using the 1.5 Microbial Tube than by using Trypticase soy broth. Studies on the mechanism of this lower recovery suggested that the contents of the 1.5 Microbial Tube are toxic to H. influenzae b in the presence of human blood. Additional clinical data are necessary before the 1.5 Microbial Tube can be recommended for detection of low-density H. influenzae b bacteremia.

Animals↗

Bacteremia with Streptococcus bovis and Streptococcus salivarius: clinical correlates of more accurate identification of isolates.

Two biotypes of Streptococcus bovis can be identified by laboratory testing and can be distinguished from the phenotypically similar organism Streptococcus salivarius. We assessed the clinical relevance of careful identification of these organisms in 68 patients with streptococcal bacteremia caused by these similar species. S. bovis was more likely to be clinically significant when isolated from blood (89%) than was S. salivarius (23%). There was a striking association between S. bovis I bacteremia and underlying endocarditis (94%) compared with that of S. bovis II bacteremia (18%). Bacteremia with S. bovis I was also highly correlated with an underlying colonic neoplasm (71% of patients overall, 100% of those with thorough colonic examinations) compared with bacteremia due to S. bovis II or S. salivarius (17% overall, 25% of patients with thorough colonic examinations). We conclude that careful identification of streptococcal bacteremic isolates as S. bovis biotype I provides clinically important information and should be more widely applied.

Adolescent↗

Bacteremia-induced changes in pituitary hormone release and effect of naloxone.

Acute bacteremia in sheep caused a surge of plasma beta-endorphin/beta-lipotropin (beta-EP/beta-LPH) associated with shivering behavior, tachycardia, hyperthermia, hemoconcentration, and decreased respiration rate. The surge of plasma beta-EP/beta-LPH was immediately followed by increases (P less than 0.05) in plasma prolactin and growth hormone (GH) concentrations and a depression (P less than 0.05) of plasma luteinizing hormone. These changes in pituitary hormone release were consistent with opioid-induced changes described in the literature. To examine possible opioid mediation, naloxone (2.5 mg X kg-1 X h-1) was continuously infused intravenously from 3 h before to 3 h after induction of an E. coli bacteremia. With the exception of plasma GH, naloxone failed to alter any of the hormonal or clinical parameters associated with bacteremia. For plasma GH, naloxone delayed (P less than 0.01) the increase but did not attenuate its magnitude, suggesting that an opioid mechanism may influence the timing of the pituitary GH release resulting from bacteremia. In general, opioid mechanisms sensitive to the present dosage of naloxone do not appear to mediate bacteremia-induced changes in hormonal or clinical parameters.

Animals↗

Cardiopulmonary response of the rat to gram-negative bacteremia.

Hemodynamic and respiratory effects of a continuous 5-h intravenous infusion of live Escherichia coli were studied in rats. Control animals were infused with saline. Rats infused with 1.8 +/- 0.4 X 10(10) bacteria/h did not survive a 5-h infusion. These animals developed early hypotension and reduced cardiac output (CO) measured by thermal dilution technique. Rats infused with 8.0 +/- 0.4 X 10(9) bacteria/h survived a 5-h infusion with hypotension and reduced CO occurring later in the course of bacteremia. Heart rate was markedly elevated in both septic groups. Arterial blood gas measurements revealed that partial pressure of O2 was not affected by bacteremia, but partial pressure of CO2 was significantly decreased. Arterial pH remained within the normal range indicating respiratory compensation of a metabolic acidosis. Since hypotension and reduced CO were accompanied by a fall in right atrial pressure (RAP) during bacteremia, a third septic group was studied to evaluate cardiac performance during volume loading. After 3-5 h of bacteremia, a 40% reduction in CO was associated with a significant drop in arterial pressure and RAP. Despite volume loading, ventricular stroke work and arterial pressure were significantly reduced compared with control animals. The results indicate that severe gram-negative bacteremia produces myocardial depression in the rat. This model can be useful for further studies of cardiac dysfunction during sepsis.

Animals↗

Treatment of Salmonella gastroenteritis in infants. The significance of bacteremia.

During 1981, we treated 20 infants, less than 24 months old, for nontyphoid Salmonella (NTSal) gastroenteritis (GE). Blood cultures were obtained in 17 cases, and Salmonella bacteremia was demonstrated in 8 (47%). Of the 13 children 3 to 24 months of age, 7 (54%) had positive blood cultures. One child (8 months old) appeared septic. The patients with bacteremia were treated with parenteral ampicillin. All 20 infants recovered, and no focal infectious complications occurred. The incidence of bacteremia in NTSal GE is highest in children under 2 years of age. Previous reports have shown that the peak incidence occurs among infants less than 3 months of age. An infant with Salmonella bacteremia may be afebrile and show no symptoms of sepsis. In most cases, bacteremia is transient and does not alter the course of NTSal GE, but it may result in life-threatening complications such as septicemia and meningitis. Therefore we believe an infant with NTSal GE under 3 months old should have a blood culture and receive antibiotic treatment.

Anti-Bacterial Agents↗