Clinical significance and outcome of anaerobic bacteremia

We retrospectively studied the incidence of anaerobic bacteremia during 6 years (1991-1996) at Turku University Central Hospital (Turku, Finland). The clinical significance of a positive anaerobic blood culture, the effect of a positive culture on the choice of antimicrobial therapy, and the outcome for patients were evaluated. Cultures of blood from 81 patients yielded anaerobic bacteria (4% of all bacteremias). Anaerobic bacteremia was clinically significant in 57 patients (0.18 cases per 1,000 admissions). Only half (28) of these patients received appropriate and effective antimicrobial treatment before the results of blood cultures were reported; for 18 patients (32%), initially ineffective treatment was changed on the basis of the bacteriologic results, and for 11 patients (19%), the treatment was not changed. The mortality in these patient groups was 18%, 17%, and 55%, respectively. Empirical therapy may provide coverage for anaerobes in only half of the patients with anaerobic bacteremia, and failure to pay attention to the results of anaerobic blood cultures may have serious consequences for patients.     

Coal miners'' respiratory disease litigation

Between 1985 and 1995, 1037 bacteremic episodes were recorded in a pediatric tertiary care center and analyzed retrospectively. Gram-positive bacteria accounted for 719 episodes (68%), gram-negative bacteria for 303 (29%), fungi for 16 (2%), and anaerobes for 12 (1%). In 526 (51%) patients, primarily neonates and oncology patients, a predisposing condition was present. In 390 (38%) episodes a clinical source of infection was documented. Mortality was highest in Pseudomonas bacteremia (45%). Since the bacterial spectrum differed widely between patient groups, the choice of empirical antimicrobial therapy should be based on any underlying condition present in the patient and the clinical source of infection. As anaerobes were rarely isolated. the routine use of anaerobic blood cultures in patients without predisposing conditions does not seem warranted.     

Microbiological examinations and in-vitro testing of different antibiotics in therapeutic endoscopy of the biliary system

BACKGROUND AND STUDY AIMS: Prior to endoscopic therapeutic procedures, no antibiotic prophylaxis is administered routinely. Because of the reported incidence of infectious complications, which may reach up to 10%, a prospective study was undertaken to investigate the effects of a prophylactic dose of cefuroxime on the incidence of bacteremia and clinical signs of infection, but no significant effects could be demonstrated. In addition to this published work, blood and bile cultures obtained in this trial were also investigated, and the in-vitro susceptibility to several antibiotics was tested in order to recommend the appropriate substances. PATIENTS AND METHODS: Ninety-nine consecutive patients (51 men, 48 women; mean age 61.4 +/- 17 years) with biliary obstruction who underwent an endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography with drainage (PTCD) were included. Sequential blood cultures were taken before and up to 60 minutes after the endoscopic intervention. Bile cultures were obtained in 56 patients with biliary drainage. Aerobic and anaerobic cultures were prepared from all obtained specimens and the isolated organisms were identified. In the case of positive cultures, an in-vitro resistance test for 15 different antibiotics was performed. RESULTS: The incidence of bacteremia was 11.1% (n = 11), and 16 bacteria were isolated. Twelve different microorganisms were detected, with Escherichia coli found in four cases. From 41 positive out of 56 prepared bile cultures (73.2%), 91 isolates were found with 25 different species. A single agent was detected in eight cases (19.5%), while a mixed growth, with pathogens ranging from two to six species, was found in 33 cases (80.5%). The seven most frequently isolated germs were E. coli and Enterococcus (each n = 19), Klebsiella (n = 10), Streptococcus viridans (n = 9), Staphylococcus epidermidis (n = 5), Morganella morganii (n = 4), and Bacteroides fragilis (n = 3), representing 76% of all agents. Examination for fungal infection revealed positive cultures of Candida albicans in 16.1% of bile cultures (nine of 56). Interestingly, the use of proton-pump inhibitors (PPIs), with a consequent rise in the gastric pH value, led to an increase in the rate of bacteremia to 26.2% (five of 19) compared to the other patients not on PPIs (n = 80), who developed bacteremia in only six cases (7.5%; p = 0.02). In-vitro testing of different antibiotics was carried out in 73 isolates. Imipenem showed the best antimicrobial activity (98.4%), followed by trimethoprim and sulfamethoxazole (90%), amoxicillin plus clavulanic acid (87.3%), vancomycin (82.4%), and ofloxacin (76.9%). CONCLUSIONS: Escherichia coli was found to be the pathogen most frequently detected in blood and bile following endoscopic interventions in the biliary tract. Enterococci, Klebsiella and Streptococcus viridans were found in bile cultures with an incidence exceeding 10%. In view of the in-vitro test results, possible side effects, and contraindications, amoxicillin plus beta-lactamase inhibitors or quinolones are considered to be suitable antibiotics for the prophylaxis of biliary infections.     

Blood cultures positive for coagulase-negative staphylococci: antisepsis, pseudobacteremia, and therapy of patients

A blood culture cohort study investigating issues related to isolation of coagulase-negative staphylococci (CoNS) and other skin microflora is reported. Data were collected over 12 weeks to determine the incidence of significant CoNS bacteremia versus that of pseudobacteremia (contaminants) and to evaluate drug therapy in patients with cultures positive for CoNS. In addition, the effectiveness of 0.2% chlorine peroxide as a bactericidal disinfectant was compared to that of 10% providone iodine. A total of 3,276 cultures of blood from 1,433 patients were evaluated in the study. Eighty-nine cultures were positive for skin flora, with 81 of 89 (91%) involving CoNS. The incidence of significant CoNS bacteremia was 20 of 81 (24.7%), that of indeterminate bacteremia was 10 of 81 (12.3%), and that of contamination was 59 of 81 (72.8%). The incidence of significant bacteremia involving CoNS was double the 10 to 12% rate based on previous estimations at our institutions. In tests with the two bactericidal disinfectants, 22 of 1,639 cultures (1.3%) in the chlorine peroxide group versus 37 of 1,637 (2.3%) in the providone iodine group were considered contaminated (P = 0.065). Rates of contamination for venipuncture versus catheter collection were not significantly different (P = 0.46). The overall contamination rate was 59 of 3,276 (1.8%), which is consistent with the lower end of published quality assurance benchmark standards. The low rate was believed to be due to the professional phlebotomy staff in our institutions. There was excellent agreement between retrospective analysis by reviewers, when formal criteria were used, and the attending physicians' intuitive clinical impressions in the classification of significant bloodstream infections (100% agreement) or contamination (95% agreement). However, physicians still used antimicrobial agents to treat nearly one-half of the patients with contaminated blood cultures, with vancomycin being misused in 34% of patients. In addition, 10% of patients with significant bacteremia were treated with inappropriate agents. There were no significant adverse events or prolonged hospital stays due to the unnecessary use of vancomycin; however, the additional costs of treating patients whose cultures contained CoNS contaminants was estimated to be $1,000 per patient. Measures to limit the unnecessary use of vancomycin (and other agents) are important.     

Aerobic and anaerobic microbiology of surgical-site infection following spinal fusion

The aerobic and anaerobic microbiology of surgical-site infections (SSI) following spinal fusion was retrospectively studied. This was done by reviewing the clinical and microbiological records at the Naval Hospital in Bethesda, Md., from 1980 to 1992. Aspirates of pus from 25 infection sites showed bacterial growth. Aerobic bacteria only were recovered from 9 (36%) specimens, anaerobic bacteria only were recovered from 4 (16%), and mixed aerobic and anaerobic bacteria were recovered from 12 (48%). Sixty isolates were recovered: 38 aerobes (1.5 isolates per specimen) and 22 anaerobes (0.9 isolate per specimen). The predominant aerobes were Escherichia coli (n = 8) and Proteus sp. (n = 7). The predominant anaerobes were Bacteroides fragilis group (n = 9) and Peptostreptococcus sp. (n = 6) isolates. An increase in recovery of E. coli and B. fragilis was noted in patients with bowel or bladder incontinence. This study highlights the polymicrobial nature of SSI and the importance of anaerobic bacteria in SSI following spinal fusion.     

Zoonoses as occupational diseases in the DDR

To determine the incidence of bacteremia in healthy adults, blood cultures were obtained from 240 patients who had no demonstrable foci of infection. Five patients (2.1%) had positive blood cultures. Staphylococcus epidermidis was isolated from four patients and Alcaligenes faecalis from one. In each of these patients, the organism isolated probably represented contamination rather than bacteremia.     

An analysis of bacteremias during dental extractions. A double-blind, placebo-controlled study of chlorhexidine

BACKGROUND: The literature is unclear concerning the nature and incidence of bacteremias from oral surgical procedures, the relationship of these bacteremias to dental disease, and the preventive benefit of antibacterial mouth rinses. OBJECTIVE: To determine the incidence and nature of bacteremias during single-tooth extractions in adults. METHODS: A double-blind, randomized placebo-controlled study of 70 patients in which the status of dental disease was compared with the incidence and nature of aerobic and anaerobic bacteremias following a single-tooth extraction and the antibacterial effect of rinses with chlorhexidine hydrochloride. Multiple indicators of dental disease were evaluated and recorded before the surgical procedure. Timing of the mouth rinses, the steps in the surgical procedure, and the two blood drawings were controlled for. RESULTS: Thirty-one (94%) of 34 control patients and 62 (89%) of 70 patients overall had blood cultures positive for organisms at either the 1-minute and or 3-minute mark following the initiation of surgery. The majority of cultures yielded gram-positive cocci. Cultures yielded polymicrobial organisms in 17 patients (24%). Although there was a wide range of severity of odontogenic disease, this did not correlate with results of blood cultures. However, there was a statistically significant difference in the incidence of blood cultures positive for organisms at both shorter (<3 minutes, P=.04) and longer (>6 minutes, P=.04) surgery times. There was not statistically significant difference in either the incidence of blood cultures positive for organisms or in the nature of organisms identified between the chlorhexidine and placebo groups. CONCLUSIONS: Single-tooth extraction should be expected to cause a bacteremia regardless of the status of the dentition or periodontium. Mouth rinses with chlorhexidine not significantly alter the number of positive blood cultures or the nature of the organisms at either of the two blood drawings.     

Susceptibility of anaerobic bacteria to 23 antimicrobial agents

The antimicrobial susceptibility of 492 anaerobic bacteria, the majority of which were recent clinical isolates, was determined by the agar dilution technique. Penicillin G was active against most of the strains tested at 32 U or less/ml, but only 72% of Bacteroides fragilis strains were susceptible at this level and 9% required 256 U or more/ml. Ampicillin was effective against most of the strains except B. fragilis at 16 mug or less/ml. Amoxicillin was active against only 31% of B. fragilis, 76% of other Bacteroides species, and 67% of Fusobacterium species at 8 mug/ml. Two new penicillins, mezlocillin and azlocillin, were similar to ampicillin in their activity. Carbenicillin and ticarcillin inhibited all but a few strains at 128 mug or less/ml. BLP 1654 was somewhat more active than penicillin G against B. fragilis but had similar activity against other anaerobes. Cephalothin was inactive against B. fragilis, and only 65% of other Bacteroides species were inhibited by 32 mug or less/ml. It was effective against all other anaerobes at that level. Cefamandole showed somewhat greater activity than cephalothin against B. fragilis but generally less activity against gram-positive organisms. Cefazaflur (SKF 59962) was comparable to cephalothin against B. fragilis. Cefoxitin was distinctly more active than cephalothin against B. fragilis. These latter two agents were less active than cephalothin against the gram-positive anaerobes. Chloramphenicol remains active against anaerobic bacteria at 16 mug or less/ml, with rare exceptions. Thiamphenicol was similar to chloramphenicol in its activity. Clindamycin was very active against most of the anaerobes at 8 mug or less/ml. Erythromycin and josamycin were also tested, with josamycin showing greater activity against B. fragilis than either erythromycin or clindamycin. A new oligosaccharide, everninomicin B, was less active than clindamycin against B. fragilis but more active against clostridia and some of the other strains tested. Most of the groups of bacteria tested demonstrated a trend toward resistance to tetracycline. Doxycycline and minocycline were somewhat more active than was tetracycline. Metronidazole was active against the majority of the anaerobes tested; resistance ws demonstrated by some of the gram-positive cocci and gram-positive, non-sporeforming bacilli.     

Nosocomial pseudobacteremia. Positive blood cultures due to contaminated benzalkonium antiseptic

Pseudomonas cepacia or Enterobacter species or both were isolated from blood cultures of 79 patients in a community hospital between April 1971 and March 1972. No common exposures other than venipuncture correlated with positive blood cultures. Pseudomonas cepacia, Enterobacter, and other Gram-negative enteric bacteria were cultured from aqueous benzalkonium chloride used for skin antisepsis prior to ordinary and blood culture venipuncture. Contamination of blood cultures by organisms from the antiseptic most likely accounted for positive cultures in 35 to 38 patients (92%) with P cepacia. The remaining three patients had repeated blood cultures positive for P cepacia and circumstantial clinical evidence of bacteremia; they may have contracted disease through exposure to the contaminated antiseptic. Substitution of an iodine-alcohol antiseptic abruptly reduced the isolation of P cepacia and Enterobacter.     

Incidence of bacteremia associated with chorionic villus sampling

OBJECTIVE: To assess the frequency of transient bacteremia among women undergoing transabdominal and transcervical chorionic villus sampling (CVS). METHODS: One hundred fourteen women undergoing CVS consented to participate in a university review board-approved study protocol. Exclusion criteria included known cardiac valve anomaly or replacement (or other prosthetic) and antibiotic use within the preceding 21 days. Blood cultures (aerobic and anaerobic) were drawn by a single operator on all patients, before CVS and within 15 minutes after completing CVS. Either the catheter tip or needle tip aspirate from each procedure was also sent for culture. RESULTS: Post-procedure bacteremia was detected in two (1.8%) of the patients undergoing CVS. These two patients both had their procedures performed transcervically, resulting in a 4.1% (two of 49) bacteremia rate after transcervical CVS, compared to none (zero of 65) in the transabdominal group (P = .36). The incidence of positive cultures from sampling instruments was also higher in the transcervical group (16.3 versus 0%; P = .003), but did not result in comparable rates of bacteremia among patients with positive instrument cultures. CONCLUSIONS: In this study, CVS was associated with a low rate of bacteremia, regardless of the procedure route. Recommendations for antibiotic prophylaxis in women with abnormal cardiac valves should parallel those for spontaneous vaginal delivery and other comparable genitourinary procedures.     

Bacteremia in a community hospital: spectrum and mortality

The problem of bacteremia was studied at our 500-bed community hospital during 1974-1975. All patients with positive blood cultures for clinically significant organisms were analyzed with respect to age, sex, host factors, type, dose, and time of institution of therapy with antibiotics, and mortality. Of 142 episodes of bacteremia, outcome according to underlying host factors showed that 12/15 died in the rapidly, fatal group, 12/24 died in the ultimately fatal group, and in the nonfatal group 25/103 died. Mortality for Gram-positive bacteremia was 37% (7/54) for Gram-negative bacteremia in the nonfatal group. In addition to underlying host factors, inappropriate antibiotic therapy also contributed to higher mortality in patients with gram-negative bacteremia.     

Prognostic indicators in fungemia of the surgical patient

OBJECTIVE: The objective of this study is to identify prognostic factors affecting mortality in surgical patients with culture-proved fungemia and to examine how amphotericin B affects mortality after controlling for these factors. DESIGN: The study is based on a retrospective logistic regression analysis of general surgical patients with blood cultures positive for fungi. We analyzed the patients' ages; whether they received triple antibiotics, had diabetes, had malignant neoplasia, received steroids, had concomitant bacteremia, or took antibiotics for greater than 7 days; and total dose of amphotericin B. SETTING: The study was carried out at a university-based county hospital. PATIENTS: Analysis of microbiology records for blood cultures that were positive for fungi from November 1987 to January 1992 revealed 63 general surgical patients. Patients with burns and those undergoing organ transplantation were excluded. Forty charts were complete and available for review. MAIN OUTCOME: Death was the outcome variable studied. RESULTS: Stepwise logistic regression analysis of death revealed age to be a risk factor for mortality. Treatment with at least 210 mg of amphotericin B was associated with relative risk of death of 0.055. CONCLUSION: Amphotericin B is effective even at low doses at decreasing the mortality in surgical patients with fungemia. On the other hand, increasing age is associated with an increased risk of mortality. Found not to be associated were concomitant bacteremia, concurrent triple antibiotic therapy, malignant neoplasia, and steroid use.     

Sepsis associated with decubitus ulcers

Among 21 patients with sepsis attributed solely to decubitus ulcers, bacteremia was documented in 16 (76 per cent)9 Bacteremia involved obligate anaerobes in eight patients (50 per cent) and was polymicrobial in eight patients (50 per cent). Twelve of 17 patients who received antibiotics had persistent bacteremia; in five patients, bacteremia was terminated only after surgical debridement. Ten of these 21 patients died, eight despite appropirate antibiotics. Among 14 patients who underwent surgical debridement, only four patients died. Surgical debridement and antibiotics effective against aerobic as well as anaerobic bacteria are both important in the treatment of this serious complication.     

The impact of mucositis on alpha-hemolytic streptococcal infection in patients undergoing autologous bone marrow transplantation for hematologic malignancies

BACKGROUND: Antibacterial prophylaxis with quinolone antibiotics has resulted in an increase in streptococcal infections among bone marrow transplantation (BMT) recipients with myelosuppression. Oral ulceration (mucositis), which frequently occurs as a consequence of chemotherapy, has been implicated as a significant portal of entry for streptococci. The objectives of this study were to confirm the correlation between mucositis and streptococcal bacteremia, determine the risk associated with this correlation, and evaluate the impact of mucositis and streptococcal bacteremia on hospital course and costs associated with autologous BMT. METHODS: This was a retrospective, case-control study in which the charts of autologous BMT recipients treated for hematologic malignancies between 1990 and 1996 were reviewed. Twenty-four patients were identified who met the criteria of autologous BMT; their blood cultures confirmed (x2) alpha-hemolytic streptococcal sepsis. A control group of 45 without positive cultures was matched by gender, age, diagnosis, and treatment to the study group. RESULTS: The results confirm that ulcerative mucositis is a significant risk factor for alpha-hemolytic streptococcal bacteremia among autologous BMT patients. Of the 24 patients with bacteremia, 15 of 24 (62%) had ulcerative mucositis, compared with 16 of 45 (36%) of patients in the control population (P < 0.05). Patients with ulcerative mucositis were found to be three times as likely to develop alpha-hemolytic streptococcal bacteremia as those without ulcerative mucositis (odds ratio=3.02). Both independently and as a cofactor associated with bacteremia, mucositis adversely affected the length of hospital stay (LOS). Of all the patients studied, those with oral ulcerations had a LOS of 34 days, compared with 29 days for patients without oral ulcerations (P < 0.05). Of patients in the study group, those with oral ulcerations stayed in the hospital 6 days longer than patients without oral ulcerations (40 days vs. 34 days, P < 0.05). CONCLUSIONS: Oral ulcerative mucositis is a significant, common, and important risk factor for alpha-hemolytic streptococcal bacteremia in BMT recipients with myelosuppression; it results in longer hospital stay and increased costs.     

Increasing bacteremia due to coagulase-negative staphylococci: fiction or reality?

BACKGROUND: The role of coagulase-negative staphylococci (CNS) in bacteremias continues to be controversial. Until the 1970s, CNS were mostly recognized as contaminants, being part of the cutaneous flora. Since then, several studies have reported increasing incidence and severity of infections due to CNS. PURPOSE: To review the literature concerning the epidemiology of CNS bacteremia in the United States and Europe with reference to the multiple definitions of infection versus contamination, considering the effect of potential biases influencing the validity of the reported results. METHODS: Literature search of the MEDLINE database from January 1980 to February 1998. Studies with fewer than 500 episodes of bloodstream infections or fewer than 100 episodes of CNS bacteremia were not included in the pooled analysis. RESULTS: (1) CNS remain the most frequent contaminants (58%-83% of positive blood cultures); (2) the proportion of all bloodstream infections caused by CNS is increasing (R=.51); (3) the overall incidence of true CNS bacteremia is increasing (R=.54, P=.0014); (4) comparing the United States to Europe, there is an increasing trend in the incidence of nosocomial bacteremia due to CNS in the United States (R=.82, P=.0006), but no trend is seen in European studies; (5) the mortality associated with true CNS bacteremia varies between 4.9% and 28%. DISCUSSION: This review confirms the increasing importance of CNS bacteremias, measured both as a proportion and as an incidence of bloodstream infections. The contributions of several possible explanations for the incidence increase and the difference between the United States and Europe need further evaluation: (1) increased recognition and awareness of CNS infections among clinicians; (2) a gradual change in the definition of true bacteremia from an obligatory two positive blood cultures to one positive blood culture associated with a clinical picture compatible with infection; (3) a change in blood culture practices and techniques; (4) an increase in the numbers of blood cultures performed, which is reported both in the United States and in Europe; (5) a shift toward more elderly patients with increasingly severe underlying illnesses; and (6) increasing use of intravascular devices. CONCLUSIONS: The apparent trend of increasing CNS bacteremia seems to be valid. Whether there is a real difference between the United States and Europe concerning the increase of CNS bacteremia is difficult to establish due to the large number of confounding factors. Few studies take into account the number of blood cultures performed or the use of intravascular devices to adjust for the observed trends. Further on-site surveillance studies are needed to investigate the phenomenon more extensively.     

Randomized, open-label trial of azithromycin plus ethambutol vs. clarithromycin plus ethambutol as therapy for Mycobacterium avium complex bacteremia in patients with human immunodeficiency virus infection. Veterans Affairs HIV Research Consortium

Disseminated Mycobacterium avium complex (MAC) infection continues to be a common opportunistic infection in patients infected with human immunodeficiency virus (HIV). The optimal therapy for disseminated MAC infection is unclear. We compared azithromycin plus ethambutol with clarithromycin plus ethambutol in the treatment of disseminated MAC infection in HIV type 1-infected patients, examining the frequency of bacteremia clearance, time to clearance, and study drug tolerance after 16 weeks of therapy. Fifty-nine patients for whom blood cultures were positive for MAC were enrolled in the study from 10 university-affiliated Veterans Affairs Medical Centers. Thirty-seven patients were evaluable for determination of quantitative bacteremia and clinical outcomes. Clearance of bacteremia was seen at the final visit in 37.5% of azithromycin-treated patients and in 85.7% of clarithromycin-treated patients (P = .007). The estimated median time to clearance of bacteremia was also significantly different between the two treatment arms: 4.38 weeks for clarithromycin recipients vs. > 16 weeks for azithromycin recipients (P = .0018). Only one isolate developed macrolide resistance during therapy. Abatement of symptoms, other laboratory-evident abnormalities, and adverse effects were similar in the two groups. At the doses used in this study, clarithromycin/ethambutol produced a more rapid resolution of bacteremia than did azithromycin/ethambutol, and clarithromycin/ethambutol was more effective at sterilization of blood cultures after 16 weeks of therapy.     

Aerobic and anaerobic microbiology of empyema. A retrospective review in two military hospitals

The microbiology and clinical features of empyema were studied retrospectively in 197 patients whose specimens yielded bacterial growth after inoculation for aerobic and anaerobic bacteria. Three hundred forty-three organisms (216 aerobic or facultative and 127 anaerobic organisms) were isolated. Aerobic bacteria were isolated in 127 (64 percent) patients, anaerobic bacteria in 25 (13 percent), and mixed aerobic and anaerobic bacteria in 45 (23 percent). The predominant aerobic or facultative organisms were Streptococcus pneumoniae (70 isolates), Staphylococcus aureus (58), Escherichia coli (17), Klebsiella pneumoniae (16), and Haemophilus influenzae (12). The predominant anaerobes were pigmented Prevotella and Porphyromonas species (24), Bacteroides fragilis group (22), anaerobic cocci (36), and Fusobacterium species (20). beta-Lactamase-producing organisms were recovered in 49 (38 percent) of 128 tested specimens. These included all 42 tested S aureus and 15 B fragilis group, 4 of 9 K pneumoniae, 3 of 9 H influenzae, 3 of 8 pigmented Prevotella and Porphyromonas species, and 2 of 6 E coli. Most patients from whom S pneumoniae and H influenzae were recovered had pneumonia, and most patients with S aureus had pneumonia, aspiration pneumonia, and lung abscesses. The recovery of anaerobic bacteria was mostly associated with the concomitant diagnosis of aspiration pneumonia, and lung, subdiaphragmatic, dental, and oropharyngeal abscesses. These data highlight the importance of anaerobic bacteria in selected cases of empyema.     

Effect of sodium-hydrogen exchange inhibition on functional and metabolic impairment produced by oxidative stress in the isolated rat heart

PURPOSE: To determine the frequency, associate factors and clinical features of bacteremia in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP), with or without therapeutic procedures. METHODS: Prospectively, 42 consecutives patients undergoing 46 endoscopic retrograde cholangiopancreatographies (ERCPs) from August to December 1994 were analyzed. The search for bacteremia was done by drawing 6 blood samples for cultures from peripheral blood. Two blood samples were collected before the ERCP and 4 of them after. The bottles used for cultures were Bactec bottles. The bottles were incubated in the Bactec 9240 system, and eventual bacteria detect were identificated by the manual routine of the laboratory and also with the autoScan/Microscan system. RESULTS: All blood cultures obtained before the ERCPs were negatives. Bacteremia were detected after 7 endoscopic procedures. In two episodes of bacteremia, the microorganism identified (Staphylococcus epidermidis) was considered to be a contaminant. The other 5 episodes of bacteremia were considered true bacteremia (frequency- 10.9%), and the microorganisms identified were: Streptococcus viridans, Corynebacterium sp., Enterobacter cloacae, Klebsiello oxytoca and Enterobacter aerogenes. This episodes were more frequent in the blood cultures obtained immediately after the ERCPs (p < 0.05), and occurred exclusively in the patients who were not receiving antibiotics (p = 0.0192). Clinical manifestation of the episodes of bacteremia were not detected. CONCLUSION: The episodes of bacteremia occurred exclusively in the patients who were not receiving antibiotics, were transient and completely no symptomatic.     

Bacteriological study of otogenic cerebral abscesses: chemotherapeutic role of metronidazole

In nine consecutive patients with otogenic cerebral abscesses a mixed growth of aerobic and obligate anaerobic bacteria was isolated from the pus in five patients, and in the remaining four obligate anaerobes were the sole isolates. The commonest obligate anaerobe isolated was Bacteroides fragilis, which was present in all but one patient. The patients were all treated with metronidazole for the anaerobic organisms and with appropriate chemotherapy against the aerobic organisms isolated. All the patients recovered and only one was left with a neurological deficit. As otogenic cerebral abscesses constitute a major proportion of all cerebral abscesses, the use of metronidazole against obligate anaerobic bacteria, which tend to dominate in such abscesses, should reduce the high mortality from this condition.     

Aerobic and anaerobic bacteriology of cutaneous abscesses in children

Specimens from 209 cutaneous abscesses in children were cultured for aerobic and anaerobic microorganisms. Of these, nine (4%) were sterile and 51 (24%) yielded pure cultures that were predominantly Staphylococcus aureus. The rest of the abscesses yielded growth of two or more aerobic and/or anaerobic organisms. The data were organized according to these anatomic locations: head, neck, trunk, finger, nailbed, hand, leg, buttocks, perirectal, and vulvovaginal areas. Aerobic bacteria only were present in 92 specimens (46%), anaerobes only were isolated in 52 (26%), and mixed aerobic and anaerobic bacteria were present in 56 abscesses (28%). A total of 467 isolates (270 anaerobes and 197 aerobes) were recovered, accounting for 2.3 isolates per specimen (1.3 anaerobes and 1.0 aerobes). The presence of more than one anaerobe per abscess was obtained from the vulvo-vaginal, buttocks, perirectal, finger, nailbed, and head areas. Aerobes were more prevalent in the neck, hand, leg, and trunk areas. The predominant aerobes recovered were: S aureus (89 isolates), alpha- and nonhemolytic streptococci (29), group A beta-hemolytic streptococci (16), Enterobacter (10), and Escherichia coli (8). The predominant anaerobes recovered were anaerobic Gram-positive cocci (79 isolates), Bacteroides sp (116, including 31 B melaninogenicus group and 29 B fragilis group), and Fusobacterium sp (39). Our findings indicate the polymicrobial nature and predominance of anaerobes in cutaneous abscesses in children in perirectal, head, finger, and nailbed areas.