Streptococcus bovis new taxonomy: does subspecies distinction matter?

Bacteremia with Streptococcus bovis/equinus complex strains is associated with hepatobiliary disease, colorectal lesions (CL), and infective endocarditis (IE). This study addressed the clinical significance of subspecies distinction of previously designated S. bovis blood culture isolates according to the updated nomenclature. During 2002-2013, all blood culture isolates previously designated as S. bovis were recultured and identified using 16S rRNA gene sequencing and MALDI-TOF (Bruker BioTyper and Vitek MS, bioMérieux). Clinical data of patients aged ≥18 years were reviewed. A review of four recent case series was performed as well. Forty blood isolates were identified using 16S rRNA sequencing. Twenty-six bacteremic patients had S. gallolyticus ssp. pasteurianus, six had S. gallolyticus ssp. gallolyticus, two had S. gallolyticus ssp. macedonicus, and six had S. infantarius bacteremia. Species diagnosis using Vitek and bioMérieux MALDI-TOF technology was applicable in 37 and 36 samples, respectively, and was successful in all samples (100 %). Subspecies identification was confirmed in 30 (83 %) samples (as compared with 16S rRNA sequencing detection). IE was diagnosed in 22 (59 %) patients and CL in 8 (20 %) patients. Both complications were associated with all subspecies. Combining our results with those of four recent series resulted in, overall, 320 bacteremic cases, of which 88 (28 %) had CL and 66 (21 %) had IE. All 'bovis/equinus' complex subspecies were associated with CL or IE. From a clinical point of view, species diagnosis using MALDI-TOF MS should suffice to warrant consideration of transesophageal echocardiography and colonoscopy.

Relative incidence of phlebitis associated with peripheral intravenous catheters in the lower versus upper extremities.

Peripheral venous access in elderly, hospitalized patients is often challenging. The usual alternative is insertion of a central venous catheter, with associated risk for complications. The purpose of this investigation was to determine the relative incidence of phlebitis secondary to lower as compared to upper extremity intravenous catheters (IVCs) and associated risk factors. A non-randomized, observational, cohort-controlled study was carried out. Consecutive patients receiving a lower extremity IVC were enrolled and compared with patients receiving an upper extremity IVC. Patients were followed from insertion until removal of the IVC. The major endpoint was phlebitis. The incidence of phlebitis secondary to upper extremity IVCs was 3/50 (6 %) compared to 5/53 (9.4 %) in lower extremity IVCs (χ(2) Yates = 0.08, p = 0.776). Age, gender, obesity, diabetes mellitus, site (arm versus leg, left versus right), and size of needle were not found to be risk factors for phlebitis according to univariate analysis. None of the patients developed bloodstream infection. In elderly patients with poor venous access, lower extremity IVCs are a reasonable and low-risk alternative to central venous catheters.

Ultrasound diagnosis of Clostridium difficile-associated diarrhea.

Clostridium difficile colitis is diagnosed using an immunoassay or polymerase chain reaction (PCR) assay for toxins A/B. Since ultrasound is frequently used as a screening test for hospitalized patients suffering from different abdominal morbidities, we searched for sonographic indicators of C. difficile infection (CDI). In a prospective and blinded case-control study, abdominal ultrasound was performed on hospitalized patients for whom stool samples were sent for C. difficile toxin immunoassay. All patients with positive toxin were included as the case group and patients with negative toxin comprised the control group. Sonographic parameters of both groups were compared. Demographic variables of the 67 patients in the toxin-positive group were similar to those of the 71 patients in the toxin-negative group. The sonographic parameters which were found to be associated with CDI included colonic wall thickening, appearing in 61 (91%) patients of the toxin-positive group versus 15 (21%) patients of the toxin-negative group (p < 0.001), and also internal ring (24 versus 0%, p < 0.001), external ring (15 versus 0%, p < 0.001), ascites (24 versus 10%, p < 0.001), and diminution of large bowel content (16 versus 1%, p < 0.001). Bowel wall thickening had high positive and negative predictive values (0.80 and 0.90, respectively), while the other features had only high positive predictive values (0.7-1.0). Abdominal ultrasound may contribute to the diagnosis of C. difficile colitis in patients developing hospital-acquired diarrhea.

Risk factors for bacteriuria with carbapenem-resistant Klebsiella pneumoniae and its impact on mortality: a case-control study.

BACKGROUND: The objective of this study was to evaluate the mortality of and risk factors for bacteriuria due to carbapenem-resistant Klebsiella pneumoniae (CRKp) versus carbapenem-susceptible K. pneumoniae (CSKp) producing extended spectrum ß lactamase (ESBL). METHODS: This was a retrospective case-control study in which 135 case-patients with bacteriuria due to CRKp were compared with 127 control patients with CSKp producing ESBL. In a first step, multivariate Cox regression and Kaplan-Meier survival analysis models were used to determine the difference in mortality between the two groups and risk factors for mortality. In a second step, a univariate analysis was used to identify risk factors for CRKp colonization. RESULTS: There were no significant demographic or clinical differences between the groups. In-hospital mortality in the study and control groups was 29 and 25 %, respectively (non-significant difference). Multivariate analysis revealed that the most important risk factor for mortality in both groups was being bed ridden [hazard ratio 2.2, 95 % confidence interval (CI) 1.23-3.93; P = 0.008]. Patients with CRKp bacteriuria had a longer hospitalization time with a mean ± standard deviation of 28 ± 33 days compared to 22 ± 28 days in the control group (P < 0.05). Several univariate risk factors for acquiring CRKp bacteriuria were identified: antibiotic use [odds ratio (OR) 1.93, 95 % CI 1.18-3.17, p = 0.008], especially colistin (OR 2.04, 95 % CI 1.04-4.02; P = 0.036), presence of a urinary catheter (OR 2.09, 95 % CI 1.2-3.63; P = 0.008), surgery (OR 3.94, 95 % CI 1.85-8.37; P = 0.0002), invasive procedures (OR 3.06, 95 % CI 1.61-5.8; P = 0.0004), and intensive care unit admission (OR 2.49, 95 % CI 1.18-5.37; P = 0.015). CONCLUSION: Bacteriuria caused by CRKp as compared that caused by CSKp was not found to be a risk factor for death.

Prospective drug utilization evaluation of three broad-spectrum antimicrobials: cefepime, piperacillin-tazobactam and meropenem.

BACKGROUND: Cefepime, piperacillin-tazobactam and meropenem are among the broadest-spectrum and most expensive antimicrobials. AIM: To evaluate guidelines for appropriate use of these drugs. METHODS: We developed guidelines for use of these antibiotics, and conducted a two-phase drug utilization evaluation. We included all patients who received one of the study drugs during two 3-month periods, with an educational intervention in the intervening period. Appropriateness was determined for initiation of treatment, and for adaptation or continuation of established treatment. RESULTS: Overall, 205 patients received 271 courses with one of these antibiotics, for a total of 709 defined daily doses (DDD) of cefepime, 543 of piperacillin-tazobactam, and 680 of meropenem (8.3, 6.3 and 7.9 DDD/1000 admission days, respectively). Of these 271 courses, 234 were appropriate (86%). Treatment was continued for > or =5 days in 60%, of which 88% were appropriate (NS). Of the 271 courses, 210 (77%) were empirical (83% appropriate), while 61 (23%) were based on a relevant culture result (97% appropriate) (p < 0.001). Appropriateness differed significantly between departments (p < 0.001), and between the two phases (p < 0.001). The major difference between the two surveys was a decrease in meropenem usage (p < 0.05). DISCUSSION: The vast majority of courses with cefepime, piperacillin-tazobactam and meropenem are empirically selected and continued, underlying the importance of an optimal initial choice. Antibiotic guidelines, in conjunction with formal infectious disease consultation, can contribute to more appropriate use of these drugs.

Group A streptococcus bacteraemia: comparison of adults and children in a single medical centre.

Group A streptococcus (GAS) bacteraemia is often associated with soft-tissue infection, with significant morbidity and mortality. Little is known concerning the differences between adults and children with GAS bacteraemia. Records for 98 of 116 cases of GAS bacteraemia (60 adults and 38 children, aged 7 days to 96 years) occurring during a 10-year period (1993-2002) were located and reviewed. GAS bacteraemia comprised 0.6% of all bacteraemias in adults, compared to 3.3% in children (p < 0.001). The rate of adult GAS bacteraemia was two cases/1000 hospitalisations, compared to 13/1000 in children (p < 0.001). Seventy-six (78%) patients had concomitant tissue involvement, with skin or soft-tissue infection being the most common (62%). Fifty-three (88%) of 60 adults and five (13%) of 38 children had underlying conditions (p < 0.001). Twelve patients died, only one of whom was a child. Parameters associated with mortality were older age, lower temperature, hypotension, a need for surgical intervention, toxic shock syndrome, disseminated intravascular coagulation, thrombocytopenia, lymphopenia, hypocalcaemia, renal failure and acidosis (p < 0.05).

Prospective hospital-wide studies of 505 patients with nosocomial bacteraemia in 1997 and 2002.

We conducted surveys in 1997 and 2002 to determine the rate, underlying sources and outcome of nosocomial bacteraemia. Blood culture results were reviewed daily. All patients with positive cultures drawn >or=48 h after hospitalization were included in the study and their charts were reviewed. The underlying source of infection was determined by pre-defined clinical and/or microbiological criteria. Patients were followed until discharge or death. In 1997 and 2002, 851 and 857 patient-unique cases of bacteraemia were diagnosed, respectively, excluding contaminants; of these, 228 (27%) and 277 (32%) cases, respectively, were hospital acquired (P<0.05). The overall rate decreased from 7.5 to 7.0 per 1,000 admissions (P<0.001). The sources of bacteraemia in 1997 and 2002, respectively, were: intravascular catheters (36% and 27%, P<0.05), urinary tract (8% and 15%, P<0.05), respiratory tract (5% and 13%, P<0.01) and surgical sites (14% and 4%, P<0.001). In one-third of patients, the source of bacteraemia could not be determined. Only 52% and 54%, respectively, of these patients were discharged alive (difference was not significant). In 1997, Staphylococcus aureus was the most frequent isolate (26%), followed by coagulase-negative Staphylococcus (13%) and Klebsiella pneumoniae (11%). By 2002, the incidence of S. aureus had fallen to 11% (P<0.001), acinetobacter was the single most frequently isolated organism (increased from 6% to 17%) (P<0.001). In-hospital mortality associated with acinetobacter bacteraemia (57%) was significantly higher than that for other organisms (31-43%) (P<0.05). In conclusion, prospective surveys of nosocomial bacteraemias provide valuable information, facilitating the pursuit of successful interventions.

Non-Typhi Salmonella gastroenteritis in children presenting to the emergency department: characteristics of patients with associated bacteraemia.

The records of children with Salmonella gastroenteritis only (n = 97), and those with associated bacteraemia (n = 64), seen in one medical centre during a 12-year period, were analysed retrospectively. Mean patient age was 2.24 +/- 2.8 years (range, 0.05-16 years), and 49% were male. Children with bacteraemia presented after a longer duration of symptoms (7.0 +/- 6.9 vs. 3.9 +/- 4.6 days, p 0.0002), and had higher erythrocyte sedimentation rates (45 +/- 22 vs. 33 +/- 22 mm/h, p < 0.02) and lactate dehydrogenase values (924 +/- 113 vs. 685 +/- 165 IU/L, p 0.001). There was a trend in bacteraemic children towards immunosuppression (6.3% vs. 1.0%, p 0.08) and a lower number of siblings (2.9 +/- 1.9 vs. 3.8 +/- 2.7, p 0.063). Non-bacteraemic children had a more severe clinical appearance, and a higher percentage had a moderate to bad general appearance (51.5 vs. 29.7%, p < 0.01), with dehydration (37.1 vs. 18.8%, p 0.02) and vomiting (58.8 vs. 39.0%, p 0.02). Laboratory dehydration indicators were also markedly worse in non-bacteraemic children, with urine specific gravity of 1020 +/- 9.4 vs. 1013 +/- 9.0 (p 0.0002), base excess of - 4.2 +/- 3.0 vs. - 2.5 +/- 3.4 mEq/L (p 0.01), and blood urea nitrogen of 10.1 +/- 7.0 vs. 7.4 +/- 4.5 mg% (p 0.002). Thus, the clinical presentation of bacteraemic children was more gradual, and associated gastroenteritis and dehydration was less pronounced. These findings may contribute in part to the inadvertent discharge of bacteraemic children from the emergency department.

Serologic response to treatment of syphilis in patients with HIV infection.

BACKGROUND: Much controversy exists concerning the manifestations, therapy, and response to treatment of syphilis in patients coinfected with the human immunodeficiency virus (HIV). OBJECTIVE: To assess the effect of HIV infection on the serologic response to treatment of patients with syphilis. METHODS: Sixty-four HIV-seropositive patients with syphilis were matched with 64 patients with syphilis who were HIV negative. Matching criteria included age (+/- 5 years), sex, race, initial rapid plasma reagin (RPR) titer (+/- 1 dilution), and stage of syphilis at entry. There were 26 matched patients with early syphilis, 26 matched patients with late syphilis, and 12 matched patients with biological false-positive RPR. The HIV-positive patients with early syphilis received three doses of penicillin G benzathine. All other patients received treatment as recommended by the Centers for Disease Control and Prevention, Atlanta, Ga. Our study's major end points were clinical and serologic response to treatment. RESULTS: All 16 patients with symptomatic syphilis were cured. No patient developed clinical signs of neurosyphilis during the 12-month follow-up period. Twenty-nine (56%) of 52 HIV-positive patients with early or late syphilis did not have a fourfold decrease in RPR titer 6 months after treatment compared with 20 (38%) of 52 matched controls (P = .06). No unique characteristics identifying patients who did not respond serologically could be established. The HIV-positive patients with initial RPR less than 1:32 experienced a significantly slower decrease in RPR at 12 months than did the controls (P < .001). CONCLUSIONS: Patients with syphilis who are HIV positive are less likely to experience serologic improvement after recommended therapy than are patients with syphilis who are HIV negative. Patients with HIV infection who contract syphilis should receive intensive and prolonged follow-up, and consideration should be given to designing alternative regimens.

Streptococcal group C bacteremia. Survey in Israel and analytic review.

BACKGROUND: Data concerning group C streptococcal bacteremia come mainly from case reports; thus, population-based studies from different geographic areas are needed to validate these findings. METHODS: Eight years of data on group C streptococcal infection in Israel and cases of bacteremia in five hospitals were reviewed. We compared data from our survey as well as from other population-based studies with multiple cases published as case reports. RESULTS: The organisms were isolated in 78 cases (excluding pharyngitis); 16 had bacteremia. Ten cases of bacteremia were reviewed in five hospitals; none of the patients reported exposure to animals, and nine had severe underlying diseases. The clinical syndromes included four cases of primary bacteremia, four cutaneous infections, and one case each of meningitis and pneumonia. There were two deaths, one patient underwent amputation of a toe, one had a stroke, and one had a relapse. We compared 80 cases published as case reports with 59 cases reported in five population-based studies from different countries. We found higher rates of underlying diseases, alcohol abuse, liver diseases, and cutaneous infections, and lower rates of exposure to animals or raw products, endovascular infections, and central nervous system infections in population-based studies. Morbidity and mortality were 20% to 30% each in both types of studies. CONCLUSIONS: Group C streptococcal bacteremia affects patients with underlying diseases; exposure to animals is variable and less frequent than previously reported. Morbidity and mortality are high and probably reflect the patients' underlying state as well as the severity of the infection.

Demographic and clinical characteristics of patients admitted to medical departments.

INTRODUCTION: The significant changes, which have affected departments of medicine over the last two decades, have been much editorialized. Surprisingly few data have been published that document these changes. We describe the demographic and clinical characteristics of patients admitted to one hospital's departments of internal medicine. METHODS: During a 3 months prospective study, 1039 patients (46% of all 2277 new admissions to the departments of medicine, consisting of +/- 175 beds) were randomized for inclusion. Information was extracted from the medical records regarding demography; functional capacity; clinical data and outcome. RESULTS: The mean age of the patients was 72 +/- 16 years (mean +/- SD); 51% were male, 56% were married, and 83% lived at home. Although 293 patients (28%) were defined as dependent, the majority lived at home (170, 58%). Cognition was normal in only 74%. The four most common disease categories leading to admission were infections (383 patients, 37%), cardiovascular disorders (372, 36%), respiratory conditions (284, 27%) and genito-urinary problems (90, 9%). Overall, 98 persons died (9%). Independent risk factors for death were: mechanical ventilation; a 'do not resuscitate' order; a high APACHE-II score; a low serum albumin level; higher age; and not being married (P < 0.01). CONCLUSIONS: Geriatric patients occupy a central position in our medical wards. These data are relevant for allocation of special resources for departments with high proportions of geriatric patients; for the design of employment conditions that ascertains continuing job satisfaction; as well as for the planning of teaching opportunities for residents and students.

Surveillance of antimicrobial prophylaxis for surgical procedures.

OBJECTIVE: To assess the practice of antimicrobial prophylaxis for surgical procedures in eight surgical departments in a 550-bed teaching hospital. METHODS: A list of all major procedures performed in our hospital, with recommendations for prophylaxis based upon the literature, has been distributed since 1993 and is updated periodically. The practice of surgical prophylaxis between January 1 and March 31, 1996, was examined by assessing four variables: (1) Did the particular procedure justify prophylaxis, and was it provided? (2) Was timing optimal, ie, within 1 hour prior to surgery? (3) Was the appropriate antimicrobial selected? (4) Was duration optimal, ie, < or =24 hours? RESULTS: During the study period, 2,117 operations were performed, of which 1,631 (77%) were reviewed. Sixty-six percent were clean surgery, 28% clean-contaminated, and 6% contaminated; 72% of procedures were elective, 28% emergencies. Of 1,631 operations requiring prophylaxis, 1,142 (70%) received it, 489 (30%) did not. Of 1,631 patients, 1,392 (85%) received appropriate care: 929 (67%) appropriately received prophylaxis, and 463 (33%) appropriately did not receive prophylaxis. Of 955 patients who received prophylaxis, 26 (3%) did so inappropriately. Of 1,142 patients who should have received prophylaxis, 213 (19%) did not receive it. Female gender, clean surgery, elective operations, and infrequently performed procedures were all significant indicators of inappropriately withheld prophylaxis (P<.001). In addition, the rate of appropriately provided prophylaxis varied between departments from 71% to 97% (P<.001). Assessment of the 929 procedures for which prophylaxis was justified and given revealed that 100% of patients received it on time, the choice of antimicrobial was appropriate in 95% of cases, and duration was < or =24 hours in 91%. CONCLUSIONS: Audits of surgical prophylaxis are expected to detect different errors in different institutions. Conducting audits of surgical prophylaxis probably should be part of the routine activity of infection control teams. Feeding the information back to surgeons could improve adherence to recommended guidelines and might contribute to reduced wound infection rates.

Practical guidelines for vancomycin usage, with prospective drug-utilization evaluation.

To strengthen guidelines for vancomycin use, practical guidelines were developed. A prospective survey was conducted of all patients receiving vancomycin during two 1-month periods, 1 year apart, during which significant improvements were noted. Practical guidelines may contribute to appropriateness of vancomycin use, serve as educational tools, and facilitate improved surveillance.

The use of the arterial line as a source for blood cultures.

OBJECTIVE: To determine the reliability of blood cultures obtained through indwelling arterial lines as compared to that of blood cultures obtained by venipuncture. DESIGN: A prospective observational study. SETTING: Six-bed mixed medical surgical intensive care unit (ICU) of a 550-bed university-affiliated medical center. MEASUREMENTS: During a 3-month period blood culture sets, when clinically indicated, were drawn in parallel from indwelling arterial catheters and one-time venipuncture and the results compared. Each blood sample consisted of 15 ml and was distributed equally between three blood culture bottles: aerobic, anaerobic and one aerobic resin-containing bottle. Blood culture results from the two sources were compared according to preset definitions. MAIN RESULTS: During the study period 90 parallel blood culture sets (540 bottles) were obtained from 36 patients. Forty-three (16%) venipuncture bottles were positive versus 88 (32%) arterial line culture bottles (p < 0.001). Of the parallel sets, 83% yielded equivalent results - either both sterile or both growing the same organism. Amongst the discordant sets, the arterial line cultures grew 37 gram-positive and 18 gram-negative isolates not found in venipuncture sets (i.e. 50% of 109 arterial line isolates), while only two gram-positive isolates were solely grown in venipuncture cultures (4% of all 55 venipuncture isolates, p < 0.001). On clinical correlation, all the gram-positive organisms in the discordant cultures were found not to reflect bacteremia, while five of the 18 gram-negative isolates (28%) grown only in arterial line cultures probably did reflect ongoing bacteremia. CONCLUSION: The results of blood cultures taken from the arterial line are frequently equivalent to those taken from venipuncture. When discordant, the growth of gram-positive bacteria almost certainly reflects contamination or arterial line colonization, whereas the growth of gram-negative bacteria may have to be considered as reflecting bacteremia.

Klebsiella bacteraemia: community versus nosocomial infection.

In the period 1988-1993, 241 patients had Klebsiella bacteraemia at our medical centre. The annual number of patients with positive blood cultures increased from 306 in 1988 to 622 in 1993, representing a 4.5-6% positivity rate of drawn cultures. After E. coli, Klebsiella was the leading cause of Gram-negative bacteraemia. During this period, the absolute number of Klebsiella bacteraemia increased from 25 in 1988 to 84 in 1993; this represents a true increase in Klebsiellaa bacteraemia, from 6-7% of positive cultures in the late 1980s to 12-13% in more recent years. There were 210 cases with K. pneumoniae and 31 with K. oxytoca. A representative sample of 80 records was retrieved and subdivided into two groups: community-acquired Klebsiella bacteraemia (CAKB) vs. hospital-acquired Klebsiella bacteraemia (HAKB). Urinary tract infection was the underlying source of 58% of CAKB vs 28% of HAKB (p < 0.01); pneumonia occurred significantly more often in HAKB (25%) than in CAKB (7%) (p < 0.01). In HAKB, as compared to CAKB, serious manifestations of illness were more common, e.g. shock (65% vs. 37%, p < 0.046) and respiratory failure (45% vs. 20%, p < 0.046). Overall mortality was 32%, 22% of patients with CAKB died vs. 42% of those with HAKB (p < 0.05). Multiple drug resistance was very common: only 57% of all Klebsiella strains were susceptible to gentamicin, 66% to ceftriaxone, 70% to ciprofloxacin, and 83% to amikacin. The susceptibility rates of Klebsiella spp isolated from patients with HAKB were significantly lower (p < 0.001). Sepsis due to multiple-drug-resistant Klebsiellaa has become frequent, carrying significant morbidity and mortality. Restriction of broad-spectrum antimicrobials in the hospital and the community as well as implementation of infection control measures are needed to contain this problem.

Longitudinal surveillance of antibiotic use in the hospital.

We evaluated antimicrobial use in our hospital by department, including indications for use, source of infections, use of the microbiology laboratory, and appropriateness of prescribing, in a prospective, comparative, non-interventional study of all patients receiving antimicrobial agents. We excluded departments where antimicrobial use was negligible. The other 19 departments were followed for 3 (n=4) or 4 (n=15) months, including 2 consecutive months in the spring-summer and either 1 or 2 in the autumn-winter. Antimicrobial therapy was followed from initiation, through possible adaptations, and possible change from intravenous to oral therapy, until discontinuation of treatment. Overall, 6376 antibiotics were given to 2306 patients. Of the surveyed hospitalized patients, 62%+/-22% received antibiotics, with a range of 4-100% per department. Antibiotics were prescribed for infections acquired in the community (3037 instances, 47%), in the hospital (2182, 34%), in a nursing home (575, 9%), and for prophylaxis continued post-operatively (582, 9%). The most common indications for antimicrobial use were: respiratory tract infection (1729, 27%), urinary tract infection (955, 15%), sepsis (701, 11%), intra-abdominal infections (663, 10%), prophylaxis 582 (9%), soft-tissue infection (572, 9%), and surgical site infection (319, 5%). Univariate indicators for appropriateness of treatment were: age, department, site of infection, source of infection, antimicrobial drug and serum creatinine (all p<0.001). Forty-nine antimicrobials were prescribed in 279 combinations, 58% as single agent and 42% as drug combinations. Half of all antimicrobial use consisted of four agents: cefuroxime (19.1%), metronidazole (11.3%), gentamicin (10.6%) and ampicillin (10.2%), which together accounted for 20% of expenditure on antibiotics. Although use of as many as 53% of antimicrobials (26/49) surveyed was restricted, use in this category accounted for only 29% of all antimicrobial courses. Of 6376 antibiotic courses, 4101 (64%) were given intravenously and 2275 (36%) orally. Appropriateness of use of restricted drugs was lower (70%) than of unrestricted ones (84%, p<0.001). Of 24571 defined daily doses (DDD) given orally, 4587 (19%) were restricted, compared to 7264 (34%) of 21602 DDDs given intravenously (p<0.001). Antibiotic treatment in our hospital appears to be substantial and increasing, justifying efforts to improve appropriateness of therapy and improve clinical and financial results.

Risk factors for nephrotoxicity in elderly patients receiving once-daily aminoglycosides.

BACKGROUND: There remain concerns about the safety of once-daily dosing of aminoglycosides (AGs) in the elderly. AIM: To assess the safety of once-daily AGs in elderly patients and evaluate possible risk factors for nephrotoxicity. DESIGN: Prospective, non-interventional surveillance study. METHODS: All patients receiving AGs were monitored over 4 months. Clinicians determined the AG dose for each patient after estimating patient weight and calculating creatinine clearance (CrCl) using the Cockcroft-Gault formula. Parallel figures were calculated by the investigators using measured weight. Clinicians obtained an AG trough level 24 h after initiation of treatment, and, if non-toxic, every 5-7 days thereafter. AG toxicity was defined as an increase in serum creatinine of > or =50%. RESULTS: In the study period, 249 consecutive patients received an AG: 116 (47%) males, mean+/-SD age 75+/-16 years. Forty-two (17%) received amikacin and 207 (83%) gentamicin. An increase of > or =50% in serum creatinine was detected in 31/249 (12.4%); maximal creatinine was < or =177 micromol/l in 16/249 (6.4%), 186-265 micromol/l in nine (3.6%), and >265 micromol/l in six (2.4%). None developed oliguric renal failure. Renal damage correlated with a high AG trough level (>1.1 microg/ml) (p<0.001); haemoglobin level <10 g/dl (p<0.05); hospital admission >7 days prior to AG treatment (p<0.005); and AG treatment > or =11 days (p<0.05). Mean CrCl based on estimated weight was 52+/-18 ml/min; that based on actual weight was 71+/-37 ml/min. Despite this, mean AG dose was 1.3+/-0.6 higher than optimal. CONCLUSIONS: Oliguric and/or lasting renal toxicity is rare in elderly patients receiving once-daily aminoglycosides for <11 days, if regular trough drug levels are monitored.

In-vitro activity of cefepime and other broad-spectrum antimicrobials against several groups of gram-negative bacilli and Staphylococcus aureus.

The in vitro activity of cefepime was compared with that of amikacin, ceftazidime, imipenem, ciprofloxacin, and piperacillin-tazobactam by using the E-test against five groups of carefully selected organisms: Klebsiella pneumoniae (68 isololates), Pseudomonas aeruginosa (62), methicillin-susceptible Staphylococcus aureus (MSSA) (60), and two groups of Enterobacteriaceae (60 and 62 isolates, respectively). The bacteria were subdivided according to whether the infection was nosocomial or community-acquired, applying accepted and predefined criteria. These isolates were obtained from patients admitted to our medical center throughout 1998. We retrospectively compared antimicrobial susceptibilities of the study sample with those of the +/- 3000 bacterial strains isolated from blood stream infections since 1990: the study sample appeared to represent adequately the clinical databank. Presence of extended-spectrum beta-lactamase (ESBL) was determined in all groups of Enterobacteriaceae with the ESBL screening E-test strip. Of the 252 Gram-negative bacilli tested, 242 (96%) were susceptible to cefepime, whereas only 168 (67%) were susceptible to ceftazidime, 211 (84%) to amikacin, and 220 (87%) to piperacillin-tazobactam (p < 0.001). Imipenem was slightly superior to cefepime with only seven isolates resistant (3%), six of which were P. aeruginosa. Cefepime was more active against Enterobacteriaceae than ceftazidime (93% vs. 72%, p < 0.001). This superiority was most evident against nosocomial strains of K. pneumoniae, against which cefepime was > three times more active than ceftazidime. The high level of resistance seen in nosocomial isolates of K. pneumoniae is consistent with high rates of ESBL production (69%, compared with 15-26% in other Enterobacteriaceae). The MIC90 of cefepime to methicillin-sensitive S. aureus was 1.5 micrograms/mL, whereas that of ceftazidime was 4 micrograms/mL; the susceptibility rate of both was 100%. In conclusion, cefepime possesses in vitro potencies against MSSA and current clinical strains of Gram-negative bacilli, many of which harbor resistance to other antimicrobial agents. Hence, it seems very suitable for empiric coverage of serious nosocomial infections.

Analysis and impact of infectious disease consultations in a general hospital.

During an 18-month period, data from all patients in whose care our infectious diseases (ID) service was involved, were recorded in a computerized database. A total of 4184 new consultations was recorded. The consultations were solicited by the patients' physicians in 3326 cases (80%) and initiated by the ID service in the remainder. The purpose of the consultations was diagnosis (14%), therapy (39%), both diagnosis and therapy (40%), and prophylaxis (6%). Two thousand and ninety-four consultations (50%) were performed at the bedside, and the others by personal or telephone discussion. ID consultation was given in more than 10% of admitted patients in six departments, 46% of the admissions in the ICU, and 6.9/100 hospitalized patients. Recommendations included: antibiotic manipulation (i.e., initiation, change or discontinuation of antibiotic treatment) (51%); performance of tests (13%); performance of diagnostic or therapeutic procedures (5%); prophylaxis (4%) or no change in management (26%). Analysis of the solicited vs unsolicited consultations and of the bedside vs telephone consultations revealed that sub-groups of consultations differ significantly from each other in many aspects. Recording of consultations enables the ID service to evaluate its activity and to direct efforts to departments with high rates of infectious diseases and/or antimicrobial usage.

Susceptibility trends in bacteraemias: analyses of 7544 patient-unique bacteraemic episodes spanning 11 years (1990-2000).

The aim of the present study was to design more accurate tools for the selection of appropriate antimicrobial therapy for hospitalized patients with suspected sepsis. We created a large database comprising data on all patient-unique blood cultures obtained over an 11 year period (1 January, 1990 through 31 December, 2000). Improved statistical tools were applied to assess the trends in in vitro activity of individual antibiotic agents against various bacteria over time, and to calculate susceptibility rates of subsets of organisms. During the 11 year study period, 173571 blood cultures were obtained, of which 17703 (10.2%) were positive, with 7544 patient-unique blood cultures (4.3%). The mean annual number of positive, patient-unique cultures was 686 (standard deviation=79). The 10 most frequently isolated organisms were: Escherichia coli (1494), Staphylococcus aureus (1240), Klebsiella pneumoniae (779), Enterococcus spp. (631), Pseudomonas aeruginosa (488), Streptococcus pneumoniae (447), Enterobacter spp. (338), Acinetobacter spp. (298), Proteus mirabilis (260) and Candida spp. (254). No significant change was detected in the annual rates (means, standard deviations) per 1000 admissions of these organisms: the highest was E. coli (5.5, 1), the lowest was Candida (1, 0.3). Forty percent of organisms (N=2943) were obtained from patients in the emergency department (ED), 23% (1744) in medical departments, 15% (1134) in paediatric units, 13% (998) on surgical wards and 9% (709) in intensive care units (ICUs). Trend statistical analysis revealed a significant decrease in susceptibility in ED Enterobacteriaceae to eight of 15 (53%) tested antimicrobials, with a mean annual decrease of 1.6%+/-0.6%, in the ICU isolates, a significant decrease was detected in only five (33%) of the tested antimicrobials, with a mean annual decrease of 2.5%+/-1.3%. The difference in susceptibility between ED and ICU isolates was significant for all antimicrobials (P<0.001). A significant decrease in the susceptibility of E coli to nine of 15 drugs (60%) was detected, ranging from 0.7% to 2.7% annually. In K. pneumoniae a significant decrease in susceptibility of K. pneumoniae was detected with only two agents. Pseudomonas spp. isolates remained highly sensitive to all traditional anti-pseudomonal agents, without significant decay in sensitivity rates over time. Susceptibility of S. aureus to methicillin decreased significantly for several subsets of patients (P<0.001). Marked differences in susceptibility rates between the departments were detected. Trend statistical analyses, when appropriately applied to multi-year databases of microbial susceptibilities, may yield susceptibility tables that are significantly more accurate than traditional semi-annual or annual tables.