Effect Of Antimicrobial Treatment Research Articles

The Dilemma of Antimicrobial Treatment of Shiga Toxin-producing Escherichia coli

The Dilemma of Antimicrobial Treatment of Shiga Toxin-producing Escherichia coli

In vivo monitoring of Staphylococcus aureus biofilm infections and antimicrobial therapy by [18F]fluoro-deoxyglucose-MicroPET in a mouse model.

A mouse model was developed for in vivo monitoring of infection and the effect of antimicrobial treatment against Staphylococcus aureus biofilms, using the [(18)F]fluoro-deoxyglucose-MicroPET ([(18)F]FDG-MicroPET) image technique. In the model, sealed Vialon catheters were briefly precolonized with S. aureus strains ATCC 15981 or V329, which differ in cytotoxic properties and biofilm matrix composition. After subcutaneous implantation of catheters in mice, the S. aureus strain differences found in bacterial counts and the inflammatory reaction triggered were detected by the regular bacteriological and histological procedures and also by [(18)F]FDG-MicroPET image signal intensity determinations in the infection area and regional lymph node. Moreover, [(18)F]FDG-MicroPET imaging allowed the monitoring of the rifampin treatment effect, identifying the periods of controlled infection and those of reactivated infection due to the appearance of bacteria naturally resistant to rifampin. Overall, the mouse model developed may be useful for noninvasive in vivo determinations in studies on S. aureus biofilm infections and assessment of new therapeutic approaches.

Antibiotic treatment in otitis media reduces middle ear effusion duration

Tapiainen T, Kujala T, Renko M, Koivunen P, Kontiokari T, Kristo A, et al. Effect of Antimicrobial Treatment of Acute Otitis Media on the Daily Disappearance of Middle Ear Effusion: A Placebo-Controlled Trial. JAMA Pediatr. 2014;165:635-41. Among children with otitis media (OM), what is the therapeutic efficacy of antibiotics, compared with placebo, in resolution of middle ear effusion (MEE)? Randomized controlled trial. Outpatient clinics, Oulu, Finland. Children, 6 months to 15 years old. Time to disappearance of MEE. On day 14, 69% of children in the antimicrobial group and 38% in the placebo group had normal tympanometry findings (number needed to treat [NNT] 4; 95% CI, 2-11). On day 60, 2 children (5%) in the antimicrobial group and 10 children (24%) in the placebo group had persistent MEE (NNT 6; 95% CI, 3-22). Antimicrobial treatment effectively reduced the duration of MEE in children with AOM, and the risk for persistent MEE.

Effect of antimicrobial treatment of acute otitis media on the daily disappearance of middle ear effusion: a placebo-controlled trial.

Antimicrobial treatment reduces the symptoms of acute otitis media (AOM). The effect of antimicrobial treatment on the duration of middle ear effusion (MEE) and concomitant hearing impairment is not known. To determine whether the antimicrobial treatment of AOM reduces the duration of MEE. This randomized, double-blind, placebo-controlled trial involved a total of 84 children with AOM between 6 months and 15 years of age. Participants were recruited from September 14, 1999, to January 4, 2000; October 10, 2005, to December 16, 2005; and September 22, 2009, to June 4, 2012, from among children attending an AOM prevention trial and children visiting local outpatient clinics in Oulu, Finland. Children were randomly allocated to receive either 40 mg/kg of amoxicillin-clavulanate or a placebo mixture per day for 7 days. The primary outcome measure was the time to the disappearance of MEE as defined by a normal tympanogram finding (A curve) from both ears on 2 consecutive measurement days. Parents performed daily tympanometry at home. The study physician performed tympanometry and otoscopy at study entry, after 3 and 7 days, and then weekly until both ears were healthy. The main secondary outcome measures were the time to normal otoscopy findings and the proportion of children without persistent MEE at 14 days and 2 months. Middle ear effusion disappeared 2.0 weeks (13.7 days) earlier (P = .02) in the antimicrobial group (mean time, 2.7 weeks; 95% CI, 1.7-3.7) than in the placebo group (4.7 weeks; 95% CI, 3.6-5.7). Normal otoscopy findings were observed 1.4 weeks sooner in the antimicrobial group than in the placebo group (P = .02). On day 14, 69% of children in the antimicrobial group and 38% in the placebo group had normal tympanometry findings (number needed to treat, 3.2; 95% CI, 2.0-10.5). On day 60, 2 children (5%) in the antimicrobial group and 10 children (24%) in the placebo group had persistent MEE (P = .01). Antimicrobial treatment effectively reduced the duration of MEE and possible concomitant hearing impairment in children with AOM. Antimicrobial treatment also reduced the risk for persistent MEE. clinicaltrials.gov Identifier: NCT01244581.

Development and antimicrobial susceptibility studies of in vitro monomicrobial and polymicrobial biofilm models with Aspergillus fumigatus and Pseudomonas aeruginosa

BackgroundMixed microbial infections of the respiratory tracts with P. aeruginosa and A. fumigatus capable of producing biofilms are commonly found in cystic fibrosis patients. The primary objective of this study was to develop an in vitro model for P. aeruginosa and A. fumigatus polymicrobial biofilm to study the efficacy of various antimicrobial drugs alone and in combinations against biofilm-embedded cells. Simultaneous static cocultures of P. aeruginosa and sporelings were used for the development of in vitro P. aeruginosa-A. fumigatus polymicrobial biofilm in SD broth in 24-well cell culture plates at 35°C, and the biofilm formation was monitored microscopically and spectrophotometrically. Using P. aeruginosa-A. fumigatus sporelings cocultures we examined the effects of various antimicrobial drugs alone and in combination against polymicrobial biofilm by CFU and tetrazolium reduction assays.ResultsIn simultaneous static cocultures P. aeruginosa cells killed A. fumigatus conidia, whereas the bacterial cells showed no substantial fungicidal effect on sporelings grown for 12 h or longer at 35°C. Monospecies cultures of P. aeruginosa produced loosely adhered monomicrobial biofilm and addition of 10% bovine serum to the growth medium inhibited the formation of monomicrobial biofilm by P. aeruginosa whereas it produced tightly adhered polymicrobial biofilm in the presence of A. fumigatus mycelial growth. A. fumigatus produced firmly adherent monomicrobial and polymicrobial biofilms. A comparison of CFU and MTT assays showed that the latter is unsuitable for studying the effectiveness of antimicrobial treatment against polymicrobial biofilm. Tobramycin alone and in combination with posaconazole was highly effective against monomicrobial and polymicrobial biofilms of P. aeruginosa whereas cefepime alone and in combination with posaconazole showed excellent activity against monomicrobial biofilm of P. aeruginosa but was less effective against polymicrobial biofilm. Monomicrobial and polymicrobial biofilms of A. fumigatus showed similar susceptibility to posaconazole with and without the antibacterial drug.ConclusionsSimultaneous static coculture of A. fumigatus sporelings grown for 12 h or longer was superior to ungerminated conidia with P. aeruginosa for the development of A. fumigatus-P. aeruginosa biofilm. P. aeruginosa-A. fumigatus polymicrobial biofilm shows differential susceptibility to antimicrobial drugs whereas the susceptibility of A. fumigatus to antimicrobial drugs was unchanged.

Bacteremia and Mortality with Urinary Catheter–Associated Bacteriuria

Although catheter-associated urinary tract infection (CAUTI) and catheter-associated asymptomatic bacteriuria (CAABU) are clinically distinct conditions, most literature describing the risks of bacteriuria does not distinguish between them. We studied the relationship between catheter-associated bacteriuria and bacteremia from a urinary source in CAUTI relative to that in CAABU. Second, we investigated whether the presence or absence of urinary symptoms in catheterized patients with bacteriuria was associated with bacteremia from any source or mortality. Finally, we explored the effect of antimicrobial treatment of bacteriuria on subsequent bacteremia from any source and mortality. We performed a retrospective cohort study with 30 days of follow-up after an initial positive urine culture. CAUTI and CAABU were defined by Infectious Diseases Society of America guidelines. A large tertiary care facility. All inpatients with a urinary catheter (external or indwelling) and a positive urine culture between October 2010 and June 2011. We captured 444 episodes of catheter-associated bacteriuria in 308 patients; 128 (41.6%) patients had CAUTI, and 180 (58.4%) had CAABU. Three episodes of bacteriuria were followed by bacteremia from a urinary source (0.7%). CAUTI, rather than CAABU, was associated with bacteremia from any source, but neither CAUTI nor CAABU predicted subsequent mortality. Use of antimicrobial agents to treat bacteriuria was not associated with either bacteremia from any source or mortality. Bacteremia from a urinary source was infrequent, and there was no evidence of an association of mortality with symptomatic versus asymptomatic bacteriuria in this population. Antibiotic treatment of bacteriuria did not affect outcomes.

From ventilator-associated tracheobronchitis to ventilator-associated pneumonia

Ventilator-associated complications (VACs) are those complications that develop during the period of intubation. The most frequent VAC is infection. Ventilator-associated tracheobronchitis (VAT) is one of the ventilator-associated complications occurring in the critically ill patient. This infection represents an intermediate process between lower respiratory tract colonization and ventilator-associated pneumonia. Increased duration of mechanical ventilation has been reported in patients with VAT because of increased sputum production and airway inflammation. Two studies have shown a beneficial effect of antimicrobial treatment in patients with VAT. The optimal duration of antimicrobial treatment in patients with VAT should be further investigated because short courses of antimicrobials might be sufficient. Aerosolized antibiotics also need to be compared to systemic antibiotics in these patients.

Progress on developing endpoints for registrational clinical trials of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections: update from the Biomarkers Consortium of the Foundation for the National Institutes of Health.

Efficacy endpoints for previous registrational trials of antimicrobials for acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia (CABP) were based on nonstandardized, clinician-based observations and decisions, as well as on patient reports. More quantifiable, reproducible, and externally verifiable endpoints could improve the design of future noninferiority trials. At the request of the Food and Drug Administration, the Foundation for the National Institutes of Health convened a broadly representative scientific project team to evaluate potential endpoints for such registrational trials. Review of historical and modern data led to the conclusion that antimicrobial treatment effects are most apparent early in therapy; later outcomes provide important supportive information. Although evidence is incomplete, early response endpoints can anchor noninferiority hypotheses in ABSSSI and CABP registrational trials, thereby allowing evidence-based drug development to continue. Further research is underway to establish which short- and long-term outcomes are well-defined, reliable, and reflective of how patients feel, function, or survive.

Muskuloskelettale Infektionen im Zeitalter multiresistenter Erreger

The burden of musculoskeletal infections is permanently growing. A probable explanation for this development could be the increasing number of elderly people undergoing extensive surgery using implants and prosthetic devices while having more significant comorbidities (e.g. cardiovascular, metabolic and malignant). However, a relative reduction of acute (hematogenous) osteomyelitis compared to the occurrence of much more complex situations, such as diabetic foot syndrome or chronic osteitis and prosthetic implant infections is being observed. This poses new challenges for the clinician in managing these patients. Furthermore, there is the evolving threat of antimicrobial resistance as well as the increasing amount of infections with Gram-negative pathogens. Several aspects have to be considered for successful management of musculoskeletal infections: the site of infection and feasibility of local surgical treatment, the effectiveness of antimicrobial treatment, the inclusion of comorbidities and their specific treatment in an advanced therapeutic concept as well as the interdisciplinary approach led by surgeons and infectious disease specialists.

Cotton textiles modified with citric acid as efficient anti-bacterial agent for prevention of nosocomial infections

AimTo study the antimicrobial activity of citric acid (CA) and sodium hypophosphite monohydrate (SHP) against gram-positive and gram-negative bacteria, and to determine the influence of conventional and microwave thermal treatments on the effectiveness of antimicrobial treatment of cotton textiles.MethodTextile material was impregnated with CA and SHP solution and thermally treated by either conventional or microwave drying/curing treatment. Antibacterial effectiveness was tested according to the ISO 20743:2009 standard, using absorption method. The surfaces were morphologically observed by scanning electron microscopy, while physical characteristics were determined by wrinkle recovery angles method (DIN 53 891), tensile strength (DIN 53 837), and whiteness degree method (AATCC 110-2000).ResultsCotton fabric treated with CA and SHP showed significant antibacterial activity against MRSA (6.38 log10 treated by conventional drying and 6.46 log10 treated by microwave drying before washing, and 6.90 log10 and 7.86 log10, respectively, after 1 cycle of home domestic laundering washing [HDLW]). Antibacterial activity was also remarkable against S. aureus (4.25 log10 by conventional drying, 4.58 log10 by microwave drying) and against P. aeruginosa (1.93 log10 by conventional and 4.66 log10 by microwave drying). Antibacterial activity against P. aeruginosa was higher in samples subjected to microwave drying/curing than in those subjected to conventional drying/curing. As expected, antibacterial activity was reduced after 10 HDLW cycles but the compound was still effective. The surface of the untreated cotton polymer was smooth, while minor erosion stripes appeared on the surfaces treated with antimicrobial agent, and long and deep stripes were found on the surface of the washed sample.ConclusionCA can be used both for the disposable (non-durable) materials (gowns, masks, and cuffs for blood pressure measurement) and the materials that require durability to laundering. The current protocols and initiatives in infection control could be improved by the use of antimicrobial agents applied on cotton carbohydrate polymer.

In vitro study of biofilm formation and effectiveness of antimicrobial treatment on various dental material surfaces

Elevated proportions of Candida albicans in biofilms formed on dentures are associated with stomatitis whereas Streptococcus mutans accumulation on restorative materials can cause secondary caries. Candida albicans, S. mutans, saliva-derived and C. albicans/saliva-derived mixed biofilms were grown on different materials including acrylic denture, porcelain, hydroxyapatite (HA), and polystyrene. The resulting biomass was analysed by three-dimensional image quantification and assessment of colony-forming units. The efficacy of biofilm treatment with a dissolved denture cleansing tablet (Polident(®)) was also evaluated by colony counting. Biofilms formed on HA exhibited the most striking differences in biomass accumulation: biofilms comprising salivary bacteria accrued the highest total biomass whereas C. albicans biofilm formation was greatly reduced on the HA surface compared with other materials, including the acrylic denture surface. These results substantiate clinical findings that acrylic dentures can comprise a reservoir for C. albicans, which renders patients more susceptible to C. albicans infections and stomatitis. Additionally, treatment efficacy of the same type of biofilms varied significantly depending on the surface. Although single-species biofilms formed on polystyrene surfaces exhibited the highest susceptibility to the treatment, the most surviving cells were recovered from HA surfaces for all types of biofilms tested. This study demonstrates that the nature of a surface influences biofilm characteristics including biomass accumulation and susceptibility to antimicrobial treatments. Such treatments should therefore be evaluated on the surfaces colonized by the target pathogen(s).

Estimating the Proportion of Pneumonia Attributable to Pneumococcus in Kenyan Adults

Community-acquired pneumonia is a common cause of hospitalization among African adults, and Streptococcus pneumoniae is assumed to be a frequent cause. Pneumococcal conjugate vaccine is currently being introduced into childhood immunization programs in Africa. The case for adult vaccination is dependent on the contribution of the pneumococcus to the hospital pneumonia burden.Pneumococcal diagnosis is complex because there is no gold standard, and culture methods are invalidated by antibiotic use. We used latent class analysis to estimate the proportion of pneumonia episodes caused by pneumococcus. Furthermore, we extended this methodology to evaluate the effect of antimicrobial treatment on test accuracies and the prevalence of the disease. The study combined data from 5 validation studies of pneumococcal diagnostic tests performed on 281 Kenyan adults with pneumonia.The proportion of pneumonia episodes attributable to pneumococcus was 0.46 (95% confidence interval = 0.36-0.57). Failure to account for the effect of antimicrobial exposure underestimates this proportion as 0.32. A history of antibiotic exposure was a poor predictor of antimicrobial activity in patients' urine. Blood culture sensitivity for pneumococcus was estimated at 0.24 among patients with antibiotic exposure, and 0.75 among those without.The large contribution of pneumococcus to adult pneumonia provides a strong case for the investigation of pneumococcal vaccines in African adults.

Survival and Comfort After Treatment of Pneumonia in Advanced Dementia

Pneumonia is common among patients with advanced dementia, especially toward the end of life. Whether antimicrobial treatment improves survival or comfort is not well understood. The objective of this study was to examine the effect of antimicrobial treatment for suspected pneumonia on survival and comfort in patients with advanced dementia. From 2003 to 2009, data were prospectively collected from 323 nursing home residents with advanced dementia in 22 facilities in the area of Boston, Massachusetts. Each resident was followed up for as long as 18 months or until death. All suspected pneumonia episodes were ascertained, and antimicrobial treatment for each episode was categorized as none, oral only, intramuscular only, or intravenous (or hospitalization). Multivariable methods were used to adjust for differences among episodes in each treatment group. The main outcome measures were survival and comfort (scored according to the Symptom Management at End-of-Life in Dementia scale) after suspected pneumonia episodes. Residents experienced 225 suspected pneumonia episodes, which were treated with antimicrobial agents as follows: none, 8.9%; oral only, 55.1%, intramuscular, 15.6%, and intravenous (or hospitalization), 20.4%. After multivariable adjustment, all antimicrobial treatments improved survival after pneumonia compared with no treatment: oral (adjusted hazard ratio [AHR], 0.20; 95% confidence interval [CI], 0.10-0.37), intramuscular (AHR, 0.26; 95% CI, 0.12-0.57), and intravenous (or hospitalization) (AHR, 0.20; 95% CI, 0.09-0.42). After multivariable adjustment, residents receiving any form of antimicrobial treatment for pneumonia had lower scores on the Symptom Management at End-of-Life in Dementia scale (worse comfort) compared with untreated residents. Antimicrobial treatment of suspected pneumonia episodes is associated with prolonged survival but not with improved comfort in nursing home residents with advanced dementia.

Fecal microbiota of horses in the clinical setting: Potential effects of penicillin and general anesthesia

Antimicrobial treatment is associated with the spread of antimicrobial resistance and disturbances in the ecological balance of intestinal microbiota. In horses, the main adverse effect of antimicrobial treatment is colitis. We used culture and 16S rRNA gene based molecular methods to monitor the prevalence of antimicrobial resistance and changes in predominant fecal populations during penicillin treatment and general anesthesia of horses in the clinical setting. After 5 days of parenteral administration of penicillin, fecal Escherichia coli were resistant to multiple unrelated antimicrobial agents when compared to the pre-exposure situation. Denaturing gradient gel electrophoresis (DGGE) profiles indicated that horses have an extremely diverse fecal microbiota, with marked differences between individual horses. Most of the variation in DGGE profiles could be attributed to horse-specific factors, and penicillin, general anesthesia or both could not explain the remaining variation. Within-animal variation remained less than between-animal variation despite treatment. However, real-time PCR quantification (qPCR) indicated subclinical changes in selected bacterial groups of the penicillin treated horses.

Therapeutic effects of antimicrobial treatment during lactation of recently acquired bovine subclinical mastitis: Two linked randomized field trials

Two linked randomized field trials were performed on 39 herds in the Netherlands to 1) determine therapeutic effects of antimicrobial treatment of recently acquired subclinical mastitis (RASCM) during lactation, 2) evaluate the effect of duration of subclinical mastitis on therapeutic outcome, and 3) identify factors related to the therapeutic success of RASCM. Cows with a first elevated composite somatic cell count (CSCC) after 2 consecutive low CSCC measurements were eligible for enrollment in trial 1 (treatment at the first elevated CSCC). Quarter milk samples were collected to determine bacteriological status for major pathogens and coagulase-negative staphylococci. Cows with one or more culture-positive quarters with a quarter somatic cell count (QSCC) ≥100,000 cells/mL were defined to have RASCM and were randomly assigned treatment or control (no treatment). Untreated cows from trial 1 that had a second elevated CSCC at the next milk recording were eligible for enrollment in trial 2 (treatment at the second elevated CSCC). In trial 2, staphylococci-positive cows (Staphylococcus aureus and coagulase-negative staphylococci) were randomly assigned to treatment or control. Farmers used their own treatment protocols to treat quarters in both trials. Bacteriological cure was defined as absence of the pathogen identified pre-intervention in 2 samples post-intervention; QSCC, CSCC, and milk yield were also analyzed. Hierarchical logistic and linear models were used to determine therapeutic effects and to identify factors related to therapy outcome. Treated quarters had a higher bacteriological cure rate than control quarters for all pathogens in both trials. Treatment resulted in lower QSCC and CSCC, whereas milk yield was not affected by treatment. Bacteriological cure of RASCM was better in quarters with a low QSCC pre-intervention and in coagulase-negative staphylococci-positive quarters. Control quarters with a single culture-positive sample pre-intervention also had a higher bacteriological cure than control quarters with ≥2 culture-positive samples. Time of antimicrobial treatment affected bacteriological cure for penicillin-sensitive Staph. aureus. Bacteriological cure tended to be higher for Staph. aureus after treatment at the first elevated CSCC compared with treatment at the second elevated CSCC. Thus, early treatment of Staph. aureus might be more effective than later treatment.

Antimicrobial associated diarrhoea in the horse. Part 1: Overview, pathogenesis and risk factors

SummaryAntimicrobial associated diarrhoea (AAD) is the most commonly recognised adverse effect of antimicrobial treatment in horses, although its incidence is probably low given the frequency of antimicrobial administration. Clinical signs vary from transient self‐limiting diarrhoea to rapidly fatal toxic enterocolitis. AAD prolongs the duration of hospitalisation, increases diagnostic and therapeutic costs, and was associated with a lower case survival rate than other types of acute diarrhoea in one study. Virtually all antimicrobials have been implicated in AAD, but some pose a greater risk than others.

Establishment of new severity ratings based on analysis of hospital‐acquired pneumonia

The Japanese Respiratory Society issued its first guidelines for the management of hospital-acquired pneumonia in adults in 2002. Pathological and severity ratings were investigated based on the results of a national multicenter survey of hospital-acquired pneumonia, and the new severity ratings shown below were established (Fig. II-1). Severity ratings in the 2002 guidelines were based mainly on markers that predicted the effectiveness of antimicrobial treatment. In the current revision, severity is rated using markers that predict the prognosis of patients. Five criteria were established as factors that predict prognosis: malignant tumour or immunocompromised status; decreased level of consciousness; FiO(2) >35% required to maintain SpO(2) >90%; age >or=70 years in men or >or=75 years in women; and oliguria or dehydration. Two criteria were established as factors specifying the severity of the pneumonia itself: CRP >or=200 mg/L and shadows infiltrating more than two-thirds the area of one lung on chest radiography. Patients who satisfy up to two of the five criteria above to predict prognosis are classified in the mild group (Group A) if they do not satisfy either of the two criteria specifying severity of pneumonia, or in the moderate group (Group B) if they satisfy one or both of those two criteria. Patients who satisfy three or fewer of the five criteria to predict prognosis are classified in the severe group (Group C). When the new severity ratings were applied to the results of the national multicenter survey of hospital-acquired pneumonia, the mortality rate was found to be 12.1% (101/834) in the mild group (Group A), 24.9% (69/277) in the moderate group (Group B) and 40.8% (98/240) in the severe group (Group C). Statistically-significant differences were seen between groups, and patient classification may be useful as an indicator of prognosis (Fig. II-2).

Manejo de la infección del tracto urinario en lactantes febriles: Experiencia de tratamiento antimicrobiano intravenoso ambulatorio

To describe the feasibility, effectiveness and safety of intravenous (iv) outpatient treatment in 2 to 24 month-old children with febrile urinary tract infection (UTI).Children presenting to the ER, between April 2003-2005, with fever and no identifiable focus who had a diagnosis of UTI were randomized to receive iv antibiotic in the hospital or in an outpatient facility. Children were started on amikacin or ceftriaxona according to physician criteria followed by antimicrobial adjustment based on urine culture result and a later switch to an oral antimicrobial. Urine cultures were performed during and after completing the antimicrobial course. Adherence and effectiveness of antimicrobial treatment and treatment-associated complications were analyzed.The study included 112 patients, 58 inpatient children and 54 outpatient children, with an average age of 7.7 months. Duration of iv treatment did not differ among groups (2.8 days (SD 1.2) 2.7 +0.91 days in inpatients vs 2.9 + 1.9 days in outpatients (p = 0.22). In 100% of outpatient children and 100% of inpatient children (overall 101/101) urine cultures were negative on day 5. None of the children had a treatment-associated complication. Cost analysis yielded 73% of saving money (overall cost for inpatient treatment US 9,815 vs outpatient treatment US 2,650).Outpatient iv treatment in patients between 2 and 24 months with UTI and fever was effective, safe and of lower cost.

Treatment of urinary tract infections in febrile infants: experience of outpatient intravenous antibiotic treatment

To describe the feasibility, effectiveness and safety of intravenous (iv) outpatient treatment in 2 to 24 month-old children with febrile urinary tract infection (UTI). Children presenting to the ER, between April 2003-2005, with fever and no identifiable focus who had a diagnosis of UTI were randomized to receive iv antibiotic in the hospital or in an outpatient facility. Children were started on amikacin or ceftriaxona according to physician criteria followed by antimicrobial adjustment based on urine culture result and a later switch to an oral antimicrobial. Urine cultures were performed during and after completing the antimicrobial course. Adherence and effectiveness of antimicrobial treatment and treatment-associated complications were analyzed. The study included 112 patients, 58 inpatient children and 54 outpatient children, with an average age of 7.7 months. Duration of iv treatment did not differ among groups (2.8 days (SD 1.2) 2.7 +0.91 days in inpatients vs 2.9 + 1.9 days in outpatients (p = 0.22). In 100% of outpatient children and 100% of inpatient children (overall 101/101) urine cultures were negative on day 5. None of the children had a treatment-associated complication. Cost analysis yielded 73% of saving money (overall cost for inpatient treatment US 9,815 vs outpatient treatment US 2,650). Outpatient iv treatment in patients between 2 and 24 months with UTI and fever was effective, safe and of lower cost.

Efficacy of antimicrobial agents in lettuce leaf processing water for control of Escherichia coli O157:H7.

The objectives of this research were to study transfer and control of Escherichia coli O157:H7 during simultaneous washing of inoculated and uninoculated lettuce pieces and to determine the efficacy of antimicrobial agents (peroxyacetic acid, mixed peracid, and sodium hypochlorite) on reducing the transfer of E. coli O157:H7 through processing water with or without organic load. Lettuce leaf pieces (5 by 5 cm) were inoculated with a five-strain mixture of green fluorescent protein-labeled E. coli O157:H7 at 5.6 log CFU per piece. One inoculated lettuce piece was added to five uninoculated leaves during washing. Peroxyacetic acid and mixed peracid were tested at 10, 20, and 30 ppm, and chlorine was tested at 30 and 50 ppm. No organic load (liquefied lettuce leaves) and 10% organic load in processing water were compared. Without organic load, peroxyacetic acid at 30 ppm, mixed peracid at 10, 20, and 30 ppm, and chlorine at 30 and 50 ppm all significantly reduced E. coli O157: H7 in processing water by 1.83, 1.73, 1.50, 1.83, 1.34, and 1.83 log CFU/ml, respectively, compared with washing with water alone. These antimicrobials at all concentrations tested also significantly reduced transfer of the bacteria from an inoculated leaf to uninoculated leaves in the processing water by 0.96 to 2.57 log CFU per piece. A 10% organic load in the processing water reduced efficacy of antimicrobial agents. In this contaminated water, peroxyacetic acid at 10 and 20 ppm and chlorine at 30 ppm produced effects not significantly different from those of water alone. Therefore, it is important to understand the impact of organic load when validating the effectiveness of antimicrobial treatments.