Initial Gram Research Articles

Predictive factors of contamination in a blood culture with bacterial growth in an Emergency Department

Abstract Introduction The aim of this study is to identify predictive factors of bacterial contamination in positive blood cultures (BC) collected in an Emergency Department. Patients and methods A prospective, observational and analytical study was conducted on febrile children aged one to 36 months, who had no risk factors of bacterial infection, and had a BC collected in the Emergency Department between November 2011 and October 2013 in which bacterial growth was detected. The potential BC contamination predicting factors analysed were: maximum temperature, time to positivity, initial Gram stain result, white blood cell count, absolute neutrophil count, band count, and C-reactive protein (CRP). Results Bacteria grew in 169 BC. Thirty (17.8%) were finally considered true positives and 139 (82.2%) false positives. All potential BC contamination predicting factors analysed, except maximum temperature, showed significant differences between true positives and false positives. CRP value, time to positivity, and initial Gram stain result are the best predictors of false positives in BC. The positive predictive values of a CRP value ≤ 30 mg/L, BC time to positivity ≥ 16 h, and initial Gram stain suggestive of a contaminant in predicting a FP, are 95.1, 96.9 and 97.5%, respectively. When all three conditions are applied, their positive predictive value is 100%. Four (8.3%) patients with a false positive BC and discharged to home were revaluated in the Emergency Department. Conclusions The majority of BC obtained in the Emergency Department that showed positive were finally considered false positives. Initial Gram stain, time to positivity, and CRP results are valuable diagnostic tests in distinguishing between true positives and false positives in BC. The early detection of false positives will allow minimising their negative consequences.

Efficacy of Physiologically Active Anti-Transpirants on Excised Leaves Spathiphyllum sweet checo and Calathea rufibarba

Pot plant production in green house is most of the time under high relative humidity and frequent irrigation. While, during shipping and retailing plants may be exposed to high temperature and infrequent irrigation. These unfavorable conditions often cause water loss, desiccation of plants and short shelf life. To reduce the deteriorating effect of water loss, application of anti-transpirants is one of the integral options to implement. In this study we evaluated several physiologically active stomata closing compounds. Spathiphyllum sweet checo and Calathea rufibarba were sprayed with different active compound formulations. Weight loss of leaves as gram of water per gram of initial leaf weight and gram of water per centimeter square leaf area and stomatal conductance were measured. On both plant species most physiologically active compound treatments reduce weight loss and stomatal conductance significantly. 1.5 mM Abscisic acid (ABA), 5 mM Salicylic acid (SA) and 200 µM Sodium nitroprusside (SNP) on Spathiphyllum sweet checo and 1.5 mM ABA ,200 µM SNP and 200 µM Pyrabactin on Calathea rufibarba were the three most effective active compound treatments. Significant positive correlation were found between weight loss and stomatal conductance on both plant species (R=0.888, P<0.05), (R=0.811, P<0.05) for Spathiphyllum and Calathea respectively. The relative efficacy of different active compound treatments and the effects of leaf weight and leaf area on water loss were also inseparable in both plant species.

Potential Thai grasses for bioethanol production

Use of lignocellulosic biomass, such as wild grasses, represents a more sustainable alternative to food stocks for the creation of fuel bioethanol. There are numerous types of wild grasses grown naturally in Thailand that can be used as a feedstock for bioethanol production and several of them have been examined already for their physical characteristics and ethanol production potential. Physical characteristics such as a high dry matter yield and high percentage of cellulose make Tifton Bermuda grass a particularly attractive candidate for bioethanol production. The different studies examined in this paper used differing pretreatment methods on various types of wild grasses with varying levels of success depending on the method and grass used. The largest amount of ethanol produced per initial gram of grass was 0.14 g per gram from two separate types of vetiver grasses, likely due to a utilization of both a glucose and xylose-fermenting organism during fermentation. For any particular wild Thai grass to be used in the future as a feedstock for bioethanol production, it is essential that more research be done to optimize the process of pretreatment and fermentation.

Factores predictores de contaminación ante un hemocultivo con crecimiento bacteriano en Urgencias

IntroductionThe aim of this study is to identify predictive factors of bacterial contamination in positive blood cultures (BC) collected in an emergency department. Patients and methodsA prospective, observational and analytical study was conducted on febrile children aged on to 36 months, who had no risk factors of bacterial infection, and had a BC collected in the Emergency Department between November 2011 and October 2013 in which bacterial growth was detected. The potential BC contamination predicting factors analysed were: maximum temperature, time to positivity, initial Gram stain result, white blood cell count, absolute neutrophil count, band count, and C-reactive protein (CRP). ResultsBacteria grew in 169 BC. Thirty (17.8%) were finally considered true positives and 139 (82.2%) false positives. All potential BC contamination predicting factors analysed, except maximum temperature, showed significant differences between true positives and false positives. CRP value, time to positivity, and initial Gram stain result are the best predictors of false positives in BC. The positive predictive values of a CRP value≤30mg/L, BC time to positivity≥16h, and initial Gram stain suggestive of a contaminant in predicting a FP, are 95.1, 96.9 and 97.5%, respectively. When all 3 conditions are applied, their positive predictive value is 100%. Four (8.3%) patients with a false positive BC and discharged to home were revaluated in the Emergency Department. ConclusionsThe majority of BC obtained in the Emergency Department that showed positive were finally considered false positives. Initial Gram stain, time to positivity, and CRP results are valuable diagnostic tests in distinguishing between true positives and false positives in BC. The early detection of false positives will allow minimising their negative consequences.

Indicators for Detection of Septic Arthritis in the Acutely Swollen Joint Cohort of Those Without Joint Prostheses

Differentiating septic arthritis from culture-negative, acute atraumatic joint effusion is difficult. Studies have attempted to elucidate factors that herald infection, but, due to overlap, most conclude that the diagnosis ultimately relies on clinical judgment. Furthermore, studies are limited by broad inclusion criteria. The current retrospective case study sought to examine (1) which markers differentiate a culture-positive septic joint from culture-negative effusion in patients suspicious for infection despite no growth on Gram stain and without previous surgery in the affected joint and (2) whether threshold values of these markers exist that predict septic arthritis. The study was performed by reviewing records of those who underwent operative irrigation and debridement involving the shoulder, elbow, wrist, hip, knee, and ankle. Patients were included if they were older than 18 years and had an acutely swollen/painful joint and no organisms on initial Gram stain. Exclusion criteria were lack of serum markers or synovial fluid aspirate, antibiotics within 1 week, adjacent wound or skin infection, recent trauma to the joint, and previous joint infection or surgery to the joint. Several clinical, serological, and synovial parameters were collected and analyzed using paired t test with Bonferonni correction. Serum C-reactive protein was the only significantly different variable between groups. Serum C-reactive protein greater than 10.5 mg/dL was predictive of infection. In those suspicious for infection despite no growth on Gram stain and without previous surgery in the affected joint, C-reactive protein greater than 10.5 mg/dL is suspicious for joint sepsis and should warrant consideration for urgent irrigation and debridement.

Evaluation of BACTEC™ blood culture system for culture of normally sterile body fluids.

Sir, Infectious diseases are now the world's biggest killer of children and young adults, it is also the basis of debilitating illness all through the year keeping children away from school and preventing adults from working.[1] Conventional methods of culture are now being replaced by automated culture systems, owing to reduced time for culture and ease of laboratory work using machines and higher isolation rate against conventional methods.[2] Lot of information is available for culturing blood samples using BACTEC™ culture, but there is a paucity of data regarding sterile body fluids culture. Hence, this study was done to compare isolation rate and the time needed for the detection of microorganisms between conventional methods of culture and BACTEC™ culture. This prospective study was conducted for a period of 2 years from July 2011 to July 2013 in the Department of Microbiology of a tertiary care hospital after obtaining the Institutional Ethical Committee approval. A total of 127 body fluid samples were inoculated into BACTEC™ peds Plus™/F vials, incubated in BACTEC™ machine. Direct plating of sample onto sheep blood agar, chocolate agar, MacConkey agar and incubated aerobically at 37°C for 48 h. Organisms isolated were identified using standard microbiological procedures and tested for antimicrobial susceptibility according to Clinical and Laboratory Standards Institute guidelines.[1,2] All data were analyzed using SPSS (IBM) Descriptive statistics were derived using frequency, percentage, and mean. In this study, 21 samples out of 127, showed a positive result as compared with 4 out of 127 by conventional method. The average time taken for growth in a conventional method was 26.5 h, while that in BACTEC™ is 14.25 h. This significant increase in isolation rate with reduced time to positivity gives BACTEC™ culture edge over conventional culture methods. This is quite a significant time difference considering that presumptive identification of the pathogen was informed to the clinician 12.25 h earlier than a conventional method. This would significantly affect the change of empirical antibiotic therapy given to the patient, eventually aiding in therapy and the final clinical outcome. Furthermore, the initial Gram's stain report of positive cultures and the association of it with the bacteria isolated were compared. Though few samples showed no bacteria, but polymorphonuclear leukocytes (PMNLs) and mononuclear cells on initial Gram's stain were seen. Alberts et al.,[3] states that presence of PMNLs and lymphocytes suggests infection, and it is responsible for phagocytosis and killing of invading bacteria. Consequently even low bacterial load in the sample, which is undetectable by conventional method, can be detected by BACTEC™.[4,5] Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae and Pseudomonas aeruginosa were the frequently isolated bacteria in both methods. The fastidious bacteria like Group B and G Streptococcus, Burkholderia pseudomallei, Listeria monocytogenes, S. pneumoniae, Escherichia coli, Acinetobacter were isolated only from BACTEC™. Table 1 shows the distribution of bacteria isolated in various samples. L. monocytogenes, S. pneumoniae and Group B Streptococcus were also isolated from blood culture. Table 1 Distribution of organisms isolated from sterile body fluid samples In conclusion, BACTEC™ automated culture has higher isolation rate of pathogenic bacteria and lesser time for identification even with less bacterial load or count in the sterile body fluid sample. It also helps in guiding antimicrobial therapy especially in critically ill patients and eventually affecting patient's outcome.

Grocott methenamine silver (GMS) staining in the identification of bacterial endocarditis: Post-Mortem case report and literature review

This post-mortem case is of a 77-year-old female who presented with shortness of breath and fever. She received antibiotic treatment for left lower lobe pneumonia, however deteriorated, requiring intubation. Echocardiography demonstrated a 14 mm vegetation on a cusp of her bioprosthetic aortic valve and smaller vegetations on the remaining cusps. An autopsy was requested as no positive blood cultures had been obtained. A possible fungal aetiology was suggested by the non-destructive nature of the vegetations, along with urine and sputum cultures that grew Candida spp. H&E stained sections of the prosthetic valve demonstrated fibroelastic cusps lined by fibrin with trapped neutrophils and finely granular basophilic areas. Initial Gram stains did not demonstrate these basophilic areas as bacterial. The periodic acid-Schiff and GMS stains did not show fungal elements, however the latter stained cocci arranged in clusters and chains. These were later confirmed to be poorly staining gram-positive cocci on repeat Gram stains. GMS is known to stain bacteria and has been shown to be useful in identifying bacteria in prosthetic valve endocarditis. 1 This example is presented to emphasise the utility of Grocott methenamine silver staining in the identification of bacteria.

A Case ofBeauveria BassianaKeratitis Confirmed by Gene Sequencing

Purpose: To report a case of Beauveria bassiana keratitis that was confirmed by gene sequencing. Case summary: A 70-year-old man presented to our hospital with complaints of ocular pain and deterioration of the visual acuity in his left eye after injury caused by a wood branch one week previously. Visual acuity in the left eye was 20/400 at the time of the first visit. Slit lamp examination showed a central 0.7 × 2.5-mm-sized epithelial defect surrounded by cellular infiltration in the stroma. Scraping of the corneal lesion for microbiological examinations was performed. Initial Gram stain, potassium hydroxide (KOH) mount, and culture were negative. However, fungal hyphae were observed on a KOH mount of the repeated corneal scraping specimen, and a Beauveria species was suspected based on the culture. Beauveria bassiana was confirmed using a MicroSEQ D2 large-subunit ribosomal DNA fungal sequencing kit. Natamycin eye solution was initially instilled bihourly (every two hours), but the persistent epithelial defect and progressive stromal melting finally resulted in a descemetocele. Temporary and permanent amniotic membrane transplantations were performed, and amphotericin B eye solution was administered bihourly (every two hours). The ulcerous lesion gradually improved with no evidence of recurrence. Conclusions: Recently, cases of fungal keratitis have been increasing. Therefore, molecular diagnosis methods such as gene sequencing can be helpful in diagnosis and in improving the prognosis of fungal keratitis caused by rare fungi, as we found in this case. J Korean Ophthalmol Soc 2014;55(6):923-927

Ocular Surface Infections in Northeastern State of Malaysia

Ocular surface infections that include infections of conjunctiva, adnexa, and cornea have the potential risk of causing blindness within a given population. Empirical antibiotic therapy is usually initiated based on epidemiological data of common causative agents. Thus, the aims of this study were to determine the bacterial agents and their susceptibility patterns of isolates from ocular surface specimens in our hospital. This is a retrospective analysis and records of bacterial isolates from ocular surface specimens in Hospital Universiti Sains Malaysia from January 2001 to December 2010 were examined. Specimens were processed according to standard laboratory procedures. Antimicrobial susceptibility testing was conducted based on Clinical and Laboratory Standards Institute recommendations. Only single, nonrepetitive isolates were included in the analysis. A total of 1,267 isolates were obtained during the study period, which comprised Staphylococcus aureus (n = 299, 23.6%), Pseudomonas aeruginosa (n = 194, 15.3%), Streptococcus pneumoniae (n = 108, 8.5%), Haemophilus influenzae (n = 100, 7.9%), Haemophilus parainfluenzae (n = 84, 6.6%), and Enterobacter spp. (n = 81, 6.4%). Fungi contributed to 4.4% of the total isolates. The antimicrobial susceptibility testing demonstrated that gram-positive bacteria were generally resistant to gentamicin (19%-57%), whereas gram-negative bacteria were resistant to chloramphenicol (27%-58%). Based on the above results, knowledge of the initial Gram stain findings is imperative before the commencement of empirical antibiotic therapy. Therefore, a simple Gram staining for all eye specimens is highly recommended.

Bronchoscopy-Derived Correlates of Lung Injury following Inhalational Injuries: A Prospective Observational Study

BackgroundAcute lung injury (ALI) is a major factor determining morbidity following burns and inhalational injury. In experimental models, factors potentially contributing to ALI risk include inhalation of toxins directly causing cell damage; inflammation; and infection. However, few studies have been done in humans.MethodsWe carried out a prospective observational study of patients admitted to the NC Jaycees Burn Center who were intubated and on mechanical ventilation for burns and suspected inhalational injury. Subjects were enrolled over an 8-month period and followed till discharge or death. Serial bronchial washings from clinically-indicated bronchoscopies were collected and analyzed for markers of cell injury and inflammation. These markers were compared with clinical markers of ALI.ResultsForty-three consecutive patients were studied, with a spectrum of burn and inhalation injury severity. Visible soot at initial bronchoscopy and gram negative bacteria in the lower respiratory tract were associated with ALI in univariate analyses. Subsequent multivariate analysis also controlled for % body surface area burns, infection, and inhalation severity. Elevated IL-10 and reduced IL-12p70 in bronchial washings were statistically significantly associated with ALI.ConclusionsIndependently of several factors including initial inhalational injury severity, infection, and extent of surface burns, high early levels of IL-10 and low levels of IL-12p70 in the central airways are associated with ALI in patients intubated after acute burn/inhalation injury. Lower airway secretions can be collected serially in critically ill burn/inhalation injury patients and may yield important clues to specific pathophysiologic pathways.

Photo Quiz: A Woman on Hemodialysis for End-Stage Renal Disease with Fever

A 73-year-old woman on hemodialysis for end-stage renal disease was admitted to our institution from a subacute-rehabilitation facility due to a fever of 102°F. The patient reported some nausea, diarrhea, abdominal pain, and weakness but stated that she had been experiencing these symptoms for some time. Other than the above-mentioned gastrointestinal symptoms, the patient denied any cardiopulmonary, upper respiratory, or genitourinary symptoms. No contaminated food items were identified, and no other residents at the facility were presenting with similar symptoms. Physical examination revealed a diffusely tender abdomen without evidence of any other systemic signs. A computed tomography (CT) examination of the abdomen demonstrated possible right-sided colitis, and the patient was begun on ciprofloxacin and metronidazole. Initial blood cultures (Bactec; Becton, Dickinson and Company) collected in the emergency room demonstrated no growth; however, blood cultures collected the following day, as the patient underwent hemodialysis, grew Gram-positive bacilli. Initial Gram stainings performed directly from the aerobic and anaerobic blood culture bottles demonstrated long, chaining, Gram-positive bacilli (Fig. 1). The morphology of the Gram-positive rods was suggestive of lactobacilli. The blood culture plates demonstrated pure growth of small, pale-appearing colonies. The colonies were found to be Gram-positive coccobacilli which were catalase positive and oxidase negative. A definitive identification was made from the primary culture plates. Fig 1 Gram stain of bacilli from a blood culture bottle. (For answer and discussion, see page 1655 in this issue [doi:10.1128/JCM.01126-12].)

Errors in Interpretation of Gram Stain in The First Notification from Positive BACTEC Blood Cultures in Clinical Microbiology Laboratory of Dr. Kariadi Hospital

Background: Blood cultures in conjunction with the initial Gram stain of positive cultures have often been considered the “gold standard” for the diagnosis of bacteremia. When blood cultures turn positive, the attending physicians are usually notified immediately about Gram stain findings. However, information on the accuracy of Gram staining is very limited. We examined the error of preliminary blood culture reports provided by a local laboratory in an observational study.Design and Method: This was an observational study with a cross sectional approach. In this study, 369 blood cultures were examined. The positive blood cultures (135 samples) were then examined by Gram stain. Blood cultures handled on Bactec 9050, while the Gram stain was done in standard procedure Gram. Interpretation errors of Gram stain were confirmed by cultures result.Result: During one month (April 2011) we examined 369 blood cultures which 135 are positive (36.5%). Positive blood cultures were misread for 6 (4.4%) of 135 patients, they were two read as gram positive cocci had gram negative organisms by culture which were Acinetobacter baumannii, one read as gram positive bacilli had gram negative bacilli by culture which was Klebsiella pneumoniae. One isolate read as gram negative bacilli had gram positive bacilli which was Bacillus species, while two sample read as gram negative bacilli only had polymicrobial by culture, of these one isolate grew to be Enterobacter aerogenes and Staphylococcus aureus and the other were Escherichia coli and Acinetobacter spp.Conclusion: The overall 4.4% error rate of misinterpreted Gram stains from positive blood culture bottles is relatively high, so laboratory professionals and clinical microbiologist must be aware of the potential types of error that occur (Sains Medika, 4(1):23-29).

Comparison of Infection Rate With the Use of Antibiotic-Impregnated vs Standard Extraventricular Drainage Devices

External ventricular drainage (EVD) catheters provide reliable and accurate means of monitoring intracranial pressure and alleviating elevated pressures via drainage of cerebrospinal fluid (CSF). CSF infections occur in approximately 9% of patients. Antibiotic-impregnated (AI) EVD catheters were developed with the goal of reducing the occurrence of EVD catheter-related CSF infections and their associated complications. To present an international, prospective, randomized, open-label trial to evaluate infection incidence of AI vs standard EVD catheters. Infection was defined as (1) proven infection, positive CSF culture and positive Gram stain or (2) suspected infection: (A) positive CSF culture with no organisms identified on initial Gram stain; (B) negative CSF culture with a gram-positive or -negative stain; (C) CSF leukocytosis with a white blood cell/red blood cell count >0.02. Four hundred thirty-four patients underwent implantation of an EVD catheter. One hundred seventy-six patients in the AI-EVD cohort and 181 in the standard EVD catheter cohort were eligible for evaluation of infection. The 2 groups were similar in all clinical characteristics. Proven infection was documented in 9 (2.5%) patients (AI: 4 [2.3%] vs standard: 5 [2.8%], P = 1.0). Suspected infection was documented in 31 (17.6%) patients receiving AI and 37 (20.4%) patients receiving standard EVD catheters, P = .504. Duration of time to suspected infection was prolonged in the AI cohort (8.8 ± 6.1 days) compared with the standard EVD cohort (4.6 ± 4.2 days), P = .002. AI-EVD catheters were associated with an extremely low rate of catheter-related infections. AI catheters were not associated with risk reduction in EVD infection compared to standard catheters. Use of AI-EVD catheters is a safe option for a wide variety of patients requiring CSF drainage and monitoring, but the efficacy of AI-EVD catheters was not supported in this trial.

Microbial profile and antibiotic sensitivity pattern in bile cultures from endoscopic retrograde cholangiography patients

To identify the frequency of bacterial growth, the most commonly grown bacteria and their antibiotic susceptibility, and risk factors for bacterial colonization in bile collected from patients with different biliary diseases. This prospective study was conducted between April 2010 and August 2011. Patients with various biliary disorders were included. Bile was aspirated by placing a single-use, 5F, standard sphincterotome catheter into the bile duct before the injection of contrast agent during endoscopic retrograde cholangiopancreaticography (ERCP). Bile specimens were transported to the microbiology laboratory in blood culture bottles within an anaerobic transport system. Bacteria were cultured and identified according to the standard protocol used in our clinical microbiology laboratory. The susceptibilities of the organisms recovered were identified using antimicrobial disks, chosen according to the initial gram stain of the positive cultures. Ninety-one patients (27% male, mean age 53.7 ± 17.5 years, range: 17-86 years) were included in the study. The main indication for ERCP was benign biliary disease in 79 patients and malignant disease in 12 patients. The bile culture was positive for bacterial growth in 46 out of 91 (50.5%) patients. The most frequently encountered organisms were Gram-negative bacteria including Escherichia coli (28.2%), Pseudomonas (17.3%) and Stenotrophomonas maltophilia (15.2%). There were no significant differences between patients with malignant and benign disease (58% vs 49%, P = 0.474), patients with acute cholangitis and without acute cholangitis (52.9% vs 50%, P = 0.827), patients who were empirically administered antibiotics before intervention and not administered (51.4% vs 60.7%, P = 0.384), with regard to the bacteriobilia. We observed a large covering spectrum or low resistance to meropenem, amikacin and imipenem. We did not find a significant risk factor for bacteriobilia in patients with biliary obstruction. A bile sample for microbiological analysis may become a valuable diagnostic tool as it leads to more accurate selection of antibiotics for the treatment of cholangitis.

Exact certification in global polynomial optimization via sums-of-squares of rational functions with rational coefficients

We present a hybrid symbolic-numeric algorithm for certifying a polynomial or rational function with rational coefficients to be non-negative for all real values of the variables by computing a representation for it as a fraction of two polynomial sum-of-squares (SOS) with rational coefficients. Our new approach turns the earlier methods by Peyrl and Parrilo at SNC’07 and ours at ISSAC’08 both based on polynomial SOS, which do not always exist, into a universal algorithm for all inputs via Artin’s theorem. Furthermore, we scrutinize the all-important process of converting the numerical SOS numerators and denominators produced by block semidefinite programming into an exact rational identity. We improve on our own Newton iteration-based high precision refinement algorithm by compressing the initial Gram matrices and by deploying rational vector recovery aside from orthogonal projection. We successfully demonstrate our algorithm on (1) various exceptional SOS problems with necessary polynomial denominators from the literature and on (2) very large (thousands of variables) SOS lower bound certificates for Rump’s model problem (up to n = 18 , factor degree = 17 ).

Urinary Tract Infection In Immunocompromised Children Under Chemotherapy

AbstractAbstract 4765 Purpose:Infection is the most important cause of death in immunosuppressed cancer patients. And the urinary tract is a common source of infection in children. So we investigated the frequency of urinary tract infection (UTI) and the treatment outcome in children with cancer who were receiving antineoplastic therapy. Methods:We reviewed the medical records of children who were diagnosed as UTI during chemotherapy because of hematologic malignancies or solid tumors from January 2003 to July 2010 in Kyungpook National University Hospital. We defined as UTI when the patient showed high fever over 38.5°C and the single bacterial organism was cultured over 10,000/mL in urine sample using midstream urine collection technique. The bacterial strain, duration of fever, laboratory tests including urinalysis and gram stain, and imaging studies were demonstrated. Results:There were 63 cancer patients (male:female = 39:24) and 47 of them (74.6%, male:female = 30:17) experienced UTI during chemotherapy at least once. No one showed urinary symptom/sign like dysuria, frequency, urgency, flank pain or costo-vertebral angle tenderenss. The total episodes of UTI were 133 (male:female = 96:37) and the number of infection was mean 2.8 (1~10) per one patient. The common organism was Escherichia coli (25.6%), Enterococcus faecalis (15.0%), Klebsiella pneumoniae (10.5%), Enterococcus faecium (6.8%), Proteus mirabilis (6.8%) and Stenotrophomonas maltophilia (5.3%). Initial urinalysis was performed in 115 cases, but only 4 of them (3.5%) revealed pyuria. All gram stain results were negative. Duration of fever was mean 2.1 (1~6) days. The initial absolute neutrophil count (ANC) was average 1,930/μ L (0 ~ 12,610/μ L). The renal cortex scan using dimercaptosuccinic acid was performed for 43 cases to verify pyelonephritis. One showed decreased tracer uptake of upper pole of right kidney, and another 3 revealed diffuse decreased tracer uptake in both kidneys without specific photon defect. One episode of 3 was considered as urosepsis because the same organism (Klebsiella pneumoniae) was cultured from not only urine but also blood. The patient revealed hypotension and decreased renal function (glomerular filtration rate 41.4 mL/min). No mortality was observed. Conclusion:UTI is a very common infection in immunocompromised cancer children regardless of ANC which showed excellent prognosis with broad spectrum antibiotics. The bacterial strain was not different from that of immunocompetent children. But their symptom/sign was silent and the initial urinalysis and gram stain were not much help. So it is important to check urine culture for febrile cancer children under chemotherapy although the complication is very rare after UTI. Disclosures:No relevant conflicts of interest to declare.

Changes in the aerobic vaginal flora after treatment with different intravaginal devices in ewes

The objective of this study was to characterize the vaginal bacterial flora and subsequent pregnancy rates after AI in sheep subjected to 4 different estrous synchronization regimes – the use of two intravaginal devices (silicone or polyurethane sponges), and two different treatment periods (7 or 14 days). Twenty-one multiparous Texel ewes were randomly allocated to 4 treatment groups during the breeding season. In the ewes from Group I ( n = 6) and Group II ( n = 5), a polyurethane sponge containing 60 mg MAP was inserted in the vagina for a period of 7 or 14 days, respectively. In the ewes of Group III ( n = 5) and Group IV ( n = 5), an intravaginal progesterone releasing insert (IVP4) containing 160 mg of progesterone in an inert silicone device, was inserted for 7 or 14 days, respectively. At device withdrawal, each ewe was treated with 200 IU eCG i.m. Standard bacteriological procedures were performed on vaginal mucus samples obtained before the introduction of the devices, at device withdrawal and on the day of AI in all groups. Estrus was recorded with the aid of vasectomized rams every 12 h, and AI was performed 52–54 h after device withdrawal, using fresh semen. The intervals between device withdrawal and estrus were: Group I: 56.4 ± 21.5 h; Group II: 42.0 ± 33.9 h; Group III: 51.6 ± 21.5 h; Group IV: 37.2 ± 10.7 h, while the pregnancy rates were: Group I: 83.3%; Group II: 60.0%; Group III: 60.0%; Group IV: 60.0%. The pregnancy rates and the interval between device withdrawal and the occurrence of estrus did not differ between treatments. The predominant bacterial flora population at device insertion was mostly gram positive (G+) (90%) bacteria. The strains most frequently found were Bacilllus sp., Staphylococcus sp. and Corynebacterium sp. Of the 19 isolates made at device removal, 79% were gram negative, with the Escherichia sp. being the most frequently isolated. At the time of AI and regardless of the device used, the 14-day treatment group presented an initial gram positive bacterial flora, while the 7-day groups presented gram negative flora (82%). It could be concluded that the use of intravaginal devices, regardless of their composition (silicone or polyurethane), may generate changes in the normal vaginal bacterial flora of the vaginal mucus. These changes did not reflect on the subsequent fertility. The use of intravaginal devices should however include the adoption of strict hygiene procedures, to minimize the growth of bacterial flora.

Alternative Use for Spectra MRSA Chromogenic Agar in Detection of Methicillin-Resistant Staphylococcus aureus from Positive Blood Cultures

Spectra MRSA agar (Remel, Lenexa, KS), a novel chromogenic medium originally developed to detect methicillin-resistant Staphylococcus aureus (MRSA) from nasal swabs, was evaluated in this multicenter study for the detection of MRSA from positive blood cultures exhibiting Gram-positive cocci upon initial Gram staining.

Positive Dialysate Gram Stain Predicts Outcome of Empirical Antibiotic Therapy for Peritoneal Dialysis‐associated Peritonitis

Empirical antibiotic treatment with a first-generation cephalosporin plus gentamicin for peritoneal dialysis (PD)-associated peritonitis before culture results are available is still wildly used due to concerns regarding the economic burden and antibiotic-resistant bacterial infections. The aim of this study is to define the factors that predict the outcome of empirical antibiotic therapy for PD peritonitis. This is a retrospective study of patients with PD peritonitis over the last 10 years. Patients who had been treated empirically with intermittent intraperitoneal first-generation cephalosporin and gentamicin were enrolled. Eighty-three patients had 192 episodes of PD peritonitis. In total, 159 peritonitis episodes were treated with intraperitoneal antibiotics combined with first-generation cephalosporin and gentamicin empirically. Twenty-five peritonitis episodes had no pathogens identified by dialysate culture. In total, 122 (122/159, 76.7%) PD peritonitis episodes were caused by bacteria, 9 (9/159, 5.7%) were fungal, and 3 (3/159, 1.9%) were Mycobacterium tuberculosis peritonitis. Sixty-four (64/159, 40.3%) peritonitis episodes were successfully cured by empirical intraperitoneal antibiotic therapy. Empirical antibiotic treatment failed in 95 episodes (95/159, 59.7%). The positive rates of dialysate Gram stain in the empirical treatment success and failure groups were 15.6% and 40.0%, respectively (P = 0.001). The odds ratio of empirical treatment failure with a positive bacteria Gram stain was 3.60 (95% CI: 1.65-7.82). The dialysate Gram staining result was a significant predictor of empirical antibiotics treatment outcome for PD-associated peritonitis. Therefore, using an empirical antibiotic regimen for patients with an initial positive bacterial Gram stain of the dialysate should be introduced cautiously.

Impact of Reporting Gram Stain Results From Blood Cultures on the Selection of Antimicrobial Agents

The reporting of Gram stain results from positive blood culture bottles clearly impacts the early selection of proper antimicrobial treatment. Mackenzie et al1 recognized that bacteremia is associated with serious morbidity and mortality, especially in certain groups of patients. Despite the broad range of antimicrobial agents available, a delay in inappropriate antibiotic administration can result in “progressive deterioration and the development of intractable complications.”2 Criteria for determining the appropriate antibiotic treatment for the specific clinical situation must include spectrum of activity, achievable blood levels, toxic effects, dosing and duration of therapy, and cost-effectiveness.3 Clinicians often face difficult therapy decisions that must be made well before a definitive identification of the pathogen causing the bacteremia is determined. Blood cultures in conjunction with the initial Gram stain of positive cultures have often been considered the “gold standard” for the diagnosis of bacteremia.4 The Gram stain, developed in 1884 by Hans Christian Gram, is one of the most important and most useful laboratory tests used in the clinical microbiology setting.5 Physicians continue to rely on the Gram stain result during the first 24 to 48 hours for the selection of appropriate antibiotic treatment for patients with positive blood cultures because susceptibility results usually cannot be provided in less than 48 to 72 hours. Gram-negative sepsis results in death 50% of the time during the first 2 days of the illness, demonstrating the importance of immediate and appropriate treatment.6 To be useful in guiding …