Majority Of Bacteremias Research Articles

1216. ASP Initiated Blood Culture Service Is Highly Accepted, Reduced Antibiotic Durations Associated with Good Safety Outcomes

Abstract Background NUH is a 1200 bed academic medical center with quaternary medical services ; the ASP program was initiated in 2014. A 2020 review found 18.5% of bacteremic patients were on inappropriate antibiotics (ABX) or wrong duration, and the overall majority of bacteremias were gram-negative (E .coli and Klebsiella). Since out ASP program has been promoting shorter durations in general, we hypothesized that a blood culture service where recommendations for de-escalation and appropriate duration were given early would help shorten ABX durations in patients with uncomplicated bacteremias. On March 15, 2021, we initiated an ASP led blood culture (BC) service (SVC) which reviewed case notes of patients Monday to Friday as soon as blood culture (BC) susceptibilities were available. We report on the types of interventions (INV), acceptance rate, and the impact and outcomes of our BC SVX between patients in whom the INV was accepted versus rejected. Methods Prospective data on BC SVC interventions, acceptance rate, and patient status at five days were collected. Antibiotic duration (IV and oral), Length of Stay (LOS) and 30-day mortality as well as Charlson Comorbidity Index (CCI) were determined from electronic medical records for all ASP BCSVX interventions between March 15, 2021- December 31, 2022. Statistical analysis was performed in excel and STATA. Results 790 INVs were made on 625 patients and 693 courses of ABX with an 83.9 % overall acceptance rate. De-escalate ABX and treatment duration were the most common INVs (Table 1). 92.5% of patients had improved or no change in Day 5 status when ASP INV was accepted compared to 84.3% when rejected (p=0.003). Mean days of ABX per course was 5.9 versus 7.3 (p= 0.008) in the accepted versus rejected groups. CCI and LOS were similar, while 30-day mortality almost reached significance in the accepted INV group (Table 2). Conclusion ASP led BC SVC was well accepted, saved 2.14 days of ABX per intervention, and was very safe. Disclosures All Authors: No reported disclosures

Rare and Under Reported Causes of Bacteremia: Case Series from a Tertiary Health Care Centre of Northern India

With increasing medical interventions, immunosuppressants, hospital stay and antibiotic use; people are finding increased cases of hospital acquired infections. Bacteremia and sepsis are important cause of morbidity and mortality in tertiary health care centres. Majority of bacteremia are caused by the Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp (ESKAPE) pathogens. However, in some cases hospital environment bacteria can cause bacteremia and sepsis, especially in immunocompromised patients. Each bacterium is unique with specific antibiotic susceptibilities. So, accurate identification up to species level is important for management of infections. Automated culture and identification systems like VITEK and Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) helps a lot in these processes. Here, the authors presents a case series of bacteremia caused by rare bacteria; namely Campylobacter coli, Sphingomonas paucimobilis, Paenibacillus thiaminolyticus and Cuprividus gilardii. All bacteria were grown in bactec culture and identifications were confirmed by MALDI-TOF MS and drug susceptibility testing was done by VITEK-2. All the patients were having co-morbidities and antibiotic history. Patients responded to guided antibiotic therapy. The authors reiterate that increased suspicion of infection by these bacteria, especially in bacteremia cases of patients have co-morbidities (like agammaglobulinemia, end stage renal disease, diabetes mellitus, kidney failure, etc). Latest identification techniques like VITEK and MALDI-TOF MS should be utilised for diagnosis and treatment of these infections.

148. Retrospective Evaluation of Acute Cholangitis and Clinical Implication and Management of Secondary Bacteremia

BackgroundOptimum duration of antimicrobial therapy for acute bacteremic cholangitis is not well established; however, 4–7 days is recommended by the 2018 Tokyo guidelines in those without Gram-positive bacteremia.MethodsA retrospective study performed at Mayo Clinic - Rochester, Florida and Arizona sites was conducted, reviewing all adult patients with the first episode of acute cholangitis secondary to biliary stone obstruction, between January 1, 2012 and December 31, 2017. We reviewed the duration of prescribed antimicrobials.ResultsAmong 331 included cases, 197(60%) were men, 66 (20%) were immuno-compromised. Presenting symptoms included fever in 202 (61.5%), abdominal pain in 289 (87%), jaundice 128(38.7%), and altered mentation in 49 (15%). Among these, 256 (77%) were classified as “definite” and 38 (11.5%) were “suspected” using the 2018 Tokyo guideline classification. Cholangitis grade was grade III in 134 (40.5%); grade II in 115 (34.7%); and grade I in 82 (24.8%). Majority of cases, 321 (97%), underwent source control—most commonly 309 (96%) achieved by endoscopic retrograde cholangiopancreatography (ERCP). Source control occurred within 24 hr of presentation in 197 (61.4%) of the cases. Bacteremia was documented in 131/277 (47%). Majority of bacteremias were due to Gram-negative organisms in 119 (91%). Mean duration of antibiotic therapy following “source control” was 9.6 days (SD 7.0). Cases with bacteremia, resulted in longer treatment duration, mean of 13 days (SD 5.6), regardless of the isolated organism. Overall 30 day mortality was 14/331 (4.2%). No mortality difference was noted in patients who underwent early (within 12 hours) vs. later source control (4.55% Vs. 4.53%), nor in those who received more or less than 6 days of antibiotic therapy after source control (4.7% Vs. 3.9%, P = 0.76). No difference in mortality was observed in those with or without bacteremia.ConclusionOur results note the use of longer courses of antimicrobials for management of bacteremic cholangitis, regardless of the organism type. This population could be a prime target for an antimicrobial stewardship intervention, to decrease the duration of prescribed antimicrobials in accordance with recent guidelines.Disclosures All authors: No reported disclosures.

Caracterización clínica y microbiológica de la bacteriemia por Staphylococcus aureus

Introducción: Staphylococcus aureus es una frecuente causa de bacteriemias y el incremento en las tasas de resistencia dificulta su tratamiento inicial. La incidencia de bacteriemias por S. aureus resistente a meticilina (SAMR) ha aumentado, principalmente en las infecciones adquiridas en el medio hospitalario. Este estudio pretende caracterizar clínicamente a los pacientes con bacteriemia por S. aureus detectados en un hospital de Medellín y definir su perfil de resistencia microbiana. 
 Métodos: cohorte retrospectiva en un hospital de tercer nivel. Se incluyeron pacientes ≥16 años con aislamiento para Staphylococcus aureus en sangre periférica. Se registró información relacionada con el episodio, el sitio de adquisición, la clasificación microbiológica y las características clínicas. 
 Resultados: de 775 reportes de hemocultivos positivos para S. aureus, finalmente se ingresaron 698 pacientes al estudio. La mediana de edad fue de 58 años (RIQ=42-69), 383 eran hombres (54.9%). En 354 pacientes (50.7%) la bacteriemia era de origen nosocomial y el 26.2% (n=183) eran SAMR. En 123 (17.6%) bacteriemias adquiridas en la comunidad, la frecuencia de SAMR fue 33.3% (n=41). El antecedente más frecuente fue tener un catéter vascular en 321 pacientes (46%). Se inició terapia empírica en 67.2% de los casos (n=469). Respecto a la gravedad, la mediana del puntaje SOFA fue de 4 (RIQ=1-5), APACHE II de 15 (RIQ=10-19) y la mortalidad fue del 24.9% (n=174). 
 Conclusiones: a pesar de que la mayoría de bacteriemias son de origen nosocomial, el reporte más frecuente fue SAMS tanto en el grupo nosocomial como en el de la comunidad. Sin embargo, la mortalidad en el grupo de bacteriemia nosocomial fue inferior comparada con la de la comunidad.

Bacterial bloodstream infections and antimicrobial susceptibility pattern in pediatric hematology/oncology patients after anticancer chemotherapy.

PurposeBloodstream infections in pediatric hematology and oncology represent a major problem worldwide, but this has not been studied in Qatar. In this study, we investigated the burden of infection and the resistance pattern in the bacterial etiology, in the only tertiary pediatric hematology and oncology center in Qatar.MethodsAll pediatric cancer patients (n=185) were evaluated retrospectively during the period 2004–2011; a total of 70 (38%) patients were diagnosed with bloodstream infections. Bacterial etiology was determined, along with their susceptibility patterns. Neutropenia, duration of neutropenia, fever, duration of fever, and C-reactive protein (CRP) were evaluated throughout the study.ResultsA total of 70 patients (38%) were diagnosed with acute leukemias, lymphomas, solid tumors, or brain tumors; those patients experienced 111 episodes of bacteremia. The most common Gram-positive (n=64 [55%]) isolates were Staphylococcus epidermidis (n=26), Staphylococcus hominis (n=9), and Staphylococcus haemolyticus (n=7), and the common Gram-negative (n=52 [45%]) isolates were Klebsiella pneumoniae (n=14), Pseudomonas aeruginosa (n=10), and Escherichia coli (n=7). There was a significant association observed between fever with positive blood culture and different types of cancer (P=0.035). The majority of bacteremia (n=68 [61.3%]) occurred in nonneutropenic episodes. Elevated values of CRP (≥5 mg/L) were detected in 82 (95.3%) episodes and were negatively correlated with absolute neutrophil count (ANC) (r=−0.18; P=0.248) among all cases. However, the infection-related fatality rate was 2.2% (n=4), with three caused by Gram-negative pathogens. Multidrug resistant organisms were implicated in 33 (28.4%) cases and caused three of the mortality cases.ConclusionMultidrug resistant organisms cause mortality in pediatric cancer patients. Investigation of antimicrobial susceptibility of these organisms may guide successful antimicrobial therapy and improve the surveillance and quality of pediatric malignancy care.

Molecular Epidemiology of Enterococcal Bacteremia in Australia

Enterococci are a major cause of health care-associated infections and account for approximately 10% of all bacteremias globally. The aim of this study was to determine the proportion of enterococcal bacteremia isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to ampicillin and the glycopeptides, and to characterize the molecular epidemiology of the Enterococcus faecalis and Enterococcus faecium isolates. From 1 January to 31 December 2011, 1,079 unique episodes of bacteremia were investigated, of which 95.8% were caused by either E. faecalis (61.0%) or E. faecium (34.8%). The majority of bacteremias were health care associated, and approximately one-third were polymicrobial. Ampicillin resistance was detected in 90.4% of E. faecium isolates but was not detected in E. faecalis isolates. Vancomycin nonsusceptibility was reported in 0.6% and 36.5% of E. faecalis and E. faecium isolates, respectively. Unlike Europe and the United States, where vancomycin resistance in E. faecium is predominately due to the acquisition of the vanA operon, 98.4% of E. faecium isolates harboring van genes carried the vanB operon, and 16.1% of the vanB E. faecium isolates had vancomycin MICs at or below the susceptible breakpoint of the CLSI. Although molecular typing identified 126 E. faecalis pulsed-field gel electrophoresis pulsotypes, >50% belonged to two pulsotypes that were isolated across Australia. E. faecium consisted of 73 pulsotypes from which 43 multilocus sequence types were identified. Almost 90% of the E. faecium isolates were identified as CC17 clones, of which approximately half were characterized as ST203, which was isolated Australia-wide. In conclusion, the Australian Enterococcal Sepsis Outcome Programme (AESOP) study has shown that although they are polyclonal, enterococcal bacteremias in Australia are frequently caused by ampicillin-resistant vanB E. faecium.

Differing burden and epidemiology of non-Typhi Salmonella bacteremia in rural and urban Kenya, 2006-2009.

BackgroundThe epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change.MethodsAs part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006–2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured.ResultsNTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy.ConclusionsNTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa.

Blood stream infections throught the entire course of acute lymphoblastic leukemia treatment

The incidence, type and mortality of bacteremias were evaluated in a pediatric patient cohort, during the entire course of treatment for acute lymphoblastic leukemia (ALL). Eighty-six patients with newly diagnosed ALL were studied. A bacteremic episode was defined as blood isolation of a pathogen in the presence of clinical symptomatology of septicaemia. Bacteremias were analyzed according to the treatment element being delivered and the degree of neutropenia. A central venous catheter (CVC) was inserted at diagnosis in all patients. Fifty-two episodes of bacteremias were encountered in 38/86 (44%) patients, while 48/86 patients had no positive blood culture. Three out of the 38 patients had bacteremia and CVC area infection, simultaneously. Most blood stream infections (29/52, 56%) were documented during the induction phase. Isolated Gram-positive organisms were 48%, Gram-negative 50% and 2% of the positive blood cultures represented fungaemias. The most common Gram-positive isolates were Staphylococcus species (N=22) and the commonest Gram-negative isolated pathogens were Escherichia coli and Pseudomonas aeruginosa. The majority of bacteremias (75%) occurred during neutropenia. The initial antibiotic treatment was ceftazidime or piperacillin/tazobactam and amikacin or tobramycin. CVC was not removed in the majority of bacteremias (94%). No infection related fatality was recorded. Bacteremias constituted a severe and common complication in our patient cohort. However, infection-related fatality rate was negligible, most probably due to the prompt initiation of broad coverage antimicrobial therapy.

Infections in a pediatric patient cohort with acute lymphoblastic leukemia during the entire course of treatment

To assess the type, frequency, severity, and outcome of all infectious episodes in a pediatric patient cohort with acute lymphoblastic leukemia (ALL) from a single institution during the entire length of leukemia treatment. Eighty-six patients were treated according to a modified ALL Berlin-Frankfurt-Munster protocol. Retrospective analysis of all types of infections according to the treatment phase and the degree of neutropenia is presented. A total of 610 infectious episodes were recorded. Most infections were documented during maintenance (57%), followed by the induction phase (20.3%). During maintenance, 347 episodes were encountered, with nonspecific viral upper respiratory tract infections (URIs) being the commonest diagnosis (40.0%). Additionally, 38 of 58 total specific viral infections occurred during maintenance: 16 herpes simplex, 7 varicella, 10 herpes zoster infections [varicella-zoster virus (VZV), 45%]. The majority of bacteremia and fever of unknown origin occurred during induction (20%). The number of Gram-negative bacteremia was 50% of the total (26 of 52). The majority of the infections (59.5%) occurred without neutropenia [absolute neutrophil count (ANC) >1,000 microl(-1)]. Fewer infections (9.3%) were recorded with concurrent very severe neutropenia (ANC <100 microl(-1)), although 38.5% of positive blood cultures were documented with severe neutropenia. No infection-related fatality occurred. Most of the severe infections occurred during induction. Gram-positive bacteremia and Gram-negative bacteremia were almost equal. URIs were the commonest infections during the entire treatment and during maintenance. Specific viral infections represented a smaller percentage of the total (VZV was the commonest pathogen). Infectious complications represented a significant morbidity factor, but notably, mortality was negligible.

Survival and function of phagocytes in blood culture media.

The survival and function of human phagocytes in sterile aerobic and anaerobic blood culture media were investigated using neutrophil morphology, white blood cell count in a haemoanalyser, flow cytometry, oxidative burst response, and bactericidal effect in Colorbact and Septi-Chek blood culture media and Bact/Alert. When comparing agitation to stationary incubation no difference in phagocytic activity was found. The methods showed the same trends demonstrating that the phagocytes' viability and activity were prolonged by oxygen and shortened by anaerobic conditions and sodium polyethanol sulfonate (SPS). Best preserved activity and viability were found in the aerobic media containing less than 0.5 g/l SPS, in which significant phagocyte oxidative burst and bactericidal activity were found up to 4 days after inoculation. Considering that the majority of bacteremias are due to aerobic or facultatively anaerobic bacteria, the present data suggest that most bacteria may be recovered by the use of one aerobic bottle with SPS concentration below 0.5 g/l to protect meningococci and other SPS-sensitive bacteria and one above 0.5 g/l to stop phagocytic activity, plus one anaerobic bottle with SPS below 0.5 g/l.

Hickman catheters in association with intensive cancer chemotherapy

Hickman catheters were the major venous access devices utilized at the University of Maryland Cancer Center from November 1978 to 1987. This study provided an opportunity to standardize insertion technique, to manage catheter-related activities and daily maintenance procedures in order to examine the progression of Hickman-catheter-related problems, to identify those factors that may minimize them, and to develop guidelines for the management and prevention of complications and malfunctions. In all, 690 Hickman catheters (368 double lumens) were placed in patients with acute leukemia and other cancers: 401 catheters were placed in patients with leukemia; 269 were placed during neutropenia; and 230 at platelet counts of < 50,000/microliters. Two surgeons inserted 490 catheters, and the remaining 200 were placed by a group of rotating surgeons. All catheters were placed with the intention that they would remain in place as long as clinically necessary. Total Hickman catheter days were 134273. Infectious complications included exit site infections (160), tunnel infections (46) and bacteremias (397). There were 438 instances of noninfectious complications including thrombosis, lack of function, catheter migration, fracture and hemorrhage. Recommendations for prevention and treatment of Hickman-catheter-related complications include the development of a select group committed to placement, daily maintenance and management of problems; prompt removal of catheters with Candida sp. fungemia and bacteremia due to Bacillus sp. or a bacteremia that persists for > 48 h after initiation of appropriate antibiotics, tunnel infections or Hickman-catheter-associated thrombosis. The majority of bacteremias and exit site infections can be effectively treated with antibiotics and local care.