Incidence Of Anaerobic Bacteremia Research Articles

Distribution, Trends, and Antimicrobial Susceptibility of Bacteroides, Clostridium, Fusobacterium, and Prevotella Species Causing Bacteremia in Japan During 2011-2020: A Retrospective Observational Study Based on National Surveillance Data.

The increasing prevalence of anaerobic bacteremia is a major concern worldwide and requires longitudinal monitoring. We present one of the largest and longest longitudinal studies on the prevalence and antimicrobial resistance of Bacteroides, Clostridium, Fusobacterium, and Prevotella spp. isolated from blood culture samples using national comprehensive surveillance data in Japan during 2011-2020 as part of the Japan Nosocomial Infections Surveillance. Data for 41 949 Bacteroides spp., 40 603 Clostridium spp., 7013 Fusobacterium spp., and 5428 Prevotella spp. isolates were obtained. The incidences of bacteremia caused by Bacteroides fragilis, Clostridium perfringens, and Fusobacterium nucleatum significantly increased during the period (P < .0001). Among the 20 species analyzed, 18 showed no significant changes in susceptibility over time, including B. fragilis, C perfringens, and F. nucleatum. However, resistance to clindamycin increased in B. thetaiotaomicron (P = .0312), and resistance to ampicillin increased in B. ovatus (P = .0008). Our comprehensive national surveillance data analysis demonstrated a continuous increase in the incidence of anaerobic bacteremia, particularly in B. fragilis, C. perfringens, and F. nucleatum. This may be linked to the increasing number of colorectal cancer cases or advancing methods for species identification and susceptibility testing, requiring cautious interpretation. The discovery of an upsurge in anaerobic bacteremia and potential alterations in susceptibility highlights the necessity for more extensive studies in this field.

Identification and distribution of anaerobic bacteria isolated from clinical specimens in a University Hospital: 4 years’ experience

Anaerobes, which are components of microbiota, can cause life-threatening infections. Because of their fastidious nature, they are difficult to isolate and are often overlooked. The goal of this study was to identify the anaerobic bacteria isolated from clinical specimens at the Central Laboratory of Hacettepe University Hospital in 2015-2018 and to evaluate the distribution of the isolated bacterial species among the different specimen types. The anaerobic bacteria isolated from the specimens were identified by the conventional methods and MALDI-TOF MS. Overall, 15,300 anaerobic cultures were studied. Of these, 14,434 (94.3%) were blood samples and 866 (5.7%) were other clinical specimens. A total of 138 anaerobic bacteria were isolated: 62 (44.9%) were isolated from blood samples and 76 (55.1%) from other specimens. The most isolated anaerobes from blood cultures were Bacteroides spp. (41.9%), followed by Cutibacterium acnes (25.8%) and Clostridium spp. (9.7%). The most isolated anaerobes from the other specimens were Gram-negative bacilli, including Bacteroides spp. (15.8%), Fusobacterium spp. (14.5%), Prevotella spp. (14.5%), and Porphyromonas spp. (2.6%). Anaerobic Finegoldia magna represented the major species among the isolated Gram-positive bacteria (10.5%). Anaerobic growth was observed in 0.4% of all the blood cultures and in 5.8% of the positive blood cultures. The results of our study showed that the incidence of anaerobic bacteremia was stable during the 2015-2018 period.

Rapidly Growing Aneurysm with Ulcer-like Projection Complicated with Bacteroides ovatus Bacteremia

The incidence of anaerobic bacteremia has been increasing over the past several decades. Further, antibiotic resistance in Bacteroides is a pertinent issue. A 76-year-old man was brought to our hospital with complaints of fever, chills, and abdominal pain. Empiric antibiotics induced minimal relief. The blood culture was positive for multi-drug resistant Bacteroides ovatus. Our patient developed a periaortic abscess in the abdominal aorta and a thoracic aortic aneurysm with ulcer-like projection (ULP), which rapidly increased in size. He was transferred to the tertiary medical institution for surgical drainage. This case suggests that bacteremia can exacerbate aneurysms with ulcerative lesions. Anaerobic bacteremia is a possible differential diagnosis when periaortic abscess formation is present. Early surgical consultation and appropriate antibiotic selection are crucial in anaerobic bacteremia treatment.

Yield of Anaerobic Blood Cultures in Pediatric Emergency Department Patients.

Anaerobic bacteremia is rare in children and current recommendations advocate against the routine use of anaerobic cultures in children. However, the incidence of anaerobic bacteremia and the utility of anaerobic blood cultures in children have not been assessed in recent years. Our pediatric emergency department (PED) policy still supports the use of both aerobic and anaerobic blood cultures in all cases of suspected bacteremia. This allowed us to re-evaluate the yield of anaerobic cultures in PED settings. Retrospective data of all blood cultures taken in the PED in a single tertiary center from 2002 to 2016 were collected. The incidence and characteristics of children with positive anaerobic blood cultures were assessed. Risk factors for anaerobic bacteremia were defined. Of the 68,304 blood culture sets taken during the study period, 971 (1.42%) clinically significant positive cultures were found. Pathogenic obligatory anaerobic bacteria were isolated in 33 (0.05%) cultures. The leading risk factors for anaerobic bacteremia were head and neck abscess and intra-abdominal infection. Of all the true positive cultures, 187 (22%) were only detected in the anaerobic culture and would have otherwise been missed. True anaerobic bacteremia is extremely rare in children admitted to the PED. Nevertheless, using anaerobic cultures may increase the overall yield of blood cultures.

Bacteriemia por anaerobios estrictos: estudio de 68 pacientes

There is some controversy regarding the current rates of anaerobic bacteremia. Some authors have described an increasing incidence in recent years, whereas others report declining rates. There is even debate over whether to routinely perform anaerobic blood cultures. We present a prospective analysis of anaerobic bloodstream infections diagnosed at our medical center from January 2003 to May 2008. Sixty-eight patients had bloodstream infection caused exclusively by anaerobic bacteria. Median age was 64+/-19 years and 63.2% had at least one comorbid condition, including 20.6% with a solid neoplasm, often related to the gastrointestinal tract. The main focus of anaerobic bacteremia was the abdomen (42.6%). The most common isolates were several species from the Bacteroides fragilis group (36.7%), Clostridium spp. (17.6%), Peptostreptococcus spp. (16.1%), and Prevotella spp. (16.1%). Empirical antimicrobial treatment was adequate in 69.1%. Overall mortality was 23.5%, and bacteremia-related mortality was 9.2%. Sepsis, septic shock, and a Pitt score >4 were independent predictors of mortality. The incidence of anaerobic bacteremia in our hospital was 0.89 cases per 1000 hospital admissions. Patients at high risk were elderly persons with associated underlying diseases including malignant disease. Mortality was high.

An Increase in the Incidence of Anaerobic Bacteremia: True for Tertiary Care Referral Centers but Not for Community Hospitals?

An Increase in the Incidence of Anaerobic Bacteremia: True for Tertiary Care Referral Centers but Not for Community Hospitals?

Reemergence of Anaerobic Bacteremia

During 1974-1988, the incidence of anaerobic bacteremia at the Mayo Clinic (Rochester, MN) decreased. This trend occurred nationally, prompting calls for discontinuation of routine anaerobic blood cultures. However, recently, the sites of anaerobic infection have been shown not to be as predictable as once thought, and since 1993, the incidence of anaerobic bacteremia has increased significantly in our medical center. Records from the Mayo Clinic Division of Clinical Microbiology were used to tabulate the number of cases of anaerobic bacteremia in patients at the clinic for the 12-year period from 1993 through 2004. Medical records for patients with anaerobic bacteremia were reviewed from the periods of 1993-1994 and 2004 to identify differences between these 2 patient populations with different rates of bacteremia. The mean incidence of anaerobic bacteremias increased from 53 cases per year during 1993-1996 to 75 cases per year during 1997-2000 to 91 cases per year during 2001-2004 (an overall increase of 74%). The total number of cases of anaerobic bacteremia per 100,000 patient-days increased by 74% (P<.001). The number of anaerobic blood cultures per 1000 cultures performed increased by 30% (P=.002). Organisms from the Bacteroides fragilis group, other species of Bacteroides, and Clostridium species were most commonly isolated. Anaerobic bacteremia has reemerged as a significant clinical problem. Although there are probably multiple reasons for this change, the increasing number of patients with complex underlying diseases makes the clinical context for anaerobic infections less predictable than it once was. Anaerobic blood cultures should be routinely performed in medical centers with a patient population similar to ours.

Routine Anaerobic Blood Cultures: Back Where We Started?

aerobic blood cultures should be routinely performed in the hospital setting has been ongoing for >15 years [1-3]. Previously, reports that the incidence of anaerobic bacteremia was decreasing, that most positive culture results correlated with predictable clinical findings, and that routine use of anaerobic cultures rarely resulted in clinically relevant diagnostic or therapeutic gains compelled some authors to argue that only selective ordering of these tests should be considered [1, 3, 4]. Selective cultures were proposed only for patients considered to be at high risk for anaerobic infection, as determined by the clinician. This would require the development of guidelines or policies to properly select atrisk patients, as well as some determination of the feasibility of this approach. To date, despite calls to selectively obtain anaerobic blood cultures and to consider ad-

Bacteremia at a Danish University Hospital during a Twenty-five-year Period (1968-1892)

In the 25-year period 1968-92, 3,317 out of 477,420 patients admitted to Frederiksberg Hospital experienced 3,491 episodes of bacteremia. Enterobacteriaceae dominated as causative agents (57%), following by Gram-positive cocci (31%) and anaerobes (7%). Polymicrobial bacteremia was found in 8% of the episodes. The incidence of Enterobacteriaceae bacteremia culminated in the middle (1978-82) of the period (4.7/1,000 admissions) and decreased during the last decade. Gram-positive bacteremia increased throughout the period (from 1.8 to 2.9; p < 0.001), due mainly to increasing incidences of bacteremia caused by non-hemolytic streptococci, Streptococcus pneumoniae and coagulase-negative staphylococci. Bacteroides fragilis accounted for a rising incidence of anaerobic bacteremia (from 0.3 to 0.7; p < 0.05). Clinical data were available for the 2,599 bacteremic episodes in the 20-year period 1968-87. 59% of these were hospital acquired. Of those, 38% were associated with indwelling catheters, mainly bladder catheters (28%) and i.v. lines (7%). The urinary tract dominated as source of bacteremia (46%), followed by the respiratory (11%) and the gastrointestinal tract (9%). Half of the patients had predisposing underlying diseases, most frequently malignancies (20%) and diabetes mellitus (7%). The mortality rate related to bacteremia decreased from 25% to 11% (p < 0.001). More than half (55%) of the fatal cases related to bacteremia occurred within the first 2 days after the first positive blood culture was obtained. Logistic regression analysis defined 7 variables that independently influenced the outcome related to bacteremia: age, source, culture verification of source, shock, body temperature, leukocyte count and empiric antibiotic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical significance of anaerobic bacteremias in a general hospital. A prospective study from 1988 to 1992.

A prospective study was designed to investigate anaerobic bacteremias and evaluate their incidence and significance in a general hospital. One or more blood cultures positive for anaerobic microorganisms were analyzed from each of a total of 61 patients hospitalized between January 1988 and April 1992, in accordance with an established protocol. The clinical repercussions of bacteremia were also analyzed. Two percent of blood cultures were positive for anaerobes, with an incidence of 0.6 cases per 1000 hospitalized patients. The most frequently isolated anaerobes were Bacteroides fragilis and Clostridium perfringens. Intraabdominal disease was the route of entry in 50% of the patients. A death rate of 37.3% was mostly attributed to B. fragilis. Hospitalization in the surgical department, nosocomial acquisition, previous surgery, critical initial clinical status and the presence of complications were significantly associated with increased death rates. No significant differences were found in the clinical course between patients whose antibiotic treatment was judged adequate and those for whom it was considered inadequate. The frequency and incidence of anaerobic bacteremia was low in our hospital. The well-known clinical and epidemiological characteristics of these infections facilitates their prompt diagnosis and empirical treatment with antibiotics of proven effectiveness against anaerobes.