The importance of susceptibility testing of anaerobes: A clinician's perspective (original) (raw)
Related papers
National hospital survey of anaerobic culture and susceptibility methods: III
Anaerobe, 2008
The methods for performing anaerobic bacterial isolation and identification continue to change and improve. Anaerobic susceptibility testing has become controversial, and method-dependent variability has been noted. To assess the status of clinical anaerobic bacteriology in the United States, we surveyed, by means of a questionnaire, 120 hospitals, selected at random, with bed capacities of 200 to 1,000, and we received responses from 88 (73%). All hospitals performed cultures for anaerobes. The media and methods used for transport, initial processing, incubation, and identification varied between the different regions in the United States. Thirty percent of laboratories did not perform susceptibility studies, 16% used a reference laboratory, and 54% performed them in house. For half the laboratories, susceptibility testing was performed on isolates depending on the source; in this case, blood cultures were tested by 97% of the laboratories, serious infections were tested by 60%, sterile body sites were tested by 73%, pure cultures were tested by 47%, and tests were done by physician request by 39%o. For laboratories doing testing, the broth disk method, no longer sanctioned by the National Committee for Clinical Laboratory Standards, was used most often (56%), followed by microdilution (33%), P-lactamase testing (25%), macrotube dilution (2%), and agar dilution (2%).
Incidence and Clinical Significance of Anaerobic Bacteremia in a Community Hospital
Clinical Infectious Diseases, 1993
Recent studies have shown that anaerobes account for 0.5-9% of all episodes of bacteraemia in hospitalised patients, with variations according to geographical location and demographic characteristics, most notably age, but few data are available for cancer patients. This study investigated retrospectively the incidence of anaerobic bacteraemia in cancer patients who received non-surgical treatment over a 6-year period at a tertiary oncology centre. Gastrointestinal (27%) and haematological (29%) malignancies were the most common underlying diseases. Among 45 isolates of anaerobic bacteria recovered from 45 patients, Bacteroides spp. and Clostridium spp. were the most frequent pathogens (60% and 22%, respectively). Twenty episodes of bacteraemia were polymicrobial, most frequently with aerobic Gramnegative bacilli (18 cases). The mortality rate for patients with adequate antimicrobial therapy from the outset was 14%, compared with 63% for patients who were not treated adequately at any time.
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2018
There has been an increased interest in the study of anaerobic bacteria, which cause human infection during the past decade. Many new genera and species have been described by to use 16S rRNA gene sequencing of clinical isolates obtained from different infection sites with commercially available special culture media to support the growth of anaerobes. Several systems, such as anaerobic pouches, boxes, jars and chambers provide suitable anaerobic culture conditions to isolate even strict anaerobic bacteria successfully from clinical specimens. Beside the classical, time consuming identification methods and automated biochemical tests, the matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized identification of even unusual and slow growing anaerobes directly from culture plates, giving the possibility to provide timely information about anaerobic infections. The aim of this review article is to present methods for routine labor...
Bacteremia due to anaerobic bacteria: epidemiology of a north of Bari hospital
Microbiologia Medica, 2015
Background. Anaerobic bacteria are part of the commensal bacterial flora of skin and mucosae. Iatrogenic and pathological conditions altering this commensal relationship cause life-threatening diseases. Materials and Methods. We analysed the blood cultures sent to the microbiology of our hospital between 2008 and the first quarter of 2013 to measure the frequency of bacteraemia caused by anaerobia. We examined 3138 vials of blood cultures for anaerobia, inoculated following in-house standard procedures. The colonies grown in absence of air were subjected to biochemical analysis. The MICs of metronidazole for 23 of the 26 organisms was tested. Results. Twelve bacteria of the Bacteroides genus were identified, 9
Clinical Significance and Outcome of Anaerobic Bacteremia
Clinical Infectious Diseases, 1998
We retrospectively studied the incidence of anaerobic bacteremia during 6 years (1991-1996) at Turku University Central Hospital (Turku, Finland). The clinical significance of a positive anaerobic blood culture, the effect of a positive culture on the choice of antimicrobial therapy, and the outcome for patients were evaluated. Cultures of blood from 81 patients yielded anaerobic bacteria (4% of all bacteremias). Anaerobic bacteremia was clinically significant in 57 patients (0.18 cases per 1,000 admissions). Only half (28) of these patients received appropriate and effective antimicrobial treatment before the results of blood cultures were reported; for 18 patients (32%), initially ineffective treatment was changed on the basis of the bacteriologic results, and for 11 patients (19%), the treatment was not changed. The mortality in these patient groups was 18%, 17%, and 55%, respectively. Empirical therapy may provide coverage for anaerobes in only half of the patients with anaerobic bacteremia, and failure to pay attention to the results of anaerobic blood cultures may have serious consequences for patients.
Survey of anaerobic susceptibility patterns: A French multicentre study
International Journal of Antimicrobial Agents, 1998
In 1996, the in vitro antibiotic susceptibility of 463 anaerobes was measured in five hospitals using the reference agar dilution method. None of the 209 B. fragilis group strains showed resistance to imipenem or ticarcillin-clavulanic acid. High resistance rates (29%) were observed for cefotetan and clindamycin. i-Lactamase production was detected respectively in 64% of the Pre6otella and 7% of the Fusobacterium strains. Because the same standardized methods were used for many years, the authors were able to evaluate the evolution of antibiotic resistance. Clindamycin resistance had increased within the B. fragilis group (from 14% in 1992 to 29% in 1996) and also among strains of clostridia (32%), P. acnes (18%) and Peptostreptococcus (28%). In the B. fragilis group multidrug resistance was unlikely to occur.
Drugs, 2010
Anaerobic bacteria are the predominant indigenous flora of humans and, as a result, play an important role in infections, some of which are serious with a high mortality rate. These opportunistic pathogens are frequently missed in cultures of clinical samples because of shortcomings in collection and transport procedures as well as lack of isolation and susceptibility testing of anaerobes in many clinical microbiology laboratories. Correlation of clinical failures with known antibacterial resistance of anaerobic bacteria is seldom possible. Changes in resistance over time, and the discovery and characterization of resistance determinants in anaerobic bacteria, has increased recognition of problems in empirical treatment and has even resulted in changes in treatment guidelines. This review discusses the role of anaerobic bacteria in the normal flora of humans, their involvement in different mixed infections, developments in antibacterial resistance of the most frequent anaerobic pathogens and possible new treatment options. Anaerobic bacteria are important pathogens in many different types of infections and may be involved in a special way in certain other processes as well, such as bacterial overgrowth syndrome. The indigenous flora of the body is the principal reservoir of these organisms, but some clostridial infections may have an exogenous source. The spectrum of severity of anaerobic infections varies from mild to severe and lifethreatening. Although there are currently many
Retrospective analysis of two hundred and twelve cases of bacteremia due to anaerobic microorganisms
European Journal of Clinical Microbiology, 1985
Cases of bacteremia caused by anaerobic microorganisms and occurring during a four year period in a non-selected patient group in a Spanish general hospital were analysed retrospectively. Microbiological data was collected on 212 patients and clinical data on 103 patients. Cases of anaerobic bacteremia represented 8.6 % of the total number of cases of bacteremia. Of the 232 anaerobic microorganism causing bacteremia, gram-negative bacilli were responsible in 113 cases (48.7 %), gram-positive bacilli in 92 cases (39.6 %), grampositive cocci in 25 cases (10.7 %), and Veillonella spp. in two cases (0.8 %). The most important clinical features were fever (64 %), anemia (56 %), septic shock (22 %) and metastatic abscesses (21%). Patients with anaerobic bacteremia were hospitahzed for an average of 51.7 days. The overall mortality was 32 % and factors associated with poor prognosis were severe underlying disease, nosocomial acquisition, presence of shock, presence of metastatic loci of infection, and absence of adequate surgical drainage. The mortality rate of patients who received adequate antimicrobial therapy was 30 % and that of patients who received inadequate treatment or none was 29 %. It is concluded that anaerobic bacteremia has a significant rate of morbidity and mortality and that undedying disease and surgical debridement and/or drainage have greater prognostic significance than the use of antimierobial agents.