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The recent literature on clostridial infections of animals and infections due to gram-negative anaerobic rods is reviewed. It is stressed that quite recently the literature is concerned with animal models for the evaluation and study of the chemotherapy, immunity mechanisms and pathogenesis of Fusobacterium and Bacteroides infections in animals came into being.
Thirty patients with gas-producing infections were treated with surgery, antibiotics and hyperbaric oxygen during 1964-1977. Fourteen patients were infected with C. perfringens or C. septicum, 8 patients with B. fragilis or B. melaninogenicus, in 7 patients only aerobic bacteria were found, and in one patient no bacteria could be demonstrated. Thirteen patients had infections due to wounds, lacerations and/or compound fractures. Nine patients had gas-producing infection after surgery. Eight patients had abscesses and gas-producing infection. Of the 14 patients with clostridial infections, 2 patients died, and 6 underwent amputation. Four of the 8 patients with Bacteroides infection died, no amputation having been performed. Of the 7 patients in whom only aerobic bacteria were demonstrated, 3 patients died.
A new procedure for detecting and counting enteroviruses based on the VIRADEN method applied to 10 liters of seawater was examined. It improved the efficiency of detection by taking into account both the number of positive isolations and numbers found with traditional methods. It was then used to quantify viruses in bathing waters. A number of bacterial indicators and bacteriophages were also tested. Cultivable enteroviruses were detected in 55% of the samples, most of which complied with bacteriological criteria. In contrast, viral genomes were only detected in 20% of the samples by reverse transcription-PCR. Somatic coliphages outnumbered all other indicators. F-specific RNA phages were detected in only 15% of the samples, whereas phages infecting Bacteroides thetaiotaomicron were detected in 70% of samples. A numerical relationship between the numbers of enteroviruses and the numbers of enterococci and somatic coliphages was observed. In situ inactivation experiments showed that viruses persisted significantly longer than the bacterial indicators. Only somatic coliphages and bacteriophages infecting Bacteroides persisted longer than the viruses. These results explain the numbers of enteroviruses and indicators in bathing waters attending the numbers usually found in sewage in the area. Somatic coliphages show a very good potential to predict the risk of viruses being present in bathing waters.
The ability of Bacteroides fragilis and Escherichia coli to produce synergistic mortality when mixed into intraperitoneal (IP) fibrin clots was tested in rats. The addition of B fragilis (2 X 10(9) colony-forming units/clot) to E coli (2 X 10(8) colony-forming units/clot) in the clot significantly enhanced both early and late mortality rates when compared to either E coli or B fragilis alone. Multiple washings of B fragilis prior to mixing with E coli in the clot delayed the enhancement of lethality from 24 to 48 hours. By seven days, washed B fragilis was as synergistic with E coli as unwashed B fragilis plus E coli. Furthermore, unwashed killed B fragilis was as synergistic when mixed with E coli in the fibrin clot as unwashed living B fragilis. However, washed dead B fragilis plus E coli produced no greater mortality than E coli alone. The lethality of an IP clot containing E coli was significantly increased when B fragilis was mixed with it in the same clot, injected free IP, and or implanted into a separate IP clot. Intraperitoneal E coli-fibrin clot lethality was not increased by subcutaneous B fragilis and was only slightly enhanced by intravenous B fragilis inoculation. The strain of B fragilis used in these studies did not produce fibrinolysins at any concentration. The data support the idea that synergistic mortality between E coli and B fragilis in this model is caused by a heat-stable surface factor produced by B fragilis, which acts to increase the lethal effects of E coli.
The objectives of this study are to generate knowledge about methods to track the sources of faecal pollution in surface waters, with the aim of having one or a few easy procedures applicable to different geographic areas in Europe. For this, a first field study using already proposed methods (genotypes of F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, phenotypes of faecal coliforms and enterococci, and sterols) has been done in five areas representing a wide array of conditions in Europe. The present faecal indicators (faecal coliforms, enterococci, sulfite reducing clostridia and somatic coliphages) have also been included in this first field study. At the same time some emerging methods have been settled or adapted to water samples and assayed in a limited number of samples. The results of this first field study indicate that no single parameter alone is able to discriminate the sources, human or non-human, of faecal pollution, but that a 'basket' of 4 or 5 parameters, which includes one of the present faecal indicators, will do so. In addition, numerical analysis of the data shows that this 'basket' will allow the successful building of predictive models. Both the statistical analyses and the studied predictive models indicate that genotype II of F-specific RNA bacteriophages, the coprostanol and the ratio coprostanol: coprostanol+epicoprostanol are, out of the studied parameters, those with a greater discriminating power. Either because unsuccessful adaptation of the methods to water samples or because the preliminary assays in water samples indicated low discriminating capability, only three (sorbitol-fermenting bifidobacteria, some species of bifidobacteria detected by PCR with specific primers and phages infecting Bacteroides tethaiotaomicron) of the newly assayed methods have been considered for a second field study, which is currently underway. Expectations are that these new tools will minimize the number of parameters in the 'basket', or at least minimize the difficulty in assaying them.
Cefoxitin, a beta-lactamase-resistant cephalosporin, was found to be more effective than cephalothin against an experimental mixed infection containing Bacteroides fragilis and Fusobacterium necrophorum.
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PURPOSE: To detect the distribution of P. gingivalis and B. forsythus in the infected root canals from Chinese chronic apical periodontitis, and investigate the colonization relationship between them in the root canals. METHODS: P. gingivalis and B. forsythus in the root canal samples of thirty-eight teeth with chronic apical periodontitis from 31 subjects who were referred to the Sichuan University West China Dental Hospital for dental treatment were studied with a 16S rDNA-directed polymerase chain reaction method. Fisher's exact tset was used to detect B. forsythus in the infected root canals with or without P. gingivalis. OR was used to analyse the relationship between them. RESULTS: The prevalence in 38 teeth was 39.5% for P. gingivalis, and 26.3% for B. forsythus, respectively. Significant positive relationship was shown in the combination of P. gingivalis and B. forsythus (OR=12, P<0.05). CONCLUSION: Both P. gingivalis and B. forsythus colonized in the root canals with chronic apical periodontitis and there was a positive relationship between P. gingivalis and B. forsythus in the infected root canal flora.
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We report the isolation of metronidazole-resistant Bacteroides fragilis from a post-operative wound abscess in a 72-year-old woman who had not been treated with metronidazole during the preceding 9 months. The case illustrates the need for caution when identifying anaerobes on the basis of metronidazole sensitivity.
Anaerobic bacterial organisms are a frequent cause of female genital tract infections. There has been a lack of appreciation of the significant role anaerobes play in obstetric and gynecologic infections. Utilization of newer appropriate anaerobic culture techniques has shown the importance of these organisms as pathogens in serious infections of the genital tract. Many species of anaerobic bacteria appear to be part of the normal microflora of the lower genital tract in female subjects. Similar organisms are frequently isolated from pelvic infections. Bacteroides, anaerobic cocci, and Clostridia are the most commonly isolated anaerobes associated with clinical infections. The clinician must recognize the presence of anaerobic infections, utilize proper anaerobic culture methods, and institute appropriate antibiotic and/or surgical therapy.
Out of 200 infections due to Bacteroides fragilis occurring over a period of three years 133 were related to the intestinal tract, 55 to the genitourinary tract, and the remainder were in bedsores and ulcers; 56% occurred in patients undergoing major intestinal surgery.B. fragilis was isolated in pure culture from 56% of the infections. In mixed culture it was most commonly associated with Klebsiella and Enterobacter species. Other anaerobic bacteria were isolated in 9% of the mixed cultures.Altogether 131 (65.5%) of the patients recovered without antibiotic therapy or further surgery, but 59 (29.5%) developed complications and 10 (5%) died. The commonest complication was abscess formation, and the incidence was highest with infections associated with malignancy (44%) and lowest with obstetric infections (5%). The mortality was 5% overall but in the presence of bacteraemia it rose to 33%.Only 43 patients received appropriate chemotherapy. Clindamycin was the most effective antibiotic, having a recovery rate of 78%, but this rate was little better than in untreated patients (65%). The role of prophylactic antibiotic therapy in preventing bacteroides infection remains to be studied.The incidence of the isolation of bacteroides from wound infections after major intestinal surgery rose from 13% in 1970 to 81% in 1973. This increase was due to both the accurate collection and care of specimens while in transit to the laboratory and the use of selective media for the isolation of bacteroides in laboratory culture. The importance of these precautions is emphasized.
Six cases of infections in children with Bacteroides corrodens are reported. In five the infection was mixed but in one fatal extradural and subdural empyema the organism was found in pure culture. The bacteriological findings are presented. It is suggested that Bacteroides corrodens may assume a pathogenic role and the rarity of its isolation may be due to delay in the appearance of the colony.
Today, 10 black-pigmented Bacteroides (BPB) species are recognized. The majority of these species can be isolated from the oral cavity. BPB species are involved in anaerobic infections of oral and non-oral sites. In the oral cavity, BPB species are associated with gingivitis, periodontitis, endodontal infections and odontogenic abscesses. Cultural studies suggest a specific role of the various BPB species in the different types of infection. Bacteroides gingivalis is closely correlated with destructive periodontitis in adults as well as in juveniles. Bacteroides intermedius seems to be less specific since it is found in gingivitis, periodontitis, endodontal infections and odontogenic abscesses. The recently described Bacteroides endodontalis is closely associated with endodontal infections and odontogenic abscesses of endodontal origin. There are indications that these periodontopathic BPB species are only present in the oral cavity of subjects suffering from periodontal breakdown, being absent on the mucosal surfaces of subjects without periodontal breakdown. BPB species associated with healthy oral conditions are Bacteroides melaninogenicus, Bacteroides denticola and Bacteroides loescheii. There are indications that these BPB species are part of the normal indigenous oral microflora. Many studies in the past have documented the pathogenic potential and virulence of BPB species. This virulence can be explained by the large numbers of virulence factors demonstrated in this group of micro-organisms. Among others, the proteolytic activity seems to be one of the most important features. Several artificial substrates as well as numerous biological proteins are degraded. These include anti-inflammatory proteins such as alpha-2-macroglobulin, alpha-1-antitrypsin, C3 and C5 complement factors and immunoglobulins. B. gingivalis is by far the most proteolytic species, followed by B. endodontalis. Like other bacteria, the lipopolysaccharide of B. gingivalis has shown to be active in bone resorption in vitro and is capable in stimulating interleukin-1 production in human peripheral monocytes. Based on the well documented association with periodontal disease and the possession of relevant virulence factors, BPB species must be considered as important micro-organisms in the etiology of oral infections. B. gingivalis seems to be the most pathogenic and virulent species.
Two Santa Gertrudis cattle from a herd of 105 aborted within a 24-hour period. Bacteroides fragilis was isolated from tissues of each aborted fetus. Histopathologic lesions included placentitis and bronchopneumonia in which gram-negative, rod-shaped organisms were visible. The diagnostic workup failed to reveal other causes of abortion. Anaerobes are rarely implicated in bovine abortions, and no other report was found that described abortion in cattle due to B. fragilis.
The sinus mucosa of 16 rabbits was experimentally infected with Bacteroides fragilis. This paper describes and discusses large inclusion bodies, which were found in abundance by light and electron microscopy inside ciliated cells of the sinus epithelium in 3 of the studied animals. The spindle-shaped inclusions were located in the apical portion of the cytoplasm. They were bound by a trilaminar membrane with several coils to the interior as well as to the exterior. The interior of an inclusion body consisted to a large extent of electron-lucent, floccular substance, but fibrogranular aggregates and rod-shaped crystals with a line periodicity center-to-center of about 15 nm were also conspicuous. These peculiar formations may be constituted by abnormally stored material from defective synthesis of cilia.
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Our clinical experience with new antibiotics giving special consideration to the individual cephalosporin groups is discussed. Although newer cephalosporins from cefamandol and cefoxitin to cefotiam and cefoperazon already showed increased effectiveness (for example, cefoxitin in bacteroides infection) in comparison to older ones, the real breakthrough regarding enterobacteriaceae was only made with cephalosporins of the cefotaxime group. This group's main indication is non-specific initial therapy of severe nosocomial infections, especially processes in which the presence of resistant enterobacteriaceae must be assumed. Because of its broad spectrum of action, cefotaxime can to a large extent replace the combinations with aminoglycosides which were used previously. When required, cefotaxime proves to be a good partner for combinations with pseudomonas antibiotics.