Bacteroides Melaninogenicus Group Research Articles

Variant of Lemierre's Syndrome Secondary to Trauma

Classic Lemierre's syndrome is a septic internal jugular venous (IJV) thrombophlebitis secondary to oropharyngeal anaerobic infection in adolescent and young adult. Though upper respiratory tract infection is the most common antecedent, it has also been described following skin, soft tissues, genitourinary and gastrointestinal infections. Fusobacteria necrophorum is the commonest pathogen isolated from blood and tissue cultures but other bacteria like Eikenella correndens, Bacteroides melaninogenicus and Non Group A Streptococcal species have also been reported. The overall incidence of Lemierre's and Lemierre's like syndromes has declined since the first case report in 1936. There is however, a resurgence of cases in recent years due to more judicious use of antibiotics for treatment of upper respiratory tract infection among medical practitioners. The main stay of treatment of complete Lemierre's syndrome is prolonged antibiotic coverage and surgical drainage of nonresolving abscesses. Currently, there is no consensus opinion on the use of anticoagulation in patient with complete Lemierre's syndrome complicated by septic internal jugular thrombosis and embolism. High index of suspicion is required for early diagnosis of Lemierre's and Lemierre's like syndromes. Early and effective antibiotics therapy may prevent the development full spectrum of the syndrome and its associated complication.

Diagnosis and Management of Anaerobic Infections of the Head and Neck

Anaerobic bacteria are important pathogens in head and neck infections such as chronic otitis media, chronic sinusitis, chronic mastoiditis, head and neck abscesses, cervical adenitis, parotitis, and postoperative infection. Bacteroides sp (Bacteroides melaninogenicus group, Bacteroides oralis, and Bacteroides fragilis group), Peptostreptococcus sp, and Fusobacterium sp predominate. The observed recent increase in the number of beta-lactamase-producing strains of Bacteroides sp isolated in head and neck infections has been associated with increased failure rates of the penicillins in the management of these infections. The pathogenicity of these organisms is expressed through their ability not only to survive penicillin therapy but also to shield penicillin-susceptible pathogens from the drug. Because of these direct and indirect virulent characteristics of anaerobic bacteria, appropriate antimicrobial therapy must be directed against all pathogens in mixed infections.

Aerobic and anaerobic microbiology of periapical abscess

Aspirates of pus from periapical abscesses in 39 patients were studied for aerobic and anaerobic bacteria. Bacterial growth was present in 32 specimens. A total of 78 bacterial isolates (55 anaerobic and 23 aerobic and facultative) were recovered, accounting for 2.4 isolates per specimen (1.7 anaerobic and 0.7 aerobic and facultatives). Anaerobic bacteria only were present in 16 (50%) patients, aerobic and facultatives in 2 (6%), and mixed aerobic and anaerobic flora in 14 (44%). The predominant isolates were Bacteroides spp. (23 isolates, including 13 Bacteroides melaninogenicus group), Streptococcus spp. (20), anaerobic cocci (18), and Fusobacterium spp. (9). Beta-lactamase-producing organisms were recovered from 7 of the 21 (33%) specimens that were tested. This study highlights the polymicrobial nature and importance of anaerobic bacteria in periapical abscess.

Aerobic and anaerobic microbiology of peritonsillar abscess

Thirty-four aspirates of pus from peritonsillar abscesses that were studied for aerobic and anaerobic bacteria showed bacterial growth. A total 107 bacterial isolates (58 anaerobic and 49 aerobic and facultative) were recovered, accounting for 3.1 isolates per specimen (1.7 anaerobic and 1.4 aerobic and facultatives). Anaerobic bacteria only were present in 6 (18%) patients, aerobic and facultatives in 2 (6%), and mixed aerobic and anaerobic flora in 26 (76%). Single bacterial isolates were recovered in 4 infections, 2 of which were Streptococcus pyogenes and 2 were anaerobic bacteria. The predominant bacterial isolates were Staphylococcus aureus (6 isolates), Bacteroides sp (21 isolates, including 15 Bacteroides melaninogenicus group), and Peptostreptococcus sp (16) and S. pyogenes (10). beta-Lactamase-producing organisms were recovered from 13 (52%) of 25 specimens tested. This retrospective study highlights the polymicrobial nature and importance of anaerobic bacteria in peritonsillar abscess.

Aerobic and anaerobic microbiology of acute suppurative parotitis

Aspirates of pus from acute suppurative parotitis were studied for aerobic and anaerobic bacteria. Bacterial growth was present in 23 specimens. A total of 36 bacterial isolates (20 anaerobic and 16 aerobic and facultative) were recovered, accounting for 1.6 isolates per specimen (0.9 anaerobic and 0.7 aerobic and facultative). Anaerobic bacteria only were present in 10 (43%) patients, aerobic and facultatives in 10 (43%), and mixed aerobic and anaerobic flora in 3 (13%). Single bacterial isolates were recovered in 9 infections, 6 of which were Staphylococcus aureus and 3 were anaerobic bacteria. The predominant bacterial isolates were S. aureus (8 isolates), Bacteroides sp. (6 isolates, including 4 Bacteroides melaninogenicus group), and Peptostreptococcus sp. (5). beta-Lactamase-producing organisms were recovered from 11 (73%) of the 15 specimens tested. This study highlights the polymicrobial nature and importance of anaerobic bacteria in acute suppurative parotitis.

Microbiological studies of decubitus ulcers in children

Specimens from 58 children with decubitus ulcers were cultured for aerobic and anaerobic bacteria. Aerobic bacteria only were present in 29 (50%) ulcers, anaerobic bacteria only were recovered in 5 (9%), and mixed aerobic and anaerobic flora were present in 24 (41%). A total of 132 isolates (79 aerobes, 53 anaerobes) were recovered, an average of 2.3 isolates per specimen (1.4 aerobes, 0.9 anaerobes). The smallest number of isolates was recovered in ulcers of the skull (1.7 per site), and the highest number of isolates was found in ulcers of the buttocks (4.1 per site). The predominant isolates were Staphylococcus aureus (25 isolates), Peptostreptococcus species (22), Bacteroides fragilis group (10), and Pseudomonas aeruginosa (7). Forty-two of the organisms isolated from 38 (66%) patients produced the enzyme β-lactamase. Most of the S aureus isolates were recovered from ulcers of the hand and the leg. Organisms that resided in the mucous membranes close to the ulcer predominated in the wounds next to these areas. Enteric gram-negative rods, group D streptococci, and B fragilis group predominated in ulcers of the buttocks. Group A streptococci, Haemophilus influenzae, Bacteroides melanino-genicus group, and Fusobacterium species were most frequently recovered in ulcers of the skull. The polymicrobial etiology of decubitus ulcers in hospitalized children and the association of bacterial flora with the anatomical site of the ulcer are demonstrated.

Microbiology of Empyema in Children and Adolescents

The microbiology of empyema was studied in 72 children and adolescents whose specimens yielded bacterial growth after inoculation for aerobic and anaerobic bacteria. A total of 93 organisms, 60 aerobic or facultative and 33 anaerobic, were isolated. Aerobic bacteria was isolated in 48 (67%) patients, anaerobic bacteria in 17 (24%), and mixed aerobic and anaerobic bacteria in 7 (10%). The predominant aerobic or facultative bacteria were Haemophilus influenzae (15 isolates), Streptococcus pneumoniae (13), and Staphylococcus aureus (10). The predominant anaerobes were Bacteroides sp (15 isolates, including 7 Bacteroides fragilis group and 5 Bacteroides melaninogenicus group), anaerobic cocci (9), and Fusobacterium sp (6). beta-lactamase activity was detected in at least one isolate in 20 (37%) of the 54 tested patients. These included all 8 tested S aureus and 7 B fragilis group, 3 of 10 H influenzae, 2 of 4 B melaninogenicus group, and 1 of 2 Klebsiella pneumoniae. Most cases of S pneumoniae and H influenzae were associated with pneumonia. The recovery of anaerobic bacteria was mostly associated with the concomitant diagnosis of aspiration pneumonia, lung abscess, subdiaphragmatic abscess, and abscesses of dental or oropharyngeal origin. The data highlight the importance of anaerobic bacteria in selected cases of empyema in children and adolescents.

Microbiology of Wound Infection after Head and Neck Cancer Surgery

Specimens of pus were obtained from 24 patients who developed postoperative wound infection after head and neck cancer surgery. Aerobic bacteria only were isolated in two instances (8%), anaerobic bacteria only in one (4%), and mixed aerobic and anaerobic bacteria in 21 (88%). A total of 146 isolates were recovered (66 aerobic and 80 anaerobic), an average of six isolates per specimen (2.7 aerobic and 3.3 anaerobic). The most frequently recovered isolates were Peptostreptococcus sp, Staphylococcus aureus, Bacteroides sp, Fusobacterium, and enteric gram-negative rods. Twenty-two isolates recovered from 17 wounds (71%) produced beta-lactamase. These included all five isolates of S aureus and nine of 17 (53%) of the Bacteroides melaninogenicus group. The polymicrobial aerobic/anaerobic nature of postoperative wound infections after head and neck cancer surgery and the presence of beta-lactamase-producing bacteria may have important implications for the management of these infections.

Quantitative Bacterial Cultures and Beta-Lactamase Activity in Chronic Suppurative Otitis Media

Aspiration of the exudate through open perforation was performed in 54 children with chronic suppurative otitis media. Eighty aerobic and 81 anaerobic isolates were recovered. Aerobic bacteria only were involved in 20 patients (37%), and anaerobic organisms only in seven (13%). Mixed aerobic and anaerobic isolates were recovered from 27 patients (50%). The most common bacteria isolated were anaerobic gram-positive cocci, Bacteroides melaninogenicus group, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. There were 45 beta-lactamase-producing bacteria (BLPB), 30 aerobes, and 15 anaerobes recovered from 38 patients (70%). beta-Lactamase activity was detected in 30 of the 38 ear aspirates (79%) that contained BLPB. All but one of these organisms were in excess of 10(4) colony-forming units/mL. The detection of beta-lactamase activity in the ear aspirates provides evidence of the role of BLPB in the failure of penicillin therapy to eradicate chronic ear infection.

Emergence and persistence of beta-lactamase-producing bacteria in the oropharynx following penicillin treatment.

The emergence and persistence of aerobic and anaerobic beta-lactamase-producing bacteria (BLPB) were investigated in 26 children treated with penicillin for otitis media or pharyngitis and in 28 nontreated control children. beta-Lactamase-producers were isolated in three (12%) of the treated children before therapy, in 12 (46%) seven to ten days after completion of therapy, in nine (35%) 40 to 45 days after therapy, and in seven (27%) 85 to 90 days after therapy. These organisms were present in three (11%) of the nontreated children, and the number of patients harboring BLPB stayed constant throughout the three-month follow-up. The predominant BLPB were Bacteroides species (Bacteroides melaninogenicus group, Bacteroides oralis, and Bacteroides oris-buccae), Staphylococcus aureus, Haemophilus influenzae, and Branhamella catarrhalis. The emergence and persistence of BLPB after penicillin therapy may have important implications for the antimicrobial management of infections of the upper respiratory tract.

Beta-lactamase-producing bacteria in head and neck infection.

We have summarized our experience in recovery of beta-lactamase-producing bacteria (BLPB) in head and neck infection (HNI). These HNI include conjunctivitis, serous and chronic otitis media, cholesteatoma, chronic mastoiditis, chronic sinusitis, adenoiditis, recurrent tonsillitis in children and adults, peritonsillar abscess, and retropharyngeal abscess. Beta-lactamase-producing bacteria were found in 262 (51%) of 513 patients with HNI; 72% had aerobic BLPB and 57% had anaerobic BLPB. The infections, where these organisms were most frequently recovered, were adenoiditis (85% of patients), tonsillitis in adults (82%) and children (74%), retropharyngeal abscess (71%), and chronic otitis media (57%). The predominant BLPB were Staphylococcus aureus (49% of patients with BLPB), the Bacteroides-melaninogenicus group (28%), the Bacteroides fragilis group (20%), Pseudomonas aeruginosa (13%), Hemophilus influenzae (5%), and Branhamella catarrhalis (3%). The high incidence of recovery of BLPB in head and neck infections may have important implications on the antimicrobial management of these infections.

Rapid method for detection of lactose fermenting oral microorganisms.

Abstract A rapid inexpensive assay for lactose fermentation which can be performed on individual colonies in situ and which does not negate subcultivation is described. The assay is based on the ability of bacterial β‐galactosidase to hydrolyze 4‐methylumbelliferyl‐β‐D‐galactoside (MUG) and form 4‐methylumbelliferone, a compound which is brightly fluorescent under long‐wave ultraviolet light. 1% MUG in dimethyl sulfoxide was stable at room temperature for at least 21 days. Maximal MUG fluorescence reactions required viable bacterial cultures. The MUG test represents a convenient means to distinguish the lactose‐negative Bacteroides intermedius and Haemophilus actinomycetemcomitans, both suspected major periodontopathogens, from the lactose‐positive Bacteroides melaninogenicus group and Haemophilus aphrophilus, organisms of little or no periodontopathic significance. The MUG test may also greatly help in distinguishing lactose from nonlactose fermenting organisms of nonoral origin.

Microbiology of retropharyngeal abscesses in children.

Aspiration of retropharyngeal abscesses was performed in 14 children. Cultures were taken from aspirates for aerobic and anaerobic bacteria, and all yielded bacterial growth. Anaerobes were isolated in all patients; they were the only organisms isolated in two patients (14%) and were mixed with aerobes in 12 patients (86%). There were 78 anaerobic isolates (5.6 per specimen). The predominant anaerobes were Bacteroides species, Peptostreptococcus species, and Fusobacterium species. There were 26 aerobic isolates (1.9 per specimen). The predominant aerobes were alpha- and gamma-hemolytic streptococci, Staphylococcus aureus, Haemophilus species, and group A beta-hemolytic streptococci. beta-Lactamase production was noted in 16 isolates recovered from ten patients (71%). These included all isolates of S aureus, six of 18 Bacteroides melaninogenicus group (33%), and two of three Bacteroides oralis (67%). These findings demonstrate the major role of anaerobic organisms in retropharyngeal abscesses and the presence of beta-lactamase-producing organisms in two thirds of the patients.

Anaerobic osteomyelitis in children

Twenty-six pediatric patients with osteomyelitis caused by anaerobic bacteria are presented. The etiologic factors were chronic mastoiditis (7 patients), decubitus ulcers (5), chronic sinusitis (4), periodontal abscesses (3), bites (3), paronychia (2), trauma (1) and scalp infection after fetal monitoring (1). Seventy-four organisms (2.8 isolates/specimen), including 63 anaerobes (2.4/specimen), and 11 facultative and aerobic bacteria (0.4/specimen) were recovered. The predominant organisms were anaerobic cocci (29 isolates), Bacteroides sp. (21), Fusobacterium sp. (8), Streptococcus sp. (5) and Clostridium sp. (4). The organisms generally reflected the microbial flora of the mucous surface adjacent to the infected site. Ten beta-lactamase-producing organisms were recovered from 7 (27%) patients. These included all isolates of the Bacteroides fragilis (4) and of Staphylococcus aureus (3), 2 of the 12 Bacteroides melaninogenicus group and 1 of 3 Bacteroides oralis. The clinical, diagnostic and therapeutic aspects of anaerobic osteomyelitis in children are discussed.

A note on ultra-violet red fluorescence of anaerobic bacteria in vitro.

Anaerobes other than the Bacteroides melaninogenicus group isolated from clinical material produce an ultra-violet red fluorescence when grown under certain conditions in vitro. These organisms include other members of the genus Bacteroides as well as strains of some species of Clostridium, Bifidobacterium and Actinomyces. The major fluorescent pigment was identified as protoporphyrin IX. Factors necessary for the production of fluorescence are the presence of blood or haem and a fermentable carbohydrate during growth on a solid medium. Fluorescence intensity was related to the concentration of blood and fermentable carbohydrate present but was independent of inoculum size. Certain commercially available blood agar bases designed specifically for the isolation of fastidious anaerobes from clinical material which contain added carbohydrate were shown to induce fluorescence in certain organisms. This may lead to the misidentification of some anaerobes as B. melaninogenicus.

Prevalence of β-Lactamase–Producing Bacteria in Chronic Suppurative Otitis Media

Aspiration of the exudate through open perforation was performed in 48 children with chronic suppurative otitis media. Eighty-two aerobic and 93 anaerobic isolates were recovered. Aerobic bacteria only were involved in 22 patients (46%), and anaerobic organisms only were involved in five patients (10%). Mixed aerobic and anaerobic isolates were recovered from 21 patients (44%). The most common bacteria isolated were Bacteroides melaninogenicus group (40% of patients), Pseudomonas aeruginosa (29%), Klebsiella pneumoniae (10%), and Staphylococcus aureus (10%). There were 50 beta-lactamase-producing organisms (26 anaerobes and 24 aerobes) recovered from 33 patients (69%). Forty-four of these bacteria were isolated from the 37 patients recently treated with a penicillin. These included all ten isolates of S aureus and Bacteroides fragilis group, 11 of 19 of B melaninogenicus group, five of the 14 P aeruginosa, three of ten K pneumoniae, three of six of Bacteroides oralis, four of six of Haemophilus influenzae, two of three of Staphylococcus epidermidis, and two of four of Branhamella catarrhalis. The beta-lactamase-producing organisms have a possible role in the failure of penicillin therapy.

Importance of Encapsulated Anaerobic Bacteria in Mixed Infection

Aspirates obtained from infections adjacent to mucous membrane surfaces generally contain a complex bacterial population consisting of several species. 1 The relative importance of the various bacteria isolated in clinical specimens is not clear. Polymicrobic infections are more pathogenic for experimental animals than those involving single organisms. 2 Studies of the successful transmission of infections in animals inoculated with defined mixtures of aerobic and anaerobic organisms, including the Bacteroides melaninogenicus group, have been reported by many investigators. 3,4 Except for some strains of B melaninogenicus , 5 most organisms in these mixtures were not pathogenic alone, 3 although these were required for the pathogenicity of the mixture. Several recent studies demonstrated the pathogenicity of encapsulated anaerobes and their ability to induce abscesses alone. Onderdonk et al 6,7 correlated the virulence of Bacteroides fragilis strains with the presence of capsule, and Simon et al 8 described decreased phagocytosis of the encapsulated B

Beta-Lactamase-producing bacteria recovered after clinical failures with various penicillin therapy.

The presence of beta-lactamase-producing bacteria in clinical specimens was investigated in 185 children with orofacial or respiratory tract infections. All of these patients failed to respond to antimicrobial therapy, including penicillins, that was administered to 148 (80%) of them. beta-Lactamase-producing aerobic and anaerobic bacteria were detected in 75 (40.5%) of the 185 children. The beta-lactamase-producing strains included all 11 strains of the Bacteroides fragilis group, 30 (45.4%) of the 66 strains of Bacteroides melaninogenicus group, five (41.7%) of the 12 strains of Bacteroides oralis, and 41 (97.6%) of 42 strains of Staphylococcus aureus. All beta-lactamase-producing Bacteroides strains were resistant to penicillin as compared with the non-beta-lactamase-producing strains. Clinical cure was achieved after surgical drainage and a change in antimicrobial therapy in most of the patients. In treatment of orofacial and respiratory tract infections, the clinician should consider the presence of beta-lactamase-producing Bacteroides sp and S aureus as a possible cause of clinical failure with various penicillin therapies.

In vivo protection of penicillin-susceptible Bacteroides melaninogenicus from penicillin by facultative bacteria which produce beta-lactamase.

We investigated the possibility that beta-lactamase producing strains of Klebsiella pneumoniae and Staphylococcus aureus can protect organisms of the Bacteroides melaninogenicus group from penicillin. A mixed infection was induced in mice in the form of a subcutaneous abscess involving a penicillin-susceptible encapsulated B. melaninogenicus, and a beta-lactamase producing strain of either K. pneumoniae or S. aureus. The infected animals were treated for 7 days with single or combined antimicrobial therapy. The single agents used were penicillin, clavulanic acid, metronidazole, and gentamicin. The antimicrobial combinations were penicillin and clavulanic acid, penicillin and gentamicin, and metronidazole and gentamicin. Administration of a single agent was effective in treating abscesses caused by susceptible organisms. The only effective therapy for mixed infections was by combination therapy of penicillin and clavulanic acid or metronidazole and gentamicin. This study supports the hypothesis that beta-lactamase producing facultative bacteria may shield their anaerobic counterparts from penicillin therapy, thereby contributing to the persistence of the infection.

Bacteroides melaninogenicus. Its recovery from tonsils of children with acute tonsillitis.

The presence of encapsulated and abscess-forming organisms belonging to the Bacteroides melaninogenicus group was investigated in 25 children with acute tonsillitis, and in 23 children without tonsillar inflammation (control). Encapsulated organisms of the B melaninogenicus group were found in 23 of 25 children with acute tonsillitis as compared with five of 23 controls. Subcutaneous inoculation into mice of the Bacteroides strains isolated from patients with tonsillitis produced abscesses in 17 of 25 instances, as compared with nine of the 23 of the controls. Group A streptococci were recovered from the tonsils of five children with tonsillitis and from four of the control group. These findings suggest a possible pathogenic role for the B melaninogenicus group in acute tonsillar infection in children.