Biomedical subjects

I Brook

Publications and source records attributed to I Brook.

At least 253 records · Page 14Linked to original sources

PubMed1989

Anaerobic bacterial bacteremia: 12-year experience in two military hospitals.

Clinical and microbiologic data of 296 patients with anaerobic bacteremia were reviewed. Anaerobes were isolated with aerobic or facultative bacteremia in 23 instances. The Bacteroides fragilis group accounted for 148 (70%) of 212 isolates of Bacteroides species. B. fragilis accounted for 78% and B. thetaiotaomicron for 14%. Among other species, there were 20 (6%) Fusobacterium organisms, 63 (18%) Clostridium isolates, and 53 (15%) anaerobic cocci. Seventy-five patients died: 40 had B. fragilis group isolates - B. fragilis, 28, and B. thetaiotaomicron, 8 - and 21 had Clostridium organisms isolated. The primary portals of entry were the gastrointestinal tract (42%), decubiti and gangrene (10%), the female genital tract (8%), and the oropharynx (7%). The gastrointestinal tract, decubiti, and gangrene were the predominant sources for B. fragilis and Clostridium organisms, the female genital tract and oropharynx for anaerobic cocci and Fusobacterium species, and the oropharynx for pigmented Bacteroides. Foreign body was associated with Propionibacterium acnes and Clostridium species. Factors predisposing to bacteremia were abscesses, 53; malignancy, 51; surgery, 30; and intestinal obstruction or perforation, 27.

Adolescent↗

PubMed1989

Treatment of patients with acute recurrent tonsillitis due to group A beta-haemolytic streptococci: a prospective randomized study comparing penicillin and amoxycillin/clavulanate potassium.

The failure of penicillin to eradicate Group A beta-haemolytic streptococcal tonsillitis may be caused by beta-lactamase producing bacteria in the tonsillar tissue. A prospective randomized clinical study comparing the efficacy of penicillin-V potassium with amoxycillin plus clavulanate potassium (Augmentin) in the treatment of acute episodes of recurrent streptococcal tonsillitis was conducted. Twenty children were included in each group. Surface tonsillar cultures were obtained before therapy, ten days after termination of therapy, and then once every two months for up to one year. beta-Lactamase producing aerobic and anaerobic bacteria were present in 34 of the 40 (85%) tonsillar cultures prior to treatment. Group A beta-haemolytic streptococci were eradicated in 14 of 20 (70%) patients treated with penicillin and in all those treated with amoxycillin/clavulanate potassium (P less than 0.001). In a one-year follow-up, 11 of the 19 patients treated with penicillin and two of the 18 treated with amoxycillin/clavulanate potassium had recurrent streptococcal tonsillitis (P less than 0.005). This study demonstrates the efficacy of amoxycillin/clavulanate potassium in the therapy of acute episodes of recurrent tonsillitis and prevention of recurrent infection.

Adolescent↗

PubMed1989

The concept of indirect pathogenicity by beta-lactamase production, especially in ear, nose and throat infection.

A recent increase in numbers of beta-lactamase-producing strains of aerobic and anaerobic Gram-negative bacteria in upper respiratory tract infections has been associated with increased failure rates of penicillins in eradication of these infections. These organisms include Staphylococcus aureus, Haemophilus influenzae, Branhamella catarrhalis and Bacteroides spp. These infections include chronic otitis media, chronic sinusitis and mastoiditis, and chronic recurrent tonsillitis. The indirect pathogenicity of these organisms is apparent through their ability not only to survive penicillin therapy but also to protect penicillin-susceptible pathogens from these drugs. The direct and indirect virulence characteristics of these bacteria require the administration of appropriate antimicrobial therapy directed against all pathogens in mixed infections.

Bacteria↗

PubMed1989

Aerobic and anaerobic microbiology of intra-abdominal abscesses in children.

In this study of the aerobic and anaerobic microbiology of 23 intra-abdominal abscesses, aerobic bacteria alone were present in one specimen, anaerobic bacteria only in four, and mixed aerobic and anaerobic flora in 18. Ninety bacterial isolates (3.9 isolates per specimen), 63 anaerobic (2.7 per specimen), and 27 aerobic and facultative (1.2 per specimen) isolates were recovered. The predominant organisms were Bacteroides fragilis group (23 isolates), Peptostreptococcus sp (20 isolates), and Escherichia coli (15 isolates). This study demonstrates the polymicrobial aerobic-anaerobic etiology of intra-abdominal abscesses in children.

Abdomen↗

PubMed1989

Trehalose dimycolate enhances resistance to infection in neutropenic animals.

Bacterial infections are lethal complications of neutropenia, and antibiotics alone are inadequate therapy for these infections. Irradiated mice become severely neutropenic and remain susceptible to infection for 2 to 3 weeks, depending on the dose and quality of radiation. Some bacterial cell wall derivatives stimulate nonspecific host defense mechanisms against a variety of microbes which might cause postirradiation infection. In this study we determined if the cell wall glycolipid trehalose dimycolate (TDM), derived from Mycobacterium phlei, or a synthetic preparation of TDM was able to (i) enhance survival in mice when given before or after lethal doses of 60Co radiation and (ii) increase nonspecific resistance to postirradiation infection. Treatment with TDM oil-in-water emulsions and with synthetic TDM significantly enhanced survival before and after lethal doses of 60Co irradiation. This result correlated with the ability of TDM to reduce the translocation of intestinal bacteria and to stimulate hematopoiesis. With respect to nonspecific resistance to infection, TDM injected 1 h after sublethal irradiation increased resistance to a lethal Klebsiella pneumoniae challenge (10 50% lethal doses of K. pneumoniae in 30 days [LD50/30]) 4 or 14 days later. Increasing the dose of K. pneumoniae to 5,000 LD50/30 on day 4 overwhelmed the ability of TDM-treated mice to overcome infection. However, TDM treatment 1 h postirradiation combined with ceftriaxone antibiotic therapy (days 5 through 14) enhanced survival, even when the higher dose of bacteria (5,000 LD50/30) was used. These results indicate that in irradiated mice, TDM can be used to enhance survival and, as a potent stimulant of nonspecific resistance to infection in neutropenic mice, can act synergistically with antibiotic therapy to reduce sepsis and mortality.

Adjuvants, Immunologic↗

PubMed1989

Aerobic and anaerobic microbiology of biliary tract disease.

A retrospective analysis of the experiences of two military hospitals over 4 years in the recovery of organisms from biliary tract specimens was done. Bacterial growth was obtained in 123 bile specimens. Aerobic and facultative bacteria only were present in 59 specimens (48%), aerobic bacteria only were present in 4 specimens (3%), and mixed anaerobic and aerobic or facultative bacteria were present in 60 specimens (49%). Of 286 isolates recovered, 216 were aerobic or facultative (1.8 per specimen) and 70 were anaerobic (0.6 per specimen). The predominant bacteria were Escherichia coli (71 isolates), group D streptococci (42 isolates), Klebsiella sp. (29 isolates), Clostridium sp. (27 isolates), Bacteroides sp. (28 isolates), and Enterobacter sp. (16 isolates). Polymicrobial infections were present in 108 instances (88%). A higher recovery rate of anaerobes was present in patients with chronic infections than in those with acute infections and did not correlate with the presence of gallstones or use of antimicrobial prophylaxis.

Acute Disease↗

PubMed1989

Microbiology of postthoractomy sternal wound infection.

Specimens from 74 patients with postthoractomy sternal wound infection were studied for aerobic and anaerobic bacteria. Bacterial growth was obtained in specimens from 65 patients (88%). Aerobic or facultative bacteria only were recovered in 50 specimens (77%), anaerobic bacteria only in 6 (9%), and mixed aerobic, facultative, and anaerobic bacteria in 9 (14%). Eighty-seven isolates were recovered (1.3 per specimen): 68 aerobic or facultative (1.0 per specimen) and 19 anaerobic (0.3 per specimen). The predominant aerobes were Staphylococcus epidermidis (28 isolates), Staphylococcus aureus (21 isolates), and members of the family Enterobacteriaceae (14 isolates). The predominant anaerobes were Peptostreptococcus spp. (10 isolates), Bacteroides spp. (4 isolates), and Clostridium spp. (3 isolates). Polymicrobial infection occurred in 18 instances (28%). A single organisms was recovered in 47 instances (72%); these included 20 isolates of S. epidermidis, 15 of S. aureus, 5 of Enterobacteriaceae, and 4 of anaerobes. These data highlight the previously unrecognized polymicrobial aerobic and anaerobic bacteriology in a percentage of patients with postthoractomy sternal wound infection.

Adolescent↗

PubMed1989

Microbiology of infected pilonidal sinuses.

Aspirates of pus from infected pilonidal sinuses in 75 patients showed bacterial growth. Anaerobic bacteria only were recovered in 58 (77%) specimens, aerobic bacteria only in three (4%), and mixed aerobic and anaerobic bacteria in 14 (19%). Two hundred and nine isolates were recovered: 147 anaerobes (2.0 isolates a specimen) and 62 aerobes (0.8 a specimen). The predominant anaerobes were Bacteroides sp (81 isolates, including 29 Bacteroides fragilis group) and 51 anaerobic cocci. The predominant aerobes were Escherichia coli (n = 15), Proteus sp (n = 9), group D streptococcus (n = 7), and Pseudomonas sp (n = 7). This study highlights the polymicrobial nature and predominance of anaerobic bacteria in infected pilonidal sinuses.

Adolescent↗

PubMed1989

Metronidazole and spiramycin therapy of mixed Bacteroides spp. and Neisseria gonorrhoeae infection in mice.

The in vitro and in vivo activity of metronidazole and spiramycin, used singly or in combination, was tested in the eradication of infection caused by Bacteroides spp. and Neisseria gonorrhoeae alone or in combination. The in vitro tests consisted of determinations of the minimal inhibitory concentrations (MIC), carried out with or without the addition of a constant amount of the other antimicrobials. The MIC of both Bacteroides bivius and Bacteroides fragilis for metronidazole were significantly reduced by the addition of spiramycin (from 0.5 to 0.125 micrograms/ml). The in vivo tests were carried out in mice and consisted of measurements of the effects of the antimicrobial agents on the bacterial contents of abscesses induced by subcutaneous injection of bacterial suspension. Synergism between metronidazole and spiramycin was noted against Bacteroides spp. in abscesses caused by either Bacteroides spp. alone, or in combination with N. gonorrhoeae. Furthermore, an additional reduction in the number of N gonorrhoeae was noted in mixed infection with Bacteroides that was treated with metronidazole alone. This study demonstrates the in vitro and in vivo efficacy of the combination of metronidazole and spiramycin in the treatment of infections caused by either Bacteroides spp. alone or in combination with N. gonorrhoeae.

Abscess↗

PubMed1989

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.

Adolescent↗

PubMed1989

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.

Adult↗

PubMed1989

Bacteriology of chronic maxillary sinusitis in adults.

Aspirates of 72 chronically inflamed maxillary sinuses were processed for aerobic and anaerobic bacteria. Bacterial growth was present in 66 of the 72 specimens (92%). Anaerobic bacteria were isolated in 58 of the 66 culture-positive specimens (88%). Anaerobes only were recovered in 37 cases (56%) and in 21 (32%) they were mixed with aerobic or facultative bacteria. Aerobic or facultative bacteria were present in eight cases (12%). A total of 185 isolates (2.8 per specimen)--131 (2.0 per specimen) anaerobes and 54 (0.8 per specimen) aerobes or facultatives--were isolated. The predominant anaerobic organisms were anaerobic cocci and Bacteroides sp, and the predominant aerobes or facultatives were Streptococcus sp and Staphylococcus aureus. Twelve of the 27 Bacteroides sp that were tested for beta-lactamase (44%) produced the enzyme. These findings indicate the major role of anaerobic organisms in chronic sinusitis.

Adult↗

PubMed1989

Direct and indirect pathogenicity of beta-lactamase-producing bacteria in mixed infections in children.

The recent emergence of numerous aerobic and anaerobic beta-lactamase-producing bacterial strains has been associated with an increase in the failure rate of penicillins in the therapy of infection caused by these organisms. These include respiratory tract, skin of soft tissue, female genital tract, intra-abdominal, and other miscellaneous infections. The important aerobic beta-lactamase-producing bacteria (BLPB) include Staphylococcus aureus, Branhamella catarrhalis, Haemophilus sp., Neisseria gonorrhoeae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Legionella sp. The anaerobic BLPB are all Bacteroidiaceae and include Bacteroides fragilis group, B. melaninogenicus group, B. oralis, B. oris-buccae, and Fusobacterium sp. Laboratory, animal, and clinical studies that support the indirect pathogenicity of these organisms and the distribution of these BLPB in various infections are reviewed. BLPB may not only have a direct pathogenic role in causing the infection, but also an indirect pathogenic role. The indirect pathogenicity of these organisms is apparent through their ability not only to survive penicillin therapy, but also to protect penicillin-susceptible pathogens from that drug. These direct and indirect virulence characteristics of aerobic and anaerobic BLPB require the administration of appropriate antimicrobial therapy directed against all pathogens in mixed infections.

Bacteria↗

PubMed1989

Microbiology of infected epidermal cysts.

Specimens from 231 epidermal cyst abscesses were inoculated on media supportive for growth of aerobic and anaerobic bacteria. Of these, 192 yielded bacterial growth. Aerobic or facultative bacteria only were recovered in 84 specimens (44%), anaerobic bacteria only in 57 specimens (30%), and mixed aerobic and anaerobic bacteria in 51 specimens (26%). A total of 315 isolates (162 anaerobes and 153 aerobes) were recovered. An average of 0.8 aerobic or facultative isolates per infected cyst were recovered, and this number was unrelated to the cysts' anatomic sites. However, the number of anaerobic bacteria varied; they were isolated more frequently in perirectal (1.5 isolates per specimen), vulvovaginal (1.4), and head (1.1) infections, and less frequently in trunk (0.7) and extremities (0.4) infections. The predominant aerobic or facultative bacteria were Staphylococcus aureus (81 isolates), group A streptococcus (9 isolates), and Escherichia coli (7 isolates). The predominant anaerobic organisms were Peptostreptococcus species (85 isolates) and Bacteroides species (55 isolates, including 12 Bacteroides melaninogenicus and 9 Bacteroides fragilis groups). The study highlights the polymicrobial nature and predominance of anaerobes in cyst abscesses in the perirectal, vulvovaginal, and head areas.

Adolescent↗

PubMed1989

Human and animal bite infections.

Although often innocuous initially, human and animal bites can cause serious local and systemic infections as well as other complications. Bites to a site where joints or bones are close to the skin are especially prone to severe complications. Bites to the hand, therefore, require meticulous radiographic and surgical evaluation if a puncture or a severe laceration has occurred. Since the normal human oral flora harbors more pathogens than that of animals, human bites have a higher incidence of serious infections and complications. The oral flora of both humans and animals is anaerobic-aerobic, and initial empiric treatment requires the most broad spectrum antimicrobial therapy available, in addition to scrupulous wound management and, when required, immunization against rabies and tetanus.

Animals↗

PubMed1989

A 12 year study of aerobic and anaerobic bacteria in intra-abdominal and postsurgical abdominal wound infections.

Findings from the study of aerobic and anaerobic bacteria in intra-abdominal infections from 339 specimens of the peritoneal cavity after intestinal perforation, 83 specimens from abdominal abscesses and 89 specimens from postsurgical abdominal wounds are presented. Anaerobic bacteria alone were present in 43 (13 per cent) of the peritoneal specimens, aerobic bacteria alone in 38 (11 per cent) and mixed aerobic and anaerobic flora in 258 (76 per cent). A total of 985 bacterial isolates were recovered in peritoneal specimens (2.9 per specimen), with 436 aerobes (1.3 per specimen) and 549 anaerobes (1.6 per specimen). Anaerobic bacteria alone were present in 13 (16 per cent) of 83 specimens from abdominal abscesses, aerobes alone in two (2 per cent) and mixed flora in 68 (82 per cent). A total of 235 bacterial isolates were recovered in abdominal abscesses--128 anaerobes (1.5 per specimen) and 107 aerobes (1.3 per specimen). Anaerobic bacteria alone were present in 11 (12 per cent) of 89 specimens from abdominal wounds, aerobic only in ten (11 per cent) and mixed flora in 68 (76 per cent). A total of 258 isolates were recovered (2.9 per specimen)--137 anaerobes (1.5 per specimen) and 121 aerobes or facultatives (1.4 per specimen). The predominant aerobes and facultatives in abdominal infections were Escherichia coli and Streptococcus species. The predominant anaerobes were Bacteroides, Peptostreptococcus and Clostridium species. Recovered were 334 isolates of the Bacteroides fragilis group--222 in peritoneal cultures, 63 in abscesses and 49 in wounds. Of the B. fragilis group, B. fragilis accounted for 129 (58 per cent) of isolates in peritoneal aspirates, 45 (75 per cent) in aspirates from abscesses and 30 (61 per cent) in wounds. Results from this study demonstrate the polymicrobial aerobic and anaerobic cause and importance of all members of the B. fragilis group in intra-abdominal postsurgical infections.

Abdominal Injuries↗

PubMed1989

Aerobic and anaerobic microbiology of Bartholin's abscess.

Aspirates of pus from an abscess of Bartholin's gland in 28 patients were studied for aerobic and anaerobic bacteria. Bacterial growth was obtained on culture in 26 specimens. A total of 67 bacterial isolates (43 anaerobic and 24 aerobic and facultative) were recovered, accounting for 2.6 isolates per specimen (1.7 anaerobic and 0.9 aerobic and facultatives). Anaerobic bacteria only were present in eight patients, aerobic and facultatives in five and mixed aerobic and anaerobic flora in 13. Single bacterial isolates were recovered in six infections. The predominant anaerobic organisms were Bacteroides species (23 isolates, including six Bacteroides melaninogenicus group, five Bacteroides fragilis group and four Bacteroides bivius) and Peptostreptococcus species. The predominant aerobic and facultative bacteria were Escherichia coli and Neisseria gonorrhoeae. In this study, the polymicrobial nature of abscess of Bartholin's gland is highlighted.

Abscess↗

PubMed1988

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.

Adolescent↗