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Biomedical subjects

I Brook

Publications and source records attributed to I Brook.

At least 217 records · Page 12Linked to original sources
PubMed1991

Pathogenicity of Propionibacterium acnes in mixed infections with facultative bacteria.

Single and mixed infections with 11 clinical isolates of Propionibacterium acnes and three facultative bacteria (Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae) were studied in a subcutaneous abscess model in mice. Abscesses were induced by pure cultures of six of 11 strains of P. acnes and by the three facultative bacteria. The abscesses produced by each of the six "virulent" P. acnes isolates mixed with S. aureus, E. coli or K. pneumoniae were larger than those induced by the single organisms in 16 of the 18 combinations. There was a significant increase in the numbers of the six P. acnes strains in 13 of the 18 bacterial mixtures and in the numbers of the facultative bacteria in 17 of the 18 combinations. These data illustrate the potential virulence of some P. acnes strains and their synergic capacity with facultative bacteria.

Abscess↗
PubMed1991

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.

Adolescent↗
PubMed1991

Ofloxacin and penicillin G combination therapy in prevention of bacterial translocation and animal mortality after irradiation.

The efficacies of 40 mg of ofloxacin per kg/day given orally and 250 mg of penicillin per kg/day given intramuscularly, alone or in combination, were evaluated in the prevention of mortality of C3H/HeN female mice given 8.2 Gy of 60Co radiation. Mortalities were 51 of 60 mice (85%) in the control group, 46 of 60 mice (77%) among those treated with penicillin, 32 of 60 mice (53%) among those treated with ofloxacin (P less than 0.05), and 5 of 60 mice (8%) among those treated with ofloxacin and penicillin (P less than 0.001). The organisms recovered from the livers of control mice were members of the family Enterobacteriaceae and Streptococcus spp. A reduction in the number of the Enterobacteriaceae was noted only in ofloxacin-treated mice, and a reduction in the number of Streptococcus spp. was noted only in the penicillin-treated mice. Reductions in the numbers of both groups of organisms were noted only in the animals treated with both agents. This study shows the advantage of the combination of ofloxacin and penicillin in the prevention of bacterial translocation and animal mortality after irradiation.

Animals↗
PubMed1991

Adherence of Bacteroides fragilis group species.

The ability of piliated and capsulated Bacteroides fragilis and Bacteroides ovatus to adhere to intestinal cells and mucus was investigated. The adherence of piliated and capsulated strains was at least five times greater than the adherence of their nonpiliated and noncapsulated or capsulated only counterparts. These data illustrate the importance of pili as promoters of adherence of B. fragilis group species to the gastrointestinal mucosa.

Animals↗
PubMed1991

The role of beta-lactamase-producing bacteria in obstetrical and gynecological infections.

Pelvic inflammatory disease (PID) is a polymicrobial infection that evolves multiple aerobic and anaerobic bacteria. Several of the bacterial pathogens that participate in PID can produce the enzyme beta lactamase. These include Bacteroides species (including Bacteroides bivius, Bacteroides disiens, and Bacteroides fragilis group), Neisseria gonorrheae, Enterobacteriaceae and Staphylococcus aureus. A recent increase in numbers of beta-lactamase-producing strains of these organisms in PID has been associated with increased failure rates of penicillins in eradication of this infection. These organisms cannot only survive penicillin therapy but also protect penicillin-susceptible pathogens from the drug. These direct and indirect virulence characteristics of beta-lactamase-producing bacteria require the administration of appropriate antimicrobial therapy directed against all of these pathogens in the therapy of PID.

Anti-Bacterial Agents↗
PubMed1991

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.

Acute Disease↗
PubMed1991

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.

Adolescent↗
PubMed1991

Quinolone therapy in the prevention of mortality after irradiation.

The effect of oral therapy with three quinolones (ofloxacin, ciprofloxacin, and pefloxacin) in the prevention of postirradiation bacteremia and mortality was tested in B6D2F1 mice given 9.5 Gy 60Co gamma radiation. Only 8 of 60 (13%) untreated mice survived for 30 days, compared to 47 of 60 (78%) mice treated with ofloxacin, 44 of 60 (74%) mice treated with ciprofloxacin, and 42 of 60 (70%) mice treated with pefloxacin (P less than 0.05). The organisms recovered from the mice were Streptococcus spp. and Enterobacteriaceae. More Enterobacteriaceae were recovered from the livers of untreated animals than from the mice treated with the quinolones. However, no reduction in the number of Streptococcus spp. was noted in the animals given quinolones when compared to controls. This study shows that quinolones prolonged survival and decreased systemic spread of Enterobacteriaceae up to 30 days after exposure of mice to lethal irradiation.

Animals↗
PubMed1991

Aerobic and anaerobic microbiologic factors and recovery of beta-lactamase producing bacteria from obstetric and gynecologic infection.

Specimens obtained from 736 patients with obstetric and gynecologic infections were studied for aerobic and anaerobic bacteria. Bacterial growth was present in 714 specimens. These included 53 specimens of infected fallopian tubes, 470 of infected endometrium, 94 of infected amniotic fluid, 57 of aspirates of cul-de-sacs in instances of pelvic inflammatory disease, 14 labial and vaginal abscesses and 26 of Bartholyn's cyst abscess. A total of 2,052 isolates (2.9 per specimen), 1,139 anaerobes (1.6 per specimen) and 913 aerobic or facultative (1.3 per specimen) were recovered. The most commonly isolated anaerobic bacteria was Bacteroides species (566 isolates), which included Bacteroides bivius (151), Bacteroides fragilis group (130), Bacteroides melaninogenicus group (110) and Bacteroides ureolyticus (47). Others included an anaerobic gram-positive cocci (391), Clostridium species (48) and Fusobacterium species (36). The most frequently recovered aerobic and facultative bacteria were Lactobacillus species (169), Escherichia coli (85), Neisseria gonorrhoeae (62), Staphylococcus aureus (59) and Group B streptococcus (55). Three hundred and sixty-five (18 per cent) of the isolates recovered from 276 (39 per cent) patients were beta-lactamase producing organisms (BLPO); 222 (61 per cent) anaerobes and 143 (39 per cent) aerobes or facultatives. The most common BLPO were B. fragilis group, B. bivius, B. melaninogenicus, B. disiens, Enterobacteriaceae and S. aureus. These data illustrate the polymicrobial nature and important role of BLPO in obstetric and gynecologic infection.

Abscess↗
PubMed1990

Aerobic and anaerobic bacteriology of wounds and cutaneous abscesses.

The aerobic and anaerobic microbiologic characteristics of 584 wounds and 676 skin or soft-tissue abscesses were studied and correlated with the infection site. In wounds, aerobic or facultative bacteria only were present in 223 specimens (38%), anaerobes only in 177 specimens (30%), and mixed flora in 184 specimens (32%). In total there were 1470 isolates, 558 aerobic and 912 anaerobic, an average of 2.5 isolates per wound (1.6 anaerobic and 0.9 aerobic isolates). In abscesses, aerobic or facultative bacteria were recovered in 177 specimens (26%), anaerobes only in 243 specimens (36%), and mixed flora in 256 specimens (38%). In total there were 1702 isolates, 602 aerobic and 1100 anaerobic, an average of 2.5 isolates per abscess. The highest rates of anaerobes in wounds were in the inguinal, buttocks, and trunk areas and in abscesses in the perirectal, external genitalia, neck, and inguinal areas. The predominant aerobic organisms were Staphylococcus aureus (363 isolates), group A streptococci (98 isolates), and Escherichia coli (97 isolates). The predominant anaerobic organisms were Bacteroides species (986 isolates), Peptostreptococcus species (559 isolates), Clostridium species (153 isolates), and Fusobacterium species (109 isolates). The predominance of certain isolates in certain anatomical sites was correlated with their distribution in the normal flora adjacent to the infected site. These data highlight the polymicrobial nature of wounds and cutaneous abscesses.

Abscess↗
PubMed1990

Lack of influence of beta-lactamase-producing flora on recovery of group A streptococci after treatment of acute pharyngitis.

Because production of beta-lactamase by normal pharyngeal flora could account for penicillin treatment failure, we studied the effect of anaerobic and aerobic beta-lactamase-producing bacteria on bacteriologic outcome in acute group A beta-hemolytic streptococcal (GABHS) pharyngitis. We compared 10-day courses of orally administered phenoxymethyl penicillin and amoxicillin-clavulanic acid, using a randomized, single-blind treatment protocol. Eligible patients were 2 to 16 years of age and had culture-proven acute GABHS pharyngitis; 89 patients (43 penicillin, 46 amoxicillin-clavulanic acid) were compliant with therapy. beta-Lactamase-producing organisms were isolated before therapy from the throats of 67% of patients treated with penicillin and 63% treated with amoxicillin-clavulanic acid. Throat cultures after completion of therapy were positive for GABHS in 7 (7.9%) of 89 patients. The initial GABHS T type persisted (treatment failure) in only 4 (4.5%) of 89 patients, including 3 (6.5%) of 46 who received amoxicillin-clavulanic acid and in 1 (2.3%) of 43 who received penicillin (not statistically significant). Bacteriologic treatment failure was unrelated to recovery of beta-lactamase-producing bacteria at the time of enrollment or after treatment. We conclude that beta-lactamase production by normal pharyngeal flora does not fully explain the failure of penicillin therapy for acute streptococcal pharyngitis. Using an antibiotic effective against beta-lactamase-producing bacteria will not eliminate the problem of bacteriologic treatment failure.

Adolescent↗
PubMed1990

Aerobic and anaerobic microbiology of paronychia.

Pus specimens from 28 patients with paronychia of the finger yielded bacterial growth by techniques for cultivation of aerobic and anaerobic bacteria. Anaerobic and aerobic organisms only were isolated in pure culture in five (18%) and eight patients (29%), respectively; mixed aerobic and anaerobic flora were present in 15 patients (54%). Seventy-two isolates were recovered, or 2.6 isolates per specimen. The predominant anaerobic organisms were Gram-positive anaerobic cocci, Bacteroides species, and Fusobacterium species. The predominant aerobic organisms were Staphylococcus aureus, gamma-hemolytic streptococci, Eikenella corrodens, group A beta-hemolytic streptococci, alpha-hemolytic streptococci, and Klebsiella pneumoniae. Candida albicans was recovered in four cases. This study demonstrates the mixed aerobic and anaerobic bacteriology of paronychia.

Adult↗
PubMed1990

Quantitative study of wound infection in irradiated mice.

Bacterial infection of simple wounds was studied directly and quantitatively in adult mice given 6.5 Gy 60Co. Three days later, when neutropenia was evident, the skin and the medial gluteus muscle of anaesthetized mice were incised. A suspension of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae or Streptococcus pyogenes was inoculated into the wound. Bacteria per mg muscle were enumerated 3, 4 or 7 days later. The geometric means of bacteria per mg were greater in irradiated than in non-irradiated mice. Phagocytic cells were present in the wounded tissue. Hence sublethal ionizing radiation enhanced the susceptibility of mice to infections of wounds by these four bacterial species.

Animals↗
PubMed1990

Intra-abdominal abscess in children: a 13-year experience.

The microbiology of intra-abdominal abscess in children is similar to that of adults--a mixture of aerobes and anaerobes. In abscess specimens taken from 36 children, predominant pathogens were Bacteroides fragilis group species, Peptostreptococcus species, and Escherichia coli.

Abdomen↗
PubMed1990

Cefoxitin in the prevention and treatment of infections.

A review of the literature indicates that cefoxitin is an effective single-agent therapy for community-acquired intra-abdominal infections, pelvic infections, and surgical prophylaxis. Hospital-acquired intra-abdominal infections may require the addition of an aminoglycoside.

Biliary Tract Diseases↗