Microbiology of neonatal conjunctivitis: the role of anaerobes.
Explore the source record for details and available documents.
Bacteria, Anaerobic↗
Biomedical subjects
I Brook
Publications and source records attributed to I Brook.
Pathogenicity of aeromonas.
The ability of 15 Aeromonas sobria and 9 Aeromonas hydrophila isolates to cause subcutaneous lesions was tested. An inoculum of 10(11) colony forming units/l was injected subcutaneously into mice. Surviving animals developed a subcutaneous abscess and/or localised skin sloughing and loss of hair (alopecia). An abscess was induced by all nine A. hydrophila isolates and by three of the 15 A. sobria isolates. The induction of local epidermal sloughing and loss of hair followed challenge with either A. hydrophila or A. sobria and correlated with the organisms' lethality for mice and their cytotoxicity in the Y-I adrenal cell assay. Local epidermal sloughing was not induced by the media used for growing the organisms or by sonicated cells of the isolates. The ability to cause epidermal sloughing was lost by incubating viable cells at 45 degrees C for 35 minutes. These yet unreported in vivo features of Aeromonas sp. may be useful in studies of the pathogenicity of the species as well as for rapid assay of toxicity of strains.
Abscess↗
Interaction between penicillin, clindamycin or metronidazole and gentamicin against species of clostridia and anaerobic and facultatively anaerobic gram-positive cocci.
Seven anaerobic and facultative Gram-positive cocci and 12 clostridial species were tested for in-vitro and in-vivo susceptibilities to penicillin, clindamycin, and metronidazole, used singly or in combination with gentamicin. The in-vitro tests consisted of determination of minimal inhibitory concentration (MIC), done without or with constant amounts of gentamicin. When used alone or in combination with penicillin or metronidazole, gentamicin had negligible effects on the bacteria. When used with clindamycin, gentamicin significantly reduced the MIC for one strain each of Peptococcus magnus and Clostridium difficile. The in-vivo tests were carried out in mice and consisted of studying the bacterial contents of abscesses induced by subcutaneous injection of bacterial suspensions. Synergy between gentamicin and penicillin, clindamycin or metronidazole was shown respectively in five, three and one strain. Consistency between in-vitro and in-vivo findings was present in the above mentioned strains only between gentamicin and clindamycin. The synergy between penicillin, clindamycin or metronidazole and gentamicin in Gram-positive anaerobic and facultative organisms may have clinical implications.
Animals↗
Enhancement of growth of aerobic and facultative bacteria in mixed infections with Bacteroides species.
The potential for mutual enhancement of growth of the Bacteroides fragilis and B. melaninogenicus groups and the aerobic and facultative organisms commonly isolated with them in mixed infections was evaluated. Enhancement was studied by measuring the relative increase in CFU of the two bacterial components inducing subcutaneous abscesses in mice. Of the 42 combinations between three isolates each of the B. fragilis and B. melaninogenicus groups and seven aerobic or facultative organisms, Bacteroides spp. were enhanced in only 8 and inhibited in 4. The aerobic and facultative bacteria were enhanced in 31 of the 42 combinations and depressed in 2. The organisms uniformly enhanced by all of the Bacteroides spp. were group A streptococci and Escherichia coli (all six instances), followed by Staphylococcus aureus and Klebsiella pneumoniae (five of six instances), Pseudomonas aeruginosa (four instances), group D streptococci (in three instances only by the B. fragilis group), and Haemophilus influenzae (one instance). It is apparent that the growth rate of facultative and aerobic bacteria is enhanced much more in mixed infections with Bacteroides spp. than that of their anaerobic counterparts.
Abscess↗
Enzyme-linked immunosorbent assay for detection of antibodies to Staphylococcus aureus cell walls in experimental osteomyelitis.
An enzyme-linked immunosorbent assay was used to evaluate and compare the immunoglobulin G antibody response to Staphylococcus aureus cell walls of rabbits with either chronic staphylococcal osteomyelitis or subcutaneous abscesses. Osteomyelitis of the femur was produced by the intramedullary application of a sclerosing agent (3% sodium tetradecyl sulfate) and S. aureus. Radiographic evidence of osteomyelitis was observed in 10 of the 13 animals that survived the 10-week experimental period, and the diagnosis was confirmed by histopathology in 8 of the 10 instances. Abscess formation was initiated in a separate group of rabbits by the subcutaneous injection of S. aureus cells. All 10 of these rabbits subsequently developed abscesses, which usually resolved spontaneously within 3 to 5 weeks. Elevated levels of immunoglobulin G antibodies to the cell wall antigen were detected in 7 of 10 rabbits with osteomyelitis at 21 days postinfection, and these animals continued to display high antibody levels even at 59 days postinfection. In contrast, elevated levels of anti-cell-wall antibodies were only detected in 1 of 10 rabbits with subcutaneous abscesses. The enzyme-linked immunosorbent assay was found to be a rapid and sensitive serological technique for the detection of cell wall antibodies in this experimental osteomyelitis model and may be useful for the diagnosis of staphylococcal bone infections in humans.
Abscess↗
The role of encapsulation in the pathogenesis of anaerobic gram-positive cocci.
The pathogenicity of 22 anaerobic and facultative Gram-positive cocci (AFGPC) was investigated by inoculating them into mice and determining their ability to cause subcutaneous abscesses. Only 11 heavily encapsulated isolates (greater than 50% of the cells were encapsulated) induced abscesses. However, when the other 11 isolates were injected with Bacteroides sp. or facultative and aerobic bacteria, abscesses were formed in 8 of the 11 combinations. The AFGPC recovered from the mixed infections contained many encapsulated cells. Encapsulation also occurred in cocci injected with capsular material or with Formalin-killed cells of Klebsiella pneumoniae or capsule-positive Bacteroides sp. After acquisition of capsules, these strains could induce abscesses on reinoculation in mice.
Abscess↗
Treatment of patients with a history of recurrent tonsillitis due to group A beta-hemolytic streptococci. A prospective randomized study comparing penicillin, erythromycin, and clindamycin.
Forty-five patients with a history of recurrent tonsillitis associated with Group A beta-hemolytic streptococcal (GABHS) infection participated in a prospective, randomized study comparing penicillin, erythromycin, or clindamycin therapy. Surface tonsillar cultures were obtained before therapy, 10 days after termination of therapy, and once a month for a period of 12 to 18 months. The specimens were processed for aerobic and anaerobic bacteria. Beta lactamase-producing aerobic and anaerobic bacteria were present in 43 of the 45 (96%) tonsillar cultures. GABHS colonization was eradicated in two of 15 patients treated with penicillin, in six of 15 treated with erythromycin, and in 14 of the 15 treated with clindamycin. In long-term follow-up, 12 of 14 patients treated with penicillin, eight of 14 treated with erythromycin, and one of 15 treated with clindamycin (p less than 0.0001 when compared to penicillin and p = 0.002 when compared to erythromycin) continued to suffer from recurrent tonsillitis.
Adolescent↗
Prevalence of beta-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.
Adolescent↗
Possible association of mucous blanket integrity with postirradiation colonization resistance.
Radiation-induced infections can be associated with changes in colonization potential of the intestine. Since the mucous blanket, which overlays the epithelium, is a major mucosal structure and is heavily colonized by microorganisms, we examined the status of the mucus after radiation and evaluated susceptibility to intestinal challenge with bacteria. A downward shift (2.5 X 10(8) cells/g to 5.3 X 10(5)) of total facultatively anaerobic bacteria of the ileum of C3HeB/FeJ mice was detected by 3 days post exposure to 10 Gy 60Co. Numbers of flora returned to normal by 11 days after radiation. Scanning electron microscopy was used to show that the loss of bacteria could be associated with major disruptions of the continuity of the mucous blanket. The pathogen Pseudomonas aeruginosa adhered to mouse mucous films used in in vitro assays. When irradiated mice were challenged orally with 1 X 10(5) P. aeruginosa on days 1, 2, or 3 after irradiation, a progressive increase in susceptibility was seen, but no animals died before Day 4 postirradiation. Sensitivity to subcutaneous (sc) challenge with Pseudomonas also increased by Day 3 and was probably due largely to the profound neutropenia observed. Immunoglobulin G (Gamimmune), which protected burned mice infected with Pseudomonas, was ineffectual in treatment of 7 or 10 Gy irradiated mice challenged either orally or sc with the organism. The ileal mucosal barrier was compromised after radiation in ways which could facilitate epithelial colonization, an event which combined with other immunological and physiological decrements in this model can compromise the effectiveness of therapeutic modalities.
Animals↗
Rapid practical method for detection of beta lactamase-producing bacteria.
A method is described for rapid detection of beta lactamase-producing organisms within 24 h. The specimen is plated on agar medium, and a standard penicillin susceptibility disc is placed at the site of the lung inoculum. Penicillin resistant bacteria will grow at the area of inhibition. Beta lactamase activity can then be ascertained by utilizing a rapid disc test.
Bacteria↗
Balloons as a cause of suffocation.
Explore the source record for details and available documents.
Asphyxia↗
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.
Adolescent↗
Bacteriology of chronic tonsillitis in young adults.
Tonsils were obtained from 22 young adults (mean age, 23 years) suffering from chronic tonsillitis. Mixed aerobic and anaerobic flora was obtained from core tonsillar cultures in all patients, yielding an average of 9.0 isolates (5.3 anaerobes and 3.7 aerobes) per specimen. The predominant anaerobic isolates were Bacteroides sp, Fusobacterium sp, and gram-positive cocci. The predominant aerobic isolates were alpha-hemolytic streptococci, Staphylococcus aureus, Branhamella catarrhalis, beta-hemolytic streptococci, and hemophilus sp. beta-Lactamase-production was noted in 32 isolates recovered from 18 tonsils (82%). These included all eight isolates of S aureus and five B fragilis, and 11 of 24 B melaninogenicus group (46%). Our findings indicate the polymicrobial nature of deep tonsillar flora in young adults with chronic tonsillitis, and demonstrate the presence of beta-lactamase-producing organisms in most of the patients.
Adolescent↗
Pathogenicity of piliated and encapsulated Bacteroides fragilis.
Of 20 isolates of the Bacteroides fragilis group, only three were encapsulated (C+) and these induced abscesses in mice. After coinoculation with live, formalized or capsular material from other bacteria seven other isolates formed abscesses. The Bacteroides recovered from these abscesses were C+; those that had been inoculated with Klebsiella had pili-like and bacteriophage-like structures. Once encapsulated, the Bacteroides isolates induced abscesses when injected alone.
Abscess↗
Sputum cultures for evaluation of anaerobes in cystic fibrosis.
Explore the source record for details and available documents.
Bacteria, Anaerobic↗
Synergistic effect of bacteroides, Clostridium, Fusobacterium, anaerobic cocci, and aerobic bacteria on mortality and induction of subcutaneous abscesses in mice.
The potential for synergy between aerobic, facultative, and anaerobic bacteria was studied by subcutaneous inoculation of mixtures of these organisms into mice and observation of subsequent mortality and abscess formation. The anaerobic bacteria tested included 12 strains of gram-positive cocci and two strains each of Bacteroides species, Clostridium species, and Fusobacterium species. The facultative and aerobic bacteria included one strain each of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Mortality increased significantly when each aerobic organism was inoculated along with either of the Bacteroides species. A similar increase occurred when the anaerobic gram-positive cocci were inoculated along with P. aeruginosa (four of six combinations) or S. aureus (four of six). The rate of abscess induction increased significantly when 10 of the 12 strains of anaerobic gram-positive cocci were injected along with B. fragilis and when nine of these strains were inoculated along with Bacteroides asaccharolyticus . The results demonstrate synergistic potential between Bacteroides species and all aerobic bacteria tested, between Bacteroides species and most anaerobic gram-positive cocci, and between most anaerobic gram-positive cocci and P. aeruginosa or S. aureus.
Abscess↗
Occurrence of bacteremia in febrile children seen in a hospital outpatient department and private practice.
Blood cultures were obtained during a one-year period from 147 febrile children seen in the hospital outpatient clinic (group 1), and 42 seen in a private practice office (group 2). Although the two clinics were located in the same geographic area, they served different socioeconomic groups. Bacteremia was detected in 12 (8.2%) of the children in group 1; the organisms recovered were Streptococcus pneumoniae in nine and Haemophilus influenzae in three. Bacteremia was observed in two (4.8%) of the children seen in group 2, and both cases were due to S pneumoniae. The difference in prevalence rates for bacteremia between groups was not significant by chi-square testing (P = .46). The age of all the 13 patients with bacteremia was less than 24 months, their temperature was above 104 F (40 C), their polymorphonuclear leukocyte count was above 15,000/cu mm, and a localized site of infection was present in ten of them. These data suggest that the presence of bacteremia in febrile children depends more on the patients' clinical and laboratory findings than on the medical facility in which they are seen.
Child, Preschool↗
Synergism between penicillin, clindamycin, or metronidazole and gentamicin against species of the Bacteroides melaninogenicus and Bacteroides fragilis groups.
Clinical isolates of the Bacteroides melaninogenicus and Bacteroides fragilis groups were tested for in vitro and in vivo susceptibility to penicillin, clindamycin, and metronidazole, used singly or in combination with gentamicin. The in vitro tests consisted of determinations of minimal inhibitory concentrations (MICs) carried out with or without constant amounts of gentamicin. When used alone, gentamicin had negligible effects on the bacteria but significantly reduced the MICs of penicillin, clindamycin, and metronidazole against 11, 10, and 3, of the 15 strains of the B. melaninogenicus group, respectively. The 15 strains of the B. fragilis group were all beta-lactamase producers and were highly resistant to penicillin or the combination of penicillin and gentamicin. However, gentamicin reduced the MICs of clindamycin and metronidazole against 1 and 7 strains of this group, respectively. The in vivo tests were carried out in mice and consisted of measurements of the effects of the antimicrobial agents on the sizes and bacterial content of abscesses induced by subcutaneous injection of bacterial suspensions. The results of the in vivo tests were generally consistent with those obtained in vitro with strains of the B. melaninogenicus group. Synergism between gentamicin and penicillin, clindamycin, or metronidazole was shown in 13, 10, and 3 strains of this group, respectively. In vivo synergism was not clearly demonstrated with the strains of the B. fragilis group, possibly because clindamycin and metronidazole used alone were highly efficacious. We suggest that the synergistic effect of gentamicin is due to its increased transport into the bacterial cell in the presence of penicillin and, possibly, other antimicrobial agents. The newly recognized in vitro and in vivo synergism between penicillin and other antimicrobial agents and an aminoglycoside in B. melaninogenicus may have clinical implications that deserve to be investigated.
Abscess↗