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Biomedical subjects

I Brook

Publications and source records attributed to I Brook.

At least 127 records · Page 7Linked to original sources
PubMed1995

The aerobic and anaerobic microbiology of pustular acne lesions.

Specimens from 32 pustular acne lesions that were inoculated on media supportive for the growth of aerobic and anaerobic bacteria showed bacterial growth. Only aerobic or facultative bacteria were recovered in 15 (47%) specimens, only anaerobic bacteria in 11 (34%) specimens, and mixed aerobic and anaerobic bacteria in 6 (18%) specimens. A total of 57 isolates, 31 anaerobes (1.0 per specimen) and 26 aerobes (0.8 per specimen) were recovered. The predominant isolates were Staphylococcus sp. (19 isolates), Peptostreptococcus sp. (15), and Propionibacterium sp. (10). Twelve (37.5%) of the comedones yielded only one organism. This retrospective study highlighted the polymicrobial nature of over two-thirds of culture positive pustular acne lesions and suggests the potential for pathogenic role of aerobic and anaerobic organisms other than P. acnes and Staphylococcus sp. in acne vulgaris.

Journal Article↗
PubMed1995

Microbiology of chronic suppurative otitis media in children in Surabaya, Indonesia.

The aerobic and anaerobic microbiology of 38 children from Surabaya, Indonesia, who suffered from chronic suppurative otitis media (CSOM) was studied using strict microbiological methodology. A total of 106 isolates (49 anaerobic and 57 aerobic) were recovered. Aerobic organisms alone were isolated from 11 (29%), anaerobic bacteria only in 4 (11%) and mixed aerobic and anaerobic flora were present in 23 (60%). The predominant organisms were Peptostreptococcus sp., Prevotella sp., Bacteroides sp., Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Fusobacterium sp. Thirty-nine beta-lactamase-producing bacteria were recovered from 22 (58%) patients. These findings demonstrate the role of penicillin resistant aerobic and anaerobic bacteria in the polymicrobial etiology of CSOM in children from Indonesia. Judicious use of antimicrobial therapy may prevent the development of antimicrobial resistance.

Adolescent↗
PubMed1995

Role of anaerobic bacteria in chronic otitis media and cholesteatoma.

Otitis media (OM), a common infection in children, can cause significant morbidity. Selection of the most appropriate treatment regimen directed against the pathogens responsible for the OM can minimize complications. The most frequently isolated bacteria from chronic OM are Staphylococcus aureus, Pseudomonas aeruginosa and anaerobic bacteria. The predominant anaerobes are Peptostreptococcus spp., pigmented Prevotella and Porphyromonas spp., Bacteroides spp. and Fusobacterium spp. Many of the organisms causing OM can produce beta-lactamase, which can contribute to the failure of penicillins therapy. The appropriate surgical and medical therapy for chronic OM is reviewed.

Bacteria, Anaerobic↗
PubMed1995

Expression of capsules by Haemophilus influenzae in mixed infections.

The pathogenicity of eight clinical isolates of non-type b Haemophilus influenzae was investigated by inoculating them subcutaneously into mice, alone or mixed with viable or non-viable bacteria of certain other species. Three of the H. influenzae isolates were non-capsulated while five were slightly capsulated (less than 1% of organisms had capsules). The other strains of bacteria tested were four isolates of capsulated and four isolates of non-capsulated pigmented strains of Prevotella sp. and Porphyromonus sp. as well as a capsulate Klebsiella pneumoniae ("helpers"). None of the non-capsulated strains induced an abscess when inoculated alone. Following co-inoculation of viable or non-viable "helpers" with H. influenzae, abscesses were formed in all instances in which the "helper" had a capsule. Profusely capsulated cells of H. influenzae were recovered, however, only from abscesses induced with the five slightly capsulated strains of H. influenzae. These capsulated organisms were found serologically to be of type b and induced abscesses when inoculated alone. Our findings illustrate the ability of non-capsulated strains of H. influenzae to produce progeny of capsulated type b organisms after co-inoculation with certain other species.

Abscess↗
PubMed1995

Antimicrobial management of chronic sinusitis in children.

This study retrospectively investigated the microbiology and management of 40 children who suffered from chronic sinusitis. The sinuses infected were the maxillary (15 cases), ethmoid (13), and frontal (seven). Pansinusitis was present in five patients. All aspirates were cultured for aerobic and anaerobic bacteria. A total of 121 isolates (97 anaerobic and 24 aerobic) were recovered. Anaerobes were recovered from all 37 culture-positive specimens, and in 14 cases (38 per cent) they were mixed with aerobes. Twenty-three beta-lactamase-producing bacteria were isolated from 16 (43 per cent) patients. The 15 patients who received clindamycin had the most rapid response to therapy and a change of therapy and surgical drainage was required in one case. Of the 16 patients who received amoxycillin or ampicillin, 16 responded to therapy, six needed a change of therapy, including four who also had surgical drainage. Of the six who were treated with erythromycin, three needed antibiotic change, two with surgical drainage. Of the three that received cefaclor, two were cured, and one had an antibiotic change. Resistant organisms were recovered in all the cases that required therapeutic change. These findings support the important role of anaerobic bacteria in the polymicrobial cause of chronic sinusitis in children, and the superiority of therapy effective against these organisms.

Adolescent↗
PubMed1995

Changes in the core tonsillar bacteriology of recurrent tonsillitis: 1977-1993.

Microbiological studies of the core of tonsils removed from children with recurrent tonsillitis due to group A beta-hemolytic streptococci were conducted during three periods, with 50 patients in each period: 1977-1978 (period 1), 1984-1985 (period 2), and 1992-1993 (period 3). Mixed flora were present in all tonsils, with 8.1 organisms per tonsil (3.8 aerobes and 4.3 anaerobes). The predominant isolates in each period were Staphylococcus aureus, Moraxella catarrhalis, Peptostreptococcus species, pigmented Prevotella species, Porphyromonas species, and Fusobacterium species. The rate of recovery of Haemophilus influenzae type b increased from 24% in period 1 to 76% in period 2 (P < .001); a decline to 12% in period 3 correlated with a concomitant increase in the frequency of recovery of non-type b strains of H. influenzae from 4% and 10% in periods 1 and 2, respectively, to 64% in period 3 (P < .001). Both the rate of recovery of beta-lactamase-producing bacteria and the number of these organisms per tonsil increased over time. Specifically, beta-lactamase-producing strains were detected in 37 tonsils (74%) during period 1, in 46 tonsils (92%) during period 2, and in 47 tonsils (94%) during period 3, and the number of such strains per tonsil increased from 1.1 in period 1 to 2.9 and 3.3 in periods 2 and 3, respectively.

Adolescent↗
PubMed1995

Clostridial infection in children.

A survey of the isolation of Clostridium spp. from 1543 specimens sent to anaerobic microbiology laboratories revealed 113 isolates from 107 specimens (7.0% of all specimens) from 96 children. The isolates comprised 43 (38%) unidentified Clostridium spp., 37 (33%) C. perfringens, 13 (12%) C. ramosum, five (4%) C. innocuum, six (5%) C. botulinum, three (3%) C. difficile, two (2%) C. butyricum, and one isolate each of C. bifermentans, C. clostridiiforme, C. limosum and C. paraputrificum. Most clostridial isolates were from abscesses (38), peritonitis (26), bacteraemia (10), and chronic otitis media (7). Predisposing or underlying conditions were present in 31 (32%) cases. These were immunodeficiency (12), malignancy (9), diabetes (7), trauma (7), presence of a foreign body (6) and previous surgery (6). The clostridia were the only bacterial isolates in 14 (15%) cases; 82 (85%) cases had mixed infection. The species most commonly isolated with clostridia were anaerobic cocci (57); Bacteroides spp. (B. fragilis group) (50), Escherichia coli (22), pigmented Prevotella or Porphyromonas spp. (18) and Fusobacterium spp. (10). Most Bacteroides and Escherichia coli isolates with clostridia were from abdominal infections and skin and soft tissue infections adjacent to the rectal area; most pigmented Prevotella and Porphyromonas isolates were from oropharyngeal, pulmonary, and head and neck sites. Antimicrobial therapy was given to all patients, in conjunction with surgical drainage in 34 (35%). Only two patients died. These data illustrate the importance of Clostridium spp. in paediatric infections.

Abscess↗
PubMed1995

Prevotella and Porphyromonas infections in children.

From 1974 to 1994, 504 isolates of Prevotella and Porphyromonas spp. were obtained from 435 (21%) of 2033 specimens from 418 children. They included 160 (32%) Pr. melaninogenica, 105 (21%) Pr. intermedia, 84 (17%) P. asaccharolytica, 58 (12%) Pr. orisbuccae, and 58 (12%) Pr. oralis. Most Prevotella and Porphyromonas spp. were isolated from abscesses (176), pulmonary infections (85), ear infections (82), wound infections (44), peritonitis (38), paronychia (15) and chronic sinusitis (14). Predisposing conditions were noted in 111 (27%) of the cases; these included previous surgery in 41 (10%), foreign body in 36 (9%), neurological deficiencies in 29 (7%), immunodeficiency in 21 (5%), steroid therapy in 12 (4%), diabetes in 8 (2%) and malignancy in 7 (2%). Prevotella and Porphyromonas spp. were the only isolates in 14 (3%) patients, and mixed infection was encountered in 404 (97%). The micro-organisms most commonly isolated with Prevotella and Porphyromonas spp. were anaerobic cocci (393 isolates), Fusobacterium spp. (108), Bacteroides spp. (B. fragilis group) (95), Escherichia coli (56) and other gram-negative anaerobic bacilli (52). Most Bacteroides spp. and E. coli were isolated from intra-abdominal infections and skin and soft tissue infections around the rectal area, whereas most Fusobacterium spp. were isolated from oropharyngeal, pulmonary and head and neck sites. beta-Lactamase production was detected in 191 (38%) Prevotella and Porphyromonas isolates from all body sites. All patients received antimicrobial therapy, and surgical drainage was performed in 173 (41%) cases. Four patients died from their infection. These data illustrate the spectrum and importance of Prevotella and Porphyromonas spp. in infections in children.

Abscess↗
PubMed1995

Bacteroides infections in children.

From 1974 to 1990, 336 Bacteroides isolates were obtained from 312 specimens from 274 patients. They comprised 180 (54%) B. fragilis isolates, 55 (16%) B. theta-iotaomicron, 36 (11%) B. vulgatus, 34 (10%) B. distasonis, 21 (6%) B. ovatus and 10 (3%) B. uniformis. Infections in 253 (92%) patients were polymicrobial, but in 21 (8%) children, a Bacteroides sp. was isolated in pure culture. Most Bacteroides isolates were from peritoneal fluid (114), abscesses (110), wound infections (20), blood cultures (10) and from patients with pneumonia (14) or chronic otitis media (8). Predisposing conditions were present in 145 (53%) children; these were previous surgery (46), trauma (28), malignancy (21), prematurity (19), immunodeficiency (18), steroid therapy (12) foreign body (10), diabetes (9) and sickle cell disease (7). The micro-organisms isolated most commonly mixed with Bacteroides spp. were anaerobic cocci (221), Escherichia coli (122), Fusobacterium spp. (38) and Clostridium spp. (30). All patients received antimicrobial therapy in conjunction with surgical drainage or correction of pathology in 197 (72%) cases. All but 12 (5%) patients recovered. These data illustrate the importance of Bacteroides spp. in infections in children.

Abscess↗
PubMed1995

Microbiology of gastrostomy site wound infections in children.

Specimens of pus were obtained from gastrostomy site wound infections in 22 children. Polymicrobial flora was found in 21 of the 22 wounds. Aerobic or facultative bacteria only were isolated in eight (36%) instances and mixed aerobic-anaerobic flora were isolated from the other 14 (64%) wounds. A total of 102 bacterial isolates (57 aerobic and 45 anaerobic) and seven cultures of candida were obtained. The most frequent isolates were Escherichia coli (16 isolates). Peptostreptococcus spp. (14), Enterococcus spp. (14), Bacteroides spp. (12) and Staphylococcus aureus (6). Twenty-eight strains producing beta-lactamase were isolated from 16 (73%) patients. The presence of polymicrobial aerobic-anaerobic infection, and the isolation of E. coli and Bacteroides spp. were more frequent in wounds with gastric leakage than in wounds without gastric leakage (p < 0.05). Bacteria similar to those isolated from the wound were also isolated from blood cultures from three patients-two isolates of E. coli and one each of B. fragilis and S. aureus. All patients received local therapy and 11 were treated with systemic antimicrobial agents. The polymicrobial aerobic-anaerobic flora of gastrostomy site wound infections, especially in association with gastric leakage, and the presence of beta-lactamase producers in most of these infections may have important implications for their management.

Adolescent↗
PubMed1995

In vitro and in vivo effects of penicillin and clindamycin on expression of group A beta-hemolytic streptococcal capsule.

Encapsulation of group A beta-hemolytic streptococci (GABHS) is an important virulence factor. The changes that occur in the frequency of encapsulation of GABHS during pharyngotonsillitis, in 20 patients treated with penicillin and 20 treated with clindamycin, were investigated. The effects of subinhibitory concentrations of these agents were also evaluated in vitro. At day 4, 8 of 10 (80%) GABHS isolates recovered from children treated with penicillin were encapsulated, compared with 1 of 5 (20%) of those from children treated with clindamycin (P < 0.05). Two days following 10 days of therapy, GABHS was eliminated from 13 of the 20 (65%) children treated with penicillin and from all treated with clindamycin (P < 0.05). At that time, six of the seven GABHS isolates recovered in patients treated with penicillin were encapsulated. GABHS were not detected after 4 days of therapy in those treated with clindamycin. Incubation of GABHS isolates with one-half of the MIC of clindamycin reduced the frequency of encapsulation, compared with that after incubation with one-half of the MIC of penicillin (12.5 versus 67.5%). These data illustrate the superiority of clindamycin over penicillin in reducing the expression of a capsule by GABHS.

Bacterial Capsules↗
PubMed1995

Microbiology of secondary bacterial infection in scabies lesions.

Aerobic and anaerobic bacteria were grown from specimens obtained from 30 children with secondarily infected scabies lesions. Aerobic or facultative bacteria only were present in 14 (47%) patients, anaerobic bacteria only were present in 6 (20%) patients, and a mixed anaerobic-aerobic flora was present in 10 (33%) patients. Fifty isolates were recovered (1.7 per specimen); 27 were aerobic or facultative bacteria and 23 were strict anaerobes. The predominant aerobic and facultative bacteria were Staphylococcus aureus (nine isolates), group A streptococci (five isolates), and Pseudomonas aeruginosa (three isolates). The predominant anaerobes were Peptostreptococcus sp. (nine isolates) and pigmented Prevotella and Porphyromonas spp. (four isolates). Single bacterial isolates were recovered from nine (30%) patients; five of these were S. aureus. Sixteen organisms isolated from 12 (40%) patients produced the enzyme beta-lactamase. Organisms that resided in the mucous membranes close to or in contact with the lesions predominated in those infections. Enteric gram-negative rods were recovered in leg and trunk lesions. Group A streptococci and S. aureus predominated in finger and hand lesions. Bacteroides fragilis group and Clostridium sp. were isolated from leg lesions, and pigmented Prevotella sp. and Porphyromonas and Fusobacterium spp. were recovered from finger lesions. The polymicrobial etiology of secondarily infected scabies lesions in children and the association of bacterial flora with the anatomical sites of the lesions are demonstrated.

Bacteria, Aerobic↗
PubMed1995

Clinical and microbiological features of necrotizing fasciitis.

The microbiological and clinical characteristics of 83 patients with necrotizing fasciitis (NF) treated over a period of 17 years are presented. Bacterial growth was noted in 81 of 83 (98%) of specimens from patients with NF. Aerobic or facultative bacteria only were recovered in 8 (10%) specimens, anaerobic bacteria only were recovered in 18 (22%) specimens, and mixed-aerobic-anaerobic floras were recovered in 55 (68%) specimens. In total, there were 375 isolates, 105 aerobic or facultative bacteria and 270 anaerobic bacteria, for an average of 4.6 isolates per specimen. The recovery of certain bacteria from different anatomical locations correlated with their distribution in the normal flora adjacent to the infected site. Anaerobic bacteria outnumbered aerobic bacteria at all body sites, but the highest recovery rate of anaerobes was in the buttocks, trunk, neck, external genitalia, and inguinal areas. The predominant aerobes were Staphylococcus aureus (n = 14 isolates), Escherichia coli (n = 12), and group A streptococci (n = 8). The predominant anaerobes were Peptostreptococcus spp. (n = 101), Prevotella and Porphyromonas spp. (n = 40), Bacteroides fragilis group (n = 36), and Clostridium spp. (n = 23). Certain clinical findings correlated with some bacteria: edema with B. fragilis group, Clostridium spp., S. aureus, Prevotella spp. and group A streptococci; gas and crepitation in tissues with members of the family Enterobacteriaceae and Clostridium spp.; and foul odor with Bacteroides spp. Certain predisposing conditions correlated with some organisms: trauma with Clostridium spp.; diabetes with Bacteroides spp., members of the family Enterobacteriaceae, and S. aureus; and immunosuppression and malignancy with Pseudomonas spp. and members of the family Enterobacteriaceae. These data highlight the polymicrobial nature of NF.

Bacteria, Aerobic↗