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Biomedical subjects

I Brook

Publications and source records attributed to I Brook.

At least 55 records · Page 3Linked to original sources

Interference by aerobic and anaerobic bacteria in children with recurrent group A beta-hemolytic streptococcal tonsillitis.

OBJECTIVE: To compare the frequency of recovery of aerobic and anaerobic bacteria with interfering capability of group A beta-hemolytic streptococci (GABHS) in the tonsils of children with and without a history of recurrent GABHS pharyngotonsillitis. PATIENTS AND METHODS: Tonsillar cultures were taken from a group of 20 children with and 20 without history of recurrent GABHS pharyngotonsillitis. RESULTS: Eleven aerobic and anaerobic isolates with interfering capability with GABHS were recovered from 6 (30%) of the 20 children with recurrent GABHS, and 40 such organisms were isolated from 17 (85%) of the 20 without recurrences (P<.01). The interfering organisms included aerobic (alpha-hemolytic and nonhemolytic streptococci) and anaerobic organisms (Prevotella and Peptostreptococcus species). CONCLUSIONS: The tonsils of children with a history of recurrent GABHS infection contain fewer aerobic and anaerobic bacteria with interfering capability of GABHS than those without the history of recurrent GABHS infection. The presence of these interfering bacteria may play a role in preventing GABHS infection.

Adolescent↗

Microbiology of infected pustular psoriasis lesions.

BACKGROUND: Bacterial infections can occur in lesions of pustular psoriasis (PP). The objective of this study was to establish the aerobic and anaerobic microbiology of secondarily infected PP. METHODS: A retrospective 10-year review was carried out of clinical and microbiology laboratory records from patients with secondarily infected PP lesions, whose specimens of infected sites were processed for the presence of aerobic and anaerobic bacteria. RESULTS: Bacterial growth was noted in 23 specimens. Aerobic or facultative anaerobic bacteria only were present in 12 patients (52%), anaerobic bacteria only in four (17%), and mixed anaerobic-aerobic flora was present in seven (30%). Thirty-six isolates were recovered (1.6 per specimen), 23 aerobic or facultative bacteria and 13 strict anaerobes. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Group D Enterococcus (two isolates), and Escherichia coli (two isolates). The predominant anaerobes were Peptostreptococcus spp. (six isolates) and Bacteroides fragilis group, Propionibacterium acnes, and pigmented Prevotella spp. in two each. Single bacterial isolates were recovered in 14 patients (61%), 11 of which were S. aureus. Nineteen of the organisms isolated from 18 patients (78%) produced the enzyme beta-lactamase. S. aureus was isolated from all body sites. Organisms that resided in the mucous membranes close to the lesions predominated in these infections. Enteric Gram-negative rods and Bacteroides fragilis group predominated in lesions on the legs and buttocks. Group A beta-hemolytic streptococci, pigmented Prevotella, and Fusobacterium spp. were most frequently recovered in lesions of the hand. CONCLUSIONS: The polymicrobial etiology of secondarily infected PP lesions and the association of bacterial flora with the anatomic site of the lesions were demonstrated.

Adult↗

Soft tissue and muscular infections (including group A streptococci).

Skin, soft tissue and muscular infections are very common and can progress to induce serious life-threatening local and systemic complications. They often occur in sites that have been compromised or injured by foreign bodies, trauma, ischaemia, malignancy or surgery. In addition to group A streptococci and Staphylococcus aureus, the indigenous local microflora is usually responsible for these infections. Anatomical sites that are subject to faecal or oral contamination are particularly at risk. The early recognition and proper medical and surgical management of these infections are of primary importance.

Fasciitis↗

Bacterial interference in the nasopharynx and nasal cavity of sinusitis prone and non-sinusitis prone children.

The aim of this study was to compare the frequency of recovery of potential pathogens and aerobic and anaerobic interfering bacteria in the nasopharynx and nasal cavity of sinusitis prone (SP) children, with their recovery in non-sinusitis prone (N-SP) children. Nasopharyngeal and nasal cultures were taken from 20 SP and 20 N-SP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these micro-organisms were identified. Twenty-one potential pathogens (1.05 patient) were isolated from nasopharyngeal cultures from 14 of the 20 SP children, and 10 (0.5 patient) were recovered from 6 of the 20 NSP (p < 0.05). Bacterial interference between two aerobic (alpha and non-haemolytic streptococci) and two anaerobic species (Prevotella and Peptostreptococcus species) and four potential pathogens was observed. Bacterial interference was noted in 64 instances against 4 potential pathogens by 24 normal flora isolates that were recovered from 7 of the SP group and in 144 instances by 47 isolates from 18 of the NSP group (p < 0.05). Nineteen potential pathogens (0.95/patient) were isolated from nasal cultures of 13 of the 20 SP children and 8 (0.4/patient) were recovered from 5 of the 20 NSP (p < 0.05). Bacterial interference by similar micro-organisms was noted in 21 instances by 9 normal flora isolates that were recovered from 5 of the SP group, and in 63 instances by 26 isolates from 15 of the NSP group (p < 0.05). Our findings illustrate for the first time that the nasopharyngeal and nasal flora of NSP children contains more aerobic and anaerobic micro-organisms with interfering capability and less potential pathogens than that of SP children.

Adolescent↗

Bacterial interference.

Bacterial interactions, antagonistic and synergistic, help maintain the balance in the normal endogenous flora. The production of bacteriocins by microorganisms is one of the important mechanisms used for interference. The ability of various microorganisms to produce bacteriocins and exhibit interfering capability is detailed in the review. These organisms include Gram-positive and Gram-negative aerobic and anaerobic bacteria. The role of bacterial interference (BI) in clinical infections and the effect of this phenomenon on their eradication is detailed. The infections discussed include those of the upper respiratory (pharyngo-tonsillitis, otitis media), urogenital, and gastrointestinal tracts. The influence of antimicrobial agents on these organisms and their interactions with other bacteria are also described.

Antibiosis↗

Aerobic and anaerobic microbiology of axillary hidradenitis suppurativa.

A retrospective review of the microbiological and clinical data of 17 specimens obtained from axillary hidradenitis suppurativa (HS) over a period of 6 years was undertaken to study the aerobic and anaerobic microbiology of this condition. A total of 42 bacterial isolates (2.5 per specimen) were obtained, 12 aerobic or facultative (0.7 per specimen) and 30 anaerobic or micro-aerophilic (1.8 per specimen). Aerobic and facultative bacteria only were isolated in six (35%) cases, anaerobic bacteria only in seven (41%) and mixed aerobic and anaerobic bacteria in four (24%). The predominant aerobic bacteria were Staphylococcus aureus (six isolates), Streptococcus pyogenes (three) and Pseudomonas aeruginosa (two). The most frequently isolated anaerobes were Peptostreptococcus spp. (10), Prevotella spp. (seven), micro-aerophilic streptococci (four), Fusobacterium spp. (three) and Bacteroides spp. sensu stricto (three). This study highlights the polymicrobial nature and predominance of anaerobic bacteria in axillary HS and the need for antimicrobial thereby to reflect this.

Adult↗

Aerobic and anaerobic microbiology of surgical-site infection following spinal fusion.

The aerobic and anaerobic microbiology of surgical-site infections (SSI) following spinal fusion was retrospectively studied. This was done by reviewing the clinical and microbiological records at the Naval Hospital in Bethesda, Md., from 1980 to 1992. Aspirates of pus from 25 infection sites showed bacterial growth. Aerobic bacteria only were recovered from 9 (36%) specimens, anaerobic bacteria only were recovered from 4 (16%), and mixed aerobic and anaerobic bacteria were recovered from 12 (48%). Sixty isolates were recovered: 38 aerobes (1.5 isolates per specimen) and 22 anaerobes (0.9 isolate per specimen). The predominant aerobes were Escherichia coli (n = 8) and Proteus sp. (n = 7). The predominant anaerobes were Bacteroides fragilis group (n = 9) and Peptostreptococcus sp. (n = 6) isolates. An increase in recovery of E. coli and B. fragilis was noted in patients with bowel or bladder incontinence. This study highlights the polymicrobial nature of SSI and the importance of anaerobic bacteria in SSI following spinal fusion.

Bacteria, Anaerobic↗

Immune response to Fusobacterium nucleatum and Prevotella intermedia in patients with chronic maxillary sinusitis.

Our objective was to study the immune response to 2 anaerobic bacteria in patients with chronic maxillary sinusitis. Immunoglobulin G class antibody titers to Fusobacterium nucleatum and Prevotella intermedia were measured by enzyme-linked immunosorbent assay. Serum levels in the patients were determined on the day sinus aspiration for culture was done, and 75 to 90 days later, after completion of antimicrobial therapy, Prevotella intermedia was isolated from 16 aspirates, and F. nucleatum from 12. Median antibody levels at day 1 for F. nucleatum and P. intermedia were significantly higher in patients whose serum aspirates harbored these organisms than at days 75 to 90 in those who were cured (p < .05). However, the levels stayed elevated in the 5 patients who did not improve. The elevated antibody levels to F. nucleatum and P. intermedia, known oral pathogens, suggest a potential pathogenic role for these organisms in chronic maxillary sinusitis.

Adolescent↗

Resistance to antimicrobials used for therapy of otitis media and sinusitis: effect of previous antimicrobial therapy and smoking.

We undertook to identify the antimicrobial susceptibility of the pathogens isolated from patients with otitis media or maxillary sinusitis who failed to respond to antimicrobial therapy, and correlate it with previous antimicrobial therapy and smoking. We analyzed isolates recovered from 2 consecutive cultures obtained from middle ear aspirate obtained through an open perforation in 22 children with otitis, and maxillary sinus aspirate collected by endoscopy from 20 patients. Forty-seven isolates were repeatedly recovered from 42 culture-positive individuals. The organisms isolated were Streptococcus pneumoniae (15 isolates), Haemophilus influenzae (14), Staphylococcus aureus (7), Moraxella catarrhalis (6), and Streptococcus pyogenes (5). Resistance of at least 2 tube dilutions to the antimicrobial agents used was found in 23 of the 47 (49%) isolates that were found in 20 (48%) of the patients. These included 10 of 15 (67%) isolates of S pneumoniae, 4 of 14 (29%) H influenzae (all were beta-lactamase producers), 4 of 7 (57%) S aureus (all beta-lactamase producers), 5 of 6 (83%) M catarrhalis (all beta-lactamase producers), and none of 5 S pyogenes. In the 21 patients who failed to respond to amoxicillin, H influenzae and S pneumoniae predominated. Streptococcus pneumoniae was recovered from 4 of the 11 (36%) after trimethoprim-sulfamethoxazole, 4 of 21 (19%) after amoxicillin, 2 of 3 (67%) after azithromycin dihydrate, and 1 of 4 (25%) after cefixime. A statistically significant higher recovery of resistant organisms was noted in those treated 2 to 6 months previously, and in those with sinusitis who smoked. The data illustrate the relationship between resistance to antimicrobials and failure of patients with otitis media and sinusitis to improve.

Adolescent↗

Microbiology of subphrenic abscesses: a 14-year experience.

The objective of the review was to study the aerobic and anaerobic microbiology of subphrenic abscesses in relation with predisposing conditions. A retrospective review of clinical and laboratory data of 52 patients treated between 1974 and 1988 was conducted. Forty-three (83%) patients developed the abscesses after an operative procedure. These included 11 patients after colonic, 9 patients after gastric or duodenal, 7 patients after abdominal trauma, 7 patients after biliary, and 6 patients after appendix surgery. A total of 194 organisms (3.7 isolates/specimen), 83 aerobic (1.6/specimen), and 111 anaerobes (2.1/specimen) were recovered. Aerobic bacteria only were recovered in 7 (13%) abscesses, anaerobic bacteria only in 11 (21%), and mixed aerobic and anaerobic bacteria in 34 (65%). Polymicrobial infection was present in 47 (90%). The predominant aerobic isolates were Escherichia coli (28 isolates), Enterococcus group D(9), and Staphylococcus aureus (9). The predominant anaerobes were Peptostreptococcus species (33 isolates), Bacteroides fragilis group (25), Clostridium species (13), and Prevotella species (6). The number of isolates/site varied. The number of anaerobic bacteria/site outnumbered or was equal to the number of aerobic or facultatives in all instances, except in abscesses after biliary surgery. Their number/site was especially high in abscesses after appendectomy, and the number of aerobic and anaerobic bacteria was the lowest after gastric or duodenal surgery. S. aureus predominated after gastric, duodenal and posttrauma surgery; B. fragilis predominated after colonic, appendix, and postabdominal trauma surgery; Enterococcus group D predominated after biliary surgery; Fusobacterium and Prevotella species predominated after gastric or duodenal surgery; and Clostridium species predominated after colonic or appendix surgery. These data highlight the polymicrobial aerobic-anaerobic nature of subphrenic abscesses and their correlation with predisposing surgery.

Adolescent↗

Microbiology of nosocomial sinusitis in mechanically ventilated children.

OBJECTIVE: To assess the bacteriology of nosocomial sinusitis in mechanically ventilated children. METHOD: Retrospective review of sinus aspirate specimens obtained from 20 children with nosocomial sinusitis. The specimens were processed for aerobic and anaerobic bacteria. RESULTS: A total of 58 isolates (2.9 per specimen), 30 aerobic or facultative (1.5 per specimen) and 28 anaerobic (1.4 per specimen), were recovered. Aerobes only were present in 8 patients (40%), anaerobes only in 5 (25%), and mixed aerobic and anaerobic flora in 7 (35%). The predominant aerobes were Pseudomonas aeruginosa (6 isolates), Staphylococcus aureus (5 isolates), Escherichia coli (3 isolates), and Klebsiella pneumoniae (3 isolates). The predominant anaerobes were Peptostreptococcus species (8 isolates), Prevotella species (6 isolates), and Fusobacterium species (4 isolates). Forty-one beta-lactamase bacteria were recovered from 14 specimens (70%). Thirty isolates similar to the sinus isolates were also recovered from the trachea, 6 from blood culture specimens, and 6 from other sites. Anaerobes were more commonly isolated from sinus aspirate samples obtained after 18 days of mechanical ventilation (21 vs 7, P<.05 by chi2). CONCLUSION: This study demonstrates the polymicrobial aerobic-anaerobic flora of nosocomial sinusitis in mechanically ventilated children.

Adolescent↗

Microbiologic characteristics of persistent otitis media.

OBJECTIVE: To identify the pathogens isolated from children with acute otitis media who did not respond to antimicrobial drug therapy. METHODS: Retrospective analysis of cultures obtained by tympanocentesis from 46 children. RESULTS: Organisms were recovered from 34 children (74%), and 43 isolates were recovered from these individuals. The organisms were Streptococcus pneumoniae (16 isolates), Haemophilus influenzae non-type b (12 isolates), Moraxella catarrhalis (5 isolates), Streptococcus pyogenes (5 isolates), Staphylococcus aureus (3 isolates), and Peptostreptococcus species (2 isolates). Resistance to the antimicrobial agent used was found in 27 (63%) of 43 isolates found in 22 patients (48%). Of patients who did not respond to amoxicillin therapy, H influenzae predominated. Streptococcus pneumoniae was recovered from 5 (56%) of 9 of those who did not respond to trimethoprim and sulfamethoxazole therapy, 4 (44%) of 9 patients after azithromycin therapy, 3 (25%) of 12 patients after amoxicillin therapy, and 2 (40%) of 5 patients after cefixime therapy. Streptococcus pyogenes was recovered from 2 (40%) of 5 patients after trimethoprim and sulfamethoxazole therapy and from 2 (40%) of 5 patients after cefixime therapy. CONCLUSIONS: The data illustrate the relation between resistance to antimicrobial drug therapy and failure of patients with otitis media to improve. They also highlight the importance of diagnostic tympanocentesis in establishing the presence of resistant microorganisms.

Acute Disease↗

Persistence of group A beta-hemolytic streptococci in toothbrushes and removable orthodontic appliances following treatment of pharyngotonsillitis.

OBJECTIVE: To investigate the persistence of group A beta-hemolytic streptococci (GABHS) in toothbrushes and removable orthodontic appliances (ROAs) in children who suffer from acute GABHS pharyngotonsillitis and the association with penicillin treatment failure. SETTING: Private practice setting. PATIENTS AND METHODS: Pharyngotonsillar and toothbrush cultures were obtained from 104 children with acute GABHS pharyngotonsillitis before and after 10 days of penicillin V potassium therapy. Cultures of ROAs were also obtained from 21 children. The persistence of GABHS in 10 daily rinsed and 10 nonrinsed toothbrushes was studied in vitro. RESULTS: Group A beta-hemolytic streptococci were isolated from 11 (11%) of the toothbrushes and 18 (17%) of the patients after the completion of penicillin therapy. Toothbrushes of 5 (28%) of the 18 children who harbored GABHS were colonized with the organism. Group A beta-hemolytic streptococci were also isolated from 4 (19%) of 21 ROAs after therapy. In vitro studies illustrated the persistence of GABHS in nonrinsed toothbrushes for up to 15 days. In contrast, the organism was not isolated from rinsed toothbrushes beyond day 3. CONCLUSION: Toothbrushes and ROAs that harbor GABHS may contribute to the persistence of GABHS in the oropharynx and may account for the failure of penicillin therapy in some cases of pharyngotonsillitis.

Child↗

Aerobic and anaerobic infection associated with malignancy.

The goal of this work was to study the microbiology and clinical characteristics of patients with infections associated with malignancy treated over a period of 17 years. A total of 668 specimens were obtained from 605 patients. The malignancies include 224 hematological malignancies and 381 nonhematogenic malignancies. Anaerobic bacteria only were isolated in 201 (30%) specimens, aerobic bacteria in 226 (34%), mixed aerobic-anaerobic bacteria in 231 (35%) and Candida spp. in 10 (1%). A total of 683 anaerobic (1.0 isolates per specimens) and 592 aerobic or facultative (0.9 per specimen) organisms were recovered. The predominant anaerobic bacteria included Bacteroides fragilis group isolates (181), Peptostreptococcus spp. (166), Prevotella spp. (106), Clostridium spp. (70), and Fusobacterium spp. (43). The predominant aerobic bacteria included Escherichia coli (133), Staphylococcus aureus (100), Klebsiella pneumoniae (48), and Pseudomonas aeroginosa (45). The type of infections included abscesses (221), bacteremia (198), wounds (175), including 61 cellulitis, 24 post-surgical wounds and 23 decubitus ulcers), peritonitis (48), empyema (12), cholecystitis (6) and thrombophlebitis (5). S. aureus and Peptostreptococcus spp. were isolated from all sites. However, organisms of the oropharyngeal flora (Prevotella and Fusobacterium spp.) predominated in local infections and bacteremia that originated from this site (head and neck wounds and abscesses and pulmonary infections), and organisms of the gastrointestinal tract flora predominated in infections that originated from this site (peritonitis, abdominal abscesses and decubitus ulcers). This retrospective study demonstrates polymicrobial features of many infections associated with malignancies.

Adolescent↗

Aerobic and anaerobic microbiology of dacryocystitis.

PURPOSE: To investigate the aerobic and anaerobic microbiology of dacryocystitis. METHOD: Retrospective review of the 62 clinical and microbiologic records collected between 1980 and 1990. RESULTS: Aerobic or facultative bacteria were recovered in 32 cases (52%), anaerobic bacteria only in 20 cases (32%), mixed aerobic and anaerobic bacteria in seven cases (11%), and fungi in three cases (5%). A total of 94 organisms (1.5 per specimen), which included 56 aerobic or facultative anaerobic organisms, 35 anaerobic organisms, and three fungi, were recovered. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Staphylococcus epidermidis (13 isolates), and Pseudomonas species (seven isolates). The most frequently recovered anaerobes were Peptostreptococcus species (13 isolates), Propionibacterium species (12 isolates), Prevotella species (four isolates), and Fusobacterium species (three isolates). The predominant fungus was Candida albicans (two isolates). Polymicrobial infection was present in 28 cases (45%). CONCLUSION: These data highlight the potential importance of anaerobic bacteria in dacryocystitis.

Adolescent↗