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Biomedical subjects

Itzhak Brook

Publications and source records attributed to Itzhak Brook.

At least 37 records · Page 2Linked to original sources
PubMed2005

The association of anaerobic bacteria with infectious mononucleosis.

This review summarizes the information that supports the potential importance of anaerobic bacteria in the pharyngo-tonsillitis (PT) associated with infectious mononucleosis (IM). Evidence supportive of the potential of involvement of bacteria in IM was provided by several studies that showed increased recovery of bacteria on the tonsillar surfaces in IM. Several studies demonstrated that metronidazole therapy alleviated the clinical symptoms of tonsillar hypertrophy and shortened the duration of fever in IM. Metronidazole has no antimicrobial activity against aerobic bacteria and is only effective against anaerobic bacteria. A possible mechanism of its action is the suppression of the oral anaerobic flora that might contribute to the inflammatory process induced by the Epstein-Barr virus. This explanation is supported by the increased recovery of Prevotella intermedia and Fusobacterium nucleatum from the tonsillar surfaces during the acute phases of IM and an immune response against these organisms by patients with IM. Although more studies are needed, these findings support the possible pathogenicity of Gram-negative anaerobic bacteria in the PT associated with IM.

Journal Article↗
PubMed2005

Microbiology of intracranial abscesses and their associated sinusitis.

OBJECTIVE: To evaluate the organisms recovered from infected sinuses and associated intracranial abscesses (IAs). DESIGN: Retrospective review of findings from aspirate of pus from 10 infected sinuses and their corresponding IAs. SETTING: Academic medical center. PATIENTS: Ten patients diagnosed as having sinusitis (age range, 7-58 years). MAIN OUTCOME MEASURE: Aerobic and anaerobic bacteria findings from infected sinuses and IAs. RESULTS: Polymicrobial flora was found in 9 sinuses and 8 IAs. Anaerobes were isolated from all sinuses and 9 IAs. A total of 26 isolates (2.6 isolates per specimen) were recovered from the sinuses: 19 anaerobic, 6 aerobic or facultative, and 1 microaerophilic; 17 isolates were found in the IAs (1.7 isolates per site): 13 anaerobic, 2 aerobic or facultative, and 2 microaerophilic. The predominant anaerobes were Fusobacterium species (in 5 corresponding sinuses and abscesses, 1 in a sinus only, and 1 in an IA only), Prevotella species (in 3 corresponding sinuses and abscesses), Peptostreptococcus species (in 2 corresponding sinuses and abscesses, and 4 in a sinus only), Staphylococcus aureus, Haemophilus influenzae type b, microaerophilic streptococci, and Bacteroides ureolyticus (in 1 corresponding sinus and abscess each). Streptococcus pneumoniae was recovered 2 times, only from a sinus. Alpha-hemolytic streptococci and beta-hemolytic streptococci group F were each isolated once from the sinus. Concordance in the microbiological findings between the sinus and the IA was found in all instances. However, certain organisms were present at only one or the other site. CONCLUSION: These data illustrate the concordance in the recovery of organisms from infected sinuses and their associated IA and confirm the importance of anaerobic bacteria in sinusitis and IA.

Abscess↗
PubMed2005

Recovery of potential pathogens and interfering bacteria in the nasopharynx of otitis media-prone children and their smoking and nonsmoking parents.

OBJECTIVE: To study the frequency of isolation of potential pathogens and interfering bacteria in the posterior nasopharynx of otitis media-prone (OMP) children and their smoking and nonsmoking parents to possibly explain why active and passive exposure to smoking is associated with carriage of potentially pathogenic bacteria and an increased risk of respiratory tract infection in both adults and children. SETTING: Outpatient clinic. PARTICIPANTS: Twenty OMP children and their smoking parents (smoking group) and 20 OMP children and their nonsmoking parents (nonsmoking group). INTERVENTIONS: Posterior nasopharynx cultures were taken from 20 OMP children and their smoking parents and 20 OMP children and their nonsmoking parents. MAIN OUTCOME MEASURE: Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. RESULTS: Fourteen potential pathogens were isolated from smoking parents, and 17 were recovered from their children. Concordance in isolation of a pathogen between a parent and child was noted in 11 instances. Three potential pathogens were isolated from nonsmoking parents (P<.001 compared with the parents and children in the smoking group and children in the nonsmoking group), and 16 were recovered from their children. Bacterial interference by normal flora isolates against potential pathogens was noted in 58 instances in smoking parents and in 55 instances in their children (P<.05). Bacterial interference was noted in 129 instances in nonsmoking parents (P<.05 compared with the parents and children in the smoking group and children in the nonsmoking group) and in 55 instances in their children. CONCLUSIONS: A high recovery rate of potential pathogens and a low number of interfering organisms were observed in OMP children. This was not related to their parents' smoking habits. The posterior nasopharynx flora of smoking parents contained more potential pathogens similar to the ones recovered from OMP children and fewer interfering organisms than nonsmoking parents.

Adult↗
PubMed2005

Effects of amoxicillin and cefdinir on nasopharyngeal bacterial flora.

OBJECTIVE: To compare the effects of cefdinir (14 mg/kg per day) and amoxicillin (90 mg/kg per day) antimicrobial therapy on the nasopharyngeal flora of children with acute otitis media. DESIGN: Nasopharyngeal cultures for aerobic and facultative bacteria were obtained before therapy and 2 to 4 days after completion of therapy. SETTING: Outpatient clinic. PATIENTS: Fifty children, aged 7 months to 5 years 4 months. MAIN OUTCOME MEASURES: After completion of therapy, 22 (88%) of the 25 patients treated with cefdinir and 16 (64%) of the 25 patients treated with amoxicillin were considered clinically cured (P<.05). A significant reduction in the number of all isolates occurred following therapy in those treated with cefdinir (36 vs 71, P<.01) or with amoxicillin (56 vs 73, P<.05). However, the total number of isolates recovered after therapy was significantly lower in those treated with cefdinir (36) compared with those treated with amoxicillin (56) (P<.01). RESULTS: The recovery of potential pathogenic organisms (eg, Streptococcus pneumoniae, Staphylococcus aureus, beta-hemolytic streptococci, Haemophilus species, and Moraxella catarrhalis), as well as penicillin-resistant bacteria, was lower following completion of therapy in the cefdinir group (6 pathogens, including 5 that were penicillin resistant), compared with the amoxicillin group (27 pathogens, including 16 that were penicillin resistant) (P<.01). CONCLUSION: This study illustrates the greater ability of cefdinir compared with amoxicillin to reduce the number of potential nasopharyngeal pathogens as well as penicillin-resistant bacteria in children with acute otitis media.

Acute Disease↗
PubMed2005

Minimum inhibitory concentrations of herbal essential oils and monolaurin for gram-positive and gram-negative bacteria.

New, safe antimicrobial agents are needed to prevent and overcome severe bacterial, viral, and fungal infections. Based on our previous experience and that of others, we postulated that herbal essential oils, such as those of origanum, and monolaurin offer such possibilities. We examined in vitro the cidal and/or static effects of oil of origanum, several other essential oils, and monolaurin on Staphylococcus aureus, Bacillus anthracis Sterne, Escherichia coli, Klebsiella pneumoniae, Helicobacter pylori, and Mycobacterium terrae. Origanum proved cidal to all tested organisms with the exception of B. anthracis Sterne in which it was static. Monolaurin was cidal to S. aureus and M. terrae but not to E. coli and K. pneumoniae. Unlike the other two gram-negative organisms, H. pylori were extremely sensitive to monolaurin. Similar to origanum, monolaurin was static to B. anthracis Sterne. Because of their longstanding safety record, origanum and/or monolaurin, alone or combined with antibiotics, might prove useful in the prevention and treatment of severe bacterial infections, especially those that are difficult to treat and/or are antibiotic resistant.

Anti-Bacterial Agents↗
PubMed2005

Chronic sinusitis in children and adults: role of bacteria and antimicrobial management.

The nasopharynx serves as the reservoir for anaerobic bacteria as well as pathogenic bacteria that can cause respiratory infections including sinusitis. Some of these organisms possess the ability to interfere with the growth of potential pathogens and may play a role in preventing infections. Anaerobic bacteria emerge as pathogens as the infection becomes chronic. This may result from the selective pressure of antimicrobial agents that enable resistant anaerobic organisms to survive, and from the development of conditions appropriate for anaerobic growth, which include the reduction in oxygen tension and an increase in acidity within the sinus. Anaerobes were identified in chronic sinusitis in adults and children whenever techniques for their cultivation were employed. The predominant isolates were pigmented Prevotella, Fusobacterium, and Peptostreptococcus spp. The choice of antimicrobial agent in chronic sinusitis should provide coverage for the usual pathogens in acute sinusitis as well as beta-lactamase-producing aerobic and anaerobic organisms.

Adult↗
PubMed2005

The role of anaerobic bacteria in acute and chronic mastoiditis.

Mastoiditis (M) is the most common intratemporal complication of otitis media. The incidence of M has decreased since the advent of antimicrobial agents. In the last decade, however, there has been a marked increased in the incidence of acute M in several communities, sometimes in association with the growing resistance of pneumococci. Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Haemophillus influenzae are the most common organisms recovered in acute M. Several recent studies demonstrated the predominance of Pseudomonas aeruginosa in this infection. However, because P. aeruginosa colonizes the ear canal it can contaminate specimens obtained through the non-sterile ear canal. P. aeruginosa, Enterobacteriaceae, S. aureus and anaerobic bacteria are the most common isolates in chronic M. Anaerobes predominate in studies where adequate methods for their isolation are employed. Management of uncomplicated M requires the administration of parenteral antimicrobial therapy and myringotomy with or without tympanostomy tube placement. If no improvement occurs within 48 h, surgical intervention and drainage may be necessary. The procedure generally employed is simple mastoidectomy, and tympanostomy tube placement. Radical mastoidectomy is performed only if there is no improvement after simple mastoidectomy.

Journal Article↗
PubMed2005

A pooled comparison of cefdinir and penicillin in the treatment of group a beta-hemolytic streptococcal pharyngotonsillitis.

OBJECTIVE: This pooled analysis compared the clinical cure and bacterial eradication rates achieved by cefdinir and penicillin in the treatment of group A beta-hemolytic streptococcal (GABHS) pharngotonsillitis. METHODS: Data from 4 multicenter, randomized, controlled, investigator-blinded trials, 2 in children receiving oral suspensions and 2 in adults receiving capsules/tablets, were pooled and analyzed in terms of clinical cure rates, microbiologic eradication rates, and adverse events. RESULTS: A total of 2751 patients were enrolled (age <13 years, n = 1274; age > or =13 years, n = 1477). Patients were randomized to receive cefdinir once daily (n = 569) or twice daily (n = 1086) for 5 or 10 days, or penicillin 4 times daily (n = 1096) for 10 days. Of the 2751 patients enrolled, 2198 were evaluable for clinical and microbiologic outcomes. Compared with the 10-day penicillin regimens, the cefdinir regimens for 5 or 10 days produced higher clinical cure and microbiologic eradication rates. Combined clinical cure rates were significantly higher for cefdinir compared with penicillin (94% vs 83%, respectively; P < 0.001). Combined microbiologic eradication rates were also significantly higher for cefdinir compared with penicillin (92% vs 77%; P < 0.001). Both cefdinir and penicillin were well tolerated, as >98% of patients completed the course of therapy. CONCLUSION: In this pooled analysis of data from 4 multicenter, randomized, controlled, investigator-blinded trials in children and adults, 5- and 10-day regimens of cefdinir achieved significantly higher clinical cure and microbiologic eradication rates compared with 10-day penicillin regimens in the treatment of GABHS pharyngotonsillitis.

Adolescent↗
PubMed2005

Treatment of non-streptococcal tonsillitis with metronidazole.

The potential role of anaerobic bacteria in acute tonsillitis was investigated in a retrospective study that evaluated the efficacy of antimicrobial therapy with metronidazole on the management of acute episodes of non-beta-hemolytic streptococcal tonsillitis (NST). Forty children suffering from NST were included, 20 that were treated with metronidazole 250 mg b.i.d. for 10 day, and 20 that had received no therapy. The efficacy of therapy was evaluated by the ability to alleviate the symptoms of acute infection. As compared with the untreated group, the group that received metronidazole, had a significant reduction in fever and sore throat one day after initiation of therapy, a significant reduction in the presence of fever, pharyngeal injection and sore throat within 2 days, and reduction in pharyngeal injection and tonsillar size at day 3. These findings illustrated that metronidazole therapy was more efficacious than no therapy in relieving the signs and symptoms of acute episodes of NST. These findings should encourage further studies that are prospective and blinded that are needed to evaluate the use of antimicrobials effective against anaerobic bacteria in the treatment of non-GABHS (group A-beta-hemolytic streptococcus) tonsillitis.

Adolescent↗
PubMed2005

The role of anaerobic bacteria in tonsillitis.

This review summarizes the information that supports the potential importance of anaerobic bacteria in tonsillitis. Some anaerobic bacteria possess interfering capability with Group A beta-hemolytic streptococci (GABHS) and other pathogens. The possible role of anaerobes in the acute inflammatory process in the tonsils is supported by several observations: anaerobes have been isolated from the cores of tonsils of patients with recurrent GABHS and non-GABHS tonsillitis (NST); the recovery of anaerobes as predominant pathogens in abscesses of tonsils, in many cases without any aerobic bacteria; their recovery as pathogens in well-established anaerobic infections of the tonsils (Vincent's angina); the increased recovery rate of encapsulated pigmented Prevotella and Porphyromonas spp. in acutely inflamed tonsils; their isolation from the cores of recurrently inflamed NST; and the response to antibiotics in patients with NST. Furthermore, immune response against Prevotella intermedia is present in patients with recurrent NST, and an immune response can also be detected against P. intermedia and Fusobacterium nucleatum in patients who recovered from peritonsillar cellulitis or abscesses, infectious mononucleosis and acute non-streptococcal and GABHS tonsillitis. Although more studies are needed, these findings support the possible pathogenicity of Gram-negative anaerobic bacilli in tonsillitis.

Antibodies, Bacterial↗
PubMed2005

Microbiology and management of infected neck cysts.

PURPOSE: To review and describe the microbiology, diagnosis, and management of infected neck cysts. METHOD: Review the current medical literature and current textbooks. RESULTS: Staphylococcus aureus and Streptococcus pyogenes are the predominant aerobic isolates, while pigmented Prevotella and Porphyromonas spp., and Peptostreptococcus spp., all part of the oral flora, are the predominant anaerobes. Therapy includes administration of antibiotics effective against the causative pathogen(s). Proper selection of therapy can be guided by culture of the lesion. Surgical drainage and resection may be necessary in case of suppuration. Prevention of suppuration can be achieved by surgical removal of cysts before acquisition of infection, or removal of those recurrently infected. CONCLUSION: Recognition of the importance of the skin or the oral flora in infected neck cysts can assist in the proper selection of antimicrobial therapy.

Abscess↗
PubMed2005

The role of bacteria in chronic rhinosinusitis.

Sinusitis generally develops as a complication of viral or allergic inflammation of the upper respiratory tract. The bacterial pathogens in acute sinusitis are S. pneumoniae, H. influenzae, and M. catarrhalis, while anaerobic bacteria and S. aureus predominant in CRS.

Acute Disease↗
PubMed2005

The role of bacterial interference in otitis, sinusitis and tonsillitis.

Bacterial interactions that include antagonism (interference) and synergism help maintain balance between the members of the normal endogenous flora. Alpha-streptococci that predominate in the normal respiratory tract flora attracted most attention in studies of bacterial interference. Other organisms that possess interfering characteristics in upper respiratory tract infections (URTIs) are nonhemolytic streptococci, and Prevotella and Peptostreptococcus spp. The production of bacteriocins by some microorganisms is one of the important mechanisms of interference. The role of bacterial interference in the development of URTI and its effect on the eradication of these infections is discussed. These infections include pharyngo-tonsillitis, otitis media, and sinusitis. Treatment with various antimicrobial agents can affect the balance between members of the oro-pharyngeal bacterial flora and interfering organisms. Implantation into the indigenous microflora of low virulence bacterial strains that are potentially capable of interfering with colonization and infection with other more virulent organisms has been used in preliminary studies as a means of coping with the failure of antimicrobials in the treatment of several URTI.

Anti-Bacterial Agents↗
PubMed2005

Clindamycin in dentistry: more than just effective prophylaxis for endocarditis?

Clindamycin is a broad-spectrum antibiotic with activity against aerobic, anaerobic, and beta-lactamase-producing pathogens. This antibiotic has been used for many years as prophylactic treatment during dental procedures to prevent endocarditis. However, the spectrum and susceptibility of the bacteria species involved in dental infections indicate that clindamycin would also be an effective treatment option for these conditions. In addition to its antiinfective properties, clindamycin has high oral absorption, significant tissue penetration, including penetration into bone, and stimulatory effects on the host immune system. This review discusses the microbiologic and clinical evidence supporting the efficacy and safety of clindamycin for the successful management of dental infections.

Anti-Bacterial Agents↗
PubMed2005

Management of human and animal bite wounds: an overview.

Serious infections can result from wounds that are caused by bites from animals and humans. Organisms recovered from bite wounds generally originate from the oral cavity of the biting animal, as well as from the patient's skin flora. Anaerobes have been isolated from animal and human bite wound infections, especially those associated with abscess formation. In addition to local wound infections, common complications, such as lymphangitis, septic arthritis, tenosynovitis, and osteomyelitis, and uncommon complications, such as endocarditis, meningitis, brain abscess, and sepsis, may occur. Wound management includes proper local care and, when needed, antimicrobial therapy.

Animals↗
PubMed2005

Microbiology of acute and chronic maxillary sinusitis associated with an odontogenic origin.

OBJECTIVES: : To study the microbiology of sinusitis associated with odontogenic origin. METHODS: : Aspirates of 20 acutely and 28 chronically infected maxillary sinuses that were associated with odontogenic infection were processed for aerobic and anaerobic bacteria. RESULTS: : A total of 66 isolates were recovered from the 20 cases of acute sinusitis (3.3/specimen), 16 aerobic and facultatives, and 50 anaerobic. Aerobes alone were recovered in 2 (10%) specimens, anaerobes only in 10 (50%), and mixed aerobic and anaerobic bacteria in 8 (40%). The predominant aerobic were alpha-hemolytic streptococci (5), microaerophilic streptococci (4), and Staphylococcus aureus (2). The predominant anaerobes were anaerobic Gram-negative bacilli (22), Peptostreptococcus (12), and Fusobacterium spp. (9). A total of 98 isolates were recovered from the 28 cases of chronic sinusitis (3.5/patient): 21 aerobic and facultatives and 77 anaerobic. Aerobes were recovered in 3 (11%) instances, anaerobes only in 11 (39%), and mixed aerobic and anaerobic bacteria in 14 (50%). The predominant aerobes were alpha-hemolytic streptococci (7), microaerophilic streptococci (4), and S. aureus (5). The predominant anaerobes were Gram-negative bacilli (41), Peptostreptococcus (16), and Fusobacterium spp. (12). Thirteen beta-lactamase-producing bacteria (BLPB) were recovered from 10 (50%) patients with acute sinusitis and 25 BLPB from 21 (75%) patients with chronic sinusitis. No correlation was found between the predisposing odontogenic conditions and the microbiological findings. CONCLUSIONS: : These data illustrate the similar microbiology of acute and chronic maxillary sinusitis associated with odontogenic infection where anaerobic bacteria predominate in both types of infections.

Acute Disease↗
PubMed2005

Recovery of anaerobic bacteria from wounds after lawn-mower injuries.

Accidental injury while using lawn mowers can cause serious infectious complications in the injured extremity. Anaerobic bacteria were rarely recovered from this infection. Two children who sustained injury in their foot by a lawn mower developed severe wound infection. Culture of the wound from 1 patient had heavy growth of Clostridium bifermentans and Peptostreptococcus magnus, and the culture from the other child grew Clostridium perfringens. Antimicrobial therapy directed at the pathogens and vigorous surgical irrigation and debridement led to complete recovery from the infection. This report illustrates the recovery of anaerobic bacteria from children that had wound infection after lawn-mower injury.

Bacteria, Anaerobic↗