Beta-Lactamase Activity in Anaerobic Bacteria

Tonsils were obtained from 50 children suffering from recurrent tonsillitis. Patients' ages ranged from 2.5 to 17 years (mean 6 years); 29 were males and 21 females. The tonsils were sectioned in half after heat searing of the surface and the core material was cultured for aerobic and anaerobic microorganisms. Mixed aerobic and anaerobic flora was obtained in all patients, yielding an average of 7.8 isolates (4.1 anaerobes and 3.7 aerobes) per specimen. There were 207 anaerobes isolated. The predominant isolates were 101 Bacteroides sp (including 10 B fragilis group, and 47 B melaninogenicus group), 39 Fusobacterium sp, 34 Gram-positive anaerobic cocci (25 Peptococcus sp and 9 Peptostreptococcus sp) and 16 Veillonella sp. There were 185 aerobic isolates. The predominant isolates were 41 α-hemolytic streptococci, 24 Staphylococcus aureus, 19 β-hemolytic streptococci (11 group A, 4 group B, and 2 each group C and F), 14 Haemophilus sp (including 12 H influenzae type B) and 5 H parainfluenzae. Beta-lactamase production was noted in 56 isolates recovered from 37 tonsils. These were all isolates of S aureus (24) and B fragilis (10), 15 of 47 B melaninogenicus (32%), 5 of 12 B oralis (42%), and 2 of 12 H influenzae type B (17%). Our findings indicate the polymicrobial aerobic and anaerobic nature of deep tonsillar flora in children with recurrent tonsillitis, and demonstrate the presence of many β-lactamase-producing organisms in 74% of the patients.

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Emergence of beta-lactamase producing anaerobic bacteria in the tonsils during penicillin treatment

European Journal of Clinical Microbiology ◽

10.1007/bf02075694 ◽

1986 ◽

Vol 5 (4) ◽

pp. 399-404 ◽

Cited By ~ 45

Author(s):

K. Tunér ◽

C. E. Nord

Keyword(s):

Anaerobic Bacteria ◽

Beta Lactamase ◽

Penicillin Treatment

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Microbiology and antimicrobial management of sinusitis

The Journal of Laryngology & Otology ◽

10.1258/0022215054020304 ◽

2005 ◽

Vol 119 (4) ◽

pp. 251-258 ◽

Cited By ~ 44

Author(s):

Itzhak Brook

Keyword(s):

Chronic Sinusitis ◽

Anaerobic Bacteria ◽

Allergic Inflammation ◽

Acute Sinusitis ◽

High Dose ◽

Beta Lactamase ◽

Upper Respiratory Tract ◽

Penicillin Therapy ◽

Antimicrobial Management ◽

Potential Pathogen

Sinusitis generally develops as a complication of viral or allergic inflammation of the upper respiratory tract. The bacterial pathogens in acute sinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, while anaerobic bacteria and Staphylococcus aureus are predominant in chronic sinusitis. Pseudomonas aeruginosa has emerged as a potential pathogen in immunocompromised patients and in those who have nasal tubes or catheters, or are intubated. Many of these organisms recovered from sinusitis became resistant to penicillins either through the production of beta-lactamase (H. influenzae, M. catarrhalis, S. aureus, Fusobacterium spp., and Prevotella spp) or through changes in the penicillin-binding protein (S. pneumoniae). The pathogenicity of beta-lactamase-producing bacteria is expressed directly through their ability to cause infections, and indirectly through the production of betalactamase. The indirect pathogenicity is conveyed not only by surviving penicillin therapy, but also by ‘shielding’ penicillin-susceptible pathogens from the drug. The direct and indirect virulent characteristics of these bacteria require the administration of appropriate antimicrobial therapy directed against all pathogens in mixed infections. The antimicrobials that are the most effective in management of acute sinusitis are amoxycillin-clavulanate (given in a high dose), the newer quinolones (gatifloxacin, moxifloxacin) and the second generation cephalosporins (cefuroxime, cefpodoxime, cefprozil or cefdinir). The antimicrobials that are the most effective in management of chronic sinusitis are amoxycillinclavulanate, clindamycin and the combination of metronidazole and a penicillin.

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Susceptibilities of bovine summer mastitis bacteria to antimicrobial agents.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.1.157 ◽

1996 ◽

Vol 40 (1) ◽

pp. 157-160 ◽

Cited By ~ 11

Author(s):

H Jousimies-Somer ◽

S Pyörälä ◽

A Kanervo

Keyword(s):

Antimicrobial Agents ◽

Anaerobic Bacteria ◽

Fusobacterium Necrophorum ◽

Penicillin G ◽

Dilution Method ◽

Agar Dilution Method ◽

Beta Lactamase ◽

Bacterial Isolates ◽

Amoxicillin Clavulanate ◽

Agar Dilution

The susceptibility to 9 antimicrobial agents of 32 aerobic bacterial isolates and to 10 antimicrobial agents of 37 anaerobic bacterial isolates from 23 cases of bovine summer mastitis (16 Actinomyces pyogenes isolates, 8 Streptococcus dysgalactiae isolates, 3 S. uberis isolates, 3 S. acidominimus isolates, 2 Streptococcus spp., 15 Peptostreptococcus indolicus isolates, 10 Fusobacterium necrophorum isolates, and 12 isolates of anaerobic gram-negative rods) was determined by the agar dilution method. All isolates except one Bacteroides fragilis isolate (beta-lactamase producer) were susceptible to penicillin G, amoxicillin, amoxicillin-clavulanate, cefoxitin, clindamycin, and chloramphenicol (the B. fragilis strain was susceptible to the last four), which had MICs at which 90% of isolates were inhibited (MIC90s) of < or = 0.06, < or = 0.06, < or = 0.06 0.25, < or = 0.06, and 4.0 micrograms/ml, respectively. Spiramycin was active against the gram-positive aerobes (MIC90, 1.0 microgram/ml) but not against the anaerobes (MIC90, 16.0 micrograms/ml). Similar trends were noted for susceptibilities of aerobic and anaerobic bacteria to ofloxacin (MIC90s, 2.0 and 8 micrograms/ml, respectively). Occasional strains of aerobic streptococci were resistant to oxytetracycline, but all anaerobes were susceptible. Tinidazole was active against all anaerobes (MIC90, 2.0 micrograms/ml). beta-Lactamase was produced only by the B. fragilis isolate.

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